description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to methods and apparatus for facilitating the connection of tubulars using a top drive and is more particularly, but not exclusively for facilitating the connection of a section or stand of casing to a string of casing.
2. Description of the Related Art
In the construction of wells such as oil or gas wells, it is usually necessary to line predrilled holes with a string of tubulars known as casing. Because of the size of the casing required, sections or stands of say two sections of casing are connected to each other as they are lowered into the well from a platform. The first section or stand of casing is lowered into the well and is usually restrained from falling into the well by a spider located in the platform's floor. Subsequent sections or stands of casing are moved from a rack to the well centre above the spider. The threaded pin of the section or stand of casing to be connected is located over the threaded box of the casing in the well to form a string of casing. The connection is made-up by rotation therebetween.
It is common practice to use a power tong to torque the connection up to a predetermined torque in order to perfect the connection. The power tong is located on the platform, either on rails, or hung from a derrick on a chain. However, it has recently been proposed to use a top drive for making such connection either alone or in combination with a power tong.
It has been observed that sections or stands of tubulars are often not as uniform as desired. In particular, the sections or stands of tubulars are often not straight. The top drive is in perfect alignment with the centre of the spider in the platform of an oil or gas rig. However, a section or stand of tubulars located in the spider would not always be in alignment with the top drive.
SUMMARY OF THE INVENTION
According to a first aspect of the present invention there is provided an apparatus for facilitating the connection of tubulars using a top drive, the apparatus comprising a stator attachable to said top drive, and a supporting member for supporting a tool wherein means are provided to allow substantially horizontal movement of said supporting member.
According to a second aspect of the present invention there is provided a method for facilitating the connection of tubulars using a top drive, the method comprising the steps of attaching a tool to the top drive using a supporting member and adjusting the supporting member to cause the tool to be displaced horizontally relative to the top drive.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention and in order to show how the same may be carried into effect reference will now be made, by way of example, to the accompanying drawings, in which:
FIG. 1 is a side view in perspective of an apparatus in accordance with an embodiment of the invention in use;
FIG. 2 is an enlarged view of parts of FIG. 1 , with parts inserted in a tubular and with parts cut away;
FIG. 3 is an enlarged cross-sectional view in perspective of part of the apparatus of FIG. 1 ;
FIG. 4 is an enlarged view of parts of the supports of FIG. 1 in a displaced position;
FIG. 5 is an enlarged view of parts of the apparatus of FIG. 1 in a second displaced position;
FIG. 6 shows the apparatus of FIG. 1 in a further stage of operation; and
FIG. 7 shows a second embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 there is shown an apparatus which is generally identified by reference numeral 1 .
The apparatus I depends from a rotor 2 ′ of a top drive 3 . A tool 4 for gripping a tubular depends from the lower end of the apparatus 1 . A rigid guide member 5 is provided to guide the rotor 2 of the apparatus 1 . The rigid guide member 5 is fast with a stator 5 ′ of the top drive 3 . The rotor 2 ′ of the top drive 3 is coupled by a threaded connection to the rotor 2 of the apparatus 1 . The rigid guide member 5 may be provided with a clamp for clamping the rotor 2 of the apparatus I so that the threaded connection to the rotor 2 ′ of the top drive 3 can be made, after which the clamp would be released.
An elevator 6 is provided on the end of bails 7 , 8 which are hung from the top drive 3 . Piston and cylinders 9 , 10 are arranged between the bails 7 , 8 and the top drive 3 for moving the elevator 6 from below the top drive 3 to an out of the way position.
Referring now to FIG. 2 , there is shown the apparatus 1 which comprises a plate 11 which is fixed to a connecting tubular 12 by a collar 13 . The connecting tubular 12 passes through a hole 14 in rigid body 5 and connects with the rotor 2 ( FIG. 1 ). The plate 11 has two projections 15 and 16 which have holes 17 for accommodating axles 18 which are rotationally disposed therein. The axles 18 are integral with a rigid body 19 . A slider 20 is arranged on runners 21 on either side of the rigid body 19 . Arms 22 are connected at one end to the slider 20 via spherical bearings 23 .
The other end of arms 22 are connected to a supporting member 24 via spherical bearings 25 .
The arms 22 and are provided with lugs 26 to which one end of a piston and cylinder 28 and 29 is attached and are movable thereabout. The other end of each piston and cylinder 28 and 29 is attached to lugs 30 and 31 and is movable thereabout. The lugs 30 and 31 are fixed to plate 11 .
A mud pipe 32 is provided between the plate 11 and the supporting member 24 for carrying mud to the inside of a tubular therebelow. The mud pipe 32 is located in cylindrical sections 33 and 34 which are attached to the plate 11 and the supporting member 24 . The mud pipe 32 is provided with a lobe 35 formed on the outer surface thereof and is located in a corresponding recess 36 in a cylindrical section 33 ( FIG. 3 ). A lobe 37 is slidably arranged on the lower end of the mud pipe 32 with an O-ring seal 38 arranged therebetween to inhibit fluid from leaking therebetween. The lobe 37 is located in a corresponding recess 39 in cylindrical section 34 . This arrangement allows a ball and socket type movement between the plate 11 and the supporting member 24 and relative longitudinal movement therebetween.
Referring back to FIG. 2 , a tool 4 for gripping a tubular is fixed and depends from the supporting member 24 of the apparatus 1 . Such a tool may be arranged to be inserted into the upper end of the tubular, with gripping elements of the tool being radially displaceable for engagement with the inner wall of the tubular so as to secure the tubular to the tool.
In use, a tubular 40 to be connected to a tubular string held in a spider (not shown), is located over the tool 4 . The tool 4 grips the tubular 40 . The apparatus 1 and the tubular 40 are lowered by moving the top drive so that the tubular 40 is in close proximity with the tubular string held in the spider. However, due to, amongst other things, manufacturing tolerances in the tubular 40 , the tubular often does not align perfectly with the tubular held in the spider. The apparatus 1 allows minor vertical and horizontal movements to be made. The piston and cylinders 28 and 29 allow vertical movement, and may be controlled remotely. The piston and cylinders 28 and 29 may be of the pneumatic compensating type, i.e. their internal pressure may be adjusted to compensate for the weight of the tubular 40 so that movement of the tubular may be conducted with minimal force. Pneumatic compensating piston and cylinders also reduce the risk of damage to the threads of the tubulars. This can conveniently be achieved by introducing pneumatic fluid into the piston and cylinders 28 and 29 and adjusting the pressure therein. The piston and cylinders 28 and 29 may be hydraulic or may be hydraulic and provided with pneumatic bellows.
Tubular manipulating equipment such as stabbing guides may be used to direct the pin (not shown) of the tubular 40 into the box of the tubular string held in the spider. The apparatus I allows horizontal movement of the tubular 40 relative to the top drive 3 . Once the tubular 40 is in line with the tubular string, the top of the tubular 40 may be brought in line with the top drive which may be carried out with pipe handling equipment. The top drive 3 is now in direct alignment with the tubular string held in the spider, and can now rotate the apparatus 1 and hence the tool 4 and the tubular 40 to perfect a connection between the tubular 39 and the tubular string.
FIG. 4 shows the supporting member 24 , the tool 4 and the tubular 40 laterally in a ‘Y’ direction out of alignment with the top drive 3 . The mud pipe 32 has moved in recesses 36 and 39 and longitudinally in relation to O-ring seals 38 . The piston and cylinders 28 and 29 have moved about lugs 26 , 27 , 30 and 31 . Arms 22 and 22 ′ have moved about spherical bearings 23 , 23 ′, 25 and 25 ′.
FIG. 5 shows the supporting member 24 , the tool 4 and the tubular member 40 laterally in an ˜x′ direction. The mud pipe 32 has moved in recesses 36 and 39 and longitudinally in relation to O-ring seals 38 . The piston and cylinders 28 and 29 have moved about lugs 26 , 27 , 30 and 31 . Rigid member 19 has moved about axles 18 and 18 ′ and spherical bearings 23 .
FIG. 6 shows the elevator 6 swung in line with the top drive 3 by rotation of the piston and cylinders 9 and 10 acting on bails 7 and 8 . The elevator 3 is located below a box 41 of tubular 40 . The tubular 40 may be released from engagement with the tool 4 . The elevator 6 may now be raised to take the weight of the tubular 40 and tubular string. The tubular string may now be lowered into the well.
FIG. 7 is a second embodiment of the present invention and is generally similar to that of FIGS. 1 to 6 further incorporating adjusting piston and cylinders 42 and 43 so that actuation of the piston and cylinders 42 and 43 can move the supporting member 24 , the tool 4 and the tubular 40 depending therebelow in a horizontal plane in an x and y axis.
The piston and cylinder 42 is arranged between the plate 11 and the rigid member 19 on lugs 44 and 45 . Actuation of the piston and cylinder 42 moves the supporting member 24 , the tool 4 and the tubular 40 along a generally x-axis about axles 18 and 18 ′.
The piston and cylinder 43 is arranged between an extension of arm 22 and slider 20 on lugs 46 and 47 . Actuation of the piston and cylinder 43 moves the supporting member 24 , the tool 4 and the tubular 40 along a generally y-axis about spherical bearings 23 , and 25 and the corresponding spherical bearings arranged in arm 22 ′.
The piston and cylinders 42 and 43 may be hydraulically of pneumatically operable and may be controlled via a remote control unit (not shown).
In use, a tubular 40 may be gripped by the tool 4 in the way described above and lowered into close proximity with the tubular string held in a spider. The adjusting piston and cylinders 42 and 43 may then be actuated to obtain alignment of the pin of the tubular 40 with the box of the tubular string held in the spider. The tubular 40 may then be rotated to obtain a partial connection or be held in alignment with an additional tool. The piston and cylinders 42 and 43 may then be returned to their original positions to obtain alignment with the top drive 3 . The top drive 3 may then be used to torque the connection up to a predetermined torque to complete the connection.
It is envisaged that various modifications may be made to the above described embodiments, such as using a hydraulic motor in place of the supporting member 24 . | An apparatus for facilitating the connection of tubulars using a top drive, the apparatus comprising a stator attachable to said top drive, and a supporting member for supporting a tool, wherein means are provided to allow substantially horizontal movement of said supporting member. | 4 |
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention pertains to a coupling apparatus that is designed to provide a vertical pivoting coupling between an upstream multichannel air conveyor and a downstream multichannel air conveyor enabling the downstream multichannel air conveyor to be moved vertically between upwardly inclined and downwardly inclined orientations relative to the upstream air conveyor. In particular, the present invention provides a multichannel pivoting connection between an upstream multichannel air conveyor and a downstream multichannel air conveyor. The connection mechanism that can be selectively controlled to simultaneously adjust the lateral width dimensions of the slots between opposed flanges of the connection to coincide with adjustments in the lateral width dimensions of the slots between the opposed flanges of the upstream and downstream multichannel air conveyors. The multichannel air conveyors of the type employed with the pivoting coupling apparatus of the invention convey streams of plastic bottles suspended by their neck rings in the slots and the lateral spacing between pairs of flanges that define the slots can be quickly changed over for conveying plastic bottles of different neck dimensions and different neck ring diameters.
(2) Description of the Related Art
Air conveyors are typically employed in the rapid transport of empty plastic bottles of the type having an annular rim or a neck ring at the top of the bottle neck. A typical air conveyor includes a pair of flanges that are spaced from each other defining an elongated slot between the flanges. A multichannel air conveyor includes a multiple of pairs of flanges that extend side-by-side, defining a multiple of conveying slots. For air conveyors of considerable longitudinal length, conveyor sections are connected end-to-end so that the pairs of flanges of one section are aligned with the pairs of flanges of other adjacent conveyor sections and the slots of the pairs of flanges, aligned end-to-end, define the conveyor path. The spacings between the flanges of the conveyor sections is sufficiently large to enable a portion of the bottle neck just below the neck ring to pass through the spacing with the bottle suspended from the top surfaces of the flanges by the neck ring engaging on the top surfaces. A series of air jets or orifices are positioned along the flanges above and/or below the flanges. A plenum of the air conveyor sections supplies a flow of air to the orifices. The orifices are oriented so that air ejected from the orifices will contact the plastic bottles pushing the bottles along the pathway defined by the elongated slots of the aligned pairs of conveyor flanges with the neck rings of the bottles sliding along the top surfaces of the pairs of flanges. An example of this type of conveyor is disclosed in the of Ouellette U.S. Pat. No. 5,628,588, issued May 13, 1997 and incorporated herein by reference. Multichannel air conveyors are basically the same as that disclosed in the patent, except that they include a multiple of pairs of flanges that extend side-by-side, defining a multiple of conveyor slots.
In some types of air conveyors the opposed flanges that define the slot of the conveyor path are mounted in laterally spaced side walls of the air conveyor that define a conveying channel between the side walls. Air ducts also pass through these pairs of side walls feeding the flow of air to the orifices that also emerge from these side walls. The side walls are provided with mutually opposed, longitudinally extending grooves. The pairs of flanges are mounted in these grooves. The grooves are designed to be sufficiently deep so that the flanges can be adjustably positioned in the grooves enabling the pair of opposed flanges to be moved laterally toward each other or laterally away from each other. This enables the lateral spacing between the pairs of flanges that defines the conveyor slot to be adjusted to accommodate different diameter neck rings of bottles to be conveyed through the conveyor, for example, an adjustment between the typical 28 mm thread diameter bottle neck and the 38 mm thread diameter bottle neck. The flanges are secured in the grooves in their relative adjusted positions by a series of set screws that are spacially arranged along the length of the conveyor channel side walls and are tightened down to secure the flanges in their adjusted positions in the opposed grooves of the side walls.
Although the ability to adjust the lateral spacing between the opposed flanges of an air conveyor is a very desirable feature in order to be able to use the same air conveyor in conveying plastic bottles of different neck diameters, the desirable flange lateral adjustment feature of this type of air conveyor has the disadvantage of the time required to adjust or change the lateral spacing between the flanges of each conveyor section. For each conveyor section the series of set screws along the lower sections of the conveyor channel side walls must first be loosened. Then, the opposed pairs of flanges are moved to their new adjusted positions and then each of the plurality of set screws in the opposed lower sections of the channel side walls along the longitudinal length of the conveyor section must be tightened down while the pair of opposed flanges are held in their new adjusted positions. This adjustment procedure is very time consuming for a single length of an air conveyor. The time involved in the adjustments can be multiplied several times for an air conveying system that is comprised of several sections of air conveyors. The time involved in adjusting the lateral spacing between opposed pairs of conveyor flanges is multiplied even further in the case of multichannel air conveyors.
The problem of down time in adjusting the lateral spacing between opposed pairs of flanges of air conveyors has been addressed and overcome by an apparatus that automatically and simultaneously changes over the lateral slot spacing between adjacent pairs of conveyor flanges between two previously determined and previously adjusted lateral slot spacings. The apparatus that performs this function is disclosed in the pending of Ouellette, U.S. patent application Ser. No. 09/228,831, incorporated herein by reference. However, the apparatus disclosed in the patent application is employed on horizontal lengths or sections of air conveyors. It is often necessary to join adjacent lengths of air conveyors by a pivoting connection, for example, a connection that would allow a downstream air conveyor section to pivot vertically relative to an upstream air conveyor section. Connecting adjacent lengths of air conveyors by a pivoting connection is made more complicated where the air conveyor sections have automatically adjustable flange spacings such as that disclosed in the above-referenced patent application. This is made even more complicated where the adjacent lengths of air conveyors are multichannel air conveyors that have automatically adjustable flange spacings. Such a pivoting connection would not only require that the downstream air conveyor section be capable of pivoting relative to the upstream air conveyor section, but it would also have to include opposed pairs of flanges that are laterally adjustable between two lateral spacings that would match the lateral adjustability of the opposed pairs of flanges of the upstream air conveyor and the downstream air conveyor section.
SUMMARY OF THE INVENTION
The present invention overcomes the disadvantages described above by providing a vertically pivoting connection apparatus for multichannel air conveyors that includes a mechanism for quickly changing over the lateral spacing width between pairs of opposed flanges of the connection between two previously determined and previously adjusted spacing distances, for example the lateral spacing distances that accommodate both the typical 28 mm thread diameter plastic bottle and the 38 mm thread diameter plastic bottle.
In the preferred embodiment of the invention it connects an upstream, longitudinally extending multichannel air conveyor to a downstream, longitudinally extending multichannel air conveyor. In addition, the connection the apparatus of the invention provides between the upstream and downstream multichannel air conveyors is a pivoting connection that enables the downstream air conveyor to be inclined upwardly or downwardly relative to the horizontally extending upstream air conveyor. Each of the air conveyors have a multiple of slots defined by the pairs of opposed flanges of each air conveyor. The slots define the flow paths or multiple channels through which the necks and neck rings of streams of plastic bottles are conveyed. In this preferred embodiment, the pairs of flanges of both the upstream and downstream air conveyors are adjustable laterally inwardly and outwardly to accommodate bottles having different neck dimensions and neck ring diameters. The apparatus of the invention receives the stream of bottles from the upstream air conveyor and conveys the stream of bottles to the downstream air conveyor, and therefore also has the same number of bottle conveying channels as the two conveyor sections. The channels are each defined by mutually opposed pairs of flanges that are capable of being laterally adjusted toward and away from each other, just as the pairs of flanges of the upstream air conveyor section and the downstream air conveyor section.
The apparatus of the invention is comprised of an upstream base and a downstream base that are connected together by two pivot joints on laterally opposite sides of the two bases. The upstream base is connected to the upstream air conveyor and receives a flow of air from the plenum of the upstream air conveyor. In a like manner, the downstream base is connected to the downstream air conveyor and receives a flow of air from the plenum of downstream air conveyor. The connection provided by the apparatus enables the downstream air conveyor to pivot vertically relative to the upstream air conveyor. Both the upstream base and the downstream base are similar in construction to each other, and therefore only the upstream base will be further described.
The upstream base has a multiple of longitudinally extending slots formed in its underside that are defined by opposed pairs of downwardly depending side walls of the base. Each of the slots aligns with an air conveyor slot of the upstream air conveyor. Pairs of laterally spaced and mutually opposed flanges are mounted to the bottoms of the base side walls for sliding movement laterally toward and away from each other. Each flange as a pair of nozzle heads that depend downwardly from the flange and reciprocate laterally with the flange. The nozzle heads each have an air ejecting orifice that is oriented to direct air toward a bottle suspended in the slot by the pair of opposed flanges to push the bottle through the slot toward the downstream air conveyor. The base has a plurality of air flow conducting passages that receive air flow from the plenum of the upstream air conveyor and direct the air flow to the air ejecting orifices of the nozzle heads. A lateral slot is cut into the top of the base. The slot has a lateral sliding surface at its bottom in the interior of the base. A plurality of vertical air flow passages, equal in number to the plurality of flanges extend downwardly through the base. The vertical passages extend downwardly through the side walls of the base and open through the bottoms of the side walls. These vertical passages provide air flow to the nozzle heads on the flanges.
A pair of laterally extending racks are mounted side-by-side in the slot of the base. The lateral length of the racks is slightly smaller than that of the slot, enabling the racks to reciprocate side-by-side laterally through the slot. Each rack has a plurality of fingers that extend downwardly from the rack through one of the vertical air flow passages of the base. A first of the two racks has fingers that extend downwardly through the vertical passages of the base and engage with a first flange of each pair of flanges. A second rack of the pair of racks has fingers that extend downwardly through the vertical passages of the base and engage with a second flange of each pair of flanges. Thus, by laterally reciprocating the first and second racks in opposite directions in the base slot, the first and second flanges of each pair of opposed flanges are simultaneously moved laterally toward and away from each other. The lateral reciprocating movement of the racks is adjustable and by the adjustment of the extent of their lateral movement the lateral spacing between the pairs of flanges can be adjusted between first and second laterally spaced positions of the flanges.
The actuator mechanism of the apparatus that drives the reciprocating movement of the first and second racks is provided by first and second pneumatic actuators. A control system for the apparatus selectively supplies air pressure to the first and second actuators to cause piston rods extending from the actuators to be reciprocated between first and second, extended and retracted positions. The piston rods of the first and second actuators are connected to the first and second racks, respectively. Thus, when the first and second actuators are selectively supplied with pressure to control their piston rods to be extended and retracted, the first and second racks are laterally reciprocated in the base slot and the first and second flanges of each pair of flanges are moved between their first lateral spacing and second lateral spacing.
Thus, the apparatus of the invention provides a pivoting connection between adjacent lengths of multichannel air conveyors and includes a mechanism that can be selectively controlled to simultaneously adjust the lateral width dimension of the slots between opposed flanges of a multichannel air conveyor. When employed with a multichannel air conveyor that conveys plastic bottles suspended by their neck rings in the slots, the apparatus quickly changes over the air conveyor for conveying plastic bottles of different neck dimensions and neck ring diameters.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and features of the invention are revealed in the following detailed description of the preferred embodiment of the invention and in the drawing figures, wherein:
FIG. 1 is a partial end view of one type of multichannel air conveyor with which the apparatus of the invention may be employed;
FIG. 2 is a schematic representation of a side elevation view of an upstream multichannel air conveyor section pivotally coupled to a downstream multichannel air conveyor section by the apparatus of the invention;
FIG. 3 is a detailed side elevation view of the multichannel neck ring change-over and vertical pivot apparatus of the invention;
FIG. 4 is an end elevation view of one base section of the apparatus of the invention;
FIG. 5 is a top plan view of the base section of FIG. 4;
FIG. 6 is a bottom plan view of the base section of FIG. 4;
FIG. 7 is a view of the base section of FIG. 4 removed from the apparatus of the invention;
FIG. 8 is a bottom plan view of the base section of FIG. 7;
FIG. 9 is an elevation view of the opposite side of the base section of FIG. 7;
FIG. 10 is a plan view of the top of the base section of FIG. 7;
FIGS. 11 and 12 are elevation views of a pair of racks employed in the base section of FIG. 4;
FIGS. 13 and 14 are side views of the two base sections of the apparatus showing their pivot connections; and
FIG. 15 is a partial elevation view of a flange and nozzle head of the apparatus of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a partial end view of one type of multichannel air conveyor with which the neck ring change-over and vertical pivot apparatus of the invention may be employed. These types of air conveyors can have two or more conveying channels extending parallel with each other along the length of the conveyor section. Single channel air conveyors of this type are described in the of Ouellette, U.S. Pat. No. 5,628,588, issued May 13, 1997. Multichannel air conveyors of this type having mechanisms that automatically adjust the spacing between the opposed pairs of flanges for each channel between two laterally adjusted positions are described in the pending of Ouellette, U.S. patent application Ser. No. 09/228,831. Both the patent and application are assigned to the assignee of the present application and are incorporated herein by reference.
FIG. 2 is a schematic representation of the neck ring change-over and vertical pivoting apparatus 12 of the invention. The apparatus 12 is shown providing a vertical pivoting connection between an upstream length 14 of a multichannel air conveyor and a downstream length 16 of a multichannel air conveyor. The direction of the conveyed stream of bottles is indicated by the horizontal arrow A in FIG. 2 . The pivoting apparatus 12 of the invention provides the combined benefits of a pivoting connection between the two conveyor sections 14 , 16 that enables the downstream section 16 to pivot vertically as represented by the arced line B in FIG. 2, and also provides a connection between the two lengths of multichannel air conveyors of the type having opposed pairs of flanges that can be laterally adjusted relative to each other. The coupling also has opposed pairs of laterally spaced flanges. The lateral spacing between each pair of flanges can be automatically adjusted to match that of the two conveyor sections the coupling connects.
FIG. 3 is an enlarged view of the apparatus schematically represented in FIG. 2 . The apparatus includes an upstream base 24 and a downstream base 26 connected together by two pivot connections on laterally opposite sides of the pair of bases. In viewing FIG. 3, the longitudinal flow direction is from left to right. FIG. 13 shows the upstream base 24 disassembled from the upstream air conveyor and the downstream base. FIG. 14 shows the downstream base 14 disassembled from the downstream air conveyor and the upstream base. In FIGS. 13 and 14 it can be seen that the pivot connections on the laterally opposite ends of the two bases are comprised of a pair of lower hinge knuckles 28 projecting from the upstream base 24 and a pair of upper hinge knuckles 32 projecting from the downstream base 26 . A cylindrical pivot pin 34 is positioned between each opposing lower hinge knuckle 28 and upper hinge knuckle 32 on laterally opposite sides of the pair of bases 24 , 26 and together with the hinge knuckles forms the pivoting connections at the laterally opposite sides of the bases.
FIG. 4 shows the pair of pivot pins 34 set on the lower hinge knuckles 28 of the upstream base 24 with the downstream base 26 removed. With the pivot connection provided by the pair of pivot pins 34 and the lower 28 and upper 32 hinge knuckles, the downstream air conveyor 16 is free to pivot vertically relative to the generally horizontal upstream air conveyor 14 either inclining the downstream air conveyor upwardly or downwardly as represented by the arced arrow B in FIG. 2 .
The upstream base 24 is connected to the upstream air conveyor 14 and receives a flow of air from the plenum 36 of the upstream air conveyor. In a like manner, the downstream base 26 is connected to the downstream air conveyor 16 and receives a flow of air from the plenum 38 of the downstream air conveyor. Both the upstream and the downstream bases are identical to each other except for their respective hinge knuckles, and therefore only the construction of the upstream base 24 will be further described.
The upstream base 24 is machined from a block of metal such as aluminum, but may be constructed of other materials. It is formed with a general rectangular configuration having a lateral width that extends across the width of the upstream air conveyor 14 as shown in FIG. 4, and a much shorter longitudinal length as shown in FIG. 3 . Referring to FIG. 4 which shows the upstream base assembled to the air conveyor 14 , and FIG. 8 which shows the bottom of the upstream base disassembled from the air conveyor, the upstream base is provided with a multiple of longitudinally extending slots 42 formed into the underside of the base. Each of the slots is defined by opposed pairs of downwardly depending side walls 44 of the base that extend along opposite sides of the slots. The number of slots 42 corresponds to the number of air conveying slots of the upstream and downstream air conveyor sections. Each of the slots aligns with one of the multiple of slots or channels of the upstream air conveyor. Each slot has an interior volume sufficiently large to allow the neck and neck ring of a plastic bottle to pass easily therethrough, as is conventional in the construction of these types of air conveyors. The base also has a plurality of air flow conducting passages machined into the base. These include horizontally extending air flow conducting passages 48 , vertically extending air flow conducting passages 50 and horizontally extending air flow conducting pockets 52 that open through the bottoms of the sidewalls 44 . In viewing FIGS. 3, 9 and 10 , it can be seen that the horizontal air flow conducting passages 48 enter the base from the side of the base attached to the upstream air conveyor 14 . These horizontal air flow conducting passages 48 receive a flow of air from communicating passages 56 of the plenum 36 of the upstream air conveyor. Referring to FIGS. 3, 13 and 14 , the horizontal air flow conducting passages 48 extend longitudinally into the base and intersect with the vertical air flow passages 50 . As shown in FIGS. 7-9, an equal number of vertical air flow conducting passages 50 intersect with the horizontal air flow conducting passages 48 and extend downwardly therefrom to the pockets 52 that open through the bottom of the base 24 . These vertical air flow conducting passages 50 receive the flow of air from the horizontal air flow conducting passages 48 and channel the flow of air downwardly to the air flow pocket openings 52 in the bottom of the base 24 . A lateral slot 58 is also cut into the middle of the base 24 from the top surface of the base. As shown in FIGS. 7 and 9, the lateral slot 58 extends downwardly about half way through the height of the base 24 to a bottom sliding surface 62 of the slot. As shown in FIGS. 3, 7 , 9 , 13 and 14 , vertical finger passages 103 intersect with the lateral slot 58 at the bottom of the slot and extend downwardly to the bottoms of the base side walls 44 . These additional vertical finger passages 103 will be further described later.
As shown in FIGS. 4 and 6, pairs of mutually opposed first 66 and second 68 flanges are mounted on the bottoms of the base side walls 44 . The detail of one of the flanges 66 is shown in FIG. 15 . The first flange 66 of each pair has three oblong slots 72 and the second flange 68 of the pair has four oblong slots 74 , the slots extending laterally. Threaded fasteners 76 pass through the slots of the pairs of flanges thereby mounting the flanges to the base side walls 44 for laterally reciprocating movement toward and away from each other as shown in FIG. 15 . The fasteners 76 are not tightened down so the flanges 66 , 68 are free to reciprocate toward and away from each other. The fasteners are of the type such as NYLOK® fasteners that will not back out on vibration. Each flange is also provided with a recess 78 in its top surface and an air flow passage 82 that passes through the flange also as shown in FIG. 15 . Pairs of nozzle heads 84 are secured by a fastener 86 to the bottoms of each of the flanges. Each of the nozzle heads 84 has an air flow passage 88 passing therethrough that emerges from the nozzle head through an outlet orifice 92 as shown in FIG. 15 . The orientation of the nozzle heads 84 and the outlet orifices 92 directs jets of air towards the conveying slots 94 defined between each pair of opposed flanges 66 , 68 to contact bottles and convey bottles through the slots in a downstream direction just as in the air conveyors 14 , 16 and air conveyors of the type disclosed in the earlier referenced patents. The nozzle heads 84 reciprocate with the pairs of flanges 66 , 68 laterally toward and away from each other. As best seen in FIG. 15, the air flow passage 88 of the nozzle head communicates with the flange air flow passage 82 which in turn communicates with the air flow pocket opening 52 in the bottom of the sidewall 44 . The bottom pocket opening 52 communicates with one of the vertical air flow conducting passages 50 of the base side wall 44 . The bottom pocket opening 52 is sufficiently large horizontally so that it will remain in communication with the flange air flow passage 82 and the nozzle head air flow passage 88 when the flange is reciprocated between its two laterally adjusted positions. In this way, each of the nozzle heads 84 is provided with a flow of air when each of the opposed pairs of flanges 66 , 68 is laterally adjusted between their two laterally spaced positions. As seen in FIG. 3, the pivot connection between the upstream base 24 and the downstream base 26 positions the two bases sufficiently close to each other to enable the nozzle heads 84 of each base to convey bottles across the pivot connection despite the angled orientation of the downstream base 26 relative to the upstream base 24 . In this manner, the change-over and pivot apparatus 12 of the invention provides a pivoting connection between the upstream air conveyor 14 and the downstream air conveyor 16 that conveys streams of plastic bottles across the connection between the two conveyors despite the angled orientation of the downstream air conveyor 16 relative to the upstream air conveyor.
A pair of laterally extending racks 96 , 98 are mounted in the lateral slot 58 of the base 24 for laterally reciprocating sliding movement across the bottom sliding surface 62 of the slot. The side-by-side positioning of the racks 96 , 98 is shown in FIG. 5 . The racks are shown removed from the base in FIGS. 11 and 12. In FIGS. 11 and 12, it can be seen that the racks are mirror images of each other. Each of the racks has a plurality of downwardly depending fingers 102 . With the two racks assembled side-by-side in the lateral slot 58 of the base 24 , the fingers 102 of the first rack 96 extend downwardly through the vertical finger passages 103 in the base side walls 44 and into the flange recesses 78 of the first flanges 66 . The fingers 102 of the second rack 98 also extend downwardly through the vertical finger passages 103 of the base 24 and into the flange recess 78 of the second flanges 68 . It should be appreciated that as each of the racks 96 , 98 is moved between two laterally reciprocated positions in the base lateral slot 58 , the fingers 102 of the racks move in their associated finger passages 103 and move the opposed pairs of flanges 66 , 68 laterally toward each other and laterally away from each other between two laterally spaced positions of the flanges. As shown in FIG. 4, a pair of brackets 106 are mounted on the opposite lateral ends of the base 24 and a set screw 108 with a lock nut 110 is screw threaded through each of the brackets. The extent to which the set screws 108 are screw threaded through the brackets adjusts the lateral reciprocating movement of the racks 96 , 98 in the base lateral slot 58 . In the preferred embodiment, the extent of lateral movement of the racks is adjusted so that as they are reciprocated through their two positions, they move the opposed pairs of flanges 66 , 68 between a lateral spacing that accommodates a typical 28 mm thread diameter bottle neck and a lateral spacing that accommodates a typical 38 mm thread diameter bottle neck. However, the adjustment of the reciprocating movement of the racks can be varied to accommodate other bottle sizes.
The actuator mechanism of the apparatus that drives the reciprocating movement of the first and second racks is provided by first 112 and second 114 pneumatic actuators. As shown in FIGS. 4 and 5, each of the actuators 112 , 114 is a double-acting piston-cylinder actuator. Each actuator has an air inlet 116 for retracting the piston and piston rod into the actuator cylinder and a second air inlet 118 for extending the piston rod from the cylinder, as is conventional. By the selective supply of air pressure to the two air inlets, the piston rods of the actuators can be controlled to be simultaneously extended, thereby moving the opposed pairs of flanges 66 , 68 laterally toward each other, or retracted thereby moving the pairs of opposed flanges 66 , 68 laterally away from each other. A control system (not shown) for the apparatus selectively supplies air pressure to the first and second actuators to cause the piston rods extending from the actuators to be reciprocated between the first and second, extended and retracted, positions. The piston rods of the first and second actuators are connected to the first and second racks 96 , 98 respectively. Thus, when the first and second actuators are selectively supplied with pressure to control the piston rods to be extended and retracted, the first and second racks are laterally reciprocated in the base slot 58 and the first and second flanges 66 , 68 of each pair of flanges are moved between their first lateral spacing and second lateral spacing.
Thus, the apparatus of the invention provides a compact pivoting connection between upstream and 35 downstream multichannel air conveyors. The apparatus is also capable of simultaneously adjusting the lateral width dimensions of the slots between opposed pairs of flanges of the pivoting connection to match the adjusted lateral width dimensions of the multichannel upstream and downstream air conveyors.
While the present invention has been described by reference to a specific embodiment, it should be understood that modifications and variations of the invention may be constructed without departing form the scope of the invention defined in the following claims. | A multichannel pivoting coupling between an upstream multichannel air conveyor and a downstream multichannel air conveyor includes a mechanism that can be selectively controlled to simultaneously adjust the lateral width dimensions of the slots between opposed flanges of the coupling to coincide with adjustments in the lateral width dimensions of the slots between the opposed flanges of the upstream and downstream multichannel air conveyors. The multichannel air conveyors of the type employed with the pivoting coupling apparatus convey streams of plastic bottles suspended by their neck rings in the slots and the lateral spacing between pairs of flanges that define the slots can be quickly changed over for conveying plastic bottles of different neck dimensions and different neck ring diameters. | 1 |
[0001] This application is a divisional of Ser. No. 11/383,563, filed May 16, 2006.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of integrated circuits; more specifically, it relates to dual wired integrated circuit chips and methods of fabricating dual wired integrated circuit chips.
BACKGROUND OF THE INVENTION
[0003] As the density of integrated circuits increases the number of circuits increase. The increased circuit density results in smaller chip while the increased circuit count results in increased contact pads counts for connecting the integrated circuit to the next level of packaging. Therefore, there is an ongoing need for greater wiring density and increased contact pad count for connection of integrated circuit chips to the next level of packaging.
SUMMARY OF THE INVENTION
[0004] A first aspect of the present invention is a method of fabricating a semiconductor structure, comprising: forming one or more devices in a silicon-on-insulator substrate, the substrate comprising a buried oxide layer between an upper silicon layer and a lower silicon layer and a pre-metal dielectric layer on a top surface of the upper silicon layer; forming a first set of wiring levels over the pre-metal dielectric layer, each wiring level of the first set of wiring levels comprising electrically conductive wires in a corresponding dielectric layer, a lowermost wiring level in physical contact with a top surface of the pre-metal dielectric layer; removing the lower silicon layer from the substrate to expose a bottom surface of the buried oxide layer; forming electrically conductive first contacts to the devices, one or more of the first contacts extending from the top surface of the pre-metal dielectric layer to the devices, one or more wires of the lowermost wiring level of first set of wiring levels in electrical contact with the first contacts; forming electrically conductive second contacts to the devices, one or more of the second contacts extending from the bottom surface of the buried oxide layer to the devices; and forming a second set of wiring levels over the buried oxide layer, each wiring level of the second set of wiring levels comprising electrically conductive wires in a corresponding dielectric layer, a lowermost wiring level of the second set of wiring levels in physical contact with a top surface of the buried oxide layer, one or more wires of the lowermost wiring level of the second set of wiring levels in electrical contact with the second contacts.
[0005] A second aspect of the present invention is the first aspect wherein the devices include field effect transistors comprising source/drains formed in the upper silicon layer and gate electrodes formed over the upper silicon layer and separated from the upper silicon layer by a gate dielectric layer.
[0006] A third aspect of the present invention is the second aspect, wherein the forming the one or more devices includes forming an electrically conductive metal silicide layer on top surfaces of the source/drains and the gate electrodes.
[0007] A fourth aspect of the present invention is the third aspect, wherein at least one of the first contacts extends from the top surface of the pre-metal dielectric layer to the metal silicide layer on a corresponding gate electrode.
[0008] A fifth aspect of the present invention is the third aspect, wherein at least one of the first contacts extends from the top surface of the pre-metal dielectric layer to the metal silicide layer on a corresponding source/drain.
[0009] A sixth aspect of the present invention is the third aspect, further including: forming one or more silicon contact regions in the upper silicon layer and forming the metal silicide layer on top surfaces of the one or more silicon contact regions; and wherein at least one of the first contacts extends from the top surface of the pre-metal dielectric layer to the metal silicide layer on a corresponding silicon contact region of the one or more silicon contact regions, and wherein at least one of the second contacts extends from the bottom surface of the buried oxide layer through the upper silicon layer to the metal silicide layer on the corresponding silicon contact region.
[0010] A seventh aspect of the present invention is the third aspect, further including: forming a dielectric trench isolation in regions of the upper silicon layer, the trench isolation extending from the top surface of the upper silicon layer to the buried oxide layer; and wherein at least one of the first contacts extends from the top surface of the pre-metal dielectric layer to the trench isolation to physically and electrically contact a corresponding contact of the second contacts, the corresponding contact extending from the bottom surface of the buried oxide layer through the trench isolation.
[0011] An eighth aspect of the present invention is the third aspect, further including: forming one or more dummy gate electrodes in the pre-metal dielectric layer and forming the metal silicide layer on top surfaces of the one or more dummy gates; and forming one or more dummy gate electrodes in the pre-metal dielectric layer and wherein the forming the electrically conductive metal silicide layer also includes forming the metal silicide layer on top surfaces of the one or more dummy gates, wherein at least one of the second contacts extends from said bottom surface of the buried oxide layer through a trench isolation formed in the upper silicon layer, through a gate dielectric layer formed under the gate electrode to said metal silicide layer on the corresponding dummy gate electrode.
[0012] A ninth aspect of the present invention is the third aspect, forming one or more dummy gate electrodes in the pre-metal dielectric layer; and wherein the forming the electrically conductive metal silicide layer also includes forming the metal silicide layer on top surfaces of the one or more dummy gates, wherein at least one of the first contacts extends from the top surface of the pre-metal dielectric layer to the metal silicide layer of a corresponding dummy gate electrode of the one or more dummy gate electrodes, and wherein at least one of the second contacts extends from the bottom surface of the buried oxide layer through a trench isolation formed in the upper silicon layer, through a gate dielectric layer formed under the gate electrode to the dummy gate electrode.
[0013] A tenth aspect of the present invention is the third aspect, further including: forming an opening in the BOX layer over a corresponding source/drain to expose a bottom surface of the source/drain; depositing a metal layer in the opening on top of the bottom surface of the source/drain; forming a metal silicide region in the source/drain, the silicide region extending from the bottom surface of the source/drain to the silicide layer on the top surface of the source/drain region; and wherein at least on of the second contacts extends to and is in electrical contact with the metal silicide region.
[0014] A eleventh aspect of the present invention is the third aspect, wherein at least one of the second contacts extends from the bottom surface of the buried oxide layer through the upper silicon layer to the metal silicide layer on a corresponding source/drain.
[0015] A twelfth aspect of the present invention is the third aspect, wherein the metal silicide layer comprises platinum silicide, titanium silicide, cobalt silicide or nickel silicide.
[0016] A thirteenth aspect of the present invention is the second aspect, wherein the forming the one or more devices includes forming electrically conductive metal silicide regions of a metal silicide in the source/drains and electrically conductive metal silicide regions of the metal silicide in the gate electrodes, the metal silicide regions of the source/drains extending from top surfaces of the source/drains to bottom surfaces of the source drains and the metal silicide regions of the gate electrodes extending from top surfaces of the gate electrodes to bottom surfaces of the gate electrodes.
[0017] A fourteenth aspect of the present invention is the thirteenth aspect, wherein at least one of the first contacts extends from the top surface of the pre-metal dielectric layer to the metal silicide region of a corresponding gate electrode.
[0018] A fifteenth aspect of the present invention is the thirteenth aspect, wherein at least one of the first contacts extends from the top surface of the pre-metal dielectric layer to a corresponding metal silicide region of a corresponding source/drain.
[0019] A sixteenth aspect of the present invention is the thirteenth aspect, further including: forming one or more silicon contact regions in the upper silicon layer and forming metal silicide regions of the metal silicide in the one or more silicon contact regions, the metal silicide regions of the one or more silicon contact regions extending from a top surface of the one or more silicon contract regions to bottom surfaces of the one or more silicon contact regions; and wherein at least one of the first contacts extends from the top surface of the pre-metal dielectric layer to the metal silicide region of a corresponding silicon contact region of the one or more silicon contact regions, and wherein at least one of the second contacts extends from the bottom surface of the buried oxide layer to the metal silicide region of the corresponding silicon contact region.
[0020] A seventeenth aspect of the present invention is the thirteenth aspect, further including: forming a dielectric trench isolation in regions of the upper silicon layer, the trench isolation extending from the top surface of the upper silicon layer to the buried oxide layer; and wherein at least one of the first contacts extends from the top surface of the pre-metal dielectric layer to the trench isolation to physically and electrically contact a corresponding contact of the second contacts, the corresponding contact extending from the bottom surface of the buried oxide layer through the trench isolation.
[0021] A eighteenth aspect of the present invention is the thirteenth aspect, further including: forming one or more dummy gate electrodes in the pre-metal dielectric layer and forming metal silicide regions of the metal silicide in the one or more dummy gates, the metal silicide regions extending from top surfaces of the one or more dummy gates to bottom surfaces of the one or more dummy gates; and wherein at least one of the first contacts extends from the top surface of the pre-metal dielectric layer to a metal silicide region of a corresponding dummy gate of the one or more dummy gate electrodes, and wherein at least one of the second contacts extends from the bottom surface of the buried oxide layer to the metal silicide region of the corresponding dummy gate electrode.
[0022] A nineteenth aspect of the present invention is the thirteenth aspect, wherein at least one of the second contacts extends from the bottom surface of the buried oxide layer to the metal silicide region of a corresponding source/drain.
[0023] A twentieth aspect of the present invention is the thirteenth aspect, wherein the metal silicide comprises platinum silicide, titanium silicide, cobalt silicide or nickel silicide
[0024] A twenty-first aspect of the present invention is the first aspect, wherein each the corresponding dielectric layer of the first and second sets of wiring levels comprises a material independently selected from the group consisting of silicon dioxide, silicon nitride, silicon carbide, silicon oxy nitride, silicon oxy carbide, organosilicate glass, plasma-enhanced silicon nitride, constant having a dielectric) material, hydrogen silsesquioxane polymer, methyl silsesquioxane polymer polyphenylene oligomer, methyl doped silica, organosilicate glass, porous organosilicate glass and a dielectric having relative permittivity of about 2.4 or less.
[0025] A twenty-second of the present invention is the first aspect, further including: before the removing the lower silicon layer, attaching a handle substrate to an uppermost dielectric layer of the first set of wiring levels, the uppermost dielectric layer of the first set of wiring levels furthest away from the lower silicon layer.
[0026] A twenty-third aspect of the present invention is the twenty-second aspect further including: after the forming the second set of wiring levels, removing the handle substrate.
[0027] A twenty-fourth aspect of the present invention is the twenty-third aspect, further including: after forming the second set of wiring levels, dicing the substrate into one or more integrated circuit chips.
BRIEF DESCRIPTION OF DRAWINGS
[0028] The features of the invention are set forth in the appended claims. The invention itself, however, will be best understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
[0029] FIGS. 1A through 1E are cross-sectional drawings illustrating fabrication of an integrated circuit chip according to a first embodiment of the present invention;
[0030] FIGS. 2A and 2B are cross-sectional drawings illustrating fabrication of an integrated circuit chip according to a second embodiment of the present invention;
[0031] FIGS. 3A and 3B are cross-sectional drawings illustrating fabrication of an integrated circuit chip according to a third embodiment of the present invention; and
[0032] FIGS. 4A through 4E are cross-sectional drawings illustrating fabrication of an integrated circuit chip according to a fourth embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0033] It should be understood that the integrated circuit chips of the embodiments of the present invention are advantageously formed on integrated circuit substrates called wafers and that multiple integrated circuits may be fabricated simultaneously on the same wafer and may be separated by a dicing process after fabrication is complete.
[0034] FIGS. 1A through 1E are cross-sectional drawings illustrating fabrication of an integrated circuit chip according to a first embodiment of the present invention. In FIG. 1A , a wafer 100 A is fabricated through pad level. Wafer 100 A includes a silicon-on-insulator (SOI) substrate 105 which includes a silicon substrate 110 A, a buried oxide layer (BOX) 115 formed on the silicon substrate and a single-crystal silicon layer 120 formed on the BOX. Formed in silicon layer 120 are trench isolation 125 and source/drains 135 and channel regions 140 of field effect transistors (FETs) 130 . Also formed in silicon layer 120 are optional silicon regions 150 . Formed over channel regions 140 are a gate dielectric (not shown) and, in one example, polysilicon gates 145 of FETs 130 as well as a dummy gate 146 . In one example, silicon regions 150 are highly doped N or P-type (between about 1E19 atm/cm 3 and about 1E21 atm/cm 3 ) in order to reduce the resistance of the contact to less than about 0.5 micro-ohms. An electrically conductive metal silicide layer 152 is formed on exposed silicon surfaces of source/drains 135 , gates 145 and diffusion contacts 150 prior to formation of a pre-metal dielectric (PMD) layer 155 to further reduce the “contact” resistance of a metal structures to silicon structures as described infra. Metal silicides are formed by deposition of a metal layer on a silicon surface, heating the silicon surface high enough to cause the metal layer to react with the silicon, and then dissolving away any unreacted metal. Examples of metal silicides include, but are not limited to, platinum, titanium cobalt and nickel silicides.
[0035] Formed on top of silicon layer 120 is PMD layer 155 . Formed in PMD layer 155 are contacts 160 A and 160 B. Contacts 160 A and 160 B are electrically conductive. Contacts 160 A electrically contact silicide layer 152 on source/drains 135 and on silicon contact 150 . Some of contacts 160 A are dummy contacts extending to trench isolation 125 . Contacts 160 B contact silicide layer 152 on gates 145 and dummy gates 146 . PMD layer 155 and contacts 160 A and 160 B may be considered a wiring level.
[0036] Contacts 160 A and 160 B may be fabricated independently in separate operations or simultaneously. When fabricated simultaneously, first and second type contacts may be formed by etching the respective trenches in situ using a single mask or fabricated using various combinations of photolithographic and hard masks and etches to define the trenches separately, followed by a single metal fill and a chemical mechanical polish (CMP) operation.
[0037] Formed on PMD layer 155 is a first inter-level dielectric layer (ILD) 165 including electrically conductive dual-damascene wires 170 in electrical contact with contacts 160 . Formed on ILD 165 is a second ILD 180 including electrically conductive dual-damascene wires 180 in electrical contact with wires 170 . Formed on ILD 175 is a third ILD 190 including electrically conductive dual-damascene I/O pads 190 in electrical contact with wires 180 . Alternatively, wires 170 , 180 and pads 190 may be single damascene wires or pads in combination with single damascene vias.
[0038] A damascene process is one in which wire trenches or via openings are formed in a dielectric layer, an electrical conductor of sufficient thickness to fill the trenches is deposited on a top surface of the dielectric, and a CMP process is performed to remove excess conductor and make the surface of the conductor co-planar with the surface of the dielectric layer to form damascene wires (or damascene vias). When only a trench and a wire (or a via opening and a via) is formed the process is called single-damascene.
[0039] A dual-damascene process is one in which via openings are formed through the entire thickness of a dielectric layer followed by formation of trenches part of the way through the dielectric layer in any given cross-sectional view. All via openings are intersected by integral wire trenches above and by a wire trench below, but not all trenches need intersect a via opening. An electrical conductor of sufficient thickness to fill the trenches and via opening is deposited on a top surface of the dielectric and a CMP process is performed to make the surface of the conductor in the trench co-planar with the surface the dielectric layer to form dual-damascene wires and dual-damascene wires having integral dual-damascene vias.
[0040] The etches used in single-damascene and dual damascene processes to form trenches may advantageously be reactive ion etches (RIEs).
[0041] In one example, PMD layer 155 comprises boro-phosphorus silicate glass (BPSG) or phosphorus-silicate glass (BSG). In one example, contacts 160 A and 160 B comprise a titanium/titanium nitride liner and a tungsten core. In one example, ILD 165 , 175 and 185 comprise silicon dioxide or a layer of silicon dioxide over a layer of silicon nitride. In one example, wires 170 and 180 and I/O pads 190 comprise a tantalum/tantalum nitride liner and a copper core.
[0042] In one example, ILD layers 165 , 175 and 185 independently comprise silicon dioxide (SiO 2 ), silicon nitride (Si 3 N 4 ), silicon carbide (SiC), silicon oxy nitride (SiON), silicon oxy carbide (SiOC), organosilicate glass (SiCOH), plasma-enhanced silicon nitride (PSiN x ) or NBLok (SiC(N,H)).
[0043] In one example, ILD layers 165 , 175 and 185 independently comprise a low K (dielectric constant) material, examples of which include but are not limited to hydrogen silsesquioxane polymer (HSQ), methyl silsesquioxane polymer (MSQ), SiLK™ (polyphenylene oligomer) manufactured by Dow Chemical, Midland, Tex., Black Diamond™ (methyl doped silica or SiO x (CH 3 ) y or SiC x O y H y or SiOCH) manufactured by Applied Materials, Santa Clara, Calif., organosilicate glass (SiCOH), and porous SiCOH. In one example, a low K dielectric material has a relative permittivity of about 2.4 or less.
[0044] In FIG. 1B , a passivation layer 195 is formed on third ILD 185 and I/O pads 190 and a handle wafer 200 attached to passivation layer 195 using an adhesive (not shown) or by other methods known in the art.
[0045] In FIG. 1C , bulk substrate 110 (see FIG. 1B ) is removed to expose BOX 115 . In one example, bulk substrate 110 is removed by a grinding operation to substantially thin of the bulk substrate operation followed by (1) a chemical etch in a strong base such as aqueous potassium hydroxide or (2) a chemical etch in a mixture of hydrofluoric, nitric and acetic acids or (3) any chemical etch which is selective to etch silicon over silicon dioxide to remove the remaining bulk substrate.
[0046] In FIG. 1D , electrically conductive first backside contacts 205 are formed through BOX 115 and silicon layer 120 . Contacts 205 extend from the top surface of BOX 115 to silicide layer 152 on source/drains 135 and silicon contact 150 . In one example, contacts 205 are formed by a single damascene process. In one example, contacts 205 comprise a titanium/titanium nitride liner and a tungsten core.
[0047] Electrically conductive second backside contacts 210 are formed through BOX 115 and trench isolation 125 . Contacts 210 extend from the top surface of BOX 115 to silicide layer 152 on dummy gate 146 and to selected contacts 160 A. In the case of dummy gate 146 , contact 210 extends through the gate dielectric layer (not shown) as well.
[0048] Contacts 205 and 210 may be fabricated independently in separate operations or simultaneously. When fabricated simultaneously, first and second type contacts may be formed by etching the respective trenches in situ using a single mask or fabricated using various combinations of photolithographic and hard masks and etches to define the trenches separately, followed by a single metal fill and CMP operation.
[0049] In FIG. 1E , formed on BOX 115 is first inter-level dielectric layer (ILD) 165 A including electrically conductive dual-damascene wires 170 A in electrical contact with contacts 160 A. Formed on ILD 165 A is second ILD 180 A including electrically conductive dual-damascene wires 180 A in electrical contact with wires 170 A. Formed on ILD 175 A is third ILD 190 A including electrically conductive dual-damascene I/O pads 190 A in electrical contact with wires 180 A. Alternatively, wires 170 A, 180 A and pads 190 A of may be single damascene wires in combination with single damascene vias. A passivation layer 195 A is formed on third ILD 185 A and I/O pads 190 A and handle wafer 200 is removed. This completes fabrication of wafer 100 A which know can be externally wired (via pads 190 and 190 A) on two opposite sides.
[0050] FIGS. 2A and 2B are cross-sectional drawings illustrating fabrication of an integrated circuit chip according to a second embodiment of the present invention. The second embodiment of the present invention differs from the first embodiment of the present invention by contact 210 of FIGS. 1D and 1E being replaced by contacts 205 in a wafer 100 B. Processing as illustrated in FIGS. 1A through 1C and described supra in are performed and then FIG. 2A replaces FIG. 1D and FIG. 2B replaces FIG. 1E .
[0051] In FIGS. 2A and 2B a contact 205 is in electrical and physical contact with the polysilicon of dummy gate 146 . In one example, dummy gate 146 is advantageously highly doped N or P-type (between about 1E19 atm/cm 3 and about 1E21 atm/cm 3 ) in order to reduce the resistance of the contact to less than about 0.5 micro-ohms. Thus all backside contacts are etched to the same depth.
[0052] FIGS. 3A and 3B are cross-sectional drawings illustrating fabrication of an integrated circuit chip according to a second embodiment of the present invention. The third embodiment of the present invention differs from the first embodiment of the present invention by utilization of silicide-to-silicide contacts in a wafer 100 C. Processing as illustrated in FIGS. 1A through 1C and described supra in are performed and then FIG. 3A replaces FIG. 1D and FIG. 3B replaces FIG. 1E .
[0053] In FIGS. 3A and 3B , an electrically conductive metal silicide layer 153 is formed from the backside of wafer 100 C in selected source/drains 135 by forming contact openings in BOX layer 115 , depositing a metal layer, annealing to form a metal silicide and removing the excess metal. Then contact metal (i.e. titanium/titanium nitride liner and a tungsten core) is used to fill the contact openings. Silicide layer 153 is in physical and electrical contact with silicide layer 152 on selected source/drains 135 and a contact 215 is in physical and electrical contact with silicide layer 153 . Also an electrically conductive metal silicide layer 154 is formed in the polysilicon of dummy gate 146 after a contact openings is formed through BOX layer 115 , PMD layer 125 and the gate dielectric layer (not shown) and a contact 205 is in physical and electrical contact with silicide layer 154 . Again, examples of metal silicides include, but are not limited to, platinum, titanium cobalt and nickel silicides.
[0054] FIGS. 4A through 4E are cross-sectional drawings illustrating fabrication of an integrated circuit chip according to a third embodiment of the present invention. The third embodiment of the present invention differs from the first embodiment of the present invention with fully silicided source/drains, gates and silicon contacts replacing the silicide layer of the first embodiment.
[0055] FIG. 4A is the same as FIG. 1A except a wafer 100 B differs from wafer 100 D (see FIG. 1A ) in that source drains 135 (see FIG. 1A ) are replaced with fully silicided source/drains 136 , gates 145 (see FIG. 1A ) are replaced with fully silicided gates 148 , dummy gates 146 (see FIG. 1A ) are replaced with fully silicided dummy gates 149 and silicon contact 150 (see FIG. 1A ) is replaced with fully silicided contact 156 . A fully silicided source drain is one in which the silicide layer extends from a top surface of the source drain to BOX 115 . Note, that the silicide does not extend the fully silicided gates. A fully silicided gate is one in which the silicide layer extends from a top surface of the gate to the gate dielectric layer. A fully silicided silicon contact is one in which the silicide layer extends from a top surface of the silicon contact to BOX 115 .
[0056] Fully silicided source/drains, gates and silicon contacts are formed by deposition of a thick metal layer on a silicon surface, heating the silicon surface high enough to cause the metal layer to react with the silicon, and then dissolving away any unreacted metal. The thickness of the metal layer is great enough to supply sufficient metal, by thermal diffusion through the silicon, to react with silicon atoms throughout the source/drain, gate or silicon contact. Again, examples of metal silicides include, but are not limited to, platinum, titanium cobalt and nickel silicides.
[0057] FIGS. 4B and 4C are essentially the same as FIGS. 1B and 1C respectively except for the differences described supra.
[0058] FIG. 4D is the same as FIG. 1D except for the differences described supra and the replacement of contacts 205 and 210 of FIG. 1D by respective contacts 215 and 220 of FIG. 4D . In FIG. 4D , electrically conductive backside contacts 215 are formed through BOX 115 . Contacts 215 extend from the top surface of BOX 115 to the bottoms of fully silicided source/drains 136 and silicon contact 156 . In one example, contacts 215 are formed by a single damascene process. In one example, contacts 215 comprise a titanium/titanium nitride liner and a tungsten core.
[0059] Electrically conductive second backside contacts 220 are formed through BOX 115 and trench isolation 125 . Contacts 220 extend from the top surface of BOX 115 to the bottom surface of fully silicided dummy gate 146 and to selected contacts 160 A. In the case of dummy gate 146 , contact 220 extends through the gate dielectric layer (not shown) as well. Thus, contacts 215 and 220 do not have to etched as deeply or through silicon as contacts 205 and 210 of FIG. 1D .
[0060] First and second contacts 215 and 220 may be fabricated independently in separate operations or simultaneously. When fabricated simultaneously, first and second type contacts may be formed by etching the respective trenches in situ using a single mask or fabricated using various combinations of photolithographic and hard masks and etches to define the trenches separately, followed by a single metal fill and CMP operation.
[0061] FIG. 4E is essentially the same as FIG. 1E except for the differences described supra.
[0062] While each of wafers 100 A, 100 B, 110 C and 110 D has been illustrated with a single contact level, two wiring levels and a pad level, more or less contact and wiring levels may be fabricated and wafers 100 A and 110 B may be fabricated with different numbers of contact and/or wiring levels. Also, handle wafer 200 A may be detached from wafers 100 A, 100 B, 110 C and 110 D before or after dicing of wafers 100 A, 100 B, 110 C and 110 D into individual integrated circuits.
[0063] Thus, the embodiments of the present invention provide for greater wiring density and increased contact pad count for connection of integrated circuit chips to the next level of packaging.
[0064] The description of the embodiments of the present invention is given above for the understanding of the present invention. It will be understood that the invention is not limited to the particular embodiments described herein, but is capable of various modifications, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, it is intended that the following claims cover all such modifications and changes as fall within the true spirit and scope of the invention. | A semiconductor device having wiring levels on opposite sides and a method of fabricating a semiconductor structure having contacts to devices and wiring levels on opposite sides. The method including fabricating a device on a silicon-on-insulator substrate with first contacts to the devices and wiring levels on a first side to the first contacts, removing a lower silicon layer to expose the buried oxide layer, forming second contacts to the devices through the buried oxide layer and forming wiring levels over the buried oxide layer to the second contacts. | 7 |
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and system for processing a semiconductor device and, more particularly, to an improved conditioning mechanism for conditioning chemical mechanical polish (CMP) pad of a CMP machine.
BACKGROUND OF THE INVENTION
Advances in electronic devices generally include reducing the size of the components that form integrated circuits. With smaller circuit components, the value of each unit area of a semiconductor wafer becomes higher. This is because the ability to use all of the wafer area for integrated circuit components improves. To properly form an integrated circuit that employs a much higher percentage of usable wafer area, it is critical that contaminant particle counts on the semiconductor wafer surface be reduced below levels which previously may have been acceptable. For example, minute particles of oxides and metals of less than 0.2 microns are unacceptable for many of the popular advanced circuit designs, because they can short out two or more conducting lines. In order to clean a semiconductor wafer and to remove unwanted particles, chemical mechanical polishing or chemical mechanical polish (hereinafter "CMP") process has become popular.
CMP is a process for improving the surface planarity of a semiconductor wafer and involves the use of mechanical pad polishing systems usually with a silica-based slurry. CMP offers a practical approach for achieving the important advantage of global wafer planarity. However, CMP systems for global planarization have certain limitations.
CMP systems place a semiconductor wafer in contact with a polishing pad that rotates relative to the semiconductor wafer. The semiconductor wafer may be stationary, or it may also rotate on a carrier that holds the wafer. Problems of conventional methods of performing a chemical mechanical polish is that they produce nonuniform wafers and produce larger than desirable edge exclusion areas. Both of these problems impair operation of resulting electronic components formed from the semiconductor devices. Semiconductor wafer non-uniformity may cause undesirable layers not to be removed at some places and desirable layers to be removed at other places on the wafer surface. This causes various areas on the wafer surface to be unusable for forming semiconductor devices. Process uniformity from wafer to wafer is also important in CMP processing. Known CMP systems, however, suffer from significant wafer-to-wafer non-uniformities. This can also adversely affect the throughput and yield of the CMP process.
Another limitation of existing CMP systems relates to a part of the system known as the CMP polish pad. The CMP polish pad contacts the semiconductor wafer and polishes the wafer. A slurry is usually applied to the CMP polish pad to lubricate the interface between the wafer and the CMP polish pad. The slurry also serves the function, because of its silica content, of mildly abrading or affecting the surface of the semiconductor wafer.
A problem that often occurs with these particles and the slurry within the cell structure of the pad is a densification of the slurry within the voids. To overcome this problem, most CMP systems use a CMP polish pad conditioner that includes a diamond-encrusted end effector that rakes or scratches the pad surface. This scratching removes the slurry within the pad cellular structure to, in effect, "renew" the CMP polish pad surface.
A problem of conventional CMP polish pad conditioning end effectors is detaching from the end effector holder mechanism. Known systems typically attach the end effector using a double-sided tape or film that sticks to both the end effector and a surface of an end effector holding mechanism. When the end effector detaches from the double-sided tape, it remains on the CMP polish pad and often damages the semiconductor device.
Another problem of known CMP polish pad conditioning mechanisms is that slurry and semiconductor device particles often form deposits that clog in openings of the end effector. These deposits adversely affect the conditioning operation and limit the usable life span of both the CMP polish pad and the end effector.
Still another problem of existing end effectors is that they wear unevenly due to slurry deposits and an uneven surface that develops on the end effector, due primarily to an uneven interface that develops between the end effector and the holder mechanism.
SUMMARY OF THE INVENTION
Therefore, a need has arisen for improved method and apparatus for conditioning a CMP polish pad.
There is a need for a CMP polish pad conditioning end effector that remains in position during the polish pad conditioning operation and does not detach from the end effector holder.
There is a further need for a CMP polish pad conditioning end effector that avoids the formation of slurry deposits.
There is yet a further need for an improved CMP polish pad conditioning end effector that maintains a more uniform surface after numerous polish operations.
Still a further need for an improved CMP polish pad conditioning end effector that prolongs the life of the conditioned CMP polish pad by more uniformly conditioning the pad and eliminating areas of uneven wear.
In accordance with the present invention, a method and apparatus for conditioning a CMP polish pad is provided that substantially eliminates or reduces disadvantages and problems associated with previously developed CMP polish pad conditioning mechanisms.
More specifically, the present invention provides a method for conditioning a CMP polish pad that includes the steps of placing a spacer mechanism (such as a plurality of separate or individual spacers or a spacer ring) in at least one predetermined location of a end effector holder mechanism. The method places the spacer mechanism in an end effector recess of the holder mechanism in positions that associate with openings in the end effector. The end effector attaches through the spacer mechanism to the holder mechanism using a fastening device such as a screw or pin. The method further includes the steps of conditioning the CMP polish pad by placing the end effector in contact with a CMP polish pad having a layer of slurry deposited on the CMP polish pad for conditioning the CMP polish pad while the slurry passes through the end effector openings.
Another aspect of the present invention is an apparatus for conditioning a CMP polish pad that includes an end effector for contacting the CMP polish pad. A holder mechanism includes an end effector recess for receiving the end effector. The spacer mechanism is also located in at least one predetermined location in the end effector recess. The spacer opening locations associate with end effector openings in the end effector. The end effector firmly attaches through the spacer mechanism to the holder mechanism using a fastening device such as a screw or pin. Because of the spacer mechanism, the end effector is at a distance from the holder mechanism that permits slurry deposited on the CMP polish pad to pass through the end effector openings.
A technical advantage of the present invention is it overcomes the problem of conventional polish pad conditioner end effectors. Because the end effectors firmly fastens to the holder mechanism through the spacer mechanism, there is not the possibility of the end effector detaching from the conditioning end effector holder.
Another technical advantage that the present invention provides is a practical solution to the problem slurry and semiconductor device particles forming deposits in openings of the end effector. The CMP polish pad end effector of the present invention permits complete flushing of the end effector openings. This cleans out potential slurry and particle deposits from the end effector openings. The result is an always fresh and clean end effector surface for conditioning the CMP polish pad.
Yet another technical advantage of the present invention it solves the problem of existing end effectors of wearing unevenly due to slurry deposits and an uneven interface that develops between the end effector and the holder mechanism. The present invention rigidly and securely mounts the end effector to the holder mechanism. This differs from the compliant tape or film that conventional conditioners use. Because of the rigid mounting of the end effector, together with the elimination of slurry and particle deposits, more even wear of the end effector, and more uniform conditioning of the CMP polish pad results.
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 which is to be taken in conjunction with the accompanying drawings in which like reference numerals indicate like features and wherein:
FIGS. 1 and 1A illustrate an exploded view of one embodiment of the present invention;
FIG. 2 shows a facial view of the end effector of the present embodiment;
FIG. 3 shows a cut-away view of the conditioning end effector apparatus of the present embodiment;
FIG. 4 shows an application of the present embodiment in a CMP process;
FIGS. 5 and 6 provide plots of a CMP polish pad thicknesses after numerous conditioning operations to show further benefits of the apparatus of the present embodiment.
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention are illustrated in the FIGUREs like numerals being used to refer to like and corresponding parts of the various drawings.
FIGS. 1 and 1A show an exploded view of conditioning end effector apparatus 10 that includes holder mechanism 12. Holder mechanism 12 includes shaft 14 and base 16. Base 16 includes end effector recess 18 for receiving end effector 20. The spacer mechanism for the present embodiment may be spacers 22 fit in end effector recess 18 and evenly space end effector 20 from the face of recess 18. Instead of using a plurality of spacers the spacer mechanism may be a spacer ring 22' may be useful to separate end effector 20 from the face of recess 18. FIG. 1A shows this alternative embodiment. Referring simultaneously to FIGS. 1 and 1A, therefore, screws 24 pass through opening 26 of end effector 20 and fasten in screw holes 28 of base 16. FIGS. 1 and 1A also show slot 30 and hole 32 in shaft 14 for receiving a robotic arm of an associated CMP system for holding conditioning end effector apparatus 10. Set screw 34 comprises slot 30 to the robotic arm to attach end effector apparatus 10 to the robotic arm.
FIG. 2 shows a face view of conditioning end effector apparatus 10 including the bottom face of holder mechanism 12 and end effector 20 positioned within recess 18. End effector 20 is of stainless steel construction and includes a diamond-encrusted surface. The diamond-encrusted surface may be formed by any of a variety of known encrusting or layering techniques. As FIG. 2 illustrates, screws 24 hold end effector 20 firmly in place within recess 18. Screws 24 in end effector 20 are recessed within holes 26 so that they do not contact CMP polish pad 40 when end effector 20 contacts CMP polish pad
FIG. 3 shows a cut-away side view of conditioning end effector apparatus 10 of the present embodiment. In FIG. 3, holder mechanism 12 is shown with spacers 22 separating end effector 24 from recess face 36. As FIG. 3 shows, slurry 38 forms a lubricating layer between conditioning end effector 10 and CMP polish pad 40. As conditioning end effector 10 conditions CMP polish pad 40, slurry 38 passes through opening 26 of end effector 20.
FIG. 4 shows a typical operation employing conditioning end effector 10 of the present embodiment. In particular, FIG. 4 shows CMP mechanism 50 that includes polish pad 40 on which carrier device 44 is positioned. Carrier device 44 holds a semiconductor wafer in contact with CMP polish pad 40. As carrier device 44 holds a semiconductor device in contact with CMP polish pad 40, it rotates in a direction opposite the rotation of CMP polish pad 40. To condition CMP polish pad 40, robotic arm 46 places conditioning end effect apparatus in contact with CMP polish pad 40. Robotic arm 46 moves conditioning end effector apparatus 10 back and forth to condition CMP polish pad 40. After conditioning, robotic arm 46 moves conditioning end effector apparatus 10 to home position 52. At home position 52, spray nozzle 54 sprays end effector apparatus 10 with water or another solvent as a cleaning fluid to remove slurry from end effector 20. The preferred embodiment of the invention includes three spray nozzles 54 that may thoroughly clean openings 26 of end effector 20. This promotes complete use of end effector 20 and prolongs the life of the CMP polish pad 40 and end effector 20. Because of the space between end effector 20 and recess face 36, spray nozzles 54 more effectively clean end effector 20.
FIGS. 5 and 6 show a particularly important aspect of the present embodiment. FIG. 5 shows the results of using the conditioning end effector apparatus 10 of the present embodiment. FIG. 6 shows results that a conventional conditioning end effector produces. FIG. 5 provides a plot of the CMP polish pad thickness in inches versus distance from the edge of CMP polish pad 40, for example. Referring momentarily to FIG. 4, as robotic arm 46 moves back and forth it creates a path of travel for conditioning end effector apparatus 10. FIG. 5 shows that as a result of the improved structure that the present embodiment provides, a more uniform area of wear 60 results. FIG. 6, on the other hand, shows the rather erratic wearing of the area of CMP polish pad 40 along the path of the conventional conditioning end effector apparatus.
The present embodiment provides the technical advantage of not having end effector 20 separate from holder mechanism 12. A problem with conventional devices is that end effector 20 is held in contact with recess face 368 using a two-sided tape or film. In operation, the two-sided tape loses its grip and end effector 20 separates from holder mechanism 12. The result is that end effector 20 may come in contact with the spinning carrier device 44 to destroy or damage the semiconductor wafer or device being polished.
Another advantage that the present embodiment provides is a more uniform distribution of wear and force as a result of spacers 22. Spacers 22 and fasteners 24 provide a rigid and level foundation for holding end effector 20 that uniformly distributes forces between conditioning end effector apparatus 10 and CMP polish pad 40. In conventional devices, uneven wear results on the diamond-encrusted end effector 20. This produces the uneven wear that FIGS. 5 and 6 show. Moreover, this expends the surface of end effector 20 more rapidly than does the present embodiment. For example, the even wear that FIG. 5 depicts is the result of polishing approximately 450 wafers. To the contrary, the uneven results of FIG. 6 occur only after polishing as many as 150 wafers.
Still another technical advantage that the present embodiment provides includes the spacing of end effector 20 a small distance from recess face 36. This permits slurry to pass through openings 26 of end effector 20. This eliminates slurry and semiconductor particles in openings 26 of end effector 20. This is far superior than the two-sided tape of previous conditioning end effector devices that would cause uneven wear of the diamond encrusted end effector surface.
One possible additional feature of the present embodiment is to assist in the removal of slurry from the end effector apparatus 10 using a means of vibration or agitation. One attractive method of providing a desireable level of agitation is vibrating the end effector using an ultrasonic vibration device. One known such ultrasonic vibration device is an ultrasonic transducer having the name MEGASONIC® ultrasonic transducer. Such an ultrasonic transducer device may be a stationary device that can be attached to the end effector apparatus 10 to dislodge attached slurry for its removal. The ultrasonic transducer device may be located at the rinse station and energized once the water is applied to the end effector at that location. On the other hand, the ultrasonic transducer device may be formed as an integral part of the end effector. The ultrasonic transducer transducer may operate by dialing in the desired frequency and vibration strength, for example, a frequency of 50 MHz (or within a range of frequencies from 40-60 MHz) can be applied to cause the necessary dislodging of the slurry particulate.
Although the invention has been described in detail herein with reference to the illustrative embodiments, it is to be understood that this description is by way of example only and is not to be construed in a limiting sense. It is to be further understood, therefore, that numerous changes in the details of the embodiments of the invention and additional embodiments of the invention, will be apparent to, and may be made by, persons of ordinary skill in the art having reference to this description. It is contemplated that all such changes and additional embodiments are within the spirit and true scope of the invention as claimed below. | A conditioning end effector apparatus (10) for conditioning a CMP polish pad (40) includes an end effector (20) for contacting CMP polish pad (40). Holder mechanism (12) includes end effector recess (18) for receiving end effector (20). Spacer mechanism (22 or 22') is also located at predetermined locations in end effector recess (18) to associate with end effector openings (26) in end effector (20). End effector (20) firmly attaches through spacer mechanism (22 or 22') to holder mechanism (12) using a fastening device (24). Because of spacer mechanism (22 or 22'), end effector (20) is at distance from recess face (36) to permit slurry (38) that is deposited on CMP polish pad (40) to pass through end effector openings (26). | 1 |
FIELD OF THE INVENTION
The present invention relates generally to data communication and more particularly relates to a digital transmitter utilizing a digital signal generator and associated stored waveforms.
BACKGROUND OF THE INVENTION
Digital data communication systems are currently enjoying widespread use due to their benefits over analog communication systems. Typically, most data communication systems utilize filters in generating the data to be transmitted. Filters are especially used in communication systems that employ modems to transmit digital data over analog transport facilities. Most modems include wave shaping circuitry for generating appropriate signals for transmission over the analog communication channel. Note that the analog communication channel may comprise copper, waveguide, optical fiber, RF, microwave, IR, etc.
The function of the modem is to accept the digital data to be transmitted and generate analog signals suitable therefrom for transmission over the analog communication channel. To perform this function, modems employ wave shaping circuitry to first shape the input digital waveform and subsequently modulate this waveform with a carrier frequency signal. The wave shaping is performed to provide the transmitted signal with spectral characteristics suitable to the particular communication channel the data is to be transmitted on.
The shaping circuitry used in prior art transmission systems typically utilized large amounts of memory storage to store the waveform to be used in shaping the input digital data U.S. Pat. No. 5,548,541, issued to Bierman et al. teaches a finite impulse response (FIR) filter for shaping a one bit serial digital data pulse train. The filter employs a delay element for sequentially receiving binary data bits in the data pulse train at fixed data cycle intervals and outputting simultaneously in parallel a plurality of data bits representing the most recent history of the past N data cycle intervals. Also included is a sample element for sampling the pulse train and a memory device for storing output values.
With this type of system, as the number of samples for each symbol increases, the memory required for storage of the waveform also increases by a large amount. Thus, there is a need for a communication system which reduces the storage requirements for a given number of waveform samples per symbol.
SUMMARY OF THE INVENTION
The present invention is a digital signal generator (digital data generator) which can be utilized to provide an efficient way to implement a digital transmitter based on storage of waveforms in a memory device such as a ROM or PROM. Assuming a symbol rate of 1T and a transmitter basic waveform having a duration 2NT, the digital signal generator presented herein reduces storage requirements by a factor of 2 N+1 relative to prior art classical approaches which are typically memory based, e.g., ROM or RAM implementations.
The digital data generator employs a shift register into which the received digital data is input. The length of the shift register is 2N which represents the number of symbol periods of the output shaping waveform. For example, if the symbol period is denoted by T, the shaping waveform may span 8 symbol periods. Thus, the length of the shift register in this example would be 8 and N would equal 4.
The shift register is divided into precursor and postcursor portions since the shaping waveform typically comprises both past and future portions. To accommodate the future portion of the shaping waveform, the data transmitted at any time t corresponds to the center of the shift register with equal size data considered for the precursor and the postcurcor portions.
The output of the shift register is input to an address generator circuit which outputs the address bits for input to a memory storage device such as a ROM or PROM. A counter functions to count modulo the number of samples per symbol. The output of the memory storage device is further processed to yield the digital output signal.
Due to the independence of the postcursor and precursor contributions to the output waveform, the output waveforms for the precursor and postcursor portions of the shift register can be divided into two parts and generated independently. Thus, a reduction in the amount of memory storage required may be achieved by storing waveform data only for either the postcursor or the precursor. In this case, the same storage device is used but the addresses is alternatively applied for the precursor and the postcursor. The postcursor and precursor outputs of the memory storage device are stored and the two output values are summed to generate the digital output data signal. Given that n s denotes the number of samples per symbol, this provides a reduction in the required memory space from n s ·2 2N (the prior art requirement) to 2·n s ·2 N which represents a reduction by a factor of 2 N 2 .
In addition, advantage can be taken of the fact that the shaping waveform is mostly symmetrical around the y-axis (which is usually the case) and thus only ½ of the samples need be stored. This provides a reduction in the required memory space from 2·n s ·2 N to n s ·2 N which represents a reduction by a factor of 2.
A further reduction in storage memory can be achieved by taking advantage of the substantial symmetry in amplitude of the waveform data. Since the input data is a real binary bit stream, the waveforms corresponding to ‘0’ and ‘1’ bits are inverted with respect to each other, e.g., +1 and −1. Thus, only a single version of the shaping waveform need be stored, the other being generated by multiplying by −1. This provides another reduction in the required memory space from n s · 2 N to 1 2 n s 2 N
which represents an additional reduction by a factor of 2.
In total, the present invention yields a reduction in memory storage requirements by a factor of 2 N+1 .
There is provided in accordance with the present invention a digital data generator for shaping an input digital data stream in accordance with a shaping waveform to yield a digital output data stream, the digital data generator comprising a delay element of length 2N wherein 2N represents the time duration of the shaping waveform, the delay element adapted to receive the input digital data stream and is divided into a precursor portion and a postcursor portion, an address generator for generating a precursor address in accordance with the precursor portion and a postcurcor address in accordance with the postcursor portion, a multiplexor for muxing the precursor address and the postcursor address to yield a first lookup address and a second lookup address during each sample cycle, lookup means operative to output a first value in accordance with the first lookup address and a second value in accordance with the second lookup address, summing means adapted to sum together the first value and the second value output from the lookup means to yield the digital data output stream and wherein the number of entries required in the lookup means is equal to n s · 2 N 2 ,
where n s represents the number of samples per symbol and N represents ½ the number of periods of the shaping waveform.
There is also provided in accordance with the present invention a digital data generator for shaping an input digital data stream in accordance with a shaping waveform to yield a digital output data stream, the digital data generator comprising a delay element of length 2N wherein 2N represents the time duration of the shaping waveform, the delay element adapted to receive the input digital data stream and is divided into a precursor portion and a postcursor portion, an address generator for generating a precursor address in accordance with the precursor portion and a postcurcor address in accordance with the postcursor portion, lookup means operative to output a first value of a shaping waveform sample in accordance with the first lookup address and a second value of a shaping waveform sample in accordance with the second lookup address, summing means adapted to sum together the first value and the second value output from the lookup means to yield the digital data output stream and wherein the number of entries required in the lookup table is equal to n s · 2 N 2 ,
where n s represents the number of samples per symbol and N represents ½ the number of periods of the shaping waveform.
The delay element may comprise a serial in/parallel out shift register and the address generator may comprise a precursor address generator and a postcursor address generator. The lookup means comprises a memory storage device which may utilize a random access memory (RAM) device, read only memory (ROM) device, programmable read only memory (PROM) device, Flash memory device, electrically erasable programmable read only memory (EEPROM) device or electrically programmable read only memory (EPROM) device.
There is further provided in accordance with the present invention, in a digital transmission system, a method of shaping an input digital data stream in accordance with a shaping waveform to yield a digital output data stream, the method comprising the steps of providing a lookup table of stored shaping waveform samples wherein the number of entries required in the lookup table is equal to n s · 2 N 2 ,
where n s represents the number of samples per symbol and N represents ½ the number of periods of the shaping waveform, delaying the input digital data stream so as to form a precursor portion and a postcursor portion, looking up a precursor value from the lookup table in accordance with the precursor portion, looking up a postcursor value from the lookup table in accordance with the postcursor portion and summing the precursor value and the postcursor value to yield the digital data output stream.
There is also provided in accordance with the present invention a digital transmitter for transmitting a Binary Phase Shift Keying (BPSK) signal comprising a digital data generator for generating a digital output data stream in accordance with an input data stream and a pervasively stored shaping waveform, a digital to analog converter coupled to the output of the digital data generator, the digital to analog converter for converting a digital input signal into an analog output signal and up converter means for performing baseband to radio frequency (RF) conversion in response to the analog output signal and a local oscillator signal, the up converter amplifying and transmitting the RF signal.
There is still further provided in accordance with the present invention a digital transmitter for transmitting a Quadrature Phase Shift Keying (QPSK) signal comprising means for generating an I and a Q data stream from a source of input data, a first digital data generator for generating an I digital output data stream in accordance with the I data stream and a pervasively stored shaping waveform, a second digital data generator for generating a Q digital output data stream in accordance with the Q data stream and a pervasively stored shaping waveform, a first digital to analog converter coupled to the output of the first digital data generator, the first digital to analog converter for converting the I digital output data stream signal into an I analog output signal, a second digital to analog converter coupled to the output of the second digital data generator, the second digital to analog converter for converting the Q digital output data stream into a Q analog output signal and up converter means for performing baseband to radio frequency (RF) conversion on the I analog output signal, the Q analog output signal and a local oscillator signal, the up converter amplifying and transmitting the RF signal.
In addition, there is provided in accordance with the present invention a digital transmitter for transmitting a Quadrature Amplitude Modulation (QAM) signal comprising means for generating an I and a Q data portion from a source of input data, the I portion comprising a plurality of bits, the Q portion comprising a plurality of bits, a first plurality of digital data generators, each digital data generator adapted to receive one of the plurality of bits in the I portion of the input data, a second plurality of digital data generators, each digital data generator adapted to receive one of the plurality of bits in the Q portion of the input data, first multiplying means for multiplying the outputs of the first plurality of digital data generator by a predetermined plurality of weights, second multiplying means for multiplying the outputs of the second plurality of digital data generator by the plurality of weights, a first summer for adding the output of the first multiplying means, a second summer for adding the output of the second multiplying means, a first digital to analog converter coupled to the output of the first summer, the first digital to analog converter for converting the digital output of the first summer into an I analog output signal, a second digital to analog converter coupled to the output of the second summer, the second digital to analog converter for converting the digital output of the second summer into a Q analog output signal and up converter means for performing baseband to radio frequency (RF) conversion on the I analog output signal, the Q analog output signal and a local oscillator signal, the up converter amplifying and transmitting the RF signal.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein:
FIG. 1 is a block diagram illustrating an example digital transmitter employing a digital signal generator constructed in accordance with the present invention;
FIG. 2 is a block diagram illustrating a prior art digital signal generator in more detail;
FIG. 3 is a block diagram illustrating the digital signal generator of the present invention;
FIG. 4 is a block diagram illustrating the digital signal generator of the present invention in more detail;
FIG. 5 is a block diagram illustrating a digital transmitter suitable for QPSK modulation employing the digital signal generator of the present invention; and
FIG. 6 is a block diagram illustrating a digital transmitter suitable for QAM modulation employing the digital signal generator of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Notation Used Throughout
The following notation is used throughout this document.
Term
Definition
BPSK
Binary Phase Shift Keying
D/A
Digital to Analog
DSG
Digital Signal Generator
EEPROM
Electrically Erasable Programmable Read Only Memory
EPROM
Electrically Programmable Read Only Memory
FIR
Finite Impulse Response
IR
Infrared
MPSK
M-ary Phase Shift Keying
PROM
Programmable Read Only Memory
QAM
Quadrature Amplitude Modulation
QPSK
Quadrature Phase Shift Keying
RAM
Random Access Memory
RF
Radio Frequency
ROM
Read Only Memory
General Description
A block diagram illustrating an example digital transmitter suitable for BPSK modulation employing a digital signal generator constructed in accordance with the present invention is shown in FIG. 1 . The digital transmitter, generally referenced 10 , comprises a digital signal generator 12 , a digital to analog (D/A) converter 14 , baseband to RF converter 16 , an amplifier 18 , antenna 22 and a local oscillator 20 .
The input data comprises a baseband signal y(t) which is expressed below in Equation 1. y ( t ) = ∑ n = - ∞ ∞ a n h ( t - nT ) ( 1 )
wherein T is the symbol time interval, a n is the data symbol sequence at a symbol rate R=1T and h(t) is the basic transmitted waveform for each symbol. It is important to note that in most modern communication schemes, the transmission waveform h(t) associated with each symbol is typically longer tana the width of the symbol itself. For example, if the symbol time period is represented by T, the transmission waveform may span any number of symbol times, e.g., 3T, 4T, 5T, 6T, 7T, etc. Ideally, it is preferable for each symbol to be transmitted using an infinitely long transmission symbol, but this is not practical in reality.
For the simplest case, a n is real and binary, i.e., a n=± 1, and h(t) is a real waveform. The transmitter basic waveform h(t) has a duration of 2NT. The signal generated by the digital signal generator and input to the D/A is discrete with n s samples per input symbol. Note that each input symbol may represent multiple bits or may represent a single bit. In this case, a n has more than two values. The value of n s should be greater than or equal to 2 which means the signal output by the digital signal generator should have a minimum rate of 2R samples/symbol in order to satisfy the Nyquist criteria, assuming the bandwidth of the signal is 1/R Hz.
The output of the digital signal generator functions to generate a digital data stream representing the signal to be transmitted. The D/A functions to convert the digital output of the digital signal generator to analog format. The baseband to RF converter modulates the analog signal and shifts it up in frequency in accordance with the frequency of the local oscillator 20 . The output of the converter is amplified and input to the antenna 22 . The baseband to RF converter may also comprise an uplink modulator which modulates the analog signal for transmission to a satellite. The digital tansmitter may be utilized, for example, with a plurality of stations with each station employing at least one digital transmitter.
A block diagram illustrating a prior art digital signal generator in more detail is shown in FIG. 2 . In this example, the value of N is equal to 4, thus the transmitter basic waveform h(t) has a duration of 8T. The conventional approach to generate the output signal is to calculate the signal samples off-line and to store them in a table. The table may comprise a memory storage device such as a ROM or RAM memory. The input data is a bit stream which is input to a shift register 32 . The shift register in this example comprises 8 bits and is divided into two groups of four bits each. The two groups include post cursors and precursors. The middle of the shift register, between the third and fourth bits, represents time t. The waveform to be generated at time t depends on the four bits that came before it, i.e., the precursors, and the four bits that come after it, i.e., the postcursors.
The parallel outputs of the shift register are input to an address generator 34 which also receives the output of a counter 30 . The counter functions to count modulo the number of samples per symbol.
Each of the n s samples making up a symbol depends on 2N symbols (N symbols before it and N symbols after it), therefore the storage required is equal to n s ·2 2N . The value 2 2N represents the number of combinations of the 8 input bits in the shift register that are input to the address generator. For each combination n s samples must be generated thus yielding n s ·2 2N required locations.
The expression for the signal output by the digital signal generator is shown in Equation 2 below. y ( t ) = ∑ n = k - N + 1 k + N a n h ( t - nT ) ( 2 )
for kT<t<kT+T. The implementation to generate y(t) is shown in FIG. 2 for the case where N=4. Assuming that the sampling instants are at times iT n s = kT - T 2 n s
for i=1,2, . . . , n s . If h(t)=0 for |t|>NT then the n s samples in the interval (kT, kT+T) depend on the symbols a k−N+1 , . . . , a k+N . For example, for N=4, n =0 and n s =8, the 8 samples at time instants iT 8 + T 16 ,
where i=0, 1, . . . , n s −1, depend on a −3 , a −2 , a −1 , a 0 , a 1 , a 2 , a 3 and a 4 . The values of y(t) are stored in the look up table 36 , e.g., a RAM memory device. The values of y(t) correspond to the sampling instants of the basic transmitted waveform.
Digital Signal Generator of the Present Invention
The digital signal generator of the present invention functions to generate a digital output, representing the digitized samples of the output waveform to be modulated by the baseband to RF converter, while reducing the memory storage requirements of the look up table. As the number of samples per symbol and the number of bits per sample increase, the memory storage required also increases.
The digital signal generator of the present invention functions to reduce the amount of memory, i.e., RAM, ROM, etc., required to generate the digital output by splitting the memory storage into two portions. One portion corresponds to the N postcursors and the other portion correspond to the N precursors. Using separate memories for the postcursors and the precursors effectively splits the effect of symbols associated with a sample into the first N symbols that effect the precursors and the second N symbols that effect the postcursors. The effects of the postcursor and the precursor are then summed using an adder.
As described previously, each of the n s samples per symbol depends on N symbols of the precursor and N symbols of the postcursor. Therefore, the storage required can be expressed as 2·n s ·2 N . The cost of reducing the storage requirements is an adder. An expression for y(t) is give by Equation 3 below. y ( t ) = ∑ n = k - N + 1 k a n h ( t - nT ) + ∑ n = k + 1 k + N a n h ( t - Nt ) ( 3 )
for kT<t<kT+T. The first summation is due to the precursor and the second summation is due to the postcursor.
For the sampling instants iT n s + kT + T 2 n s ,
the n s samples in the interval (kT, kT+T) depend on the precursor symbols a k−N+1 , . . . , a k and post cursor symbols a k+1 , . . . , a k+N . For example, for the case when N=4, n=0 and n s =8, the 8 samples at time instants iT 8 + T 16 ,
wherein i=0, 1, . . . , n s −1 depends on the presecursor data a −3 , a −2 , a −1 , a 0 and the postcursor data a 1 , a 2 , a 3 and a 4 .
A block diagram illustrating the digital signal generator of the present invention is shown in FIG. 3 . The digital signal generator 12 comprises a shift register 42 having a length equal to 2N and split into a postcursor portion of length N and a precursor portion of length N. The shift register functions to store the input data bits as they are clocked in. The shift register also functions as a delay element wherein each input bit is delayed by one symbol period as it is clocked through the shift register. The input data is input to the shift register and the output bits are ignored. The output of a modulo n s counter 40 is input to both the postcursor and precursor address generators 44 , 46 . The counter outputs the current sample number modulo n s .
The postcursor output bits of the shift register are input to the postcurcor address generator 44 and the precursor output bits are input to the precursor address generator 46 . The address generator functions to calculate the address to the lookup table as a function of the counter output and the precursor (or postcursor) bits. The lookup table may comprise any suitable memory storage device such as RAM, ROM, PROM, FLASH, EPROM, EEPROM, etc.
The outputs of both the postcurcor and precursor address generators are input to a 2 to 1 multiplexor 48 . The multiplexor chooses between the postcursor and precursor address. The output of the mux is then input to a lookup table 50 . The lookup table stores the signal samples comprised of contributions of the postcursors and the precursors. The output of the lookup table is stored in a precursor register 52 and a postcurcor register 54 . The outputs of the precursor and postcurcor registers 52 , 54 , representing the signal contributions of the precursor and postcursor responses, are summed by adder 56 . The output of the adder 56 forms the signal output of the digital signal generator 12 .
The implementation shown in FIG. 3 is for case where N=4, i.e., the basic transmitter waveform has a duration of 2NT. The basic tansmitter waveform is the shaping waveform used to provide the input digital data with suitable spectral properties. The same lookup table is used to generate the samples for the postcurcor and precursor portions of the shift register. The postcurcor and precursor addresses are muxed at a clock rate twice the normal clock rate. In addition, the registers storing the output of the lookup table are also clocked at twice the normal clock rate, i.e., twice per sample period.
Lemma 1
The following Lemma 1 is used to obtain a reduction in the storage requirements for the lookup table. Lemma 1 is based on the symmetry of h(t), i.e., h(t)=h(−t).
Lemma 1: for a symmetric h(t), the contribution of the precursor of a on sample i is the same as the contribution of the post cursor a R on sample n s −1−i.
If a represents a vector of data symbols of length N and a R represents the vector a with the components in the reversed order, it is proved below that for a symmetric h(t), the contribution of the precursor of a on sample i is the same as the contribution of the post cursor a R Ronsample n s −1−i.
Lemma 1 Proof
The proof of Lemma 1 follows. In order to prove this statement, let us consider the precursor given below in Equation 4. y ( t ) = ∑ n = k - N + 1 k a n h ( t - nT ) ( 4 )
for kT<t<kT+T. Substituting t = iT n s + kT + T 2 n s ,
i =0, 1, . . . , n s −1 yields Equation 5. y ( t ) = ∑ n ″ = k - N + 1 k a n h ( iT n s + kT + T 2 n s - nT ) ( 5 )
We then replace k−n=n″ to yield Equation 6. y ( t ) = ∑ n ″ = N - 1 0 a - n ″ + k h ( iT n s + T 2 n s + n ″ T ) y ( t ) = ∑ n ″ = 0 N - 1 a k - n ″ h ( iT n s + T 2 n s + n ″ T ) ( 6 )
For comparison, let us consider the postcursor given by Equation 7. y ( t ) = ∑ n = k + 1 k + N a n h ( t - nT ) ( 7 )
for kT<t<kT+T. Substituting t = iT n s + kT + T 2 n s ,
wherein i 0, 1, . . . , 8 yields Equation 8. y ( t ) = ∑ n = k + 1 k + N a n h ( iT n s + kT + T 2 n s - nT ) ( 8 )
Substituting n′ for n−k−1 and using symmetry yields Equation 9. y ( t ) = ∑ n ′ = 0 N - 1 a n ′ + k + 1 h [ ( n s + 1 - i ) n s + T 2 n s + n ′ T ] ( 9 )
A comparison of Equations 6 and 9 with n=n′=n″ reveals that the calculation of the precursor contribution and of the postcursor contribution are similar except that (1) i is replaced by n − 1−i and (2) the order of the symbols of the precursor and of the postcursor for each n is given by Table 1 below.
TABLE 1
n
Shift Register Portion
0
1
. . .
N-1
Precursor
a k
a k−1
. . .
a k−N+1
Postcursor
a k+1
a k+2
. . .
a k+N
Further reduction in memory storage required for the lookup table can be obtained by using Lemma 2 below.
Lemma 2
Lemma 2: the fact that the contribution of the precursor/postcursor of − a of sample i is minus the contribution of the precursor/postcursor a of sample i. This can be observed from Equation 1 by multiplying both sides by −1. This property can be utilized to require only half the values to be stored in the lookup table. For example, only those precursors/postcursors with a k =1 will be stored. The precursors/postcursors with a k =−1 are then calculated from the stored values.
The storage required after applying Lemma 1 and Lemma 2 can be expressed below as shown in Expression (10). n s · 2 N 2 ( 10 )
This value is smaller by a factor of 2 N+1 relative to the prior art classical approach described hereinabove.
A block diagram illustrating the digital signal generator of the present invention in more detail is shown in FIG. 4 . The digital signal generator, generally referenced 60 , comprises a shift register 62 having postcursor and precursor portions, a clock 64 , divide by 2 circuit 66 , modulo 8 counter 68 , 2 to 1 multiplexors 70 , 72 , 74 , 76 , XOR gates 80 , 82 , 84 , 86 , 88 , 90 , RAM lookup table 78 , multiplier 96 , register 92 and adder 94 .
This example digital signal generator is for the case where N=4 and the number of samples per symbol n s =8. The input data, e.g., input I/Q data, is clocked into shift register 62 . The shift register comprises the postcursor and precursor which contain Boolean values. The shift register is clocked once every symbol period T. The lookup table 78 comprises memory storage, e.g., RAM, ROM, etc., that contains an 8 bit representation of the precursor response. The counter 68 counts from 0 to 7 yielding 8 samples per symbol period T (for n s =8).
A clock source 64 is used to derive a main clock which drives the lookup table and is also input to a divide by 2 circuit 66 . Both non inverted and inverted clock signals are used. An inverter 98 provides the inverted clock signal to the counter 68 and the adder 94 . The non inverted clock is provided to the multiplexors and the register. When the clock is low, the precursor response is read from the lookup table, i.e., the control input to the muxes is low. Conversely, when the control input to the muxes is high, the postcursor response is read from the lookup table. At the end of the clock cycle, the precursor response and the postcursor response are summed via adder 94 and form the I/Q data output from the digital signal generator. Note that the main clock is obtained by dividing the clock source 64 by 2 which is used to drive the lookup table clock. Thus, the lookup table is read twice every sample time.
Binary Representation of Data
The data a n can have the values ±1. The actual logic circuitry used to implement the digital signal generator, however, can represent only the values 0 and 1. Therefore, the Boolean data values 0 and 1 shall be denoted as b n and are related to a n in accordance with the following Equation 11.
a n =(−1) b n (11)
Thus, for example, b n =0 corresponds to an=1 and b n =1 corresponds to a n =−1.
Address Generation
The precursor data vector is given by a =a k , . . . a k−N+1 or in Boolean representation as b =b k , . . . , b k−N+1 . According to Lenmmas 1 and 2 described above, memory storage is required only for the samples associated with the precursor response, and only for data vectors such that b k =0, i.e., a k =1. The response of the precursors for data vectors wherein b k =1 and the response of the postcursors can be calculated by simple operations from the response stored in the lookup table for the b k =0 precursor response. Thus, the lookup table memory only need contain an 8 bit representation of the precursor response for b k =0.
For precursors represented by data vector b with the value b k =0 the address of a sample at sampling time iT n s + kT + T 2 n s ,
i=0, 1, 2, . . . , n s −1, is given by (b k−1 , b k−2 , . . . , b k−N−1 ,i) wherein i is i expressed in a binary representation. The value stored and read from the lookup table is the precursor response.
For precursors represented by data vector b with the value b k =1, the address of a sample at sampling time iT n s + kT + T 2 n s ,
i=0, 1, 2, . . . , n s −1, is given by ( b k−1 , b k−2 , . . . , b k−N−1 ,i) where {overscore (z)} denotes the inverse of z. The value read from the lookup table must first be inverted in order to obtain the precursor response.
For postcursors represented by data vector b with the value b k+1 =0, the address of a sample at sampling time iT n s + kT + T 2 n s ,
i=0, 1, 2, . . . , n s −1, is given by (b k+2 , b k+3 , . . . , b k+N , n s −1−i ), where n s −1−i is n s −1−i expressed in a binary representation. The value read from the lookup table is the postcursor response.
For postcursors represented by data vector b with the value b k+1 =1, the address of a sample at sampling time iT n s + kT + T 2 n s ,
i=0 , 2, . . . , n s −1, is given by ({overscore (b)} k+2 , {overscore (b)} k+3 , . . . , {overscore (b)} k+N , n s −1−i ). The value read from in the lookup table must be inverted in order to obtain the postcursor response.
Note that the 2 to 1 multiplexors function to choose between the precursor and the postcursor portion of the shift register. The XOR gates unction to generate a 6 bit address as function of the output of the counter and the output of the multiplexors. The XOR gates connected to the output of the multiplexors function to invert the address for the precursors having a value b k =1 and for the postcursors having a value b k+1 =1.
In addition, the XOR gates connected to the counter output function to change the value i to n s −1−i. The multiplier 96 functions to invert the output of the lookup table, e.g., RAM, for precursors having a value b k =1 and postcursors having a value b k+1 =1. The register 92 is used to temporarily store the precursor response which is to be added to the postcursor response. The adder sums the output of the multiplier with the output of the register, i.e., the postcursor response and the precursor response, at the end of the clock cycle to yield the I/Q data output.
Extension to Non Binary and Complex Signal Generation
A non binary, complex signal can be expressed as given below in Equation 12. y ( t ) = ∑ n = - ∞ ∞ I n h ( t - nT ) + j ∑ n = - ∞ ∞ Q n h ( t - nT ) ( 12 )
wherein j stands for {square root over (−1)}. The terms I n , and Q n represent QAM signals which take the values ±1, ±3, ±5, . . . , ±(L −1), wherein L depends on the constellation size. Alternatively, I n and Q n may represent a PSK signal wherein
I n =cos(φ n ) (13)
and
Q n =sin(φ n ) (14)
wherein φ n , is the transmitted phase that is dependent on the data.
Inspecting the transmitted signal y(t) as expressed in Equation 12 above, one skilled in the signal processing art can extend the principles of the present invention to a complex non-binary signal in a straight forward manner by separately calculating the real and the imaginary components of the complex signal The signal for all possible combinations of I n and Q n are calculated and stored and used in the same manner as the lookup table values as scribed hereinabove.
A block diagram illustrating a digital transmitter suitable for QPSK modulation employing the digital signal generator of the present invention is shown in FIG. 5 . The digital transmitter, generally referenced 100 , comprises I n /Q n formation module 102 , I n digital signal generator (DSG) 104 , D/A converter 108 , Q n DSG 106 , D/A converter 110 , baseband to RF up converter 112 , local oscillator 114 , amplifier 116 and antenna 118 .
The extension of the digital signal generator (DSG) of the present invention to QPSK modulation first involves forming the I n and Q n data streams. The I n and Q n data streams are then processed separately via DSGs 104 , 106 , respectively. The I n and Q n outputs of the DSGs are input to D/A converters 108 , 110 , respectively, where they are converted to analog signals. The I analog signal is modulated by the local oscillator signal and Q analog signal is modulated by the local oscillator signal shifted by 90 degrees. The modulated signals are combined and output to the amplifier 116 which boosts the signal to a suitable level to be transmitted by antenna 118 .
It is important to note that in the QPSK digital transmitter 100 , the memory look up tables within each DSG comprise identical content. Thus, a common memory can be used in which both I and Q channels share the memory storage. If a common shared memory is used, the memory storage devices used preferably have multiple ports to support multiple access.
The principles of the present invention can further be extended to support QAM modulation. A block diagram illustrating a digital transmitter suitable for QAM modulation employing the digital signal generator of the present invention is shown in FIG. 6 . The digital transmitter, generally referenced 120 , comprises I n /Q n formation module 122 , I n digital DSGs 124 , summer 128 , D/A converter 130 , Q n DSGs 154 , summer 150 , D/A converter 148 , baseband to RF up converter 140 , local oscillator 146 , amplifier 142 and antenna 144 .
The QAM signal y(t) can be expressed using Equation 12 above. In the case of QAM, however, the bits making up a symbol are split to form I and Q portions. For example, consider 64 QAM wherein each symbol represents 6 bits. The 6 bits of each symbol can be split into 3 bits forming an I portion and 3 bit forming a Q portion. This is illustrated in FIG. 6. A separate DSG is used for each bit of the 6 bits making up each input data word (symbol). An expression for I n is shown below in Equation 15.
I n =α 1 a 1n +α 2 a 2n +α 3 a 3n (15)
where a 1n , a 2n , a 3n have values ±1 depending on the input data and α 1 , α 2 , α 3 are weights. The output of the DSGs are multiplied by the weights before being summed by summer 128 with the output of the summer constituting I n . For example, the weights for α 1 , α 2 , α 3 may be 1, 2, 4, respectively.
Similarly, an expression for Q n is shown below in Equation 16.
Q n =α 1 b 1n +α 2 b 2n +α 3 b 3n (16)
where b 1n , b 2n , b 3n have values ±1 depending on the input data and α 1 , α 2 , α 3 are weights. The output of the DSGs are multiplied by the weights before being summed by summer 150 with the output of the summet constituting Q n .
In the general QAM case, multiple DSG units are used for both the I signal and the Q signal. The number of DSG units used depends on the level of QAM used. For 256 QAM, for example, the 8 bit symbol can be split into 4 bits of I associated with 4 DSG units and 4 bits of Q data associated with another 4 DSG units. Note that this is only one possible application, there being numerous variations on QAM modulation schemes.
Note also, that similar to the QPSK example above, all the lookup tables in DSGs 124 , 154 have the same content. Either duplicate memories can be used or a common multiple ported memory can be shared among all the DSG units.
In addition, one skilled in the communication arts can extend the principles of the present invention to the case of MPSK where M represents any number, e.g., 4PSK, 8PSK, etc. The digital transmitter illustrated in FIG. 6 can be used for MPSK, the difference being that different values for α 1 , α 2 , α 3 are used. Note that the case of 2PSK is equivalent to the system shown in FIG. 1 .
While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made. | A digital signal generator which can be utilized to provide an efficient way to implement a digital transmitter based on storage of waveforms in a memory device such as a ROM or PROM. Assuming a symbol rate of 1/T and a transmitter basic waveform having a duration 2NT, the digital signal generator presented herein reduces storage requirements by a factor of 2 N+1 relative to prior art classical approaches which are typically memory based implementations. A shift register is employed into which the received digital data is input. The length of the shift register is 2N which represents the number of symbol periods of the output shaping waveform. The shift register is divided into precursor and postcursor portions for handling both past and future portions of the shaping waveform. An address generator circuit generates the address bits for a memory storage device from the output of the shift register. The storage device contains the digitized waveform samples to be transmitted. The present invention takes advantage of the fact that the shaping waveform is symmetrical around the y-axis and thus only ½ of the samples need be stored. In addition, since the input data is a real binary bit stream, the waveforms corresponding to ‘0’ and ‘1’ bits are inverted with respect to each other. Thus, only a single version of the shaping waveform need be stored, the other being generated by multiplying by −1. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of applicant's application Ser. No. 13/304,102 filed on Nov. 23, 2011 now U.S. Pat. No. 8,434,769 that issued on May 7, 2013 and is a continuation-in-part of applicant's application Ser. No. 12/899,321 filed on Oct. 6, 2010 now U.S. Pat. No. 8,066,299 which issued on Nov. 29, 2011, which claims priority to application Ser. No. 61/249,743 filed Oct. 8, 2009 the entire contents of which is hereby expressly incorporated by reference herein.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
Not Applicable
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to improvements in trailer hitching and trailer tracking systems. More particularly, the present trailering improvements include an adjustable hitching system, a guiding system for determining a hitching position and a tracking system for moving a trailer.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98.
Trailering a vehicle requires a number of different operations that are often difficult to perform by a single person. Because the hitching position is often located in a place that is difficult to view it is often best performed with two people. In many cases this is not possible. When the trailer vehicle is heavy locating the hitch often requires multiple attempts to line the tow vehicle up with the trailer. There have been several patents that have issued that allow for vertical adjustment of the hitch to secure the trailer with the tow vehicle.
U.S. Pat. No. 6,229,191 issued Oct. 9, 2001 and U.S. Pat. No. 6,536,793 issued Mar. 25, 2003, both to Frank T. Sargent disclose a Double-Acting Trailer Hitch. Both of these patents allow for vertical adjustment and limited angular adjustment of the tow ball. While these patents provide for some adjustment, the location of the tow vehicle to the trailer must still be placed within inches of the desired location.
U.S. Pat. No. 4,664,403 issued May 12, 1987 to C. Glen Livingston discloses a Hitch Adapter for Double Caster Wheel Trailer. This patent provides for limited side-to-side adjustment of the tow ball. The side-to-side adjustment provides improved tracking of the towed vehicle. While this patent provides some adjustment to the hitch ball position the locating is limited to the amount of tracking that is possible with the caster wheels of the tow vehicle.
U.S. Pat. No. 6,900,724 issued May 31, 2005 to Keith R. Johnson, U.S. Pat. No. 7,243,431 issued Jul. 17, 2007 to W. Lee Godwin and U.S. Pat. No. 7,354,057 issued Apr. 8, 2008 to Gary Milner each disclose the use of a laser type sighting device, but none of these patents disclose using a pair of laser devices that provide distance and cross when the tow vehicle is in a preferred position.
U.S. Pat. No. 3,211,467 issued Oct. 12, 1965 to S. G. Siddal and U.S. Pat. No. 3,520,549 issued Jul. 14, 1970 to M. S. De Lay both disclose a steering mechanism for steering trailing wheels. While both of these patents disclose steering mechanisms for steering trailering wheels, neither of them disclose the steering mechanism as disclosed in this application.
What is needed is a complete overhaul of trailer hitching, tracking and steering to significantly reduce the time and effort to connect and trailer and steer a trailer once it is connected to a tow vehicle. The proposed improvements provide these solutions with the introduction of a new class of Recreational Vehicle (RV) the “Wagon Style RV” with axle's front and back like most cars and trucks and most particularity like wagons, not in the center like all trailers. In addition to the above improvements the RV wagon will reduce or eliminate tow vehicle passenger bounce at road bumps and dips, RV sway problems, eight miscellaneous loose hitching parts to assemble and disassemble, weighing 40 to 50 pounds, each time the RV is hitched or unhitched to the tow vehicle, number of times the trailer front jack stand has to be cranked up and down to effect the hitching process, 400 to 900 pounds of weight on the back of the tow vehicle, exposed propane tanks and batteries in addition to the front jack stand on most trailers, skids or skid wheels at the back of the trailer and reducing the time it takes to hitch or unhitch from 15 or 20 minutes to under 2 minutes with no loose parts to assemble. The proposed improvements provide these solutions.
BRIEF SUMMARY OF THE INVENTION
It is an objective of the improvements in trailer hitching and tracking steering to provide a hitch that is expandable to accommodate hitching where the tow vehicle is misaligned with the new Wagon Style RV. The misalignment is accommodated by telescoping arms on the tow bar hitch. The telescoping sections are movable to connect the hitch to the tow vehicle's hitch receiver. Once the tow bar is connected, the tow vehicle can be moved forward until the tow bar extends and the spring driven tapered pins lock the arms of the tow bar in the extended position for travel. By withdrawing the tapered spring driven pins out of the telescoping arms the tow bar can be removed from the tow vehicle hitch receiver and raised up and into the hitch compartment to be stored out of the way and out of sight when the hitch compartment door is closed. This also will reduce the parked area used by the Wagon Style RV and further reduce the possibility of harm to a person that may accidentally walk into the lowered tow bar.
It is an object of the improvements in trailer hitching and tracking steering to provide a front wheel suspension with bi-directional caster for steering a Wagon Style RV in both a forward and a reverse direction. The wheels caster setting can be re-directed, depending upon the direction of travel of the RV, to allow the wheels to automatically shift caster direction based upon the direction of travel of the tow vehicle.
It is another object of the improvements made possible with the Wagon Style RV to improve the steering and tracking of the towed vehicle. This system will provide caster for the front wheels to follow the tow vehicle in forward or reverse and the system also provides steering of the rear wheels to minimize the amount the rear of the RV will cut the corner when making turns. In addition to eliminating wheel scrubbing that occurs when all the wheels only track in a straight forward or rearward direction.
It is still another object of the improvements in RV hitching and tracking steering to utilize two or more visible laser light beams to easily and effectively guide a tow vehicle driver to position the tow vehicle in the correct position to hitch the RV without any help. Keep in mind that the tow bar mechanism allows for a miss-alignment of more than 8 inches in either direction making the positioning of the tow vehicle very easily done without assistance. The laser lights on the front of the RV are adjusted to converge in the center of the rear window of the tow vehicle when the tow vehicle reaches a place near the optimum position to hitch the RV to the tow vehicle. The laser lights produce two small red dots on the back window that will move together as the tow vehicle is backed toward the RV. This makes it easy to stop just the right distance from the RV and the red dots only have to converge in the vicinity of the center of the back window because the tow bar hitch affords ample side to side adjustment if the tow vehicle is not in the exact right place. The driver will see the laser beams in his inside rear view mirror.
Various objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention, along with the accompanying drawings in which like numerals represent like components.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
FIG. 1 shows the tow bar hitch in the travel position.
FIG. 2 shows a top view of the tow bar hitch in the retracted position.
FIG. 3 shows a second preferred embodiment of the tow bar hitch in the travel position.
FIG. 4 shows a top view of the second preferred embodiment of the tow bar hitch in the retracted position.
FIG. 5 shows a front view of the tow bar hitch in the out of use or put away position.
FIG. 6 shows a side view of the tow bar storage compartment with another contemplated version of sectional doors.
FIG. 7 shows a side view of the tow bar storage compartment with another contemplated version of a one piece door rotating out and up.
FIG. 8 shows a prior art pivoting caster.
FIG. 9 shows a Bi-Directional Caster.
FIG. 10 shows an electrical pictorial diagram of a directional switching system.
FIG. 11 is a second preferred embodiment of a bi-directional caster.
FIG. 12 is a third preferred embodiment of a bi-directional caster
FIG. 13 is a rear view of the pivoting axis according to a fourth embodiment.
FIG. 14 is a side view of the pivoting axis according to the fourth embodiment.
FIG. 15 is a side view of the fourth embodiment showing the different camber directions for forward and reverse.
FIG. 16 is an isometric view of the hitch connection from FIGS. 3 and 4 .
FIG. 17 is a top view of a first preferred embodiment of a steerable rear suspension.
FIG. 18 is a top view of a second preferred embodiment of a steerable rear suspension.
FIG. 19 shows a dual laser sighting mechanism.
FIG. 20 shows an image on a rear window for the dual laser sighting mechanism.
FIG. 21 shows a spring driven tapered locking pin with the tapered pin in an installed orientation.
FIG. 22 shows a spring driven tapered locking pin with the tapered pin in a retracted orientation.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a top view of the tow bar hitch in the “in use travel position”. FIG. 2 shows a top view of the tow bar hitch 20 in the retracted position. In FIG. 1 , both side rails 27 and 28 are locked in place by the spring loaded, tapered locking pins 37 and 38 . It is important to note that the telescoping stabilizer bar 85 is shown closed in FIG. 1 and open in FIG. 2 . The stabilizer bar 85 stabilizes the tow bar assembly to a rigid configuration that is necessary to tow the RV and more particularly to push the RV backward when parking. In the “in use travel position” the coil spring 26 is resisting the weight of the hitch assembly making it easy to lower down to the travel position and raise back up again to the out of use or put away position as shown in FIG. 2 . When not in use the hitch assembly is raised upright with the tubular base 25 rotating inside of the three supports 22 , 23 and 24 . This position represents the put away or stored position. While the RV is parked and the tow bar is in the put away position the locking pins 37 and 38 are withdrawn and the two side rails 27 and 28 are in the telescope closed position making the entire assembly much shorter and more compact.
The stabilizer bar 85 telescopes to allow for side to side motion of the actual hitch stem in order to align the stem with the hitch receiver on the back of the tow vehicle. The stabilizer bar is connected to the two side rails at points 45 and 87 which is a pivotal connection that allows for side to side movement. The ends 83 and 84 of the two side rails 27 and 28 pivot vertically at points 88 and 89 to allow for rotational positioning.
To use the tow bar 20 a person takes hold of the tow bar at the ball and socket assembly 86 and begin to swing out and down to the level of the hitch receiver at the back of the tow vehicle that you have positioned in front of the RV to hitch up. The person then pulls the assembly toward the tow vehicle to a position of about half of the full extension of the two side rails 27 and 28 . At this point the stem of the ball and socket assembly can be moved from side to side because the two side rails 27 and 28 are not locked in place in this position. This allows for aligning the stem with the hitch receiver on the back of the tow vehicle if the vehicle was not parked in exactly the right place. Once the stem is aligned with the hitch receiver the stem can be inserted into the receiver and safety pin and cotter key installed. At this point the two side rails 27 and 28 are not yet completely extended and the locking pins 37 and 38 are still withdrawn. Now move the two spring loaded locking pins to the ready position so they will spring to the lock position when the side rails reach the fully extended position at which point the locking pin spring will drive the locking pins in the hole. This will take place when the driver starts to move the tow vehicle forward and pull the two side rails out to the extended position and make the Tow Bar secure for travel.
To unhitch a person begins by removing the cotter key and safety pin at the trailer hitch receiver at the rear of the tow vehicle. The person withdraws the two locking pins 37 and 38 and while holding the ball and socket assembly 86 they pull the stem out of the trailer hitch receiver. This will cause the two side rails 27 and 28 to begin to telescope closed and when the stem is clear of the hitch receiver begin to raise the tow bar up and toward the front of the RV at which time the two side bars will slide all the way to the telescope closed position and when you have the tow bar all the way up it is in the out of use put away position.
FIG. 3 shows a top view of the tow bar hitch in the “in use travel position”. FIG. 4 shows a top view of the tow bar hitch 50 in the retracted position. In FIG. 3 , both side rails 27 and 28 are locked in place by the spring loaded, tapered locking pins 37 and 38 . In the “in use travel position” the coil spring 26 is resisting the weight of the hitch assembly making it easy to lower down to the travel position and raise back up again to the out of use or put away position as shown in FIG. 4 . When not in use the hitch assembly is raised upright with the tubular base 25 rotating inside of the three supports 22 , 23 and 24 . This position represents the put away or stored position. While the RV is parked and the tow bar is in the put away position the locking pins 37 and 38 are withdrawn and the two side rails 27 and 28 are in the telescope closed position making the entire assembly much shorter and more compact.
To use the tow bar 50 a person takes hold of the universal joint 31 hitch 36 and begin to swing out and down to the level of the hitch receiver at the back of the tow vehicle that you have positioned in front of the RV to hitch up. The person then pulls the assembly toward the tow vehicle to a position of about half of the full extension of the two side rails 27 and 28 . At this point the stem of the ball and socket assembly can be moved from side to side because the two side rails 27 and 28 are not locked in place in this position. This allows for aligning the stem with the hitch receiver on the back of the tow vehicle if the vehicle was not parked in exactly the right place. Once the stem is aligned with the hitch receiver the stem can be inserted into the receiver and safety pin and cotter key installed. At this point the two side rails 27 and 28 are not yet completely extended and the locking pins 37 and 38 are still withdrawn. Now move the two spring loaded locking pins to the ready position so they will spring to the lock position when the side rails reach the fully extended position at which point the locking pin spring will drive the locking pins in the hole. This will take place when the driver starts to move the tow vehicle forward and pull the two side rails out to the extended position and make the Tow Bar secure for travel.
To unhitch a person begins by removing the cotter key and safety pin at the trailer hitch receiver at the rear of the tow vehicle. The person withdraws the two locking pins 37 and 38 and while holding the universal joint 31 hitch 36 they pull the stem 36 out of the trailer hitch receiver. This will cause the two side rails 27 and 28 to begin to telescope closed and when the stem is clear of the hitch receiver begin to raise the tow bar up and toward the front of the RV at which time the two side bars will slide all the way to the telescope closed position and when you have the tow bar all the way up it is in the out of use put away position.
FIG. 5 shows a front view of the tow bar hitch 20 or 50 in the out of use or put away position. FIG. 6 shows a side view of the tow bar storage compartment with another contemplated version of a sectional door 18 . FIG. 7 shows a side view of the tow bar storage compartment with another contemplated version of a one piece door 19 .
FIG. 8 shows a prior art pivoting caster. Prior art pivoting casters are those found on the front of baby buggies, shopping carts, swivel chairs and many more moveable objects. These casters are able to go in any direction by swiveling around a full 360 degrees around the central axis 40 . These Casters have a straight up and down vertical axis 41 rather than a tilted one like the automotive wheel suspension. The vertical axis 40 is not tilted but strait up and down and the wheel is free to move from forward 47 caster to rearward caster based upon the direction of travel, pull or drag on the bottom 44 of the wheel 43 . The wheel 43 and axle 41 is offset 42 from the vertical axes 41 so the wheel 43 has the inclination to follow whatever direction it is pulled or pushed.
FIG. 9 shows a Bi-Directional Caster. The bi-directional caster allows the wheels to self-steer the trailing wheels 53 while moving forward 47 and or backward using a variation of the utility caster system rather than the usual automotive caster system. In an automotive caster system the caster on the front wheels of most automotive vehicles, motorcycles and bicycles is primarily to keep the vehicle going straight if the driver lets go of the steering wheel or handlebars. This arrangement makes the vehicle come back to straight after making a turn. This caster has a secondary characteristic in that it makes the wheels want to follow the tow vehicle when being towed. This allows people with motor homes to tow a car behind their motor home.
The self-tracking is performed because of the caster design of the car front suspension system allows for forward tracking but does not provide for tracking in a reverse direction or back up. The existing automotive caster system is achieved by swinging 51 the vertical axis of the front wheels 53 back at the top and forward at the bottom. The purposed bi-directional caster provides a means to easily and effectively change the caster of the front wheels of a towed vehicle so they will caster in both directions. This allows the wheel 53 to caster going forward 52 and backward 54 when being towed by a tow vehicle. This system will make it possible to move the two axles on a travel trailer chassis from the center of the trailer to one axle in front and the other in back much the same as most all four wheeled vehicles. This would be better described as a travel wagon because with one axle in front and one axle in back it resembles a child's toy wagon or a farmers' hay wagon.
The proposed solution retained the utility casters ability to caster in both directions but not swivel around to accomplish this. The spindle 48 and spindle arm 55 can swing in a limited arc fashion between the two stops 56 and 57 . The arm 55 is lifted over the central axis 58 of the pivot 59 to lock the arm 55 at the end ( 56 or 57 ) of the swing to the new position because the weight of the travel wagon works to keep it there until shifted to the other direction when the vehicle is to change direction.
FIG. 10 shows an electrical pictorial diagram of a directional switching system used with the pivoting arm 55 . The method of shifting the front wheels of the towed vehicle between forward caster and backward caster. When the tow vehicle is shifted to reverse an electrical circuit on the vehicle sends electricity to the back-up lights at both taillights on the back of the vehicle. By tapping into this electric circuit and directing the flow of electricity to the towed vehicle (travel wagon) through the existing power cable connection to the vehicle being towed we have a means to send a measured amount of electrical current to temporarily apply the electric front wheel brakes 70 on the vehicle being towed. By applying the two front brakes 70 on the towed vehicle we have caused them to hold the front wheels still as the tow vehicle begins to move backward and push the towed vehicle back. This will cause the front wheels 71 now attached to the second spindle arm 55 to swing to the rearward caster position and therefore caster properly while being backed up. When the driver shifts back to drive (forward) the electric current will temporarily apply the towed vehicle front brakes again and hold the wheels from rolling while the tow vehicle and towed vehicle move forward until the caster shifting is complete and the electric brakes are released.
The tow vehicle is free to pull the travel wagon just like the motor home pulls a car but unlike the motor home and the car, the travel wagon can be backed up by simply shifting the tow vehicle to reverse which automatically adjusts the RV front wheels to reverse caster. When electric solenoid 72 is activated the arm of the solenoid will open the reverse switch 73 and when the solenoid 72 is de-activate the arm of the solenoid will allow reverse switch 73 to close and open forward switch 74 which intern adjusts the RV front wheels back to forward caster for driving forward. The motion of the spindle arm 55 will change the position of reverse switch 75 and forward switch 76 to complete the shifting of the front wheels caster.
FIG. 11 is a second preferred embodiment of a bi-directional caster. In this embodiment the spindle arm 61 is attached to the end of the axle 63 where the front wheel spindle is normally attached to a stock trailer or wagon. A second spindle arm 62 pivots at bearing 64 in a limited arc of movement for a wheel spindle 63 . The location of the second spindle arm 62 is changeable based upon the direction of travel of the trailer or wagon to move the second spindle arm 62 in a forward or reverse caster position. A slot 65 in the first spindle arm provides a limited amount of arc travel to the second spindle arm 62 with the use of a bolt 66 , or similar device that is installed through the slot 65 from the back side of the first spindle arm 61 and threaded into the second spindle arm 62 .
A third preferred and contemplated method of providing bi-directional caster is shown in FIG. 12 . This method will roll or slide the spindle 80 and vehicle wheel forward and in back of the vertical axes 58 of the suspension system rather than the swinging motion described. This system also provides a “lock in place” characteristic made possible by the arc design 81 in the center section where the spindle wheel 82 will travel from forward to rearward caster position. As seen in FIG. 9 , the spindle positioned at the lower end of the second spindle arm this spindle roller will be locked in place at the end of its travel by the weight of the RV. This configuration is as shifted from forward and backward caster in the same way by using the front wheel brakes the same as previously shown and described. This rolling or sliding spindle assembly would be installed on the vehicle front suspension by removing the existing spindle and replacing it with this sliding assembly to accomplish the forward and rearward caster desired.
FIG. 13 is a rear view of the pivoting axis according to a fourth embodiment, FIG. 14 is a side view of the pivoting axis according to the fourth embodiment and FIG. 15 is a side view of the fourth embodiment showing the different camber directions for forward and reverse. In FIG. 13 the two outside tires 53 are shown mounted on the outsides of the central shaft 63 and resting on the ground 44 . The axle 63 supports the weight of the trailer on leaf springs 40 . A pivot arm 55 changes the tilt or caster of the wheel 53 from forward caster 51 to backward caster 39 based upon the direction of travel of the trailer as shown in FIG. 15 . A switching mechanism, similar to the mechanism shown in FIG. 10 , can use a drive motor 67 to turn a screw 64 that changes the caster angle of the pivot arm 55 as shown in FIG. 14 . The drive motor 67 can be mounting to the underside 68 of the trailer.
When the tow vehicle is shifted into reverse an electric circuit on the tow vehicle sends electricity to the back-up lights of the tow vehicle. The electrical circuit of the reverse lights can be detected and a relay or other device can use this detection to set the caster direction of the tires using the electrical connection between the tow vehicle and the trailer. Using this system the electrical motor 67 can be activated to shift the pivot arm 55 to the reverse caster position to allow for backward travel. When the back-up lights are not energized the drive motor 67 will change to caster direction for forward 51 travel of the vehicle.
FIG. 16 is an isometric view of the hitch connection from FIGS. 3 and 4 . The universal joint 31 hitch 36 allows rotation 34 of the hitch 36 when the trailer rocks from side to side relative to the tow vehicle. A universal joint 31 , 32 and 33 allow for three directions of free rotation to allow for angular yaw pitch and roll of the trailer relative to the tow vehicle. This construction eliminates the typical ball and socket connection between a trailer and a tow vehicle but uses the standard receiver that is present on most tow vehicles. The universal joint 31 hitch 36 is shown with the connecting arms 27 and 28 of the trailer tow bar.
FIG. 17 is a top view of a first preferred embodiment of a steerable rear suspension. FIG. 18 is a top view of a second preferred embodiment of a steerable rear suspension. These top views of the RV chassis or frame 100 show the front wheels 102 and 103 in a right turn position. The rear wheels 104 and 105 are in a slight left turn position to keep the rear of the RV from cutting the corner in a right turn. The tie rods for front and back wheels keep the wheels turning left and right in unison. A first lever arm 108 (moved side to side by the front wheel tie rod 106 when the front wheels turn left or right). A second lever arm 109 (moved side to side by the first lever arm and in turn moves the rear wheel tie rod 107 side to side which ultimately steers the rear wheels 104 and 105 in the opposite direction of the front wheels to keep the rear of the vehicle from cutting the corner when turning. The pivotal anchor point 120 of the first lever arm is attached to the chassis. The sliding connection of the first lever arm 108 to the front wheel tie rod 106 that moves the lever arm side to side when the front wheels 102 and 103 turn left or right. Ultimately, turning the rear wheels by moving the second lever arm side to side. Sliding connection 121 connects the front lever arm 108 to the front wheel tie rod 106 . The sliding connection 122 of the first lever arm to the second lever arm 109 that provides the side to side motion necessary to ultimately steer the rear wheels 104 and 105 in the direction desired to limit the rear of the vehicle from cutting the corner when turning. The sliding connection 123 of the second lever arm 109 to the rear tie rod 107 that moves the tie rod side to side ultimately turning the rear wheels 104 and 105 in the desired direction to limit the vehicle from cutting the corner when turning. The pivotal anchor point 124 of the second lever arm attached to the chassis 100 .
In the embodiment shown in FIG. 18 , the resulting steering is essentially the same, but the method of turning the wheels is different. In this embodiment, a steel cable 116 connects the front wheel tie rod 106 with the rear wheel tie rod 107 . Because of the elongated length of the steel cable 116 a plurality of guides 111 and 112 maintain the steel cable 116 in proper position for its travel between the front pulleys 115 and the rear pulleys 110 . The front tie rod 106 is connected to the steel cable 116 with a connector 113 and the rear tie rod 107 is connected to the steel cable 116 with a connector 114 . These connectors 113 and 114 allow both the front and rear wheels to turn in unison. When the front wheels 102 and 103 are turned to the right the tie rod 106 moves to the left which pulls the steel cable 116 to the left and moves the rear wheel 104 and 105 tie rod 107 to the right ultimately turning the rear wheels 104 and 105 in the desired direction to limit the vehicle from cutting the corner when turning. The amount of rear wheel steering is expected to be about one half of the front wheel steering and should be adjusted by the manufacturer to provide optimum performance.
FIG. 19 shows a dual laser sighting mechanism. The RV wagon 90 is shown behind the tow vehicle 91 . The tow bar hitch 20 or 50 is shown attached to the RV wagon 90 with the tow bar stem 96 ready to insert into the tow vehicle hitch receiver 97 . When connecting an RV wagon 90 to a tow vehicle (unlike the present day RV trailer) the tow vehicle only has to be in the vicinity of the RV wagon to hitch up because of the flexibility of the tow bar hitch system. To assist in aligning the receiver 97 with the tow bar stem 96 an intersecting set of laser light beams 92 and 93 are disclosed. The beams 94 and 95 of light from these lasers can be seen in darkness and in daylight. In the preferred embodiment the lights are adjusted to converge in the center of the rear window 98 of the tow vehicle 91 when the tow vehicle is in the ideal location. When this occurs the driver only needs to be in the vicinity to insert the tow bar stem into the hitch receiver.
FIG. 20 shows an image on a rear window for the dual laser sighting mechanism. As seen in FIG. 18 the driver has backed the tow vehicle toward the RV wagon until the laser beam spots on the rear window converge somewhere in the vicinity of the center of the window. It's easy to back the tow vehicle until the beams converge and then stop but it's harder to hit the exact center of the window from side to side. That's where the flexibility of the tow bar hitch mechanism makes it easy to hit an acceptable position within approximately eight inches on either side of center. These laser lights can be turned on and off from the drivers' seat of the tow vehicle with the use of a key chain remote like the one used to unlock the doors of most automobiles. While this embodiment shows the laser light beams 94 and 95 emitting from the RV 90 to the tow vehicle 91 it is further contemplated that the laser light beams can emit from the tow vehicle 91 where they project and image onto the RV 90 that is visible to the person driving the tow vehicle 91 . It is further contemplated that the laser lights 92 and 93 can be electrically connected to the back-up light circuit of the vehicle to only emit light when the tow vehicles is in reverse.
FIG. 21 shows a spring driven tapered locking pin with the tapered pin in an installed orientation and FIG. 22 shows a spring driven tapered locking pin with the tapered pin in a retracted orientation. These views only show one side rail 27 and one tapered locking pin 37 . While only one side rail and associated tapered locking pin is shown and described, this is typical of the construction of the tapered locking pin that is contemplated to eliminate a requirement for loose parts for assembly and hitching. In FIGS. 1 and 2 only the handle of the locking pin 37 is shown with a housing 133 that contains the sub assembly. Within the housing 133 an extension spring 134 pushes the tapered pin 130 into a tapered receiver 132 . The end of the tapered pin 130 is rounded 136 to assist in guiding the tapered pin 130 into the hole 132 . To remove the tapered pin 130 the tapered pin 130 is pulled back quickly and should release the tapered pin 130 from the tapered hole 132 because of the tapered configuration. It is also contemplated that the same or similar spring driven tapered pin configuration can be used at the trailer hitch receiver on the back of the tow vehicle instead of the pin and cotter key that is currently being used in most tow vehicles.
Thus, specific embodiments of a trailer hitching and tracking steering system have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. | Improvements in a trailer hitching and tracking steering system are disclosed include a new style RV or wagon style RV that includes an extendable, variable position tow bar that accommodates misalignment of a tow vehicle. The tow bar can be rotated for storage within the RV wagon. Further improvements include a wheel steering mechanism to improve tracking of a towed vehicle using a bi-directional caster front suspension for steering a wagon style RV in both a forward and reverse direction. The caster of the front wheels is automatically re-directed depending upon the direction of travel of the RV. The suspension system includes a steerable rear suspension that minimizes the amount the back wheels will cut the corner when turning. The improvements also include the use of visible light beams to guide a tow vehicle backing up to an RV to be correctly positioned for hitching without assistance. | 1 |
FIELD OF THE INVENTION
This invention relates to the reaction products of polyoxyalkylene polyamines, diisocyanates and sym-dialkylethylenediamines. More particularly, this invention relates to the preparation of aliphatic polyureas possessing a wide variation in properties which are useful in making fibers and hot melt adhesives.
The speed of reaction can be controlled by the selection of the dialkylethylenediamine.
BACKGROUND OF THE INVENTION
RIM products have been known in the art for a long time. Polyurethane materials were the first polymers to be used in the RIM process. Early systems consisted of polyether polyols, glycol chain extenders, catalysts and aromatic polyisocyanates. These systems exhibited problems such as low mold filling viscosity, long cycle times and the lack of a workable internal mold release capability.
The RIM materials which dominate the automotive market consist of polyether polyols, diamine chain extenders and aromatic polyisocyanates. These materials still suffer from relatively poor high temperature dimensional stability and internal release capabilities.
More recently RIM systems have been developed which consist of polyether polyamines, diamine chain extenders, such as DETDA and aromatic polyisocyanates. No catalysts are required in these RIM systems using polyether polyamines.
Representative patents describing the polyurea RIM systems include the following, assigned to Texaco Chemical Co.:
U.S. Pat. No. 4,297,444
U.S. Pat. No. 4,433,067
U.S. Pat. No. 4,444,910
U.S. Pat. No. 4,448,904
U.S. Pat. No. 4,474,900
U.S. Pat. No. 4,474,901
U.S. Pat. No. 4,487,908
U.S. Pat. No. 4,487,912
U.S. Pat. No. 4,499,254
U.S. Pat. Nos. 4,396,729; 4,444,910 and 4,433,067 concern elastomers prepared using a high molecular weight amine terminated polyether, an aromatic diamine chain extender and an aromatic polyisocyanate which may merely be a polyisocyanate or a quasi-prepolymer prepared from a polyol reacted with a polyisocyanate wherein some isocyanate groups are left unreacted. Various patents have been applied for and received using this basic combination as well as various mold release agents and other additives.
It would be a substantial advance in the art if new methods were developed to alter the properties of RIM materials in predictable ways and to vary the rate of reaction.
SUMMARY OF THE INVENTION
In accordance with the foregoing the present invention describes the reaction of polyoxyalkylene polyamines, m-TMXDI and sym-dialkylethylenediamines to provide polyureas with widely varying properties. Meltable materials can be obtained and the speed of the reaction can be changed by using different dialkylethylenediamines. The materials can be used to make fibers or hot melt adhesives.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The reactants useful in the instant invention include a polyether polyamine, diisocyanate and dialkylethylenediamine.
The polyether polyamine starting materials for the present invention include polyoxyalkylene polyamines. The amine reactants may contain both ethylene oxide and propylene oxide and mixtures of from about 5 to about 95 wt % of ethylene oxide with, correspondingly, from about 95 to 5 wt % of propylene oxide. Where mixed propylene oxide/ethylene oxide polyols are employed, the ethylene oxide and propylene oxide may be premixed prior to reaction to form a heterocopolymer, or the ethylene oxide and the propylene oxide may be sequentially added to the ethoxylation kettle to form blocked oxypropylene/oxyethylene copolymers.
In general, the starting material may be defined as a polyoxyalkylene polyamine having the formula: ##STR1## wherein R is the nucleus of an oxyalkylation-susceptible polyhydric alcohol containing 2 to 12 carbon atoms and 2 or 3 hydroxyl groups, R' is hydrogen or methyl, n is a number having an average value of 0 to 100, and m is an integer having a value of 2 to 3.
The polyoxyalkylene polyamine can alternatively be a polyoxypropylene triamine. In general, the average molecular weight of the polyoxypropylene triamine starting material will be from about 400 to about 5000. Examples of appropriate polyoxypropylene triamines that may be used as a starting material for the present invention include triamines sold by Texaco Chemical Company as JEFFAMINE® T-series products having the formula: ##STR2## wherein A represents the nucleus of an oxyalkylation susceptible trihydric alcohol containing about 3 to about 6 carbon atoms, w, y and z are numbers and the average value of the sum of w+y+z is from about 6 to about 100.
An example of such a product is a commercial product having an average molecular weight of about 400 wherein A represents a trimethylol propane nucleus, and the product contains about 5 to about 6 moles of propylene oxide (JEFFAMINE® T-403 amine). Another is a product having an average molecular weight of about 5000 wherein A represents a glycerol nucleus and the product contains about 85 moles of propylene oxide (JEFFAMINE® T-5000).
Another group of appropriate polyoxyalkylene polyamines that may be used are polyoxyalkylene diamines sold by the Texaco Chemical Company as JEFFAMINE® D-series products having the formula: ##STR3## wherein R' independently represents methyl and x is a number having an average value of about 2 to about 70.
Representative products having this structural formula include polyoxypropylene diamines (wherein R' is methyl) having an average molecular weight of about 230 wherein the value of x is between 2 and 3 (JEFFAMINE® D-230 amine), polyoxypropylene diamines having an average molecular weight of about 400 wherein x has a value between about 5 and 6 (JEFFAMINE® D-400 amine), a polyoxypropylene diamine product having an average molecular weight of about 2000 wherein x has a value of about 33 (JEFFAMINE® D-2000 amine), and a product having an average molecular weight of about 4000 wherein x has a value of about 60 (JEFFAMINE® D-4000 amine).
It can be observed from Examples 10 through 19 that polytetrahydrofurans can be substituted for polyoxyalkylene polyamines in the method of the instant invention. Polytetrahydrofurans with suitable properties include aminated polytetrahydrofuran as disclosed, for example, in U S. Pat. No. 5,003,107, and incorporated herein by reference, and α, ω-bis(3-aminopropyl)polytetrahydrofuran.
In general, the isocyanates which can be used include aliphatic isocyanates. Examples include tetramethylxylene diisocyanate and isophorone diisocyanate. Good results were obtained using α,α,α,α-tetramethyl-m-xylene diisocyanate. This material is produced by American Cyanamid under the trade name m-TMXDI.
In previous work in the field either a catalyst and/or a long reaction time and/or heat were generally required in manufacturing reaction products of polyols and isocyanates.
Polyoxyalkylene polyamines are very reactive with isocyanates and unlike the reaction between polyols and isocyanates, no heat or catalyst is required to carry out the reaction between polyoxyalkylene polyamines and isocyanates. Since the reaction between polyoxyalkylene polyamines and isocyanates takes place quickly and without the addition of a catalyst, it is necessary to provide methods which will encourage the uniform mixing at a rate as fast as or faster than the rate at which the reaction is taking place to promote uniform mixing and uniform reaction throughout the mixture. If a vessel is used to provide mixing with a moving or static mechanical stirrer, then the stirring must be at such a rate to provide this uniform and speedy mixing so that the reaction will be homogeneous throughout the mixture. The stirring may also be done by other means known to those skilled in the art such as impingement mixing. In impingement mixing two or more streams are impacted at a high velocity and the resulting turbulence provides intimate mixing very rapidly. Impingement mixing is known to those skilled in the art and, as is known to those in the field of reaction injection molding, the head of a RIM machine relies on impingement mixing to mix reactants together.
Depending on the type of polyoxyalkylene polyamine and the type of isocyanate, the speed of mixing necessary to provide the uniform homogeneous reaction would vary. For example, in the case of a typical aliphatic diisocyanate reacted with a polyoxyalkylene polyamine, the reaction rate, although fast, might be slow enough to allow mechanical mixing means such as stirrers to be used if desired. Stirring may be faciliated by raising the reaction and subsequent stirring temperature if the polyurea formed is meltable. However, where the reaction takes place at a very rapid rate, normal mixing means such as stirrers may not be practical since they cannot mix the two components rapidly enough to avoid non-homogeneous reaction phases in the final product. In this case the impingement mixing technique or a mixing technique known to those skilled in the art which is at least as rapid and thorough as impingement mixing might need to be used in order that the final product be mixed rapidly and in such a homogeneous manner that the final reacted product is uniform throughout.
When an amount of active hydrogen-containing material, whether it be polyol or polyoxyalkylene polyamine, is used which is less than half the stoichiometric amount needed to react with the isocyanate present, the product is generally called a quasi-prepolymer. When the reaction product consists of one half the stoichiometric amount of active hydrogen material and isocyanate, the product is generally called a prepolymer. These materials are useful for the manufacture of plastics called polyurethanes if the final plastic contains only hydroxyl-isocyanate linkages, polyurea/polyurethane if they contain both hydroxyl-isocyanate linkages and amine-isocyanate linkages or polyurea products if they contain only amine-isocyanate linkages.
When used to manufacture the above-mentioned polyurethane and/or polyurea plastics, it is necessary to further react the quasi-prepolymers with additional active hydrogen-containing material, including but not limited to polyoxyalkylene polyamines, polyols and chain extenders. The products that may be made are known in the art and include products ranging from flexible foams to cast and RIM elastomers or rigid foams and other variations. These products and their manufacture are known to those skilled in the art.
Additional ingredients which may be used if desired for specific applications include blowing agents, catalysts, fillers, coloring agents and surfactant materials.
In the preparation of polyurea RIM in general, chain extenders are desirable and are incorporated into the reaction between the quasi-prepolymer and either polyols or polyoxyalkylene polyamines of high molecular weight. Generally hydroxyl-containing chain extenders such as ethylene glycol, 1,4-butane diol and the like may be used. Also useful are aromatic diamine chain extenders and aliphatic chain extenders, for example, as described in U.S. Pat. Nos. 4,246,363 and 4,269,945.
In the instant invention it has been discovered that certain sym-dialkylethylenediamines added to a quasi-prepolymer or isocyanate and polyamine allow for variation in the properties of the product and variation in the speed of reaction. The sym-dialkylethylenediamines which work in the invention are those in which the alkyl group contains 1 to 3 carbons. Suitable sym-dialkylethylenediamines include sym-dimethylethylenediamine (DMEDA), diethylethylenediamine (DEEDA), sym-diisopropylethylenediamine (DIPEDA) and sym-di-n-propylethylenediamine.
The reaction can take place at ambient temperatures. Where some heat is desirable, the temperature should preferably not exceed 250° C.
It can be observed from Example I, that use of DMEDA results in a very hard composition which forms a bond between two aluminum surfaces and the bond cannot be separated by hand. DEEDA allowed for the formation of a mixture from which flexible fibers could be pulled for about a minute before the composition hardened.
DIPEDA provided a product with properties similar to those of DEEDA in Example 2 and sym-di-t-butylethylenediamine (DTBEDA) gave a tacky and soft product which did not give a permanent bond between aluminum surfaces or possess the capability of fiber formation. In addition, as the data in Tables I through IV indicate different combinations of various polyetherpolyamines and sym-dialkyletheylenediamines provide variations in gel time.
Those skilled in the art will see the advantages inherent in the method of the instant invention. The following examples are given in the way of illustration and are not intended to limit the invention in any way.
EXAMPLE 1
To 27.73 (71.5 meq) of a quasi-prepolymer prepared from 40 parts m-TMXDI and 60 parts polyoxypropylenediamine of molecular weight 2000 (JEFFAMINE® D-2000) was added 3.00 g (68.1 meq) sym-dimethylethylenediamine (DMEDA). On mixing, the reactants gelled. The mass was remelted in a 150° C. oven, applied between two aluminum strips and clamped to give a 1/2" overlap. On cooling a bond formed which could not be separated when pulled by hand.
EXAMPLE 2
The reaction of Example 1 was repeated substituting sym-diethylethylenediamine (DEEDA) for DMEDA and adjusting the mass of isocyanate to the equivalent weight of DEEDA. Mixing of the reactants was accomplished by hand and weak but flexible fibers could be pulled from the mixture for about 1 minute after mixing. Bonding to aluminum plates was accomplished as in Example 1 to give the same results.
Reaction of sym-diisopropyl- and sym-di-t-butylethylenediamines (DIPEDA and DTBEDA, respectively) were similarly carried out. The former gave results parallel to Example 2, while the latter gave a tacky and soft product which did not give a permanent bond between aluminum surfaces or possess the capability of fiber formation. Table I summarizes the results of these examples.
TABLE I______________________________________Aliphatic Polyureas from sym-Dialkylethylenediamines Components, gEXAMPLE 1 2 3 4______________________________________40/60 m-TMXDI/ 27.73 26.65 25.98 25.06D-2000 Quasi2.577 meq/gDMEDA 3.0022.689 meq/gDEEDA 3.8017.21 meq/gDIPEDDA 4.6013.86 meq/gDTBEDA 5.3011.606 meq/gapproximate on 1 2-6 >50gel time* mixing min min min______________________________________ *time at which fibers could be drawn
EXAMPLES 5-9
Several other reactions were carried out in a smaller manner using m-TMXDI and polyoxypropylene polyamines instead of quasi-prepolymers. All polyureas contained 55% by weight hard block (DIPEDA+m-TMXDI wt %). The preparations described in Examples 6 and 8 caused fast reactions which did not allow fibers to be pulled. The products were placed in a 150° C. oven; products from Examples 5 and 9 melted while that from Example 8 did not. Products of Examples 6 and 7 partially melted at 150° C.
TABLE II______________________________________m-TMXDI/Polyoxypropylene Polyamine/DIPEDA Polyurea Components, gEXAMPLE 5 6 7 8 9______________________________________m-TMXDI 7.33 10.48 9.04 9.67 7.188.187 meq/gDIPEDA 3.68 0.51 1.98 1.33 3.8213.86 meq/gD-2000 9.001.00 meq/gD-230 9.008.75 meq/gD-400 9.005.17 meq/gT-403 9.006.75 meq/gT-5000 9.000.65 meq/ggel time 3 min fast 2.8 min fast >1 min______________________________________
EXAMPLES 10-13
Several polyureas were prepared using α,ω-bis(3-aminopropyl)polytetrahydrofurans in place of the polyoxypropylene polyamines. Results are summarized in Table III. Products from Examples 11-13 melted in a 150° C. oven, while that from Example 10 did not.
TABLE III______________________________________m-TMXDI/Bis(aminopropyl)poly(THF)/DIPEDA Polyurea Components, gEXAMPLE 10 11 12 13______________________________________m-TMXDI 10.88 7.56 7.13 6.768.187 meq/gDIPEDA13.86 meq/g 2.43 2.87 3.24Bis(aminopropyl)poly(THF)Mw 204 9.109.790 meq/gMw 750 10.002.824 meq/gMw 1100 10.001.861 meq/gMw 2100 10.001.042 meq/g% hard block 54.46 49.98 50.00 49.99gel time fast 4 min 3:15 2:30______________________________________
EXAMPLES 14-19
Polyureas containing amines obtained by the direct amination of poly(tetrahydrofuran), poly(THF), were prepared in an analogous fashion. The products from Examples 16-18 melted in a 150° C. oven, while those from Examples 14, 15 and 19 partially melted. Methanol dissolved the products from Examples 17 and 18 and caused the other products to swell. The product from Example 19 could not be broken by repeated blows with a hammer at room temperature.
TABLE IV______________________________________m-TMXDI/Aminated Poly(THF)/DIPEDA Polyureas Components, gEXAMPLE 14 15 16 17 18 19______________________________________m-TMXDI 12.16 10.25 7.54 7.15 6.71 7.018.187 meq/gDIPEDA 2.47 2.84 3.29 3.0013.86 meq/gDBGDA.sup.a 7.9012.6 meq/gTBGDA.sup.b 9.808.56 meq/gAminated Poly(THF)6374-79.sup.c 10.002.751 meq/g6374-63-2.sup.d 10.001.919 meq/g6374-83-3.sup.e 10.000.933 meq/g6640-14.sup.f 10.001.58 meq/g% hard block 60.6 51.1 50.0 50.0 50.0 50.0gel time, min fast fast 1.0 2.5 1.5 fast______________________________________ .sup.a Dibutyleneglycol Diamine .sup.b Tributyleneglycol Diamine .sup.c Aminated Mw 650 Poly(THF) .sup.d Aminated Mw 1000 Poly(THF) .sup.e Aminated Mw 2000 Poly(THF) .sup.f Aminated Mw 1000 Poly(THF) containing a high secondary amine content.
EXAMPLES 20-22
D-2000/m-TMXDI/DIPEDA polyureas were prepared at different hard block contents as shown in Table V. All were subsequently placed in a 125° C. oven for 1 hour at which temperature all were molten. The product from Example 20 was soft and flexible at room temperature and crept slowly. A tough and flexible article was obtained from Example 21. A hard and brittle material was obtained from Example 22.
TABLE V______________________________________m-TMXDI/D-2000/DIPEDA Polyurea Components, gExample 20 21 22______________________________________m-TMXDI 4.40 6.74 9.10DIPEDA 1.59 3.26 4.94D-2000 14.00 10.00 6.00% hard block 30.0 50.0 70.1______________________________________
EXAMPLE 23
A three necked flask fitted with a mechanical stirrer, thermometer, nitrogen inlet and addition funnel was charged with 16.3 g (226 meq) DIPEDA and 50.0 g (50.0 meq) D-2000. To this mixture was added 33.7 g (276 meq) m-TMXDI dropwise at 26° to 110° C. The temperature rose during the addition and was further increased by heating in order to lower the viscosity of the reacting mass. The mixture was subsequently heated to 153° C. for 1 hour and poured onto aluminum foil coated with mold release agent to give an off white and slightly brittle elastomer. Testing of the product as an adhesive was carried out by melting it onto aluminum plates in a 150° C. oven and pressing the plates together in a clamp according to ASTM D-b 1002 and D-1876 to give values of 1140 lb/in 2 (tensile sheer) and 3.4 pli (T-peel). | Disclosed is a method for preparing aliphatic polyureas in varying reaction times which comprises reacting polyoxyalkylene polyamines, an aliphatic diisocyanate and a sym-dialkylethylenediamine. | 2 |
TECHNICAL FIELD
[0001] Provided is an article of jewelry such as bracelets, necklaces, rings, etc. More specifically, provided is a jewelry item with the added function of being able to automatically rotate.
BACKGROUND
[0002] Pieces of jewelry are works of art limited only by the imagination and creativity of the artists themselves. Gemstones are inherently beautiful. For example, diamonds are beautiful and extremely valuable and are often incorporated into jewelry for the purpose or being worn and to display their beauty. When jewelry is offered for sale at a jewelry store, it is commonly presented in a manner that highlights its elegance and scintillating brilliance. This is accomplished through the use of bright lighting and open display to allow light to reach the piece from all angles. Often, jewelry is Shown in a case upon a turntable or other rotating mechanism, an that potential buyers can view the jewelry from multiple angles and visually experience the way the light interacts with the piece.
[0003] Additionally, many pieces of jewelry have beautiful features that cannot be fully realized when worn. For example, a diamond ring may have diamonds all around its circumference, yet only the top of the ring may be seen by others when worn.
[0004] Pieces of jewelry with movement and modifiable parts have been long known, however these prior jewelry constructions fail to provide both movement and modification at the same time. They also do not provide programmable and controllable movement for rotation of the jewelry.
SUMMARY
[0005] According to one aspect of this invention, movable jewelry device may comprise: an article of jewelry comprising: ( 1 ) a plurality of selectively connectable links each comprising: (a) an ornamental surface; and, (b) jewelry gear teeth; and, ( 2 ) a it that holds the plurality of links together a motion apparatus comprising: ( 1 ) a movement magnet; ( 2 ) a return magnet; ( 3 ) a movement spring, ( 4 ) a return spring; and, ( 5 ) motion gear teeth; and, a control apparatus comprising: ( 1 ) a first electric actuator; ( 2 ) a second electric actuator; and, ( 3 ) a control switch. The plurality of links are may he movable with respect to the frame by manually activating the control switch: to: activate the first electric actuator to engage the movement magnet to: ( 1 ) engage the jewelry gear teeth with the motion gear teeth; and, ( 2 ) move the motion apparatus and thus the plurality of connectable links with respect to the frame; then: ( 1 ) deactivate the first electric actuator; and, ( 2 ) maintain the engagement of the jewelry gear teeth to the motion gear teeth using a force from the movement spring; there activate the second electric actuator to engage the return magnet to separate the jewelry gear teeth from the motion gear teeth; and, then: ( 1 ) deactivate the second electric actuator; and, ( 2 ) maintain the separation of the jewelry gear teeth from the motion gear teeth using a force from the return spring.
[0006] According to another aspect of this invention, as long as the control switch is manually activated the plurality of links continue to move with respect to the frame.
[0007] According to another aspect of this invention, each of the links comprises: ( 1 ) an inner surface upon which the jewelry gear teeth are positioned; ( 3 ) an outer surface upon which the ornamental surface is positioned; and, ( 4 ) first and second sides; the plurality of links form a ring shape; the frame is ring shaped; and, one to the plurality of links and the frame comprises a groove and the other of the plurality of links and the frame comprises a protrusion that is received within the groove to movably connect the frame to the plurality of links.
[0008] According to another aspect of this invention, each of the links has a first end with a. first interlocking arm and a second end with a second interlocking arm; and, the first interlocking arm of a first link engages the second interlocking arm of a second link to attach the first link to the second link.
[0009] According to another aspect of this invention, each of the first interlocking arms extend relatively inward and each of the second interlocking arms extend relatively outward.
[0010] According to another aspect of this invention, the movable jewelry device may further comprise a compartment that: ( 1 ) is affixed to the frame; ( 2 ) houses the motion apparatus; and, ( 3 ) houses the control apparatus.
[0011] According to another aspect of this invention, the control apparatus comprises: ( 1 ) an electronic control board; ( 2 ) a recharging connector; and, ( 3 ) a battery; and, the compartment comprises across to the plurality of links whereby the plurality of inks can be replaced.
[0012] According to another aspect of this invention, the plurality of selectively connectable links together define one of: a bracelet; a necklace; and, a ring.
[0013] According to another aspect of this invention, the plurality of selectively connectable links together define a dual bracelet; and, the frame is W-shaped.
[0014] According to another aspect of this invention the control apparatus comprises an electronic control module that is user programmable to program the control apparatus to vary at least one of: ( 1 ) directions the plurality of inks are movable with respect to the frame; ( 2 ) speeds the plurality of links are movable with respect to the frame:, and ( 3 ) durations the plurality of links are movable with respect to the frame.
[0015] According to another aspect of this invention, a method may comprise the steps of: (A) providing a movable jewelry device comprising: an article of jewelry comprising: ( 1 ) a plurality of selectively connectable links each comprising: (a) an ornamental surface; and, (b) jewelry gear teeth; and, ( 2 ) a frame that holds the plurality of links together; a motion apparatus comprising: ( 1 ) a movement magnet; ( 2 ) a return magnet; ( 3 ) a movement spring; ( 4 ) a return spring, and, ( 5 ) motion gear teeth; and, a control apparatus comprising: ( 1 ) a first electric actuator; ( 2 ) a second electric actuator; and, ( 3 ) a control switch; and, (B) moving the plurality of links with respect to the frame by manually activating the control switch: to: activate the first electric actuator to engage the movement magnet to: ( 1 ) engage the jewelry gear teeth with the motion gear teeth; and, ( 2 ) move the motion apparatus and thus the plurality of connectable links with respect to the frame; then: ( 1 ) deactivate he first electric actuator; and, ( 2 ) maintain the engagement of the jewelry gear teeth to the motion gear teeth using a force from the movement spring; then: activate the second electric actuator to engage the return magnet to separate the jewelry gear teeth from the motion gear teeth; and, then: ( 1 ) deactivate the second electric actuator; and, ( 2 ) maintain the separation of the jewelry gear teeth from the motion gear teeth using a force from the return spring.
[0016] According to another aspect of this invention, step (B) comprises the step of: continuing to move the plurality of links with respect to the frame as long as the control switch is manually activated.
[0017] According to another aspect of this invention, step (A) comprises the steps of: providing each of the links to comprise: ( 1 ) an inner surface upon which the jewelry gear teeth are positioned; ( 3 ) an outer surface upon which the ornamental surface is positioned; and, ( 4 ) first and second sides; providing the plurality of links to form a ring shape; providing the frame to he ring shaped; and providing one of the plurality of links and the frame to comprise a groove and the other of the plurality of links and the. frame to comprise a protrusion that is received within the groove; and, step (B) comprises the step of: moving the protrusion with respect to the groove as the plurality of links is moved with respect to the frame.
[0018] According to another aspect of this invention, the step of: providing an article of jewelry comprising a plurality of selectively connectable links comprises the steps of providing each of the links to have a first end with a first interlocking arm and a second end with a second interlocking arm; and, engaging the first Interlocking arm of each link to the second interlocking arm of a juxtaposed link.
[0019] According to another aspect of this invention, step (A) comprises the step of: providing a compartment attached to the frame; and, the method further comprises the step of: accessing the plurality of links through the compartment to replace at least one of the plurality of links.
[0020] According to another aspect of this invention, step (A) comprises the step of: providing the control apparatus with a programmable electronic control module; and, the method further comprises the step of: using the programmable electronic control module to vary directions that the plurality of links are movable with respect to the frame.
[0021] According to another aspect to this invention, step (A) comprises the step of providing the control apparatus with a programmable electronic control module; and, the method farther comprises the step of: using the programmable electronic control module to vary speeds the plurality of links are movable with respect to the frame.
[0022] According to another aspect of this invention, step (A) comprises the step of: providing the control apparatus with a programmable electronic control module; and, the method further comprises the step of: using the programmable electronic control module to vary durations the plurality of links are movable with respect to the frame.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a diagram of the motion apparatus perspective;
[0024] FIG. 2 is a diagram of an exemplary article of motion jewelry;
[0025] FIG. 3 is a diagram of the link perspective;
[0026] FIG. 4 is a diagram of the link top view;
[0027] FIG. 5 is a diagram of the link side view (teeth side)
[0028] FIG. 6 is a diagram of the link side view (connection side);
[0029] FIG. 7 is a diagram of the link end view;
[0030] FIG. 8 is a diagram of the motion apparatus enlarged in conjunction with the links;
[0031] FIG. 9 is a diagram of the motion apparatus front view;
[0032] FIG. 10 is a diagram of the motion apparatus side view; and,
[0033] FIG. 11 is a diagram of the frame inside view.
DESCRIPTION
[0034] A piece of jewelry such as bracelets, necklaces, rings, etc . . . is provided which is capable of both movement and modification while simultaneously being worn by a user. In an exemplary embodiment the article of motion jewelry is a bracelet which has a frame that has a substantially “W” shaped cross section ( FIG. 11 ) and forms a ring. The “W” shaped frame 11 includes a first outer portion, a second outer portion, an inner portion, a base portion and two raised protrusions 16 which lit into the corresponding grooves 17 and function to hold the links 18 together, secure them to the frame 11 and keep them in the proper position in relation to the motion apparatus 4 , The “W” shaped frame 11 holds two exemplary bracelets 19 with each bracelet made up of multiple links 18 . Said links each have art ornamental surface 10 , gear teeth 14 , a guide groove 17 , and two interlocking arms 7 . The two interlocking arms 7 are arranged so that two or more links can be combined to form the bracelet 19 ( FIG. 8 shows a side view of the interlocking arms 7 connected to each other as contemplated in this exemplary bracelet). These uniquely shaped interlocking arms 7 allow the links to be attached to each other without the need for mechanical attachment devices, such as a clasp or a pin, or through welding. This allows for the links to be exchanged should the wearer desire a different design or look of the article of motion jewelry. The links 18 themselves could be made of precious metals, steel, titanium, polymers, plastic, or other suitable materials which would be apparent to one skilled in the art. The gear teeth 14 on the bottom of the links 18 may form a complete gear when attached to a sufficient number of additional links to form a complete ring. The links 18 and the associated gear teeth 14 may serve as a “pinion” type gear with the motion apparatus 4 and movement gear 5 functioning substantially as the “rack.”
[0035] Another embodiment of the article of motion jewelry may be a ring capable of being worn on any finger or thumb.
[0036] Yet another embodiment of the article of motion jewelry may be a necklace whose design may be limited only by the imagination and skill of the artist.
[0037] FIG. 1 shows an exemplary motion apparatus 4 which includes the movement magnet 1 , the movement spring 2 , the return spring 3 , the movement gear 5 , and the return magnet 6 . In one embodiment of the motion apparatus 4 the body of the motion apparatus is made out of polycarbonate polymer which is both light weight and durable. In one embodiment, the motion apparatus 4 and movement gear 5 are both made of polycarbonate polymer.
[0038] In an exemplary embodiment, the motion apparatus 4 is functional to move the jewelry piece in any direction. This movement is accomplished through the following procedure:
[0039] A) The wearer activates the movement control switch 9 ; thereby causing a first electric actuator 13 to engage the movement magnet 1 by generating an identical magnetic pole on the movement magnet 1 which may Farce the movement gear 5 forward. The engagement of the movement gear 5 effectuates the rotation of the jewelry. The movement gear 5 is held in contact with the gear teeth 14 by the movement spring 2 allowing the first electric actuator 13 to be deactivated.
[0040] B) Upon completion of the movement step, a second electric actuator 12 is activated which creates an identical magnetic pole on the return magnet 6 which engages the return magnet 6 to bring the movement gear back 5 back to its original position away from the links 18 where it is held in place by the return spring 3 , thus allowing the second electric actuator 12 to be deactivated.
[0041] The repetition of this process may allow for continuous movement of the jewelry piece within its frame. In an exemplary embodiment of the jewelry piece, controlling the first actuator 13 and second actuator 12 is accomplished through the employment of a programmable electronic control board and microcontroller which controls the speed and duration of the rotation. The electronic control board is capable of being programmed with various movement styles based on the wearer's preference. Such movement Style programming may he downloaded by the wearer from the internet and specific to the type and style of the particular piece of jewelry. In one embodiment, the downloaded control programs may include continuous motion. Another embodiment might include timed motion, moving the piece at a specific interval set by the user. Yet another embodiment may be custom movement where the piece only moves when the user activates the program. Other program options would be apparent to one skilled in the art.
[0042] FIG. 2 shows an exemplary example of the dual bracelet 19 with the “W” shaped frame 11 base portions removed, revealing the gear teeth 14 on the bottom side of the links 18 . An accessible compartment 15 is affixed to the “W” shaped frame 11 and houses the motion apparatus 4 along with the electronic control board, the data and recharging connector 8 , movement control switch 9 , a battery, and access point for replacing the links 18 . The links 18 are shown in the dual bracelet 19 embodiment as a complete ring having an ornamental surface 10 facing outward. This ornamental surface 10 may be adorned with gemstones, engravings, or any other ornamental design as desired by the wearer. The chosen design is limited only by an artist's imagination.
[0043] FIG. 3 shows a perspective of an individual link 18 as depicted in the exemplary bracelet embodiment 19 . The link 18 is shown having an ornamental surface 10 , gear teeth 14 , the guide groove 17 , and the interlocking arms 7 .
[0044] FIG. 4 is a top view of an exemplary embodiment link 18 showing the groove 17 , gear teeth 14 , and interlocking arms 7 in more detail.
[0045] FIG. 5 is a side view of an exemplary embodiment link 18 showing the gear teeth 14 .
[0046] FIG. 6 is a side view of the ornamental surface 10 of an exemplary embodiment link 18 .
[0047] FIG. 7 is an end view of an exemplary embodiment link 18 showing the groove 17 .
[0048] FIG. 8 shows an enlarged view of the movement apparatus 4 in relation to the exemplary bracelet 19 which is depleted as a semi-circle which may be comprised of multiple links 18 . Shown in an exemplary embodiment, the movement apparatus is oriented against the “W” shaped frame 11 with the first movement actuator 13 , movement magnet 1 , second movement actuator 12 , and return magnet 6 positioned alongside the links 18 . The movement gear 5 is aligned with the gear teeth 14 of the links 18 . The movement spring 2 and return spring 3 are shown within the body of the motion apparatus 4 , which is contained in the accessible compartment 15 .
[0049] FIG. 9 shows the motion apparatus 4 viewed from the front, looking, at the movement gear 5 . Interior and behind the movement gear 5 is the movement spring 2 . Also shown are the proper orientation of the movement magnet 1 , return magnet 6 , and the return spring 3 .
[0050] FIG. 10 shows a side view of the motion apparatus 4 with the return magnet 6 , movement gear 5 , movement spring 2 , and return spring 3 .
[0051] FIG. 11 is a cross sectional view to the “W” shaped frame 11 showing the protrusions 16 that secure the links 18 within the shaped frame 11 via the groove 17 .
[0052] While the article of motion jewelry has been described in connection with various illustrative embodiments, it is to be understood that other similar embodiments may be used or modifications and additions may be made to the described embodiments for performing the marine function disclosed herein without deviating therefrom. Further, all embodiments disclosed are not necessarily in the alternative, as various embodiments may be combined or subtracted to provide the desired characteristics. Variations can be made by one having ordinary skill in the art without departing from the spirit and scope hereof, Therefore, the article of motion jewelry should not be limited to any single embodiment, but rather construed in breadth and scope in accordance with the recitations of the appended claims. | A movable jewelry device may include an article of jewelry having multiple connectable links containing ornamental surfaces and gear teeth. A motion apparatus may contain gear teeth that engage the gear teeth on the article of jewelry to move article of jewelry. | 0 |
This application is a continuation of application Ser. No. 598,118, filed Oct. 16, 1990, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to methods and apparatus for non-surgical alteration of corneal curvature in the human eye.
Refractive errors in the function of the eye are quite common in the human population. In fact, moderate levels of far-sightedness ("hyperopia"), near-sightedness ("myopia"), and astigmatism are so widespread as to be considered normal. Less common are the pathological cases which can be severe or degenerative in nature. While Telatively mild refractive errors often can be corrected by external lenses, larger and more complex refractive errors are more difficult and sometimes impossible to correct with external refraction alone.
In the field of surgery, a known technique for treatment of certain forms of refractive errors, such as acute myopia , hyperopia, and astigmatism is to surgically remove an anterior segment of the cornea down into the stroma, to reshape the removed segment as by surgical grinding in a frozen state, and to restore the reshaped segment into the eye. In this type of operation, known as keratoplasty, the eye heals by reformation of the outer epithelium layer over the reshaped stroma.
Alternatively, a layer of the cornea can be opened as a flap, an artificial or donor lenticular implant then inserted under the flap, and the flap sutured up again.
Such invasive corneal procedures are typically limited to treatment of severe conditions, and are generally viewed as a procedures of last resort because of the attendant surgical risks. Nonetheless, a substantial portion of the eye's refractive power is determined by the corneal curvature and reshaping the cornea has been the object of much research and experimental efforts as a means for correction of refractive errors.
Thermokeratoplasty, a class of procedures involving the application of heat to the cornea, has been proposed for hyperopic correction of optical defects. The collagen which forms the corneal stroma is known to shrink by about one third of its initial length when treated to a temperature between about 60°-70° C. This shrinkage appears to be permanent, with the potential of little or no lasting opacity of the treated site resulting from the treatment. Hence, various thermokeratoplasty techniques seek to exploit such collagen shrinkage profile, including inserting a nicrome wire into the cornea and heating the surrounding collagen tissue to a non-damaging temperature to cause permanent shrinkage of the collagen tissue. This shrinkage beneficially changes the curvature of the cornea. Other techniques include application of RF current or laser energy to effect permanent change in the corneal collagen.
A problem with heating of the eye lies in the possibility of damage to the epithelium and Bowman's membrane on the anterior side of the cornea, as well as Descemet's membrane and the endothelium on the corneal posterior, as heat energy is applied to develop a critical shrinkage temperature in the internal stromal collagen. It is therefore desirable to minimize the heating effect in these sensitive membranes, and particularly in the endothelium, while still obtaining the desired 60°-70° C. temperature range in the stroma. Thus, the treatment duration and other paremeters that affect the thermal dose to the cornea must be precisely controlled in any treatment delivery system.
It is therefore an object of the present invention to provide a non-surgical and non-damaging thermal treatment method and apparatus for the correction of the refractive power of the cornea.
It is another object of the present invention to provide a method and apparatus particularly useful for hyperopic and astigmatic correction by selectively applying heat to the cornea to induce volumetric coagulation in the corneal collagen and thereby steepen regions of the central cornea.
SUMMARY OF THE INVENTION
Methods and apparatus for correction of optical defects in vision are disclosed, employing an infrared radiation source and a focusing element, for changing the curvature of the eye by application of focused infrared radiation into the collagenous tissue of the cornea in a controlled manner.
In one aspect of the present invention, an apparatus for performing thermokeratoplasty includes a radiation source for delivery of infrared radiation into the cornea of an eye, and a focusing arrangement for focusing radiation from the source into the cornea in a controlled manner such that the focus of the radiation is limited to a predetermined depth, whereby the radiation effects heat-induced shrinkage of the collagenous tissue of the cornea and thereby changes the corneal curvature.
The radiation source can be laser or a non-coherent infrared radiation source, preferably operating at a wavelength ranging from about 1.8 micrometers to about 2.3 micrometers. The output can be pulsed or continuous wave ("CW"). Examples of laser radiation sources include Holmium:YAG lasers and CoMgF 2 lasers. Such laser sources can be configured to deliver radiation at a fixed wavelength or be tunable over at least a portion of the infrared spectrum.
The radiation source can be coupled to a handpiece which is utilized by the practitioner to create irradiation patterns or zones in the eye. The radiation source can be coupled to the handpiece by an optical fiber or other waveguide, and the handpiece can also include a focusing mechanism, which focuses the radiation into a cone-shaped beam and thereby defines a conical coagulation zone in the cornea. The focusing apparatus can be formed by refractive elements, such as lens, or reflective elements, such as mirrors, or combinations of such elements. Alternatively, the focusing apparatus can be incorporated into the waveguide, such as by the use of a tapered fiber terminus, which internally focuses the radiation into a cone. In any event, the focusing elements preferably focus the laser radiation to a depth of less than about 450 micrometers in the corneal tissue.
The apparatus can further include one or more interface-matching elements, disposed either between the fiber terminus and the focusing elements, or between the focusing elements and the surface of the cornea, or both. The interface-matching elements can have an index of refraction which provides a less abrupt transition between the different transmission media and thereby minimizes reflective or scattering losses. The interface-matching element can be a fluid medium or a graded optical element.
In one illustrated embodiment of the invention, the apparatus includes a laser infrared radiation source, a handpiece incorporating a focusing means, and a fiber optic cable which connects the laser to the handpiece. The focusing means is mounted on the handpiece and including a lens arrangement, from which a beam of laser radiation may be projected to a depth of about 300 to 450 micrometers into the cornea of the eye when the handpiece is brought into proximity with the corneal surface and the laser is activated.
In another aspect of the invention, a method for shrinking collagen tissue in an eye to correct refractive errors is disclosed which includes generating a beam of radiation in the infrared range, focusing the beam to a controlled focal depth and applying the focused radiation to the cornea of an eye such that the beam is focused into the cornea, causing the collagenous tissue in the focal region to shrink. Preferably, the beam is focused to a point about 300 to 450 micrometers in the eye.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features and advantages of the present invention will be more fully understood by reference to the following detailed description in conjunction with the attached drawing in which like reference numerals refer to like elements and in which:
FIG. 1 is a schematic view of an embodiment of the present invention in cooperation with an eye shown in cross-section;
FIG. 2 is a more detailed view of another embodiment of the present invention operating upon an eye;
FIG. 3 is a more detailed schematic view of a focusing mechanism for use in the present invention; and
FIG. 4 shows changes in the cornea after treatment according to the invention.
DETAILED DESCRIPTION
An embodiment of the present invention is shown in FIGS. 1 and 2 in cooperation with a human eye. A typical human eye 10 includes a cornea 12, iris 16, pupil 18, lens 20 and retina 21 at the back of the eye. These parts receive light rays 19 from the environment and convert the captured light rays 19 into electrical impulses for processing in the brain. The outer portion of eye 10, the sclera 15 (commonly referred to as the "whites" of the eye), is attached to and bounds the periphery 13 of the cornea. The typical radius of curvature of the outer surface of cornea 12 in the human eye is about 8 millimeters, which is smaller than the average radius of curvature of the sclera, thus giving the cornea its characteristic bulged-out contour, as shown. Cornea 12 is a layered structure the curvature of which provides a major portion of the refractive power of the eye.
As shown in more detail in FIG. 2, the cornea includes several layers: the anterior epithelium 28, Bowman's membrane 30, the relatively thick collagenous stroma 32, Descemet's membrane 34, and the posterior endothelium 36. The human corneal thickness, from the outer surface 29 of epithelium 28 to the outer surface 37 of endothelium 36, is typically about 450 micrometers. The cornea is formed having a multiplicity of collagen fibers 44 generally extending between the cornea anterior surface 29 and posterior surface 37.
In practice of the invention, selected portions of the collagen fibers are shrunk by application of a focused beam 41 of heat energy from a focusing system 55 of delivery device 53, forming a coagulation cone 43. The beam preferably generates a temperature of at least about 60° C. in the target area, so as to safely cause a volume coagulation of portions 44' of fibers 44. The coagulation cone 43 extends essentially from behind Bowman's membrane 30 at the anterior side 47 of cone 43 to region of the beam's focal point 42 within the stroma 32 and anterior to Descemet's membrane 34. The contracted fiber portions 44' cause a correlated contraction of the cornea, thus achieving a desired corrected index of refraction of the cornea.
Various corrective procedures can be accomplished by selective heating of the cornea and consequent selective shrinkage of the stromal collagen. In one technique, simple hyperopic corrections can be achieved by formation of a ring-shaped pattern of coagulation spots about the optical axis. Larger hyperopic corrections can be achieved by applying two or more concentric ring patterns. Astigmatic corrections can be achieved by applying a line of coagulation spots to induce steepening along a treatment axis. Corrections of myopia can be achieved by either central application of the focused energy beam or by the application of radial patterns. These techniques can also be practiced in combination to achieve an overall correction of multiple refractive errors.
The curvature of cornea 12 is shown in FIG. 4 before and after treatment in practice of the present invention to correct hyperopia. The pretreatment corneal curve 40 is shown in dotted outline having a first radius R1 and the post treatment corneal curve 46 is shown in solid outline having a lesser radius R2. The change from radius R1 to R2 correlates to a refractive correction which can be achieved by application of the techniques disclosed herein.
Careful application of heat energy is essential to avoid damaging the delicate layers and structures anterior or posterior of stroma 52. Nevertheless, enough heat must be applied to the stroma to effect permanent fiber shrinkage. Hence, the applied heat energy is preferably controlled to generate sufficient heat in the stroma at desired sites without generating damaging heat in surrounding tissues. A ring marker can be used to mark the cornea and to locate exposure sites on the ring circumference. A series of exposures are then made along the ring circumference. This creates a plurality of conical exposure sites within the cornea, with a consequent reformation of the cornea.
Apparatus 100 of the invention, shown in FIGS. 1 and 2, applies infrared radiation from a radiation source 49 (e.g., a Ho:YAG laser), guided by fiber 48 and via delivery device 53, to cornea 12. Delivery device 53 can include a handpiece 54 and a corneal contact adapter 56, with a focusing system 55 (e.g., a tapered optical waveguide as shown in FIG. 1 or equivalent) mounted in adapter 56 (or in handpiece 54) for focusing beam 41, delivered by fiber 48 from source 49, to focal point 42.
Various focusing mechanisms can be used to implement focusing means 55. For example, in FIG. 3 a configuration of two lenses 50, 51 is shown. The first lens 50 collimates the output of fiber 48 and the second lens 51 focuses the beam. As shown, three separate chambers 57a, 57b, and 57c are filled with index matching fluid. The fluid in each chamber can be the same or different depending on the optic properties desired. Lenses 50, 51 can be plano-convex or otherwise fabricated as a convergent lens system to effect a conical exposure volume within the cornea. (It should be clear that various other optical focusing elements, including single lens systems, three or more lens arrangements, reflective elements, light pipes, Fresnel lenses, microlenslets, and graded refractive index lenses, can be employed to achieve similar conical exposure volumes within the cornea.)
Returning to FIG. 2, it can be seen that the focusing means 55 creates a shallow conical exposure region, i.e., a shallow cone 43 typically extending to a depth of about 300 to 400 micrometers into the cornea. Hence, the infrared energy of the radiation source will be focused slightly beyond the center of the stroma, at focal point 42, which isolates the heat damage to cone 43 away from the more sensitive anterior and posterior layers 28, 30, 34, 36. By means of this pattern control, a precise coagulation pattern (generally coincident with cone 43) can be obtained with the greatest heat intensity located around the mid-stroma 33. The coagulation of the treated stroma thus causes a local pinching effect on the cornea, with resulting optical correction. Furthermore, it has been observed that in this embodiment there is a very rapid decrease of the beam fluence beyond focal point 42, thus preventing damage to the highly sensitive endothelial layer.
The corneal contact adapter 56 can have a concave shaped receiver end 61 which facilitates applying delivery device 53 directly to the surface of the cornea, and therefore affords accurate presentation of the radiation beam to the eye. Contact adapter 56 can also be removably attached to handpiece 54 (such as by mechanical and/or frictional engagement) such that adapter 56 can be discarded (or sanitized) after use. This provides an added degree of safety and convenience in practice of the presently disclosed invention.
Contact adapter 56 can be filled with a fluid medium 57 having an index of refraction which provides a transition from fiber 48 to the cornea to be treated, so as to more accurately define the treatment zone in the eye. When a conical focusing element is used as the focusing element 55, as shown in FIG. 1, it can be bathed in fluid medium 57 (e.g., a saline or other solution) within adapter 56.
It will now be appreciated that as a result of the present invention, it is possible to recontour the corneal curvature by radially shrinking collagen fibers axially cooperating with the cornea surface. Volumetric coagulation is achieved without injuring the surface of the cornea or stroma. Furthermore, as a result of focusing the radiation beam, it is possible to obtain a nearly homogeneous coagulation pattern in cone 43 because the energy loss due to absorption is partially compensated by the focusing.
In one embodiment of the invention, a commercially available Ho:YAG laser (available, for example, from Schwarz Corporation, Orlando, Fla., USA) tuned to a wavelength of 2.06 micrometers, was employed with favorable results. The beam was guided by a quartz fiber (having a diameter of 400 micrometers) and was applied by a handpiece to the eye. A lens system (as specified above) was mounted in the handpiece to focus the beam about 300-400 micrometers in front of the handplece into the eye with the handpiece in contact with the cornea. The energy output was maximally 35 mJ at a pulse repetition rate of 4 Hertz. Pulse duration was 200 microseconds. The output was adjusted from 10 to 35 mJ per pulse by changing the lamp voltage. Thirty pulses were applied to each coagulation site.
In one group of experiments performed on four blind eyes, two different pulse energies were studied: two eyes with 35 mJ per pulse, two eyes with 25 mJ per pulse. Coagulation sites were established using corneal marker rings having various diameters so that a series of exposures could be made on the circumference of a ring or rings, so to control the corneal shrinkage. The angle was carefully controlled to be wide so as to prevent damage to the endothelium. The treatment was under topical anesthesia. The post-operative medication consisted of Gentamicin ointment three to five times per day for three days. The patients have been followed with the following observations:
The principal change in corneal curvature, after eight coagulations and ring diameter of 6 millimeters, was a central steepening. The irregular corneal surface present during the first postoperative days disappeared after one week.
Refractive change (spherical equivalent) depended on pulse energy. There appears to be a therapeutic threshold at about 8 to 10 mJ per pulse and saturation limit at energies above 15 mJ per pulse. At about 15 mJ per pulse the effect is approximately linearly related with pulse energy.
The hyperopic correction is linearly related to the distance of the coagulations from the center of the cornea. However the hyperopic correction decreases linearly with increasing ring diameter in the range between 5 and 9 millimeters.
In the experiments, the coagulation stopped at about 15 micrometers from the Descemet's membrane, thus guaranteeing a safety zone between the coagulation and endothelium.
Intraoccular pressure dropped after surgery by 5 to 8 milligram Hg but returned to preoperative values after one week. Also, patients reported foreign body sensation during the first week. At postoperative day three, the epithelium was healed. No recurrent erosions were observed. The two patients treated with 35 mJ per pulse developed discrete flair in the anterior chamber which apparently resolved after about one week. The coagulation spots appeared to be homogeneously white during the first days. After one week there was an already detectable and later on more extensive transparent zone formed inside the coagulation cone. This opacification clears slowly.
Thus, it has been found that, in practice of the present invention, coagulation cones can be produced which end a sufficient distance (perhaps about 15 micrometers) from the endothelium. This is mainly due to focusing of the laser beam in conjunction with the strong absorption of infrared light by the corneal tissue, resulting in a penetration depth of about 300-400 micrometers. As stated above, the focused laser beam produces a cone-shaped coagulation. This leads to a more pronounced shrinkage of the collagen fibers in the anterior stroma compared to those of the posterior stroma resulting in a greater refractive effect and eventually increased stability, compared to exposure without such focused beams.
The need for caution in the use of the present invention is self-evident. If laser energy is too high, or improperly focused, damage to the endothelial layer is possible. This may be indicated by circumferential Descemet folds appearing immediately after treatment. To prevent the folds, and endothelial damage, the laser energy is diminished to a lower level and/or a shorter focal length lens system is employed, to assure that heat to the Descemet's membrane is maintained below approximately a safety threshold of 70° C.
The stability of the refractive outcome of the present invention is marked. After some fluctuation during the first week, with reduction of the induced astigmatism, the keratometer readings became stable for four months within the measurement errors. Essentially there was no reduction of the hyperopic effect of the treatment zone beyond about one month of recovery.
Generally, when a pulsed radiation source is employed, the laser energy delivered to the eye per pulse can range from about 5-50 mJ (preferably 15-35 mJ). As noted above, the radiation source can be either CW or pulsed. If the radiation source is pulsed, the pulse rate and duration should be chosen to deliver an effective amount of heat within the coagulation zone to induce collagen shrinkage. For example, the pulse rate can vary from about 0.1 to about 20 Hertz and the pulse duration can vary from about 700 nsec to 5 microsec. Typically, the total energy to the eye per spot will range from about 250 mJ to 1.2 J.
It will be understood that the above description pertains to only several embodiments of the present invention. That is, the description is provided by way of illustration and not by way of limitation. The invention, therefore, is to be defined according to the following claims. | Methods and apparatus for correction of optical defects in vision, employing an infrared radiation source and a focusing element, for changing the curvature of the eye by application of focused infrared radiation into the collagenous tissue of the cornea in a controlled manner. | 0 |
FIELD OF THE INVENTION
[0001] This application claims priority to U.S. Provisional application Ser. No. 61/688,836 filed on May 21, 2012, which is incorporated herein in its entirety by this reference thereto.
[0002] The present device relates to musical instruments and percussion instruments. More particularly, the disclosed device and method, relates to a planar surfaced electrical musical instrument configured to support both feet of a user concurrently, which is employable to generate sound, such as drums, using one or a plurality of sensors or electronic signal generating components that generate an electronic signal when one or both feet of the user, impact the planar surface. Operatively employing the device herein, a user may generate music with either or both feet, concurrently or independently, while standing or sitting.
BACKGROUND OF THE INVENTION
[0003] Entertainers presenting live music performance frequently do so in groups of musicians. In the group setting, each has an instrument which is played to generate a portion of the music. More often than not, such a group will have a drummer to provide the rhythm and beat which audiences expect in a live performance, especially if there is dancing.
[0004] Further, many musicians play their instruments while tapping or moving their feet to the rhythm simultaneously. Such body movements with the feet and legs are in fact common among musicians and non-musicians alike who tap their feet and move their legs in accompaniment and in concurrence with the music in which they are playing, or in which they are hearing. The present invention provides a means for allowing this accompaniment and time-keeping motion of people, for the purpose of music creation.
[0005] While the performance of live music, with it's expected beat and percussion is easily accomplished by a plurality of musicians where one is a drummer, for the solo musician without an accompanying drummer a quandary arises. While guitars, vocals, and other melodic instruments have a pleasant sound, and can be combined for performances, many individuals and smaller musical groups without drums are often precluded from performing in certain musical venues which require the pulse and beat of loud, present, rhythmic percussion for their audiences. The present invention solves this quandary by allowing a performer to accompany themselves on percussion, while playing a secondary instrument with the hands.
[0006] While some solo artists and small groups can employ a drum machine, or recorded drum tracks with amplified music which the group accompanies, there are a number of problems with this scenario. First, many audiences are simply turned off by the lack of a live drummer. This may be because a live audience generally will request certain songs be played and not necessarily in any real order. Consequently for the group or band using recorded drums, it is hard to anticipate and accommodate such out of order musical performances and to incorporate the recorded tracks from electronic memory correctly if at all.
[0007] Attempts at remedying the shortfalls of conventional art have been presented, for example electronic drum machines of the kind disclosed in U.S. Pat. No. 4,479,412. Such devices conventionally playback stored samples or digital recordings of percussive sounds. However, employment of such devices is often impractical for use in live musical performance by a single performer, because they require the user to employ their hands for normal operation. Additionally, because such devices employ prerecorded drum recordings they do not allow the musician the flexibility to instantly adjust tempo, nor do they allow the performer to spontaneously alter rhythm signatures or musical song selection in mid-performance, should the desire arise. Further, a performer playing their instrument with their hands, cannot use their hands to attempt to simultaneously alter tempo or rhythm instructions or to alter recordings on a drum machine.
[0008] As such, there is an unmet need for a musical device which allows a musician playing a hand manipulated instrument, to include a percussion instrument sound with their live music. Such an instrument or device, when employed, should not only produce percussion sounds to the live music being played, it should also allow for an instant tempo adjustment, or a spontaneous alteration of rhythm signatures and/or musical song selection in mid-performance, should the desire or need arise. Finally, such an instrument should provide the cure to these noted shortfalls of conventional art in a manner which does not require the artist to remove or reposition their hands from the instrument they are already playing.
[0009] The forgoing examples of related art and limitation related therewith are intended to be illustrative and not exclusive, and they do not imply any limitations on the invention described and claimed herein. Various limitations of the related art will become apparent to those skilled in the art upon a reading and understanding of the specification below and the accompanying drawings.
OBJECTS OF THE INVENTION
[0010] It is an object of the present invention to allow a person to make use of one of their most natural rhythmic time-keeping motions, the tapping of their feet, to create an accompaniment for their music easily.
[0011] It is an additional object of this invention to allow tapping of one foot to produce sounds from different instruments than tapping of the other of their two feet.
[0012] It is another object of the present invention to provide a musical instrument which is planar in shape, replicating the floor, configured structurally to accommodate the full weight of a user to stand upon its surface with both feet substantially level, in a natural position for standing or sitting, and to amplify and modify sound emitted from the device when the planar surface is impacted.
SUMMARY OF THE INVENTION
[0013] In accordance with the purposes of the present invention, as embodied and broadly described herein, the present invention provides a means for a musician playing music on a hand-operated instrument, to generate concurrent drum and percussion sounds, through the tapping of their feet on a planar surface adapted to support their weight, to create an accompaniment for their music.
[0014] The disclosed device, employing a percussive actuation and transmission surface, which is dimensioned sufficiently broad and sturdy to support the user's entire weight communicated by both feet on a planar surface of the device. The planar surface is sized to allow the user to safely and comfortably stand on it with both feet fully in contact with the planar surface in an as-used, static position. A sufficient planar surface in an annular ring or perimeter area surrounding a central area occupied by the user's feet is also provided so the user is afforded a reasonable range of movement forward and aft, and to the right and to the left of the initial respective foot position of each foot in the central area. This provision of a central area and perimeter insures the user is able to maintain full contact with the planar surface across their foot bottom while in the central area, and that they are able to tap on the planar surface, either in the central area or the perimeter area, depending on their personal style and body movements, and maintain their balance.
[0015] In a primary mode of the device, the acoustic properties of the planar actuation surface are such that acoustic vibrations generated by one or both feet of the user, impacting the planar surface, are efficiently transmitted throughout the device to one or more electronic signal generating components operatively positioned to be in a communication with the planar surface. In this simplest mode of the device, with the planar surface sized to accommodate the user with the central and perimeter areas, where only one instrument is being activated by foot tapping or similar contact with the planar surface, there is no need for precise foot positioning or impacting to actuate the device with either or both feet. In modes of the device where one foot may activate a sound, and the other a separate distinct sound, for example two types of drums, acoustical isolation can be achieved by positioning a dampening material in-between underlying electronic signal generating components for the right and left sides respectively. In modes where more than two different instruments or instrument types are being activated, somewhat more precise tapping may be required, and an increase in the perimeter area of the planar surface may also be provided to allow more and quicker movements and insure contact with the planar surface during such.
[0016] In a preferred form of the device, the electronic signal generating components, such as one or a plurality of transducers, are operatively attached to the device in positions underlying the planar surface, or are embedded in the substantially planar surface used for foot contact and activation by the user. The transducer so positioned captures and converts the acoustic and vibrational energy of the user's foot contacting the planar actuation surface into an electronic signal suitable for further transmission and manipulation. The output of these transducers may be ganged together, or may be processed independently.
[0017] The device may contain one or more electronic control features which allow the user to perform various operations such as turning the device off and on, selecting various sounds and modes of operation, etc. Further, a video display component, or touch screen, may be contained within or upon the device as a visual means for a user to ascertain the modes of operation, and/or status of the device, and aids in selecting the modes of operation.
[0018] In a preferred mode of the device, electronic components adapted for providing a signal conditioning and processing stage is provided which allows a user to perform desirable and useful manipulations of the transducer or other signal generator outputs. One such function may be noise reduction or signal threshold limiting so that acoustic vibrations created by inadvertent user motions when their feet contact the planar surface, or other spurious sources, are suppressed. Another such function may be to adjust the transducer output amplitude or frequency spectrum for optimal input to an analog sound system. Another such function may be to convert the transducer output from analog to digital for input to a musical instrument digital interface (MIDI) and/or a digital waveform generator. A further such function may be the changing of sounds and controlling of volume of the output, based on the velocity of contact with the planar surface and resulting output voltages of the signal generating devices.
[0019] An optional digital waveform storage and transmission device which uses the output of the signal conditioning and processing stage to trigger the transmission of digitally synthesized and/or sampled sound waveforms may also be included. This output signal is adapted to provide an input to an operatively engaged sound creation device, such as a musical amplifier and/or speaker system which converts the received input signal into audible sound.
[0020] In a preferred mode of the device, a top planar surface and other components of the chassis are formed of a material which conducts vibration and sound well and communicates it to the operatively engaged signal generating components, such as wood or plastic. Because the planar top surface of the device herein is at least large enough to allow a user to stand in a natural stance with both feet supported by the continuous planar surface from heel to toe, and surrounded by a perimeter area, great utility is provided. The user's ability to use the toe portions, heel portions, and entire foot portions, of both feet concurrently while standing on the planar surface, to generate the output signal used for percussion, without having to look at the planar surface or worry about balance, thereby allows the user to use both hands and to concentrate on playing their hand-operated instrument. Additionally, perimeter area of the planar surface surrounding central area occupied by the feet of the user, allow for lateral movement such as for heel or toe tapping and as such, is preferred.
[0021] In another manner for output signal attenuation through the adjustment of the signal generated by the sensing components, the interior of the device between the planar top surface may be chambered to accommodate the operative positioning of the signal generating components such as the noted transducers. Alternatively the interior area of the chassis may be divided, or vibrationally sectioned, into different interior compartments. Such will then allow for foot or other contact with the planar top surface in communication with each respective compartmentalized signal generating device, to be perceived and translated differently. This separation and activation of differing instruments can be provided and also enhanced by the choice of location of the signal generating components, the physical separation thereof, inclusion of dampening material in between signal generating components, and enabled by software and relays and filters and the like, adapted to the task.
[0022] Should the device require onboard electrical power for functioning in any mode herein, such may be communicated in a conventional fashion with cables from AC power or adapter, or using onboard electrical storage such as batteries.
[0023] With respect to the above description, before explaining at least one preferred embodiment of the herein disclosed invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangement of the components in the following description or illustrated in the drawings. The device herein described and disclosed in the various modes and combinations is also capable of other embodiments and of being practiced and carried out in various ways which will be obvious to those skilled in the art. Any such alternative configuration as would occur to those skilled in the art is considered within the scope of this patent. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
[0024] As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for designing of other planar two-footed triggering and music generation structures, methods and systems for carrying out the several purposes of the present disclosed device. It is important, therefore, that the claims be regarded as including such equivalent construction and methodology insofar as they do not depart from the spirit and scope of the present invention.
[0025] It is an object of the present invention to allow a person to make use of one of their most natural rhythmic time-keeping motions, the tapping of their feet, to create accompaniment music easily, while employing their hands to play a separate instrument.
[0026] It is another object of the present invention to provide a musical instrument which is planar in shape, replicating the floor, configured to allow a user to stand upon it's surface with both feet level, in a natural position for standing or sitting, and to amplify and modify sound emitted from the device when the planar surface is impacted.
[0027] These and other objects, features, and advantages of the present invention, as well as the advantages thereof over existing prior art, which will become apparent from the description to follow, are accomplished by the improvements described in this specification and hereinafter described in the following detailed description which fully discloses the invention, but should not be considered as placing limitations thereon.
BRIEF DESCRIPTION OF DRAWING FIGURES
[0028] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate some, but not the only nor exclusive examples of embodiments and/or features of the disclosed device. It is intended that the embodiments and figures disclosed herein are to be considered illustrative of the invention herein, rather than limiting in any fashion.
[0000] In the drawings:
[0029] FIG. 1 depicts a musical performer standing in an operative position with both feet positioned in a central area of a planar surface of the device.
[0030] FIG. 2 shows a prior art common acoustic bass drum pedal.
[0031] FIG. 3 shows an exemplar of an exploded view of one preferred mode of constructing the device.
[0032] FIG. 4 depicts a mode of the device where signal generating components on the right are separated by a dampener from signal generating components on the left.
[0033] FIG. 5 depicts the device having transducers functioning as the electronic signal generating components which are positioned in quadrants which may be physically segmented from other quadrants with scoring or spacing of sections.
[0034] FIG. 6 is a schematic block diagram illustrating analog signal conditioning and processing stages of the device.
[0035] FIG. 7 shows a digital mode of processing the generated electronic signals from the transducers or other signal generators, and employing MIDI processing where velocity of impact can generate differing sounds.
[0036] FIG. 8 depicts the device built directly into a performance stage floor.
[0037] FIG. 9 depicts a schematic block diagram illustrating analog to digital signal conversion and the transmission of digitally sampled sound from the device.
DETAILED DESCRIPTION OF THE INVENTION
[0038] Now referring to drawings in FIGS. 1-9 , wherein similar components are identified by like reference numerals, there is seen in FIG. 1 , the device configured with a top planar surface 11 , having a central area 17 sized to accommodate both feet of a standing user 15 in a static position in the as-used mode of the device 10 , ready for contact of the feet with the planar surface 11 . Shoes in the United States for adults range from approximately 8 inches to 15 inches in length depending on the respective shoe size of the individual. Consequently a central area 17 of substantially 15 to 16 inches will accommodate most user's shoed feet.
[0039] A perimeter area 19 surrounding this central area 17 of planar surface 11 is also preferably provided such that the user 15 standing in the central area 17 is balanced on both feet, and comfortable, and the user 15 may tap or contact the planar surface 11 in the central area 17 during use, or if lateral movement is favored by the user 15 , they may contact the planar surface 11 in the perimeter area 19 . Many users 15 may tap the planar surface 11 directly under their respective foot, however many may tend to tap in a lateral direction from the original position, or change for some types of music, and thus both the central area 17 and perimeter area 19 are preferred.
[0040] A current total size configured to the disclosed purpose, which experimentation has shown to work well, is between a width of 19 to 30 inches along an imaginary line running through both feet of the user 15 , with a length dimension running perpendicular to the imaginary line, of between 10 to 20 inches. However, because users 15 come in all sizes, and have their own comfort zone for feet movement to impact the planar surface 11 with sufficient area of a planar surface 11 to maintain their balance, the device 10 may be provided in a plurality of sizes, for user choice depending on their own style of foot contact with the planar surface 11 during use. Currently a central area 17 of at least the length of the user's feet from heel to toe, as noted above as substantially 8-15 inches, would be a minimum size, and ideally at least a 4-6 inch wide perimeter area 19 can be provided.
[0041] This sizing allows most users 15 to stand with feet apart in a normal upright stance, balanced in the central area 17 , while using a hand-operated instrument, and to move their feet to operate the device 10 by impacting the planar surface 11 with either or both feet and use the front, rear, or the entire foot surface of both feet individually, to contact the planar surface 11 and thereby communicate a vibration and sound therefrom to the underlying signal generating components.
[0042] As seen in FIG. 2 , the prior art in the area of employing a pedal to operate a drum while playing music with the hands is shown. Such pedals have been employed by “one man bands” concurrently with the playing of a stringed instrument to provide for a drum sound. As can be seen, the pedal has an inclined surface which only accommodates one foot, and depressing the pedal with a foot already in an inclined position, tends to throw the user off balance. In addition the user is limited to a single sound.
[0043] In a preferred mode of the device 10 shown in FIG. 3 , signal generating components 21 which may be any electronic component which will generate an output electronic signal when vibration and/or sound is communicated thereto. Such signal generating components 21 include but are not limited to, microphones, magnetic pickups such as for guitars, and piezoelectric force sensors, although others as would occur to those skilled in the art are considered within the scope of this patent.
[0044] In FIGS. 3-5 , the electronic signal generating components 23 are depicted as piezoelectric force sensors 23 . In FIG. 3 , the piezoelectric force sensors 21 are placed as a pair in a simple mode of the device 10 , although a single piezoelectric force sensor 23 would also work in this mode. The output signal from both piezoelectric force sensors 23 are routed to a common output signal to the electronic device such as an amplifier and loudspeaker, to produce sound relative to the user's contact with the planar surface 11 .
[0045] In FIG. 4 is shown a mode of the device 10 , which allows the user to use each foot, by a respective contact with the planar surface 11 , to generate a different sound as the plurality of piezoelectric force sensors 23 is routed to a left and right output feed. A simple separation on the piezoelectric force sensors 23 in their positionings on the underlying section 18 will produce separate outputs. However, enhanced separation can be provided by a formed gap 20 between sections of the underlying section 18 . Additionally enhanced separation of the signals from the respective right and left piezoelectric force sensors 23 can be achieved by the positioning of a vibration damping material 25 in the gap 20 which impedes communication of vibration and acoustics between the two halves of the underlying section 18 . Such material may be any material suited to blocking vibration from contact with one side of the planar surface 11 from being communicated to electronic signal generation devices on the opposite side. Such can include one or a plurality of materials from a group including such damping material as rubber, polymeric material, plastic material, ceramic material, fiberglass, metalized fiberglass, sorbethane, closed and open cell foam, or mixtures of these materials in combination, or other damping materials of differing durometer and damping effects to alter or reduce or increase the conductive properties for vibration and sound, in a space between sections of the top planar surface 11 and the signal generating components 21 which are all in a vibrational communication with the planar surface 11 .
[0046] This two output mode of the device is a significant enhancement to the device 10 in that two different instruments, for example a bass drum, and a tom, can be controlled by the user 15 by using the right and left foot respectively. Contact by the right and left foot with portions of the top planar surface 11 in vibrational communication with the piezoelectric force sensors 23 in an underlying section 18 , will thus produce separate independent signals, each of which may be routed electronically to play a separate sound.
[0047] In the mode where separation is enhanced, such as with a gap 20 and/or damping material 25 , the acceleration of the user's foot contact with the top planar surface 11 can be employed to impart differing tonal and volume characteristics to the sound generated.
[0048] As shown in FIG. 5 , the device 10 may employ multiple signal generators shown as piezoelectric force sensors 23 which are positioned in quadrants or sections 30 of the underlying component 18 . As shown, the device 10 has signal generating components 21 such as piezoelectric force sensors 23 , positioned in sections 30 formed by sectionalizing the surface of the underlying section 18 , and the top section 14 forming the top planar surface. This sectioning serves to partially or fully isolate the signal generating components 21 such as piezoelectric force sensors 23 , from each other and from the differing sections of the top section 14 if also separated.
[0049] In any quadrant mode of the device, a tap from one foot on the top planar surface 11 overtop a quadrant would be sufficiently vibrationally isolated from other quadrants, such that the electronic signal would be generated by the signal generating component corresponding to the tapped quadrant. Using software, or hardware adapted to the task of only communicating the strongest of a plurality of electronic signals from the signal generating components 21 , at a given time, the device 10 could employ each quadrant for switching separately.
[0050] The sections 30 are not limited to four, and could be any number adapted to the task. Further, the signal generating components 21 may be mixed or matched in the sectionalized mode by mounting any of the group including microphones, piezoelectric force sensors, and magnetic pickups in individual sections 30 , wired to generate distinct sounds. As noted above, FIG. 6 is a schematic block diagram illustrating operatively constructed circuits to and through other electronic components of the device. Components may include one or a combination of filters, signal gains, preamplifiers, noise reduction processes, signal limiters, analog or digital effects such as reverb or delay, or other signal processes and/or effects. The flow of the processing of the signal may be handled in any order and the depicted flow is for illustrative purposes and is not intended to limit the scope of the present invention.
[0051] FIG. 7 shows a digital mode of processing the generated electronic signals from the electronic signal generators, and employing MIDI processing for the device.
[0052] FIG. 8 depicts the device built directly into the surface of a live performance stage. The present invention could be devised and formulated into other objects as well, such as into a guitar case.
[0053] FIG. 9 depicts a schematic block diagram illustrating the signal generating component's electronic signal, generated by either or both feet of the user on the top planar surface 11 , directed to an analog to digital signal conversion stage and a digital waveform storage and transmission component of the device. As shown, the output of the signal processing stage is conditioned to trigger the transmission of digitally synthesized and/or sampled sound waveforms. The output of the digital waveform storage and transmission component is a signal appropriate for input to a sound creation component such as a musical amplifier and/or speaker system. Optionally, the outputted signal may be configured to be communicated by wired or wireless means from device 10 .
[0054] As noted, any of the different configurations and components can be employed with any other configuration or component shown and described herein. Additionally, while the present invention has been described herein with reference to particular embodiments thereof and steps in the method of production, a latitude of modifications, various changes and substitutions are intended in the foregoing disclosures, it will be appreciated that in some instance some features, or configurations, or steps in formation of the invention could be employed without a corresponding use of other features without departing from the scope of the invention as set forth in the following claims. All such changes, alternations and modifications as would occur to those skilled in the art are considered to be within the scope of this invention as broadly defined in the appended claims.
[0055] Further, the purpose of any abstract of this specification is to enable the U.S. Patent and Trademark Office, the public generally, and especially the scientists, engineers, and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. Any such abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting, as to the scope of the invention in any way. | A planar surfaced electrical musical instrument is provided which is configured to support both feet of a user standing upon it during use. Supported by the device, the standing user may generate sound, such as drums, through a contact of one or both feet with the planar upper surface which is in operative contact with electronic signal generating components which generate an electronic signal correlating to vibrations emanating from the contact point of the user's foot with the planar surface. | 6 |
RELATED APPLICATION
This application claims the benefit of U.S. Provisional Application No. 60/481,103 filed Jul. 17, 2003, the entire disclosure of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
Commercially available pipe typically is manufactured to a nominal outer diameter which varies plus and minus depending on the tolerance range. Collets are used to hold or clamp pipes during, for example, welding of the pipes. Welding can be accomplished with, for example, an orbital weld head of the type shown generally in U.S. Pat. No. 4,379,215, the entire disclosure of which is hereby incorporated by reference. A collet for a given pipe size needs to provide enough compliance to securely hold pipes that have a size anywhere within the given tolerance range for that pipe size. The collet typically must fit certain space constraints. Some prior art pipe collet designs use integrally machined components to provide spring-like compliance, but these designs can be inconsistent and relatively expensive, and can require mating collet components that also are relatively expensive.
The use of rigid collets for holding the pipe during the welding operation is much preferred as compared to split and/or adjustable collets or similar holding devices. The reason for this is that during the welding operation, thermal stresses tend to cause the pipe to move creating misalignment between the two sections. The movement is greater and/or more likely to happen with the split collets and the adjustable collets or holders. With respect to the solid or rigid collets, however, there are problems in assuring that pipe throughout the range of standard commercial tolerances can be held properly. That is, a typical commercially available pipe used for fluid systems and the like, has, for example, a nominal outside diameter of 3.000 inches which varies ±0.030 inches. It has been difficult to compensate for the diameter variations which result from the tolerance variations and, at times, it has been difficult to properly hold the pipe during the welding operation. Also it has at times been difficult to hold out of round pipes or tubes in the proper position relative to the weld head.
Some prior art pipe collets, designed to accommodate a significant amount of size variation, use a series of slots that are cut into the base collet material to form resilient fingers. The slots can be cut either radially outward from the theoretical center of the object to be held, or they can be cut tangentially with respect to that theoretical center. The geometry of these slots enable the collet fingers to flex, or bend, in response to the geometry of the pipe that is being clamped within the collet. Where a large amount of compliance is not required, the collets can be left solid, that is, without machined slots. Some manufacturers cut the inside diameters of these collets on the true center of the collet, and some manufacturers offset the ID cut.
SUMMARY OF THE INVENTION
The present invention relates to work holders and, more particularly, to a collet for holding cylindrical workpieces in alignment with an axis of the collet. The invention is especially suited for use in a pipe clamp for association with an orbital welder and will be described with particular reference thereto. The invention is, however, capable of broader application and could be incorporated in a wide variety of work holders and clamping units for different types of work pieces and tools. For example, the invention may be used with a facing or other finishing tool. The invention may also be used with tubes in addition to pipes, although commercially available tube collets are often sufficient to accommodate the tolerance variation in tube sections.
In one embodiment, the invention relates to a collet for holding a workpiece having an axis. The collet includes a collet base defining a collet axis. A plurality of contact points that are not integral with the collet base are supported on the collet base for movement relative to the collet base in directions generally toward and away from the collet axis. The collet is self-aligning whereby the contact points help to align the workpiece coaxially with the collet base.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other features of the invention will become apparent from the following description when read in conjunction with the accompanying drawings wherein:
FIG. 1 is a pictorial view of a pipe clamping fixture including two collets that are a first embodiment of the invention;
FIG. 2 is an elevational view of a portion of the fixture of FIG. 1 showing the two collets in a closed condition;
FIGS. 3-5 are views similar to FIG. 2 showing the two collets in a condition clamping pipes of different sizes;
FIG. 6 is an exploded sectional view of parts of one plunger;
FIG. 7 is a sectional view of a portion of one collet with a plunger shown in a first position;
FIG. 8 is a view similar to FIG. 7 showing the plunger shown in a second position;
FIG. 9 is an exploded perspective view of one collet;
FIG. 10 is a schematic view of a collet that is another embodiment of the invention;
FIGS. 11-13 are a series of views of a collet that is another embodiment of the invention; and
FIGS. 14-15 illustrate another clamping fixture in accordance with the invention.
DETAILED DESCRIPTION
FIG. 1 shows a pipe clamp fixture 10 which is intended to be used with an orbital welding head. The fixture 10 is designed to hold two pipe sections in aligned relationship with their facing ends abutting so that an electrode of an orbital welding head (for example as shown schematically at 11 ) can rotate about the mating pipe ends to perform a butt weld operation.
The pipe clamp fixture 10 includes a pair of clamping units 12 and 14 which are joined to opposite sides of an intermediate spacer 16 . The various components are formed from stainless steel, aluminum, or the like and the clamp units 12 and 14 are removably joined to the spacer 16 in any convenient manner such as through the use of machine screws. The clamp units 12 and 14 are joined to the spacer 16 to form a somewhat U-shaped structure with an open welding space 20 adapted to receive the orbital welding head 11 . The fixture 10 may if desired be secured to the welding head 11 by screws, for example.
In the illustrated embodiment, the clamping units 12 and 14 are of identical construction except that they are mirror images of one another. Therefore, only the clamp unit 14 is described herein.
As best shown in FIGS. 2 and 3 , the clamp unit 14 comprises a pair of opposed clamp halves 22 and 24 . The clamp halves 22 and 24 are connected with each other by a hinge or hinge mechanism which permits the clamp halves to be moved toward and away from one another between a closed position as shown in FIGS. 1 and 2 and an open position (not shown). The two clamp halves 22 and 24 are releasably connected in their engaged or clamping position by a releasable latch or lock fixture such as the one shown at 28 .
Each one of the clamp halves 22 and 24 carries a collet 30 . The collets 30 cooperate to define a circular work piece clamping opening 32 ( FIG. 2 ) that is centered on an axis 34 . The collets 30 of the two clamp halves 22 and 24 are identical to each other. The clamp halves 22 and 24 together form a collet holder that holds the two collets 30 .
Each collet 30 includes a collet base 40 . The collet base 40 as illustrated is a rigid metal member that is secured to the clamp half 22 by a pair of mounting screws (not shown). The collet base 40 has a circumferential extent of about 180 degrees about the axis 34 . The collet base 40 has a cylindrical inner surface or base surface 44 centered on the axis 34 .
The collet base 40 has one or more plunger openings 46 . The plunger openings are spaces or cavities or chambers or recesses that receive and guide contact points 60 and springs 80 , as described below. The contact points 60 are the portions of the collet 30 that actually contact the workpiece. The contact points 60 are formed separately from and are not integral with the collet base 40 .
In the illustrated embodiment, the collet base 40 has two plunger openings in the form of recesses 46 . The plunger openings 46 are formed in the base surface 44 of the collet base 40 and extend radially outward.
Each plunger opening 46 is defined by a cylindrical side surface 48 and a circular bottom end surface 50 both centered on a radially extending plunger axis 52 . A threaded bore 54 extends from the plunger opening 46 . Associated with each plunger opening 46 is a locking screw opening 56 that extends transverse to the bore 54 and that intersects the bore near its bottom end. In the illustrated embodiment, two plunger openings 46 are provided, spaced ninety degrees apart about the axis 34 . A different number of plunger openings 46 could be provided, and different spacing could be provided between the openings. The plunger openings could alternatively be formed or configured in another manner—for example, they might not need to be recessed from the base surface 44 .
Disposed within each one of the plunger openings 46 is a plunger assembly 58 ( FIG. 6 ). The plunger assembly 58 includes a contact point or plunger 60 ; a mounting screw 70 ; and spring 80 .
The plunger 60 is a movable member or contact point that) (together with the other plungers 60 ) forms that portion of the collet 30 which the workpiece contacts. The plunger 60 is movable relative to the collet base and to the axis 34 , as described below. The plunger 60 is formed separately from and is not integral with the collet base 40 .
The plunger 60 in the illustrated embodiment is an open-ended, hollow cylindrical member adapted to fit closely within the plunger opening 46 . The plunger 60 is preferably made from 416 stainless steel, and has a hardness of 36 to 42 on the Rockwell C scale. Parts that are of this hardness have acceptable wear characteristics without being so hard that they would be brittle. The invention is not limited, however, to any particular material for the plungers.
The plunger 60 has a cylindrical side wall 62 that defines a central opening 64 centered on the axis. The side wall 64 has an annular top end surface 66 and an annular bottom end surface 68 . The plunger 60 has a bottom flange 69 that extends radially inward from the side wall 62 to narrow the central opening 64 at the bottom (radially outer) end of the plunger.
The mounting screw 70 is an element or assembly that retains the plunger 60 in the plunger opening 46 , that is, that keeps the plunger from moving radially inward past a certain position. In the illustrated embodiment, the retaining screw 70 is a socket head screw with a head 72 and a threaded shank 74 . The head 72 of the retaining screw 70 is smaller in diameter than the central opening 64 of the plunger 60 , but larger in diameter than the bottom flange 69 of the plunger.
The spring 80 is an element or assembly that biases the plunger 60 radially inward in a direction along the plunger axis 52 . In the illustrated embodiment, the spring 60 is a stack 82 of Belleville washers 84 . Other types of springs 80 could be used, for example, a compression spring. Thus, the term “spring” when used herein could refer to a single member that provides a biasing force or to a plurality of members or elements that act together to provide a biasing force. For example, a coil spring 80 could provide adequate compliance and loading, but not necessarily within the same small space as the Belleville washers 84 . Polymer (as opposed to metal) springs 80 might also be used, but might not be able to withstand the temperatures commonly encountered when welding.
Each one of the Belleville washers 84 is dished or cupped. In the illustrated embodiment, the washers 84 are stacked in a particular manner so as to increase both load (resistance) and travel (total available deflection). A single Belleville spring 84 has a specific load and deflection. Belleville springs in stacked arrangements provide increased load and/or deflection. Specifically, two springs stacked in parallel (in the same direction or orientation) provide double the load or resistance of the single spring, with no increase in total deflection available. Two springs stacked in series (in the opposite direction or orientation) provide the same load or resistance as the single spring, with double the total deflection available. A parallel-series combination results in the load or resistance of two springs and the total available deflection of two springs.
In the illustrated embodiment, the washers 84 are stacked in a pattern that repeats three times. The pattern includes two washers 84 cupped down (in parallel with each other) and the next two washers cupped up (in parallel with each other but in series with the first pair). This arrangement provides a total of twelve washers 84 .
The number and pattern of washers 84 illustrated herein is only exemplary. Different numbers of washers 84 could be provided, and they could be stacked in a different order or pattern. Different types of individual spring elements could be used, also, in the spring 80 .
When the collet 30 is assembled, the stack 82 of washers 84 is disposed loosely in the plunger opening 46 in the collet base 40 . The side wall surface 48 of the collet base 40 locates the washers 84 and keeps them centered in the plunger opening 46 . The plunger 60 is located over the stack 82 of washers 84 , resting on the uppermost washer. The shank 74 of the retaining screw 70 extends through the plunger 60 and through the stack 82 of washers 84 and is screwed into the threaded lower portion 54 of the plunger opening 46 . The retaining screw 70 is preferably screwed in only until the head 72 of the retaining screw engages the bottom flange 69 of the plunger 60 , taking the play or looseness out of the stack 82 of washers 84 . Attempted further threading in of the retaining screw 70 would begin to compress the washers 84 , which would resist such motion strongly and rapidly. The retaining screw 70 is left in this position where the spring 80 is not compressed by any significant amount.
A locking screw 88 , which could be a socket set screw, is screwed into the locking screw opening 56 in the collet base 40 and engages the shank 74 of the retaining screw 70 . The engagement of the locking screw 88 with the retaining screw shank 74 helps to hold the retaining screw 70 in the desired position relative to the collet base 40 .
In the desired position, a portion but not all of the plunger 60 projects from the base surface 44 of the collet base 40 . Up to one third to one half the length of the plunger 60 might project from the base surface 44 . Preferably, no more than about twenty per cent of the plunger 60 projects from the base surface 44 . The side wall surface 48 of the plunger opening 46 helps to guide the plunger 60 and keep it aligned, to minimize skewing. The head 72 of the retaining screw 70 is recessed below the base surface 44 , as are all of the washers 84 . The plungers 60 are the only portions of the collet 30 that contact the workpiece; the collet base 40 , itself, does not.
When the fixture 10 is fully assembled, it includes four of the collet assemblies 30 , two on each one of the clamping units 12 and 14 . Each one of the clamping units 12 and 14 includes one collet 30 on its upper clamp half and one collet 30 on its lower clamp half.
FIG. 3 illustrates schematically the clamping unit 12 in use clamping a pipe 90 . The four plungers that are included in the two collets 30 are in engagement with the pipe 90 . Specifically, the top end surface 66 of each plunger 60 is in engagement with the outer side surface 92 of the pipe 90 . Because the plungers 60 are located on opposite sides of the pipe 90 , their combined resistance is averaged out to approximately center the pipe between them. This works for round pipe 90 , as well as for out-of-round pipe, which often, from handling, has an oval outside profile. In this respect, the collet 30 (or a set of collets 30 ) can be considered to be self-aligning or self-centering.
FIG. 4 shows the fixture 10 in use in clamping a pipe 90 having a relatively larger diameter. FIG. 5 shows the fixture in use in clamping a pipe 90 having a relatively smaller diameter.
The clamping unit 14 is capable of rigidly and tightly engaging the outer diameter of a pipe of a particular size depending on the diameter of the collet base surface 44 . By changing collet bases 40 , the clamping unit 14 can be made to accommodate tubing or piping of different size ranges. Additionally, by providing different size collets in one clamping unit 14 relative to those in the other clamping unit 12 , it is possible to bring into alignment two workpieces of different sizes such that it is possible to weld various pipe and fitting combinations.
The upper collet 30 and the lower collet 30 of a clamping unit 12 or 14 are the same and are interchangeable. Some other collet designs are sold as matched sets—if one collet becomes damaged to the point where it can no longer be used, the other collet half must be scrapped, because the new collets must be ordered as a set.
Another advantage of the collet 30 is cost-effectiveness. A collet in accordance with the present invention can be relatively inexpensive to make, because the majority of machined surfaces are clearance surfaces. Also, wear components of the collet 30 , such as the plungers 60 and the washers 84 , can be replaced very easily, while retaining the collet base 40 itself. This can provide the collet 30 with a very long service life. For example, if the spring 80 begins at some point to lose its temper, it can be easily and inexpensively replaced—in comparison to a collet with integral spring fingers in which case the entire collet must be replaced.
FIG. 10 illustrates schematically a collet 30 a that is an alternative embodiment of the invention. The collet 30 a functions similarly to a camera aperture. The collet includes a plurality of contact points in the form of plates 92 that slide about a center point. The plates 92 are biased radially inward by springs shown schematically at 94 . The plates 92 open and close equally so as automatically to center a pipe that is captured between them. In this respect, the collet 30 a can be considered to be self-aligning or self-centering.
FIGS. 11-13 illustrate schematically a collet 30 b that is another alternative embodiment of the invention. The collet 30 b includes a base ring 100 on which are rotatably mounted four contact points in the form of eccentric cams 102 . Rotation of the cams 102 is controlled by a slider ring 104 that engages the cams. Relative rotation of the slider ring 104 about the base ring 100 causes the cams 102 to pivot.
FIG. 11 shows the eccentric cams 102 fully open. A pipe section 110 is disposed within the collet 30 b in a position not centered in the collet. FIG. 12 shows the cams 102 rotating as the slider ring 104 is rotated relative to the base ring 100 , in a counter-clockwise direction as viewed in FIG. 12 . The cams 102 move radially inward, two of the cams contact the pipe 110 , and the pipe begins to move towards the center of the collet 30 b . FIG. 13 shows all four cams 102 in contact with the pipe section 110 . The pipe section 110 is centered within the collet 30 b . In this respect, the collet 30 b can be considered to be self-aligning or self-centering.
FIGS. 14 and 15 illustrate still another embodiment of the invention. In this embodiment, a collet includes contact points in the form of plunger assemblies at two axially spaced locations (that is, spaced apart in a direction along the axis of the workpiece being clamped) to help improve clamping accuracy and squareness.
FIG. 14 shows a clamping fixture 120 with an attached or inserted weld head 122 . The clamping fixture 122 includes four collets (numbered 30 c in FIG. 14 ) like the collet 10 . Each one of the collets is modified by the addition of two additional plunger assemblies.
In the collet 30 c , the collet base 40 c has an outer side surface 124 to which are attached two cantilever arms 126 . The cantilever arms 126 are attached to the collet base 40 c by mounting screws 128 and pins 130 , or other mounting structure. The arms 126 may be attached to the collet base 40 c at locations that are spaced apart circumferentially from the locations of the plunger assemblies 58 . The arms 126 extend axially away from the collet base 40 c (that is, in a direction along the axis of the workpiece being clamped).
At the outer end of each arm 126 is a contact point in the form or a plunger assembly 58 c that is preferably similar to or identical to the plunger assemblies 58 . The plunger assembly 58 c is by virtue of its location on the cantilever arm 126 spaced apart axially from the collet base 40 c . As a result, the plunger assembly 58 c is spaced apart axially from the other plunger assemblies 58 that are in the collet base 40 c . The pipe section is thereby clamped at two locations along its length. This can help to increase the clamping accuracy (squareness) of the fixture 120 by an order of magnitude or more. This can be useful when welding on a vertical run of pipe, for example.
Collets formed in accordance with the subject invention can be used in a variety of structures and clamping assemblies. For example, the collet could be used in a fixture for holding a pipe to be end faced (squared). Also, the collet could be used in a welding fixture for welding a fitting to a pipe, with the two clamp units being of different sizes. Accordingly, applicant intends to include all such modifications and alterations as part of the invention insofar as they come within the scope of the appended claims. | A collet for holding a workpiece having an axis includes a collet base defining a collet axis. A plurality of contact points that are not integral with the collet base are supported on the collet base for movement relative to the collet base in directions generally toward and away from the collet axis. The collet is self-aligning whereby the contact points help to align the workpiece coaxially with the collet base. | 1 |
TECHNICAL FIELD
The present invention relates to a base station, a mobile station, a cooperating mobile station, a transmission method and a reception method that perform client collaboration.
BACKGROUND ART
The IEEE (Institute of Electrical and Electronics Engineers) 802.16 Working Group is developing the 802.16m air interface specification to meet the requirements of IMT (International Mobile Telecommunications)—Advanced next generation mobile systems. Based on the IEEE 802.16m draft standard (e.g., see Non-Patent Literature 1), the WiMAX (Worldwide Interoperability for Microwave Access) Forum is working out the WiMAX Release 2.0 MSP (Mobile System Profile) and PICS (Protocol Implementation Conformance Statement). The IEEE 802.16m standard and the WiMAX Release 2.0 MSP and PICS are expected to be finalized in early 2011.
The IEEE 802.16 Working Group has also started envisioning the future 802.16/WiMAX networks beyond 802.16m/WiMAX 2.0. There is a common understanding among 802.16/WiMAX community that future 802.16/WiMAX networks should support explosive mobile data traffic growth driven by large screen devices, multimedia applications as well as more connected users and devices. Future 802.16/WiMAX networks should also interwork efficiently with other radio technologies, e.g., 802.11/Wi-Fi (Wireless Fidelity).
Future 802.16/WiMAX networks should be enhanced significantly compared with 802.16m network in terms of various performance metrics such as throughput and SE (Spectral Efficiency). For example, in urban-coverage scenario, future 802.16/WiMAX networks target at the cell-edge SE of two times of 802.16m/WiMAX 2.0 network in both UL (Uplink) and DL (Downlink) (e.g., see Non-Patent Literature 2). Note that 802.16m/WiMAX 2.0 network has at least a DL cell-edge SE of 0.06 bps/Hz/sec with 4×2 antenna configuration and an UL cell-edge SE of 0.03 bps/Hz/sec with 2×4 antenna configuration.
CO-Operative techniques, e.g., CliCo (Client Collaboration), have promised significant improvements in the cell-edge SE and total network energy efficiency of a wireless communication system. CliCo is a technique where clients interact to jointly transmit/receive data in wireless environments (e.g., see Non-Patent Literature 3). In CliCo, client clustering and peer-to-peer communication are exploited to transmit/receive information over multiple paths between BS and client. As a result, the cell-edge SE can be improved without increase in infrastructure cost. Furthermore, the battery of clients with poor channels can be extended.
A diagram illustrating an exemplary wireless communication system 100 with CliCo is shown in FIG. 1 . Wireless communication system 100 is configured of BS (Base Station) 102 and a plurality of MSs (Mobile Stations) such as MS 104 and MS 106 .
A block, diagram illustrating exemplary BS 102 is shown in FIG. 2 . BS 102 is equipped with WiMAX communication function only, which is configured of WiMAX PHY block 130 and WiMAX MAC block 120 . WiMAX MAC block 120 implements WiMAX OFDMA (Orthogonal Frequency Division Multiple Access)-based media access control protocols. WiMAX PHY block 130 implements the WiMAX OFDMA-based physical layer protocols under the control of WiMAX MAC block 120 .
With reference to FIG. 2 , WiMAX MAC block 120 further is configured of control section 122 , scheduler 124 , message generation section 126 , and message processing section 128 . Control section 122 controls general MAC protocol operations. Scheduler 124 schedules the allocation of resources to the MSs under the control of control section 122 . Message generation section 126 receives resource allocation scheduling information from scheduler 124 and then generates data packets and DL control information. Message processing section 128 analyzes data packets and UL control information received from the plurality of MSs under the control of control section 122 and reports its analysis result to control section 122 .
Note that data packets and DL control information generated by message generation section 126 are transmitted by BS 102 to the plurality of MSs via an OFDMA transmitter (not shown in FIG. 2 ) inside WiMAX PHY block 130 . Data packets and UL control information analyzed by message processing section 128 are received by BS 102 via an OFDMA receiver (not shown in FIG. 2 ) inside WiMAX PITY block 130 .
With reference to FIG. 2 , there are HFBCH (HARQ Feedback Channel) generation section 132 and resource allocation generation section 134 inside message generation section 126 , where HARQ stands for Hybrid Automatic Repeat Request.
HFBCH generation section 132 generates HARQ feedback channels for UL data transmission, which carry HARQ feedback information (e.g., ACK/NACK) for UL data transmission. Resource allocation generation section 134 generates resource allocation control information for DL/UL data transmission, which carries resource allocation information for each of the plurality of MSs.
In terms of GRA (Group Resource Allocation), resource allocation control information generated by resource allocation generation section 134 may contain group configuration information as well as group resource allocation information including indexing information of HFBCH for DL/UL GRA transmission. The HFBCHs generated by HFBCH generation section 132 may contain HARQ feedback information for UL GRA transmission.
With reference to FIG. 2 , there exists HFBCH analyzing section 136 inside message processing section 128 . HFBCH analyzing section 136 analyzes the received HFBCHs for DL data transmission and determines whether the corresponding DL data transmission is successful or not. In terms of GRA, HFBCH analyzing section 136 may derive HARQ feedback information for DL GRA transmission from the received UL control information.
A block diagram illustrating exemplary MS 104 is shown in FIG. 3 . MS 104 is equipped with both WiMAX and Wi-Fi communication functions, which is configured of WiMAX PHY block 142 , Wi-Fi PHY block 144 , WiMAX MAC block 146 , Wi-Fi MAC block 148 , and GLL (Generic Link Layer) block 150 . WiMAX MAC block 146 implements WIMAX OFDMA-based MAC (media access control) protocols. WiMAX PHY block 142 implements the WiMAX OFDMA-based physical layer protocols, under the control of WiMAX MAC block 146 . Wi-Fi MAC block 148 implements Wi-Fi CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance)-based MAC (media access control) protocols. Wi-Fi PHY block 144 implements the Wi-Fi OFDM (Orthogonal Frequency Division Multiplexing)/DSSS (Direct Sequence Spread Spectrum)-based physical layer protocols, under the control of Wi-Fi MAC block 148 . GLL block 150 functions as managing interworking between heterogeneous WiMAX and Wi-Fi links.
With reference to FIG. 3 , WiMAX MAC block 146 further is configured of control section 154 , message generation section 152 , and message processing section 156 . Control section 154 controls general MAC protocol operations. Message generation section 152 generates UL control information and data packets under the control of control section 154 . Message processing section 156 analyzes data packets and DL control information received from BS 102 under the control of control section 154 , and provides its analysis result to control section 154 .
Note that data packets and UL control information to generated by message generation section 152 are transmitted from MS 104 to BS 102 via an OFDMA transmitter (not shown in FIG. 3 ) inside WiMAX PHY block 142 . Data packets and DL control information analyzed by message processing section 156 are received by MS 104 via an OFDMA receiver (not shown in FIG. 3 ) inside WiMAX PHY block 142 .
With reference to FIG. 3 , there are resource analyzing section 151 and HFBCH analyzing section 153 inside message processing section 156 . HFBCH analyzing section 153 analyzes the received HFBCHs for UL data transmission and determines whether the corresponding UL data transmission is successful or not. Resource analyzing section 151 analyzes the received resource allocation control information and derives the resource allocation information specific to MS 104 . In ease of UL data transmission, data packet generated by message generation section 152 under the control of control section 154 will then be transmitted by MS 104 to BS 102 according to the derived resource allocation information. In case of DL data transmission, data packet transmitted by BS 102 to MS 104 will then be received by MS 104 according to the derived resource allocation information.
In terms of GRA, resource analyzing section 151 inside message processing section 156 may derive group configuration information as well as group resource allocation information including indexing information of HFBCH for DL/UL GRA transmission from received resource allocation control information. HFBCH analyzing section 153 may derive HARQ feedback information for UL GRA transmission from the received. HFBCHs.
With reference to FIG. 3 , there exists HFBCH generation section 155 inside message generation section 152 , HFBCH generation section 155 generates HARQ feedback channels, which include HARQ feedback information, for DL data transmission. In terms of GRA, HFBCH generation section 155 may generate HARQ feedback channels for DL GRA transmission.
A block diagram illustrating exemplary MS 106 is shown in FIG. 4 . MS 106 is also equipped with both WiMAX and Wi-Fi communication functions, which has a very similar structure and functionality as MS 104 . A main difference between MS 104 and MS 106 is that unlike MS 106 , there is scheduler 158 inside Wi-Fi MAC block 148 of MS 104 as shown in FIG. 3 , which is used for cooperation scheduling for CliCo.
With reference to FIG. 1 , BS 102 communicates with MS 104 via WiMAX links 108 a and 108 b , and communicates with MS 106 via WiMAX links 110 a and 110 b . MS 104 communicates with MS 106 via peer-to-peer Wi-Fi links 112 a and 112 b . Alternatively, MS 104 may communicate with MS 106 via other radio technologies if available, such as WiMAX, Bluetooth, or 60 GHz mmW (Millimeter Wave).
Note that CliCo can be implemented in both DL and UL of wireless communication system 100 . As an example, the operation of UL CliCo in wireless communication system 100 is described below.
With reference to FIG. 1 , when the signal quality of WiMAX link 108 a between BS 102 and MS 104 becomes poor, MS 104 may start the UL CliCo procedure such as neighbor discovery and cooperator selection/allocation. If the signal quality of WiMAX link 110 a between BS 102 and MS 106 is good. MS 104 may select MS 106 as its cooperator. In the context of CliCo, MS 104 is called originating MS, and MS 106 is called cooperating MS.
CliCo may happen in various scenarios. For example, originating MS 104 may be deep inside a cafeteria and thus the signal quality of WiMAX links for originating MS 104 may be very poor. However, cooperating MS 106 may be much closer to window or entrance of the cafeteria than originating MS 104 , and thus cooperating MS 106 may have a much better signal quality of WiMAX links than originating MS 104 .
A diagram illustrating an exemplary frame structure 200 is shown in FIG. 5 , which can be applied to wireless communication system 100 with CliCo as shown in FIG. 1 . With reference to FIG. 5 , each of frame 202 and frame 212 is configured of eight subframes. Five of them are DL subframes, and the others are UL subframes.
So far as UL CliCo is concerned, during first DL subframe 204 of frame 202 , BS 102 may transmit MAP 220 indicating control information to a plurality of MSs connected to BS 102 , including originating MS 104 and cooperating MS 106 engaged in CliCo, MAP 220 is configured of a plurality of MAP IEs (Information Elements). Some of MAP IEs may carry HARQ feedback information for UL data transmission; and some of MAP IEs may carry resource allocation information for DL/UL data transmission. One MAP IE in MAP 220 carrying HARQ feedback information forms one HBFCH for UL data transmission.
During time period 208 between first DL subframe 204 and first UL subframe 206 of frame 202 , originating MS 104 and cooperating MS 106 , respectively, need to decode MAP 220 to obtain their resource allocation information including HFBCH indexing information. Also originating MS 104 needs to transmit UL data burst 250 to cooperating MS 106 via peer-to-peer Wi-Fi link 112 a.
During first UL subframe 206 of frame 202 , if originating MS 104 successfully decodes MAP 220 sent by BS 102 via WiMAX link 108 b , it will transmit UL data burst 250 to BS 102 via WiMAX link 108 a according to its received resource allocation information. On the other hand, if cooperating MS 106 successfully decodes MAP 220 sent by BS 102 via WiMAX link 110 b and successfully receives UL data burst 250 sent by originating MS 104 via peer-to-peer Wi-Fi link 112 a , cooperating MS 106 will simultaneously transmit the same UL data burst 250 to BS 102 via WiMAX link 110 a according to its received resource allocation information. Consequently BS 102 can combine two copies of UL data burst 250 received from WiMAX link 108 a and WiMAX link 110 a to improve the quality of received signal.
During second DL subframe 214 of frame 212 , BS 102 to may transmit MAP 240 to the plurality of MSs connected to BS 102 , including originating MS 104 and cooperating MS 106 engaged in CliCo. As mentioned above, some of HFBCHs in MAP 240 may carry HARQ feedback information for UL data burst 250 transmitted by originating MS 104 and cooperating MS 106 during first UL subframe 206 of frame 202 .
During time period 218 between second DL subframe 214 and first UL subframe 216 of frame 212 , originating MS 104 and cooperating MS 106 , respectively, need to decode the corresponding HFBCHs in MAP 240 to obtain their HARQ feedback information for UL data burst 250 according to their HFBCH indexing information which are obtained by decoding MAP 220 during time period 208 .
During first UL subframe 216 of frame 212 , if the HARQ feedback information implies that BS 102 does not successfully decode UL data burst 250 transmitted by originating MS 104 and cooperating MS 106 during first UL subframe 206 of frame 202 , originating MS 104 and cooperating MS 106 may need to retransmit UL data burst 250 .
As mentioned above, future 802.16/WiMAX networks should support explosive mobile data traffic. Furthermore, future 802.16/WiMAX networks should provide enhanced quality of experience for mobile internet applications, such as VoIP (Voice over Internet Protocol). Considering VoIP has a periodic traffic pattern and with relatively fixed payload size, various PHY/MAC mechanisms have been designed especially to improve quality of experience for VoIP such as PA (Persistent Allocation) and GRA. In the present invention, the application of GRA to CliCo is addressed.
GRA mechanism specified in the IEEE 802.16m draft standard (e.g., sec Non-Patent Literature 1) does not deal with CliCo. However, GRA mechanism can be applied to CliCo in a straightforward manner.
According to the IEEE 802.16m draft standard (e.g., see Non-Patent Literature 1). GRA mechanism allocates resources to multiple users as a group in order to save control overhead. This resource allocation is performed per transport flow. With reference to FIG. 1 , the method of applying GRA to CliCo is configured of two operations: That is, i) BS 102 adds flows of originating MS 104 and cooperating MS 106 into a group or deletes flows of originating MS 104 and cooperating MS 106 from a group.
ii) BS 102 allocates resources to the flows of originating MS 104 and cooperating MS 106 within the same group.
According to the IEEE 802.16m draft standard (e.g., see non-Patent Literature 1), when adding a flow of originating MS 104 (or cooper g MS 106 ) into a group, BS 102 transmits group configuration information in a unicast MAC control message to originating MS 104 (or cooperating MS 106 ). When allocating resources to the flows of originating MS 104 and/or cooperating MS 106 within the group, BS 102 transmits group resource allocation information including HFBCH indexing information in a multicast MAP IE to originating MS 104 and cooperating MS 106 . Note that group configuration information transmitted in the unicast MAC control message and group resource allocation information transmitted in the multicast MAP IE are generated by message generation section 126 as shown in FIG. 2 .
According to the IEEE 802.16m draft standard (e.g., see Non-Patent Literature 1), the group configuration information transmitted in the unicast MAC control message can be used to interpret the group resource allocation information transmitted in the corresponding multicast MAP IE. The content of the group configuration information includes:
Flow identifier; User bitmap size; UBI (User Bitmap Index); Group identifier; Allocation periodicity; and MIMO (Multiple Input Multiple Output) mode set or the like
The flow identifier is used to inform an MS which of its flows is added into a group, which has a size of 4 bits. The user bitmap size indicates the number of bits used for user bitmap transmitted in the multicast MAP IE. The user bitmap size may be one of 4 bits, 8 bits, 16 bits, and 32 bits. The UBI indicates the index of the flow of MS in the user bitmap, which has a size of 5 bits. The group identifier uniquely identifies the DL/UL group to which the flow of MS is added, which has a size of 12 bits. The allocation periodicity specifics how often the multicast MAP IE carrying the corresponding group resource allocation information is transmitted, which may be one of 1 frame, 2 frames, 4 frames, and 8 frames. The MIMO mode set signals MIMO modes supported in the group.
A main difference between the group configuration information for originating MS 104 and cooperating MS 106 is that the UBIs of originating MS 104 and cooperating MS 106 are different. Furthermore, since the group configuration information is unicast to originating MS 104 and cooperating MS 106 , respectively, cooperating MS 106 does not know the UBI of originating MS 104 ; vice versa.
According to the IEEE 802.16m draft standard (e.g., see Non-Patent Literature 1), the group configuration information may further include a set of four HARQ burst sizes. For example, the set of four HARQ burst sizes may be {6 bytes, 8 bytes, 9 bytes, 10 bytes}. Note that the burst size is the size of encoded packet which a may be partitioned into a plurality of FEC (Forward Error Correction) blocks. The burst size may include the addition of CRC (Cyclic Redundancy Code) per burst and/or per FEC block when applicable.
Corresponding to each of four HARQ burst sizes, the group configuration information may also include a set of eight resource sizes. For example, for the HARQ burst size of 9 bytes, the set of eight resource sizes may be {1 LRU, 2 LRUs, 3 LRUs, 4 LRUs, 5 LRUs, 6 LRUs, 7 LRUs, 8 LRUs} where LRU stands for Logical Resource Unit. For each of other three HARQ burst sizes of 6 bytes, 8 bytes and 10 bytes, the set of eight resource sizes may be different or the same as the HARQ burst size of 9 bytes.
According to the IEEE 802.16m draft standard (e.g., see Non-Patent Literature 1), a portion of the group resource allocation information is carried by bitmaps transmitted in the multicast MAP IE. A diagram illustrating exemplary bitmaps carrying partial group resource allocation information according to the IEEE 802.16m draft standard (Non-Patent Literature 1) is shown in FIG. 6 . There are two bitmaps used to carry partial group resource allocation information. One is user bitmap 302 , and the other is resource allocation bitmap 304 .
According to the IEEE 802.16m draft standard (e.g., see Non-Patent Literature 1), user bitmap 302 uses 1 bit per flow to signal which flows are scheduled in the current frame. With reference to FIG. 6 , the UBI of originating MS 104 is “00000”, and therefore the first bit of user bitmap 302 is referenced. The UBI of cooperating MS 106 is “00011” and so the fourth hit of user bitmap 302 is referenced. So the flows (corresponding to data) of both originating MS 104 and cooperating MS 106 are specified by resource allocation map 304 and transmitted to the current frame.
With reference to FIG. 6 , resource allocation bitmap 304 is configured of a plurality of 5-bit resource allocation indications, each of which is for a specific scheduled flow. In each of 5-bit resource allocation indications, the first 2 hits is used to signal HARQ burst size and the last 3 bits is used to signal resource size.
With reference to FIG. 6 , the HARQ burst sizes are selected from among four burst sizes {6 bytes, 8 bytes, 9 bytes, 10 bytes} and indicated by “00,” “01,” “10” and “11.”
In FIG. 6 , both originating MS 104 and cooperating MS 106 are indicated by “10” and therefore both HARQ burst sizes are 9 bytes.
The resource sizes of originating MS 104 and cooperating MS 106 are indicated by “111” and “001”, respectively. So the resource sizes of originating MS 104 and cooperating MS 106 may be 8 LRUs and 2 LRUs, respectively.
According to the IEEE 802.16m draft standard (e.g., see Non-Patent Literature 1), in addition to user bitmap 302 and resource allocation bitmap 304 , another bitmap called MIMO bitmap may be used if multiple MIMO modes are supported in a group.
A table illustrating an exemplary GRA MAP IE for transmitting the group resource allocation information according to the IEEE 802.16m draft standard (e.g., see Non-Patent Literature 1) is shown in Table 1.
TABLE 1
Size
Syntax
(bit)
Description/Notes
GRA_MAP_IE( ){
MAP IE type
4
GRA MAP IE
User bitmap
Variable
Indicate scheduled MSs in a
group.
The size of the bitmap is equal
to the User Bitmap Size signaled
to each MS in the group
configuration information.
Resources Offset
7
Indicate starting LRU for
resource allocation to this
group.
HFA offset
6
Indicate the start of the HFBCH
index used for scheduled
allocations.
Resource
Variable
Indicate the HARQ burst
Allocation Bitmap
size/resource size for each of
scheduled MSs.
. . .
}
In addition, according to the IEEE 802.16m draft standard (e.g., see Non-Patent Literature 1), the HFBCH index for a scheduled flow in a group is a predetermined function of its UBI and the HFA offset as shown in Table 1. In other words, each of originating MS 104 and cooperating MS 106 can compute its HFBCH index according to its UBI after decoding the GRA MAP IE as shown in Table 1.
A flowchart illustrating method 400 of receiving resource allocation information at originating MS 104 (or cooperating MS 106 ) according to the IEEE 802.16m draft standard (e.g., see Non-Patent Literature 1) is shown in FIG. 7 . Method 400 starts at Step 402 . At Step 404 , originating MS 104 (or cooperating MS 106 ) cheeks the user bitmap according to its UBI. At Step 406 , originating MS 104 (or cooperating MS 106 ) determines whether its flow is scheduled in the current frame. If the flow of originating MS 104 (or cooperating MS 106 ) is scheduled in the current frame, at Step 408 , it proceeds to check the resource allocation bitmap to derive its HARQ burst size and resource size according to its UBI. After that at Step 410 , originating MS 104 (or cooperating MS 106 ) computes its HFBCH index according to its UBI. At Step 406 , if the flow of originating MS 104 (or cooperating MS 106 ) is not scheduled in the current frame, method 400 stops at Step 412 .
CITATION LIST
Non-Patent Literature
NPL 1
IEEE P802.16m/D5, DRAFT Amendment to IEEE Standard for local and metropolitan area networks—Part 16: Air Interface for Broadband Wireless Access Systems Advanced Air Interface
NPL 2
IEEE C802.16-10/0016r1, Future 802.16 Networks: Challenges and Possibilities
NFL 3
IEEE C802.16-10/0005r1, Client Cooperation in Future Wireless Broadband Networks
SUMMARY OF INVENTION
Technical Problem
According to the IEEE 802.16m draft standard (e.g., see Non-Patent Literature 1), both originating MS 104 and cooperating MS 106 engaged in CliCo handle the same data burst. One HFBCH for both originating MS 104 and cooperating MS 106 is enough. However, due to different UBIs in the same group, originating MS 104 and cooperating MS 106 have two different HFBCHs. This would waste valuable HFBCH resource.
It is an object of the present invention to provide a base station, a mobile station, a cooperating mobile station, a transmission method and a reception method capable of avoiding unnecessary HFBCH resource waste by using one HBCH for a plurality of MSs that deals with the same data burst.
Solution to Problem
In accordance with an aspect of the present invention, a base station (BS) that communicates with a plurality of mobile stations (MSs), employs a configuration including: a control signal generation section that generates control signals indicative of resource allocation information for each of the plurality of MSs, and a transmission section that transmits the control signals to the plurality of MSs, in which a control signal for a mobile station (MS) contains information on another MS.
In accordance with an aspect of the present invention, a BS communicates with a plurality of MSs including en originating MS and a cooperating MS, which is exploited to communicate between the BS and the originating MS, and includes: a control signal generation section that generates control signals indicative of resource allocation information for each of the plurality of MSs, and a transmission section that transmits the control signals to the plurality of MSs, in which a control signal for the cooperating MS contains information on the originating MS.
In accordance with an aspect of the present invention, when a flow of the cooperating MS is added into a same group as the originating MS, the control signal for the cooperating MS contains information on the originating MS.
In accordance with an aspect of the present invention, the information on the originating MS is contained into resource allocation information for the cooperating MS.
In accordance with an aspect of the present invention, the information on the originating MS is replaced with burst size information for the cooperating MS.
In accordance with an aspect of the present invention, the number of bits of the information on the originating MS varies depending on the number of MSs which belong to a same group as the originating MS.
In accordance with an aspect of the present invention, the number of bits of the information on the originating MS varies with increasing of the number of bits of the burst size information for the cooperating MS and with decreasing of the number of bits of the resource size information for the cooperating MS, depending on the number of MSs which belong to a same group as the originating MS.
In accordance with an aspect of the present invention, if the number of bits of the resource size information for the cooperating MS is decreased, an actual resource size of the cooperating MS results from a bitwise operation of a resource size of the originating MS and a nominal resource size of the cooperating MS.
In accordance with an aspect of the present invention, a resource size of the cooperating MS is same as that of the originating MS, and the information on the originating MS is replaced with burst size information and resource size information for the cooperating MS.
In accordance with an aspect of the present invention, an actual resource size of the cooperating MS results from a bitwise operation of a resource size of the originating MS and a nominal resource size of the cooperating MS.
In accordance with an aspect of the present invention, a resource size of the cooperating MS is set to a predetermined size, and the formation on the originating MS is replaced with burst size information and resource size information for the cooperating MS.
In accordance with an aspect of the present invention, the information on the originating MS is identification information of the originating MS.
In accordance with an aspect of the present invention, the information on the originating MS is an offset of identification information of the originating. MS relative to identification information of the cooperating MS.
In accordance with an aspect of the present invention, an MS includes: a reception section that receives a control signal for the MS containing information on another MS; and a resource calculating section that computes a transmission resource according to the control signal and the information on the other MS.
In accordance with an aspect of the present invention, a cooperating MS exploited to communicate between a BS and an originating MS includes: a reception section that receives a control signal for the cooperating MS containing information on the originating MS; a resource calculating section that computes a transmission resource according to the control signal and the information on the originating MS; and a transmission section that transmits a signal received from the originating MS, to the BS via the transmission resource.
In accordance with an aspect of the present invention, if the information the originating MS indicates identification information of the cooperating MS, the transmission section stops transmitting the signal to the BS.
In accordance with an aspect of the present invention, if the information on the originating MS indicates identification information of the cooperating MS, the transmission section stops transmitting the signal to the BS for a predetermined or configurable time period.
In accordance with an aspect of the present invention, a part of the information on the originating MS is contained into resource allocation information for the cooperating MS and other part of the information on the originating MS is contained into group configuration information sent to the cooperating MS.
In accordance with an aspect of the present invention, a transmission method performed in a BS which communicates with a plurality of MSs includes: generating control signals indicative of resource allocation information for each of the plurality of MSs, and transmitting the control signals to the plurality of MSs, in which a control signal for a MS contains information on another MS.
In accordance with an aspect of the present invention, a transmission method performed in a BS which communicates with a plurality of MSs including an originating MS and a cooperating MS, which is exploited to communicate between the BS and the originating MS includes: generating control signals indicative of resource allocation information for each of the plurality of MSs, and transmitting the control signals to the plurality of MSs, in which a control signal for the cooperating MS contains information on the originating MS.
In accordance with an aspect of the present invention, a reception method performed in an MS includes: receiving a control signal for the MS containing information on another MS; and computing a transmission resource according to the control signal and the information on the other MS.
In accordance with an aspect of the present invention, a reception method performed in a cooperating MS exploited to communicate between a BS and an originating MS includes: receiving a control signal for the cooperating MS containing information on the originating MS; computing a transmission resource according to the control signal and the information on the originating MS; and transmitting a signal received from the originating MS, to the BS via the transmission resource.
These and other features and advantages of the present invention will be better understood with reference to the following detailed description of the present invention, along with the accompanying figures, and appended claims.
Advantageous Effects of Invention
The invention uses one HFBCH for a plurality of MSs which handles the same data burst, so that unnecessary HFBCH resource waste can be avoided.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 shows a diagram illustrating an exemplary wireless communication system with CliCo (Client Collaboration);
FIG. 2 shows a block diagram illustrating an exemplary BS (Base Station);
FIG. 3 shows a block diagram illustrating an exemplary originating MS (Mobile Station);
FIG. 4 shows a block diagram, illustrating an exemplary cooperating MS (Mobile Station);
FIG. 5 shows a diagram illustrating an exemplary frame structure;
FIG. 6 shows a diagram illustrating exemplary bitmaps for carrying partial group resource allocation information according to the prior art;
FIG. 7 shows a flowchart illustrating a method of receiving group resource allocation information at the originating MS (or cooperating MS) according to the prior art;
FIG. 8 shows a flowchart illustrating a method of receiving group resource allocation information at a cooperating MS according to Embodiment 1 of the present invention;
FIG. 9 shows a diagram illustrating exemplary bitmaps for carrying partial group resource allocation information in case of 4-bit user bitmap according to Embodiment 2 of the present in vent on;
FIG. 10 shows a flowchart illustrating a method of receiving group resource allocation information in case of 4-bit user bitmap at the cooperating MS according to Embodiment 2 of the present invention;
FIG. 11 shows a diagram illustrating exemplary bitmaps for carrying partial group resource allocation information in case of 8-bit user bitmap according to Embodiment 2 of the present invention;
FIG. 12 shows a flowchart illustrating a method of receiving group resource allocation information in case of 8-bit user bitmap at the cooperating MS according to Embodiment 2 of the present invention;
FIG. 13 shows a diagram illustrating exemplary bitmaps for carrying partial group resource allocation information in case of 32-bit use bitmap according to Embodiment 2 of the present invention;
FIG. 14 shows a flowchart illustrating a method of receiving group resource allocation information in case of 32-bit user bitmap at the cooperating MS according to Embodiment 2 of the present invention;
FIG. 15 shows a diagram illustrating exemplary bitmaps for carrying partial group resource allocation information in case of 4-bit user bitmap according to Embodiment 3 of the present invention;
FIG. 16 shows a diagram illustrating exemplary bitmaps for carrying partial group resource allocation information in case of 8-bit user bitmap according to Embodiment 4 of the present invention; and
FIG. 17 shows a diagram illustrating exemplary bitmaps for carrying partial group resource allocation information in case of 8-bit user bitmap according to Embodiment 5 of the present invention.
DESCRIPTION OF EMBODIMENTS
Various embodiments of the present invention will now be described in detail with reference to the annexed drawings. In the following description, a detailed description of known functions and configurations incorporated herein has been omitted for clarity and conciseness.
Embodiment 1
According to Embodiment 1 of the present invention, with reference to FIG. 1 , a basic idea of the method of applying GRA to CliCo is that BS 102 shares the UBI of originating MS 104 with cooperating MS 106 using the group configuration information. In more details, when BS 102 adds a flow of cooperating MS 106 into a group, the group configuration information unicast by BS 102 to cooperating MS 106 also includes the UBI of originating MS 104 . The content of the group configuration information unicast by BS 102 , to cooperating MS 106 can be described below:
Flow identifier of cooperating MS 106 ; User bitmap size; UBI of originating MS 104 ; UBI of cooperating MS 106 ; Group identifier; Allocation periodicity; and MIMO mode set or the like.
According to Embodiment 1 of the present invention, since cooperating MS 106 knows the UBI of originating MS 104 , cooperating MS 106 is able to use the UBI of originating MS 104 instead of its own UBI to derive its HFBCH index. As a result, only an identical HFBCH is allocated for both originating MS 104 and cooperating MS 106 engaged in CliCo. So unnecessary HFBCH resource waste is avoided.
A flowchart illustrating method 500 for receiving resource scheduling information at cooperating MS 106 according to Embodiment 1 of the present invention is shown in FIG. 8 . Method 500 starts at Step 502 . At Step 504 , cooperating MS 106 checks the user bitmap according to its UBI. At Step 506 , cooperating MS 106 determines whether its flow is scheduled in the current frame or not. If the flow of cooperating MS 106 is scheduled in the current frame, at Step 508 , it proceeds to check the resource allocation bitmap to derive its HARQ burst size and resource size according to its UBI. At Step 510 , cooperating MS 106 computes its HFBCH index according to the UBI of originating MS 104 . At Step 506 , if the flow of cooperating MS 106 is not scheduled in the current frame, method 500 stops at Step 512 .
According to Embodiment 1 of the present invention, the content of group configuration information unicast by BS 102 to originating MS 104 , and the content of group resource allocation information multicast by BS 102 to originating MS 104 and cooperating MS 106 are the same as the IEEE 802.16m draft standard (e.g., see Non-Patent Literature 1). However, the content of group configuration information unicast by BS 102 to cooperating MS 106 is different from the IEEE 802.16m draft standard (e.g., see Non-Patent Literature 1).
According to Embodiment 1 of the present invention, an alternative is that the group configuration information is multicast by BS 102 to both originating MS 104 and cooperating MS 106 . The content of the group configuration information multicast by BS 102 to both originating MS 104 and cooperating MS 106 can be described below:
Flow identifier of originating MS 104 ; Flow identifier of cooperating MS 106 ; User bitmap size; UBI of originating MS 104 ; UBI of cooperating MS 106 ; Group identifier; Allocation periodicity; and MIMO mode set or the like.
According to Embodiment 1 of the present invention, the group configuration information can be transmitted in either a MAC control message or a MAP IE.
Embodiment 2
According to Embodiment 1 of the present invention, a demerit is that extra control overhead may be introduced in group configuration information before starting group resource allocation due to sharing the UBI of originating MS 104 with cooperating MS 106 .
With reference to FIG. 1 , as mentioned above, originating MS 104 and cooperating MS 106 engaged in CliCo handle the same data burst, and thus have the same HARQ burst size. So HARQ burst size indication for one of originating MS 104 and cooperating MS 106 is redundant. In addition, the length of UBI which is actually required depends on the user bitmap size. For example, if the user bitmap size is 8 bits, only 3-bit UBI is really required instead of 5-bit UBI.
According to Embodiment 2 of the present invention, a basic idea of the method of applying GRA to CliCo is that BS 102 shares the UBI of originating MS 104 with cooperating MS 106 using the group resource allocation information instead of the group configuration information in Embodiment 1 of the present invention. In more details, when BS 102 allocates resources to originating MS 104 and cooperating MS 106 , a variable portion of the 5-bit resource allocation indication for cooperating MS 106 in resource allocation bitmap is used to indicate the UBI of originating MS 104 . The length of the variable portion depends on the user bitmap size. The remaining portion in the 5-bit resource allocation indication for cooperating MS 106 is used to indicate its resource size. However, the ways for indicating the resource size of cooperating MS 106 are different, depending on the user bitmap size.
According to Embodiment 2 of the present invention, since the UBI of originating MS 104 is embedded in resource allocation bitmap, no extra control overhead is introduced in group configuration information.
A diagram illustrating exemplary bitmaps carrying partial group resource allocation information in case of 4-bit user bitmap according to Embodiment 2 of the present invention is shown in FIG. 9 . With reference to FIG. 9 , in resource allocation bitmap 604 , the first 2 bits (e.g., “00”) of 5-bit resource allocation indication for cooperating MS 106 are used to indicate the UBI of originating MS 104 instead of the HARQ burst size of cooperating MS 106 , and the last 3 bits (e.g. “010”) are used to signal the resource size for cooperating MS 106 . Note that the first 2 bits (“10”) of 5-bit resource allocation indication for originating MS 104 are used to signal the HARQ burst size of both originating MS 104 and cooperating MS 106 .
A flowchart illustrating method 700 for receiving group resource allocation information at cooperating MS 106 in ease of 4-bit user bitmap according to Embodiment 2 of the present invention is shown in FIG. 10 . Method 700 starts at Step 702 . At Step 704 , cooperating MS 106 checks the user bitmap according to its UBI. At Step 706 , cooperating MS 106 determines whether its flow is scheduled in the current frame. If the flow of cooperating MS 106 is scheduled in the current frame, at Step 708 , it proceeds to check the resource allocation bitmap to derive the UBI of originating MS 104 and its resource size according to its UBI. At Step 710 , cooperating MS 106 proceeds to check the resource allocation bitmap again to derive its HARQ burst size according to the UBI of originating MS 104 . At Step 712 , cooperating MS 106 then computes its HFBCH index according to the UBI of originating MS 104 . At Step 706 , if the flow of cooperating MS 106 is not scheduled in the current frame, method 700 stops at Step 714 .
A diagram illustrating exemplary bitmaps for carrying partial group resource allocation information in case of 8-bit user bitmap according to Embodiment 2 of the present invention is shown in FIG. 11 . With reference to FIG. 11 , in resource allocation bitmap 804 , the first 3 hits of 5-hit resource allocation indication for cooperating MS 106 are used to indicate the UM of originating MS 104 , and the last 2 bits are used to indicate the nominal resource size of cooperating MS 106 instead of the actual resource size of cooperating MS 106 .
There are various ways of calculating the actual resource size indication of cooperating MS 106 from its nominal resource indication. In one way, the actual resource size indication of cooperating MS 106 may result from a bitwise XOR operation of the resource size indication of originating MS 104 and the nominal resource size indication of cooperating MS 106 . With reference to FIG. 11 , the resource size indication of originating MS 104 is “111”, and the nominal resource size indication of cooperating MS 106 is “01”. So the actual resource size indication of cooperating MS 106 is “111 XOR 01=110”. In another way, the actual resource size indication of cooperating MS 106 may result from a bitwise OR or AND operation of the resource size indication of originating MS 104 and the nominal resource size indication of cooperating MS 106 .
A flowchart illustrating method 900 for receiving group resource allocation information at cooperating MS 106 in case of 8-bit user bitmap according to Embodiment 2 of the present invention is shown in FIG. 12 . Method 900 starts at Step 902 . At Step 904 , cooperating MS 106 checks the user bitmap according to its UBI. At Step 906 , cooperating MS 106 determines whether its flow is scheduled in the current frame. If the flow of cooperating MS 106 is scheduled in the current frame, at Step 908 , it proceeds to check the resource allocation bitmap to derive the UBI of originating MS 104 . At Step 910 , cooperating MS 106 proceeds to check the resource allocation bitmap again to derive its HARQ burst size and resource size according to its URI and the UBI of originating MS 104 . At Step 912 , cooperating MS 106 then computes its HFBCH index according to the UBI of originating MS 104 . At Step 906 , if the flow of cooperating MS 106 is not scheduled in the current frame, method 900 stops at Step 914 .
According to Embodiment 2 of the present invention, similar to the ease of 8-bit user bitmap, in case of 16-bit user bitmap, in the resource allocation bitmap, the first 4 bits of 5-hit resource allocation indication for cooperating MS 106 are used to indicate the UBI of originating MS 104 , and the last 1 bit is used to indicate the nominal resource size of cooperating MS 106 instead of the actual resource size of cooperating MS 106 .
A diagram illustrating exemplary bitmaps for carrying partial group resource allocation information in case of 32-bit user bitmap according to Embodiment 2 of the present invention is shown in FIG. 13 . With reference to FIG. 13 , in resource allocation bitmap 1004 , the whole 5-bit resource allocation indication for cooperating MS 106 is used to indicate the UBI of originating MS 104 . The resource size of cooperating MS 106 is signaled by the 3-bit resource size indication for originating MS 104 . In other words, in ease of 32-bit user bitmap, originating MS 104 and cooperating MS 106 have always the same resource size.
A table illustrating an exemplary GRA MAP IE for transmitting the group resource allocation information according to Embodiment 2 of the present invention is shown in Table 2.
TABLE 2
Syntax
Size (bit)
Description/Notes
GRA_MAP_IE( ){
MAP IE Type
4
GRA MAP IE
User Bitmap
Variable
Indicate scheduled MSs in a
group. The size of the bitmap is
equal to the User Bitmap Size
signaled to each MS in the
group configuration
information
Resources Offset
7
Indicate starting LRU for
resource allocation to this
group
HFA Offset
6
Indicate the start of the HFBCH
index used for scheduled
allocations
Resource
Variable
Indicate the UBI of the
Allocation Bitmap
corresponding originating
MS/resource size for scheduled
cooperating MS and indicate
the HARQ burst size/resource
size for each of other scheduled
MSs. Note that the ways of
indicating the resource size for
scheduled cooperating MS
depends on the User Bitmap
Size
. . .
}
A flowchart illustrating method 1100 for receiving group resource allocation information at cooperating MS 106 in case of 32-bit user bitmap according to Embodiment 2 of the present invention, is shown in FIG. 14 . Method 1100 starts at Step 1102 . At Step 1104 , cooperating MS 106 checks the user bitmap according to its UBI. At Step 1106 , cooperating MS 106 determines whether its flow is scheduled in the current frame. If the flow of cooperating MS 106 is scheduled in the current frame, at Step 1108 , it proceeds to check the resource allocation bitmap to derive the UBI of originating MS 104 . At Step 1110 , cooperating MS 106 proceeds to cheek the resource allocation bitmap again to derive its HARQ burst size and resource size according to the UBI of originating MS 104 . At Step 1112 , cooperating MS 106 then computes its HFBCH index according to the UBI of originating MS 104 . At Step 1106 , if the flow of cooperating MS 106 is not scheduled in the current frame, method 1100 stops at Step 1114 .
From the perspective of cooperating MS 106 , the difference among methods 700 , 900 and 1100 is the way of deriving its resource size. In method 700 , the resource size of cooperating MS 106 is derived according to its own UBI. In method 900 , the resource size of cooperating MS 106 is derived according to its own UBI and the UBI of originating MS 104 . In method 1100 , the resource size of cooperating MS 106 is derived according to the UBI of originating MS 104 only.
According to Embodiment 2 of the present invention, an alternative in case of 8-bit user bitmap is that in the resource allocation bitmap, the first 3 hits of 5-bit resource allocation indication for cooperating MS 106 are used to indicate the UBI of originating MS 104 and the last 2 bits are used to directly signal the actual resource size of cooperating MS 106 instead of the nominal resource size of cooperating MS 106 . Similarly, an alternative in case of 16-bit user bitmaps is that in the resource allocation bitmap, the first 4 bits of 5-bit resource allocation indication for cooperating MS 106 are used to indicate the UBI of originating MS 104 , and the last 1 bit is used to indicate the actual resource size of cooperating MS 106 .
According to Embodiment 2 of the present invention, an alternative in case of 4-hit user bitmap is that in the resource allocation bitmap, the first 2 bits of 5-bit resource allocation indication for cooperating MS 106 are used to indicate the UBI of originating MS 104 , and the last 3 bits are used to indicate the nominal resource size of cooperating MS 106 instead of the actual resource size of cooperating MS 106 . The actual resource size indication of cooperating MS 106 can be derived from the resource size indication of originating MS 104 and the nominal resource size indication of cooperating MS 106 in the above-mentioned manners.
According to Embodiment 2 of the present invention, an alternative in case of 32-bit user bitmap is that the whole 5-bit resource allocation indication of cooperating MS 106 in the resource allocation bitmap is used to signal the UBI of originating MS 104 , but the resource size of cooperating MS 106 is always set to a predetermined value.
According to Embodiment 2 of the present invention, the content of group configuration information unicast by BS 102 to originating MS 104 or cooperating MS 106 is the same as the IEEE 802.16m draft standard (e.g., see Non-Patent Literature 1). However, the content of group resource allocation information multicast by BS 102 to originating MS 104 or cooperating MS 106 is different from the IEEE 802.16m draft standard (e.g., see Non-Patent Literature 1).
According to Embodiment 2 of the present invention, the group resource allocation information can be transmitted in either multicast MAC control information or a multi east MAP IE.
Embodiment 3
According to Embodiments 1 and 2 of the present invention, the UBI indication of originating MS 104 in resource allocation bitmap is assumed to be different from the UBI of cooperating MS 106 . In the following, the case that the UBI indication of originating MS 104 in resource allocation bitmap is the same as the UBI of cooperating MS 106 is addressed.
A diagram illustrating exemplary bitmaps for carrying partial group resource allocation information in ease of 4-bit user bitmap according to Embodiment 3 of the present invention is shown in FIG. 15 . With reference to FIG. 15 , in resource allocation bitmap 1204 , the first 2 bits of 5-bit resource allocation indication for cooperating MS 106 are used to indicate the UBI of originating MS 104 . If the UBI indication of originating MS 104 (e.g. “10”) is the same as the UBI of cooperating MS 106 , various implications may be incurred. For example, this may imply that corresponding MS 106 will not transmit/receive the UL/DL data burst in the following N consecutive allocation periods, where N is predetermined. Alternatively, the value of N is indicated by the last 3 bits of 5-bit resource allocation indication for cooperating. MS 106 . Alternatively, this may imply that cooperating MS 106 will no longer transmit/receive the data burst.
According to Embodiment 3 of the present invention, in case of 8-bit, 16-bit or 32-bit user bitmap, if the UBI indication of originating MS 104 in resource allocation bitmap is the same as the UBI of cooperating MS 106 , implications similar to those in the ease of 4-bit user bitmap may be incurred.
Embodiment 4
According to Embodiments 1, 2 and 3 of the present invention, the length of the UBI indication of originating MS 104 is dependent on the user bitmap size. As a result, in ease of 4-bit user bitmap, 3 bits can be used to signal the resource size of cooperating MS 106 . Thus a full set of 8 resource sizes can be used for allocating resources to cooperating MS 106 . However, in case of 8-bit, 16-bit, or 32-bit user bitmap, only a subset of 8 resource sizes can be used for allocating resources to cooperating MS 106 . This would decrease the scheduling flexibility of BS 102 .
A diagram illustrating exemplary bitmaps for carrying partial group resource allocation information in ease of 8-bit user bitmap according to Embodiment 4 of the present invention is shown in FIG. 16 . With reference to FIG. 16 , in resource allocation bitmap 1304 , only the first 2 bits of 5-bit resource allocation indication for cooperating MS 106 are used to indicate the offset of the UBI of originating MS 104 relative to the UBI of cooperating MS 106 , and the last 3 bits are used to indicate the resource size of cooperating MS 106 .
A table illustrating an exemplary GRA MAP IE for transmitting the group resource allocation information according to Embodiment 4 of the present invention is shown in Table 3.
TABLE 3
Size
Syntax
(bit)
Description/Notes
GRA_MAP_IE( ){
MAP IE Type
4
GRA MAP IE
User Bitmap
Variable
Indicate scheduled MSs in a
group. The size of the bitmap is
equal to the User Bitmap Size
signaled to each MS in the group
configuration information
Resource Offset
7
Indicate starting LRU for
resource allocation to this
group
HFA offset
6
Indicate the start of the HFBCH
index used for scheduled
allocations
Resource
Variable
Indicate the UBI offset of
Allocation Bitmap
corresponding originating MS
relative to scheduled
cooperating MS/resource size
for scheduled cooperating MS
and indicate the HARQ burst
size/resource size for each of
other scheduled MSs.
. . .
}
According to Embodiment 4 of the present invention, since only 2 bits are used for the UBI indication of originating MS 104 in ease of 8-bit, 16-bit, or 32-bit user bitmap, various constraints need to be imposed when BS 102 adds flows of originating MS 104 and cooperating MS 106 into a group. For example, BS 102 may suffer the following constraints when adding flows of originating MS 104 and cooperating MS 106 into a group:
the UBI of originating MS 104 is smaller than the UBI of cooperating MS 106 ; and The difference between the UBIs of originating MS 104 and cooperating MS 106 is not larger than 4.
According to Embodiment 4 of the present invention, since 3 bits are used to indicate the resource size of cooperating MS 106 , a full set of 8 resource sizes can be used for allocating resources to cooperating MS 106 , even in ease of 16-bit, or 32-bit user bitmap.
Embodiment 5
According to Embodiment 4 of the present invention, some constraints need to be imposed when BS 102 adds the flows of originating MS 104 and cooperating MS 106 into a group. This may decrease group configuration flexibility of BS 102 .
A diagram illustrating exemplary bitmaps for carrying partial group resource allocation information in case of 8-bit user bitmap according to Embodiment 5 of the present invention is shown in FIG. 17 . With reference to FIG. 17 , in resource allocation bitmap 1404 , the first 2 hits of 5-bit resource allocation indication for cooperating MS 106 are used to indicate a first portion of the UBI of originating MS 104 and the last 3 bits are used to indicate the resource size of cooperating MS 106 .
A table illustrating an exemplary GRA MAP IE for transmitting the group resource allocation information according to Embodiment 5 of the present invention is shown in Table 4.
TABLE 4
Size
Syntax
(bit)
Description/Notes
GRA_MAP_IE( ){
MAP IE Type
4
GRA MAP IE
User Bitmap
Variable
Indicate scheduled MSs in a
group. The size of the bitmap
is equal to the User Bitmap
Size signaled to each MS in the
group configuration
information
Resource Offset
7
Indicate starting LRU for
resource allocation to this
group
HFA Offset
6
Indicate the start of the
HFBCH index used for
scheduled allocations
Resource
Variable
Indicate a first portion of UBI
Allocation Bitmap
of the corresponding
originating MS/resource size
for scheduled cooperating MS
and indicate the HARQ burst
size/resource size for each of
other scheduled MSs.
. . .
}
According to Embodiment 5 of the present invention, the group configuration information unicast by BS 102 to cooperating MS 106 includes a second portion of the UBI of originating MS 104 . The content of the group configuration information unicast by BS 102 to cooperating MS 106 can be described below:
Flow identifier of cooperating MS 106 ; User bitmap size; A second portion of the UBT of originating MS 104 ; UBI of cooperating MS 106 ; Group ID; Allocation periodicity; and MIMO mode set or the like.
According to Embodiment 5 of the present invention, since 3 bits carried in group configuration information and group resource allocation information are used for the UBI indication of originating MS 104 in case of 8-bit user bitmap, no constraints need to be imposed when BS 102 adds the flows of originating MS 104 and cooperating MS 106 into a group.
According to Embodiment 5 of the present invention, the first portion of the UBI of originating MS 104 may be 2 LSBs (Least Significant Bits) of the UBI of originating MS 104 . The second portion of the UBI of originating MS 104 may be 1 MSB (Most Significant Bit), 2 MSBs and 3 MSBs of the UBI of originating MS 104 in case of 8-bit, 16-bit and 32-bit user bitmap, respectively.
According to Embodiment 5 of the present invention, alternatively the first portion of the UBI of originating MS 104 may be 2 MSBs of the UBI of originating MS 104 . The second portion of the UBI of originating MS 104 may be 1 LSB, 2 LSBs and 3 LSBs of the UBI of originating MS 104 in case of 8-bit, 16-bit and 32-bit user bitmap, respectively. According to the above-mentioned embodiments of the present invention, BS 102 shares the UBI of originating MS 104 with cooperating MS 106 such that cooperating MS 106 is able to use the UBI of originating MS 104 to calculate its HFBCH index. It will be naturally appreciated by a person skilled in the art that numerous variations and/or modifications may be made to the present invention, in which BS 102 shares the UBI of cooperating MS 106 with originating MS 104 .
According to the above-mentioned embodiments of the present invention, in addition to originating MS 104 , only one cooperating MS 106 is involved in CliCo. It will be naturally appreciated by a person skilled in the art that numerous variations and/or modifications may be made to the present invention, in which more than one cooperating MSs involve in CliCo, and BS 102 shares the UBI of one of the originating MS and the cooperating MSs engaged in CliCo with the others.
It will be naturally appreciated by a person skilled in the art that other numerous variations and/or modifications may be made to the present invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects to be illustrative and not restrictive.
Although cases have been described with the above embodiments as examples where the present invention is configured by hardware, the present invention can also be realized by software in interworking with hardware.
Each function block employed in the description of each of the aforementioned embodiments may typically be implemented as an LSI constituted by an integrated circuit. These may be individual chips or partially or totally contained on a single chip.
“LSI” is adopted here but this may also be referred to as “IC,” “system LSI,” “super LSI,” or “ultra LSI” depending on differing extents of integration.
Further, the method of circuit integration is not limited to LSI's, and implementation using dedicated circuitry or general purpose processors is also possible. After LSI manufacture, utilization of a programmable FPGA (Field Programmable Gate Array) or a reconfigurable processor where connections and settings of circuit cells within an LSI can be reconfigured is also possible.
Further, if integrated circuit technology comes out to replace LSI's as a result of the advancement of semiconductor technology or a derivative other technology, it is naturally also possible to carry out function block integration using this technology. Application of biotechnology is also possible.
The disclosure of Japanese Patent Application No. 2010-097026, filed on Apr. 20, 2010, including the specification, drawings and abstract is incorporated herein by reference in its entirety.
INDUSTRIAL APPLICABILITY
The present invention is applicable to a mobile communication system or the like. | A base station (BS) which communicates with a plurality of mobile stations (MSs) is configured so as to comprise a control signal generation unit which generates control signals showing information on the allocation of resources for each of the plurality of mobile stations (MSs), and a transmission unit which transmits the control signals to the plurality of mobile stations (MSs). A control signal for a given mobile station (MS) includes information relating to another mobile station (MS). | 7 |
This invention relates to fluorinated amide compounds used in the manufacture of fluorinated rubber and a process for preparing the same.
BACKGROUND OF THE INVENTION
Prior art known fluorinated amide compounds include those of the following formula (i).
Herein R 11 is a substituted or unsubstituted monovalent hydrocarbon group, R 12 is hydrogen or a substituted or unsubstituted monovalent hydrocarbon group, Q 1 is a group of the following general formula (ii) or (iii):
wherein R 13 is a substituted or unsubstituted divalent hydrocarbon group which may be separated by an oxygen, nitrogen and/or silicon atom, and R 12 is as defined above,
wherein R 14 and R 15 each are a substituted or unsubstituted divalent hydrocarbon group, Rf 1 is a divalent perfluoro-alkylene or divalent perfluoropolyether group, and “a” is an integer inclusive of 0.
It would be desirable to have siloxane or silalkylene bond-bearing fluorinated amide compounds which yield fluorinated rubber having excellent chemical resistance and solvent resistance.
SUMMARY OF THE INVENTION
It has been found that a novel fluorinated amide compound of the general formula (1) is obtained by effecting hydrosilylation reaction of a compound of the general formula (9) with a compound of the general formula (10), the formulae being defined later; that a fluorinated rubber having excellent chemical resistance and solvent resistance is obtained by subjecting the fluorinated amide compound to radical crosslinking with the aid of an organic peroxide, for example; that when the fluorinated amide compound has an unsaturated bond within its molecule, a fluorinated rubber having excellent chemical resistance and solvent resistance is obtained by reacting the fluorinated amide compound with a SiH group-containing compound in the presence of a platinum group catalyst; and that the fluorinated amide compound is otherwise applicable as a pressure-sensitive adhesive, binder, coating or agent having excellent chemical resistance and solvent resistance.
The present invention provides a fluorinated amide compound of the following general formula (1).
A—(Rf—Q) n —Rf—A (1)
Herein Rf is a divalent perfluoroalkylene group C m F 2m wherein m is an integer of 2 to 15, or a divalent perfluorooxy-alkylene group selected from groups of the following formulae (2), (3) and (4):
wherein X is each independently F or CF 3 , p and q each are an integer of 0 to 200, r is an integer of 2 to 6, s is an integer of 1 to 6, t and u each are 1 or 2,
wherein X is as defined above, v and w each are an integer of 1 to 100,
—CF 2 CF 2 —(OCF 2 CF 2 CF 2 ) y —OCF 2 CF 2 — (4)
wherein y is an integer of 1 to 200.
A is a monovalent organic group of the following formula (5) or (6):
wherein R 1 is a monovalent hydrocarbon group selected from among alkyl, cycloalkyl, aryl, aralkyl groups of 1 to 10 carbon atoms and substituted ones of the foregoing groups in which some or all of the hydrogen atoms are substituted with halogen atoms,
R 2 is hydrogen or a monovalent hydrocarbon group selected from among alkyl, cycloalkyl, aryl, aralkyl groups of 1 to 10 carbon atoms and substituted ones of the foregoing groups in which some or all of the hydrogen atoms are substituted with halogen atoms,
Z is a divalent organic group of the formula (7):
wherein R 3 is an oxygen atom or a divalent hydrocarbon group selected from among alkylene, cycloalkylene, arylene groups of 1 to 8 carbon atoms, substituted ones of the foregoing groups in which some of the hydrogen atoms are substituted with halogen atoms, and combinations of alkylene with arylene,
R 4 is a monovalent hydrocarbon group selected from among alkyl, cycloalkyl, aryl, aralkyl groups of 1 to 10 carbon atoms and substituted ones of the foregoing groups in which some or all of the hydrogen atoms are substituted with halogen atoms,
R 5 is a monovalent hydrocarbon group selected from among alkyl, cycloalkyl, aryl, aralkyl groups of 1 to 10 carbon atoms, aliphatic unsaturation-bearing monovalent hydrocarbon groups of 2 to 20 carbon atoms, and substituted ones of the foregoing groups in which some or all of the hydrogen atoms are substituted with halogen atoms.
Q is a divalent organic group of the following formula (8):
wherein R 1 , R 2 and Z are as defined above. The subscript n is an integer of at least 1.
The present invention also provides a process of preparing a fluorinated amide compound of the general formula (1), comprising the step of effecting hydrosilylation reaction of a compound of the general formula (9) with a compound of the general formula (10):
wherein R 1 to R 5 and Rf are as defined above.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 , 2 and 3 are diagrams showing IR spectra of the compounds prepared in Examples 1, 2 and 3, respectively.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The fluorinated amide compounds of the present invention have the following general formula (1).
A—(Rf—Q) n —Rf—A (1)
Herein Rf is a divalent perfluoroalkylene group: C m F 2m wherein m is an integer of 2 to 15, or a divalent perfluorooxyalkylene group selected from groups of following formulae (2), (3) and (4).
Herein X is each independently F or CF 3 ; p and q each are an integer of 0 to 200, preferably 1 to 100, and p+q is preferably 2 to 200; r is an integer of 2 to 6, s is an integer of 1 to 6, t and u each are an integer of 1 or 2.
Herein X is as defined above, v and w each are an integer of 1 to 100, preferably 1 to 50.
—CF 2 CF 2 —(OCF 2 CF 2 CF 2 ) y —OCF 2 CF 2 — (4)
Herein y is an integer of 1 to 200, preferably 1 to 100.
The divalent perfluoroalkylene groups may be straight or branched and include, for example, —C 2 F 4 —, —C 3 F 6 —, —C 4 F 8 —, —C 6 F 12 —, —C 8 F 16 —, —C 10 F 20 —and —C 2 F 4 CF(CF 3 )C 4 F 8 —.
Examples of suitable divalent perfluorooxyalkylene groups are given below.
In formula (1), A is a monovalent organic group of the following formula (5) or (6).
In formulae (5) and (6), R 1 is a monovalent hydrocarbon group selected from among alkyl, cycloalkyl, aryl, aralkyl groups of 1 to 10 carbon atoms and substituted ones of the foregoing groups in which some or all of the hydrogen atoms are substituted with halogen atoms; R 2 is hydrogen or a monovalent hydrocarbon group selected from among alkyl, cycloalkyl, aryl, aralkyl groups of 1 to 10 carbon atoms and substituted ones of the foregoing groups in which some or all of the hydrogen atoms are substituted with halogen atoms; and Z is a divalent organic group of the following formula (7).
In formula (7), R 3 is an oxygen atom or a divalent hydrocarbon group selected from among alkylene, cycloalkylene, arylene groups of 1 to 8 carbon atoms, substituted ones of the foregoing groups in which some of the hydrogen atoms are substituted with halogen atoms, and combinations of alkylene with arylene; R 4 is a monovalent hydrocarbon group selected from among alkyl, cycloalkyl, aryl, aralkyl groups of 1 to 10 carbon atoms and substituted ones of the foregoing groups in which some or all of the hydrogen atoms are substituted with halogen atoms; R 5 is a monovalent hydrocarbon group selected from among alkyl, cycloalkyl, aryl, aralkyl groups of 1 to 10 carbon atoms, aliphatic unsaturation-bearing monovalent hydrocarbon groups of 2 to 20 carbon atoms, and substituted ones of the foregoing groups in which some or all of the hydrogen atoms are substituted with halogen atoms.
Suitable monovalent hydrocarbon groups represented by R 1 , R 2 and R 4 include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, hexyl, octyl, and decyl; cycloalkyl groups such as cyclopentyl, cyclohexyl and cycloheptyl; aryl groups such as phenyl, tolyl, xylyl and naphthyl; aralkyl groups such as benzyl, phenylethyl, phenylpropyl and methylbenzyl; and substituted ones of the foregoing groups in which some or all of the hydrogen atoms are substituted with halogen atoms, such as chloromethyl, chloropropyl, bromoethyl and trifluoropropyl.
Examples of the alkyl, cycloalkyl, aryl and aralkyl groups of 1 to 10 carbon atoms and halogenated ones thereof represented by R 5 are the same as enumerated above.
Examples of the aliphatic unsaturation-bearing monovalent hydrocarbon groups represented by R 5 are vinyl, propenyl, isopropenyl, butuenyl, isobutenyl, hexenyl, cyclohexenyl, and groups of the following structures (wherein Si is depicted for indicating the position at which the structure is bonded to silicon), and substituted ones of the foregoing groups in which some or all of the hydrogen atoms are substituted with halogen atoms.
R 3 is an oxygen atom or a divalent hydrocarbon group of 1 to 8 carbon atoms. Examples of the divalent hydrocarbon group represented by R 3 include alkylene groups such as methylene, ethylene, propylene, methylethylene, butylene, and hexamethylene; cycloalkylene groups such as cyclohexylene; arylene groups such as phenylene, tolylene and xylylene; substituted ones of the foregoing groups in which some of the hydrogen atoms are substituted with halogen atoms; and combinations of alkylene with arylene.
Again in formula (1), Q is a divalent organic group of the following formula (8).
Herein R 1 , R 2 and Z are as defined above.
In formula (1), n is an integer of at least 1, preferably 2 to 200, more preferably 5 to 100, and most preferably 8 to 80. Accordingly, the compound of formula (1) preferably has a number average molecular weight (Mn) of about 20,000 to 2,000,000, and more preferably 50,000 to 1,000,000, and a kinematic viscosity of about 2 to 100 mm 2 /s , especially about 10 to 50 mm 2 /s in a 10 wt % solution thereof in nonafluorobutyl methyl ether (C 4 F 9 OCH 3 ).
The fluorinated amide compound of formula (1) according to the invention can be prepared by reacting a compound of the general formula (9) with a compound of the general formula (10) in the presence of a hydrosilylation reaction catalyst.
Herein R 1 to R 5 and Rf are as defined above.
A reaction proportion between the compound of formula (9) and the compound of formula (10) is desirably set to a molar ratio (9)/(10) of from 2/3 to 3/2, and most desirably a molar ratio (9)/(10) close to 1/1.
The hydrosilylation reaction catalysts used herein are preferably transition metals, for example, platinum group metals such as Pt, Rh and Pd and transition metal compounds.
Since these compounds are generally noble metal compounds which are expensive, platinum compounds are often used because of ease of availability.
Exemplary platinum compounds include, but are not limited thereto, chloroplatinic acid, complexes of chloroplatinic acid with olefins such as ethylene, complexes of chloroplatinic acid with alcohols or vinylsiloxanes, and platinum on silica, alumina or carbon.
Suitable platinum group metal compounds other than platinum compounds include rhodium, ruthenium, iridium and palladium compounds such as RhCl(PPh 3 ) 3 , RhCl(CO)(PPh 3 ) 2 , RhCl(C 2 H 4 ) 2 , Ru 3 (CO) 12 , IrCl(CO)(PPh 3 ) 2 , and Pd(PPh 3 ) 4 wherein Ph stands for phenyl.
The amount of the catalyst used is not critical and is preferably determined from the standpoints of economy and effective reaction so as to provide 0.1 to 1,000 ppm, more preferably 0.1 to 500 ppm of platinum group metal based on the weight of the reactants combined.
The reaction temperature may be in the range of 0 to 200° C., and preferably 50 to 150° C. The reaction time varies over a wide range and is usually about 5 minutes to 2 hours.
The reaction may be carried out in a diluted state using an organic solvent as long as the solvent does not adversely affect hydrosilylation. The organic solvent, if used, is preferably a partially or entirely fluorine-modified organic solvent.
As understood from the foregoing description, the fluorinated amide compound obtained by the above process is terminated with an end group of formula (11) or (12).
CH 2 ═CH— (11)
H—Z—CH 2 CH 2 — (12)
Most often, these end groups of formulae (11) and (12) are admixed at the terminus of the resulting compound. Particularly when the compounds of formulae (9) and (10) are reacted in equimolar amounts, the end groups of formulae (11) and (12) are admixed in an equimolar state at the terminus of the resulting compound, but in trace amounts which are undetectable by ordinary analysis means such as IR and NMR.
By combining the fluorinated amide compound of the invention with a crosslinking agent such as an organic peroxide for inducing radical crosslinking, a rubber having good chemical resistance and solvent resistance is obtained. When the fluorinated amide compound has an unsaturated bond within its molecule, a fluorinated rubber having excellent chemical resistance and solvent resistance is obtained by reacting the fluorinated amide compound with a SiH group-containing compound in the presence of a platinum group catalyst. Moreover, the fluorinated amide compound is applicable as a pressure-sensitive adhesive, binder, coating or other agent having excellent chemical resistance and solvent resistance.
EXAMPLE
Examples of the invention are given below by way of illustration and not by way of limitation. Me is methyl, and Ph is phenyl.
Example 1
A 300-ml separable flask equipped with a stirrer, thermometer, Dimroth condenser and dropping funnel was charged with 100.0 g of a compound of formula (13) shown below (vinyl convent=0.0122 mol/100 g), 100.0 g of 1,3-bistrifluoromethylbenzene, and 3.34 g of a compound of formula (14) shown below, which were homogeneously dissolved. To the flask, 0.10 g of a toluene solution of a catalyst in the form of chloroplatinic acid modified with CH 2 ═CHSiMe 2 OSiMe 2 CH═CH 2 (platinum concentration 0.5 wt %) was added dropwise. With stirring, reaction was conducted for one hour at 100° C. The reaction solution was stripped for about 2 hours under conditions: 160° C./5 mmHg, distilling off the reaction solvent. Subsequent cooling to room temperature yielded 103.3 g of a pale yellow clear gum-like compound. On analysis of the compound by 1 H-NMR (TMS standard), Si—CH═CH 2 and Si—H groups were below the detection limit. The 1 H—NMR (TMS standard) analysis confirmed the presence of Si—CH 3 (0.17 ppm), N—CH 3 (3.35 ppm), CF 2 CH═CH 2 (5.7-6.1 ppm), and N—Ph—Si (7.0-7.6 ppm). An IR analysis ( FIG. 1 ) revealed the absorption peak associated with C═O at 1690 cm −1 . From these analysis results, the compound was identified to be a polymer comprising recurring units of formula (15) shown below. A 10 wt % solution of the compound in nonafluorobutyl methyl ether (C 4 F 9 OCH 3 ) showed a kinematic viscosity of 18.3 mm 2 /s.
Example 2
A 300-ml separable flask equipped with a stirrer, thermometer, Dimroth condenser and dropping funnel was charged with 100.0 g of a compound of formula (13) (vinyl convent=0.0122 mol/100 g), 100.0 g of 1,3-bistrifluoro-methylbenzene, and 1.25 g of a compound of formula (16) shown below, which were homogeneously dissolved. To the flask, 0.10 g of a toluene solution of a catalyst in the form of chloroplatinic acid modified with CH 2 ═CHSiMe 2 OSiMe 2 CH═CH 2 (platinum concentration 0.5 wt %) was added dropwise. With stirring, reaction was conducted for one hour at 100° C. The reaction solution was stripped for about 2 hours under conditions: 160° C./5 mmHg, distilling off the reaction solvent. Subsequent cooling to room temperature yielded 101.2 g of a pale yellow clear gum-like compound. On analysis of the compound by 1 H-NMR (TMS standard), Si—CH═CH 2 and Si—H groups were below the detection limit. The 1 H—NMR (TMS standard) analysis confirmed the presence on Si—CH 2 —Si (—0.19 ppm), Si—CH 13 (0.17 ppm), N—CH 3 (3.35 ppm), and N—Ph—Si (7.0-7.6 ppm). An IR analysis ( FIG. 2 ) revealed the absorption peak associated with C═O at 1690 cm −1 . From these analysis results, the compound was identified to be a polymer comprising recurring units of formula (17) shown below. A 10 wt % solution of the compound in nonafluorobutyl methyl ether (C 4 F 9 OCH 3 ) showed a kinematic viscosity of 12.8 mm 2 /s.
Example 3
A 300-ml separable flask equipped with a stirrer, thermometer, Dimroth condenser and dropping funnel was charged with 100.0 g of a compound of formula (13) (vinyl convent=0.0122 mol/100 g), 100.0 g of 1,3-bistrifluoro-methylbenzene, and 4.05 g of a compound of formula (18) shown below, which were homogeneously dissolved. To the flask, 0.10 g of a toluene solution of a catalyst in the form of chloroplatinic acid modified with CH 2 ═CHSiMe 2 OSiMe 2 CH═CH 2 (platinum concentration 0.5 wt %) was added dropwise. With stirring, reaction was conducted for one hour at 100° C. The reaction solution was stripped for about 2 hours under conditions: 160° C./5 mmHg, distilling off the reaction solvent. Subsequent cooling to room temperature yielded 104.0 g of a pale yellow clear gum-like compound. On analysis of the compound by 1 H—NMR (TMS standard), Si—CH═CH 2 and Si—H groups were below the detection limit. The 1 H—NMR (TMS standard) analysis confirmed the presence of Si—CH 3 (0.17 ppm), N—CH 3 (3.35 ppm), and N—Ph—Si (7.0-7.6 ppm). An IR analysis ( FIG. 3 ) revealed the absorption associated with C═O at 1690 cm −1 .
From these analysis results, the compound was identified to be a polymer comprising recurring units of formula (19) shown below. A 10 wt % solution of the compound in nonafluorobutyl methyl ether (C 4 F 9 OCH 3 ) showed a kinematic viscosity of 15.6 mm 2 /s.
There have been described fluorinated amide compounds having siloxane bonds or silalkylene bonds, which yield rubber having excellent chemical resistance and solvent resistance.
Japanese Patent Application No. 2001-245891 is incorporated herein by reference.
Although some preferred embodiments have been described, many modifications and variations may be made thereto in light of the above teachings. It is therefore to be understood that the invention may be practiced otherwise than as specifically described without departing from the | Novel fluorinated amide compounds having siloxane bonds or silalkylene bonds, when crosslinked with organic peroxides, yield fluoro-rubber having excellent chemical resistance and solvent resistance. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to vehicle anti-lock braking systems, and particularly to brake simulation mechanisms used with such systems.
2. Description of the Related Art
Vehicle anti-locking brake control systems differ from conventional brake systems in that the hydraulic pressure is applied to the brake cylinders as a series of time-spaced pulses, in order to prevent the road wheels from skidding or sliding on low friction road surfaces, e.g. snow, ice or loose gravel. A person accustomed to the steady state action of conventional brake systems is sometimes surprised by the pulsing action of anti-lock brake systems. Occasionally persons purchasing a vehicle equipped with anti-lock brakes will complain to the dealer that the brakes seem to be defective, due to the pulsating effect perceived at the brake pedal.
When such complaints are received, the normal practice is to have the salesperson and customer make a road test of the vehicle. During such a test, the salesperson can point out to the customer that the pulsating brake action is a normal condition, not a product defect. However, a road test is somewhat costly and time-consuming, as well as a customer inconvenience and possibly a cause of an accident due to preoccupation with pedal action.
The present invention relates to a mechanism that can be used to simulate normal operation of a vehicle anti-lock braking system, without requiring a vehicle road test.
SUMMARY OF THE INVENTION
The invention relates to electronic mechanism for applying road wheel slippage signals to an electronic control module of an anti-lock brake system while the vehicle is in a stand-still condition. A person seated in the vehicle's driver seat can depress the brake pedal and experience the pulsating effect associated with actual operation of an anti-lock brake system during hard braking in the real time environment. The invention is a low cost method of informing and instructing a vehicle owner as to the normal pedal feel and pulsation effects and pump noise experienced with anti-lock braking systems.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic representation of a vehicle equipped with an anti-lock braking system that forms the environment for the present invention.
FIG. 2 is a diagrammatic representation of the operation of a road wheel speed sensor in the FIG. 1 anti-lock brake system.
FIG. 3 is a diagnostic trouble code readout tool that can be used with the FIG. 1 vehicle to practice the present invention.
FIG. 4 is a perspective view of a brake control unit in a vehicle environment in which the invention can be used.
FIG. 5 is a flow chart of a computer program that can be used to practice the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The drawings show a conventional anti-lock vehicle braking system that includes a brake master cylinder 10 having a hydraulic fluid reservoir 12, a vacuum-operated booster 14, actuating foot pedal 16, front wheel brake assemblies 18, and rear wheel brake assemblies 20. Each brake assembly includes a brake cylinder that is supplied with pressurized brake fluid by a hydraulic line 22.
The anti-lock feature is provided by a central electronic-hydraulic control unit 24 that includes an electronic control module 25 and a hydraulic power unit 27. The hydraulic power unit comprises a hydraulic pump 29 (FIG. 4) and solenoid valves 30 for controlling hydraulic pressure in each hydraulic line 22. During anti-lock brake action the solenoid valves are cycled on and off (opened or closed) to raise or lower the pressure at the wheel cylinders, whereby the vehicle is prevented from skidding or sliding in an uncontrolled fashion.
Electronic control module 25 comprises a computer that receives electronic control signals from wheel speed sensors 32 via electric lines 33. As shown diagrammatically in FIG. 2, each wheel speed sensor comprises a magnetic pick up 34 in near proximity to magnetically permeable teeth 36 on the shaft of the rotating road wheel, whereby the sensor generates an electronic pulse 37 having a frequency related to wheel speed. The electronic module 25 compares the pulses generated by the wheel speed sensors to determine how the solenoid valves 30 are to be controlled (cycled). The system uses current supplied by the vehicle battery for energizing the solenoid valves in variable pulse fashion (several times per second).
The electronic control unit is equipped with an on-board self-testing system designed to detect malfunctions in the electronic control module or associated components, e.g. the wheel speed sensors, pump motor, or solenoid valves. This self testing system is normally energized by an external (portable) diagnostic readout tool 38 (FIG. 3) having a display screen 39 adapted to display alpha numeric diagnostic trouble codes detected by the self testing system. Readout tool 38 can be a commercially available structure manufactured by the Hickock Electrical Instrument Co., of Cleveland, Ohio, under its parts designation No. 2490-822. As shown in FIG. 3, the readout tool is equipped with a menu dial control 40, cancel keys 41, screen button keys 42, and trigger keys 43. The tool includes a vehicle interface module 45 that has a cable 47 connected to a vehicle data link connector 49. Connector 49 has plural electrical sockets adapted to plug onto pin terminals 51 of a data link connector 53 located in the vehicle, e.g. under the steering column. Data link connector 53 has a permanent cable connector 55 with electronic control module 25, such that when connector 49 is plugged into data link connector 53 electrical connections are established between control module 25 and readout tool 38.
Tool 38 has a side access slot adapted to selectively receive different program cards appropriate to different vehicle makes and models. When the appropriate card is inserted into the access slot in tool 38 the tool is conditioned to display alpha numeric diagnostic trouble codes detected by the self testing system in module 25. The self testing system has a scanning (multiplexed) capability that can be sequentially connected to different points in the electronic control module 25, e.g. the solenoid valve terminals, the origination points for wheel speed sensor lines 33, and the pump 29 motor energization terminals. The self test system detects voltages, resistances or current valves that are outside the ranges required for proper operation of the electronic brake control system. Any out-of-range value is transmitted through data link connector 53 to the readout tool where it is displayed as an alpha numeric trouble code on display screen 39. The present invention uses the readout tool 38 as a signal delivery device, rather than as a signal receiver device. A program, constructed according to the FIG. 5 flowchart, is incorporated into a program card 57 sized for insertion into the side access slot in readout tool 38. With program card 57 inserted into the access slot, tool 38 is adapted to function as a device for transmitting substitute control signals representative of anti-lock brake variables, e.g. pedal height, pump and valve operation profile and wheel slippage (incorporated on card 57) to the data line connector 53 on board the vehicle. The data link connector transmits such control signals to the line 33 origination points on electronic control module 25, whereby the control module functions as though the vehicle were moving on road terrain corresponding to the pulse frequency being transmitted from card 57 to data link connector 53.
The program contained on card 57 has an electric output corresponding to three different road wheel slippage conditions on ice, or snow and gravel, or dry pavement. These pulsed outputs are incorporated into card 57 on the basis of prior knowledge gained from experimental oscilloscope instrumentation on test vehicles.
Readout tool 38 can have various operational modes displayable on screen 39 by manual manipulation of menu dial control 40. Two such operational modes are the vehicle-engine selection mode, and the diagnostic data link mode. Assuming the readout tool is placed in the data link mode, the program card 57 will cause various instructions to appear on display screen 39, in accordance with the program depicted in flow chart form in FIG. 5.
In a typical scenario the brake simulation test operation will be carried out in a showroom atmosphere on a normally-operating vehicle, with a customer seated in the vehicle (that is equipped with the readout tool 38). With the vehicle in a stand-still condition the vehicle ignition switch will be turned to the engine running condition (but with the vehicle in a stand still condition), whereby electrical power is supplied to electronic control module 25. The salesperson or service technician will handle readout tool 38 while the customer is seated in the driver's seat. The display screen displays a first question 60 (FIG. 5) on the display screen 39; after receiving the appropriate decision (selection) from the customer, the salesperson presses the appropriate buttons on the readout tool to advance the program to the next decision point represented by the second question 62 displayed on the screen. The customer is then in position to carry out a test of the anti-lock brake system while the vehicle remains in the stand-still condition. The test can be carried out (or repeated), using different simulated road conditions (pulse frequencies). The test closely approximates actual anti-lock brake operation in actual on-the-road conditions.
The system depicted in the drawings uses existing electronic modules and readout tools. The mechanism for generating the substitute wheel speed signals and delivering such signals to the data link connector 53 can be incorporated entirely on program card 57. Readout tool 38 is unmodified, and in its original condition, with its normal trouble code readout and display capabilities retained.
The drawings show one specific form that the invention can take. However, it will be appreciated that the invention can be practiced in various forms and configurations. | A diagnostic readout tool can be programmed to generate and deliver electronic signals representative of different road wheel slippage conditions on various road surfaces, such as ice, snow, gravel or dry pavement. The artificially-created signals can be applied to an electronic control module in a vehicle anti-lock brake system, thereby permitting a person seated in the vehicle to experience the action and feel of the anti-lock brake operation while the vehicle is in a stand-still condition. | 1 |
FIELD OF THE INVENTION
[0001] This invention has to do with dispenser pumps for dispensing discrete doses of a flowable material from a container on which the pump is fitted. The present proposals have particular relevance to dispenser pumps for use with viscous or pasty materials. They are also relevant when material to be dispensed needs to be protected from contact with air e.g. to prevent drying out or degradation. We particularly envisage that the invention may be embodied in a toothpaste dispenser.
BACKGROUND OF THE INVENTION
[0002] In recent years toothpaste dispensers have become widely available in which a relatively large volume of paste is contained in a free standing container, and a piston-and-cylinder dispenser pump with a fixed discharge nozzle is provided at the top of the container to dispense a dose of toothpaste when the pump piston is depressed. Known pumps include arrangements for covering, blocking or shielding the discharge nozzle outlet between operations of the pump to keep the residual paste in the pump from drying out and to help separate the tail end of each dispensed dose from the nozzle end. Toothpaste is extremely sticky and there are often problems in that slugs of paste issuing forth are not cleanly cut off, leading to toothpaste being smeared on the outside of the discharge nozzle by the cover arrangement which is precisely the opposite of what is wanted.
SUMMARY OF THE INVENTION
[0003] This application addresses, independently and in combination, various technical aspects of dispenser pumps of the kind described. One particular aspect is a novel arrangement for closing off a discharge nozzle of such a pump. Another aspect is proposals for inlet and outlet valves in such a pump. Any and all of these features may be combined in a dispenser, especially a toothpaste dispenser.
[0004] In general terms, a dispenser pump of the relevant kind will have a pump chamber whose volume is alterable in a pumping stroke by relative movement between a body of the pump and a plunger which is reciprocable relative to the body by hand actuation. Typically the plunger has a piston which works in a cylinder of the pump body, the piston and cylinder defining a pump chamber between them. An inlet is provided for flowable material to enter the pump chamber from a container to which the pump is secured, and an outlet of the pump chamber leads to a discharge passage which extends to a discharge nozzle having an external nozzle opening. Usually a one-way inlet valve is provided for the pump chamber, and usually (in some cases, necessarily) a one-way outlet valve.
[0005] A first proposal relates to a closure valve at the discharge nozzle opening. We propose the use of a closure comprising resiliently flexible material, providing a wall whose periphery is retained and constrained at the surrounding discharge nozzle structure, the wall having one or more discharge openings closed in a rest condition of the wall, but open when the wall is caused to bulge outwardly under pressure of discharged product from the pump. In particular, we envisage the use of a closure where the wall is outwardly concave, so that under forward fluid pressure it must pass through a peak of compressive strain before reaching a wholly or partially outwardly convex configuration in which the discharge opening opens. Closure valves of this kind are known. They can offer the advantage of a very positive cutting or closure action when pressure is relieved because the sides of the discharge opening(s) are positively pressed together as the wall returns to its rest condition. Also, the axial retraction of the wall as its opening shuts helps to detach adherent material. Typically the discharge opening has one or more slits.
[0006] Such closures have previously been used in squeezable containers; this proposal is distinctive in using such a closure at the nozzle of a pump which has its own discrete outlet valve (essentially a one-way valve) upstream of the mentioned resilient closure.
[0007] The retraction of such a concave closure wall at the end of discharge calls for some retreat of material still in the discharge passage behind it. Otherwise full closure of the discharge opening(s) may be inhibited.
[0008] To improve performance, we therefore propose to use an outlet valve for the pump which will accommodate an appreciable degree of reverse flow after the discharge stroke. We prefer an outlet valve whose movable valve element is a swinging flap, preferably of flexible material and more preferably resiliently flexible material. So that the suck-back need not require a large distance of movement at the pump outlet valve, we prefer that the discharge flow area at the outlet valve be greater than the flow area at the discharge nozzle spanned by the closure wall. A preferred arrangement has the pump outlet valve as an annular flap acting between the pump chamber and an annular outlet chamber which communicates with the discharge channel proper e.g. from one point on its circumference. For a compact construction, the annular outlet valve may be disposed surrounding an inlet to the pump chamber.
[0009] Deformable e.g. elastomeric elements for the inlet and outlet valves may be formed together as a one-piece valve entity, with a central formation for the inlet and a peripheral flap for the outlet. This is in itself known, although not in pumps of particular kinds described here.
[0010] One embodiment of such a one-piece valve module has the inlet valve formed as a duckbill valve. This is believed to be new as such and is proposed here as an independent invention as well as in combination with other features disclosed here. A duckbill valve has the feature of closing itself resiliently with only a small movement with a one-way action and without requiring separate biasing so that it is particularly suitable for use in thick pasty products such as toothpaste.
[0011] A container to which the pump body is secured with its inlet in communication is not particularly limited. However for products such as toothpaste, which suffer from contact with air, a vented container is not preferred. Instead it may have a follower piston as a base, or be a collapsible container which is preferred. In particular, the container may have a thin collapsible wall connected integrally to a thicker securing collar which plugs into or onto a corresponding securing formation of the pump body. A corresponding dispenser apparatus preferably surrounds the collapsible container with a rigid shell or support, which may have any or all of the functions of protecting the collapsible container, disguising the collapsible container and serving as a support stand or hand grip.
[0012] A preferred format for a dispenser system, suitable for e.g. toothpaste, provides a lower container shell (which may itself be a container, or may surround a collapsible bag container as mentioned) with a base surface for standing, and a pump module mounted on top of the lower container with a plunger axis of the pump generally upright (it may be inclined, e.g. slightly rearwardly), with a fixed discharge channel extending up alongside the pump chamber from the pump chamber outlet, which is adjacent the bottom of the pump, up to the discharge nozzle which opens generally sideways adjacent the top of the pump. The pump plunger may be pressed directly by hand. More preferably a pivoted lever is provided e.g. in the form of a swinging button cap, which may contact the plunger top so as to give some mechanical advantage in the pumping action.
[0013] A further particular feature proposed herein, which may be embodied in dispensers and pump dispensers of other types, is a particular conformation of a collapsible bag from which product is to be dispensed. With collapsible containers measures are needed to prevent uncontrolled collapse of the container leading to bodies of product becoming isolated from the pump inlet by folds of the container wall. One conventional arrangement has a central finned rod extending down into the container from the centre of the pump body, keeping the container longitudinally extended and providing riser channels for the product even when nearly exhausted. This is not easily combined with certain constructions of pump inlet. A proposal here is to provide the wall of the collapsible container with a longitudinally extended preformed corrugation which can to some extent stiffen the wall of the bag longitudinally at one or a few parts of its circumference: other parts may be plain. In the collapsed condition, the corrugation helps to keep open a flow channel to the pump inlet. Additionally or alternatively, the collapsible bag wall may have a longitudinally-graduated wall thickness. Thus, it may be more readily collapsible at its base than nearer the top, encouraging a gradual turning of the bag inside out from the bottom as dispensing proceeds, rather than “waisting” higher up as is otherwise the tendency.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Examples of our proposals are now described with reference to the accompanying drawings, in which
[0015] FIG. 1 is an axial cross-section through the upper part of a toothpaste dispenser;
[0016] FIG. 2 is a front view of that part of the dispenser;
[0017] FIG. 3 is an axial cross-section of the upper part of a second toothpaste dispenser showing a modified valve module;
[0018] FIG. 4 and FIG. 5 are respectively top and bottom oblique views of a one-piece valve module from a FIG. 3 pump, and
[0019] FIGS. 6 to 9 are first and second side elevations, a top view and a section at O-O (see FIG. 7 ) of a collapsible bottle or container for holding paste to be dispensed.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0020] FIG. 1 is a section on line A seen in FIG. 2 . The major elements of the dispenser include
a collapsible polymeric bag container 8 for containing toothpaste; a pump base component 11 into which the top of the bag 8 is plugged, and having an inlet 112 ; a pump cylinder body 12 plugging into the top of the pump base 11 to define a pump chamber 4 ; a pump plunger 2 having a stem 21 and a piston 23 working in the cylinder 12 ; a discharge channel 13 , 15 extending up alongside the cylinder 12 to a transversely-directed outlet with a special elastomeric closure 16 ; a pivotable plunger cap 22 for operating the plunger 2 , and an outer container shell 9 with upper and lower parts 92 , 91 which snap together to surround the bag 8 , provide a stable support base and to locate the above-mentioned components relative to one another while exposing the pivotable plunger button 22 .
[0028] A skilled person will readily understand the general operation of the pump dispenser from the drawings. The plunger button 22 , pivoted at P, bears on the top of the plunger stem 21 via a contact pad 221 forwardly of the rear of the cap, so that pressing on the rear of the cap 22 gets a modest mechanical advantage. The plunger 2 descends against the action of a return spring 3 external to the pump chamber 4 . The piston is retained in the chamber by an inturned top portion 121 of the cylinder body 12 .
[0029] The pump base 11 has a generally cylindrical surround wall into which the cylinder body 12 is a snap-fit, with the cylinder itself slightly offset to the rear. The pump base 11 has an annular trough 111 around the inlet 112 , defining an annular discharge space 61 . To the front of the pump, this discharge space 61 communicates up into an upward tubular extension 13 of the pump body unit, connected in turn to an elbow tube 15 and a snapped-on end adaptor 151 , defining between them a riser portion 62 and a nozzle portion 63 of the pump's discharge channel.
[0030] The cylinder 12 is mounted in the body casing with its plunger axis tilted slightly rearwardly at the top to make best use of the casing space above the container 8 . Its lower end is open and has a circular downwardly-directed edge 125 . This acts as a seat for the circular, radial flap 64 of an elastomeric outlet valve piece, whose centre is anchored in the base plate 11 by a tubular part 65 plugging through the base plate inlet opening 112 . This radial flap 64 separates the pump chamber 4 from the annular discharge space 61 .
[0031] An inlet valve body 5 has a top blocking plate dimensioned to lie sealingly over the top of the inlet bore, anchored by toothed springy legs 511 extending through the bore so that the valve body 5 can slide up to a limited extent to open the inlet. In this construction the inlet valve body 5 seals against an upper elastomer surface of the outlet valve body.
[0032] Adjacent the discharge nozzle, the discharge passage construction (mostly enclosed in the top casing 92 ) has a rubber closure valve 16 to protect toothpaste in the passage from the outside air, and to assist with a clean cut off of toothpaste dispensed. This valve is a single moulded rubber entity, preferably of silicone rubber, and has an outwardly-concave circular front wall 162 closing off the front opening of the discharge nozzle, held in place in the assembly by an integral cylindrical mounting sleeve 161 with a rear bead 163 trapped between the elbow 15 and adaptor 151 of the discharge channel. A thinner linking portion 164 joins the thicker body of the concave front wall 162 to the connecting sleeve 161 . A discharge orifice in the front wall is provided by a set of radial through-slits 165 (see also FIG. 2 ), in this case a crossed pair of straight slits. Closures of this general type are in themselves known and are commercially available, as the skilled person will know, typically for use on squeeze containers. They have a characteristic “snap” operation, remaining closed until a threshold outward pressure is reached sufficient to force the concave wall 162 through its highest-energy compressed condition to a position in which the “petals” between the slits 165 can bend forward and open the nozzle. When the pressure is relaxed the elastic restoration of the wall 162 to its concave rest condition first closes the slits 165 and then retracts them as the wall returns, helping to break away from the dispensed material.
[0033] Thus, in operation of the pump (assuming that the pump chamber 4 is already primed through a previous use) a user presses the rear of the plunger button 22 which swings down (around pivot P) to force the piston 23 down in the cylinder 12 , expelling toothpaste from the pump chamber 4 through the large annular area available at the discharge valve flap 64 . By way of the discharge chamber 61 , dispensed material passes up the discharge passage 62 , 63 and out through the slitted closure 16 in the manner described above. At the end of each dispensing stroke, as the plunger bottoms and starts to rise again pushed by the spring 3 , the outward pressure abruptly stops and is followed by a back-pressure as the plunger rises; this of course lifts the inlet valve 5 to refill the pump chamber 4 .
[0034] Also at this moment of pressure drop the slitted elastomeric closure 16 retracts. Being closed during its retraction, it must retract against the resistance of the body of toothpaste in the discharge channel 63 behind it. The large area of the elastomeric discharge valve flap 64 is also closing with an appreciable delay, and because of its large area permits an appreciable back-flow of material into the pump chamber 4 before the flap 64 meets the seat edge 125 and prevents all further flow save through the inlet valve 5 . This reverse flow action at the discharge valve facilitates a proper positive retraction of the slitted closure 16 at the nozzle outlet.
[0035] The cooperation between the closure valve 16 and the discharge valve of the pump chamber can be “tuned” in dependence on the dimensions and properties of the nozzle closure by adjusting correspondingly the dimensions and properties of the pump discharge valve member. This can be achieved by testing.
[0036] FIGS. 3 to 5 describe a variant construction of the pump chamber valves. Here the inlet valve and outlet valve are provided by a one-piece elastomeric component 56 having a circular radial flap 64 as before, a tubular central plug 58 as before, to anchor it down into the inlet hole 112 of the pump base 11 , doubling back to form an internal tube 59 open to the container interior at its bottom, and terminating in a duckbill valve 55 at the top. A duckbill valve provides a resilient non-return function in a single component, by means of a slit 57 at its tip. Use of a duckbill valve as the inlet valve to a dispenser pump is not conventional, particularly when combined in one piece with an outlet valve in the manner described.
[0037] FIGS. 1 and 3 also show how the lower part 91 of the outer casing 9 is generally coextensive with the bag container 8 so as to support and contain it for assembly. The lower periphery of the upper casing part 92 has an internal securing ring 921 , and sprung teeth 911 of the lower part snap behind this ring 921 to hold the dispenser casing together on assembly. The casing also makes a locating engagement 99 with a rear extension of the pump base 11 , to assure the rotational alignment of this base.
[0038] The flexible bag container which contains the toothpaste has a special construction and this is shown in more detail in FIGS. 6 to 9 .
[0039] Firstly, as mentioned, it has a thickened top neck 81 and locating flange 82 to fix and locate it in and relative to the pump base 11 . The lower, collapsible part of the bag may feature a gradual decrease in wall thickness from the top to the bottom of the bag, to promote collapse of the bag from the bottom upwards as product is gradually dispensed. This is a first measure to reduce the chance of a body of product becoming trapped at the bottom of the bag as the upper regions collapse. A second feature shown here, which may be an addition or an alternative to the graduated wall thickness, is a corrugated formation 83 extending down one side of the bag, for most of the length of the collapsible part. As shown in FIG. 9 , this corrugation provides rib projections 84 running side by side up the bag with a recess 85 between. As the bag collapses, the rib projections 84 tend to keep the clearance 85 open as a communication channel, reducing the possibility of bodies of product becoming isolated from the pump intake. | A pump dispenser suitable for dispensing toothpaste in which a pump chamber has a resiliently flexible flap outlet valve leading into a discharge passage leading to a discharge nozzle. The discharge nozzle features a closure valve, in the form of a concave wall with radial slits, which opens only under appreciable forward pressure. When released, the closure valve closes and retracts forcibly, giving a clean cut-off of product and a degree of backflow via the large outlet valve area of the flap valve as it closes. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The benefits of Provisional Application No. 61/407,009 filed Oct. 26, 2010 by Walter John Simmons and Walter Neal Simmons and entitled “Filling of Partitioned Film Packages for Anchoring Systems for Mines” are claimed under 35 U.S.C. §119(e), and the entire contents of this application are expressly incorporated herein by reference thereto.
FIELD OF THE INVENTION
[0002] The invention relates to anchoring systems and methods of use thereof. The invention further relates to resin systems for anchoring bolts and other supports in mines.
BACKGROUND OF THE INVENTION
[0003] The primary roof support systems used in coal mines include headed rebar bolts typically 4 feet to 6 feet in length, ¾ inch and ⅝ inch in diameter, and used in conjunction with resin grouting in 1 inch diameter holes. Multi-compartment resin cartridges are used to supply the resin grouting for the support systems. Among the cartridges known for this purpose are those disclosed in U.S. Pat. No. 3,795,081 to Brown, Jr. et al., U.S. Pat. No. 3,861,522 to Llewellyn et al., U.S. Pat. No. 4,239,105 to Gilbert, and U.S. Pat. No. 7,681,377 B2 to Simmons et al., the entire contents of each being incorporated herein by reference thereto. Cartridges typically are available in a variety of lengths ranging from 2 feet to 6 feet and in diameter from ¾ inch to ¼ inch. The cartridges also typically include two compartments: a first compartment with a reinforced, thixotropic, polyester resin mastic (a fluid) therein, and a second compartment with an organic peroxide catalyst (also a fluid) therein. The resin and catalyst are segregated from one another in order to prevent a reaction prior to puncturing of the compartments to allow contact and mixing to occur.
[0004] In use, a cartridge and bolt (or other reinforcing member) are placed in a borehole so that they abut one another. In order to puncture the cartridge so that the contents of the compartments may be released and mixed, the bolt for example may be rotated in place to shred the cartridge, thereby mixing the components and permitting solidification of the mastic. Mixing of the resin and catalyst (due to cartridge rupture as well as spinning of the bolt in the borehole) results in hardening that allows the bolt to be held in place.
[0005] When multi-compartment resin cartridges are manufactured, such as in the form of partitioned film packages, a series of cartridges may be formed using a package-forming apparatus. The cartridges may be separated from one another at a clipping head associated with the package-forming apparatus, where the cartridges are cut from one another and sealed. Alternatively, a series of cartridges may be separated from one another in a different operation from the cartridge forming operation, i.e., off-line using a cutter separate from the clipping head. In particular, the cartridges may be separated from one another proximate their clipped ends, i.e., proximate the regions of the opposite ends of the cartridges which are each clipped so as to retain the resin and catalyst in the package. Thus, before being separated, adjacent cartridges have two clips adjacent each other with some cartridge packaging disposed therebetween. A cut is made between the adjacent clips to separate the cartridges.
[0006] U.S. Pat. No. 4,616,050 to Simmons et al. discloses filler-containing hardenable resin products. In particular, a hardenable resin composition is disclosed that is adapted for use in making set products, e.g., a hardened grout for anchoring a reinforcing member in a hole. A course/fine particulate inert solid filler component, e.g., limestone and/or sand, is used. In one composition, a resin component and a catalyst component are provided in a 70:30 percentage ratio. In one example, the resin component is describes as a mixture of 21% of a resin formulation and 79% filler (limestone or limestone in combination with sand). The base resin formulation consisted approximately of 64.0% of a polyester resin, 17.1% styrene, 14.2% vinyl toluene, 1.9% fumed silica, and 2.9% stabilizers and promoters. The polyester resin was the esterification product of maleic anhydride, propylene glycol, and diethylene glycol, the maleic anhydride having been partially replaced with phthalic anhydride (30% maleic anhydride, 23% phthalic anhydride, 17% propylene glycol, and 30% diethylene glycol). The catalyst component was a mixture of 72.5% filler (i.e., limestone), 19.1% water, 0.4% of methylcellulose, and 8.0% of a benzoyl peroxide (BPO) catalyst paste consisting, approximately, of 49.3% BPO, 24.7% butyl phenyl phthalate, 14.8% water, 7.9% polyalkylene glycol ether, 2.0% zinc stearate, and 1.3% fumed silica. Two grades of limestone were used as specified in Table A, and both “coarse” and “fine” filler particles were used. Examples of disclosed compositions are as follows:
[0000]
TABLE A
Product
Filler
Product I
Filler in Resin: [12.5% coarse particles and 87.5% fine
particles]
38% “Grade A” limestone:
33% of the particles averaged larger than 1.19 mm (with
10% of these larger than 2.3 mm, 3% larger than 4.76 mm,
and none larger than 9.53 mm); an average of 42% of the
particles were smaller than 0.59 mm (with 17% smaller
than 0.297 mm, and 5% smaller than 0.149 mm)
62% “Grade B” limestone:
an average of 99.8% of the particles were smaller than
0.84 mm, with 98.7% smaller than 0.297 mm, 97.9%
smaller than 0.250 mm, 91.5% smaller than 0.149 mm, and
69.6% smaller than 0.074 mm
Filler in Catalyst:
100% Grade B limestone
Product II
Filler in Resin: [31.9% coarse particles and 68.1% fine
particles]
38% sand:
83.9% of the particles averaged larger than 1.00 mm
(with 59.6% of these larger than 1.19 mm); 6.6% of the
particles averaged smaller than 0.84 mm (with 1.9%
smaller than 0.59 mm, 0.8% smaller than 0.42 mm, and
0.2 smaller than 0.297 mm)
62% Grade B limestone
Filler in Catalyst:
100% Grade B limestone
Product III
Filler in Resin:
100% Grade B limestone
Filler in Catalyst:
100% Grade B limestone
Product V
Filler in Resin: [12.4% coarse particles, 87.6% fine
particles]
37.5% Grade A limestone
62.5% Grade B limestone
Filler in Catalyst:
100% Grade B limestone
Product VI
Filler in Resin:
62.5% Grade B limestone
37.5% coarse sand
all particles passed through a 3.18-mm screen and were
held on a 1.59-mm screen
Filler in Catalyst:
100% Grade B limestone
[0007] As used herein, the terms “grouting,” “grouting system,” “grout,” and “grout system” mean a substance that hardens to anchor a reinforcing member in a space. For example, grouting can be provided in the form of a cartridge with a compartment housing a polyester resin and a compartment housing an initiator/catalyst, such that when the cartridge is shredded and the resin is mixed with the initiator/catalyst, a reinforcing member can be anchored in a space.
[0008] In manufacturing grouting, from a materials cost perspective, as more filler is used the cost becomes less expensive. In other words, the more filler used instead of actual resin or catalyst, the less expensive the materials required to form the composition. Moreover, filler permits better performance to be achieved by increasing the strength of the hardened grout. However, the tradeoff with using more filler in a composition is that the composition becomes more viscous. For example, the more that filler is used in the resin, the more difficult it is to pump the resin mastic into the package (cartridge) because the resin becomes “thick” (the viscosity increases). High resin mastic pumping pressures become necessary with such high viscosity compositions. Also, the more that filler is used in the overall grouting composition, the more difficult it becomes for the mine bolt to be able to penetrate the cartridge when spun.
[0009] In basic principle, when larger (e.g., coarse) filler particles are used in a composition, the particles overall provide lower surface area than when smaller (e.g., fine) particles are used. Use of such larger particles thus permits a lower viscosity grouting and advantageously aids in shredding of the cartridge and mixing of the cartridge components. In contrast, smaller (e.g., fine) particles can have a very substantial effect on viscosity of a composition because of the high overall surface area that they provide. The use of larger (e.g., coarse) filler particles involves other tradeoffs as well. The resin and catalyst are delivered to the packaging (cartridge) through so-called fill tubes, which are sized to be accommodated with respect to the compartments of the cartridge. The fill tubes thus can only be of a certain diameter in order to be used in the cartridge manufacturing process. The internal diameter of the fill tubes limits the size of the filler particles that can be delivered through those tubes. Separately, when cartridges are clipped at either end during the manufacturing process to seal the resin and catalyst within the cartridge, larger diameter particles can interfere with the clips, causing leakage of resin or catalyst proximate the cartridge free ends and/or rupture of the cartridge when the cartridge is squeezed during installation of a clip. The use of larger diameter filler particles thus can result in a higher rejection rate of manufactured product due to quality control. For these reasons, it is known that clipping requirements are a limiting factor in the filler particle size used in grouting. Prior art compositions, for example, have had a maximum particle size of 3/16 inch. But even then, if a particle of such maximum size is present proximate a clip, the cartridge typically ruptures and has to be discarded rather than sold. It is for this reason that during cartridge manufacture, only a small percentage of larger (e.g., coarse) filler particles are used (e.g., 0-5%) such that the number of rejected cartridges due to leakage and/or rupture remains tolerable (e.g., 1-2%).
[0010] It also needs scarcely to be emphasized that rolling diaphragm piston pumps and progressive cavity pumps for pumping resin mastic and catalyst mastic during manufacture of the cartridges are extremely expensive, costing on the order of several hundred thousand dollars each not including regular maintenance costs.
[0011] One significant problem with the use of such pumps for delivering resin mastic through a filler tube to the compartment of a cartridge is that the pumps typically are operated proximate their highest rated pressure (e.g., 1,250 psi or 1,000 psi). At such an elevated pressure, the speed at which cartridges may be produced is significantly limited. Thus, there exists a need for methods and apparatuses for decreasing the pressure at which the resin mastic pumps are operated in connection with cartridge compartment filling and concomitantly for increasing the speed at which the cartridges may be produced.
[0012] The concept of adding a layer of lubricant around a plug flow of high viscosity material, such as sludge or concrete, to lower pumping pressure and provide increased capability of pumping the material greater distances at a given pressure is known for example from U.S. Pat. No. 5,361,797 to Crow et al. However, the challenges associated with a sludge pipeline lubrication system specifically involve issues of long distance transport rather than a problem associated with packaging a resin mastic let alone with a small diameter fill tube of changing cross-sectional shape (e.g., a portion of the length of the fill tube may have a circular cross-section while another portion may have a D-shaped cross-section; this is because of the shape of the shape of the compartment in the cartridge, as shown for example in U.S. Pat. No. 7,681,377 B2 to Simmons et al.). In yet another context, the outer surface of submarines may be lubricated by bubbles of hot air and oil vapor exhaust. But again, the challenges associated with moving a vessel the size of a submarine through the ocean are quite different from the problems associated with delivering resin mastic through a small diameter fill tube.
[0013] Given that the use of fillers was contemplated in resins for mine bolt grouting since at least the mid-1960s, e.g., as disclosed in U.S. Pat. No. 3,731,791 to Fourcade et al., there has been a long-felt but unsolved need for methods and apparatuses for decreasing the pressure at which the resin mastic pumps are operated in connection with delivering the resin mastic to the cartridge compartment and concomitantly for increasing the speed at which the cartridges may be produced.
SUMMARY OF THE INVENTION
[0014] A method of forming a partitioned package for grouting for an anchoring system for a mine includes: pumping a mastic into the package through a fill tube while a processing lubricant is separately introduced onto an inner wall of the fill tube. The mastic may be a resin mastic or a catalyst mastic. A progressive cavity pump may be used for the pumping.
[0015] The processing lubricant may have less than 60% by weight of filler therein. In some embodiments, the mastic may have 70% to 98% of filler.
[0016] The processing lubricant may include bentonite.
[0017] In some embodiments, the mastic may be a resin mastic and the processing lubricant may be selected from the group consisting of mineral oil, petroleum oil, diethylene glycol, water-soluble cellulose ether, water, hydroxyethyl cellulose in water, unsaturated polyester resin in styrene, gypsum in water, calcium carbonate in water, and sodium bentonite in water.
[0018] The processing lubricant may have from 0 wt % to 20 wt % of filler, and in some embodiments the processing lubricant may have from 0 wt % to 10 wt % of filler.
[0019] In some embodiments, the processing lubricant may be substantially free of filler.
[0020] The processing lubricant may be introduced at a flow rate that is from 0.1% to 10% of the flow rate of the mastic at a free end of the fill tube from which mastic is delivered to the package.
[0021] The processing lubricant may include a colorant which for example may be a pigment.
[0022] The weight percent of filler in the processing lubricant may be no greater than the weight percent of filler in the mastic prior to being in contact therewith.
[0023] Filler in the processing lubricant may have a lower Turner Sclerometer hardness than filler in the resin mastic.
[0024] Pumping pressure of the mastic flowing adjacent processing lubricant may be at least 50% lower than pumping pressure of the mastic without processing lubricant adjacent thereto.
[0025] Flow of the mastic flowing adjacent processing lubricant may be at least 50% greater than flow of the mastic without processing lubricant adjacent thereto at a given pumping pressure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] As used herein, the term “mastic” means liquid component with filler. For example, there can be resin mastic (liquid component plus filler) as well as catalyst mastic (liquid component plus filler).
[0027] As used herein, the terms “catalyst” and “initiator” mean a substance that initiates polymerization and optionally is consumed during polymerization.
[0028] In an exemplary embodiment, a compartment of a multi-compartment cartridge is filled with resin mastic by lubricating the inner wall of a fill tube with a processing lubricant. The processing lubricant may be selected, for example, from a variety of fluids such as mineral oil, SAE 30 motor (petroleum) oil (“Oil #30”), diethylene glycol (“DEG”), methylcellulose and hypromellose water-soluble cellulose ethers (e.g., Dow Chemical Company's METHOCEL™), water, water with a gelling/thickening agent such as hydroxyethyl cellulose (“HEC”), unsaturated polyester resin in styrene (“Resin”; e.g., Reichhold Polylite® 32332-10) that may be promoted to reduce gel time between 5 s to 240 s, gypsum (calcium sulfate dihydrate) mixed in water (to form a slurry) in an amount to provide a stable, nonsettling solution with a higher viscosity than water, calcium carbonate in water, or bentonite (a clay) mixed in water (to form a slurry) in an amount to provide a stable, nonsettling solution with a higher viscosity than water (e.g., agricultural grade bentonite, or Optigel® WH unmodified sodium bentonite from Southern Clay Products, Inc. having a density of 21.7 lb/gal, a bulking value of 0.0461 gal/lb, a maximum moisture of 6%, and a particle size with 90% of the particles being less than 325 mesh).
[0029] In some embodiments, other processing lubricants for example may be selected from carboxymethylcelluloses, polyvinyl alcohols, starches, carboxy vinyl polymers, and other mucilages and resins such as galactomannans (e.g., guar gum), polyacrylamides, and polyethylene oxides. Potential gelling/thickening agents are listed in U.S. Pat. No. 4,280,943, the entire content of which is hereby incorporated by reference herein.
[0030] Potential resins for use with the systems as described herein include, but are not limited to, polyester with a styrene monomer cross-linking agent as well as acrylates and acrylic resins and combinations thereof, unsaturated polyester resins dissolved in a suitable ethylenically unsaturated monomer or mixture of monomers such as styrene, alpha methyl styrene, vinyl toluene, and methyl methacrylate. Potential resins are provided in U.S. Pat. Nos. 3,731,791 to Fourcade et al. entitled “Securing of Fixing Elements Such as Anchor Bolts” and 7,411,010 B2 to Kish et al. entitled “Composition for Anchoring a Material in or to Concrete or Masonry,” the entire contents of which are incorporated herein by reference thereto.
[0031] A colorant such as a pigment or dye may be included in the processing lubricant such as for ease in identifying that the lubricant is being dispensed into the fill tube.
[0032] Advantageously and unexpectedly, the use of processing lubricant permits a substantial decrease in the pump pressure necessary for pumping resin mastic. Such a decrease in pump pressure has numerous benefits. First, the lower pumping pressure permits a substantially greater production speed for cartridges. While operating the resin mastic pump proximate its highest rated pressure (e.g., 1,250 psi or 1,000 psi) has heretofore been the speed limiting factor in cartridge production, at lower pressures a much higher cartridge production rate is possible with the pump no longer serving as the limiting factor (the ability of personnel on the production line to handle the cartridges at higher production rates may be a limiting factor). Second, rolling diaphragm or progressive cavity pumps typically are used for pumping resin mastic for filling cartridges. Without lubricant on the wall of the fill tube, pumps capable of on the order of 1,000 psi are needed to deliver the resin mastic into the compartment of the film cartridge. This is because the fill tube used to deliver the resin mastic into the compartment has a small size (e.g., an outer diameter of 0.75 inch with a wall thickness of 0.062 inch) and a length of 12 to 40 inches. Such a pump rated for 1,000 psi is not off-the-shelf, and thus may be quite expensive (on the order of several hundred thousand dollars). By substantially decreasing the required pump pressure, readily available progressive cavity pumps may be acquired at a small fraction of the cost for pumping the resin mastic and the cost of pump maintenance concomitantly is lowered as well. The cost savings realized by using lower pressure pumps is considerable particularly when several production lines, each having separately pumped resin mastic, are run as occurs in commercial operations.
[0033] Table I below provides test results for the use of the following processing lubricants: mineral oil, Oil #30, DEG, water, water thickened with HEC, and unsaturated polyester resin in styrene (Reichhold Polylite® 32332-10) promoted to reduce gel time between 5 s to 240 s. Testing was conducted using a rolling diaphragm piston pump initially operating at about 1,000 psi to deliver resin mastic through piping to a fill tube and subsequently into a compartment of a multi-compartment cartridge at a flow rate of 9.7 kg/min. Processing lubricant was introduced onto the inner wall of the resin mastic stainless steel fill tube at about 30 inches from the distal end thereof (the fill tube having an overall length of 37.25 inches). Pumping pressure was measured using a pressure gauge located at the discharge of the rolling diaphragm piston pump. The rate of injection of processing lubricant onto the inner surface of the fill tube was increased from 20 g/min. to 105 g/min. while the flow of resin mastic (a mixture of 80-86% limestone filler and 14-20% Polylite 32332-10) was held constant at 9.7 kg/min. Testing results are not included for up to 20 g/min. due to pressure instabilities when using lower flow rates of processing lubricant.
[0000]
TABLE I
THICK
THICK
THICK
FLOW OF
WATER
WATER
WATER
PROCESSING
MINERAL
OIL
1.4%
0.7%
0.35%
LUBRICANT
OIL
#30
DEG
HEC
HEC
HEC
RESIN
WATER
(g/min.)
(psig)
(psig)
(psig)
(psig)
(psig)
(psig)
(psig)
(psig)
0
1,000
1,000
1,000
1,000
1,000
1,000
1,000
1,000
20
215
197
463
950
unstable
27
212
184
460
925
unstable
55
219
182
410
183
200
218
900
unstable
105
217
220
315
175
200
200
825
unstable
213
230
unstable
[0034] As seen in Table I, each of the processing lubricants permitted pumping of resin mastic at a pressure lower than the 1,000 psi reached when not using such processing lubricants. The Resin processing lubricant provided the least decrease in pumping pressure, while each of the other lubricants, at a given flow, permitted about a 50% to about an 85% decrease in pump pressure to be realized. While mineral oil tested well, however, in terms of decreasing required pumping pressure for the resin mastic, it was found to leak from within the sealed cartridges that were produced during testing such that a slippery coating formed on the outside of the cartridges. Thus, mineral oil was determined to not be a preferred choice of processing lubricant due to the issues it caused with cartridge handling.
[0035] Turning next to Table II, test results are provided for pumping with a processing lubricant Optigel® WH unmodified sodium bentonite from Southern Clay Products, Inc. (a clay) mixed in water in an amount to provide a stable, nonsettling solution with a higher viscosity than water. Table II shows a % packaging rate increase from a baseline of 18 m/min. achievable without the use of processing lubricant. Processing lubricant was introduced at a constant flow rate of 83 g/min., whereas the table shows delivery of resin mastic at varying flow rates. The ratio of processing lubricant to resin mastic being pumped is calculated, for example, by dividing the flow rate of 83 g/min. of processing lubricant by the flow rate of 9.1 kg/min. of resin mastic.
[0036] At a packaging speed (cartridge production speed) of 18 m/min., production of cartridges was limited by the high pump pressure (1,000 psi). However, through the use of processing lubricant on the inner wall of the resin mastic fill tube, a decrease of more than 70% in required pump pressure was realized. Such a decreased pump pressure advantageously permits faster production because more resin can be pumped through the fill tube per unit time. Sodium bentonite thus is an exemplary preferred processing lubricant in view of the test results.
[0037] The testing for which data is listed in Table II was conducted using a rolling diaphragm piston pump initially operating at about 1,000 psi to deliver resin mastic through piping to a fill tube and subsequently into a compartment of a multi-compartment cartridge. Processing lubricant was introduced onto the inner wall of the resin mastic stainless steel fill tube at about 30 inches from the distal end thereof (the fill tube having an overall length of 37.25 inches). Pumping pressure was measured using a pressure gauge located at the discharge of the rolling diaphragm piston pump.
[0000]
TABLE II
RATIO OF
DISCHARGE
PROCESSING
PRESSURE
LUBRICANT TO
PACKAGING
OF RESIN
RESIN MASTIC
% PACKAGING
SPEED
MASTIC PUMP
BEING PUMPED
RATE
(m/min.)
(psig)
(%)
INCREASE
18.00
1000
0.00
0.00
18.00
292
0.91
0.00
18.00
307
0.91
0.00
18.25
330
0.90
1.39
18.50
340
0.88
2.78
18.75
360
0.86
4.17
19.00
360
0.85
5.56
19.50
363
0.84
8.33
19.75
370
0.83
9.72
20.00
392
0.81
11.11
20.25
408
0.79
12.50
20.50
413
0.78
13.89
20.75
441
0.75
15.28
20.75
440
0.75
15.28
21.00
440
0.75
16.67
21.00
450
0.75
16.67
21.50
460
0.73
19.44
22.00
486
0.72
22.22
22.25
495
0.70
23.61
22.50
502
0.69
25.00
22.75
514
0.69
26.39
23.00
515
0.68
27.78
23.00
520
0.68
27.78
23.25
520
0.67
29.17
[0038] To summarize the results of Table II, it can be seen that at a production rate of 18.0 m/min., the pump pressure is 1000 psi. Such a pump pressure limits production because to pump resin mastic any faster would require an increase to a pressure at which resin mastic pumps are not typically operated. When a small amount of bentonite mixed in water was added in the fill tube at a rate of 83 g/min., the pump pressure dropped to 292 psi (more than a 70% drop from 1,000 psi). Such a substantial decrease in the pump pressure is quite surprising. The lower pump pressure, in turn, permitted the production rate to be increased from 18.0 to 24.0 m/min. (a 33% increase) while pump pressure remained extremely low (560 psi). An even greater production increase was possible, but limited by the ability of personnel handling the cartridges to keep pace with the increased production rate.
[0039] Moreover, through the use of processing lubricant, an additional increase in pumping rate can be realized because the reduced operating pressure within the fill tube means that a thinner-walled tube with greater cross-sectional area for flow may be used. Concomitantly, such thinner-walled tubes are lighter and less expensive.
[0040] Filler tubes are difficult to replace and such maintenance can result in significant loss in production. Advantageously, the use of processing lubricant can allow for a longer lifetime of the filler tubes to be realized due to slower wear of the tubes. In prior art packaging systems, the fill tubes have significant wear problems such that their regular replacement is necessary (e.g., once per month). However, through the use of processing lubricant, it is possible to significantly extend the lifetime of the fill tubes. The lifetime can be further increased by using processing lubricants that have no filler or fillers with a hardness less than the hardness of the filler in the mastic.
[0041] The use of processing lubricants as described herein with respect to the flow of resin mastic in fill tubes also is applicable to the flow of catalyst mastic in fill tubes. Fill tubes for catalyst mastic typically are smaller in cross-sectional area than fill tubes used for resin mastic as disclosed herein. The reason such fill tubes are smaller is because there is generally less weight of catalyst mastic than resin mastic in a cartridge. For example, a cartridge may have 30 wt % of catalyst mastic and 70 wt % of resin mastic. Nevertheless, processing lubricants still permit a substantial decrease in pump pressure to be realized for pumping catalyst through a fill tube using rolling diaphragm or progressive cavity pumps.
[0042] Potential catalysts for use with processing lubricants described herein include, but are not limited to, peroxide types such as benzoyl peroxide (BPO) with a water or oil base. Other such initiators include cyclohexane peroxide, hydroxy heptyl peroxide, 1-hydroxy cyclohexyl hydroperoxide-1, t-butyl hydroperoxide, 2,4-dichlorobenzoyl peroxide and the like, methyl ethyl ketone peroxide as well as inorganic peroxides alone or mixed with organic peroxides, such as sodium percarbonate, calcium peroxide, and sodium peroxide. Potential initiators are listed in U.S. Pat. No. 3,324,663 to McLean entitled “Rock Bolting,” the entire content of which is incorporated herein by reference thereto.
[0043] While various descriptions of the present invention are described above, it should be understood that the various features can be used singly or in any combination thereof. Therefore, this invention is not to be limited to only the specifically preferred embodiments depicted herein.
[0044] Further, it should be understood that variations and modifications within the spirit and scope of the invention may occur to those skilled in the art to which the invention pertains. Accordingly, all expedient modifications readily attainable by one versed in the art from the disclosure set forth herein that are within the scope and spirit of the present invention are to be included as further embodiments of the present invention. The scope of the present invention is accordingly defined as set forth in the appended claims. | A method of forming a partitioned package for grouting for an anchoring system for a mine includes pumping a mastic into the package through a fill tube while a processing lubricant is separately introduced onto an inner wall of the fill tube. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Reference is made to commonly assigned U.S. patent application No. 08/019,935 filed 19 Feb. 1993 to Fleming et al, entitled "RECORDABLE OPTICAL ELEMENT HAVING A LEUCO DYE", and U.S. patent application No. 08/019,943 filed 19 Feb. 1993 to Fleming et al, entitled "OPTICAL RETRIEVAL APPARATUS USING A LEUCO DYE" the teachings of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to optical recording elements, particularly to those that are useful as recordable compact discs.
BACKGROUND OF THE INVENTION
There are many types of optical recording materials that are known. In many of the materials, the mode of operation requires that the unrecorded material have a high absorption and that the recorded areas, often referred to as pits, have high reflection. The high reflection pits are made by ablating away the high absorption recording material, usually exposing an underlying reflective support.
One of the currently popular forms of optical recordable element is the compact disc or CD. Digital information is stored in the form of low reflectivity marks or pits on an otherwise reflective background, the exact opposite of the above described optical recording materials. In this format, the optical information is most often in the form of read only memory or ROM. Optical information is not usually recorded in real time but rather is produced by press molding. In a typical process, the optical recording substrate is first press molded with a master containing the digital information to be reproduced. The thus formed information is then overcoated with a reflective layer and then with an optional protective layer. In those areas having the deformations or pits, the specular reflectivity is lower than in those areas not having the deformations.
It is desirable to produce optical recording elements which, when recorded in real time, produce a record that mimics the conventional CD on read out. In this manner, information can be added to the CD and the CD can be used on a conventional CD player.
One recently disclosed system of this type is the so called "Photo CD". In this system, conventional photographic film is first processed in a conventional manner. Then, the images from the film are digitized and the digital information is recorded in a CD readable form on an optical recording material. Images can then be played back on a conventional CD type player into a conventional television. Since a CD has a capacity for a number of digitized images that is greater than the typical roll of consumer film, it is anticipated that the user will want to add images and information to a partially recorded CD. Thus there exists the need for recordable, CD compatible optical recording material.
One method for forming a recordable element that mimics conventional mold pressed CD elements is to provide a transparent heat deformable support having thereon, in order, a layer of a dye that absorbs recording radiation and a reflective layer. Exposure of the recording layer through the support by the recording beam heats the recording layer to an extent that it is said that the surface of the heat-deformable support just adjacent to the recording-layer surface is deformed. Materials of this type are described in U.S. Pat. No. 4,940,618, European Patent Application 0353393 and Canadian Patent 2,005,520.
In the U.S. Patent and the European application mentioned above, the preferred dyes for the recording layer are indodicarbocyanine dyes. However, this type of dye does not have archival light stability and will in fact fade to an unusable state in only a few days of exposure to intense sunlight. These applications also disclose one phthalocyanine dye, that is a phthalocyanine dye that has a tert-butyl substituent in one of the β positions on the aromatic rings of the dye. Similarly, the Canadian application mentioned above describes a large number of phthalocyanine dyes. However, all of these phthalocyanine dyes, while having excellent stability, are difficult and expensive to make. For a discussion of cyanine dyes, see Infrared Absorbing Dyes, edited by M. Matsuoka, Pages 19-33, Plenum Publishing Corporation, New York (1990)
For example, the phthalocyanine dyes of the Canadian application are made by first preparing components of the completed ring, which components have the necessary substituents, and then forming the phthalocyanine ring structure by thermally reacting the mixture with a metallic derivative and effecting ring closure. This is an expensive process characterized by low yield and difficult processes for separation of the desired dye from unreacted components. In a mass produced consumer product, cost of the recording layer dye is a major concern.
SUMMARY OF THE INVENTION
Thus, it is an object of this invention to provide a recordable element which incorporates a need for optical recording materials that do not depend on thermal deformation and are less expensive than previously used phthalocyanine dyes.
This object is achieved by a recordable element having a substrate and on the surface of the substrate, a recording layer and a light-reflecting layer, the improvement wherein the recording layer includes:
a leuco dye which upon exposure to a thermally-generated acid becomes an absorption dye;
a sensitizing dye that absorbs light to produce heat which can be used to activate a bronsted acid; and
a thermal acid generator which, upon heating, produces a strong acid which can be used to oxidize a leuco dye.
It is an advantage of this invention that the dye generation can be the product of thermal or photochemical generation of an acid. The acid thus produced can function as an oxidant to produce a dye from a leuco dye. A leuco dye can be selected to have little or no absorption to allow high reflectivity of the read laser where information has not been recorded, yet be highly absorptive in recorded areas where light has been absorbed by the sensitizing dye.
Other advantages of the present invention include:
(1) Critical demands on the optical constants of the dye layer are lifted.
(2) The sensitizing dye(s) may be selected such that broad wavelength sensitivity is possible.
(3) The leuco dye(s) and its conjugate infrared absorbing dye(s) may be selected such that broad wavelength readability is possible.
(4) The recording medium does not require a deformable substrate or interlayer.
(5) Dyes in accordance with this invention permit the use of a binder which can improve the structural integrity of the package, such as by employing polymeric binders in the dye layer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation, in cross-section, of one element in accordance with the invention; and
FIG. 2 is a schematic representation, in cross-section, of another element in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
Optical elements according to this invention as shown in FIGS. 1 and 2 include at least three layers. The substrate 10 has thereon, an optical recording layer 12, and a reflective layer 14. Protective layers may also be used but will not be discussed since they are not necessary for the practice of this invention. See James C. Fleming, "Optical Recording in Organic Media: Thickness Effects", Journal of Imaging Science, Vol. 33, No. 3, May/June 1989, Pages 65-68.
In FIG. 1 the substrate is transparent and light which illuminates the recording layer 12 passes through the substrate 10. In FIG. 2, the substrate is opaque or transparent and light directly illuminates the recording layer.
Recording is accomplished by dye marking in the recording layer 12 with a write laser focused on the recording layer 12, either through the substrate (FIG. 1) or directly (FIG. 2). A second dye is formed in the recording layer in response to light absorbed by the sensitizing dye. The second dye is absorptive toward the light of the read laser. The record thus consists of dark marks of relatively low reflectivity on a background of relatively high reflectivity in relation to the read laser light.
The preferred embodiment of the invention is that of a writable compact disc (CD) as shown in FIG. 1. The write and read lasers are of the laser diode type and operate in the infrared region between 770 and 830 nm. It will be understood to those skilled in the art, that this invention can be applied in other regions of the spectrum. The write laser power is selected to cause a chemical reaction of the leuco dye to produce a dye forming a dark spot whereas the power of the read laser will not cause such a chemical reaction. For a more complete explanation of optical recording and playback processes as well as the construction of compact discs, see Optical Recording, Alan B. Marchant, Pages 23-40, Addison-Wesley Publishing Company, Reading, Mass. (1990).
The following is a more detailed discussion of the optical element.
The Support
For FIG. 1, supports can be made from optically transparent resins with or without surface treatment. For FIG. 2, the substrate may be opaque relative to write/read laser light. The preferred resins for the FIG. 1 embodiment are polycarbonates and polyacrylates. The support may include a guide groove for laser tracking.
Recording Layer
The recording layer includes a leuco dye, a thermal acid, a sensitizing dye and a binder. In addition, useful addenda for the recording layer, may include stabilizers, surfactants, binders and diluents.
Solvent Coatings
Coating solvents for the recording layer are selected to minimize their effect on the support. Useful solvents include alcohols, ethers, hydrocarbons, hydrocarbon halides, cellosolves, ketones and water. Examples of solvents are methanol, ethanol, propanol, pentanol, 2,2,3,3-tetrafluoropropanol, tetrachloroethane, dichloromethane, diethyl ether, dipropyl ether, dibutyl ether, methyl cellusolve, ethyl cellusolve, 1-methoxy-2-propanol, methyl ethyl ketone, 4-hydroxy-4-methyl-2-pentanone, hexane, cyclohexane, ethylcyclohexane, octane, benzene, toluene, and xylene. Other less desirable solvents include dimethylsulfoxide and dimethylformamide. Preferred solvents are hydrocarbon solvents and alcohol solvents since they have the least effect on the preferred polycarbonate substrate.
The Reflective Layer
The reflective layer can be any of the metals conventionally used for optical recording materials. Useful metals can be vacuum evaporated or sputtered and include gold, silver, aluminum, copper, and alloys thereof. Gold is the preferred reflective layer material.
Binders
The binders are selected to be substantially nonabsorbtive toward the wavelengths of the write and read diode laser light. Examples of binder materials are set forth in subsequent examples.
Sensitizing Dye
A sensitizing dye is any dye that absorbs at a desired wavelength such as 780 nm. Preferable dyes are those which absorb strongly such that, at a concentration of ≦5% of the recording layer in the control formulation below, the collimated beam reflectance as measured through the substrate at 780 nm after gold coating in between 50% and 90%.
Leuco dye
A leuco dye will for the purpose of this disclosure be defined as an organic reagent which absorbs at wavelengths which are shorter than when it is converted to a dye. Such a dye will absorb substantially at longer wavelengths upon thermochemical or photochemical reaction. These chemical reactions include thermally or photochemically induced changes such as oxidation, reduction, protonation, deprotonation, ring opening, metallization, condensation, dehalogenation, dehydrohalogenation, dehydration, rearrangement, polymerization, etc.
Procedure for the Identification of a Leuco Dye Useful in an Optical Recording Element
A leuco dye may be identified as being useful in an optical recording element by coating the material in an optical disc format along with a sensitizing dye and a binder, writing on the element with the appropriate wavelength with a focussed laser, and examining the recorded disc for evidence of dye formation.
Test Formulation and Coating
A solution of the materials to be coated can be prepared at 3% solids in a suitable solvent such as methoxypropanol, as defined in Table I. The test leuco dye is present at 40% of the solids. A control formulation is similarly prepared where the test leuco dye is replaced with an equal weight of binder.
TABLE I______________________________________Melt Composition Test ControlComponent Example formulation Formulation______________________________________Leuco dye Test dye 120 mg 0 mgSensitizing I (See 15 mg 15 mgdye Example I)Binder II 165 mg 285 mg (See Example II)Solvent 1-methoxy- 10 ml 10 ml 2-propanol______________________________________
The solutions are spin coated onto a featureless polycarbonate substrate of compact disc dimensions to a dry thickness of approximately 200 nm (e.g. flood speed of 300 rpm, dwell time/speed of 8.4 sec/500 rpm, ramp speed/time 500-2000 rpm/20 sec). The disc is completed for testing by the sputtering or thermal evaporation of 100 nm or more of a gold reflector layer onto the dye layer. A protective lacquer layer may also be present.
In the test formulation the total amount of sensitizing dye and binder can be conveniently set at 60% of the solids. The amount of the sensitizing dye is selected so that the collimated beam reflectivity as measured through the substrate at 780 nm after gold coating is from 50 to 90%. In the case of dye I (Table I) the sensitizing dye is present at 5% of the solids and affords a reflectivity of 71%.
Disc Testing and Evaluation
The disc is recorded on by a focussed laser operating at near 780 nm. A power series from 4 to 16 mW of 3.56 μm marks and spaces is written to the disc at a spinning velocity of 2.8 m/s. A maximum CNR in the test disc which is greater than in the control disc maximum is suggestive of a useful dye. Confirmation of the utility of the leuco dye is made by evaluation of the electronic wave forms associated with the recorded tracks and/or examination of the tracks microscopically. Wave form analysis must indicate that the recorded signal derives from marks whose reflectivity is reduced through the length of the mark. That is, dye formation occurred rather than dye bleach, which would cause an increase in reflectivity. The control disc must show no persistent reduction in reflectivity through the length of the mark when examined by either the electronic or microscopic technique.
One class of leuco dye that can be used in accordance with this invention is a tellurapyranyl Te(IV) leuco dye that has the following structure: ##STR1## wherein:
R 1 , R 3 , and R 5 each independently represent hydrogen, alkyl, aryl, (CR6═CH)nCR7-A1 or (CH═CH)mA2 provided that one, and only one of R 1 , R 3 , and R 5 is (CR6═CH)nCR7═A1 or (CH═CH)mA2; R 2 and R 4 each independently represents hydrogen, alkyl, or halogen;
R 2 and R 3 , or R 4 and R 5 , taken together with all the carbon atoms to which they are attached, form a mononuclear or polynuclear fused carbocyclic ring having form about 5 to 20 carbon atoms;
R 6 and R 7 are each independently hydrogen, cyano, akyl or aryl;
A1 represents a monocyclic or polycyclic heterocyclylidene group such as, but not limited to, oxazolylidene, thiazolylidene, selenazolylidene, imidazolylidene, pyranylidene, thiapyranylidene, selenapyranylidene, tellurapyranylidene, oxoindolazinylidene, benzoxazolylidene, benzothiazolylidene, benzoselenazolyidene, benzopyranylidene, benzothiapyranylidene, benzoselenapyranylidene, or benzotellurapyranylidene;
A2 represents aryl, amino, diakylamainoaryl, alkylamino, arylamino, dialkylamino, diarylamaino, or a monocyclic or polycyclic heterocyclyl group such as, but not limited to, oxazolyl, tetrahydroguinolinyl, 9-jololidyl, thiazolyl, selenazolyl, imidazolyl, benzoxazolyl, benzothiazolyl, or naphthyl;
n represents a number from 0 to 5;
m represents a number from 0 to 5;
X represents a functional group such as, but not limited to, Br, Cl, F, I, CH 3 CO 2 ; and
Z represents an anion such as, but not limited to, BF 4 , ClO 4 , CF 3 SO 3 , FSO 3 , PF 6 , Cl, Br, I.
A preferred tellurapyranyl Te(IV) material is benzotellurapyranyl Te(IV) materials wherein either R 2 and R 3 , or R 4 and R 5 , taken together with the carbon atoms to which they are attached, form a fused carbocylic ring having six carbon atoms. They have the structure: ##STR2## wherein:
R 8 and R 10 each independently represents hydrogen, alkyl, aryl, (CR 6 ═CH) n CR 7 -A 1 or (CH═CH)mA2 provided that one, and only one of R 8 and R 10 is (CR 6 ═CH) n CR7═A 1 or (CH═CH) m A 2 ;
A 1 , A 2 , R 6 , R 7 , n, m, and X are as previously defined;
R 9 represents hydrogen or alkyl;
R 11 , R 12 , R 13 , and R 14 each independently represent hydrogen, alkyl, halogen, hydroxy, or alkoxy.
"Alkyl" includes a branched- or straight-chain hydrocarbon having up to 20 carbon atoms, such as methyl, butyl, dodecyl, tertiary-butyl, and isobutyl as well as substituted alkyl groups such as hydroxyethyl, hydroxypropyl, and the like; "aryl" includes phenyl, naphthyl, anthryl, and the like substituted aryl such alkoxyphenyl and dialkylaminophenyl and the like.
Upon thermal treatment via the write laser and the sensitizing dye, the tellurapyranyl Te(IV) dyes undergo reductive elimination of X 2 to give tellurapyrylium dyes having one of the following structures with all groups defined above. ##STR3##
General Procedure for the Preparation of Te(IV) Dichlorides
A stock solution of chlorine in carbon tetrachloride was prepared by bubbling chlorine gas into the solvent. The weight of chlorine added was used to compute molarity (approximately 0.5M). The chlorine solution (1.5 equivalents ) was added via syringe to the tellurapyrylium dye in dichloromethane (approximately 0.3M) . The resulting solution was stirred 15 min at ambient temperature and was then diluted with an equal volume of ether. The Te(IV) dichloride precipitated, was collected by filtration, washed with ether and dried.
LD2
89% of a red solid, mp 185°-188° C.(dec) (See ref. 5); λ max (CH 2 Cl 2 ) 548 nm (Ε 55,000 L mol -1 s -1 ); IR (KBr) 2960, 1550 (s), 1470, 1365, 1313, 835 (s) cm -1 .
LD4
80% of an orange-gold solid, mp 178°-181° C. (dec); λ max (CH 2 Cl 2 ) 532 nm (Ε 60,000 L mol -1 s -1 ); 1 H NMR (CD 3 CN) δ 8.59 (d×d, 1H,J=12, 15 Hz), 8.46 (s, 2H), 7.16 (d, 1H,J=15 Hz), 7.025 (s, 1H), 6.97 (d, 1H,J=12 Hz), 6.49 (s, 1H), 1.61 (s, 18H), 1.58 (s, 9H), 1.50 (s, 9H); IR (KBr) 2960, 1555, 1475, 1365, 963, 838 cm -1 .
LD6
89% of an orange-gold crystalline solid, mp 198°-202° C.(dec); λ max (CH 2 Cl 2 ) 535 nm (Ε 59,000 L mol -1 s -1 ); 1 H NMR (CD 3 CN) δ 8.64 (d×d, 1H,J=12, 15 Hz), 8.49 (s, 2H), 7.18 (d, 1H,J=15 Hz), 7.05 (s, 1H), 6.98 (d, 1H,J=12 Hz), 6.50 (s, 1H), 1.61 (s, 18H), 1.58 (s, 9H); IR (KBr) 2960, 1554 1470, 1365, 1315, 1280, 1225, 1200 cm -1 . Anal. Calcd for C 29 H 43 Cl 2 SeTe.Cl: C, 49.44; H, 6.15. Found: C, 49.44; H, 5.73.
LD10
89% yield of a maroon solid, mp 177°-180° C.(dec); λ max (CH 2 Cl 2 ) 548 nm (Ε 56,000 L mol -1 s -1 ) . Anal. Calcd for C 29 H 43 Cl 2 Te 2 .Cl: C, 46.24; H, 5.75. Found: C, 45.80; H, 5.46.
LD11
90% of a jet-black solid, mp 171°-175° C.(dec); λ max (CH 2 Cl 2 ) 530 nm (Ε 48,000 L mol -1 s -1 ); 1 H NMR (CD 3 CN) δ 8.34 (d, 1H,J=13.7 Hz), 8.14 (br s, 1H), 7.75 (br s, 1H), 7.58 (d, 1H, J=13.7 Hz), 721 (br d, 2H), 7.03 (s, 1H), 6.66 (s, 1H), 3.61 (s, 6H), 1.57 (s, 9H), 1.52 (s, 9H). Anal. Calcd for C 23 H 32 Cl 2 NTe.PF 6 :C, 41.48; H, 4.84; N, 2.10. Found: C, 40.87; H, 4.78; N, 2.12.
LD12
54% of a brick-red solid, mp 203°-206° C.(dec); λ max (CH 2 Cl 2 ) 535 nm (Ε 59,000 L mol -1 s -1 ); 1 H NMR (CD 3 CN) δ 8.13 (d, 1H,J=13.7 Hz), 7.93 (s, 1H), 7.60 d, 1H,J=13.7 Hz), 7.59 (s, 1H), 7.01 (s, 1H), 6.68 (s, 1H), 3.91 (br t, 4H,J=5.5 Hz), 1.88 (br t, 4H,J=5.5 Hz), 1.57 (s, 9H), 1.52 (s, 9H), 1.36 (s, 6H), 1.32 (s, 6H) . Anal. Calcd for C 31 H 44 Cl 2 NTe.PF 6 : C, 48.10; H, 5.73; N, 1.81. Found: C, 47.85; H, 5.54; N, 1.76
General Procedure for the Preparation of Te(IV) Dibromides
A stock solution of bromine in carbon tetrachloride was prepared (approximately 0.5M) . The bromine solution (1.5 equivalents) was added via syringe to the tellurapyrylium dye in dichloromethane (approximately 0.3M) . The resulting solution was stirred 15 min at ambient temperature and was then diluted with an equal volume of ether. The Te(IV) dibromide precipitated, was collected by filtration, washed with ether, and dried.
LD1
92% of an orange solid, mp 264°-268° C.(dec); λ max (CH 2 Cl 2 ) 522 nm (Ε 59,000 L mol -1 s -1 ); IR (KBr) 2960, 1590 (sh), 1560, 1365, 1313, 1280, 840 cm -1 . Anal. Calcd for C 29 H 43 Br 2 STe.PF 6 : C, 40.69; H, 5.06. Found: C, 39,95; H, 4.84.
LD5
79% of an orange solid, mp 195°-200° C.(dec); λ max (CH 2 Cl 2 ) 544 nm (Ε 62,000 L mol -1 s -1 ); 1 H NMR (CD 3 CN) δ 8.59 (d×d, 1H,J=12, 15 Hz), 8.46 (s, 2H), 7.155 (d, 1H,J=15 Hz), 7.02 (s, 1H), 6.95 (d, 1H,J=12 Hz), 6.51 (s, 1H), 1.61 (s, 27H), 1.53 (s, 9H); IR (KBr) 2960, 1590, 1552 (s), 1470, 1363, 1312, 1274, 838 cm -1 .
LD13
96% of a brick-red solid, mp 185°-189° C.(dec); λ max (CH 2 Cl 2 ) 535 nm (Ε 59,000 L mol -1 s -1 ); 1 H NMR (CD 3 CN) δ 8.14 (d, 1H,J=13.7 Hz), 7.93 (s, 1H), 7.58 (d, 1H,J=13.7 Hz) 7.60 (s, 1H), 7.01 (s, 1H), 6.68 (s, 1H), 3.91 (br t, 4H,J=5.5 Hz), 1.89 (br t, 4H,J=5.5 Hz), 1.60 (s, 9H), 1.52 (s, 9H), 1.36 (s, 6H), 1.32 (s, 6H) . Anal. Calcd for C 31 H 44 Br 2 NTe.PF 6 : C, 43.14: H, 5.14; N, 1.62. Found: C, 42.62; H, 5.04; N, 1.58.
The following examples are presented for a further understanding of the invention:
Leuco dyes are well known intermediates in dye formation. Samples of the following leuco dyes have been prepared and converted into permanent dyes that are usable in accordance with this invention. These compounds are prepared by the following: ##STR4## Structural details and spectral data for such leuco dyes and permanent dyes are compiled in Table II.
TABLE II______________________________________Tellurapyranyl Dihalide Leuco dyes Which GenerateNear-Infrared-Absorbing Dyes Upon Heating Leuco dye Reduced .sup.λ max Dye .sup.λ max (CH.sub.2 Cl.sub.2), (CH.sub.2 Cl.sub.2),Compound R X Y Z nm nm______________________________________LD1 H Br S PF.sub.6 535 750LD2 H Cl Te PF.sub.6 548 833LD3 H Br Se Cl 541 786LD4 H Cl Se Cl 544 786LD5 H Br Se PF.sub.6 544 786LD6 H Cl Se PF.sub.6 532 786LD7 H Br Te PF.sub.6 565 833LD8 H Br Te Cl 565 833LD9 CH.sub.3 Cl Se ClO.sub.4 542 847LD10 H Cl Te Cl 548 833LD11 -- Cl -- PF.sub.6 530 713LD12 -- Cl -- PF.sub.6 524 768LD13 -- Br -- PF.sub.6 525 768LD14 -- Br -- BF.sub.4 525 760LD15 -- Cl -- BF.sub.4 497 760LD16 -- I -- BF.sub.4 530 760LD17 -- Cl -- PF.sub.6 544 753______________________________________
A second class of leuco dye that can be used in accordance with this invention is a chalcogenapyran of the following structures: ##STR5## wherein:
Y is O, S, Se, or Te and R 1 , R 2 , R 3 , R 4 , and R 5 are as described above. Alternatively, the leuco dye may have the following structure: ##STR6## wherein:
Y is O, S, Se, or Te and R 8 , R 10 , R 11 , R 12 , R 13 and R 14 are as described above. Alternatively, the leuco dye may have the following structure: ##STR7## wherein:
Y is O, S, Se, or Te and R 1 , R 2 , R 3 , R 4 , R 5 R 8 , R 10 , R 11 , R 12 , R 13 and R 14 are described above and R 2 ' is defined the same as R 4 , and R 9 ' is defined the same as R 9 .
These leuco dyes are oxidized to infrared-absorbing dyes upon thermal or photochemical reaction of the write laser with a thermal acid generator or photoacid generator, respectively.
GENERAL PROCEDURE FOR LEUCO DYE SYNTHESIS
The chalcogenapyrylium dye was dissolved in ethanol (1 gram of dye in 50 to 250 mL of ethanol). Excess sodium borohydride (approximately 0.1 gram of sodium borohydride per gram of dye) was added. After the dye color had faded indicating complete consumption of dye, the reaction mixture was poured into water and the leuco dyes were extracted with dichloromethane. The combined dichloromethane extracts were dried over sodium sulfate and concentrated to give the leuco dyes LD19, LD20, LD22, and LD23.
Sodium borohydride reduction of chalcogenapyrylium dyes in ethanol gives excellent yields of neutral leuco dyes from hydride addition. As shown below, hydride addition occurs primarily at the central methine carbon to give symmetrical leuco dyes LD19. The minor products from these reactions gave hydride addition at the carbons bearing the tert-butyl groups. The overall chemical yield was 79% for the reduction of 18a, 85% for the reduction of 18b, and 91% for the reduction of 18c. ##STR8##
The structural assignments of LD19 and LD20 followed from 1 H NMR spectra. The symmetrical products LD19 were characterized by a triplet for the central methylene and doublets for the two bridging methine signals. For LD19a and LD19b, two tert-butyl signals were apparent as were two olefinic signals for the pyranyl protons. Compound 19c was characterized by four tert-butyl signals, four olefinic singlets, and two sets of olefinic doublets. For compounds LD30, four tert-butyl signals were accompanied by a non-olefinic methine doublet, and three olefinic singlets. The field desorption mass spectra of the mixtures were consistent with the addition of a hydride to the dye nucleus.
The regiochemistry of hydride addition was sensitive to the steric bulk of substituents. The dichloro trimethine dye 21 gave a much different product ratio upon hydride reduction. The symmetrical selenapyranyl compound LD22 was the minor component (30% of the mixture) while the unsymmetrical selenapyran LD23 was the major component (70% of the mixture). The chlorine groups are much larger than a proton leading to decreased hydride addition at the central methine carbon atom. The mixture of LD22 and LD23 was isolated in 86% yield. ##STR9##
PREPARATION AND OPERATION OF CD DISCS
EXAMPLE I
A solution was prepared by mixing the following chemicals and filtering through a 0.2 micron filter to remove any insoluble residue.
______________________________________SensitizingComponent Reference Amount______________________________________Dye I (See Below) 7.5 mgLeuco dye LD1 60.0 mgBinder II (See Below) 82.5 mgSolvent 1-Methoxy-2- 5.0 ml propanol______________________________________
The following is an example of how to form a recordable element:
______________________________________ ##STR10## ##STR11##R Mole Percent______________________________________ ##STR12## 50 ##STR13## 33 ##STR14## 17II______________________________________
The recording layer was formed by spin coating the solution onto a 120 mm featureless polycarbonate substrate to a thickness of approximately 200 nm.
A gold reflector layer approximately 130 nm thick was applied to the recording layer by resistive heating vacuum evaporation.
The optical recording medium had a reflectivity of 61.4% when measured through the substrate with collimated light at 780 nm.
The disc was recorded on by a focused laser (788 nm) operating through the substrate, while spinning at 2.4 m/s, 2× the normal CD speed. Dark marks on a reflective background were formed as evidenced by their wave forms and by subsequent examination of the recording by brightfield microscopy at 780 nm.
A 4-16 mW power series of Ill marks was written on the disc. When read back with the write laser at reduced power (0.6 mW), the disc exhibited good recording contrast and sensitivity. A CNR of 61 dB was obtained at 10 mW write power.
A track of Ill marks (i.e. mark=space=3.56 um) was recorded at 10 mW and the optical contrast (Ill/Itop) was found to be 0.73. A track of I3 marks (0.97 μm marks and spaces) gave an optical contrast of 0.28.
EXAMPLE II
The procedure of Example I was repeated except that LD2 (Table II) was employed as the leuco dye. Dark marks on a reflective background were formed as evidenced by brightfield microscopy at 780 nm. The CNR of a track of Ill marks was found to be 48 dB at 16 mW while a control coating without leuco dye exhibited a CNR of only 34 dB.
EXAMPLE III
The procedure of Example I was repeated except that LD4 (Table II) was employed as the leuco dye. Dark marks on a reflective background were formed as evidenced by brightfield microscopy at 780 nm. The CNR of a track of Ill marks was found to be 55 dB at 16 mW while a control coating without leuco dye exhibited a CNR of only 34 dB.
EXAMPLE IV
The procedure of Example I was repeated except that LD6 (Table II) was employed as the leuco dye. Dark marks on a reflective background were formed as evidenced by brightfield microscopy at 780 nm. The CNR of a track of Ill marks was found to be 51 dB at 16 mW while a control coating without leuco dye exhibited a CNR of only 34 dB.
EXAMPLE V
The thermal acid generator chosen for the following example was a compound which has the structure: ##STR15## Generation of trifluoromethanesulfonic acid would be initiated via thermal formation of the orthocyanobenzyl radical and thioanisole cation radical.
Preparation of an Optical Disc
Two solutions were prepared by mixing the following chemicals and filtering through a 0.2 micron filter to remove any insoluble residue.
______________________________________Component Solution 1 Solution 2______________________________________Sensitizing Dye I 15 mg 15 mgLeuco dye LD-23 None 100 mgThermal Acid III None 100 mgBinder III 285 mg 85 mg1-Methoxy-2-propanol 10 cc 10 cc______________________________________
Optical discs were prepared by spin coating the solutions onto 120 nm featureless polycarbonate substrates to a thickness of approximately 200 nm. A gold reflector layer approximately 130 nm thick was applied to the layers by resistive heating vacuum evaporation.
The discs were recorded on by a focused laser (788 nm) operating through the substrate, while spinning at 2.4 m/s. A power series of Ill marks was written on the discs.
The disc (#2) prepared from Solution 2 afforded a focused beam reflectivity of 58%. Writing caused the formation of dark marks on the reflective background as evidenced by the electronic wave forms and by microscopic observation (780 nm brightfield illumination). Ill/ltop increased to 0.30 through the 2-18 mW power series. The CNR signal peaked at 44 dB.
In the control disc (#1), prepared from the Solution 1, the focused beam reflectivity was 66%. Writing caused slight marking of the media as evidenced by distortion of the gold layer as seen by gold incident DIC microscopy. This was comparable to that observed in disc #1. However, there was observation of dark marks on the reflective background when observed throughout the substrate under 780 brightfield illumination, nor was there any observation of a significant electronic wave form indicative of reduced reflectivity. Ill/ltop stayed at 0.04±0.01 throughout the 2-18 mW power series. CNR peaked at 34 dB.
The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention. | There is disclosed a recordable optical element that includes a dye. The element has a substrate and on the surface of the substrate, a dye containing recording layer and a light reflecting layer. The dye is a leuco dye which upon exposure to a thermally-generated acid becomes an absorption dye. | 8 |
PRIORITY CLAIM TO RELATED APPLICATIONS
This application is related to and claims priority from U.S. Provisional Application Ser. No. 61/062,914, filed Jan. 29, 2008, entitled Target Identification Tool For Intra-Body Localization, and U.S. Provisional Application Ser. No. 61/051,632, filed May 8, 2008, entitled Target Identification Tool For Intra-Body Localization. The entireties of each are incorporated by reference herein.
BACKGROUND OF THE INVENTION
In the case of a suspected lung mass in a high risk patient for lung cancer, it is the current standard of care to send the patient for radical removal of the mass. Certain portions of these surgeries are made by Video Assisted Thoracotomy Surgery (VATS), which is a minimally invasive surgery, and invasive Thoracic Surgery. Obtaining accurate diagnosis in the least invasive means possible as quickly as possible is essential. During VATS, it is often very hard to recognize the suspected small lung masses during the procedure. VATS success is limited by the ability to visualize and palpate the nodule if it is less than 10 mm in size and if it is more than 5 mm from a pleural surface. Historically, in 63% to 82% of cases there is an inability to visualize or palpate a detected nodule. (1. Burdine, et al. CHEST 2002; 122:1467, 2. Suzuki, et al. CHEST 1999; 115:563). Minimally invasive surgery is becoming more and more popular and holds similar challenges to those seen in VATS when used in the abdominal cavity, the urogenital system or other parts of the body.
A lung mass (solitary pulmonary nodules (SPN) or other) in the periphery of the lungs that is identified by X-ray machine or CT must also be physically identified by the surgeon for removal. However, visual identification of the mass may often be difficult due to tissue obstructions, such as, when the nodule is buried deep in the lung tissue.
Lack of visual identification creates problems. In some instances, surgeons discover lesions during surgery that were not earlier identified by a referring physician or radiologist. In this case, the surgeon needs to decide which of the lesions is suspected to be cancerous. Therefore, to avoid mistakes, the surgeon typically removes a larger portion of the tissue, ensuring the entire lesion is removed but also increasing tissue trauma, the possibility of complications, patient suffering, and so forth. In other cases, lack of visual identification results in the excision of healthy tissue rather than the targeted lesion.
In other body cavities similar challenges are encountered since visibility and the means to identify specific pre-planned lesions as were identified by medical imaging, is often limited.
Most current methods for identifying masses and other such lesions and tissues may best be characterized as “from the outside to the inside,” and are often rather complex, invasive and risky. Such methods include, for example, manual identification (e.g., finger palpation through the rib cage), intrathorascopic ultrasound, transthoracic placement of an external wire, injecting solidifying liquids, dye injection, TC-99 injection, radiopaque markers such as barium or injectable coils, guidance by CT, intrathorascopic ultrasound, fluoroscopy-assisted thoracoscopic resection, etc.
There are current challenges with external beam radiation delivery due to the inability to see the tumor during treatment. Accurate alignment of sterotactic planning onto the patient, before the procedure, is required for accurate real-time tracking of the tumor. Additionally, tumor position in the lungs is changing as a result of the normal respiratory cycle, unpredictable baseline shifts and variable amplitude of respiratory rates. Consequently, an insufficient dose of radiation may be delivered due to its toxic effects on surrounding healthy lung tissue and may lead to failure to control tumor growth. Because of these challenges, fiducial markers are often used in soft tissue to guide focused-beam radiation treatment.
One of the major drawbacks to fiducial marker placement is delivery of the marker transthoracically. This approach can lead to pneumothorax or collapsed lungs because often the patients already have compromised lung function. In addition to the risk of pneumothorax there is also the complication of marker migration. Unlike the relatively static, homogeneous tissue of the prostate, the lung tissue moves significantly with the breathing cycle and is also porous and interlaced with airways. As a result, an implanted seed is prone to migrate, typically out of the channel formed during placement, and fall down an airway. Once in the airway, the seed will either settle in a distal portion of the lungs, or be coughed out.
Another potential application for marker or catheter placement within the lungs may be for the delivery of therapies such as brachytherapy, cryotherapy, or drug delivery through a deposited drug depot.
If an inert or active marker seed or temporary catheter migrates, the target is lost. If the therapy vehicle is expectorated, the treatment ends prematurely. Even worse, if the delivery vehicle migrates away from the target, therapy is administered to healthy tissue instead of a tumor, thereby damaging the healthy tissue and sparing the tumor.
There is a need for an improved identification device or marking device and method of introducing this device into the body. More specifically, there is a need for an identification device or marking device that: 1) can be placed within the location of interest or adjacent to it and permits identification of masses or other location of interest, through the surrounding tissues, 2) is minimally invasive, and 3) has a minimal damaging effect on the tissue to avoid complications.
There may also be a need for a method of extracting this device from the body in a minimally invasive manner.
There is also a need for anchoring an identification or therapeutic device or marking device within the body.
There is also a need for a method of communication or bringing between two tools, one from “inside out” and the other one from “outside in”. The first is the so called identification device or marking device and the second is the complementary counterpart, which is an assembly of detector device and interventional device, capable to identify the signal emitted by the identification device or marking device, thus, the precision in localization is achieved and the task can be performed with great confidence.
There is also a need for a marker or therapeutic seed that includes an anchoring mechanism that prevents the seed from migrating once positioned.
OBJECTS AND SUMMARY OF THE INVENTION
In view of the foregoing, one aspect of the present invention is to provide an identification or marking device and method that overcomes the limitations of the prior art.
Another aspect of the present invention is to provide an identification or therapeutic device that may be placed permanently or semi-permanently (removable only with excision of the surrounding tissue) or removably (without significant trauma to the surrounding tissue).
Another aspect of the present invention is to provide an identification or therapeutic device that may be pre-, intra- or post operatively activated and implanted in the location of interest or adjacent to the location of interest within the body (for example, at or near a mass and surrounding tissues desired for extraction).
Another aspect of the present invention is to provide a body portion of the identification device that will be sufficiently illuminating to be seen through adjacent tissues and/or sufficient to indicate the exact location of interest by visualization of the light via the naked eye and/or through any kind of endoscope and/or sufficient to indicate the exact location of interest by sound, ultrasound, radioactive material electromagnetic emitting device or other form of energy.
Another aspect of the present invention is to provide a complementing counterpart, which is a permanent assembly or add-on detector device, coupled to an interventional device (e.g. light endoscope, Geiger meter), and capable of identifying the signal emitted by the identification device or marking device and communicating its location to the user.
Yet another aspect of the invention provides various anchoring devices that prevent the markers or therapeutic seeds of the present invention from migrating once implanted.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of an embodiment of the device of present invention;
FIG. 1 a is a side view of an embodiment of the device of the present invention;
FIG. 2 is a side view of the embodiment of the device of FIG. 1 implanted into body tissue;
FIG. 3 is a perspective view of an embodiment of the device of the present invention;
FIG. 4 is a perspective view of the embodiment of the device of FIG. 3 implanted into body tissue;
FIG. 5 is a perspective view of an embodiment of the device of the present invention;
FIG. 6 is a perspective view of the embodiment of the device of FIG. 5 implanted into body tissue;
FIG. 7 is a perspective view of an embodiment of the device of the present invention;
FIG. 8 is an end view of the embodiment of the device of FIG. 7 of the present invention;
FIG. 9 is a side view of an embodiment of the device of the present invention;
FIG. 10 is an end view of the embodiment of the device of FIG. 9 ;
FIG. 11 is a perspective view of an embodiment of the device of the present invention being injected into body tissue;
FIG. 12 is a side view of the embodiment of the device of FIG. 11 implanted in tissue;
FIG. 13 is a side elevation of an embodiment of the device of the present invention; and,
FIGS. 14 and 15 are side elevations of the device of FIG. 13 being implanted into tissue.
DETAILED DESCRIPTION OF THE INVENTION
In general, the present invention includes an identification or therapeutic device comprising a body portion and an anchoring portion, which is introducible into an intra-body structure (e.g., a mass or lesion) and/or an anatomical space to mark a location of interest (e.g., a tissue layer and/or lumen of a body cavity). The identification device of the present invention may include a power source, either external to the body or internally at or near the body portion or some combination thereof. It is understood that any of the various anchoring portions described below may be used with any of the body portions. It is also understood that the body portions may give off energy, such as light energy (i.e. glow-in-the-dark materials, LEDs, incandescent devices, etc.), thermal energy, radiation, RF energy, acoustic energy, or cryoenergy.
Furthermore, the various embodiments of the body portions may be constructed of various application-specific materials. For example, the body portions may be loaded with chemicals or dyes that enhance localization. Non-limiting examples include: BaSO4, bismuth, copper, gold, and platinum. Also, the body portions could be loaded with drugs and/or chemotherapy agents for treatment and have features such as controlled elution and diffusion rates. Non-limiting examples of these agents include antineoplastics, antibiotics and others.
One embodiment of the present invention is shown in FIGS. 1, 1 a , and 2 which illustrate an identification or therapeutic device 10 , including a body portion 12 and anchoring portion 14 . The body portion 12 may be any energy source or simply a marker or a focusing element for RF energy, as described above. If an energy source is used, it is understood that appropriate additional equipment will be used in order to receive and identify the energy being transmitted. The body portion 12 may also comprise a hollow body in the event that the device 10 is implanted in an airway.
The anchoring portion 14 is shaped and oriented to render it introducible into or adjacent to an intra-body structure. The anchoring portion 14 , may also include hooks or barbs 15 , to improve the anchoring ability of the anchoring portion 14 . Preferably, the barbs 15 are small enough to allow removal with minimal tissue damage. As shown in FIG. 2 , the anchoring portion of the identification or therapeutic device 10 is inserted into an intra-body structure (e.g., a tissue layer) 16 . The anchoring portion 14 leaves the body portion 12 oriented adjacent to the tissue layer 16 , providing fixed, yet removable illumination or therapy. (“Illumination” is being used in a general sense to include acoustic energy, radioactive energy, electromagnetic energy or other form of energy and should not be construed as being limited to casting visible light on a subject.) In this illustration of the embodiment, the device 10 may be pulled out of the tissue layer and removed from the body or the tissue may be excised with the identification device 10 still affixed thereto.
Another embodiment of the present invention is shown in FIG. 3 , in which an identification or therapeutic device 20 includes a body portion 12 and at least one anchoring mechanism 24 . The anchoring portion 24 is one or more barbed rings encircling the device 20 . The barbs on the rings may be evenly spaced around the device 20 , thereby providing ease of implantation as orientation-specific deployment is not necessary. Preferably, the barbs are strong enough to penetrate tissue yet flexible enough to lay flat in a deployment catheter. If the device 20 is intended to be non-permanent, the barbs should be short and flexible enough to allow removal without excessive tissue damage. FIG. 4 illustrates the device 20 inserted into an adjacent tissue layer 26 via the at least one anchoring mechanism 24 .
Yet another embodiment of the present invention is shown in FIG. 5 , in which an identification or therapeutic device 30 includes a body portion 12 and an anchoring portion 34 . The anchoring portion 34 includes, for example, a mesh and/or tissue adhesive affixed on at least a portion of the surface of the body portion 12 . The mesh may be bioreactive. The anchoring portion 34 adheres to a tissue layer 36 . The anchoring portion 34 is large enough to connect with the tissue layer 36 , such that it will remain attached until some amount of applied force is used to remove the identification device 30 from the tissue layer 36 . FIG. 6 illustrates the identification device 30 affixed to a tissue layer 36 .
Another embodiment of the present invention is shown in FIGS. 7 and 8 , in which an identification or therapeutic device 40 includes a body portion 12 and an anchoring portion 44 . In this embodiment, the anchoring portion 44 is disposed within a body lumen and may or may not penetrate the surrounding tissue layer 46 . One example of the anchoring portion 44 contemplated for use in this embodiment of the invention would include a coil or stent 44 with a body portion 12 attached to an inside surface of the stent 44 . The anchoring portion 44 expands, either via balloon or self-expanding design, to fit the surrounding tissue layer 46 . The anchoring portion 44 is deliverable by any known or unknown methods. For example, the anchoring portion 44 may be collapsed to fit in or around a delivery catheter (not shown) and delivered and expanded in a desire location.
Another embodiment of the present invention is shown in FIGS. 9 and 10 , in which an identification or therapeutic device 50 includes a body portion 12 and an anchoring portion 54 . In this embodiment, the anchoring portion 52 is a staple that connects the device 50 to a tissue layer 56 . Removal of the identification device 50 may occur via excision of all or part of the surrounding tissue layer 56 .
The identification devices described above may be introduced and placed into the body by various delivery devices and methods. Such delivery devices and methods may include, alone or in combination, use of catheters, guiding catheters, guide wires, stents, balloons, needles, bronchoscopy procedures and tools and/or the superDimension localization system, as described in U.S. patent application Ser. No. 11/571,796 filed on Jan. 8, 2007, which is incorporated by reference herein in its entirety. In particular, such deliveries may be made into branches of the lungs, blood vessels and other points of interest (body cavities, lumens).
For example, one embodiment of a device 60 of the present invention that is injected into tissue is shown in FIGS. 11 and 12 . The identification device 60 includes a body portion 12 that is injected into a tissue layer 64 . The surrounding tissue layer 64 may effectively hold the identification device 60 in place. However, an additional anchoring portion may be added, such as any of the above described anchoring portions or merely a rough surface to prevent migration. FIG. 11 illustrates a needle 66 containing an identification or therapeutic device 60 prior to delivery into a tissue layer 64 . FIG. 12 illustrates the placement of the identification device 60 within the tissue layer 64 , post-injection.
FIGS. 13-15 illustrate an embodiment of a device 70 of the present invention that is specifically designed to be injected into tissue. The device includes a capsule 74 surrounding the body portion 72 to allow the device 70 to be smoothly injected into tissue 78 . Once in contact with the tissue, the capsule 74 quickly dissolves, allowing the tissue 78 to close in around the body portion 72 . Preferably, the body portion 72 includes one or more anchoring features 76 , such as ridges, spikes, rough surfaces, barbs, or other shapes or mechanisms that would prevent the device 70 from migrating.
The capsule 74 is smooth such that minimal tissue trauma occurs during insertion. The capsule may be constructed, for example, of a quickly dissolving material such as many water-soluble polymers.
Another embodiment of the present invention includes a device that is specifically designed to be injected into the target location for external localization. The entire device may be dissolvable or biodegradable thus eliminating the necessity for removal. The biodegradable material may be impregnated with a material such as metallic particles specifically selected to for image-guidance. The rate of degradation could be dependent on a known therapeutic dose to control or affect the targeted disease tissue. Examples of some biodegradable polymers include, but are not limited to: PEVA poly(ethyl-vinyl-acetate), PBMA poly(butyl-methylacrylate), PLGA poly(lactic-glycolic acid), PLA (Polylactide), PLGA/PLA combination, HA (hydroxyapetite), PLGA-PEG (polyethylene glycol), Tyrosine derivatives, Polyanhydrides, Polyorthoesters, PBMA, DLPLA—poly(dl-lactide), LPLA—poly(l-lactide), PGA—polyglycolide, PDO—poly(dioxanone), PGA-TMC—poly(glycolide-co-trimethylene carbonate), PGA-LPLA—poly(l-lactide-co-glycolide), PGA-DLPLA—poly(dl-lactide-co-glycolide), LPLA-DLPLA—poly(l-lactide-co-dl-lactide), PDO-PGA-TMC —poly(glycolide-co-trimethylene carbonate-co-dioxanone). Examples of metallic or other image-guidance materials include but are not limited to: radiopaque dyes or contrast agents such as BaSO4 or Ominpaque, metallic particles such as copper or gold particles.
Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention.
For example, the above-described needle and syringe or plunger arrangement could be used to deliver an identification or therapeutic device internally, injecting said tool directly into a tissue layer from within the body cavity. Alternatively, a needle of sufficient construction both to penetrate the chest cavity (e.g., between the ribs of a patient) and accommodate the dimensions of an identification or therapeutic device such that can be injected from outside a patient's body into a desired location (e.g., directly into surrounding tissues near a body cavity; into a fibroid or tumor that is intended to be excised from the body; etc).
The identification device could be delivered via a bronchoscope having a catheter attached therethrough which is advanced through the lungs of a patient to a point of interest. The catheter will be equipped to push the identification device into a lumen of a body cavity near a tissue layer or into a tissue layer.
Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof. | A marker device that aids in the subsequent identification of a particular area is equipped with an anchoring device that prevents migration once placed in the tissue of that particular area. The device may include a chemical agent or drug that adds a therapeutic function to the marker device. | 0 |
FIELD OF THE INVENTION
[0001] The present invention relates to clock selection for communications systems having a sleep mode. In particular, the invention is directed to wireless communications systems having an accurate network clock, a low speed clock for a sleep mode, and a host clock for an operational mode.
BACKGROUND OF THE INVENTION
[0002] FIG. 1A shows a prior art communications system, which includes a System on a Chip (SoC) 110 , typically comprising baseband processing for a wireless communications system, which is coupled to an RF Front End 112 which accepts signals from antenna 113 , and performs the sequential operations of RF amplification, mixing to baseband using a local oscillator, and conversion to digital sampled signals using an analog to digital converter (ADC), and delivering these signals to the SoC 110 over interface 111 . A transmit stream may be generated by SoC 110 , which is provided to RF front end 112 as a baseband digital signal, which the RF front end 112 converts to an analog signal using a digital to analog converter (DAC). Thereafter, the analog signal is mixed to a modulation frequency, amplified, and transmitted to antenna 113 . The SoC 110 accepts a clock signal NET_CLK generated by an accurate network clock source 106 . Generating the baseband modulation signals requires a relatively accurate clock compared to the other operations of the SoC 110 , and a low frequency SLEEP_CLK is sourced by a sleep clock generator 104 . The SLEEP_CLK may be coupled to a power sequencer 114 such as for powering up the SOC 110 and RF front end 112 when periodic beacons are received. The SoC 110 may also receive a HOST_CLK from a host clock generator 108 , which is also coupled to an applications processor 102 through host interface 116 , which may be a synchronous interface according to a known standard such as Peripheral Component Interconnect (PCI as described in www.pcisig.com), Universal Serial Bus (USB as described in www.usb.org), Secure Digital IO (SDIO as described in www.sdcard.org), or any host interface known for interconnecting an applications processor to a communications system through an interface.
[0003] For battery powered devices, power saving modes are related to the useful time the device may be operated on a single charge. One prior art power saving mode uses a power sequencer 114 , which powers down various components of the system, which is shown as separated into components related to transmitting and receiving wireless signals PD 2 such as associated with the baseband interface 111 of the SoC 110 . For example, if there is no anticipated activity on baseband interface 111 , PD 2 may be asserted, thereby putting RF front end 112 into a powerdown state when no transmit or receive activity is anticipated, and PD 1 may be asserted when there is no anticipated data across the host interface 116 . The assertion of partial powerdown for power-consuming parts of a processing element is known as a “sleep mode”, and may involve operation at a lower clock rate, or partial or complete powerdown of the associated system. Crystal oscillators such as those used to generate the host clock 108 and network clock 106 tend to consume a large amount of power compared to low frequency sleep clock 104 , in part because the displacement currents generated by each clock transition in the oscillator as well as the circuitry the clock is delivered to are proportional to clock rate, such that for all other considerations being equal, a lowest rate clock tends to result in a lower power dissipation.
[0004] One problem of power saving operations is the requirement for the SoC 110 to maintain any existing network connections, and create new connections as required, both operations which require the SoC 110 to come out of sleep mode periodically and check for any pending traffic to be received or transmitted before going back into a sleep mode, and to be able to do this in a manner which does not cause any network connections or requests to time out for failure to respond. In one prior art system, the sleep clock 104 operates a wake-up timer within power sequencer 114 , such that the SoC 110 and RF front end 112 are powered up to receive periodically transmitted signals such as beacons, and any required transmit frames are sent during these intervals.
[0005] Outside of such wake-up intervals, if the communication SoC 110 does not have a clock, it will not be able to serve incoming requests 103 from the application processor 102 . In one prior art system, the SoC 110 indicates to the application processor 102 that it is entering a sleep mode, and the applications processor 102 uses a wakeup protocol with sequencer 114 to bring the system out of sleep mode when making a request 103 . In this system, the application processor 102 will queue requests and assert a powerup request to sequencer 114 . When the SOC 110 comes out of sleep mode and has clock signals available, it indicates to the application processor 102 through a handshake mechanism across interface 116 that the application processor 102 may start sending requests and other relevant events.
[0006] FIG. 1B shows the timing associated with this prior art wake-up method. Until request time 152 , only sleep clock 168 is active, and the host clock 164 and network clock 170 are powered down. After host request 152 , HOST_CLK 164 is in a shutdown state until Wakeup SoC is asserted 154 , where the HOST_CLK stabilizes during an initialization time, and at time 156 , the HOST_CLK is stabilized and the request is handled, with the network clock 170 applied thereafter 156 . After the network events are handled from time 156 to time 158 , host clock 164 enters a shutdown mode at time 158 . The network clock 170 may stay active after end of request handling at time 158 to time 160 to complete the processing of any transmit network traffic which is generated, and enters a sleep mode thereafter 160 .
[0007] There are many drawbacks associated with the process of FIGS. 1A and 1B . The latency in response from time 152 to time 154 followed by initialization until time 156 consumes additional time, during which interval the SOC has to be in a wake up mode prior to handling any actual requests, which also represents a power consumption inefficiency. The latency from time 152 to time 156 also results in reduced throughput if there are many such requests handled sequentially. Another inefficiency is that the applications processor 202 buffers the pending events without any of them being handled until the wake-up process from time 152 to time 156 is completed. Additionally, certain protocols such as Voice Over IP (VOIP) require immediate handling without the latency associated with wake-up protocols.
OBJECTS OF THE INVENTION
[0008] A first object of this invention is a clock switching circuit for providing a glitch-free transition from one clock source to another clock source at a different frequency.
[0009] A second object of the invention is a first and second doublet register, the first doublet register input coupled to a select input through an OR gate, the OR gate having another input coupled to the second doublet register output, an AND gate having one input coupled to the select input and the other input coupled to the first doublet register output, the output of the AND gate coupled to the input of the second doublet register input, and a clock output generated by the output of a second OR gate having inputs coupled to the outputs of a second AND gate and a third AND gate, the second AND gate coupled to a first clock source and the inverted output of the first doublet register, and second AND gate coupled to a second clock source and the output of the second doublet register, the first doublet register being clocked by the falling edge of the first clock and the second doublet register being clocked by the falling edge of the second clock.
SUMMARY OF THE INVENTION
[0010] A clock selection function accepts a first clock input, a second clock input, a clock select, and generates a selected clock output. A first and second doublet register is formed by two registers having a doublet input coupled to one register and a doublet output coupled to the other register output, with the remaining register output coupled to the remaining register input, both registers of the doublet clocked by the same clock input. The first doublet register input is coupled to the output of an OR gate, the OR gate having one input coupled to the select input, and the other OR gate input coupled to the second doublet output. The second doublet has an input coupled to the output of an AND gate, the AND gate having a first input coupled to the select input and the other input coupled to the output of the first doublet. The first doublet output is inverted and coupled to a second AND gate, with the other input of the second AND gate coupled to the first clock input. The second doublet output is coupled to an input of a third AND gate, with the third AND gate other input coupled to the second clock input. The outputs of the second AND gate and third AND gate our ORed together to form the clock output.
[0011] In another embodiment of the invention for use when either of a HOST_CLK or a NET_CLK clock source is unavailable, as indicated by an associated HST_CLK_AVAIL or NETCLK_OFF input, respectively, a clock select state machine clocked by NET_CLK has a first input HCA formed from a doublet register clocked by NET_CLK and a second input NCO formed from a doublet register clocked by NET_CLK. The clock select state machine generates EN_HSTCLK output, which is ANDED with HST_CLK_AVAIL and fed to a first doublet register clocked by HOST_CLK to generate SEL_HSTCLK, which is ANDED with HOST_CLK and ORed with the ANDing of EN_NETCLK and NET_CLK. The state machine moves between an IDLE state where EN_NETCLK is enabled and EN_HSTCLK is not enabled, a SLEEP state where EN_NETCLK is not enabled and EN_HOSTCLK is enabled, and WAIT, where neither EN_NETCLK nor EN_HOSTCLK is enabled. The state transitions are IDLE to SLEEP when NCO is asserted, SLEEP to WAIT when NCO is not asserted, and WAIT to IDLE a programmable number of NET_CLK cycles after entering WAIT.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1A shows the block diagram for a prior art wireless system.
[0013] FIG. 1B shows a time diagram for sleep mode and active modes for the system of FIG. 1A .
[0014] FIG. 2A shows the block diagram for a wireless signal processor having a clock selection for sleep mode.
[0015] FIG. 2B shows a time diagram for sleep mode and active modes for the system of FIG. 2A .
[0016] FIG. 3 shows a schematic diagram for a clock switching circuit with two available clocks.
[0017] FIG. 4 shows the timing diagram for the switching circuit of FIG. 3 .
[0018] FIG. 5 shows a block diagram for a clock switching circuit with one available clock and another clock having a startup delay time.
[0019] FIG. 6 shows the block diagram for an example clock selection for use in FIG. 5 .
[0020] FIG. 7 shows a state diagram for a controller for FIG. 6 .
[0021] FIG. 8 shows a timing diagram for the clock selector of FIG. 6 .
DETAILED DESCRIPTION OF THE INVENTION
[0022] FIG. 2A shows a wireless communications processor 200 including a wireless processor system on a chip (SOC) 208 coupled to an applications processor 202 which sends and receives data to the SOC 208 through a host interface 206 . The SOC 208 integrates all of the functions of the wireless system other than the front end components 234 described in FIG. 1A , including ADC, DAC, mixers, amplifiers, and other functions required to modulate and demodulate from antenna 236 to baseband digital interface 232 . The wireless processor 208 includes a host interface 216 to an internal bus 222 , which bus is also coupled to peripherals 218 , a DMA controller 220 , processor 228 , memory 230 , an interface 226 to the front end 234 , and a sleep state machine 224 . System on a chip wireless processor 208 accepts a network clock 212 which has higher accuracy than host clock 204 or sleep clock 214 . During sleep mode, the sleep clock 214 is coupled to sleep state machine 224 , which may provide periodic wake-up signals to the processor 208 . Network clock 212 may be in a powerdown state, such as under control of the sleep state machine 224 , and during intervals when it is not important to transmit or receive wireless signals using the accurate but high power load network clock 212 , the wireless processor 208 may operate on host clock 212 , which is selected by selector 210 and delivered. The clock selector 210 is controlled by applications processor 208 such as through a request through the host interface 206 . The processor of FIG. 2A may operate in a sleep mode when there is no activity, or if there is no network activity, it can operate on HOST_CLK, and finally, when there is network traffic to receive or transmit, the wireless processor 208 can power the network clock and use this clock for wireless transmit and receive protocols.
[0023] FIG. 2B shows the time sequence of operation of FIG. 2A for a host request which initiates a transmit operation. The wireless processor 208 runs on HOST_CLK from time 250 until the arrival of a host request at time 252 , whereupon the processor clock 262 is switched from HOST_CLK to NET_CLK for the duration of time required to handle the request to time 256 , after which the HOST_CLK is selected by 210 and provided to processor 204 .
[0024] In operation with the communications processor 200 of FIG. 2 , the clock selector 210 keeps the wireless processor 204 and associated circuits such as network clock 212 and front end components 234 in a low power state. In a sleep mode state, the network clock 212 will be switched off and a sleep counter 224 coupled to sleep clock 214 will be maintained. The sleep counter 224 will wake up the SOC on a periodic basis to maintain existing network connections to remote stations coupled to antenna 236 . In case of a pending request from the host processor 202 , the wireless processor 208 will service this event by using HOST_CLK as CLK_OUT 238 . If there is a need to immediately 9 service the request, such as for a VOIP packet, the wireless processor 208 can interrupt the sleep state machine and enable the network clock oscillator 212 . Once the network clock 212 oscillator has stabilized, the sleep state machine can instruct the clock select 210 to switch over to the network_clock 212 source and service the event.
[0025] FIG. 3 shows one example embodiment for the clock selector 210 of FIG. 2A , suitable for the case where both HOST_CLK and NET_CLK provided to clock selector 210 are continuously present. The clock selector 300 accepts a first clock input CLK 1 and a second clock input CLK 2 , along with a SELECT input 302 . Registers 306 and 308 form a first doublet register 322 with an input coupled to first register 306 input, register 306 output coupled to register 308 input, and register 308 output forming the doublet register output. The first doublet register 322 is clocked with the negative edge of the first clock CLK 1 , shown with the convention for inversion as a inversion bubble at the clock input. Second doublet register 324 is similarly arranged, with first register 314 and second register 316 similarly configured with inverted clock for clocking the falling edge of second clock input CLK 2 . First doublet register 322 generates SEL_CLK 1 and second doublet register 324 generates SEL_CLK 2 , as will be described. OR gate 304 has one input coupled to the SEL select input 302 and the other input coupled to the second doublet 324 output SEL_CLK 1 . First AND gate 312 has one input coupled to SEL input 302 and the other input coupled to first doublet register output SEL_CLK 1 , with first AND gate output coupled to the input of second doublet register 322 . The first doublet register 322 output is also inverted and coupled to second AND gate 310 , with the remaining second AND gate input coupled to the first clock input. The second doublet register 324 output is coupled to an input of third AND gate 318 , which other AND gate input is coupled to the second clock input CLK 2 . Second OR gate 320 generates the selected clock output CLK_OUT 320 by performing an OR operation on the outputs of second AND gate 310 and third AND gate 318 .
[0026] FIG. 4 shows the operation of the clock selection circuit of FIG. 3 . First clock 350 may represent the clock waveform for a first clock such as the host clock ordinarily used for transferring requests from the host processor interface 206 of the wireless processor 204 of FIG. 2A . Second clock input waveform 352 may represent the network clock required by the wireless processor 208 for wireless transmit and receive operations, although the power consumption for the higher frequency and higher power network clock is higher. In the first embodiment of the invention, the clock selection circuit may change from a sleep state with no clocks running to selecting a host clock for first processing requests, and then switching to the accurate network clock for transmitting or receiving wireless packets, as required by the clocking accuracy. For clarity of the example, CLK 1 is shown at a slightly lower frequency than CLK 2 , however in a typical system the two frequencies may be any frequencies suitable for clocking static registers as shown. When SEL waveform 354 is low, /SEL_CLK 1 356 and SEL_CLK 2 358 settle to LOW values, which cause gate 310 to enable first clock CLK 1 and disable second clock CLK 2 , thereby coupling CLK_OUT 320 to CLK 1 waveform 360 . When SEL 354 is asserted, /SEL_CLK 1 is asserted two negative CLK 1 edges later, and SEL_CLK 2 358 is asserted two clock edges after the assertion of /SEL_CLK 1 . During this interval shown as 364 , no output clock is generated. Upon the assertion of SEL_CLK 2 358 , CLK 2 is coupled to CLK_OUT 360 , as shown during interval 366 .
[0027] As mentioned earlier, the clock select circuitry of FIG. 3 is suitable for the case where CLK 1 and CLK 2 are both available during the transition from one clock source to the other clock source. FIG. 5 shows a generalized clock selection 518 in the context of a wireless processor 506 where the HOST_CLK may not be available, as indicated by HST_CLK_AVAIL, and with a network clock NET_CLK, which is disabled by DIS_NETCLK and provided by sleep state machine 528 which generates NETCLK_OFF a stabilization time later, such that NETCLK_OFF is asserted to the state machine several cycles before and after DIS_NETCLK, such that a reliable and settled NET_CLK is available before and after NETCLK_OFF is asserted. Sleep clock 508 is a low frequency clock source which is continuously running and used by sleep state machine 528 to assert NETCLK_OFF during powerdown states, and to control powerup of the processor 506 during intervals such as beacons, when the wireless processor 506 needs to be ready to receive remote transmissions. The wireless processor 506 may include any other elements, including a bus 524 for interconnecting a processor 532 with memory 534 , interfaces 530 to the front end 512 , DMA controller 540 , peripherals 538 , and a host interface 536 to application processor 502 over an interface bus 504 , which may include a host processor request 516 indicating a pending request for wireless processor 506 response.
[0028] In one embodiment of the invention as shown in FIG. 5 , the application processor 502 provides data for one or more packets to be transmitted, and the related packet data is accepted and queued in a buffer of host interface 536 , using the host clock 520 to buffer these packets. The buffering of packets to be transmitted by the wireless processor 506 allows the application processor to complete the transfer operation and continue with other operations. After packets from the application processor 502 are queued into the SOC 506 such as by using the host clock 520 as the clock source, the SOC 506 may start a wakeup sequence whereby the network clock 508 is enabled and settles, after which the clock select 518 may switch to network clock for those parts of the system needing it. During this mode of the invention, packets are transferred from the applications processor when the HOST_CLK is available and the NET_CLK is not available.
[0029] In another aspect of the invention, packets have been queued from the applications processor 502 for transmission, and the HOST_CLK is turned off by the applications processor. In this mode, the sleep state machine 528 requests the network clock NET_CLK 522 be taken out of disabled state such as by unasserting DIS_NETCLK, and the clock selection state machine 518 switches to NET_CLK when it is available, such as after HOST_CLK has been disabled. During this mode of operation, packets which were previously queued from the applications processor may be transmitted by the SOC 506 when the NET_CLK is available and the HOST_CLK is not available.
[0030] FIG. 6 shows a block diagram for one embodiment of the clock selection 518 of FIG. 5 . A HOST_CLK 602 is provided, such as by the host processor interface, which interface includes an indicator HST_CLK_AVAIL, which enables the selection of HST_CLK only when this clock source is available. HST_CLK_AVAIL is generated by logic in the Host Interface 536 . It is unasserted at the end of a data transaction on the host bus 504 , anticipating the removal of the Host Clock, and is asserted again when a fresh transaction starts on the host interface and the HOST_CLK is again active. Similarly, when asserted, NETCLK_OFF indicates that NET_CLK is not available, a power savings measure taken by the sleep state machine 528 of FIG. 5 . First doublet register 632 is clocked on the negative edge of HOST_CLK, and each doublet register such as 632 has an input coupled to first register 634 a with an output coupled to the input of second register 634 b, whose output forms the doublet output. Clock selection state machine 622 generates EN_HSTCLK and EN_NETCLK from inputs HCA (host clock available HST_CLK_AVAIL 604 through doublet register 610 ) and NCO (net clock off from NETCLK_OFF through doublet register 614 ). The clock select state machine 622 , second doublet 610 and third doublet 614 are clocked on the negative edge of NET_CLK.
[0031] Clock selection 518 of FIG. 6 includes a first doublet register 632 clocked on the negative edge of HOST_CLK, the first doublet register 632 having an input coupled to the output of a first AND gate 606 , and the output of the first doublet register 632 generating SEL_HSTCLK and coupled to the input of a second AND gate 626 , the other input of which is coupled to HOST_CLK. A second doublet register input is coupled to HST_CLK_AVAIL, which is also coupled to an input of first AND gate 606 . Second doublet register 610 output generates HCA, which is coupled to a clock selection state machine, and generates EN_HSTCLK which is coupled to the other input of the first AND gate 606 . Third doublet register 614 input is coupled to NETCLK_OFF 612 , and third doublet register output generates NCO, which is also coupled to the input of the clock select state machine 622 . EN_NETCLK is generated by the clock select state machine, and is coupled to an input of third AND gate 624 , the other input of which is coupled to NETCLK 620 . An OR gate generates CLK_OUT from the output of the second AND gate and the output of the third AND gate. The clock select state machine, second doublet register, and third doublet register are clocked on the negative edge of NET_CLK.
[0032] One embodiment of a clock select state machine suitable for use in FIG. 6 622 is shown in FIG. 7 , where the state machine generates outputs EN_NETCLK and EN_HOSTCLK, which are preferably synchronous outputs generated from state bits of the state machine, as is known in the art of state machine design. One possible set of states is IDLE 704 , for which only EN_NETCLK is asserted, transitioning to SLEEP 706 if NCO=1, indicating that the network clock is about to be disabled, and in SLEEP state, only EN_HOSTCLK is asserted. SLEEP state 706 transitions to the no clock WAIT state if network clock has been turned on as indicated by NCO=0. The WAIT state prevents the propagation of glitches on CLK_OUT in the condition where NCO becomes ‘0’ and around the same time HCA becomes ‘1’. A glitch can be created when FF 634 b is 1 and EN_NETCLK goes ‘1’. Waiting for a fixed duration ensures that SEL_HSTCLK reaches ‘0’ before EN_NETCLK is asserted. The transition from WAIT 702 with both clocks disabled to IDLE 704 requires that N clock stages pass, with the first N- 1 710 in state WAIT, and the final Nth 712 in state IDLE 704 .
[0033] FIG. 8 shows the timing diagram for the example embodiment described in FIGS. 6 and 7 . NET_CLK 802 is enabled by NETCLK_OFF such that the network clock oscillator runs for a longer time before and after NETCLK_OFF is unasserted. The HOST_CLK 804 is unavailable at time 830 , as indicated by HST_CLK_AVAIL, and does not return until time 834 . Similarly, NET_CLK 804 is turned on at time 832 and off at time 836 . As can be seen from FIG. 6 , HCA is a doublet delay from Host Clock Available 806 , and NCO is a doublet delay from NETCLK_OFF 808 . For simplicity, the diagram shows a two cycle delay, although it is understood that first doublet 632 is operative on HOST_CLK, which is not always present, and second doublet 610 , third doublet 614 , and clock select state machine 622 are operative on NET_CLK, which may similarly not be available during certain intervals, for which the state machine remains in a previous state until the NET_CLK becomes available again. It is generally desirable for the NET_CLK to be asserted before and after NETCLK_OFF sufficiently long enough for the state machine to reach state SLEEP, where HOST_CLK is generated. Additionally, it is desirable for HOST_CLK to be active for a sufficient time following HST_CLK_AVAIL for the state machine to reach state WAIT, where no clock is generated until NET_CLK is again active. | A clock selector operative on two clocks operating on different domains and responsive to a SELECT input provides a transition from a first clock to a second clock, and from a second clock to a first clock with a dead zone therebetween. The delay is provided by a doublet register having a first register coupled to a second register, the two registers operative on one of the clock domains. Additionally, a clock selector is operative on two clocks which are each accompanied by a clock availability signal where the state machine provides a variety of states to create a dead zone between selections, and to bring the state machine to a known state until a clock signal is again available. | 6 |
FIELD OF INVENTION
[0001] The invention pertains to apparatus for mixing solutions. More particularly, the invention relates to pneumatically operated mixers for use in closed, sterile environments.
BACKGROUND OF THE INVENTION
[0002] Bioreactors have been used for cultivation of microbial organisms for production of various biological or chemical products in the pharmaceutical, beverage and biotechnological industry. A production bioreactor contains culture medium in a sterile environment that provides various nutrients required to support growth of the biological agents of interest. Conventional bioreactors use mechanically driven impellors to mix the liquid medium during cultivation. The bioreactors can be reused for the next batch of biological agents after cleaning and sterilization of the vessel. The procedure of cleaning and sterilization requires a significant amount of time and resources, especially, to monitor and to validate each cleaning step prior to reuse for production of biopharmaceutical products. Due to the high cost of construction, maintenance and operation of the conventional bioreactors, single use bioreactor systems made of disposable plastic material have become an attractive alternative.
[0003] While several mixing methods of liquid in disposable bioreactors have been proposed in recent years, none of them provides efficient mixing for large scale (greater than 1000 liters) without expensive operating machinery. For this reason, a number of non-invasive and/or disposable mixing systems that do not require an external mechanical operation have been developed. Many of these systems work well within certain size ranges, however, problems sometimes arise as larger mixing systems are attempted. Some relevant examples of prior art pneumatic mixing systems include the following.
[0004] U.S. Pat. No. 6,032,931, issued to Plunkett, discloses an aeration device for use in a pond. Compressed gas is supplied to a conduit to form bubbles as the gas/air exits from a series of apertures. As the bubbles rise, they drive turbines to rotate and thereby create additional mixing turbulence.
[0005] U.S. Pat. No. 6,322,056, issued to Drie describes a submarine type liquid mixer with aeration. The buoyancy shells provide a downwardly facing upwardly concave surface for capturing gas bubbles so as to provide a buoyancy force to the struts. The bubbles may be naturally involved within the liquid due to chemical processes or they may be released from a gas inflow into the tank. As the gases are captured by a series of shells, each in turn is displaced upwardly whereupon the gas is released at the top of tank. At this point, one of the shells loses its buoyancy while the lower shell has received gas bubbles, enabling it to be displaced and thus the motion of the shells is reversed. This up and down cyclic motion of the shells mixes the liquid in the tanks.
[0006] U.S. Pat. No. 6,406,624, issued to De Vos discloses a flocculation apparatus and apparatus for floating upwardly in a liquid and for moving downwardly in the liquid under the influence of gravity. The flocculation apparatus includes a paddle apparatus and a flotation and compressed gas discharge apparatus. A pressurized or compressed air line with a branch line extending upwardly into the flotation and compressed gas discharge apparatus is also provided. When gas is introduced through the lines into the gas discharge apparatus, the apparatus becomes increasingly buoyant and floats upwardly in the liquid within the basin and thereby moves the paddle apparatus and frame apparatus upwardly in the liquid as well. When the apparatus reaches the top, the compressed air is released and the frame apparatus along with the paddle apparatus are pulled downwardly in the liquid by gravity. During the upward and downward movement of the paddle members, the paddle members agitate or stir the liquid contained within the basin.
[0007] U.S. Pat. No. 6,390,455, issued to Lee et al. describes a bubble generating device having a float connected thereto. The object of the invention is to provide a bubble generating device that can be operated in a desired depth of water which ultimately is used to agitate the water and provide a supply of oxygen to the water. The device includes a porous portion which is connected to a source of air through a pipe to generate bubbles while the float maintains the apparatus at a desired level in a water container.
[0008] U.S. Pat. No. 5,645,346, issued to Thuna is directed to a food preparation blender with a rotating and vertically oscillating mixing blade. The blender includes a pressure plate which causes a first shaft to be raised, thus raising the mixing blades while mixing takes place.
[0009] U.S. Pat. No. 6,649,117, issued to Familletti discloses an improved reactor/fermentor apparatus useful for carrying out cell culture and fermentation. The apparatus utilizes novel design features to provide optimum agitation of the cells while minimizing mechanical shear force. The reactor is composed of two chambers; an upper, wider chamber and a lower, small diameter chamber which are connected by inwardly sloping side walls. Agitation is accomplished by utilizing a gently flowing centrally disposed gas stream.
[0010] U.S. Pat. No. 3,96,3581, issued to Giacobbe et al. describes an air lift fermentor comprising in combination a hollow cylindrical body, vertically located and subdivided into three zones by a pair of diaphragms parallel to the axis of said cylindrical body, the central zone of which is destined to fermentation of the liquor, and the two lateral zones serve for recirculating the liquor itself, after its passage through a heat exchanger and an air distributor, both located near the bottom of said cylindrical body.
[0011] It is an objective of the present invention to provide a pneumatic bioreactor that is capable of efficiently and thoroughly mixing solutions without contamination. It is a further objective to such a reactor that can be scaled to relatively large sizes using the same technology. It is a still further objective of the invention to a bioreactor that can be produced in a disposable form. It is yet a further objective of the invention to provide a bioreactor that can be accurately controlled by internal pneumatic force, as to speed and mixing force applied to the solution without creating a foaming problem. Finally, it is an objective to provide a bioreactor that is simple and inexpensive to produce and to operate while fulfilling all of the described performance criteria.
[0012] While some of the objectives of the present invention are disclosed in the prior art, none of the inventions found include all of the requirements identified.
SUMMARY OF THE INVENTION
[0013] The present invention addresses all of the deficiencies of prior art pneumatic bioreactor inventions and satisfies all of the objectives described above.
[0014] (1) A pneumatic bioreactor providing all of the desired features can be constructed from the following components. A containment vessel is provided. The vessel has a top, a closed bottom, a surrounding wall and is of sufficient size to contain a fluid to be mixed and a mixing apparatus. The mixing apparatus includes at least one gas supply line. The supply line terminates at an orifice adjacent the bottom of the vessel. At least one buoyancy-driven mixing device is provided. The mixing device moves in the fluid as gas from the supply line is introduced into and vented from the mixing device. When gas is introduced into the gas supply line the gas will enter the mixing device and cause the device to mix the fluid.
[0015] (2) In a variant of the invention, the buoyancy-driven mixing device further includes at least one floating mixer. The mixer has a central, gas-holding chamber and a plurality of mixing elements located about the central chamber. The mixing elements are shaped to cause the mixer to agitate the fluid as the mixer rises in the fluid in the containment vessel. The central chamber has a gas-venting valve. The valve permits escape of gas as the central chamber reaches a surface of the fluid. A constraining member is provided. The constraining member limits horizontal movement of the floating mixer as it rises or sinks in the fluid. When gas is introduced into the gas supply line, the gas will enter the gas holding chamber and cause the floating mixer to rise by buoyancy in the fluid while agitating the fluid. When the gas venting valve of the central chamber reaches the surface of the fluid, the gas will be released and the floating mixer will sink toward the bottom of the containment vessel where the central chamber will again be filled with gas, causing the floating mixer to rise.
[0016] (3) In another variant, means are provided for controlling a rate of assent of the floating mixer.
[0017] (4) In still another variant, the means for controlling the rate of assent of the floating mixer includes a ferromagnetic substance attached to either of the floating mixer or the constraining member and a controllable electromagnet located adjacent the bottom of the containment vessel. The gas flow is interrupted by an on/off switch which is controlled by interactions of two magnetic substances. Therefore, the volume of gas supplied into the gas-holding chamber is determined by the strength of the electromagnetic power since the gas flow stops as the floating device starts to rise when the buoyancy becomes greater than the magnetic holding force.
[0018] (5) In yet another variant, the central, gas-holding chamber further includes an opening. The opening is located at an upper end of the chamber. A vent cap is provided. The vent cap is sized and shaped to seal the opening when moved upwardly against it by buoyancy from gas from the supply line. A support bracket is provided. The support bracket is located within the chamber to support the vent cap when it is lowered after release of gas from the chamber. When the chamber rises to the surface of the fluid the vent cap will descend from its weight and the opening will permit the gas to escape, the chamber will then sink in the fluid and the vent cap will again rise due to buoyancy from a small amount of gas permanently enclosed in the vent cap, thereby sealing the opening.
[0019] (6) In a further variant, a second floating mixer is provided. A second constraining member is provided, limiting horizontal movement of the second mixer as it rises in the fluid. At least one additional gas supply line is provided. The additional supply line terminates at an orifice adjacent the bottom of the vessel. At least one pulley is provided. The pulley is attached to the bottom of the containment vessel. A flexible member is provided. The flexible member attaches the chamber of the floating mixer to a chamber of the second floating mixer. The flexible member is of a length permitting the gas venting valve of the chamber of the floating mixer to reach the surface of the fluid while the chamber of the second floating mixer is spaced from the bottom of the containment vessel. When the floating mixer is propelled upwardly by buoyancy from the gas from the supply line the second floating mixer is pulled downwardly by the flexible member until the gas is released from the chamber of the floating mixer as its gas venting valve reaches the surface of the fluid. The chamber will then sink in the fluid as the second floating mixer rises by buoyancy from gas introduced from the second supply line.
[0020] (7) In yet a further variant, the containment vessel is formed of resilient material, the material is sterilizable by gamma irradiation methods.
[0021] (8) In still a further variant, the buoyancy-driven mixing device further includes at least one floating plunger. The plunger has a central, gas-holding chamber and at least one disk located about the central chamber. The disk is shaped to cause the plunger to agitate the fluid as the plunger rises in the fluid in the containment vessel. The central chamber has a gas-venting valve. The valve permits escape of gas as the central chamber reaches a surface of the fluid. A mixing partition is provided. The partition is located in the containment vessel adjacent the floating plunger and has at least one aperture to augment a mixing action of the floating plunger. A constraining member is provided. The constraining member limits horizontal movement of the plunger as it rises or sinks in the fluid. When gas is introduced into the gas supply line the gas will enter the gas holding chamber and cause the floating plunger to rise by buoyancy in the fluid while agitating the fluid. When the gas venting valve of the central chamber reaches the surface of the fluid, the gas will be released and the floating plunger will sink toward the bottom of the containment vessel where the central chamber will again be filled with gas, causing the floating plunger to rise.
[0022] (9) In another variant of the invention, a second floating plunger is provided. A second constraining member is provided, limiting horizontal movement of the second plunger as it rises in the fluid. At least one additional gas supply line is provided. The additional supply line terminates at an orifice adjacent the bottom of the vessel. At least one pulley is provided. The pulley is attached to the bottom of the containment vessel. A flexible member is provided. The flexible member attaches the chamber of the floating plunger to a chamber of the second floating plunger. The flexible member is of a length permitting the gas venting valve of the chamber of the floating plunger to reach the surface of the fluid while the chamber of the second floating plunger is spaced from the bottom of the containment vessel. The mixing partition is located between the floating plunger and the second floating plunger. When the floating plunger is propelled upwardly by buoyancy from the gas from the supply line the second floating plunger is pulled downwardly by the flexible member until the gas is released from the chamber of the floating plunger as its gas venting valve reaches the surface of the fluid. The chamber will then sink in the fluid as the second floating plunger rises by buoyancy from gas introduced from the second supply line.
[0023] (10) In still another variant, the pneumatic bioreactor further includes a cylindrical chamber. The chamber has an inner surface, an outer surface, a first end, a second end and a central axis. At least one mixing plate is provided. The mixing plate is attached to the inner surface of the chamber. First and second flanges are provided. The flanges are mounted to the cylindrical chamber at the first and second ends, respectively. First and second pivot points are provided. The pivot points are attached to the first and second flanges, respectively and to the containment vessel, thereby permitting the cylindrical chamber to rotate about the central axis. A plurality of gas holding members are provided. The members extend from the first flange to the second flange along the outer surface of the cylindrical chamber and are sized and shaped to entrap gas bubbles from the at least one gas supply line. The gas supply line terminates adjacent the cylindrical chamber on a first side of the chamber below the gas holding members. When gas is introduced into the containment vessel through the supply line it will rise in the fluid and gas bubbles will be entrapped by the gas holding members. This will cause the cylindrical chamber to rotate on the pivot points in a first direction and the at least one mixing plate to agitate the fluid.
[0024] (11) In yet another variant, a rate of rotation of the cylindrical chamber is controlled by varying a rate of introduction of gas into the gas supply line.
[0025] (12) In a further variant, a second gas supply line is provided. The second supply line terminates adjacent the cylindrical chamber on a second, opposite side of the chamber below the gas holding members. Gas from the second supply line causes the cylindrical chamber to rotate on the pivot points in a second, opposite direction.
[0026] (13) In still a further variant, the at least one mixing plate has at least one aperture to augment mixing of the fluid in the containment vessel.
[0027] (14) In yet a further variant, the containment vessel further includes a closable top. The top has a vent, permitting the escape of gas from the gas supply line through a sterile filter.
[0028] (15) In another variant of the invention, a temperature control jacket is provided. The jacket surrounds the containment vessel.
[0029] (16) In yet another variant, a pneumatic bioreactor includes a containment vessel. The vessel has a top, a closed bottom, a surrounding wall and is of sufficient size to contain a fluid to be mixed and a mixing apparatus. The mixing apparatus includes at least one gas supply line. The supply line terminates at an orifice at the bottom of the vessel. At least one floating impeller is provided. The impeller has a central, gas-containing chamber and a plurality of impeller blades arcurately located about the central chamber. The impeller blades are shaped to cause the impeller to revolve about a vertical axis as the impeller rises in fluid in the containment vessel.
[0030] The central chamber has a gas-venting valve. The valve permits escape of gas as the central chamber reaches a surface of the fluid. An outside housing is provided. The housing is ring-shaped and surrounds the floating impeller and constrains its lateral movement. At least one supporting pole is provided. The pole extends from the bottom upwardly toward the top. The outside housing is slidably attached to the supporting pole. The floating impeller is rotatably attached to the outside housing. When gas is introduced into the gas supply line the gas will enter the gas containing chamber and cause the floating impeller to rise in the fluid while rotating and mixing the fluid. When the gas venting valve of the central chamber reaches the surface of the fluid, the gas will be released and the floating impeller will sink toward the bottom of the containment vessel where the central chamber will again be filled with gas, causing the floating impeller to rise.
[0031] (17) In still another variant, the impeller blades are rotatably mounted to the central chamber and the central chamber is fixedly attached to the outside housing.
[0032] (18) In a further variant, the impeller blades are fixedly mounted to the central chamber and rotatably mounted to the outside housing.
[0033] (19) In still a further variant, the outside housing further includes a horizontal interior groove located on an inner surface of the housing. The impeller blades include a projection, sized and shaped to fit slidably within the groove.
[0034] (20) In yet a further variant, means are provided for controlling a rate of assent of the floating impeller.
[0035] (21) In another variant of the invention, the means for controlling a rate of assent of the floating impeller includes a ferromagnetic substance attached to either the floating impeller or the outside housing and a controllable electromagnet located adjacent the bottom of the containment vessel.
[0036] (21) In still another variant, the central, gas-containing chamber further includes an opening located at an upper end of the chamber. A vent cap is provided. The vent cap is sized and shaped to seal the opening when moved upwardly against it by pressure from gas from the supply line. A support bracket is provided. The support bracket is located within the chamber to support the vent cap when it is lowered after release of gas from the chamber. When the chamber rises to the surface of the fluid the vent cap will descend from its weight and the opening will permit the gas to escape. The chamber will then sink in the fluid and the vent cap will again rise due to pressure from gas introduced into the chamber from the gas line, thereby sealing the opening.
[0037] (22) In yet another variant, the vent cap further includes an enclosed gas cell. The cell causes the cap to float in the fluid and thereby to reseal the opening after the gas has been released when the chamber reached the surface of the fluid.
[0038] (23) In a further variant, the pneumatic bioreactor further includes a second floating impeller. A second outside housing surrounding the second floating impeller is provided. At least one additional supporting pole is provided. At least one additional gas supply line is provided. The additional supply line terminates at an orifice at the bottom of the vessel. The second outside housing is slidably attached to the additional supporting pole. The second floating impeller is rotatably attached to the second outside housing. At least one pulley is provided. The pulley is attached to the bottom of the containment vessel.
[0039] A flexible member is provided. The flexible member attaches the chamber of the floating impeller to a chamber of the second floating impeller. The flexible member is of a length to permit the gas venting valve of the chamber of the floating impeller to reach the surface of the fluid while the chamber of the second floating impeller is spaced from the bottom of the containment vessel. When the floating impeller is propelled upwardly by pressure from the gas from the supply line the second floating impeller will be pulled downwardly by the flexible member until the gas is released from the chamber of the floating impeller as its gas venting valve reaches the surface of the fluid, the chamber will then sink in the fluid as the second floating impeller rises under pressure from gas introduced from the second supply line.
[0040] An appreciation of the other aims and objectives of the present invention and an understanding of it may be achieved by referring to the accompanying drawings and the detailed description of a preferred embodiment.
DESCRIPTION OF THE DRAWINGS
[0041] FIG. 1 is a perspective view of a first embodiment of the invention illustrating floating impellers and their control mechanisms;
[0042] FIG. 2 is a top view of the FIG. 1 embodiment illustrating the floating chamber affixed to the constraining member with the impeller blades rotating upon the chamber;
[0043] FIG. 2A is a top view of the FIG. 1 embodiment illustrating the floating chamber rotating within the constraining member with the impeller blades fixed to the chamber;
[0044] FIG. 3 is a side elevational view of the FIG. 1 embodiment;
[0045] FIG. 4 is a side elevational view of the FIG. 2A embodiment of the floating impeller;
[0046] FIG. 4A is a side elevational view of the FIG. 2 embodiment of the floating impeller;
[0047] FIG. 5 is a perspective view of a second embodiment of the invention illustrating floating plungers and their control mechanisms;
[0048] FIG. 6 is a top view of the FIG. 5 embodiment illustrating the floating plungers;
[0049] FIG. 7 is a perspective view of the gas supply line and magnetic assent control mechanism;
[0050] FIG. 8 is a cross-sectional side elevation of the floating chamber illustrating the vent cap in a closed position;
[0051] FIG. 9 is a cross-sectional side elevation of the floating chamber illustrating the vent cap in an open position;
[0052] FIG. 10 is a perspective view of a third embodiment of the invention illustrating a rotating drum mixer with gas supply line;
[0053] FIG. 11 is an end view of the FIG. 10 embodiment illustrating a single gas supply line;
[0054] FIG. 12 is an end view of the FIG. 10 embodiment illustrating a pair of gas supply lines;
[0055] FIG. 13 is a side elevational view of the FIG. 10 embodiment illustrating a containment vessel;
[0056] FIG. 14 is a perspective view of the FIG. 5 embodiment illustrating a closable top and sterile filters; and
[0057] FIG. 15 is a perspective view of the FIG. 5 embodiment illustrating a temperature control jacket surrounding the vessel.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0058] (1) A pneumatic bioreactor 10 , as illustrated in FIGS. 1-3 , providing all of the desired features can be constructed from the following components. A containment vessel 15 is provided. The vessel 15 has a top 20 , a closed bottom 25 , a surrounding wall 30 and is of sufficient size to contain a fluid 35 to be mixed and a mixing apparatus 40 . The mixing apparatus 40 includes at least one gas supply line 45 . The supply line 45 terminates at an orifice 50 adjacent the bottom 25 of the vessel 15 . At least one buoyancy-driven mixing device 55 is provided. The mixing device 55 moves in the fluid 35 as gas 60 from the supply line 45 is introduced into and vented from the mixing device 55 . When gas 60 is introduced into the gas supply line 45 the gas 60 will enter the mixing device 55 and cause the device to mix the fluid 35 .
[0059] (2) In a variant of the invention, the buoyancy-driven mixing device 55 further includes at least one floating mixer 65 . The mixer 65 has a central, gas-holding chamber 70 and a plurality of mixing elements 75 located about the central chamber 70 . The mixing elements 75 are shaped to cause the mixer 65 to agitate the fluid 35 as the mixer 65 rises in the fluid 35 in the containment vessel 15 . The central chamber 70 , as illustrated in FIGS. 8 and 9 , has a gas-venting valve 80 . The valve 80 permits escape of gas 60 as the central chamber 70 reaches a surface 85 of the fluid 35 . A constraining member 90 is provided. The constraining member 90 limits horizontal movement of the floating mixer 65 as it rises or sinks in the fluid 35 . When gas 60 is introduced into the gas supply line 45 , the gas 60 will enter the gas holding chamber 70 and cause the floating mixer 65 to rise by buoyancy in the fluid 35 while agitating the fluid 35 . When the gas venting valve 80 of the central chamber 70 reaches the surface 85 of the fluid 35 , the gas 60 will be released and the floating mixer 65 will sink toward the bottom 25 of the containment vessel 15 where the central chamber 70 will again be filled with gas 60 , causing the floating mixer 65 to rise.
[0060] (3) In another variant, means 95 , as illustrated in FIG. 7 , are provided for controlling a rate of assent of the floating mixer 65 .
[0061] (4) In still another variant, the means 95 for controlling the rate of assent of the floating mixer 65 includes a ferromagnetic substance 100 attached to either of the floating mixer 65 or the constraining member 90 and a controllable electromagnet 105 located adjacent the bottom 25 of the containment vessel 15 .
[0062] (5) In yet another variant, as illustrated in FIGS. 8 and 9 , the central, gas-holding chamber 70 further includes an opening 110 . The opening 110 is located at an upper end 115 of the chamber 70 . A vent cap 117 is provided. The vent cap 117 is sized and shaped to seal the opening 110 when moved upwardly against it by buoyancy from gas 60 from the supply line 45 . A support bracket 120 is provided. The support bracket 120 is located within the chamber 70 to support the vent cap 115 when it is lowered after release of gas 60 from the chamber 70 . When the chamber 70 rises to the surface 85 of the fluid 35 the vent cap 115 will descend from its weight and the opening 110 will permit the gas 60 to escape, the chamber 70 will then sink in the fluid 35 and the vent cap 115 will again rise due to buoyancy from a small amount of gas 60 permanently enclosed in the vent cap 115 , thereby sealing the opening 110 .
[0063] (6) In a further variant, as illustrated in FIGS. 1-3 , a second floating mixer 125 is provided. A second constraining member 130 is provided, limiting horizontal movement of the second mixer 125 as it rises in the fluid 35 . At least one additional gas supply line 135 is provided. The additional supply line 135 terminates at an orifice 143 adjacent the bottom 25 of the vessel 15 . At least one pulley 140 is provided. The pulley 140 is attached to the bottom 25 of the containment vessel 15 . A flexible member 145 is provided. The flexible member 145 attaches the chamber 70 of the floating mixer 65 to a chamber 150 of the second floating mixer 125 . The flexible member 145 is of a length permitting the gas venting valve 80 of the chamber 70 of the floating mixer 65 to reach the surface 85 of the fluid 35 while the chamber 70 of the second floating mixer 125 is spaced from the bottom 25 of the containment vessel 15 . When the floating mixer 65 is propelled upwardly by buoyancy from the gas 60 from the supply line 45 the second floating mixer 125 is pulled downwardly by the flexible member 145 until the gas 60 is released from the chamber 70 of the floating mixer 65 as its gas venting valve 80 reaches the surface 85 of the fluid 35 . The chamber 70 will then sink in the fluid 35 as the second floating mixer 125 rises by buoyancy from gas 60 introduced from the second supply line 135 .
[0064] (7) In yet a further variant, the containment vessel 15 is formed of resilient material 155 , the material is sterilizable by gamma irradiation methods.
[0065] (8) In still a further variant, as illustrated in FIGS. 5 and 6 , the buoyancy-driven mixing device 10 further includes at least one floating plunger 160 . The plunger 160 has a central, gas-holding chamber 70 and at least one disk 165 located about the central chamber 70 . The disk 165 is shaped to cause the plunger 160 to agitate the fluid 35 as the plunger 160 rises in the fluid 35 in the containment vessel 15 . The central chamber 70 has a gas-venting valve 80 . The valve 80 permits escape of gas 60 as the central chamber 70 reaches a surface 85 of the fluid 35 . A mixing partition 170 is provided. The partition 170 is located in the containment vessel 15 adjacent the floating plunger 160 and has at least one aperture 175 to augment a mixing action of the floating plunger 160 . A constraining member 180 is provided. The constraining member 180 limits horizontal movement of the plunger 160 as it rises or sinks in the fluid 35 . When gas 60 is introduced into the gas supply line 45 the gas 60 will enter the gas holding chamber 70 and cause the floating plunger 160 to rise by buoyancy in the fluid 35 while agitating the fluid 35 . When the gas venting valve 80 of the central chamber 70 reaches the surface 85 of the fluid 35 , the gas 60 will be released and the floating plunger 160 will sink toward the bottom 25 of the containment vessel 15 where the central chamber 70 will again be filled with gas 60 , causing the floating plunger 160 to rise.
[0066] (9) In another variant of the invention, a second floating plunger 185 is provided. A second constraining member 190 is provided, limiting horizontal movement of the second plunger 185 as it rises in the fluid 35 . At least one additional gas supply line 135 is provided. The additional supply line 135 terminates at an orifice 143 adjacent the bottom 25 of the vessel 15 . At least one pulley 140 is provided. The pulley 140 is attached to the bottom 25 of the containment vessel 15 . A flexible member 145 is provided. The flexible member 145 attaches the chamber 70 of the floating plunger 160 to a chamber of the second floating plunger 185 . The flexible member 145 is of a length permitting the gas venting valve 80 of the chamber 70 of the floating plunger 160 to reach the surface 85 of the fluid 35 while the chamber 70 of the second floating plunger 185 is spaced from the bottom 25 of the containment vessel 15 . The mixing partition 170 is located between the floating plunger 160 and the second floating plunger 185 . When the floating plunger 160 is propelled upwardly by buoyancy from the gas 60 from the supply line 45 the second floating plunger 185 is pulled downwardly by the flexible member 145 until the gas 60 is released from the chamber 70 of the floating plunger 160 as its gas venting valve 80 reaches the surface 85 of the fluid 30 . The floating plunger 160 will then sink in the fluid 35 as the second floating plunger 185 rises by buoyancy from gas 60 introduced from the second supply line 135 .
[0067] (10) In still another variant, as illustrated in FIGS. 10-13 , the pneumatic bioreactor 10 further includes a cylindrical chamber 195 . The chamber 195 has an inner surface 200 , an outer surface 205 , a first end 210 , a second end 215 and a central axis 220 . At least one mixing plate 225 is provided. The mixing plate 225 is attached to the inner surface 200 of the chamber 195 . First 230 and second 235 flanges are provided. The flanges 230 , 235 are mounted to the cylindrical chamber 195 at the first 210 and second ends 215 , respectively. First 240 and second 245 pivot points are provided. The pivot points 240 , 245 are attached to the first 230 and second 235 flanges, respectively and to the containment vessel 15 , thereby permitting the cylindrical chamber 195 to rotate about the central axis 220 . A plurality of gas holding members 250 are provided. The members 250 extend from the first flange 230 to the second flange 235 along the outer surface 205 of the cylindrical chamber 195 and are sized and shaped to entrap gas bubbles 255 from the at least one gas supply line 45 . The gas supply line 45 terminates adjacent the cylindrical chamber 195 on a first side 260 of the chamber 195 below the gas holding members 250 . When gas 60 is introduced into the containment vessel 15 through the supply line 45 it will rise in the fluid 35 and gas bubbles 255 will be entrapped by the gas holding members 250 . This will cause the cylindrical chamber 195 to rotate on the pivot points 240 , 245 in a first direction 262 and the at least one mixing plate 225 to agitate the fluid 35 .
[0068] (11) In yet another variant, a rate of rotation of the cylindrical chamber 195 is controlled by varying a rate of introduction of gas 60 into the gas supply line 45 .
[0069] (12) In a further variant, as illustrated in FIG. 12 , a second gas supply line 135 is provided. The second supply line 135 terminates adjacent the cylindrical chamber 195 on a second, opposite side 265 of the chamber 195 below the gas holding members 250 . Gas 60 from the second supply line 135 causes the cylindrical chamber 195 to rotate on the pivot points 240 , 245 in a second, opposite direction 270 .
[0070] (13) In still a further variant, as illustrated in FIGS. 10 and 13 , the at least one mixing plate 225 has at least one aperture 275 to augment mixing of the fluid 35 in the containment vessel 15 .
[0071] (14) In yet a further variant, as illustrated in FIG. 14 , the containment vessel 15 further includes a closable top 280 . The top has a vent 285 , permitting the escape of gas 60 from the gas supply line 45 through a sterile filter 290 .
[0072] (15) In another variant of the invention, as illustrated in FIG. 15 , a temperature control jacket 295 is provided. The jacket 295 surrounds the containment vessel 15 .
[0073] (16) In yet another variant, as illustrated in FIGS. 1-3 , a pneumatic bioreactor 10 includes a containment vessel 15 . The vessel 15 has a top 20 , a closed bottom 25 , a surrounding wall 30 and is of sufficient size to contain a fluid 35 to be mixed and a mixing apparatus 40 . The mixing apparatus 40 includes at least one gas supply line 45 . The supply line 45 terminates at an orifice 50 at the bottom 25 of the vessel 15 . At least one floating impeller 300 is provided. The impeller 300 has a central, gas-containing chamber 70 and a plurality of impeller blades 305 arcurately located about the central chamber 70 . The impeller blades 305 are shaped to cause the impeller 300 to revolve about a vertical axis 310 as the impeller 300 rises in fluid 35 in the containment vessel 15 .
[0074] The central chamber 70 has a gas-venting valve 80 . The valve 80 permits escape of gas 60 as the central chamber 70 reaches a surface 85 of the fluid 35 . An outside housing 315 is provided. The housing 315 is ring-shaped and surrounds the floating impeller 300 and constrains its lateral movement. At least one supporting pole 320 is provided. The pole 320 extends from the bottom 25 upwardly toward the top 20 . The outside housing 315 is slidably attached to the supporting pole 320 . The floating impeller 300 is rotatably attached to the outside housing 315 . When gas 60 is introduced into the gas supply line 45 the gas 60 will enter the gas containing chamber 70 and cause the floating impeller 300 to rise in the fluid 35 while rotating and mixing the fluid 35 . When the gas venting valve 80 of the central chamber 70 reaches the surface 85 of the fluid 35 , the gas 60 will be released and the floating impeller 300 will sink toward the bottom 25 of the containment vessel 15 where the central chamber 70 will again be filled with gas 60 , causing the floating impeller 300 to rise.
[0075] (17) In still another variant, as illustrated in FIGS. 2 and 4 A, the impeller blades 305 are rotatably mounted to the central chamber 70 and the central chamber 70 is fixedly attached to the outside housing 315 .
[0076] (18) In a further variant, as illustrated in FIGS. 2A and 4 , the impeller blades 305 are fixedly mounted to the central chamber 70 and rotatably mounted to the outside housing 315 .
[0077] (19) In still a further variant, the outside housing 315 further includes a horizontal interior groove 322 located on an inner surface 325 of the housing 315 . The impeller blades 305 include a projection 330 , sized and shaped to fit slidably within the groove 322 .
[0078] (20) In yet a further variant, as illustrated in FIG. 7 , means 95 are provided for controlling a rate of assent of the floating impeller 300 .
[0079] (21) In another variant of the invention, the means 95 for controlling a rate of assent of the floating impeller 300 includes a ferromagnetic substance 100 attached to either the floating impeller 300 or the outside housing 315 and a controllable electromagnet 105 located adjacent the bottom 25 of the containment vessel 15 .
[0080] (21) In still another variant, as illustrated in FIGS. 8 and 9 , the central, gas-containing chamber 70 further includes an opening 110 located at an upper end 115 of the chamber 70 . A vent cap 115 is provided. The vent cap 115 is sized and shaped to seal the opening 110 when moved upwardly against it by pressure from gas 60 from the supply line 45 . A support bracket 120 is provided. The support bracket 120 is located within the chamber 70 to support the vent cap 115 when it is lowered after release of gas 60 from the chamber 70 . When the chamber 70 rises to the surface of the fluid 35 the vent cap 115 will descend from its weight and the opening 110 will permit the gas 60 to escape. The floating impeller 300 will then sink in the fluid 35 and the vent cap 115 will again rise due to pressure from gas 60 introduced into the chamber 70 from the gas line 45 , thereby sealing the opening 110 .
[0081] (22) In yet another variant, the vent cap 115 further includes an enclosed gas cell 310 . The cell 310 causes the cap 115 to float in the fluid 35 and thereby to reseal the opening 110 after the gas 60 has been released when the chamber 70 reached the surface 85 of the fluid 35 .
[0082] (23) In a further variant, as illustrated in FIGS. 1 and 3 , the pneumatic bioreactor 10 further includes a second floating impeller 317 . A second outside housing 324 surrounding the second floating impeller 317 is provided. At least one additional supporting pole 326 is provided. At least one additional gas supply line 135 is provided. The additional supply line 135 terminates at an orifice 143 at the bottom 25 of the vessel 15 . The second outside housing 324 is slidably attached to the additional supporting pole 325 . The second floating impeller 317 is rotatably attached to the second outside housing 324 . At least one pulley 140 is provided. The pulley 140 is attached to the bottom 25 of the containment vessel 15 .
[0083] A flexible member 145 is provided. The flexible member 145 attaches the chamber 70 of the floating impeller 300 to a chamber 70 of the second floating impeller 317 . The flexible member 145 is of a length to permit the gas venting valve 80 of the chamber 70 of the floating impeller 300 to reach the surface 85 of the fluid 35 while the chamber 70 of the second floating impeller 317 is spaced from the bottom 25 of the containment vessel 15 . When the floating impeller 300 is propelled upwardly by pressure from the gas 60 from the supply line 45 the second floating impeller 315 will be pulled downwardly by the flexible member 145 until the gas 60 is released from the chamber 70 of the floating impeller 300 as its gas venting valve 80 reaches the surface 85 of the fluid 35 , the floating impeller 300 will then sink in the fluid 35 as the second floating impeller 315 rises under pressure from gas 60 introduced from the second supply line 135 .
[0084] An appreciation of the other aims and objectives of the present invention and an understanding of it may be achieved by referring to the accompanying drawings and the detailed description of a preferred embodiment. | A pneumatic bioreactor includes a vessel containing a fluid to be mixed and at least one mixing device driven by gas pressure. A first embodiment includes a floating impeller that rises and falls in the fluid as gas bubbles carry it upward to the surface where the gas is then vented, permitting the impeller to sink in the fluid. The floating impeller may be tethered to a second impeller with a flexible member and pulley. The mixing speed is controlled with electromagnets in the vessel acting upon magnetic material in the impeller or its guides. In another embodiment, floating pistons mix the fluid, pushing it through a mixing plate with one or more apertures. In a third embodiment, the mixing device is a rotating drum with bubble-catching blades and rotating mixing plates with apertures. The top of the vessel for these mixers may include a closed top and sterile filters. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates to non-volatile memory cells generally and to methods of reading them in particular
BACKGROUND OF THE INVENTION
[0002] Dual bit memory cells are known in the art. One such memory cell is the NROM (nitride read only memory) cell 10 , shown in FIG. 1 to which reference is now made, which stores two bits 12 and 14 in a nitride based layer 16 sandwiched between a conductive layer 18 and a channel 20 . NROM cells are described in many patents, for example in U.S. Pat. No. 6,649,972, assigned to the common assignees of the present invention, whose disclosure is incorporated herein.
[0003] Bits 12 and 14 are individually accessible, and thus, may be programmed (conventionally noted as a ‘0’), erased (conventionally noted as a ‘1’) or read separately. Reading a bit ( 12 or 14 ) involves determining if a threshold voltage Vt, as seen when reading the particular bit, is above (programmed) or below (erased) a read reference voltage level RD.
[0004] FIG. 2 , to which reference is now made, illustrates the distribution of programmed and erased states of a memory chip (which typically has a large multiplicity of NROM cells formed into a memory array) as a function of threshold voltage Vt. An erased bit is one whose threshold voltage has been reduced below an erase threshold voltage EV. Thus, an erase distribution 30 has typically its rightmost point in the vicinity of (and preferably at or below) the erase threshold voltage EV. Similarly, a programmed bit is one whose threshold voltage has been increased above a program threshold voltage PV. Thus, a programmed distribution 32 has typically its leftmost point in the vicinity of (and preferably at or above) the program threshold voltage PV.
[0005] The difference between the two threshold voltages PV and EV is a window W 0 of operation. Read reference voltage level RD is typically placed within window W 0 and can be generated, as an example, from a read reference cell. The read reference cell is usually, but not necessarily, in a non-native state, as described in U.S. Pat. No. 6,490,204, assigned to the common assignee of the present invention, whose disclosure is incorporated herein by reference. In such case, the threshold voltage of read reference cell may be at the RD level in FIG. 2 .
[0006] The signal from the bit being read is then compared with a comparison circuit (e.g. a differential sense amplifier) to the signal generated by the read reference level, and the result should determine if the array cell is in a programmed or erased state. Alternatively, instead of using a reference cell, the read reference signal can be an independently generated voltage or a current signal. Other methods to generate a read reference signal are known in the art.
[0007] Since the sensing scheme circuitry may not be perfect, and its characteristics may vary at different operating and environmental conditions, margins M 0 and M 1 are typically required to correctly read a ‘0’ and a ‘1’, respectively. As long as the programmed and erased distributions are beyond these margins, reliable reads may be achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which:
[0009] FIG. 1 is a schematic illustration of a prior art NROM cell;
[0010] FIG. 2 is a schematic illustration of the distribution of programmed and erased states of a memory chip of NROM cells as a function of threshold voltage Vt;
[0011] FIG. 3 is a schematic illustration of erase and programmed distributions at some point after the start of operation of an exemplary memory array,
[0012] FIG. 4 is a schematic illustration of erase and programmed distributions once the distributions have shifted from those of FIG. 3 ;
[0013] FIGS. 5A, 5B and 5 C are schematic illustrations of a method of reading memory cells, constructed and operative in accordance with the present invention, using a moving read reference level which may move as a function of changes in the window of operation; and
[0014] FIGS. 6A, 6B and 6 C are schematic illustrations of alternative locations of history cells and memory cells, useful in implementing the method of FIGS. 5A, 5B and 5 C.
[0015] It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.
DETAILED DESCRIPTION OF THE INVENTION
[0016] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention.
[0017] Applicants have realized that the window of operation may change over time as the cells go through multiple erase and programming cycles. The window of operation may shrink and/or may drift, both of which may affect the accuracy of the read operation.
[0018] Reference is now made to FIG. 3 , which illustrates erase and programmed distributions 40 and 42 , respectively, at some point after the start of operation of an exemplary memory array.
[0019] Although each bit may be erased to a threshold voltage below erase voltage EV, erase distribution 40 may appear to be shifted slightly above erase voltage EV. Applicants have realized that this may be due to the fact that the two bits of a cell have some effect on each other. If both bits are erased, then the threshold voltage of each bit may be below erase voltage EV (as indicated by the smaller distribution 44 within erase distribution 40 ). However, if one of the bits is programmed while the other bit is erased, the threshold voltage of the erased bit may appear higher, due to the programmed state of the other bit This is indicated by the second small distribution 46 within erase distribution 40 , some of whose bits may have threshold voltages that appear to be above erase voltage EV. This is typically referred as a “second bit effect”.
[0020] Applicants have additionally realized that, after repeated program and erase cycles, programmed distribution 42 may shift below programming voltage PV. This may be due to charge redistribution within the trapping layer, aging characteristics, or retention properties of the cells after many erase/program cycles. This downward shift of the programmed distribution 42 is time and temperature dependent, and the shift rate also depends on the number of program/erase cycles that the cell has experienced in its past.
[0021] The result of these shifting distributions may be to shrink the window of operation to a different window Wm of operation. Applicants have realized that the different window Wm may or may not be aligned with the original window W 0 . FIG. 3 shows an exemplary window Wm with its center shifted from the center of the original window W 0 . Applicants have realized that one or both of these changes may have an effect on the quality of the read operation. This is illustrated in FIG. 4 , to which reference is now made.
[0022] As mentioned in the Background, a margin M 1 may be required to compensate circuit deficiencies and to ensure a correct read of an erased bit. The original placement of the erased bits below the EV level (typically after an erase operation), provided a larger than M 1 margin, and thus a reliable read of ‘1’ bits. Unfortunately, as shown in FIG. 4 , since erase distribution 40 may have drifted above erase threshold voltage EV, margin M 1 may no longer be maintained. There may be some bits within erase distribution 46 , indicated by solid markings, which may be wrongly read (i.e. read as programmed) since their threshold voltages are not below margin M 1 .
[0023] Reference is now made to FIGS. 5A, 5B and 5 C, which together illustrate a method of reading memory cells, constructed and operative in accordance with the present invention, using a moving read reference level MRL, which may move as a function of changes in the window of operation.
[0024] In accordance with a preferred embodiment of the present invention, shortly after an erase and a program operation ( FIG. 5A ), moving read level MRL may be placed at a read level RD 1 between an erase distribution 50 A and a programmed distribution 52 A, where erase distribution 50 A is now slightly above erase threshold voltage EV (due to the second bit effect) and programmed distribution 52 A is now entirely or almost entirely above programming threshold voltage PV. Suitable margins M 1 and M 0 may be defined from read level RD 1 to overcome circuit and sensing scheme deficiencies and to ensure correct detection of the bit states. In FIG. 5A , the erase and program distributions are beyond margins M 1 and M 0 , respectively. Therefore, at this point, read level RD 1 may successfully and reliably read both 1's and 0's.
[0025] If the cells have already passed multiple programming and erase cycles, then, after a period of time, the distributions may shift. In FIG. 5B , the program distribution, now labeled 52 B, has moved lower and thus, a significant part of it is below program threshold voltage PV. However, the erase distribution, here labeled 50 B, has typically also moved lower. Even if the window of operation W B is close to or the same width as that in FIG. 5A (labeled W A ), its center has changed As a result, read reference level RD 1 with margin M 0 may no longer correctly read all the bits in the program distribution 52 B as ‘0’.
[0026] In accordance with a preferred embodiment of the present invention, for the situation of FIG. 5B , moving read level MRL may move to a second read level RD 2 . In this situation, when reading bits with reference to read level RD 2 , margins M 0 and M 1 are maintained, but relative to the shifted RD 2 read level, and therefore all the bits in both distributions ( 50 B and 52 B) may be correctly read as erased (‘1’) or programmed (‘0’).
[0027] FIG. 5C shows a third case where the distributions may have shifted further, resulting in a window of operation W C that is further shrunk and/or shifted. In accordance with a preferred embodiment of the present invention, moving read level MRL may move to a third read level RD 3 (along with margins M 0 and M 1 ) to accommodate the changed window of operation, and to ensure a reliable read of all the bits in the distributions 50 C and 52 C.
[0028] It will be appreciated that read levels RD 1 and RD 2 would not successfully read the distribution of FIG. 5C . Both read levels RD 1 and RD 2 would erroneously read at least some of the 0's (since the distance of the left side of the program distribution 52 C to the read level is smaller than the required margin M 0 ). Similarly, third read level RD 3 would erroneously read some of the 1's had it been used for the distributions of FIGS. 5A and 5B since the right sides of distributions 50 A and 50 B do not maintain a required margin M 1 from the read level RD 3 .
[0029] Selecting which read level to utilize at any given time may be done in any suitable manner and all such methods are included in the present invention. An example is shown in FIG. 6A , to which reference is now made. In this example, the memory array, labeled 60 , may comprise memory cells 62 to be read, and history cells 64 . At least one history cell 64 may be associated with a subset of memory cells 62 and may pass through substantially the same events and preferably substantially at the same time and with the same conditions as its corresponding subset of memory cells 62 .
[0030] A specific example is shown in FIG. 6B , to which reference is now made. In this example, a history cell 64 A may be associated with a row A of memory cells 62 and may be programmed and erased at the same time as cells 62 in row A, always being brought back to a its known predetermined state. This predetermined state may be, for example, such that both bits (i.e. both storage areas) of the cell are in a programmed state, or, in a different case, only one of the bits is in a programmed state while the other bit remains erased.
[0031] Another example is shown in FIG. 6C , to which reference is now made. In this example, a set of history cells 64 G may be associated with a section G in array 60 . History cells 64 G may be anywhere in the memory array as long as they pass through substantially the same events at substantially the same conditions as the subset of memory cells with whom they are associated. The history cells 64 G are always brought back to a predetermined state. Some of the history cells may have both bits (i.e. both storage areas) in a programmed state while other history cells may have only one of their bits in a programmed state.
[0032] The history cells 64 may be utilized to determine the most appropriate reference read level to use for reading the subset of memory cells 62 to which they are associated. The reference read level, or more preferably, the highest reference read level, that may produce a correct readout of history cells 64 (a ‘0’ readout, since the history cells 64 typically are in a programmed state) may be utilized to read its associated subset of memory cells 62 .
[0033] The reference read level used to correctly read history cell 64 may be known as a “history read reference level”. The associated subset of memory cells 62 may be read with a “memory read reference level” which may be the same as the history read reference level or it may have a margin added to it.
[0034] In one example, there may be three available reference read levels RD 1 >RD 2 >RD 3 . If a programmed history cell 64 is incorrectly read using RD(j) (i.e. it is read as erased), but correctly read using RD(j+1), then the associated subset of memory cells 62 may preferably be read using the RD(j+1) reference read level, with or without a margin added to it.
[0035] Alternatively, if a programmed history cell 64 cannot be read with enough margin (Mh) using RD(j) (i.e. it is read as erased using RD(j)+Mh), but can be read with enough margin using RD(j+1) (i.e. it is read as programmed using RD(j+1)+Mh), then the associated subset of memory cells 62 may preferably be read using the RD(j+1) reference read level. The margin Mh may be defined as the amount of desired margin between the reliable readout of the history cell and the reliable readout of the memory cells 62 associated therewith.
[0036] The most appropriate reference read level to be used for reading each of the subsets of memory cells 62 may be determined in any one of a number of ways, of which four are described hereinbelow.
A) reading all or part of the history cells 64 vs. all or part of existing read reference cells having read reference levels RD(j). B) reading all or part of the history cells 64 vs. specific reference cells placed at the read reference levels RD(j) plus some margin Mh. There can be separate margins Mh(j) for each read level RD(j). C) reading all or part of the history cells 64 vs. all or part of the existing read reference cells having read reference levels RD(j) but activating the word lines of the history cells 64 at a different level than the word line of the read reference cells, in order to introduce some margin. D) reading all or part of the history cells 64 vs. all or part of the existing read reference cells having read reference levels RD(j) but introducing some margin Mh(j) at each of these read operations, for example by adding or subtracting a current or voltage signal to the signals of at least one of the history or the read reference cells.
[0041] These operations may be performed “on the fly’ (before reading the associated subset of memory cells 62 ) in applications that allow sufficient time to read the history cells 64 vs. the different read reference levels and to determine the optimal memory read reference level for reading the associated subset of memory cells 62 . Alternatively, the history cells 64 may be read at predetermined times and, after analyzing the readouts and choosing the appropriate read reference level for each set of history cells, the results may be stored for later use when a read of memory cells 62 may be required. Such predetermined times may be at power-up of the device, prior to or after long operations (e.g. program or erase) or at idle times. The history cells 64 may be read serially, in parallel, and in a mixed serial/parallel form.
[0042] The history cells 64 may be of the same type of multi bit NROM cells as the array memory cells 62 . They may be operated in a one bit per cell mode, in a dual bit per cell mode, or in a multilevel mode. The programmed state of history cells 64 may be achieved by programming only one or both bits in their cells. The history cells 64 may be erased close to, together with, or while erasing their associated memory cells 62 . The programming of the history cells may be performed shortly after erasing them and their associated memory cells 62 , or close to programming a subset of bits in their associated memory cells 62 .
[0043] While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention. | A method includes changing a read reference level for reading a group of memory cells as a function of changes in a threshold voltage distribution of a different group of memory cells. The changing step includes determining a history read reference level for correct reading of at least one history cell, selecting a memory read reference level according to the first read reference level, and reading non-volatile memory array cells associated with the at least one history cell using the memory read reference level. | 6 |
FIELD
[0001] The present disclosure relates to interactive voice response (IVR) systems, and more specifically to a user-side IVR system.
BACKGROUND
[0002] Interactive Voice Response (IVR) systems are commonly used by today's companies and organizations. IVR systems allow for the automatic handling of many user requests without the costlier involvement of human respondents.
[0003] From a user's perspective, interaction with different IVRs is often similar because of the standardization of menu choices and the repeated request for the same information. For example, many IVRs authenticate a user by asking for the user's personal identification number (PIN), mother's maiden name, and/or personal data (e.g., social security number or date of birth). The user may have to go through long-winded, multi-level menus before being able to perform the action that the user wants to perform. Further, the user may not have information requested by the IVR system readily available. The user may also have to repeat information (e.g., difficult to pronounce names or other information) one or more times, and may have to repeat the process numerous times if, for example, the user chooses an incorrect menu choice which leads the user to an undesired part of the IVR system decision tree. This inconvenience can be made worse when a user has a foreign accent and the IVR system cannot recognize or decipher the foreign accent.
[0004] Therefore, there remains a need to improve the interaction between a user and an IVR system.
SUMMARY
[0005] A method and system for interacting with an IVR system is disclosed. In one aspect, a computing device receives a user request to connect to an IVR system to perform an action. A request for information (e.g., a request to select from a plurality of menu options) is obtained from the IVR system. In response to the request, the computing device automatically supplies an answer to the request for information to the IVR system. In one embodiment, the answer is a dual-tone multi-frequency (DTMF) signal. The obtaining and supplying steps are repeated until the action has been performed.
[0006] In one embodiment, the computing device performs a training stage so that the computing device can correctly supply answers to the IVR system. In one embodiment, the training stage includes the computing device connecting to one IVR system in a plurality of IVR systems, where each IVR system comprises a decision tree. The computing device learns the decision tree for the one IVR system by traversing through every option in the decision tree, and repeats the connecting and learning steps for each IVR system in the plurality of IVR systems.
[0007] In one embodiment, the computing device transmits the request for information to a user via an output device (e.g., a speaker or a telephone) and enables the user to supply an answer to the request for information using the computing device. The computing device can also provide (e.g., display) an indication to the user that the activity has been performed.
[0008] These and other aspects and embodiments will be apparent to those of ordinary skill in the art by reference to the following detailed description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] In the drawing figures, which are not to scale, and where like reference numerals indicate like elements throughout the several views:
[0010] FIG. 1 is a block diagram of a computing device in communication with an IVR system in accordance with an embodiment of the present invention;
[0011] FIG. 2 is a block diagram of a computing device in communication with a server communicating with an IVR system in accordance with an embodiment of the present invention;
[0012] FIG. 3 is a flowchart illustrating steps performed by the server of FIG. 2 in accordance with an embodiment of the present invention;
[0013] FIG. 4 is a flowchart illustrating steps performed by the server of FIG. 2 during a training stage in accordance with an embodiment of the present invention; and
[0014] FIG. 5 is a high level block diagram of a computing device in accordance with an embodiment of the present invention.
DESCRIPTION OF EMBODIMENTS
[0015] Embodiments are now discussed in more detail referring to the drawings that accompany the present application. In the accompanying drawings, like and/or corresponding elements are referred to by like reference numbers.
[0016] Various embodiments are disclosed herein; however, it is to be understood that the disclosed embodiments are merely illustrative of the invention that can be embodied in various forms. In addition, each of the examples given in connection with the various embodiments is intended to be illustrative, and not restrictive. Further, the figures are not necessarily to scale, some features may be exaggerated to show details of particular components (and any size, material and similar details shown in the figures are intended to be illustrative and not restrictive). 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 disclosed embodiments.
[0017] In one embodiment, and referring to FIG. 1 , a computing device 105 is in communication with an IVR system 110 over a communication channel 120 , such as a wire or a wireless channel. For purposes of this disclosure, a computer or computing device such as the computing device 105 includes a processor and memory for storing and executing program code, data and software which may be stored or read from computer readable media. Computers can be provided with operating systems that allow the execution of software applications in order to manipulate data. Computing device 105 can be any device that can communicate with the IVR system 110 and that can be used by a user. Personal computers, personal digital assistants (PDAs), wireless devices, smart phones, cellular telephones, internet appliances, media players, home theater systems, and media centers are several non-limiting examples of computing devices.
[0018] As described above, the communication channel 120 can be a wire or a wireless communication channel between the computing device 105 and the IVR system 110 . In one embodiment, the communication channel 120 is a channel transmitting information over a network, such as the Internet.
[0019] IVR systems such as IVR system 110 are systems that detect voice and keypad inputs. An IVR system can respond with pre-recorded or dynamically generated audio to direct users on how to proceed. IVR systems can be used to control functions where the interface can be broken down into a series of menu choices. Specifically, each IVR system includes one or more decision trees specifying a plurality of choices that can be taken when communicating with the IVR system. Examples of typical IVR applications include, but are not limited to, telephone banking, telephone voting, prescription refills, and credit card transactions. Companies typically use IVR services to extend the business hours of operation.
[0020] For the purposes of this disclosure, a computer readable medium is a medium that stores computer data in machine readable form. By way of example, and not limitation, a computer readable medium can comprise computer storage media for tangibly storing data, as well as communication media, methods or signals. Computer storage media for tangible storage includes volatile and non-volatile, 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. Computer storage media includes, but is not limited to, RAM, ROM, EPROM, EEPROM, flash memory or other solid state memory technology; CD-ROM, DVD, or other optical storage; cassettes, tape, disk, or other magnetic storage devices; or any other medium which can be used to tangibly store the desired information and which can be accessed by the computer or processor.
[0021] In one embodiment, a user provides (e.g., types in) a user request 125 to computing device 105 to connect to IVR system 110 to perform an action. For example, the user request 125 may be to connect to the IVR system 110 to pay a bill or to refill a prescription. In one embodiment, the user request 125 specifies the telephone number of the IVR system 110 to which to connect in order to perform the action. The computing device 105 connects to the IVR system 110 (e.g., a web site displayed on the computing device 105 creates a Voice over Internet Protocol (VOIP) telephone link to the IVR system). The IVR system 110 transmits a request for information 130 to the computing device 105 . The request for information 130 may include one or more menu options.
[0022] In one embodiment and in response to receiving the request for information 130 , the computing device 105 automatically provides an answer 140 to the request. The answer 140 can be one or more dual-tone multi-frequency (DTMF) signals. In one embodiment, the computing device 105 determines the answer 140 to the request for information 130 from one or more decision trees stored in a database 150 . The computing device 105 can also use speech recognition to determine an appropriate answer to the request for information 130 . In one embodiment, the computing device 105 requests answers from the user to questions that the computing device 105 has determined will be asked by the IVR system 110 . For example, upon the receipt of a user request 125 , the computing device 105 can ask the user to enter information associated with the user, such as the user's full name, birth date, social security number, home address, and/or personal identification number. Alternatively, the computing device 105 has already dealt with the user and, upon receiving a user request 125 from a particular user, the computing device 105 retrieves from its memory (e.g., cache) stored information about the particular user. The computing device 105 can then use this user information during its communication with the IVR system 110 . The stored user information can be transmitted by the computing device 105 to the IVR system 110 via, for example, DTMF or speech synthesis, or by playing out stored audio from the user.
[0023] In one embodiment, computing device 105 receives multiple user requests and communicates with a plurality of IVR systems in parallel to complete the actions specified in the user requests.
[0024] In one embodiment, the computing device 105 creates an instant messaging (IM) window and communicates with the IVR system via the IM window. Specifically, the requests for information 130 are displayed in the IM window and the computing device 105 answers the requests 130 with answer 140 entered into the IM window. In another embodiment, the computing device 105 transmits DTMF signals to the IVR system 110 using a voice card or via a cellular telephone line.
[0025] In one embodiment, decision trees can be purchased and downloaded to the computing device 105 . For example, a user may be able to use the computing device 105 to navigate to a particular web site that sells decision trees for a variety of companies. The user may then purchase one or more of the available decision trees and download the decision tree(s) onto the computing device 105 . Once the decision tree for a particular company has been downloaded to the computing device 105 , the computing device 105 can then (correctly) interact with the company's IVR system 110 .
[0026] FIG. 2 shows a block diagram of an embodiment of a computing device 205 in communication with a server 210 over a network 215 , such as the Internet. FIG. 3 is a flowchart of an embodiment of steps performed by server 210 (or computing device 105 ). As described in more detail below, in one embodiment (and as shown with dashed lines), the server 210 (or computing device 105 ) performs a training stage in step 305 . The training stage is performed by the server 210 (or computing device 105 ) in order to facilitate the correct interaction with IVR systems. The training stage may be a simple training or a complex training. In one embodiment, the training stage involves a user pushing buttons on the computing device 105 and the computing device 105 then repeating the pushed buttons the next time the computing device 105 receives a request for information 130 from the IVR system 110 or the computing device 205 transmitting the sequence of pushed buttons to the server 210 . In another embodiment, no training stage is performed.
[0027] The server 210 is then ready to receive user requests. In one embodiment, a user uses the computing device 205 to access a web page on which the user can submit a user request 220 . In one embodiment, the user request 220 identifies (e.g., via a telephone number) an IVR system that the user wants to connect to in order to perform one or more actions, such as to pay a bill. The computing device 205 transmits the user request 220 over the network 215 to server 210 . The server 210 receives, in step 310 , the user request 220 and determines (from the user request 220 ) to connect to IVR system 225 (step 315 ). In response to connecting with the server 210 , the IVR system 225 requests one or more pieces of information 230 from the server 210 (step 320 ). In one embodiment, the server 210 retrieves a stored decision tree associated with the IVR system 225 in step 325 (shown with dashed lines) for use in performing step 330 . In another embodiment, the server 210 performs speech recognition to determine how to respond to the request 230 for information. In response to each request 230 , the server 210 automatically transmits an answer 240 to the request 230 (step 330 ). This answer 240 may be based on the decision tree retrieved from database 218 , from speech recognition, and/or from stored user information associated with the user that has sent the user request 220 . The server 210 continues receiving requests 230 for information from the IVR system 225 and providing answers 240 to the IVR system 225 until the action specified in the user request 220 has been performed (steps 320 through 335 ).
[0028] In one embodiment, if the server 210 cannot determine (e.g., based on its training) the correct answer to a request 230 for information, the server 210 transmits the request 230 for information to the computing device 205 for analysis by the user. The user can use the computing device 205 to indicate how to respond to the request 230 for information. The computing device 205 can transmit this instruction to the server 210 , and the server 210 can then use this instruction to respond with an answer 240 .
[0029] In one embodiment, when the server 210 completes the action or progresses in the IVR system's menu options as far as the server 210 can go, the server 210 transmits a status message 260 back to the computing device 205 . The status message 260 can indicate to the user how far the server 210 went in completing the specified action. The status message 260 can be, for example, an email, a web page, or part of another web page.
[0030] Similar to computing device 105 , the server 210 can receive multiple user requests from one or more computing devices. In one embodiment, the server 210 communicates with a plurality of IVR systems in parallel to complete the actions specified in the user requests.
[0031] FIG. 4 illustrates a flowchart describing the training stage performed by the server 210 . In step 405 , the server 210 connects to an IVR system in a plurality of IVR systems. The server 210 then learns the decision tree for the IVR system by traversing through every option in the decision tree (step 410 ). The server 210 can store, in step 415 , the learned decision tree in memory, such as in database 218 . The server 210 then determines whether there is another IVR system to connect to in step 420 . In one embodiment, the server 210 maintains a list of IVR systems to which the server 210 can connect. This list can be updated by, for example, the user of the computing device 205 . If there is another IVR system to connect to, the server 210 connects to the IVR system (step 425 ) and repeats steps 410 through 420 . If not, then the training stage has completed and the server 210 is ready to process user requests.
[0032] The description herewith describes the present invention in terms of the processing steps required to implement an embodiment of the invention. These steps can be performed by an appropriately programmed computing device or computer, the configuration of which is well known in the art. An appropriate computing device can be implemented, for example, using well known computer processors, memory units, storage devices, computer software, and other components. A high level block diagram of such a computing device is shown in FIG. 5 . Computing device 502 is an example of computing devices 105 , 205 and contains a processor 504 which controls the overall operation of computing device 502 by executing computer program instructions which define such operation. The computer program instructions can be tangibly stored in a storage media 512 (e.g., magnetic or optical disk or other computer readable medium now known or to become known) and loaded into memory media 510 or read directly from media 510 when execution of the computer program instructions is desired. Computing device 502 also includes one or more interfaces 506 for communicating with other devices (e.g., locally or via a network). Computing device 502 also includes input/output 508 which represents devices which allow for user interaction with the computing device 502 (e.g., display, keyboard, mouse, speakers, buttons, etc.).
[0033] One skilled in the art will recognize that an implementation of an actual computing device will contain other components as well, and that FIG. 5 is a high level representation of some of the components of such a computing device for illustrative purposes, which may be, for example, a personal computer, PDA, wireless device, internet appliance, cellular telephone, or such processor driven technology. In addition, the processing steps described herein can also be implemented using dedicated hardware, the circuitry of which is configured specifically for implementing such processing steps. Alternatively, the processing steps can be implemented using various combinations of hardware, firmware and software.
[0034] Those skilled in the art will recognize that the methods and systems of the present disclosure can be implemented in many manners and as such are not to be limited by the foregoing exemplary embodiments and examples. In other words, functional elements being performed by single or multiple components, in various combinations of hardware and software or firmware, and individual functions, can be distributed among software applications at either the first or second computers or server or both. In this regard, any number of the features of the different embodiments described herein can be combined into single or multiple embodiments, and alternate embodiments having fewer than, or more than, all of the features described herein are possible. Functionality can also be, in whole or in part, distributed among multiple components, in manners now known or to become known. Thus, myriad software/hardware/firmware combinations are possible in achieving the functions, features, interfaces and preferences described herein. Moreover, the scope of the present disclosure covers conventionally known manners for carrying out the described features and functions and interfaces, as well as those variations and modifications that can be made to the hardware or software or firmware components described herein as would be understood by those skilled in the art now and hereafter.
[0035] The foregoing Description is to be understood as being in every respect illustrative and exemplary, but not restrictive, and the scope of the invention disclosed herein is not to be determined from the Description, but rather from the claims as interpreted according to the full breadth permitted by the patent laws. It is to be understood that the embodiments shown and described herein are only illustrative of the principles of the present invention and that various modifications may be implemented by those skilled in the art without departing from the scope and spirit of the invention. Those skilled in the art could implement various other feature combinations without departing from the scope and spirit of the invention. | Disclosed is a method and system for interacting with an IVR system. In one aspect, a computing device receives a user request to connect to an IVR system to perform an action. A request for information (e.g., a request to select from a plurality of menu options) is obtained from the IVR system. In response to the request, the computing device automatically supplies an answer to the request for information to the IVR system. In one embodiment, the answer is a dual-tone multi-frequency (DTMF) signal. The obtaining and supplying steps are repeated until the action has been performed. | 7 |
[0001] This application claims priority under 35 U.S.C. § 119(e) from provisional application Nos. 60/364,648 filed Mar. 15, 2002, 60/382,659 filed May 22, 2002 and 60/443,239 filed Jan. 28, 2003 respectively. The provisional applications are incorporated by reference herein, in their entirety, for all purposes.
FIELD OF THE INVENTION
[0002] This invention relates generally to replicating files over a network. More particularly, the present invention is a method and apparatus for permitting members of a group to replicate data in the form of files over a network in a secure manner with knowledge of changes made to the files by other members of the group.
BACKGROUND OF THE INVENTION
[0003] The Internet was launched over thirty years ago. Many advances in technology have ensued and many applications have evolved, and yet some technologies have change very little over the years. Today, e-mail is the primary means of communication between users of the Internet. While augmented by instant messaging, the fundamental technologies have changed little. Moreover, files are stilled shared using the file transfer protocol (“FTP”) or as attachments to electronic mail. Users receive little information about the files that are sent to them or which they download. Where file sharing is part of a collaborative effort among a number of authors, it is important that participants in that effort know the file “status”, which includes when the file was last changed, what was changed, who made the changes, and who has knowledge of the changes. Additional information useful to participants in the collaborative effort includes the evolution of the file and statistics on resources used to create the file at each point in its evolution. The file transfer systems currently in use today either do not provide the file status or file history in any meaningful detail or require that file transfer functions utilize a central server accessible by all participants in the collaborative effort.
[0004] One approach to collaboration is by using an Internet-based web server. Various server-based offerings were implemented in the early days of the Internet. Some of these programs combined address books, bulletin board, file sharing, discussions, project management, and other typical collaboration tools together into a hosted solution.
[0005] Hosted solutions were viewed has having the great advantage of not requiring IT installation and support while easily supporting communications between people at different companies behind firewalls. However, hosted solutions never became prevalent for a variety of reasons. One of the problems was that of scale. Since all of the users were required to connect to the same servers, the maximum number of users that service could handle was limited by the computing power of the servers used. Yahoo serves as a case in point. During the growth of the Internet in the 1990s, it spent virtually all of its computing resources ensuring that response time was acceptable for the growing number of users of the Internet.
[0006] Another problem with the hosted solutions is the location of the intellectual property. The hosted systems require that a participant's documents (intellectual property) be placed on a third party's server, thus raising significant policy questions for participants. Similarly, that intellectual capital may not really be preserved in the long run because it cannot be moved inside the organization.
[0007] Some of the hosted solutions offer sales of their servers to enterprises. While that sometimes provides a good Intranet solution, it places the organization in the same business as the hosted provider and requires that they make their collaborative servers accessible on the Internet for any work between organizations. It also creates a single point of failure—if the collaboration server fails, all of the data is inaccessible until the server is restored from backup.
[0008] A second approach based on peer-to peer (P2P) technology emerged in 2000. Groove Networks, Endeavors Technology, Roku, and others created a means for sharing information without requiring that all information be saved on a central, hosted server. These companies focused on direct connections between individual client systems and offered either access to files or replication of files. Each of these companies created a switch of sorts—a system that clients could connect to using an outbound connection and then routed requests between connected systems. This is virtually identical to the way that Instant Messaging services provided by Yahoo and AOL work.
[0009] While these solutions resolved many of the problems caused by firewalls, the solutions had problems of their own. First, scale again is an issue—none of the solutions focus on scale—their primary concern is functionality rather than building huge switches. In contrast, the reason that AOL Instant Messenger and Yahoo Instant Messenger work is because their functionality is trivial and the bulk of the computing resources are applied to providing enough computer power to move messages between users with a minimum of latency. In order to make a technology like Groove or Endeavors work, the company would have to virtually dedicate itself to making fast switches.
[0010] Further, client computers systems do not have the same operational characteristics that servers do. They are often turned off on a regular basis. They may not ever have the same IP address or may shift from network to network. They will also have varying bandwidth. Mobile users may have high speed Internet at the office but dial-up from the road. The performance of direct connections between systems, then, is often problematic.
[0011] There have been several efforts relating to data synchronization and transport between systems, including efforts that deal with high latency connections. A UCLA project called Ficus involved file replication within a LAN environment. This was implemented through a file system layer within Unix, requiring kernel modifications, and thus being dependent on the specific version of Unix. Trusted Information Systems and UCLA married the security aspects with the file sharing of Ficus into a later project called Truffles. This eventually evolved from its kernel level implementation to a user level, background process implementation, initially called Rumor and ultimately (with the security pieces) called User Level Truffles (ULT). Truffles/Ficus used a connection-oriented protocol to move information instead of the store and forward messaging infrastructure. Several other replication projects exist, including rsync, which focus on replication in both high and low bandwidth environments. None use the messaging infrastructure as a channel for data transmission, but some of these systems offer techniques for synchronization.
[0012] Another approach is taught by PCT Application WO 01/16804 filed by Chandhock et al. entitled “Maintaining Synchronization in a Virtual Workspace” (herein, Chandhock). Chandhock teaches the sharing of files among members of a workgroup via email messages that include a synchronization command in the embedded in the multipurpose Internet mail extension (MIME) of the email header and a MIME file attachment. Upon detection of an add or update synchronization command in a message from a group member, a user agent will determine whether a local copy the MIME file attachment resides on the recipient's computer. If a local copy of the attached file exists, the user agent makes a backup copy of the local file and saves it to a specified directory, then replaces the recipient's copy of the attached file with the sender's copy. According to Chandhock, files may be shared and synchronized in this way among group members.
[0013] Implicit in the approach taken by Chandhock and other is that synchronization of shared files among members of a group is achievable. In this context, “synchronization” means the sharing of a file that is believed by members of the group to be the same file. When a member of the group makes a change to the file, the changed file is conveyed to all other members and the changed file replaces previous versions of the file as stored by the other group members. In a “synchronized” environment, there is only one file,and all members are believed to possess it.
[0014] If this definition is what is meant by synchronization, then true synchronization may be unattainable. In a group of three or more members, it becomes increasingly difficult to be confident that a file possessed by one member is the latest version. Members may make changes and exchange files at approximately the same time resulting in multiple versions of the file to exist at the same time. This is not synchronicity.
[0015] Applicant, in previous writings it used the term “synchronizing” to describe the behavior of Applicant's system, which was not really a synchronizing files at all. In fact, Applicant's system was in reality a data “replication” system and method. “Replication” in this context refers to the copying of a version of a file from one member's system to the system of all other members of a group without requiring that existing versions of that file be replaced. Accordingly, in this application Applicant has adopted a lexicon that describes a process of file exchange in terms of “replicating” files among group members.
[0016] What would be particularly useful is a system and method for the formation of groups, each member of which is trustworthy, and for the secure replication of information among members of the group without the need for a central server. The system and method would additionally permit participating members to determine the most current information in the possession of that member.
SUMMARY OF THE INVENTION
[0017] An embodiment of the present invention is a data replication system (DRS). The DRS comprises two layers—an application layer and a communications layer. The communications layer implements a message redirector and collects DRS messages for the application layer. The application layer handles the DRS messages in the context of whatever application it implements. In one embodiment, a DRS message is used within an e-mail system to form groups and replicate files among group members participating in a collaborative effort. In this embodiment, the e-mail stream passes through a message router comprising an application layer interface. The message router extracts DRS messages while allowing e-mail messages to pass. Once extracted, the DRS message is parsed and instructions conveyed by the DRS message are implemented by a command processor. Command sets comprise instructions for both group formation and file management and update.
[0018] It is therefore an aspect of the present invention to facilitate the formation of groups of trustworthy members through the exchange of invitations among potential group members.
[0019] Another aspect of the present invention is to facilitate the replication of files among members of a group in a secure environment.
[0020] It is yet another aspect of the present invention to facilitate the efficient replication of files among group members by capturing changes to a version of a file in a patch and sending the patch to members of the group.
[0021] It is still another aspect of the present invention to apply a patch to a version of a file in the possession of a group member only after determining if that version of the file in the possession of the group member is the same as the version of the file used to create the patch.
[0022] Another aspect of the present invention is to permit the reconstruction of a version of a replicated file by maintaining a database of patches.
[0023] It is still another aspect of the present invention to associate a file status with a replicated file wherein the file status identifies the date of the last change made to the file, the identity of the user making the last change, and the identity of the users who have knowledge that the change was made.
[0024] It is a further aspect of the present invention to permit a group member to reconcile divergent versions of a file by identifying the structure of a file and merging the divergent versions of a file to create a reconciled version.
[0025] It is still a further aspect of the present invention to utilize existing network protocols for the file transfer and to facilitate file replication on an ad hoc basis wherein a third party intermediary is not required.
[0026] It is still another aspect of the present invention to facilitate file replication on a peer-to-peer basis between and among users of a network accessing the network through computers, personal data assistants, cell phones, and similar devices.
[0027] It is yet another aspect of the present invention to facilitate file replication between and among users of a network wherein the users have defined rights of access to the replicated file and have defined permissions relating to changing a replicated file.
[0028] It is a further aspect of the present invention to provide trading partners the ability to communicate the status of a transaction.
[0029] It is another aspect of the present invention to establish permissions to access files in an asymmetrical manner so as to establish controls over documents comprising multiple files.
[0030] It is yet another aspect of the present invention to provide additional information useful to group members participating in the collaborative effort which includes the evolution of the file and statistics on resources used to create the file at each point in its evolution.
[0031] It is a further aspect of the present invention to incorporate routing instructions in a group member's profile, thereby permitting files to be automatically routed to a third party group member once received by a group member recipient, together with the appropriate file status information noting changes to the version being routed.
[0032] These and other aspects of the present invention will become apparent from a review of the general and detailed descriptions that follow.
[0033] An embodiment of the present invention is a data replication system (DRS). The DRS comprises two layers—an application layer and a communications layer. The communications layer implements a message redirector and collects DRS messages for the application layer. The application layer handles the DRS messages in the context of whatever application it implements. In one embodiment, a DRS message is used within an e-mail system to form groups and replicate files among group members. In this embodiment, the e-mail stream passes through a message router comprising an application layer interface. The message router extracts DRS messages while allowing e-mail messages to pass. Once extracted, the DRS message is parsed and instructions conveyed by the DRS message are implemented by a command processor. A group of instructions comprises a command set. In an embodiment of the present invention there are command sets for both group formation and file management and update.
[0034] In an embodiment of the present invention, group formation is managed by a group formation and management command set. Commands are inserted in an email header. When detected, the commands are forward to and implement by a command processor. Potential new members of a group are “invited” to join the group by an existing member. If the invitation is accepted, the invitee is now a “new member.” The inviting member sends a “welcome” message to the new member, which welcome message comprises a group membership list. The new member sends an “introduce” message to each group member identified on the inviting member's group membership list. An existing member of the group (other than the inviting member) accept the new member by sending a “welcome” message and a copy of the group membership list according that member. In this way, the new member establishes a relationship with each of the existing group members.
[0035] In another embodiment, the invitation and acceptance message exchange is accompanied by an exchange of public keys. In yet another embodiment, a third party manages the key exchange.
[0036] In still another embodiment, the replication of files is managed by a file replication data set. A tag comprising instructions is inserted into an email identifying the message as a DRS message. When detected, the instructions are forwarded to and implemented by a command processor. Each member of a group designates a directory where files that are to be replicated are stored. The DRS computes signatures and patches as it detects changes in a local file. Each time an exchanged file changes, a new hash, signature and patch are computed and stored. The hash and the patch are transmitted to all of the other members of the group. The hash value is compared to the hash value of the file targeted for update and, if they match, the patch is applied. The patch messages comprise a binary differential representing the changes made to the targeted file. The hash value is compared to the hash value of the file targeted for update and, if they match, the patch is applied. This mechanism is backed up with a database of patches and signatures. Each version of the file generates an additional patch and signature, which are used to apply changes as patches arrive. Because of this, the database can be used to generate any previous version of the files within. Similarly, file versions that are created from receipt of PATCH messages are also stored in the database. This provides a complete version history of a single file. Every patch record is tagged with the email address identifying where the file change came from.
[0037] In another embodiment, the shared files are part of a larger shared document. Participating members have different rights with respect to the document and its component shared files. In this embodiment, a participating member with document control authority can limit the component shared files that are readable and editable by each participating member. Additionally, until the participating member with document control approves of a modification by another participating member, the modification is noted as pending and the document is presented as unchanged.
[0038] In still another embodiment, the shared file may be replicated by a participating member to others within that member's organization on an automated basis. This is accomplished by the participating member who is a member of, for example GROUP 1 comprising members inside and outside of that member's organization. That member forms another internal group, for example GROUP 2, comprising internal members only. When a file is replicated into the participating member's file as a result of that member being in GROUP 1, it is automatically replicated into the files of those members of the participating member's internal organization, GROUP 2. Thus the present invention can permit this replication to occur in an automated way so that a chain is formed from the participating member, as a member of GROUP 1, to those in that member's organization GROUP 2. Thus the recipients within the member's organization GROUP 2 can be assured that the replicated file is coming from a trusted source. In this instance the participating member is designated as both a recipient and a source of files, allowing the replication to occur. Thus secure, private distribution of a file from an external source is achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] [0039]FIG. 1 illustrates the basic architecture of a data replication system according to an embodiment of the present invention.
[0040] [0040]FIG. 2 illustrates an implementation of a data replication system in a user environment according to an embodiment of the present invention.
[0041] [0041]FIG. 3 illustrates an invitation process according to an embodiment of the present invention.
[0042] [0042]FIG. 4 illustrates an introduction process according to an embodiment of the present invention.
[0043] [0043]FIG. 5 illustrates a structure of an exchanged file according to an embodiment of the present invention.
[0044] [0044]FIG. 6 illustrates the internal routing of files originating from an external source according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0045] An embodiment of the present invention is a data replication system (DRS). The DRS comprises two layers-an application layer and a communications layer. The communications layer implements a message redirector and collects DRS messages for the application layer. The application layer handles the DRS messages in the context of whatever application it implements. In one embodiment, a DRS message is used within an e-mail system to form groups and replicate files among group members. In this embodiment, the e-mail stream passes through a message router comprising an application layer interface. The message router extracts DRS messages while allowing e-mail messages to pass. Once extracted, the DRS message is parsed and instructions conveyed by the DRS message are implemented by a command processor. Command sets comprise instructions for both group formation and file management and update.
[0046] Referring to FIG. 1, a data replication system (DRS) 100 according to an embodiment of the present invention is illustrated. The DRS 100 comprises two layers-an application layer 105 and a communications layer 110 . The communications layer 110 comprises a POP3 client 112 , a message redirector 114 , a queue manager 120 , a POP3 server/proxy module 124 and a SMTP client module 128 . The applications layer 105 comprises a command processor 130 , an invitation manager 135 , a group manager 140 , an HTTP Server and XSLT Processor 145 , a directory manager/file scanner 150 , and an instruction encoder/decoder 155 . The queue manager 120 exchanges DRS messages with the command processor 130 of the application layer 105 .
[0047] The communications layer 110 manages the connectivity between nodes of DRS software. Using e-mail addresses as an identifier, DRS nodes communicate with each other by sending e-mail messages. Because most e-mail addresses are associated with individuals using e-mail accounts, the communications layer 110 is implemented as a message redirector, retrieving DRS messages from an e-mail server and routing the other messages to the e-mail client.
[0048] In one embodiment of the present invention, a DRS message uses an x-header in MIME format to distinguish DRS messages from ordinary e-mail messages and to encode their content. For purposes of illustration and not as a limitation, an x-header would be in the form x-drs. The x-drs header in conjunction with message redirector 114 operates as a simple switch, indicating that the message is a DRS message instead of a common e-mail message. In this embodiment, the actual DRS message is encoded in XML for convenience. The MIME-type of an attachment is not the generic text/xml, but rather is x-drs/instructions to enable different message encodings other than XML.
[0049] As will be appreciated by those skilled in the art, other means may be used to distinguish DRS messages from ordinary email messages without departing from the scope of the present invention. By way of illustration, the “subject” line or the attachment file name may incorporate a tag or unique string that identifies the email message as DRS message.
[0050] In an embodiment of the present invention, the DRS message comprises three non-application specific components: the ID, the FROM, and the TO elements. The ID, a transaction ID, is a Universal Unique Identifier (UUID). In this embodiment, the UUID is generated using ISO-11578, but this is not meant as a limitation. As will be apparent to those skilled in the art, other means of generating a unique identifier may be utilized without departing from the scope of the present invention so long as no other transactions for a particular application will see the same transaction ID. The FROM and TO elements identify the original sender and intended recipient of the message. These elements are embedded in the message to enable it to be routed through a third party if necessary.
[0051] The communications layer 110 further comprises modules that implement specific e-mail protocols—SMTP, POP3, and IMAP4 (only POP3 modules are illustrated in FIG. 1). Because the communications layer 110 functions as a message redirector, both client and servers for these protocols are implemented in the system.
[0052] The POP3 client module 112 retrieves e-mail messages from the user's e-mail server. It implements the core POP3 protocol elements, enabling e-mail server login, message header retrieval, message retrieval, and UIDL retrieval. The POP3 client module 112 can be activated using one of two methods—the proxy method or the side-by-side method.
[0053] When the DRS POP3 server module 124 receives the user id and password, it parses out the e-mail server from the user id and uses that information to connect to the real e-mail server using the POP3 client module 112 . The POP3 client module 112 then connects to the actual e-mail server and retrieves the headers for each of the e-mail messages on the server. Any messages that have an x-drs header are retrieved, posted to the queue manager 120 , and deleted from the e-mail server. The remaining message headers are stored in a local table within the POP3 client module 112 and are numbered sequentially. Since POP3 servers do not actually delete message numbers until the QUIT command is issued, the POP3 client module 112 must maintain a lookup table mapping the message numbers presented to the e-mail client with those actually on the e-mail server.
[0054] This effectively removes all DRS messages from the perspective of the e-mail client. The POP3 server/proxy module 124 then uses the POP3 client as a proxy, passing through most requests back to the actual e-mail server. Certain POP3 commands are intercepted and handled all or partially in the POP3 client module 112 . For example, the POP3 command RSET will undelete messages. Since the desired effect is to undelete only those messages that the e-mail client is aware of, RSET only removes the deletion mark from the local table.
[0055] The side-by-side method has similar functionality except that the POP3 client module 112 is triggered with a timer instead of with the POP3 server/proxy module 124 . In this case, the user does not need to alter their e-mail settings, but may see DRS messages in their inbox. The side-by-side method works well for advanced e-mail clients like Outlook, where a user can filter out the DRS messages manually. It also works well when the e-mail client connects to an IMAP4 or Exchange server, where the messages may briefly show up in the e-mail client before being deleted from the server.
[0056] When the side-by-side method is enabled, the user must configure the DRS software with all of the e-mail account information necessary to make the connection. This includes the user id, password, e-mail server name (both POP3 and SMTP) and user's e-mail address (typically not a combination of the user id and e-mail system name). In contrast, the proxy method requires an alteration to the e-mail client's configuration, but only requires the user's e-mail address and the SMTP server name.
[0057] In side-by-side mode, the POP3 client module 112 runs every few minutes (a configurable setting) and retrieves the DRS messages from the e-mail server and then deletes them. Any messages retrieved are posted the queue manager 120 for handling.
[0058] The queue manager 120 runs two queues—an inbound queue and an outbound queue. These two queues play different roles in the operation of the DRS 100 .
[0059] The inbound queue accepts messages from the POP3 client module 112 and posts them to the application layer's command processor module 130 for handling. Aside from the contents of the message, the queue manager 120 must be told the ID of the message and the sender for inbound messages. Inbound messages are processed by a background thread that cycles through the inbound queue periodically. Messages that fail processing are held in the queue for retry.
[0060] Inbound messages can be retained in the queue's persistent store, allowing the POP3 client module 112 to asynchronously retrieve and post messages. The queue's persistent store serves as an excellent backup mechanism should the client system fail. But most important, the queue helps manage out-of-sequence messages. While not generally visible to e-mail users, most e-mail clients automatically order messages by the date they were sent. This leads to the presumption that the e-mail messages were actually delivered in that order, which is often not the case. In fact, e-mail messages are typically delivered in order of size—the smaller ones are transmitted from server to server more quickly by SMTP nodes if they open up multiple connections, while larger messages take longer to deliver. In an embodiment of the present invention, the inbound queue allows messages to be held and processed in the proper order.
[0061] The outbound queue is responsible for transmitting messages to the recipient using the SMTP client module 128 . This queue exists to provide both a background process to asynchronously e-mail the DRS messages as well as handling the situation where the DRS is operating in disconnected mode. The DRS outbound queue will periodically attempt to connect to the outbound e-mail server and send the messages in its queue.
[0062] The application layer 105 of DRS implements the group file replication elements of the system. The group file replication elements implement a protocol wherein files associated with a group by each group member are replicated on every other group member's system. Groups are identified by a title, description, and UUID, ensuring that titles do not have to be unique in the system. A group is created by one individual, who then invites others to join the group. Each user is identified by his/her e-mail address. Files are associated with a group by being stored in a designated directory location. Files are also associated with a group member such that the files of the recipient are not overwritten by the receipt of a file from a group member.
[0063] Referring to FIG. 2, an implementation of a DRS 100 in a user environment according to an embodiment of the present invention is illustrated. Email from e-mail server 230 is received by e-mail client/DRS software 205 where DRS messages are identified and routed. As illustrated, the user of e-mail client/DRS software 205 is a member of two groups and has designated a group A directory 210 and a group B directory 215 . Email client/DRS software 205 routes replicated files received from members of group A to the group A directory 210 and routes replicated files received from members of group B to the group B directory 210 . Each the file in a directory is presumed to be replicated among members of a group. Thus, any change made to a file in the group A directory 210 will be replicated in the comparable directory of all of the members of group A. The mechanism by which this replication occurs is described below.
[0064] The group formation and file replication functions are built into a single command processor module. Interacting with that module is a set of application specific modules that handle each of the processes necessary to manage groups, update files and directories, process invitations and interact with the user.
[0065] In an embodiment of the present invention, the communications and application functionality are separated. This means that the message redirection components need no knowledge of the application protocols. This attribute permits other applications take advantage of the DRS communications layer.
[0066] In an embodiment of the present invention, the command processor implements the complete command set for the group file replication application. In this embodiment, each message posted to the command processor is encoded in XML, which the instruction encoder decodes into a memory-based structure. The message is expected to contain the required elements for the communications layer (ID, FROM, TO) as well as these group file application specific elements: GROUP, VERB, ARGUMENTS, CONFIRM, and LAST. The GROUP element identifies for which group the message is intended. The GROUP element, as mentioned earlier, contains the group's UUID. This ensures the correct disposition of the enclosed action. The VERB element is the action that will be applied to the group. The ARGUMENTS are specific to the particular action specified in the VERB, although all arguments are designated in name/value pairs. There are currently twelve (12) verbs, plus ACK and NAK, organized into three groups or command sets.
[0067] The first command set comprises the actions for group formation and management. The following verbs belong to this command set:
[0068] a. INVITE
[0069] b. DECLINE
[0070] c. WELCOME
[0071] d. ACCEPT
[0072] e. INTRODUCE
[0073] f. QUIT
[0074] g. REVOKE
[0075] Referring to FIG. 3, an invitation process according to an embodiment of the present invention is illustrated. An existing member sends the potential member an invitation message that comprises an INVITE action. When a potential member is invited to join a group, the INVITE action comprises only the group's UUID, title, and description. It does not comprise a member list. This information is sent after the potential member accepts the invitation when the inviting member sends a WELCOME action that contains the membership list. The ID for each of these transactions is the same, since this is viewed as the same transaction repeated with two acknowledgements. If for some reason the potential member sends an ACCEPT message for a group to which he/she was either not invited to or expelled from, the existing member can send back a NAK indicating a failure to ACCEPT. After a new member has accepted the invitation and receives the member list, the member uses the INTRODUCE action to introduce him/herself to the other group members.
[0076] Referring to FIG. 4, an introduction process is illustrated according to an embodiment of the present invention. In the introduction cycle, a new member sends the INTRODUCE message to other existing members. This message is essentially a request that each member reveal his/her list of known members. This helps manage the problem of some members not knowing about other members. The new invitee then updates his or her list of members and possibly sends out introductions to those additional members. Two additional messages (not illustrated) are part of the group formation suite—QUIT and REVOKE. The REVOKE verb is used to revoke the membership of a group participant. It is sent to all members of the group, identifying which group member is no longer on the list. An ACK is expected in response from all members except the one from whom membership was revoked. The QUIT verb is used to indicate that a member is leaving the group voluntarily. It is also used as a response to messages containing group IDs to which the user doesn't belong. This can happen occasionally in this system because of the latency in data transmission between group members.
[0077] In another embodiment of the present invention, a second instruction set comprises the actions for file management and update:
[0078] a. PATCH
[0079] b. ERASE
[0080] c. REQUEST
[0081] Each of these actions simply requires an ACK for a successful response or a NAK for an unsuccessful one.
[0082] The PATCH action contains a set of bytes that either creates a new file or updates an existing one. In an embodiment of the present invention, the PATCH action for files smaller than 1 MB is a single transaction, while those larger than 1 MB are split into multiple blocks and sent as a series of PATCH messages. However, this is not meant as a limitation. As would be apparent to those skilled in the art, other schemes for conveying patches of varying size may be utilized without departing from the scope of the present invention. Each PATCH action consists of a group identifier, the name of the file to update or create, two hash values, and the patch data. The hash values represent the before and after hashes for the patch. If the “before” patch is zero length, then the patch contains the data necessary to create a new file. If the hash value of the updated file does not match the “after” patch, then the PATCH action fails and a NAK is returned.
[0083] As noted above, in an embodiment of the present invention, PATCH actions for files larger than 1 MB are split into 1 MB chunks and transmitted individually. The first block is sent in a “master” PATCH. That message contains a tag indicating that the PATCH action is a “master” action and includes a count of the total number of blocks in the entire patch. In addition to that header information, the “master” PATCH message contains the first block of the transmission. Other blocks are each sent in “partial” PATCH messages, identifying which block number the message contains. The “master” PATCH is not processed until all of the “partial” PATCH messages have been received. At that point, the data blocks are reassembled and then applied to update or create the file.
[0084] The ERASE verb simply removes a file from the group. In addition to the name of the file to erase, the ERASE action also holds a hash value. This hash value is used to ensure that the file to be erased is the same file that the sending system has erased. If the hash values are different, the file is not erased and the action fails.
[0085] The REQUEST verb is designed to allow a group member to reconcile an exchange of modified documents by asking for files or patches to be resent. The REQUEST can be acknowledged with an ACK. Upon receipt, the files identified in the REQUEST action are to be sent to the requesting group member.
[0086] In another embodiment of the present invention, a third instruction set comprises the actions for transaction management:
[0087] a. REQTRAN
[0088] b. NOOP
[0089] The REQTRAN action is used to request a missing transaction. Since e-mail is not a perfect transmission medium, it can be anticipated that messages will be lost in transmission. The REQTRAN verb simply requests that a particular transaction ID for a group be resent. If the transaction ID does not exist, then a NOOP is currently returned so that the request is satisfied.
[0090] The REQTRAN plays an important role in all of the transaction processing because it is coupled with an optional LAST tag in each of the messages. The LAST tag identifies the transaction ID of the message preceding the message currently being processed. This ensures that the order of the messages is preserved even though the messages may not have been delivered in order. Not all messages require a LAST tag (INVITE, for example), but all of the messages that operate on files, either updating, erasing or creating them, require that the predecessor transaction be identified.
[0091] In an embodiment of the present invention, file replication is accomplished by creating a basis file and then applying patches made up of binary differentials. The DRS computes a digital signature and patch as it detects a change in a local file. Each time a replicated file is changed, a new hash, signature and patch are computed and stored. The hash and the patch are transmitted to all of the other members of the group. The hash value is compared to the hash value of the file targeted for update and, if they match, the patch is applied.
[0092] This mechanism is backed up with a database of patches and signatures. Each version of the file generates an addition patch and signature, which are used to apply changes as patches arrive. Because of this, the database can be used to generate any previous version of the files within. Similarly, file versions that are created from receipt of PATCH messages are also stored in the database. This provides a complete version history of a single file. Every patch record is tagged with the e-mail address identifying where the file change came from.
[0093] Because it is possible that the same file might be changed simultaneously, the database is structured as a tree of version information. If a patch arrives and the target file is not the same version, the DRS system can use the “from” hash in the PATCH message to walk through the version history to find the records necessary to rebuild the basis file. The new patch can be stored in the database alongside all of the other patches. On demand, the system can generate that version of the file or any other.
[0094] In one embodiment of DRS, concurrent updates generate parallel versions and reconciliation of the different versions is left to the user. This will be entirely satisfactory in many cases, partly because the probability of conflict is usually very low and partly because the users will easily be able to merge the different versions. In another embodiment, the structure of a file is determined and hooks are provided to merge concurrent files automatically.
[0095] By way of example, a distributed web logger—or “blog” in informal lingo—comprises entries identified by contributor. Each entry is a paragraph of text and it is considered acceptable for the ordering of the paragraphs to be approximate. Blogs are particularly interesting in the context of DRS because they can be used within a group to provide commentary about the changes of more formal files such as Word documents or Excel spread sheets.
[0096] Referring again to FIG. 1, the group manager 140 and invitation manager 135 act as data accessing modules, responsible for managing persistent storage. The group manager 140 creates and manipulates groups, while the invitation manager 135 does something similar for invitations. A small amount of management in the invitation manager 135 is set for handling multiple invitations to the same group—currently these are collapsed into a single invitation. Neither of these modules is an “active” module—they do not run on background threads. However, the group manager 140 is responsible for starting up the monitoring threads for the directory manager 150 as the groups are enabled.
[0097] The directory manager 150 monitors the files in a replication directory to determine if any of the files have been changed. If a file has changed, the directory manager 150 starts the process of computing a version change—a signature and patch are computed for the file and then stowed in the database that holds those values. The patch is then forwarded to the command set for transmission.
[0098] In an embodiment, the directory manager 150 is not tied to group membership. When patches are posted, the command processor receives the file's location instead of its group ID. This allows the replication directory files to participate in more than one group. When the file updates are transmitted, the location is resolved into one or more group IDs.
[0099] In addition to supporting a common Windows user interface, the DRS contains a small web server with a built-in Sablotron XSLT processor. The web server is wired through an initialization file that specifies the url, the XML to retrieve and the XSLT to apply.
[0100] [0100]FIG. 5 illustrates a structure of an exchanged file according to an embodiment of the present invention. The root url (“/”) is tied to the index.xsl file and the “groups” XML. This instructs the URL handler to retrieve the information from the group manager in XML format and apply the index.xsl XSLT style sheet. The retrieval of XML data from the different system manager may also include parameters. Each XML retriever has a different selection of parameters available. The HTTP server provides support for interprocess communications and remote access.
[0101] In yet another embodiment, the DRS uses a key exchange process to provide security. Each node of the Data Replication Service generates an RSA (or similar) key pair for the user of that node. It also maintains a key ring for the user, associating keys with e-mail addresses. Keys will be added to the ring initially through the process of group invitation—when an invitation is sent, it will include the public key of the member. When the invitation is accepted, the public key of the new member is returned to the existing group member. In one embodiment, keys are generated and used without third party signers. In yet another embodiment, key exchange is managed by the use of certificates and trusted third parties.
[0102] Once keys are exchanged, all messages between the group members are encrypted. The focus of message encryption will be the core message body in the x-drs/instructions packet, rather than attempting to encompass all of the capabilities of S/MIME.
[0103] In another embodiment, a DRS routes information between groups. Since two groups may replicate the same set of files, the opportunity exists to route changes made by one group to the members of another group. Instead of viewing the replication relationship as the equivalent of a distributed implementation of a set of replicated files, the overlapping group relationships become something akin to routers. For example, two or more people who are in different organizations may set up a replication relationship, and then one of them may replicate the files with an internal group.
[0104] In another embodiment of the DRS, transport protocols other than e-mail are used where appropriate. For example, in one embodiment, where direct connection among peers is possible, more traditional protocols such as FTP can be used. In another embodiment, replication of files is accomplished among cell phones and other devices using Short Message Service (SMS).
[0105] An entirely different form of routing is possible for propagation of updates. In the present design, each node automatically sends its updates to all of the others in the same relationship. However, in some environments, it may not be possible to address or route changes between any two participants. For example, if direct connections are being used, but some participants had only limited connectivity or could interact directly with only some of the participants, changes could be pushed out with instructions to relay them to the other participants.
[0106] In another embodiment, the “replicated file” is an executable and the message redirector (FIG. 1, 114) permits the user of the sending computer to control the receiving computer remotely using inbound SMS messages.
[0107] Referring now to FIG. 6 the internal routing of files originating from an external source is illustrated. In this instance the concern for those within an organization using a document related to whether that document is from a trusted source or not. If it is not, and is propagated through an organization, a virus may be spread, or erroneous information on which decisions are based may be propagated throughout the organization. To assist in the replication of files from trusted sources, the present invention allow for groups to be “chained” together. Members 200 and 202 are part of a trusted group. Member 202 may also be a member of another group internal to that member's organization here illustrated as a group comprising internal members 202 , 206 , and 206 . When a file is replicated in to the file of member 202 by virtue of its membership in the group comprising 200 and 202 , it is automatically replicated into the files of the internal group comprising 202 , 204 , and 206 . Thus two groups are chained together. In this case group member 202 is designated as both a recipient and a source of files. It further accomplished the objective of providing confidence to group members 204 , and 206 that the files being received are from a trusted source even if the files are originating external to the organization of which 204 and 206 are members.
[0108] A data replication system and method have now been illustrated. It will also be understood that the invention may be embodied in other specific forms without departing from the scope of the invention disclosed and that the examples and embodiments described herein are in all respects illustrative and not restrictive. Those skilled in the art of the present invention will recognize that other embodiments using the concepts described herein are also possible. | A data replication system and method. The method and apparatus provides for an efficient means of replicating data over a network in the form of a file between two individuals, or within defined groups of individuals, using a variety of devices to access the Internet, including computers, personal data assistants (“PDA”s) and wireless devices. A group is formed through an exchange of invitation, acceptance, and welcome messages. A group member designates a replication directory on the group member's computer. Files placed in the directory are replicated and stored in the replication directory of each of the other members of the group. Any change to a replicated file causes a message by one member to be sent to all other members. Changes are conveyed via patches that represent the changes made to a replicated file. Replicated files are saved without replacing previous versions of the replicated file. The group formation and file replication processes are accomplished using existing network protocols. | 6 |
TECHNICAL FIELD
The present invention relates to a device for the non-contact actuating of a moving part of a vehicle, in particular a trunk lid, a side door or the like, comprising a first detection means for detecting an object in a first detection area and a second detection means for detecting an object in a second detection area such that the actuation of the moving part can be activated by means of the detection means.
BACKGROUND
Actuating a trunk lid without contact can be useful for example when a person has their hands full with objects and manually operating the trunk lid is not possible or only possible with difficulty. The object detected by the detection means can be a person who approaches the vehicle with the intention of actuating the trunk lid or a side door or the like. The actuating of the trunk lid, the side door or the like thereby designates both an opening action, for example when a person wants to place an object held in both hands in the trunk or passenger compartment, or the actuation relates to a closing action when the person takes an object out of the trunk or passenger compartment using both hands.
EP 1 902 912 A1 discloses a generic device for actuating a vehicle trunk lid without contact. A detection means in the form of a sensor arrangement is proposed therein which monitors some of the area outside the vehicle for the presence of an object or part of a user's body. The sensor device is installed and aligned such that it can detect part of a leg or a foot of the person standing next to the vehicle.
Detection thereby further comprises a body movement, for example related to the lifting or turning of the leg or the foot of the person within the area outside of the vehicle monitored by the sensor arrangement. A signal to actuate the trunk lid can thereby also be disadvantageously triggered in cases not necessarily involving the person's leg or foot. For example, animals can pass through the area outside of the vehicle monitored by the sensor arrangement or an object, for example a ball, can move or roll through the monitored outside area. It is thus advantageous to prevent a malfunctioning of the vehicle trunk lid actuation.
A further device for actuating a trunk lid of a vehicle without contact using detection means is known from DE 10 2004 041 709 B3. This document proposes arranging a first detection means for detecting an object in a first detection area and a second detection means for detecting an object in a second detection area such that said detection means can activate the trunk lid actuation. Reference is made to vehicle devices known as distance detection systems or PDC systems (park distance control systems) as the detection means. These systems operate via ultrasound or radar sensors and serve to monitor an area outside of the vehicle.
Ultrasound sensors or radar sensors used as detection means for detecting objects in the area outside of the vehicle exhibit high power consumption. Therefore, continuous monitoring of the area outside of the vehicle by such sensors cannot be satisfactorily realized. The vehicle's battery is used as the energy source to supply said sensors such that the device for the non-contact actuating of a trunk lid cannot remain switched on permanently.
BRIEF SUMMARY
The invention provides a device for actuating a moving part of a vehicle without contact which overcomes the disadvantages of the aforementioned prior art and enables continuous monitoring of the area outside of a vehicle. To be particularly enabled is a reliable and low-energy monitoring of the area outside of a vehicle.
The invention comprises the technical teaching that the first detection means is configured as a first capacitance sensor and the second detection means is configured as a second capacitance sensor and wherein means are provided with which the detection areas can be specified in individually separate areas. Further detection means, likewise with their own detection areas, can additionally be provided.
Within the context of the present invention, the term “moving part” refers to any vehicle door, side door, sliding door, hatch or the like having at least one closed position and one open position, whereby the closed position is realized by means of an electrical and/or mechanical lock in order to prevent inadvertent or unauthorized opening. In particular, the lock of said moving part can interact with the vehicle's central locking system, preferably an “active or passive Keyless Go system.” The vehicle itself can be a motor vehicle.
Realizing the detection means as capacitance sensors yields a device for the non-contact actuating of a moving part of a vehicle of very low energy consumption. This in turn yields the advantage that the capacitance sensors can be kept in continuous operation to monitor an area outside of the vehicle, preferably in the area of the trunk lid or the side doors. The capacitance sensors can be configured and dimensioned such that their energy consumption is less than 100 μA, at least in static state. Such low power consumption enables continuous monitoring of the area outside of the vehicle such that the device for the non-contact actuating of a moving part of a vehicle can always remain in a state of operational readiness.
A further improvement of the function of the device for the non-contact actuating of a moving part is achieved by providing means with which the detection areas can be predefined into individually separate areas. This thus achieves the advantage that the first detection area will not overlap the second detection area. Individually separate detection areas enables different parts of a person's body to be detected independently. Using the inventive means to spatially separate the detection areas can reduce the power consumption of the capacitance sensors even further. The capacitance sensors can respectively comprise one or more sensor electrodes in capacitive coupling to the immediate vicinity, whereby the greater the charge density, the higher the capacitive coupling.
Yet providing the inventive means to specify the respective detection areas can result in a lower electrical charge stored on the sensor electrodes so as to still achieve high sensitivity for the capacity sensors. The consequence is that the power consumption is further reduced, achieving a further improvement of the device for actuating the moving part without contact.
One advantageous embodiment of the device comprises both means for the first as well as means for the second detection area. More than two detection means can also be provided so that there can also be a third or further detection area(s). These detection means can be of identical or similar configuration to the first and/or second detection means and can thus also comprise the respective capacitance sensors having clearly-defined detection areas. The means for the detection areas are realized such that the first detection area exhibits a substantially horizontal extension whereas the second detection area exhibits a substantially vertical extension. A third detection area of a third detection means can be arranged for example adjacent the first or second detection area. It is also conceivable for a third detection area to be arranged between the first and second detection area. This thus enables the reliable, precise metrological detecting of an object and/or a respective motion pattern of the object, whereby improper actuation of the moving part can be reliably prevented. To actuate a trunk lid, the capacitance sensors can preferably be arranged at the rear end of the vehicle and in particular in and/or on the rear bumper of the vehicle. The capacitance sensors are arranged such that the first capacitance sensor having the horizontal detection area can detect for example a leg of an upright moving person as the object to be detected. Hence, if a person approaches the rear end of the vehicle, this motion is detected by the first capacitance sensor having the horizontal detection area. When the person then stands behind the vehicle and moves a foot in the area underneath the rear bumper, this motion can be detected by the second capacitance sensor having the vertical detection area. To actuate a side door in the door sill area of the vehicle, the capacitance sensors can in particular be arranged in and/or on the bottom of the vehicle side door. It is also conceivable for the capacitance sensors to be directly arranged on or in the door sill and not the side door itself. As with the trunk lid, it is preferable here to provide for at least one horizontal and one vertical detection area.
Making use of at least two detection areas allows the device to recognize the intent to actuate the moving part of the vehicle from a motion pattern produced by the object. For example, if the person lifts his foot, a further change in the charge on the sensor electrode of the second capacitance sensor can occur. Hence, the actuating of the trunk lid can be linked to a predefined motion pattern of the person and in particular a motion pattern of the person's foot. This motion pattern can for example ensue after the person approaches the vehicle and encompasses a single or preferably double or repeated movement of the foot.
It is also conceivable for the capacitance sensor to initially detect the movement of a leg, wherein e.g. the second capacitance sensor first switches on. When the second capacitance sensor switches on, it attempts to metrologically detect the respective foot of the leg, for example detecting the foot entering into the second detection area. This motion pattern can be used to trigger the actuating of the moving part. It is also conceivable that the foot needs to be promptly pulled back out of the second detection area as applicable in order to trigger the actuating of the moving part. Likewise, the leg may possibly also need to be withdrawn from the first detection area before the actuating of the moving part can be triggered. It is moreover conceivable for a third detection means, which can likewise be configured as a capacitance sensor, to first detect a person approaching the vehicle, whereupon the monitoring of the motion pattern starts or is switched on. The detected approach can also serve to initially switch on the first and second detection means.
The first and/or the second capacitance sensor can be configured in the form of a wire or a foil, wherein the wire or foil forms the sensor electrode of the capacitance sensor. Preferably, the wire or foil sensor electrode can extend over one part or preferably over the entire width of the vehicle bumper, respectively the width of the vehicle side door. In consequence thereof, the device for actuating a vehicle trunk lid or side [door] can be used from different areas in close proximity to the rear or the respective side door of the vehicle. The sensor electrodes can be a component of the rear bumper, the side door or the door sill, or can be adhesively affixed or secured with fastening means in the interior of same. The sensor electrodes can further be incorporated by injection molding during the manufacturing of the bumper. In so doing, the capacitance sensors exhibit a spatial separation within the bumper, the side door or the door sill such that the first capacitance sensor is positioned more in the vertically-extending area whereas the second capacitance sensor is preferably positioned in the lower area of the rear bumper, side door or door sill which gives way to the horizontal.
To improve the defining of the geometrically individually separated detection areas, the means provided thereto are designed in the form of metallic shields. Said metallic shields extend to the side of the capacitance sensors facing away from the first and the second detection area so that the shields surround the capacitance sensors as a half shell, whereby at least one insulating layer is provided between the capacitance sensors and the shields. The metallic shields further exhibit the same electrical potential as the respective sensor electrodes, whereby the metallic shields can be electrically connected to the respective sensor electrodes hereto. This thereby forms an “active shield” which influences or defines the detection area of the sensor electrodes. The detection area is thereby substantially obstructed in the direction toward the interior of the bumper, the side door or the door sill. In order to be able to have a very specific orientation to the arrangement of the capacitance sensor detection area, it is proposed for the shields to at least partly surround the capacitance sensors in a U shape, whereby the capacitance sensors are arranged in the U-shaped opening and the respective detection area of the capacitance sensors is situated in front of the U-shaped opening of the shield. Hence, the capacitance sensors in this case (U-shaped shield) are not only shielded at the remote rear side of the detection area by the shield, but also to the greatest possible extent at the respective lateral edges. A metallic ground shield can additionally be employed, which can be arranged behind the respective capacitance sensors with their active shields. Same are thus arranged at the rear of the detection area of the respective sensor toward the vehicle. The additional ground shield enables the detection area to be reliably directed away from the vehicle toward the desired area to be monitored.
It is also conceivable to employ so-called compensation or balancing electrodes, each of which are electrically insulated, in addition to the capacitance sensors, e.g. arranged to the left and right of the actual capacitance electrode. Said balancing electrodes can optionally also be shielded by the shield. To the extent that a U-shaped shield is provided, the balancing electrodes are arranged along with the capacitance electrode in the U-shaped opening. The balancing electrodes thereby serve to detect and compensate for metrological malfunctions, e.g. due to contaminating impurities, rain or the like in the detection area of the capacitance electrodes in order to prevent measuring errors on the part of the capacitance sensors.
The metallic shields of the respective capacitance sensors, along with the above-cited compensation or balancing electrodes as applicable, can be realized together with the sensor electrodes as one single component of sandwich-like structure. Insulation is thereby provided between the metallic shields and the sensor electrodes, and the compensation or balancing electrodes as applicable, as well as any ground shield such that the metallic shield maintains a geometric distance to the sensor electrode in the form of conducting paths or in the form of a foil. In particular, the metallic screen surrounds the sensor electrodes along the lateral edges (e.g. U-shaped as described above), wherein this enables further improving the geometric separating of the respective detection areas from one another.
In accordance with a further advantageous development of the inventive device, a control unit is provided which is connected to the capacitance sensors and operatively connected to an actuating unit for the moving part of the vehicle. The control unit can comprise means serving to feed and operate the capacitance sensors. The control unit can furthermore comprise a logical element between the capacitance sensors and an actuating unit to operate the moving part of the vehicle. Thus, the capacitance sensors can supply the information to the control unit as to whether an object is situated in the respective detection area of the capacitance sensors. The identifying of a given motion pattern can thereby occur in the control unit so that the actuating unit to open or close the moving part is not triggered until the required motion pattern occurs.
It is likewise conceivable for an illuminating and/or display means to be activated after a first signal or once a defined motion pattern has occurred, same illuminating in particular the detection areas. The illumination shows the person which detection area is then waiting for a measurement signal, respectively an object in the detection area. The illuminating and/or display means can also display the actual state of a conditional access system or sensor system. It is thus possible to display the lettering “OPEN” or “CLOSED” on the sidewalk or the street next to or behind the vehicle, in particular by means of a laser diode. This display can be coupled with the detecting of an ID transmitter for the vehicle; i.e. the illuminating and/or display means is only activated when the given sensor system detects the correct ID transmitter in the vicinity of the vehicle.
To operate the device according to the invention, it can further be provided that an ID transmitter be operatively connected to the control unit, preferably by means of a wireless communication link. Such ID transmitters are also known as conditional access systems for vehicle users and are frequently called “Keyless Go systems.” When the vehicle user has such an ID transmitter, it is recognized by a transceiver within the vehicle thereby authenticating the user of the vehicle so that he can for example open the vehicle or turn it on. Such an ID transmitter can furthermore be configured to communicate with the control unit component of the inventive device.
In accordance with the invention, the control unit can be further improved such that the moving part is not actuated until the control unit detects the presence of an ID transmitter. For example, if the person with the ID transmitter is not in the area of the vehicle, while the capacitance sensors can detect the motion pattern of a person within the vehicle's detection area, the control unit will not trigger the opening or closing of the trunk lid. Not until the ID transmitter is present and thus an authentication conducted is the moving part actuated by the motion pattern concurrently detected by the capacitance sensors.
The trigger to open or close the moving part can be made further dependent on whether the vehicle is moving or stationary, whereby actuation of the moving part is preferably only triggered when the vehicle is stationary and a speed of “zero” is detected.
As needs dictate, the activating of the moving part can simultaneously control an electro-mechanical lock for the moving part by means of which the moving part can be opened or closed. The moving part can additionally be provided with a raising mechanism with which said moving part can be independently conveyed from its closed position into the open position and vice versa. The opening or closing action can thus ensue fully automatically. The noted raising mechanism can be fully or partially integrated into the electromechanical lock.
In accordance with a further development of the control unit, same is configured such that the moving part is not actuated until the first capacitance sensor detects the presence of a leg within the first detection area and the second capacitance sensor detects the presence of a foot within the second detection area. Of course the actuation of the moving part is then only triggered pursuant this detection pattern when the control unit of the device has previously, concurrently or afterwards recognized the ID transmitter.
According to yet another embodiment, the control unit is configured such that the moving part is only actuated when the first capacitance sensor detects the leg prior to the second capacitance sensor detecting the foot. This thereby prevents that alone the approach of a person will be enough to trigger the closing or opening motion of the trunk lid or side door when there is an object in the area beneath the rear bumper or a side door. The control unit monitors the speed of the vehicle here as well, which preferably needs to be “zero” in order to trigger the opening or closing motion of the trunk lid, such that the vehicle is stationary.
The invention also relates to a method for actuating a moving part of a vehicle, in particular a motor vehicle, with the above-described inventive device. Features and details described in conjunction with the inventive method thereby of course also apply in relation to the inventive device and vice versa.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference will be made in the following to the figures in describing further measures improving the invention together with the description of preferred embodiments of the invention in greater detail. Shown are:
FIG. 1 a an embodiment of the device for actuating a trunk lid without contact comprising a first capacitance sensor and a second capacitance sensor as well as respective means to specify the detection areas,
FIG. 1 b an embodiment of the device for actuating a side door without contact comprising a first capacitance sensor and a second capacitance sensor,
FIG. 2 an embodiment of the device according to the invention for triggering the actuation of a trunk lid by means of a person's leg and foot,
FIG. 3 a schematic top plan view of the arrangement of the capacitance sensors inside the rear bumper of a vehicle,
FIG. 4 a schematic side view of the arrangement of the second capacitance sensor inside the rear bumper of a vehicle comprising a metallic shield, and
FIG. 5 a schematic of the control unit operatively connected to the capacitance sensors, the ID transmitter and the trunk lid.
DETAILED DESCRIPTION
FIG. 1 a shows an embodiment of an inventive device for the non-contact actuating of a trunk lid 10 . 1 as a moving part 10 of a vehicle 1 constituting a motor vehicle. The moving part 10 is held in the closed position and secured by an electromechanical lock 25 . The device comprises a first detection means 11 for detecting an object 17 , 18 in a first detection area 11 a and a second detection means 12 for detecting an object in a second detection area 12 a . The detection means 11 and 12 are configured as capacitance sensors 11 and 12 and only indicated schematically in the figure. Detection area 11 a covers the horizontal area behind the rear bumper 16 of the vehicle 1 . On the other hand, detection area 12 a covers the lower area beneath the rear bumper 16 . Thus, a first detection area 11 a and a second detection area 12 a are created which are geometrically separated from one another and have no common area external of the rear bumper 16 . The detection areas 11 a and 12 a are indicated by beams which however only indicate areas depicting a change in dielectric constant between the capacitance sensors 11 and 12 and the vicinity of the rear bumper 16 . This change in dielectric constant causes a change to the charge storable on the electrodes of the capacitance sensors 11 and 12 which the device can detect. Thus, the capacitance sensors 11 and 12 can furnish the presence of an object, in particular the presence of part of a person's body, with minimum power consumption.
Means 13 and 14 , configured in the form of metallic shields 13 and 14 and which surround the capacitance sensors 11 and 12 in arc-like or half-shell-like manner, extend behind said capacitance sensors 11 and 12 . The shields 13 and 14 predefine both the respective detection areas 11 a and 12 a , thereby enabling improved separation of the detection areas 11 a and 12 a from one another. The metallic shields 13 and 14 exhibit the same electrical potential as the respective capacitance sensors 11 and 12 . Thus, they are so-called “active shields” 13 , 14 . Additional ground electrodes 24 , respectively ground shields 24 , can be provided behind said “active shields” 13 , 14 , with which the detection areas 11 a , 12 a of the capacitance sensors 11 and 12 can be orientated in the reverse direction to the ground shields 24 ; i.e. away from said ground shields 24 .
FIG. 1 b shows a similar embodiment of the inventive device for the non-contact actuating of a side door or a sliding door 10 . 1 as the moving part 10 of a vehicle 1 . The two capacitance sensors 11 and 12 are arranged here in the door sill area 23 and orientated comparably to the aforementioned bumper 16 at the vehicle rear end 15 . The two capacitance sensors 11 and 12 can optionally also be arranged in the lower area 27 of the side door 10 . 2 , preferably under a stone guard. An object approaching the side door 10 . 2 can be detected by the first capacitance sensor 11 or the proximity sensor of the conditional access system, usually arranged in the door handle 28 . The embodiments in FIGS. 1 to 5 do not differ with respect to the detection means 11 , 12 further detecting a motion pattern for actuating the moving part 10 . Said detection means 11 , 12 with associated means 13 , 14 can also be optionally provided with a ground shield 24 .
FIG. 2 shows a side view of a detail of the rear bumper 16 , respectively the lower area of the side door 10 . 2 , in which the capacitance sensors 11 and 12 with the respective shields 13 and 14 are positioned. According to the representation, part of a person's leg 17 is depicted as protruding into the horizontally-extending first detection area 11 a . The foot 18 at the end of the leg 17 , on the other hand, protrudes into the vertically-extending detection area 12 a underneath the rear bumper 16 or door sill area 23 . The person has for example approached the vehicle 1 near the rear bumper 16 or the side door 10 . 2 . Hence, the first capacitance sensor 11 can detect the person's approach by the leg 17 entering into the first detection area 11 a . If the person signals the intent to actuate the moving part 10 by moving his foot 18 inward into the second detection area 12 a , this produces a predefined motion pattern of the person. The coupled detection of both the leg 17 as well as the foot 18 can trigger the actuation of the trunk lid 10 . 1 , respectively the side door 10 . 2 . The respective detection areas 11 a , 12 a can likewise be illuminated by a not shown illuminating and/or display means. Lettering can also show the state of the moving part 10 on the sidewalk or the street next to the vehicle. The electro-mechanical lock 25 can be displaced upon the actuation such that the moving part 10 is released, whereby it can be conveyed from a closed position into an open position. The opening and/or closing action can even occur mechanically by the raising mechanism 26 indicated in FIG. 1 which is likewise activated by the actuation.
Ground electrodes 24 , respectively ground shields 24 , can also be optionally provided in FIG. 2 in addition to the “active shields” 13 , 14 .
FIG. 3 shows the arrangement of the capacitance sensors 11 and 12 within the rear bumper 16 of the vehicle 1 in a top plan view. The rear bumper 16 extends the entire rear end 15 of the vehicle, whereby the bumper 16 is shown in its entire width. Pursuant the depiction, it can be recognized that the capacitance sensors 11 and 12 can extend over virtually the entire width of the bumper 16 . Therefore, a person can approach any point across the entire rear end 15 of the vehicle 1 and make the leg 17 as well as the foot 18 movement as described in FIG. 2 .
The depiction shows the arrangement of the first capacitance sensor 11 in the vertical area of the bumper 16 while the second capacitance sensor 12 with its surrounding shield 14 is indicated in the lower area of the bumper 16 . The capacitance sensors 12 can be positioned in or run through the width of the bumper 16 as a foil or a conductive path. The capacitance sensors 11 and 12 with the respective shields 13 and 14 are preferably arranged inside the bumper 16 .
FIG. 4 shows a schematic side view of the arrangement of the second capacitance sensor 12 within the bumper 16 which can also just as readily be arranged in or on the side door 10 . 2 or the associated door sill. The capacitance sensor 12 is depicted in cross-section and exhibits a planar extension. The capacitance sensor 12 is enclosed on the rear side by a metallic shield 14 which exhibits the same potential as sensor 12 such that the detection area 12 a is only directed toward the underside of the rear bumper 16 . To improve the shielding effect, the ground shield 24 connected to a ground contact 19 illustrated as a grounding and connecting the shield 24 to the vehicle ground is additionally provided. Doing so thus further improves the directional defining of the detection area 12 a.
FIG. 5 shows the operative connection of the control unit 20 to the first capacitance sensor 11 and the second capacitance sensor 12 in a schematic view. The control unit 20 comprises a logical element 22 configured as a logical AND element.
The logical AND element 22 effects an activation of the trunk lid 10 when at least the first capacitance sensor 11 and the second capacitance sensor 12 detect the presence of an object. If only one of the capacitance sensors 11 or 12 detect the presence of an object, for example a leg 17 or a foot 18 , the control unit 20 will not actuate the trunk lid 10 . The actuation of the trunk lid 10 will not be triggered until both capacitance sensors 11 and 12 detect the presence of an object.
An ID transmitter 21 is further indicated which communicates with the control unit 20 by wireless connection. The ID transmitter 21 provides conditional access authorization to authenticate a person and is read by the control unit 20 . Actuation of the trunk lid 10 will not be triggered until the presence of such an ID transmitter 21 and the positive signal from both capacitance sensors 11 and 12 .
The realization of the invention is not limited to the above-indicated preferred embodiment. In fact, a number of variants which also make use of the represented solution in fundamentally different implementations are conceivable. All the features and/or advantages yielded by the claims, the description or the drawings, including structural details, spatial arrangements and method steps, can be essential to the invention both alone as well as in any combination. Thus, e.g. more than two capacitance sensors with additional detection areas can also be used. | The present invention relates to a device for actuating a moving part ( 10 ) of a vehicle ( 1 ), particularly a trunk lid ( 10.1 ), a side door ( 10.2 ), or the like, without contact, comprising a first detection means ( 11 ) for detecting an object in a first detection area ( 11 a ) and a second detection means ( 12 ) for detecting an object in a second detection area ( 12 a ) so that the actuation of the moving part ( 10 ) can be activated through the detection means ( 11, 12 ). According to the invention, the first detection means ( 11 ) is designed as a first capacitance sensor ( 11 ), and the second detection means ( 12 ) is designed as a second capacitance sensor ( 12 ), wherein means ( 13, 14 ) are provided, with which the detection areas ( 11 a, 12 a ) can be specified in areas separated from each other. | 4 |
BACKGROUND OF THE INVENTION
The invention relates to methods for changing bobbins in flyer spinning frames with stationary, rotatably suspended flyers and with bobbins rotatably supported in a bobbin rail which is movable up and down, wherein the bobbin rail, after the bobbins have been wound, is lowered into a position in which the bobbins are located outside the flyers and in which the bobbin rail is tipped forward in order to change the bobbins and then tipped back into the horizontal position after the bobbins have been changed and finally moved upward again into the initial position for resuming the bobbin winding process. The invention further relates to apparatuses for performing these methods.
On such machines as described above, in order to be able to pull the bobbins from the bobbin spindles, on which they are supported during their rotation, it is necessary to lower the bobbin rail and thus to move the bobbins outward out of the flyers. However, it requires a considerable exertion of force to lift the full bobbins, weighing several kilograms each, vertically upward by 40 to 50 cm from their lowermost position only a short distance above the floor and then to pull them horizontally outward in order to remove them from their bobbin spindles. This is particularly difficult in the case of the bobbin located in the rear bobbin row further away from the operator.
Thus, as noted above, it is already known to tip the bobbin rail forward when it is in its lowermost position, so that when the bobbins are pulled off they need no longer be lifted vertically upward but can instead be lifted by the operator toward his own body, which requires substantially less exertion of force. (See German Offenlegungsschrift No. 25 21 057.) However, even here, the operator must still bend over, and on lifting the bobbins must lift up not only the weight of the bobbins but also the weight of his own body each time as well. From the point of view of functional efficiency, this is very unfavorable.
OBJECTS AND SUMMARY OF THE INVENTION
It is accordingly a principal object of the present invention to provide a method and apparatus for exchanging or doffing full bobbins for empty tubes which is more favorable in terms of functional efficiency.
This object is attained by means of the method steps and apparatus of the invention wherein the bobbin rail is lowered after the bobbins have been filled. The bobbin rail is tipped forward at an angle and then raised where the full bobbins may be comfortably and easily removed and replaced by empty bobbins. It is not necessary in each case to lower the bobbin rail into its lowermost position. Instead, it is frequently sufficient to lower the bobbin rail, depending on the construction of the flyers, only to such an extent that tipping the bobbin rail is possible without the bobbin striking the flyer arms or the spring fingers. In the raised comfortable doffing position of the bobbin rail, the operator can pull off the full bobbins and place the empty tubes on the spindles without having to bend down or stretch. The heavy, filled bobbins are presented to the operator at a height and in a position which are efficient for grasping and can be pulled off with a short lifting path. The position of the bobbin spindles is equally favorable for subsequently placing the empty tubes thereon.
Once the empty bobbins are placed on the bobbin rail the bobbin rail is lowered, tipped back to its horizontal position and raised into place for filling the empty bobbins. This method requires a much less strenuous work day for the operator.
The method steps of the invention, from the point of stopping the machine after the bobbin winding is completed through the lifting of the bobbin rail into the position for removing the bobbins, may be made to begin and run their course automatically. In accordance with the invention, however, it is proposed to subdivide the essential method steps for bobbin changing into those which begin and run their course automatically and those which are initiated by the operator and then run their course automatically. As a result, for example, the bobbin rail is prevented, without the operator's supervision, from tipping outward into the service corridor and colliding with bobbin carriers or other obstructions. Accordingly, the automatic course of the various movements of the machine during bobbin changing is only interrupted when this is called for or advantageous in terms of the efficiency of the operation--that is, in order to tip the bobbin rail outward, to pull off the filled bobbins and place the empty tubes on the spindles, and to apply the roving threads onto the empty tubes. Subsequent to these occasions when the machine is stopped, the automatic method is again resumed, each time as a result of signals provided by the operator.
In a further embodiment of the method according to the invention, it is proposed to perform further necessary method steps, which are known in themselves, for changing bobbins on flyer spinning machines simultaneously with the first of the method steps of the invention.
In order that neither the flyer arms nor the spring fingers are in the way of the bobbin when the bobbin rail is moved upward, not only must the arms be brought to a stop in a position in which they hinder the action of pulling off the bobbins as little as possible, but also the spring fingers must be moved all the way inward toward the axis of the flyers. Apparatuses by means of which the arms can be brought to a stop in a predetermined position are known (see German Pat. No. 751,504). It has been demonstrated that the intended position of the spring fingers can be attained very easily and reliably by means of one of the method steps of the invention.
The apparatus for performing the method steps of the invention is derived from a flyer spinning frame of the general type described at the outset, which includes reversible-direction drive means for moving the bobbin rail upward and downward and a control apparatus with switching elements for influencing the drive means. This reversible-direction drive means, which is known in itself, is intended first for bringing about, in a manner which is also already known, the relative movement between the bobbins and the flyers required for building up the bobbin winding with parallel winding layers of gradually decreasing length. In addition, this drive means, again in a known manner, effects the lowering of the bobbin rail in order to move the bobbins out of the flyers and, after the bobbins have been exchanged, again raises the bobbin rail into the initial position for the beginning of the bobbin winding process.
Beyond these known features, the drive means in the present invention also effects the raising of the bobbin rail from its lowered position into the position for pulling off the bobbins and effects the subsequent relowering of the bobbin rail.
The drive means may be embodied in a conventional manner as a switchable reversing gear, which is driven by the primary motor of the spinning frame and moves the bobbin rail up and down by means of pinions which are disposed on longitudinal shafts and mesh with racks on vertically guided cantilevers supporting the bobbin rail. As a rule, in order to raise and lower the bobbin rail in connection with the exchange of bobbins, the drive means is drivable by an auxiliary drive when all the other elements of the spinning frame are stopped.
The movement up and down of the bobbin rail may also take place without the use of the reversing gear such as by means of an auxiliary motor whose rotary direction is reversible. However, the invention may also be carried out on flyer spinning frames by using a different lifting drive means, such as hydraulic piston/cylinder units.
In order to cause the spring fingers to move inward as mentioned above, the invention may include an inching device utilizing a button to be pressed, which can be activated by hand and by means of which the drive can be switched on at least for the flyers, causing the appropriate rotary movements and rotary hesitation movements and the necessary arrest and angular position of the flyers. In a preferred embodiment, the inching device is embodied as an automatic switching device, which upon actuation and in accordance with the initial position of the flyers automatically directs a surge of current of corresponding magnitude and/or duration onto the drive of the flyers, which causes the drive to effect the appropriate movement.
Tipping the bobbin rail outward and inward may be undertaken by the operator by hand, when suitable operating means are provided which permit unendangered actuation with a reasonable expenditure of time and force. However, a feature for accomplishing this in accordance with the invention is preferred. A number of known devices are suitable as functional elements, such as hydraulically or pneumatically actuated lifting or rotary elements, electromotors which either mesh by means of a pinion or a screw with a toothed segment disposed on the bobbin rail or rotate cams which effect the pivoting motion of the bobbin rail, and others. The invention also includes an entirely automatic pivoting of the bobbin rail.
The invention will be better understood as well as further objects and advantages thereof become more apparent from the ensuing detailed description of a preferred embodiment taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a substantially schematic, cross-sectional view through a flyer spinning frame, wherein only those parts necessary for an understanding of the present invention are shown in the position which they assume after the winding of the bobbin is completed;
FIG. 2 is a cross-sectional view corresponding to FIG. 1 after the bobbin rail has been lowered into its lowermost position;
FIG. 3 is a cross-sectional view corresponding to FIG. 2 after the bobbin rail has been tipped;
FIG. 4 is a cross-sectional view corresponding to FIG. 3 after the bobbin rail has been raised into the position intended for removing the filled bobbins and placing the empty tubes on the spindles;
FIG. 5 is a plan view of a detail of the bobbin rail in a position corresponding to FIG. 1, showing the drive and control devices; and
FIG. 6 is a plan view of a detail of the bobbin rail in a position corresponding to FIG. 3 or 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1-4, there is shown a schematic view of the machine stand 1 of a flyer spinning frame of conventional type, which will therefore not be shown and described in every detail. Above the machine stand 1, in bearing brackets (not shown), is disposed a draw frame 2 comprising a plurality of roller pairs. The machine stand 1 has a fixed flyer support or head 3, in which a number of flyers 4 (for example, 80) are rotatably supported at their head in two rows and are driven by drive means (not shown), which may take the form of, for example, pairs of helical gears, via longitudinal shafts. The flyers 4 each have a hollow flyer arm, at the lower end of each of which a spring finger 5 is pivotably supported.
Guided vertically in a straight line on a guide 6 in the machine stand 1 is a cantilever 7, on which a bobbin rail 9 is tiltably supported at the pivot point 8. Bobbins 10 are rotatably supported on bobbin spindles in this bobbin rail 9, coaxial with the flyers 4, and are driven via longitudinal shafts by drive means (not shown), which may take the form of, for example, pairs of helical gears.
Articulated on the cantilever 7 on the one hand and the bobbin rail 9 on the other are several telescoping cylinders 11 or other generally familiar hydraulic or pneumatic functional elements distributed over the length of the bobbin rail, by means of which the bobbin rail 9 can be tilted by about 40° out of its horizontal position and away from the machine stand 1.
It will be appreciated that the flyer spinning frame also has a number of other units, such as control devices; gears for the drive of the flyers 4, of the draw frame 2 and of the bobbins 10 whose rotational speed is variable; weight equalizers for the bobbin rail 9; thread supply frames; thread monitors; suction devices; and so forth. However, these units are not only well known but are not necessary for the understanding of the present invention and are therefore not discussed herein.
From FIG. 5 it may be understood that a primary drive electromotor 14 of the flyer spinning frame, supplied with current via a relay 12 from a grid power supply 13 drives a primary shaft 16 of the flyer spinning frame and the input shaft 17 of a reversing gear via a belt-type back gear 15 with an interposed infinitely adjustable gear (not shown here). Two bevel gears 18 and 19 are loosely rotatable on the input shaft 17, but they can be connected in alternation with the input shaft 17 upon rotation by means of electromagnetically actuatable couplings 20 and 21.
Meshing with the bevel gears 18 and 19 is a further bevel gear 22 on a shaft 23, on which a screw which engages a helical gear 24 is also disposed. The helical gear 24 is disposed on a longitudinal shaft 24' which extends over virtually the entire length of the flyer spinning frame and has pinions 24" which mesh with toothed areas 25 on the cantilevers 7 supporting the bobbin rail 9. An auxiliary electromotor 27 can also be connected with the shaft 23 by means of a coupling 26. This electromotor 27 is supplied with current via a relay 28 from the grid power supply 13. The elements 17-27 comprise the drive apparatus for moving the bobbin rail 9 up and down.
The reversal in the direction of movement of the bobbin rail 9 during the application of the winding is effected by means of a conventional switching device 29 (not described in detail here), which alternatively actuates the couplings 20 and 21.
A final shutoff switch 30, in a manner to be described further below, affects the relay 12, the switching device 29, the coupling 26 of the electromotor 27, and the electromotor 27 itself. The signals entering the system from switching devices 32-35 are processed, in a manner which is also to be described further below, and control the auxiliary electromotor 27 and a valve 36 for the purpose of acting upon the functional elements or cylinders 11.
The switching devices 32-35 are disposed in such a fashion that
(a) one switching device 32 (FIG. 2) is actuated by the bobbin rail 9, when the bobbin rail 9 has reached its lowermost position;
(b) one switching device 33 (FIG. 3) is actuated by the bobbin rail 9 in its outwardly tipped position;
(c) one switching device 34 (FIG. 4) is actuated by the cantilever 7 or the bobbin rail 9 in the position provided for pulling off the bobbin; and
(d) one switching device 35 (FIG. 4) can be actuated by the operator.
While the winding is being applied, the switching device 29 controls the couplings 20 and 21 of the reversing gear 18, 19, 22 in such a way that the roving, supplied to the draw frame 2 from thread supply cannisters (not shown) via a grid and delivered thereto in drafted form, is wound up on the rotating bobbins 10 in parallel, cylindrical layers growing gradually shorter, by means of the upward and downward movement of the bobbin rail 9 relative to the rotating flyers 4 which remain locally stationary.
When the bobbin winding has been completed (FIG. 1), the final shutoff switch 30 initiates the bobbin exchanging process by actuating the relay 12 for shutting off the primary motor 14, by initiating the switching device 29 to open both couplings 20 and 21, by closing the coupling 26 at the auxiliary electromotor 27, and by switching on this auxiliary electromotor 27. At the same time, this final shutoff switch 30 can switch on the apparatuses, known per se and not shown here, by means of which the reserve supply of roving is created at the head of the flyers, the infinitely adjustable gear is set back into its initial position, and the flyers are rotated into the position most suitable for the application of the rovings onto the empty tubes.
The auxiliary electromotor 27 rotates the longitudinal shaft 24' in such a manner that the bobbin rail 9 is lowered (FIG. 2, arrow A). When it has reached a position in which it can be tipped forward without being hindered by the flyers, the switching device 32 is actuated, which shuts off the auxiliary electromotor 27. The machine remains in this position until the operator actuates the switching device 35.
When the operation in accordance with the invention is to be resumed, the operator actuates the switching device 35, reverses the valve 36 for actuating the functional elements or cylinders 11, causing the bobbin rail 9 to tip forward (FIG. 3, arrow B). When the bobbin rail 9 reaches its outwardly tipped position (FIG. 3), it then actuates the switching device 33, which switches on the auxiliary electromotor 27 for the purpose of raising the bobbin rail 9 (FIG. 4, arrow C). When the bobbin rail 9 has reached the intended position for pulling off the bobbins, it actuates the switching device 34, which shuts off the auxiliary electromotor 27. The level of this position for pulling off the bobbins may be determined by the arrangement of the switching device 33 and may be selected to suit particular circumstances.
Now the operator can pull off the filled bobbins and place the empty tubes on the spindles in a comfortable position. Then he actuates the switching device 35, which then switches on the auxiliary electromotor 27 in order to lower the bobbin rail 9 (arrow D). When it has reached its lowermost position (FIG. 3), it activates the switching device 33 again, which stops the auxiliary electromotor 27 and reverses the valve 36 for tipping the bobbin rail inward (arrow E) by means of the functional elements or cylinders 11.
When the bobbin rail 9 has reached the inwardly tipped position (FIG. 2), it again actuates the switching device 32, which again switches on the auxiliary electromotor 27 in order to raise the bobbin rail 9 into the position for bobbin winding (arrow F). In the position of the bobbin rail 9 intended for bobbin winding, the auxiliary electromotor 27 is shut off. After applying the roving threads onto the empty tubes, the operator actuates the switch for turning on the machine and thus causes the machine to start. The bobbin exchanging process is thus ended.
It is apparent that the switching devices 32-35 upon actuation, depending upon the position of the parts during the carrying out of the method of the invention, furnish various different switching commands. This requires a logic-type interconnection of the various switching elements and the elements which are affected by them. The arrangement of a logic circuit of this kind is familiar to every person skilled in the art and will therefore not be described in detail here.
The foregoing relates to a preferred exemplary embodiment of the invention, it being understood that other embodiments and variants thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims. | A method and apparatus for changing bobbins in a flyer spinning frame which includes a bobbin rail for supporting bobbins adjacent the flyers movable both vertically and tiltably, the bobbin rail being moved sequentially from an upper bobbin winding position, a lower horizontal position, a forwardly tipped position, then upwardly in the tilted position into a comfortable bobbin doffing position, downwardly into the lower position, back into a horizontal position while in the lower position then finally upwardly into the upper bobbin winding position. | 3 |
This Application claims priority from Provisional Application Ser. No. 60/041,178, filed Mar. 21, 1997.
FIELD OF THE INVENTION
This invention relates to ultrasonic motors and, more particularly, to an ultrasonic motor wherein a rotational and/or a linear movement is generated by means of a piezoelectric effect upon a metal-ceramic composite driving element.
BACKGROUND OF THE INVENTION
Metal-ceramic composite structures have been utilized for both sensing and actuation applications. In U.S. Pat. Nos. 4,999,819 and 5,276,657 to Newnham et al., a central piezoelectric wafer has metal end caps adhered to the peripheries of either surface of the piezoelectric wafer. The piezoelectric wafer is poled across its thickness dimension so that application of a voltage thereacross results in a radially directed movement of the wafer's circumference and a concurrent flexure of the attached end caps. Further, application of a force to the end caps causes a voltage to be induced across the piezoelectric wafer.
In an actuator embodiment, application of a voltage across the piezoelectric wafer causes a radially directed inward movement of the circumference of the wafer, thereby causing a distortion of the end caps and a resultant movement of an actuation surface thereof. In a sensor embodiment, application of a pressure to the end caps is translated through the joinder thereof to the wafer into a physical distortion of the wafer which, in turn, induces an output voltage proportional to the applied pressure. In both of the embodiments, the end caps either (i) respond to a lateral movement of the piezoelectric wafer by moving in a direction orthogonal to the surface of the wafer (actuator) or (ii) respond to an applied pressure in the orthogonal direction by stressing the wafer (sensor). Neither device has the capability of producing movements in the rotary direction or responding thereto.
The prior art includes teachings relating to the structure and operation of ultrasonic motors. U.S. Pat. No. 5,254,899 to Suzuki et al. discloses an ultrasonic motor which employs traveling wave bending modes that are excited on a ring-type unimorph piezoelectric element. Conventional ultrasonic motor designs evidence complex structures. Further, the traveling wave type ultrasonic motor requires plural power supplies, one for a sine voltage and one for a cosine voltage.
U.S. Pat. No. 5,296,776 to Wind et al. describes timepiece motor which utilizes a piezoelectrically driven rotor to incrementally rotate within a fixed stator arrangement.
It is an object of this invention to provide an improved ultrasonic motor which evidence's a simple and inexpensive design.
It is another object of his invention to provide an improved ultrasonic motor which is capable of providing both rotary and linear motions.
SUMMARY OF THE INVENTION
An improved motor employs a stator which includes a piezoelectric wafer that is poled across its thickness 35 dimension so that a signal applied thereacross results in either an inward or outward movement of the periphery of the wafer. A pair of end caps are placed on opposed surfaces of the wafer and are adhered thereto at their respective peripheries. Each end cap includes a centrally located driving segment, a series of peripheral segments adhered to periphery of the wafer and a plurality of arms connecting the peripheral segments to the driving segment. A rotor includes a driven portion which mates with the driving segment and is driven thereby. Application of a signal across the thickness of the piezoelectric wafer results in rotary motion being imparted to the driving segment via flexure of the arms (as a result of movement of the peripheral segments of the end caps).
In the preferred embodiment, the peripheral segments of the opposed end caps are displaced from each other by 45 degrees, thus enabling transfer of radial vibrations into longitudinal and angular vibrations. The combination of these vibrations result in an elliptical motion at the periphery of the piezoelectric wafer which, in turn, is translated by the arms into rotary motion of the driving segment. Further embodiments provide both rotary and linear motions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing a rotary ultrasonic motor in accordance with the invention.
FIG. 2 shows a perspective view of the stator element of the ultrasonic motor of FIG. 1.
FIG. 3a shows a top view of an end cap of the ultrasonic motor of FIG. 1.
FIG. 3b shows a side view of the end cap of FIG. 3a.
FIG. 4 shows a cross-sectional view of the ultrasonic motor of FIG. 1.
FIG. 5a shows a top view of the end cap of FIG. 3 when it is subjected to a radial shrinking motion of the piezoelectric wafer.
FIG. 5b shows a side view of the end cap of FIG. 5a.
FIG. 6a shows the top view of the end cap of FIG. 3 when it is subjected to a radial expansion motion of the piezoelectric wafer.
FIG. 6b shows a side view of the end cap of FIG. 6a.
FIG. 7 is a perspective view of the linear ultrasonic motor in accordance with the invention.
FIG. 8 shows a cross-sectional view of the linear ultrasonic motor of FIG. 7.
FIG. 9 shows a perspective view of a stator employing an end cap with three slotted actuator arms.
FIG. 10 shows a perspective view of a stator end cap with six slotted actuator arms.
FIG. 11a shows a cross-section of a second embodiment of a rotary ultrasonic motor in accordance with the invention.
FIG. 11b shows a top view of the end cap used in the embodiment of FIG. 11a, when the piezoelectric wafer shrinks in a radial direction.
FIG. 11c shows a side view of the end cap of FIG. 11b.
FIG. 12a shows a perspective view of a third embodiment of an ultrasonic motor constructed in accordance with the invention.
FIG. 12b shows the movement of the end cap used with the with the embodiment of FIG. 12a, when the piezoelectric wafer shrinks in a radial direction.
FIG. 13a shows a perspective view of a further embodiment of an ultrasonic motor arrangement in accordance with the invention hereof which provides both rotational and linear motion.
FIG. 13b shows a side sectional view of a piezoelectric ring used in the stator of the motor of FIG. 14a, when an energizing signal is applied thereacross.
FIG. 14 shows an exploded perspective view of a further ultrasonic motor embodiment incorporating the invention hereof.
FIG. 15a shows a plot of speed vs. torque for an ultrasonic motor constructed in accordance with the invention.
FIG. 15b shows a plot of speed vs. applied voltage for an ultrasonic motor constructed in accordance with the invention.
FIG. 16 is a plot of transient speed and the output torque, as a function of time, for an experimental motor constructed in accord with the invention.
FIG. 17 is a plot of maximum torque versus input voltage for an experimental motor constructed in accord with the invention.
FIG. 18 is a plot of speed versus input voltage for an experimental motor constructed in accord with the invention under load and no-load conditions.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a perspective view of a rotary ultrasonic motor 10 constructed in accordance with the invention. Motor 10 comprises a stator structure 12, a rotor 14 and a rotor bearing 16. Stator structure 12 comprises a piezoelectric wafer 18 having electrodes 20 and 22 emplaced on opposite faces thereof. It is preferred that piezoelectric wafer 18 be shaped in the form of an annulus or ring; however, wafer 18 can also be in the form of a continuous disk, while such structure is less preferred. Wafer 18 is poled across its thickness dimension as shown by arrow 24. Preferred materials for piezoelectric wafer 18 comprise the class of lead zirconate titanates.
An AC signal source 26 is connected between electrodes 22 and 20 and provides a pulsed signal voltage across piezoelectric ring 18. As is known to those skilled in the art, application of such a voltage across piezoelectric ring 18 causes alternate expansion and contraction thereof in its radial dimensions (see arrow 28). The pulsed signal applied from source 26 is preferably adjusted to a frequency which approximates the radial mode resonance frequency of stator structure 12. In such manner, a maximum amount of ring distention is accomplished so as to achieve substantial distortion of end caps 30 and 32 (whose effect on rotor 14 will be described below).
End caps 30 and 32, preferably comprised of resilient metal, are positioned on opposed major surfaces of piezoelectric ring 18 and each comprises a plurality of outer peripheral segments 34 which are, respectively, bonded to the outermost regions of electrodes 20 and 22, and piezoelectric ring 18. Note that each outer peripheral segment 34 is preferably bonded at its outermost points of contact with the respective electrodes, leaving the remainder of the peripheral segments free to move and flex. It is to be noted, that the upper and lower end caps shown in the embodiment of FIG. 1 are offset by 45° in orientation from each other.
FIG. 2 is a perspective view of stator structure 12, with rotor 14 removed. Each outer peripheral segment 34 of end cap 30 is joined to a central driving segment 36 via an arm 38. A plan view of end cap 30 is shown in FIG. 3a and a sectional view thereof, taken along line 3b--3b is shown in FIG. 3b. Driving segment 36 preferably takes the form of a truncated cone having side walls 40 and a top section 42.
FIG. 4 is a sectional view of motor 10 taken along line 4--4 in FIG. 1. Rotor 14 includes a driven segment 44 which fits over and mates with driving segment 36 of end cap 30. As indicated above, driving segment 36 takes the form of a truncated cone and, when mated with driven segment 44, tends to center stator 12 and rotor 14 along center line 50. Further, side walls 40 and top section 42 of driving segment 32 interact with the interior surfaces of driven segment 44 to control rotation of rotor 14. Such rotation occurs due to frictional interaction (i) between the inside surface of driven segment 44 and the outer surfaces of driving segment 36, and (ii) at contact surface 48 between the lower surface of driven segment 44 and the upper surface of arms 38.
The driving action will be better appreciated by referring to FIGS. 5 and 6 in conjunction with FIG. 4. FIGS. 5a and 5b illustrate the distortions of arms 38 and driving segment 36 when piezoelectric ring 18 is caused to shrink in its radial direction as a result of an applied voltage. When no power is applied, arms 38' reside in their unstressed state. When an appropriate voltage is applied between electrodes 20 and 22, piezoelectric ring 18 shrinks along its radial dimension and peripheral segments 34 exert a distorting torque on arms 38, causing them to bow in a counterclockwise direction. This action causes driving segment 36 to rotate counterclockwise by a small amount (e.g. 1-2°).
Referring to FIG. 4, the distortion of arms 38 cause top section 42 of driving segment 36 to be driven upwardly, causing driven segment 44 to be likewise driven in an upward direction. This action causes a separation between the uppermost surfaces of arms 38 and lowermost surface of driven segment 44. Accordingly, a substantial lessening of the frictional engagement between driven segment 44 and driving segment 36 is experienced.
By contrast (see FIGS. 6a and 6b), when an oppositely poled voltage is applied across electrodes 20, 22, arms 38' are caused to bow in a clockwise direction by the torque exerted thereon by the outward movements of peripheral segments 34. Such action causes (see FIG. 6b) upper section 42 of driving segment 36 to move downward, thereby enabling contact surface 48 to drive driven segment 44 (via frictional engagement with arms 38) in a clockwise direction. As AC source 26 is operated at an ultrasonic frequency (e.g. 128 kHz), the continuously applied signal pulses cause clockwise rotation of driven segment 44 and rotor 14 due to the periodic frictional engagement therebetween.
Motor structure 10 is preferably housed in an enclosure having an end wall 60 (only partially shown in FIG. 4). End wall 60 exhibits an acoustic impedance that is different from the material of end caps 32 so as to enable vibrations to be reflected back into stator structure 12. The acoustic mismatch between surface 60 and end cap 32 enables such acoustic reflections.
Turning now to FIG. 7, stator structure 12 is shown mounted on a pair of rails 62 and 64. FIG. 8 is a sectional view of the structure of FIG. 7, taken along line 8--8. The motor structure shown in FIGS. 7 and 8 provides a linear drive action of stator structure 12 along rails 62 and 64. In this configuration, when arms 38 are in their relaxed position, there is lessened surface contact between them and rail surfaces 66 and 68 due to a stand-off affect created by the diameter of driving segment 36 being made slightly larger than the distance between rails 62 and 64. When, however, piezoelectric ring 18 is caused to shrink in the direction indicated by arrows 70, the diameter of driving segment 36 constricts, enabling greater frictional contact between arms 38 and rail surfaces 66 and 68, along the contact length thereof. Accordingly, rotor structure 12 tends to move along rails 62 and 64 in accordance with the drive signal polarity which results in the aforementioned interaction between arms 38 and rail surfaces 66, 68, respectively.
FIGS. 9 and 10 illustrate perspective views of stator structures which utilize end caps having three arms and six arms, respectively. It is to be noted, that while the upper and lower end caps shown in the embodiment of FIG. 1 are offset by 45°, in the configuration of FIG. 9, the upper and lower end caps are offset from each other by 60° and, as shown in FIG. 10, by 30°. Otherwise, the operation of the structures shown in FIGS. 9 and 10 is identical to that described above.
Turning now to FIGS. 11a-11c, a further embodiment of the invention is illustrated wherein a driving segment 100 of end cap 102 is recessed into center aperture 104 within piezoelectric ring 106. Driven segment 108 of rotor 14 mates with driving segment 100 of end cap 102 as shown. Application of an excitation signal to piezoelectric ring 106 causes a distortion of the arms of end cap 102 in the manner shown in FIG. 11b. Note that when piezoelectric ring 104 shrinks in diameter, the interior surfaces of driving segment 100 tend to move towards one another, thereby gripping driven segment 108 more firmly and causing it to rotate in a counterclockwise direction.
When piezoelectric ring 104 is caused to expand outwardly, the gripping action of driving segment 100 is released, reducing its frictional engagement with driven segment 108 and enabling rotor 14 to remain in place until a next signal pulsation is applied to piezoelectric ring 106.
Referring to FIGS. 12a and 12b, a further embodiment of an ultrasonic motor embodying the invention is illustrated. In this arrangement, a cylindrical rod 110 is utilized as the rotor and a pair of oppositely poled piezoelectric rings 112 and 114 are bonded to each other. A pair of end caps 116 and 118 are bonded concentrically to the top and bottom surfaces of piezoelectric rings 112 and 114 in the manner described above. Each of end caps 116 and 118 is provided with a plurality of inwardly directed arms 120.
A planar view of end cap 116 is shown in FIG. 12b. The ends of arms 120 are shaped in a concave manner so as to closely mate with the external surface of rotor 110. In the same manner as described for the motor structure of FIG. 1, only the external edges of end caps 116 and 118 are bonded to their respective supporting piezoelectric rings. Accordingly, when piezoelectric rings 112 and 114 are driven in such a manner as to shrink in diameter, the concave portions of arms 120 act to drive rotor 110, causing it to rotate. By contrast, when piezoelectric rings 112 and 114 expand in diameter, arms 120 are released from contact with rotor 110.
More specifically, as shown in FIG. 12b, shrinkage of diameter of the outer peripheral portion of end cap 116 causes a slight counterclockwise movement of arms 120 which, via frictional engagement tends to drive rotor 110 in a clockwise direction. Upon expansion of piezoelectric rings 112 and 114, arms 120 return to their original position, awaiting a next excitation cycle.
FIGS. 13a and 13b show a single-phase driven roto-linear ultrasonic motor arrangement which includes a rotor 134. Stator structure 130 includes a piezoelectric ring 136 that is bonded to an end cap 138, and stator structure 132 includes a piezoelectric ring 140 which is bonded to an end cap 142. Note that the thickness of end cap 138 is different from end cap 142, thereby causing each stator structure to exhibit a different resonant frequency. Piezoelectric rings 130 and 132 are poled in opposing directions and encircle rotor 134 which passes therethrough. A single signal source 146 drives both piezoelectric rings 136 and 140, but in opposition.
Assuming signal source 146 exhibits an output frequency that is equal to the resonance frequency of stator structure 130, piezoelectric ring 136 is excited at a radial mode resonance frequency which causes the inwardly directed arms of end cap 138 to flex and cause a rotational movement of rotor 134, as described for the embodiment of FIG. 12. By contrast, if the resonance frequency of stator structure 132 is arranged such that it is about one-half the frequency of signal source 146, piezoelectric ring 140 is excited at its first flexural mode resonance frequency. Such flexure causes a cup-like distortion of piezoelectric ring 140, as shown in FIG. 13b. The resulting deflection of the inner diameter of piezoelectric ring 140 causes the inwardly directed arms 148 of end cap 142 to be flexed in a direction which causes a longitudinal movement of rotor 134.
Accordingly, to obtain clockwise rotation, stator structure 130 is excited at its radial mode resonance frequency and stator structure 132 is excited at an off-resonance frequency so as to generate a small displacement of rotor 134 along its axis. A linear motion in the right direction can be obtained if stator structure 130 is excited at its first flexural mode. Recall that the first flexural mode is excited when an applied signal exhibits a frequency that is about one-half the frequency required to excite the radial resonance mode. Stator structure 132 can cause rotor 134 to rotate in the counterclockwise direction or move towards the left if it is excited at its radial mode resonance frequency or first flexural mode resonance frequency, respectively. Thus, dual direction linear motions and dual direction rotary motions can be achieved from the motor structure shown in FIG. 13.
Referring now to FIG. 14, a further single phase-driven ultrasonic motor arrangement is disclosed. Rotor 150, in this arrangement, rotates due to frictional interaction between the top and bottom surfaces of cylindrical segment 152 and the touching surfaces of end caps 154 and 155, respectively. The thickness of end cap 154 is different from that of end cap 155, assuring that stators 158 and 160 exhibit different resonance frequencies. Piezoelectric rings 160 and 162 are poled as shown by arrows by 164 and 166, respectively. Further, as described above, only the peripheral segments of end caps and 154 and 155 are bonded to piezoelectric rings 169 and 162, respectively.
If piezoelectric ring 160 is excited at a frequency equal to the radial mode resonance frequency of stator 156, the flexure of the arms of end cap 154 causes rotor 150 to rotate in a counterclockwise direction. Note that when a stator is excited at other than its resonant frequency, whatever radial movement occurs is but a fraction of that experienced when the exciting signal is at the resonant frequency of the stator. A clockwise rotation of rotor 150 can be obtained by exciting stator 158 at its radial mode frequency. In either case, flexure of the arm segments of each of end caps 154 and 155 is transferred into torsional displacement of rotor 150 by frictional engagement with the upper and lower surfaces of cylindrical segment 152.
EXPERIMENTAL
An ultrasonic motor taking the configuration shown in FIG. 1 was constructed having the following dimensions:
Outer diameter of the piezoelectric disk: 12.7 mm
Thickness of the piezoelectric disk: 0.5 mm
Thickness of metal end cap (phosphor bronze or brass): 0.2 mm
Diameter of inner circular part of end cap: 4.0 mm
Height of truncated conical part of end cap: 0.7 mm
The piezoelectric ceramic material utilized was PZT8d and the stator radial mode resonance frequency was found to be approximately 140 kHz, in the free state. After mounting the stator inside a housing unit, the motor was driven at 128 kHz, at 40 to 100 volts, peak-to-peak. The decrease in resonance frequency was due to a pre-stress applied on the outer side of the rotor bearing to keep the rotor and stator together.
The resulting variation of torque with speed is shown in FIG. 15a and the variation of speed with applied voltage is shown in FIG. 15b. A linear motor structure, along the lines shown in FIGS. 7 and 8 was also constructed and the frequency applied to cause movement in one direction was 93 kHz and in the reverse direction was 110° kHz.
For a transient response measurement of the motor, a stator as shown in FIG. 11a was used, with the following dimensions:
outer diameter of the piezoelectric ring 11.0 mm
inner diameter of the piezoelectric ring 5.0 mm
thickness of the piezoelectric disk 0.7 mm
thickness of metal phosphor bronze endcap 0.15 mm
diameter of inner circular part on endcap 4.0 mm
height of the inner conical/cylindrical part on endcap 0.7 mm
To measure motor torque from transient response, a metal disk (50 gram) with a relatively high moment of inertia (1.5e-5 kgm 2 ) was mounted on the rotor as a load. Then the motor was driven for different applied voltages at 130.8 KHz and the position of the rotor was recorded using a digital scope. In order to record the position of the rotor, thin aluminum foil was attached to the rotor and its position was detected by a photocell pair. This position data was recorded over a time required for the motor to reach steady state, starting from zero speed.
The derivative of the recorded position data with respect to time gives the motor transient speed. The second derivative of the record data gives the angular acceleration; and the product of the angular acceleration and the moment of inertia of the rotating disk gives the motor transient torque. At 46 V input rms voltage, the transient speed and the output torque are shown in FIG. 16, as a function of time. At this voltage, the steady state speed reached 870 rpm in 2 seconds while the maximum motor torque read about 1.36 mNm. Similar curves were obtained for different input voltages.
A plot of the maximum value of torque attained for applied rms voltages between 25 to 46 volts is shown in FIG. 17. It can be concluded, based on this plot, that in this range of applied voltage, the motor output torque increases rapidly as the input voltage increases, and tends towards saturation as the input approaches 46 V. The torque is expected to saturate beyond 46 V, but observations were not made beyond this range due to risks involving sample damage.
Steady state speeds, with applied voltages between 25 and 46 V, were calculated under no-load and full-load conditions, from the recorded position data. This plot is shown in FIG. 18. The obtained speed was also verified by measuring the motor speed by using an RPM meter. Hence from FIG. 18, it can be observed that no-load and full-load curves monotonically increase with the applied voltage and that the no-load curve tends to saturate towards the 46 V end. Accordingly:
i. A maximum value of torque of about 1.36 mNm was obtained at 46 rms input voltage. This torque was obtained before the motor speed reached steady state.
ii. The motor torque steadily increased with applied input voltage, in the range of 25 and 45 volts.
iii. The steady state speed of the motor increased within the same range of applied input voltages.
It should be understood that the foregoing description is only illustrative of the invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variances which fall within the scope of the appended claims. | An improved motor employs a stator which includes a piezoelectric wafer that is poled across its thickness dimension so that a signal applied thereacross results in either an inward or outward movement of the periphery of the wafer. A pair of end caps are placed on opposed surfaces of the wafer and are adhered thereto at their respective peripheries. Each end cap includes a centrally located driving segment, a series of peripheral segments adhered to periphery of the wafer and a plurality of arms connecting the peripheral segments to the driving segment. A rotor includes a driven portion which mates with the driving segment and is driven thereby. Application of a signal across the thickness of the piezoelectric wafer results in rotary motion being imparted to the driving segment via flexure of the arms (as a result of movement of the peripheral segments of the end caps). Further embodiments provide both rotary and linear motions. | 7 |
CROSS-REFERENCES TO RELATED APPLICATIONS
This application is a continuation-in-part of application Ser. No. 07/695,103, filed May 1, 1991, and now abandoned, and application Ser. No. 07/698,917, filed May 13, 1991, and now U.S. Pat. No. 5,197,314.
BACKGROUND OF THE INVENTION
The present invention relates generally to the field of latching systems and, in its most preferred embodiments, to the field of key operated, T-handle latching systems for use in vending machines.
A latching system secures a link between two or more bodies. It is well known that the strength and precision of this connection, as well as the speed and ease with which it can be both established and disengaged, are factors which affect the usefulness of a latching system. By way of example, but not limitation, one environment which requires a latching assembly to perform well with respect to each of these factors is that of vending machines. A vending machine door and the frame to which it is attached are two bodies which require a link that is strong and precise, as well as one which can be both created and disengaged both quickly and easily. Many vending machines contain money boxes and currency validators which attract hordes of vandals attempting to illegally access the machines; therefore, vending machines require latching systems which provide very strong links. Also, many vending machines are actually large refrigerated containers and, therefore, require a good seal which results from a precise connection. Furthermore, vending machines require frequent attention by service operators who replenish the supply of vendable items and collect money. The speed and ease with which the latching system may be operated are factors which affect the operator's productivity and efficiency.
One well-known type of latching system frequently used in the vending machine field is the common T-handle system. This type of latching system typically includes a T-handle housing connected to the vending machine door, a T-handle nested therein, a key-operated cylinder lock contained within the T-handle, a post member connected to the T-handle, and a receiving assembly connected to the vending machine frame for receiving the post member, thereby a link. In unlatching a typical T-handle assembly, rotation of a key causes a lock bolt of the cylinder lock to retract, allowing a spring to extend a nested T-handle from within a T-handle housing. Upon extension, the T-handle may be rotated by the operator to release the post member from the receiving assembly, thus allowing the door to be opened. A few typical T-handle systems are disclosed in the following U.S. Pat. Nos.: 3,089,329, 3,089,330, 3,111,833, 3,122,012, 3,213,654, 3,222,899, 3,234,765, 3,285,043, 3,299,678, 3,302,434, 3,550,412, 4,552,001.
The post member and receiving assembly incorporated by many of the common T-handle systems include a post member with a threaded distal end and a receiving assembly which includes a correspondingly threaded nut. Although many of these screw & nut systems provide strong and precise links, the amount of time and degree of effort required to create and disengage the links through repetitively rotating the T-handle are drawbacks to many of these systems. This problem was at least partially addressed in U.S. Pat. No. 4,974,888, which disclosed a faster-acting receiving assembly which reduced the amount of time required to create a link. However, because the post member still required "unscrewing", the amount of time required to disengage the link was not significantly reduced by the device therein disclosed.
Other common T-handle systems, such as that disclosed in U.S. Pat. No. 3,234,765, utilize a cam-type (quarter-turn) post member along with a locking cam and an inclined locking shoulder connected to the door frame. This type of latching system only requires the T-handle to be rotated through a fraction of a turn to alternately create or disengage a link. Although quick-releasing, one drawback of this type of latching system is that the vending machine door must first be placed in contact with the vending machine frame before the T-handle can be rotated to create a secured link. In other words, unlike the quick-receiving latching system discussed above with reference to U.S. Pat. No. 4,974,888, the linking process disclosed in U.S. Pat. No. 3,234,765 does not include the option of first pushing the T-handle into the T-handle housing so that the lock bolt extends to secure the nesting and then simply closing the door, thereby transferring the axial force used to close the door into force which directly accelerates the linking process. Furthermore, many cam-type latching systems provide less security than other types of latching systems.
In an attempt to provide latching systems which overcome these and other problems, the inventor of the present invention has previously invented several quick-acting latching systems, some embodiments of which utilize a T-handle assembly (and others which do not), including U.S. patent Ser. No. 07/358,888, filed May 30, 1989, allowed Apr. 23, 1990, now U.S. Pat. No. 5,027,630, and U.S. patent Ser. No. 07/403,665, filed Sep. 6, 1989, allowed Oct. 16, 1990 and now U.S. Pat. No. 5,022,243. These latching systems are what shall be referred to herein as fractional-rotation latching systems which are quick-acting with respect to both creating and dissolving a link and are also systems which transfer door closure force directly into force which accelerates the linking process and strengthens the resulting link. Because of the abundance of T-handle systems currently being used in vending machines throughout the world, especially those utilizing the screw & nut method, there is a need to be able to retrofit those systems with quick-acting systems, thus utilizing the various existing T-handles and T-handle housings. In furtherance of this objective, several problems exist in adapting the various typical T-handle systems.
Because of the prevalence of the T-handle systems which utilize the screw & nut method, operators frequently assume that a particular T-handle is to be continuously rotated to unscrew the post member. Because the present inventor's previously patented latching systems do not employ the typical screw & nut method, continuous rotation of a T-handle in those inventions is a waste of time. There is, therefore, a need in the industry to provide a means of identifying to an operator whether a particular T-handle assembly requires continuous rotation or whether mere fractional rotation will suffice.
One of the objects of the present invention is to provide a retrofit-capable, latching system which mechanically identifies the latching system to an operator as a fractional-rotation latching system by limiting the amount of allowable relative rotation between the T-handle and T-handle housing. With respect to the previously discussed cam-type (quarter-turn) latching system, as disclosed in U.S. Pat. No. 3,234,765, a cam washer is used in conjunction with a stop pin extending exteriorly from the T-handle housing to limit the amount of allowable rotation. However, many currently existing T-handle housings which utilize the screw & nut method, thus having no clearly inherent reason to limit rotation, do not include an externally extending stop pin. Therefore, the rotation-limiting device disclosed in that patent could not be used with many of the existing T-handle housings which do not include an externally extending stop pin.
Another aspect of many of the T-handle systems which employ the screw & nut method relates to the lost motion feature. During closure, after the seal has become sufficiently tight through rotation of the T-handle, the T-handle may not be in alignment with the T-handle housing. Further turning of the T-handle in the tightening direction, in order to align the T-handle with the T-handle housing, often requires an inordinate amount of rotation force, but rotation of the T-handle in the un-tightening direction to align the T-handle and T-handle housing often unacceptably reduces the pressure on the seal. Many of the common T-handle systems solve that problem through providing a lost motion connection between the T-handle and the post member, as disclosed in U.S. Pat. No. 3,122,012. This feature allows for a limited degree of reverse rotation after tightening so that the T-handle may be aligned with and then pushed into the T-handle housing This reverse rotation is disassociated from the post member so that the post member remains in a tight configuration, hence the lost motion.
This lost motion function is frequently accomplished through interaction between a pair of clutch lugs attached to the rear bearing wall of the T-handle and a clutch pin attached to the post member. The clutch pin is allowed to rotate freely between the clutch lugs so that a certain amount of "slop" is provided for the lost motion function. The rear passageway in the T-handle is also regularly circular, thus providing no restriction against this relative rotation between the T-handle and the post member. By contrast, in fractional-rotation latching systems, the presence of "slop" is detrimental to the latching system's reliable operation. There exists, therefore, a need for a device which will remove this "slop" and provide for a more continuous rotational connection between a post member and a variety of the existing T-handles.
U.S. Pat. No. 4,552,001, discussed above, discloses a T-handle which does not contain the common clutch lugs, but provides a square-shaped passageway which interacts with a cam-type post member which has a segment with an axially extending square cross-sectional profile. Although the T-handle and post member are in continuous rotational connection, many common T-handles include a regularly circular rear passageway rather than this irregularly-shaped rear passageway. There is a need, therefore, to provide a retrofit-capable device for eliminating "slop" in many of the currently existing T-handle assemblies.
SUMMARY OF THE INVENTION
Briefly described, the fractional-rotation latching system with retrofit capability of the present invention includes, in its most preferred embodiment with reference to an example vending machine environment, a T-handle housing to be connected to a vending machine door, a T-handle designed to be at least partially nested within the T-handle housing, a key-operated cylinder lock contained within the T-handle, a fractional-rotation post member connected to the T-handle, corresponding receiving assembly connected to the vending machine frame for receiving the post member, thereby creating a link sufficient to secure the vending machine door to the vending machine frame, a rotation limitation assembly connected to the post member which includes a cam washer and a flanged washer located within the T-handle housing, and a guide block interposed between the post member and the T-handle to secure a continuously engaging connection between the post member and the T-handle and to limit axial movement between the T-handle and the T-handle housing to an arrangement where the lock bolt is readily externally accessible.
It is, therefore, an object of the present invention to provide a quick-acting, fractional-rotation latching system.
Another object of the present invention is to provide a fractional-rotation latching system with a retrofit capability.
Another object of the present invention is to provide a fractional-rotation latching system which includes an assembly for mechanically indicating, upon operation, that the latching system is a fractional-rotation latching system.
Another object is to provide such an invention which provides indication through limiting the amount of allowable relative rotation between a handle and a handle housing.
Another object of the present invention is to provide a fractional-rotation latching system which includes a receiving assembly for directly gripping a gripping surface of a post member to create a link between two bodies and an assembly which defines limits of allowable rotation of the post member.
Another object is to provide such an invention wherein the rotation-limiting assembly includes a cam washer and a flanged washer connected around the post member and located within a T-handle housing.
Another object of the present invention is to provide a fractional-rotation latching system which includes an assembly for indicating, through limiting the amount of allowable relative rotation between a handle and a handle housing, that the latching system is a fractional-rotation latching system, which assembly includes a cam washer and a flanged washer connected around a post member and located within the handle housing.
Another object is to provide such an invention wherein the cam washer includes a central passageway and a radial passageway extending therefrom which enables an operator to connect the cam washer around the post member from a side position rather than needing to insert one end of the post member through the central passageway of the cam washer.
Another object of the present invention is to provide an assembly for limiting the amount of relative rotation between a handle and a handle housing which assembly is constructed so as to be connected around a post member and located inside a handle housing of a latching system.
Another object is to provide such an invention which includes a cam washer connected to receive rotation force from and rotate in conjunction with the post member and a flanged washer which is connected to rotate freely relative to the post member, is located at least partially within a recess within the handle housing to receive resistance force from the handle housing, and is in contact with the cam washer.
Yet another object of the present invention is to provide a fractional-rotation latching system which includes a T-handle which includes a rear bearing wall which includes clutch lugs and defines a circular rear passageway through which a guide block protrudes, which guide block includes block lugs in continuous contact with the clutch lugs to receive rotation force from the T-handle whenever the T-handle is rotated.
Yet another object is to provide such an invention wherein the guide block defines a non-circular central passageway through which a non-circular section of a post member protrudes, thereby receiving rotation force from the guide block.
Yet another object is to provide such an invention wherein the guide block defines a roll pin valley for receiving a roll pin attached to one end of the post member to maintain a connection between the post member and the guide block, wherein the roll pin valley is deep enough to allow enough extension of the T-handle to provide access to a lock bolt of a cylinder lock located within a front end of the T-handle.
Still another object of the present invention is to provide a fractional-rotation latching system for linking a first body and a second body which includes, at least, a handle housing which is attachable to the first body, a handle which is designed to be at least partially nested within the handle housing, a fractional-rotation post member connected to the handle, a corresponding receiving assembly for releasably gripping the post member to create a link between the first body and the second body, an assembly for indicating, upon operation, that the latching system is a fractional-rotation latching system, and a guide block interposed between the post member and the handle.
Still another object of the present invention is to provide a retrofit assembly which utilizes the T-handle and T-handle housing of an existing T-handle assembly and replaces the post member assembly and receiving assembly, thus providing a quick-action, fractional-rotation latching system.
Still another object is to provide such an invention wherein the post member assembly includes a post member, an assembly for limiting relative rotation between the T-handle and the T-handle housing, and a guide block to connect the post member to the T-handle.
Other objects, features and advantages of the present invention will become apparent upon reading and understanding the present specification, when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional side view of a Fractional-Rotation Latching System in accordance with the preferred embodiment of the present invention shown in a locked position.
FIG. 2 is an exploded perspective view of the T-handle assembly and front end of the post member assembly of FIG. 1.
FIG. 3 is a cross-sectional side view of the front end of the post member assembly and the T-handle assembly of FIG. 1 shown in an un-locked position.
FIG. 4 is a cross-sectional side view of the front end of the post member assembly and the T-handle assembly of FIG. 1 shown in an un-locked/un-latched position.
FIG. 5a is an isolated front view of the guide block of FIG. 1.
FIG. 5b is an isolated side view of the guide block of FIG. 5a.
FIG. 5c is an isolated cross-sectional side view of the guide block of FIG. 5a taken along line 5c--5c of FIG. 5a.
FIG. 5d is an isolated cross-sectional side view of the guide block of FIG. 5a taken along line 5d--5d of FIG. 5a.
FIG. 6a is an isolated rear view of the cam washer of FIG. 1.
FIG. 6b is an isolated side view of the cam washer of FIG. 1.
FIG. 7a is an isolated front view of the flanged washer of FIG. 1.
FIG. 7b is an isolated top view of the flanged washer of FIG. 1.
FIG. 8a is an isolated side view of the front end of the post member of FIG. 1.
FIG. 8b is an isolated end view of the front end of the post member of FIG. 1.
FIG. 8c is an isolated cross-sectional end view of the post member of FIG. 1 taken along line 8c--8c of FIG. 8a.
FIG. 9a is a cross-sectional end view of the present invention as shown in FIG. 3 taken along line 9a--9a of FIG. 3.
FIG. 9b is a cross-sectional end view similar to FIG. 9a showing an alternate embodiment of the T-handle housing and an alternate orientation of the flanged washer.
FIG. 10a is a cross-sectional end view of the present invention as shown in FIG. 3 taken along line 10a--10a of FIG. 3.
FIG. 10b is a cross-sectional end view similar to FIG. 10a showing an alternate embodiment of the T-handle and an alternate orientation of the post member assembly.
FIG. 11a is a cross-sectional end view of the present invention as shown in FIG. 3, without the T-handle housing, barrel spring, or klipring, taken along line 11a--11a of FIG. 3.
FIG. 11b is a cross-sectional end view similar to FIG. 11a showing alternate orientations for use with a T-handle housing such as the one depicted in FIG. 9b.
FIG. 11c is a cross-sectional end view similar to FIG. 11a showing alternate orientations for use with a T-handle such as the one depicted in FIG. 10b.
FIG. 11d is a cross-sectional end view similar to FIG. 11a showing alternate orientations for use with a T-handle housing such as the one depicted in FIG. 9b and a T-handle such as the one depicted in FIG. 10b.
FIG. 11e is a cross-sectional end view similar to FIG. 11a showing an alternate orientation of the flanged washer and cam washer and showing an alternate embodiment of the cam washer.
FIG. 11f is an isolated rear view of an alternate embodiment of a cam washer.
FIG. 12 is an exploded perspective view similar to FIG. 2 and shows an alternate embodiment of the front end of the post member assembly.
FIG. 13a is an isolated side view similar to FIG. 8a of a front end of a post member and a cam pin in accordance with another embodiment of the present invention.
FIG. 13b is an isolated end view of the front end of the post member of FIG. 13a.
FIG. 13c is an isolated cross-sectional end view of the postmember of FIG. 13a taken along line 13c--13c of FIG. 13a.
FIG. 14 is an isolated front view of a cam washer in accordance with the alternate embodiment of the present invention shown in FIG. 13a.
FIG. 15a is a cross-sectional end view similar to FIG. 11a in accordance with the alternate embodiment of the present shown in FIGS. 13a and 14.
FIG. 15b is a cross-sectional end view similar to FIG. 15a showing another orientation of the flanged washer.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now in greater detail to the drawings in which like numerals represent like components throughout the several views, a preferred embodiment of the fractional-rotation latching system 10 of the present invention is seen in FIG. 1 as including a T-handle assembly 11 connected to door 12, post member assembly 40, and receiving assembling 34 connected to frame 33. In the preferred embodiment and in an example vending machine environment, door 12 and frame 33 represent a vending machine door and a vending machine frame to which the door is attached, respectively. T-handle assembly 11 is representative of a variety of common T-handle assemblies and is seen including T-handle housing 25 connected to door 12, T-handle 15, and lock assembly 20 located therein.
In the preferred embodiment, T-handle housing 11 defines a unitary construction and includes rectangular portion 26, middle portion 27, and housing bearing wall 31. Rectangular portion 26 is the portion of T-handle housing 11 which is connected to door 12. Common methods of creating this connection are considered known within the industry and include, at least, both threaded screws and spot welding. Furthermore, T-handle housing 25 is frequently included as an element in a larger face plate assembly attached to door 12. Middle portion 27 of T-handle housing 25 is seen including a housing lock bolt channel 28 wherein lock bolt 21 of lock assembly 20 is seen protruding. Housing bearing wall 31 is seen connected to middle portion 27 and bears most of the axial force from post member assembly 40. The post member assembly 40 and T-handle assembly 11 of FIG. 1 are shown in an exploded perspective view in FIG. 2 where housing bearing wall 31 is seen including a hex recess 29 formed by hex shoulder 30.
In FIG. 1, T-handle 15 is seen nested into T-handle housing 25 and includes grip section 16, cylinder section 17, and handle bearing wall 19. Cylinder section 17 includes handle lock bolt channel 18 through which lock bolt 21 of lock assembly 20 is seen protruding. Referring to FIGS. 1 and 2, handle bearing wall 19 includes clutch lugs 14a and 14b and defines a circular handle rear passageway 24 and handle rear recess 23. Lock assembly 20 remains within T-handle 15 and represents one of a variety of common cylinder locks which include a lock bolt 21 and key entry channel 22. It is understood that alternate embodiments of T-handle assembly 11 which define alternate shapes, dimensions, and orientations are within the scope of the present invention.
Post member assembly 40 is seen including post member 38 represented in a cut-away form. The distal end of post member 38, not shown, cooperates with receiving assembly 34 so that a link between door 12 and frame 33 is alternately created or disengaged through rotating post member 38 in alternate directions about its longitudinal post axis 39 for a fraction of a rotation. The distal end of post member 38 and the internal design of receiving assembly 34 of the preferred embodiment are fully disclosed and explained with reference to FIG. 1 and the "Operation" section of U.S. patent application Ser. No. 07/403,665, filed Sep. 6, 1989, allowed Oct. 16, 1990, U.S. Pat. No. 5,022,243, which specification and drawings are incorporated herein by reference. The distal end of post member 38 and the internal design of receiving assembly 34 of an alternate embodiment of the present invention are fully disclosed and explained with reference to the description of the bar and the ball and cam collar disclosed in U.S. Pat. No. 4,900,182, which specification and drawings are incorporated herein by reference. The distal end of post member 38 and the internal design of receiving assembly 34 of yet another alternate embodiment of the present invention are fully disclosed and explained with reference to the description of the locking cam and inclined shoulder disclosed in U.S. Pat. No. 3,234,765, which specification and drawings are incorporated herein by reference. The scope of the present invention includes distal ends of post member 38 and receiving assemblies 34 which require only a fractional rotation to function properly, and is not limited to the specific embodiments stated above.
FIG. 8a shows an isolated side view of the front end of post member 38 of the preferred embodiment of the present invention. The front end of post member 38 includes rear groove 41, middle groove 42, and front groove 43. Cam segment 44 is seen adjacent to front groove 43 and defined by flat cam surfaces 48a and 48b. Its cross-sectional profile is shown in FIG. 8c which is taken along lines 8c--8c of FIG. 8a. Coupling segment 45 is seen adjacent to cam segment 44. FIG. 8b shows a front end view which reveals the relatively extended rectangular shape of coupling segment 45. Pin hole 47 is also seen extending through coupling segment 45.
Referring back to FIGS. 1 and 2, E-ring 50 and klipring 51 are seen attached around post member 38 at middle groove 42 and front groove 43, respectively. These retention rings do not prevent rotation of post member 38 about its longitudinal post axis 39, but prevent substantial axial movement of post member 38 with respect to T-handle housing 25. E-ring washer 52 provides additional width to further restrict the aforementioned axial movement. Rear groove 41 is used in alternate embodiments of the present invention which utilize T-handle housings 25 with thicker rear bearing walls 31. FIG. 1 shows barrel spring 66 in a compressed state wherein, by virtue of its barrel feature, it collapses into itself to reduce the amount of axial space required when compressed.
Flanged washer 55 and cam washer 60 are also seen connected around post member 38. Flanged washer 55 is seen located within hex recess 29 formed by hex shoulder 30 of housing bearing wall 31. Referring also to FIG. 7a, which shows an isolated front view, flanged washer 55 defines a hex-shaped outer perimeter and a circular central passageway 57. The hex-shaped outer perimeter cooperates with the hex recess 29 in T-handle housing 25 to prevent flanged washer 55 from substantially rotating with respect to T-handle housing 25. This cooperation between a hex-shaped recess and a hex-shaped washer (without a flange member) is known in the prior art. The circular central passageway 57 enables post member 38 to rotate freely about longitudinal post axis 39. In FIG. 1, flange member 56 is seen extending from flanged washer 55 in a direction at least partially parallel to the longitudinal post axis 39 with an axial length sufficient to enable interaction with cam washer 60. Referring also to FIG. 7b, which shows an isolated top view of flanged washer 7b, the radial extension of flange member 56 is small enough to avoid interfering with the fit of flanged washer 55 within hex recess 29 of T-handle housing 25. Furthermore, flange member 56 extends in a manner which ensures interaction with klipring 51.
Referring now to FIGS. 1 and 2, cam washer 60 is seen connected around cam segment 44 of post member 38. Cam recess 67 is defined by bend flat surface 61 and leg flat surface 62. The details of these elements are seen more clearly by also referring to FIGS. 6a and 6b, which show isolated rear and side views, respectively, of cam washer 60 of the preferred embodiment of the present invention. Cam recess 67 is seen extending around the outer edge of cam washer 60 between bend flat surface 61 and leg flat surface 62. Cam washer 60 defines cam central passageway 64 and radial slot 65 which provides access from an edge of cam washer 60 to cam central passageway 64. Inner cam surfaces 63a and 63b are seen within cam central passageway 64 and are placed in contact with flat cam surfaces 48a & 48b of cam segment 44 when cam washer 60 is assembled around post member 38. Radial slot 65 enables cam washer 60 to be assembled directly onto cam segment 44 without having to pass around either end of post member 38.
Referring now to FIGS. 1, 2 and 5a-5d, guide block 70 is seen interposed between post member 38 and T-handle 15 and protruding through handle rear passageway 24. The axial position of guide block 70 within handle rear passageway 24 is secured by block lugs 73a and 73b and C-ring 72 which fits around guide block 70 at block groove 71 and into handle rear recess 23. Block lugs 73a and 73b are shaped to fit between clutch lugs 14a and 14b to secure the angular position of guide block 70 and to receive rotation force from clutch lugs 14a and 14b while preventing "slop" in the rotational connection between T-handle 15 and post member 38. Guide block 70 defines post slot 75 which extends axially through guide block 70 and has substantially the same shape as coupling segment 45 of post member 38 to transfer rotation force to post member 38.
Pin valley 74 extends radially across the front end of guide block 70 to receive roll pin 46 when T-handle assembly 11 is in the un-locked state, as shown in FIG. 3. Roll pin 46 and cam segment 44 ensure that coupling segment 45 remains within post slot 75. The depth of pin valley 74, along with the length of coupling segment 45, determine how far T-handle 15 is allowed to extend during the un-locked state. In the preferred embodiment, T-handle 15 must be allowed to extend far enough to provide access to lock bolt 21 so that it may be depressed below handle lock bolt channel 18 which allows lock assembly 20 to be removed and replaced without necessitating disassembly of the latching system of the present invention. However, the standard length of cylinder section 17 of T-handle 15 limits the amount of axial distance between guide block 70 and the rear of lock assembly 20. Also, because of the standard overall length of many T-handle housings 25, the length of cam segment 44 is another factor which affects the length of coupling segment 45. During an attempted break-in, klipring 51, and thus cam segment 44, bear a large amount of force; therefore, cam segment 44 must have sufficient length to withstand this attempted security breach. Pin valley 74 must, therefore, be deep enough to ensure adequate extension of T-handle 15 in light of limitations such as these.
In the preferred embodiment, guide block 70 is manufactured through a powder metal process to achieve the required detailed shapes and edges. To assist in achieving the required depth of pin valley 74, yet avoid damaging the press used in the production of guide block 70 due to the resulting high density of guide block 70 below pin valley 74, the density of the powder metal before the pressing step is kept low.
OPERATION
Referring to FIG. 1, the preferred embodiment of fractional-rotation latching system 10 is shown in a locked position. Beginning with door 12 closed with respect to frame 33, receiving assembly 34 maintains a latched grip on post member 38 to prevent forced opening of door 12 from frame 33. T-handle assembly 11 is shown in a locked position wherein T-handle 15 is securely nested into T-handle housing 25 because lock bolt 21 protrudes into housing lock bolt channel 28. Furthermore, roll pin 46 is shown displaced from pin valley 74, and barrel spring 66 is shown in a compressed state. Finally, cam washer 60 is oriented so that flange member 56 of flanged washer 55 is located adjacent to leg flat surface 62.
In beginning the un-locking/un-latching procedure, an operator inserts and rotates a key within lock assembly 20 to cause lock bolt 21 to retract from housing lock bolt channel 28, thus allowing axial movement between T-handle 15 and T-handle housing 25. As soon as lock bolt 21 retracts from housing lock bolt channel 38, T-handle 15 is forced to extend out from T-handle housing 25 by the force from decompressing barrel spring 66. The distance travelled by T-handle 15 is limited by the distance between roll pin 46 and the bottom of pin valley 74, as is discussed above.
FIG. 3 shows the front end of post member assembly 40 and an un-locked T-handle assembly 11. T-handle 15 is extended from T-handle housing 25, providing complete access to grip section 16 and lock bolt 21. As discussed above, lock bolt 21 may then be manually compressed to allow removal of lock assembly 20. Roll pin 46 is seen resting within pin valley 74, thus maintaining a connection between T-handle 15 and post member 38. Barrel spring 66 is shown in a decompressed state, and the orientation of cam washer 60 remains unchanged. At this point, T-handle assembly 11 is in an un-locked position, yet post member 38 remains latched to the receiving assembly 34 of FIG. 1.
To un-latch post member 38, the operator grasps grips section 16 and subsequently supplies a rotation force around longitudinal post axis 39 (a counterclockwise rotation force for the orientation shown in FIG. 1). Referring also to FIG. 2, this rotation force is transferred to guide block 70 through clutch lugs 14a and 14b. Block lugs 73a and 73b immediately receive the rotation force, and through the rotation of guide block 70, transfer the rotation force to coupling segment 45 of post member 38 located within post slot 75. Because there is no "slop" in the connection between post member 38 and T-handle 15, post member 38 rotates in, substantially, complete conjunction with T-handle 15. After a predetermined amount of rotation, post member 38 is released from receiving assembly 38, thus un-latching the present invention to allow door 12 to be opened.
As a result of the rotation of post member 38, cam segment 44 rotates cam washer 60 through interaction between flat cam surfaces 48a and 48b of cam segment 44 and inner cam surfaces 63a and 63b of cam washer 60. During the rotation of cam washer 60, flange member 56 rides in cam recess 67 toward bend flat surface 61. In the preferred embodiment, after a quarter of a rotation, bend flat surface 61 collides with flange member 56. Because flanged washer 55 defines an outer hex shape which corresponds to the hex recess 29 of T-handle housing 25 wherein flanged washer 55 is located, and because flanged washer 55 defines circular central passageway 57 which does not restrict rotation of post member 38, flanged washer 55 remains substantially stationary with respect to T-handle housing 25. In some embodiments of the present invention, flange washer 55 is slightly smaller than hex recess 29, thus allowing a small amount of play.
One result of the relatively stationary positioning of flanged washer 55 is reduction in wear on housing bearing wall 19. Another result is the transfer of resistance rotation force (which may also be referred to as opposing, reactionary, or stationary force) to flange member 56 from T-handle housing 25. As bend flat surface 61 contacts and exerts rotation force on flange member 56 during rotation of post member 38, flange member 56 responds by supplying opposing resistance force to stop the movement of cam washer 60, thus preventing further rotation of post member 38 and T-handle 15. The non-circular outer shape of flanged washer 55 is thus utilized for at least two different purposes: reducing wear on T-handle housing 25 and assisting in limiting rotation of T-handle 15.
This un-locked/un-latched position is represented in FIG. 4, which shows the front end of post member assembly 40 and T-handle assembly 11 in an un-locked/un-latched position. T-handle 15 has been rotated through a quarter of a rotation, thus the small width of the rectangular grip 16, along with clutch lugs 14a and 14b are seen in FIG. 4. Referring also to FIG. 2, guide block 70 has been rotated so that roll pin 46 is no longer visible, and the small width of coupling segment 45 is seen. Furthermore, cam washer 60 is seen rotated so that bend flat surface 61 contacts flange member 56, and leg flat surface 62 is located on the bottom of cam washer 60.
In the preferred embodiment, after the vending machine has been serviced, the operator grasps the grip section 16 and rotates it in a clockwise direction to align T-handle 15 with T-handle housing 25. T-handle 15 is not allowed to rotate past this point due to similar interaction between leg flat surface 62 and flange member 56. This rotation results in the position shown in FIG. 3. The operator then pushes T-handle 15 into T-handle housing 25 against the yielding barrel spring 66 to the point where lock bolt 21 once again protrudes up through handle lock bolt channel 28 to secure T-handle 15 into T-handle housing 25. This compression action results in the position shown in FIG. 1. The vending machine may then be closed by simply closing door 12 which once again creates a link between receiving assembly 34 and post member 38. In the alternate embodiment discussed above which includes a locking cam and an inclined shoulder, the operator closes door 12 and then rotates grip section 16 and pushes T-handle 15 into T-handle housing 25.
ALTERNATE EMBODIMENTS AND ORIENTATIONS
Refer now to FIGS. 3 and 9-15b. FIG. 9a shows a cross-sectional end view of the present invention as shown in FIG. 3 taken along line 9a--9a of FIG. 3. Various T-handle housings 25 include housing bearing walls 31 with hex shoulder 30 oriented differently than that of FIG. 3. FIG. 9a shows the orientation of the embodiment shown in FIG. 3. Flanged washer 55, including flange member 56, is shown connected around post member 38 and located inside hex shoulder 30 of handle bearing wall 31 so that the upper edge of flanged washer 55 is horizontal. FIG. 9b shows an alternate embodiment of housing bearing wall 31' and hex shoulder 30' wherein the upper edge of flanged washer 55 is vertically, rather than horizontally, oriented. In the present invention, flanged washer 55 may be oriented by the operator to adapt to either of these orientations of hex shoulder 30. Furthermore, it should be understood that the scope of the present invention includes other alternate embodiments wherein flanged washer 55 and the recess in housing bearing wall 31 define other geometric shapes rather than a hex, such as, but no limited to, a triangle, a square, or a pentagon, or other means for preventing rotation of a flanged washer relative to a housing.
FIG. 10a shows a cross-sectional end view of the present invention as shown in FIG. 3 taken along line 10a--10a of FIG. 3. Various T-handles 15 include handle bearing walls 19 with clutch lugs 14a and 14b oriented differently than that of FIG. 3. FIG. 10a shows the orientation of the embodiment shown in FIG. 3. Guide block 70 is seen connected around coupling segment 45 of post member 38 and positioned so that block lugs 73a and 73b are located between clutch lugs 14a and 14b. Roll pin 46 is also seen resting in pin valley 74. In this embodiment, coupling segment 45 is substantially vertically oriented. In FIG. 10b, by contrast, clutch lugs 14a' and 14b' of handle bearing wall 19' are oriented so that the resulting orientation of coupling segment 45 is substantially horizontal. In the present invention, guide block 70, and thus coupling segment 45, may be oriented by the operator to adapt to either of these orientation of clutch lugs 14a and 14b. It should also be understood that other embodiments which include alternate shapes of clutch lugs 14a and 14b, as well as block lugs 73a and 73b, are within the scope of the present invention.
FIG. 11a shows a cross-sectional end view of the present invention as shown in FIG. 3, without the T-handle housing 25, barrel spring 66, or klipring 51, taken along line 11a--11a of FIG. 3. Flanged washer 55 including flange member 56 is seen connected behind cam washer 60, including leg flat surface 62, cam recess 67, and bend flat surface 61, which is connected around cam segment 44 and behind vertically oriented coupling segment 45. This orientation of cam washer 60 and flanged washer 55 is adapted for the orientations of T-handle 15 and T-handle housing 25 shown in FIGS. 9a and 10a, respectively. FIG. 11b is a cross-sectional end view similar to FIG. 11a showing an alternate orientation of flanged washer 55 and cam washer 60 which is adapted for the orientations of T-handle 15 and T-handle housing 25 shown in FIGS. 9b and 10a, respectively. FIG. 11c is a cross-sectional end view similar to FIG. 11a showing alternate orientations for use with the alternate orientations of T-handle 15 and T-handle housing 25 shown in FIGS. 9a and 10b, respectively. FIG. 11d is a cross-sectional end view similar to FIG. 11a showing alternate orientations for use with the alternate orientations of T-handle 15 and T-handle housing 25 shown in FIGS. 9b and 10b, respectively.
FIG. 11e shows a cross-sectional end view similar to FIG. 11a showing another alternate orientation of cam washer 60' and flanged washer 55 for use with the preferred orientations of T-handle 15 and T-handle housing 25 and further showing an alternate embodiment of cam washer 60'. The extended length of cam recess 67' shown in FIG. 11e provides for a greater amount of allowable rotation of T-handle 15. Cam washer 60' is shown including similarly placed leg flat surface 62 and alternately placed bend flat surface 61' resulting from the longer cam recess 67'.
Also, radial slot 65 (FIG. 6a) is not included in cam washer 60'. This distinction is useful in some arrangements because it provides greater structural integrity and enables cam washer 60' to better resist deformation due to rotational forces received through inner cam surfaces 63a and 63b. However, because there is no radial slot 65, cam washer 60' must be assembled onto cam segment 44 by passing it around one end of post member 38. Referring also to FIG. 11f briefly, FIG. 11f shows an isolated rear view of another alternate embodiment of cam washer 60" which is very similar to the cam washer 60' of FIG. 11e. One of the differences between them is the existence of radial slot 65' which proceeds through cam washer 60" and through inner cam surface 63a. This slot allows cam washer 60" to be more readily assembled onto post member 38 by passing coupling segment 45 through radial slot 65', rather than the method required by cam washer 60' of FIG. 11e. Although cam washer 60' of FIG. 11e may provide more structural integrity than cam washer 60" of FIG. 11f because of radial slot 65', the size of radial slot 65' and its placement in inner cam surface 63a enable cam washer 60' to, in some environments, provide more structural integrity than that found in cam washer 60 of FIG. 11a. Furthermore, the outer edges of radial slot 65' are rounded to prevent any binding which may be prone to occur in some environments.
Referring back to FIG. 11e, the alternate orientation of cam washer 60' and flanged washer 55 may be used when a different orientation of klipring 51 (shown in FIGS. 1 & 2) is preferred. In this alternate orientation, klipring 51 is positioned so that less of the klipring contact surfaces 53a and 53b are adjacent to flat cam surfaces 48a and 48b, thus providing more strength to the link because more radial surface contact is provided between klipring 51 and cam segment 44. In all embodiments of the present invention, flange member 56 is angled away from flange washer 55, thus interacting with klipring 51 to help insure the strongest link during the locked orientation with respect to cam segment 44. In addition, alternate shapes of klipring 51, which are also included within the scope of the present invention, affect the choice of which orientation of cam washer 60' and flanged washer 55 to employ.
FIG. 12 shows an exploded perspective view which is similar to FIG. 2 and shows an alternate embodiment of the front end of post member assembly 40'. Post member 38' is seen with an alternately located cam segment 44'. Rather than being located between front groove 43 and coupling segment 45, cam segment 44', shown with flat cam surface 48b', is located between front groove 43 and middle groove 42. Also, the relative locations of klipring 51 and cam washer 60 are different from those shown in FIG. 2. In this alternate embodiment, klipring 51 maintains an equal amount of radial surface contact with the front cylindrical section 49 of post member 38' throughout different angular orientations of klipring 51. Thus unlike the preferred embodiment, the strength of the link is not affected by the angular orientation of klipring 51. Furthermore, flange member 56 is shorter, thereby avoiding contact with klipring 51, which klipring 51 consequently rotates in conjunction with post member 38 to maintain a constant angular orientation.
FIGS. 13a-15b show selected elements of yet another alternate embodiment of the present invention. FIG. 13a is an isolated side view similar to FIG. 8a of a front end of a post member 38" and a cam pin 78; FIG. 13b is an isolated end view of the front end of the post member 38" of FIG. 13a; and FIG. 13c is an isolated cross-sectional end view of the post member 38" of FIG. 13a taken along line 13c--13c of FIG. 13a.
The structure and operation of the post member 38" of this alternate embodiment are very similar to the structure and operation of the post member 38 of the preferred embodiment of FIGS. 1 & 2. The main difference between the two embodiments involves the cam segment 44' which is cylindrical, having no flat surfaces such as the flat cam surfaces 48a, 48b of the preferred embodiment. Also, the cam segment 44' includes a cylindrical cam pin pit 77 extending radially into the cam segment 44'. Additionally, a cam pin 78, having a length which is slightly greater than the depth of the cam pin pit 77, is normally positioned partially within the cam pin pit 78 and partially extending out from the cam pin pit 78.
FIG. 14 is an isolated front view of a cam washer 60"' in accordance with the alternate embodiment of the present invention shown in FIG. 13a. The cam washer 60"' is similar to the cam washer 60' of FIG. 11e with the exception of a generally round cam central passageway 64' and a cam pin slot 80. During assembly the cam washer 60"' is passed around one end of the post member 38" and positioned around the cam segment 44' so that the cam pin 78 is located inside the cam pin slot 80. FIG. 15a is a cross-sectional end view similar to FIG. 11a in accordance with the alternate embodiment of the present invention shown in FIGS. 13a and 14, and FIG. 15b is a cross-sectional end view similar to FIG. 15a showing another orientation of the flanged washer 55. During operation, the cam pin 78, the cam pin slot 80, and the cam pin pit 77 cooperate to rotate the cam washer 60"' in conjunction with rotation of the post member 38".
While the embodiments of the present invention which have been disclosed herein are the preferred forms, other embodiments of the method and apparatus of the present invention will suggest themselves to persons skilled in the art in view of this disclosure. Therefore, it will be understood that variations and modifications can be effected within the spirit and scope of the invention and that the scope of the present invention should only be limited by the claims below. It is also understood that the relative dimensions and relationships shown on the drawings are given as the preferred relative dimensions and relationships, but the scope of the invention is not to be limited thereby. | A fractional-rotation latching system with retrofit capability which includes, in its most preferred embodiment with reference to an example vending machine environment, a T-handle housing to be connected to a vending machine door, a T-handle designed to be nested at least partially within the T-handle housing, a key-operated cylinder lock contained within the T-handle and including a radial lock bolt, a fractional-rotation post member connected to the T-handle, corresponding receiving assembly connected to the vending machine frame for receiving the post member, thereby creating a link sufficient to secure the vending machine door to the vending machine frame, a rotation limitation assembly connected to the post member which includes a cam washer and a flanged washer located within the T-handle housing, and a guide block interposed between the post member and the T-handle to secure a continuously engaging connection between the post member and the T-handle and to limit axial movement between the T-handle and the T-handle housing to an arrangement where the lock bolt is readily externally accessible. | 4 |
FIELD OF THE INVENTION
The present invention relates to an ink composition excellent in light resistance and moisture resistance, an ink set comprising the ink composition, a recording process using the ink composition or the ink set, and recorded matter.
BACKGROUND OF THE INVENTION
Ink jet recording is a process in which an ink composition are ejected as droplets through minute nozzles to record letters or images (hereinafter also simply referred to as images) on surfaces of recording media. Ink jet recording systems put into practical use include a process in which an electric signal is converted to a mechanical signal by the use of an electrostrictive element to intermittently ejecting an ink composition stored in a nozzle head section, thereby recording letters or images on a surface of a recording medium; and a process in which an ink composition stored in a nozzle head section is rapidly heated at a portion very close to an ejection portion to generate bubbles, and the ink composition is intermittently ejected by volume expansion due to the bubbles to record letters or images on a surface of a recording medium.
Further, the ink composition for ink jet recording is generally a solution of various dyes in water, an organic solvent or a mixture thereof, and requires severer requirements than an ink composition for writing materials such as a fountain pen and a ball point pen in terms of stability and printing characteristics.
In view of the fact that ink jet printers have recently been employed for the preparation of printed matter for advertisement, even severer requirements have come to be required in forming a color image using a plurality of ink compositions.
The reason for this is that when even one color inferior in hue exists in the color image formed by the plurality of ink compositions, the hue causes poor color balance as the whole image, resulting in the difficulty of obtaining a high-quality image.
In particular, “photographic image quality” printing with color ink jet printers has reached a level not inferior to that of “silver salt photographs” and has also become “equivalent to photographs” in image quality by successive improvements of heads, ink compositions, recording processes and media, respectively. On the other hand, keeping quality of images obtained has also been improved by improvements of ink compositions and media. In particular, light resistance has been improved to a level having practically no problem. However, it does not reach a level comparable to the silver salt photographs. As for evaluation of the ability of light resistance, judgments have normally been made using the color fading rate of a pure color pattern (the optical density is about 1.0) of each of Y, M and C as an index. With respect to the ability of heat resistance of ink compositions carried by printers commercially available on the market at present, the ability of magenta ink compositions is lowest when judged using the above-mentioned evaluation technique. Accordingly, it leads to improvement in the light resistance of images equivalent to photographs to improve the light resistance of the magenta compositions.
From such a viewpoint, the present inventors have provided ink sets containing magenta ink compositions improved in the light resistance of images equivalent to photographs by using compounds having specific structures as colorants for the magenta ink compositions (Japanese Patent Application Nos. 2002-120069 and 2002-120070).
In subsequent studies, the present inventors have added a carboxyl group-containing aromatic compound or a salt thereof to the above-mentioned compounds having the specific structures. As a result, the present inventors have known that moisture resistance of the images is also improved.
SUMMARY OF THE INVENTION
The invention has been made based on the finding as described above, and an object of the invention is to provide an ink composition which can record an image excellent in light resistance and moisture resistance.
Another object of the invention is to provide an ink set containing the ink composition. A still other object of the invention is to provide a recording process using the ink set. A yet still other object of the invention is to provide recorded matter recorded by the ink set.
Other objects and effects of the invention will become apparent from the following description.
The above-mentioned objects of the invention have been attained by providing an ink composition, a recording process and recorded matter having the following constitutions.
1. An ink composition according to the invention comprising at least water; at least one member selected from compounds represented by the following formula (1) and/or salts thereof; and at least one member selected from carboxyl group-containing aromatic compounds and/or salts thereof:
wherein A represents an alkylene group, a phenylene group-containing alkylene group or
(R means hydrogen or alkyl) and X represents NH 2 , OH or Cl.
2. In the above 1, the ink composition according to the invention preferably contains the compound represented by formula (1) and/or salt thereof in an amount of 0.2 to 10% by weight based on the total amount of the ink composition.
3. In the above 1 or 2, the ink composition according to the invention preferably contains the carboxyl group-containing aromatic compound and/or salt thereof in an amount of 0.2 to 10% by weight based on the total amount of the ink composition.
4. In the ink composition according to the invention in any one of the above 1 to 3, the content ratio of the compound represented by formula (1) and/or salt thereof to the carboxyl group-containing aromatic compound and/or salt thereof is preferably from 4:1 to 1:10.
5. In the ink composition according to the invention in any one of the above 1 to 4, the carboxyl group-containing aromatic compound and/or salt thereof is preferably a naphthalene skeleton-containing compound and/or a salt thereof.
6. In the ink composition according to the invention in the above 5, the naphthalene skeleton-containing compound and/or salt thereof is preferably a compound having a carboxyl group at the 2-position and/or a salt thereof.
7. In the ink composition according to the invention in the above 6, the compound having a carboxyl group at the 2-position and/or salt thereof is preferably at least one of 2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 6-hydroxy-2-naphthoic acid, 4-hydroxy-benzoic acid, 6-methoxy-2-naphthoic acid and salts thereof.
8. In the ink composition according to the invention in any one of the above 1 to 7, the salt of the carboxyl group-containing aromatic compound is preferably a lithium salt.
9. In the ink composition according to the invention in the above 8, the carboxyl group-containing aromatic compound and/or salt thereof is preferably lithium 2-naphthoate, lithium 3-hydroxy-2-naphthoate, lithium 6-hydroxy-2-naphthoate, lithium 4-hydroxy-benzoate or lithium 6-methoxy-2-naphthoate.
10. In any one of the above 1 to 9, it is preferred that the ink composition according to the invention further contains a nonionic surfactant.
11. In the ink composition according to the invention in the above 10, the nonionic surfactant is preferably an acetylene glycol-based surfactant.
12. In the above 10 or 11, the ink composition according to the invention preferably contains the nonionic surfactant in an amount of 0.1 to 5% by weight based on the total amount of the ink composition.
13. In any one of the above 1 to 12, it is preferred that the ink composition according to the invention further contains a penetration accelerator.
14. In the ink composition according to the invention in the above 13, the penetration accelerator is preferably a glycol ether.
15. In any one of the above 1 to 14, the ink composition according to the invention preferably has a pH of 8.0 to 10.5 at 20° C.
16. In any one of the above 1 to 15, the ink composition according to the invention is preferably used in an ink jet recording process.
17. In any one of the above 1 to 16, the ink composition according to the invention is preferably a magenta ink composition.
18. An ink jet recording process according to the invention comprises ejecting a droplet of an ink composition, and depositing the droplet onto a recording medium to perform printing, wherein the ink composition is one described in any one of the above 1 to 17.
19. Recorded matter according to the invention is recorded matter recorded using an ink composition described in any one of the above 1 to 17.
DETAILED DESCRIPTION OF THE INVENTION
The ink composition of the invention comprises at least a compound represented by the above-mentioned formula (1) (including a salt thereof, the description of which is hereinafter omitted) as a colorant and a carboxyl group-containing aromatic compound (including a salt thereof, the description of which is hereinafter omitted) as a moisture resistance improver in water or an aqueous medium comprising water and a water-soluble organic solvent, and may further comprise a humectant, a viscosity modifier, a pH adjustor and other additives as needed.
The compound represented by the above-mentioned formula (1), which is used in the invention, may be produced by any method, but can also be produced, for example, by a method described below.
(1) Benzoylacetic acid ethyl ester is reacted with 1-methylamino-4-bromoanthraquinone in a solvent to obtain 1-benzoyl-6-bromo-2,7-dihydro-3-methyl-2,7-dioxo-3H-dibenzo[f,ij]isoquinoline.
(2) Then, the compound obtained in the above (1) is reacted with m-aminoacetanilide in a solvent to obtain 3′-[1-benzoyl-2,7-dihydro-3-methyl-2,7-dioxo-3H-dibenzo[f,ij]isoquinoline-6-ylamino]acetanilide.
(3) Subsequently, the compound obtained in the above (2) is reacted in fuming sulfuric acid to obtain trisodium 6-amino-4-[2,7-dihydro-3-methyl-1-(3-sulfonatobenzoyl)-2,7-dioxo-3H-dibenzo[f,ij]isoquinoline-6-ylamino]benzene-1,3-disulfonate.
(4) After that, the compound obtained in the above (3) is reacted with cyanuric chloride in water to obtain a primary condensation product, which is further reacted with a diamine having a connecting group A to obtain a secondary condensation product.
(5) Then, the compound obtained in the above (4) is condensed as such, or hydrolyzed or reacted with ammonia to prepare a tertiary condensation product, thereby obtaining the desired compound represented by the above-mentioned formula (1).
In the invention, as the colorant used in the ink composition, there can be used a single kind of compound selected from the compounds represented by the above-mentioned formula (1). However, a plural kind of compounds selected therefrom may be used.
The ink composition containing the compound represented by the above-mentioned formula (1) is excellent in light resistance, compared to an ink composition containing a magenta dye which has conventionally been used.
The concentration of the colorant contained in the ink composition can be appropriately selected according to the color value of the compound represented by formula (1), which is used as the colorant. However, it is preferred that the ink composition usually contains the compound represented by formula (1) in an amount of 0.2 to 10% by weight. When the content is 0.2% by weight or more, color development can be secured. When the content is 10% by weight or less, properties to be satisfied as the ink jet composition and reliability such as reliability in terms of clogging are easily secured.
Further, in the invention, a magenta ink composition as a matter of course, and even an ink composition having a color different from magenta such as a black ink composition or a dark yellow ink composition can be improved in moisture resistance by using the carboxyl group-containing compound together, as long as the ink composition contains the compound represented by the above-mentioned formula (1). In order to prepare these various ink compositions, dyes which have hitherto been known can be used together.
In the invention, the carboxyl group-containing aromatic compound used in the ink composition as the moisture resistance improver may be any, as long as it is an aromatic compound having at least one carboxyl group in its molecular structure. As the salt thereof, preferred is an alkali metal salt, and a lithium salt is particularly preferred among others in terms of clogging resistance. Further, a naphthalene skeleton-containing compound having a carboxyl group at the 2-position and/or a salt thereof is preferred, and more preferred examples thereof include an alkali metal salt (particularly, a lithium salt) of a naphthalene skeleton-containing compound having a carboxyl group at the 2-position.
Specific examples of the carboxyl group-containing aromatic compounds include 2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 6-hydroxy-2-naphthoic acid, 4-hydroxy-benzoic acid, 6-methoxy-2-naphthoic acid and salts thereof (particularly, lithium salts thereof).
Although the content of the carboxyl group-containing aromatic compound is determined depending on the kind of carboxyl group-containing aromatic compound, the kind of dye, the kind of solvent ingredient, etc., it ranges from 0.2 to 10% by weight, and preferably from 0.5 to 5% by weight, based on the total weight of the ink composition.
In the ink composition of the invention, the content ratio of the compound represented by the above-mentioned formula (1) to the carboxyl group-containing aromatic compound is preferably from 4:1 to 1:10, more preferably from 2:1 to 1:6, and still more preferably from 1:1 to 1:4. The effect of improving moisture resistance is sufficiently obtained by increasing the ratio of the carboxyl group-containing aromatic compound to more than 4:1, and ejection characteristics and reliability against clogging can be easily secured by decreasing the ratio of the carboxyl group-containing aromatic compound to less than 1:10.
When the aqueous medium is acidic, the solubilities of the compound represented by the above-mentioned formula (1) and the carboxyl group-containing aromatic compound are lowered. Accordingly, in order to stably dissolve required amounts of the compound represented by the above-mentioned formula (1) and the carboxyl group-containing aromatic compound, the pH (at 20° C.) of the ink composition is preferably 8.0 or more. Further, considering resistance properties to various materials with which the ink composition comes into contact, the pH of the ink composition is preferably 10.5 or less. In order to allow these matters to be compatible, it is more preferred that the pH of the ink composition is adjusted to 8.5 to 10.0.
In the ink composition of the invention, water or a mixed solution of water and a water-soluble organic solvent is preferably used as a main solvent.
As the water, there can be used ion-exchanged water, ultrafiltrated water, reverse osmosis-treated water, distilled water or the like. From the viewpoint of long-term storage, water subjected to various chemical sterilization treatments such as ultraviolet irradiation and addition of hydrogen peroxide is preferred.
In the ink composition of the invention, the content of the water used as the main solvent is preferably from 50 to 90% by weight, and more preferably from 60 to 80% by weight, based on the total weight of the ink composition.
The ink composition of the invention can further contain a humectant selected from water-soluble organic solvents having a vapor pressure lower than that of pure water and/or saccharides.
In the ink jet recording system, the inclusion of the humectant can inhibit the evaporation of water to retain moisture. Further, in the case of the water-soluble organic solvent, ejection stability can be improved, or viscosity can be easily altered without changing ink characteristics.
The water-soluble organic solvent means a medium capable of dissolving a solute, and is selected from water-soluble solvents which are organic and have a vapor pressure lower than that of water. Specifically, preferred examples thereof include polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, pentanediol, 2-butene-1,4-diol, 2-methyl-2,4-pentanediol, glycerol, 1,2,6-hexanetriol, diethylene glycol, triethylene glycol and diproylene glycol; ketones such as acetonylacetone; esters such as triethyl phosphate; furfuryl alcohol, tetrahydrofurfuryl alcohol and thiodiglycol.
Further, preferred.examples of the saccharides include maltitol, sorbitol, gluconic lactone and maltose.
The humectant is added preferably in an amount of 5 to 50% by weight, more preferably in an amount of 5 to 30% by weight, and still more preferably in an amount of 5 to 20% by weight, based on the total amount of the ink composition. When the humectant is added in an amount of 5% by weight or more, moisture retention is obtained. Further, 50% by weight or less results in easy adjustment to viscosity used in ink jet recording.
It is preferred that the ink composition of the invention contains a nonionic surfactant as an additive effective for obtaining rapid fixing (permeability) of the ink and keeping the circularity of one dot.
The nonionic surfactants used in the invention include, for example, acetylene glycol-based surfactants. Specific examples of the acetylene glycol-based surfactants include Surfynol 465, Surfynol 104 and Olfin STG (trade names, manufactured by Nissin Chemical Industry Co., Ltd.). The amount thereof added is from 0.1 to 5% by weight, and preferably from 0.5 to 2% by weight, based on the total amount of the ink composition. Addition of the nonionic surfactant in an amount of 0.1% by weight or more allows sufficient permeability to be obtained. Further, 5% by weight or less results in easy prevention of the occurrence of blurring in images.
Furthermore, in addition to the nonionic surfactant, a glycol ether can be added as a penetration accelerator, thereby increasing permeability and decreasing bleeding at the boundary between adjacent color inks in color printing to obtain very clear images.
The glycol ethers used in the invention include ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether and triethylene glycol monobutyl ether. The amount thereof added is from 3 to 30% by weight, and preferably from 5 to 15% by weight, based on the total amount of the ink composition. Addition of the glycol ether in an amount of 3% by weight or more allows the sufficient bleed preventing effect to be obtained. Further, 30% by weight or less results in easy prevention of the occurrence of blurring in images, and easy securing of keeping stability of the ink.
Further, a pH adjuster such as triethanolamine or a hydroxide of an alkali metal, a hydrotropy agent such as urea or a salt thereof, a water-soluble polymer such as sodium alginate, a water-soluble resin, a fluorine surfactant, an antifungal agent, a corrosion inhibitor or the like may be added to the ink composition of the invention as needed.
In the ink composition of the invention, the optional ingredients described above may be used alone or as a mixture of a plurality of optional ingredients selected from the same category or different categories.
Further, in the ink composition of the invention, the amounts of all ingredients of the ink composition are preferably selected so that the viscosity of the ink composition is less than 10 mPa.s at 20° C.
Furthermore, the ink composition has a surface tension of 45 mN/m or less, and preferably ranging from 25 to 45 mN/m.
Processes for preparing the ink composition of the invention include, for example, a process of thoroughly mixing and dissolving the respective ingredients, filtering the resulting solution under pressure through a membrane filter having a pore size of 0.8 μm, and then, conducting deaeration treatment with a vacuum pump to prepare the ink composition.
The recording process of the invention using the ink composition described above will be described below. As the recording process of the invention, an ink jet recording system of ejecting the ink composition as droplets through minute nozzles and depositing the droplets onto a recording medium to perform printing is especially suitably used. However, it goes without saying that the process is also usable for applications such as general writing materials, recorders and pen plotters.
As the ink jet recording system, any known system can be used. In particular, it is possible to perform excellent image recording in a process in which the droplets are ejected utilizing vibration of an electrostrictive element (a recording process using an ink jet head which forms the droplets of the ink composition by mechanical deformation of an electrostrictive element) and a process utilizing thermal energy.
EXAMPLES
The present invention will be illustrated in greater detail with reference to the following Examples and Comparative Example, but the invention should not be construed as being limited thereto.
Examples 1 to 12 and Comparative Example 1
Ink compositions of Examples 1 to 12 and Comparative Example 1 were each prepared by mixing and dissolving respective ingredients at compounding ratios shown in Table 1, followed by filtration under pressure through a 1-μm membrane filter. The values of the respective ingredients of the ink composition shown in Table 1 indicate percents by weight of the respective ingredients based on the total amount of the ink composition, and the balance is water.
For a colorant in Examples and Comparative Example, there was used as a compound represented by the following formula (2) as an example of the compound represented by formula (1) (and the salt thereof) was used as M dye 1.
M=NH 4 or Na
(NH 4 and Na are present in the compound in a molar ratio of 1:1)
TABLE 1 Comp. Example Ex. 1 2 3 4 5 6 7 8 9 10 11 12 1 Colorant M dye 1 2 2 2 2 2 2 2 2 2 2 2 4 2 Organic Glycerol 10 9 10 10 10 10 10 9 10 10 10 9 10 Solvent Triethylene glycol 3 4 3 4 3 3 3 6 6 6 3 3 9 2-Pyrrolidone 2 2 2 1.5 2 2 2 3 2 2 2 1.5 3 Olfin E1010 (manufactured 1 1 1 1 1 — 1 1 1 1 1 1 1 by Nissin Chemical Industry Co., Ltd.) Olfin STG (manufactured — — — — — 0.3 — — — — — — — by Nissin Chemical Industry Co., Ltd.) Triethylene glycol monobutyl 10 10 10 10 10 10 — 10 10 10 10 10 10 ether Diethylene glycol monobutyl — — — — — — 10 — — — — — — ether Alkali Triethanolamine 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Sodium hydroxide — — — — — — — — — — 0.93 — — Lithium hydroxide 1 0.9 0.9 1.22 — 1 0.9 0.5 0.45 0.45 — 1 — (monohydrate) Moisture 2-Naphthoic acid 4 — — — — — — 2 — — 4 4 — Resistance 3-Hydroxy-2-naphthoic acid — 4 — — — — — — 2 — — — — Improver 6-Hydroxy-2-naphthoic acid — 4 — — — — — 2 — — — 4-Hydroxybenzoic acid — — — 4 — — — — — — — — — Sodium 2-naphthoate — — — — 4 — — — — — — — — 1-Naphthoic acid — — — — — 4 — — — — — — — 2-Hydroxy-1-naphthoic acid — — — — — — 4 — — — — — — Preservative Proxel XL-2 (manufactured 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 by Avecia) Other Water Bal. Bal. Bal. Bal. Bal. Bal. Bal. Bal. Bal. Bal. Bal. Bal. Bal. Unit: % by weight
Printing of Printed Matter
Each of the ink compositions of Examples 1 to 12 and Comparative Example 1 was loaded into an exclusive cartridge (magenta chamber) of an ink jet printer Stylus Color 880 (manufactured by Seiko Epson Corporation), and printing was performed by the use of the printer on a recording medium exclusive to ink jet printing (PM photographic paper manufactured by Seiko Epson Corporation, type: KA420PSK) in the following manner.
Evaluation of Light Resistance
Printing was performed, using the above-mentioned cartridge and adjusting the duty so that the OD (optical density) value fell in the range of 0.9 to 1.1. The resulting printed matter was allowed to stand in an environment of ordinary temperature and humidity protected from the direct sunlight for one hour, and then, the light resistance of the resulting recorded matte was evaluated under the following conditions.
Using a fluorescent fade meter SFT-11 (manufactured by Suga Test Instruments Co., Ltd.), the recorded matter was irradiated under the conditions of 24° C. and 60% RH at an illuminance of 70,000 luxes for 7 days, 14 days, 21 days and 28 days, respectively.
The OD value (optical density) of the exposed sample was measured with a reflection densitometer (Spectrolino, manufactured by Gretag). Each measured value was substituted in the following equation, thereby obtaining the relict optical density (ROD) after fading:
ROD (%)=( D n /D 0 ) X 100
(D n : OD after the irradiation test, D 0 ; OD before the irradiation test)
Then, each approximated curve was determined by plotting the irradiation period (days) on abscissa and the resulting ROD on the ordinate. The period required until the ROD had decreased to 70% was determined, and the light resistance was evaluated according to the following criteria:
A: The ROD does not decrease to 70% until 25 days have elapsed.
B: The period required until the ROD has decreased to 70% is from more than 20 days to 25 days or less.
C: The period required until the ROD has decreased to 70% is from more than 15 days to 20 days or less.
D: The period required until the ROD has decreased to 70% is from more than 10 days to 15 days or less.
E: The period required until the ROD has decreased to 70% is from more than 5 days to 10 days or less.
The results thereof are shown in Table 2.
Evaluation of Moisture Resistance
Using the above-mentioned cartridge, characters and outline characters were printed under such ejection conditions as to give an amount ejected of 1.5 to 2.2 mg per inch square. The resulting printed matter was dried in the environment of 25° C. and 40% RH for 24 hours, and then, allowed to stand in the environment of 40° C. and 85% RH for required periods of time. Bleeding of the dye (outline characters getting out of shape) was visually confirmed, and the moisture resistance was evaluated according to the following criteria:
A: Bleeding of the dye is scarcely observed.
B: Bleeding of the dye is slightly observed, and outlines of the characters somewhat get out of shape.
C: Bleeding of the dye is observed, and outlines of the characters get out of shape.
D: Bleeding of the dye is observed, and the characters are thickened and the outline characters are entirely dyed.
E: Bleeding of the dye is significantly observed, and the characters and the outline characters are illegible.
The results thereof are shown in Table 2.
Evaluation of Clogging
Using the above-mentioned cartridge, printing was continuously carried out for 10 minutes, and it was confirmed that the ink composition was normally ejected through all nozzles. Then, in order to accelerate a dry state in the nozzles, a recording head was dismounted from a head cap with the ink cartridge installed, and allowed to stand in the environment of 40° C. for 2 weeks. After standing, a cleaning operation was repeated until the ejection of all nozzles recovered equivalently to the initial ejection. The ease of recovery was evaluated according to the following criteria:
A: The ejection recovers equivalently to the initial ejection by repeating the cleaning operation 1 to 4 times.
B: The ejection recovers equivalently to the initial ejection by repeating the cleaning operation 5 to 8 times.
C: The ejection recovers equivalently to the initial ejection by repeating the cleaning operation 9 to 12 times.
D: The ejection does not recover by practical repetitions of the cleaning operation.
The results thereof are shown in Table 2.
TABLE 2
Comp.
Example
Example
1
2
3
4
5
6
7
8
9
10
11
12
1
Light Resistance
A
A
A
A
A
A
A
A
A
A
A
A
A
Moisture
24 hours
A
A
A
A
A
A
A
A
A
A
A
A
A
Resistance
72 hours
A
A
A
A
A
A
A
A
A
A
A
A
B
40° C.*85% RH
168
A
A
A
A
A
A
A
B
B
B
A
B
C
hours
Clogging Resistance
A
A
A
A
B
A
A
A
A
A
B
A
—
In the evaluation of moisture resistance, the hydroxyl group-containing compounds showed a higher effect as the moisture resistance improver than the hydroxyl group-free compounds, although both were graded to the same class. Further, in the case of the naphthalene skeleton-containing compounds, the compound having a carboxyl group at the 2-position showed a higher effect than the compound having a carboxyl group at the 1-position.
As described above, according to the invention, the ink composition is allowed to contain the above-mentioned compound represented by formula (1) as the colorant, and the above-mentioned carboxyl group-containing aromatic compound, whereby the recorded matter using the ink composition is excellent in light resistance and moisture resistance, and the performance of recording using the ink composition achieves an excellent effect also in clogging resistance.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.
The present application is based on Japanese Application No. 2002-254611 filed Aug. 30, 2003, the contents thereof being herein incorporated by reference. | The present invention provides an ink composition including at least water; at least one member selected from compounds represented by the following formula (1) and/or salts thereof; and at least one member selected from carboxyl group-containing aromatic compounds and/or salts thereof:
wherein A represents an alkylene group, a phenylene group-containing alkylene group or
(R means hydrogen or alkyl) and X represents NH 2 , OH or Cl. | 2 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] The present application claims the benefit of provisional U.S. Application No. 60/805,323 (Attorney Docket No. 021834-002000US), filed Jun. 20, 2006, the full disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The systems and methods of this invention relate to electrical stimulation of the cochlea of the ear and to cochlear nerves and to regions proximal to cochlear nerves of the ear as a treatment for hearing loss. Specifically, the present invention relates to methods and apparatus for applying such stimulation to selected regions of the cochlea without the use of leads of conventional cochlear implant systems.
[0004] 2. Description of the Background Art
[0005] Electrical stimulation in the cochlea of the ear for the purpose of treating patients with hearing loss has been known and actively practiced for several decades. Application of an electrical field between electrodes in the cochlea stimulates cochlear nerve tissues and is known to effectively modify signal pathways to the brain to emulate the sensation of hearing sounds. These applications currently use several components including externally applied parts and implanted parts, collectively referred to as a cochlear implant system (CIS). A cochlear implant system consists of a microphone, which picks up sound from the environment; a sound-speech processor, which selects and arranges sounds picked up by the microphone; a transceiver-stimulator, which receives signals from the sound-speech processor and converts them into electric impulses; and electrodes, which collect the impulses from the transceiver-stimulator and applies them to the cochlea. As the cochlea is stimulated, signals are sent to the brain and interpreted by the brain as sound.
[0006] A CIS device does not restore or create normal hearing, nor does it amplify sound like a hearing aid. CIS provides a train of stimulation pulses that are correlated with sound and provides this interpreted pattern of impulses to the brain. The brain is capable of associating these substituted impulses as sound which enables the patient/brain to reform environmental sound recognition and speech recognition. Depending on the individual patient, cochlear stimulation can effectively activate signal pathways along the cochlear nerve, to the brain, and the brain associates these artificially induced impulses with sounds. For example, speech recognition can be accomplished in profoundly deaf patients who learn to associate these stimuli with sound, particularly in combination with reading lips. Treatment regimens and targeted cochlear nerve locations are known in related art through use of current, common stimulation devices and methods. Commonly implanted CIS devices for cochlear nerve stimulation are made by such companies as Med El Medical Electronics, Advanced Bionics, Cochlear Inc. and others.
[0007] As illustrated in FIG. 1 , the hearing system is an anatomical structure that begins at the ear canal. Sound travels through the canal to the ear drum which vibrates and sets in motion bones in the inner ear. This motion causes the fluid in the cochlea to move small hair cells. The hair cells transduce this movement into electrical impulses in the cochlear nerve which sends the impulses to the brain, which then interprets the impulses as sound.
[0008] CIS is a well known medical treatment used primarily to restore speech recognition in the patients with conditions that prevent the hair cells in the cochlea from activating, particularly in the profoundly deaf. Use of the CIS components (microphone, sound-speech processor, transceiver-stimulator, and electrodes) for a conventional CIS device is illustrated in FIG. 2 a . The Microphone is typically worn behind the ear and configured for wear to hook over the top of the ear or alternatively can be worn on the clothing or placed in a pocket. There is a direct connection from the Microphone, via a wire, to the Sound-speech processor. Alternative embodiments sometimes include the Microphone and the Sound-speech processor in the same device. The Sound-speech processor interprets the sound waves it receives and converts the frequency of the sound waves into trains of pulses with varying pulse durations. The series of pulses is then sent to the Transceiver-stimulator to be converted into electrical signals to be sent between electrodes that are positioned in the cochlea. This series of pulses is communicated from the Sound-speech processor either by direct wired connection to the Transceiver-stimulator or by radiofrequency communication between the two components. The Transceiver-stimulator is implanted subcutaneously between the patient's skin and skull and the Sound-speech processor may be mounted externally on the skull proximate to the Transceiver-stimulator. The Electrodes are connected to the Transceiver-stimulator via a lead that is tunneled from the cochlea to the Transceiver-stimulator. Electrodes are dispersed along the distal end of the lead and positioned throughout the cochlea so that a variety of locations in the cochlea can be stimulated independently. Prior art describes effective processes and algorithms to convert sound into impulse trains and to send those trains to electrodes in selected cochlea regions to stimulate the cochlear nerves.
[0009] In CIS systems, electrical energy is delivered through lead wires to the electrodes. As shown in FIG. 2 b , CIS implanted electrodes are positioned throughout the spiral structure of the cochlea in order to stimulate different regions in the cochlear nerve. CIS uses the implanted electrodes to deliver a variety of stimulation modalities along the cochlea and thus along the cochlear nerve with the electric pulse waveform defined by a plurality of variables, including but not limited to: pulse width or pulse frequency (Hz).
[0010] As described above, CIS devices are battery-powered electronic devices connected via insulated metal lead(s) to electrodes which are placed in the cochlea around or in close proximity to the cochlear nerve or cochlear nerve bundle. The implanted electrodes for CIS are positioned on leads that are placed percutaneously, through needle punctures or through direct surgical access to position the electrodes along the spiral shaped cochlea. A typical application may utilize 16 electrodes (for example, selected and used as 8 pairs of electrodes) positioned in regions that are targeted for electrical stimulation. The implanted leads are then subcutaneously tunneled to the Transceiver-stimulator (also referred to as a controller) that is implanted in a subcutaneous pocket between the skin and the skull. The use of these lead wires is associated with significant problems such as complications due to infection, lead failure, lead migration, and electrode/lead dislodgement. Application of electrodes to the cochlea can be difficult because of the need to locate electrodes for effective therapy. Additionally, the implanted Transceiver-stimulator must be in communication with the external Sound-speech processor. This requires that the implanted Transceiver-stimulator have a percutaneous connection to the Sound-speech processor or that an RF or magnetic coupling be maintained. A percutaneous connection is often a source for infection and wound control.
[0011] Other prior art in many stimulation applications has attempted to deal with the complications and limitations imposed by the use of electrical leads. For example, self-contained implantable microstimulators and remotely powered microstimulators have been described; however each approach suffers from some significant limitation. A self-contained microstimulator must incorporate a battery or some other power supply; this imposes constraints on size, device lifetime, available stimulation energy, or all three. Constant communication from the Speech Processor would be required with the microstimulator imposing further constraints on maintaining a constant communication between the two devices. Due to high use or high energy requirements of the therapeutic stimulation some CIS devices contain rechargeable batteries or are powered remotely with the RF coupling to the controller.
[0012] For non-percutaneous connection solutions, between the Sound-speech processor and the Transceiver-stimulator, CIS devices have previously utilized either radiofrequency (RF) or electromagnetic transformer power transmission. RF energy transmission, unless the transmitting and receiving antennae are placed in close proximity, suffers from inefficiency and limited safe power transfer capabilities, limiting its usefulness in applications where recharging or stimulation must be accomplished at any significant depth (>1-2 cm) within the body. Electromagnetic coupling can more efficiently transfer electrical power, and can safely transfer higher levels of power (devices with capacity in excess of 20 Watts have been produced) but again relies on close proximity between transmitting and receiving coils.
[0013] The methods and apparatus of the current invention utilize vibrational energy, particularly at ultrasonic frequencies, to overcome many of the limitations of currently known solutions for cochlea stimulation, by achieving a cochlea stimulation capability without direct connection to the Sound-speech processor or without the use of leads connected to a controller.
[0014] The following patents, all of which are incorporated in this disclosure in their entirety, describe various aspects of using electrical stimulation for achieving various beneficial effects by cochlear implant systems. U.S. Pat. No. 3,751,605 titled “Method for Inducing Hearing” by Michelson describes methods for inducing the sensation of intelligible hearing by direct electrical excitation of the auditory nerve endings distributed along the basilar membrane within the cochlea. U.S. Pat. No. 4,400,590 titled “Apparatus for multichannel cochlear implant hearing aid system” by Michelson describes an intra-cochlear electrode array for electrically stimulating predetermined locations of the auditory nerve within the cochlea of the ear. U.S. Pat. No. 4,819,647 titled “Intracochlear electrode array” by Byers et al. also describes an intra-cochlear electrode array for electrically stimulating the cochlea of the ear. U.S. Pat. No. 6,671,559 titled “Transcanal, transtympanic cochlear implant system for the rehabilitation of deafness and tinnitus” by Goldsmith et al. describes an implantable application for cochlea stimulation using a system that couples communication and energy via RF or inductive coupling. U.S. Pat. No. 6,889,094 titled “Electrode array for hybrid cochlear stimulator” by Kuzma describes an implantable cochlear electrode array. U.S. Pat. No. 5,405,367 titled “Structure and Method of Manufacture of an Implantable Microstimulator” by Schulman et al. describes an implantable microstimulator used generally for stimulation of tissue. U.S. Pat. No. 6,037,704 titled “Ultrasonic Power Communication System” by Welle describes the use of ultrasound energy transfer from a transmitter to a receiver for purposes of powering a sensor or actuator without being connected by a lead/wire. U.S. Pat. No. 6,366,816 titled “Electronic Stimulation Equipment with Wireless Satellite Units” by Marchesi describes a tissue stimulation system based on a wireless radio transmission requiring the charging of a battery at the receiver and separate command signals used to control the delivery of stimulation. German patent application DE4330680A1 titled “Device for Electrical Stimulation of Cells within a Living Human or Animal” by Zwicker describes a general approach to power transfer using acoustic energy for tissue stimulation.
BRIEF SUMMARY OF THE INVENTION
[0015] This invention relates to methods and devices for using electrical stimulation in the cochlea of the ear as a treatment for hearing loss, effectively modifying signal pathways along the cochlear nerve, to the brain, to provide a functional capability of hearing, particularly for environmental sound recognition and speech recognition. This invention uses vibrational energy as a means to transmit energy and signal information from a first device, to a second device containing means to receive such vibrational energy and converting it into electrical energy and then apply that electrical energy to stimulating electrodes. The first device is intended to be either implanted or to be used externally. The second device is intended to be either permanently or temporarily implanted with stimulating electrodes in the cochlea of the ear.
[0016] This application of electrical stimulation is to specifically eliminate one or more direct lead connections between the components of a Cochlear Implant System. The invention is a system comprising a microphone, a sound-speech processor, a controller-transmitter, and an implanted receiver-stimulator with stimulation electrodes, such that the stimulation electrodes would be implanted in the cochlea of the ear, in close proximity to the cochlear nerve or cochlear nerve bundle to be stimulated to facilitate a sensation of sound in the brain. Systems incorporating the concepts presented herein are advantageous with respect to currently available devices, particularly by eliminating the requirement for leads connecting components of conventional CIS systems, and by providing the capability for simultaneous or sequenced stimulation of multiple sites.
[0017] In one preferred embodiment, the controller-transmitter is applied on the external surface of the skin. In another embodiment, the controller-transmitter is implanted subcutaneously beneath the skin. The receiver-stimulator is implanted such that electrodes of the receiver-stimulator are within the cochlea of the ear. In one embodiment of the receiver-stimulator, the receiver-stimulator is positioned at one implantation site and connected to the electrodes in the cochlea via a lead. In another embodiment of the receiver-stimulator, the receiver-stimulator is adapted to be implanted within the cochlea and multiple electrodes are dispersed on the device throughout the cochlea. In yet another embodiment of the receiver-stimulator, the receiver-stimulator is miniaturized to contain a pair of electrodes and multiple receiver-stimulator devices are individually positioned within the cochlea. The transmitted vibrational energy is directed to the receiver-stimulator to cause electrical stimulation at the electrodes of the receiver-stimulator.
[0018] In the implanted embodiment of the controller-transmitter, the sound-speech processor communicates with the controller-transmitter via RF, electromagnetic or acoustic coupling. In the external embodiment of the controller-transmitter, the controller-transmitter may be directly connected to the sound-speech processor or be incorporated with the sound-speech processor into a single device. The acoustic energy from the external controller-transmitter is coupled through the skin as well as any underlying tissues, to the implanted receiver-stimulator device. The external controller-transmitter is under control of the sound-speech processor. Thus, when the microphone picks up sound, the sound-speech processor converts the sound into associated stimulation characteristics, for example the frequency or pulse duration of the stimulating waveform or selected electrodes in specific regions within the cochlea, the stimulation characteristics are communicated to the controller-transmitter and vibrational energy is transmitted to the receiver-stimulators. This process enables the system to convert sound into stimulation impulses in the cochlea without direct connections the electrodes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a schematic showing the basics of the ear/hearing anatomy.
[0020] FIGS. 2 a and 2 b are schematics showing a typical cochlear implant system in application with an external microphone and sound-speech processor and an implantable transceiver-stimulator and electrodes for stimulation in the cochlea of the ear.
[0021] FIGS. 3 a , 3 b , and 3 c are schematics showing the leadless stimulation system of the present invention with an externally applied acoustic transmitter-controller and implanted receiver-stimulators for stimulation in the cochlea of the ear.
[0022] FIGS. 4 a and 4 b are block diagrams showing the components of the acoustic transmitter-controller and acoustic receiver-stimulators of the present invention.
[0023] FIG. 5 illustrates representative acoustic and electrical signals useful in the systems and methods of the present invention.
[0024] FIGS. 6 a , 6 b , and 6 c are schematic illustrations showing components of the receiver-stimulator of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] The systems and devices described here comprise a controller-transmitter device that will deliver vibrational energy and information to one or more implanted receiver-stimulator device(s) that will convert the vibrational energy to electrical energy of a form that can be used to electrically stimulate cochlear nerves. The vibrational energy can be applied with ultrasound as a single burst or as multiple bursts or as a continuous wave with appropriate selection of the following parameters:
[0000]
Parameter
Value Range
Ultrasound frequency
20 kHz-10 MHz
Burst Length (#cycles)
3-Continuous
Stimulation Pulse
0.1 μsec-Continuous
Duration
Duty Cycle
0-100%
Mechanical Index
≦1.9
[0026] The controller-transmitter device would contain one or more ultrasound transducers of appropriate size(s) and aperture(s) to generate sufficient acoustic power to achieve the desired stimulation at the location of an implanted receiver-stimulator device. Additionally, multiple implanted receiver-stimulator devices may be placed within the region insonified by the controller-transmitter device. Multiple receiver-stimulator implants may function simultaneously; and, it is possible for multiple devices to function independently, either by responding only to a specific transmitted frequency, or through the use of a selective modulation technique such as pulse width modulation, or through encoding techniques such as time-division multiplexing.
[0027] A receiver-stimulator would be placed percutaneously or surgically. Utilizing a percutaneous needle delivery technique to access the cochlea, a miniaturized receiver-stimulator device disposed within the delivery needle is implanted into the cochlea. Various techniques and tools for surgical access and probing of the cochlea that are currently used, or have been described in the literature, could be adapted to facilitate delivery of the receiver-stimulator to these locations; the receiver-transmitter may incorporate means to provide permanent attachment to the implant site including possibly helical coils, barbs, tines, or the like or would be adapted in form to expand/spring against the tissue to maintain its position.
[0028] Functionally, the receiver-stimulator device comprises an ultrasound transducer to receive acoustic energy and transform it into electrical energy, an electrical circuit to transform the alternating electrical energy into a direct current, and electrodes to transfer the electrical field energy between an electrode pair to the cochlea.
[0029] Additionally, a controller-transmitter device is adapted for directional, vibrational energy transmission emitted by the device to intersect the implanted receiver-stimulator. In an external version of the controller-transmitter, the transducer portion of the transmitter would be placed over the skin directionally angled to the target region containing the receiver-stimulator with acoustic gel, or other means, used for coupling the acoustic energy to the skin. In an implanted version, the controller-transmitter device containing the transmitting transducer is implanted typically just beneath the skin in a subcutaneous space.
[0030] The controller-transmitter device would contain elements similar to most currently available CIS systems, including a power source, stimulation control and timing circuitry. In its external embodiment, it would be possible to integrate the function of a sound-speech processor into a single enclosure with the controller-transmitter, or still yet integrate the function of the microphone, the sound-speech processor, and the controller transmitter into a single enclosure. In its implantable embodiment, the controller-transmitter would communicate with an outside sound-speech processor component via RF, electromagnetic, or acoustic means for data transmission of device function. Additionally, the controller-transmitter device would contain an ultrasound amplifier and one or more ultrasound transducers to generate acoustic energy, and transmit such energy in the general direction of the receiver-stimulator implanted in the body. The duration, timing, and power of the acoustic energy transmission would be controlled as required, per sound-speech processing parameters that are constructed for specific sound sensations.
[0031] A single receiver-stimulator device is implanted with the electrodes positioned within the cochlea of the ear. The single receiver-stimulator device may be adapted to contain multiple electrodes dispersed through the cochlea. Alternatively, it would be possible to implant a plurality of miniaturized receiver-stimulator devices throughout the cochlea to stimulate either simultaneously by receiving the same transmitted acoustic energy or independently by responding only to acoustic energy of a specific character (i.e., of a certain frequency, amplitude, or by other modulation or encoding of the acoustic waveform) intended to energize only that specific device. This enables a much more robust utilization of site and region specific stimulation not currently practical with current lead-based implementations whose electrode spacing is fixed on the lead set selected for use and may not adapt itself to the structure of the cochlea. Selecting multiple sites and regions for treatments would be greatly enhanced by eliminating the need to connect multiple electrode sites to the stimulation energy source by anticipating the required spacing between electrodes.
[0032] These examples are representative and in no way limiting the applications in which a stimulator based on using vibrational energy may be utilized in this invention to stimulate within the cochlea of the ear to treat provide a sound sensation to the brain.
[0033] The delivery of ultrasound energy and, therefore, electrical stimulation would be automatically triggered based on sound information received through a microphone and through a sound-speech processor. More specifically, the timing of the initiation of the delivery and/or the duration of the delivery and/or the energy content of the delivery and/or the information content of the delivery would be based upon processing sound picked up through this CIS system.
[0034] Examples of such an acoustic CIS system as a cochlea stimulator are illustrated in FIGS. 3 a - 3 c.
[0035] In FIG. 3 a , a sound processing device 31 containing a sound microphone, amplifier, sound processing circuitry, ultrasound amplifier, and battery circuitry to receive ambient sound is shown mounted over the ear. The sound processing device 31 is connected via a lead/cable to one or more controller-transmitter transducers 30 , shown here mounted to the outside surface of the skull, on the scalp. It should be appreciated that the functional components of the sound processor and controller-transmitter could be partitioned as desired into one or more enclosures with the important function of the acoustic energy transfer being applied through a transmission transducer directly to the external surface of the body. A receiver-stimulator consisting of a receiver 32 , a lead connection 33 , and electrodes 34 is implanted in the body. The receiver 32 is situated such that the directional angle of the transmitted ultrasound beam from the controller-transmitter transducer 30 would intersect the receiver 32 . An ultrasound signal is transmitted by controller-transmitter transducer 30 through intervening tissue to the receiver 32 containing means to receive this acoustic energy and convert it into an electrical waveform which may then be applied to the attached electrodes. The sound processing circuitry of sound processing device 31 would separate the sound into multiple channels associated with the multiple electrodes 34 implanted in the cochlea; the multiple channels of information would then be encoded into the transmitted ultrasound signal through an appropriate modulation technique. Thus, the transmitted modulated ultrasound signal will comprise an energy component to provide power to the implanted circuitry and an information component to provide signal content to multiple electrodes. Implanted receiver 32 contains both an ultrasound receiving transducer and the necessary electronics circuitry to convert the acoustic energy into electrical power, to demodulate the signal content within the ultrasound signal into one or multiple signal channels, and one or multiple circuits to process the signal content and apply the product to the electrodes 34 , which are disposed on an implantable lead 33 , whose distal end is placed within the cochlea.
[0036] In FIG. 3 b , an alternative embodiment of the present invention is illustrated. In FIG. 3 b , sound processing device 31 containing a sound microphone, amplifier, sound processing circuitry, ultrasound amplifier, and battery circuitry to receive ambient sound is shown mounted over the ear. The sound processing device 31 is connected via a lead/cable to one or more controller-transmitter transducers 30 , shown here mounted to the outside surface of the skull, on the scalp. A receiver-stimulator consisting of a receiver 32 and electrodes 34 is implanted fully within the cochlea. The receiver 32 is situated such that the directional angle of the transmitted ultrasound beam from the controller-transmitter transducer 30 would intersect the receiver 32 . An ultrasound signal is transmitted by controller-transmitter transducer 30 through intervening tissue to the receiver 32 containing means to receive this acoustic energy and convert it into an electrical waveform which may then be applied to the attached electrodes. The sound processing circuitry of sound processing device 31 would separate the sound into multiple channels associated with the multiple electrodes 34 implanted in the cochlea; the multiple channels of information would then be encoded into the transmitted ultrasound signal through an appropriate modulation technique. Thus, the transmitted modulated ultrasound signal will comprise an energy component to provide power to the implanted circuitry and an information component to provide signal content to multiple electrodes. Implanted receiver 32 contains both an ultrasound receiving transducer and the necessary electronic circuitry to convert the acoustic energy into electrical power, to demodulate the signal content within the ultrasound signal into one or multiple signal channels, and one or multiple circuits to process the signal content and apply the output to the electrodes 34 which are disposed on receiver-stimulator, where the entirety of the receiver-stimulator is disposed within the cochlea.
[0037] In FIG. 3 c , an alternative embodiment of the present invention is illustrated. In FIG. 3 c , a sound processing device 31 containing a sound microphone, amplifier, sound processing circuitry, ultrasound amplifier, and battery circuitry to receive ambient sound is shown mounted over the ear. The sound processing device 31 is connected via a lead/cable to one or more controller-transmitter transducers 30 , shown here mounted to the outside surface of the head, beneath the ear. It should be appreciated that the functional components of the sound processor and controller-transmitter could be partitioned as desired into one or more enclosures with the important function of the acoustic energy transfer being applied through a transmission transducer directly to the external surface of the body. Multiple receiver-stimulators consisting of a receiver 32 and electrodes 34 are implanted in the cochlea. The individual receiver-stimulators are situated such that the directional angle of the transmitted ultrasound beam from the controller-transmitter transducer 30 would intersect the multiple receivers 32 . An ultrasound signal is transmitted by controller-transmitter transducer 30 through intervening tissue to the receivers 32 containing means to receive this acoustic energy and convert it into an electrical waveform which may then be applied to the attached electrodes. The sound processing circuitry of sound processing device 31 would separate the sound into multiple channels associated with the multiple receivers 32 implanted in the cochlea; the multiple channels of information would then be encoded into the transmitted ultrasound signal through an appropriate modulation technique. Thus, the transmitted modulated ultrasound signal will comprise an energy part to provide power to the implanted circuitry and an information part to provide signal content to multiple receivers. Implanted receiver 32 contains both an ultrasound receiving transducer and the necessary electronic circuitry to convert the acoustic energy into electrical power, to demodulate the signal content within the ultrasound signal into one or multiple signal channels, and one or multiple circuits to process the signal content and apply the product to the electrodes 34 which are disposed on the individual receiver-stimulator, each of the receiver-stimulators disposed within the cochlea
[0038] It can be appreciated form FIGS. 3 a , 3 b , and 3 c that alternatively (not shown) a controller-transmitter could be implanted in a subcutaneous space and that the sound processing system would communicate via RF, electromagnetic, or acoustic means to initiate ultrasound transmission from the controller-transmitter to the receiver-stimulator.
[0039] FIGS. 4 a and 4 b show more functional details of the system described above and shown in FIGS. 3 a - 3 c . In FIG. 4 a the sound processing and controller-transmitter device 41 comprises: a battery 10 , a microphone 11 , sound amplifier and conditioning circuitry 12 , a sound processor and control and timing module 14 , an ultrasound amplifier 15 , and an ultrasound transducer 16 . The battery 10 which provides power for the sound processing and controller-transmitter device may be of a type commonly used in CIS devices such as a lithium iodine cell or which is optionally a rechargeable battery. The microphone 11 is used to detect ambient sound. Sound pick-up is connected to sound amplifier and conditioning circuitry 12 and used by the circuitry to adjust delivery of stimulation. Sound characteristics would be processed into an associated stimulation therapy by the sound processor and control and timing module 14 . Device parameters would include adjustments to transmission frequency, power amplitude, pulse duration, duty cycle, electrode selection, and the like in order to correlate ambient sound into a stimulation therapy. The sound processor and control and timing module 14 uses device parameters in conjunction with the acquired sound to generate the required control signals for the ultrasound amplifier 15 which in turn applies electrical energy to the ultrasound transducer 16 which in turn produces the desired acoustic beam. Ultrasound transducer 16 is made of piezoelectric ceramic material, a piezoelectric single crystal, or piezoelectric polymer or copolymer films suitable for generating sufficient acoustic energy. The controller-transmitter device 41 is enclosed in case 17 . It should be appreciated that the functional elements of the sound processing and controller-transmitter device 41 could be encased in multiple enclosures and connected appropriately with direct wire connections or through communication via RF, electromagnetic, or acoustic signaling.
[0040] Referring to FIG. 4 b , the receiver-stimulator device 42 , implanted in the path of the acoustic beam, contains an ultrasound transducer 20 , an electrical circuit 21 , and electrodes 22 . Ultrasound transducer 20 , typically made of a piezoelectric ceramic material, a piezoelectric single crystal, or piezoelectric polymer or copolymer films, intercepts a portion of the transmitted acoustic energy and converts it into an electrical current waveform from the original alternating nature of the applied ultrasound pressure wave. This electrical signal is applied to an electrical circuit 21 which may be one of a type commonly known as an envelope detector, and which may have one of many known circuit configurations, for example a full-wave rectifier, a half-wave rectifier, a voltage doubler or the like. Electrical circuit 21 produces a voltage pulse with amplitude proportional to the amplitude of the transmitted ultrasound burst and with a pulse length generally equal to the length of the transmitted burst. The circuit 21 may also be of different configurations and function, and provide output signals having characteristics other than a pulse. This signal is then applied to electrodes 22 , which are typically made of platinum, platinum-iridium, gold, or the like. These may be incorporated onto the outer surface of the device and thus in direct contact within the cochlea. Alternatively, the electrodes 22 are connected via wires/leads to a main body that consists of the transducer 20 and electrical circuit 21 and the electrodes 22 are adapted to be shapeable, malleable configurations that conform to the structure of the cochlea. Electrodes may be adapted that are round, long, segmented, etc. to increase surface area or to control current density at the electrode. Electrodes may be placed along portions of the cochlea in linear alignment with the cochlea or in any arrangement suitable for the size and location of the regions of the cochlea targeted as a stimulation site. The receiver-stimulator device 42 is also enclosed within a sealed case 23 of biologically compatible material
[0041] Referring also to previously described FIGS. 4 a and 4 b , FIG. 5 provides detail representing example acoustic and electrical signals of the present system. FIG. 5 first depicts a train of electrical stimulation pulses 51 which have a desired width and are repeated at a desired interval. The controller-transmitter device 41 produces acoustic transmissions 52 , for the desired stimulation pulse width and repeated at the desired stimulation pulse interval, which are emitted from the ultrasound transducer 16 . Below the waveform 52 is shown an enlargement 53 of a single acoustic burst. This burst again has a desired width, a desired oscillation frequency F=1/t, and also a desired acoustic pressure indicated by the peak positive pressure P+ and peak negative pressure P−. The acoustic pressure wave, when striking the receiving transducer 20 of the receiver-stimulator device 42 generates an electrical signal 54 having frequency and burst length matching that of the transmitted waveform 53 and amplitude proportional to the transmitted acoustic pressure (˜+/−P). This electrical waveform is then rectified and filtered by the circuit 21 producing the desired pulse 55 with length equal to the burst length of the transmitted waveform 53 and amplitude (VPULSE) proportional to the amplitude of the electrical signal 54 . Thus, it can be seen that it is possible in this example to vary the stimulation rate by varying the time between ultrasound bursts, to vary the duration of any one stimulation pulse by varying the duration of the ultrasound burst, and to vary the amplitude of the stimulation pulse by varying the amplitude of the transmitted ultrasound waveform. Circuit 21 could be configured to produce a direct current (DC) output or an alternating current (AC) output, or an output with any arbitrary waveform. Varying the use of signal information within the ultrasound transmission for pulse duration, pulse amplitude, and duty cycle would result in any type of burst sequencing or continuous delivery waveform effective for cochlear nerve stimulation. Using signal information in the ultrasound transmission the resultant waveshape may be a square wave, triangle wave, biphasic wave, multi-phase wave, or the like.
[0042] In practice, the amount of acoustic energy received by the implanted receiver-stimulator device will vary with ultrasound attenuation caused by loss in the intervening tissue, with spatial location of the receiver of the receiver-stimulator device with respect to the transmitted ultrasound beam as such a beam is typically non-uniform from edge-to-edge, and possibly with orientation (rotation) of the receiver-stimulator device with respect to the first. Such variation would affect the amplitude of the stimulating pulse for a given ultrasound transmit power (acoustic pressure amplitude). This limitation can be overcome by adjusting the ultrasound transmit power until the resultant stimulation waveform is consistent, a technique similar to that used currently to determine stimulation thresholds at the time of cardiac pacemaker implantation. Another approach would be to adjust automatically using sensing and logic within the first device. The first device would periodically sense the electrical output of the receiver-stimulator device and adjust power transmission accordingly to compensate for any change in the system including relative movement between the transmitting and receiving devices. Yet another embodiment for overcoming this limitation is where the transducer incorporated into the receiver-stimulator device is omni-directional in its reception capability. For example, to improve omni-directional sensitivity, the transducer may be spherical in shape or have specific dimensional characteristics relative to the wavelength of the transmitted ultrasound. Alternatively, multiple transducers are disposed at appropriate angles to reduce or eliminate the directional sensitivity of the device.
[0043] Referring also to previously described FIGS. 4 a and 4 b , FIGS. 6 a through 6 c illustrate two embodiments of a miniature implantable receiver-stimulator of a cylindrical profile, suitable perhaps for placement by stylet or by percutaneous injection through a hypodermic needle. FIG. 6 a shows in plan view and 6 b in perspective view such a receiver-stimulator 42 having a hollow, cylindrical ultrasound transducer 71 , a circuit assembly 72 comprising the detector, and two electrodes 73 at either end of the assembly. It can be appreciated that any number of electrodes may be adapted to this embodiment. The transducer 71 would be made of an appropriate piezoelectric ceramic material, having two electrical activity contacts deposited on the outer and inner surfaces of the cylinder, respectively. The transducer and circuit would be encapsulated in an electrically insulating but acoustically transparent medium 74 . The transducer 71 would be of a rigid piezoelectric material, typically a piezo-ceramic with electrodes deposited on the outer and inner surfaces of the cylinder. The circuit assembly 72 may be fabricated using known surface-mount or hybrid assembly techniques, upon either a fiberglass or ceramic substrate. Stimulation electrodes 73 would be fabricated of material commonly used in implanted electrodes, such as platinum, platinum-iridium, or the like. Necessary electrical wiring between the transducer, circuit board, and electrodes is not shown in these drawings. Typical dimensions of such a device would be 0.8 cm in length and 1.5 mm in diameter, and preferably smaller. Multiple electrodes could be adapted as appendages to the embodiment (not shown) or incorporated into fixation elements such as helical screws or barbs (not shown).
[0044] As shown in FIG. 6 c , by using hybrid circuit techniques it may be possible to further miniaturize the circuit assembly 72 such that it would fit inside the hollow interior of the transducer 71 . This would have the benefit of substantially reducing the length of the finished device.
[0045] While exemplary embodiments have been shown and described in detail for purposes of clarity, it will be clear to those of ordinary skill in the art from a reading of the disclosure that various changes in form or detail, modifications, or other alterations to the invention as described may be made without departing from the true scope of the invention in the appended claims. For example, while specific dimensions and materials for the device have been described, it should be appreciated that changes to the dimensions or the specific materials comprising the device will not detract from the inventive concept. Accordingly, all such changes, modifications, and alterations should be seen as within the scope of the disclosure. | Systems and methods are disclosed to enable hearing in the deaf by stimulating sites in the cochlea. The invention uses electrical stimulation in the cochlea, where vibrational energy from a source is received by an implanted device and converted to electrical energy and the converted electrical energy is used by implanted electrodes to stimulate the cochlear nerve. The vibrational energy is generated by a controller-transmitter, which could be located either externally or implanted. The vibrational energy is received by a receiver-stimulator, which contains multiple electrodes to stimulate along selected sites in the cochlea. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to technology for assembling magnetic circuitry for use In a magnetic resonance imaging (MRI) system, and more specifically to a method of installing pole pieces at predetermined positions of permanent magnets.
2. Description of Related Art
Magnetic resonance imaging (MRI) is an imaging technique used primarily in medical settings or diagnoses to produce high quality images of the inside of the human body. MRI is based on the principles of nuclear magnetic resonance, a spectroscopic technique to obtain microscopic chemical and physical information about molecules,
As is known in the art, resistive electromagnets, permanent magnets, and super-conducting electromagnets have been used in the magnet field generators of MRI systems. The resistive electromagnets consist of many winding or coils of wire wrapped around a cylinder or bore through which an electric current is passed. Among these magnets, the super-conducting electromagnets are by far the most commonly used.
However, with the improvement of characteristics of permanent magnets using rare-earth elements, it is a current practice to use the permanent magnets in the MRI systems wherein the magnetic field strength is less than 0.5-Tesla (for example). Hereinafter, the permanent magnets made of rare-earth elements are referred to as magnets or permanent magnets.
In the MRI system using the permanent magnets, two magnets typically disk-shaped are installed in the system such as to face each other within a yoke structure. The two magnets respectively carry pole pieces on the major surfaces thereof (viz., at the predetermined positions of the magnets) such as to face each other in order to generate a uniform magnetic field in the space between the two magnets.
Each of the disk-shaped magnets, used in the MRI system, has usually a diameter of about 1(one) meter. Since it is practically impossible to fabricate the magnet with such a large diameter as a single unit, the magnet is manufactured by bringing together a plurality of magnetized blocks to assemble the permanent magnet Each magnetic block is fabricated by compressing magnetic power into a cube (for example) with each side ranging 4 to 10 cm, and thereafter sintering the cube and magnetizing the same. Such blocks, once magnetized, have extremely strong magnetic strengths, and the attracting force between the two magnets or between each magnet and a plate yoke on which the permanent magnets are assemble, reaches as strong as approximately 0.5-ton. Accordingly, in order to bring together the magnet blocks to form the disk-shaped magnets on the plain yoke, it is inevitable to prepare very stout and rigid assembling tools or structures. However, the manner of assembling the disk-shaped magnet using the blocks on the plate yoke is not directly concerned with the present invention, and accordingly, the description thereof will be omitted for the sake of simplifying the instant disclosure.
Before turning to the present invention, it is deemed preferable to briefly describe, with reference to FIGS. 1 and 2 , the prior art relevant to the present invention, which is disclosed in the Japanese Laid-open Patent Application No. 2000-51175.
FIG. 1 is a diagram schematically showing a magnetic field generator 8 for use in an MRI system. As shown, the generator 8 comprises a pair of substantially rectangular plate yokes 10 and 12 , which are rigidly coupled to four cylindrical column yokes 14 a - 14 d, forming magnetic circuits or magnetic flux paths therewith. A disk-shaped magnet 18 is formed using a plurality of magnetic blocks 16 , and being provided on the upper surface of the plate yoke 10 , and carrying thereon a disk-like polo piece 19 which has a protrusion along the circumference thereof. As shown in FIG. 2 , a magnet 17 is provided on the inner surface of the plate yoke 12 which carries a pole piece 21 which corresponds to the pole piece 19 .
The magnetic field generator 8 shown in FIG. 1 is assembled as follows. Although not shown in the drawings, a plurality of magnetized blocks 16 are brought together to form the magnet 18 on the major surface of the plate yoke 10 . Thereafter, the pole piece 19 is positioned on the magnet 18 against extremely strong magnetic forces therebetween. In more specific terms, when the pole piece 19 is brought into in the vicinity of the magnet 16 , the magnetic attracting force reaches approximately 10-ton. Therefore, according to the prior art, the pole piece 19 is very slowly lowered using a crane with extreme care and attention. It is understood that such a crane should be very strong so as to resist the above-mentioned attracting forces of about 10-ton exerted on the pole piece 19 .
Thereafter, the four column yokes 14 a - 14 d are attached to the four corners of the plate yoke 10 as shown in FIG. 1 . On the other hand, the other pole piece 21 (see FIG. 2 ) is positioned on permanent magnet 17 in the same manner as mentioned above while the magnet 17 faces upward. Subsequently, the plate yoke 12 , which carries the magnet 17 and the pole piece 21 thereon, is upset so that the combined magnet 17 and pole piece 21 face downward. Following this, the plate yoke 12 is pulled upward using a large came and moved above the plate yoke 10 as best shown in FIG. 2 . Then, the plate yoke 12 is carefully lowered inch-by-inch. A plurality of rods 20 , which are received in corresponding holes 22 provided at the undersurface of the plate yoke 12 , are to prevent the yoke plate 12 from undesirably fluctuating due to the strong magnetic field.
Thus, the prior art as mentioned above has encountered the problem that the installation of the pole pieces inevitably necessitates a stout or strong installing apparatus such as a strong crane, with the result that the settings of the pole pieces on the permanent magnets are expensive and time consuming to a considerable extent.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide technology via which the pole pieces can be installed at the predetermined positions of the corresponding magnets without difficulty and at a low cost as compared with the prior art.
In brief, the object is achieved by the techniques wherein an MRI system comprises two permanent magnets provided within a yoke structure such as to face each other for generating magnetic field in the space defined therebetween. The MRI system further comprises two pole pieces respectively provided on opposing surfaces of the permanent magnets. Each of the pole pieces is installed at a predetermined position of the permanent magnet by sliding the pole piece on the permanent magnet in a direction parallel with a main surface of the permanent magnet on which the pole pieces is to be installed.
One aspect of the present invention resides in a method of assembling magnetic circuitry for an MRI (magnetic resonance imaging) system, the MRI system comprising two permanent magnets provided within a yoke such as to face each other for generating a magnetic field in a space defined therebetween, and two pole pieces respectively provided on opposing surfaces of said permanent magnets, said method comprising the step of: installing one of the pole pieces at a predetermined position of the corresponding permanent magnet by sliding the pole place on said corresponding permanent magnet in a direction parallel with a main surface of said corresponding permanent magnet on which said one of the pole pieces is to be installed.
Another aspect of the present invention resides in a method of assembling magnetic circuitry for an MRI (magnetic resonance imaging) system, the MRI system comprising two permanent magnets provided within a yoke such as to face each other for generating magnetic field in a space defined therebetween, and two pole pieces respectively provided on opposing surfaces of the permanent magnets, the method comprising the steps of: installing one of the pole pieces at a predetermined position of the corresponding permanent magnet by sliding the one of the pole pieces on the corresponding permanent magnet in a direction parallel with a main surface of the corresponding permanent magnet on which the one of the pole pieces is to be installed; and installing the other pole piece at a predetermined position of the other permanent magnet by sliding the other pole piece on the permanent magnet in a direction parallel with a main surface of the permanent magnet on which the pole piece is to be installed.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the present invention will become more clearly appreciated from the following description taken in conjunction with the accompanying drawings in which like elements or portions are denoted by like reference numerals and in which:
FIG. 1 is a diagram showing a conventional magnetic field generator, having been described in the opening paragraphs of the instant disclosure;
FIG. 2 is a diagram showing a manner of constructing the magnetic field generator of FIG. 1 ;
FIG. 3 is a diagram showing a magnetic field generator with which a preferred embodiment of the present invention will be described;
FIG. 4 is a diagram showing a manner of incorporating one of two pole pieces into the magnetic field generator of FIG. 3 ;
FIG. 5 is a sketch schematically showing part of a structure used for incorporating a pole piece into the magnetic field generator of FIG. 3 ; and
FIG. 6 is a diagram showing a manner of incorporating the other pole piece into the magnetic field generator of FIG. 3 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the present invention will be described with reference to FIGS. 3 to 6 .
FIG. 3 is a schematic side view of a magnetic field generator 38 to which the present invention is applicable. As shown, the magnetic field generator 38 comprises two plate yokes 40 and 42 supported in parallel by way of two pillar or column yokes (only one is shown and denoted by 44 ). The generator 38 further comprises two permanent magnets 46 and 48 , which carry respectively two pole pieces 50 and 52 on opposite surfaces thereof as in the prior art referred to in the opening paragraphs. As mentioned above, each of the magnets 46 and 48 is fabricated using a plurality of magnetized rectangular or cubic blocks. Each of the magnets is typically an Nd—Fe—B, Sm—Co, or Sm—N—Fe type magnet by way of example. Further, each of the pole pieces 50 and 52 comprises a soft iron substrate on which laminated silica-steel boards are provided, or made of soft ion. Comparing the two magnetic field generators 10 and 38 respectively shown in FIGS. 1 and 3 , the generator 38 is provided with two pillar yokes. However, this difference in structure has no meaning, and the present invention can also be applied to the generator 10 of FIG. 1 .
The embodiment of the present invention will be described in detail. It is assumed that the permanent magnets 48 and 48 have already been installed on the plate yokes 40 and 42 , respectively.
FIG. 4 is a diagram schematically showing how to install the pole piece 52 under the magnet 48 (viz., at a predetermined position defined on the lower surface of the magnet 48 ) using an assembling apparatus (denoted by 60 ). Although not shown in FIG. 4 , the assembling apparatus 60 is strongly held by a suitable supporter that is typically rested on the floor on which the plate yoke 40 is placed. As an alternative, the supporter might be settled within the yoke structure. The assembling apparatus 60 generally comprises a hollow rectangular guide case 62 which is roughly exemplified in FIG. 5 , a screwed rod 64 , and a cap or lid 66 through which the rod 64 rotatably advances toward the magnet 48 . The guide case 62 is preferably made of non-magnetic material such as aluminum, and has upper and lower plates 64 a - 64 b and side plates 64 c and 64 d ( FIG. 5 ) for defining the path along which the pole piece 52 is inserted and advanced. Although it is not shown in FIGS. 4 and 5 how to attach or fasten the cap 66 to the end of the guide case 62 , the cap 66 can detachably be attached to the end of the guide case 62 using known technology, and as such, the detail thereof is omitted for brevity.
When the apparatus 60 is set to a predetermined position as illustrated in FIG. 4 , the inner surface of the upper side 64 a is aligned with the lower major surface of the magnet 48 . When starting the installation of the pole piece 52 , the rod 64 is removed together with the cap 66 . Subsequently, the pole piece 52 is inserted into the guide case 62 as shown in FIG. 5 , and the cop 66 is attached after which the rod 64 is inserted into a screwed hole provided in the cap 66 . In the above, it is preferable to apply suitable lubricant such as grease to the upper surface of the pole piece 62 and also to the lower surface of the magnet 48 in order to reduce the friction therebetween. Thereafter, the pole piece 52 is advanced toward the magnet 48 by rotating the screw rod 84 as schematically shown in FIG. 4 , until being positioned under the center portion of the lower surface of the magnet 48 .
As mentioned above, the magnetic attracting forces between the magnet 48 and the pole piece 52 reaches as large as about 10-ton. However, according to the experiment conducted by the inventor, the maximum force required to push the pole piece 52 until setting the same on the predetermined position under the magnet 48 was as small as about 2-ton. More specifically, the experiment was implemented with the following conditions. That is, the frame structure such as shown in FIG. 3 has 1.5 meters in width, 2 meters in depth, and 1.4 meters in height. The plate yokes 40 and 42 were supported using two pillars as shown in FIG. 3 . Further, two Nd—Fe—B type magnets 46 and 48 are provided, between which there exists magnetic field strength of about 0.2-Tesla. The pole piece 52 was disk-shaped and has a diameter of 1 meter, and 100 mm in height including the circumferential protrusion. Still further, a normal type machine grease was applied to the top surface of the pole piece 52 and the lower surface of the magnet 48 .
After the pole piece 52 has been installed onto the lower surface of the magnet 48 , the other pole piece 50 is then installed onto the magnet 46 as shown in FIG. 6 . In FIG. 6 , the members or potions corresponding to those described in FIG. 4 are denoted by like numerals plus primes. It is readily understood from the foregoing that the process of installing the lower pole piece 50 is substantially identical to that discussed above, and accordingly, further description thereof is deemed redundant, and as such, will be omitted for brevity.
It is to be noted that the order of installing the pole pieces 52 and 60 is optional and in no way limited to that described above. In the above, the screw rod 64 is used to push the pole pieces 50 and 52 . However, it is within the scope of the present invention to employ other known suitable pushing apparatus such as using a piston and cylinder. Still further, it is possible to install both the pole pieces 50 and 52 simultaneously by devising the supporters for supporting both the assembling apparatuses 60 and 60 ′.
The foregoing descriptions show only one preferred embodiment. However, other various modifications are apparent to those skilled in the art without departing from the scope of the present invention which is only limited by the appended claims. Therefore, the embodiment described are only illustrated, not restrictive. | Assembling magnetic circuitry for an MRI system is disclosed. The MRI system comprises two permanent magnets provided within a yoke structure such as to face each other for generating magnetic field in the space defined therebetween, and two pole pieces respectively provided on opposing surfaces of the permanent magnets. Each of the pole pieces is installed at a predetermined position of the corresponding permanent magnet by sliding the pole piece on the corresponding permanent magnet in a direction parallel with a main surface of the corresponding permanent magnet on which the pole pieces is to be installed. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a continuation of U.S. patent application Ser. No. 09/829,306, filed on Apr. 9, 2001, which is a continuation-in-part of U.S. patent application Ser. No. 09/325,297, filed Jun. 3, 1999, now abandoned, and U.S. patent application Ser. No. 09/534,274, filed Mar. 23, 2000, issued as U.S. Pat. No. 6,554,868, which is also a continuation-in-part of U.S. patent application Ser. No. 09/325,297, filed Jun. 3, 1999, now abandoned.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to prosthetic devices and more particularly to a hypobarically-controlled artificial limb for amputees and to a method for removing perspiration from the space between the residual limb and the liner by means of an osmotic membrane and an applied vacuum.
[0003] An amputee is a person who has lost part of an extremity or limb such as a leg or arm which commonly may be termed as a residual limb. Residual limbs come in various sizes and shapes with respect to the stump. That is, most new amputations are either slightly bulbous or cylindrical in shape while older amputations that may have had a lot of atrophy are generally more conical in shape. Residual limbs may further be characterized by their various individual problems or configurations including the volume and shape of a stump and possible scar, skin graft, bony prominence, uneven limb volume, neuroma, pain, edema or soft tissue configurations.
[0004] Referring to FIGS. 1 and 2 , a below the knee residual limb 10 is shown and described as a leg 12 having been severed below the knee terminating in a stump 14 . In this case, the residual limb 10 includes soft tissue as well as the femur 16 , knee joint 18 , and severed tibia 20 and fibula 22 . Along these bone structures surrounded by soft tissue are nerve bundles and vascular routes which must be protected against external pressure to avoid neuromas, numbness and discomfort as well as other kinds of problems. A below the knee residual limb 10 has its stump 14 generally characterized as being a more bony structure while an above the knee residual limb may be characterized as including more soft tissue as well as the vascular routes and nerve bundles.
[0005] Referring to FIG. 2 , amputees who have lost a part of their arm 26 , which terminates in a stump 28 also may be characterized as having vascular routes, nerve bundles as well as soft and bony tissues. The residual limb 10 includes the humerus bone 30 which extends from below the shoulder to the elbow from which the radius 34 and ulna 36 bones may pivotally extend to the point of severance. Along the humerus bone 30 are the biceps muscle 38 and the triceps muscle 40 which still yet may be connected to the radius 34 and the ulna, 36 , respectively.
[0006] In some respects, the residual limb amputee that has a severed arm 26 does not have the pressure bearing considerations for an artificial limb but rather is concerned with having an artificial limb that is articulable to offer functions typical of a full arm, such as bending at the elbow and grasping capabilities. An individual who has a paralyzed limb would also have similar considerations wherein he or she would desire the paralyzed limb to having some degree of mobility and thus functionality.
[0007] During the day, as the residual limb amputee walks on an artificial limb, perspiration builds up between the residual limb and the liner which cushions the residual limb in the artificial limb socket. As this perspiration buildup continues, the residual limb begins to slip around within the liner, causing a feeling to the wearer of losing contact with the artificial limb. This slippage often also causes irritation to the residual limb, which may be worsened by a growth of bacteria in the warm, moist environment between the residual limb and the liner.
[0008] There is a need for an improved hypobarically-controlled artificial limb that will offer total contact relationship with the residual limb; absorb and dissipate shock, mechanical and shear forces typically associated with ambulation, twisting and turning and weight bearing with an artificial limb; control residual limb volume by way of even weight distribution; use negative pressure as a locking device to hold the residual limb into the socket without causing swelling of the residual limb into the socket; and control the buildup of perspiration on the residual limb. One of the ways of controlling the buildup of perspiration is to use a vacuum system to wick away this perspiration from the residual limb.
[0009] U.S. Pat. No. 5,888,230 discloses the use of a vacuum pump connected between the limb and a liner. However, this invention is essentially inoperable because the liner will conform to the stump at all times, by an interference fit, so that there is no space between the residual limb and the liner against which to draw a vacuum. In any case, the patent does not disclose application of vacuum to the socket cavity in such a manner as to draw the residual limb firmly and totally against the interior of the socket. Instead, the patent discloses the use of shims between the liner and the socket. Without total contact between the residual limb and the socket, the limb may swell into the space between the limb and the socket. Also, the patent does not disclose the use of vacuum to remove perspiration.
[0010] U.S. Pat. No. 5,549,709 discloses several embodiments of a hypobarically-controlled artificial limb. However, all of these embodiments required two sockets: an outer socket and an inner socket. Applicant has found that the present invention offers improved performance without the requirement for two sockets. A single socket works equally well or better than two sockets. Also, this patent does not disclose a mechanism for maintaining vacuum in the presence of air leakage into the socket.
[0011] It has been found that it is essentially impossible to maintain a perfect, airtight seal between the residual limb and the sockets disclosed in U.S. Pat. No. 5,549,709, with the result that slow air leakage into the sockets diminishes the vacuum in the sockets. With the reduction in vacuum, the beneficial effects of the vacuum also slowly diminish. Consequently, there is a need for a means for maintaining the vacuum in the socket cavity in the presence of some air leakage past the seal.
SUMMARY OF THE INVENTION
[0012] A system for removing perspiration from a residual limb inserted in a prosthesis comprising an nonporous prosthesis socket, a porous thin sheath adjacent the socket, a nonporous liner adjacent the sheath, an osmotic membrane adjacent the liner allowing water vapor to pass from the limb but preventing liquid from passing to the limb, a nonporous seal that prevents air leakage between the residual limb and the socket; and a vacuum source to reduce the pressure in a space between the limb and socket.
[0013] A method of removing perspiration from a residual limb in a prosthesis comprising the steps of inserting the residual limb into a sleeve comprising an osmotic membrane that allows water vapor to pass from the limb but prevents liquid from passing to the limb. The residual limb and osmotic membrane sleeve are inserted into a flexible, nonporous liner. The residual limb, osmotic membrane sleeve, and liner are inserted into a porous sheath. The residual limb, osmotic membrane sleeve, liner, and sheath are inserted into a prosthetic socket cavity having a volume and shape to receive the residual limb. The socket cavity is sealed with a nonporous seal, and vacuum applied to the socket cavity in the space between the membrane and the socket to draw the residual limb and liner into firm contact with the socket and provide a reduced pressure in the socket cavity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a side elevational view of the tissue and skeletal structure of an amputee's residual limb;
[0015] FIG. 2 is a side elevational view of a residual limb in the form of an amputated arm showing the skeletal and muscular structure of the residual limb;
[0016] FIG. 3 is an exploded elevational view of the residual limb donning the polyurethane sleeve, stretchable nylon sleeve, liner, osmotic membrane, nylon sheath and socket of an artificial limb;
[0017] FIG. 4 is a cross-section along the lines 4 of FIG. 3 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] FIGS. 3 and 4 show one embodiment of the apparatus 50 of the present invention. The hypobarically-controlled artificial limb 50 includes a single socket 60 , shin 54 , and foot 56 . The socket 60 has a volume and shape to receive a substantial portion of the residual limb 14 with a space 58 therebetween.
[0019] The apparatus 50 further includes a cavity 62 in the socket 60 with a volume and shape for receiving a substantial portion of the residual limb 14 .
[0020] A vacuum source 70 may conveniently be attached to the shin or pylon 54 . The vacuum source 70 may preferably be a mechanical or motor-driven pump 72 . The vacuum source 70 may be connected to a power source 83 , which may be a battery.
[0021] A vacuum valve 74 is suitably connected to the vacuum source 70 . The vacuum valve 74 may preferably be disposed on the socket 60 . A vacuum tube 76 connects the vacuum valve 74 to the cavity 62 . It will be seen that the vacuum source will cause the residual limb 14 to be drawn into firm contact with the inner surface 64 of the socket 60 .
[0022] The hypobarically-controlled artificial limb 50 also includes a regulator means 80 for controlling the vacuum source 70 . Preferably, the regulator means 80 may be a digital computer 82 . Alternately, the regulator means may be a vacuum regulator. The regulator means 80 is connected to a power source 83 , which may be a battery.
[0023] A seal means 84 makes an airtight seal between the residual limb 14 and the socket 60 . Preferably, the seal means 84 is a nonfoamed, nonporous polyurethane suspension sleeve 86 which rolls over and covers the socket 60 and a portion of the residual limb 14 . Alternatively, the seal means 84 may be any type of seal which is airtight.
[0024] The apparatus 50 may also include a nonfoamed, nonporous polyurethane liner 92 receiving the residual limb 14 and disposed between the socket 60 and the residual limb 14 . The liner 92 provides a total-contact hypobaric suction, equal weight distribution socket liner. The liner 92 readily tacks up to the skin of the residual limb 14 and provides total contact with the limb 14 . The liner 92 absorbs and dissipates shock, mechanical and shear forces typically associated with ambulation.
[0025] The hypobarically-controlled artificial limb 50 may also include a thin sheath 90 between the liner 92 and the inner surface 64 of the socket 60 . As vacuum is applied to the cavity 62 , the sheath 90 will allow the vacuum to be evenly applied throughout the cavity 62 . Without the sheath 90 , the liner 92 might “tack up” against the inner surface 64 and form a seal which might prevent even application of the vacuum to the cavity 62 . The sheath 90 may also be used to assist the amputee into a smooth and easy fitting into the inner socket 60 . The sheath 90 is preferably made of thin knitted nylon.
[0026] The hypobarically-controlled artificial limb 50 may also include a stretchable nylon second sleeve 94 for rolling over and covering the suspension sleeve 86 to prevent clothing from sticking to and catching the suspension sleeve 86 .
[0027] The hypobarically-controlled artificial limb 50 may also include an osmotic membrane 100 encompassing the residual limb 14 and creating a space 102 between the residual limb 14 and the liner 92 . The osmotic membrane 100 allows perspiration to pass in one direction only from the residual limb outward toward the liner 92 .
[0028] This beneficial effect of the osmotic membrane is achieved as follows. The osmotic membrane allows water vapor to pass through the membrane from the side of the membrane with a higher partial water vapor pressure (the residual limb side) to the side of the membrane with a lower partial water vapor pressure (the liner side), but not in the opposite direction. Eventually, the partial water vapor pressure on the two sides of the osmotic membrane would become equal, and transmission of vapor through the membrane would cease. However, application of vacuum to the space 102 will continually lower the partial water vapor pressure on the liner side of the membrane 100 , so that water vapor will continue to pass through the membrane. In turn, this lowers the partial water vapor pressure on the residual limb side of the membrane 100 , allowing perspiration on the residual limb to change from the liquid state to the vapor state.
[0029] Appropriate materials for the osmotic membrane 100 are the Sympatex hydrophylic polyester block copolymer from Sympatex Technologies, One Merrill Industrial Drive, Suite 201, Hampton, N.H. 03842; the Goretex® material from A.W. Gore & Associates, www.gore.com; the Gill 02 Fabric from Gill North America, 1025 Parkway Industrial Park, Buford, Ga. 30581; and the SealSkinz product from Porvair, Estuary Road, King's Lynn, Norfolk, PE30 2HS, United Kingdom.
[0030] The osmotic membrane may be laminated onto a supporting fabric, such as a cloth stump sock.
[0031] An important aspect of the osmotic membrane 100 is that it should have no pores into which the skin of the residual limb 14 may be drawn under the influence of vacuum.
[0032] Optionally, vacuum from the vacuum source may be applied to the space 102 between the osmotic membrane 100 and the liner 92 . Application of vacuum lowers the boiling point of water, allowing perspiration passing through the osmotic membrane 100 to evaporate and be removed from the space 102 .
[0033] Referring to FIG. 3 , the polyurethane tubular sleeve 86 may be appreciated alone and in combination with the urethane liner 92 together with the optional nylon sheath 90 and second stretchable nylon sleeve 94 .
[0034] More specifically, the amputee takes the stretchable nylon second sleeve 94 , suitably made of a spandex-like material and rolls it up over the stump 14 to the upper portions of the residual limb suitably as the thigh of a leg 12 . Next, the polyurethane sleeve 86 is also rolled upwardly over the residual limb 10 . The amputee than places the osmotic membrane 100 over the residual limb 14 . Thereafter, the liner 92 is donned.
[0035] Next, the amputee may optionally utilize the nylon sheath 90 which is suitably of a non-stretching, thin, friction reducing nylon. As stated, this sheath 90 optionally may be used to assist the amputee into a smooth and easy fitting into the socket 60 . Alternatively, the sheath 90 may be avoided and the liner 92 simply inserted into the socket 60 of the artificial limb 50 .
[0036] Next, the amputee simply grasps the rolled over portion of the polyurethane sleeve 86 and rolls it over a substantial portion of the socket 60 . The sleeve 86 makes an airtight seal between the residual limb 14 and the socket 60 .
[0037] As can be appreciated, the polyurethane sleeve 86 is tacky. Consequently, the stretchable nylon second sleeve 94 may be utilized and rolled over the polyurethane sleeve 86 .
[0038] The amputee then sets the regulator means 80 to cause the vacuum source 70 to apply vacuum through the vacuum valve 74 and vacuum tube 76 to the cavity 62 . Enough vacuum is applied to cause the residual limb (with optional coverings) to be drawn firmly against the inner surface 64 of the socket 60 , which is flexible. The vacuum source 70 may preferably maintain a vacuum in the range of 0 to 25 inches of mercury (ideally ten to twenty five inches).
[0039] It will be seen that the vacuum within the socket 60 will cause the hypobarically-controlled artificial limb 50 to be suspended from the residual limb 14 . The vacuum will lock the residual limb 14 into the socket 60 without causing swelling of the residual limb into the socket, because of the total contact of the residual limb 14 with the socket 60 . That is, there is no open chamber between the residual limb 14 and the socket 60 which would draw on the residual limb.
[0040] As the volume of the residual limb 14 decreases during the day due to weight-bearing pressures, the regulator means 80 may appropriately adjust the vacuum source 70 to draw the residual limb 14 more firmly against the socket 60 and thus compensate for the loss of residual limb volume. The vacuum may also partially or completely oppose the loss of fluids from the residual limb caused by weight-bearing pressures.
[0041] The vacuum within the socket 60 is also applied to the space 102 between the osmotic membrane 100 and the liner 92 . Application of vacuum to the space 102 lowers the boiling point of water, causing perspiration wicking through the osmotic membrane to evaporate and be drawn out of the space 102 .
[0042] The vacuum source 70 may be a weight-actuated vacuum pump and shock absorber as disclosed in U.S. patent application Ser. No. 09/534,274, filed Mar. 23, 2000 and herein incorporated by reference.
[0043] To maintain the vacuum in the cavity, either a regulator means 80 , or a weight-actuated vacuum pump and shock absorber as disclosed in U.S. patent application Ser. No. 09/534,274, may be employed.
[0044] The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention. | A system for removing perspiration from a residual limb inserted in a prosthesis comprising an nonporous prosthesis socket, a porous thin sheath adjacent the socket, a nonporous liner adjacent the sheath, an osmotic membrane adjacent the liner allowing water vapor to pass from the limb but preventing liquid from passing to the limb, a nonporous seal that prevents air leakage between the residual limb and the socket; and, a vacuum source to reduce the pressure in a space between the limb and socket. A method of removing perspiration from a residual limb in a prosthesis. | 0 |
BACKGROUND OF THE INVENTION
The invention concerns a process for the manufacture of hydroquinones and more particularly 2, 3, 5 trimethylhydroquinones through the catalytic reduction of the corresponding quinone with hydrogen at low pressures and temperatures.
German patent application publication 1956381 teaches forming hydroquinone derivatives, for example, 2, 3, 5 trimethylhydroquinone through catalytic hydrogenation, using copper chromite catalytic agents, of the corresponding quinone in solution at elevated pressures (80-150 atmospheres) and temperatures (50°-150°C, or higher). As a solvent one can use alcohol (for example, methanol, ethanol, etc.), ether (for example, dioxane) or water. The processing at elevated pressures and temperatures requires complex equipment. The process has the further drawback that the end products are not pure and must be purified through recrystallization in the presence of a stabilizer.
German patent 683908 teaches catalytic hydrogenation of trimethyl-p-quinone in the presence of an organic solvent and a palladium catalyst, to trimethylhydroquinone. Solvents that can be used are ether, glacial acetic acid, dilute acetic acid, toluol alcohol and alcohol, apparently ethanol. In working in accordance with the teaching of this patent with methanol or ethanol one obtains in part very impure end products. These show strong coloration even if a filtrate is separated from the catalyst in the absence of atmospheric oxygen, and evaporated as it is passed through carbon dioxide, as called for in the patent.
In particular during hydrogenation in reaction vessels made of stainless steel one obtains exceptionally strongly colored trimethylquinone caused by the formation of black quinhydrone which makes it impossible to use the end product for further processing as for example in the manufacture of vitamin E. If one uses one of the other solvents called for in patent 683908, then the trimethylhydroquinone resulting from the hydrogenation precipitates and the catalyst becomes encrusted and enclosed and therefore ineffective shortly after starting the process. The same is true in the utilization of aromatic hydrocarbons, for example toluol, aliphatic or cycloaliphatic hydrocarbons alone or mixed with each other, for example, in hexane ligroine and cyclohexane in higher alcohols, for example n-heptanol. Under these circumstances, the high boiling solvents are separated from the end product only with the greatest difficulty.
German patent application publication 1940386 carries out the hydrogenation of trimethyl-p-quinone with hydrogen to trimethylhydroquinone in the presence of an alcohol of 3-5 carbon atoms and at a temperature of 60°-180°C. In this way, the autooxidation, as indicated by the coloration of the end product, is said to be greatly reduced, particularly if one uses branched alcohols of the described type as solvents. However the drawbacks of this process are that the hydrogenation, in contrast to patent 683908, must be carried out at elevated temperatures and that on the basis of the relatively high solubility of the end product in the alcohol used, the starting brine must be used several times. Thereby the impurities are continually enriched, which eventually can lead to a reduction of quality of the trimethylhydroquinone through cocrystallization of by-products, which should particularly be avoided.
It is therefore an important object of the present invention to provide an economical process which will not be characterized by the cited drawbacks and which will lead in particular to very pure and light hydroquinones.
SUMMARY OF THE INVENTION
The process for the fabrication of a substituted hydroquinone, in particular 2, 3, 5 trimethylhydroquinone comprises the catalytic hydrogenation of the corresponding quinone at normal pressures or slightly elevated pressures and at room temperature or slightly elevated temperatures in the presence of a mixture of inert aromatic, aliphatic or cycloaliphatic hydrocarbon solvent and a low, non-branched, aliphatic alcohol in a volume ratio of inert hydrocarbon to alcohol of at least 1 to 1.4 between 0° and 60°C, preferably at 20°-25°C.
The inert hydrocarbon must be fluid under the conditions of the reactions, and is preferably selected from the class consisting of toluene, benzene, hexane, cyclohexane and ligroine. The volume ratio relationship of the inert hydrocarbon solvent to the low alcohol is selected in such a way that the resulting reaction product remains dissolved in the solvent mixture during the reaction. Generally that is the case for a volume relationship of hydrocarbon to alcohol in accordance with Table 1.
Table 1______________________________________ Methanol Ethanol Propanol Isopropanol______________________________________Toluene 1:1 1:1.45 1:1.7 1:1.45Benzene 1:1 1:1.45 1:1.7 1:1.45Hexane -- 1:1.45 1:2.0 1:2.0Cyclohexane -- 1:1.45 1:2.0 1:1.85Ligroine -- 1:1.45 1:2.3 1:2.0______________________________________
In this way the catalyst can be separated from a homogeneous solution after the reaction and the hydroquinone form can be precipitated through the addition of water. In contrast to the process in accordance with the German patent 683908 the separation of the catalyst can be carried out in the presence of atmospheric oxygen so that the need for expensive equipment is thereby avoided.
As catalysts, all known hydrogenation catalysts can be used, e.g. Raney nickel, Raney cobalt, platinum, palladium, ruthenium, rhodium and rhenium catalysts. Preferably they are used as carrier catalysts in the form of 1-5 weight percent catalyst in reference to the carrier material. Examples of usable conventional carriers are carbon and aluminum oxide. In general, one adds the catalyst in an amount of 0.1 to 3.0, preferably 1.5 weight percent in reference to the quinone. In the case of the Raney catalyst, one preferably uses about 10 weight percent in reference to the quinone.
The catalysts can be used several times in sequence. For example, it has been observed that when using the palladium catalyst on carbon (5%) there is no noticeable decrease in activity after the tenth use. The reaction is exothermic and takes place in the region of 0° to 60°C preferably at room temperature (20°-25°C). The quinone is hydrogenated for such a period of time until hydrogen takeup stops of its own accord and in this way the theoretical amount of hydrogen is taken up. The hydrogenation takes place in the region of 1 to 50 atmospheres, preferably at 1 to 8 atmospheres; it can also be carried out continuously, e.g. in reactor tubes or cascades.
For the production of 2, 3, 5 trimethylquinone according to the German publication 1932362, solutions of the quinone in aromatic, aliphatic or cycloaliphatic hydrocarbons are particularly suitable. One adds to these solutions exactly such amount of low alcohol as for example methanol, ethanol, propanol or isopropanol that the end product resulting from the hydrogenation remains in solution. The necessary relationship of the quinone containing solution to alcohol is in accordance with Table 1 above.
The use of such trimethylquinone solutions is particularly economical, because in this way the quinone of itself does not need to be isolated and purified, but it can be hydrogenized in the solution to the end product immediately after its formation.
After completing the takeup of hydrogen, half of the solution mixture is distilled off and the remainder is replaced with an equal amount of 0.5% sodium sulfite solution. In this way the hydroquinone is precipitated as a light precipitate. The yield lies above 90% of the theoretical value. The inert solvent material which separates itself in the filtrate can be re-used in a particularly economical way in the fabrication of new quinone solutions, as for example, in accordance with the German publication 1932362.
Trimethylhydroquinone and 2, 6 dimethylhydroquinone are, for example, important intermediate products for the manufacture of tocopherol (vitamin E), the use of which is described in Ullmann's Encyclopedia of Technical Chemistry Vol. 18, p. 241 (1967).
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The following non-limiting example illustrates the practice of the inventive process.
EXAMPLE 1
350ml, of a toluene solvent, quinone solute, solution, which contained 141.5 grams (0.95 mole) trimethyl-p-quinone, were displaced with 1.5 grams palladium catalyst (2.5%) on carbon and 350 ml methanol in a one-liter stirring pressure reaction vessel of stainless steel. Then the vessel was flushed with nitrogen and then the modified solution was hydrogenized by admitting hydrogen to the vessel and establishing a hydrogen pressure of 4-8 atmospheres and a temperature of 20° to 25°C and stirring until the end of the hydrogen takeup. The duration of hydrogenation was 30 to 40 minutes. Then the hydrogenated material was separated from the catalyst (which was usable for the next charge) and half of the solvent material was distilled off. Into the remainder of the solution 325 ml 0.5% sodium bisulfite solution was dripped while continuously stirring while sucking off liquid from the precipitated trimethylhydroquinone. The precipitate was washed first with 125 ml toluene, then with 250 ml 0.5% sodium bi-sulfite solution and dried in vacuum at 70°C. The toluene which separated off in the filtrate was recycled back into the quinone fabrication. This produced 136 grams of trimethylhydroquinone, equal to approximately 94.3% of the theoretical value. The melting point of the substance produced was 169°-170°C.
EXAMPLE 2
360 ml of a toluene solvent, quinone solute, solution containing 127.5 grams (0.85 mole) trimethyl-p-quinone, were displaced with 15 grams Raney-Nickel and 360 ml methanol in a one-liter stirring pressure reactor vessel of stainless steel. This was hydrogenated at 50°C under a pressure of 30-50 atm. and worked further as described in Example 1.
The yield of trimethylhydroquinone was 122.5 grams which is equal to approximately 95% of theoretical yield. The melting point of the product was 169°-170°C.
EXAMPLE 3
A solution of 237 grams (1.58 mole) trimethyl-p-quinone, dissolved in 400 ml cyclohexane, was displaced with 2.4 grams platinum catalyst on carbon (approximately 5%) and 1120 ml propanol in a two-liter stirring pressure reactor vessel of stainless steel and hydrogenated and worked as in Example 1. The yield of trimethylhydroquinone was 225 grams, (equal to approximately 93.8% of theoretical). The melting point was 169°-170°C.
EXAMPLE 4
A solution of 225 grams (1.5 mole) trimethyl-p-quinone, dissolved in 375 ml hexane, was displaced with 1 gram of rhodium catalyst (5% on carbon) and 750 ml ethanol in a one-liter stirring pressure reactor vessel and hydrogenated and worked as in Example 1. The yield was 219 grams, equal to approximately 96% of theoretical and the melting point was 169°-170°C.
EXAMPLE 5
A solution of 300 grams (2 moles) trimethyl-p-quinone, dissolved in 500 ml benzene, was displaced with 1.5 grams ruthenium catalyst (5% on carbon) and 700 ml methanol in a two-liter stirring pressure reactor vessel and hydrogenated at room temperature at a pressure of 4-8 atmospheres until the end of hydrogen takeup and worked as described in Example 1. The yield was 295 grams, equal to approximately 97% of theoretical and the melting point was 169°-170°C.
EXAMPLE 6
A solution of 136 grams (1 mole) 2,6 dimethylquinone, dissolved in 250 ml toluene, was displaced with 350 ml methanol and 1.0 grams rhodium catalyst (3% on aluminum oxide) and hydrogenated at room temperature and normal pressures to the end of hydrogen takeup. The process was carried out as in Example 1 and the yield of 2,6 dimethylhydroquinone was 133.5 grams, equal to approximately 96.7% of theoretical and the melting point was 150°-152°C.
EXAMPLE 7
A solution of 300 grams (2 moles) of trimethyl-p-quinone, dissolved in 500 ml of ligroine, was displaced with 1.5 grams of palladium catalyst (3% on carbon) and 1400 ml isopropanol in a three-liter stirring pressure reactor vessel and hydrogenized and worked in the manner set out in Example 1. The yield of trimethylhydroquinone so produced was 293 grams, corresponding to 96.4% of theoretical and the melting point thereof was 169°-170°C.
EXAMPLE 8
2, 3, 6-trimethylphenol was dissolved in toluene and sulfonated by addition of concentrated sulfuric acid to the solution in dropwise form and stirring phenolsulfonic acid precipitated in solid form from the solution. A further addition of diluted sulfuric acid to the liquid caused redissolving of the solid phenolsulfonic acid therein. The redissolved phenolsulfonic acid was oxidized by addition of sodium dichromate dissolved in water to the liquid in dropwise form. An organic phase containing the 2, 3, 6-trimethylquinone product produced by oxidation was separated from the liquid and 2 moles of this quinone dissolved in toluene were displaced with 700 ml of methanol and a 1.5 gram of palladium (3% on carbon) catalyst in a two-liter stirring pressure reactor vessel and hydrogenized and worked in accordance with Example 1. The yield was 260 grams, equal to approximately 90% in reference to 95% phenol and the melting point of the end product was 169°-170°C.
EXAMPLE 9
A solution of 136 grams (1 mole) of 2, 3-dimethylquinone, dissolved in 250 ml of toluene, was displaced with 350 ml of methanol and 1.0 gm. rhodium catalysts (3% on aluminum oxide carrier) and hydrogenized and worked according to the procedure of Example 1. The yield of the 2, 3-dimethylhydroquinone thus obtained was 132 grams, equalling approximately 95.5% of theoretical yield, and the product melting point was 218°-220°C.
The following examples are similarly processed as in Example 1.
Example 10:starting material: 2,5-dimethylquinone (1 gram mole)solvent: 250 ml toluenedisplaced by: 350 ml methanolcatalyst: 1.5 gm palladium (2.5% on charcoal)end product yield: 130 gm (93.5% theoretical)melting point: 211-213°C.Example 11:starting material: 2-methyl-5-isopropyl-quinone (1 gram mole)solvent: 250 ml benzenedisplaced by: 350 ml methanolcatalyst: 1.5 gm ruthenium (5% on charcoal)end product yield: 159 gm (95.8% theoretical)melting point: 137-138°C.Example 12:starting material: 2,5-di-tert.-tritylguinone (1 gram mole)solvent: 250 ml toluenedisplaced by: 350 ml methanolcatalyst: 1.0 gm rhodium (3% on aluminum oxide)end product yield: 213 gm (96% theoretical)melting point: 210-212°C.Example 13:starting material: 2-methyl-6 ethyl-quinone (1 gram mole)solvent: 250 ml toluenedisplaced by: 350 ml methanolcatalyst: 2.0 gm platinum (5% on charcoal)end product yield: 144 gm (94.7% theoretical)melting point: 98-100°C.Example 14:starting material: 2,5-dimethyl-3-ethylquinone (1 gram mole)solvent: 250 ml benzenedisplaced by: 400 ml methanolcatalyst: 1.5 gm palladium (3% on charcoal)end product yield: 158 gm (95.2% theoretical)melting point: 160-162°C.Example 15:starting material: 2,3,5,6-tetramethylquinone (1 gram mole)solvent: 250 ml toluenedisplaced by: 400 ml methanolcatalyst: 1 gm ruthenium (5% on charcoal)end product yield: 159 gm (95.8% theoretical)melting point: 226-227°C.
as used herein "%" refers to theoretical value unless otherwise indicated.
We have therefore described in several embodiments a new process which enables the economic production of substituted hydroquinones in high yields through catalytic hydrogenation of their corresponding quinones. Those skilled in the art, once given the benefit of the foregoing disclosure can make additional variations and uses of the herein described process. It is therefore intended that the foregoing disclosure shall be read as illustrative and not in a limiting sense and that the invention is limited only in accordance with the scope and spirit of the appended claims. | Substituted quinones are catalytically hydrogenated in the presence of a mixture of (1) low unbranched alcohols and (2) hydrocarbons which are inert and fluid under the conditions of the hydrogenation reaction and which may be aromatic, aliphatic or cycloaliphatic to economically produce corresponding substituted hydroquinones of high purity and low discoloration and in high yields thereof. | 2 |
BACKGROUND OF THE INVENTION
This invention relates to a vehicle constant speed driving apparatus and, more particularly, to a vehicle constant speed driving apparatus for controlling the opening of a throttle valve by operating a hydraulic (vacuum) actuator having a modulator valve for adjusting pressure by a duty control, such as a rate of operating time.
Conventional modulator valves have had drawbacks that their capacity to adjust pressure varies in response to changes in the voltage of associated power sources and changes in the resistance of solenoids of the modulator valves thereby resulting in deviations in driving speeds. Changes in the voltage of a power source may be compensated for by maintaining at a constant value the voltage applied to a solenoid of a modulator valve, but it is difficult to compensate for the changes in the resistance of a solenoid resulting from changes in the temperature. The latter problem may be solved by maintaining at a constant value the current flowing through a solenoid of a modulator valve, but this is difficult in view of the inductance of the solenoid, because the ON-OFF repetition cycle of the solenoid is fast (ordinarily 20-80 Hz) in a valve system for adjusting pressure by the rate of operating time.
SUMMARY OF THE INVENTION
Therefore, the present invention has for its object to employ the facts that a solenoid of a releasing valve for directing atmosphere into a hydraulic actuator when the releasing valve solenoid releases a constant speed driving is continuously in ON-condition (not causing ON-OFF repeated operation) to isolate the interior of the hydraulic actuator from the atmosphere during the constant speed driving and that the modulator valve solenoid and the releasing valve solenoid are located adjacent to each other to be held in a substantially same thermal condition, so that the current flowing to the releasing valve solenoid is controlled to a constant value and a voltage varied by such constant current control is applied to the modulator valve solenoid to compensate for changes in the temperature and the voltage applied to the modulator valve solenoid, thereby maintaining at a constant value the current flowing to the modulator valve solenoid and thus providing a vehicle constant speed driving apparatus for minimizing a variation in the driving speed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram of an embodiment of the present invention;
FIG. 2 is a graph of the operating characteristics of an actuator according to an embodiment of the present invention;
FIG. 3 is a graph showing the operating characteristics of a modulator valve solenoid and a modulator valve according to an embodiment of the present invention; and
FIG. 4 is a graph showing a relation between errors in the speed and changes in the rate of operating time of a modulator valve solenoid according to an embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1, there is provided a circuit for generating a voltage in response to a vehicle speed referred to by a reference numeral 1 and which includes a thermal lead switch 3 operated by a magnet rotor 2 rotating at a same speed as that of a speed meter cable of the vehicle, the switch being connected at its one end to a ground 4 and at the other end to one end of a diode 5 which, in turn is connected at its other end to one end of each of resistors 7, 8 and a capacitor 9. The other end of the resistor 7 is connected to a constant voltage bus 10 and the other end of the capacitor 9 is connected to the ground 4. The other end of the resistor 8 together with one end each of diodes 12, 13 are connected to an input terminal of NAND gate 11 of a metal oxide semiconductor (MOS) device. The diodes 12, 13 are connected at their other ends to the bus 10 and the ground 4, respectively. Connected to an output terminal of the NAND gate 11 is a capacitor 14 which serves to determine a metastable time of a monostable multivibrator constituted by a resistor 15 connected at its one end to the capacitor 14 and at its opposite end to the bus 10 and by a resistor 16 and a NAND gate 17. A resistor 18 connected to an output terminal of the NAND gate 17 and a capacitor 19 constitute an integrating circuit.
A reference numeral 20 designates a circuit for memorizing a desired target vehicle speed and generating a signal corresponding to a speed differential between the actual speed and the targeted speed, the circuit 20 comprising an input resistor 21, a memory capacitor 22 and a gate of an impedance converting FET 23 connected in series, a drain terminal of FET 23 connected to the constant voltage bus 10 and a source terminal of FET 23 connected to the ground 4 through a resistor 24. A numeral 25 designates an analog switch FET a drain terminal of which is connected to the gate of FET 23, and a source terminal of FET 25 is connected to a connecting point between resistors 26 and 27 for dividing the voltage between the bus 10 and the ground 4. The gate of FET 25 is connected through a resistor 28 to an output terminal of NAND gate 29. Similarly, the output terminal of NAND gate 29 is connected to a connecting point of the resistor 21 and the capacitor 22 through a diode 30 and a resistor 31. An input terminal of NAND gate 29 receives a signal derived through a resistor 32 from a set switch 33 connected at its opposite end to the ground 4 as will be described later. A resistor 34 serves to bias the NAND gate 29 and is connected to the bus 10 and the opposite end of the switch 33. Connected between this opposite end and the resistor 32 is a circuit for suppressing noise comprising a resistor 35, diodes 36, 37 and 38 and a capacitor 39.
A numeral 40 designates a comparator circuit including a voltage comparator 41, a negative input terminal of the comparator being connected through a resistor 42 to the source terminal of FET 23 and its positive input terminal being connected through a resistor 43 to a connecting point between resistors 44 and 45 for dividing the voltage between the bus 10 and the ground 4 and further connected through a resistor 46 and a diode 47 to the set switch 33. A capacitor 48 connected across the input terminals of the comparator 41 serves to suppress noises. An output terminal of the comparator 41 has connected thereto one end of a load resistor 49 the other end of which is connected to the bus 10. A numeral 50 designates a circuit for generating a negative feed-back signal and which comprises a resistor 51 connected to the output terminal of the comparator 41, a capacitor 52 for integration and a resistor 53 for feeding back the integration output to the connecting point between the resistor 21 and the capacitor 22. A connecting point between the resistor 51 and the capacitor 52 is connected to the set switch 33 through a resistor 54 and a diode 55.
A numeral 60 designates a power source circuit which is of a known arrangement and includes a diode 58 for absorbing an inverse voltage from a power source supplied from a battery 56 through a main switch 57, a capacitor 59 for suppressing noises and a constant voltage circuit comprising a transistor 61, a Zener diode 62, resistors 63, 64 and a capacitor 65 for suppressing ripples.
A numeral 70 designates a power amplifier including a constant current circuit and connecting the output of the comparator 41 through a resistor 66 to a base of a transistor 67.
Transistors 68, 69 and a resistor 136 constitute a constant current circuit the value of the current of which is determined by the resistor 136. A base of a transistor 137 is connected through a resistor 138 to the ground 4 and also through a resistor 139 to a collector of a transistor 73, and an emitter of the transistor 137 is connected to the ground 4 and a collector of the transistor 137 is connected through resistors 140, 141 to a power source line 120. A connecting point between the resistors 140 and 141 is connected with a base of a transistor 142 an emitter of which is connected to the line 120 and a collector of the transistor 142 is connected to through a resistor 143 to the base of the transistor 68 and to the collector of the transistor 69. The emitter of the transistor 67 is connected to the ground 4 and its collector is connected through a resistor 144 to a connecting point of the emitter of transistors 68, 145 the base of the transistor 69 and the resistor 136. The emitter of the transistor 68 is connected through the resistor 136 to one end a releasing valve solenoid 84 of a vacuum actuator 100. The emitter of the transistor 69 is connected to the opposite end of releasing valve solenoid 84.
A numeral 80 designates a self-holding circuit which comprises a bi-stable multivibrator including transistors 71, 73, a collector of the transistor 71 being connected to the base of the transistor 73 through resistors 74, 75 and a diode 76. The collector of the transistor 73 is connected to the base of the transistor 71 through resistors 77, 78 and a diode 79. The bases of the both transistors 71, 73 are further connected to the ground 4 through resistors 81, 82. A capacitor 83 is connected between the ground 4 and a connecting point between the resistors 77 and 78. Furthermore, the collector of the transistor 71 is connected to the bus 10 through a resistor 146. A resistor 85 is connected between the collector of the transistor 73 and the bus 10. Diode 86 is connected between the collector of the transistor 73 and the base of the transistor 67. Diode 135 is connected between the collector of the transistor 73 and the integrated signal level of capacitor 52 and further through diodes 87, 88, 89 to a stop switch 91, a clutch switch 92 and a parking brake switch 93, respectively.
A numeral 90 designates a set and releasing signal circuit in which resistors 94, 95 and capacitor 96 are connected in series between the bus 10 and the ground 4, a connecting point between the resistors 94 and 95 being connected through a diode 97 to one end of a stop lamp 98 and to the stop switch 91, and a connecting point between the resistor 95 and the capacitor 96 being connected to the base of the transistor 73 through a diode 99 and a resistor 101. A connecting point between the stop switch 91 and the diode 87 is connected through a fuse 102 to the battery 56 and also through a resistor 103 to the ground 4. The connecting point between the resistor 75 and the diode 76 is connected through a diode 104 to a resume switch 106 and through a diode 105 to the set switch 33. The set switch 33, the clutch switch 92, the parking brake switch 93 and the resume switch 106 are of a normally open type and are connected at their one end to the ground 4. The stop lamp 98 is also connected at its opposite end to the ground 4.
A numeral 110 designates a low limiter circuit comprising a resistor 107 connected to the capacitor 19 which is the output end of the circuit 1, a resistor 108 connected to the bus 10, a NAND gate 109 receiving an input from a connecting point between these resistors and its output being connected through a diode 111 and a resistor 112 to the base of the transistor 73.
The vacuum actuator 100 is described in detail below.
A diaphragm 114 is sealingly mounted on a housing 113 to form a pressure chamber 115 within the housing 113. Disposed within the pressure chamber is a pressure plate 118 fixed to the diaphragm 114 by a rivet 117 having an output end 116. A compression spring 119 is provided between the pressure plate 118 and an inside of the housing 113 to exert a force on the diaphragm 114 always to urge it in the leftward direction as viewed in the drawing.
A numeral 121 designates a releasing valve normally separated by a spring 122 from a valve seat 123 provided on the housing 113, the releasing valve 121 being for communicating between the pressure chamber 115 and the exterior (atmosphere). When the releasing valve solenoid 84 is energized, the releasing valve 121 is engaged with the valve seat 123 to interrupt the communication between the chamber 115 and the atmophere. The solenoid 84 is connected at its one end to the emitter of the transistor 69 and at the other end to the ground 4. A diode connected between the opposite ends of the solenoid 84 serves to absorb surging.
A numeral 125 designates a modulator valve interposed between a vacuum nozzle 126 and an atmosphere nozzle 127, the vacuum nozzle 126 being for introducing a negative pressure from an intake manifold 130 of the engine. The modulator valve 125 is normally closed against the vacuum nozzle 126 by a spring 128, thereby normally keeping open the atmosphere nozzle 127. When the modulator valve solenoid 72, held in the same enviromental condition (thermally joined) as that of the releasing valve solenoid 84, is energized, the vacuum nozzle 126 is opened and the atmosphere nozzle 127 is closed. The solenoid 72 is connected at its one end to the collector of the transistor 145 and at the other end to the ground 4. A diode 129 for absorbing surging is connected to the opposite ends.
The output end 116 of the vacuum actuator 100 is connected by a chain 131 and the like to a lever 133 for displacing a throttle valve 132 so that when the diaphragm 114 moves in the rightward direction as viewed in the drawing the throttle valve 132 is open. Spring 134 functions as a return spring for the valve 132.
The operation of the apparatus of the present invention will now be described.
When the main switch 57 is closed, the power is supplied through the line 120 to the power source circuit in which the inverse voltage is absorbed by the diode 58 and noises of relatively high frequency are absorbed by the capacitor 59. If the voltage supplied through the negative voltage resistor 63 to the constant voltage bus 10 is higher than the Zener voltage of the Zener diode 62, the transistor 61 increases its conductivity to lower the voltage of the bus 10, and if the voltage of the bus 10 is lower than the Zener voltage, the conductivity will be reduced to increase the voltage of the bus 10. In this manner, the voltage of the bus is maintained at a constant value. The capacitor 65 absorbs a ripple. Since the magnet rotor 2 is rotated at a speed in proportion to the vehicle speed during driving, the switch 3 is repeatedly closed and opened to generate so-called speed responsive pulses in proportion to the speed of the vehicle.
By the ON-OFF operation of the switch 3, the voltage at the connecting point between the resistor 7 and the capacitor 9 is varied towards the voltage of the bus 10 and towards the voltage of the ground 4. This voltage is then supplied through the resistor 8 to the NAND gate 11 and thus the output thereof is changed to the voltage of the bus 10 or "H" level and to the voltage of the ground 4 or "L" level. The capacitor 9 serves to absorb the effect of chattering in a short time when the switch 3 closes, and the diodes 12, 13 serve to protect the NAND gate 11 from the surge voltage.
The timer circuit comprising the capacitor 14 and the resistor 15 adjusts the time in which when the output of NAND gate 11 turns to "L" the input of NAND gate 17 turns to "L" through the resistor 16 and thereafter the input voltage of NAND gate 17 attains the threshold voltage through the resistor 15. This time is substantially constant and for every opening and closing of the switch 3 the input of NAND gate 17 turns to "L" for a predetermined period and the output of NAND gate 17 turns to "H". Since resistors 15, 16, and NAND gate 17 together act as a monostable multivibrator, by integrating the output of NAND gate 17 with the resistor 18 and capacitor 19 the voltage across the capacitor 19 is proportional to the ON-OFF cycle of the switch 3, and thus is proportional to the speed of the vehicle.
The circuit 20 for generating an error signal between a memorized speed and the actual speed receives the output of the circuit 1 for generating the speed responsive voltage through the resistor 21. When memorizing the vehicle speed, as the set switch 33 closes the input of NAND gate 29 which has been at "H" through the resistors 34, 35, 32 turns to "L" level. As a result, the output of NAND gate 29 turns to "H", so that the gate of FET 25 will turn to "H" through the resistor 28. Thus, FET 25 becomes conductive so that a source voltage, which is the voltage of bus 10 divided by the resistors 26, 27 is applied to the capacitor 22 and the gate of FET 22.
If this source voltage is defined as a reference voltage "C", a voltage "A-C", determined by substracting the reference voltage "C" from a speed responsive voltage "A", is held by the memory capacitor 22. The gate voltage of FET 23 is held at "C" and this voltage is impedance converted and picked up as the source voltage of FET 23 connected with a source follower. When the switch 33 is open, the input of NAND gate 29 becomes "H" and the output becomes "L" and thus the gate of FET 25 becomes "L" to shut off FET 25. At the same time, the cathode of the diode 30 becomes "L", so that the voltage "A" applied across the memory capacitor 22 varies to a voltage "B" (B<A), which is a speed responsive voltage divided by the resistors 21, 31, and the voltage of the gate of FET 23 becomes a value determined by substracting a voltage "A-B" from the voltage "C", namely "C-(A-B)". The gate voltage and source voltage of FET 23 are substantially equal to each other and thus the voltage "C-(A-B)" will be suppied as an output from the source of FET 23, as far as the vehicle speed varies.
If the vehicle is on a down slope and when the actual speed increases to increase by a value "a" the speed responsive voltage at the point between the resistor 21 and the capacitor 22, the voltage across the capacitor 22 is not varied and is held at "(A-C)" and thus the gate and source of FET 23 assume a voltage "C (A-B)+a". Therefore, the source voltage of FET 23 is increased by a voltage corresponding to the increase in the vehicle speed. If the vehicle is on a up slope and when the actual speed decreases, the source voltage of FET 23 will be descreased in response thereto. In this manner, the circuit 20 refers to the source voltage of FET 23 when memorizing a desired vehicle speed and serves to increase the output voltage when the speed increases and decrease the output voltage when the speed decreases.
The comparator circuit 40 is supplied at the positive input terminal of the voltage comparator 41 through the resistor 43 with a constant voltage produced by dividing the voltage of bus 10 by the resistors 44, 45. The negative input terminal is supplied through the resistor 42 with the source voltage of FET 23. The output of the comparator 41 is "H" if the voltage applied to the positive input terminal is higher than that of the negative input terminal and is "L" when the applied voltage of the former is lower than that of the latter. The transistors 67, 145 of the power amplifier 70 operated by this output are in ON-condition when the output of the comparator 41 is "H" and in OFF-condition when that output is "L". If the voltage divided by the resistors 44, 45 is set at a level a little higher than the voltage "C-(A-B)" just after memorizing the vehicle speed, the voltage applied to the positive input terminal of the comparator 41 will be higher than that applied to the negative input terminal and the transistor 67 will be biased to be in ON-condition.
The self-holding circuit 80 is operated such that when the main switch 57 closes the base current flows through the transistor 73 by way of the resistor 146, the resistor 74, the diode 76 and the resistor 75 and instantaneously the transistor 73 turns on. On the other hand, the base current is to flow through the transistor 71 by way of the bus 10, the resistors 85, 77, 78, and the diode 79, but the base current of the transistor 71 is delayed by the capacitor 83 so that it does not turn on prior to the transistor 73. Actually, if the transistor 73 turns on prior to the transistor 71, the transistor 71 continues to be off and the transistor 73 to be on.
While the transistor 73 is held in ON-condition, the current to flow through the resistor 66 to the base of the transistor 67 flows through the diode 86 and the transistor 67 does not turn on even if the output of the comparator 41 is "H". When the set switch 33 or the resume switch 106 closes, the voltage applied to the base of the transistor 73 through the diode 105 or 104 is reduced to prevent the flow of the base current so that the transistor 73 turns off and the collector voltage is increased to cause the flow of the base current through the transistor 71 by way of the resistors 77, 78 and the diode 79 and thus the transistor 71 turns on. When the transistor 71 turns on, the base current does not flow through the transistor 73 and this condition is maintained in which the transistor 71 is on and the transistor 73 is off (even if the set switch 33 and resume switch 106 are open). In this condition, the base current of the transistor 67 is not absorbed through the diode 86 and the transistor 67 will turn on, if the base current flows.
By turning off the transistor 73, the base current is directed to the transistor 137 through the resistors 85, 139 thereby turning on the transistor 137. As a result, current flows from the resistor 140 through the transistor 137 to turn on the transistor 142. This results in the flow of base current through the resistor 143 to the transistor 68 to turn on the transistor 68, thereby causing the flow of current through the resistor 136 to the releasing valve solenoid 84 so that the releasing valve 121 is magnetically attracted against the action of the spring 122 to sealingly engage the valve seat 123.
Since it is designed that immediately after the vehicle speed has been memorized, the positive input terminal of the voltage comparator 41 is supplied with a voltage a little higher than that of the negative input terminal, the output of the comparator 41 becomes "H" and the transistors 67, 145 turn on to energize the modulator valve solenoid 72 so that the modulator valve 125 is operated to open the vacuum nozzle 126 against the action of the spring 128 and close the atmosphere nozzle 127. Consequently, the negative pressure in the intake manifold 130 is introduced into the pressure chamber 115 of the vacuum actuator 100 and thus the pressure differential between this pressure and the atmospheric pressure on the left side of the diaphragm 114 generates a force urge the compression spring 119 in the rightward direction. This force is transmitted through the chain 131 to the throttle valve 132 to open the latter and this condition is maintained by the vacuum actuator 100, even if an accelerator (not shown) is not operated by the driver. The operation of the vacuum actuator 100 is determined by the negative pressure within the pressure chamber 115. This negative pressure is determined by the volume of the pressure chamber 115, the rate of restriction of the vacuum nozzle 126 and the time for which the nozzle 126 is open. The negative pressure generated in the intake manifold 130 during a constant speed driving is not largely varied. Therefore, a longer time of energization of the modulator valve solenoid 72 causes a larger opening of the throttle valve 132.
The signal of this energization time is produced by the negative feed-back signal generating circuit 50 in which the output of the voltage comparator 41 is integrated by the resistor 51 and the capacitor 52. The output thereof is fed back through the resistor 53 to the connecting point of the memory capacitor 22 and the resistor 21 so that when, for example, the vehicle speed is lowered below the memorized speed the voltage applied through the resistor 21 to the capacitor 22 is lowered to reduce the gate and source voltages of the FET 23 and the negative input voltage of the comparator 41, and the output of the comparator 41 is turned to "H". At this time, the modulator valve 125 opens the vacuum nozzle 126 and the throttle valve 132. In this condition, if the opening of the throttle valve 132 is discontinued when the vehicle speed has attained the memorized speed, the vehicle speed will excessively increase, because the vehicle is being accelerated and the throttle valve is largely opened. When the speed has excessively increased, the modulator valve 125 acts to close the vacuum nozzle 126 and open the atmosphere nozzle 127 and if the opening of the atmosphere nozzle 127 is discontinued when the vehicle speed has attained the memorized speed, the vehicle speed will excessively decreases, because the vehicle is being decelerated and the throttle valve is extremely throttled. Therefore, a hunting phenomenon is caused in the operation and the apparatus is unavoidable as a constant driving apparatus and the feeling is also bad.
These problems are effectively solved by the negative feed-back signal generating circuit 50. For example, when the vehicle speed is lowered, the output of the comparator 41 turns to "H" to energize the modulator valve solenoid 72, thereby gradually increasing the voltage of the integrating capacitor 52. This voltage is added through the resistor 53 to the vehicle speed responsive voltage and thus, before the actual speed attains the memorized or targeted speed, a signal for indicating that the vehicle speed is already increased is caused to suppress the acceleration thereby preventing over-acceleration above the memorized speed.
In the event that the speed is excessively increased, the output of the comparator 41 turns to "L" to de-energize the modulator valve 72 thereby displacing the throttle valve towards its closing position and the integrated voltage of the capacitor 52 is also reduced before the vehicle speed is lowered to the memorized speed so that the voltage of the point between the capacitor 22 and the resistor 21 corresponds to the signal that the vehicle speed is already lowered to the memorized speed.
In this manner, control can be initiated before the vehicle speed attains the targeted or memorized speed, or the control can be made to have an advanced phase relative to the actual vehicle speed, and thus over-acceleration and over-deceleration of the vehicle can be prevented.
The operation of the power amplifier 70 will be described in detail below.
Since the output of the circuit 10 contains a little ripple, the output of the circuit 50 also contains a ripple caused by integrating the ON-OFF signals of the comparator 41 and the voltage applied to the negative input terminal of the comparator 41 contains a little ripple, the output of the comparator 41 is rapidly and repeatedly turned to "H" and "L". Such output of the comparator 41 is applied to the modulator valve solenoid 72 through the resistor 66 and the transistors 67, 145. Therefore, in the modulator valve 125 in which the duty control is made by the relatively rapid ON-OFF repetition in response to the output of the comparator 41, its characteristic for adjusting the pressure is varied by the voltage applied to its solenoid 72 and the resistivity of the solenoid 72 itself. This will be described with reference to FIG. 2.
A solid line A shows the pressure adjusting characteristic of the modulator valve 125 measured in room temperature and under the condition of the defined voltage having a repetition frequency, the characteristic being the ratio of the rate of the energization period and the pressure-adjusting pressure. However, when the voltage applied to the modulator lowers or the resistance of the solenoid 72 itself increases (the solenoid being ordinarily made of a copper wire having a temperature-resistance factor which increases as the temperature rises), an increase has to be made in the rate of the energization period to provide a same pressure-adjusting pressure (for example, 2/4P, that is 50% of the supplied pressure) as shown by a dash line B in the drawing. When the voltage increases or the resistance of the solenoid 72 lowers, the rate of the energization period to provide a same pressure-adjusting pressure has to be lowered as shown by a dot-and-dash line C.
Describing this more in detail, when the signal of the rate of the energization period (40%) shown in FIG. 3(a) is applied to the modulator valve solenoid 72, if the voltage of the power source is high or the resistance of the solenoid is small, current flows through the solenoid 72 as shown in FIG. 3(b), so that the modulator valve 125 is operated by the operating current I 1 and returned by the returning current I 2 of the modulator valve 125. This condition is shown in FIG. 3(d). The modulator valve 125 takes about 38% of the operating time. If the voltage applied to the modulator valve solenoid 72 lowers or the resistance of the solenoid 72 increases, the current flowing through the solenoid 72 will be as shown in FIG. 3(c) Nevertheless, the signal shown in FIG. 3(a) is added to the solenoid 72, and the operating time of the modulator valve 125 is only about 34% as shown in FIG. 3(e).
The rate of the energization period of the modulator valve solenoid 72 becomes larger as the vehicle speed lowers, and the deviation in the speed from the determined speed and thus the variation in the ratio of the speed error and the energization time are in the relation as shown in FIG. 4, as an example. In such an example, the rate of the energization time varies by 10% for every 4 km/h variation in the speed. If there are 38% and 34% of the operating time of the modulator valve 125 as described above, the difference is 4% and the corresponding difference in the speed is 1.6 km/h. Assuming that, for example, the vehicle is driven at a speed of 80 km/h at which the constant speed apparatus is, in turn, operated to provide zero error in such a condition of the modulator valve 125 as is shown in FIG. 3(d), the driving speed will be lowered to cause a difference of about 1.6 km/h, because the temperature around the attachment of the modulator valve increases to increase the resistance of the solenoid 72.
To avoid this speed error, the constant current circuit is operated and when the resistance of the releasing valve solenoid 84 is low or when the voltage of the power source is high the current flowing through the solenoid 84 passes through the resistor 136, so that when the rate of flow of the current increases the voltage across the resistor 136 is increased to render the transistor 69 more conductive to lower the base and emitter voltages of the transistor 68 thereby reducing the rate of flow of the current through the releasing valve solenoid 84 to maintain it at a determined value. If the voltage of the power source lowers or the resistance of the solenoid 84 increases, the reduction in the rate of flow of the current through the resistor 136 acts to operate the transistor 69 towards its non-conductive condition to increase the base and emitter voltages of the transistor 68 thereby maintaining the rate of flow of the current through the releasing valve solenoid 84 at a constant value. Since the releasing valve solenoid 84 and the modulator valve solenoid 72 are in a substantially same environmental condition and in a same temperature condition, a switching operation of the transistor 145 is caused by the emitter voltage of the transistor 68 to energize the modulator valve solenoid 72 through the emitter and collector of the transistor 145, so that its energization current (the saturated current when energized) is maintained at a substantially constant value to remove the adverse effects of changes in the voltage of the power source and changes in the resistance of the modulator valve solenoid 72. Therefore, the deviation in the driving speed due to the changes in the temperature is minimized to provide a precise and constant speed driving.
During closure of the set switch 33, the voltage of the positive terminal of the comparator 41 is lowered below that of the negative terminal by the diode 47 and the resistor 46 so that the output of the comparator 41 is turned to "L" and the modulator valve solenoid 72 is not energized and thus the pressure in the pressure chamber 115 of the vacuum actuator 100 is the atmospheric pressure to close the throttle valve 132 and reduce the vehicle speed. The vehicle speed is memorized instantaneously with opening the set switch and therefore, a so-called deceleration setting operation can be accomplished in which the set switch is held in its closed condition and thereafter it is opened to decelerate the vehicle speed to make the memory setting. At this time, the charges of the integrating capacitor 52 are cleared through the diode 55 and the resistor 54.
The output of the comparator 41 controls the rapid repetition of "H" and "L", and makes a so-called duty control so that, when the vehicle speed lowers, the time of "H" becomes longer than that of "L". This repeated cycle is substantially equal to the pulse responsive to the vehicle speed, is relatively rapidly repeated so that the pressure in the pressure chamber 115 of the vacuum actuator 100 is hardly varied by the effect of integration of its volume, and is responsible for the duty of operating the modulator valve 125. A voltage responding to this duty is applied across the capacitor 52. This integrated voltage is added to the speed signal and applied to the capacitor 22 through the resistor 53 so that when the switch 33 closes for a short time the value of the resistance is not extremely reduced When the time constant of the resistor 54 and the capacitor 52 is selected to about 1-2 seconds the voltage of the actual speed through the resistor 21 plus the voltage of the negative feed-back through the resistor 53 is memorized as a vehicle speed signal when setting the vehicle speed memory. Thus a speed higher than the actual speed is memorized, contrary to the ordinary setting of the vehicle speed (deceleration setting) described hereinabove. If this operation (the short time closing of the set switch) is repeated, an acceleration setting can be accomplished wherein the memorized speed is progressively increased. The degree of increase in the speed at this time becomes large as the period of closure of set switch 33 is short. When the period of closure of the set switch 33 is long, the capacitor 52 is discharged through the resistor 54 and diode 55 and is not added to the vehicle speed responsive voltage, thereby setting the deceleration. The timing of closure of the set switch makes it possible to perform deceleration setting, acceleration setting and the adjustment of their degrees. In order to release the automatic driving during the constant speed driving, the stop switch 91, or the clutch switch 92 and the parking brake switch 93, may be temporally closed.
When the stop lamp switch 91 is closed, the current which is flowing from the bus 10 through the resistor 94 and diode 97 to the stop lamp 98 flows through the resistor 95, the diode 99 and the resistor 101 to the base of the transistor 73. Transistor 73, in turn, turns on to turn off the transistor 71 and makes the releasing valve solenoid 84 non-conductive. The releasing valve 121 disengages from the valve seat 123 to bring into communication, through a relatively large diameter opening, the pressure chamber 115 of the vacuum actuator 100 and the atmosphere outside thereof, thereby rapidly filling the pressure chamber 115 with the atmosphere to return the diaphragm 114 under the action of the spring 119 to rapidly close the throttle valve 132. At the same time, the base current of the transistor 67 flows through the diode 86 to the collector of the transistor 73. Furthermore, the charges of the integrating capacitor 52 are cleared by the diode 135 to make ready for the subsequent vehicle speed selection or resume operation. The capacitor 96 of the brake releasing line serves to absorb noises conveyed through wires to the stop lamp and other devices.
When the clutch switch 92 and parking brake switch 93 are closed, the current to flow through the diode 86 to the base of the transistor 71 is absorbed to turn off the transistor 71 and turn on the transistor 73 and such condition is held. If the actual vehicle speed lowers below the defined value due to the operation of the low limit circuit 110, the input voltage of the NAND gate 109 becomes lower than the threshold voltage to turn its output to "H". Thus the base current flows through the diode 111 and the resistor 112 to turn on the transistor 73 as in the case of the stop switch 91 being closed. In this manner, even if there is no output of the vehicle speed responsive voltage generating circuit 1 for sensing the vehicle speed, the automatic releasing will be accomplished without causing excessive over driving. The stop switch 91 most frequently utilized in the releasing operation is provided with fuse 102. If this fuse is broken down, no base current will flow through the transistor 73, even when the stop switch 91 is closed. However, the base current of the transistor 71 will be absorbed through the diode 87 to make an automatic releasing.
After the operation of the brake and clutch has been released, when it is desired to make again the automatic driving at the speed before such releasing, the resume switch 106 is temporally closed. The resume switch 106 absorbs the base current of the transistor 73 through the diode 104, thereby turning off the transistor 73 and turning on the transistor 71 to energize the releasing valve solenoid 84. The ON-OFF operation of the transistor 67 is caused in response to the output of the comparator 41 to energize the modulator valve solenoid, thereby maintaining the vehicle speed at the desired value.
As described above, the present invention brings forth remarkable effects in that the driving speed is affected neither by changes in the voltage of the power source nor by changes in the temperature. Thus precise and good constant speed driving can be accomplished.
It should be understood by those skilled in the art that although various circuits, such as the speed memory circuit and the error signal generating circuit, and the analog circuit are used in the embodiment described above, the present invention can easily be practiced by using a digital control. | Vehicle constant speed driving apparatus including a solenoid of a releasing valve for directing atmosphere into a hydraulic actuator when the releasing valve solenoid releases a constant speed driving which is in ON-condition (not causing ON-OFF repeated operation) in order to isolate an interior chamber of the hydraulic actuator from the atmosphere during the constant speed driving, and a modulator valve solenoid located adjacent to a releasing valve solenoid so that both solenoids are held in a substantially same thermal condition. The current flowing to the releasing valve solenoid is controlled to a constant value and a voltage varied by such constant current control is applied to the modulator valve solenoid to compensate for changes in the temperature of and the voltage supplied to the modulator valve solenoid, thereby maintaining at a constant value the current flowing to the modulator valve solenoid and providing a vehicle constant speed driving apparatus for minimizing a variation in the driving speed. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 62/279,706 filed on Jan. 16, 2016, entitled “Fire Control Mechanism for Striker-Fired Pistols with Enhanced Safety Features,” which is hereby incorporated by reference in its entirety for all that is taught and disclosed therein.
BACKGROUND AND SUMMARY
[0002] The present invention relates to the improvement of trigger pull characteristics and mechanical safety of certain striker fired pistols which incorporate a pivoting sear to hold back the striker, and which is actuated by a trigger bar.
[0003] Certain striker-fired pistols such as the SIG SAUER® P320 incorporate a pivoting sear in the frame or receiver. This sear is spring loaded to interpose the sear face before the striker, thus holding it back in a cocked position against the substantial tension of the striker spring and positive engagement angles, unless and until the sear is rotated to free the striker and permit it to travel forward as it normally would to fire a primed cartridge.
[0004] The sear must present adequate engagement to the striker, and be sufficiently sprung, as to provide an objective measure of mechanical resistance to releasing the striker if the pistol is dropped or jarred. Certain pistol designs are dependent upon positively angled sear engagement surfaces and substantial sear spring tension to hold the striker and sear in engagement with an acceptable margin of mechanical safety.
[0005] During the normal sequence of operation, actuation of the sear to discharge the pistol is effected by the action of a trigger bar which transmits pressure and movement of the trigger to a leverage point on the sear. Pressure applied to the trigger must overcome the resistance of the sear engagement and springs to rotate the sear, defeat the striker safety lock mechanism, release the striker, and thus discharge the pistol. That sear engagement and springing have a direct effect upon both measurable and subjective trigger pull weight and feel, and therefore certain service pistols like the P320 are designed with relatively heavy trigger pulls measuring well above 6 pounds.
[0006] Competitive marksmen and other discerning or elite pistol users often prefer lighter trigger pulls with less perceived movement of the sear engagement and a more cleanly defined sear release feel as a demonstrable aid to precision marksmanship. Conventional methods of achieving a more preferable trigger pull typically involve reduced sear engagements, altered sear angles and reduced sear and striker springs to thus reduce both measurable and perceived trigger pull weight, and enhance subjective feel. Such methods typically compromise the original design's margin of mechanical safety against accidental mishandling or extreme use, if not eliminating that margin altogether. More sophisticated methods for achieving improved trigger qualities are typically not cross and reverse compatible within the applicable model line and involve custom tuning, limiting the practical utility of same as drop-in kits or for mass production as a factory-installed system.
[0007] This invention comprises a set of fire control components which may be configured to reduce trigger pull weight, enhance the subjective feel of the trigger pull, and improve the shooting qualities of the applicable pistol, while providing simple mechanisms to improve the system's mechanical reliability and safety values related to resistance to unintentional discharge from being dropped, jarred or otherwise mishandled.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a side view of the invention according to a preferred embodiment.
[0009] FIG. 2 is a side view of the invention according to a preferred embodiment.
[0010] FIG. 3 is a side view of the invention according to a preferred embodiment of the invention.
[0011] FIG. 4 is a side view of the invention according to a preferred embodiment of the invention.
[0012] FIG. 5 is a side view of a preferred embodiment of the invention.
[0013] FIG. 6 is a side schematic view of a preferred embodiment of the invention.
[0014] FIG. 7 is a side schematic view of a preferred embodiment of the invention.
[0015] FIG. 8 is a side schematic view of a preferred embodiment of the invention.
[0016] FIG. 9 is a side schematic view of a preferred embodiment of the invention.
[0017] FIG. 10 is a side schematic view of a preferred embodiment of the invention.
[0018] FIG. 11 is a left side isometric view of a preferred embodiment of the invention.
[0019] FIG. 12 is a bottom left side isometric view of a preferred embodiment of the invention.
[0020] FIG. 13 is a right side isometric view of a preferred embodiment of the invention.
[0021] FIG. 14 is a bottom right side isometric view of a preferred embodiment of the invention.
[0022] FIG. 15 is a right side isometric view of a preferred embodiment of the invention.
[0023] FIG. 16 is a top isometric view of a preferred embodiment of the invention.
[0024] FIG. 17 is a side isometric view of a preferred embodiment of the invention.
[0025] FIG. 18 is an isometric bottom view of a preferred embodiment of the invention.
[0026] FIG. 19 is an isometric view of a preferred embodiment of the invention.
[0027] FIG. 20 is a side isometric view of a preferred embodiment of the invention.
[0028] FIG. 21 is a schematic view of a preferred embodiment of the invention.
[0029] FIG. 22 is a schematic view of a preferred embodiment of the invention.
[0030] FIG. 23 is a schematic view of a preferred embodiment of the invention.
[0031] FIG. 24 is a schematic view of a preferred embodiment of the invention.
[0032] FIG. 25 is a schematic view of a preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0033] This invention is a fire control mechanism for the SIG SAUER® P320 with operating principles applicable to other pistol models, comprised of the following components:
[0034] A) Sear, with enhanced sear face geometry and reset timing, and novel drop-safety-cam features. ( FIGS. 1, 2 ).
[0035] B) Trigger, with features to enhance trigger bar leverage, and interchangeable trigger shoes. ( FIGS. 3, 4 ).
[0036] C) Trigger bar control cam plate, novel design which controls the movement of the trigger bar to keep it in engagement with the sear safety cam ( FIG. 5 ).
[0037] D) Disconnector, novel design which controls the movement of the trigger bar, provides trigger bar disconnect function, and thus provides for shorter net trigger reset travel as a reverse-compatible alternate embodiment within the invention system ( FIG. 6 ).
[0038] E) Limit ring and sear housing pin assembly, which limits trigger pretravel, controls the vertical movement of the trigger bar in it's at-rest position, prevents disassembly of the trigger and bar without tools. Plus, an alternate design. ( FIG. 7 )
[0039] F) Over travel stop pin tube; used with the disconnector option to time and reduce trigger overtravel after striker release.
[0040] G) Safety lever and sear pins, designed to properly locate and retain components of the invention.
[0041] H) Sear and trigger bar springs, designed to be installed in various specific combinations to yield predictable trigger pull weights within a predetermined range.
[0042] Sear. The safety-cam sear is at the heart of the invention. Its design features provide the essential functional qualities and attributes which yield superior trigger pull characteristics and reduced pull weight, while enhancing reliability and mechanical safety values necessary for the safe use of the pistol. It is made from tool steel, optimally heat treated to resist wear and failure, polished and treated to provide a low coefficient of friction. Its elements include:
[0043] Safety-cam device (element 2 ), which connects the sear to the trigger bar and thus transmits trigger bar spring tension directly to the sear. This tension augments the upload exerted upon the sear by the sear spring(s), thus increasing the load required to rotate the sear down out of its resting position of engagement with the striker when cocked and the trigger is forward, as would be the condition of the fire control mechanism if the pistol were to be dropped whilst cocked. Downward rotation of the sear, as required to release the striker, is impeded by the relatively poor leverage this cam surface applies to the trigger bar, which is driven forward and down against substantial spring tension as the sear rotates out of engagement. The cam is shaped to drive the trigger bar down and forward at an optimum angle in relation to the vertical axis of the receiver, thus preventing it from rotating the safety lever upwards, and preventing it from defeating the striker safety lock. In a modified sear housing, this cam can have substantially greater engagement with the trigger bar, but is not necessary for function as claimed.
[0044] Maximum-engagement sear face (element 4 ). This sear profile features significantly increased total sear engagement over the original factory sear. This increased standing sear face engagement accomplishes several important functions. It compensates for the considerable vertical clearance between the P320 slide and frame, and between the striker housing and slide assembly, each of which introduces an inconsistent gun-to-gun variable in net sear to striker engagement, thus preserving safely adequate engagement in worn and out of spec pistols. This increased engagement requires a correspondingly greater arc of rotation for the sear to release the striker, and a correspondingly greater dislocation of the trigger bar under tension, thus enhancing the drop-safe benefit provided by the cam-safety device.
[0045] This increased engagement is more resistant to any tendency for the striker to push it out of the way as it hits the sear when the action closes into battery during normal operation of the pistol's action. The longer arc of rotation required for the sear to release the striker assists in the proper timing of trigger bar release and reset, placing the striker release and trigger bar release points closer together relative to trigger travel, thus opening the critical tolerances for the sear to trigger bar relationship to a consistently attainable dimension for production.
[0046] Sear face with leverage change (element 6 ). When fully rotated up into full engagement, this sear face profile presents the contacting surface of the striker with a virtually neutral angle relative to its pivot point. Thus, unlike the stock sear, this sear does not significantly cam the striker back against its spring tension as it begins its downward rotation. This greatly reduces the weight of this initial sear travel; as she presses the trigger to the rear to release a shot, the operator perceives this initial sear travel as blending innocuously into trigger pre-travel, rather than as disagreeable “creep” normally associated with increased sear engagements. This initial neutral engagement is engineered to positively reset to full engagement under sear spring tension if the trigger is partially pressed and released.
[0047] As the operator continues to press the trigger through this initial pre-travel and neutral engagement, the sear face presents the striker engagement with an increasing rate of angle change relative to the sear pivot axis. In the approximate final third of its engagement, the striker spring begins to load the sear as the striker is cammed back slightly. This leverage change is timed to coincide with the increased resistance felt through the trigger by the disconnect cam function of the trigger bar, and can be calibrated to yield more or less total breaking trigger pull weight. This provides the operator with a defined pressure wall at the end of perceived pre-travel or trigger take-up, and a sensation of a relatively crisp striker release, or trigger break, that is more consistent with an action featuring significantly less safe sear engagement values.
[0048] This increased sear engagement, by its greater standing height before the striker being more tolerant of unintended striker release or bypass malfunctions due to jarring or violent slide cycling, can thus permit of reduced sear spring tension whilst preserving an adequate measure of mechanical safety. Reduced sear spring tension obviously reduces the trigger force required to rotate the sear. It also has the effect of making the self-disconnecting and reset function of the trigger bar and sear relationship more positive and certain at significantly lighter trigger pulls.
[0049] B) Modular trigger assembly. The trigger is connected via it's axle to the receiver, and to the trigger bar via the drive stud. It functions conventionally by rotating on its axis in the receiver, which motion draws the trigger bar forward to actuate the safety lever, defeat the striker safety lock, and make contact with the lower leg of the sear, rotating the sear down and out of engagement with the striker to fire the pistol. This assembly consists of three pieces and one accessory: the top section with axle, shoe mounting dovetail (element 8 ), and drive stud (element 10 ); the shoe retaining screw (element 12 ); the trigger shoe (element 14 ); and the over travel stop pin tube (element 16 ).
[0050] The top section has a number of important features. The axle is machined or formed to maximum dimensions to fit the P320 receiver to reduce lost motion during trigger manipulation. The drive stud location is engineered to exert maximum leverage against the trigger bar, consistent with proper fit within the grip module and disconnect function. This yields a significant reduction in trigger pull weight at no compensatory cost to sear springing, mechanical safety, or engagement values. The axle incorporates a groove at its rear right to provide clearance for the trigger bar. The shoe mounting dovetail, interchangeable trigger shoes, and drive stud are positioned to provide the optimal over travel stop location for the original self-disconnecting function of the P320, as well as for the alternative slide-actuated disconnector embodiment when used with the accessory over travel stop tube.
[0051] The interchangeable trigger shoe is retained to the trigger top section by a transverse dovetail and a simple screw. The interchangeable feature provides modularity (element 20 ) to permit adjustment of trigger reach, shape and texture to suit the operator's personal preferences. The accompanying drawing is generically representative of the myriad of possible shapes. To compensate for the increased cranking leverage the trigger bar drive stud location yields while maintaining drop-safety integrity, the trigger shoes are made from a lighter material than the stock factory triggers (element 22 ).
[0052] C) Bar control cam plate. This plate is made from tool steel, hardened and treated for maximum wear resistance and low friction. It mounts to the rear right side of the receiver via an elongated sear housing pin and safety lever pin (element 24 ). It serves several important functions. First, the top rear contour of the plate forms a shelf (element 26 ) upon which the topmost bearing of the trigger bar rests when the trigger is in its forward at-rest position. This shelf prevents the trigger bar from dropping straight down on the vertical axis of the receiver, thus keeping it up in contact with the sear safety cam feature unless and until the trigger bar is first drawn forward some distance. This shelf is sufficient to prevent the trigger bar from falling straight down out of engagement with the sear of its own inertia if the pistol is dropped from a reasonable height or comparably jarred, thus holding the much less massive sear in place and enhancing drop-safety integrity under circumstances most likely to result in sear-hold failure.
[0053] This shelf provides significant resistance to the sear's downward rotation, since the safety cam must exert substantial force through poor leverage to push the trigger bar forward off the shelf first, before the bar can drop. The bar control cam plate is shaped to permit the trigger bar to move forward and down under load from the sear safety cam, but limits this movement to prevent the trigger bar from escaping it's track on the sear housing and becoming dislodged out of position. The trigger bar and trigger thus cannot be dismounted from the receiver without the use of a simple tool, I.E. a pin punch. A clip could be added to the opposite side of the safety lever pin that also holds the bar cam plate in position to further dissuade unauthorized or inadvertent disassembly of the fire control unit. In this way, the bar cam plate enhances reliability and serviceability with the net addition of only one new part.
[0054] The bar cam plate and sear safety cam feature work together to drive the trigger bar forward and down at an angle which prevents the bar from engaging the safety lever and rotating it sufficiently to defeat the striker safety lock in the slide. In this way, the mechanism further enhances the safety of the arm. The plate is shaped to accommodate the sear's extreme maximum downward rotation to permit full function of the takedown safety lever during field stripping. Additionally, the sear itself has been designed to improve the leverage which the takedown safety lever can exert against it to rotate it down out of engagement with the striker (Element 28 ). Additionally, the bar control cam plate has a feature which permits precise pretravel adjustment (element 30 ). It should be noted that significant pretravel reduction would require a change to the safety lever timing, which we have developed as a further optional embodiment of the invention.
[0055] D, E, F) Disconnector, limit ring and sear housing pin assembly, and trigger over travel stop pin tube suite. This suite of novel components are designed to function together as an alternative trigger enhancement embodiment incorporating the core functional attributes of the invention, expressed in a different manner.
[0056] The disconnector is made from tool steel, hardened and treated to withstand wear and shock, and to provide a low coefficient of friction. It fits against the rear right side of the receiver. It pivots from its front (muzzle) end on an extended safety lever pin (element 32 ), and engages the trigger bar in the slot formed between bearing surfaces at its rear end (element 34 ). It is actuated by the camming action of a corresponding cam cut in bottom of the right rear slide rail (element 36 ). On the current standard P320, this cut would be approximately 0.027″ deep, and extend the approximate length of the disconnector with its forward (muzzle) end tailing out to provide a specific amount of rear slide travel before engagement (element 38 ). The depth of this cut would be adjusted to suit different slide rail groove thickness, to best exploit the leverage ratio available to this design. The ratio of net trigger bar drop to slide cam cut is approximately 1.8:1, sufficient to positively disconnect the trigger bar from the sear in a P320 pistol exhibiting substantial slide to frame fit clearance.
[0057] The disconnector eliminates the need for the self-disconnecting trigger bar mechanism of the original P320 design. Thus, the excess trigger over travel after striker release required to function that self-disconnecting mechanism can be eliminated. This over travel reduction is easily accomplished by installing the over travel stop pin tube over the stop pin, increasing its diameter and halting the trigger's rearward rotation in time to striker release, but prior to auto-disconnect function. This tube is made from hardened steel.
[0058] The limit ring and sear housing pin assembly is a steel cylinder of sufficient diameter to block rearward travel of the trigger bar, and sufficiently long to locate laterally within the grip module, bored through with a 2.5 mm hole to accept an extended rolled spring pin. This pin is affixed to the cylinder to prevent it from drifting out (element 42 ). It is installed from the right in place of the factory P320 sear housing pin and thus does not increase the net parts count of the pistol.
[0059] This assembly performs at least three important functions. First, the limit ring bears against the lower rear angled corner of the trigger bar when it is at rest; this angled contact laps the ring by approximately 0.020″, which helps keep the bar in contact with the sear if jarred and offers some resistance to the camming action of the sear against the trigger bar (element 44 ). Second, the diameter of the limit ring can be calibrated to provide a precise reduction in trigger pretravel, much as the bar cam plate can be (element 46 ). Third, the assembly can be easily adapted to prevent full dismounting of the trigger bar and trigger without the use of tools. It's installation and function does not require modification to the pistol.
[0060] An alternative design to the limit ring assembly utilizes a shaped cam that is indexed to the receiver through a locating tab, and a modified trigger bar that engages at a shallower angle to enhance its resistance to vertical displacement (element 48 , Fig.). This alternative design yields drop safety performance comparable to the first system described herein utilizing the bar cam plate.
[0061] G,) Special sear and safety lever pins. The trigger bar cam plate requires two specialized pins to locate and retain it to the receiver. The rear pin replaces the factory sear housing pin, and is longer to assure that adequate projection is available to locate the plate. The front pin replaces the factory safety lever pin, and in its basic form is simply longer to afford location. The bar cam plate's two holes are sized to permit the plate to float on these pins slightly, to prevent cramping which could potentially bind the trigger bar.
[0062] In a more advanced form, these pins may be used as positive retainers against unauthorized or inadvertent disassembly of the fire control unit. The trigger bar cannot be dismounted from the receiver without first freeing the bar cam plate. Circlips, punched ends or other fasteners could be employed for that added feature.
[0063] The same extended safety lever pin which locates the bar cam plate also functions with the disconnector alternative system. For use with the disconnector, and alternate sear pin featuring a thin, large diameter head which is installed from the left side of the receiver and retained by the safety takedown lever is required.
[0064] H) 0028 Sear and trigger bar springs. Springs to augment or replace the factory sear and trigger bar springs, calibrated to provide predictable trigger pull weights in graduated steps for fine-tuning the fire control system for personal preferences or to meet preset production standards.
[0065] These springs include two different rate sear springs, which paired together or in combination with a factory spring, can yield trigger pull weights in a wide range between sub-4 pounds to approximately 6.5 pounds. The original factory springs tend towards a relatively progressive spring rate, and tend to exert less tension when the sear is fully rotated up at rest than when rotated down and compressed. Our alternate sear springs feature smaller diameter wire with more coils and a longer free length, for a flatter spring rate. This flatter rate spring exerts proportionally more tension at rest to provide for less net sear tension to overcome as trigger pull weight, while attenuating sear flutter and providing adequately snappy return.
[0066] 0029 The trigger bar spring is reduced in wire diameter and has a slightly different bend to yield more tension to the bar in its downward movement, but maintain proportionally less tension in its lateral movement to be overcome as trigger pull weight. This helps reduce the net trigger pull weight stacking effect of the auto-disconnect function induced by the camming surface of the sear housing track and trigger bar as the trigger reaches the striker release point. Yet, this spring maintains acceptable tactile trigger reset sensation, and important feature.
Preferred Embodiment
[0067] The two main alternative expressions of this invention described herein each serve to fulfill two different practical applications, and are equally valid in their respective roles. The first system, utilizing the original factory self-disconnecting trigger bar as a function of trigger overtravel, has several advantages. First, this system is completely reverse and cross compatible with all variations of the current SIG SAUER® P320 platform. Thus, this system can be dropped in to a stock pistol, function properly to a higher standard of trigger pull quality while preserving at least comparable drop safety integrity, and then be removed and the pistol restored to stock configuration in minutes, without permanent alterations to the pistol.
[0068] Additionally, the bar cam plate feature adds significantly to the drop safety integrity of this system, permitting somewhat more critical tuning with reduced sear spring rates than may be possible with the disconnector system for comparable drop safety integrity.
[0069] The disadvantage to the first system is the relatively critical dimensional tolerancing required to effect consistent trigger bar disconnect timing in a true no-fitting, drop-in scheme. However, we've demonstrated that these parts can be made to function within the range of current, typical factory tolerances. With allowance for selective assembly in a mass-production scenario, that concern evaporates. The basic system of leverage enhancement with dimensionally consistent auto-disconnect timing has been tested exhaustively.
[0070] The second system utilizing our disconnector design and limit ring assembly offers the prospect of dramatically reduced net trigger travel, trigger reset travel, and assured reliability from the same core trigger and sear set. It may not provide the same degree of added drop safety enhancement at the extreme low end of trigger pull weight possible for this platform with our sear and trigger system, but at moderate weights it is quite effective.
[0071] A variation of the second (I.E. disconnector) system utilizing a shaped cam block pinned and indexed to the receiver in place of the sear housing pin, and which engages a corresponding cam cut in the rear lower trigger bar has been developed (element 50 ). This third alternate embodiment of the core invention provides a positive shelf for the trigger bar to rest upon to the same effect as in the first embodiment, significantly increasing the trigger bar's resistance to being displaced downward by it's own inertia or by action of the sear safety cam. This approach offers comparable advantages in pretravel adjustment while being compatible with the disconnector.
[0072] The mating cam surfaces between cam block and trigger bar forming this shelf are angled to permit the disconnector to overcome this resistance. This action can be enhanced by timing the depression of the sear by the striker to precede disconnector function upon manual retraction of the slide with the striker forward, as after dry-firing the pistol (element 52 ). | A pistol has a frame with a striker operably connected to the frame. A trigger is operably connected to the frame. A transmission element is operably connected between the trigger and striker to motivate the striker to discharge the firearm in response to actuation of the trigger. The transmission element is movable between a first position in which operation connection from the trigger to the striker is enabled, and a second position in which operation connection from the trigger to the striker is disabled in response to acceleration forces due to dropping the pistol. | 5 |
INTRODUCTION
This invention is related to the production and use of novel neutralizing monoclonal antibodies against botulinum neurotoxin serotype F (BNT/F) which are completely protective in vivo against BNT/F, and hybridomas which produce monoclonal antibodies against BNT/F. The invention is directed to the antibodies, to processes of preparing the antibodies, to diagnostic, prophylactic, and therapeutic methods and compositions employing the antibodies, and to investigational, pharmaceutical , and other methods and compositions employing the antibodies.
The sporulating, anaerobic gram-positive bacillus Clostridia botulinum produces seven distinct neurotoxins (BNTs) which are among the most potent toxins known. Human botulism poisoning is generally caused by type A, B, E and sometimes, F toxin. Foodborne botulism poisoning is caused by the toxins present in contaminated food, but wound and infant botulism are caused by in vivo growth in closed wounds and the gastrointestinal tract respectively. The toxins primarily act by blocking the neurotransmitter acetylcholine at the neuromuscular junction, causing paralysis. The mechanisms for this blockage are currently under investigation (Schiavo, G. et al. 1992. Nature 359: 832-773. All documents cited herein are hereby incorporated by reference thereto).
Each botulinum neurotoxin is first synthesized by the bacteria as a single polypeptide chain with a molecular weight of about 150,000. In most botulinum serotypes, this single chain form is then "nicked" by endogenous protease(s), about one third of the way between the amino- and carboxy-termini, to produce the di-chain form. The latter consists of one light chain ( molecular weight about 50,000), and one heavy chain (molecular weight about 100,000), covalently linked by at least one disulfide bond. The light chain contains the original amino-terminal region of the parent single chain form, while the heavy chain has the original carboxy-terminus. (See: DasGupta, B., and Sugiyama, H (1972) Biochem. Biophys. Res. Comm. 48: 108-112; Dolly, J. (1992) in Handbook of Experimental Pharmacology (H. Herken and F. Hucho, Eds.), pp 681-717. Springer-Verlag, Berlin.
Until now the only protection against botulism poisoning has been immunization with botulinum toxoid, inactivated toxin(s) which stimulate the production of endogenous anti-toxin, but which often produces severe side-effects. There are seven serotypes of BNT, which have little detectable immunological cross reactivity. This has led to the development of the current pentavalent vaccine which is a mixture of five different botulinum toxoids, one each of serotypes A, B, C, D, and E (See: Siegel, L (1988) J. Clin. Microbiol. 26, 2352-2356; Anderson, J., and Lewis, G. E. (1981) in Biomedical Aspects of Botulism (G. E. Lewis, Ed.), pp 233-246. Academic Press, Inc., New York). However, there are numerous regions of homology between these seven serotypes, which suggests the potential of producing a protective cross reactive immune response.
Two research groups have identified possible cross reacting monoclonal antibodies (mAbs; Hambleton, P. et al. In Bacterial Protein Toxins. ed. J. E. Alouf et al., Academic Press 1984, London. Tsuzuki, K. et al. 1988. Infect. Immun. 56: 898-902). These mAbs were obtained by immunization with toxoided BNT, a botulinum neurotoxin that has been rendered non-toxic ("toxoided", chemically inactivated) by incubation with formaldehyde (For example, see: Singh, B., and DasGupta, B. (1989) Toxicon 27: 403-410) or with light chains of BNT alone. The mAbs were considered neutralizing or cross reacting or neither. All the antibodies in these publications were assayed in passive neutralization tests, wherein the antibody and toxin are premixed in different ratios, then injected into mice. If no toxicity remains (i.e. no mice die) then the antibody can be considered protective. Based on this criteria, then in the publications referenced, only the anti-tetanus monoclonal antibody afforded protection. This mAb recognizes a conformational epitope which can be lost if the protein is sufficiently perturbed (Arunachalam, B. et al. 1992. Hybridoma 11: 165-179). Of 17 mAbs to BNT serotype E (BNT/E) toxoid, all were to heavy chain and 5 were neutralizing. However, light chain is not free from heavy chain in nature, and a role for non-native epitopes in the immune response cannot be discounted.
We note that BNT/A is used in human therapy for several neurological conditions (Anderson, T. J. et al. 1992. J. Royal Soc. Med. 85: 524-529. Newman, N. J. and Labert, S. R. 1992. Neurology 42: 1391-1393. Zwimer, P. et al. 1992. Laryngoscope 102: 400-406. Burgunder, J. -M. 1992. Schweiz Med. Wochenschr 122: 1311-1316). Low doses of BNT/A are administered repeatedly and physicians have found that some patients lose responsiveness to the therapy. Neutralizing antibody responses have been found in some of these patients (Hambleton, P. et al. 1992. Brit. Med. J. 304: 959-960), suggesting that it is possible to produce mAbs to native BNT.
There are no monoclonal antibodies currently available which neutralize any or all serotype of botulinum neutotoxin based on the requirement that an antibody afford protection against a toxin without the necessity of premixing the two. That is, the toxin and antibody could be administered to an animal by different routes and/or at different times, and the animal would survive. Those which claim neutralization in print, instead provide delayed times to death (Shone, C. et al. 1985. Applied and Environmental Microbiology 50:63-67; Kozake, S. et al. 1987. Infec. Immun. 55: 3051-3056; Noah, C. W. et al. 1995. J. AOAC International 78: 381-385). Therefor, there is a need for a monoclonal antibody which can neutralize the toxin and provide protection against the different serotypes of BNT.
In addition, a new vaccine leading to improved titers and/or a long term immunity is of value. Unfortunately, there is no direct experimental evidence to provide guidance regarding immunogen selection for this new BNT vaccine. A neutralizing monoclonal antibody can provide guidance as to epitopes useful in vaccine development for cross protection.
SUMMARY
The subject invention relates to a monoclonal antibody, referred to as 7F8G2.H3, and to the uses thereof.
The production of monoclonal antibodies in general was first described by Kohler and Milstein (Nature 256: 495, 1975) where monoclonal antibodies directed to sheep red blood cells were prepared by fusing a specific antibody-producing B lymphocyte with a tumor cell, resulting in an "immortal" self-reproducing hybrid clone (or "hybridoma") than can synthesize, in a test tube (in vitro) or an animal (in vivo), a single, monoclonal antibody. Such a hybridoma, is in effect, a self-reproducing cell "factory" which can produce a potentially limitless supply of an antibody with single, predefined specificity.
We undertook to prepare novel self-producing cell lines which synthesized monoclonal antibodies directed toward BNT. All previous investigations have taken the approach of immunizing an animal with a toxoid and searching for an antibody response to the toxoid which will cross react with the toxin and which will be protective. Priming the immune response with irrelevant epitopes will predispose the immune response to those epitopes, even in the event the animal is later boosted with native toxin. We believe it is necessary to avoid priming the immune system to toxoided epitopes of the botulinum neurotoxin. We avoided mis-directed immune responses by immunizing with increasing sub-lethal doses of the native toxins. This is the first instance of immunizing against botulinum toxin using only active botulinum toxin as an immunogen. Furthermore, we began with botulinum neurotoxin serotype E, which can be purified in a single chain form (BNT/Esc) which is 100 fold less toxic than the nicked form. This allowed us to begin with higher doses than would have been possible with other serotypes. To produce a monoclonal antibody against serotype F, we employed reported cross reactivity between serotypes E and F. Mice, previously immunized against BNT/E could tolerate higher doses of BNT/F compared to naive mice. This led to the isolation of the monoclonal antibody 7F8.G2.H3 which is capable of providing in vivo protection when injected intravenously followed one hour later by an intraperitoneal injection of the toxin.
Accordingly, it is one object of the present invention to provide self-producing carrier cells, capable of producing a neutralizing monoclonal antibody against BNT/F.
It is a further object to provide the antibodies so produced.
A still further object is to provide an in vitro process for producing the antibodies.
An even further object is to provide an in vivo process for mass-producing the antibodies from the carrier cells.
Another object is to provide methods and compositions for using the antibodies in the diagnosis, prophylaxis, and treatment of disease caused by Clostridium botulinum.
Still another object is to provide compositions containing the antibodies useful for immunological or biochemical analyses of Clostridium botulinum.
An even further object is to provide compositions containing the antibodies suitable for isolating or purifying toxins from mixtures containing toxins and other substances.
Another object is to provide compositions containing the antibodies useful for the neutralization and/or removal of BNT from other material and solutions.
Yet another object of the present invention is to provide an antigenic neutralizing epitope by mapping the antigenic determinant recognized by the monoclonal antibody of the present invention, said antigenic determinant being common to all the botulinum neurotoxin serotypes. Such an epitope would be useful for designing a vaccine protective against all the seven serotypes of botulinum.
Other objects 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.
DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a Western blot of mAb 7F8.G2.H3 against botulinum neurotoxins E and F.
FIG. 2 shows a native blot of mAb 7F8.G2.H3 against botulinum neurtotoxins E and F.
DETAILED DESCRIPTION
The present invention provides monoclonal antibodies which neutralize BNT/F. The antibodies are produced by hybridoma, F197/7F8.G2.H3 deposited on May 2, 1996 at the American Type Culture Collection, Rockville, Md. 20854, USA, an International Depository Authority, with the ATCC designation HB-12102.
Also provided by this invention is a process for producing such antibodies, said process encompassing culturing said hybridomas in vitro or in vivo. A hybridoma is characterized by the ability to produce a homogeneous antibody (monoclonal antibody) specific to a certain antigenic determinant and also is capable of growing and reproducing in vitro.
The preparation and characterization of hybridomas and resulting antibodies reactive with BNT/F as well as various methods and compositions employing the antibodies, will be better understood by reference to the following description, which sets forth the preferred embodiments of the invention.
As indicated, the scope of the present invention embraces any hybridomas, including, but not limited to, F197/7F8.G2.H3 ATCC designation HB-12102 which produces monoclonal antibody 7F8.G2.H3 and reacts with BNT/F. This specification describes in detail the steps taken by the inventors to produce the above cell line.
Generally, hybridomas are obtained by the following process. Firstly, spleen cells (splenocytes: hereinafter sometimes referred to as S cells) from a mammal such as a mouse or rat are fused with myeloma cells which are deficient in hypoxanthine-guanine phosphoribosyl transferase (hereinafter sometimes referred to as M cells), in the presence of a fusion mediator such as polyethylene glycol (PEG). The fused cells are cultivated using a multiwell plate in a medium containing hypoxantine-aminopterin-thymidine (HAT) in order to effect the selective growth of S-M hybrids while preventing the growth of the other cells including M-M hybrids and the remaining M cells which did not participate in the cell fusion. Hybridoma cells secreting the desired antibody are then cloned by an appropriate method such as the limiting dilution method from the wells in which the cells propagated. The hybridoma thus cloned can be cultivated in vitro or in vivo, e.g., in a mouse abdominal cavity, in order to have it produce the monoclonal antibody in large amount.
The antibody of the present invention is produced by the cultivation of a hybridoma which is obtained by the cell fusion of two type of cells, one being antibody producing cells of a mammal, e.g., a mouse, which has been immunized with biologically active botulinum neurtotoxin. The mammal may be selected from such animals as mice, rats, rabbits, guinea pigs, etc. which are normally employed for raising antibodies. For example, a mouse can be immunized intraperitoneally or subcutaneously with BNT/Esc. The administration should be repeated several times at intervals of 2 to 3 weeks with an initial dose of 1 ng or less, increasing by factors of 5 to 10 for succeeding doses, in 50 μl of adjuvant, until an antibody response can be detected by ELISA or 1 microgram of antigen (toxin) can be administered. Following a course of immunizations with BNT/Esc, mice can be successfully immunized with nanogram doses of other, active, cross reactive, BNTs, such as BNT/F. In the three days prior to excision of the spleen, the antigen (toxin) is administered in microgram amounts both intravenously and intraperitoneally. Spleen cells are then obtained and used for the production of hybridoma cells lines.
Since cross reactivity between BNT/Esc and BNT/F has been detected by a native blotting technique, which was not readily detected by ELISA, a similar analysis can be utilized in order to detect cross reactions between BNT/Esc and other serotypes. In addition, monoclonal antibodies specific for other serotypes of BNT can be prepared by, for example, procuring the single chain form of other serotypes of BNT, immunizing mice with this less toxic variant of BNT, isolating monoclonal antibodies specific for the administered BNT sertotype, and then finding cross reactions between the said serotype and other BNT serotypes. For example, the single chain, less toxic form of BNT/B (BNT/Bsc) can be used for immunizing mice and the resulting monoclonal antibodies against BNT/B used to find cross reactions between BNT/B and other serotypes.
When carrier cells are employed in the invention, they are principally characterized by being self-reproducible, and by having genes that code for the production of monoclonal antibodies which neutralize BNT/F. These carrier cells can be cells lines such as human-nonhuman (Nowinski et al., Science, 210:537, 1980) or wholly nonhuman hybridomas (Kohler and Milstein, 1975, supra) or transformed parental lymphoid cells (Steinitz et al., Nature 269:420, 1977). Each of the above four publication is hereby incorporated by reference. These references, in combination with the following Examples, would enable a person skilled in the art to prepare carrier cells of a human or nonhuman animal species capable of producing monoclonal antibodies reactive with BNT/F. For example, spleen cells or peripheral blood lymphocytes obtained from human donors immunized with or previously exposed to toxins can be fused with a mouse myeloma fusion partner, yielding a self-reproducing human-mouse hybridoma which produces human monoclonal antibody reactive with BNT/F.
Another approach to the preparation of self-reproducing carrier cells that secrete human or nonhuman monoclonal antibodies reactive with botulinum toxin involves virus transformation of the appropriate B lymphocyte clone. Steinitz et al. (1977, supra) employed such a procedure to prepare specific human antibody to the synthetic hapten NNP(4hydroxy-3,5dinitrophacetic acid). According to this technique, for example, peripheral blood lymphocytes from human donors immunized with the toxin or previously exposed to the toxin can be isolated on Ficoll-Hypaque. A B lymphocyte population enriched in respect to the production of antibodies reactive with the toxin is prepared and infected with Epstein-Barr Virus (EBV). The EBV-infected B lymphocytes are transformed into continuously proliferating cell lines ("immortal"), and those secreting antibodies reactive with the toxin are identified by ELISA or other appropriate assay and cloned, essentially as described for hybridomas previously.
The procedures outlined above for obtaining human or nonhuman monoclonal antibodies reactive with botulinum toxin employing B lymphocytes fused with tumor cells (hybridomas) and virus-transformed B lymphocytes are similar in all respects except the method by which "immortalization" of the appropriate B lymphocyte clone is achieved. Both techniques entail preparation of biologically active botulinum neurotoxin, immunizing with ever increasing sub-lethal dosed of native toxins, immunizing with a more lethal dose of a cross-reacting active toxin, selecting and cloning of self-reproducing carrier cells producing monoclonal antibodies reactive with the toxin, growth of these cells in continuous culture, and recovery of the monoclonal antibodies produced.
Just as a variety of different systems and methods might be employed to select for and reproduce genes specifying the production of monoclonal antibodies reactive with botulinum neurotoxin, so might a variety of antibodies result from these measures that are distinct from the specific antibody illustrated in the Examples below yet still clearly within the definition of the invention. Once again, the salient feature of such antibodies, for the purposes of this invention, besides their monoclonality, is their ability to neutralize BNT/F in vitro and in vivo. Thus, the invention includes any monoclonal antibody that neutralizes BNT/F, regardless of species of origin, isotype, molecular specificity, affinity, method of production (whether in vitro or in vivo), or type of carrier cell employed in its production.
The monoclonal antibody of this invention is a reagent that may be used to identify BNT/F, or microorganisms bearing BNT/F, in the tissues or body fluids of patients (or animals) infected with these microorganisms, thus permitting rapid and accurate immunological diagnosis of such infections. This form of diagnosis is made possible, in part, by the great specificity of the monoclonal antibody of this invention compared with conventional, polyclonal antibodies reactive with BNT/F.
The monoclonal antibody of this invention is also useful for the immunological detection of BNT/F or BNT/F-bearing organisms present as contaminants in water, biologicals, pharmaceuticals or other materials. Detection is rapid, sensitive, and highly specific.
A diagnostic composition in accordance with the present invention contains a concentration of the antibody effective to diagnose an infection, detect toxin, or demonstrate toxin bearing microorganisms. The antibody can be packaged and sold in freeze-dried or other acceptable form for diagnostic use. It may be mixed with a suitable carrier, attached to an appropriate solid phase (e.g., latex particle, or plastic microtiter plate), conjugated with an enzyme or dye, or radiolabeled, depending on what immunological method is employed.
In a diagnostic or detection method in accordance with this invention, the antibodies of the present invention may be mixed with a sample of body fluid or blood or tissue removed from a person (or animal) suspected of being infected with a BNT/F bearing microorganism, or sample of water, biological, pharmaceutical or other material contaminated with endotoxin or an endotoxin-bearing microorganism, and the degree of reaction in the resulting mixture measured. The amount of antibody required to carry out the diagnosis or accomoplish the detection depends upon factors that include the amount of sample to be tested, the amount of toxin or number of microorganisms present, an the type of assay used. The monoclonal antibody of the present invention can be employed in any diagnostic or detection assay system, of which immuno-fluorescence assays, radioimmunoassays, and enzyme-linked immunosobent assays are examples. Further, the monoclonal antibody of the present invention can be used in a competitive binding or inhibition assay to measure other antibodies, either monoclonal or polyclonal, reactive with BNT/F.
The monoclonal antibody of this invention is a reagent that may be used for the immunoprophylaxis or therapy of Clostridia botulinum infections, or their consequences. These clinical applications of the monoclonal antibody of the invention are supported by its specificity for BNT/F, its ability to neutralize the biological activity of BNT/F, and its producability in virutally limitless supply.
A composition according to the present invention contains a concentration of the antibody effective in preventing or treating (i.e. ameliorating) infections caused by BNT/F-bearing microorganisms, or the consequences of such infections. The antibodies can be packaged and sold in freeze-dried or other acceptable form, and/or mixed with a therapeutically acceptable carrier, such as a balanced aqueous salt solution.
An immunoprophylactic or therapeutic method in accordance with this invention entails the administration of the monoclonal antibody of the invention by injection or infusion prior to (prophylaxis) or following (therapy) the onset of an infection caused by a BNT/F-bearing microorganism. The amount of antibody required to prevent or treat such an infection or its consequences depends upon such factors as the type and severity of the infection, the size and weight of the infected patient, and the effectiveness of other concomitantly employed modes of prophylaxis or therapy.
The monoclonal antibody of the present invention is useful as a reagent for research related to the structure and function of botulinum neurotoxins. The exquisite specificity as well as its ability to neutralize BNT/F allows it to be used for immunochemical and structure-activity analyses of Clostridia botulinum neurotoxins. Mapping of the antigenic epitope recognized by the monoclonal antibody of the present invention will lead to the identification of similar epitopes present on other serotypes of botulinum, and the development of a vaccine protective against all the seven serotypes of botulinum neurotoxin.
Mapping of the antigenic epitope can be accomplished by several methods known to people in the art, one of which is described for an example. Monoclonal antibody (mAb) 7F8.G2.H3 detects native BNT/F by ELISA and on native blots. Either technique can be employed to define the epitope. The first step is to determine which chain, light or heavy, mAb 7F8.G2.H3 binds to. These chains can be separated gently on a reducing native polyacrylamide gel. The separated chains can be blotted to nitrocellulose and probed with mAb 7F8.G2.H3. The following comments assume binding to the heavy chain, as its analysis will be more involved. However, should it bind to the light chain the analysis would proceed in an analogous fashion. The heavy chain can be further sub divided by enzymatic cleavage or though employment of molecular biological techniques. Repeated blots of smaller and smaller fragments will eventually result in fragments of BNT/F which are not bound by mAb 7F8.G2.H3. Conformation of the BNT/F may be essential to binding. As one identifies a fragment of BNT/F which does not bind while a similar but somewhat larger one does, the possibility of loss of conformation of the BNT/F fragment must be considered. Eventually, a minimal fragment required for recognition by mAb 7F8.G2.H3 will be generated. At this point, synthetic polypeptides can be produced and used to compete with the minimal fragment for binding with the mAb 7F8.G2.H3. In this way, discontinuous epitopes can be defined.
Described below are examples of the present invention which are provided only for illustrative purposes, and not to limit the scope of the present invention. In light of the present disclosure, numerous embodiments and uses of the invention within the scope of the claims will be apparent to those skilled in the art.
EXAMPLES
Initial Immunization with Botulinum Neurotoxin, Serotype E
The dose of botulinum neurotoxin, serotype E, single chain form (BNT/Esc) which is lethal to 50% of the mice (mLD50) when injected by intraperitoneal (IP) route was determined. This dose would become the immunizing dose received by the initial group of mice.
Mice were anesthetized prior to the intrasplenic injections with 0.05 to 0.07 ml of the following mixture: 1.5 ml Ketamine (100 mg/ml), 1.5 ml Xylazine (20 mg/ml), 0.5 ml Acepromazine (10 mg/ml). A small incision was made on the left side of each mouse to reveal the spleen. The spleen was injected with the previously determined dose (1 IP mLD50) of BNT/Esc in a 50 μl volume in Ribi adjuvant. The peritoneum was closed with adsorbable suture material and the skin was closed with surgical staples, which were later removed. Surgery was performed on approximately thirty mice per day. It was noted that 1 IP mLD50 dose was not equivalent to 1 mLD50 dose given by an intrasplenic (IS) route. The administered dose was increased over the next two days of surgery until the IS mLD50 was apparently exceeded, where upon the dose was reduced.
______________________________________Immunization/Challenge with BNT/EscGroup Day Dose Survivors/Total______________________________________I 0 1.1 ng 31/32II 2 1.5 ng 23/31III 6 3.0 ng 12/29IV 8 2.0 ng 24/29______________________________________
Surviving mice received increasing doses of BNT/Esc, in Ribi adjuvant, via subcutaneous route approximately every two weeks. Final booster immunizations were of 1.4 μg of BNT/Esc.
Immunization of BNT/Esc Immunized Mice with Botulinum Neurotoxin, Serotype F(BNT/F)
Six month old mice from the above BNT/Esc immunization were immunized with BNT/F. Mice received increasing doses of BNT/F SC, in a 50 μl of Ribi adjuvant on the days indicated below.
______________________________________Immuno-challenge with BNT/FDay ng IP mLD50 Survivors/Total______________________________________0 1 18 3/815 1 20 3/349 6 105 3/359 28 500 3/370 170 3,050 3/3117 1,000 18,000 3/3118 2,000 36,000 3/3119 5,000 90,000 3/3______________________________________
Discovery of 7F8
The mice were sent to a contractor for construction of hybridomas (fusion F197). Hybridoma culture supernates were returned for assay by enzyme-linked immunosorbant assay (ELISA). Original screening was by sandwich ELISA. Horse anti-BNT/F (100 μl) was applied to polystyrene plates at a 1:1000 dilution, at room temperature for one hour. Excess horse anti-BNT/F was washed off and the plates were blocked with 275 μl per well of 5% bovine serum albumin (BSA). Blocking was accomplished overnight at 4° C. BNT/F was added to each well at 2ng per well in a 100 μl volume. This was incubated for one hour at room temperature. Excess BNT/F was washed off and the plates were incubated with 100 μl of hybridoma culture supernates per well for one hour at room temperature. Hybridoma culture supernates were washed off and 100 μl of goat anti-mouse-Ig(GAM) conjugated to horse radish peroxidase (HRP) was applied to each well at a 1:400 dilution. The rest of the reagents were standard to the K&P ELISA kit. Results from one of the plates (plate 7) is shown below.
__________________________________________________________________________1 2 3 4 5 6 7 8 9 10 11 12__________________________________________________________________________A -0.128 +0.147 -0.097 -0.085 +0.084 -0.071 +0.208 -0.109 -0.133 -0.105 +0.018 P0.000B +0.110 -0.091 -0.049 +0.006 -0.110 -0.053 +0.198 -0.019 +0.293 -0.081 +0.446 +0.643C -0.102 -0.034 -0.056 +0.440 -0.066 +0.006 +0.284 -0.064 +0.232 -0.036 +0.414 -0.676D +0.073 -0.028 -0.071 +0.245 -0.012 -0.086 +0.189 -0.031 -0.056 -0.073 +0.292E +0.010 -0.062 +0.154 -0.067 -0.006 +0.030 -0.076 +0.006 -0.084 -0.023 +0.400F -0.047 -0.040 -0.069 +0.263 +0.038 -0.037 +0.046 +0.519 +0.001 +0.044 +0.064G -0.027 +0.087 +0.020 +0.087 +0.048 +0.319 +0.009 +0.399 +0.169 +0.053 +0.018H -0.083 +0.012 -0.008 +0.125 +0.119 +0.163 +0.126 +0.111 +0.331 +0.010 +0.136__________________________________________________________________________
The cell line from plate 7, row F, column 8 (F197/7F8), in addition to eight others, was selected for further study.
Preliminary tube neutralization data (not shown) indicated clone F197/7F8 was of interest. Limiting dilution was performed twice in order to clone this cell line. Production of the monoclonal 7F8 was monitored by indirect ELISA. Conditions were similar to that described above for the sandwich ELISA, with the following exceptions. Polystyrene plates were coated directly with 200 ng of BNT/F per well. 5% skim milk was used as the blocking agent. The secondary antibody, goat anti-mouse(GAM)-HRP was used at a 1:5000 dilution.
All subclones produced monoclonal antibodies with essentially the same ELISA data (not shown). Cell line F197/7F8.G2.H3 ATCC designation HB-12102, which produces monoclonal antibody (mAb) 7F8.G2.H3, was selected for further study.
Test Tube Neutralization Assay
Preparation of diluted BNT/F. The stock solution of BNT/F, from WFRI, (Wisconsin Food Research Instituted, University of Wisconsin) contained 1.8×10 7 mLD50 per mg (1 mg/ml). We prepared 50 IP mLD50/ml in PBS. Each mouse would receive 280 picograms.
Positive and negative controls were conducted by administration of 1:100 dilutions of mouse anti-BNT/F (MaF/E) or normal mouse sera (NMS) were prepared in PBS.
Preparation of 7F8.G2.H3. Serial 10 fold dilutions of mAb 7F8.G2.H3 were made.
Neutralization of BNT/F. Diluted BNT/F (0.5 ml) was mixed with 2.0 ml of hybridoma culture supernate from or the control serum dilutions. These were incubated at 25° C. for 1 hour.
Bioassay. Half a ml was injected ip into four mice per preparation. Results are expressed as survivors/total.
______________________________________Stoichiometry of 7F8.G2.H3 against BNT/F. Ten fold dilutions.Dilution Day 1 2 4 9 19Factor 7F8/Tube S/T S/T S/T S/T S/T______________________________________10.sup.-1 1.12 mg 4/4 4/4 4/4 4/4 4/410.sup.-2 112 ug 4/4 4/4 4/4 4/4 4/410.sup.-3 11.2 ug 4/4 4/4 4/4 4/4 4/410.sup.-4 1.12 ug 4/4 2/4 2/4 2/4 2/410.sup.-5 112 ng 4/4 0/410.sup.-6 11.2 ng 2/4 1/4 1/4 1/4 1/410.sup.-7 1.12 ng 1/4 0/410.sup.-8 112 pg 0/41:200 MaF/E 4/4 4/4 4/4 4/4 4/41:200 NMS 0/4______________________________________
The neutralization experiment were repeated to further define the neutralizing capability of this mAb.
Dilutions of 7F8.G2.H3 from 10 -2 .7 to 10 -4 .2 were tested for protection from BNT/F and more concentrated 7F8.G2.H3 for protection from BNT/E SC . Dilutions of 7F8.G2.H3: To make the initial 10 -0 .3 dilution, 1.250 ml of the original ascites were added into 1.25 ml PBS.
To make the secondary 5 fold dilutions of 10 -1 and 10 -1 .7, 0.5 ml of the 10 -0 .3 dilution were added into 2.0 ml. Repeat using the 10 -1 .0 dilution.
The appropriate volume from the first two tubes was removed to result in 2 ml final volume. These two were used to test neutralization of BNT/Esc.
A tertiary 10 fold dilution, 10 -2 .7, was made with 400 μl from the 10 -1 .7 dilution, adding it to 3.6 ml to give 4 ml.
The quaternary two fold dilutions were made by taking 2 ml of 10 -2 .7 dilution and serially diluting it two fold, and five times to conclude with a 10 -4 .2 dilution. This gave a range from 22.4 ug 7F8 to 700 ng 7F8 per tube.
As a positive control for BNT/F, 12.5 ul of pooled mouse anti-BNT/F sera, from the 27 Oct. 1994 bleed was diluted in 1.983 ml of PBS, to yield 2.0 ml. The end result is a 1:200 dilution.
As a negative control for BNT/F, 12.5 ul of pooled normal mouse sera was diluted in 1.983 ml of PBS, to yield 2.0 ml. The end result is a 1:200 dilution.
Preparation of BNT/Esc: 20 mice received 5 mLD50. Therefore required 3.0 ml of 50 mLD50 per ml (125 mLD50 total).
Preparation of BNT/F: 32 mice received 5 mLD50. Therefore required 5 ml of 50 mLD50 per ml (250 mLD50 total).
Neutralization of BNT/F
Half a ml of the diluted BNT/F stock or BNT/Esc stock was added, as appropriate, (25 mLD50s) to each of the appropriate 2.0 ml of diluted 7F8.G2.H3, or serum dilutions or negative controls resulting in a final volume of 2.5 ml which will contain 5 LDSOs per 0.5 ml. All the serum/BNT/E SC or serum/BNT/F preparations were incubated at 25° C. for 1 hour. Four mice were injected per preparation with 0.5 ml, IP.
______________________________________Stoichiometry of 7F8.G2.H3 against BNT/F. Two fold dilutions. Day 1 2 3 6 29dil. Ab/tube BNT S/T S/T S/T S/T S/T______________________________________10.sup.-2.7 22.4 ug F 4/4 4/4 4/4 4/4 4/410.sup.-3.0 11.2 ug F 4/4 4/4 4/4 4/4 4/410.sup.-3.3 5.6 ug F 4/4 4/4 4/4 4/4 4/410.sup.-3.6 2.8 ug F 4/4 4/4 4/4 2/4 2/410.sup.-3.9 1.4 ug F 4/4 2/4 1/4 1/4 1/410.sup.-4.2 700 ng F 3/4 0/4 1:200 MAF F 4/4 4/4 4/4 4/4 4/4 1:200 NMS F 1/4 1/4 1/4 1/4 1/4Stoichiometry of 7F8.G2.H3 against BNT/F.10.sup.-0.3 5.60 mg Esc 2/4 2/4 2/4 2/4 2/410.sup.-1.0 1.12 mg Esc 0/410.sup.-1.7 224 ug Esc 1/4 1/4 1/4 1/4 1/4 1:200 MAF Esc 4/4 4/4 4/4 4/4 4/4 1:200 NMS Esc 0/4______________________________________
Protein Immunoblots Following SDS PAGE or Native PAGE
BNT/F and BNT/E SC stock solutions were mixed with equal volumes of 2× SDS sample buffer and heated to 95° C. for five minutes prior to use (FIG. 1). Alternatively both stock solutions were mixed with equal volumes of 2× sample buffer without SDS and kept at -20° C. until needed (FIG. 2). Reducing agents were not used. Samples volumes were adjusted to apply 1.5 μg of protein in 2 to 5 ul volumes. SDS PAGE was conducted on 10% total acrylamide gels, with 3% cross-linking, while Native PAGE was conducted on 7.5% acrylamide gels, with 3% cross-linking. SDS-PAGE was run at 20 mA and Native PAGE was run at 10 mA, with cooling. Proteins were transferred to nitrocellulose for blotting using Tris-Glycine buffers with 20% methanol (for SDS-PAGE) or without methanol (for Native PAGE). Nitrocellulose was blocked with 5% skim milk. All primary antibodies and the secondary HRP-conjugated antibody were used at 1:2000 dilutions. The luminol-based assay system of Kirkegaard & Perry was employed to develop the blots.
Results from SDS-PAGE are shown in FIG. 1. Monoclonal antibody 7F8.G2.H3 does not detect either BNT/E SC nor BNT/F when the BNT is denatured. The mouse sera from BNT/F immunized mice does recognize denatured BNT/F as well as BNT/E SC . The mice had been previously immunized with BNT/E SC . However mice that had been immunized only with BNT/E SC had sera that recognized denatured BNT/E, but not denatured BNT/F.
Results from Native PAGE are shown in FIG. 2. Monoclonal antibody 7F8.G2.H3 does not detect native BNT/E SC , but does detect native BNT/F. The mouse sera from BNT/F immunized mice still recognize BNT/F as well as BNT/E SC . Mice that had been immunized with BNT/E SC have sera that recognize BNT/E, but also recognize native BNT/F.
In Vivo Neutralization Assay
Mice received an intravenous (IV) injection of 50 μl of the stock ascites antibody (7F8.G2.H3) in PBS (280 ug mouse antibody per mouse) or PBS. One hour later they were challenged with 5 IP mLD50 (280 pg/mouse). Results are expressed as survivors/total.
______________________________________In vivo neutralization assay: Day 1 2 3 6 10 21Group S/T S/T S/T S/T S/T S/T______________________________________7F8 Ascites 4/4 4/4 4/4 4/4 4/4 4/4PBS 1/4 0/4______________________________________
Second In Vivo Neutralization Assay
Mice received an intravenous (IV) injection of 50 μl of the stock ascites antibody (7F8.G2.H3) in PBS (280 ug mouse antibody per mouse) or PBS. One hour later they were challenged with varying IP mLD 50 doses. Results are expressed as survivors total.
______________________________________DATA is expresses as Survivors/Total BNT/FGroup IV IP mLD.sub.50 1d 2d 3d 5d 21d______________________________________Control 1 PBS 5 2/3 2/31 1/3 1/3 1/3Control 2 PBS 50 0/3Test 1 7F8 5 4/4 4/4 4/4 4/4 4/4Test 2 7F8 50 4/4 4/4 4/4 4/4 4/4Test 3 7F8 500 4/4 1/4 1/4 1/4 1/4Test 4 7F8 5000 1/4 1/4 1/4 1/4 1/4Test 5 7F8 50000 0/4______________________________________ | Antibodies which neutralize botulinum neurotoxin serotype F are produced using biologically active botulinum neurotoxin instead of toxoid for immunization and exploiting the importance of cross reaction between various serotypes to obtain immune responses, or monoclonal antibodies, to additional serotypes of interest. Methods of preparation and uses of the neutralizing botulinum neurotoxin antibodies are described. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to photometric devices of the TTL (through the lens) type, and more particularly, to an exposure meter in a single-lens reflex camera which measures the light rays passing through the reflex mirror of the camera.
2. Description of the Prior Art
A photometric device of the so-called TTL type exposure meter which measures light rays passing through the camera lens of a single-lens reflex camera wherein the light receiving element is arranged behind the reflex mirror to receive the light rays passing through the reflex mirror which is designed to partially pass the light rays coming from the camera lens and to reflex most of the light rays to the view finder optical system, has been known (Japanese Laid Open Specification No. 67623/1974). The camera provided with such a photometric device, however, has several disadvantages. Thus, as the light receiving element of the photometric device is arranged out of the path of the light rays passing through the reflex mirror, and the light transmitted to the reflex mirror is reflected to the light receiving element by a further reflecting member placed in front of the focal plane shutter, the reflecting member should necessarily be obliquely disposed with respect to the optical axis of the photo-taking lens. The reflecting member of the prior art is required to be large enough, especially in cameras equipped with the so-called center-weighted measurement system, to cover a wide photometric range; and, moreover, it becomes larger because the reflecting member is angularly disposed with respect to the optical axis. Therefore, the increased mass or inertial moment of the enlarged reflecting member may cause undesired movement or vibration when the reflex member is withdrawn from the photo-taking light path at the time of photographing.
Further, the angular disposition of the reflecting member may cause another difficulty in that a high degree of tolerance is required in the disposition of geometry of the reflecting member to maintain sufficient photometric accuracy, since a small difference in the disposition, or geometric error of the reflecting member greatly affects the advancing direction of the light reflected by the reflecting member towards the light receiving element.
SUMMARY OF THE INVENTION
Accordingly, I have conceived a device of the class described wherein I combine a photometric device for an exposure meter of simple construction with a single-lens reflex camera, wherein the above disadvantages have been removed and the photometric accuracy thereof cannot be adversely affected by a small change in the location or position of the reflecting member.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject of the claims appended hereto. Those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purpose of the invention. It is important, therefore, that the claims be regarded as including such equivalent constructions as do not depart from the spirit and scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Specific embodiments of the invention have been chosen for purpose of illustration and description, and are shown in the accompanying drawings, forming a part of the specification wherein:
FIG. 1 is a diagrammatic illustration of the first embodiment of the present invention;
FIG. 2(A) is a diagrammatic illustration of a modified light receiving element;
FIG. 2(B) is a diagrammatic illustration of another modified light receiving element;
FIG. 3 is a diagrammatic illustration of the second embodiment of the present invention; and
FIG. 4(A) and 4(B) are diagrammatic illustrations of the third embodiment of the present invention, FIG. 4(A) showing the arrangement of the elements when they are in the light path of the camera lens, and FIG. 4(B) showing the arrangement of the elements when they are out of the light path of the camera lens.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1 which illustrates the first embodiment of the invention, the light rays from an object passing through a camera lens 3 are reflected at a reflex mirror 10 to enter the view finder optical system composed of a focusing plate 4, a condenser lens 2, a pentaprism 1, partially shown here, and an eyepiece lens 5. A part 10a of the reflex mirror 10 reflects all the incident rays thereto and the remaining part 10b thereof is semi-transparent or has a plurality of transmitting holes to reflect a part of the light rays, which pass through the camera lens 3, to the view finder optical system and to transmit or pass the remaining part of said rays. There is a concave mirror 8 positioned between a focal plane shutter 6, which is directly in front of the film 12, and the reflex mirror 10 to cover the central photometric range A in the central part of the photo-taking picture B limited by a picture frame 7. The concave mirror 8 is disposed so that the optical axis thereof is coincident with that of the camera lens 3.
Accordingly, the light rays to enter the central photometric range A through the light passing part 10b of the reflex mirror 10 is reflected at the concave mirror 8a to enter a light receiving element 9 of the exposure meter disposed on the optical axis of the camera lens or in the neighborhood thereof. The light receiving element 9 photoelectrically converts intensity of light incident thereon into electrical signal. The surface 9a of the light receiving element 9 is substantially conjugate with respect to the film surface 12.
Before photographing, the reflecting mirror 10 is moved by conventional means from the photo-taking light path to a position 10' in which the mirror 10 is out of the light path, and the concave mirror 8 and the light receiving element 9 are also moved from the photo-taking light path in response to the movement of the reflecting mirror 10 immediately before photographing.
As the light receiving element 9 is placed in the path of the light rays passing through the reflecting mirror, it shields a part of the trasmitted light so that although the luminous flux reaching the surface of the light receiving element 9 is partially cut near the optical axis, if the photometric range A and the size of the concave mirror 8 are large enough, compared with the size of the light receiving element 9, the effect of the cut on the photometric accuracy is minimal and can be ignored. When a silicon photocell 1 to 2 mm. square packed by transparent resin is employed as the light receiving element 9, the abovementioned conditions will be satisfied. As the surface 9a of the light receiving element 9 receives the light rays condensed by the concave mirror 8, the illumination intensity thereof becomes high. Therefore, the fact that silicon photo-cells have a small absolute sensitivity and show poor linearity at a very low illumination intensity does not have an unfavourable effect on the photometric accuracy.
Accordngly, the location of the light receiving element 9 on the optical axis should be determined in consideration of the degree of the cut of the light and the condensing power of the condenser such as a concave mirror, so as to obtain the desired illumination intensity at the surface 9a. The inverse incident rays 11 passed to the reflecting mirror 10 through the eyepiece lens 5, the pentaprism, the condenser lens 2 and the focusing plate 4 have little effect on the photometric accuracy since they scarcely reach the surface 9a of the light receiving element.
Referring to FIG. 2(A), it will be seen that even when the light receiving element 9 is attached to the backside of the reflecting mirror 10,, the inverse incident rays 11 have little effect on the photometric accuracy because I provide a shield member 9b against such incident rays reaching the surface 9a.
Further, referring to FIG. 2(B), the light receiving element 9 may be attached to the backside of the reflecting mirror 10 in such a manner that the light receiving surface 9a is directed downwardly, and the prism 9d may be provided at the light receiving element so that the reflecting surface 9c of the prism can reflect the light from the reflecting-concentrating member 8 toward the light receiving surface 9a of the light receiving element. In this case, the disturbing effect of the inverse incident rays 11 is also reduced.
In the second embodiment of this invention shown in FIG. 3, a convex lens 18, one surface of which is made to reflect the light rays, is used as the reflecting-concentrating member. The back surface 18a of the convex lens 18 is used as a reflecting surface so that after the light rays passing through the reflecting mirror 10 enter pass the surface 18b of the lens 18, they are reflected by the reflecting surface 18a and then exit from the surface 18b to enter into the surface 9a of the light receiving element. This structure aims at the gentle radius curvature of the convex lens 18 and therefore permits the use of a thin convex lens.
On the contrary, in the third embodiment of the present invention, as shown in FIG. 4, a concave lens 28 is used as a reflecting-concentrating member of which the surface 28a is made the reflecting surface. The back surface 28a of the concave lens 28 seen in FIG. 4(A) is designed to reflect the light rays, so that even if the reflecting surface 28a is a spherical one which may be easily machined, it is possible to focus the light rays at a point by the action of the concave lens 28.
Further, in the embodiment, when the reflecting-concentrating member 28 and the reflecting mirror 10 are moved from the photographing light path, the light receiving element 9 can be disposed in the space formed by the concave surface of the concave lens 28 and the reflecting mirror 10 as shown in FIG. 4(B) efficiently to utilize the space.
From the foregoing description, it will be seen that, according to my invention, the reflecting-concentrating member, such as a concave mirror 8 or a convex lens 18 or concave lens 28, with a back surface mirror, is not angularly disposed but perpendicularly disposed with respect to the optical axis of the photo-taking lens 3, so that it is easy to secure the accuracy of the position of the reflecting-concentrating member and the member can be made compact and light in weight. Further, the location error or geometric error in manufacturing and assembly has no significant effect on the photometric measuring accuracy. It is also true that the effect of inverse incident light from the eyepiece is negligible.
I believe that the contruction and utilization of my novel device will now be understood, and that the advantages thereof will be fully appreciated by those persons skilled in the art. | A photometric device for a through the lens type exposure meter in a single lens reflex camera. The reflecting mirror provides a region transmitting a part of the light rays incident thereon. The light passing through said region is reflected by a reflecting-concentrating member and received by a light receiving member, the surface of which is adjacent to the film and disposed on or in the vicinity of the optical axis of the phototaking lens. The reflecting-concentrating member is disposed to substantially cover the photometry range of the film and the optical axis of the reflecting-concentrating member is substantially coincident with the optical axis of the phototaking lens. | 6 |
The Government may have certain rights in the invention pursuant to grant No. 2-S07-RR07187-11.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method of identifying and treating patients at risk or in early onset of diabetes mellitus by first determining gastric emptying patterns and then treating with an appropriate drug. Treatment comprises administration of a pharmaceutical preparation having the ability to inhibit or block gastric emptying. In particular, drugs that affect gut motility are useful as a method of treatment in reducing gastric emptying rates to a near normal range, effectively slowing delivery of glucose to the duodenum and reducing hyperglycemia.
2. Description of Related Art
In recent years the role of the stomach in glucose homeostasis has become recognized (1). In 1982, Thompson described gastric emptying as an important determinant of the oral glucose tolerance test and suggested that the glucose tolerance test could be used to assess gastric emptying. In 1983 Brener et aI. (2) described characteristic gastric emptying of glucose solutions in normal human subjects In their studies they discovered that glucose empties from the stomach in a constant and linear fashion at an average of 2.13 kcal/min regardless of the concentration of the glucose solution Prior to this study, it was widely believed that all liquids emptied in an exponential manner. It is Brener's hypothesis that a dynamic "closed loop" feedback interrelationship exists between the stomach and the duodenum to control the delivery of calories from the stomach.
Keshavarzian et aI. (3) have studied gastric emptying in a heterogeneous group of diabetics with insulin-dependent diabetes mellitus and non-insulin dependent diabetes mellitus who had been diagnosed for more than 5 years. Although Keshavarzian emphasized the delay in gastric emptying, particularly with solids, some diabetic subjects in the study exhibited a more rapid gastric emptying compared to controls. Liquid gastric emptying was generally the same for both the controls and diabetics with the gastric half-emptying time (t1/2) showing no significant difference. It was noted that some of the patients exhibited abnormally fast emptying, but no significance was associated with the observation.
Campbell et aI. (4) described delayed gastric emptying in 10 of 12 diabetic subjects. Although the majority of the patients showed delayed gastric emptying, two of the subjects exhibited more rapid gastric emptying rates compared with controls.
Horowitz et aI. (5) described delayed gastric and esophageal emptying in 20 subjects with non-insulin dependent diabetes mellitus. The duration of known diabetes in the subjects ranged from 1-20 years. Although two of the subjects exhibited more rapid than normal liquid gastric emptying, the group of 20 as a whole exhibited delayed liquid gastric emptying (t1/2 slower than in normal patients, p<0.05). There was significant delay of solid food emptying in these patients (increased retention of solid food at 100 min, p<0.001).
Gastric emptying has been studied as a non-invasive diagnostic tool as an indicator of metabolic and neural disturbances. For example, chronic forms of gastric stasis can be caused by innervation abnormalities in diabetics with autonomic neuropathy (6). Many other conditions have been studied, including those in patients who had stomach operations or diseases of the gastrointestinal tract. Generally, the majority had delayed gastric emptying (7). In particular, delayed gastric emptying appears to be a phenomenon associated with diabetes. It has been recognized that by delaying nutrient absorption, glucose disposal and insulin economy may be enhanced (14).
Methods of regulating pyloric functions are known in the art. Diabetic gastroparesis and hypertrophic pyloric stenosis are examples of conditions successfully treated (8); delayed gastric emptying has been treated with drugs that accelerate the emptying process, for example metoclopramide or domperidone (11). An opposite effect is shown by Propantheline and opiates which delay gastric emptying (11).
There is some information on the effects of different compounds on enzyme components of pancreatic secretion, for example, the role of cholecystokinin (CCK) (12) and possible regulatory control by other gut hormones, such as VIP which stimulate insulin release from the pancreas (9). It is known that CCK has a significant role in regulating glucose homeostasis in humans (13) and that it delays gastric emptying and reduces hyperglycemia (14). However, the connection between CCK secretion on gastric emptying and insulin release in normal and diabetic patients has not yet been fully evaluated (10).
Studies so far reported indicate that in diabetic patients, delayed gastric emptying is typical. However, until now, there was no realization that certain classes of patients, those-not yet manifesting diabetes, those at risk to develop diabetes and those in early stages of diabetes or having non-insulin dependent diabetes, exhibit abnormally rapid gastric emptying. It was this unexpected and surprising discovery that led to the development of a method of a simple treatment By delaying gastric emptying in this group of patients at high risk to develop diabetes, insulin and plasma glucose levels may be maintained at levels much closer to normal levels. This is a first and significant step in early treatment of those at risk for developing debilitating forms of diabetes, even insulin-dependent diabetes, and may delay or forestall completely the usual progress of the disease.
SUMMARY OF THE INVENTION
The invention is based on the unexpected and surprising discovery that early non-insulin dependent diabetics exhibit significantly more rapid gastric emptying than normal controls. This finding forms the rationale for methods of diagnosis and for treatments designed to delay the onset of symptomatic diabetes and possibly to alter the course of the disease. Treatment is based on the use of compounds known to delay gastric emptying, several of which may be employed.
In general, the invention relates to a method of restoring or maintaining glucose metabolic indicators at normal or near-normal levels in an animal or human exhibiting rapid gastric emptying. The method utilizes a substance that will alter gastric emptying and is given in an amount to delay gastric emptying so that normal or near normal emptying rates are attained.
Glucose metabolic indicators relate to interconnected metabolic events. Such parameters include blood glucose levels, blood insulin levels, post prandial glucose and insulin levels, hemoglobin AlC, C-peptide, quantitation of insulin resistance and blood levels of gastric inhibitory peptide (GIP) and cholecystokinin (CCK). One or more of these parameters may exceed normal range without indication to the individual that altered metabolic patterns are developing. These patterns are frequently very early symptoms of diabetes mellitus. For example, blood glucose levels may be high and sugar may be present in the urine. An individual may experience increased thirst and frequency in urination or, in females, vaginal yeast infections without awareness that a health problem exists or is developing. Some of these subjects may exhibit rapid gastric emptying. Rapid gastric emptying is known to affect several parameters relating to the feedback controlling pyloric contraction. The process is complex, but delaying gastric emptying appears to slow delivery of glucose to the duodenum thereby reducing postprandial hyperglycemia. Therefore, in delaying gastric emptying, a treatment is provided which may control the development or at least delay the onset of symptoms that are frequently associated with the onset of diabetes mellitus.
Diabetes mellitus in its early stages may exhibit symptoms that are virtually unnoticed. As the disease develops, later stages may include problems with vision, neuropathy and a marked increase in the number of infections. Later stages of the disease may be associated with loss of vision and atherosclerosis, the latter resulting in circulatory problems, including coronary heart disease.
A particular aspect of the invention therefore is the treatment of a mammal, particularly a human, exhibiting rapid gastric emptying and also showing signs of an early or prediabetic condition, such as elevated blood glucose levels, glycosuria or high levels of endogenous insulin. Using this method of treatment, one first identifies an early or prediabetic condition in an individual. In the more usual circumstance, gastric emptying studies are performed after these symptoms appear; however, some groups of individuals are known to be at risk to develop diabetes. These groups include the morbidly obese, those with a family history of diabetes and most particularly certain ethnic or minority groups, including Hispanics, Eskimos, American Indians, Asian Indians, Chinese, Japanese, Polynesians and those of Jewish descent. In such cases, prudent medical practice would indicate a test of gastric emptying rates. Individuals exhibiting abnormally rapid gastric emptying would then be treated with a therapeutically effective dose of a gastric emptying inhibiting substance. This will be an amount sufficient to alleviate or eliminate symptoms associated with early or prediabetes, particular symptoms including elevated blood glucose and insulin levels, insulin resistance, increased susceptibility to infection and/or glycosuria while also maintaining gastric emptying within normal levels. Individuals at risk or in early stages of diabetes may generally be identified by measuring blood glucose and insulin peak levels after glucose administration.
Any of a number of known gastric emptying inhibiting substances may be used to delay gastric emptying, including gut hormones and analogs, aluminum hydroxide compounds, opiates, estrogens, trypsin inhibitors and tricyclic compounds. Some useful polypeptides might include bombesin, somatostatin, secretin, gastric inhibitory peptide (GIP), VIP, glucagon or gastrin. Propantheline is recognized as delaying gastric emptying. Trypsin inhibitors would be expected to be useful, including Bowman-Birk inhibitor and Camostate. A most preferred substance is cholecystokinin, well studied in humans nd known to effectively delay gastric emptying. Other compounds delaying gastric emptying may be used, including substances that act directly to stimulate a feedback which effectively delays gastric emptying.
The invention is also envisioned as useful in assessing risk of diabetes mellitus in subjects who do not show any abnormalities in glucose metabolism but who have other factors which experience has shown indicate a tendency to develop diabetes mellitus. For example, the morbidly obese, those with a family history of diabetes, those with mature onset diabetes. Non-insulin dependent diabetes is typically seen in individuals over 30 years of age who are able to control the diabetes through diet or oral hypoglycemic drugs.
Another risk group is women who develop diabetes during pregnancy, often distinguished as gestational diabetes because it may first appear to develop during pregnancy. Babies from these pregnancies have an increased risk of birth defects. Rapid gastric emptying would indicate a potential to develop high blood sugar. Control through delaying of gastric emptying might prevent detrimental effects on the fetus during the pregnancy.
Gastric emptying rates may be measured using dye dilution methods and x-ray images after a barium-loaded meal. More preferable techniques include sonography, electrical impedance or scintigraphic methods which are rapid and noninvasive. A most preferable method is scintigraphic determination of ingested 99m technetium-sulfur colloid using low energy gamma cameras.
Yet another aspect of the invention is a pharmaceutical composition which combines insulin and cholecystokinin in a vehicle suitable for injection This may be saline, a suitable buffer such as phosphate or acetate, an oil-based vehicle or the like. pH modifying substances may be added if necessary to maintain near-neutral or slightly acidic pH. A most preferable mode of injection is intramuscular or subcutaneous because this is normally the mode by which most diabetics self-administer insulin. This composition would be suitable for patients who require insulin and exhibit rapid gastric emptying.
The invention also comprises a pharmaceutical composition of a compound that delays gastric emptying and an oral hypoglycemic in an orally acceptable pharmaceutical formulation. Pharmaceutically acceptable formulating agents include powders, granules, capsules, coated tablets, syrupy preparations and aqueous suspensions. Formulating agents employed may be solid or liquid, including but not limited to such solids as calcium phosphate, calcium carbonate, dextrose, sucrose, dextrin, sucrose ester, starch, sorbitol, mannitol, crystalline cellulose, talc, kaolin, synthetic aluminum silicate, carboxymethyl cellulose, methylcellulose, cellulose acetate phthalate, alginates, polyvinyl pyrrolidone, polyvinyl alcohol, gum arabic, tragacanth gum, gelatin, bentonite, agar powder, shellac, Tween 80, carrageenans and psyllium. Flavor enhancers may be added to oral preparations, including taste masking substances such as sweeteners and citrus flavors. Other additives, including color, preservatives, bulk or antifoam agents may also be included in the formulation. Examples of compounds that delay gastric emptying and may be administered orally are trypsin inhibitors, preferably Bowman-Birk inhibitor or Camostate. These may be mixed with any suitable oral hypoglycemic indicated for the patient, such as chlorpropamide, tolbutamide, tolazamide, glipizide or glyburide.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the gastric emptying pattern of six subjects with non-insulin dependent diabetes mellitus and an equal number of age and sex-matched controls.
FIG. 2 compares the gastric half-emptying time for subjects with non-insulin dependent diabetes and non diabetics.
FIG. 3 shows the percent glucose remaining in the stomach 75 min after administration of a glucose solution to non-insulin dependent diabetes mellitus patients and to control patients.
FIG. 4 compares plasma glucose concentrations between subjects with non-insulin dependent diabetes mellitus and controls at 15 min intervals up to 120 min.
FIG. 5 shows plasma glucose levels in mg/dl over a period of 120 min in subject 1. Plasma glucose levels following ingestion of glucose solution without CCK infusion are indicated by •. Plasma glucose levels following ingestion of glucose solution with simultaneous CCK infusion are indicated by .
FIG. 6 shows plasma glucose levels in mg/dl over a period of 120 min in subject 2. Plasma glucose levels following ingestion of glucose solution without CCK infusion are indicated by •. Plasma glucose levels following ingestion of glucose solution with simultaneous CCK infusion are indicated by .
FIG. 7 shows percent of stomach contents emptied in subject 1 (gastric emptying) measured over a period of 160 min. Gastric emptying of glucose solution with simultaneous CCK infusion is represented by •. Gastric emptying of glucose solution without CCK infusion is represented by .
FIG. 8 shows percent of stomach contents emptied in subject 2 (gastric emptying) measured over a period of 120 min. Gastric emptying of glucose solution with simultaneous CCK infusion is represented by •. Gastric emptying of glucose solution without CCK infusion is represented by .
FIG. 9A and FIG. 9B show the effect of CCK infusion on GIP levels in two subjects measured over a period of 120 minutes Gastric emptying of glucose solution without CCK is represented by . Gastric emptying of glucose solution with simultaneous CCK infusion is represented by •.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Subjects
Six subjects with early NIDDM (diagnosed for less than two years) and six sex and age matched nondiabetic subjects underwent gastric emptying studies. The subjects (10 males, 2 females) ranged in age from 35 to 62 years of age. Five of the six subjects with NIDDM were Hispanic Americans, one an Iranian. All 6 non-diabetic subjects were non-Hispanic Caucasians with normal fasting glucose values. The subjects with NIDDM had been previously diagnosed as being diabetic using a 75 g oral glucose tolerance test (OGTT) with blood sampled fasting and at 2 hr according to current WHO criteria. All the subjects with NIDDM were taking oral hypoglycemic medication which they discontinued the evening prior to the study. All studies were begun between 7-8 am following a 12 hr fast.
Statistical Methods
The data were analyzed using a paired t-test. The gastric half-emptying time for each patient was calculated by linear interpolation.
Materials
Sources of drugs and materials are as indicated. Bowman-Birk trypsin inhibitor is available from Nestech, Ltd, Devey, Switzerland. ONA Pharmaceuticals, Ltd., Osaka, Japan, may be contacted for availability of another trypsin inhibitor, Camostate.
The following examples are presented for illustrative purposes and are not intended to be limiting
EXAMPLE 1
Gastric Emptying in Human Subjects
Gastric emptying studies utilizing a gamma camera (Scintronix USA Inc., Woburn MA, USA) were performed with a modified 0.62 M (50g glucose in 450 ml water) glucose solution. The use of this glucose solution in gastric emptying has been previously studied (9). Approximately 200 μCi of 99 metastable technetium sulfur colloid ( 99m Tc-SC, CIS-US, Bedford, MA, USA) were added and mixed with the glucose solution. The subjects drank the glucose solution in its entirety in a 5 minute span shortly after the 99m Tc-SC had been added to the solution.
The subjects were then placed in a semi-reclining position (45 degrees from horizontal) and the gamma camera was positioned anteriorly. Only anterior views were used in calculating the gastric emptying since it has been shown (12) that the geometric means of the anterior and posterior projections, using liquid meals, were very similar to those of the anterior views alone. Data were collected continuously and summed at 60 second intervals. Images were acquired during an interval of 120 minutes. Blood samples were drawn at 15 minute intervals beginning just prior to ingestion of the glucose solution and ending at 120 minutes. The blood was collected in vacutainer tubes containing potassium oxalate and sodium fluoride (Becton Dickinson Vacutainer Systems, Rutherford, N.J., USA). Glucose analysis was performed on a Paramax instrument (Baxter Healthcare Corp., Irvine, CA, USA).
The Scintronix gamma camera was used with low energy, all purpose collimator at a 20% window setting centered at 140 keV. The camera was connected to a Medical Data Systems Computer (An Arbor, MI, USA). Counts in the stomach region of interest were calculated in each 60 second image. After correcting for radioactive decay, the count rates were converted to percentage of the maximum count rate recorded.
The half emptying time was significantly (P=0.009) shorter for the subjects with non-insulin dependent diabetes (average=32.6 min, SE=5.5) than for the non-diabetics (average=64.3, SE =5.5) as shown in FIGS. 1 and 2. The area under the gastric-emptying curve during the first hour, representing an overall time-weighted average, for the subjects with non-insulin dependent diabetes mellitus was 74% of the area under the curve for the non-diabetics (P=0.016). The area under the curve during the two hours for the subjects with NIDDM was 60% of the area under the curve for the non-diabetics (P=0.002). The half-emptying time and the area under the curve indicate substantially faster emptying for the subjects with NIDDM. The largest mean separation between subjects with NIDDM and non-diabetics occurred at 75 minutes (P=0.004) as shown in FIG. 3.
The fasting glucose concentrations were significantly different between the subjects with NIDDM and non-diabetics (P=0.009). The glucose concentrations also were different between diabetics and non-diabetics at 15 min intervals as shown in FIG. 4. At other times post ingestion, glucose concentration was not measured on all subjects.
The area under the glucose concentration curve during the first hour, representing an overall time-weighted average, for the subjects with NIDDM was 252% of the area under the curve for the non-diabetics (P=0.006). The area under the curve during the two hours for the subjects with NIDDM was 292% of the area under the curve for the non-diabetics (P=0.003). Even though the subjects with NIDDM had more rapid gastric emptying, their plasma glucose peak was delayed (60-75 min) when compared to the normal controls (45 min).
The average rate of calories emptied into the intestine (calculated using the time of half gastric emptying) by the subjects with NIDDM was 3.1 kcal/min, while non-diabetic controls emptied at a rate of 1.6 kcal/min. The extremes in caloric emptying varied between a diabetic subject emptying at a rate of 7.1 kcal/min and a non-diabetic subject emptying at 1.2 kcal/min.
EXAMPLE 2
Control of Gastric Emptying by Administration of CCK
Two subjects with early NIDDM (diagnosed for less than 2 years) underwent two separate gastric emptying studies. Subjects were Hispanic Americans, ages 37 and 49, both previously diagnosed as diabetic according to current WHO criteria using a 75 g glucose tolerance test (OGTT) with blood sampled fasting and at 2 hr. The one subject on oral hypoglycemic medication discontinued his medication the evening prior to the study. All studies were begun between 7-8 am following a 12 hour fast.
An 18 gauge angiocatheter was placed in one antecubital fossa for blood drawing while another 18 gauge angiocatheter was placed in the other antecubital fossa for a 0.9% (normal saline) infusion (60 ml/min). Gastric emptying studies utilizing a gamma camera (Scintronix USA, Inc., Woburn MA) were performed with a modified 0.62 M (50 g glucose in 450 ml water) glucose solution. This solution has been used previously in gastric emptying studies (9). Approximately 200 μCi of 99 metastable technetium sulfur colloid ( 99m Tc-SC, CIS-US, Bedford, MA) was added and mixed with the glucose solution. The subjects drank the entire glucose solution within 5 min shortly after the 99m Tc-SC had been added to the solution.
The subjects were then seated at a 90 degree angle in front of a gamma camera. The subjects were instructed to stand at 10 min intervals so that anterior, posterior and left anterior oblique views could be obtained (one minute each) by the camera for a total of 120 min. Images were thus acquired every 10 min. The Scintronix gamma camera was used with a low-energy, all purpose collimator at a 20% window setting centered at 140 keV. The camera was connected to a Medical Data Systems Computer (Ann Arbor, MI). Counts in the stomach region of interest were calculated in each second image. After correcting for radioactive decay, the count rates were converted to a percentage of the maximum count rate recorded.
Blood samples were drawn from the indwelling 18 gauge angiocatheter in the antecubital fossa at 15 min intervals beginning just prior to ingestion of the glucose solution and ending at 120 min. Blood for glucose evaluation was collected in grey-top vacutainer tubes containing potassium oxalate and sodium fluoride. Blood for insulin and C-peptide was collected in red top tubes. Samples for hemoglobin A-1-C, gastric inhibitory polypeptide (GIP) and CCK were collected in lavender top tubes containing EDTA. All glass tubes were from Becton Dickinson Vacutainer Systems, Rutherford, NJ. Glucose analysis were performed on a Paramax instrument (Baxter Healthcare Corp., Irvine, CA). Hemoglobin AIC was performed by the micro column test (Bio-Rad, Hercules, CA 94547).
The C-peptide assay was performed by Smith Kline Bioscience Laboratories, Van Nuys, CA by radioimmunoassay (Diagnostic Products, Los Angeles, CA 90045). The assay for insulin was performed by Smith Kline Bioscience Laboratory, St. Louis, MO by radioimmunoassay (Pharmacia Diagnostics, Fairfield, NJ 07004). Assays for GIP and CCK were performed by radioimmunoassay by the Gastroenterology Unit at Mayo Clinic (Rochester, MN 55905) using in-house kits.
In the first test each subject drank the glucose solution. A gastric emptying study was then performed with simultaneous infusion of normal saline during a two hour period.
The second study was performed 3 days later. Subjects drank the glucose solution and a gastric emptying study was performed with simultaneous infusion of CCK (Kinevac™, Squibb Diagnostics, Princeton, NJ 08543) at 48 pM/kg/hr.
Both the saline and the CCK solutions were infused using an Abbott/Shaw Life Care™ Pump, Model 4 (Abbott Laboratories, North Chicago, IL 60064). The saline and CCK solutions were delivered by the pump through a vented Abbott/Shaw IV, Lifecare™ pump set (Abbott Hospitals, Inc., North Chicago, IL 60064). The pump was set to deliver 60 ml fluid per hr. The infusate of CCK solution consisted of 3 vials of lyophilized CCK (5 μg each) rehydrated with 5 ml normal saline each. A total of 135 ml of normal saline was added to the rehydrated CCK for a total of 150 ml. The 150 ml was injected into an Empty Evacuated Container (Abbott Laboratories, North Chicago, IL 60064).
Infusions of the saline solution for the first test and the CCK solution for the second test were begun 10 min prior to ingestion of the glucose solution.
At the initiation of the study, subject 1 had a hemoglobin AIC level of 4.3% and C-peptide of 4.0 ng/ml. Subject 2 had a hemoglobin AIC level of 9.0% and a C-peptide of 2.9 ng/ml.
In the first test with a controlled saline infusion, plasma glucose levels in subject 1 peaked at 60 min at 272 mg/dl with insulin levels also peaking at 60 min at 111μU/ml. In subject 2 plasma glucose levels were maximal at 45 min at 488 mg/dl while insulin levels remained low, reaching a maximum level of 30 μU/ml at 90 min. Gastric half-emptying time was 25 min for subject I and 15 min for subject 2. CCK levels in subject 1 peaked at 90 minutes at the level of 81.0 pg/ml. GIP levels peaked at 30 min at 608 pg/ml. CCK levels in subject 2 peaked at 30 min at a level of 61 pg/ml. Data are shown in FIGS. 5-9 and Table 1. GIP levels insubject 2 peaked at 30 min at 1169 pg/ml, see FIG. 9.
TABLE 1______________________________________Insulin Levels With and Without Simultaneous CCKAdministration (μU/ml) Subject 1 Subject 2Time (min) No CCK CCK No CCK CCK______________________________________ 0 24 41 19 1915 36 36 23 1830 64 29 19 1845 84 38 24 1860 111 28 25 1975 98 30 24 1890 128 34 30 18105 95 32 21 19120 82 46 20 19______________________________________
The effect of CCK infusion on gastric emptying was studied in each subject. In subject 1, plasma glucose levels remained steady throughout the two hour study and ranged from 121 mg/dl to 125 mg/dl as shown in FIG. 5. Insulin levels also remained in a narrow range (28-46 μU/ml, Table 1). The gastric emptying time, as indicated in FIG. 7, was markedly delayed with only 11% of the total volume emptying after 120 min. At the end of the two hr period, the CCK infusion was stopped and a more rapid gastric emptying pattern ensued. One hundred forty min after ingestion of the glucose solution, 55% of the total volume remained in the stomach, 41% after I60 min, FIG. 7. CCK levels peaked at 120 min post ingestion of the glucose solution. GIP levels peaked at 30 min.
In subject 2, CCK infusion delayed peak plasma glucose levels by approximately 30 min from 45 to 75 min as shown in FIG. 6. Insulin levels were low throughout the two hr test period, ranging between 18-19 μU/ml. The gastric half-emptying time was 43 min as shown in FIG. 8. CCK levels peaked at 105 min post ingestion of the glucose solution. GIP levels peaked at 60 min. Differences in GIP kinetics before and after CCK administration are shown in FIG. 9.
The present invention has been described in terms of particular embodiments found by the inventors to comprise preferred modes of practice of the invention. It will be appreciated by those of skill in the art that in light of the present disclosure numerous modifications and changes can be made without departing from the intended scope of the invention. For example, other methods than drugs might be used to delay gastric emptying, such as cellulose derivatives and gastric bubbles. All such modifications are intended to be within the scope of the claims.
REFERENCE
The references listed below are incorporated herein by reference to the extent they supplement, explain, provide a background for or teach methodology, techniques and/or compositions employed herein.
1. Thompson, D. G., Wingate, D. L., Thomas, M. and Harrison, D., Gastroenterology 82, 51-55 (1982).
2. Brener, W., Hendrix, T. R., MoHugh, P. R., Gastroenterology 85, 76-82 (1983).
3. Keshavarzian, A., Iber, F. L., Vaeth, J., Am. J. Gastroenterology 82, 29-35 (1987).
4. Campbell, I. W., Heading, R. C., Tothill, P., :Buist, T. A. S., Ewing, D. J., Clarke, B. F., Gut 18, 462-467 (1977).
5. Horowitz, M., Harding, P. E., Maddox, A. F. et al., Diabetologia 32, 151-159 (1989).
6. Smout, J. J. P. M., Z. Gastroenterol. 24/supp 2, 45-54 (1986).
7. Pellegrini, C. A., Broderick, W. C., VanDyke, D. and Way, L. W., Am. J. Surg. 145, 143-151 (1983).
8. Akkermans, L. M. A., Houghton, L. A. and Brown, N. J., Scand. J. Gastroenterol Suppl. 24, 27-31 (1989).
9. Schwartz, J. G., Phillips, W. T. and Aghebat-Khairy, B. Clin. Chem. 36, 125 (1990).
10. Liddle, R. A., Fed. Res. in Progress, Natl. Inst. Diabetes and Dig. Dis., 1990.
11. Chaudhuri, T. K and Fink, S., Am J. Gastroenterology 85, 223-231 (1990).
12. Liddle, R. A. et aI., J. Clin. Invest. 77, 992 (1986).
13. Liddle, R. A., Rushakoff, R. J., Morita, E. T., Beccaria, L., Carter, J. D. and Goldfine, I. D., J. Clin Invest. 81. 1675-1681 (1988).
14. Jenkins, D. J. A., Thomas, M. S., Wolever, M. S., Ocana, A. M., Vuksan, V., Cunnane, S. C., Jenkins, M., Wong, G. S., Singer, W., Bloom, S. R., Blendis, L. M. and Josse, R. G., Diabetes 39, 775-780 (1990). | The invention relates to a method of diagnosing and treating individuals with diabetes or at risk to develop diabetes mellitus. In particular, gastric emptying determinations are used to assess risk. Risk or early symptoms associated with subsequent development of diabetes mellitus may be controlled or alleviated by delaying gastric emptying. Delay or
The Government may have certain rights in the invention pursuant to grant No. 2-S07-RR07187-11. | 8 |
TECHNICAL FIELD
The present invention relates to novel compounds having activity to inhibit leukotriene effects, to pharmaceutical compositions comprising these compounds, and to a medical method of treatment. More particularly, the present invention concerns symmetrical bis-heteroarylmethoxyphenylcycloalkyl compounds which inhibit leukotriene effects, to pharmaceutical compositions comprising these compounds and to a method of inhibiting leukotriene biosynthesis.
BACKGROUND OF THE INVENTION
The leukotrienes are extremely potent substances which produce a wide variety of biological effects, often in the nanomolar to picomolar concentration range. Leukotrienes are important pathological mediators in a variety of diseases. Alterations in leukotriene metabolism have been demonstrated in a number of disease states including asthma, allergic rhinitis, rheumatoid arthritis and gout, psoriasis, adult respiratory distress syndrome, inflammatory bowel disease, endotoxin shock syndrome, atherosclerosis, ischemia induced myocardial injury, and central nervous system pathology resulting from the formation of leukotrienes following stroke or subarachnoid hemorrhage.
Compounds which prevent leukotriene biosynthesis are thus useful in the treatment of disease states such as those listed above in which the leukotrienes play an important pathophysiological role.
U.S. Pat. No. 4,970,215 to Mohrs et al. discloses and claims certain 4-(quinolin-2-ylmethoxy)phenyl cycloalkyl acetic acids as inhibitors of leukotriene biosynthesis.
European Patent Application 0 349 062 to Zamboni et al. discloses and claims certain 2-quinolylmethoxyphenyl substituted thioalkanoic acid derivatives as leukotriene biosynthesis inhibitors. Prasit et al. in Bioorganic and Medicinal Chemistry Letters, 1: 645-648 (1991) describe { 4-(4-chlorophenyl)-1- 4-(2-quinolylmethoxy)phenyl!-butyl!thio}acetic acid, L-674,636, as a new, potent and orally active leukotriene synthesis inhibitor.
U.S. Pat. No. 5,358,955 to Brooks et al. discloses and claims certain quinolylmethoxyphenyl derivatives as inhibitors of leukotriene biosynthesis.
SUMMARY OF THE INVENTION
In its principal embodiment, the present invention provides certain symmetrical bis-heteroarylmethoxyphenylcycloalkyl carboxylate compounds and pharmaceutically acceptable salts thereof having the formula I: ##STR2##
In the compound of formula I above, m is an integer of 1 to 9, inclusive and n is an integer of 1 to 4, inclusive
The group W is the same at each occurrence and is selected from the group consisting of (a) unsubstituted quinolyl; (b) quinolyl substituted with one, two, or three susbstituents selected from the group consisting of halogen, C 1-6 alkyl, and C 1-6 alkoxy; (c) unsubstituted benzothiazoyl; (d) benzothiazoyl substituted with one, two, or three susbstituents selected from the group consisting of halogen, C 1-6 alkyl, and C 1-6 alkoxy; (e) unsubstituted quinoxalyl; and (f) quinoxalyl substituted with one, two, or three susbstituents selected from the group consisting of halogen, C 1-6 alkyl, and C 1-6 alkoxy.
The group Y is one to four optional substituents selected from: halogen, C 1-6 alkyl, and C 1-6 alkoxy;
X is absent or is selected from the group consisting of (a) C 1-6 alkylene; (b) C 1-6 alkenylene; and (c) C 1-6 alkynylene.
Z is selected from the group consisting of (a) COB; (b) C(R 2 ) 2 --O--N═A--COB; and (c) C(R 2 )═N--O--A--COB where A is C 1-6 alkylene, and B is selected from the group consisting of (a) --OH, (b) --O--M + where M is a pharmaceutically acceptable cation; (c) --OR 6 where R 6 is hydrogen or alkyl of one to six carbon atoms; (d) --NR 6 R 7 where R 6 is as previously defined and R 7 is selected from the group consisting of hydrogen, alkyl of one to six carbon atoms, hydroxy, and alkoxy or from one to six carbon atoms, or R 6 and R 7 , together with the atom to which they are attached, form a ring of five to eight members containing one optional heteratom selected from N, O and S; and (e) --O--D where D is a metabolically cleavable group.
The present invention also provides pharmaceutical compositions which comprise a leukotriene biosynthesis inhibitory effective amount of compound as defined above in combination with a pharmaceutically acceptable carrier.
The invention further relates to a method of inhibiting leukotriene biosynthesis in a host mammal in need of such treatment comprising administering to a mammal in need of such treatment a therapeutically effective amount of a compound as defined above.
DETAILED DESCRIPTION
As used throughout this specification and the appended claims, the following terms have the meanings specified.
The term alkyl refers to a monovalent group derived from a straight or branched chain saturated hydrocarbon by the removal of a single hydrogen atom. Alkyl groups are exemplified by methyl, ethyl, n- and iso-propyl, n-, sec-, iso- and tert-butyl, and the like.
The terms alkoxy and alkoxyl denote an alkyl group, as defined above, attached to the parent molecular moiety through an oxygen atom. Representative alkoxy groups include methoxy, ethoxy, propoxy, butoxy, and the like.
The terms alkenyl as used herein refer to monovalent straight or branched chain groups of 2 to 6 carbon atoms containing a carbon-carbon double bond, derived from an alkene by the removal of one hydrogen atom and include, but are not limited to groups such as ethenyl, 1-propenyl, 2-propenyl, 2-methyl-1-propenyl, 1-butenyl, 2-butenyl and the like.
The term alkylene denotes a divalent group derived from a straight or branched chain saturated hydrocarbon containing by the removal of two hydrogen atoms, for example --CH 2 --, --CH 2 CH 2 --, --CH(CH 3 )CH 2 -- and the like.
The term alkenylene denotes a divalent group derived from a straight or branched chain hydrocarbon containing at least one carbon-carbon double bond. Examples of alkenylene include --CH═CH--, --CH 2 CH═CH--, --C(CH 3 )═CH--, --CH 2 CH═CHCH 2 --, and the like.
The terms alkynylene refers to a divalent group derived by the removal of two hydrogen atoms from a straight or branched chain acyclic hydrocarbon group containing at least one carbon-carbon triple bond. Examples of alkynylene include --CH.tbd.CH--, --CH.tbd.C--CH 2 --, --CH.tbd.CH--CH(CH 3 )-- and the like.
The term aryl as used herein refers to a monovalent carbocyclic group containing one or more fused or non-fused phenyl rings and includes, for example, phenyl, 1- or 2-naphthyl, 1,2-dihydronaphthyl, 1,2,3,4-tetrahydronaphthyl, and the like.
The term cycloalkyl as used herein refer to a monovalent saturated cyclic hydrocarbon group. Representative cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, bicyclo 2.2.1!heptane and the like.
Cycloalkylene denotes a divalent radical derived from a cycloalkane by the removal of two hydrogen atoms.
The term haloalkyl denotes an alkyl group, as defined above, having one, two, or three halogen atoms attached thereto and is exemplified by such groups as chloromethyl, bromoethyl, trifluoromethyl, and the like.
The term metabolically clearable group denotes a group which is cleaved in vivo to yield the parent molecule of the formula I indicated above wherein M is hydrogen. Examples of metabolically cleavable groups include --COR, --COOR, --CONRR and --CH 2 OR radicals where R is selected independently at each occurrence from alkyl, trialkylsilyl, carbocyclic aryl or carbocyclic aryl substituted with one or more of C 1 -C 4 alkyl, halogen, hydroxy or C 1 -C 4 alkoxy. Specific examples of representative metabolically cleavable groups include acetyl, methoxycarbonyl, benzoyl, methoxymethyl and trimethylsilyl groups.
The terms phenylene, pyridylene, thienylene, and furylene refer to divalent radicals derived by the removal of two hydrogen atoms from the ring systems of benzene, pyridine, thiophene, and furan, respectively.
By pharmaceutically acceptable salt it is meant those salts which are, within the scope of sound medical judgement, suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic response and the like, and are commensurate with a reasonable benefit/risk ratio. Pharmaceutically acceptable salts are well known in the art. For example, S. M. Berge, et al. describe pharmaceutically acceptable salts in detail in J. Pharmaceutical Sciences, 1977, 66:1-19. The salts can be prepared in situ during the final isolation and purification of the compounds of the invention, or separately by reacting the free base function with a suitable organic acid. Representative acid addition salts include acetate, adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphersulfonate, titrate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, fumarate, glucoheptonate, glycerophosphate, hemisulfate, heptonate, hexanoate, hydrobromide, hydrochloride, hydroiodide, 2-hydroxy-ethanesulfonate, lactobionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, toluenesulfonate, undecanoate, valerate salts, and the like.
Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, and the like, as well as nontoxic ammonium, quaternary ammonium, and amine cations, including, but not limited to ammonium, tetramethylammonium, tetraethylammonium, methylamine, dimethylamine, trimethylamine, triethylamine, ethylamine, and the like.
Asymmetric centers may exist in the compounds of the present invention. The present invention contemplates the various stereoisomers and mixtures thereof. Individual stereoisomers of compounds of the present invention are made by synthesis from starting materials containing the chiral centers or by preparation of mixtures of enantiomeric products followed by separation as, for example, by conversion to a mixture of diastereomers followed by separation by recrystallization or chromatographic techniques, or by direct separation of the optical enantiomers on chiral chromatographic columns. Starting compounds of particular stereochemistry are either commercially available or are made by the methods detailed below and resolved by techniques well known in the organic chemical arts
In one preferred embodiment of the present invention, compounds of the present invention have the generic structure I indicated above wherein W is unsubstituted quinolyl or quinolyl substituted with one, two, or three susbstituents selected from the group consisting of halogen, C 1-6 alkyl, and C 1-6 alkoxy.
In another preferred embodiment, compounds of the present invention have the generic structure I indicated above wherein W is unsubstituted benzothiazolyl or benzothiazolyl substituted with one, two, or three susbstituents selected from the group consisting of halogen, C 1-6 alkyl, and C 1-6 alkoxy.
In yet another preferred embodiment, compounds of the present invention have the generic structure I indicated above wherein W is unsubstituted quinoxalyl or quinoxalyl substituted with one, two, or three substituents selected from the group consisting of halogen, C 1-6 alkyl, and C 1-6 alkoxy.
In a particularly preferred embodiment of the present invention, W is unsubstituted or substituted quinolyl, m is an integer of from 1 to three, inclusive, and X is methylene.
Examples of compounds falling within the scope of the present invention include, but are not limited to:
4,4-bis-(4-(2-quinolylmethoxy)phenyl)cyclohexane carboxylic acid;
4,4-bis-(4-(2-quinolylmethoxy)phenyl)cyclohexane carboxylic acid sodium salt;
4,4-bis-(4-(2-quinolylmethoxy)phenyl)cyclohexyliminoxyacetic acid sodium salt;
4,4-bis-(4-(2-quinolylmethoxy)phenyl)cyclohexyliminoxy-2-propionic acid sodium salt;
4,4-bis-(4-(2-quinolylmethoxy)phenyl)-1-cyclohexylmethyliminoxyacetic acid; and
4,4-bis-(4-(2-quinolylmethoxy)phenyl)-1-cyclohexyloximinoacetic acid
Lipoxygenase Inhibition Determination
Leukotriene biosynthesis inhibitory activity of representative compounds of the present invention was evaluated in an assay involving calcium ionophore-induced LTB 4 expressed in human polymorphornuclear leukocytes (PMNL). Human PMNL isolated from heparinized (20 USP units/mL) venous blood (25 mL) obtained from healthy volunteers was layered over an equal volume of Ficoll-Hypaque Mono-Poly Resolving Medium (ICN Flow, Costa Mesa, Calif.) and centrifugated at 400×g for 40 min at 20° C. The PMNL was collected, erythrocytes lysed and washed 2× and suspended at 1.0×10 7 cells/mL in Earle's balanced salt solution with 17 mM Earle's HEPES. Aliquots of the cell suspension were preincubated with test compounds dissolved in DMSO (final concentration <2%) for 15 min. and stimulated with calcium ionophore (final concentration 8.3 μM) for 10 min. at 37° C. Incubations were stopped with the addition of two volumes of ice-cold methanol followed by centrifuging the cell suspensions at 4° C. for 10 min at 450×g. The mount of LTB 4 in the methanol extract was analyzed by enzyme-linked immunoassay or by HPLC analysis.
The compounds of this invention inhibit leukotriene biosynthesis as shown by the data for representative examples in Table 1.
TABLE 1______________________________________Inhibitory Potencies Against Calcium Ionophore StimulatedLeukotriene Formation in Human Polymorphonuclear Leukocytes Example IC.sub.50 (nM)______________________________________ 1 59 2 47 5 37______________________________________
Pharmaceutical Compositions
The present invention also provides pharmaceutical compositions which comprise compounds of the present invention formulated together with one or more non-toxic pharmaceutically acceptable carriers. The pharmaceutical compositions may be specially formulated for oral administration in solid or liquid form, for parenteral injection, or for rectal administration.
The pharmaceutical compositions of this invention can be administered to humans and other animals orally, rectally, parenterally, intracisternally, intravaginally, intraperitoneally, topically (as by powders, ointments, or drops), bucally, or as an oral or nasal spray. The term "parenteral" administration as used herein refers to modes of administration which include intravenous, intramuseular, intraperitoneal, intrasternal, subcutaneous and intraarticular injection and infusion.
Pharmaceutical compositions of this invention for parenteral injection comprise pharmaceutically acceptable sterile aqueous or nonaqueous solutions, dispersions, suspensions or emulsions as well as sterile powders for reconstitution into sterile injectable solutions or dispersions just prior to use. Examples of suitable aqueous and nonaqueous carriers, diluents, solvents or vehicles include water, ethanol, polyols (such as glycerol, propylene glycol, polyethylene glycol, and the like), and suitable mixtures thereof, vegetable oils (such as olive oil), and injectable organic esters such as ethyl oleate. Proper fluidity can be maintained, for example, by the use of coating materials such as lecithin, by the maintenance of the required particle size in the case of dispersions, and by the use of surfactants.
These compositions may also contain adjuvants such as preservative, wetting agents, emulsifying agents, and dispersing agents. Prevention of the action of microorganisms may be ensured by the inclusion of various antibacterial and antifungal agents, for example, paraben, chlorobutanol, phenol sorbic acid, and the like. It may also be desirable to include isotonic agents such as sugars, sodium chloride, and the like, Prolonged absorption of the injectable pharmaceutical form may be brought about by the inclusion of agents which delay absorption such as aluminum monostearate and gelatin.
In some cases, in order to prolong the effect of the drug, it is desirable to slow the absorption of the drug from subcutaneous or intramuscular injection. This may be accomplished by the use of a liquid suspension of crystalline or amorphous material with poor water solubility. The rate of absorption of the drug then depends upon its rate of dissolution which, in turn, may depend upon crystal size and crystalline form. Alternatively, delayed absorption of a parenterally administered drug form is accomplished by dissolving or suspending the drug in an oil vehicle.
Injectable depot forms are made by forming microencapsule matrices of the drug in biodegradable polymers such as polylactide-polyglycolide. Depending upon the ratio of drug to polymer and the nature of the particular polymer employed, the rate of drug release can be controlled. Examples of other biodegradable polymers include poly(orthoesters) and poly(anhydrides) Depot injectable formulations are also prepared by entrapping the drug in liposomes or microemulsions which are compatible with body tissues.
The injectable formulations can be sterilized, for example, by filtration through a bacterial-retaining filter, or by incorporating sterilizing agents in the form of sterile solid compositions which can be dissolved or dispersed in sterile water or other sterile injectable medium just prior to use.
Solid dosage forms for oral administration include capsules, tablets, pills, powders, and granules. In such solid dosage forms, the active compound is mixed with at least one inert, pharmaceutically acceptable excipient or carrier such as sodium citrate or dicalcium phosphate and/or a) fillers or extenders such as starches, lactose, sucrose, glucose, mannitol, and silicic acid, b) binders such as, for example, carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidone, sucrose, and acacia, c) humectants such as glycerol, d) disintegrating agents such as agar-agar, calcium carbonate, potato or tapioca starch, alginic acid, certain silicates, and sodium carbonate, e) solution retarding agents such as paraffin, f) absorption accelerators such as quaternary ammonium compounds, g) wetting agents such as, for example, cetyl alcohol and glycerol monostearate, h) absorbents such as kaolin and bentonite clay, and i) lubricants such as talc, calcium stearate, magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate, and mixtures thereof. In the case of capsules, tablets and pills, the dosage form may also comprise buffering agents.
Solid compositions of a similar type may also be employed as fillers in soft and hard-filled gelatin capsules using such excipients as lactose or milk sugar as well as high molecular weight polyethylene glycols and the like.
The solid dosage forms of tablets, dragees, capsules, pills, and granules can be prepared with coatings and shells such as enteric coatings and other coating well known in the pharmaceutical formulating art. They may optionally contain opacifying agents and can also be of a composition that they release the active ingredient(s) only, or preferentially, in a certain part of the intestinal tract, optionally, in a delayed manner. Examples of embedding compositions which can be used include polymeric substances and waxes.
The active compounds can also be in micro-encapsulated form, if appropriate, with one or more of the above-mentioned excipients.
Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, solutions, suspensions, syrups and elixirs. In addition to the active compounds, the liquid dosage forms may contain inert diluents commonly used in the art such as, for example, water or other solvents, solubilizing agents and emulsifiers such as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butylene glycol, dimethyl formamide, oils (in particular, cottonseed, groundnut, corn, germ, olive, castor, and sesame oils), glycerol, tetrahydrofurfuryl alcohol, polyethylene glycols and fatty acid esters of sorbitan, and mixtures thereof.
Besides inert diluents, the oral compositions can also include adjuvants such as wetting agents, emulsifying and suspending agents, sweetening, flavoring, and perfuming agents.
Suspensions, in addition to the active compounds, may contain suspending agents as, for example, ethoxylated isostearyl alcohols, polyoxyethylene sorbitol and sorbitan esters, microcrystalline cellulose, aluminum metahydroxide, bentonite, agar-agar, and tragacanth, and mixtures thereof.
Compositions for rectal or vaginal administration are preferably suppositories which can be prepared by mixing the compounds of this invention with suitable nonirritating excipients or carriers such as cocoa butter, polyethylene glycol or a suppository wax which are solid at room temperature but liquid at body temperature and therefore melt in the rectum or vaginal cavity and release the active compound.
Compounds of the present invention can also be administered in the form of liposomes. As is known in the art, liposomes are generally derived from phospholipids or other lipid substances. Liposomes are formed by mono- or multi-lamellar hydrated liquid crystals that are dispersed in an aqueous medium. Any non-toxic, physiologically acceptable and metabolizable lipid capable of forming liposomes can be used. The present compositions in liposome form can contain, in addition to a compound of the present invention, stabilizers, preservatives, excipients, and the like. The preferred lipids are the phospholipids and the phosphatidyl cholines (lecithins), both natural and synthetic.
Methods to form liposomes are known in the art. See, for example, Prescott, Ed., Methods in Cell Biology, Volume XIV, Academic Press, New York, N.Y. (1976), p. 33 et seq.
Dosage forms for topical administration of a compound of this invention include powders, sprays, ointments and inhalants. The active compound is mixed under sterile conditions with a pharmaceutically acceptable carrier and any needed preservatives, buffers, or propellants which may be required. Opthalmic formulations, eye ointments, powders and solutions are also contemplated as being within the scope of this invention.
Actual dosage levels of active ingredients in the pharmaceutical compositions of this invention may be varied so as to obtain an amount of the active compound(s) that is effective to achieve the desired therapeutic response for a particular patient, compositions, and mode of administration. The selected dosage level will depend upon the activity of the particular compound, the route of administration, the severity of the condition being treated, and the condition and prior medical history of the patient being treated. However, it is within the skill of the art to start doses of the compound at levels lower than required for to achieve the desired therapeutic effect and to gradually increase the dosage until the desired effect is achieved.
Generally dosage levels of about 1 to about 50, more preferably of about 5 to about 20 mg of active compound per kilogram of body weight per day are administered orally to a mammalian patient. If desired, the effective daily dose may be divided into multiple doses for purposes of administration, e.g. two to four separate doses per day.
Preparation of Compounds of this Invention
The commercially available, ethyl 4-oxocyclohexanecarboxylate I is reacted with phenol in the presence of a cone. H 2 SO 4 to provide adduct II. Adduct II is convened to the corresponding bis-quinoline derivative III by treatment with heteroarylmethylhalide (W--CH 2 X where X is Cl, Br, or I) in the presence of a suitable base such as K 2 CO 3 . The bis-quinoline intermediate III is hydrolyzed with hydroxide to provide the compounds of this invention represented by IV.
The compound IV can be reduced to alcohol V using standard methods and then transformed into additional compounds of this invention, the iminoxy alkylcarboxylate VI by applying methods outlined in Scheme 2.
1,4-Cyclohexanedione moncethylene ketal I is reduced by known methods such as with NaBH 4 to provide the corresponding hydroxy intermediate II. The hydroxy intermediate II is reacted with phenol in the presence of conc. H 2 SO 4 to provide diphenol derivative III. The diphenol derivative III is then reacted with the requisite heteroarylmethylhalide (W--CH 2 X) in the presence of a suitable base as K 2 CO 3 to afford adduct IV. The adduct IV is converted to the corresponding hydroxylamine derivative by known methods such as the Mitsunobu reaction with N-hydroxyphthalimide as nucleophile to provide the intermediate V which is converted to the correspoding O-alkylhydroxylamine VI by the known method or treatment with hydrazine hydrate. The O-alkylhydroxylamine derivative VI is then reacted in a standard manner with the requisite carbonyl unit, O═CR--A--COB to provide the compounds of this invention represented by the general structure VII. ##STR3##
The compound IV from Scheme 2 is oxidized by standard conditions like PCC in CH 2 Cl 2 to provide ketone derivative VIII. The ketone is then reacted with hydroxylamine to provide an oxime IX. Treatment of oxime IX cesium salt with ethyl bromoacetate followed by hydrolysis of the ester in standard conditions leads to a new compound of this invention, derivative X as shown in Scheme 3. ##STR4##
The foregoing may be better understood by reference to the following examples which are provided for illustration and not intended to limit the scope of the invention as it is defined by the appended claims.
EXAMPLE 1
Preparation of 4,4-bis-(4(2-quinolylmethoxy)phenyl)cyclohexane carboxylic acid ##STR5##
Phenol (1.1 g, 11.8 mmol) was diluted with water (0.53 mL) and cooled to 0° C. with stirring. Ethyl 4-oxocyclohexanecarboxylate (0.94 mL, 5.87 mmol) was added followed by dropwise addition of concentrated H 2 SO 4 (2.11 g). After 10 min the mixture was warmed to room temperature and allowed to stir for 4 hr. The mixture was then diluted with water and the product extracted with EtOAc (2×). The organic layer was washed with water, brine, dried over MgSO 4 and concentrated in vacuo. The residue was purified by chromatography (silica gel, 2:1 Hexane/EtOAc) to give 1.01 g (51%) of 4,4-bis(4-hydroxyphenyl)cyclohexane carboxylic acid ethyl ester.
To a solution of intermediate diphenol (0.93 g, 2.73 mmol) and K 2 CO 3 (1.04 g, 7.52 mmol) in DMF (50 mL) at room temperature was added 2-chloromethylquinoline hydrochloride (0.97 g, 5.27 mmol) and the mixture was allowed to stir for 24 hr. The mixture was diluted with water and the product extracted with EtOAc (2×). The organic layer was washed with water, brine, dried over MgSO 4 and concentrated in vacuo. The residue was triturated with hexanes and the precipitating solid was filtered and washed with hexanes to give 1.30 g (77%) of 4,4-bis(4-(2-quinolylmethoxy)phenylcyclohexanecarboxylic acid ethyl ester as a white powder.
The ester (0.52 g, 0.84 mmol) was suspended in EtOH at room temperature and 1N NaOH (1.01 mL, 1.01 mmol) was added to the solution. The resulting mixture was refluxed for 6 hr. The reaction mixture was then cooled and diluted with water. The EtOH was removed in vacuo. and the resulting aqueous solution was acidified with 10% citric acid to pH 3. The solid was filtered under vacuum and washed with water followed by hexanes to give 0.50 g (99%) of the title compound as a white powder: mp 194°-199° C.; 1 H NMR (300 MHz, DMSO-d 6 ) δ 1.45 (m, 2H), 1.76 (m, 2H), 1.88 (m, 2H), 2.33 (m, 1H), 2.62 (m, 2H), 5.31 (d, J=10.50 Hz, 4H), 6.90 (d, J=9 Hz, 2H), 7.00 (d, J=9 Hz, 2H), 7.13 (d, J=9 Hz, 2H), 7.28 (d, J=9 Hz, 2H, 7.62 (m, 3H), 7.68 (d, J=9 Hz, 1H), 7.78 (m, 2H), 8.00 (m, 4H), 8.40 (t, J=7.50 Hz, 2H), 12.04 (br s, 1H); MS (DCI-NH 3 ) m/z 595 (M+H) + ; Anal. Calcd for C 39 H 34 N 2 O 4 .0.70 H 2 O: C, 77.13; H, 5.87; N, 4.61; Found: C, 77.20; H, 5.84; N, 4.45.
EXAMPLE 2
Preparation of 4,4-bis-(4-(2-quinolylmethoxy)phenyl)cyclohexane carboxylic acid sodium salt
To the acid (0.62 g, 1.05 mmol), as prepared in Example 1, in THF (10 mL) was added 1N NaOH (1.0 mL, 1.0 mmol) was added and the mixture was allowed to stir for 2 hr at room temperature. The organic solvent was removed in vacuo and the residue was triturated with Et 2 O and filtered under vacuum. The solid was washed many times with Et 2 O to remove the remaining carboxylic acid to give 0.60 g (93%) of the title compound as a white powder. 1 H NMR (300 MHz, DMSO-d 6 ) δ 1.43 (m, 2H), 1.63 (m, 2H), 1.80 (m, 4H), 2.56 (m, 1H), 5.29 (d, J=9 Hz, 4H), 6.89 (d, J=9 Hz ,2H), 6.97 (d, J=9 Hz, 2H), 7.12 (d, J=9 Hz, 2H), 7.25 (d, J=9 Hz, 2H), 7.61 (m, 2H), 7.67 (d, J=9 Hz, 2H), 7.78 (m, 2H), 8.00 (m, 4H), 8.39 (dd, J=9, 6 Hz, 2H); MS (DCI-NH 3 ) m/z 617 (M+Na) + , 639 (M+2Na-H) + ; Anal. Calcd for C 39 H 33 N 2 O 4 Na.1.30H 2 O: C, 73.18; H, 5.60; N, 4.38; Found: C, 73.23; H, 5.33; N, 4.25.
EXAMPLE 3
Preparation of 4,4-bis-(4(2-quinolylmethoxy)phenyl)-1-cyclohexymethanol ##STR6##
The starting ester (0.60 g, 0.96 mmol) was dissolved in anhydrous THF at room temperature with stirring. Solid lithium aluminum hydride (0.09 g, 2.4 mmol) was added to the solution and the mixture was allowed to stir overnight. The product was worked-up following the standard Fieser & Fieset procedure. The organic layer was dried over Na 2 SO 4 , filtered and concentrated in vacuo. The residue was purified by chromatography (silica gel, 1:1Hexane/EtOAc) to give 250 mg of the title compound as a white powder: mp 61°-68° C.; 1 H NMR (300MHz, DMSO-d 6 ) δ 0.99 (m, 2H), 1.47 (m, 1H), 1.63 (m, 2H), 1.76 (m, 2H), 2.67 (m, 2H), 3.11 (m, 2H), 4.31 (m, 1H), 5.28 (s, 2H), 5.32 (s, 2H), 6.88 (d, J=9 Hz, 2H), 6.99 (d, J=9 Hz, 2H), 7.12 (d, J=9 Hz,2H), 7.27 (d, J=9 Hz, 2H), 7.65 (m, 4H), 7.78 (m, 2H), 8.00 (m, 4H), 8.40 (t, J=9 Hz, 2H), MS (APCI) m/z 581 (M+H) + . Anal. Calcd for C 39 H 36 N 2 O 3 .0.85 H 2 O: C, 78.59; H, 6.38N, 4.70; Found: C, 78,64; H, 6.41; N, 4.21.
EXAMPLE 4
Preparation of 4,4-bis(4-(2-quinolylmethoxy)phenyl)cyclohexyliminoxyacetic acid sodium salt ##STR7##
To a solution of 1,4-cyclohexanedione monoethylene ketal (3.12 g, 20 mmol) in dioxane (25 mL) and ethanol (45 mL) was added NaBH 4 (0.38 g, 10 mmol) and the resulting mixture was refluxed for 45 min. The mixture was then cooled to room temperature, acidified to pH 5 with 10% citric acid and extracted with ethyl acetate to afford crude 1-hydroxy-4-cyclohexanone ethylene ketal (2.8 g).
A mixture of ketal intermediate (2.8 g, 17.7 mmol) and phenol (5.64 g, 60 mmol) in dioxane (10 mL) and water (10 mL) at 0° C. was treated dropwise with conc. H 2 SO 4 (20 mL). The mixture was allowed to warm to room temperature and stirred at this temperature for the next 6 h. The reaction mixture was then poured into ice-water and extracted with ethyl acetate. The acetate layer was washed with water, brine, dried with anhydrous MgSO 4 and concentrated in vacuo to provide 4,4-bis(4-hydroxyphenyl)cyclohexanol (5 g) contaminated with phenol.
The diphenol derivative was dissolved in DMF (100 mL) and treated with anhydrous K 2 CO 3 (11.04 g, 80 mmol) and 2-chloromethylquinoline hydrochloride (12.84 g, 60 mmol) for 20 h at ambient temperature. The mixture was then diluted with water (500 mL) and extracted with ethyl acetate. The organic layer was washed with water, brine, dried with anhydrous MgSO 4 and concentrated in vacuo. The residue was purified by chromatography (silica gel, 4:1 CH 2 Cl 2 /EtOAc) to provide 4,4-bis(4-(2-quinolylmethoxy)phenyl)cycohexanol (5.25 g).
To a solution of cyclohexanol intermediate (5.25 g, 9.27 mmol). Ph 3 P (5.24 g, 20 mmol) and N-hydroxyphthalimide (1.52 g, 9.3 mmol) in THF (5.50 mL) was added dropwise DIAD (4 mL, 20 mmol) in THF (10 mL). The reaction mixture was stirred at ambient temperature for 18 h and then concentrated in vacuo. The residue was chromatographed (silica gel, 15:1 CH 2 Cl 2 /EtOAc) to provide N-phthaloyl intermediate (7.1 g).
The phthaloyl intermediate in dioxane (25 mL) and ethanol (25 mL) was refluxed with hydrazine hydrate (1.2 ml, 20 mmol) for 30 min. The mixture was then diluted with 10% sodium carbonate (50 mL) and extracted with ethyl acetate. The organic extract was washed with water, brine, dried with anhydrous MgSO 4 and concentrated in vacuo. The residue was purified by chromatography (silica gel, 2:1 CH 2 Cl 2 /EtOAc) to provide O-4,4-bis(4-(2-quinolylmethoxy)phenyl)cyclohexylhydroxylamine (0.94 g).
A mixture of hydroxylamine derivative (0.35 g, 0.6 mmol), glyoxylic acid (0.055 g, 0.6 mmol) and acetic acid (0.04 mL, 0.6 mmol) in dioxane (20 mL), methanol (10 mL) and water (5 mL) was stirred at room temperature for 12 h. The organics were then removed under reduced pressure and the residue was diluted with water (30 mL). The pH was adjusted to 3 with 10% citric acid and the solid was filtered and dried under reduced pressure to afford 4,4-bis(4-(2-quinolylmethoxy)phenyl)cyclohexyliminoxyacetic acid (0.37 g, 97%).
To a solution of iminoxyacid in THF (30 mL) was added solid NaOH (0.025 g, 0.64 mmol) followed by water (10 mL) and the resulting mixture was stirred at room temperature for 1 h. The water (20 mL) was added and the THF was removed in vacuo. The water solution was frozen and lyophilized to provide the title compound (0.38 g, 90%): 1 H NMR (300 MHz, DMSO-d 6 ) δ 1.45 (m, 2H), 1.76 (m, 2H), 2.02 (m, 2H), 2.45 (m, 2H), 4.04 (m, 1H), 5.30 (two s, 4H), 6.91 (d, 2H, J=9 Hz), 6.98 (d, 2H J=9 Hz), 7.20 (d, 2H, J=9 Hz), 7.27 (d, 2H, J=9 Hz), 7.62 (m, 4H), 7.78 (m, 1H), 8.00 (m, 4H), 8.40 (two d, 2H, J=8 Hz); MS (FAB(+)) m/z 638 (M+H) + , 660 (M+Na) + ; MS (FAB(-)) m/z 636 (M-H)-.Anal. Calcd for C 40 H 34 N 3 O 5 Na: C, 72.82; H, 5.19; N, 6.36; Found: C, 72.51; H, 5.35; N, 6.71.
EXAMPLE 5 ##STR8##
Preparation of 4,4-bis(4-(2-quinoloylmethoxy)phenyl)cyclohexyliminoxy-2-propionic acid sodium salt
The solution of O-4,4-bis(4-(2-quinolylmethoxy)phenyl)cyclohexylhydroxylamine resulting from Example 4 (0.58 g, 1 mmol) and methyl pyruvate (0.1 mL, 1 mmol) in dioxane (20 mL) and methanol (10 mL) was treated with acetic acid (0.06 mL, 1 mmol) at room temperature for 10 h. The mixture was concentrated in vacuo, dissolved in ethyl acetate and washed with saturated NaHCO 3 , brine, dried with anhydrous MgSO 4 and concentrated in vacuo. The residue was chromatographed (silica gel, 4:1 CH 2 Cl 2 /EtOAc) to provide 4,4-bis(4-(2-quinolylmethoxy)phenyl)cyclohexyliminoxy-2-propionic acid methyl ester (0.54 g).
To a solution of iminoxyester from above in dioxane (15 mL) and methanol (10 mL) was added 1N NaOH (1 mL) and the reaction mixture was stirred at room temperature for 10 h. The organics were removed in vacuo, the residue was diluted with water (25 mL) and acidified to pH 3 with 10% citric acid. The solid was filtered and dried in vacuo. The crude acid was redissolved in THF, filtered and concentrated in vacuo to get 4,4-bis(4-(2-quinolylmethoxy)phenyl)cyclohexyliminoxy-2-propionic acid (0.52 g).
A powder NaOH (0.032 g, 0.8 mmol) was added to a solution of iminoxyacid intermediate (0.52 g, 0.8 mmol) in THF (50 mL) followed by addition of water (10 mL) and the mixture was stirred at room temperature for 30 min. The water (15 mL) was added and the THF was removed in vacuo. The water solution was frozen and lyophilized to get the title compound: mp 107°-113° C.; 1 H NMR (300 MHz, DMSO-d 6 ) δ 1.47 (m, 2H), 1.73 (m+s, 5H), 2.05 (m, 2H), 2.44 (m, 2H), 4.07 (m, 1H), 5.30 (two s, 4H), 693 (d, 2H, J=9 Hz), 6.98 (d, 2H, J=9 Hz), 7.21 (d, 2H, J=9 Hz), 7.26 (d, 2H, J=9 Hz), 7.63 (m, 4H), 7.78 (m, 2H), 8.00 (m, 4H), 8.40 (two d, 2H, J=8 Hz); MS (FAB(+)) m/z 652 (M+H) + , 674 (M+Na) + ; MS (FAB(-)) m/z 650 (M-H)-.Anal. Calcd for C 41 H 36 N3O 5 Na×2H 2 O: C, 69.38; H, 5.68; N, 5.92; Found: C, 69.27; H, 5.63; N, 5.83.
EXAMPLE 6
Preparation of 4,4-bis(4-(2-quinolylmethoxy)phenyl)-1-cyclohexylmethyliminoxyacetic acid ##STR9##
The desired material was prepared according to the procedure of Example 4 except substituting 4,4-bis(4-(2-quinolylmethoxy)phenyl)-1-cyclohexylmethanol, resulting from Example 3, for 4,4-bis(4-(2-quinolylmethoxy)phenyl-1-cyclohexanol mp 91°-97° C.; 1 H NMR (300MHz, DMSO-d 6 ) δ 1.10 (m, 2H), 1.66 (m, 2H), 1.81 (m, 3H), 2.67 (m, 2H), 3.99 (d, J=7.5 Hz, 2H), 5.28 (s, 2H), 5.32 (s, 2H), 6.88 (d, J=9 Hz, 2H), 7.00 (d, J=9 Hz, 2H), 7.11 (d, J=9 Hz, 2H), 7.28 (d, J=9 Hz, 2H), 7.51 (s, 1H), 7.62 (m, 3H), 7.68 (d, J=9 Hz, 1H), 7.78 (m, 2H), 8.00 (m, 4H), 8.40 (t, J=9 Hz, 2H); MS (APCI) m/z 652 (M+H) + . Anal. Calcd for C 41 H 37 N 3 O 5 .0.50 H 2 O: C, 74.52; H, 5.79; N, 6.35; Found: C, 74.60; H, 5.91; N, 5.89.
EXAMPLE 7
Preparation of 4,4-bis(4-(2-quinolylmethoxy)phenyl)-1-cyclohexyloximinoacetic acid ##STR10##
To a mixture of 4,4-bis(4-(2-quinolylmethoxy)phenyl)cyclohexanol (resulting from Example 4) (1.13 g, 2 mmol) and molecular sieves (3 g) in CH 2 Cl 2 (40 mL) was added PCC (0.65 g, 3 mmol) and the resulting mixture was stirred at room temperature for 30 min. The mixture was filtered through the Celite, the filtrate was concentrated in vacuo to 10 mL and then chromatographed (silica gel, 4:1 CH 2 Cl 2 /EtOAc) to afford 0.25 g of 4,4-bis(4-(2-quinolylmethoxy) phenyl)cyclohexanone.
A mixture of ketone from above (0.25 g, 0.44 mmol), H 2 NOH×HCl (0.035 g, 0.5 mmol) and AcONa×3H 2 O (0.68 g, 0.5 mmol) in dioxane (15 mL), MeOH (10 mL) and H 2 O (8 mL) was stirred at room temperature for 18 h and then concentrated in vacuo. To the residue was added water (30 mL), the solid was filtered and dried in vacuo to provide 0.22 g of 4,4-bis(4-(2-quinolylmethoxy)phenyl)cyclohexanone oxime.
The solution of oxime (0.022 g, 0.38 mmol) in DMF (20 mL) was treated with ethyl bromoacetate (0.06 mL, 0.5 mmol) in the presence of Cs 2 CO 3 (0.17 g, 0.5 mmol) for 48 h at room temperature. The mixture was then diluted with water and extracted with ethyl acetate. The acetate layer was washed with water, brine, dried with MgSO 4 and concentrated in vacuo. The residue was chromatographed (silica gel, 2:1 CH 2 Cl 2 /EtOAc) to give 0.125 g of 4,4-bis(4-(2-quinolylmethoxy)phenyl)cyclohexyloximinoacetic acid ethyl ester.
A solution of 1N NaOH (0.3 mL, 0.3 mmol) was added to ester (0.125 g, 0.19 mmol) in dioxane (10 mL) and EtOH (6 mL) and the reaction was continued at room temperature for the next 6 h. The organics were removed in vacuo, the residue was diluted with water and acidified to pH 3 with 10% citric acid. The solid was filtered, dried in vacuo and crystallized from dioxane-water to provide 0. 11 g (90%) of the title compound: mp 109°-111° C.; 1 H NMR (300 MHz, DMSO-d 6 ) δ 2.14 (m, 2H), 2.33 (m, 4H), 2.45 (m, 2H), 4.43 (s, 2H), 5.30 (s, 4H), 6.97 (d, J=9 Hz, 4H), 7.25 (d, J=9 Hz, 4H), 7.63 (m, 4H), 7.78 (m, 2H), 8.00 (m, 4H), 8.40 (d, J=8 Hz, 2H); MS (APCI+QIMS LMR UP LR) m/z 638 (M+H) + . Anal. Calcd for C 40 H 35 N 3 O 5 ×0.75 H 2 O: C, 73.77; H, 5.64; N, 6.45. Found: C, 73.77; H, 5.54; N, 6.17.
EXAMPLE 8
Preparation of 4,4-bis-(4-(2-benzothiazolylmethoxy)phenyl)cyclohexane carboxylic acid ##STR11##
The method of Example 1 is used with substitution of 2-chloromethylbenzothiazole for 2-chloromethylquinoline.
EXAMPLE 9
Preparation of 4,4-bis-(4-(2-quinoxalylmethoxy) phenyl)cyclohexane carboxylic acid ##STR12##
The method of Example 1 is used with substitution of 2-chloromethylquinoxaline for 2-chloromethylquinoline.
EXAMPLE 10
Preparation of 4,4-bis-(4-(7-chloro-2-quinolylmethoxy)phenyl)cyclohexane carboxylic acid ##STR13##
The method of Example 1 is used with substitution of 7-chloro-2-chloromethylquinoline for 2-chloromethylquinoline.
EXAMPLE 11
Preparation of 4,4-bis-(4-(2-benzothiazolylmethoxy)phenyl)cyclohexylmethanol ##STR14##
The method of Example 3 is used with the product of Example 8.
EXAMPLE 12
Preparation of 4,4-bis-4-2-quinoxalylmethoxy)phenyl)cyclohexylmethanol ##STR15##
The method of Example 3 is used with the product of Example 9.
EXAMPLE 13
Preparation of 4 4-bis-(4-(7-chloro-2-quinolylmethoxy)phenyl)cyclohexylmethanol ##STR16##
The method of Example 3 is used with the product of Example 10.
EXAMPLE 14
Preparation of 4,4-bis-(4(2-benzothiozolylmethoxy)phenyl)cyclohexylmethyliminoxy acetic acid ##STR17##
The method of Example 6 is used with the product of Example 11.
EXAMPLE 15
Preparation of 4,4-bis-(4-(2-quinoxalylmethoxy)phenyl)cyclohexylmethyliminoxy acetic acid ##STR18##
The method of Example 6 is used with the product of Example 12.
EXAMPLE 16
Preparation of 4,4-bis-(4-(7-chloro-2-quinolylmethoxy)phenyl)cyclohexylmethyliminoxy acetic acid ##STR19##
The method of Example 6 is used with the product of Example 13.
EXAMPLE 17
Preparation of 4,4-bis(4-(2-benzothiazolylmethoxy)phenyl)cyclohexyliminoxy-2-propionic acid sodium salt ##STR20##
The method of Example 5 is used with substitution of 2-chloromethylbenzothiazole for 2-chloromethylquinoline.
EXAMPLE 18
Preparation of 4,4-bis-(4-(2-quinoxalylmethoxy)phenyl)cyclohexyliminoxy-2-propionic acid sodium salt ##STR21##
The method of Example 5 is used with substitution of 2-chloromethylquinoxaline for 2-chloromethylquinoline.
EXAMPLE 19
Preparation of 4,4-bis-(4-(7-chloro-2-quinolylmethoxy)phenyl)cyclohexyliminoxy-2-propionic acid sodium salt ##STR22##
The method of Example 5 is used with substitution of 7-chloro-2-chloromethylquinoline for 2-chloromethylquinoline.
EXAMPLE 20
Preparation of 4,4-bis-(4-(2-benzothiazolylmethoxy)phenyl)cyclohexyliminoxyacetic acid sodium salt ##STR23##
The method of Example 4 is used with substitution of 2-chloromethylbenzothiazole for 2-chloromethylquinoline.
EXAMPLE 21
Preparation of 4,4-bis-(4-(2-quinoxalylmethoxy)phenyl)cyclohexyliminoxyacetic acid sodium salt ##STR24##
The method of Example 4 is used with substitution of 2-chloromethylquinoxaline for 2-chloromethylquinoline.
EXAMPLE 22
Preparation of 4,4-bis-(4-(7-chloro-2-quinolylmethoxy)phenyl)cyclohexyliminoxyacetic acid sodium salt ##STR25##
The method of Example 4 is used with substitution of 7-chloro-2-chloromethylquinoline for 2-chloromethylquinoline.
EXAMPLE 23
Preparation of 4,4-bis-(4-(2-benzothiazolylmethoxy)phenyl)cyclohexyloximinoaeetic acid ##STR26##
The method of Example 7 is used with the cyclohexanol intermediate from Example 20.
EXAMPLE 24
Preparation of 4,4-bis-(4(2-quinoxalylmethoxy)phenyl)cyclohexyloximinoacetic acid ##STR27##
The method of Example 7 is used with the cyclohexanol intermediate from Example 21.
EXAMPLE 25
Preparation of 4,4-bis-(4-(7-chloro-2-quinolylmethoxy)phenyl)cyclohexyloximinoacetic acid ##STR28##
The method of Example 7 is used with the cyclohexanol intermediate from Example 22.
EXAMPLE 26
Preparation of 5,5-bis-(4-(2-quinolylmethoxy)phenyl)cyclooctanecarboxylic acid ##STR29##
The method of Example 1 is used with substitution of 5-oxocyclooctane-1-carboxylic acid (Curran, D. P.; Shen, W. Tandem Tetrahedron 1993, 49, 755-770) for ethyl 4-oxocyclohexanecarboxylate.
EXAMPLE 27
Preparation of 3,3-bis-(4-(2-quinolylmethoxy)phenyl)cyclobutanecarboxylic acid ##STR30##
The method of Example 1 is used with substitution of methyl 3-oxocyclobutane-1-carboxylate (Bashir-Hashemi, A.; Hardee, J. R. J. Org. Chem. 1994, 59, 2132-2134) for ethyl 4-oxocyclohexanecarboxylate.
EXAMPLE 28
Preparation of 3,3-bis-(4-(2-quinolylmethoxy)phenyl)cyclopentanecarboxylic acid ##STR31##
The method of Example 1 is used with substitution of methyl 3-oxocyclopentyl-1-carboxylate (Bashir-Hashemi, A.; Hardee, J. R. J. Org. Chem. 1994, 59, 2132-2134) for ethyl 4-oxocyclohexanecarboxylate.
EXAMPLE 29
Preparation of 3,3-bis-(4-(2-quinolylmethoxy)phenyl)cyclohexanecarboxylic acid ##STR32##
The method of Example 1 is used with substitution of methyl 3-oxocyclohexyl-1-carboxylate (Dowd, P.; Choi, S. C. Tetrahedron 1989, 45, 77-90) for ethyl 4-oxocyclohexanecarboxylate.
EXAMPLE 30
Preparation of 3,3-bis-(4-(2-quinolylmethoxy)phenyl)cycloheptanecarboxylic acid ##STR33##
The method of Example 1 is used with substitution of methyl 3-oxocycloheptyl-1-carboxylate (Dowd, P.; Choi, S. C. Tetrahedron 1989, 45, 77-90) for ethyl 4-oxocyclohexanecarboxylate.
EXAMPLE 31
Preparation of 3,3-bis-(4-(2-quinolylmethoxy)phenyl)cyclooctanecarboxylic acid ##STR34##
The method of Example 1 is used with substitution of methyl 3-oxocycloctyl-1-carboxylate (Dowd, P.; Choi, S. C. Tetrahedron 1989, 45, 77-90) for ethyl 4-oxocyclohexanecarboxylate.
EXAMPLE 32
Preparation of 3,3-bis-(4-(2-quinolylmethoxy)phenyl)cyclobutyliminoxyacetic acid sodium salt ##STR35##
The method of Example 4 is used with substitution of 3-oxocyclobutanone (Tenud, L.; Weilenmann, M.; Dallwigk, E. HelveticalChimica Acta 1977, 60, 975-977) for 1-hydroxy-4-cyclohexanone ethylene ketal.
EXAMPLE 33
Preparation of 3,3-bis-(4-(2-quinolylmethoxy)phenyl)cyclopentyliminoxyacetic acid sodium salt ##STR36##
The method of Example 4 is used with substitution of 3-oxocyclopentanone (Mcintosh, J. M.; Beaumier, P. J. Org. Chem. 1938, 57, 2905-2906) for 1-hydroxy-4-cyclohexanone ethylene ketal.
EXAMPLE 34
Preparation of 3,3-bis-(4-(2-quinolylmethoxy)phenyl)cyclooctylliminoxyacetic acid sodium salt ##STR37##
The method of Example 4 is used with substitution of 3-oxocyclooctanone (Cope, A. C.; Fiaher, B. S.; Funke, W.; Mcintosh, J. M.; McKervey, M. A. J. Org. Chem. 1969, 34, 2231-2234) for 1-hydroxy-4-cyclohexanone ethylene ketal. | Compounds having the structure ##STR1## where m is an integer of from one to nine; n is an integer of from one to four; W is selected from substituted or unsubstituted quinolyl, benzothiazolyl, or quinoxalyl, X is selected from C 1-6 alkylene, C 2-6 alkenylene and C 2-6 alkynylene; Y is selected from halogen, C 1-6 alkyl and C 1-6 , alkoxy; and Z is selected from --C(O)B; --C(R 2 ) 2 --O--N═A--C(O)B; and --C(R 2 )═N--O--A--C(O)B where A is C 1-6 alkylene and B is --OH, --O--M + , --OD where D is a metabolically cleavable group, --OR 6 where R 6 is hydrogen or C 1-6 alkyl, --NR 6 R 7 where R 7 is hydrogen, C 1-6 alkyl, hydroxy or C 1-6 alkoxy, or where R 6 and R 7 taken together form a five to eight membered ring optionally containing one heteroatom selected from nitrogen, oxygen or sulfur, are inhibitors of leukotriene biosynthesis. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to a hub assembly for holding a replacable wheel where the hub assembly may be manually disassembled to release a previously-held wheel and reassembled to hold and to rotate a fresh wheel. The present invention more closely relates to such an assembly of demountable hub and wheel where wheel replacement is achieved with minimal manual intervention.
While the present invention is hereinafter described in relation to a hub and wheel assembly for use in a document moving track in a document encoder, it is not intended that this illustrated use should represent a limitation upon the application of the present invention which may be used in any situation where a wheel must periodically be replaced or removed, such as in office equipment, mechanical gear boxes, and for vehicular wheels. The present invention may be employed securely to hold any object which requires to be rotated about the axis or shaft.
In document encoding machinery such as is used for automated processing of check in banking, it is usual to employ a document track into which checks are fed one by one from a stack for automated processing as the checks pass along the length of the track. In order to avoid the inadvertent movement along the track of two or more checks together, it is the practice to provide in the track a pair of opposed rubber wheels one of which rotates with a small angular velocity and the other of which rotates with a high angular velocity. When a check passes therebetween, if there is only one check present it is gripped by the wheel of low angular velocity and the wheel of high angular velocity rubs at high speed against the other face of the check. If two or more checks come along the document track together, the wheel of high angular velocity engages the additional check or checks and projects them at higher speed along the document track to avoid the checks passing together along the track. Thus, the wheel of high angular velocity scrubs continuously against either the wheel of low angular velocity or the rear of a document to be processed. Only on very rare occasions when two documents come along the document track together is the wheel of high angular velocity free from scrubbing against objects moving much more slowly than itself and therefore free from the high attritional wear attendant thereon. The wheel of high angular velocity is therefore subject to frequent replacement as its dimensions and consequent elastic pressure in opposition to the wheel of low angular velocity are reduced by frictional attrition.
In the past, it has been the practice to provide as the scrub wheel of high angular velocity a wheel and hub assembly wherein a replacable wheel having an elastic tire fitted thereon is held on the hub, the hub consisting in a base member and a holding member. The holding member was attached to the base member to clamp the wheel between the holding member and the base member by means of displacable elastic arms having a clip at the distal end of each for engaging the base member. In order to remove the holding member it was necessary to use some kind of tool and two hands. The elastic arms of the holding member were liable to fatigue fracture making the life expectancy of the holding member very short in terms of the number of times that a wheel could be changed. The replacement of the wheel required to be undertaken by skilled personnel whose presence and time was costly. The amount of time during which a machine was out of use while its wheel or wheels were being changed was high.
Other mechanical arrangements for holding a wheel were envisaged. Each arrangement required the provision of complex machined parts, costly in themselves to produce.
It is, therefore, desirable to provide a wheel and hub assembly where replacement of the wheel is rapidly and readily achieved by unskilled personnel without the use of tools and without stress to the hub assembly so that the hub assembly may indefinitely be used to hold replacement wheels without risk of stress fractures. Further, it is desirable that the wheel and hub assembly be of a simple construction capable of being made in a low cost fabrication process such as moulding.
SUMMARY OF THE INVENTION
The present invention consists in an assembly comprising a wheel and a demountable hub, said wheel being removably mountable upon said hub to receive rotational drive therefrom; said hub comprising a base member where said base member is mountable upon a driven shaft to receive said rotational drive therefrom, where said base member comprises a mounting surface for receiving said wheel for said wheel to be rotated co-axially with the shaft, and where said mounting surface comprises coupling means for coupling said rotational drive from said base member to said wheel; and said hub further comprising a top member, where said top member comprises a bearing member for engaging said wheel to trap said wheel between said bearing member and said base member, and a clamping member for reversibly engaging said base member to urge said bearing member towards said base member, said top member being removable from said base member when said clamping member is not in engagement with said base member to allow removal of said wheel, said clamping member comprising a handle for manual depression and rotation of said clamping member relative to said bearing member: said clamping member comprising a first catch and said bearing member comprising a first catch receiver for mutual engagement therebetween to retain said clamping member in association with said bearing member when said clamping member is not in engagement with said base member in a first or a second primary retention position having a first angular spacing therebetween, passage between said first and second primary retention positions being achieved by depression, rotation and release under elastic restitution of said clamping member relatively to said bearing member; and said clamping member further comprising a second catch for insertion into said base member if and only if said clamping member is in said first primary retention position and if said top member is in a predetermined angular relationship to said base member, said base member comprising a second catch receiver operable to receive said second catch to urge said top member towards said base member subsequently to said insertion of said second catch into said base member, in response to said passage of said clamping member between said first and said second primary retention positions, and in consequence of said elastic restitution.
In a preferred embodiment of the present invention a wheel and hub assembly is provided preferably as the scrub wheel of high rotational speed in a document track for separating double documents which may inadvertently pass along the track.
In the preferred embodiment there is provided a cylindrical base member co-axially mounted to rotate upon a driven shaft. The base member comprises a cylindrical mounting surface for accepting a cylindrical inner surface of a wheel rim whereon an elastic tire is held. The mounting surface comprises a keyway for accepting a key on the inner surface of the wheel rim, thereby to impart rotational torque from the shaft to the wheel rim and thus to the elastic tire.
The preferred embodiment also comprises a top member which mounts upon the base member to clamp the wheel therebetween. The base member comprises a base rim whereon the wheel can rest. The top member comprises a top rim which, when the top member is co-axially assembled upon the base member, traps the wheel between itself and the base wheel. The top member in its turn comprises a bearing member whereon the top rim is affixed and a clamping member for holding and urging the top member towards the base member. The bearing member preferably is affixed co-axially within the base member and the clamping member preferably is situated co-axially within the bearing member. The clamping member comprises a first catch and a first catch receiver for holding the clamping member within the bearing member against opposition by a helical spring. The first catch preferably comprises an elastic arm with a clip at its distal end which, as the clamping member is inserted into the bearing member, engages a cutaway portion inside the bearing member which affords a first and a second angularly displaced primary retention position. The clamping member also comprises a second catch in the form of a retention arm which extends axially towards the base member and comprises a retaining lug proximate to its distal end. The base member comprises a perforate ledge wherethrough the retention arm and its lug can pass if and only if the top member and the base member are in a predetermined angular relationship one to the other and if the clamping member is in the first primary retentioned position. The requisite orientation between the top member and the base member before the retention arm may pass through the ledge in the base member is further assisted by a projection on the outer surface of the bearing member to be co-axially inserted into the base member and a gap in the upper edge of the bearing surface of the base member operative such that the projection enters the gap to allow entry of the bearing member with its retention arm into the base member if and only if the base member and the top member are in the required predetermined angular relationship one to the other.
Having thus passed the retention arm and the lug at its distal end through the ledge in the base member the clamping member is depressed and rotated to cause the lug to pass beneath the ledge on its lower surface in the base member and engage a recess wherein, upon release of the clamping member, the lug is urged by the elastic restitution afforded by the helical spring between the clamping member and the bearing member to hold the top member firmly in association with the base member and urge the base member and the top member together to hold the wheel therebetween.
The lug engages the recess when the clamping member is positioned relative to the bearing member in the second of the two primary retention positions. The axial length of the retention arm is chosen such that, with the lug in the recess, the first catch does not fully engage the axially uppermost edge of the cutaway portion within the inside wall of the bearing member for the full force of the helical spring between the clamping meber and the bearing member to urge the bearing member and the base member together.
DESCRIPTION OF THE DRAWINGS
The present invention is further described by way of an example by the following description taken in conjunction with the appended drawings in which:
FIG. 1 shows a schematic projected view of the the preferred embodiment of the present invention in the form of a high rotational speed scrub wheel in a document track.
FIG. 2 shows an exploded projected view of the base member, the wheel and the top member of the preferred embodiment.
FIG. 3A shows an exploded view of the clamping member and the bearing member together making up the top member shown in FIG. 2.
FIG. 3B shows a plan view from above of the bearing member shown in FIG. 3A.
FIG. 3C shows a plan view from below of the bearing member shown in FIG. 3A.
FIG. 3D shows a cross-sectional view taken along the line A--A' of FIG. 3A of the bearing member and showing details of the cutaway indended section of the first catch.
FIG. 3E shows a plan view from the top of the clamping member of FIG. 3A.
FIG. 3F shows a plan view from below of the clamping member of FIG. 3F.
FIG. 3G shows a first side elevation of the clamping member of FIG. 3A.
FIG. 3H shows a second side elevation of the clamping member otherwise shown in FIGS. 3A and 3G, the side elevation of FIG. 3H being from a viewpoint circumferentially 90° around from that shown in FIG. 3G.
FIG. 3I shows a cross-sectional view taken through a diameter consistent with the side elevation of FIG. 3G of the clamping member installed in the bearing member.
FIG. 3J shows the view from above of the base member of FIG. 2.
FIG. 3K shows a view from below of the base member of FIG. 2.
FIG. 3L shows a cross-sectional view of the base member taken along the line B--B' shown in FIG. 3K.
FIG. 3M shows a cross-sectional view of the base member taken along the line C--C' of FIG. 3K.
FIG. 3N shows a cross-sectional view of the base member taken along the line D--D' of FIG. 3K.
FIG. 3P shows a cross-sectional view of the base member taken along the line E--E' of FIG. 3K.
FIG. 4A shows a plan view from below of the assembled top member of FIG. 2 with the clamping member in the first primary retention position.
FIG. 4B shows the assembled top member of FIG. 4A with the clamping member in the second primary retention position.
FIG. 5A shows a plan view from above of the wheel assembly of FIG. 2.
FIG. 5B shows a plan view from below the wheel assembly of FIG. 2.
FIG. 6A shows the first stage in the assembly of the hub and wheel of the preferred embodiment.
FIG. 6B shows the second stage in the assembly of the hub and wheel, and
FIG. 6C shows the final stage in the assembly of the hub and wheel of the preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows the preferred embodiment in the present invention installed as part of a document track in a document encoding machine. A first sheet of paper 10 moves along a document track on a base 12 between a drive wheel 14 and a scrub wheel 16. The drive wheel 14 rotates as indicated by a first arrow 18 with a small angular velocity to urge the first sheet of paper 10 in the direction of a second arrow 20. The scrub wheel 16 rotates with a high angular velocity. When only the first sheet of paper 10 is present between the two wheels 14, 16 the co-efficients of friction of the drive wheel 14 and the scrub wheel 16 are so chosen that the first sheet of paper 10 is more strongly held by the drive wheel 14 and progresses slowly along the document track. In this circumstance, the scrub wheel 16 rubs against the back of the first sheet of paper 10. If however a second sheet of paper 22 (shown in broken outline) is present along with the first sheet of paper 10 the scrub wheel 16 engages the second sheet of paper 22 and causes it to slide against the first sheet of paper 10 with a high velocity in consequence of the rotation of the scrub wheel 16 as indicated by the third arrow 24. The second sheet of paper 22 thus is moved rapidly down the track to be separated from the first sheet of paper 10. The second sheet of paper may be either be processed along the track or may be discarded for later reloading.
FIG. 2 shows an exploded view of the scrub wheel assembly 16 of FIG. 1. The scrub wheel assembly 16 comprises a base member 26, a wheel 28 and a top member 30. The base member comprises a gap 32 for engaging a projection on the top member 30 not shown in FIG. 2. The base member further comprises a pair of keyways 34 for engaging a corresponding pair of keys 36 in the wheel 28. The base member yet further comprises an insert 38 for engaging a corresponding void in the wheel 28 not shown in FIG. 2 and designed to prevent the wheel 28 from being inserted over the base member 26 upside down.
The wheel 28 comprises a wheel rim 40 supporting an elastic tire 42 which may be made of natural or synthetic rubber having the desired coefficient friction against the paper to give the above-described properties in separating two sheets of paper 10,22.
The top member 30 comprises a clamping member 44 held within a bearing member 46. The clamping member 44 comprises a handle 48 whereby the clamping member 44 may be depressed and rotated relative to the bearing member 46 and the base member 26.
FIG. 3A shows an exploded view of the top member 30 shown in FIG. 2. The clamping member 44 comprises a top disc 50 immediately beneath the handle 48 having a pair of missing segments 52 whose purpose is later to be described. The clamping member 44 further comprises a spring supporting disc 54 for supporting one end of a helical spring 56. The clamping member 44 yet further comprises a diametrically-opposed pair of retention arms 58 at the distal end of each of which is provided a retaining lug 60 whose purpose is later to be described. The clamping member 44 further comprises a diametrically-opposed pair of resilient elastic arms 62 at the distal end of each of which is provided a clip 64.
The bearing member 46 comprises a barrel portion 66 having a pair of cutaway channels 68 allowing the ingress of the retaining lugs 60 of the clamping member 44 into the bearing member 46. The bearing member 46 further comprises a bearing face 70 for pushing against the top surface of the wheel 28 when the assembly of the present invention is in an assembled condition.
The bearing member 46 further comprises a first catch receiver in the form of a cutaway portion 72 formed by partway cutting through the barrel portion 66 of the bearing member from the inside. As will later be explained, the first part of a first catch provided in the form of the clip 64 engages the second part of the second catch provided in the form of the cutaway portion 72 to provide first and second primary retention positions angularly spaced for the clamping member 44 relative to the bearing member 46.
FIG. 3B shows a top view of the bearing member 46 of FIG. 3A. The FIG. 3B more clearly shows how the channels 68 for the admission of the retaining lugs are cut into the material of the bearing member 46. The inner surface of the barrel portion 66 of the bearing member 46 comprises a spring retaining ledge 74 for engaging the other end of the helical spring 56 shown in FIG. 3A. Printed on the top surface 76 of the bearing member 46 are a first pair of colored areas 78 and a second pair of colored areas 80. The first pair of colored areas 78 are visible through the missing segments 52 of the top disc 50 of the clamping member 44 when the clamping member 44 is in the first primary retention position. The second pair of colored areas 80 are visible through the missing segments 52 when the clamping member 44 is in the second primary retention position.
FIG. 3C shows a plan view from the bottom of the bearing member 46 otherwise shown in FIG. 2 and in FIG. 3A. The barrel portion 66 of the bearing member 46 comprises the projection 82 for engaging the gap 32 otherwise shown in FIG. 2 to arrange that the top member 30 is in the correct angular orientation with respect to the base member 26 before the top member 30 can be inserted fully into the base member 26. The cutaway portion 72 comprises a first gap 84 angularly spaced from a second gap 86 having an intervening extension 88 which, as shown in FIG. 3A, extends only partway down the cutaway portion 72.
FIG. 3D shows a plan view of the bearing member 46 when bisected by the line A--A' as indicated in FIG. 3A and looking in the direction of the arrows. Clearly shown in FIG. 3D are a collar 90 of such a height that the handle 48 of the clamping member 44 is fully contained within the collar 90 when the assembly of the preferred embodiment is completed.
FIG. 3E shows a top view of the clamping member 44 of FIG. 3A showing in greater detail the spring supporting disc 54, the missing segments 52 and the handle 48.
FIG. 3F shows a bottom view of the clamping member 44 shown in FIG. 2 and FIG. 3A. FIG. 3F clearly shows the retaining lugs 60 extending down from cylindrical wall portions 92 (hereinafter referred to as third cylindrical wall portions) from which the retention arm 58 depends. FIG. 3F further shows how the resilient elastic arms 62 are formed by the provision of cuts 94 through the material of the cylindrical walls.
FIGS. 3G and 3H show further aspects of FIG. 3F in the form of first and second elevations of the clamping member 44 viewed from two points circumferentially 90° apart.
FIG. 3I shows a cross-sectional view of the assembled top member 30 of FIG. 2 illustrating how the spring supporting disc 54 and the spring supporting wedge 74 cooperate to trap the helical spring 56 therebetween such that the helical spring 56 tends to urge the clamping member 44 out of the bearing member 46 wherein the clamping member 44 fits concentrically.
FIG. 3J shows a plan view from above of the base member shown in FIG. 2. The base member 26 comprises cylindrical walls 94 (hereinafter referred to as third cylindrical walls) wherein the keyways 34 and the gap 32 are set as previously described. The outer surface of the cylindrical walls 94 form a mounting surface for the wheel rim 40 of FIG. 2. The insert 38 extends to a lower bearing surface 96 from midway up the cylindrical walls 94 of the base member 26.
The base member comprises therein a central shaftway 98 for accepting a driven shaft to rotate the base member 26. Between the central shaftway and the cylindrical walls 94 of the base member 26 there is provided a ledge 100 having channels 102 for the passage therethrough of the retaining lugs 60 and slots 104 allowing the retention arms 56 a degree of rotation within the ledge 100 after the retaining lugs 60 have been inserted through the channels 102. FIG. 3J shows an upper surface 106 of the ledge 100.
FIG. 3K shows a projected view from below of the base member 26 of FIG. 2. FIG. 3K shows a lower surface 108 of the ledge 100 wherein are set a pair of diametrically-opposed radial recesses 110 separated from the channels 102 by an angle equal to the separation between the first and second primary retention positions of the clamping member 44 in the bearing member 46. The central shaftway 98 at its lower end is shown flatted, the better to engage flats on the driven shaft to accept rotational torque therefrom.
FIG. 3L shows a cross-sectional view of the base member 26 viewed along the line B--B' of FIG. 3K illustrating how the ledge 100 at that point is of a first thickness extending all the way between the central shaftway 98 and the cylindrical walls 94 of the base member 26 thus supporting the cylindrical walls 94 of the base member 26 on the shaftway 98.
FIG. 3M shows a cross-section of the base member 26 taken along the line C--C' shown in FIG. 3K. FIG. 3M illustrates how the recesses 110 pass only partway axially through the ledge 100 and are separated from the central shaftway 98 by the slots 104.
FIG. 3N shows a cross-section of the base member 26 taken along the line D--D' of FIG. 3K and illustrates how the ledge 100 in the vicinity of the slots 104 is separated from the central shaftway 98.
FIG. 3P shows a cross-section of the base member 26 taken along the line E--E' of FIG. 3K illustrating how in the region of the channels 102 of the cylidnrical walls 94 of the base member 26 are completely clear of the central shaftway 98 by virtue of the ledge 100 (not shown in FIG. 3P) being completed absent.
FIG. 4A shows a plan view from the bottom of the assembled top member 30 of FIG. 2 when the clamping member 44 is in the first primary retention position. In this position the clip 64 engages the first gap 84 in the cutaway portion 72. As the top member 30 is assembled by insertion of the clamping member 44 inside the barrel portion 66 of the bearing member 46, so the clip 64 is displaced at the tip of the elastic resilient arms 62 until it meets the first gap 84 in the cutaway portion 72 wherein it is forced to enter by virture of the retaining lugs 60 running in the channels 68 in the bearing member 46.
FIG. 4B shows a similar view to that of FIG. 4A with the exception that the top member 44 is in the second primary retention position with respect to the bearing member 46. In this position the clip 64 rests in the second gap 86 of the cutaway portion 72. The clamping member 48 is moved from one position to the other by depression of the handle 48 against the elastic restitutional force of the helical spring 56 until the tip of the clip 64 clears the extension 88 at which point the handle 48 may be released to allow the clip 64 to fall into the selected gap 84,86. In moving from the first to the second gap 84,86 so the retaining lugs 60 are rotated.
FIG. 5A shows a view from the top of the wheel 28 otherwise shown in FIG. 2 illustrating keys 34 on the inner surface of the wheel rim 40 supportive of the elastic resilient tyre 42. FIG. 5B on the other hand shows a view from the bottom of the wheel 28 otherwise shown in FIG. 2 showing how keys 34 pass all the way down the inner surface of the wheel rim 40. FIG. 5B also shows a void 114 of complementary shape to the insert 38 and extending halfway up the inner wall 116 of the wheel rim 42. When assembling the wheel 28 onto the base member 26 the void 114 and the insert 38 co-operate to prevent the wheel 28 being placed on the base member 26 in anything other than the correct way up. In initial manufacture of high rotational speed scrub wheel assemblies 16 the tire 42 is buffed in a preferred direction and the wheel 28 is therefore preferred to rotate in its own preferred direction wherein its coefficient of friction is highest. Accordingly, it is desirable to mount the wheel 28 a correct way up and the void 114 and the insert 38 ensure that this must happen.
FIG. 6A shows a first stage in the assembly of the preferred embodiment of the present invention. The wheel 28 is slid onto the base member 26 such that the keys 36 engage the keyways 34 and the void 114 engages the insert 38 for the wheel 28 to be slid all the way home onto the base member 26.
FIG. 6B shows the second stage of assembly of the preferred embodiment of the present invention. The top member 30 is assembled such that its barrel portion 66 slides within the cylindrical walls 94 of the base member 26. The tips of the retention arms 58 engage the upper surface 106 of the ledge 100 preventing further ingress of the top member 30 into the base member 26. Similarly, the projection 82 rests upon the upper surface of the cylindrical walls 94 of the base member 26. The top member 30 is rotataed as indicated by the arrow 118 until the retaining lugs 60 engage the channels 102 in the ledge 100 which event occurs simultaneously with the projection 82 entering the gap 32 thus allowing further ingress of the top member 30 into the base member 26. The gap 32 and the projection 82 co-operate to prevent relative rotation between the top member 30 and the base member 26.
The top member 30 cannot be inserted into the base member 26 unless the clamping member 44 is in the first primary retention position as illustrated in FIG. 4A. If the clamping member 44 is in the second primary retention position as illustrated in FIG. 4B the retaining lugs 60 will be in the wrong angular position to permit their insertion into the channels 102 in the ledge 100 in the base member 26 simultaneously with entry of the projection 82 into the gap 32. Should this be the case, the clamping member 44 must be returned to the first primary retention position as illustrated in FIG. 4A. Assembly of the preferred embodiment of the present invention is thus prevented if the top member 30 is wrongly position within itself.
FIG. 6C shows the final stage in assembly of the preferred embodiment of the present invention. The handle 48 is depressed into the bearing member 46 behind the collar 90 and rotated to bring the clamping member 44 into the second primary retention position illustrated in FIG. 4B simultaneously with bringing the retaining lugs 60 over the recesses 110. The handle 48 is then released allowing the retaining lugs 60 to fall back into the recesses 110. The depth of the second gaps 86 of the cutaway portion 72 is such that the retaining lugs 60 engage the recesses 110 before a clip 64 engages the second gap 86 of the cutaway portion 72 thus ensuring that the entire force of the helical spring 56 is applied between the clamping member 44 and the base member 26.
In the above-described manner the wheel 28 is clamped between the top member 30 and the base member 26 and may be unclamped by a simple reversal of the procedure, that is; depressing the handle 48, rotating the handle until the first primary retention position is reached, and thereafter releasing the handle 48 which allows the retaining lugs 60 to be removed through the channels 102 for the top member 30 to be removed from the base member 26 and the wheel 28 extracted.
While the present invention has been described in relation to a scrub wheel in a document track for document processing machinery, it is to be appreciated that the wheel 28 may be replaced by any other kind of wheel such as a gear wheel, a vehicular wheel, or indeed any piece of rotary machinery where it is desired to have a simple yet positive means of replacable attachment to a shaft. In the present invention the shaft may be rotated in either direction without prejudice to the operation of the invention. While the present invention has been shown using pairs of diametrically-opposed clips and catches, it is to be appreciated that almost any circumferential pattern of such catches, retaining lugs and the like may be used.
The shape of the retaining lugs 44 and of the recesses 110 may be so chosen that as torque is applied to the base member 26 the top member 30 may be more positively driven into the base member 26 rather than expelled therefrom. During assembly of the preferred embodiment of the present invention the channels 68 in the walls 66 of the bearing member 46 are, in the position illustrated in FIG. 6B where the retaining lugs 60 are about to pass through the channels 102 in the ledge 100, in radial circumferential and axial alignment with the channels 102 in the ledge 100.
When assembled, the cylindrical walls of the bearing member 44 are arranged to rest at their far ends upon the ledge 100 of the base member 26, though it is to be appreciated that, if it is desired directly to trap the wheel 28 between the base member 26 and the top member 30 under the action of the helical spring 56, this condition is not a necessary feature of the present invention. | A scrub wheel is provided in document processing equipment where a wheel is removable and replaceable. The wheel is held between a base member and a top member where the top member comprises retaining lugs at the distal ends of retention arms which engage the lower surface of a ledge in the center of the base member subsequent to passage therethrough when in a correct angular orientation, the lower surface comprising recesses which bind the top member and the base member under the elastic restitution force of a helical spring in the top member. | 1 |
FIELD OF THE INVENTION
This invention relates to a trailer hitch attachment to be used on a trailer hitch where a trailer hitch head is removably coupled to a trailer hitch drawbar to eliminate essentially all the play in a coupling of a trailer hitch head to a trailer hitch drawbar.
BACKGROUND OF THE INVENTION
Trailer hitches consisting of a trailer hitch drawbar and a trailer hitch head are generally of the load equalizing design. The drawbar is mounted to the towing vehicle frame and the hitch head is removably coupled to the drawbar and secured thereto by way of a locking member, such as a clevis pin. However, in order to facilitate manual assembly of the hitch, the parts are not tightly fitted together and there is a certain amount of play in the coupling of the hitch head to the drawbar. When a trailer is attached to the hitch and is being towed, this play results in wear on all the components of the trailer hitch, which in turn results in more play in the coupling of the hitch head to the drawbar. As the play increases the trailer begins to move relative to the towing vehicle to set up unusually large shock loads on the hitch. These loads are then transmitted to the towing vehicle and subsequently damage the frame and transmission of the vehicle. The trailer which becomes difficult to control as a result of the play can sway or even fishtail to create a hazard on the road.
It is therefore an object of this invention to provide an attachment to be used on a trailer hitch where a trailer hitch head is removably coupled to a trailer hitch drawbar to eliminate essentially all of the play in the coupling of a hitch head to a drawbar.
It is another object of the invention to eliminate essentially all of the wear on the individual components of a trailer hitch of a load equalizing design.
It is a further object of the invention to provide a trailer hitch attachment to reduce wear and damage to the frame and transmission of a towing vehicle.
It is yet another object of the invention to provide a trailer hitch attachment which is adjustable and easy to mount to a trailer hitch having a drawbar and removably coupled hitch head.
It is yet a further object of the invention to provide an attachment to be used with a trailer hitch of a load equalizing design to provide more control over a trailer and to prevent a trailer from swaying and fishtailing.
BRIEF SUMMARY OF THE INVENTION
The attachment according to this invention is to be mounted on a trailer hitch where a drawbar is secured to an automobile frame and a hitch head is removably coupled to the drawbar. The attachment includes a length adjustment or spacing means which consists of one or more adjustable spacing members so that the length of the attachment may be adjusted in a direction parallel to the longitudinal axis of the hitch. One end of the attachment is mounted to the hitch head and the other end is mounted to the drawbar. As the length of the attachment is adjusted, the hitch head moves relative to the drawbar. This adjustment is continued unitl the hitch head can no longer move with respect to the drawbar while the clevis pin is in a locking position and virtually all the play in the coupling is eliminated. The adjustable members of the spacing means are then locked at the desired adjusted length by way of a locking means which is also provided on the attachment.
DESCRIPTION OF THE DRAWINGS
The aforementioned and other objects, advantages and features of the invention will become apparent in the following detailed description of the preferred embodiments according to this invention as shown in the drawings wherein;
FIG. 1 is a partial elevational view of an uncoupled trailer hitch of the load equalizing design showing a preferred embodiment of a trailer hitch attachment according to this invention in position to be mounted to a trailer hitch.
FIG. 2 is an elevational view showing additional preferred features of the trailer hitch attachment of FIG. 1.
FIG. 3 is a partial elevational view of a coupled trailer hitch showing the attachment of FIG. 1 mounted to a trailer hitch according to this invention.
FIG. 4 is a partial elevational view of an uncoupled hitch of the load equalizing design showing an alternate preferred construction of an unmounted trailer hitch according to this invention.
FIG. 5 is a partial elevational view of a coupled trailer hitch showing the trailer hitch attachment of FIG. 4 mounted to a trailer hitch.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 through 3 a trailer hitch comprises a hitch head generally indicated at 1, a drawbar generally indicated at 5, a locking member in the form of a clevis pin 9 and a cotter pin 11. The hitch head 1 is provided with a shank 2, a ball 3 and a shank clevis pin aperture 4. The drawbar 5 is provided with a hollow tubular member 6 adapted to receive the shank 2, a lip 7 at its free end and a drawbar clevis pin aperture 8. Clevis pin 9 is provided with cotter pin aperture 10.
In this preferred embodiment the attachment comprises a first plate 12, a second plate 18 and an adjustable spacing means 24 which is located between the first and second plates. The first plate 12 is provided with a first skirt portion 14 and a first aperture 16. The second plate 18 has a second skirt portion 20 and a second aperture 22. Both apertures have a shape and size adapted to permit the shank to extend through them. Preferably they are approximately 2inches square and the are located in the central part of the plates. The second plate may be provided with a second aperture having a bevelled edge 23 to accommodate fillet weld when the rectangular portions 13 are welded to shank 2. Spacing means 24 includes two spacer members as shown in FIGS. 1 through 3. Each spacing member includes a bolt 26, which is provided with threads 28, a means for facilitating adjustment in the form of bolt head 30, a spacer member adjustor in the form of nut 32 which is provided with cooperating threads 34 and a locking means in the form of lock nut 36. When employing two members they should be positioned adjacent opposing sides of the shank 2, opposite one another equal distances slightly above or below the centre of the shank 2 as shown in the drawings. This will tilt the hitch and attached trailer upwardly or downwardly relative to the drawbar and when the trailer is tilted in this manner it cannot rock up and down and is easier to control. Furthermore, because the spacer members are mounted on opposing sides of the shank, they essentially prevent any sideways movement of the plates and preclude fishtailing of a trailer being towed by an automobile.
The faces of skirt portions 14 and 20 which are mounted to drawbar 5 and hitch head 1 respectively may each be provided with resilient backing 37. The resilient material should be no more than 1/8 of an inch in thickness and is preferably about 1/16 of an inch thick. Skirt portion 20 may also be provided on its forward face with locaters 40 and bolts 26 with locater receiving means 38 as seen in FIG. 2.
In operation, second plate 18 is mounted on the hitch head 1 by fitting shank 2 through second aperture 22 and abutting second skirt portion 20 against rectangular portions 13 of hitch head 1 to prevent rearward movement of second plate 18 with respect to the hitch head. First plate 12 is mounted on drawbar 5 with skirt portion 14 abutting lip 7 at the free end of hollow tubular member 6 to prevent forward movement of first plate 12 with respect to the drawbar, and shank 2 extending through first aperture 16 into the hollow tubular member. Clevis pin 9 is fitted through drawbar clevis pin aperture 8 and shank clevis pin aperture 4 to lock the shank in the hollow tubular member. Cotter pin 11 is then fitted in cotter pin aperture 10 to hold the clevis pin in a locking position.
As noted above, adjustable spacing means 24 is located between first plate 12 and second plate 18. One end of the spacing means contacts first skirt portion 14 and the other end contacts second skirt portion 20. The threads 28 of bolts 26 are threadably engaged with cooperating threads 34 of nuts 32. The heads 30 are accessible for adjustment by a tool. The attachment is adjusted by grasping heads 30 with a first tool and turning bolts 26 with respect to spacer nuts 32 to extend the length of the spacing means. In this embodiment the nuts 32 are either secured to the second skirt portion by means such as welding or held against rotation by means of a second tool. This adjustment continues until the length of spacing means 24 can no longer be extended while shank 2 is locked in hollow tubular member 6 by clevis pin 9 and any play which is the result of a poor or loose fit or earlier wear is essentially eliminated by the spreading action of the attachment. Lock nuts 36 are then adjusted to maintain the desired adjusted length of the spacing members. The resilient backing 37 acts as a sound dampener to eliminate noise travelling through the hitch.
With reference to FIGS. 4 and 5 showing an alternate construction of a preferred embodiment, a third plate generally indicated at 48 is mounted on and secured to hitch head 1 by means such as welding with a shank 2 extending through third aperture 50. Fourth plate 42 is mounted on or near the free end of hollow tubular member 6 and secured thereto by means such as welding. Shank 2 extends through fourth aperture 46 and is secured in hollow tubular member 6 by clevis pin 9. Third skirt portion 52 includes spacer member apertures 53.
The spacing means generally indicated at 54 consists of two spacing members. The spacing members include bolts 55 provided with threads 56, means for facilitating adjustment in the form of heads 58, spacer member adjustors in the form of nuts 62 which are mounted on fourth skirt portion 44 and which are provided with cooperating threads 64 to threadably engage threads 56 of bolts 54, and locking means in the form of lock nuts 60. Bolts 55 are fitted in spacer member apertures 53 such that heads 58 which cannot pass through the bolt apertures abut the rearward face of third skirt portion 52 and threads 56 extend through the bolt apertures and beyond the forward face of third skirt portion 52. The spacer members should be placed adjacent opposite sides of shank 2 opposing one another equal distances slightly above or below the centre of the shank as shown in the drawings.
When the attachment is in use, threads 56 of bolts 55 are threadably engaged with cooperating threads 64 of nuts 62. Accessible heads 58 which can easily be grasped by a tool and are turned to adjust bolts 54 with respect to nuts 62 to shorten the length of the spacing means and to clamp the hitch head to the drawbar. Nuts 62 can either be secured to fourth plate 42 or held by a second tool to prohibit rotation of the nuts. The adjustment is continued until the length of the spacing members can no longer be shortened while the shank 2 is secured in the hollow tubular member 6 by clevis pin 9. Essentially all of the play in the coupling of the trailer hitch head to the drawbar is thus eliminated by the clamping action of the attachment. In this embodiment, the attachment not only eliminates play in the coupling, but the attachment also acts as a second locking means to lock the hitch head to the drawbar should the clevis pin fail.
Although the above preferred embodiments have shown the use of plates and adjustable spacing means including spacing members in the form of threaded nuts and bolts, it would be apparent to one skilled in the art that the ends of the spacing means could be mounted directly to the hitch head and the drawbar respectively and that the spacing means could consist of any type of adjustable spacing member such as a pneumatic piston or the like. Therefore, although the preferred embodiments of the invention have been described in detail, it will be understood by those skilled in the art that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims. | An attachment for a trailer hitch to eliminate essentially all the play in a coupling of a trailer hitch head to a trailer hitch drawbar includes an adjustable spacing means to space the hitch head from the drawbar. The distance between the two ends of the attachment is adjustable in a direction parallel to the longitudinal axis of the trailer hitch. One end of the attachment is mounted on the drawbar and the other end of the attachment is mounted on the hitch head. When the spacing means is adjusted the hitch head is moved relative to the drawbar in a direction parallel to the longitudinal axis of the hitch to eliminate essentially all of the play in the hitch. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser. No. 13/133,674, filed Jun. 9, 2011, which is a National Stage of International Application No. PCT/EP2009/008622, filed on Dec. 3, 2009, which claims the priority of German Patent Application No. 10 2008 060 864.5, filed on Dec. 9, 2008. The contents of both applications are hereby incorporated by reference in their entirety.
FIELD OF DISCLOSURE
The invention relates to a closure cap for receptacles for receiving medical liquids, in particular for receptacles filled with infusion or transfusion solutions or liquids for enteral nutrition. The invention further relates to a receptacle for receiving medical liquids, in particular a bottle, with a closure cap of this kind.
BACKGROUND
A method known as a blow-fill-seal method (BFS method) is known in which receptacles, for example bottles made of extruded PE or PP, are blown in a sterile and pyrogen-free state into a desired shape in one operation and, directly after cooling, are filled aseptically with a sterile filler and hermetically sealed. The receptacles, in particular bottles, produced by the blow-fill-seal method are also referred to as BFS receptacles.
If the known BFS receptacles are used to receive sterile medical liquids, for example infusion solutions, the receptacles require a closure cap that allows the infusion solution to be transferred to the patient by means of an infusion appliance. The addition of medicaments to the infusion solution should likewise be possible.
WO 2008/095665 A1 discloses a closure cap for a receptacle for receiving medical liquids, in particular a BFS bottle. The known closure cap has a lid part and an edge part, with an injection part arranged in the lid part. The injection part has an outwardly directed connector part, with a conical recess that sealingly receives the conical stem of a needleless injection syringe, and an inwardly directed closure part, in which a self-sealing membrane is fitted. In addition to the injection part, the closure cap also has a withdrawal part for withdrawing a medical liquid using a spike.
A closure cap, which has a withdrawal part for withdrawing liquid and also an injection part for injecting an additive, is known from WO 2006/042579 A1.
The closure caps known from WO 2008/095665 A1 and from WO 2006/042579 A1 are characterized in that both closure caps have only one withdrawal part and one injection part. Both closure caps have proven effective in practice. The injection part permits subsequent injection of an additive or the injection of several additives in succession into the medical liquid. The injection part is closed in a sterile manner by a break-off part. A disadvantage is that, although the receptacle is still tightly sealed by the self-sealing membrane after the break-off part of the injection part has been broken off, the connector part of the injection part is exposed to a non-sterile environment. Therefore, there is in principle a danger of contamination of the injection part unprotected on the outside, and this proves disadvantageous if a further additive is to be injected at the injection part.
Closure caps for receptacles containing solutions for enteral nutrition are also known from U.S. Pat. No. 5,125,522 and U.S. Pat. No. 4,951,845. These closure caps only have one withdrawal site. In addition to the withdrawal site, the known closure caps have a vent opening, which is closed with a sterile filter.
WO 2006/115969 A3 describes a closure cap designed for a receptacle and having a large number of openings of different designs, for example round or star-shaped openings. All of the openings are distributed peripherally about the center of the closure cap.
Conical connectors with a conical stem and a conical sleeve whose conical surfaces are standardized are known in medical technology for connecting medical appliances. The unlockable cone connections with standardized cone surfaces are known as Luer connectors, and the lockable cone connections are known as Luer lock connectors. Luer syringes without screw connections and Luer lock syringes with screw connections are thus also known.
It is an object of the invention to make available a closure cap for receptacles for receiving medical liquids, in particular for receptacles filled with infusion or transfusion solutions or liquids for enteral nutrition, which closure cap is particularly easy to handle and can be used universally. It is also an object of the invention to make available a receptacle for receiving medical liquids, in particular a bottle, which is easy to handle and can be used universally.
According to the invention, these objects are achieved by the features specified in claims 1 and 17 . Preferred embodiments of the invention are set forth in the dependent claims.
The closure cap according to the invention is characterized by two injection parts arranged separately from each other and each designed for injection of an additive. One injection part is used for injection of an additive using a needleless syringe, while the other injection part is used for injection of an additive using an injection syringe that has a needle. It is therefore possible to inject different additives into the medical liquid contained in the receptacle using a needleless injection syringe and also using an injection syringe with needle. The closure cap according to the invention can thus be used universally.
If, for example, a first additive has been injected via the first injection part, a second additive can be injected via the second injection part. Both injection parts are preferably closed tightly with a break-off part. If the break-off part of one injection part is broken off, the other injection part remains protected by the break-off part that has not been broken off. This has the advantage that the as yet unused injection part cannot be contaminated.
In a preferred embodiment, the closure cap has a lid part and an edge part, wherein the lid part has an inner portion and an outer portion which protrudes outward from the inner portion. The first and second injection parts and the withdrawal part are preferably arranged on the outer outwardly protruding portion of the lid part. Thus, the injection site and the withdrawal site extend forward such that the injection sites and the withdrawal site on the closure cap are easily accessible.
In a preferred embodiment, the first and second injection parts and the withdrawal part are arranged preferably lying next to one another in a row on the outer portion of the lid part. The outer portion of the lid part should extend as far as possible across the entire width of the lid part. In this way, sufficient space is made available for the arrangement of the injection parts and of the withdrawal part.
In an alternative embodiment, the injection parts and the withdrawal part are arranged offset in relation to one another on the outer portion of the lid part. In this alternative embodiment, the outwardly protruding portion of the lid part preferably has a substantially rectangular shape, such that sufficient space is made available for the injection parts and the withdrawal part.
The break-off parts for closing the injection parts and the withdrawal part preferably have lateral grip tabs, which preferably extend across the outer portion of the lid part. In this way, the grip tabs can be easily gripped from the side.
The injection part for the needleless injection syringe has an outwardly directed connector part, with a recess for receiving the conical stem of the syringe, and an inwardly directed closure part, in which a self-sealing membrane is arranged. The outwardly directed connector part of the first injection part preferably has an outer thread, such that a known Luer lock syringe can be attached to the connector part. However, it is also possible that the connector part of the injection part has no outer thread, such that only the attachment of a known Luer syringe is possible.
In one embodiment a hollow body with a point is arranged in the recess of the connector part of the injection part which is designed for injecting an additive into the medical liquid using a needleless injection syringe, wherein the membrane and the hollow body are arranged in the recess of the connecting part in such a manner that the membrane is pierced when the syringe is connected to the connecting part, wherein the membrane is arranged above the hollow body in the recess of the connecting part and therefore, when the syringe is connected to the connecting part, the membrane is pressed by the syringe onto the point of the hollow body. In one embodiment the hollow body is designed as a cannula with a ground section. In a further embodiment the hollow body in the recess of the connecting part is fastened to a disk-shaped body which preferably has openings, preferably for ventilation purposes. These openings in the disk-shaped body are for instance bores which can be distributed circumferentially around the hollow body.
The receptacle according to the invention, in particular an infusion or transfusion receptacle or a receptacle for receiving a solution for enteral nutrition, is preferably designed as a bottle, in particular an SBM (stretch-blow-molding) bottle that is closed with the closure cap according to the invention.
According to one embodiment the closure cap comprises or consists of polypropylene and/or polyethylene. In one further embodiment the membrane comprises or consists of polyisoprene and/or brominebutyl and/or chlorinebutyl.
According to one embodiment the withdrawal part for withdrawing the medical liquid using a spike is adapted to receive a spike having a diameter in the range of approximately at least 5 mm to approximately 6.5 mm. In another embodiment the injection part for injecting an additive into the medical liquid using a needleless injection syringe is adapted to receive a Luer-Lock syringe having a cone diameter of about 4 mm. In one further embodiment the second injection part designed for injecting an additive into the medical liquid using an injection syringe that has a needle is adapted to receive a needle having a diameter up to about 5 mm. For instance the outer diameter of the closure cap is in the range of 30 mm to 40 mm. For instance the maximum height the closure cap (including the break-off parts) is in the range of 25 mm to 35 mm.
BRIEF DESCRIPTION OF THE DRAWINGS
Two illustrative embodiments of the invention are explained in more detail below with reference to the drawings, in which:
FIG. 1 shows an illustrative embodiment of the closure cap according to the invention in a plan view in which the injection parts and the withdrawal part are arranged in a row,
FIG. 2 shows the closure cap from FIG. 1 in a view from underneath,
FIG. 3 shows the closure cap from FIG. 1 in a sectional view, wherein the break-off part is broken off from an injection part in order to inject an additive using a syringe that has a needle,
FIG. 4 shows the closure cap from FIG. 1 in a sectional view, wherein the break-off part is broken off from the other injection part in order to inject an additive using a needleless syringe,
FIG. 5 shows the closure cap from FIG. 1 in a sectional view, wherein the break-off part is broken off from the withdrawal part in order to withdraw liquid using a spike,
FIG. 6 shows a second illustrative embodiment of the closure cap according to the invention in a view from above, in which the injection parts and the withdrawal part are arranged offset in relation to one another,
FIG. 7 shows the closure cap from FIG. 6 in a view from underneath, and
FIG. 8 shows an illustrative embodiment of receptacle according to the invention with a closure cap according to the invention.
FIG. 9 shows a zoom of an illustrative embodiment of the injection part with a hollow body for piercing the membrane.
DETAILED DESCRIPTION
FIGS. 1 and 2 show a first illustrative embodiment of the closure cap according to the invention in a plan view and a bottom view, while FIGS. 3 to 5 show the closure cap in sectional views, wherein an additive is injected using an injection syringe or a liquid is withdrawn using a spike. Apart from the pierceable membranes, the closure cap is a one-piece plastic component that can be produced inexpensively in large numbers.
The closure cap 1 has a lid part 2 and an edge part 3 . The lid part 2 has a flat inner portion 4 , from which an outer portion 5 protrudes outward. The outer portion 5 of the lid part 2 has an elongate shape with two substantially rectilinear portions 5 A, which are adjoined at both sides by substantially semicircular portions 5 B. The outer portion 4 extends across the whole width of the inner portion 4 of the lid part 2 . A first injection part 6 , a second injection part 7 and a withdrawal part 8 are located on the top of the outer portion 5 of the lid part 2 in a manner easily accessible to the user. The first injection part 6 is used for injection of an additive using an injection syringe that has a needle ( FIG. 3 ), while the second injection part 7 is used for injection of an additive using a needleless injection syringe ( FIG. 4 ). The withdrawal part 8 is used for withdrawal of liquid using a spike ( FIG. 5 ).
The two injection parts 6 and 7 and the withdrawal part 8 are arranged lying close to one another in a row on the outer portion 5 of the lid part 2 . They lie on an axis 9 that corresponds to the longitudinal axis of the outer portion 5 of the lid part 2 . The two injection parts 6 and 7 , which have a smaller diameter than the withdrawal part 8 , are arranged lying closely next to each other, while the withdrawal part 8 lies close to the two injection parts 6 , 7 .
The two injection parts 6 , 7 and the withdrawal part 8 are described below in more detail with reference to FIGS. 3 to 5 .
The first injection part 6 , arranged on the outer edge of the lid part 2 and designed for injection of an additive using an injection syringe ( FIG. 3 ) that has a needle, comprises an outwardly directed annular shoulder 10 , which encloses the injection site. The annular shoulder 10 is closed with a break-off part 11 , which adjoins the upper end of the annular portion 10 via an annular break-off zone 12 ( FIGS. 4 and 5 ). The break-off part 11 has a round cap 13 , to which a grip tab 15 is adjoined via a narrow web 14 , which grip tab 15 extends across the outer portion 5 of the lid part 2 and downward as far as the edge part 3 of the closure cap 1 .
From the annular portion 10 of the first injection part 6 , a closure part 16 is directed inward and has a recess 17 . A pierceable, self-sealing membrane 18 is fitted in the recess 17 of the closure part 16 . The membrane 18 is secured with a snap-fit in the recess 16 . The recess 16 has an upper cylindrical portion 16 A, which adjoins the annular portion 10 of the first injection part 6 . The upper cylindrical portion 16 A is adjoined by a lower cylindrical portion 16 B, which has a greater internal diameter than the upper cylindrical portion 16 A. The self-sealing membrane 18 accordingly has a lower cylindrical portion 18 A with a greater external diameter, which sits in the lower cylindrical portion 16 B of the recess 16 . The lower cylindrical portion 18 A of the membrane 18 is adjoined by an upper cylindrical portion 18 B with a smaller external diameter, which sits snugly in the upper cylindrical portion 16 A of the recess 16 .
To fix the membrane 18 with a clamping action in the recess 17 , the closure part 16 has an inwardly projecting edge 19 at the lower end of the closure part 16 that engages under the membrane 18 . The membrane 18 has a flat top and bottom and is not slotted. This means that, when the needle of an injection syringe has been pulled out, the membrane reliably seals again and no liquid escapes.
The second injection part 7 , arranged centrally, has an outwardly directed connector part 20 for the connection of a needleless Luer lock syringe ( FIG. 4 ). Otherwise, the second injection part 7 does not differ from the first injection part 6 . The connector part 20 of the second injection part has a conical recess 20 A, for sealingly receiving the conical stem of the syringe, and an outer thread 20 B. The conical recess 20 A and the outer thread 20 B are designed in such a way that a commercially standard Luer lock syringe can be attached to the connector part.
The connector part 20 is closed with a break-off part 21 , which is attached to the upper end of the connector part via an annular break-off zone 22 . The break-off part 22 has a round cap 23 which is adjoined, via a narrow web 24 , to a lateral grip tab 25 , which extends outward across the outer portion 5 of the lid part 2 and as far as the inner portion 4 of the lid part 2 .
The second injection part 7 also has a closure part 26 , which corresponds to the closure part 16 of the first injection site 6 . The closure part 26 of the second injection site again has a recess 27 , in which a membrane 28 is fixed with a clamping action. The closure part 26 of the second injection part 7 differs from the closure part of the first injection part 6 in terms of the membrane 28 , which has a lower annular portion 28 A adjoined, via a central web 28 B, to an upper plate-shaped portion 28 C, which has a cup-shaped depression 28 D. The plate-shaped portion 28 C of the membrane 28 is provided with one or more slits, for example being slotted crosswise.
The withdrawal part 8 of the closure cap 1 has an outwardly directed connector part 29 for the attachment of the spike of an infusion appliance ( FIG. 5 ). The connector part 29 has a recess 30 into which the spike of the infusion appliance is inserted. The recess 30 has an upper conical portion 30 A and a lower cylindrical portion 30 B, wherein the upper conical portion serves to center the spike, and the lower cylindrical portion serves to receive the spike sealingly. The recess 30 of the connector part 29 is closed with a break-off part 31 , which is attached to the upper end of the connector part via an annular break-off zone 32 . The break-off part 31 again has a lateral grip tab 33 which, like the grip tab of the break-off part of the first injection part, protrudes outward across the outer portion 5 of the lid part 2 and extends as far as the edge part 3 of the closure cap 1 .
The withdrawal part 8 has an inwardly protruding closure part 34 with a recess 35 , in which once again a pierceable, self-sealing membrane 36 is fixed with a clamping action. The self-sealing membrane 36 of the withdrawal part 8 has an outer annular upper portion 36 A, to which a plate-shaped lower portion 36 C is adjoined via a central web 36 B. The central web 36 B of the membrane 36 is held and clamped by an inwardly protruding edge 37 at the lower end of the closure part 34 .
At the lower edge of the edge part 3 , the closure cap 1 has a bead-shaped edge 38 , which has a circumferential groove 39 on the underside. The closure cap can be fitted onto a bottle, wherein the upper edge of the bottle neck engages in the groove 29 of the bead-shaped edge 38 of the closure cap 1 .
FIG. 8 shows a bottle 40 , in particular an SMB bottle, which is closed with the closure cap 1 according to the invention. The closure cap 1 sits securely on the bottle neck 41 of the bottle 40 , which is filled with an infusion solution for example. Since the bottle neck is not closed in the head area and is instead open, the liquid is in direct contact with the cap. It is therefore possible to inject a medicament using a needleless injection syringe or using an injection syringe with needle. The closure cap can be designed as a screw cap, which is screwed onto the bottle neck of the bottle. However, it is also possible to weld the closure cap to the bottle neck.
The handling of the closure cap 1 is described below.
To withdraw a liquid, for example an infusion solution, the break-off part 31 is broken off from the closure cap 1 , such that the membrane 36 of the withdrawal part 8 is exposed. The spike of the infusion appliance is then attached to the connector part 29 of the withdrawal part 8 ( FIG. 5 ). If a medicament is to be injected using an injection syringe with needle, the break-off part 11 of the first injection part 6 is broken off, such that the membrane 18 of the first injection part can be pierced by the needle of the syringe. In doing this, however, the second injection site remains protected by the associated break-off part ( FIG. 3 ). If a medicament is to be injected using a needleless injection syringe (Luer lock syringe), the break-off part 21 of the second injection part 7 is broken off, whereupon the Luer lock syringe can be screwed onto the connector part 20 of the second injection part 7 ( FIG. 4 ).
FIGS. 6 and 7 show an alternative embodiment of the closure cap 1 ′ according to the invention, which differs from the closure cap described with reference to FIGS. 1 to 5 only in terms of the arrangement of the two injection parts and of the withdrawal part on the outer portion of the lid part. Therefore, the same reference signs are also used for the parts that correspond to each other. In the embodiment in FIGS. 6 and 7 , the outer portion 5 of the lid part 2 of the closure cap 1 ′ has a substantially rectangular shape with rounded corners. The two injections parts 6 , 7 and the withdrawal part 8 are arranged offset in relation to one another on the top of the upper portion 4 of the lid part 2 . The first injection part 6 and the withdrawal part 8 lie on one half, and the second injection part 7 on the other half, on the top of the outer portion 5 of the lid part 2 . The grip tabs 15 , 25 , 33 of the injection parts 6 , 7 and of the withdrawal part 8 are directed radially outward. They extend outward across the outer portion 5 of the lid part 2 and reach downward as far as the edge part 3 of the closure cap 1 . The individual accesses are identified as injection parts or withdrawal part by the upwardly or downwardly directed arrows 42 on the grip tabs 15 , 25 , 33 of the break-off parts 11 , 21 , 31 .
Finally FIG. 9 shows a zoom of an illustrative embodiment of the injection part 7 with a hollow body 100 for piercing the membrane 28 . In this embodiment upon connection of a syringe to the closure cap, the membrane 28 is pressed onto the point 102 or tip 102 of the hollow body 100 which is arranged below the membrane 28 . In this embodiment, the point 102 of the hollow body 100 is not at a distance from the membrane 28 but rather is directly therebelow, preferably in contact with the membrane 28 . In a non-shown embodiment the hollow body 100 is at a distance from the membrane 28 , i.e. not in contact. Due to the hollow body 100 the reliability of the membrane opening and/or membrane closing is enhanced.
Preferably the hollow body 100 for piercing the membrane 28 upon connection of the syringe is integrally formed on a disk-shaped body 101 which sits together with the membrane 28 in the recess 27 of the lid part 2 of the closure cap. The membrane 28 and the hollow body 100 together with the disk-shaped body 101 are held clamped in the recess 27 by a projecting, encircling extension 105 which engages under the disk-shaped body 101 . In this case, the lower portion 28 A of the membrane 28 is supported in the recess 27 of the lid part 2 of the closure cap by means of an upper, projecting extension 106 and the disk-shaped body 101 is supported therein by means of a lower, projecting extension 106 . However, it is also possible to adhesively bond or to weld the disk-shaped body to the lid part 2 of the closure cap. In one embodiment the projecting, encircling extension 105 is provided as a beading flange. | The invention relates to a closure cap ( 1 ) for receptacles for receiving medical liquids, in particular receptacles filled with infusion solutions, transfusion solutions or liquids for enteral nutrition. The invention further relates to a receptacle ( 40 ) for receiving medical liquids, in particular a bottle, comprising such a closure cap. The closure cap ( 1 ) according to the invention is characterized by two injection parts ( 6 and 7 ) arranged separately from one another, each for injecting an additive. One injection part ( 6 ) serves to inject an additive with an injection syringe that has a needle (cannula), while the other injection part ( 7 ) serves to inject an additive with a needle-less injection syringe. | 1 |
FIELD OF THE INVENTION
This invention relates to a current detection unit and a relay terminal array capable of detecting failures which contains a number of current detection units.
BACKGROUND OF THE INVENTION
There are many types of relay terminals, including relay terminals which are not capable of transmission, relay terminals with transmitting capability, and I/O relay terminals with, for example, photocoupler input and transistor output.
Since none of these existing relay terminals is capable of detecting relay failures (welding of contacts, faulty contacts, and so on) by themselves, faulty relays are slow to be detected. This delay leads to inconvenience, such as down time until a new relay can be installed.
To detect a faulty relay, one could use a logic circuit which has as its inputs the presence or absence of a load current from the relay and an output signal from the relay coil. Based on these inputs, the circuit could judge whether there were a relay fault. With this proposed circuit however, certain problems can occur:
(1) The range of load current which can be detected is limited;
(2) There are limitations on the shape and dimensions of the current sensor;
(3) It is difficult to provide adequate isolation between primary and secondary circuits and among the different poles; and
(4) Such a device cannot be assembled efficiently.
SUMMARY OF THE INVENTION
In light of the problems listed above, this invention has the advantage of providing a relay terminal which is compact and easy to assemble as well as being capable of detecting failures in a compact current detection unit.
The current detection unit of this invention has an annular core with a gap; a case which has a compartment to hold the annular core and a hole which corresponds to the location of the air gap in the annular core contained in the compartment; a circuit board which is mounted on one side of the case and has a magnetic-to-electric converter element on it which is inserted into the air gap of the annular core through the hole in the case; and a coil which is wound on the core compartment of the case.
The relay terminal array of this invention has a housing unit with an open top to hold electronic circuitry; a number of current detection units supported adjacent to each other within the housing unit, each of which has an annular core with a gap; a case which has a compartment to hold the annular core and a hole which corresponds to the location of the air gap in the annular core contained in the compartment, a circuit board which is mounted on one side of the case and has a magnetic-to-electric converter element on it which is inserted into the air gap of the annular core through the hole in the case, and a coil which is wound on the core compartment of the case; and an upper case which has terminals to which one end of each of the coils found on the corresponding current detection unit are connected and terminals to which the other ends are connected. This upper case covers the opening on the top of the housing unit and includes a relay installation containing a number of relays. In summary, the relay terminal array of this invention comprises a housing unit, a number of current detection units, and an upper case.
The current detection unit operates as follows. When a current flows through the coil wound on the core compartment of the case, lines of magnetic force are generated in the core contained in the compartment. These lines of magnetic force are detected by the magnetic-to-electric converter element placed in the air gap in the core. The magnetic field which is detected is converted to an electrical signal and is output as a signal indicating the presence of a current. When there is no current flowing through the coil, no lines of magnetic force are generated in the core. The magnetic-to-electric converter element does not detect a magnetic field, so a signal indicating the absence of a current is output.
This current detection unit has a core in a compartment provided in a case and a coil which is wound on that compartment. A circuit board which has a current detection circuit featuring a magnetic-to-electric converter element is mounted on one side of the case. The case is comprised of two halves which fit together symmetrically, so it can be assembled merely by joining the halves.
If a relay remains on in the relay terminal array when it should be off, because of a failure such as contact welding or faulty contact, a current will continue to flow in the coil in the current detection unit, and the magnetic field generated in the core will be detected by the magnetic-to-electric converter element as described above. If a relay goes off due to a failure when it should be on, no current will flow in the coil, and the magnetic-to-electric converter element will not detect a magnetic field in the core. The output signal from the magnetic-to-electric converter element in these circumstances is used by a logic circuit to determine, based on this signal and the on/off state of the relay, that a relay has failed. This result is transmitted to external circuitry.
In this relay terminal array, the housing unit contains the electronic circuitry as well as a number of the current detection units. The opening on the top of the housing unit is covered by the upper case. Inside the housing unit, a vertical spacer is provided which has vertical partitions between each of at least two current detection units. This provides sufficient isolation of the different poles from one unit to the next, and it prevents external devices from interfering with the current detection units.
The current detection unit of this invention achieves the following advantages:
(1) The current flowing through a circuit flows through a coil so that it can be detected as a magnetic field by a magnetic-to-electric converter element. This scheme insures that the current in the coil will be detected reliably. Since this detection device is built into a relay terminal array, failures of relays can be detected reliably by a logic circuit;
(2) The spatial relationship between the magnetic-to-electric converter element and the core is firmly fixed during assembly;
(3) Sufficient isolation is provided between the primary and secondary elements;
(4) The device can-be assembled efficiently. Since the case is composed of two symmetrical halves, it can be assembled merely by fitting two pieces together, a highly efficient mode of assembly; and
(5) The configuration of this invention allows the unit to be assembled easily and enables it to be made more compact.
The relay terminal array of this invention contains a number of the current detection units and provides the following advantages:
(1) A logic circuit swiftly and reliably detects the failure of a relay based on the presence or absence of a current detected by the current detection unit, and on the on/off status of the relay. This allows a failure to be responded to quickly;
(2) Each current detection unit, and indeed the entire device, is easy to assemble;
(3) Since all components are arranged compactly, the terminal unit itself is compact;
(4) The partitions in the spacer ensure that there is adequate isolation between different poles of adjacent current detection units; and
(5) The partitions in the spacer prevent interference from external sources from reaching the current detection units.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial exploded perspective view of the current detection unit of this invention;
FIG. 2 is a partial exploded perspective view of the current detection unit pictured in FIG. 1;
FIG. 3 is a perspective view of the exterior of the relay terminal array of this invention;
FIG. 4 is a perspective view of the exterior of the housing unit on the relay terminal array pictured in FIG. 3;
FIG. 5 is a partial exploded perspective view focusing on the spacers in the relay terminal array pictured in FIG. 3;
FIG. 6 is a partial exploded perspective view focusing on the current detection units in the relay terminal array pictured in FIG. 3; and
FIG. 7 is a partial exploded perspective view focusing on the upper case in the relay terminal array pictured in FIG. 3.
DETAILED DESCRIPTION OF THE INVENTION
An example of a current detection unit is shown in exterior oblique view in FIG. 1 and in partial exploded oblique view in FIG. 2. Current detection unit 1 has two bobbins (half cases) 10, 20. Bobbins 10, 20 fit together symmetrically and contain core compartments 11, 21, respectively. Compartments 11, 21 form an annular chamber into which the core is inserted. The top halves of the compartments protrude from bobbins 10, 20. Annular core 30, which is contained in compartments 11, 21, has a partially isolating air gap 31 in it.
The inner side of bobbin 10 has a snap fitting 12 and a boss 13 on it. Bobbin 20 has a depression 22 which corresponds to snap fitting 12 and a hole 23 into which boss 13 fits.
Circuit board 40 is mounted to the outside of bobbin 10 by means of self-tapping screws 42 which are inserted through holes 43 in circuit board 40 and holes 14, 24 in bobbins 10, 20. A single Hall element 41 is mounted on the inside of circuit board 40, the side facing the bobbin. This is the magnetic-to-electric converter element which detects the magnetic field generated in core 30 and converts it to an electrical signal. Since circuit board 40 is mounted on the outer side of bobbin 10, Hall element 41 can pass through hole 15, through air gap 31 in core 30, and partially penetrate hole 25 in bobbin 20. This configuration allows Hall element 41 to detect with certainty the lines of magnetic force generated in core 30. On the front of circuit board 40 is the current detection circuit, which comprises various electronic components. In the relay terminal array, circuit board 40 is connected to another circuit board 80 (see FIG. 6) through connectors 45.
Magnet wire 35 is wound a predetermined number of turns on compartments 11, 21 of bobbins 10, 20 to produce coil 36. In one aspect of the invention, coil 36 is wound starting from the top and ending at the top, so that both halves are wound in the same direction.
In a current detection unit 1 configured in this way, core 30 is enclosed in compartments 11, 21 of bobbins 10, 20. When bobbins 10, 20 are joined, snap fitting 12 on bobbin 10 engages with depression 22 on bobbin 20 and boss 13 on bobbin 10 goes into hole 23 in bobbin 20. In this way bobbins 10, 20 are formed into an integral unit. Circuit board 40 is mounted on the side of bobbin 10. When coil 36 is wound and placed in compartments 11, 21, the assembly is complete.
In the configuration described above, Hall element 41 is easily and reliably positioned in air gap 31 of core 30 at the time of assembly. This insures that the spatial relationship between Hall element 41 and core 30 will remain fixed. It also guarantees a sufficient isolation distance between the primary and secondary circuits and improves the efficiency of the entire assembly process.
The operation of current detection unit 1 is described below. When a current flows through coil 36, lines of magnetic force are generated in core 30 inside compartments 11, 21. These lines of magnetic force are detected by Hall element 41 in air gap 31 and converted to an electrical signal. A signal indicating the presence of a current is output by the current detection circuit. When there is no current flowing through coil 36, no magnetic field is generated in core 30. Hall element 41 does not detect a magnetic field, and a signal indicating the absence of a current is output.
The relay terminal array which contains current detection units 1 described above will now be explained. A perspective view of the exterior of a preferred embodiment of this relay terminal array is shown in FIG. 3. Exploded perspective views showing components are provided in FIGS. 4-7. Relay terminal array 2 comprises housing unit 50, which is open on top, and upper case 100, containing a number of relays 120 (in this case, four), which is mounted on the top of housing unit 50 so that it can be put on and taken off.
As shown in FIG. 4, housing unit 50 has four holes 52 close to its open top 51. By means of tabs 101 on upper case 100 (see FIG. 7) which engage in holes 52, the upper case is mounted on housing unit 50 so that it can easily be removed and put back on. Fixture rail 53 engages with the bottom of housing unit 50.
As can be seen in FIG. 7, six terminals 105 are attached to upper case 100 by screws 106, and six terminals 106 are attached by screws 108. Cover 109 is mounted over anti-static plate 93 (see FIG. 5) which discharges the static electricity from circuit board 90, which is exposed on the top of upper case 100. Cover 110 is mounted over the portion of the relay terminal array where terminals 105, 107 are mounted and so that it is removable. Cover 111 is installed on top of LEDs 94 (see FIG. 5), which are mounted on circuit board 90.
Inside housing unit 50 is a spacer 60, which is shaped as shown in FIG. 5. On the top surface of spacer 60 are snap fittings 61, which engage with holes 102 in upper case 100 (see FIG. 7) to secure spacer 60 to the upper case.
In FIG. 6 one can see that inside spacer 60 there are a number (in this case, four) of the current detection units 1 arranged one next to the other. The tops of circuit boards 40 in these current detection units 1 engage in guide grooves (not shown) in spacer 60 so that the units are supported vertically in fixed positions with respect to the spacer. As shown in FIG. 5, spacer 60 has three isolation barriers (partitions) 63, which extend vertically from the top of the spacer. Each of these isolation barriers 63 extends between two detection units 1. Barriers 63 insure that there is an adequate isolation distance between the different poles of neighboring detection units 1.
Connectors 45 on circuit board 40 of each detection unit 1 are inserted into holes 81 in circuit board 80 and soldered. The output circuit, which is composed of various electronic components, is built on circuit board 80. The ends of circuit board 80 go between paired tooth-shaped positioning guides which are furnished in three places on spacer 60 to keep the board in the correct position on the spacer.
Circuit board 80 is connected to circuit board 70 by means of connectors 85, which are inserted through holes 82 on board 80 and holes 72 on board 70 and soldered in place. Circuit board 70 has a number of circuits on it, including a power supply circuit, a reset circuit, a driver/receiver circuit(s) and a control circuit(s) for transmitting. These circuits are comprised of electronic components 71. The ends of circuit board 70 fit between paired tooth-shaped positioning guides which are furnished in four places on spacer 60 (see FIG. 5) to keep the board in the correct position on the spacer.
As shown in FIG. 5, there is another circuit board 90 on top of spacer 60. Circuit board 90 is supported by guides (not shown) on upper case 100 and by terminals 107, which are inserted into holes 97 in circuit board 90 and then soldered. Relays 120 (see FIG. 3) on circuit board 90 comprise four relay sockets 91 (the relay installation), which are mounted to be removable; four opening detection switches 92; discharge plate 93 for static electricity; and six LEDs 94. An output circuit is also mounted on circuit board 90. By operating levers 91a of relay sockets 91, one can release relays 120 from their mountings on sockets 91.
There are four terminals 99 (the connection terminals for the relays), each of which has one of its ends inserted through a hole 98 in circuit board 90. The other end goes through one of rectangular holes 64 in spacer 60 and protrudes into the interior of the spacer. One end of the coil 36 in each current detection unit 1 is soldered to the end of each terminal 99 which protrudes from circuit board 90. The other end of each coil 36 is soldered to one of four terminals 105.
As shown in FIGS. 5 and 6, circuit boards 70 and 90 are connected to each other through connector 75 on board 70 and flat cable 77 which is mounted onto connector 95 on board 90. Circuit boards 80 and 90 are connected to each other through connector 85 on board 80 and flat cable 86, which is mounted onto connector 96 on board 90. To connect an external power source or transmission circuitry, harness 78, which is joined to connector 76 on circuit board 70, is soldered to two of terminals 105 and two of terminals 107.
A relay terminal array 2 constructed in this fashion will automatically detect a failure of one of relays 120 and transmit to the external circuitry a signal indicating the detection of this failure. When a failure, such as contact welding or a faulty contact, occurs in one of relays 120 which are mounted on relay sockets 91, the current detection units 1 will transmit a signal indicating the presence or absence of a current to a logic circuit. Based on this signal and the on/off status of relays 120, the logic circuit will determine whether a failure has occurred. If, for example, current detection unit 1 detects a current when a relay 120 is in the off state, or if it does not detect a current when the relay is in the on state, the logic circuit will produce a judgment that a failure has occurred. This function allows failures to be reported swiftly so that countermeasures can be taken promptly to eliminate down time. | A compact current detection unit which detects a failure in a relay terminal and provides a relay terminal array which has a failure detection function and is compact and easy to assemble. The current detection unit includes two symmetrical bobbins; a core located within compartments of bobbins and has an air gap in it; holes in the bobbins which correspond to air gap in the core; coil wound on the compartments; and a circuit board fastened to the side of one of the bobbins on which a Hall element is mounted. A Hall element is inserted through and fixed in position by the holes in the bobbins and the air gap in the core. If a current is flowing through the coil, the lines of magnetic force generated in the core are detected by the Hall element located in the air gap. If no current is flowing, no lines of force are detected. | 7 |
This is a continuation-in-part application of U.S. Ser. No. 07/576,301, filed Aug. 31, 1990, now pending.
FIELD OF THE INVENTION
This invention relates generally to hydraulic fluid compositions and, more specifically, to hydraulic fluids characterized by enhanced fire resistance.
BACKGROUND OF THE INVENTION
In the past, polyalkylene glycol-based hydraulic fluids have generally required the presence of water therein in order to provide a degree of fire resistance sufficient to meet the Factory Mutual Research, Group I, Class No. 6930 approval (so-called "FM approval") with regard to the flame resistance of the fluid. Water is undesirable as an additive in hydraulic fluids for several reasons, most notably due to operating pressure limitations imparted by the vapor pressure of water and potential corrosion problems caused by water on the metal surfaces of the hydraulic system.
As an alternative to the use of water additives in polyalkylene glycol-based hydraulic fluids, polyol ester-type fluids, e.g. trioleate esters of trimethylol propane, typically utilize high molecular weight polymer anti-mist additives in order to provide FM approval. Unfortunately, such anti-mist additives tend to degrade when subjected to the shear forces typically encountered by hydraulic fluids during use. Accordingly, hydraulic fluids containing such prior art anti-mist additives tend to have relatively short useful lives of a few months or less, dependant upon the operating conditions and service requirement for the particular application for which the hydraulic fluid is employed. Additionally, polyol ester type lubricant bases are also subject to hydrolysis under certain conditions, which can alter the performance characteristics of the hydraulic fluid.
In view of the above, new non-aqueous hydraulic fluids that exhibit an improved combination of flame retardancy and shear stability would be highly desired by the hydraulic fluid manufacturing community.
SUMMARY OF THE INVENTION
In one aspect, the present invention relates to a hydraulic fluid composition comprising:
(a) a synthetic base fluid having a flash point of at least 400° F. selected from the group consisting of esters, diesters, polyol esters, polyalkylene glycol esters, polyalkylene glycols, and combinations thereof, and
(b) as an anti-mist additive, an alkylene-vinyl ester copolymer having a molecular weight of between about 5,000 and about 100,000 (preferably 10,000-50,000) and soluble in said base fluid.
In another aspect, the present invention relates to a process for imparting flame retardancy, hydrolytic stability, and reduced wear characteristics to a hydraulic system which comprises adding to the hydraulic system a hydraulic fluid composition comprising:
(a) a synthetic base fluid having a flash point of at least 400° F. selected from the group consisting of esters, diesters, polyol esters, polyalkylene glycol esters and polyalkylene glycols, and combinations thereof, and
(b) as an anti-mist additive, an alkylene-vinyl ester copolymer having a molecular weight of between about 5,000 and about 100,000 and soluble in said base fluid.
These and other aspects will become apparent upon reading the following detailed description of the invention.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the present invention, it has now been surprisingly found that a hydraulic fluid composition can be provided that provides excellent anti-wear properties as well as enhanced flame retardancy over time during use. The hydraulic fluid is polyalkylene glycol based and contains an anti-mist additive exhibiting an improved shear-stable characteristic relative to those utilized in polyol ester type hydraulic fluids.
The polyalkylene glycols useful as the base fluid in the hydraulic fluids of the present invention are generally anionically or cationically catalyzed using, for example, an alkali metal salt of a lower alkanol initiator. An illustrative example is a potassium hydroxide catalyzed butanol initiated polypropylene glycol. The various polyalkylene glycols, including monols, diols, triols, and the like, are well-known in the art and are commercially available, for example, under various trademarks, including Olin Corporation's POLY-G trademark, Union Carbide Corporation's UCON trademark, and BASF Corporation's PLURACOL trademark.
The preferred anti-mist additive useful in the present invention is an alkylene-vinyl ester copolymer having a molecular weight of between about 5,000 and about 100,000, wherein the alkylene compound is preferably selected from the group consisting of ethylene, propylene, butylene, and combinations thereof. The copolymer can be a random or block-type copolymer with the ratio of alkylene groups to vinyl ester groups in the copolymer being between about 1:10 and about 10:1 with the proviso that the copolymer be soluble in the base fluid. The most preferred copolymer is an ethylene-vinyl ester copolymer commercially available as V-152, a product of Functional Products Corporation of Cleveland, Ohio. The copolymer is suitably prepared using known techniques for ethylene-vinyl ester copolymerizations as disclosed, for example, in U.S. Pat. Nos. 3,254,063 and 3,591,502, both incorporated herein by reference in their entirety.
Illustratively, the alkylene-vinyl ester copolymer is suitably prepared by copolymerizing the alkylene compound (e.g., ethylene, propylene, butylene, or combinations thereof) with a copolymerizable unsaturated ketone. Suitable ketones include, for example vinyl methyl ketone, vinyl n-octyl ketone, vinyl-isooctyl ketone, vinyl dodecyl ketone, vinyl-cyclohexyl ketone, 3-pentene-2-one, and combinations thereof. The molar percent of alkylene compound to ketone is suitably between 5 and 80 percent based upon the total amount of alkylene compound plus ketone employed to produce the copolymer.
The amount of anti-mist additive in the hydraulic fluid of the present invention is preferably between about 0.1 and about 20 weight percent, and more preferably between about 0.5 and about 10 weight percent based upon the total amount of anti-mist additive plus base fluid in the hydraulic fluid.
The hydraulic fluid of the present invention is non-aqueous or "essentially water free" which is intended to designate that the hydraulic fluid contains no more than 5 weight percent water, preferably no more than 2 weight percent water, based upon the weight of the hydraulic fluid.
In compositions of this invention, it is essential that both the component (a) and the component (b) be present in order to provide the desired flame retardancy and anti-wear properties. Additional optional additives are also suitably employed as desired, including, for example, the functional fluids of this invention will normally contain very minor amounts, typically from about 0.01% to about 5.0% by weight of various additives of the type commonly incorporated in formulating hydraulic fluids and lubricants such as rust and oxidation inhibitors, corrosion inhibitors, metal passivators, antiwear agents and other special purpose additives.
Rust and corrosion inhibitors and metal passivators suitably employed include tolyltriazole, benzothiazole and benzotriazole and their derivatives, alkyl and aryl phosphites and sarcosine and succinic acid derivatives. Antioxidants include dialkylthiodiproprionate, for example, dilaurylthiodiproprionate etc. organic amines, for example, dioctyldiphenylamine, phenylnaphthylamine, hindered phenols, phenothiazine, etc. Antiwear additives include dithiophosphates, amine phosphates, organo-molybdenum compounds, phosphorothionates, carbamates, etc. The suitably of such optional additives will depend upon the operating conditions, and the service requirements for the particular application that the hydraulic fluid is employed in. Except for the requirements given above, the relative proportions of and the maximum amount of each of these components and the combination thereof that should be present is not critical to the present invention. Economic factors also help determine what optimum amounts should be used. If used, the optional additives are suitably employed in an amount up to about 40 weight percent base upon the total weight of the hydraulic fluid.
The hydraulic fluid composition of the present invention preferably has a viscosity of between about 15 and about 3000 centistokes at 40° C.
The following examples are intended to illustrate, but in no way limit the scope of, the present invention. All patents referred to herein are incorporated herein by reference in their entirety.
EXAMPLES 1-7
Preparation of Hydraulic Fluids and Testing Thereof
Hydraulic fluid compositions within the scope of the present invention are shown in Table I, Example Formulations. Comparative example formulations are shown in Table II. The listed components are added into a reaction vessel in random order and mixed thoroughly at a temperature of from 40° C. to 60° C. for at least 1/2 hour. All formulations are given in weight percent.
TABLE I__________________________________________________________________________ Example FormulationsFormulation Components 1 2 3 4 5 6 7__________________________________________________________________________POLY-G ® WI-165.sup.1 60.9 61.9POLY-G ® WI-285 34.9 90.8 38.3 32.6POLY-G ® WI-625 5.7 57.5POLY-G ® WI-700D 96.8POLY-G ® WI-200N 96.8TMP-Oleic Acid Ester 94.5Phenothiazine 0.5 0.5 0.5 0.5 0.5 0.5Dioctyldiphenylamine 0.2Triphenylphosphorothionate 0.5 0.5 0.5 0.5 0.5 0.5Ciba Geigy Irgalube 349 0.2 0.5 0.2 0.2 0.5 0.5V-152(ethylene-vinyl ester) 3 2 3 2 3 4 4Iso Grade 46 68 100 150 100 46 68Factory Mutual Result P P P P P P NT__________________________________________________________________________ Flash PointBase Fluid Initiator Molecular Weight (COC)__________________________________________________________________________WI-165 Butanol 750 425° F.WI-285 Butanol 1040 425° F.WI-625 Butanol 1840 440° F.WI-700D Propylene Glycol 2000 465° F.WI-200N Nonylphenol 810 455° F.TMP-Oleic Acid Ester Trimethylol Propane 970 590° F.__________________________________________________________________________ P = Pass, F = Fail, NT = Not Tested .sup.1 POLYG is a registered trademark of Olin Corporation.
TABLE II______________________________________Comparative Examples Comparative FormulationsFormulation Components 1 2 3 4______________________________________POLY-G ® WI-285 0 92.1 92.5 0POLY-G ® WI-625 0 5.6 5.7 0TMP-Oleic Acid Ester 0 0 0 98POLY-G ® WI-200N 99.8 0 0 0Phenothiazine 0 0 0.5 0Dioctyldiphenylamine 0.2 0 0 0.5Triphenylphosphorothionate 0 0.5 0.5 0.5Ciba Geigy Irgalube 349 0 0.8 0.8 0.5V-152 (ethylene-vinyl ester) 0 0 0 0Ciba Geigy Irganox L-57 0 0.5 0 0Ciba Geigy Irganox L-130 0 0.5 0 0.5Iso Grade 100 68 100 68Factory Mutual Result F F F NT______________________________________ P = Pass, F = Fail, NT = Not Tested
A commercially available polyol ester hydraulic fluid was used as a comparison, namely Cosmolubric® HF130 hydraulic fluid manufactured by E. F. Houghton Co. of Valley Forge, Pa.
The formulations were tested using a laboratory hydraulic fluid pump test in accordance with ASTM-D2882 in order to measure the extent of pump wear resulting from the use of a specific fluid. Briefly, this test is conducted as follows:
Five gallons of a hydraulic fluid are circulated through a rotary vane pump system for 100 hours at a pump speed of 1200±60 rpm and a pump outlet pressure of 2000±40 psi. Fluid temperature at the pump inlet is 150±5° F. The result obtained is the total cam ring and vane (12) weight losses during the test.
The results of several pump wear tests ranged from 0.1 mg to 10.0 mg, indicating that this fluid is a premium performance hydraulic fluid. In comparison, the polyol ester hydraulic fluid wear amount ranged from 2.0-15 mg of weight loss during the 100 hour wear test.
The hydraulic fluids were also tested for fire resistance in accordance with the test procedure of Factory Mutual Research, Group II, Class No. 6930. Briefly, this test was conducted as follows:
A sample of fluid is heated to 140° F. in a steel container, then pressurized to 1000 psig with nitrogen. The sample is discharged into an open space from a 80° hollow cone HAGO oil burner nozzle rated for 1.5 gal/hr at 100 psig. This apparatus is used for both the flame propagation and hot surface tests described below:
Flame Propagation test - A propane torch is introduced into an atomized spray for each fluid at points of 6 inches and 18 inches from the nozzle tip. Ten attempts at ignition are made at each distance and any resulting fluid ignition is timed. Ignition lasting more than 5 seconds for any one of the ten attempts is considered a failure.
Hot Surface Ignition Test - A steel channel iron inclined 30° from the horizontal and equipped with side heat shields is heated from below by two propane-air burners to 1300° F. The burners are turned off, then fluid is discharged for 60 seconds at a distance of 6 inches. The fluid can pass if ignition occurs, but the flame must not follow the spray when directed away from the hot surface.
The results of the fire resistance testing indicated that the butanol initiated polyalkylene glycol-containing compositions of the present invention (Table I, Examples 1, 2, 3 and 6) passed the test and maintained their fire resistance for a time period of at least three times longer than the comparison polyol-ester type fluid (24 hours on average versus less than 8 hours on average for the comparison fluid in the pump test). This is based on periodic sampling of the two fluids during ASTM D2882 pump testing. It must be noted that the equipment used as part of this pump stand includes a pressure control valve thus creating an extreme shear condition, the degree of which is not experienced in normal field service. It is also noted that this fire resistance test was also performed on an analogous formulation to that described above, but replacing the butanol-initiated polypropylene glycol with a polypropylene glycol diol (Table I, Example 4). This analogous formulation also passed the fire resistance test.
It is also noted that this fire resistance test was also performed on analogous formulations to that described above, but replacing the butanol-initiated polypropylene glycol with a nonylphenol-initiated polypropylene glycol (Table I, Example 5). This analogous formulation also passed the fire resistance test. Note that comparative examples (Table II, Comparative Formulations) which contained no anti-mist additives failed the fire resistance test. It should also be noted that antioxidant selection or concentration does not cause the formulation to pass the fire resistance test. Although not tested, base fluids other than polyalkylene glycols may be expected to pass the fire resistance test provided those base fluids have a flash point above 400° F. Examples of alternative base fluids include, but are not limited to, esters, diesters, polyol esters and polyalkylene glycol esters. Esters are the reaction product of an alcohol with an acid. Esters suitable for use as base fluids include esters of polyols and of C 4 to C 24 straight or branched chained monocarboxylic acids. These compounds are prepared by reacting a polyol such as pentaerythritol, dipentaerythritol, tripentaerythritol, trimethylol propane, trimethylol ethane, trimethylol butane, neopentylglycol, glycerol, propylene oxide adducts and/or ethylene oxide adducts of the above polyols and the like with carboxylic acids such as butyric acid, valeric acid, isovaleric acid, caproic acid, hexanoic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, stearic acid, oleic acid, etc. polyalkylene glycol esters include the reaction products of butanol or other mono alcohol initiated propylene oxide and/or ethylene oxide adducts with the above mentioned carboxylic acids or poly functional carboxylic acids, for example, malonic acid, succinic acid, adipic acid, subonic acid, phthalic acid, etc. or poly functional alcohol initiated propylene oxide and/or ethylene oxide adducts, for example, diols, triols tetrols, and the like, reacted with the above-mentioned carboxylic mono acids.
The fluids were also analyzed by GPC in order to determine the loss in molecular weight of the anti-mist additive utilized in the present invention as compared to the additive utilized in the comparison fluid. The additive of the present invention did decrease in molecular weight with time in the pump but did not change significantly in concentration in the hydraulic fluid formulation over time. In contrast, the comparison fluid suffered a decrease both in molecular weight and in concentration in the comparison hydraulic fluid over time in the pump during the period of the pump test.
While the invention has been described above with reference to a specific embodiment thereof, it is apparent that many changes, modifications and variations can be made without departing from the inventive concept disclosed. Accordingly, it is intended to embrace all such changes, modifications and variations that fall within the spirit and broad scope of the appended claims. All publications cited herein are incorporated by reference in their entirety. | The present invention relates to a hydraulic fluid composition comprising: (a) a base fluid and (b) as an anti-mist additive, an alkylene-vinyl ester copolymer having a molecular weight of between about 5,000 and about 100,000 and soluble in said base fluid. In another aspect, the present invention relates to a process for imparting flame retardancy and reduced wear characteristics to a hydraulic system which comprises adding to the hydraulic system the above-identified hydraulic fluid composition. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to automotive braking systems and in particular to spot-type automotive disc brakes incorporating a secondary or parking brake function.
2. Description of the Related Art
The state of development of spot-type automotive disc brakes is such that it is indisputable that the absence of a simple and successful and cost-effective parking brake function comes as a surprise and is indicative of serious technical difficulties in providing this fundamental requirement for automotive vehicles, bearing in mind the considerable investment of the automotive industry in design and development of disc brake systems over four or five or more decades.
Automotive vehicles incorporating disc brake systems are of course provided with parking and secondary brake systems which are in use, and these will be reviewed below together with the most pertinent ones of the paper proposals which are also known to the applicants. So far as parking brake systems in actual use are concerned, the position is that (with one exception, see below) there is not in actual commercial use, to the best of the Applicants' knowledge, a spot type automotive disc brake in which a parking or secondary brake function is provided using the same friction elements as are actuated by the primary braking system. Usually of course the primary braking system is a hydraulic system. The nearest approach to such a dual purpose disc brake is provided on certain models of Jaguar cars and utilises an additional pair of friction elements and an associated additional mechanical actuating mechanism for these, so that the primary hydraulic disc brake system is provided with a secondary mechanical disc brake offering the parking brake function. Such an arrangement is an undesirable response to the need for a simple and economical disc brake system which would be applicable to small inexpensive vehicles as well as to larger and more costly ones.
All the other parking brake systems currently used in relation to automotive vehicles having disc brakes involve some use of drum brakes, such as the provision of rear drums (in substitution for the rear disc), or the provision of rear drums as a supplement to the rear disc brakes, or the provision of a drum-type transmission brake. None of these proposals, likewise, meets the requirement for a simple and cost-effective and compact disc brake system providing both primary and secondary/parking brake functions.
So far as paper proposals are concerned, the applicants are aware of:
U.S. Pat. No. 4,499,977 (Wang)
U.S. Pat. No. 3,941,221 (Pringle)
U.S. Pat. No. 3,724,605 (Naismith)
and these prior proposals will be reviewed.
The Wang specification discloses an integral park brake mechanism for a disc brake of the fixed disc and moving caliper kind in which the usual hydraulic piston and cylinder assembly 1 , 15 in the caliper on one side of the disc acts through a rod 2 so as to actuate the friction element at that side of the disc (and through the moving caliper the other friction element is also actuated). The parking brake function is integrated with the hydraulic actuating function by means of an apertured locking collar 3 through which the rod 2 extends and which can be tilted to grip the rod and to apply to the rod an actuating thrust from a parking brake lever 4 .
This arrangement is stated to meet the requirement for locking during actuation and self-releasing after actuation. However, the Applicants know that such an arrangement is technically undesirable for actual commercial use due to the obvious fact that a simple locking mechanism involving a rod and a locking collar, with the rod sliding in a bore formed in the hydraulic piston, is completely undesirable in terms of mechanical reliability for a mechanism located in the hostile environment of automotive disc brakes where temperature extremes and significant amounts of water and dust and other foreign matter are routinely applied to the mechanism during routine daily use. As a result, the mechanism is obviously unreliable and the statements in the description at column 4 line 25 onwards that the operation of the park brake mechanism is quite independent of the operation of the hydraulic brake, and the reference to the failure of one of the brakes not affecting the function of the other, is clearly technically wrong. Obviously a locking mechanism of the kind disclosed is liable to stay locked after use in the conditions described. Likewise the free sliding of the rod 2 within the bore in the hydraulic piston is likely to become restricted and finally prevented so that the hydraulic and parking brake functions are locked together and rendered unreliable if not inoperative. Hence the reasons why this mechanism has never been introduced in actual commercial use.
The Pringle brake takes a different approach to the construction of the parking brake mechanism by adopting a mechanical actuator located within the piston and cylinder assembly of the primary brake actuator system. This is also the “one exception” mentioned earlier and a fixed disc disc brake having such a parking brake (but otherwise not constructed as disclosed in Pringle) is in commercial use. Such an arrangement is mechanically difficult and costly to construct. This is partly because the mechanism has to be constructed relatively so small due to the space constraints imposed by the correspondingly small piston and cylinder assemblies utilised in disc brakes for the rear wheels of small vehicles, taking account of the front/rear braking proportions which are conventionally utilised. As a result, the mechanical parking brake mechanism within the hydraulic cylinder is effectively a mechanism almost of watch-like construction complexity and proportions and which is required to operate in the hostile environment of a braking system in terms of the temperatures and hydraulic fluid. In short, such an arrangement is technically and commercially undesirable as a solution to the requirement for a simple and cost effective mechanism. These same comments apply equally to the Naismith disclosure which shows a similar mechanism.
Two additional prior art references which have come to the attention of the applicants are:
GB2177171A (Kelsey Hayes)
WO98/05879 (Brake Technologies Pty)
The Kelsey-Hayes specification discloses improvements in self-adjusting parking brakes, particularly for use on rear-axle disc brake assemblies. The parking brake actuator is preferably a “bolt-on” type assembly intended for external mounting to a disc brake caliper. Use of a “bolt-on” parking-brake actuating assembly eliminates the necessity of having front and rear axle disc brake assemblies of different design since the parking brake mechanism is not an integral part of the disc brake assembly (page 1, column 1, at lines 35 to 40). Therefore, as shown in FIG. 3, the parking brake arrangement is asymmetrically arranged with respect to the main structure of the brake, and such is unacceptable in terms of its effect on the operation of the primary braking mechanism due to the need for balanced and uniform operating and wear characteristics, as far as possible. The deliberate adoption of an asymmetric configuration causing corresponding non-uniformity of operating and wear characteristics is generally unacceptable.
In the Brake Technologies Pty specification, there is disclosed a disc brake assembly of the kind in which the brake disc 23 is oil-immersed, and provided with full-annulus (or substantially full-annulus) friction element engagement facilities. Brakes of this kind are conventionally used as transmission brakes in heavy duty vehicular applications, including tractor brakes, for example. A primary actuating mechanism of the hydraulic kind is provided, together with a fail-safe emergency/parking type braking mechanism based upon spring elements 62 , 63 to cause application of the emergency-parking brake in the event of failure of the hydraulic fluid system. The general arrangement of the brake can be seen in FIGS. 1 and 2, and it is evident that such a brake is not of the spot-type automotive disc brake kind employing a lever-operated parking brake mechanism. Therefore, taking account both of disc brake systems in use and prior proposals, there remains a substantial requirement for a lever-operated parking and/or secondary brake system for use in spot-type automotive disc brakes and meeting one or more of the requirements outlined above, or at least providing a better compromise between the various conflicting factors than the disclosures in the prior proposals discussed above.
BRIEF SUMMARY OF THE INVENTION
Thus, we have identified a need for the provision of a parking brake assembly in which the complexity and cost and unreliability of the Naismith and Wang disclosures is mitigated or overcome, while preserving the lack of asymmetry of the actuating arrangements therein. Likewise, we have identified the need for eliminating the asymmetry which is fundamental to the approach in the Kelsey-Hayes disclosure and for eliminating the duplication of hardware likewise inherent in the Jaguar construction. Thus the embodiments of the present invention seek to provide, particularly for the cost-conscious spot-type automotive disc brake market, a parking or secondary brake assembly which is able to use the simple thrust-generating capabilities of a lever mechanism while avoiding duplication of actuation systems and friction pads, and avoiding likewise the actuation asymmetry which has represented the Achilles heel of the other proposals discussed above.
In the described embodiments of the invention, there is provided a parking brake arrangement in which, by adopting a lever mechanism which is constructed and adapted in accordance with the format of the primary brake operating mechanism (primarily by symmetrically accommodating either a single central cylinder or two spaced actuating cylinders), the combination of the convenient and effective generation of actuation thrust by the lever mechanism, and a simple symmetrical thrust-application system in which the friction elements have a reasonable chance to wear uniformly.
By adopting a lever construction which can straddle a single actuating cylinder, or the equivalent arrangement in which twin actuating cylinders straddle a single lever assembly, the problem which led the prior art to adopt mechanisms of watch-like complexity and/or an out-of-balance asymmetry, is solved.
Therefore, taking account both of disc brake systems in use and prior paper proposals, there remains a substantial requirement for a parking and/or secondary brake system for use in automotive disc brakes and meeting one or more of the requirements outlined above, or at least providing a better compromise between the various conflicting factors than do the prior proposals discussed above.
According to the present invention there is provided a disc brake as defined in the accompanying claims.
In an embodiment of the invention described below the primary and secondary actuating mechanisms of the brake are constructed so as to be completely independent with respect to each other. As a result, the thrust applied by each actuating mechanism to the same one of the friction elements (on that side of the disc) reaches that friction element by a path which is independent and separate from that of the other mechanism. As a result, there is no common thrust transmission component in the primary and secondary actuating mechanism (as is the case in the Wang and Naismith references). Each of these mechanisms acts on the same friction element, but in fact applies its thrust to that friction element through an end thrust delivering surface which is spaced from the corresponding surface of the other actuating mechanism. In other words, the two mechanisms act on the friction element at laterally spaced-apart locations. In one embodiment, the piston of the primary hydraulic actuating mechanism acts on the friction element though a part-circular or cylindrical projecting structure integral with the piston, and the thrust delivering end of the parking brake mechanism is received (with clearance) in a slot formed therein and engages the friction element generally on the axis of and thus symmetrically with respect to the piston and through the curved surface of a profiled thrust-applying member.
In an alternative arrangement in which the primary actuating mechanism has spaced apart twin cylinders, the secondary or parking brake mechanism is disposed symmetrically between these.
Other aspects of the independent relationship of the primary and secondary actuating mechanisms include the following. Firstly, a malfunction of one mechanism has no effect on the other mechanism whereas, for example, in the Wang mechanism the adoption of thrust paths for the two mechanisms which coincide at the rod 2 of Wang means that a failure of one mechanism is likely to seriously affect the other mechanism. Likewise, the complete independence of the primary and secondary actuating mechanisms in the embodiments of the present invention also means that the parking brake mechanism imposes no constraints on the retraction of the primary or hydraulic system after use, such as would occur in Wang when the rod 2 no longer slides freely within the bore of the piston 1 . Moreover, in specific contradistinction to Wang, the piston of the hydraulic mechanism in the embodiments of the present invention provides no mounting whatever for the parking brake mechanism. The piston of the embodiments serves only to generate brake-actuating thrust. According to another important feature of the embodiments of the present invention, the rotatable disc is mounted so as to be capable of sliding movement axially thereof and said friction elements being mountable on a fixed caliper or bridge structure straddling the disc, whereby the brake-applying thrust applied by the secondary actuating mechanism to provide a secondary or parking brake function causes frictional engagement of the disc with the other one of the pair of friction elements without the need to transmit a thrust to that friction element through a moving caliper or bridge structure, and the reaction thrust generated by both said primary and secondary actuating mechanisms is resisted by said fixed caliper or bridge structure. In other words, by virtue of adopting a sliding disc configuration for the disc brake, the parking brake function can likewise adopt a simple one-sided configuration without the need (such as arises in a fixed disc brake assembly) to provide a corresponding oppositely-directed thrust to the friction element on the other side of the disc. This latter friction element is simply squeezed against a fixed stop (provided by the fixed caliper or bridge) by the axial movement of the disc under the action of the parking brake lever mechanism, and the reaction thrusts are all resisted well.
To put it another way, the general configuration of the disc brake utilising a sliding disc and a fixed caliper in the embodiments means not only that the one-sided lever action is sufficient to apply both friction elements to the disc, but also the general structure of the brake is such that the reaction forces generated by the lever mechanism can be conveniently applied to the robust and fixed and stable structure which supports the fixed caliper or bridge of the brake and in no way compromises the effective operation of the primary braking system.
In order to create a well-balanced actuation arrangement for the brake, the embodiments provide the secondary brake actuating mechanism comprising a bifurcated lever member which straddles the piston and cylinder assembly of the primary actuating mechanism so as to be able to apply a balanced and symmetrically distributed thrust therewith to the friction element generally on the axis of the piston. Where the brake comprises a pair (or more) of piston and cylinder assemblies, then the lever mechanism can be disposed symmetrically between these without the need actually to invade the central space of the piston (by means of a slot etc therein) as described above.
To compensate for wear of the friction elements, the secondary brake actuating mechanism is provided with an adjustment mechanism. In one embodiment, the adjustment mechanism is adapted to move the pivot of the lever mechanism towards the actuated friction element as wear of the friction element occurs, whereby the lever is maintained in a constant actuating attitude relative to the friction element despite the wear of the latter.
In an alternative adjustment arrangement the lever of the lever mechanism is provided with an adjustment member which progressively moves as the friction element wears so as to change the dimensions of the lever member accordingly. In one arrangement, this is achieved by a pivoted sub-lever mounted on the main lever and controlled by a simple ratchet mechanism.
Further embodiments of the invention provide two or more slidable discs with interleaved axially movable friction elements between the discs. The brake may be provided as a front (or even intermediate) wheel of a vehicle as well as or alternatively to the use of the brake on a rear wheel of a vehicle.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:
FIG. 1 shows an isometric view of a disc brake assembly;
FIG. 2 shows an end elevation view of the assembly of FIG. 1 as seen on arrow II;
FIG. 3 shows a side elevation view of the assembly of FIG. 1, as seen in the direction indicated by arrow III in FIG. 1;
FIG. 4 show a section on the line IV—IV in FIG. 3;
FIG. 5 shows a planned view, corresponding to the sectional view of FIG. 4, and as seen in the direction of arrow V in FIG. 1;
FIGS. 6 and 6A show perspective and side elevation views of a second embodiment of the invention comprising a disc brake assembly partially exploded disc brake assembly;
FIG. 7 shows, diagrammatically, an indication of the structure of an adjusting arrangement for a brake actuating lever for use in the preceding embodiments;
DETAILED DESCRIPTION OF THE INVENTION
As shown in the embodiment of FIGS. 1 to 5 , a disc brake 10 comprises at least one rotatable brake disc 12 and an axially fixable mounting hub 14 therefor. A pair of friction elements 16 , 18 are provided for frictional engagement with opposite sides 20 , 22 of disc 12 .
An actuating mechanism 24 is provided for the brake 10 and is adapted to effect frictional engagement of the friction elements 16 , 18 with the opposite sides, 20 , 22 of disc 12 .
Actuating mechanism 24 comprises primary 26 and secondary 28 (including parking) actuating mechanisms which are both adapted to engage the same one namely friction element 16 , of the pair of friction elements 16 , 18 , to effect frictional engagement of friction element 16 with disc 12 as part of the process of engaging the brake. Friction element 16 is thus the actuated or active friction element whereas friction element 18 is the non-actuated or passive friction element as will be clear from the description which follows.
The primary and secondary or parking actuating mechanisms 26 , 28 respectively are constructed so as to be completely independent with respect to each other so that the thrust applied by each mechanism to the active friction element 16 reaches friction element 16 by a path which is independent and separate from that of the other mechanism. This feature of the mechanism will be discussed in further detail below.
Rotatable disc 12 of brake 10 is mounted on rotatable mounting 14 therefor so as to be capable of sliding movement axially (see axis 30 in FIG. 1) thereof whereby the thrust applied by secondary actuating mechanism 28 to active friction element 16 to produce a secondary or parking brake function causes frictional engagement of disc 12 with passive friction element 18 , without the need to transmit thrust to passive friction element 18 through a moving caliper or bridge structure straddling the disc.
Having thus identified the principal structures and functions of brake 10 , these will now be discussed in further detail below.
Disc 12 and its mounting 14 are constructed as a journalled assembly 32 to be mounted in relation to a tyre-carrying rear road wheel of an automotive vehicle accordingly. FIG. 1 indicates the drive-dogs relationship between disc 12 and its mounting 14 whereby the disc is axially slidable by means of drive-dogs 34 and corresponding grooves 36 . Mounting 14 carries wheel studs 38 .
Non-rotatably mounted with respect to disc 12 and the mounting 14 for disc 12 is a fixed bridge assembly 44 comprising a mounting plate 46 at the inboard side of disc 12 , a caliper 48 extending in the outboard direction from mounting plate 46 across the outer periphery of disc 12 , and a stop plate 50 at the outboard side of disc 12 . All this structure is fixed and non-rotatably mounted with respect to disc 12 by virtue of connecting structure (not shown) to the body of the automotive vehicle.
Friction elements 16 and 18 comprise pads 52 , 54 of friction material. In the case of active friction element 16 , its respective friction material pad 52 is bonded to a metal backing plate 56 . In the case of friction element 18 , its pad 54 is bonded to stop pate 50 . Backing plate 56 is slidably mounted on caliper 48 for axial movement in a direction generally parallel to wheel axis 30 .
Actuating mechanism 24 comprising primary actuating mechanism 26 and secondary actuating mechanism 28 will now be described further. Primary actuating mechanism 26 comprises a hydraulic piston and cylinder assembly 58 mounted on mounting plate 46 for actuation movement of the piston lengthwise of actuation axis 60 , whereby structure 62 (in the form of a flanged [see FIG. 4 ] part-cylindrical thrust collar 62 which is slidably received in and forms an extension of piston 64 of cylinder 66 , engages backing plate 56 of active friction element 16 . The details of this arrangement will be described more fully in relation to FIG. 6 below.
The headside chamber 68 between piston 64 and cylinder 66 is connected through a port 70 to the hydraulic control system for the primary (foot-pedal-operated) braking system of the vehicle.
Secondary actuating mechanism 28 comprises a lever mechanism 72 mounted on the axially fixed structure provided by caliper 48 and mounting plate 46 for pivotal clockwise movement about a lever axis 74 from the position shown in full lines in FIG. 5 .
Lever mechanism 72 comprises a bifurcated lever member 76 straddling the piston and cylinder assembly 58 of the primary actuating mechanism 26 .
As mentioned above the primary and secondary actuating mechanism 26 and 28 are constructed so as to be completely independent with respect to each other, so that the thrust applied by each mechanism to the active friction element 16 reaches that friction element by a path which is independent and separate from thrust of the other mechanism. Thus, in the case of the primary hydraulic actuating mechanism 24 , comprising piston 64 and cylinder 66 , the thrust is applied to active friction element 16 through thrust collar 62 , direct from piston 64 . A slot (not shown in FIG. 4 but illustrated by means of the slot 78 identified in FIG. 6) is formed in thrust collar 62 to allow the two lever limbs 80 , 82 which straddle piston and cylinder assembly 58 to be connected by an actuating bar 84 (FIG. 6) which is received in slot 78 with clearance. Bar 84 is provided with a smoothly curved profiled central actuating boss 86 to engage backing plate 56 of active friction element 16 generally centrally thereof and approximately on the actuation axis 60 of piston and cylinder assembly 58 .
Thus, it can be seen that the two actuating mechanisms 26 and 28 are indeed completely independent with respect to each other in terms of their mode of actuating the active friction element 16 . This is because each can apply trust to that friction element quite independently by a thrust path which shares no component with that of the other actuating mechanism and indeed applies that thrust to the friction element backing plate at a location which is laterally spaced from (yet generally symmetrically disposed with respect to) the location at which he other actuating mechanism applies its thrust. Thus, lever mechanism 72 applies its thrust generally on the actuation axis 60 and the primary actuating mechanism 28 applies its thrust around the part-cylindrical profile of thrust collar 62 . Moreover, the depth of slot 78 is such that thrust collar cannot apply thrust to backing plate 56 through actuating bar 84 and actuating boss 86 because the thrust collar engages the backing plate leaving sufficient clearance in slot 78 for actuating boss 86 not to be then engaging the backing plate.
The mode of operation of brake 10 will now, it is believed, be generally self-evident. Fluid pressure actuation of primary actuating mechanism 26 will result in advancement of piston 64 toward disc 12 causing active friction element 16 to engage the disc and to cause slight axial movement of same towards fixed friction element 18 , thereby resulting in frictional engagement of the pads 52 , 54 with opposite sides of the disc and engagement of the brake.
Actuation of secondary actuating mechanism 28 by application of tension in cable 88 connected to lever mechanism 72 causes angular movement of lever member 76 about lever axis 74 from the full line position in FIG. 5 towards the broken line position and causes similar actuation of active friction element 16 , frictional engagement of same with disc 12 and resulting engagement of passive fiction element 18 with the opposite side of the disc.
Turning now to the adjustment mechanisms for compensating for wear of friction elements 16 and 18 , FIG. 5 shows in full and broken lines the position of lever member 76 of lever mechanism 72 in its limit positions corresponding to worn and unworn conditions of the friction pads 52 , 54 .
To compensate for the wear of the friction pads adjustment means 90 is provided in FIGS. 6 and 6A which is mounted on plate 46 and adapted to move a lever pivot 92 defining lever axis 74 of the lever mechanism 72 towards the active friction element 16 as the friction elements wear.
This embodiment of the adjustment mechanism is shown in FIGS. 6 and 6A. FIGS. 6 and 6A are provided with reference numerals otherwise corresponding to those of the preceding embodiment, but these Figs show the general arrangement of the adjustment means for moving the pivot of the lever mechanism as mentioned above. For this purpose lever pivot 92 is carried on a sector-shaped adjustment member 94 which is spring-biased by a tension spring 96 acting to pivot the adjustment member outwardly (towards disc 12 ) about an adjustment pivot 97 while lever pivot 92 is guided linearly in a slot 98 formed in a guide 100 in which is mounted a cylindrical stop 101 (see FIG. 6A) located concentrically on a peg 102 .
Lever member 76 is biassed to its released position as shown in FIG. 6 by a compression spring 104 . As the friction pads 52 , 54 wear, pivot 92 progressively moves outwards in slot 98 , whereby the pad wear is compensated-for and the lever member 76 always returns to the same at rest position.
In the embodiment of FIG. 7 there is diagrammatically illustrated an adjustment means 106 wherein provision is made for the lever mechanism 108 comprising lever member 110 (which actuates active friction element 16 ) to progressively change in dimensions as the friction elements wear. This progressive change in dimensions is provided by an adjustment member 112 mounted on lever member 110 for pivotal movement about an adjustment axis 114 progressively under the control of a ratchet mechanism indicated diagrammatically at 116 , the ratchet mechanism being responsive to friction pad wear. | A spot-type automotive disc brake ( 10 ) provides parking brake and primary brake functions based on the same pair of friction elements ( 16, 18 ) and without resorting to supplemental drums or supplemental friction elements. The mechanism is simple and can be made at a size applicable to small mass produced vehicles. A sliding disc ( 12 ) has fixed ( 42 ) and actuated ( 40 ) friction elements at its opposite sides. A piston ( 64 ) and an external bifurcated lever mechanism ( 72 ) act completely independently yet symmetrically on the actuated friction element ( 16 ) without any common thrust-transmitting parts, whereby the asymmetry and complexity and consequential unreliability and high cost and duplication of mechanisms of prior proposals is avoided. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present disclosure generally relates to the fabrication of semiconductor devices, and, more particularly, to a method for forming a single diffusion break between finFET devices and the resulting devices.
[0003] 2. Description of the Related Art
[0004] In modern integrated circuits, such as microprocessors, storage devices and the like, a very large number of circuit elements, especially transistors, are provided and operated on a restricted chip area. In integrated circuits fabricated using metal-oxide-semiconductor (MOS) technology, field effect transistors (FETs) (both NMOS and PMOS transistors) are provided that are typically operated in a switching mode. That is, these transistor devices exhibit a highly conductive state (on-state) and a high impedance state (off-state). FETs may take a variety of forms and configurations. For example, among other configurations, FETs may be either so-called planar FET devices or three-dimensional (3D) devices, such as finFET devices.
[0005] A field effect transistor (FET), irrespective of whether an NMOS transistor or a PMOS transistor is considered, and irrespective of whether it is a planar or 3D finFET device, typically comprises doped source/drain regions that are formed in a semiconductor substrate that are separated by a channel region. A gate insulation layer is positioned above the channel region and a conductive gate electrode is positioned above the gate insulation layer. The gate insulation layer and the gate electrode may sometimes be referred to as the gate structure for the device. By applying an appropriate voltage to the gate electrode, the channel region becomes conductive and current is allowed to flow from the source region to the drain region. In a planar FET device, the gate structure is formed above a substantially planar upper surface of the substrate. In some cases, one or more epitaxial growth processes are performed to form epitaxial (epi) semiconductor material in recesses formed in the source/drain regions of the planar FET device. In some cases, the epi material may be formed in the source/drain regions without forming any recesses in the substrate for a planar FET device, or the recesses may be overfilled, thus forming raised source/drain regions. The gate structures for such planar FET devices may be manufactured using so-called “gate-first” or “replacement gate” (gate-last) manufacturing techniques.
[0006] To improve the operating speed of FETs, and to increase the density of FETs on an integrated circuit device, device designers have greatly reduced the physical size of FETs over the years. More specifically, the channel length of FETs has been significantly decreased, which has resulted in improving the switching speed of FETs. However, decreasing the channel length of a FET also decreases the distance between the source region and the drain region. In some cases, this decrease in the separation between the source and the drain makes it difficult to efficiently inhibit the electrical potential of the source region and the channel from being adversely affected by the electrical potential of the drain. This is sometimes referred to as a so-called short channel effect, wherein the characteristic of the FET as an active switch is degraded.
[0007] In contrast to a FET, which has a planar structure, a so-called finFET device has a three-dimensional (3D) structure. FIG. 1A is a side view of an illustrative prior art finFET semiconductor device 100 that is formed above a semiconductor substrate 105 . In this example, the finFET device 100 includes three illustrative fins 110 , a gate structure 115 , sidewall spacers 120 , and a gate cap 125 . The gate structure 115 is typically comprised of a layer of insulating material (not separately shown), e.g., a layer of high-k insulating material or silicon dioxide, and one or more conductive material layers (e.g., metal and/or polysilicon) that serve as the gate electrode for the device 100 . The fins 110 have a three-dimensional configuration. The portions of the fins 110 covered by the gate structure 115 is the channel region of the finFET device 100 . An isolation structure 130 is formed between the fins 110 . In a conventional process flow, the portions of the fins 110 that are positioned outside of the spacers 120 , i.e., in the source/drain regions of the device 100 , may be increased in size or even merged together by performing one or more epitaxial growth processes. The process of increasing the size of the fins 110 in the source/drain regions of the device 100 is performed to reduce the resistance of source/drain regions and/or make it easier to establish electrical contact to the source/drain regions.
[0008] A particular fin 110 may be used to fabricate multiple devices. FIG. 1B illustrates a cross-sectional view of the finFET device 100 along the length of one fin 110 prior to the formation of any gate structures 115 . One or more diffusion breaks 135 , 140 are formed along the axial length of the fin 110 to define separate fin portions by removing a portion of the fin 110 and replacing it with a dielectric material. The strength of the isolation provided by the diffusion break 135 , 140 depends on its size. A diffusion break having a lateral width (in the current transport direction, or gate length (GL) direction of the completed devices) corresponding to the lateral width of two adjacent gate structures 115 (later formed) is referred to as a double diffusion break 135 , and a diffusion break having a lateral width corresponding to the lateral width of one gate structure 115 is referred to as a single diffusion break 140 . The process for forming the single diffusion break gouges the fin 110 and defines recesses 145 .
[0009] FIG. 1C illustrates the device 100 after a plurality of processes were performed to define a plurality of gate structures 115 , with cap layers 125 , and sidewall spacers 120 above the fin 110 . FIG. 1D illustrates the device 100 after a self-aligned etch process was performed to recess the fin 110 using the gate structures 115 and spacers 120 as an etch mask to define recesses 150 , 155 in the fin 110 . Because of the fin gouging, the recesses 150 adjacent the single diffusion break 140 are deeper than the other recesses 155 .
[0010] FIG. 1E illustrates the device 100 after an epitaxial growth process was performed to define epitaxial regions 160 , 165 in the recesses 150 , 155 . Due to the difference in the depth of the recesses 150 , 155 , the post-fill height of the epitaxial region 160 is less than that of the epitaxial region 165 . This epitaxial material underfill changes the electrical characteristics of the device 100 in the region adjacent to the single diffusion break 140 as compared to the regions without underfill.
[0011] The present disclosure is directed to various methods and resulting devices that may avoid, or at least reduce, the effects of one or more of the problems identified above.
SUMMARY OF THE INVENTION
[0012] The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an exhaustive overview of the invention. It is not intended to identify key or critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is discussed later.
[0013] Generally, the present disclosure is directed to various methods of forming semiconductor devices. One illustrative method includes forming a fin in a semiconductor substrate. A plurality of sacrificial gate structures are formed above the fin. A selected one of the sacrificial gate structures is removed to define a first opening that exposes a portion of the fin. An etch process is performed through the first opening on the exposed portion of the fin to define a first recess in the fin. The first recess is filled with a dielectric material to define a diffusion break in the fin.
[0014] One illustrative device disclosed herein includes, among other things, a fin defined in a substrate, a plurality of gates formed above the fin, a plurality of recesses filled with epitaxial material defined in the fin, and a diffusion break defined at least partially in the fin between two of the recesses filled with epitaxial material and extending above the fin.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The disclosure may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements, and in which:
[0016] FIGS. 1A-1E schematically depict an illustrative prior art finFET device;
[0017] FIGS. 2A-2L depict various methods disclosed herein of forming single diffusion breaks in a finFET device; and
[0018] FIGS. 3A-3H depict an alternative method disclosed herein of forming single diffusion breaks in a finFET device.
[0019] While the subject matter disclosed herein is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION
[0020] Various illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
[0021] The present subject matter will now be described with reference to the attached figures. Various structures, systems and devices are schematically depicted in the drawings for purposes of explanation only and so as to not obscure the present disclosure with details that are well known to those skilled in the art. Nevertheless, the attached drawings are included to describe and explain illustrative examples of the present disclosure. The words and phrases used herein should be understood and interpreted to have a meaning consistent with the understanding of those words and phrases by those skilled in the relevant art. No special definition of a term or phrase, i.e., a definition that is different from the ordinary and customary meaning as understood by those skilled in the art, is intended to be implied by consistent usage of the term or phrase herein. To the extent that a term or phrase is intended to have a special meaning, i.e., a meaning other than that understood by skilled artisans, such a special definition will be expressly set forth in the specification in a definitional manner that directly and unequivocally provides the special definition for the term or phrase.
[0022] The present disclosure generally relates to various methods of forming finFET devices with a single diffusion break without causing significant underfill of epitaxial semiconductor regions formed in the fin and the resulting semiconductor devices. As will be readily apparent to those skilled in the art upon a complete reading of the present application, the present method is applicable to a variety of devices, including, but not limited to, logic devices, memory devices, etc. With reference to the attached figures, various illustrative embodiments of the methods and devices disclosed herein will now be described in more detail.
[0023] FIGS. 2A-2J illustrate various methods for forming a single diffusion break between finFETs in a device 200 . FIGS. 2A-2J show a cross-sectional view of the device 200 along the axial length of an illustrative fin 210 defined in a substrate 205 with a double diffusion break 215 (e.g., silicon dioxide) defined in the fin 210 . The substrate 205 may have a variety of configurations, such as the depicted bulk silicon configuration. The substrate 205 may also have a silicon-on-insulator (SOI) configuration that includes a bulk silicon layer, a buried insulation layer and an active layer, wherein semiconductor devices are formed in and above the active layer. The substrate 205 may be formed of silicon or silicon germanium or it may be made of materials other than silicon, such as germanium. Thus, the terms “substrate” or “semiconductor substrate” should be understood to cover all semiconducting materials and all forms of such materials. The substrate 205 may have different layers. For example, the fin 210 may be formed in a process layer formed above the base layer of the substrate 205 .
[0024] FIG. 2B illustrates the device after several processes were performed to define placeholder gate structures 220 (e.g., polysilicon) above the fin 210 . A cap layer 230 (e.g., silicon nitride) is formed above the placeholder gate structure 220 , and sidewall spacers 225 (e.g., silicon nitride) are formed on the placeholder gate structure 220 . Techniques for forming the gate structures 220 are known to those of ordinary skill in the art. In the illustrative embodiment, a replacement gate technique is used to form the finFET device 200 , and the placeholder gate electrode structure 220 is illustrated prior to the formation of the replacement gate structure. The placeholder gate structure 220 includes a sacrificial gate electrode material (not separately shown), such as polysilicon, and a sacrificial gate insulation layer (not separately shown), such as silicon dioxide.
[0025] FIG. 2C illustrates the device 200 after a self-aligned etch process was performed using the placeholder gate structures 220 and sidewall spacers 225 as an etch mask to define recesses 235 in the fin 210 .
[0026] FIG. 2D illustrates the device 200 after an epitaxial growth process was performed to form epitaxial material 240 in the recesses 235 . The epitaxial semiconductor material 240 will become part of subsequently defined source/drain regions of the device 200 . The epitaxial material 240 may be comprised of different materials and it may be a strain-inducing material, such as silicon germanium or silicon carbon, formed on a silicon fin 210 or silicon formed on a silicon germanium or silicon carbon fin 210 . The epitaxial material 240 may be doped in situ or an implantation process may be performed to dope the epitaxial material 240 in the source/drain regions of the device 200 . The gate cap layer 230 and the spacers 225 shield a portion of the fin 210 in a channel region of the device 200 during the epitaxial material growth process. In one embodiment, the fin 210 may not have been doped prior to the epitaxial growth process. An implantation process may be performed after the epitaxial material growth process to dope both the fin 210 and the epitaxial material 240 . If a lightly doped source/drain region is desired, an implant process may be performed on the fin 210 after forming the placeholder gate electrode structure 220 , but prior to forming the spacers 225 .
[0027] FIG. 2E illustrates the device 200 after a first conformal deposition process was performed to deposit an etch stop layer 245 (e.g., silicon nitride) above the epitaxial material 240 and a second blanket deposition process was performed to deposit an interlayer dielectric (ILD) layer 250 above the device 200 . An exemplary material for the ILD layer 250 is silicon dioxide or a low-k dielectric material (k value less than about 3.5). The etch stop layer 245 may be a stress-inducing etch stop layer.
[0028] FIG. 2F illustrates the device 200 after a planarization process (e.g., an etching and/or CMP process) was performed to remove portions of the ILD layer 250 , the etch stop layer 245 , and the cap layer 230 and thereby expose a top surface of the placeholder gate structures 220 .
[0029] FIG. 2G illustrates the device 200 after a patterned etch mask layer 255 was formed above the ILD layer 250 to expose a selected placeholder gate structure 220 A.
[0030] FIG. 2H illustrates the device 200 after a first etch process was performed to remove the selected placeholder gate structure 220 A and a second etch process was performed to define a recess 260 in the fin 210 .
[0031] FIG. 2I illustrates the device 200 after a stripping process was performed to remove the patterned etch mask layer 255 and a deposition process was performed to deposit a dielectric layer 265 (e.g., silicon dioxide) to over-fill the recess 260 and the space created by the removal of the selected placeholder gate structure 220 A. In some embodiments, the dielectric layer 265 may be formed using the same material as the double diffusion break 215 .
[0032] FIG. 2J illustrates the device 200 after a planarization process was performed to remove portions of the dielectric layer 265 and expose the remaining placeholder gate structures 220 . The remaining portion of the dielectric layer 265 defines a single diffusion break 270 . Because the single diffusion break is formed after the placeholder gate structures 220 were formed (for a replacement technique), the epitaxial material 240 adjacent the single diffusion break 270 has substantially the same profile as the epitaxial material 240 in other recesses 235 formed in the fin. This uniformity improves the performance of the device 100 and reduces the likelihood of defects in the epitaxial material 240 adjacent the single diffusion break 270 .
[0033] FIG. 2K illustrates the device after a plurality of processes were performed to form replacement gate structures 275 in place of the placeholder gate structures 220 . First an etch process was performed to remove the exposed placeholder gate structures 220 . The replacement gate structure 275 includes a gate insulation layer (not separately shown) and a conductive gate electrode (not separately shown). The gate insulation layer may include a variety of different deposited or thermally grown materials, such as, for example, silicon dioxide, a so-called high-k (k greater than 10) insulation material, such as hafnium oxide, etc. The conductive gate electrode may include one or more layers, such as one or more layers of exemplary materials, TiN, TiAlN, TiC, TaN, TaC, TaCN or W. After the materials are formed in the replacement gate cavities created by removal of the placeholder gate structures 220 , a planarization process may be performed to remove portions of the gate materials positioned outside of the replacement gate cavities.
[0034] FIG. 2L illustrates the device 200 after several processes were performed to recess the replacement gate structure 275 and form a gate cap 280 . The replacement gate structure 275 in combination with the gate cap 280 defines a gate 285 having a height. The gate 285 has a height substantially equal to the height of the single diffusion break 270 . The term “substantially equal” refers to the heights of the gate 285 with or without a gate cap layer 280 .
[0035] The process illustrated in FIGS. 2A-2L includes two planarization processes to expose the placeholder gate structures 220 , one for the replacement process of the placeholder gate structures 220 A to form the single diffusion break 270 ( FIG. 2F ), and one for the replacement process to form the replacement gate structures 275 ( FIG. 2J ). Due to the multiple planarizations, the gate height of the replacement gate structures 275 is reduced.
[0036] FIGS. 3A-3H illustrate another embodiment of a method for forming a single diffusion break in a finFET device 200 . FIG. 3A illustrates the device 200 after the first planarization process shown in FIG. 2F was performed, and after a plurality of deposition processes were performed to deposit a cap layer 300 (e.g., silicon dioxide) and hard mask layer 305 (e.g., silicon nitride) above the ILD layer 250 .
[0037] FIG. 3B illustrates the device 200 after a patterned etch mask layer 310 was formed above the hard mask layer 305 to expose a region above the selected placeholder gate structure 220 A.
[0038] FIG. 3C illustrates the device 200 after one or more anisotropic etch processes were performed to define openings in the hard mask layer 310 and the cap layer 305 , to remove the selected placeholder gate structure 220 A, and to define a recess 315 in the fin 210 .
[0039] FIG. 3D illustrates the device 200 after a stripping process was performed to remove the mask layer 310 and a deposition process was performed to deposit a dielectric layer 320 (e.g., silicon dioxide) to over-fill the recess 315 and the space created by the removal of the selected placeholder gate structure 220 A.
[0040] FIG. 3E illustrates the device 200 after a planarization process was performed to remove portions of the dielectric layer 320 using the hard mask layer 305 as a stop layer.
[0041] FIG. 3F illustrates the device 200 after a timed, wet etch process was performed to recess the dielectric layer 320 to a height approximately equal to that of the cap layer 300 .
[0042] FIG. 3G illustrates the device 200 after an etch process was performed to remove the hard mask layer 305 .
[0043] FIG. 3H illustrates the device 200 after a timed etch process (e.g., a SiConi™ etch) was performed to remove the cap layer 300 and expose the remaining placeholder gate structures 220 . The remaining portion of the dielectric layer 320 defines a single diffusion break 325 . Subsequent processing may continue as described in FIGS. 2K-2L to form replacement gate structures. Because the second planarization process is avoided, the height of the replacement gate structures is not reduced as compared to the embodiment illustrated in FIG. 2J .
[0044] The methods described herein, including forming increased height fins 210 and recessing the fins in channel regions, reduces the likelihood of source/drain epi overfill, thereby providing uniform raised source/drain height throughout densely-spaced regions and isolated regions.
[0045] The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. For example, the process steps set forth above may be performed in a different order. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention. Note that the use of terms, such as “first,” “second,” “third” or “fourth” to describe various processes or structures in this specification and in the attached claims is only used as a shorthand reference to such steps/structures and does not necessarily imply that such steps/structures are performed/formed in that ordered sequence. Of course, depending upon the exact claim language, an ordered sequence of such processes may or may not be required. Accordingly, the protection sought herein is as set forth in the claims below. | A method includes forming a fin in a semiconductor substrate. A plurality of sacrificial gate structures are formed above the fin. A selected one of the sacrificial gate structures is removed to define a first opening that exposes a portion of the fin. An etch process is performed through the first opening on the exposed portion of the fin to define a first recess in the fin. The first recess is filled with a dielectric material to define a diffusion break in the fin. A device includes a fin defined in a substrate, a plurality of gates formed above the fin, a plurality of recesses filled with epitaxial material defined in the fin, and a diffusion break defined at least partially in the fin between two of the recesses filled with epitaxial material and extending above the fin. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a driver of a display unit such as a liquid crystal display, an organic light emitting display, a plasma display or the like. More particularly, the present invention relates to a driver such as a column driver, a source driver, or a horizontal driver or the like.
[0003] 2. Description of Related Art
[0004] A display unit has recently become larger and larger in size due to development of manufacturing technique. The display unit having large size requires ability of driving large capacitance load of output of the driver. It means that output impedance of the driver needs to be decreased. If the output impedance is not substantially small, there is caused a problem such as lack of driving ability, increase of power consumption, or heat generation.
[0005] Further, recent display unit performs multi-gradation display, and there is developed a multi-bit driver of the display unit. Moreover, the driver of typical display unit has hundreds of driving outputs and includes latch circuits, level shifters, D/A converters, and buffer amplifiers.
[0006] FIG. 13 shows an example of a driving output circuit in the driver of the display unit according to a related art.
[0007] The driver shown in FIG. 13 is an output circuit having two outputs. A driver 10 of the display unit includes a latch circuit 11 , a level shifter 12 , a D/A converter 13 , an output amplifier 15 , an output switch 16 , and an output pin 17 . In this example, it is assumed that the display unit is a liquid crystal display and includes a polarity switching circuit 14 and the output switch 16 . In this example, the polarity switching circuit 14 is provided between the D/A converter 13 and the output amplifier 15 . However, the polarity switching circuit may be provided between the output amplifier 15 and the output pin 17 . In this case, the polarity switching circuit may also function as the output switch.
[0008] Hereinafter, a behavior of the driver of the display unit shown in FIG. 13 will be described in brief. The latch circuit 11 holds digital gradation information for each driving output and outputs the digital gradation information to the level shifter 12 as the output signal. The level shifter 12 performs voltage level conversion between the latch circuit 11 which is a low voltage circuit and the D/A converter 13 which is a high voltage circuit. The digital gradation information output from the level shifter 12 is converted into gradation information signal having analog value by the D/A converter 13 according to its digital value. The gradation information signal having analog value that is output from the D/A converter 13 is alternately switched by the polarity switching circuit 14 in a predetermined cycle and input to the output amplifier 15 . The output amplifier 15 amplifies the analog gradation information signal and outputs the amplified signal to the output pin 17 when the output switch 16 is in ON state.
[0009] In the multi-bit driver as stated above, the test may take longer time and accuracy is not high. In order to overcome these problems, Japanese Unexamined Patent Application Publication No. 2006-227168 discloses a technique to provide a driver of a display unit in which inspection time is reduced and inspection accuracy is improved.
[0010] In the prior art disclosed in Japanese Unexamined Patent Application Publication No. 2006-227168, the driver includes a selector selecting output of the latch circuit to output latch data from a predetermined bit, and an output selector switching a level shifter output corresponding to the predetermined bit and gradation voltage output. In normal operations, the selector is switched so as to output the gradation voltage to the driving output pin. In test operations, the selector is switched so as to output voltage (test output voltage) according to the level shifter output corresponding to the predetermined bit.
[0011] As stated above, the display unit having large size requires ability of driving large capacitance load of output of the driver. If the output impedance of the driver is not substantially small, there is caused a problem such as lack of driving ability, increase of power consumption, or heat generation.
[0012] In the prior art as in Japanese Unexamined Patent Application Publication No. 2006-227168, there is provided an output selector where gradation voltage is output to the driving output pin of the driver in the normal operation and test output voltage is output in the test operation. This output selector needs to be composed of the transistor since the output selector is implemented in the integrated circuit. The switch made of transistor has impedance in accordance with its size. Therefore, if the transistor having lower impedance is employed in order to maintain large driving ability, the size of the integrated circuit composing the selector increases. On the other hand, if the selector is composed of small transistor in order to avoid increase in size, the output impedance increases and the ability of driving the output load is lacked. Further, if the driving ability of the amplifier is enhanced in order to compensate lack of driving ability, there are caused other problems such as increase in power consumption and heat generation.
[0013] Therefore, there is a need to connect the driving output pin and the test signal without directly adding the selector which is one of factors for increasing impedance to the driving output pin which requires driving ability.
[0014] There is Japanese Unexamined Patent Application Publication No. 2006-053480 as a prior art.
SUMMARY
[0015] According to one aspect of the present invention, there is provided a driver of a display unit including a latch circuit holding gradation information, a D/A converter outputting analog signal based on the gradation information held by the latch circuit, a test circuit provided between the latch circuit and the D/A converter, the test circuit inputting or outputting test signal regarding the latch circuit, a switch connecting voltage output of the D/A converter and a driver output terminal in normal operation, and a test switch connecting the test circuit and the driver output terminal in test operation and disconnecting the test circuit and the driver output terminal in normal operation.
[0016] According to the driver of the display unit of the present invention, it is possible to output test result of an internal circuit from the output terminal of the driver and to input test signal to the output terminal of the driver with little or no change of output performance of the driver of the display unit.
[0017] According to the driver of the display unit of the present invention, it is possible to perform test without substantially degrading performance of the driver. Therefore, the test can be carried out in easier manner, and both of test time and test cost can be reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The above and other objects, advantages and features of the present invention will be more apparent from the following description of certain preferred embodiments taken in conjunction with the accompanying drawings, in which:
[0019] FIG. 1 shows an example of a configuration of a driver of a display unit according to a first embodiment of the present invention;
[0020] FIG. 2 shows an example of a specific configuration of a test circuit according to the first embodiment of the present invention;
[0021] FIG. 3 shows an example of a specific configuration of a switch of the test circuit according to the first embodiment of the present invention;
[0022] FIG. 4 is a table showing a relationship between test data and test signal according to the first embodiment of the present invention;
[0023] FIG. 5 shows an example of a specific configuration of an output amplifier according to the first embodiment of the present invention;
[0024] FIG. 6 is a timing chart of a behavior of the test circuit according to the first embodiment of the present invention;
[0025] FIG. 7 shows another example of a specific configuration of the test circuit according to the first embodiment of the present invention;
[0026] FIG. 8 shows an example of a configuration of a driver of a display unit according to a second embodiment of the present invention;
[0027] FIG. 9 shows an example of a configuration of an output amplifier of the display unit according to the second embodiment of the present invention;
[0028] FIG. 10 shows an example of a configuration of a driver of a display unit according to a third embodiment of the present invention;
[0029] FIG. 11 shows an example of a configuration of an output amplifier of the display unit according to the third embodiment of the present invention;
[0030] FIG. 12 shows an example of a configuration of a driver of a display unit according to a fourth embodiment of the present invention; and
[0031] FIG. 13 shows an example of a configuration of a driver of a display unit according to a related art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] The invention will now be described herein with reference to illustrative embodiments. Those skilled in the art will recognize that many alternative embodiments can be accomplished using the teachings of the present invention and that the invention is not limited to the embodiments illustrated for explanatory purposes.
First Embodiment
[0033] Hereinafter, the first specific embodiment to which the present invention is applied will be described in detail with reference to the drawings. In the first embodiment, the present invention is applied to a driver of a display unit.
[0034] FIG. 1 shows an example of a configuration of the driver of the display unit according to the first embodiment of the present invention. Note that the driver shown in FIG. 1 is applied to a liquid crystal display as a display unit. FIG. 1 shows an example of an output circuit having only two outputs for the sake of simplicity.
[0035] The driver 100 includes a latch circuit 101 , a test circuit 102 , a D/A converter 103 , a polarity switching circuit 104 , an output amplifier 105 , an output switch 106 , an output pin 107 , a test switch 108 , a test controller 109 , and a test signal line 110 . As stated above, the driver 100 of the first embodiment has two outputs. Therefore, symbol of a or b is given to each signal of the configuration as necessary to make a distinction.
[0036] The latch circuit 101 holds digital gradation information for each driving output and outputs the digital gradation information to the test circuit 102 as output signals. The output signals of the digital gradation information are input to the test circuit 102 through data buses DB 0 to DB 7 .
[0037] The test circuit 102 tests the output signals of the latch circuit 101 and is connected to the test signal line 110 . The test circuit 102 performs normal operation when the test switching signal is in low level and directly outputs the signals from the latch circuit 101 to the D/A converter 103 . The test circuit 102 performs test operation when the test switching signal is in high level and outputs the test signal which is the test information of the output signals of the latch circuit 101 to the test signal line 110 . The test signal of the test circuit 102 is determined by the configuration of the test circuit 102 and the test signal may be either input signal or output signal. The test data controls a behavior of the test circuit 102 . This test data is typically input to the driver 100 from a test device (not shown).
[0038] The latch circuit 101 and the D/A converter 103 are connected by the data buses DB 0 to DB 7 . The symbol “DB0 to DB7” indicates both of the name of the data bus and the signal (having a value of 0 or 1) output to the data bus for the sake of convenience.
[0039] FIG. 2 shows a specific configuration example 1 of the test circuit 102 . FIG. 2 only shows a configuration of a part of the test circuit 102 where the test operation is performed for the sake of simplicity. Therefore, although not specifically shown, the test circuit 102 directly outputs the signals from the latch circuit 101 to the D/A converter 103 in normal operation as stated above.
[0040] As shown in FIG. 2 , the test circuit 102 includes switches SW 151 to SW 157 . Each of the switches SW 151 to SW 157 has two input terminals a and b and one output terminal c. Eight data buses DB 0 to DB 7 are connected to first-stage switches SW 151 to SW 154 . For example, the DB 0 is connected to the input terminal a of the SW 151 , and the DB 1 is connected to the input terminal b of the SW 151 . The output terminals of the first-stage switches SW 151 to SW 154 are further connected to the input terminals of the second-stage switches SW 155 and SW 156 . The output terminals of the second-stage switches SW 155 and SW 156 are further connected to the third-stage switch SW 157 . These switches SW 151 to SW 157 are controlled by the test data TB 0 to TB 2 so as to connect the output terminal c and the input terminal a or b. For example, when the test data TB 0 is 0, which means the test data is in low level, the input terminals a and the output terminals c of the switches SW 151 to SW 154 are connected. On the other hand, when the test data TB 0 is 1, which means the test data is in high level, the input terminals b and the output terminals c are connected. This can also be applied to the test data TB 1 and the switches SW 155 and SW 156 , or the test data TB 2 and the switch SW 157 .
[0041] The switches SW 151 to SW 157 include CMOS transfer gates TG 151 and TG 152 and an inverter Inv 151 as shown in FIG. 3 . The transfer gates TG 151 and TG 152 are connected in parallel, and the input terminal a and the transfer gate TG 151 are connected and the input terminal b and the transfer gate TG 152 are connected. Both of the outputs of the transfer gates TG 151 and 152 are connected to the output terminal c. Further, the test data input terminal d and the input of the inverter Inv 151 are connected to each other. One of the transfer gates is exclusively selected by the input signal of the test data input terminal d and the output signal of the inverter Inv 151 . The input signal to the inverter Inv 151 is the test data.
[0042] The first-stage switches SW 151 to SW 154 , the second-stage switches SW 155 and SW 156 , and the third switch SW 157 are controlled by the test data TB 0 , TB 1 , and TB 2 . Note that each of the test data TB 0 , TB 1 , and TB 2 is binary signal. As shown in FIG. 4 , the test circuit 102 outputs one of the eight signals output from the latch circuit 101 as one of the test signals DB 0 to DB 7 by eight combinations made of test data TB 0 to TB 2 .
[0043] The D/A converter 103 converts the digital signal output from the test circuit 102 into the analog signal to output the analog signal. The analog output signal output from the D/A converter 103 a or 103 b is positive voltage output signal or negative voltage output signal. For example, if the D/A converter 103 a outputs positive voltage output signal, the D/A converter 103 b outputs negative voltage output signal.
[0044] The polarity switching circuit 104 is the switch for inverting polarity of voltage applied between a liquid crystal pixel electrode and a counter electrode in a certain cycle to prevent degradation that is occurred due to the characteristics of the liquid crystal material. Therefore, the positive voltage output of the D/A converter 103 a and the negative voltage output of the D/A converter 103 b are switched in a certain cycle by the polarity switching circuit 104 to be output to the output amplifier which is in the later stage.
[0045] The output amplifier 105 amplifies the signal from the polarity switching circuit 104 to output the amplified signal to the output switch 106 . Note that the output amplifier 105 a or 105 b may be for positive voltage or negative voltage.
[0046] FIG. 5 shows a specific configuration of the output amplifier 105 . As shown in FIG. 5 , the output amplifier 105 includes an input stage 161 and an output stage 162 . The input stage 161 includes PMOS transistors M 161 and M 162 , NMOS transistors M 163 to M 165 , and a capacitance element C 161 . The output stage 162 includes a PMOS transistor M 166 and an NMOS transistor M 167 . The input stage 161 forms differential amplifier, and the output of the D/A converter 103 a or 103 b is applied to an input IN+ in FIG. 5 through the polarity switching circuit 104 . The output of the output stage 162 is applied to an input IN−. Although the output amplifier 105 shown in FIG. 5 has differential input configuration, the output amplifier 105 may be replaced with the amplifier having single-phase input.
[0047] The test switch 108 connects the test signal line 110 to the output pin 107 in test operation. The test switch 108 can use CMOS transfer gate, for example.
[0048] The output switch 106 is the switch disconnecting the output amplifier 105 and the output pin 107 of the driver. The output switch 106 is connected when the mode is not in test mode (when the test switching signal is in low level) and the output control signal is in high level, and is disconnected when the output control signal is in low level. The output control signal is in high level while the output is driven. Note that connection between panel terminals are shorted out in order to collect charges of panel pixel immediately before the polarity of the data line is inversed. At this time, the output control signal is set to low level and the output switch 106 is turned off. Hence, the output switch 106 also has a function of effectively collecting charges of the panel during this period.
[0049] The test controller 109 forces to disconnect the output switch 106 in test operation when there is provided the output switch 106 . In the first embodiment, the output switch 106 also needs to be disconnected when the test switching signal is in high level. Therefore, the test controller 109 is formed by an inverter INV 111 inverting the test switching signal and an AND circuit AND 111 to which the output control signal and signal from the inverter INV 111 are input.
[0050] In the present invention, the level shifter described in the related art is omitted for simplicity. This is because some test circuits need to have the level shifter between the latch circuit and the test circuit, and other circuits need to have the level shifter between the test circuit and the D/A converter. Such combination is not related to the essential part of the present invention, and therefore the level shifter is not shown in this invention.
[0051] Now, the behavior of the driver of the display unit according to the first embodiment will be described. The description of the behaviors of the latch circuit, the D/A converter, the polarity switching circuit, and the output amplifier is omitted since they have already been explained in the related art.
[0052] Now, the description will be made on a case where the test switching signal is in low level (normal state). In normal state, the test switching signal is in low level, and therefore the test circuit 102 outputs the signals from the latch circuit 101 directly to the D/A converter 103 . At this time, the test switch 108 is in disconnection state. In the normal state, there are output driving period and panel charge collecting period. In the output driving period, the output control signal is in high level and the output switch 106 is in conduction state. Therefore, the output amplifier 105 and the output pin 107 are connected. The rest of the operation is the driver operation which is the same as the operation described in the related art.
[0053] In the first embodiment, it is assumed that the test signal is the output signal from the test circuit 102 . Because the test switch 108 is disconnected, the test signal output from the test circuit 102 may be either in output state or in high-impedance state. On the other hand, when the test signal is in input state, the test signal may be fixed to high level or low level since the high-impedance state occurred by disconnecting the test switch is not preferable. The test switch may be in connection state if the test circuit is not influenced by the test signal and the test signal does not influence the output pin 107 when the test switching signal is in low level (normal operation). If the test signal of the test circuit 102 has withstand voltage that can withstand gradation voltage output from the output amplifier, the connection state that is stated above may be conduction state. The connection state mentioned here means the state where the signal can be transmitted. The level may be changed in transmission. The conduction state mentioned here means the state connection is made in a relatively low impedance.
[0054] Now, the description will be made on a case where the test switching signal is in high level (test state). In the test state, the test switching signal is in high level, and the output of the latch circuit 101 is input to the test circuit 102 and the test circuit 102 performs the test and outputs the test signal to the test signal line 110 . At the same time, the output switch 106 is forced to be disconnected by the test controller 109 regardless of the state of the output control signal. The test switch 108 is in connection state at this time. Therefore, the output pin 107 does not output the output gradation voltage from the output amplifier 105 but outputs the test signal. Otherwise, it is possible to input the test control signal from an external device through the output pin 107 .
[0055] FIG. 6 shows an operation of the specific configuration example 1 of the test circuit 102 shown in FIG. 2 . The test data TB 0 , TB 1 , and TB 2 each controls connection between the input terminal a or b and the output terminal c of the first-stage switches SW 151 to SW 154 , the second-stage switches SW 155 and SW 156 , and the third-stage switch SW 157 forming the test circuit 102 . We assume here that the input terminal a and the output terminal c are connected when the test data is 0, which means the test data is in low level, and the input terminal b and the output terminal c are connected when the test data is 1, which means the test data is in high level in the switches SW 151 to 157 .
[0056] The test data TB 0 repeats binary data of 0 and 1 in predetermined clock cycle. The test data TB 1 repeats binary data of 0 and 1 in clock cycle that is twice as long as that in the test data TB 0 . The test data TB 2 repeats binary data of 0 and 1 in clock cycle that is three times as long as that in the test data TB 0 . The values of the data buses DB 0 to DB 7 (output data of the latch circuit 101 which is the test target) are sequentially output to the test signal line 110 from the test circuit 102 by periodically changing the test data TB 0 , TB 1 , and TB 2 .
[0057] Instead of periodically changing the test data TB 0 to TB 2 , it is also possible to output the values of the data buses DB 0 to DB 7 to the test signal line 110 by specific bit combination. In this case, the test circuit 102 may specify one of the output data of the latch circuit 101 selected by three bits of test data TB 0 to TB 2 to output the data as the test signal 110 . For example, when all of the test data TB 0 to TB 2 are 0, the data bus DB 0 is output as the test signal.
[0058] FIG. 7 shows a specific configuration example 2 of the test circuit 102 shown in FIG. 1 . The configuration example of the test circuit 102 detects match or mismatch between two sets of 8-bit data. The test circuit 102 of this example includes XOR circuits XOR 161 to 168 and an NOR circuit NOR 161 . As shown in FIG. 7 , the XOR circuits XOR 161 to 168 have one terminals to which 8-bit data of the latch circuit 101 output to the data buses DB 0 to DB 7 are input and the other terminals to which the 8-bit test data TB 0 to TB 7 input to the driver 100 from the test device (not shown) are input. The outputs of the XOR circuits XOR 161 to 168 are input to the NOR circuit NOR 161 and output to the test signal line 110 from the test circuit 102 as the test signal. When the 8-bit data output from the latch circuit 101 (measurement value) and the 8-bit data of the test data (expectation value) completely match, the test circuit 102 outputs the value of “True” and otherwise outputs the value of “False”. In the second example, it is possible to reduce test time since 8-bit data is compared in parallel.
[0059] The connection between the data buses DB 0 to DB 7 and the test circuit 102 is controlled by the test switching signal in both test circuits 102 shown in FIGS. 2 and 7 . Although the controller is not especially shown in FIGS. 2 and 7 , the connection can be realized by providing another switch between the data buses DB 0 to DB 7 and the input part of the test circuit 102 . The switch is closed when the test switching signal is in high level and the switch is opened when the test switching signal is in low level.
[0060] In the driver 100 according to the first embodiment, the switch between the output amplifier and the output pin does not influence the driving ability of the driver even when the test circuit is added to the driver. Therefore, there is not caused a problem that the driving ability is lacked due to increase of output impedance. Further, since it is not needed to improve the driving ability of the output amplifier to compensate the lack of the driving ability, there is not caused a problem of increased power consumption or the heat generation.
Second Embodiment
[0061] Hereinafter, the driver of the display unit according to the second embodiment of the present invention will be described with reference to FIG. 8 . FIG. 8 shows an example of a configuration of the driver of the display unit according to the second embodiment. The configurations to which the same symbols as in FIG. 1 are given are the same or similar to the configurations in FIG. 1 . The difference between the first embodiment and the second embodiment is that the output amplifier has an output enable function in the second embodiment, and there is difference in configurations of the output amplifier 120 and the test controller 124 .
[0062] The test controller 124 makes the output of the output amplifier 120 high-impedance state in test operation when the output amplifier 120 has the output enable function. In other words, the output stage of the amplifier 120 in test operation is made deactivation state. The test controller 124 is formed by an inverter INV 121 inverting the test switching signal in order to make the output of the amplifier 120 high-impedance state when the test switching signal is in high level (test operation).
[0063] Now, the amplifier 120 will be described. FIG. 9 shows an example of the amplifier having output enable function. As shown in FIG. 9 , the amplifier 120 includes an input stage 121 , a test switching circuit 122 , and an output stage 123 .
[0064] The signal from the D/A converter 103 is input to the input stage 121 . Note that the specific configuration of the input stage 121 is the same as the configuration of the amplifier input stage 161 shown in FIG. 5 .
[0065] The test switching circuit 122 includes switches SW 121 and SW 122 . The SW 121 switches the signal output from the input stage 121 and VDD voltage, and the SW 122 switches the signal output from the input stage 121 and ground voltage according to the test switching signal. The switch SW 121 is connected to the output side of the input stage 121 when the test switching signal is in low level and is connected to VDD side when the test switching signal is in high level. Similarly, the switch SW 122 is connected to the output side of the input stage 121 when the test switching signal is in low level and is connected to ground when the test switching signal is in high level.
[0066] The output stage 123 includes a PMOS transistor M 121 and an NMOS transistor M 122 in series between VDD and ground. The output from the switch SW 121 is input to a gate of the PMOS transistor M 121 . Similarly, the output from the switch SW 122 is input to the gate of the NMOS transistor M 122 . There is provided an output terminal of the amplifier 120 between the PMOS transistor M 121 and the NMOS transistor M 122 .
[0067] Hereinafter, the behavior of the driver of the display unit according to the second embodiment will be described. The description of the configurations other than the amplifier 120 and the test controller 124 are omitted since these configurations are the same as those in the first embodiment. The specific configuration and the description of the behavior of the test circuit 102 are omitted as well.
[0068] The test switching signal is in high level and the signal output from the test controller 124 is in low level in test operation. Therefore, the switch SW 121 of the test switching circuit 122 is connected to VDD side and the switch SW 122 is connected to ground side. Therefore, the high level signal is input to the gate of the PMOS transistor M 121 of the output stage 123 , and the PMOS transistor M 121 is turned off. On the other hand, the low level signal is input to the gate of the NMOS transistor M 122 and the NMOS transistor M 122 is turned off as well. Therefore, both of the transistors of the output stage 123 are in disconnection state and the amplifier output terminal is in high-impedance state. In other words, the output stage 123 is in deactivation state in test operation. At this time, the test switch 108 is in connection state and the test signal is connected to the output pin 107 . Therefore, the output pin 107 can be used as the pin for test signal.
[0069] On the other hand, the test switching signal is in low level and the signal output from the test controller 124 is in high level in normal operation. Therefore, the switches SW 121 and SW 122 of the test switching circuit 122 are connected to the output side of the input stage 121 . Therefore, the output signal of the input stage 121 is input to the output stage 123 and the output stage 123 functions as inverter amplifier. The signal from the D/A converter 103 input to the output amplifier 120 is output to the amplifier output terminal with predetermined driving ability. The rest of the operation is the same as in the normal operation of the first embodiment.
[0070] In the driver 100 according to the second embodiment, the switch between the output amplifier and the output pin does not influence the driving ability of the driver even when the test circuit is added to the driver as well as in the first embodiment. Therefore, there is not caused a problem that the driving ability is lacked due to increase of output impedance. Further, since it is not needed to improve the driving ability of the output amplifier to compensate the lack of the driving ability, there is not caused a problem of increased power consumption or the heat generation.
Third Embodiment
[0071] The driver of the display unit according to the third embodiment of the present invention will be described with reference to FIG. 10 . FIG. 10 shows an example of a configuration of the driver of the display unit according to the third embodiment. The configurations to which the same symbols are given as in FIGS. 1 and 8 indicate same or similar configurations as those in FIGS. 1 and 8 . The specific configuration and the description of the behavior of the test circuit 102 are the same as well. The difference between the second embodiment and the third embodiment is that the circuit of the output stage of the output amplifier is configured as the output buffer of the test signal in the third embodiment. There is a difference in the configurations of the output amplifier 130 and the test controller 134 . However, the third embodiment is effective only when the test signal of the test circuit 102 is output signal.
[0072] The test controller 134 connects the test signal line 110 to the output stage of the output amplifier 130 when the test switching signal is in high level (test operation). Therefore, the test controller 134 is formed by an inverter INV 131 inverting the test switching signal.
[0073] FIG. 11 shows an example of the amplifier 130 according to the third embodiment. In FIG. 11 , the amplifier 130 includes an input stage 131 , a test switching circuit 132 , and an output stage 133 . The input stage 131 and the output stage 133 have the same configurations as those of the input stage 121 and the output stage 123 shown in the second embodiment and therefore the description thereof is omitted.
[0074] The test switching circuit 132 includes switches SW 131 and SW 132 . The switches SW 131 and SW 132 switch the test signal and the signal output from the input stage 131 according to the signal obtained by inverting the test switching signal by the inverter INV 131 . The switch SW 131 is connected to the output side of the input stage 131 when the test switching signal is in low level (normal operation). The switch SW 131 is connected to the test signal line 110 side when the test switching signal is in high level (test operation). Similarly, the switch SW 132 is connected to the output side of the input stage 131 when the test switching signal is in low level (normal operation). The switch SW 132 is connected to the test signal line 110 side when the test switching signal is in high level (test operation).
[0075] Next, the behavior of the driver of the display unit according to the third embodiment will be described. However, configurations other than the test switching circuit 132 forming the amplifier 130 are the same as those in the second embodiment. Therefore, the overlapping description is omitted. The behavior in the normal operation is the same as that in the second embodiment as well, and therefore the overlapping description is omitted.
[0076] In test operation, the test switching signal is in high level and the signal output from the test controller 134 is in low level. Therefore, the switch SW 131 of the test switching circuit 132 is connected to the test signal line 110 side. Similarly, the switch SW 132 is connected to the test signal line 110 side as well. Therefore, the output stage 133 functions as the logic output buffer outputting the test signal, and the signal is output to the amplifier output terminal with predetermined driving ability.
[0077] Therefore, in the driver according to the third embodiment of the present invention, it is possible to connect the test signal and the output pin 107 in the test operation. In the normal operation, the relationship between the output amplifier 130 and the output pin 107 is equivalent to the configuration without the test circuit 102 . Therefore, there is no problem that the output impedance is increased. Further, the test signal is output through strong logic output buffer configured by the output stage 133 of the output amplifier 130 . Therefore, since there is no test switch having impedance as the driver in the first and second embodiments, it is possible to output high-speed test signal in the test operation. Hence, the test time can be reduced.
Fourth Embodiment
[0078] Now, the driver of the display unit according to the fourth embodiment of the present invention will be described with reference to FIG. 12 . FIG. 12 shows an example of a configuration of the driver of the display unit according to the fourth embodiment. The configurations to which the same symbols are given as in FIG. 1 indicate the same or similar configurations as those in FIG. 1 . The specific configuration and the description of the behavior of the test circuit 102 are the same as well. The difference between the first embodiment and the fourth embodiment is that the switch is forced to be disconnected in test operation when there is provided a switch circuit (polarity switching circuit 104 in this example) between the D/A converter 103 and the output amplifier 105 . Therefore, the configurations of the test controller 141 and the test switch 142 are different from those in the first embodiment. However, the fourth embodiment is effective only when the test signal of the test circuit is output signal.
[0079] The test controller 141 turns off the polarity switching circuit (the control signal of the polarity switching circuit is in low level) when the test switching signal is in high level (test operation). Therefore, the test controller 141 includes an inverter INV 141 , an inverter INV 142 , an AND circuit AND 141 , and an AND circuit AND 142 . The inverter INV 141 inverts the test switching signal, and the inverter INV 142 inverts the polarity switching signal. The AND circuit AND 141 outputs the output signal of the inverter INV 142 and the polarity switching signal to the polarity switching circuit as input signals, and the AND circuit AND 142 outputs the output signal of the inverter INV 141 and the output signal of the inverter INV 142 to the polarity switching circuit as the input signals.
[0080] The test switch 142 connects the test signal line 110 to the input of the output amplifier 105 when the test switching signal is in high level (test operation).
[0081] Now, the behavior of the driver of the display unit according to the fourth embodiment will be described. When the test switching signal is in low level (normal operation), the high level signal inverted by the inverter INV 141 is input to the AND circuits AND 141 and AND 142 . Therefore, the polarity switching signal and the signal obtained by inverting the polarity switching signal are directly output from the test controller 141 and the behavior is the same as that in the related art. Similarly, the test switch 142 is turned off and the test signal line 110 and the input of the output amplifier 105 are disconnected with each other.
[0082] On the other hand, in the test controller 141 , the low level signal inverted by the inverter INV 141 is input to the AND circuits AND 141 and AND 142 when the test switching signal is in high level (test operation). Therefore, the AND circuits AND 141 and AND 142 both output the low level signals, and all the polarity inverting switch 104 are in disconnection state. At the same time, the test switch 142 is in ON state and therefore the test signal line 110 and the input of the output amplifier 105 are connected. Therefore, the test signal is output to the output pin 107 with predetermined driving ability by the output amplifier 105 .
[0083] Therefore, since the relationship between the output amplifier 105 and the output pin 107 is equivalent to the configuration without the test circuit in normal operation, there is not caused a problem that the output impedance is increased. Further, the test signal is also output through the output amplifier. Therefore, there is no test switch having impedance between the test signal and the output pin as the driver in the first embodiment and the second embodiment. Therefore, it is possible to output the high-speed test signal in the test operation, which makes it possible to reduce test time.
[0084] It is apparent that the present invention is not limited to the above embodiments, but may be modified and changed without departing from the scope and spirit of the invention. For example, the driver may be applied to an organic light emitting display, a plasma display, an SED or the like. | According to one aspect of the present invention, there is provided a driver of a display unit including a latch circuit holding gradation information, a D/A converter outputting analog signal based on the gradation information held by the latch circuit, a test circuit provided between the latch circuit and the D/A converter, the test circuit inputting or outputting test signal regarding the latch circuit, a switch connecting voltage output of the D/A converter and a driver output terminal in normal operation, and a test switch connecting the test circuit and the driver output terminal in test operation and disconnecting the test circuit and the driver output terminal in normal operation. | 6 |
FIELD OF THE INVENTION
[0001] This invention relates to indirect lighting for displays and, in particular, to a display back lit by reversely mounted light emitting diodes (LEDs).
GLOSSARY
[0002] “Point” is not used in the mathematical sense of vanishingly small. A point source of light is a bright source in a small, finite space, “small” being relative to the size of the surrounding structure. Some people may quibble that a point source of light radiates uniformly in all directions. That quibble is not true in practice and does not apply here. As such, incandescent lamps, LEDs, some gas discharge lamps, and others are point sources of light even though, as in the case of LEDs, they radiate in a preferred direction.
[0003] Strictly speaking, all non-luminous objects, except black holes, reflect light, otherwise nothing would be visible. A reflecting surface is either specular (a mirror-like or polished surface), uniformly diffuse, or somewhere in-between. At a microscopic level, even a highly polished, front surface mirror is not perfectly specular, nor is any diffuse reflector perfectly lambertian. Mathematical minutiae are of no concern here. Rather the concern is with a macroscopic, practical, diffuse reflector that is reasonably, if not perfectly, lambertian. Many surfaces fulfill this criterion, such as a sheet of white paper or a sheet of white plastic. Obviously, colored paper or plastic filters the light in addition to reflecting the light.
[0004] Although the invention is described in the context of an instrument cluster for a vehicle, the invention relates to backlighting any form of display, from something as simple as a switch to something as complicated as the backdrop for a pinball machine. In other words, “display” is meant broadly and “Instrument cluster” is not intended to limit the kinds of display in which the invention can be used.
[0005] A “luminous” object emits light. Light incident upon a subject “illuminates” the subject. “Luminance” refers to the amount of light emitted from a source. “Illuminance” refers to the amount of light incident upon a subject.
[0006] A “graphic” can be text, a symbol, an arbitrary shape, or some combination thereof. A graphic can be translucent, shaded, colored, a silhouette or outline, or some combination thereof.
[0007] As used herein, a “flex circuit” is any type of substrate including conductive traces for including LEDs and other devices in an electrical circuit. As such, a flex circuit includes printed circuit boards. The flexibility of the substrate has no bearing on the invention.
[0008] As used herein, an electroluminescent (EL) “panel” is a single sheet including one or more luminous areas, wherein each luminous area is an EL “lamp.” An EL lamp is essentially a capacitor having a dielectric layer between two conductive electrodes, one of which is typically transparent. The dielectric layer can include a phosphor powder or there can be a separate layer of phosphor powder adjacent the dielectric layer. The phosphor powder radiates light in the presence of a strong electric field, using relatively little current.
BACKGROUND OF THE INVENTION
[0009] In the particular display known as an instrument cluster, one either illuminates a dial, e.g. U.S. Pat. No. 2,172,765 (Kollsman) or back lights a mask defining translucent areas corresponding to the dials for gauges or to graphics, such as turn signal indicators; e.g. U.S. Pat. No. 5,578,985 (Cremers et al.).
[0010] It is known in the unrelated art of astronomy to make a flat field projector by sandblasting an aluminum plate and illuminating the plate with four LEDs; see Simon Tulloch, Design and Use of a Novel Flat Field Illumination Light Source, Technical Note 108, Instrument Science Group, Royal Greenwich Observatory, 1996.
[0011] A diffuse light source, such as an EL panel, is often used for backlighting graphics but is not as luminous as an LED. Some indicators are preferably bright and vivid in color. An LED is generally preferred to an incandescent lamp as a source of light because the LED produces light more efficiently while producing much less heat.
[0012] For back lighting, one wants as uniform a light source as possible, and therein lies a problem. LEDs have numerous advantages over incandescent lamps but, like incandescent lamps, are point sources of light. Various forms of light guides or light channels are used to diffuse the light but the fact remains that a point source of light is often visible through the object being backlit. A result is non-uniform lighting. Light from a source that is viewed directly is “glare” and is undesirable.
[0013] The need for light guides and the like requires complex structures that are expensive to manufacture, at least for initial tooling.
[0014] Another problem with point sources of light, and schemes for diffusing and redirecting the light, is “leakage”; i.e., light from one area being visible in or affecting light in another area. The problem is especially critical for indicators, where only the desired indicator should be back lit while other indicators remain unlit. Related to this is a large, relative to the size of the graphic, minimum separation for indicators to prevent leakage. The minimum separation limits the design of instrument clusters and other displays.
[0015] The electronics for most instrument clusters are mounted on flex circuits, where circuit cost is proportional to area, among other factors. Reducing area and simplifying design changes can significantly reduce costs. Design changes can be simplified, for example, if one could change graphics only while using the same flex circuit for the new design.
[0016] In view of the foregoing, it is therefore an object of the invention to provide a display, or portion thereof, that is substantially uniformly backlit from a point source of light.
[0017] Another object of the invention is to provide an indicator that is substantially uniformly and brightly backlit and vivid in color.
[0018] A further object of the invention is to provide a display having areas that are substantially uniformly backlit by LEDs.
[0019] Another object of the invention is to provide a display combining EL lamps and reversely mounted LEDs for substantially uniform backlighting.
[0020] A further object of the invention is to provide a backlight that is less prone to light leakage and simplifies the construction of complex displays.
SUMMARY OF THE INVENTION
[0021] The foregoing objects are achieved in this invention wherein a display is back lit by reflection of light from a surface illuminated by at least one point source of light, such as an LED. The reflecting surface can be far from the source, near to the source, or even a coating on a package containing the light source. The uniformity of light from the reflecting surface can be changed by shaping the reflecting surface. The point source projects light rearwardly, i.e. away from a viewer. That is, the axis along which light emission is greatest extends from the source away from a viewer. It has been found that the LED itself obscures the point source of light and that the reflected light seen by a viewer does not create a perceptible shadow on the viewer's side of the display.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] A more complete understanding of the invention can be obtained by considering the following detailed description in conjunction with the accompanying drawings, in which:
[0023] FIG. 1 is a plan view of an instrument panel constructed in accordance with the invention;
[0024] FIG. 2 is a cross-section of an instrument panel constructed in accordance with the invention;
[0025] FIG. 3 is a cross-section of a display constructed in accordance with a preferred embodiment of the invention;
[0026] FIG. 4 is a cross-section of a display constructed in accordance with an alternative embodiment of the invention;
[0027] FIG. 5 is a cross-section of a display constructed in accordance with another aspect of the invention;
[0028] FIG. 6 illustrates another aspect of the invention;
[0029] FIG. 7 illustrates yet another aspect of the invention;
[0030] FIG. 8 is a chart of light output vs. radius from an LED covered with a diffuse reflective coating.
DETAILED DESCRIPTION OF THE INVENTION
[0031] In FIG. 1 , display 11 includes gauges 12 , 13 and 14 and indicators grouped into area 16 . The gauges include pointers that can be illuminated by light piping, as known in the art. The face or dial of each gauge has a translucent area, each preferably back lit by an EL lamp. The EL lamps are preferably part of a single panel. Gauge 12 is a speedometer, for example, and includes odometer 18 , which can be a liquid crystal display or a mechanical display fitting behind the front of panel 11 . The gauges can include opaque indicia, for example, to contrast with the backlit portions of the dials.
[0032] Display 11 further includes LED 21 backlighting turn indicator 22 and LED 23 backlighting turn indicator 24 . The LEDs are not shown in proportion to the indicators but are somewhat enlarged to show the leads. As indicated by the position of the leads, LEDs 21 and 23 are reversely mounted; i.e. the direction of greatest light emission is away from the viewer, into the plane of the drawing of FIG. 1 .
[0033] As illustrated in FIG. 2 , display 11 includes backdrop 25 having diffusely reflecting surface 26 . The surface is relatively far from the LED, i.e. several diameters away. (“Diameter” refers to the package, not to a semiconductor die.) Display 11 includes struts or supports, such as wall 27 , for attaching back drop 25 to flex circuit 28 . The struts or supports also serve the additional function of optically isolating LED 21 from other areas of the display. Flex circuit 28 includes a graphics layer that is typically manufactured separately and laminated to the flex circuit. The flex circuit has a plurality of translucent areas, indicated by stippling, that permit light from LEDs 21 and 22 to backlight corresponding graphics. Electrical leads 31 and 32 from LED 21 are attached to the flex circuit, e.g. by soldering.
[0034] Semiconductor die 34 in LED 22 emits light predominantly upwardly, as oriented in FIG. 2 . There is some scattering as emitted and further scattering as the light emerges from the plastic package enclosing die 34 . In this embodiment of the invention, LEDs 21 and 22 have substantially hemispherical ends and any light not incident normal to the air/plastic interface is refracted. Light is further scattered by backdrop 25 and travels in a direction generally opposite to the light emitted from LED 22 ; i.e., downwardly.
[0035] The unexpected result of all this is that turn indicator 24 , or any other indicator, is substantially uniformly and brightly backlit. In other words, LED 22 provides high luminance over a wide area (several diameters) without the appearance of a point source. The indicators shown in area 16 ( FIG. 1 ) can be individually back lit in the same manner. Light emitted by the LEDs themselves cannot be seen directly because light is emitted away from a viewer. Thus, there is no “hot spot” or glare in a display constructed in accordance with the invention.
[0036] FIG. 3 is a cross-section of a display constructed in accordance with a preferred embodiment of the invention. In FIG. 3 , shell 41 surrounds LED 42 to provide backlighting to a small area, represented by stippling 43 . The inner (concave) surface of shell 41 is diffusely reflective and is relatively near LED 42 ; i.e. less than several diameters away from LED 42 .
[0037] Shell 41 is made from any suitably reflective material. A molded plastic shell is extremely inexpensive and effective. As shown in FIG. 3 , LED 42 need not be symmetrically located within shell 41 and shell 41 need not be of uniform shape; i.e. a shape defined, in part, by an axis of rotation. Shell 41 could be molded into a plurality of interconnected volumes to enclose a plurality of LEDs. That is, a shell need not be separately molded for each graphic or indicator.
[0038] Optionally, a shell can be molded as part of back cover 47 or attached to the back cover by strut 48 .
[0039] As also shown in FIG. 4 , more than one LED can be contained within a single shell and, if desired, the LEDs can emit different colors, e.g. amber and red, to provide degrees of warning based upon color. Plural LEDs can be driven individually or collectively to provide a variety of visual effects. Displays can be manufactured individually for later assembly or a plurality of shells can be added to flex circuits, or printed circuit boards, after the appropriate LEDs are mounted. In any case, the cost of the display can be reduced, uniformity is increased, and the display can be thinner than in the prior art.
[0040] FIG. 5 illustrates another aspect of the invention in which the reflecting surface is a coating on the LED. The range in size, brightness, and color of commercially available LEDs is considerable and the invention can make use of many types of LED.
[0041] In FIG. 5 , LED 51 has leads extending from the sides, rather than axially, and includes reflector 52 as a coating on the outer surface of the LED. Titania or barium titanate in a suitable resin carrier can be used as the coating. Such material is also known as an ink for depositing a dielectric layer on EL lamps. When cured, the ink provides a white, diffuse, reflective coating. An LED is dipped in the carrier, withdrawn, and the solvent is cured or dried to form an adherent coating of particles suspended in resin. Many materials can be used for the coating.
[0042] In one embodiment of the invention, an LED was coated with “white out” or correcting fluid for painting over printed characters or lines on a sheet of paper. The LED functioned as a diffuse backlight. Many other materials can be used instead, such as boron nitride, which is commercially available in the form of a white powder.
[0043] FIG. 6 illustrates an LED that has been molded into a plastic package and then coated. LED 71 is a die with leads attached in a small package that has been molded into larger package 72 . Leads, such as lead 73 , extend from the side of the larger package and are preferably spaced above flex circuit 74 , to which the lead is attached. This clearance enables the light diffusely reflecting within coating 76 to fill in any shadow created by LED 71 or the electrical leads extending from LED 71 . Reflective coating 76 scatters light from LED 71 downwardly (as oriented in the drawing) for backlighting a graphic on flex circuit 74 .
[0044] FIG. 7 illustrates an LED constructed in accordance with an alternative embodiment of the invention. Two, independent changes have been made in going from the embodiment of FIG. 6 to the embodiment of FIG. 7 . Specifically, the upper surface of package 81 has conical depression 83 molded therein to enhance scattering of the light in the desired direction; namely, downwardly and around the LED to the graphic. The particular contour of the upper surface of LED 81 depends upon the pattern of light emission from die 85 and is determined empirically.
[0045] The second change is that coating 87 does not extend down to the plane of the flex circuit. It is preferred that the entire package be coated but this is not required. It is also preferred that the reflector cover substantially 2π steradians of the space around die 85 , centered on the axis of greatest emission. Below the die, or below the leads, coating 87 is reflecting reflected light. In some configurations, covering more than 2π steradians is not necessary.
[0046] There is a third difference between FIG. 6 and FIG. 7 ; viz. package 81 is wider than package 72 . The size of the package or the height:diameter ratio of the package depends upon application. Wider packages back light wider areas.
[0047] FIG. 8 is a chart generated by a computer model of an LED in a package having a coated, hemispherical upper surface. The chart shows right-hand half of the light from the LED. A mirror-image of the chart, attached along the vertical line at zero radius, would show the light from the left-hand side of the LED. There is a very slight depression near the centerline of the LED, with maximum luminosity at a radius of approximately 2 mm. The unit values along the abscissa are rounded off, which is why they may appear inconsistent. The percent light output is from zero to one hundred percent of maximum.
[0048] Light output is substantially uniform almost to a radius of 5 mm, where brightness is about half. Other simulations were run with various shapes for the reflecting surface. An axial depression in the hemisphere produced a doughnut shaped illumination pattern (circular brighter area surrounding and surrounded by dimmer areas.) To enhance the graphic being backlit, the uniformity of the light could be adjusted by shaping the reflector.
[0049] The invention thus provides a backlight that is substantially uniformly despite using point sources of light, such as LEDs. The reflecting surface can be far, near, or a coating on the LED. The LED faces rearwardly, i.e. away from a viewer, thereby eliminating glare. Despite the presence of the LED in the field of view, the LED can be positioned to avoid perceptible shadow. Alternatively, an LED can be positioned laterally away from a translucent area and be outside the field of view. An advantage of the shell ( FIG. 3 ) and particularly of the coating ( FIG. 5 ) is that a cascading color can be incorporated into the reflector to enhance color.
[0050] Having thus described the invention, it will be apparent to those of skill in the art that various modifications can be made within the scope of the invention. For example, the diffusion coating on an LED can include cascading color materials, such as dyes or phosphors, for enhancing the visual appeal of the display. Large areas can be backlit by plural LEDs or by one or more electroluminescent lamps. The reflecting surface need not be white or of uniform reflectivity. | A display is back lit by reflection of light from at least one point source of light, such as an LED. The reflecting surface can be far, near, or a coating on a package containing the point source of light. The point source of light faces rearwardly, i.e. emitting light away from a viewer, obscuring the source without creating an easily perceptible shadow. | 1 |
The present invention relates to a load modulation circuit in an analog circuit, and relates in particular to a load modulation circuit for radio frequency identification.
BACKGROUND ART
In radio frequency identification, a radio frequency identification card couples an analogue signal sent by a card reader, demodulates the data as sent by the card reader via a radio frequency circuit in the card, and sends the data to a digital circuit for processing. The digital circuit sends the processed data back to the card reader via a load modulation circuit, thus the whole communication process is completed. The process in which the data is sent back to the card reader is load modulation. Unsatisfactory load modulation waveforms or load modulation depth would impact data demodulation by the card reader. Therefore, the load modulation circuit is important and crucial which shall has idea modulation waveform and enough load modulation depth under various cases of field intensity.
A load modulation circuit of prior art, as is shown by FIG. 1 , is comprised of NMOS transistors MN 1 -MN 3 , and a phase inverter INV 1 . Wherein, the NMOS transistor MN 3 is equivalent to a switch, being open during modulation, and closed otherwise, with the DIN being a load modulation signal provided and controlled by the digital circuit. The connection or closure of the NMOS transistor MN 3 will have an impact over the antenna signals: when the NMOS transistor MN 3 is connected, the signal on the antenna are pulled down to form a trough, the trough by trough signals constituting a load modulation wave which carries data to be finally demodulated by the card reader. The inductors L 1 , L 2 , and the capacitor C 1 in FIG. 1 constitute a coupling circuit. The input signal IN is coupled to the card end via the inductors L 1 and L 2 , while the load modulation wave from the card end can also be coupled to the card reader end.
Such a structure is advantageous in its simplicity and ease of implementation, with a quite good load modulation waveform and load modulation depth under weak field intensity; its disadvantages are poor load modulation waveform and modulation depth under strong field intensity, incorrect demodulated data by most card readers, or incorrect demodulation. Incorrect demodulation by the card reader will lead to total communication failure.
SUMMARY OF INVENTION
A technical problem the present invention aims to solve is to provide a load modulation circuit for radio frequency identification, which improves load modulation waveform and load modulation depth under strong field intensity, increases compatibility of radio frequency cards, and guarantees normal communication between a radio frequency card and a card reader.
To solve at least the afore-mentioned technical problem, the load modulation circuit for radio frequency identification of the present invention comprises a first load modulation module connected to a coupling circuit; and further comprises:
a second load modulation module connected to the coupling circuit; under a specific weak field intensity, load modulation is mostly realized by the first load modulation module, with the second load modulation module contributing far less than the first load modulation module as regards to the load modulation waveform and the load modulation depth; as field intensity increases, the first load modulation module contributes less and less to the load modulation waveform and the load modulation depth; while as field intensity increases, a variable voltage controlling the second load modulation module also increases and the second load modulation module contributes more and more to the load modulation waveform and the load modulation depth under the control of the variable voltage; under a specific strong filed intensity, the load modulation is mostly realized by the second load modulation module, with the first load modulation module contributing far less than the second load modulation module as to the load modulation waveform and the load modulation depth.
The load modulation circuit of the present invention adds an additional load modulation module to the load modulation circuit of prior art, that is, the additional load modulation module is controlled by a voltage which varies with the field intensity. When working under weak field intensity, the traditional load modulation circuit works normally, while the additional load modulation module has limited impact on load modulation due to a relatively small control voltage and thus a barely opened modulation MOS thereof. Hence load modulation is mostly realized by the load modulation module of prior art under weak field intensity. When the working field intensity increases, the load modulation module of prior art still functions, albeit with a poor load modulation waveform and load modulation depth, and contributing less and less to the load modulation waveform and load modulation depth as the field intensity increases. As for the adds-on load modulation module, the variable voltage controlling it increases with the increase of the field intensity, and the load modulation MOS which controlled by the variable voltage opens wider and wider, and the adds-on load modulation module begins to function and to contribute to the load modulation waveform and the load modulation depth. As the working field intensity continues to increase, for example when increasing to 7.5 A/m, which being a strong field intensity, the voltage on both ends of the antenna will also be very large, resulting in saturation of the load modulation module of prior art and very small contribution therefrom to the load modulation waveform and the load modulation depth. As for the adds-on load modulation module, with an already quite large voltage controlling it, that is, a sufficiently opened load modulation MOS, furnishes a comparatively ideal load modulation waveform and load modulation depth under strong field intensity, and realizes most of the job of the load modulation.
The improved load modulation circuit generates a good load modulation waveform and a deep load modulation depth both under weak field intensity and strong field intensity. It improves load modulation waveform and load modulation depth under strong field intensity. Further, it substantially increases compatibility for radio frequency cards so as to be compatible to various card readers, and guarantees normal communication between a radio frequency card and a card reader.
BRIEF DESCRIPTION OF THE DRAWINGS
In combination with drawings and embodiments hereunder provided, the present invention will be enunciated in more details:
FIG. 1 shows a schematic diagram of a load modulation circuit of prior art;
FIG. 2 shows a schematic diagram of the load modulation circuit for radio frequency modulation of the present invention.
DETAILED DESCRIPTION
As is shown on FIG. 2 , the load modulation circuit for radio frequency identification of the present invention has two load modulation modules, that is, a first load modulation module and a second load modulation module. Both the load modulation modules are connected with a coupling circuit. An amplitude limiter circuit provides for the second load modulation module a variable voltage VLIM, which changes as the field intensity changes. When working under weak field intensity, the variable voltage VLIM is comparatively low, and will increase as the field intensity increases. When working under strong field intensity, the variable voltage VLIM will increase so as to be able to control the second load modulation module to participate in load modulation. The coupling circuit is comprised of inductors L 1 , L 2 , and a first capacitor (C 1 ). The first capacitor C 1 is connected in parallel with both ends of the inductor L 2 , an input signal IN is coupled to a radio frequency identification card via the inductors L 1 and L 2 and resonates with the first capacitor (C 1 ) to generate a relatively high resonant voltage; at the meantime, a carrier signal and an envelope signal are coupled to the radio frequency card from a card reader. A demodulation circuit demodulates a corresponding digital signal from the envelope signal and then sends it to the digital circuit for processing. Data processed by the digital circuit also requires the coupling circuit to couple the data from the radio frequency identification card to the card reader. Coupling of data processed by the digital circuit from the radio frequency identification card to the card reader is conducted by means of load modulation, that is, the digital circuit realizes load modulation by means of controlling the voltage on the DIN end of the first load modulation module and the second load modulation module.
The first load modulation module, being structurally identical to the load modulation circuit of prior art as is shown on FIG. 1 , is involved in load modulation under all levels of field intensity ; but under strong field intensity it contributes less to load modulation.
The first load modulation module is comprised of a first NMOS transistor MN 1 , a second NMOS transistor MN 2 , a third NMOS transistor MN 3 , and a first phase inverter INV 1 .
The gate and the drain of the first NMOS transistor MN 1 are connected with an end ANT 1 of the second inductor L 2 of the coupling circuit, the gate and the drain of the second NMOS transistor MN 2 are connected with another end ANT 2 of the second inductor L 2 of the coupling circuit. A source of the first NMOS transistor MN 1 and a source of the second NMOS transistor MN 2 are connected with the drain of the third NMOS transistor MN 3 . A control signal DIN furnished by the digital circuit is inputted via an input port of the first phase inverter INV 1 . An output port of the first phase invert INV 1 is connected with a gate of the third NMOS transistor MN 3 , with a source of the third NMOS transistor MN 3 being grounded.
The second load modulation module is a newly added load modulation module, with its contribution to load modulation being reflected in the case of a strong field intensity.
The second load modulation module is comprised of a fourth NMOS transistor MN 4 , a fifth NMOS transistor MN 5 , a sixth NMOS transistor MN 6 , a first PMOS transistor MP 1 , a second phase inverter INV 2 , and a third phase inverter INV 3 .
The drain of the fourth NMOS transistor MN 4 is connected with one end ANT 1 of the second inductor L 2 of the coupling circuit, the drain of the fifth NMOS transistor MN 5 is connected with another end ANT 2 of the second inductor L 2 of the coupling circuit. A source of the fourth NMOS transistor MN 4 and a source of the fifth NMOS transistor MN 5 are grounded. The gate of the fourth NMOS transistor MN 4 is connected with the gate of the fifth NMOS transistor MN 5 , with a node of connection being denoted as an end point A. A variable voltage VLIM furnished by an amplitude limiter circuit is inputted via a source of the first PMOS transistor MP 1 . The drain of the first PMOS transistor MP 1 and the drain of the sixth NMOS transistor MN 6 are connected with the end point A, with a source of the sixth NMOS transistor MN 6 being grounded. An input port of the second phase inverter INV 2 is connected with the gate of the sixth NMOS transistor MN 6 for input of the control signal DIN. An output port of the second phase inverter INV 2 is connected with an input port of the third phase inverter INV 3 , and an output port of the third phase inverter INV 3 is connected with gate of the first PMOS transistor MP 1 .
The amplitude limiter circuit functions to ensure a stable voltage for point B on FIG. 2 , as well as to provide a variable voltage VLIM for the second load modulation module in the embodiment.
The amplitude limiter circuit is comprised of a seventh NMOS MN 7 transistor, an eighth NMOS transistor MN 8 , a ninth NMOS transistor MN 9 , a tenth NMOS transistor MN 10 , an eleventh NMOS transistor MN 11 , a twelfth NMOS transistor MN 12 , a thirteenth NMOS transistor MN 13 , and a first resistor R 1 .
The gate and the drain of the seventh NMOS transistor MN 7 are connected with an end ANT 1 of the second inductor L 2 of the coupling circuit, the gate and the drain of the eighth NMOS transistor MN 8 are connected with another end ANT 2 of the second inductor L 2 of the coupling circuit. A source of the seventh NMOS transistor MN 7 is connected with a source of the eighth NMOS transistor MN 8 , with a point of connection being denoted as end point B. A source of the ninth NMOS transistor MN 9 , a source of the twelfth NMOS transistor MN 12 , and the drain of the thirteenth NMOS transistor MN 13 are connected with the end point B. The gate and the drain of the ninth NMOS transistor MN 9 are connected with the gate of the twelfth NMOS transistor MN 12 and a source of the tenth NMOS transistor MN 10 . The gate and the drain of the tenth NMOS transistor MN 10 are connected with a source of the eleventh NMOS transistor MN 11 . The gate and the drain of the eleventh NMOS transistor MN 11 are grounded. The drain of the twelfth NMOS transistor MN 12 is connected with an end of the first resistor R 1 and the gate of the thirteenth NMOS transistor MN 13 , a voltage of a connection point thereof being the variable voltage VLIM. A source of the thirteenth NMOS MN 13 transistor is grounded. When the voltage at point B increase and surpasses the sum of the threshold voltages of the ninth NMOS transistor MN 9 , the tenth NMOS transistor MN 10 , and the eleventh NMOS transistor MN 11 , the value of the variable voltage VLIM will increase and gradually opens the thirteenth NMOS transistor MN 13 for release of surpass current, and the voltage at point B will decrease and remain stable at the sum of the threshold voltages of the ninth NMOS transistor MN 9 , the tenth NMOS transistor MN 10 , and the eleventh NMOS transistor MN 11 . Hence, the value of the variable voltage VLIM changes in response to the changing field intensity, with a small variable VLIM voltage value corresponding to a small field intensity value, and a large variable VLIM voltage value corresponding to a large field intensity value.
Under a small field intensity, the third NMOS transistor MN 3 opens at a low level of the modulation control signal DIN to control initiation of load modulation through the first NMOS transistor MN 1 and the second NMOS transistor MN 2 , for which the first load modulation module plays a crucial role, due to the good load modulation waveform and load modulation depth it provides. While for the second load modulation module, the sixth NMOS transistor MN 6 thereof is first closed at the low level of the modulation control signal DIN, then the first PMOS transistor MP 1 is turned on to transmit the variable voltage VLIM provided by the amplitude limiter circuit to point A. As the voltage at point A controls the turning on and off of the NMOS transistors MN 4 and MN 5 , the second load modulation module also starts to conduct load modulation. Due to the small value of the field intensity, the value of the variable voltage VLIM is comparatively low, and hence the NMOS transistors MN 4 and MN 5 are barely or not turned on at all, and therefore the contribution from the second load modulation module to the load modulation waveform and the load modulation depth is relatively small.
As the working field intensity increases, the first load modulation module still functions, albeit with a poor load modulation waveform and load modulation depth, and contributing less and less to the load modulation waveform and load modulation depth as the field intensity increases. As for the second load modulation module, the voltage controlling it increases with the increase of the field intensity. As the variable voltage VLIM provided by the amplitude limiter circuit increases, the voltage at point A also increases, that is, the NMOS transistors MN 4 and MN 5 turn on gradually to participate in load modulation. The load modulation waveform and the load modulation depth are thus jointly decided by the two load modulation circuits, with their contribution being dependent on the changing field intensity. The smaller the field intensity value is, the less the contribution from the second load modulation module become; the larger the field intensity value is, the larger the contribution therefrom become.
As the working field intensity continues to increase, for example when increasing to 7.5 A/m, which being a strong field intensity, the voltage on both ends of the antenna will also be very large, resulting in saturation of the first load modulation module circuit and very small contribution therefrom to the load modulation waveform and the load modulation depth. As for the second load modulation module, with an already quite large voltage controlling it, that is, a sufficiently opened load modulation valve, furnishes a comparatively ideal load modulation waveform and a load modulation depth under strong field intensity, and realizes most of the function of the load modulation, with a comparatively small contribution from the first load modulation module. Therefore, the present invention has a good load modulation waveform and load modulation depth under medium and large field intensity, as well as under a small one.
The working field intensity for a radio frequency identification card is generally 1.5 A/m-7.5 A/m. For various radio frequency identification cards, the definition of large field intensity may vary, with field intensity over 6 A/m or 7 a/m being considered as a large one.
Similarly, for various radio frequency identification cards, the definition of small field intensity may vary considerably, with field intensity smaller than 1.5 A/m being considered as a small one.
The present invention has thus been fully explained by specific embodiments, but is not meant to be limited thereby. A person of the art shall be able to make various modifications of, or to combine the embodiments with reference to the present specification without departure from the spirit and scope of the present invention, which shall fall within the scope of protection of the present invention. | A load modulation circuit for radio frequency identification including a first load modulation module and a second load modulation module connected to a coupling circuit. Under weak field intensity, load modulation is mostly realized by the first load modulation module, with the second load modulation module contributing far less than the first load modulation module as regards to the load modulation waveform and load modulation depth. As field intensity increases, the first load modulation module contributes less and less to the load modulation waveform and load modulation depth. While field intensity increases, the second load modulation module contributes more and more to the load modulation waveform and load modulation depth under the control of a variable voltage. Under strong filed intensity, load modulation is mostly realized by the second load modulation module. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit under 35 U.S.C. §119(a) of Korean Patent Application No. 10-2010-0004053, filed on Jan. 15, 2010, in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference for all purposes.
BACKGROUND
[0002] 1. Field
[0003] The following description relates to an image fusion apparatus and method for composing multi-exposure images obtained from an image sensor, and more particularly, to a multi-exposure image fusion apparatus and method for producing a sharp high-resolution high dynamic range (HDR) image to more fully represent detail in under and over-exposed regions of an image without contrast degradation.
[0004] 2. Description of the Related Art
[0005] Examples of a conventional high dynamic range (HDR) image generation include an image obtaining method using an HDR image sensor and a multi-exposure image composition method. The image obtaining method uses an HDR image sensor to obtain an HDR image directly from an image sensor. The image obtaining method does not perform image synthesis.
[0006] The multi-exposure image compositing method includes global/local tone mapping methods, each of which captures a plurality of images with different exposures and generates HDR data. The method includes compressing the HDR data by tone mapping in accordance with a low dynamic range (LDR) to generate an output image.
[0007] The global tone mapping method may retain the global contrast, and is simple to calculate. However, in the global tone mapping method, the local contrast is degraded and an unclear image is obtained. The local tone mapping can retain the local contrast, but an inversion phenomenon and halo artifacts may occur, and a large amount of calculations are required.
[0008] In addition, the above methods are not sufficient to provide an HDR image corresponding to the recent trend of high quality images and contrast characteristics of human vision.
[0009] For example, the multi-exposure image composing method may produce an image with deteriorated quality due to contrast degradation that results from dynamic range compression. The multi-exposure image composing method may cause the occurrence of an inversion phenomenon and halo artifacts. Therefore, a new HDR image generating method that does not reduce global or local contrast is needed.
SUMMARY
[0010] In one general aspect, there is provided an image fusion apparatus for combining multi-exposure images obtained by an image sensor, the image fusion apparatus comprising an image capturing and processing unit to obtain a first input image and a second input image that have different exposures, respectively, and to perform motion alignment and exposure processing on the first and second input images, and an image generating unit to generate low-dynamic range (LDR) images by compressing the first input image and the second input image such that each of the first input image and the second input image are divided into regions according to luminance information of the second input image, and to combine the generated LDR images.
[0011] The image generating unit may comprise an exposure compensating unit to set an index according to an exposure difference between the first input image and the second input image, to compensate for an exposure of the first input image, and to generate a compensated image, a first image fusion unit to combine the second input image and the compensated image using the luminance information of the second input image on a basis of luminance regions, and to generate the LDR images that comprise a high-luminance compressed image and a low-luminance compressed image, by compressing the combined image on a basis of the luminance regions, and a second image fusion unit to combine the LDR images generated by the first image fusion unit using the luminance information of the second input image.
[0012] The exposure compensating unit may calculate a lower luminance threshold and an upper luminance threshold from a luminance mean value and a luminance maximum value of the first input image and may remap an exposure value of the first input image according to the index.
[0013] The first image fusion unit may comprise a broadband image fusion unit to generate fusion-weighted images from the luminance information of the second input image with respect to the second input image and the image generated from the exposure compensating unit, and to generate the combined image by combining over-exposed regions and under-exposed regions of the images using the fusion-weighted images, and a compressed image generating unit to generate the LDR images by compressing the combined image based on the over-exposed region and the under-exposed region such that the entire luminance range of the generated LDR images is the same as that of the image generated by the broadband image fusion unit.
[0014] The first image fusion unit may further include a fusion weight calculating unit to generate fusion-weighted images for extracting predetermined luminance regions from the respective first input image and second input image according to the corresponding exposures.
[0015] The second image fusion unit may generate region-weighted images for an over-exposed region and an under-exposed region using the luminance information of the second input image and may combines the high-luminance compressed image and the low-luminance compressed image, which are generated by the first image fusion unit, using the generated region-weighted images.
[0016] The second image fusion unit may include a region-weight calculating unit to generate region-weighted images for extracting predetermined luminance regions from the respective high luminance compressed image and low luminance compressed image which are generated by the first image fusion unit.
[0017] The image fusion apparatus may further comprise a high luminance restoration unit to restore luminance of a region of the second input image with reference to a color ratio of the first input image where the region is brighter than a predetermined luminance.
[0018] The image fusion apparatus may further comprise a post-processing unit to perform contrast enhancement, to increase luminance in an under-exposed region, and to perform halo artifact reduction on each of the high luminance compressed image and the low luminance compressed image generated by the first image fusion unit.
[0019] In another aspect, provided is an image fusion method for combining multi-exposure images obtained by an image sensor, the image fusion method comprising obtaining a first input image and a second input image with different exposures and performing motion alignment and exposure processing on the first and second input images, setting an index according to an exposure difference between the first input image and the second input image and generating a compensated image by compensating for an exposure of the first input image, combining the compensated image and the second input image using the luminance information of the second input image on a basis of luminance regions, and generating low dynamic range (LDR) images by compressing the combined image on a basis of the luminance regions, wherein the LDR images include a high-luminance compressed image and a low-luminance compressed image, and combining the LDR images using the luminance information of the second input image.
[0020] The generating of the LDR images may comprise generating fusion-weighted images from the luminance information of the second input image with respect to the second input image and the image generated from the first input image, and generating the combined image by combining over-exposed regions and under-exposed regions of the images using the fusion-weighted images, and generating the LDR images by compressing the combined image based on the over-exposed region and the under-exposed region such that the entire luminance range of the generated LDR images is the same as that of the image generated by the broadband image fusion unit.
[0021] The combining of the LDR images may include generating region-weighted images for an over-exposed region and an under-exposed region using the luminance information of the second input image and combining the high-luminance compressed image and the low-luminance compressed image using the generated region-weighted images.
[0022] The image fusion method may further comprise generating fusion-weighted images for extracting predetermined luminance regions from the respective first input image and second input image according to the corresponding exposures, generating region-weighted images for extracting predetermined luminance regions from the respective high luminance compressed image and low luminance compressed image, and performing contrast enhancement, increase of luminance in an under-exposed region, and halo artifact reduction on each of the high luminance compressed image and the low luminance compressed image.
[0023] In another aspect, there is provided an image generator to generate a combined image, the image generator comprising a first image fusion unit configured to receive a plurality of high dynamic range (HDR) images each with a different exposure, and configured to compress the plurality of HDR images into a plurality of low dynamic range (LDR) images based on a luminance of each HDR image, and a second image fusion unit configured to combine the plurality of LDR images into a combined image, and configured to output the combined image.
[0024] The first image fusion unit may compress two HDR images such that the first HDR image is compressed to a first luminance range and the second HDR image is compressed to a second luminance range that partially overlaps the first luminance range.
[0025] The plurality of HDR images may include a first HDR image comprising an over-exposed region and a second HDR image comprising an under exposed region, and the first image fusion unit ma compress the first image to a first luminance range of values and may compress the second image to a second luminance range of values that are less in value than the first luminance range of values.
[0026] The image generator may further comprise an exposure compensating unit configured to compensate the exposure of at least one of the plurality of HDR images, wherein the plurality of images may include a first image and a second image that have different exposures, the exposure compensating unit may set an index corresponding to an exposure difference between the first image and the second image, and the exposure compensating unit may compensate for the exposure of the first image using the index to generate a compensated image.
[0027] The image generator may further comprise a high luminance restoring unit configured to restore color to at least one of the plurality of HDR images, wherein the high luminance restoring unit may restore color to a region of an image that is brighter than a predetermined luminance.
[0028] The image generator may further comprise a region weight calculating unit configured to divide each of the plurality of HDR images into regions based on the luminance level of each region, and configured to generate region weighted images that represent each of the divided regions of each respective HDR image.
[0029] In another aspect, there is provided an image processing apparatus comprising an image obtaining and processing unit configured to capture a plurality of HDR images having different exposures, an image generating unit configured to compress the plurality of HDR images into a plurality of low-dynamic range (LDR) images based on a luminance of each HDR image, and configured to combine the plurality of LDR images into a combined image, and an image output unit configured to output the combined image.
[0030] The generating unit may compress two HDR images such that the first HDR image is compressed to a first luminance range and the second HDR image is compressed to a second luminance range that partially overlaps the first luminance range.
[0031] The plurality of captured HDR images may include a first HDR image comprising an over-exposed region and a second HDR image comprising an under exposed region, and the image generating unit may compress the first HDR image to a first luminance range of values and may compress the second HDR image to a second luminance range of values that are less in value than the first luminance range of values.
[0032] The image generating unit may comprise a first image fusion unit configured to receive the plurality of HDR images having different exposures, and configured to compress the plurality of HDR images into the plurality of LDR images based on a luminance of each HDR image, and a second image fusion unit configured to combine the plurality of LDR images into a combined image, and configured to output the combined image.
[0033] Other features and aspects will be apparent from the following detailed description, the drawings, and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] FIG. 1 is a diagram illustrating an example of an image fusion apparatus.
[0035] FIG. 2 is a diagram illustrating an example of an image generating unit.
[0036] FIG. 3 is a diagram illustrating another example of an image generating unit.
[0037] FIG. 4 is a graph illustrating an example of how exposure difference compensation is performed in an exposure compensating unit.
[0038] FIG. 5 is a diagram illustrating an example of a first image fusion unit.
[0039] FIG. 6 is a diagram illustrating an example of a luminance range of an image compressed by a compressed image generating unit.
[0040] FIG. 7A is a diagram illustrating an example of an image compressed based on an over-exposed region by the compressed image generating unit.
[0041] FIG. 7B is a diagram illustrating an example of an image compressed based on an under-exposed region by the compressed image generating unit.
[0042] FIG. 8 is a flowchart of an example of an image fusion method.
[0043] FIG. 9 is a diagram illustrating an example of images generated by an image fusion apparatus to generate an output image.
[0044] Throughout the drawings and the detailed description, unless otherwise described, the same drawing reference numerals will be understood to refer to the same elements, features, and structures. The relative size and depiction of these elements may be exaggerated for clarity, illustration, and convenience.
DETAILED DESCRIPTION
[0045] The following description is provided to assist the reader in gaining a comprehensive understanding of the methods, apparatuses, and/or systems described herein. Accordingly, various changes, modifications, and equivalents of the methods, apparatuses, and/or systems described herein will be suggested to those of ordinary skill in the art. Also, descriptions of well-known functions and constructions may be omitted for increased clarity and conciseness.
[0046] FIG. 1 illustrates an example of an image fusion apparatus.
[0047] Referring to FIG. 1 , the image fusion apparatus includes an image capturing unit 100 , a motion aligning unit 110 , a scene analyzing unit 120 , an exposure processing unit 130 , an image generating unit 140 , and an image output unit 150 . As described herein, the image fusion apparatus may be used to process images and may also be referred to as an image processor. The image fusion apparatus may be included in or may be a camera, a terminal, a mobile phone, and the like.
[0048] The image capturing unit 100 receives a high dynamic range (HDR) image or a plurality of images captured with different exposures from an image sensor or a camera.
[0049] The captured images may be processed by the motion aligning unit 110 to perform motion alignment. For example, the motion alignment may be in response to inter-frame global motion and object motion that may occur in the captured images. By performing the motion alignment processing, image overlap may be prevented.
[0050] The scene analyzing unit 120 analyzes a scene, for example, based on image data and information of exposure during image acquisition. If desired, the exposure processing unit 130 performs an exposure compensation process to produce an image with the same exposure or approximately the same exposure as image data obtained with an appropriate exposure.
[0051] In response to the scene analysis result, the scene analyzing unit 120 and the exposure processing unit 130 may perform exposure compensation on an image obtained with an inappropriate exposure. For example, the scene analyzing unit 120 and the exposure processing unit 130 may perform exposure compensation on an image having a saturated luminance region. In this example, if RAW data that is generated by an image sensor and has a linear input-output relationship is used, accurate exposure compensation may be realized.
[0052] The scene analyzing unit 120 and the exposure processing unit 130 may perform detail enhancement processing, in addition to the exposure compensation processing, using an unsharp masking method, for example, as in Equation 1 below.
[0000] p′ k ( i,j )= P k ( i,j )− a ( i,j )· p k ( i,j )·(1−ε)
[0000] k=R,G,B
[0000] p k (i,j): blurred version P k (i,j)
[0000] α: unsharp coefficient
[0000] ε: exposure ratio (1)
[0053] The image capturing unit 100 , the motion aligning unit 110 , the scene analyzing unit 120 , and the exposure processing unit 130 may be implemented separately according to their functionality as shown in the example illustrated in FIG. 1 . However, it should also be appreciated that two or more of these units may be implemented as a single unit such as an image obtaining and processing unit 160 that obtains images with different exposures and performs image processing such as motion alignment, exposure processing, and/or detail enhancement to produce images to be combined.
[0054] The image generating unit 140 combines the images that have undergone the above is image processing, compresses the combined images to a low dynamic range (LDR) to generate LDR images, and synthesizes the LDR images to generate an output image. For example, if the image generating unit 140 receives an HDR image, the motion alignment processing by the motion aligning unit 110 and the image synthesis processing by the image generating unit 140 may be omitted.
[0055] The image generating unit 140 may perform the synthesis processing, for example, using camera output red, green, blue (RGB) data or image sensor RAW data. The output image generated by the image generating unit 140 is displayed through the image output unit 150 .
[0056] FIG. 2 illustrates an example of an image generating unit.
[0057] Referring to FIG. 2 , the image generating unit 140 includes a first image fusion unit 200 and a second image fusion unit 210 . The image generating unit may also be referred to as an image processor.
[0058] For example, the first image fusion unit 200 may generate HDR data using n input images (where n is an integer) with different exposures and exposure information of each input image. For example, the first image fusion unit 200 may generate m LDR images (where m is an integer) for each luminance interval using the HDR data. The second image fusion unit 210 may combine the m LDR images spatially to generate an output image. As another example, the first image fusion unit 200 and the second image fusion unit 210 may use image sensor RAW data in addition to camera output RGB data.
[0059] FIG. 3 illustrates another example of an image generating unit.
[0060] Referring to FIG. 3 , in this example, the image generating unit 140 further includes an exposure compensating unit 300 , a high luminance restoring unit 310 , a fusion weight calculating unit 320 , a region weight calculating unit 330 , and a post-processing unit 340 in addition to the first image fusion unit 200 and the second image fusion unit 210 which are illustrated in FIG. 2 .
[0061] FIG. 3 illustrates an example for processing and synthesizing a first input image (represented as “EXPOSURE 1 IMAGE” in FIG. 3 ) and a second input image (represented as “EXPOSURE 2 IMAGE” in FIG. 3 ) which are obtained with different exposures.
[0062] The exposure compensating unit 300 may set an index corresponding to an exposure difference between images, for example, the first input image and the second input image, and may compensate for the exposure of one or more images, for example, the first input image using the index to generate a compensated image.
[0063] FIG. 4 is a graph that illustrates how exposure difference compensation is performed in an exposure compensating unit, for example, the exposure compensating unit illustrated in FIG. 3 .
[0064] Referring to FIG. 4 , for example, a lower luminance threshold (represented as “LOWER TH” in FIG. 4 ), an upper luminance threshold (represented as “UPPER TH” in FIG. 4 ), and a maximum luminance (represented as “MAX” in FIG. 4 ) may be calculated using a luminance mean value and a luminance maximum value in the first input image (EXPOSURE 1 IMAGE in FIG. 3 ). An index may be set in consideration of an exposure difference between the first input image and the second input image. The exposure difference may be compensated by remapping the first input image that was obtained with a smaller exposure using the index.
[0065] The high luminance restoring unit 310 may restore color information of a region of one or more the input images. For example the high luminance restoring unit 310 may restore color information of a region of the second input image with reference to a color ratio of the first input image. For example, the high luminance restoring unit 310 may restore color of a region that is brighter than a predetermined luminance.
[0066] For example, if the first input image and the second input image are obtained from the same scene but with different exposures, and saturation occurs in an over-exposed region of the second input image due to increase of the quantity of incident light and no saturation occurs in an over-exposed region of the first input image, the over-exposed region of the second input image that is brighter than a predetermined luminance may have its color information restored with reference to a color ratio of the corresponding region of the first input image.
[0067] The first image fusion unit 200 may combine the second input image and the image generated by the exposure compensating unit 300 for each luminance region according to the luminance information of the second input image.
[0068] FIG. 5 illustrates an example of a first image fusion unit.
[0069] Referring to FIG. 5 , first image fusion unit 200 includes a broadband image fusion unit 500 and a compressed image generating unit 510 .
[0070] The broadband image fusion unit 500 may generate fusion-weighted images based on luminance information. For example, the broadband image fusion unit 500 may generate fusion-weighted images based on luminance information of the second input image with respect to the image generated by the exposure compensating unit 300 and the second input image. For example, the broadband image fusion unit 500 may generate HDR data by synthesizing an over-exposed region of the image generated by the exposure compensating unit 300 and an under-exposed region of the second input image using the corresponding fusion-weighted images.
[0071] For example, the fusion-weighted images may be generated directly by the broadband image fusion unit 500 of the first image fusion unit 200 . As another example, the fusion-weighted images may be generated directly from luminance information of the two input images using a separate unit such as the fusion weight calculating unit 320 shown in the example illustrated in FIG. 3 .
[0072] The first image fusion unit 200 may use the luminance information of the second input image to obtain a weighted average of each pixel, and may generate fusion-weighted images for the respective first and second input images.
[0073] Using the fusion-weighted images, the over-exposed regions and the under-exposed regions of the input images may be combined with each other, and HDR data may be generated from the combined images.
[0074] For example, the weighted average may be calculated using a contrast blending method.
[0075] The compressed image generating unit 510 may generate images by compressing the combined image. For example, the compressed image generating unit 510 may compress the combined image based on the over-exposed region and the under-exposed region, for example, such that the entire luminance range of the generated compressed images is the same as that of the image generated by the broadband image fusion unit 500 .
[0076] FIG. 6 illustrates an example of luminance ranges of images generated by a compressed image generating unit.
[0077] Referring to FIG. 5 and FIG. 6 , the compressed image generating unit 510 may compress the HDR data generated by the broadband image fusion unit 500 such that margin values (the maximum value and the minimum value) of a luminance range of the HDR data are mapped to margin values (the maximum value and the minimum value) of luminance ranges of the compressed images (denoted by “LDR IMAGE 1 ” and “LDR IMAGE 2 ”) generated by the compressed image generating unit 510 .
[0078] FIG. 7A illustrates an example of an image compressed based on the over-exposed region by a compressed image generating unit. FIG. 7B illustrates an example of an image compressed based on the under-exposed region by a compressed image generating unit.
[0079] The example shown in FIG. 7A may correspond to the high luminance compressed image LDR IMAGE 1 shown in FIG. 6 , and the example shown in FIG. 7B may correspond to the low luminance compressed image LDR IMAGE 2 shown in FIG. 6 .
[0080] Region 700 shown in FIG. 7A corresponds to an over-exposed region in which a high-luminance region appears. Region 710 shown in FIG. 7B corresponds to an under-exposed region in which a low-luminance region appears.
[0081] For example, the images combined by the first image fusion unit 200 may be transmitted to the post-processing unit 340 (see FIG. 3 ). Accordingly, the post-processing unit 340 may perform various processes on the compressed images. For example, the post-processing unit 341 may process the high luminance compressed image LDR IMAGE 1 and the low luminance compressed image LDR IMAGE 2 , which are generated by the first image fusion unit 200 , in order to improve image quality of an output image.
[0082] For example, the images LDR IMAGE 1 and LDR IMAGE 2 from the first image fusion unit 200 may undergo additional post-processing as described herein, and a variety of methods may be used to improve the quality of an output image.
[0083] For example, the post-processing may include contrast enhancement, increase of luminance in an under-exposed region, halo artifact reduction, and the like.
[0084] In the example shown in FIG. 7A , a region other than the region 700 may correspond to an under-exposed region, and thus, it may be difficult for shapes of objects present in the under-exposed region to be clearly seen. Therefore, to enhance image quality of a final output image, luminance of the under-exposed region may be improved before image synthesis.
[0085] For example, the luminance of the under-exposed region in the high luminance compressed image shown in FIG. 7A may be increased using the weighted image for increasing the luminance of the under-exposed region.
[0086] As another example, the low luminance compressed image shown in FIG. 7B is blurry, and thus, shapes of objects present in the image are not distinct. In this example, to improve the image quality of a final output image, sharpness of outlines of the objects present in the low luminance compressed image may be increased before image synthesis.
[0087] For example, halo artifact reduction may be performed on the image using the weighted image for improving the sharpness of outlines of the objects in the low luminance image shown in FIG. 7B .
[0088] Over-exposed regions of each of the weighted image for increasing the luminance of the under-exposed region and the weighted image for improving sharpness of outlines are portions to which the weight may be applied. Regions of the original images LDR IMAGE 1 and LDR IMAGE 2 corresponding to the over-exposed regions of the respective weighted images may be applied with the weights to enhance the image quality.
[0089] After the post-processing, the LDR images may be combined together to generate a final output image.
[0090] For example, the second image fusion unit 210 may generate an output image by combining the high luminance compressed image LDR IMAGE 1 and the low luminance is compressed image LDR IMAGE 2 using LDR image fusion. In the course of LDR image fusion processing, an image which has a weighted region is generated. For example, a weighted image may be generated directly by the second image fusion unit 210 , or may be generated by the region weight calculating unit 330 as shown in the example illustrated in FIG. 3 .
[0091] The region weight calculating unit 330 may divide an image into regions according to luminance level, and may generate region-weighted images which are aimed at representing detail in each divided region as distinctly as possible with high contrast. For example, the region weight calculating unit 330 may divide each image received by the image generating unit 140 into various regions based on luminance.
[0092] For example, the region weight calculating unit 330 may create region-weighted images, respectively, for an over-exposed region and an under-exposed region using luminance information of the second input image.
[0093] In response to the receipt of the high luminance compressed image shown in FIG. 7A and the low luminance compressed image shown in FIG. 7B , the second image fusion unit 210 may generate an output image by combining the high luminance compressed image and the low luminance compressed image using the region-weighted images generated by the region weight calculating unit 330 .
[0094] For example, an image which is based on region 700 of the high luminance compressed image illustrated in FIG. 7A may be extracted from an over-exposed region of the region-weighted image for combining the high luminance images. The image has an over-exposed region represented clearly.
[0095] Thereafter, an image which is based on region 710 of the low luminance compressed image illustrated in FIG. 7B may be extracted from an over-exposed region of the region-weighted image for combining the low luminance images. The image has an under-exposed region represented clearly.
[0096] The extracted images may be combined to generate an output image. For example, when an image is divided into two or more regions and the regions are combined, the regions may be divided according to a variable luminance threshold.
[0097] FIG. 8 illustrates an example of an image fusion method.
[0098] Referring to FIG. 8 , a first input image and a second input image are acquired with different exposures from the same object, and image processing operations such as motion alignment, exposure compensation, and/or detail enhancement are performed on the first and second input images to generate images appropriate to image fusion, in 800 .
[0099] An index is set according to an exposure difference between the first input image and the second input image, and an image in which the exposure of the first input image is compensated is generated, in 810 .
[0100] The second input image and an image generated using the luminance information of the second input image are combined together on the basis of luminance regions, and the combined images are compressed on the basis of the luminance regions, in 820 .
[0101] The compressed images are combined together to generate an output image, in 830 . The output image is displayed.
[0102] FIG. 9 illustrates an example of images generated by an image fusion apparatus to generate an output image.
[0103] For example, HDR data may be generated from a first input image (EXPOSURE 1 IMAGE) and a second input image (EXPOSURE 2 IMAGE) through the above described exposure compensating unit 300 , high luminance restoring unit 310 , and first image fusion unit 200 . The LDR images (LDR IMAGE 1 and LDR IMAGE 2 ) may be generated by compressing the HDR data on the basis of the luminance. From the generated LDR images (LDR IMAGE 1 and LDR IMAGE 2 ), a final output image may be generated through the post-processing unit 340 and the second image fusion unit 210 .
[0104] The methods, processes, functions, and software described above may be recorded, stored, or fixed in one or more computer-readable storage media that includes program instructions to be implemented by a computer to cause a processor to execute or perform the program instructions. The media may also include, alone or in combination with the program instructions, data files, data structures, and the like. The media and program instructions may be those specially designed and constructed, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable storage media include magnetic media, such as hard disks, floppy disks, and magnetic tape; optical media such as CD ROM disks and DVDs; magneto-optical media, such as optical disks; and hardware devices that are specially configured to store and perform program instructions, such as read-only memory (ROM), random access memory (RAM), flash memory, and the like. Examples of program instructions include machine code, such as produced by a compiler, and files containing higher level code that may be executed by the computer using an interpreter. The described hardware devices may be configured to act as one or more software modules in order to perform the operations and methods described above, or vice versa. In addition, a computer-readable storage medium may be distributed among computer systems connected through a network and computer-readable codes or program instructions may be stored and executed in a decentralized manner.
[0105] As a non-exhaustive illustration only, the terminal device described herein may refer to mobile devices such as a cellular phone, a personal digital assistant (PDA), a digital camera, a portable game console, an MP3 player, a portable/personal multimedia player (PMP), a handheld is e-book, a portable lab-top personal computer (PC), a global positioning system (GPS) navigation, and devices such as a desktop PC, a high definition television (HDTV), an optical disc player, a setup box, and the like, capable of wireless communication or network communication consistent with that disclosed herein.
[0106] A computing system or a computer may include a microprocessor that is electrically connected with a bus, a user interface, and a memory controller. It may further include a flash memory device. The flash memory device may store N-bit data via the memory controller. The N-bit data is processed or will be processed by the microprocessor and N may be 1 or an integer greater than 1. Where the computing system or computer is a mobile apparatus, a battery may be additionally provided to supply operation voltage of the computing system or computer.
[0107] It should be apparent to those of ordinary skill in the art that the computing system or computer may further include an application chipset, a camera image processor (CIS), a mobile Dynamic Random Access Memory (DRAM), and the like. The memory controller and the flash memory device may constitute a solid state drive/disk (SSD) that uses a non-volatile memory to store data.
[0108] A number of examples have been described above. Nevertheless, it will be understood that various modifications may be made. For example, suitable results may be achieved if the described techniques are performed in a different order and/or if components in a described system, architecture, device, or circuit are combined in a different manner and/or replaced or supplemented by other components or their equivalents. Accordingly, other implementations are within the scope of the following claims. | Provided are an image fusion apparatus and method for combining multi-exposure images. The image fusion apparatus and method may generate a sharp high-resolution high dynamic image while fully representing detail in an over-exposed region and an under-exposed region of the image without contrast degradation. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority under 35 U.S.C. § 119(e) to provisional application, No. 60/346,122, filed Oct. 19, 2001, the contents of which is expressly incorporated herein by referenced as though fully set forth in full.
BACKGROUND
1. Field
The present invention relates generally to storage containers, and more particularly, to storage containers for recorded media.
2. Background
In recent years, optical discs have emerged as one of the most popular mediums for storing audio, video and computer information. To accommodate the wholesale and retail distribution of the disc, numerous storage containers have been developed. These storage containers typically include a base supporting a central hub to engage an aperture in the center of the disc. The base is generally hinged to a lid so as to open and close the storage container like a book. This design is well suited for use by the consumer, but may pose certain security risks in the retail environment. In the recent years, retailers have reported numerous incidents of theft involving the unauthorized removal of discs from the their storage containers. Labels and shrink wrap have been proposed in the past as a way to deal with this problem. However, these proposals have had limited success because of the ease at which labels and shrink wrap can be opened with a sharp item. Accordingly, there is a need for a storage container which is designed to discourage theft in the retail environment.
SUMMARY
In one aspect of the present invention, a storage container includes a lid having a lid panel and an arm extending from the lid panel, the arm including a detent having a first surface parallel to the lid panel and a second surface having a taper extending at least a portion between the first surface and a distal end of the arm, and a base configured to receive a disc, the base having a base panel and a member extending from the base panel, the member having an opening defined by an interior surface having a portion thereof parallel to the base panel, the first surface of the detent engaging the interior surface portion of the member when the storage container is closed.
In another aspect of the present invention, a storage container includes a lid, a base configured to receive a disc, and means for latching the lid to the base to close the storage container.
In yet another aspect of the present invention, a storage container includes a lid, a base having an annular wall configured to support an outer periphery of a disc, means for latching the lid to the base to close the storage container, means for clamping the outer periphery of the disc to the annular wall when the storage container is closed, and means, coupled to the lid, for preventing the disc from sliding out of the storage container.
It is understood that other aspects of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein is shown and described only exemplary embodiments of the invention, simply by way of illustration. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various 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
Aspects of the present invention are illustrated by way of example, and not by way of limitation, in the accompanying drawings in which like reference numerals refer to similar elements:
FIG. 1 is a perspective view of an exemplary storage container;
FIG. 1A is a blow up of a portion of the exemplary storage container of FIG. 1 illustrating the detail of a tab;
FIG. 1B is a blow up of a portion of the exemplary storage container of FIG. 1 illustrating the details of a catch;
FIG. 2 is a cross-section view of the exemplary storage container of FIG. 1 taken along line 2 with a disc shown prior to engagement with a hub;
FIG. 3 is a cross-section view of the exemplary storage container of FIG. 1 taken along line 2 with a disc shown in engagement with the hub;
FIG. 4 is a perspective view of an exemplary storage container in the closed position;
FIG. 5 is a cross-section view of the exemplary storage container of FIG. 4 taken along lines 5 ;
FIG. 6 is a perspective view of a portion of an exemplary storage container illustrating the details of a tab and catch latching mechanism;
FIG. 7 is a cross-section view of the tab and catch latching mechanism of FIG. 6 taken along line 7 showing the tab just prior to engagement with the catch;
FIG. 8 is a cross-section view of the tab and catch latching mechanism of FIG. 6 taken along line 7 showing the tab engaged with the catch;
FIG. 9 is a perspective view of a portion of an exemplary storage container illustrating the details of a break away tab hinged to the storage container; and
FIG. 10 is an exploded perspective view of the exemplary storage container of FIG. 9 illustrating the insertion of the break away tab into the exemplary storage container after the hinge connection is broken.
DETAILED DESCRIPTION
The detailed description set forth below in connection with the appended drawings is intended as a description of exemplary embodiments of the present invention and is not intended to represent the only embodiments in which the present invention can be practiced. The term “exemplary” used throughout this description means “serving as an example, instance, or illustration,” and should not necessarily be construed as preferred or advantageous over other embodiments. The detailed description sets forth the inventive concepts in terms of construction and function of the exemplary storage containers. It is to be understood, however, that the same, equivalent, and alternative constructions and functions may be accomplished with other storage containers which are also intended to be encompassed within the spirit and scope of the invention.
As used herein, the term “optical disc” or “disc” means any compact disc (CD), compact disc read only memory (CD-ROM), recordable compact disc (CD-R), rewriteable compact disc (CD-RW), digital video disc or digital versatile disc (DVD), recordable digital video disc or recordable digital versatile disc (DVD-R), digital video disc random access memory or digital versatile disc random access (DVD-RAM), as well as other similar media which is used for storing information.
A perspective view of an exemplary storage container is shown in FIG. 1 . The exemplary storage container includes several security features that are particularly useful for these types of containers in the retail environment. However, as those skilled in the art will appreciate, these security features are equally applicable to any type of storage container regardless of the contents. In the described exemplary embodiment, the storage container comprises a housing 12 including a lid 14 and a base 16 . The lid 14 may include a pair of clips 15 to hold pamphlets, brochures, booklets, or other printed media. The lid 14 can be attached to the base 16 in a variety of ways. By way of example, a hinge panel 18 can be attached to the lid 14 with a first living hinge 20 and attached to the base 16 with a second living hinge 22 . Various other means for attaching the lid 14 to the base 16 will be readily apparent to those skilled in the art.
The base 16 includes a base panel 24 with a peripheral base wall 26 extending along the three sides of the base panel not attached to the living hinge 22 . The base panel 24 includes an annular wall 28 to support the disc away from the base panel 24 . The annular wall 28 can be designed with a seat 30 that supports the unrecorded outer edge of the disc. The annular wall 28 may further be equipped with any number of finger holes to facilitate the removal of the disc from the storage container. In the described exemplary embodiment, there are four finger holes 32 equally spaced from one another along the circumference of the annular wall 28 . However, as those skilled in the art will readily appreciate, any number of finger holes can be used depending on the particular design requirements and manufacturing specifications. The finger hole design can take on various forms. By way of example, convex or semi-circular recesses in the annular wall 28 can be used to provide easy access to the periphery of the disc during the removal process.
A retaining member 34 extending upward from base panel 24 can be used to engage the central aperture of the disc. The retaining member 34 can be designed in any fashion that sufficiently retains the disc in the storage container. One such design includes an annular ring 36 which supports the unrecorded inner edge of the disc adjacent the central aperture. The annular ring 36 and the annular wall 28 cooperate to maintain the disc in the storage container away from the base panel 24 . Cantilevered from the annular ring 36 are six inwardly extending radial arms 38 which collectively form a hub. As best seen in FIGS. 2 and 3, the hub includes an upper surface 40 with an outwardly extending lip 42 which overlies the unrecorded inner edge of the disc when retained by the hub.
To engage the disc with the retaining member 34 , the disc is placed inside the storage container with its outer edge over the seat 30 of the annular wall 28 and its center aperture over the upper surface 40 of the hub (see FIG. 1 ). The placement of the disc over the hub prior to engagement is shown in FIG. 2 . The disc 44 can be manually pressed by the user toward the base panel 24 until the inner edge of the disc 44 defining the center aperture slides over the lip 40 and into engagement with the hub as shown in FIG. 3 . Referring to FIG. 3, the disc 44 can be removed from the retaining member 34 by applying a downward force to the upper surface 40 of the hub to force the lip 40 downward through the center aperture of the disc to free the disc from the retaining member 34 . An attractive feature of the retaining member design is that the annular ring 36 prevents the downward movement of the inner edge of the disc 44 despite any downward movement of the hub. This approach prevents the disc 44 from being damaged due to undesirable flexing of the disc 44 during removal.
Referring back to FIG. 1, the lid 14 includes a lid panel 46 with a peripheral lid wall 48 extending along the three sides of the lid panel 46 not attached to the living hinge 20 . A lip 50 can be formed at a distal end of an interior portion of the peripheral lid wall 48 on each side of the storage container. A rail 52 can be positioned on each side of the storage container along the base panel 24 each which cooperates with the peripheral base wall 26 to form a nesting slot for a respective one of the lips 50 . In at least one embodiment of the storage container, the lips 50 can be configured with a concave design that extends close to or all the way to the base panel 24 when the storage container is in the closed position. This arrangement may prevent the disc from sliding out of the storage container should the disc become dislodged. The concave design of the lips 50 may also make it more difficult for one to remove the disc from the storage container through a gap between the peripheral base and lid walls when the storage container is in the closed position. These attendant benefits may be achieved with other lip designs without departing from the inventive concepts described herein. By way of example, the lips 50 can be rectangular, triangular, or any other design which covers at least a portion of the gap formed between the peripheral base and lid walls when the storage container is in the closed position.
The storage container may be equipped with additional features that maintain the disc in engagement with the hub during transportation and handling of the closed storage container. The lid 14 may include tabs 54 which engage the outer edge of the disc when the storage container is in the closed position. Each tab can be supported by the lid panel 46 and includes a surface which extends inwards toward the center of the lid 14 and away from the peripheral lid wall 48 . Alternatively, each tab can be configured as a flat member extending directly from the front portion of the peripheral lid wall 48 inward toward the center of the lid 14 .
The tabs 54 can be designed to work alone, or alternatively, in combination with other structures to maintain the disc in engagement with the hub when the storage container is in the closed position. By way of example, the hinge panel 18 can be configured with a reinforcing rib 56 that not only increases the structural strength of the hinge panel 18 , but can be used to further maintain the disc in engagement with the hub when the storage container is in the closed position. This can be accomplished with a variety of rib designs depending on the aesthetic criteria for the storage container. By way of example, the reinforcing rib 56 can extend inwardly from the hinge panel 18 a sufficient length such that, when the storage container is in the closed position, the reinforcing rib 56 extends over the annular wall 28 and engages the unrecorded upper surface of the disc. The reinforcing rib 56 can be designed with a semi-circular recess or convex configuration for alignment with the seat 30 of the annular wall 28 to avoid placing undue stress on portions of the disc unsupported by the seat 30 .
FIG. 4 is a perspective view of an exemplary storage container in the closed position. FIG. 5 is a cross-section view of the exemplary storage container of FIG. 4 taken along line 5 . The manner in which the reinforcing rib 56 cooperates with the tabs 54 of the lid 14 to effectively clamp the outer edge of the disc to the seat 30 of the annular wall 28 is shown in FIG. 5 . In at least one embodiment of the storage container, the tab 54 can be formed with a 58 at its distal end. As shown in FIG. 5, with the storage container in the closed position, the tab 54 extends over the annular wall 28 of the base panel 24 such that the ridge 58 engages the unrecorded upper surface of the disc to securely lodge the disc between the ridge 58 and the seat 30 of the annular wall 28 . In a similar manner to the reinforcing rib 56 , the ridge 58 can be formed with an arc shape that is aligned with the seat 30 of the annular wall 28 when the storage container is in the closed position to avoid flexing the disc by placing a downward force on a portion of the disc unsupported by the seat 30 . The ridge design minimizes surface contact between the tabs and the disc. In addition, the ridge design may provide for a tighter grip on the disc since the tabs have to be located sufficiently above the disc when the storage container is in the closed position to clear the annular wall 28 . Alternatively, the tabs can be used to directly to secure the disc to the seat 30 of the annular wall 28 .
The storage container may also be equipped with a latching mechanism to discourage the unauthorized removal of the disc from the storage container during retail distribution. The latching mechanism may take on various forms depending on the overall design constraints and security objectives. By way of example, the latching mechanism can be designed in a manner that requires a significant amount of force to open the storage container. Numerous techniques may be employed to implement this type of latching mechanism. These techniques can range from a single latch to any number of latches working together to achieve a storage container which cannot be easily open without exerting considerable force.
An exemplary latching mechanism for a storage container is shown in FIG. 1 . The exemplary latching mechanism includes tabs 60 supported by the lid 14 in combination with catches 62 supported by the base 16 . The tabs 60 can be designed in various fashions depending on the design specifications and other relevant factors. In the described exemplary embodiment, the tabs 60 are fairly rigid members supported by the lid panel 46 . Increased rigidity may be achieved with a pair of reinforcing ribs 61 on each of the tabs 60 . As best seen by FIG. 1A, a detent 64 can be located at the distal end of the tab 60 . The detent 64 includes a tapered surface 65 with an undercut wall 67 . The catches 62 are also fairly rigid members extending from the base panel 24 (see FIG. 1 ). As best seen in FIG. 1B, the catch 62 includes a catch member 64 with an aperture 66 formed therein for catching the detent 64 of the tab 60 when the storage container is being closed. A support member 68 extending upward from the base panel between the aperture 66 and the peripheral base wall 26 is used to maintain rigidity of the catch 62 when the storage container is being opened and closed.
FIG. 6 is a perspective view of the tab and catch just prior to engagement as the exemplary storage container is being closed. FIG. 7 is a cross-section view of the exemplary storage container of FIG. 6 taken along line 7 . As shown in FIGS. 6 and 7, when the storage container is being closed by the user, the tapered upper surface of the detent 65 comes into contact with the upper portion of the catch member 64 . Since the tab 60 and the catch 62 are fairly rigid, the user must increase the force applied to the base and lid to bring them together to cause either the tab 60 to flex slightly backward and/or cause the catch member 64 to flex slightly forward against the support member 68 to allow the tapered upper surface of the detent 65 to slide past the exterior upper portion of the catch member 64 and snap into the aperture 66 with the undercut wall 67 facing the interior upper portion of the catch member 64 as shown in FIG. 8 . FIG. 8 is a cross-section view of the exemplary storage container of FIG. 6 taken along line 7 with the exemplary storage container in the closed position. Because of the undercut wall 67 of the detent 60 , the force to open the storage container is even greater than that required to close the storage container. To open the container, the user applies a force to the base and lid to separate them from one another. In a manner similar to that described in connection with the closing of the storage container, the applied force to the storage container must be sufficient to cause either the tab 60 to flex slightly backward and/or cause the catch member 64 to flex slightly forward against the support member 68 . However, in this case, since the undercut wall 67 of the detent 64 is not tapered, the force required to flex the tab 60 backward and/or the catch member 64 forward against the support member 68 to allow the detent 64 to clear the catch member 64 and release it from the aperture is much greater. This increased force to open the storage container may discourage the unauthorized opening of the storage container in the retail environment.
The amount of force required to open and close the storage container can be varied by altering the design the reinforcing ribs on the tab or the support member for the catch. The tabs may be designed with a support member similar to that used for catches, either alone or in combination with the reinforcing ribs, to set the amount of force required to open and close the storage container. The rigidity of the material used for the tabs and catches can also be varied. One skilled in the art will readily be able to determine the material needed for the tabs and catches, and the designs of the supporting structures, if any, to meet the specific design requirements of any particular application.
Returning to FIG. 4, the exemplary storage container can be configured with a pair of removable tabs 72 a and 72 b . During retail distribution of the storage container, the removable tabs are in the closed position as shown by the removable tab 72 a . Once the storage container is removed from the retail environment, it can be opened by first moving removable tabs to the open position as shown by the removable tab 72 b . Once the removable tabs are moved to the open position, the storage container can then be opened by separating the base 16 from the lid 14 . As best shown in FIG. 9, the removable tab can be moved between the open and closed position via a break-away hinge 74 connecting the removable tab to the base 16 . The removable tab 72 is generally square or rectangular shape with an arm 76 extending from an interior portion of the removable tab. The removable tab 72 may also include four prongs 78 with two projecting from each side of the interior portion. When the removable tab 72 is in the closed position, the arm 76 extends through a center slot 80 formed in the peripheral lid wall 48 and the prongs 78 straddle a horizontal bar 81 extending through the peripheral lid wall 48 . This configuration may provide heightened security in the retail environment by making it more difficult to open the storage container without authorization.
Once the storage container is removed from the retail environment by the consumer, the removable tab 72 can be opened and separated from the base 16 by applying an upward or twisting force to the removable tab 72 to break the hinge connection. The removable tab 72 can then be physically rotated 180° with respect its original position and reinserted into the front portion of the peripheral lid and base walls as shown in FIG. 10 . In this position, the arm 76 extends through the aperture 66 in the catch member 64 forcing the detent 64 of the tab 60 out of the aperture 66 to allow the consumer to easily open the storage container by merely applying a force to separate the base 16 from the lid 14 sufficient to overcome the insertion force of any other commonly known latches employed by the storage container. Each prong 78 may be formed with a detent 84 having a tapered surface with an undercut. When the removable tab 72 is being inserted into the front portion of the peripheral lid and base walls, the tapered portion of the detents 84 rides against interior walls 86 of the peripheral base wall 24 hereby flexing the prongs 78 toward one another. Once the detents 84 clear the interior walls 86 , the prongs 78 revert to their non-flexed state with the undercut of the detents 84 engaging the ends of the interior walls 86 . This arrangement holds the removable tabs in place once the hinges have been broken away from the base 16 .
Returning to FIG. 4, the peripheral base and lid walls 24 and 48 can be formed with slightly concave portions in the front portion. This arrangement provides an area where one can grasp the base and lid to open the storage container. These concave portions may be particularly useful to a consumer opening a storage container that does not have removable tabs that disable the latching mechanism.
Although exemplary embodiments of the present invention has been described, it should not be construed to limit the scope of the appended claims. Those skilled in the art will understand that various modifications may be made to the described embodiments. By way of example, any feature of the exemplary storage containers can be employed alone or in combination with one or more features. Moreover, to those skilled in the various arts, the inventive features described throughout can be employed with storage containers for other devices such as video cassettes and the like. It is therefore desired that the present embodiments be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than the foregoing description to indicate the scope of the invention. | A storage container includes a lid having a lid panel and an arm extending from the lid panel, the arm including a detent having a first surface parallel to the lid panel and a second surface having a taper extending at least a portion between the first surface and a distal end of the arm, and a base configured to receive a disc, the base having a base panel and a member extending from the base panel, the member having an opening defined by an interior surface having a portion thereof parallel to the base panel, the first surface of the detent engaging the interior surface portion of the member when the storage container is closed. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on and claims priority and benefit of Provisional U.S. Patent Applications No. 62/112,110 filed Feb. 4, 2015; Application No. 62/112,117 filed Feb. 4, 2015; Application No. 62/112,121 filed Feb. 4, 2015, and their entire contents of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] This invention relates in general to methods and systems to eliminate hair loss caused by the side effects of certain chemotherapy treatments and to reduce the metabolic rate of ischemic tissue along with the severity of swelling. Still more particularly, the present invention relates to methods and systems to enable the user to self-manage its entire operation without assistance.
BACKGROUND OF THE INVENTION
[0003] Therapeutic hypothermic treatments can reduce the distressing side effect of alopecia caused by chemotherapy treatment by cooling the scalp to below 19° C. during the chemotherapy session and for a brief time before and after the session. No other cooling times are required. The cold scalp temperature serves two purposes. One purpose is to reduce the circulation of blood flowing to the hair follicle cells so less chemo reaches the hair follicle cells. The second serves to decrease the uptake of the chemo drugs by the hair follicle cells preventing the chemo from getting inside the hair cells and killing them. For these reasons, scalp cooling should only be used on solid tumors not located in the head region.
[0004] Hypothermia treatment for ischemic injuries has been known for years and is generally accepted to effectively reduce the metabolic rate of ischemic tissue and the severity of swelling. Sprains and muscle pulls are commonly treated with ice packs to provide the hypothermia. The simplicity of ice pack treatment allows it to be used nearly at the same time of the injury which, in turn, has contributed to its effectiveness.
[0005] Given the known range of head sizes and head power, effective hypothermia treatment of the head region whether it be for treatment of alopecia or for ischemic injury requires overcoming a large thermal resistance associated with the thermal properties of the hair which can vary significantly from person-to-person due to, for example, amount and thickness. People skilled-in-the-art of heat transfer recognize hypothermia systems must provide a sufficiently cold surface in contact with the hair so that a large temperature difference between the cold surface and scalp will overcome the hair thermal resistance. For example, suitable cold surfaces may be achieved by pumping cold antifreeze fluids through conduits in a head surrounding cap; by cold packs placed around the head pre-cooled by dry ice or industrial grade freezers set at less than −30° C.; by cold packs made cold by endothermic chemical reactions; by cold caps made cold by piezoelectric effects; by cold gases pre-cooled by refrigeration systems or Joule-Thomson effects; or by other means.
[0006] People skilled-in-the-art of health delivery recognize the efficacy of a treatment correlates with its simplicity and ease-of-use whether implemented by trained personnel or by the user. Effective hypothermia treatment of the head region also requires the user or support personnel to be trained to fully comply with operational instructions of the device.
[0007] An inherent difficulty exists with cold packs pre-cooled by dry ice or refrigeration systems because they do not have enough thermal capacity to allow for a single cap to be used throughout the duration of cooling. Thus, fresh cold caps must replace the warmed caps approximately every 20-30 minutes. The process of removing and replacing caps increases the likelihood of poor results and is especially very difficult to do without assistance while connected to chemotherapy tubes.
[0008] Similarly, foldable cold caps formed in-situ to the user's head by wrapping, connecting tabs, filling air bladders, or by splicing multiple pieces together in a manner to improve fit require assistance to the user to don properly.
[0009] Effective hypothermia treatment of the head region also requires the device to be ready and available when needed. Cooling devices owned and maintained by the healthcare facility may not necessarily be available due to scheduling conflicts or simply not geographically near the user.
[0010] Complex hypothermia head cooling solutions such as those using refrigeration systems or multi-faceted head wraps tend to required on-site trained personnel to implement which in itself inhibits availability due to healthcare providers not wanting the capital equipment to own, store, and maintain besides the added responsibility and liability to have a trained staff for a treatment that is primarily cosmetic. These complex cooling devices tend to be more costly and may result in fewer users available to benefit from the treatment. Also, recent studies regarding therapeutic hypothermia for concussions indicate cooling may reduce primary and secondary injuries to the brain and is more effective if administered as soon as possible after an injury thus scheduling conflicts or geographic constraints will adversely impact the efficacy of this treatment.
[0011] Refrigeration systems, large equipment, sophisticated operating panels, manuals with medical jargon, and odd fluids with special handling requirements appear unwieldy and complicated to most users to self-manage, especially at a time of duress. Effective hypothermia treatment of the head region to be self-managed by the user require self-evident familiarity of equipment, its components, and controls such that operational anxiety and mistakes can be minimized. Also, self-managed devices require in real time “on-demand” services that are not available to those devices dependent on trained personnel as the middle man between the device and the user.
[0012] Effective hypothermia treatment of the head region requires certain physical data measurements such as temperature or EEG waves and machine operating conditions such as fluid flow rates or voltages be collected so that user compliance can be verified and the equipment can be improved.
[0013] Systems requiring industrial refrigerators or integrated refrigeration units tend to be expensive for medical facilities to own, store, and maintain. Although costs may be amortized across multiple users, an inherent cost exists compared to those devices that use commercially available materials, fluids, self-managed, and maintained. Effective low cost devices for hypothermia treatment of the head region requires costs to be low all aspects of operation whether it be capital, operating, maintaining, storing, user, or medical facility and personnel costs.
[0014] Large stationary or multi-user refrigeration systems reside at a clinic therefore cool down cannot start at home or in transit to the clinic. Stationary systems require the user to be tethered to the system from beginning to end and with scalp cooling for preventing hair loss, the beginning of use starts before treatment and the end of use can be several hours after the chemotherapy treatment has ended. For restroom visits, the user must temporary stop usage and hope the warm-up was not too severe to cause hair loss. Equally disconcerting for the preventing hair loss application, is that tethered to a stationary or multi-user system means the user cannot attend other appointments during the post treatment phase. Thus, mobile systems with uninterruptible power sources combined with self-managed controls are required for effective hypothermia systems to be used “on-the-go” from beginning to end of use.
SUMMARY OF THE INVENTION
[0015] Accordingly, the primary object of the present invention is to overcome the shortcomings of the prior art systems by providing a hypothermia system that can be fully implemented solely by the person using the invention, is readily available, low cost, prevents hair loss during chemotherapy, or can provide rapid application of cooling to positively affect multiple aspects of brain trauma, and includes
a flexible and conformal cap system with at least one contiguous fluid conduit from an inlet connector to an outlet connector formed to substantially encapsulate the body part to be cooled, has one or more physical measuring devices, has covering said conduit on surfaces away from said body part a stretchable insulating outer shell with chinstrap, and a secondary stretchable insulating material around said outer shell to circumferentially squeeze the conduits to close proximity to that to be cooled; a thermally conductive biocompatible liquid substantially displacing the air surrounding the user's hair strands and filling the gaps between the body part to be cooled and the conduit outer surfaces forming the interior of the cap; a ‘smart’ user interface device with logic commands to provide self-managed ease-of-use, user instructions, system control and monitoring, where said self-managed ease-of-use includes user's ability to infinitely control within predetermined bounds the rate of cool down, where said control includes algorithms to evaluate physical measuring devices and alert user for intervention, if warranted, or automatically make system adjustments; a thermally insulated cooler system with a tank, a mechanical compartment, an electrical compartment, and plumbing components, with said tank holding a thermal transfer fluid and phase change material, said mechanical compartment having one or more sensors and a pump to circulate the transfer fluid, said electrical compartment having electrical components to control and power the system including an uninterruptible power controller to automatically switch between battery power and external power.
[0020] Another object of the present invention is to provide a generally accepted user interface to control the system.
[0021] A further object of the present invention to provide a single cap for use throughout the entire treatment.
[0022] Yet another object of the present invention is for the device to be fully functional while in transit or away from the treatment center. This could be for example restroom visits, other appointments, walking to/from one's car, traveling in a car, or simply finishing the cooling phase at home.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The invention will be described in greater detail with reference to the accompanying drawings which represent a preferred embodiment thereof, wherein:
[0024] FIG. 1 is an isometric view of a preferred embodiment of the self-managed, mobile, hypothermia system;
[0025] FIG. 2 is an isometric rear left view of a user wearing a flexible and conformal cap and for depiction purposes is shown without its outer shell or supplementary headbands;
[0026] FIG. 3 is an exploded isometric cross-sectional view of a physical measuring device with some components cross-sectioned;
[0027] FIG. 4 is a combined fluid flow diagram and electrical wiring schematic of the hypothermia system;
[0028] FIG. 5 is a pictorial of three screen shots of a user's smart mobile device for monitoring and controlling the hypothermia system;
[0029] FIG. 6 is a logic flow chart of the embodiment shown in FIG. 1 .
DETAILED DESCRIPTION
[0030] With reference to FIG. 1 , a self-managed portable hypothermia system 100 , according to an embodiment of the present invention, includes a portable cooler system 101 , a flexible and conformal cap system 102 that is worn by a user, a smart mobile device 103 which is wirelessly connected to the said cooler system and remote data storage 104 as shown by the dashed lines is illustrated. The said cooler system comprises of a thermally insulated, leak proof cooler for containing a thermal transfer fluid 105 and phase change material 106 ; a telescoping handle system with casters to aid system mobility; an electrical control box; a mechanical control box; electrical and plumbing conduits 107 linking the cooler system with the said cap system; and an electrical connection 108 to a 12 volt source such as an external battery or motor vehicle or in combination with a AC/DC adapter to typical AC power such as 120 V wall sockets. The plumbing conduits 107 are encapsulated by a vapor barrier and thermal insulation 109 (shown partially) to eliminate condensation and minimize heat gain respectively.
[0031] The purpose of the phase change material 106 is for exploiting its high energy storage capacity (i.e., latent heat of fusion) at a temperature sufficiently below the desired head temperature so that as the heat transfer fluid 105 is pumped through the cap system 102 enough energy can be removed from the head and transferred to the phase change material.
[0032] The purpose of the casters and telescoping handle is to aid in the mobility object of the invention. The entire system 100 can be operated and transported by a single person.
[0033] The flexible and conformal cap system 102 consists of a single contiguous high thermal conductivity thin wall conformal conduit 110 ; a high thermal conductivity liquid agent 111 (partially shown); one or more physical measuring devices 112 for temperature or brain activity measurements, an outer shell 113 to thermally insulate the cap and assist in maintaining the cap snug against the head; a secondary flexible and conformal head band 114 ; drip-less fluid connectors 115 ; a connector 116 for sensors; and supplemental cap inverse suspenders 117 . The head band 114 improves heat transfer and sensor contact by cap circumferential squeeze. A similarly shaped head band resides under 114 (not shown) but angled downward to only cover the skin can be used to prohibit seepage of any liquid agents 111 used between the head and cap. Contributing to the ease-of-use and self-managed objects of this invention are the preferred use of gender specific plumbing connectors for direction of fluid flow and a standard everyday and familiar phone jack connector for the sensor wire connections. Said connectors 115 have their mating fluid and sensor connectors located on cooler system 101 . The user cannot connect either type together incorrectly. The design of the shape of the cap system 102 enables easy user recognition of its front and back such that it is easy for the user to orient and put on.
[0034] The liquid agent 111 is applied by the user across the entire inside surface area of the cap, copiously throughout the user's hair (not shown) that contacts the cap, and the grooves located between adjacent conduits. In the preferred embodiment, the liquid agent is a water based gel for high conductivity, ease of application, cleaning, and may optionally contain ingredients to preserve the skin or hair of the contacting body part.
[0035] The desired scalp temperature is achieved by the preferred embodiment of the hypothermia system for eliminating or reducing hair loss because of a paradigm shift of how to overcome the total thermal resistance from the head surface to the liquid phase of the phase change material. Key to this paradigm shift is use of the said gel 111 which dramatically reduces the thermal resistance of the hair to magnitudes that enable trade-offs with other thermal resistance elements in the overall heat transfer path. In essence, the gel enables other elements of the system to be simple and common such as water for the transfer fluid 105 and ice 106 for the phase change material which makes a low cost, portable, self-managed hypothermia system possible since water and ice are readily available for the user whether be at a user's home or at a local convenient store. Furthermore, the ice and water can co-mingle in the preferred embodiment which as a result eliminates all thermal resistances associated with transferring heat through whatever packaging is implemented for separating the phase change material from the transfer fluid. In the absence of gel, circulating ice water will not achieve a cold enough scalp temperature to save one's hair while undergoing chemotherapy treatments for cancer.
[0036] Although numerous methods may appear adequate to wet the hair with gel, it is important to replace the air between the hair strands with gel, have the hair/gel composite thin, and lay flat against the scalp. In the preferred embodiment for eliminating or reducing hair loss, the method for the user to apply said water based gel copiously to the user's hair is to
use a comb to part back of head near midline, apply gel to both sides of said part; make a similar part about ½-1″ to the right of first part, and apply gel to both sides again; continue making parts about 1″ to the right applying gel to both sides until ear is reached; repeat on the left side of center back part until left ear is reached; make a part down front center, apply gel to both sides; repeat part to right of center about ½-1″ until meet where gel is on right side; do to the left of center part; take wide tooth comb and comb through hair to shoulder length; while combing through, distribute hair evenly and flatten to scalp.
[0046] Also in the preferred embodiment, the said water based gel is applied copiously all over inside of cap by the user using their fingers to spread gel evenly throughout the inside of the cap, filling the grooves present between adjacent conduits.
[0047] During operation of the hypothermia system of this invention, heat is extracted from the head, through the gelled hair, to the pumped transfer fluid which returns to the cooler where the ice absorbs the energy contained in the fluid. The energy is transferred at first by warming the ice to its phase change temperature and then by changing its phase from solid to liquid. The newly formed liquid becomes additional transfer fluid available for circulation.
[0048] This invention does not preclude other material selections for the transfer fluid and phase change material. Those skilled-in-the-art of heat transfer and material science may trade-off design parameters in a manner that enables, for example, a saline solution to be used as the transfer fluid and phase change material at the expense of ease-of-use and availability. Alternatively, one may use an anti-freeze for the transfer fluid and an engineered phase change material that are kept separated by a membrane or other packaging means. Although alternative methods may achieve scalp cooling it will be at the expense of one or more objects of this invention thereby impacting its acceptance by a user, clinic, or healthcare provider.
[0049] The cooler system 101 holds sufficient transfer fluid and phase change material to maintain cooling for the duration of most treatments. An additional charge of phase change material is added to the cooler by the user for especially long treatments (e.g., 10 hours) or for embodiments having coolers with less than 15 liter capacity. The use of water and ice simplifies the user's skills required to add an additional charge. The cooler is sufficiently insulated such that the transfer fluid it holds is maintained near its phase change temperature throughout its duration of use. In the preferred embodiment, 10 pounds of ice and 1 gallon of water provide ample cooling duration for the user.
[0050] The outer shell 113 and head band 114 are of insulating and light weight material such as neoprene so user comfort is maintained throughout duration of use. The outer shell is perforated at certain locations 118 to aid in the ability to hear but not compromise on strength of the material. The cap worn over one's head has protective covering of the ears to prohibit local over cooling and has provisions for holding eye wear without impeding the performance of the device. Graspable regions around the said outer shell aid installation and facilitate a tight fit to the head and at certain locations 119 can attached to the aforementioned inverse suspenders 117 for additional assurance of a snug fit. If suspenders 117 are not used, the locations 119 can attach to each other under the user's chin. There are provisions in the outer cap 113 for circumferential elastic ribbons to further improve the snug fit and optionally worn for fashion comfort. The outer shell can be oversized beyond the cooling portion of the head for insulating bare skin regions. An even outer portion (not shown) beyond 113 can be worn for fashion comfort and even added insulation. Three to five conformal caps 102 of various sizes are required to service a broad range of head sizes.
[0051] With reference to FIG. 2 , an isometric rear left view of a user wearing a flexible and conformal cap is depicted and for delineation purposes is shown without its outer shell 113 or supplementary headbands 114 . An opening 201 at the top of the cap enables air to escape that otherwise would have been trapped between the head and cap tubes while putting on the cap due to the snug fit of the cap to the head. Large amounts of residual air will resist compression and counteract the desired cap fit. For the preferred embodiment with a water based gel, a cap is made from about a 10 meters of 5/16″ diameter, 1/16″ wall thickness silicone rubber tubing. The silicone material allows for cap flexibility, durability, and thermal conductance. The conduit 110 cross section for fluid flow is reduced in area after securing the cap to the head due to its conformal properties thereby improving its laminar heat transfer capability. The material durometer is significantly high so that pinching cannot occur. The tube is wrapped in a contiguous spiral to match typical head shapes and kept together with silicone rubber adhesive 203 (partially shown). Said adhesive is applied as a fillet at each conduit-to-conduit contact across the entire outer surface of the cap except if certain compliancy locations 204 are implemented. The fillets of adhesive seal the cap water tight thereby entrapping the said liquid agent between the scalp and cap interior. Additionally, the adhesive improves the effectiveness of the conduits heat transfer by augmenting the conduction path to the far side conduit wetted surfaces. One or more physical measuring devices 112 are attached to the conduits by adhesive. Select conduit-to-conduit contact locations may be absent of adhesive to enhance cap conformity. To assist in conforming the cap to the user's head, additional material 202 is selectively located around the top portions of the cap so reactive forces created by securing the outer shell 113 are applied to the cap at locations ensuring a consistent fit across the surface area of the head. The said compliancy locations 204 minimize conduit counter forces and allows for the conduits affected by the additional material to move closer to a surface below.
[0052] The conduits 110 are routed inside a larger anti-pinching conduit 205 having a portion of length overlapping several circumferentially wrapped conduits and another portion at least several inches beyond the largest opening of the cap. The anti-pinching conduit reinforces the cantilevered portion of the conduits so than bending or twisting of the cap does not cause the fluid channel to pinch shut.
[0053] With reference to FIG. 3 , the physical measuring device 112 comprises of a stationary part 301 that is fixed between adjacent conduits 110 (one not shown) and not attached to the component to be measured such as a person's head, a movable part 302 that can travel along its major axis within the said stationary part with one end of the movable part able to protrude from the stationary part and make contact or be in close proximity to the component to be measured such as the scalp of one's head, a restraining part 303 that attaches to the stationary part on the side opposite the component to be measured and retains the movable part within the stationary part, one or more sensors 304 such as a thermistor or EEG element with its sensing portion at the protruding end of the movable part and its electrical wires 307 exiting out near or at its other end, a spacer 308 , a spring 305 located between the cap and movable part end having wires exiting thereby applying force on the movable part such that contact or close proximity to the component occurs, a cable tie 306 that locks the restraining part 303 onto the stationary part 301 and also inhibits external forces on the wires to cause any unwanted sensor movement. The stationary part 301 is typically held in place in the cap by silicone adhesive 203 whereas the movable part, sensor, washer, and spring are mechanically held in place by the restraining part 303 and cable tie 306 .
[0054] The stationary part 301 is made of insulating material such as plastic and is hollow or of sparse interior material composition thereby effectively reducing its thermal conductivity. The inner chamber of the stationary part is for containing one or more movable parts and is sized to permit the movable part installation from the side opposite that of the component to be measured and prohibit the movable part from protruding beyond a prescribed amount by stop feature 309 . The stationary part surface in close proximity to the body part can be contoured to match the surface contour of the head.
[0055] The movable part 302 is also made of insulating material such as plastic and is hollow or of sparse interior material composition thereby effectively reducing its thermal conductivity. The stationary and movable parts can be of different material types. The movable part 302 has a hollow core spanning its entire length so that electrical wires 307 can be routed from the sensor through the core of a spring 305 and spacer 308 . The spring 305 is made of non-corrosive material such as stainless steel and exerts a force on the movable part. The spacer 308 length can be modified to tune spring force and travel. The minimum and maximum travel of the movable part is determined by a composite of spring length, length of said internal cavity, movable part length, and locations of the stop features 309 and 310 . Typical movable part travel is normal to the component to be measured with maximum inward travel yielding the sensor flush with the bottom surface of the stationary part and maximum protrusion of 3/16″. For certain cases, the travel may not be normal to the component to be measured. Non-normal travel may be desirable for hard to reach areas or if the sensor geometry is asymmetric. In the preferred embodiment of the invention, the sensor is slightly recessed into the movable part and secured with thermal conducting epoxy.
[0056] The measurement by the sensor 304 is minimally impacted by the cold transfer fluid 105 traveling through the conduits 110 because of a high thermal resistance path existing between the head and transfer fluid due to the small physical size of the measuring device components, their low material thermal conductivity, their sparse internal structure, and a gap between the movable and stationary parts. In the preferred embodiment, the movable part is ⅛″ diameter but its cross section is not required to be circular.
[0057] The retention part 303 has a relatively large internal cavity 311 for the sensor wires 307 to occupy as they move freely as the movable part travels up or down. The travel up or down occurs predominately whenever the user installs the cap on their head and travels slightly due to thermal contractions and expansions of the materials. The sensor wires are locked at one end of the cover by the cable tie 306 wedging the sensor wires against retention tab 312 thereby creating strain relief for the sensor wires.
[0058] The physical measuring device 112 is replaceable and reusable. In some cases, it may be desirable for movable part not to be installed thereby leaving its associated cavity in the stationary part available for other uses such as viewing, installing a different sensor, or as an access port to the head.
[0059] With reference to FIGS. 1 and 4 , an electrical control box 401 contains an on-board microprocessor 402 ; an uninterruptible power controller 403 , a battery 404 , and an on/off power switch 405 . The microprocessor 402 receives electrical data signals from the physical measuring device 112 , flow meter 410 , and via wireless communication master control data from the smart mobile device 103 . The microprocessor manipulates the said data and outputs control data to the pump 406 located in the mechanical control box 411 and to the master controller 103 . Not shown are the ancillary electrical components to reduce electrical noise effects on the sensor measurements and a voltage regulator to adjust incoming voltage to levels suitable for the microelectronics. For low cost and proven reliability, the preferred microprocessor embodiment employs analog signal processing for sensor measurement with digital pulse-width-modulation for variable voltage output to adjust pump flow rate in order to raise or lower the temperature of the head. The uninterruptible power controller 403 continuously monitors the supply power from the external power source 108 and on-board battery 404 . The power controller 403 automatically switches between power sources if one is deemed unacceptable for use. Re-charging the battery is also controlled by the uninterruptible power controller.
[0060] In the preferred embodiment, the pump 406 is of positive displacement type thereby able to generate sufficient pressure to force the transfer fluid though the tubes, disconnects, valves, and other plumbing components in the fluid path. A strainer 407 is located in the suction path upstream of the pump. The strainer prohibits any small particles to be introduced into the pump and is especially useful for those cases where the phase change material co-mingles with the transfer fluid. A check valve 408 is downstream of the output from cap 102 and is oriented to prohibit the cap to drain for those occurrences when the pump is off thereby trapping the high thermal capacity transfer fluid in the conduits to absorb heat from the head while the fluid is stationary. The check valve enables the microcontroller to sequence the pump on and off rather than run continuously. In the preferred embodiment, the pump runs at a 50% duty cycle. The non-continuous pump operation allows for longer battery life and contributes to achieving the mobility object of the invention. The pump may run at full power continuously if the microprocessor evaluation of the system data deems it to be necessary to meet the hypothermia objectives set by the system and user. One or more drain holes 409 are located in the mechanical box 411 in case any leakage of the plumbing hardware may occur. The electrical box 401 is isolated from the mechanical box except for a small sealed wiring conduit.
[0061] With reference to FIGS. 1 and 5 , the smart mobile device 103 is the master controller of the hypothermia system. Look and feel of its operation follows present de-facto smart phone applications in regard to input, feedback, responsiveness, pop-up alerts, and pop-up notices. Its familiarity reduces user anxiety that may exist from seemingly complicated and high tech instrumentation evident on other devices found in the healthcare industry. The smart phone device has powerful on-board computing capabilities, wireless communication components, and a high resolution display all of which are leveraged by this invention without inheriting their costs. Similarly, the smart mobile device application can automatically and securely connect to an on-line database 104 for real time updates to certain parameters of the application software. Significant revisions can occur in less that three days world-wide in today's standards. Hence, the implementation of a user's own smart mobile device contributes to satisfying the ease-of-use, low cost, and availability objects of this invention.
[0062] To operate, the self-managed portable cooler system 101 and smart mobile device 103 must be powered-on. Wireless communication with one another must occur at the beginning of operation but not necessarily throughout the entire duration of treatment. Communication occurs by the user opening the application software on the mobile device, pushing the connect button 502 on the home screen 501 then enters a unique device ID provided by the manufacturer in the application window 503 . The software automatically pairs the mobile device to the hypothermia system and locks-out all other devices. The system operation cannot proceed unless connected and the user agrees to manufacturer terms and conditions which are presented to the user automatically before the start of each session. Also included on the session screen 501 are the power level indicator 511 , sensor performance gauge 509 , status text screen 512 , tab selection buttons 504 , and user customization input slider 510 . The aforementioned screen windows are not necessarily visible to the user at all times.
[0063] Once connected and terms are agreed to, the user can choose to continue with the session or move to the information screen 505 or tools screen 506 via the tab selection buttons 504 . Instructional videos 507 and manuals 508 for how to, for example, prepare the cooler with transfer fluid and phase change material; how to put-on the cap; how to operate the application; how to service the system; how to clean the system; how to run on battery mode; and, how to interpret alarms and warnings. All are available at any time the user selects the information screen. The tools screen includes, for example, user selection 513 to customer service contacts, evaluation forms, frequently asked questions, and instructions for the system to drain itself once the hypothermia treatment has ended. The user can choose at anytime during the hypothermia treatment to text, email, or phone customer service without compromising the function of the system. Similarly, the user can open other applications found on the smart mobile device such as videos, web browsing, social networks, etc. while the hypothermia application continues to run in the background.
[0064] For the hair preservation preferred embodiment of the hypothermia system, the session screen 501 progressively illustrates six phases of operation. The six phases are cap fit, cool down, maintain, treatment, post-treatment, and conclude. The cap fit phase polls the sensors in the cap and determines if the fit of the cap is adequate to proceed to the next phase. The algorithm examines left-right, front-back, or other sensor comparisons to determine if measured variations are within expectations for the application. Once the cap fit phase ends, the user enters the cool down phase. Cold transfer fluid starts flowing through the conduits in the cap at a relatively slow flow rate. A controlled rate of cool down is tailored to the user to rates by their own choosing within certain functional bounds of the system. Twenty to thirty minutes is chosen by most users to comfortably achieve a scalp temperature below 19° C. The customization slider 510 permits the user to adjust the rate of cool down. Once the temperature is achieved, then the maintain phase begins. This phase maintains the temperature while the user is waiting for the treatment to begin. Once the treatment begins, the treatment phase begins. Post-treatment phase maintains the scalp temperature for a set time period based on the chemo regimen. This phase could last upwards of 5 hours. Due to the on-board battery 404 and uninterruptible power supply 403 , the user can freely choose to be mobile and travel at-will without compromising functionality of the hypothermia system.
[0065] With reference to FIGS. 1, 4, 5, and 6 , in many respects, the success of contributing to the self-managed object of the invention exists because of under-the-covers automatic software managed control of the hypothermia system embedded in the application software 103 and microprocessor 402 . Once the button 502 is pushed, the application attempts to establish wireless communication 601 with the microprocessor decision block 611 . Communicating and pairing activities occur continuously while both devices are powered and a successful communication pairing sets a flag 615 to one (i.e., logical TRUE). Single line bordered symbols represent function located in the smart user interface device whereas double line bordered symbols represent function located in the microprocessor. Those skilled-in-the-art of programming may choose different allocations of code blocks (single/double line) but FIG. 6 represents the preferred embodiment to satisfy several objects of the invention.
[0066] The said phases of operation have different operating parameters and block 602 determines the active phase and loads its corresponding operating parameters 603 into appropriate variables such as set points, times, limits, alarm values, etc. The hardware sensors 617 read from the microcontroller and transmitted 618 for the mobile device to read 604 . Coupled with optional user input values 605 , newly acquired information is supplied to an algorithm 606 for system evaluation. In the cool down phase, the algorithm provides a controlled rate of cool down thereby enabling the user to acclimate to the colder temperature. The user may choose to change the rate of cool down and provide a rate adjustment as a user customization value 605 .
[0067] Decision block 607 has algorithms customized to each phase. For instance, a relatively high temperature value in the cap fit phase is desirable where a high value in treatment phase is an indication of a potential fault. Acceptable operating parameters are transmitted 610 wirelessly (dotted line) to the system hardware code 616 where default values are over written.
[0068] The user may be notified for an intervention 608 if decision 607 determines a value is unacceptable. One example is if the user forgets to add transfer fluid into the system or forgets to connect the drip-less fluid connects 115 together. For this example, a flow meter would measure no flow and the algorithm would determine a fault condition and notify the user to add fluid. Another example is if the user forgets to connect the sensor connector 116 then erroneous measurements would be noticed by the software and intervention then requested.
[0069] Sensor readings 617 are modified, compared to control parameter values 619 , and with algorithm 606 control levels are adjusted to bring the system closer to desired levels. Those skilled-in-the-art of control theory can apply various control procedures such as proportional-integral-derivative algorithms to adjust pump speeds 620 to achieve a scalp temperature. In essence, the code runs continuously in a loop reading sensors 617 , transmits 618 to mobile device, combines user input 604 , set hardware controls 619 , and does error checking 606 . A fault or error that is controlled automatically (i.e., user intervention does not occur) is, for example, if 606 determines 604 is unsafe (i.e., temperature too cold), then control signal 620 sends shuts off signals the pump.
[0070] Once flag 615 is set as determined by decision block 613 , the hardware can operate to most recently updated control parameter values in the absence of wireless communication 621 . For this case, however, user inputs 605 are not available to the hardware until communication is re-established. If the flag is never set or if the control signals stipulate, the system is turned off at block 614 .
[0071] The smart mobile device code continuously monitors the system operation. It can, for example, determine if the cap is put on correctly by polling and examining sensors in the cap. It can discern if any sensors are not behaving correctly and either interrupt the user to fix or remove from the control algorithms. It can turn the system off automatically once the appropriate amount of time for a prescribed treatment has elapsed. It can discern if the battery power becomes too low for proper operation and interrupt the user for attention to switch over to wall power.
[0072] Periodically, the smart mobile device code transmits data via a communication link 609 to be retained at the remote server 104 . Sensor data, control parameters, and user information are part of the data retention package and optionally can be shown to the user at any time. All data is password protected and secured to prevailing government guidelines.
[0073] In essence, the user of the hypothermia system of this invention requires no assistance to put on, operate, take-off, or maintain whilst achieving all of the aforementioned objects of the invention. | A non-user assisted, portable, entirely self-managed capable hypothermia device to eliminate hair loss caused by the side effects of certain chemotherapy treatments or to reduce the metabolic rate of ischemic tissue along with the severity of swelling is disclosed. The device consists of a conformal cap system, a thermally conductive liquid located between the body part to be cooled and the cap system, thermal transfer fluids, phase change materials, thermally insulated cooler, physical measuring devices, mechanical and electrical components, a ‘smart’ user interface device, a battery, and an uninterruptible power controller. | 0 |
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] The present application claims the benefit of the filing date of U.S. patent application Ser. No. 61/988,681, filed May 5, 2014 (May 5, 2014), incorporated in its entirety by reference herein.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
THE NAMES OR PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not applicable.
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
[0004] Not applicable.
BACKGROUND OF THE INVENTION
[0005] 1. Field of the Invention
[0006] The present invention relates generally to a cannula for use in arthroscopic surgery and endoscopic procedures, and more particularly to a novel double port cannula that facilitates arthroscopy of synovial joints and endoscopic procedures on the abdomen and spine.
[0007] 2. Background Discussion
[0008] Arthroscopy has revolutionized the treatment of joint diseases. In the knee, arthroscopy has allowed for minimally invasive treatments of meniscal tears and cartilage pathology and facilitated other more extensive surgeries such as ACL reconstruction and meniscal transplantation. Arthroscopy has been expanded into other fields such as shoulder, hip elbow, ankle, and even the wrist. In joints, such as the hip and knee in particular, arthroscopic suturing techniques are particularly helpful for repair of the labrum and capsule. However, suture management can occasionally challenge even an experienced arthroscopist. The problem is one of access. In the hip, for instance, the presence of the femoral head and the depth of the joint can make it nearly impossible to access certain areas except with one cannula. Thus, it is impossible to implement a surgical action in that zone. In the spine, muscle-sparing approaches have been developed in the removal of disc material and the fusion of vertebral bones in the treatment of disc disease. However, access is limited to one to two pathways to the diseased area.
SUMMARY OF THE INVENTION
[0009] The current invention has been developed to provide a method and apparatus to address the issue of access by providing two ports within a single double port cannula. The inventive double port mechanism allows entry and passage of any two elongate instruments, including an endoscope through one of the channels. This dramatically increases the options for achieving the surgical goals. The inventive double port cannula allows the surgeon to implement the surgical plan through the second port. The invention has applications to the shoulder for the repair of the rotator cuff where the sutures can be pulled through the second port and can help to apply traction of the cuff or store the sutures until they are ready to be tied. It can be utilized in the hip in the repair of the labrum or treatment of cartilage lesions. It can further be utilized in the knee for the repair of ligaments such as the anterior cruciate ligament or the menisci. The invention can be used in the spine for the treatment of intervertebral disc disease with a minimally invasive methodology with the endoscope entered through one channel or portal and the pathological material removed or repaired through the second portal.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0010] The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
[0011] FIG. 1 is a lower perspective end view of the inventive cannula;
[0012] FIG. 2 is a side view in elevation of the inventive cannula shown in FIG. 1 ;
[0013] FIG. 3 is an enlarged detailed cross-sectional view of the inventive cannula taken along section line 3 - 3 in FIG. 2 ;
[0014] FIG. 4 is an enlarged detailed view of the interior (distal) end portion of the inventive cannula shown in FIG. 1 ;
[0015] FIG. 5 is an upper perspective external (proximal) end view of the inventive cannula;
[0016] FIG. 6 is a rotated and enlarged view of the proximal end portion of the inventive cannula shown in FIG. 5 ;
[0017] FIG. 7A is an exploded lower perspective view of a second preferred embodiment of the inventive cannula, which includes a threaded exterior end portion and an insertion stylette (pin);
[0018] FIG. 7B is the same view showing the insertion pin inserted into the threaded cannula;
[0019] FIG. 8A is a front view in elevation of the insertion pin of the second preferred embodiment;
[0020] FIG. 8B is a side view in elevation thereof;
[0021] FIG. 8C is a top plan view thereof;
[0022] FIG. 8D is a bottom plan view thereof;
[0023] FIG. 9A is a side view in elevation of the cannula of the second preferred embodiment;
[0024] FIG. 9B is the same view with the cannula axially rotated 90 degrees;
[0025] FIG. 9C is a top plan view thereof;
[0026] FIG. 9D is a bottom plan view thereof;
[0027] FIG. 10A is a in elevation of the second preferred embodiment assembled showing the insertion pin front side; and
[0028] FIG. 10B is the same view with the insertion pin and cannula rotated axially 90 degrees.
DETAILED DESCRIPTION OF THE INVENTION
[0029] Referring first to FIGS. 1 through 6 , wherein like reference numerals refer to like components in the various views, there is illustrated therein a first preferred embodiment of a new and improved cannula with two ports, generally denominated 10 herein.
[0030] As seen in FIGS. 1-3 , in a first preferred embodiment the cannula of the present invention 10 preferably includes a cylindrical shaft 16 , having a an interior end 12 , truncated obliquely so as to form a beveled end or “point” 20 , an exterior end 14 , a collar or ferule 18 disposed on the exterior end, and first and second generally linear and parallel bores 22 and 24 , separated by a partition 23 from the exterior end 14 to the interior end 12 . The bores can be identical or variable in diameter.
[0031] FIG. 3 provides detail showing the shaft 16 , an exterior end 14 , the collar 18 , and the interior end (or articular apparatus) 12 with the main channel opening 22 and the accessory channel opening 22 . The collar 18 may include a rim 25 that extends beyond the openings of the channels and defines a cylindrical cup 26 to facilitate placement of an arthroscope or a larger instrument, typically inserted into the exterior end (outer) entry site into the main channel. Alternatively, smaller instruments (such as radiofrequency probes, suture passers or retracting sutures) can be passed through the accessory channel.
[0032] FIG. 4 provides detail concerning the double port cannula articular end tip 20 . The beveled opening of the cannula 10 makes it able to accommodate a variety of endoscope/arthroscopes (the terms used interchangeably herein) through the interior end of the main channel 22 and other smaller instruments through the accessory channel 24 with a clear structural separation between the two channels of the cannula.
[0033] FIG. 5 is an end view in perspective showing the external end 14 . In this view, the main cannula assembly is shown. Looking from outside the external end, thus outside the patient's body, there is an outer entry hole 22 a for the main channel 22 and the accessory channel outer entry 24 a for the accessory channel 24 . An endoscope/arthroscope inserted into main channel 22 is maintained in position with a fluid seal using the endoscope/arthroscope attachment mechanism, collar 18 .
[0034] FIG. 6 is a detailed end view of the double port cannula, again showing the exterior end 14 , rotated 180 degrees from its position as seen in FIG. 5 so that accessory channel 24 is better appreciated.
[0035] FIGS. 7A through 10B show a second preferred embodiment 70 of the inventive cannula. These views show, collectively, that in a second preferred embodiment, the cannula includes an elongate shaft or tube 72 having first and second through ports 74 , 76 , separated internally by a bifurcation or partition 78 , and extending from an exterior (proximal) end 80 to an interior (distal) end 82 . The exterior end 80 includes a collar or ferrule 84 that functions as an anthroscopic attachment structure. This embodiment further includes male threads 86 , which maintain the cannula in position at the desired depth from the skin.
[0036] The second preferred embodiment next includes an insertion pin or stylette 90 having a head 92 with gripping elements 94 , including, but not limited to, nubs, knurls, fins, ribs, or any suitable surface feature that facilitates a secure finger hold. Integrally connected to head 92 are first and second split prongs 96 , 98 , each configured for insertion into the through ports 74 , 76 in cannula shaft 72 each extend to a beveled end 100 , 102 which angle inwardly to form an effective point 104 , which extends through the interior end 82 of cannula 72 when inserted. This facilitates insertion into a patient's body.
[0037] While the prongs are shown in the view having substantially the same dimensions, it will be appreciated that they may be sized for passage of different instruments while still achieving the functional features of the above-described insertion pin.
[0038] The above disclosure is sufficient to enable one of ordinary skill in the art to practice the invention, and provides the best mode of practicing the invention presently contemplated by the inventor. While there is provided herein a full and complete disclosure of the preferred embodiments of this invention, it is not desired to limit the invention to the exact construction, dimensional relationships, and operation shown and described. Various modifications, alternative constructions, changes and equivalents will readily occur to those skilled in the art and may be employed, as suitable, without departing from the true spirit and scope of the invention. Such changes might involve alternative materials, components, structural arrangements, sizes, shapes, forms, functions, operational features or the like.
[0039] Therefore, the above description and illustrations should not be construed as limiting the scope of the invention, which is defined by the appended claims. | A single shaft double port cannula having a shaft with discrete and separated channels to provide a method and apparatus that allows entry and passage of any two elongate surgical instruments through a single cannula. | 0 |
BACKGROUND OF THE INVENTION
The invention relates to an accelerator lever, particularly for projectile looms. It further refers to a projectile loom with an accelerator lever in accordance with the invention.
Striker or accelerator levers are used on projectile looms for accelerating a projectile to a high velocity in a short time. To achieve this it is helpful to keep the mass of the lever small to reduce the energy required for the acceleration of the mass of the lever and to increase the insertion capacity of a loom. CH-PS 553 864 discloses a lever for a projectile loom which has an arm made of fiber-reinforced duroplastic plastics and detachably connected to a clamping device for the transmission of forces. The surface of such a lever arm usually has a relatively low coefficient of friction. As a result the clamping device must generate a large clamping force which requires many bolts or bolts having large diameters. This renders the clamping device as well as the means of connection relatively massive since it is usually made of steel so that the large static and dynamic forces can be handled. A further disadvantage of the known accelerator lever is that the clamping device forms an edge where the lever arm protrudes from it. This leads to increased wear in that region as a result of the periodic back and forth motions of the lever arm. It has a further disadvantage that the large number of bolted connections make the replacement of the lever arm very time-consuming.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide an accelerator lever made of at least the two parts, the clamping device and the lever arm, with a connection for the parts having a considerably reduced mass with few detachable connectors, and which makes it possible to make the parts of the accelerator lever of different materials. The accelerator lever should further have reduced wear in the region where the parts are connected. The accelerator lever should further be usable as a striker lever for the acceleration of the projectiles of a projectile loom which is capable of generating higher projectile velocities and hence higher weaving capacities.
The invention further covers the use of the device in accordance with the invention in projectile looms.
The clamping device and the lever arm are firmly and detachably connected in a locking manner relative to at least a direction of rotation of the lever. The lever arm and the clamping device have at least two apertures each; for example, drilled holes, to attain the desired locking connection in the direction of shaft rotation. At least two means of connection are necessary which typically extend parallel to the axis of rotation of the drive shaft for the accelerator lever and provide a stiff, positive connection in the direction of rotation of the lever. In comparison to frictional connections, the positive connection requires considerably less pressure between the lever arm and the clamping device. As a result, the clamping device and the lever arm are subjected to lesser forces in the region of their connection and, therefore, may have a lesser mass. One advantage of the invention is therefore that the connection can be built with fewer connectors and has a very low mass. A further advantage of the invention is that the lever can be made of different materials. Thus, metals such as, for example, steel, titanium or aluminum or composite materials such as fiber-reinforced plastics using endless carbon filaments, for example, are suitable materials. An accelerator lever can therefore be assembled or changed rapidly as may be required. Further elements such as, for example, a lever arm extension or a striker piece can be lockingly secured to the lever arm. Such an accelerator lever made of a number of components further permits the replacement of only individual components when maintenance is required.
Further, the existing problem of reliably connecting an accelerator lever made of plastic to the drive shaft is expediently solved by making the clamping device, for example, of metal and the lever arm of plastic. Hence very light accelerator levers can be produced which are easy to maintain, inexpensive and readily adaptable to the prevailing needs.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an accelerator lever of a projectile loom with a lever arm extension and a striker piece as well as a projectile;
FIG. 2a shows an embodiment of an accelerator lever;
FIG. 2b is a section along A--A through the accelerator lever according to FIG. 2a;
FIG. 3a shows an embodiment of another accelerator lever;
FIG. 3b is a section along B--B through the accelerator lever according to FIG. 3a;
FIGS. 4a to 4f are perspectives of the clamping bodies;
FIG. 5 shows a further embodiment of an accelerator lever of a projectile loom with a clamping device made of a number of parts; and
FIG. 6 is a detail of FIG. 5 showing the clamping device and its attachment to the lever arm and the shaft.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows an accelerator lever made in accordance with the invention and used as a striker lever on a projectile loom. A striker piece 6 moves along an arcuate path in the direction 9 to accelerate a projectile 7 guided by a projectile guide 8 in the direction 13 of weft insertion. Instead of the striker piece 6 movably mounted to a lever arm extension 1c and rotatable about a connector 6a, the striker piece may also be secured directly to an end region of the lever arm 1b, or to the lever arm extension 1c, in the form of a small plate of hard metal, for example. In the present embodiment the accelerator lever 1 is made of three components; namely, a clamp 1ac, a lever arm 1b and a lever arm extension 1c. The clamping device 1a comprises a single part, a clamp body 1ac. An accelerator lever can of course be made of more or of fewer parts. Shaft 2 moves the accelerator lever 1 back and forth in the direction of rotation 2b, the center of rotation 2a being perpendicular to the chosen view. The clamp body lac has a slit which is parallel to the axis of rotation 2a so that clamp body 1ac has two arms 10a, 10b embracing the shaft 2. Two ends 10r, 10s of the arms are connected with connector 3, e.g., a bolt with a threaded shaft 3a. Beginning with connector 3, the clamp body 1ac has on the side opposite the axis of rotation 2a at least two recesses 10f for receiving fasteners 4. Lever arm 1b has corresponding apertures 1f, so that fasteners 4 form a positive connection between clamp 1ac and lever arm 1b relative to the direction of rotation 2b. This connection must be free of play in the direction of motion 9. Thus, fasteners 4 are preferably arranged parallel to the axis of rotation 2a. At the end remote from the shaft 2 lever arm 1b has at least two further drilled holes for connectors 5 to lockingly attach lever arm extension 1c to the lever arm 1b relative to the motion direction 9. In the present embodiment the striker piece 6 is secured to the lever arm extension 1c. Detachable connectors 4 and 5 permit the individual components of the accelerator lever 1 to be individually exchanged or replaced. An accelerator lever 1 may be assembled from components in a very simple manner. The needed components can be selected to best suit a particular need at any given time because components made of different materials having desired properties such as, for example, their strength or weight, can be selected and assembled into a complete accelerator lever 1.
The perspective view of the clamping device 1a in FIG. 4a shows the pair of arms 10a and 10b for embracing shaft 2, the ends 10r and 10s of the pair of arms each having an aperture 10e for receiving fastener 3. The clamping device 1a is frictionally connected to shaft 2. The friction generating pressure can be varied with fastener 3. Clamping device 1a and with it the entire accelerating lever 1 can be separated from the shaft 2 in a simple manner by loosening fastener 3. Beginning with the two ends 10r and 10s of the arms, the clamping device la has two further arms 10c and 10d which lie in a plane perpendicular to the center of rotation 2a. The two arms 10c and 10d include a bore 10k through which shaft 2 extends. Each arm further has at least two apertures 10f which receive fasteners 4 for a positive, locking connection to lever arm 1b. Movements of the accelerator lever 1 transverse to the direction of rotation 2b are reduced by appropriately forming the two parallel arms 10c, 10d between which the lever arm 1b is disposed. Flanges 10g and 10h of arms 10c, 10d support lever arm 1b.
FIG. 4b shows a further embodiment of a clamping device 1a with arms 10c and 10d which, in comparison with FIG. 4a, are considerably wider in the direction of rotational axis 2a so that two apertures 10e can be positioned in ends 10r and 10s of the arms for securing the clamping device. Clamping device 1a can of course be made still wider so that more than two apertures 10e can be provided. The torque which can be transmitted from shaft 2 to clamping device 1a is amongst others dependent on the size of the surfaces in contact with each other and on the magnitude of the applied clamping force which establishes the friction connection. To increase the contact area between shaft 2 and clamping device 1a flanges 10g, 10h can be widened in the direction of the shaft 2, as shown in FIG. 4c, or the clamping device 1a may include flange 10i, with all flanges connected together by ends 10r , 10s of the arms. In the same way the number of apertures 10e in the ends 10r, 10s of the arms and hence the number of fasteners employed can be varied so that the necessary pressure can be generated as is shown in FIG. 4c. By forming the region of the clamping device to which lever arm 1b is secured in such a way that lever arm 1b has to be attached identically to the differing configurations of the clamping device 1a, different clamping devices 1a and lever arms 1b may be combined in any desired manner. Thus, for example, depending upon the weft insertion capacity or the mass of the projectile 7, different accelerator levers can be assembled. If a relatively small torque is to be transmitted from the shaft 2 to the clamping device 1a, a narrow and correspondingly light clamp 1a can be employed, so that the inertia of the entire accelerating lever 1 can be adapted to its use.
FIG. 4d shows a further clamping device 1a which, in contrast to FIG. 4a, has recesses 10q on the inside of the two arms 10c, 10d. This reduces the area of contact between clamping device 1a and lever arm 1b. FIG. 4f shows another clamping device 1a which has only a single pair of arms 10a, 10b embracing shaft 2 ending in arm ends 10r, 10s. A flange 10g includes an aperture 10f for connection to lever arm 1b. FIG. 4e shows a configuration similar to FIG. 4f and differs therefrom in that lever arm 1b does not rest flat against flange 10g for securing it to clamping device la. Flange 10g is formed only in the region of aperture 10f.
FIG. 2a shows an embodiment of an accelerator lever 1 with clamping device 1a to which lever arm 1b is secured by means of at least two fasteners 4. The end of lever arm 1b remote from the clamp body 1ac has a hole 11 which can be connected to a weft insertion mechanism for projectile 7 (not shown). The lever arm 1b is symmetric about a plane of symmetry 1e and about a plane of symmetry 1d. FIG. 2b shows a cross-section taken along line A--A. In the region of connection lever arm 1b is embraced on both sides by arms 10c and 10d, which exert pressure on lever arm 1b generated by connector 4a, 4b, 4c. Connector 4a, with aperture if and the two apertures 10f, forms a positive, locking connection. Lever arm 1b and clamp body 1ac are both symmetrical about the plane of symmetry 1d. Lateral movements of accelerator lever 1 in the direction of rotational axis 2a are thereby reduced.
FIG. 3a shows an embodiment of an accelerator lever 1 which comprises a clamping device 1a to which a lever arm 1b is secured with at least two fasteners 4. At the end remote from the clamp body lac lever 1b includes a drilled hole 12 for attaching a striker piece with a connector 6a. FIG. 3b is a section taken along line B--B. The accelerator lever 1 is perpendicular to the axis of rotation 2a of the shaft 2. Ends 10r, 10s of the arms of the clamp body 1ac are secured to each other with a connector 3 including a threaded body 3a. The two arms 10c and 10d abut lever arm 1b and connector 4 with its components 4a, 4b, 4c forms a positive, locking connection which presses the two arms 10c and 10d against the lever arm 1b with an adjustable prestress. Prestress is not an absolute necessity but it can be advantageous, for example, to reduce lateral lever arm motions parallel to the axis of rotation 2a. In the vicinity of clamping device 1a lever arm 1b may be provided with two arms, made in the shape of a U and having corresponding apertures, for attachment to a clamping device 1a made, for example, as shown in FIG. 4c. In such a case the two arms will be disposed between the flanges 10g, 10h, 10i of the clamping body 1a. This provides a positive locking connection between the clamping body 1a and the lever arm 1b which is very stiff and permits the transmission of large torques.
In contrast to FIG. 2b, the lever arm 1 of FIG. 3b is not symmetric. Arms 10c, 10d of the clamping device 1a have different widths, in which case the aperture 10e in the end 10s of the arm is asymmetrically arranged in such a way that arms 10c, 10d have the same stress per unit area in the circumferential direction.
FIG. 5 shows a further embodiment of an accelerator lever composed of at least one clamping device 1a and one lever arm 1b. The clamping device 1a includes a flanged bushing 1aa and a separate clamping ring 1ab. The flanged bushing 1aa includes a flange 10g which is perpendicular to the axis of rotation 2a of the shaft 2 and which has apertures 10f. The cylindrical portion 101 of the bushing has slits 10m which are parallel to the axis of rotation 2a. Clamping ring 1ab extends about the cylindrical portion 101 and detachable connector 3 tightens the clamping ring 1ab to form a releasable friction connection between the cylindrical portion 101 and shaft 2. The lever arm 1b again has at least two apertures if which are spaced apart in the direction of rotation 2b. Connectors 4a, 4b, 4c between the lever arm 1b and the flanged bushing 1aa establish a positive, locking connection at least with respect to motions in the direction of rotation 2b. In addition to the configuration of the lever arm 1b already disclosed, for example, in FIG. 1, the lever arm includes a bore 10n at its center of rotation 2a. The bore has a diameter which is sufficiently larger than the diameter of the shaft 2 so that, when mounted, the lever arm 1b encloses shaft 2.
FIG. 6 is a detail of FIG. 5 and shows a further embodiment of a flanged bushing 1aa. The flanged bushing 1aa includes the flange 10g and a cylindrical bushing portion 101 with slits 10m parallel to shaft 2. In the region of the flange 10g the cylindrical bushing portion has a bore 10o of a diameter which is larger than the diameter of the shaft 2 and of a length 10p which is greater than the width of the flange 10g, so that, in the region of the flange 10g, the cylindrical portion 101 and the shaft 2 are not in contact. The side of flange 10g next to lever arm 1b further has a recess 10q to reduce the area of contact between the lever arm 1b and the flange 10g. The flange 10g and the lever arm 1b are secured to each other with connector 4a, 4b, 4c. The clamping ring 1ab grips the cylindrical bushing portion 101 in such a way that, when tightened, a frictional connection results between it and shaft 2. To enhance the connection the cylindrical bushing portion 101 can be provided with slits 10m which are distributed about the circumference of shaft 2. | An accelerator lever for quickly accelerating a projectile to a high velocity in a loom comprises a lever arm (1b) coupled to a rotating shaft (2) by a clamping device (1a). The clamping device includes at least two fasteners (4c) extending through holes in the lever arm and the clamping device and threadably coupled to elements (4a) on the opposite side of the lever arm. The fasteners and elements provide a positive locking connection to firmly connect the lever arm to the shaft. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. patent application Ser. No. 09/965,489 filed Sep. 27, 2001, now U.S. Pat. No. 6,821,625 the contents of which are incorporated by reference herein in their entirety.
BACKGROUND
In nearly every sector of the electronics industry, electronic circuitry involves the interconnection of an integrated chip (hereinafter “chip”) and a surface or device upon which the chip is supported. During operation of the circuitry, heat is generated and a heat flux is established between the chip and its environment. In order to remove heat more effectively to ensure the proper functioning of the circuitry, the heat flux is disseminated across a surface area larger than the surface area of the chip and transferred to an attached heat sink device. Once the heat is transferred to the heat sink device, it can be removed by a forced convection of air or other cooling means.
In some applications, multiple processors and their associated control and support circuitry are arranged on a single chip. Such arrangements may result not only in a further increase in the heat flux, but also in a non-uniform distribution of the heat flux across the surface of the chip. The non-uniformity of the distribution of the heat flux is generally such that a higher heat flux is realized in the processor core region and a significantly lower heat flux is realized in the region of the chip at which the control and support circuitry is disposed. The high heat flux in the processor core region may cause devices in this region to exceed their allowable operating temperatures. The resulting disparity in temperature between the two regions, which may be significant, may contribute to the stressing and fatigue of the chip.
A thermally conductive heat spreading device is oftentimes disposed between the chip and the heat sink device to facilitate the dissemination of heat from the chip. Such heat spreading devices are generally plate-like in structure and homogenous in composition and fabricated from materials such as copper, aluminum nitride, or silicon carbide. Newer carbon fiber composites exhibit even higher thermal conductivities than these traditional thermal spreader materials; however, they tend to be anisotropic in nature, exhibiting wide variations in thermal conductivity between a major axis normal to the face of the structure (in the Z direction) and the axes orthogonal to the major axis (in the X and Y directions). Moreover, the lower thermal conductivity in the direction along the major axis tends to have the effect of increasing the thermal resistance of the heat spreading device, thereby inhibiting the dissemination of heat from the device.
SUMMARY
A thermal spreading device disposable between electronic circuitry and a heat sink is disclosed. The device includes a substrate having a first face and a second face and a plurality of conduits extending through the substrate from the first face to the second face. The two faces of the substrate are disposed in a parallel relationship. The material of which the substrate is fabricated has a first thermal conductivity value in a direction parallel to the faces and a second thermal conductivity value in a direction normal to the faces, with the second thermal conductivity value being less than the first thermal conductivity value. The material of which each conduit is fabricated has a thermal conductivity value associated with it, with the thermal conductivity value of each conduit being greater than the second thermal conductivity value of the substrate.
One method of fabricating the thermal spreading device includes arranging a plurality of thermally conductive rods such that the rods extend longitudinally in a common direction, disposing a molding material radially about the longitudinally extending rods, hardening the molding material around the plurality of thermally conductive rods, and cutting the hardened molding material into slices in a direction perpendicular to the direction in which the rods longitudinally extend. Other methods of fabrication include press fitting or shrink fitting the thermally conductive rods into holes in the substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
The present disclosure will be better understood by those skilled in the pertinent art by referencing the accompanying drawings, where like elements are numbered alike in the several FIGURES, in which:
FIG. 1 is a perspective cutaway view of a thermal spreading device;
FIGS. 2A through 2C are perspective views of a batch process of the fabrication of a thermal spreading device;
FIGS. 3A and 3B are perspective views of a batch process of the fabrication of a thermal spreading device in which conduits are press fitted into the substrate;
FIG. 4 is a sectional view of a step in a batch process of the fabrication of a thermal spreading device in which conduits are shrink fitted into the substrate;
FIG. 5 is a sectional view of the engagement of a thermal spreading device with a chip and a heat sink;
FIGS. 6 and 7 are plan and cross sectional views of an alternate exemplary embodiment of a thermal spreading device; and
FIG. 8 is an exploded perspective view of the engagement of the thermal spreading device of FIGS. 6 and 7 with a chip.
DETAILED DESCRIPTION
Referring now to FIG. 1 , an exemplary embodiment of a thermal spreading device is shown generally at 10 and is hereinafter referred to as “thermal spreader 10 .” Thermal spreader 10 is a conduction medium that provides for thermal communication between electronic circuitry (e.g., a chip) and an environment to which thermal spreader 10 is exposed. The thermal communication is effectuated by the conduction of heat across a substrate 12 to a heat sink (shown with reference to FIG. 5 ). Because the materials from which substrate 12 are fabricated are generally of an anisotropic nature, substrate 12 is oftentimes characterized by a marked disparity in thermal conductivities in orthogonal directions. In particular, the thermal conductivity of substrate 12 in a direction shown by an arrow 16 (Z direction), which is normal to the interface of thermal spreader 10 and the circuitry (not shown), may be substantially less than thermal conductivities in the directions shown by an arrow 18 (X direction) and an arrow 19 (Y direction) along the same interface of thermal spreader 10 and the circuitry. Due to such disparities, the thermal resistance across substrate 12 (in the direction of arrow 16 ) is increased, and the rate of heat transfer (flux) across thermal spreader 10 varies dramatically from the flux in the direction (as shown by arrows 18 and 19 ) that the interface extends.
In order to enhance the thermal communication across thermal spreader 10 , substrate 12 is configured to include thermal conduits 14 . The materials from which thermal conduits 14 are fabricated generally have thermal conductivity values that are substantially higher than the thermal conductivity values in the Z direction of the material from which substrate 12 is fabricated. Because the flux through conduits 14 is greater than the flux in the same direction across the surrounding substrate 12 , heat conduction is enhanced across substrate 12 in the direction shown by arrow 16 (Z direction), viz., in the direction in which conduits 14 extend. Heat transfer is thereby optimized through substrate 12 via conduits 14 .
Conduits 14 are defined by rods or wires having substantially circular cross sectional geometries, as is shown. Rods or wires having substantially circular cross sectional geometries enable a substantially uniform transfer of heat to be maintained in the directions radial to the circular cross section. Other cross sectional geometries that may be used include, but are not limited to, elliptical, square, flat, multi-faced, and configurations incorporating combinations of the foregoing geometries. Regardless of the cross sectional geometry, conduits 14 are formed from materials having high thermal conductivities. Such materials include, but are not limited to, copper, aluminum, carbon, carbon composites, and similar materials that exhibit a high thermal conductivity along the conduit axis. The carbon materials may be fibrous or particulate in structure.
Substrate 12 provides an anchor into which conduits 14 are disposed while further providing a medium for the transfer of heat in directions along and parallel to the interface defined by the positioning of thermal spreader 10 on the chip. Exemplary materials from which substrate 12 can be fabricated include, but are not limited to, carbon and carbon composites. As noted above with respect to conduits 14 , the carbon materials may be fibrous or particulate in structure.
The configuration of thermal spreader 10 is generally such that conduits 14 are arranged to be parallel to each other, as is shown in FIG. 1 . Furthermore, conduits 14 generally extend linearly between opposing surfaces of substrate 12 . As shown, the architecture of thermal spreader 10 is further defined by a substantially uniform spatial positioning of conduits 14 over any randomly selected section of substrate 12 . The even distribution of conduits 14 facilitates and improves the conduction of heat from a first face 20 disposed adjacent the chip and an opposingly-positioned second face 24 disposed adjacent the heat sink. Such a distribution provides for the effective transfer of heat longitudinally through conduits 14 while maintaining the substantially uniform transfer of the heat in the directions radial to the surfaces of conduits 14 .
When thermal spreader 10 is mounted between a chip (shown with reference to FIG. 5 ) and a heat sink (also shown with reference to FIG. 5 ), conduits 14 enable heat generated during the operation of the chip to be communicated from first face 20 of thermal spreader 10 through conduits 14 across substrate 12 to second face 24 of thermal spreader 10 . Although the material of which substrate 12 is fabricated allows for some degree of thermal conduction between faces 20 , 24 , the anisotropic nature of the material causes heat generated by the chip and transferred to thermal spreader 10 to be more substantially dissipated through substrate 12 in the directions shown by arrows 18 and 19 . Dissipation of heat in the directions shown by arrows 18 and 19 allows for the heat to be conducted to a larger number of conduits 14 , which further allows for the more effective transfer of heat from the chip to the heat sink.
Referring now to FIGS. 2A through 2C , an exemplary batch process illustrating the fabrication of the thermal spreader is illustrated. The process comprises arranging the rods or wires by which conduits 14 are defined into an array, which is shown generally at 30 in FIG. 2A . The rods are arranged such that the longitudinal axes of the rods are parallel to each other and held fast by a jig (not shown) or other device configured to maintain the rods in their proper alignment. Molding material of which the substrate is formed is then disposed around the rods, hardened, and cured, as is shown in FIG. 2B . The hardened and cured molding material forms a block, shown generally at 32 , having thermal conduits 14 extending between first face 20 and opposing second face 24 thereof. Block 32 is then sawed or otherwise made into sheets 34 , as is illustrated in FIG. 2C . Each sheet 34 is of a thickness t S , which is slightly in excess of the desired thickness of the finished thermal dissipating device. Sheets 34 are then polished on at least one face thereof to bring thicknesses t S within the allowable tolerances of final product. Polishing of the sheets on both sides further provides sheets 34 with surface textures conducive to a more effective transfer of heat between the chip and the heat sink. Finally, sheets 34 are cut into individual thermal spreaders 10 of the desired length and width.
In another exemplary process of the fabrication of the thermal spreader, thermal conduits 14 may be press-fitted into substrate 12 , as is shown in FIGS. 3A and 3B . Referring to FIG. 3A , holes 28 are drilled, punched, or otherwise formed in block 32 . The cross sectional geometries of holes 28 correspond with the cross sectional geometries of conduits 14 insertable into holes 28 . Referring now to FIG. 3B , conduits 14 are inserted into holes 28 under a compressive force C f effectuated by a press (not shown) or a similar apparatus. The mechanical tolerances of conduits 14 are such that when conduits 14 are received in holes 28 , a tight fit is maintained between the inner surfaces of holes 28 and the outer surfaces of each conduit 14 , thereby allowing effective thermal communication to be maintained between the material of block 32 and conduits 14 . Block 32 may then be sawed or otherwise formed into sheets and polished and cut to the desired lengths and widths.
In yet another exemplary process of the fabrication of the thermal spreader, thermal conduits 14 may be shrink-fitted into substrate 12 , as is shown in FIG. 4 . In the shrink-fitting process, holes 28 are again drilled, punched, or otherwise formed in block 32 , as was described above. Block 32 is heated to a temperature that causes block 32 (and subsequently holes 28 ) to expand. Upon expansion, conduits 14 are inserted into holes 28 with little effort such that space is defined by inner surfaces 34 of holes and outer surfaces 36 of conduits 14 . Block 32 is then cooled to cause the material of fabrication of block 32 to contract, thereby constricting holes 28 and eliminating the spaces defined between the inner surfaces of holes 28 and the outer surfaces of conduits 14 . Once constricted, conduits 14 are securely retained within block 28 . Block 32 may then be sawed or otherwise formed into sheets and polished and cut to the desired dimensions in manners similar to those described above to form the final product.
Referring now to FIG. 5 , a thermal conduction package is shown generally at 38 . In thermal conduction package 38 , thermal spreader 10 is shown as it would be disposed between the chip 40 disposed in electronic communication with its associated circuitry through substrate 42 and the heat sink 44 . Thermal spreader 10 is adhered to chip 40 with an adhesive 48 , which may be a solder or an epoxy material applied to chip 40 as a thin layer upon which thermal spreader 10 is placed. A layer of thermal paste 50 , which is typically a natural or synthetic oil-based compound with thermally conductive particle filler, is applied to the exposed surface of thermal spreader 10 upon which heat sink 44 is mounted. Both adhesive 48 and thermal paste 50 facilitate the transfer of heat between chip 40 and thermal spreader 10 and thermal spreader 10 and heat sink 44 respectively, thereby enhancing the conduction of heat across thermal spreader 10 .
As is shown with reference to FIGS. 6 and 7 , another exemplary embodiment of a thermal dissipating device is shown generally at 110 . Thermal spreader 110 is substantially similar to thermal spreader 10 as illustrated above with reference to FIGS. 1 through 5 . Thermal spreader 110 , however, includes an arrangement of variably spaced conduits 114 disposed within a dissipating substrate 112 . The arrangement of variably spaced conduits 114 is configured to define regions 150 in which the density of conduits 114 is greater than the density of conduits 114 in adjacently positioned regions 152 of the same substrate 112 . The high-density regions 150 are positioned on substrate 112 to register with areas of high heat flux on a chip upon assembly of the thermal conduction package.
Referring now to FIG. 8 , the engagement of the thermal spreader with the chip is illustrated generally at 138 . When thermal spreader 110 is placed in communication with chip 140 , the high-density regions 150 register with the areas of high flux 160 on chip 140 . Such a placement allows for the increased transfer of heat from the areas of high flux 160 on chip 140 to high-density regions 150 of thermal spreader 110 while simultaneously providing a thermally adequate transfer of heat from the areas of chip 140 from which lower heat flux is realized. The disparities in the densities of the conduits in each region 150 , 152 are engineered to provide for the removal of heat from each portion of chip 140 and the transfer of heat to the heat sink to minimize disparity in heat build up at the interface of chip 140 and thermal spreader 110 . Minimization of such disparity may provide improved operability of chip 140 and increase the useful life thereof. Fabrication of thermal spreader 110 is effectuated in a batch process substantially similar to that illustrated in FIGS. 2A through 4 for thermal spreader 10 .
While the disclosure has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the essential scope thereof. Therefore, it is intended that the disclosure not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this disclosure, but that the disclosure will include all embodiments falling within the scope of the appended claims. | A thermal spreading device disposable between electronic circuitry and a heat sink includes a substrate having parallel first and second faces and conduits extending through the substrate between the faces. The substrate material has a first thermal conductivity value in a direction parallel to the faces and a second thermal conductivity value in a direction normal to the faces, with the second thermal conductivity value being less than the first thermal conductivity value. The conduit material has a thermal conductivity value associated with it, with the thermal conductivity value being greater than the second thermal conductivity value of the substrate. One method of fabricating the thermal spreading device includes disposing a molding material radially about the rods and hardening the material. Other methods include press fitting and shrink fitting the rods into a substrate material. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the area of thin film analysis. In particular, the present invention relates to a method and apparatus for combining multiple thin film analysis capabilities into a single instrument.
2. Discussion of Related Art
As the dimensions of semiconductor devices continue to shrink, accurate and efficient characterization of the components forming those devices becomes more critical. Typically, the manufacturing process for modern semiconductor devices includes the formation of a number of layers or “thin films”, such as oxide, nitride, and metal layers. To ensure proper performance of the finished semiconductor devices, the thickness and composition of each film formed during the manufacturing process must be tightly controlled. In the realm of thin film analysis, three basic techniques have evolved to measure film thickness and composition.
Grazing-incidence X-ray Reflectometry
Grazing-incidence x-ray reflectometry (GXR), which is sometimes referred to as x-ray reflectometry (XRR), measures the interference patterns created by reflection of x-rays off a thin film. FIG. 1 shows a conventional x-ray reflectometry system 100 , as described in U.S. Pat. No. 5,619,548, issued Apr. 8, 1997 to Koppel. X-ray reflectometry system 100 comprises a microfocus x-ray tube 110 , an x-ray reflector 120 , and a detector 130 . X-ray reflectometry system 100 is configured to analyze a test sample 140 that includes a thin film layer 142 formed on a substrate 141 .
Microfocus x-ray tube 110 directs a source x-ray beam 150 at x-ray reflector 120 . Source x-ray beam 150 typically comprises a bundle of diverging x-rays that can have a variety of different wavelengths. X-ray reflector 120 reflects and focuses the diverging x-rays of x-ray beam 150 into a converging x-ray beam 160 . Typically, x-ray reflector 120 is a singly- or doubly-curved monochromatizing crystal that ensures that only x-rays of a particular wavelength are included in converging x-ray beam 160 , which is directed at thin film layer 142 .
Converging x-ray beam 160 is then reflected by thin film layer 141 as an output x-ray beam 170 onto detector 130 . X-ray beam 170 forms an interference pattern on the surface of detector 130 due to constructive and destructive interference of x-ray reflections at the top and bottom surfaces of thin film layer 142 . Detector 130 is a position-sensitive detector that measures the varying intensity of this interference pattern. The resulting reflectivity curve of intensity versus position can then be used to calculate the thickness of thin film layer 142 , as described in U.S. Pat. No. 5,619,548.
GXR is best suited for measuring thickness and electron density for films in the range of 10A-2000A thick. It is well matched to the barrier/seed film stacks used in BEOL (back end of line) copper interconnects. However, GXR cannot measure thicker ECP (electrochemical plated) copper films having thicknesses greater than 1 um. Furthermore, GXR is not very good at measuring the composition of thin films—for example the composition of a barrier film such as TaN or TiSiN.
Electron Microprobe Analysis
To analyze the composition of a thin film layer, a technique known as electron microprobe (EMP) analysis is often used. EMP analysis involves the use of an electron beam (e-beam) to generate characteristic x-rays from a thin film layer. FIG. 2 shows a conventional EMP system 200 comprising an e-beam generator 210 and an x-ray detector 230 . EMP system 200 is configured to analyze a test sample 240 that includes a thin film layer 242 formed on a substrate 241 .
To perform an EMP analysis, e-beam generator 210 directs an e-beam 250 at thin film layer 242 . The high-energy electrons in e-beam 250 cause characteristic x-rays 290 to be emitted by thin film layer 242 . The properties of characteristic x-rays 290 are then measured by x-ray detector 230 to determine the composition of thin film layer 242 .
Generally, x-ray detector 230 comprises either an energy-dispersive x-ray spectrometer (EDX or EDS) or a wavelength-dispersive x-ray spectrometer (WDX or WDS). In an EDX detector, the energies of the characteristic x-rays are used to determine the composition of the thin film.
FIG. 4 a shows a conventional EDX detector 230 a that includes a detector crystal 231 and a pulse analyzer 232 . Each of characteristic x-rays 290 incident on detector crystal 231 deposits an amount of charge proportional to the energy of that particular x-ray. These charge pulses are then measured by pulse analyzer 232 . Because different elements generate x-rays having different energies, the charge pulse magnitudes read by pulse analyzer 232 can be used to determine the intensity of the characteristic x-rays, which in turn can be used to determine thin film composition and thickness.
While an EDX detector provides a relatively simple means for determining the composition of a thin film layer, x-rays having closely spaced wavelengths (i.e., energies) can be difficult to distinguish. For example, an ECP copper film may be formed over a tantalum nitride barrier film. The characteristic copper x-rays (Cu-K, indicating x-rays resulting from the ionization of the K shells of the copper atoms) and the characteristic tantalum x-rays (Ta-L, indicating x-rays resulting from the ionization of the L shells of the tantalum atoms) are only separated by 100 eV, and therefore cannot be resolved by an EDX detector, which typically has a resolution limit of greater than 150 eV. Furthermore, an EDX detector cannot detect low energy x-rays, such as those emitted by the nitrogen (N-K x-rays; i.e., x-rays resulting from the ionization of the K shells of the nitrogen atoms) in a barrier film.
In contrast, WDX detectors have a much lower resolution limit of roughly 10-20 eV, and can therefore provide much more accurate measurements than an EDX detector. The low resolution limit of a WDX detector would enable Cu-K and Ta-L x-rays to be distinguished, and also enables the detection of low-energy N-K x-rays. In a WDX detector, x-rays having specific wavelengths are detected to improve the resolution of the measurement process.
FIG. 4 b shows a conventional WDX detector 230 b that includes an x-ray reflector 238 and a proportional counter 239 . Incoming characteristic x-rays 290 are incident on x-ray reflector 238 . X-ray reflector 238 is a monochromator, and disperses the incoming characteristic x-rays 290 according to Bragg's Law. X-ray reflector 238 is configured such that only those characteristic x-rays 290 having a specific wavelength are directed onto proportional counter 239 . The specific wavelength is selected to be the characteristic wavelength of x-rays emitted by a particular element. Therefore, the output of proportional counter 239 can then be correlated to the concentration of the particular element in the thin film layer. Often, multiple WDX detectors are used simultaneously, with each of the multiple WDX detectors being configured to respond to a different element.
Whether an EDX or WDX detector is used, EMP analysis can be performed relatively quickly due to the intense characteristic x-rays produced by the thin film in response to the e-beam. Also, by varying the energy of the e-beam, an EMP system can “depth profile” a stack of thin film layers, allowing composition measurements to be taken at various positions thoughout the film stack. However, as film thickness in the test sample increases, the electrons in the e-beam must be raised to higher and higher energies to properly penetrate the film. For example, to penetrate 1-2 um thick ECP (electro-chemical plated) copper films, electrons with at least 50 keV energy must be used. Such high-energy electrons are difficult to produce and can damage the test sample. In addition, higher power e-beam generators increase the cost of an EMP system while decreasing overall system reliability. This is in addition to the inherent complexity introduced by vacuum environment required to generate the e-beam.
X-ray Fluorescence
Therefore, for analysis of “thicker” thin films, a technique known as x-ray fluorescence (XRF) is often used. In place of the e-beam used in EMP analysis, XRF analysis uses a source x-ray beam to cause emission of characteristic x-rays from a thin film. The source x-rays can penetrate the film(s) in the test sample much more easily than the electrons used in EMP analysis. For example, the molybdenum x-rays (Mo-K) commonly used in XRF systems can penetrate as much as 20 um of copper, and are therefore much more efficient than an e-beam at measuring thick copper films. FIG. 3 shows a conventional XRF system 300 that includes a microfocus x-ray tube 310 , an x-ray reflector 320 , and a detector 330 . X-ray fluorescence system 300 is configured to analyze a test sample 340 that includes a thin film layer 342 formed on a substrate 341 .
Microfocus x-ray tube 310 directs a bundle of diverging x-rays 350 at x-ray reflector 320 . X-ray reflector 320 reflects and focuses the diverging x-rays of x-ray beam 350 into a converging x-ray beam 360 , directed at thin film layer 342 . The x-rays of x-ray beam 360 cause characteristic x-rays 390 to be emitted by thin film layer 342 . The properties of characteristic x-rays 390 are then measured by x-ray detector 330 to determine the composition of thin film layer 342 , in a manner substantially similar to that used with respect to EMP system 200 shown in FIG. 2 . Detector 330 can comprise either an EDX or WDX detector, as described previously with respect to FIGS. 4 a and 4 b , respectively.
Because x-rays can penetrate a material much more easily than electrons can penetrate the same material, XRF systems are generally better suited to analyze thicker films than are EMP systems. Also, a vacuum chamber is not required for the generation of the source x-rays, which simplifies the design and operation of an XRF system. However, because the source x-rays are not absorbed by the film material as well as electrons would be, and because the source x-ray beam is not as intense as an electron beam can be, the resulting characteristic x-rays in an XRF system are weaker than the characteristic x-rays in an EMP system, making measurements on those characteristic x-rays significantly slower. Also, test samples having multiple thin film layers can be problematic since the source x-rays cannot be readily “tuned” to penetrate to a specific depth
Thus, it is clear that no single one of the aforementioned analysis techniques is ideal for all situations. However, having a different set of tools for each set of circumstances can be cumbersome and expensive. This problem can be mitigated somewhat by building multi-technique functionality into a single system. For example, Jordan Valley has produced a tool, the JVX-5000, that combines GXR and XRF capabilities. As noted previously, GXR analysis can be used to measure films less than 2000A thick, while XRF analysis is better suited for thicker films (such as ECP copper layers). However, the Jordan Valley tool incorporates an EDX detector to measure the characteristic x-rays generated during the XRF process, thereby significantly restricting the capabilities of the Jordan Valley tool. As described previously with respect to FIG. 4 a , the low resolution of an EDX detector limits its use to materials that generate x-rays having substantially different wavelengths.
Accordingly, it is desirable to provide a tool that includes multi-technique capabilities to overcome limitations associated with individual analysis techniques, while reducing instrument cost, part-count, and increasing analytical efficiency.
SUMMARY
The present invention provides a system and method for incorporating multiple film analysis techniques in a single instrument. This multi-technique capability can enable a user to perform a larger variety of analyses without purchasing multiple tools. Furthermore, combining the components required for the various analytical techniques in a single tool can lead to design and/or usage efficiencies that can reduce costs and increase throughput relative to separate single-technique tools.
According to an embodiment of the present invention, a film analysis system includes both EMP and XRF analysis capabilities. EMP capability is provided by an e-beam generator for directing an e-beam at a sample coating (i.e., a film or films to be analyzed) and an x-ray detector(s) for measuring characteristic x-rays generated by the sample coating in response to the source e-beam. The x-ray detector(s) can be either an EDX detector(s), a WDX detector(s), or a combination of both types. XRF capability is provided by a microfocus x-ray tube and an x-ray beam focusing system for focusing a source x-ray beam from the microfocus x-ray tube onto the sample coating to generate characteristic x-rays via x-ray fluorescence. These characteristic x-rays can be measured by the same x-ray detector(s) used in the EMP analysis, thereby reducing part count and cost of the film analysis system. Furthermore, the film analysis system beneficially enables rapid EMP analysis for thinner films, while providing the capability for performing XRF analysis for thicker films.
According to another embodiment of the present invention, a film analysis system includes both GXR and XRF analysis capabilities. GXR capability is provided by a microfocus x-ray tube, a x-ray beam focusing system for focusing the source x-ray beam from the microfocus x-ray tube onto a sample coating (i.e., a film or films to be analyzed), and a position-sensitive detector for measuring the interference pattern generated by the reflected x-rays from the sample coating. The film analysis system also includes a WDX x-ray detector(s) that can perform XRF analysis on the characteristic x-rays emitted by the sample coating in response the portion of the source x-ray beam that is absorbed, rather than reflected, by the sample coating. Because a separate microfocus x-ray tube and x-ray beam focusing system are not required for the XRF analysis, part count and cost of the film analysis system is reduced. Alternatively, a separate microfocus x-ray tube and x-ray beam focusing system for XRF analysis could be included so that operational settings could be optimized for both the GXR and XRF analyses. In either case, combining the two techniques in a single tool advantageously enables accurate GXR thickness measurement coupled with accurate XRF composition measurement. In addition, the film analysis system beneficially enables the GXR and XRF analyses to be performed simultaneously or in rapid succession with each other, thereby improving analysis throughput. Furthermore, by using a WDX detector(s), the resolution of the XRF analysis is significantly enhanced over conventional tools using an EDX detector(s).
According to another embodiment of the present invention, a film analysis system includes both GXR and EMP analysis capabilities. GXR capability is provided by a microfocus x-ray tube, a x-ray beam focusing system for focusing the source x-ray beam from the microfocus x-ray tube onto a sample coating (i.e., a film or films to be analyzed), and a position-sensitive detector for measuring the interference pattern generated by the reflected x-rays from the sample coating. EMP capability is provided by an e-beam generator for directing an e-beam at the sample coating, and an x-ray detector(s) for measuring characteristic x-rays generated by the sample coating in response to the source e-beam. The x-ray detector(s) can be either an EDX detector(s), a WDX detector(s), or a combination of both types. By combining the two techniques in a single tool, accurate GXR thickness measurement can be coupled with accurate XRF composition measurement. In addition, the film analysis system beneficially enables the GXR and EMP analyses to be performed simultaneously or in rapid succession, thereby improving analysis throughput.
According to another embodiment of the present invention, a film analysis system includes GXR, XRF, and EMP analysis capabilities. GXR capability is provided by a microfocus x-ray tube, a x-ray beam focusing system for focusing the source x-ray beam from the microfocus x-ray tube onto a sample coating (i.e., a film or films to be analyzed), and a position-sensitive detector for measuring the interference pattern generated by the reflected x-rays from the sample coating. EMP capability is provided by an e-beam generator for directing an e-beam at the sample coating, and an x-ray detector(s) for measuring characteristic x-rays generated by the sample coating in response to the source e-beam. The x-ray detector(s) can be either an EDX or WDX detector(s). To minimize component count, XRF capability can be provided by properly selecting and configuring the microfocus x-ray tube, so that a portion of the source x-ray beam is absorbed by the sample coating. The characteristic x-rays emitted by the sample coating in response to the absorbed source x-rays can then be measured by the x-ray detector(s) (used also in for EMP analysis).
Alternatively, to optimize XRF and GXR performance, a second microfocus x-ray tube can be included to generate the source x-ray beam for XRF analyses. In any case, combining all three techniques in a single tool provides maximum flexibility in film analysis, and allows for component count reduction and/or throughput enhancement, as described with respect to the aforementioned embodiments.
The present invention will be more fully understood in view of the following description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a conventional grazing incidence x-ray reflectometry (GXR) system.
FIG. 2 shows a conventional electron microprobe analysis (EMP) system.
FIG. 3 shows a conventional x-ray fluorescence (XRF) system.
FIG. 4 a shows a conventional energy-dispersive x-ray spectrometer (ESX).
FIG. 4 b shows a conventional wavelength-dispersive x-ray spectrometer (WDX).
FIG. 5 shows a film analysis system combining XRF and EMP, in accordance with an embodiment of the present invention.
FIG. 6 shows a film analysis system combining GXR and XRF using WDX, in accordance with an embodiment of the present invention.
FIG. 7 shows a film analysis system combining GXR and EMP, in accordance with an embodiment of the present invention.
FIG. 8 shows a film analysis system combining GXR, EMP, and XRF, in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
By combining the capability to perform multiple analysis techniques in a single instrument, the present invention advantageously improves overall tool expenses and/or improves analysis throughput.
Electron Microprobe Analysis and X-ray Fluorescence
An embodiment of the present invention provides a film analysis system that advantageously combines the rapid measurement capabilities of EMP for thinner films with the thicker film measurement capabilities of XRF. In accordance with an embodiment of the present invention, FIG. 5 shows a film analysis system 500 that comprises a microfocus x-ray tube 512 , an x-ray beam focusing system 520 , an e-beam generator 511 , and an x-ray detector 531 . Film analysis system is configured to analyze a test sample 540 that includes a sample coating 541 formed on a substrate 542 . Note that substrate 542 can comprise any material on which a coating can be formed, including silicon, gallium arsenide, and metal. Note also that sample coating 541 can comprise any material or materials that can be analyzed using EMP and/or XRF, including oxides, nitrides, copper, titanium, and tantalum, among others. Sample coating 541 can also comprise multiple layers or thin films, such as a copper layer formed over a titanium nitride or tantalum nitride layer.
To perform an EMP analysis, e-beam generator 511 directs an e-beam 580 at sample coating 541 . The high-energy electrons in e-beam 580 cause characteristic x-rays 590 to be emitted by sample coating 541 . Characteristic x-rays 590 are then measured by x-ray detector 531 to determine the composition and thickness of sample coating 541 . According to an embodiment of the present invention, x-ray detector 531 can comprise an EDX detector, as described with respect to FIG. 4 a . According to another embodiment of the present invention, x-ray detector 531 can comprise a WDX detector, as described with respect to FIG. 4 b , which would improve measurement resolution. Also, film analysis system 500 can comprise multiple x-ray detectors, as indicated by optional x-ray detector 532 . While only a single additional x-ray detector ( 532 ) is depicted for clarity, film analysis system 500 could comprise any number of x-ray detectors. Multiple WDX detectors would enable simultaneous measurement of characteristic x-rays having different wavelengths (i.e., characteristic x-rays from different elements in sample coating 541 ).
To perform an XRF operation, microfocus x-ray tube 512 directs an x-ray beam 550 at x-ray beam focusing system 520 . X-ray beam focusing system 520 focuses the diverging x-rays of x-ray beam 550 into a converging x-ray beam 560 , directed at sample coating 541 of test sample 540 . According to an embodiment of the present invention, x-ray beam focusing system 520 can comprise an x-ray reflector 521 that redirects and focuses x-ray beam 550 into x-ray beam 560 . X-ray reflector 521 could be a singly- or doubly-curved crystal, and could also be a monochromator to ensure that only x-rays of a particular wavelength are included in x-ray beam 560 . However, note that x-ray reflector 521 is depicted for explanatory purposes only, as x-ray beam focusing system 520 can comprise any system for focusing x-ray beam 550 onto sample coating 541 . For example, according to another embodiment of the present invention, x-ray beam focusing system 520 can comprise a polycapillary array, in which multiple tubular waveguides direct the incoming x-rays in x-ray beam 550 to a localized spot on sample coating 541 .
The x-rays in x-ray beam 560 cause characteristic x-rays 590 to be emitted by sample coating 541 . X-ray detector 531 then measures characteristic x-rays 590 to determine the composition and thickness of sample coating 541 , in a manner similar to that described with respect to the EMP analysis. If film analysis system 500 includes additional x-ray detectors such as x-ray detector 532 , measurements using those additional detectors could be taken at the same time. Because the XRF operation can use at least some of the same x-ray detector(s) as the EMP operation, the cost and complexity of film analysis system 500 is reduced.
The inclusion of both e-beam generator 511 and microfocus x-ray tube 512 greatly increases the flexibility of film analysis system 500 over conventional single-technique tools. For example, a semiconductor manufacturing process might include first process step comprising the formation of a copper (Cu) seed/tantalum nitride (TaN) barrier film stack on a silicon X wafer, followed by a second process step comprising electro-plating a thick copper layer over the Cu—TaN seed/barrier film stack. After the first process step, film analysis system 500 could be used to perform an EMP analysis on the thin films making if up the Cu—TaN seed/barrier stack. Then after the second process step, film analysis system 500 could be used to perform an XRF analysis on the thick ECP copper layer.
According to an embodiment of the present invention, e-beam generator 511 could be a variable-power device capable of producing an e-beam 580 having a 5 keV-35 keV energy level, while microfocus x-ray tube 512 could be configured to generate molybdenum x-rays (Mo-K). During the EMP analysis, the Cu-K, Ta-L, and N-K characteristic x-ray intensities could be measured at e-beam energies of 10 keV, 15 keV, and 25 keV to determine the copper seed film and tantalum nitride barrier film thicknesses, along with the tantalum-to-nitrogen ratio in the TaN barrier film. Note that simultaneously measuring all three types of x-rays would require three different x-ray detectors. Note further that, as mentioned previously, WDX detectors would have to be used to differentiate the Cu-K and Ta-L x-rays, as well as detect the softer N-K x-rays. Then during the XRF analysis, the Cu-K and Ta-L x-rays generated in response to the Mo-K x-rays from microfocus x-ray tube 512 could be measured to determine the total thickness of the ECP copper layer and the copper seed film. Note that a similar analytical procedure could be applied to a sample coating that included a titanium nitride barrier film instead of tantalum nitride
Grazing Incidence X-ray Reflectometry and X-ray Fluorescence
In accordance with an embodiment of the present invention, FIG. 6 shows a film analysis system 600 that advantageously combines the precision thin film thickness measurement capabilities of GXR with the high-resolution composition measurement capabilities of XRF using WDX detectors. Film analysis system 600 comprises a microfocus x-ray tube 612 , an x-ray beam focusing system 620 , a WDX x-ray detector 631 , and a position-sensitive detector 633 . Film analysis system 600 is configured to analyze a test sample 640 that includes a sample coating 641 formed on a substrate 642 . As noted previously, substrate 642 can comprise any material on which a film can be formed, while sample coating 641 can comprise a single or multiple films of various compositions.
To perform a GXR analysis, microfocus x-ray tube 612 directs a source x-ray beam 650 at x-ray beam focusing system 620 , which reflects and focuses the diverging x-rays of x-ray beam 650 into a converging x-ray beam 660 directed at sample coating 641 . According to an embodiment of the present invention, x-ray beam focusing system 620 can comprise an x-ray reflector 621 that redirects x-ray beam 650 into converging x-ray beam 660 , focused on a spot on the surface of sample coating 641 . X-ray reflector 621 could be a singly- or doubly-curved crystal, and could also be a monochromator to ensure that only x-rays of a particular wavelength are included in x-ray beam 660 . However, note that x-ray reflector 621 is depicted for explanatory purposes only, as x-ray beam focusing system 620 can comprise any system for focusing x-ray beam 650 onto sample coating 641 . For example, x-ray beam focusing system 620 could comprise a polycapillary array.
Converging x-ray beam 660 is then reflected by sample coating 641 as an x-ray beam 670 onto position-sensitive detector 633 . Position-sensitive detector 633 resolves the varying intensity of the interference pattern caused by constructive and destructive interference of x-ray reflections at the top and bottom surfaces of sample coating 641 . The resulting reflectivity curve of intensity versus position can then be used to calculate the thickness of sample coating 641 , as described previously with respect to FIG. 1 .
Film analysis system 600 can also perform an XRF analysis by making use of the fact that x-ray beam 660 is typically not totally reflected by sample coating 641 . During the GXR process, a portion of x-ray beam 660 is absorbed by sample coating 641 , rather than being reflected. Note that this proportion of absorbed x-rays can be adjusted by properly selecting and configuring microfocus x-ray tube 612 and x-ray focusing system 620 . The absorbed x-rays excite the atoms of sample coating 641 , causing them to generate characteristic x-rays 680 . Characteristic x-rays 680 can then be measured by x-ray detector 631 to determine the composition of sample coating 641 . Note that film analysis system 600 can comprise multiple WDX x-ray detectors, as indicated by optional WDX x-ray detector 632 . While only a single additional WDX x-ray detector ( 632 ) is depicted for clarity, film analysis system 600 could comprise any number of additional WDX x-ray detectors and/or an EDX detector. Multiple WDX detectors would enable simultaneous measurement of characteristic x-rays having different wavelengths (i.e., characteristic x-rays from different elements in sample coating 641 ).
By combining GXR and XRF capabilities in film analysis system 600 , the thickness of sample coating 641 can be accurately measured using GXR while the composition of sample coating 641 can be accurately determined using XRF. Furthermore, the use of WDX x-ray detector(s) 631 (and 632 ) enables film analysis system 600 to measure low-energy characteristic x-rays (e.g., N-K x-rays) and closely spaced x-rays (e.g., Cu-K and Ta-L x-rays) that cannot be resolved by the ESX detectors used in conventional tools combining GXR and XRF. For example, sample coating 641 could comprise a copper seed film formed over a tantalum nitride barrier film. According to an embodiment of the present invention, microfocus x-ray tube 612 could be configured to generate high-energy molybdenum x-rays (Mo-K) used to perform a GXR analysis on the copper seed film. At the same time, the Mo-K x-rays would be inducing Cu-K, Ta-L, and N-K characteristic x-rays from the seed/barrier stack, allowing an XRF analysis to be performed on the tantalum nitride barrier film. Because microfocus x-ray tube 612 generates high-energy Mo-K x-rays, a thick ECP copper layer subsequently formed over the copper seed film could be measured by film analysis system 600 using XRF.
According to another embodiment of the present invention, microfocus x-ray tube 612 could be configured to generate lower-energy tungsten x-rays (W-L), in which case simultaneous GXR and XRF analyses could be performed on the seed/barrier stack. A thick ECP copper film could no longer bereadily measured by such a system, and a smaller proportion of the low-energy W-L x-rays would be absorbed by sample coating 641 , resulting in a reduction in the strength of characteristic x-rays 680 . However, this reduced absorption also means a stronger reflected signal, thereby enhancing the GXR fidelity of film analysis system 600 . Note that according to another embodiment of the present invention, microfocus x-ray tube 612 could be configured to generate low-energy copper Cu-K x-rays to provide similar measurement capabilities.
In accordance with another embodiment of the present invention, separate x-ray microfocus tubes could be incorporated into film analysis system 600 , as indicated by optional microfocus tube 613 . One microfocus x-ray tube could then provide the (lower-energy) x-rays for the GXR analysis, while the other could provide the (higher-energy) x-rays for the XRF analysis. For example, microfocus x-ray tube 613 could be configured to provide high-energy Mo-K x-rays for XRF, directing an x-ray beam 651 at an x-ray beam focusing system 622 , which focuses a reflected x-ray beam 661 onto sample coating 641 . As previously described with respect to x-ray beam focusing system 620 , x-ray beam focusing system 622 can comprise any type of beam-guiding system, including an x-ray reflector 623 as depicted, or a polycapillary array (not shown). The high-energy Mo-K x-rays can then cause sample coating 641 to emit strong characteristic x-rays 680 , optimizing the associated XRF analysis. Meanwhile, microfocus x-ray tube 612 could be configured to provide lower-energy W-L (or Cu-K) x-rays for the GXR analysis, maximizing the strength of the interference pattern provided at position-sensitive detector 633 .
Grazing Incidence X-ray Reflectometry and Electron Microprobe Analysis
In accordance with an embodiment of the present invention, FIG. 7 shows a film analysis system 700 that combines GXR and EMP capabilities in a single tool, advantageously combining the precision thin film thickness measurement capabilities of GXR with the composition measurement capabilities of EMP. Film analysis system 700 comprises a microfocus x-ray tube 712 , an x-ray beam focusing system 720 , a position-sensitive detector 733 , an e-beam generator 711 , and an x-ray detector 731 . Film analysis system 700 is configured to analyze a test sample 740 that includes a sample coating 741 formed on a substrate 742 . As noted previously, substrate 742 can comprise any material on which a film can be formed, while sample coating 741 can comprise a single or multiple films of various compositions.
To perform a GXR analysis, microfocus x-ray tube 712 directs a source x-ray beam 750 at x-ray beam focusing system 720 , which reflects and focuses the diverging x-rays of x-ray beam 750 into a converging x-ray beam 760 directed at sample coating 741 . According to an embodiment of the present invention, x-ray beam focusing system 720 can comprise an x-ray reflector 721 that redirects x-ray beam 750 into converging x-ray beam 760 , focused on a spot on the surface of sample coating 741 . X-ray reflector 721 could be a singly- or doubly-curved crystal, and could also be a monochromator to ensure that only x-rays of a particular wavelength are included in x-ray beam 760 . However, note that x-ray reflector 721 is depicted for explanatory purposes only, as x-ray beam focusing system 720 can comprise any system for focusing x-ray beam 750 onto sample coating 741 . For example, by configuring microfocus x-ray tube 712 with an additional non-focusing monochromator to produce an x-ray beam 750 made up of x-rays of a single wavelength, monochromatizing by x-ray beam focusing system 720 would not be required, and x-ray beam focusing system 720 could comprise a polycapillary array.
Converging x-ray beam 760 is then reflected by sample coating 741 as an x-ray beam 770 onto position-sensitive detector 733 . Position-sensitive detector 733 resolves the varying intensity of the interference pattern caused by constructive and destructive interference of x-ray reflections at the top and bottom surfaces of sample coating 741 . The resulting reflectivity curve of intensity versus position can then be used to calculate the thickness of sample coating 741 , as described previously with respect to FIG. 1 .
To perform an EMP analysis, e-beam generator 711 directs an e-beam 780 at sample coating 741 . The high energy electrons in e-beam 780 cause characteristic x-rays 790 to be emitted by sample coating 741 . Characteristic x-rays 790 are then measured by x-ray detector 731 to determine the composition and thickness of sample coating 741 . According to an embodiment of the present invention, x-ray detector 731 can comprise an EDX detector, as described with respect to FIG. 4 a . According to another embodiment of the present invention, x-ray detector 731 can comprise a WDX detector, as described with respect to FIG. 4 b , which would improve measurement resolution. Also, film analysis system 700 can comprise multiple x-ray detectors, as indicated by optional x-ray detector 732 . While only a single additional x-ray detector ( 732 ) is depicted for clarity, film analysis system 700 could comprise any number of additional EDX and/or WDX x-ray detectors. Multiple WDX detectors would enable simultaneous measurement of characteristic x-rays having different wavelengths (i.e., characteristic x-rays from different elements in sample coating 741 ).
By combining GXR and EMP capabilities in film analysis system 700 , the relative weaknesses of each technique can be compensated for by the other. As noted previously, GXR analysis typically does not provide good composition measurement, while EMP typically cannot accurately measure the thickness of a film. However, in film analysis system 700 , the thickness of sample coating 741 can be accurately measured using GXR while the composition of sample coating 741 can be accurately determined using EMP. Furthermore, both types of analysis can be performed simultaneously or in rapid succession with each other, significantly improving analysis throughput over conventional systems in which the GXR analysis would be performed in one tool, and the EMP analysis would have to be performed in a different tool, after completion of the GXR analysis.
Grazing Incidence X-ray Reflectometry, Electron Microprobe Analysis, and X-ray Fluorescence
In accordance with an embodiment of the present invention, FIG. 8 shows a film analysis system 800 that advantageously combines the precision film thickness measurement capabilities of GXR with the efficient thin film composition measurement capabilities of EMP and the thicker film composition measurement capabilities of XRF. Film analysis system 800 comprises a microfocus x-ray tube 812 , an x-ray beam focusing system 820 , an e-beam generator 811 , an x-ray detector 831 , and a position-sensitive detector 833 . Film analysis system 800 is configured to analyze a test sample 840 that includes a sample coating 841 formed on a substrate 842 . As noted previously, substrate 842 can comprise any material on which a film can be formed, while sample coating 841 can comprise a single or multiple films of various compositions.
To perform a GXR analysis, microfocus x-ray tube 812 directs a source x-ray beam 850 at x-ray beam focusing system 820 , which reflects and focuses the diverging x-rays of x-ray beam 850 into a converging x-ray beam 860 directed at sample coating 841 . According to an embodiment of the present invention, x-ray beam focusing system 820 can comprise an x-ray reflector 821 that redirects x-ray beam 850 into converging x-ray beam 860 , focused on a spot on the surface of sample coating 841 . X-ray reflector 821 could be a singly- or doubly-curved crystal, and could also be a monochromator to ensure that only x-rays of a particular wavelength are included in x-ray beam 860 . However, note that x-ray reflector 821 is depicted for explanatory purposes only, as x-ray beam focusing system 820 can comprise any go system for focusing x-ray beam 850 onto sample coating 841 . For example, by configuring microfocus x-ray tube 812 with an additional monochromator to produce an x-ray beam 850 made up of x-rays of a single wavelength, monochromatizing by x-ray beam focusing system 820 would not be required, and x-ray beam focusing system 820 could comprise a polycapillary array.
Converging x-ray beam 860 is then reflected by sample coating 841 as an x-ray beam 870 onto position-sensitive detector 833 . Position-sensitive detector 833 measures the varying intensity of the interference pattern caused by constructive and destructive interference of x-ray reflections at the top and bottom surfaces of sample coating 841 . The resulting reflectivity curve of intensity versus position can then be used to calculate the thickness of sample coating 841 , as described previously with respect to FIG. 1 .
As described previously with respect to FIG. 6, film analysis system 800 can also perform an XRF analysis by measuring characteristic x-rays 890 generated by those x-rays in x-ray beam 860 that are absorbed by sample coating 842 , rather than being reflected. Characteristic x-rays 890 can be measured by x-ray detector 831 to determine the composition of sample coating 841 . According to an embodiment of the present invention, x-ray detector 831 can comprise an EDX detector, as described with respect to FIG. 4 a . According to another embodiment of the present invention, x-ray detector 831 can comprise a WDX detector, as described with respect to FIG. 4 b , which would improve measurement resolution. Also, film analysis system 800 can comprise multiple x-ray detectors, as indicated by optional x-ray detector 832 . While only a single additional x-ray detector ( 832 ) is depicted for clarity, film analysis system 800 could comprise any number of x-ray detectors. For example, multiple WDX detectors would enable simultaneous measurement of characteristic x-rays having different wavelengths (i.e., characteristic x-rays from different elements in sample coating 841 ).
In accordance with another embodiment of the present invention, a separate x-ray microfocus tube 813 could provide the excitation source for the XRF analysis. Microfocus x-ray tube 813 would then direct an x-ray beam 851 at an x-ray beam focusing system 822 , which would focus a reflected x-ray beam 861 onto sample coating 841 . As previously described with respect to x-ray beam focusing system 820 , x-ray beam focusing system 822 could comprise any type of beam-guiding system, including an x-ray reflector 823 as depicted, or a polycapillary array (not shown). X-ray detector(s) 831 (and 832 ) would then measure characteristic x-rays 890 generated by sample coating 841 in response to x-ray beam 861 .
Regardless of whether or not film analysis system 800 includes a separate x-ray microfocus tube for XRF analysis, at least some of the same x-ray detector(s) used in the XRF operation can also be used to perform an EMP analysis, by measuring characteristic x-rays 890 generated in response to an e-beam 880 from e-beam generator 811 . As previously described with respect to FIG. 5, by sharing some of the same x-ray detectors for both XRF and EMP, the benefits of both analysis techniques can be provided with a minimum of cost and a minimum of equipment. By using the same microfocus x-ray tube 812 for GXR and XRF, the cost and complexity of film analysis system 800 is further reduced, even as the overall capabilities of film analysis system 800 are increased.
Thus, a multi-technique film analysis system is described. Although the present invention has been described in connection with several embodiments, it is understood that this invention is not limited to the embodiments disclosed, but is capable of various modifications that would be apparent to one of ordinary skill in the art. Thus, the invention is limited only by the following claims. | A thin film analysis system includes multi-technique analysis capability. Grazing incidence x-ray reflectometry (GXR) can be combined with x-ray fluorescence (XRF) using wavelength-dispersive x-ray spectrometry (WDX) detectors to obtain accurate thickness measurements with GXR and high-resolution composition measurements with XRF using WDX detectors. A single x-ray beam can simultaneously provide the reflected x-rays for GXR and excite the thin film to generate characteristic x-rays for XRF. XRF can be combined with electron microprobe analysis (EMP), enabling XRF for thicker films while allowing the use of the faster EMP for thinner films. The same x-ray detector(s) can be used for both XRF and EMP to minimize component count. EMP can be combined with GXR to obtain rapid composition analysis and accurate thickness measurements, with the two techniques performed simultaneously to maximize throughput. | 6 |
BACKGROUND OF THE INVENTION
(a) Technical Field of the Invention
The present invention relates to a cable winch for vehicles, and in particular, to an improved structure of a cable winch with respect to the structure of planetary gear and clutching planetary gear, wherein the cable winch is rigid and secured.
(b) Description of the Prior Art
U.S. Pat. No. 6,663,086 entitled “Structure of a Cable Winch Used in Vehicle” issued to the present applicant discloses, as shown in FIG. 1 , a cable winch having a rolling cylinder component 20 having one end being mounted with a gear speed-reducing device 30 and the other end being mounted with a motor 40 so as to transmit the power of the motor 40 to the rolling cylinder component 20 by the gear speed-reducing device 30 allowing the rolling up of the cable 21 . The gear speed-reducing device includes a control button 31 , a transmission shaft 32 , a gear box 33 , a sun gear 34 , a plurality of planetary gear sets, a clutch and planet gear set 36 and a fastening ring 37 .
One end of the transmission shaft 32 is inserted into the inner hole 312 of the control button 31 and a fastening ring 321 is used to fasten. The tubular section 311 of the control button 31 is pivotally inserted into the through hole 332 position of the gear box 33 and the protruded peg 313 is matched to the recess 333 of the gear box 33 . The transmission shaft 32 is mounted at the center of the gear box 33 and the transmission shaft 32 of the gear box 33 is then mounted in sequence with a corrugated pad 38 , sun gear 34 , a plurality of planetary gear set 35 and the clutch and planet gear set 36 . A fastening ring 37 is used to fasten the moving gear 363 at the recess 322 of the transmission shaft 32 . The sun gear 34 and the planetary gear set 35 and the clutch and planet gear 36 can accept the input power from the transmission shaft 32 , and the planetary gear set 35 and the clutch and planet gear set 36 are in engagement and driven with the inner circular teeth 331 of the gear box 33 to form planetary gear-reducing device 30 . The gear box 33 is locked at one end of the rolling cylinder 20 with screw bolt 334 and the moving gear 363 of the clutch and planet gear set 36 is in engagement with the teeth portion 23 of the rolling cylinder 22 , and the transmission shaft 32 passes through the rolling cylinder 22 . The other end of the rolling cylinder 20 is pivotally mounted to the rotating shaft 41 of the mounted with a corrugated pad and a seal 44 and a screw bolt 43 is used to lock the motor 40 to the other end of the rolling cylinder 20 and the insertion hole 42 of the rotating shaft 41 is in engagement with the end terminal of the transmission shaft 32 and obtain power output from the motor 40 .
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a cable winch structure having a rolling cylinder connected to a speed-reducing device at one lateral side, and having a motor connected to one end of the roller cylinder so that the speed reducing motor transmits the power of the motor to the roller cylinder facilitating traction of the cable and the speed-reducing device including an control button, a transmission shaft, a gear box, sun gear, a predetermined planetary gear component on a base plate, a clutching gear module on a base plate and fastening rim, characterized in that the perimeter edge of the planetary gear component base plate is an integral unit perpendicularly folded to form a plurality of bridging upright faces, and a covering plate provided to the planetary gear component has perimeter edge stamped to form a plurality of recessed slots, in combination the upright faces engage with the recessed slots and then welded to enhance the strength of combination of the planet gear module the perimeter edge of the clutching planetary gear component base plate is an integral unit perpendicularly folded to form a plurality of bridging upright faces, and a covering plate provided to the clutching planet module has perimeter edge which stamped to form a plurality of recessed slots, in combination the upright faces engage with the recessed slots and then welded to enhance the strength of combination of the clutching planetary gear component to provide rigid structure of the cable winch for automobiles.
Another object of the present invention is to provide a cable winch structure for vehicle, wherein the edge of the base plate of the planetary gear component is a plurality of bridging upright surface to match with the plurality of recessed slots of the covering plate, and the bridging upright surface is mounted onto the recessed slots which are welded together to provide a secured structure.
A further object of the present invention is to provide a cable winch structure, wherein the edge of the base plate of the planetary gear component is a plurality of bridging upright surface to match with the plurality of recessed slots of the covering plate, and the bridging upright surface is mounted onto the recessed slots which are welded together to avoid dislocation of the planetary gear component and the front covering of the clutch and planetary gear component when the cable pulls a load or a vehicle.
The foregoing object and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts.
Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective exploded view of a winch structure of U.S. Pat. No. 6,663,086.
FIG. 2 is a perspective exploded view of the cable winch of the present invention.
FIG. 3 is a sectional view of a partial winch of the present invention.
FIG. 4 is a perspective exploded view of the planetary gear of the present invention.
FIG. 5 is a perspective view of the planetary gear of the present invention.
FIG. 6 is an exploded perspective view of the planetary gear of the present invention.
FIG. 7 is a perspective view of the clutching gear of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following descriptions are of exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims.
Referring to FIGS. 2 and 3 , there is shown a cable winch structure for vehicle having a rolling cylinder component 50 with one side pivotally mounted to a speed-reducing device 60 . The other end of the rolling cylinder component 50 is connected to a motor 70 so as to transmit power of the motor 70 to the rolling cylinder component 50 by the speed-reducing device 60 so as to appropriately wind-up the cable 51 . The speed-reducing device 60 has a control button 61 , a transmission shaft 62 , a gear box 63 , sun gear 64 , a plurality of planetary gear component 65 , clutch and planetary gear component 66 and a fastening rim 67 . One end of the transmission shaft 62 is inserted into the inner hole 611 of the control button 61 and is then fastened by the fastening rim 621 . The tubular section 612 of the control button 61 is pivotally mounted at the through hole 631 of the gear box 63 , and the peg 613 of the control button 61 is aligned with the recess 632 of the gear box 63 . The transmission shaft 62 is inserted into the center of the gear box 63 , and the transmission shaft 62 of the gear box 63 is mounted with a corrugated pad 68 , the sun gear 64 , a plurality of planetary gear components 65 and the clutch and planetary gear components 66 . The fastening rim 67 is fastened at the recess 622 of the transmission shaft 62 so as to pivotally secure the top face of the actuating gear 661 of the clutch and planetary gear component 66 , and at the same time, the above components are mounted, and the sun gear 64 and various planetary gear component 65 and the clutch and the planetary gear component 66 can accept the power input of the transmission shaft 62 . The planetary gear component 65 and the clutch and planetary gear component 66 are engagedly transmitting with the inner rim gear 633 of the gear box 63 , forming into planetary gear speed-reducing device 60 . The gear box 63 is locked to one end of the rolling cylinder 50 with bolt 634 and the actuating gear 661 of the clutch and planetary gear component 66 is in engagement with the gear section 53 of the rolling cylinder 52 . The transmission shaft 62 passes through the rolling cylinder 52 . The other end of the rolling cylinder component 50 is pivoted to the rotating shaft of the motor 70 by means of corrugated pad 71 and the pad 72 . Nut 73 locks the motor 70 at the other end of the rolling cylinder component 50 and the insertion hole of the rotating shaft engages with the end of the transmission shaft 62 so that the power output of the motor 70 is obtained.
Referring to FIGS. 4 and 5 , the perimeter edge of the planetary gear component 65 base plate 651 is an integral unit perpendicularly folded to form a plurality of bridging upright faces, and the covering plate 653 of the planetary gear component has perimeter edge stamped to form a plurality of recessed slots 654 . When in combination, the upright faces 652 are engaged with the recessed slot 654 and are then welded to enhance the strength of the combination.
Referring to FIGS. 6 and 7 , the perimeter edge of the clutch and planetary gear component 66 base plate 662 is an integral unit perpendicularly folded to form a plurality of bridging upright faces 663 , and a covering plate 664 is provided to the clutch and planetary gear component and has perimeter edge which stamped to form a plurality of recessed slots 665 . When in combination, the upright faces 663 are in engaged with the recessed slots 665 and are then welded to enhance the strength of the combination of the clutch and planetary gear component 66 to provide a strong combination.
It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above.
While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention. | A cable winch structure for vehicles is disclosed. The cable winch includes a rolling cylinder connected to a speed-reducing device at one lateral side, and having a motor connected to one end of the roller cylinder so that the speed reducing motor transmits the power of the motor to the roller cylinder facilitating traction of the cable and the speed-reducing device. | 1 |
BACKGROUND OF THE INVENTION
Automatic systems for shutting down internal combustion engines have typically responded when the engine's operating temperature exceeds safe engine performance limits. U.S. Pat. No. 4,074,672, "Shutoff Apparatus for Internal Combustion Engines", discolses such a shutdown system.
Shutdown systems are intended to be safety devices to protect their guarded engines. Some shutdown devices, however, create additional safety concerns by switching operating circuitry to ground. This action creates current surges and high circuit temperatures which may damage circuit elements.
The shutdown circuit in U.S. Pat. No. 4,074,672, is designed for use with ignition systems for spark-fired internal combustion engines. The circuit uses a sensor to detect when the engine is overheating. An overheated engine status switches the sensor and completes a path to ground for current normally flowing to the ignition coil for the engine. The grounded ignition coil no longer produces the needed voltage to fire the engine's spark plugs. The engine, therefore, shuts off.
The grounding circuit in U.S. Pat. No. 4,074,672, has the potential of creating current surges and high temperatures. These conditions may damage such components as an induction coil in an ignition system, solenoids in fuel valves for diesel engines, or windings on electrical motors. High temperatures during switching could also ignite flammable materials in the circuit's environment causing personal injury and equipment damage.
The above deficiencies in a grounding engine shutdown system are overcome by the invention. Instead of grounding ignition system components, the invention disconnects the circuit which energizes a power generating device. This act produces no excessive current or heat surges in the circuit.
The invention's operation may be generally applied to power generating and power transmitting devices. The invention senses a potentially device damaging condition, switches open the circuit energizing that power generating or power transmitting device, and safely turns off the device. Additionally, the invention provides diagnostic feedback to an operator to identify why the power generating or power transmitting device was automatically turned off.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a block diagram showing a power source, power generating or power transmitting device, and the invention's power interruption system.
FIG. 2 is a circuit diagram of the invention's power interruption system.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A power source 1 (FIG. 1) activates a power generating device 2, such as an internal combustion engine or diesel engine. A power interruption system 3, between the power source 1 and power generating device 2, functions as a safety device by sensing and responding to a need for interrupting the operation of the power generating device 2.
The power interruption system 3 (FIG. 2) and power generating device 2 are energized by power source 1 (FIG. 1), typically a battery 4 (FIG. 2) and an ignition system 5. A fuse 6 limits the quantity of electrical power delivered to the power interruption system 3 and the power generating device 2.
Electrical power branches to water temperature indicator light 7 and oil pressure indicator light 8 and warning horn 9, then to the reverse current flow ends of water temperature diode 10, oil pressure diode 11, and relay diode 12. Electrical current will not flow through diodes 10, 11, 12 until the normally open water temperature sensor 13 or oil pressure sensor 14 closes to complete a circuit from battery 4 to ground 15. Water temperature sensor 13 may be designed to close when the sensed temperature rises to a predetermined level which threatens the safe operation of power generating device 2. Similarly, oil pressure sensor 14 may be designed to close when the sensed oil pressure falls below a predetermined level which threatens the safe operation of power generating device 2.
Electrical current from fuse 6 also branches to a normally closed, momentary override switch 16, then to the system armed indicator light 17 and relay 18. The system armed indicator light 17 will illuminate when the power interruption system 3 is on because of the path from battery 4 to ground 15 through the system armed indicator light 17 and the normally closed, momentary override switch 16.
Electrical current flows through relay 18 to the forward current flow and of warning horn diode 11. Relay 18 will energize and interrupt operation of power generating device 2 when water temperature sensor 13 or oil pressure sensor 14 closes to complete a path to ground through diodes 10, 11, or 12.
Electrical current flows from battery 4 through ignition system 5, the normally closed portion of relay 18, energy transmission component 19, and into power generating device 2. Energy transmission component 19 may be an ignition coil, fuel valve, or unnecessary when the power generating device 2 is respectively an internal combustion engine or diesel engine.
The normally closed portion of relay 18 allows power generating device 2 to operate if power interruption system 3 is turned off because of a broken fuse 6 or manual switch 20 in the off position. This manual switch 20 allows optional operation of the power interruption system 3.
POWER INTERRUPTION OPERATION
The power interruption system 3 turns off power generating device 2 by energizing relay 18.
If water temperature sensor 13 closes because of excessively high water temperature, a completed circuit to ground occurs. Electrical current flows from battery 4 through water temperature indicator light 8 and water temperature sensor 13 to ground 15. Similarly, electrical current flows from battery 4 through warning horn 9, water temperature diode 10, and water temperature sensor 13 to ground 15. Similarly, electrical current flows from battery 4 through override switch 16, relay 18, relay diode 12, water temperature diode 10, and water temperature sensor 13 to ground 15. This completed current flow through relay 18 energizes relay electromagnet 21, pulls moveable relay throw 22 away from the contacts 23 leading to energy transmission component 19 and turns off power generating device 2.
The closing of water temperature sensor 13 will not illuminate oil pressure indicator light 7 because no path to ground 15 is completed through oil pressure sensor 14. If oil pressure sensor 14 closes because of excessively low oil pressure, the power interruption system 3 would illuminate the oil pressure indicator light 7, not the water temperature indicator light 8. The balance of the power interruption system 3 reacts as described when the water temperature sensor 13 closes.
Override switch 16 is included in the power interruption system 3 for emergency operation of power generating device 2. An operator may hold open override switch 16 so no current flows through relay 18 eventhough water temperature sensor 13 or oil pressure sensor 14 is closed. Consequently, relay electromagmet 21 would not be energized and current would flow through relay throw 22, contacts 23, energy transmission componet 19, and power generating device 2. An example of such an emergency use would be to keep an engine running long enough to move the engine driven vehicle out of traffic and onto a road shoulder.
The power interruption system 3 may include a delay device which maintains current flow through relay 18 for a predetermined time after water temperature sensor 13 or oil pressure sensor 14 closes. This optional delay feature gives a vehicle operator time to move the vehicle out of traffic and onto a road shoulder. Additionally, the vehicle's standard horn may be used as a second warning horn 24 so the movement of relay throw 22 directs current flow to the second warning horn 24. Likewise, multiple sensors for various vehicle functions, such as transmission and power train operation, could be added to the power interruption system. These would expand the diagnostic and power generating device shutdown capability of the system. | A power generating device requiring the transmission of power has a power interruption system. This system is continuously energized and has a power transmission network for the power generating device. The system has sensors for detecting a need to interrupt power transmission to the power generating device. A switching circuit, triggered by the sensors, energizes a switching device to interrupt the transmission of power to the power generating device. | 1 |
[0001] This application is a National Stage completion of PCT/EP2009/050971 filed Jan. 29, 2009, which claims priority from German patent application serial no. 10 2008 000 431.6 filed Feb. 28, 2008.
FIELD OF THE INVENTION
[0002] The invention concerns a component with inner and outer teeth, and a method for manufacturing the component.
BACKGROUND OF THE INVENTION
[0003] In an older application by the present applicant with official file number DE 10 2007 021 194.7 a component with inner and outer teeth is disclosed, which is produced as a composite structure made from a basic body and an additional component in the form of a sheet element. The component is preferably designed as the ring gear of a planetary transmission and the sheet element as a disk carrier for the disks of a shifting element—for which purpose the sheet element comprises a corresponding carrier profile.
[0004] From German patent specification 23 10 288 a planetary transmission with a ring gear is known, which is formed as a toothed rim which engages with planetary gears. The toothed rim is connected with positive interlock in the rotational direction to a drum and is fixed relative to the drum in the axial direction by means of stop elements. Drive in the rotational direction takes place by means of teeth arranged radially on the outside of the toothed rim, which engage in projections on the drum. The drum and its toothed rim functions only as a ring gear and is not designed as a disk carrier.
[0005] A disadvantage of the known drum and also of the disk carrier of the older application is that the sheet components provided with a driving profile are relatively weak in the tangential and radial directions, i.e. their shape stability is not great, so at high rotation speeds, under the influence of centrifugal force they tend to “lift off”, i.e. the profile flattens and their diameter tends to increase. Consequently, such sheet components are not very resistant to high speeds.
SUMMARY OF THE INVENTION
[0006] The purpose of the present invention is to provide a component of the type mentioned at the start, which withstands even higher rotation speeds and maintains its shape. A further purpose of the invention is to provide a method for manufacturing such a component, which enables it to be produced economically.
[0007] According to the invention, it is provided that the sheet component is connected to the basic body in the tangential and radial direction with positive interlock. Thanks to the positive connection in the radial direction the sheet component is prevented from deforming under the effect of centrifugal force, since it is held in position by the more rigid basic body. This results in higher resistance to high speeds for the components according to the invention.
[0008] In an advantageous design the outer teeth of the sheet component are formed as a driving profile, in which corresponding driving teeth arranged on the basic body engage with positive interlock. The driving teeth on the basic body need not extend over the whole of its circumference, but can be distributed zonally over individual sectors on the circumference. This positive connection between the basic body and the sheet component ensures torque transfer between the two components.
[0009] In an advantageous design the driving teeth on the basic body are teeth which are back-tapered or undercut in the area of the tooth base. In this way notches are formed on each side of the tooth base. The driving profile of the sheet component engages in these notches or undercut areas at the bases of the teeth, in such manner that an interlocked connection in the radial direction is formed. Thus, with its driving profile the sheet component conforms to the contour of the driving teeth on the basic body and so forms between adjacent teeth a kind of dovetail connection which prevents radial movement of the sheet component—for example due to the effect of centrifugal force at higher rotation speeds. This radial securing brings the advantage of a greater resistance to high rotation speeds for the component.
[0010] In an advantageous design, once the sheet component has been pushed onto the basic body the driving profile can be pressed into the undercut areas by deformation, in particular stretching the material in the tangential direction. This produces an interlocked clamping together of the two components, which is permanent because of the plastic deformation of the sheet component. At the same time, the frictional locking of the two components fixes the sheet component onto the basic body.
[0011] In a further advantageous design, the component has two functions: on the one hand the component is designed as a disk carrier, i.e. the inner disks of a disk set for a shifting element, for example a clutch or a brake, engage from the outside in the driving profile. On the other hand, the basic body forms a ring gear with inner teeth, which engage with planetary gearwheels of a planetary transmission. As the material for the basic body, a gearwheel material such as case-hardening steel can preferably be used for making the inner teeth. In contrast, for the disk carrier deep-drawing steel is preferably used. The driving profile is preferably formed as a trapezium profile.
[0012] In a further advantageous design the component or ring gear comprises a ring gear carrier which—like the disk carrier—is made as a sheet component, in particular a disk, which is advantageously connected with positive interlock to the basic body. This enables the ring gear with its disk carrier to be produced inexpensively.
[0013] The objective of the invention is also achieved by a method. According to the invention, it is provided that the basic body and the sheet component are first made separately, and are then joined. The basic body is preferably made by machining, while the sheet component, in particular its driving profile, are produced without machining, i.e. by deformation.
[0014] In an advantageous design, to produce the driving profile a preliminary profile is made first and, once the sheet component has been joined to the basic body, then the final profile is produced, which forms the positive interlock in the radial direction between the basic body and the sheet component. The preliminary profile allows the disk body to be pushed easily onto the basic body (pre-assembly).
[0015] Thereafter, by radial blocking or pressing on the concave areas, the material can be stretched in the tangential direction so that the material is forced into the undercut areas at the bases of the teeth. This results in a firm, close and durable clamping of the tooth bases by the driving profile of the sheet component. The method according to the invention is economical, particularly since no machining is involved, and therefore results in low manufacturing costs of the component according to the invention, in particular a transmission component.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] An example embodiment of the invention is illustrated in the drawing and is described in more detail below.
[0017] The drawing shows:
[0018] FIG. 1 : A ring gear carrier (individual component);
[0019] FIG. 2 : A basic body (individual component);
[0020] FIG. 3 : A disk carrier (individual component);
[0021] FIG. 4 : A ring gear with disk carrier (assembly);
[0022] FIG. 5 : A different view of the ring gear of FIG. 4 ;
[0023] FIG. 6 : Partial section through the disk carrier and the basic body before deformation; and
[0024] FIG. 7 : Partial section through the disk carrier and the basic body, after deformation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] FIG. 1 Shows a ring gear carrier 1 formed as a sheet component, illustrated as an individual component. The ring gear carrier 1 is in the form of a disk 1 a whose circumferential edge is shaped to form a fixing flange 1 b.
[0026] FIG. 2 shows a basic body 2 as an individual component, which is made in the first instance as a cast or forged blank. The basic body 2 has inner teeth 3 whose location is only indicated, which are produced by machining and then case-hardened. On its outer circumference the basic body has individual zones distributed around the circumference, with a carrier tooth array 4 consisting of individual teeth 4 a.
[0027] FIG. 3 shows a disk carrier 5 formed as a sheet component and produced by deformation. The disk carrier 5 has a driving profile 6 which serves for the positively interlocked connection of the inner disks (not shown) of a disk set for a shifting element of a transmission. The driving profile 6 is preferably trapezium-shaped and corresponds to the profile of the driving teeth 4 on the basic body 2 .
[0028] FIG. 4 illustrates the assembly of the above-mentioned individual components 1 , 2 and 5 to form a ring gear 7 . The ring gear carrier 1 is connected positively to the basic body 2 by deformation of its flange 1 b , so that the two components can rotate freely in the rotation direction but are fixed relative to one another in the axial direction. The disk carrier 5 is pushed in the axial direction over the basic body 2 , in such manner that the driving teeth zones 4 engage in the driving profile 6 and thereby form a positive connection in the rotation direction.
[0029] FIG. 5 shows the ring gear 7 from another perspective, i.e. looking at the outside of the ring gear carrier 1 . The ring gear 7 is made as a composite structure, i.e. it comprises two sheet components 1 , 5 produced by deformation and the machined basic body 2 . In general terms the ring gear 7 is also referred to as the component with inner teeth 3 and outer teeth 6 .
[0030] FIG. 6 shows a partial section in the area of the driving teeth 4 of the basic body 2 and the driving profile 6 of the disk carrier 5 . The teeth 4 a have back-tapers or undercuts in the area of their tooth bases 4 b, which are formed as rounded notches in each tooth base 4 b. A tooth 6 a of the driving profile 6 engages in each case in the tooth gap between two adjacent teeth 4 a. The tooth 6 a has two straight flanks 6 b and a tooth tip 6 c with a concave shape (arched upward in the drawing), which forms a hollow space relative to the bottom 4 c of the driving tooth 4 . The concave tooth tip profile 6 forms a preliminary profile during the production of the ring gear 7 , and with this preliminary profile the disk carriers 5 is pushed onto the driving teeth 4 of the basic body 2 .
[0031] FIG. 7 shows the same partial section as FIG. 6 , but after the driving profile 6 has been deformed, i.e. after the concave tooth tip area 6 c has been stretched, the stretched shape being indexed 6 c ′. By exerting a radially inward-directed force (not shown) on the dome of the concave area 6 c ( FIG. 6 ), the latter is stretched to a substantially straight position 6 c ′ whereby the corner areas are forced as projections 6 d, 6 e into the undercut areas 8 , 9 at the root of the tooth 4 b. This produces all-over contact between the driving profile 6 and the driving teeth 4 of the basic body 2 , and thus an interlocked connection in the manner of a dovetail. The carrier profile 6 is therefore held firmly against the basic body 2 even under the action of a centrifugal force at higher rotation speeds, and radial displacement that would lead to “lifting” of the disk carrier 5 is prevented. By virtue of frictional locking in the area of the dovetail joint, at the same time the disk carrier 5 is fixed in the axial direction relative to the basic body 2 , and thus onto the ring gear 7 .
INDEXES
[0000]
1 Ring gear carrier
1 a Disk
1 b Flange
2 Basic body
3 Inner teeth
4 Driving teeth
4 a Tooth
4 b Tooth base
4 c Tooth bottom
5 Disk carrier
6 Driving profile
6 a Tooth profile
6 b Tooth flank
6 c Tooth tip
6 c ′ Tooth tip (after deformation)
6 d Projection
6 e Projection
7 Ring gear
8 Undercut (notch)
9 Undercut (notch) | A component with inner teeth ( 3 ) and outer teeth ( 6 ). The component ( 7 ) comprising a basic body ( 2 ) provided with the inner teeth ( 3 ) and a sheet component ( 5 ) provided with the outer teeth ( 6 ). The sheet component ( 5 ) is connected to the basic body ( 2 ), during the manufacturing process, by positive interlock in both the tangential and radial directions. | 8 |
CROSS REFERENCE TO RELATED APPLICATION
This application claims the priority of German Application No. 199 23 419.1 filed May 21, 1999, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
This invention relates to a device provided in a fiber processing (spinning preparation) machine, for example, a carding machine, a cleaner or the like for measuring distances between facing surfaces. The machine has a clothed roll which cooperates with a clothed counter element, for example, a clothed flat bar. At least one stationary sensor is provided, by means of which the distance to a clothed surface may be determined.
The distance between the carding cylinder clothing and a facing component is of substantial significance as concerns the carding machine and properties of the fiber. The result of the carding process such as fiber cleaning, nep formation and fiber shortening is largely dependent from the carding gap, that is, the distance between the cylinder clothing and the clothing of the traveling flats or stationary carding elements. The channeling of air about the carding cylinder and heat removal are also dependent from the distance between the cylinder clothing and the clothed or unclothed surfaces, such as mote knife or housing shells. Such clearances are affected by various, partially counteracting factors. A wear of facing clothings leads to an enlargement of the carding gap which, in turn, results in an increase of the nep number and a decrease of the fiber shortening. An increase of the cylinder rpm, for example, for enhancing the cleaning effect, results in an enlargement of the cylinder including its clothing because of the centrifugal forces and thus diminishes the carding gap. Further, when large quantities of fiber or particular types of fiber, for example, chemical fibers are processed, the carding cylinder expands because of the temperature increase, resulting in a decrease of the distances of the cylinder clothing from adjoining components.
The carding clearance is affected particularly by the machine settings, on the one hand, and the condition of the clothing, on the other hand. The most important carding clearance of a card equipped with traveling flats is in the principal carding zone, that is, between the carding cylinder and the traveling flats assembly. Of the two clothings which define the carding clearance at least one is in motion (in most cases both are moving). To increase the output of the card, it has been desirable to select the operating rpm, that is, the operating speed of the movable elements, to be as high as permitted by the fiber processing technology. The working clearance is measured in the radial direction (starting from the rotary axis) of the carding cylinder.
In current carding processes increasingly larger fiber quantities per unit time are being handled, requiring higher speeds of the working components. Alone an increase of the fiber flow rate leads, because of the mechanical work, to an increased heat generation even if the working surface areas remain constant. At the same time, however, the technological carding results (uniformity of sliver, degree of cleaning, reduction of neps, etc.), are increasingly improved which requires larger working surfaces participating in the carding process and a closer setting of the components to the carding cylinder. The share of chemical fibers to be processed continuously increases. As compared to cotton, chemical fibers generate more heat due to their frictional contact with the working components of the fiber processing machine. In contemporary designs the working components of high-performance carding machines are enclosed from all sides in order to comply with the stringent safety requirements, to prevent particle emission into the spinning room and to minimize the maintenance requirements of the machines. Grates or even open, material-guiding surfaces which provide for an air exchange, belong to the past.
In view of the above-listed circumstances, the heat input into the fiber processing machine is significantly increased while the extent of heat removal by means of convection has been substantially reduced. The resulting significant heat-up of the high-performance carding machines leads to increased thermo-elastic deformations which, because of the non-uniform distribution of the temperature field, affect the set distances of the working components: the distances decrease between the carding cylinder and the traveling flat bars, the doffer, the stationary flat bars as well as the discharge locations. In an extreme case the set gap between the working components may completely disappear because of heat-caused expansions, so that relatively moving working components collide with one another. This results in significant damaging of the high-performance carding machine. Particularly the generation of heat in the working zone of the carding machine may lead to unlike thermal expansions between the structural components in case of excessive temperature differences.
In practice the quality of the clothing of the flat bar clothings is visually verified by an attendant at regular intervals; a wear results in an increase of the carding gap. In a known device, as disclosed in European patent document 801,158, a sensor is provided with which the working distance of carding clothings, that is, the carding gap may be measured. What is thus measured is the effective distance of the clothing points of one clothing between that of the facing clothing of the machine element. The machine element may have a clothing or may be formed by a housing shell segment having a guide surface. The sensor is conceived particularly for measuring the working distance between the carding cylinder and the flat bars of a traveling flats assembly where an optical device, positioned laterally, senses the carding clearance between the carding cylinder and the flat bar clothings. It is a disadvantage of such an arrangement that the change of the carding gap cannot lead to a conclusion whether or to what extent such change is caused by the wear of the clothing of the carding cylinder, the clothing of the flat bars or both.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved device of the above-outlined type from which the discussed disadvantages are eliminated and which makes possible particularly the detection of wear of clothing points of travelling flats of a carding machine during operation thereof.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the fiber processing machine includes a rotary roll provided with a peripheral clothing; a plurality of flat bars having a clothing cooperating with the roll clothing; and a sensor supported adjacent the flat bars and facing the flat bar clothing for determining a distance between said sensor and said flat bar clothing.
By the measures according to the invention a wear of the clothing of the traveling flat bars may be determined, particularly after a longer service period. Upon a change of the carding gap the effect of the change of the flat bar clothing is determined, directly with regard to the wear and also indirectly as concerns the change of the distance with respect to the carding cylinder. Particularly the wear of the cylinder clothing and expansions thereof due to temperature changes and centrifugal forces are established in this manner. As a result, based on a desired value, an optimal setting of the carding gap may be effected. Distance detection and adjustment may be performed during operation. It is a further advantage that the geometrically highest flat bar is found.
The invention has the following additional advantageous features:
The sensor is stationary during the sensing operation and, by distance detection, senses a wear or a shift of the flat bar clothing.
The sensor is an inductive or capacitive sensor and may be height-adjustable by a fine-threaded adjusting screw assembly which supports the sensor.
The distance measurements are utilized as input magnitudes for a control and regulating device to effect a distance regulation between the flat bar clothings on the one hand and the carding cylinder clothing, on the other hand.
The radial distance between the carding cylinder clothing and the flat bar clothing may be set by the shape and/or position of a flexible support strip mounted on a stationary mounting surface of the machine.
The electronic control and regulating device includes a memory for storing desired values for the distances.
A parameter (such as temperature) is measured which is related to the change of the working gap for producing a measuring value relating to the working gap.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic side elevational view of a carding machine incorporating the invention.
FIG. 2 is a schematic fragmentary front elevational view in section of a flat bar of a travelling flats assembly, incorporating the invention.
FIG. 3 is a schematic fragmentary side elevational view of the travelling flats assembly in the region of an end sprocket illustrating the device according to the invention.
FIG. 4 is a block diagram of a control circuitry for adjusting carding components based on sensed data.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a carding machine CM which may be, for example, an EXACTACARD DK 803 model, manufactured by Trütschler GmbH & Co. KG, Mönchengladbach, Germany. The carding machine CM has a feed roll 1 , a feed table 2 cooperating therewith, licker-ins 3 a , 3 b , 3 c , a carding cylinder 4 rotating in the direction E and having a rotary axis M, a doffer 5 , a stripping roll 6 , crushing rolls 7 , 8 , a web guide element 9 , a sliver trumpet 10 , calender rollers 11 , 12 , a travelling flats assembly 13 including end sprockets 13 a , 13 b (rotating in the directions B and A, respectively) and flat bars 14 , a coiler can 5 and a coiler 16 .
Also referring to FIG. 3, the flat bars 14 are carried, with a low speed of 80-300 mm/min by an endless toothed belt 21 trained about the end sprockets 13 a , 13 b . The flat bars glide over slide guides 22 in the working zone with the carding cylinder 4 . The flat bars 14 are carried in the direction of the arrow D through the working zone and, after being reversed by the end sprocket 13 a, they return in an idling run in the direction of the arrow C. A stationarily supported sensor 19 (which may be a capacitive or an inductive sensor) is oriented towards the clothings of the consecutive flat bars 14 in their idling run in the region of the end sprocket 13 a.
Turning to FIG. 2, three sensors 19 a , 19 b and 19 c are arranged, spaced from one another, in a direction perpendicular to the travel direction of the flat bars 14 . The respective sensor surfaces 19 ′, 19 ″ and 19 ′″ are oriented towards the clothing 20 of the momentarily adjoining flat bar 14 and are spaced at a distance a from the clothing 20 . Fine-threaded adjustment nuts 21 a, 21 b and 21 c provide for a setting of the distance a for each sensor relative to the clothing 20 . The sensors 19 a , 19 b and 19 c are secured in a holding device 22 which is secured stationarily to the machine frame by screws 23 a and 23 b.
Turning to FIG. 4, an evaluating device 26 is connected to the sensor 19 by a conductor 25 and displays and stores the magnitudes detected by the sensor 19 . The evaluating device 26 is further connected with an electronic card control device 27 which emits signals for the setting device 28 for adjusting the carding gap between the clothing 20 of the flat bars 19 , on the one hand and the clothing 4 ′ of the carding cylinder 4 , on the other hand. At the same time, this information is also applied to a carding information system which may be a KIT model, manufactured by Trützschler GmbH & Co. KG and which forms part of a computer and display device 29 where the data of an entire carding group are monitored.
Structural features relating to mechanisms for adjusting the working distances, for example, by means of radially shifting the support for the slide guide 22 in the working zone as a function of sensor signals are disclosed, for example, in U.S. Pat. No. 5,918,349 which is incorporated herein by reference.
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims. | A fiber processing machine includes a rotary roll provided with a peripheral clothing; a plurality of flat bars having a clothing cooperating with the roll clothing; and a sensor supported adjacent the flat bars and facing the flat bar clothing for determining a distance between said sensor and said flat bar clothing. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a novel paper coating composition, and more specifically to a paper coating composition which contains an alkali decomposition product of a yeast as a binder and which is suitable for the production of coated paper having excellent printability.
2. Description of the Prior Art
In printing paper such as coated paper or a certain kind of paper board, a pigment is coated on the surface of the paper. As a binder for the pigment, there have been previously used an aqueous solution of a natureal polymeric substance such as casein, soybean protein, modified starch or carboxymethyl cellulose or a synthetic polymeric material such as polyvinyl alcohol, and an emulsion of a synthetic polymer such as a latex of a styrene/butadiene copolymer, either alone or in admixture. Of these, casein has the advantages of maintaining better dispersing effect than starch or polyvinyl alcohol and also having better water resistance, and therefore is being used in great quantities in the coated paper industry. However, because the quality of casein differs greatly according to the place of origin and its cost has been rapidly on the increase as a result of the increased demand in recent years, great interest has been aroused in a substitute for casein.
On the other hand, water-soluble natural or synthetic polymeric materials such as modified starch, carboxymethyl cellulose or polyvinyl alcohol have recently been used in increasing quantities, but have not been able to supersede casein completely because of their inferior water resistance.
It has now been found that the use of an alkali decomposition product of a yeast as a binder for the pigment can lead to the removal of the above-mentioned defects, and makes it possible to provide a coated paper having high surface strength and water resistance and superior printability.
SUMMARY OF THE INVENTION
The present invention provides a paper coating composition comprisng a pigment as a main ingredient and a binder for said pigment, which is either (a) an alkali decomposition product of a yeast or (b) a mixture of said alkali decomposition product of a yeast and an emulsion of a synthetic polymer and/or an aqueous solution of a natural or synthetic polymer.
DETAILED DESCRIPTION OF THE INVENTION
Examples of the yeast that can be used in the present invention are baker's yeasts (Saccharomyces cerviciae), nucleic acid yeasts (such as Candida utilis), beer yeast (Saccharomyces cerviciae), pulp yeasts (such as Candida utilis or Mycotorula japonica) and yeasts which assimilate petrochemical products (such as methanol, acetic acid or n-paraffin) [for example, Candida utilis, Candida novellus (FRI deposit No. 705, see Japanese Patent Application No. 18562/70), or Mycotorula japonica, or Pichia miso mogii]. These yeasts may be raw yeasts as separated from the culture liquors, or dried yeasts obtained by drying the raw yeasts. Processed yeasts obtained by subjecting these yeasts to various treatments such as pulverization, elimination of nucleic acid, defatting, desalting, decolorization or autolysis are also useful in the present invention. Coated papers produced by using coating compositions using alkali decomposition products of yeasts cultivated using petrochemical products as a carbon source prove better in quality than the other yeasts.
These yeasts are used in the form of alkali decomposition products for preparing the paper coating compositions. Prior to alkali decomposition, the yeasts may be decolorized with a peroxide such as hydrogen peroxide or a reducing agent such as sodium boron hydrate. Alkalies used to decompose the yeasts may be sodium hydroxide, ammonia, slaked lime, sodium phosphate, sodium carbonate or borax. Of these, sodium hydroxide, ammonia or a mixture of these is preferred. The amount of the alklai used differs depending upon its type, but is usually such that will result in the adjustment of the pH of an aqueous suspension of the yeast to at least 8, preferably 9 to 13. A suspension of the yeast to which the alkali is added is heated usually at 30° to 120°C. for 10 minutes to 10 hours, preferably at 60° to 100°C. for 10 minutes to one hour, although the temperature and time vary depending upon the kind and amount of the alkali added, thereby to decompose the yeast. The resulting alkali decomposition product of the yeast may be used as such or after being subjected to post-treatment such as dialysis, desalting or acid addition if desired.
The pigment used in this invention is not particularly limited, but all pigments which are generally used for paper coating can be used effectively. Examples are clay, titanium oxide, satin white, and calcium carbonate.
In the paper coating composition, 5 to 50 parts by weight of the pigment binder are generally used per 100 parts by weight of the pigment. As the pigment binder, a mixture of the afore-mentioned alkali decomposition product of yeast and at least one emulsion of a synthetic polymer or aqueuos solution of a natural or synthetic polymer may also be used. Aqueous emulsions (latices) of a styrene/butadiene copolymer, butadiene/methyl methacrylate copolymer, styrene/butadiene/methyl methacrylate copolymer, ethylene/vinyl acetate copolymer, polyvinyl acetate, vinyl acetate/acrylate copolymer, styrene/acrylate copolymer, styrene/vinyl acetate copolymer, or these polymers modified with monomers containing functional groups are conveniently used as the emulsion of synthetic polymer. Examples of the water-soluble natural or synthetic polymer are casein, soybean protein, modified starch, polyvinyl alcohol or carboxymethyl cellulose. If desired, the paper coating composition of this invention may further contain auxiliary agents usually employed in pigment coated papers, such as a foam control agent, lubricant, surface active agent, insolubilizer, dispersing agent for the pigment or viscosity controlling agent.
The present invention will be illustrated specifically by the following Examples which do not limit the scope of the invention and in which all parts and percentages are by weight unless otherwise specified.
EXAMPLE 1
100 parts of Georgia kaolin were added gradually with agitation to 46 parts of an aqueous solution containing 0.3 part of sodium hexametaphosphate (SHMP) as a dispersing agent, thereby forming a slurry of the pigment. A 10% suspension (pH 11.5) of yeast (Candida novellus) composed of 100 parts of water, 10 parts of the yeast and 0.5 part of sodium hydroxide was heated with agitation at 50°C. for one hour to form a liquor containing an alkali decomposition product of the yeast.
To the pigment slurry were added the decomposed yeast and 10 parts (as solids content) of a late of a styrene/butadiene type copolymer (JSR 0668, tradename of product manufactured by Japan Synthetic Rubber Co., Ltd.) to form a coating composition having a total solids concentration of 40%.
For comparison, a coating composition was prepared by a customary method using commercially available casein or oxidized starch instead of the decomposition product of the yeast. The formulations and properties of these coating compositions are shown in Table 1--1.
Table 1-1______________________________________ Composition Comparative Comparative 1 (present composition composition B invention A______________________________________Georgia kaolin 100 parts 100 parts 100 partsSHMP 0.3 0.3 0.3JSR 0668 10 10 10Sodium hydroxide 0.5 0.4 --Yeast 10 -- --Casein -- 10 --Oxidized starch -- -- 10pH 9.4 8.9 7.3Viscosity *1 75.0 78.5 42.5______________________________________ *1 - Measured at 20°C at 60 rpm on a BL type viscometer, rotor No. 2 (unit: cps)
Each of the above coating compositions was coated on high quality paper to an extent such that the coating weight was 10 g/m 2 . After coating, the coated paper was allowed to stand overnight in an air-conditioned chamber kept at 20°C and a relative humidity of 65%, and then subjected to supercalendering at 70°C. and 135 Kg/cm. The surface strength (IGT pick resistance), water resistance and air permeability of the coated paper are shown in Table 1-2.
Table 1-2__________________________________________________________________________ Composition 1 Comparative Comparative (present invention) composition A composition B__________________________________________________________________________IGT pick re-sistance *2 185 154 148Water resistance*3 excellent excellent fairAir-per-meability *4 727 1,158 645__________________________________________________________________________ *2 - Measured at a printing pressure of 35 Kg/cm.sup.2 with a spring strength of M on an IGT printability tester using printing ink having a tack value of 16; unit cm/sec. *3 - The paper is imprinted after applying water to the coated surface, using an RI printability tester. The state of picking is evaluated on a scale of excellent, good, fair and poor. *4 - Measured on an air-permeability and smoothness tester of the Bekk type; unit seconds.
The above table demonstrates that the paper coated with the composition of this invention has superior IGT pick resistance and air-permeability to the paper coated with the composition containing casein, and superior IGT pick resistance and water resistance to the paper coated with the composition containing oxidized starch.
EXAMPLE 2
A coating composition was prepared in the same way as in Example 1 except that 10 parts of Candida utilis was used as the yeast and decomposed with 1 part of sodium hydroxide by heating for 30 minutes at 80°C. (pH 12.8). The coated paper was subjected to the same test as in Example 1. The results are shown in Table 2.
Table 2______________________________________ Composition 2 Comparative Comparative (present composition A composition B invention) (casein) (oxidized starch)______________________________________IGT pick 197 154 148resistanceWater excellent excellent fairresistanceAir- 867 1,158 645permeability______________________________________
As is clear from Table 2, the composition of this invention exhibited similar properties to that obtained in Example 1.
EXAMPLE 3
A coating composition was prepared in accordance with the formulation shown in Table 3-1 using a decomposition product of a Saccharomyces yeast obtained by decomposing the yeast with sodium hydroxide (5% of the yeast) and ammonia (53% of the yeast as NH 4 OH) at 30°C for 10 hours (pH 12.8). For comparison, coating compositions were prepared similarly using casein or oxidized starch. The properties of the coated papers (with coating weight of 20 g/m 2 as solids content) are shown in Table 3-2.
Table 3-1__________________________________________________________________________ Composition 3 Comparative Comparative (present composition C composition D invention)__________________________________________________________________________Georgia 100 parts 100 parts 100 partskaolinSHMP 0.3 0.3 0.3JSR 0668 10 10 10Yeast 5 -- --Casein 5 10 --Oxidized starch -- -- 10Sodium hydroxide 0.25 -- --Ammonia (as NH.sub.4 OH) 3.15 1.0 --pH 10.9 9.9 7.5__________________________________________________________________________
Table 3-2______________________________________ Composition Comparative Comparative 3 (present composition C composition D invention)______________________________________IGT pick 220 210 90resistanceWater excellent excellent fairresistanceAir- 5250 5400 3850permeability______________________________________
EXAMPLE 4
90 parts of Georgia kaolin was gradually added with agitation to 40 parts of water in which 0.27 part of sodium hexametaphosphate (SHMP) had been dissolved as a dispersing agent, to form a slurry of the clay.
Separately, 10 parts of water in which 0.3 part (as solids content) of poly (sodium acrylate (Aron A-20SL 2 , tradename of the product of Toa Gosei Co., Ltd.) was dissolved as a dispersant were added to 10 parts (as solids content) of satin white (product of Shiraishi Kogyo Co., Ltd.). The mixture was agitated thoroughly to form a slurry of satin white.
Sodium silicate was added to a suspension composed of 70 parts of water and 10 parts of Candida novellus to adjust its pH to 5. To this suspension was added 0.5 part by volume of 30% aqueous hydrogen perioxide, and the mixture was shaken for one hour at 30°C, followed by adding 2.5 parts by volume of 10% sodium hydroxide and then 20 parts by volume of 28% aqueous ammonia. The mixture was heated at 75°C for one hour to form a solution containing the decomposed yeast.
The satin white slurry was added to the clay slurry, and with stirring the decomposed yeast, 10 parts (as solids content) of a styrene/butadiene type copolymer latex (JSR 0668), and water were added to form a coating composition having a total solids concentration of 40%.
For comparison, a coating composition was prepared by a customary method using commercially available casein instead of the decomposition product of the yeast. The formulations and properties of these coating compositions are shown in Table 4-1 below.
Each of the above coating compositions was coated on base paper board to an extent such that the coating weight was 20 g/m 2 , and then air dried. The surface of the coated paper board was treated with a 30% aqueous solution of zinc sulfate, and dried by being left to stand overnight in an airconditions chamber at 20°C and a relative humidity of 65%.
The surface strength (IGT pick resistance) and water resistance of the resulting coated papers are shown in Table 4-2. It is seen from Table 4-2 that the paper board coated with the composition of this invention has superior IGT pick resistance and equivalent water resistance to the paper coated with the composition containing casein.
Table 4-1______________________________________ Composition 4 Comparative (present invention) composition E______________________________________Georgia kaolin 90 parts 90 partsSHMP 0.27 0.27Satin white 10 10Poly(sodium 0.3 0.3acrylate)JSR 0668 10 10Yeast 10 --Casein -- 10Sodium hydroxide 0.25 0.428% aqueous 20 --ammonia30% aqueous 0.5 --hydrogen peroxidepH 11.3 10.4Viscosity 133 83.0______________________________________
Table 4-2______________________________________ Composition 4 Comparative (present invention) composition E______________________________________IGT pick resistance 181 cm/sec. 154 cm/sec.Water resistance excellent excellent______________________________________
EXAMPLE 5
90 parts of Georgia kaolin were gradually added with stirring to 60 parts of water in which 0.27 part of sodium hexametaphosphate (SHMP) was dissolved as a dispersant, to form a slurry of the clay.
Separately, to 10 parts (as solids content) of satin white (product of Shiraishi Kogyo Co., Ltd.) was added 20 parts of water in which 0.3 part (as solids content) of poly(sodium acrylate (Aron A-20SL 2 ) was dissolved as a dispersant, to form a slurry of the satin white.
To a suspension composed of 10 parts of yeast (Candida utilis) and 40 parts of water, was added 1.4 parts of sodium peroxide, and the mixture was shaken for one hour at 30°C. Then, 20 parts by volume of 28% aqueous ammonia were added, and the mixture was treated at 30°C. for 24 hours, thereby to form a solution of the decomposition product of the yeast.
The satin white slurry was added to the above clay slurry, and with stirring, the decomposed yeast, 12 parts (as solids content) of a latex of methyl methacrylate/butadiene type copolymer (JSR 0933, product of Japan Synthetic Rubber Co., Ltd.), and water were added to form a coating composition having a total solids concentration of 40%. For comparison, a coating composition was prepared in a customary manner using modified polyvinyl alcohol (PVA, Denka Size PC-100, Denki Kagaku Kogyo Co., Ltd.) instead of the decomposed yeast. The formulations and properties of these coating compositions are shown in Table 5-1.
Each of the above coating compositions was coated on base paper board to an extent such that the amount of coating was 20 g/m 2 , and then dried. The surface of the coated paper was treated with a 3% aqueous solution of zinc sulfate, and dried by being left to stand overnight in an air-conditioned chamber kept at 20°C and relative humidity of 65%.
The surface strength (IGT pick resistance) and water resistance of the coated papers are shown in Table 5-2. It is seen that the paper board coated with the composition of this invention has superior IGT pick resistance and water resistance to the paper coated with the composition containing the modified polyvinyl alcohol.
Table 5-1______________________________________ Composition 5 Comparative (present invention) composition F______________________________________Georgia kaolin 90 parts 90 partsSHMP 0.27 0.27Satin white 10 10Poly(sodium 0.3 0.3acrylate)JSR 0933 12 12Denka PC-100 -- 4Yeast 4 --Sodium peroxide 1.4 --28% aqueous ammonia 20 --pH 10.8 7.3Viscosity 38 172______________________________________
Table 5-2______________________________________ Composition 5 Comparative (present invention) composition F______________________________________IGT pick resistance 137 cm/sec. 77 cm/sec.Water resistance excellent good______________________________________
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. | A paper coating composition comprising (A) a pigment as a main ingredient and (B) a binder for said pigment which is either (a) an alkali decomposition product of a yeast or (b) a mixture of said alkali decomposition product of a yeast and an emulsion of a synthetic polymer and/or an aqueous solution of a natural or snythetic polymer and the paper coating composition coated paper product are disclosed. | 3 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation application of and claims priority to U.S. Pat. No. 9,476,512, application Ser. No. 13/602,712, filed Sep. 4, 2012, entitled ROTARY VALVE SYSTEM.
BACKGROUND OF THE INVENTION
Field of the Invention
The disclosed and claimed concept relates to forming a cup-shaped body and, more specifically, to providing a rotary valve for use in a cup ejection system.
Background Information
It is known in the container-forming art to form two-piece containers, e.g. cans, in which the walls and bottom of the container are a one-piece cup-shaped body, and the top, or end closure, is a separate piece. After the container is filled, the two pieces are joined and sealed, thereby completing the container. The cup-shaped body typically begins as a flat material, typically metal, either in sheet or coil form. Blanks, i.e., disks, are cut from the sheet stock and then drawn into a cup. That is, by moving the disk through a series of dies while disposed over a ram or punch, the disk is shaped into a cup having a bottom and a depending sidewall. The ram may have a concave end. The device structured to form the cup is identified as a “cupper.” In some cuppers, after the ram and dies separate, the formed cup remains disposed over the ram until ejected therefrom, typically by a jet of air. The cup may be drawn through additional dies to reach a selected length and wall thickness. Cuppers are shown in U.S. Pat. Nos. 4,343,173; 5,628,224; and 6,014,883.
Cuppers may employ an operating mechanism having a single drive shaft coupled to multiple rams, for example, it is known to have multiple rams move essentially simultaneously. Thus, one cycle of the operating mechanism produces multiple cups. It is further known to slightly stagger the impact of the rams on the sheet material and/or dies, by positioning the rams, sheet material and/or dies at slightly different elevations. At the end of the forming cycle, the cups may remain on the end of the rams. The cups may be removed therefrom by a jet of air, or other fluid, that is passed through the ram and into the space between the cup and the concave end of the ram, as shown in U.S. Pat. No. 4,343,173.
Compressed air, or another fluid, is supplied either continuously or intermittently to the ram via a compressed gas system. Each configuration of such compressed gas systems has problems. For example, if the system is structured to provide a continuous supply of compressed gas, much of the gas is wasted. That is, during the drawing of the cup and during most of the time the ram is being retracted, the cup is not free to move from the end of the ram. Thus, gas supplied to the ram during such operations is wasted. Further, the gas must be vented and such venting may be very noisy. Alternatively, the flow of gas may be controlled by one or more valves that open only when a cup is to be ejected. Given that cuppers produce thousands of cups per hour, such valves must also open and close thousands of times an hour leading to wear and tear as well as the need to replace the valves. Further, the opening and closing of the valves requires a control system or a mechanical linkage structured to time the operation of the valve to the position of the ram. Electronic control systems are expensive and mechanical systems are subject to wear and tear.
There is, therefore, a need for a compressed gas system for a copper that uses less gas and is less noisy.
SUMMARY OF THE INVENTION
The disclosed and claimed compressed gas system provides for the use of a rotary valve assembly. A compressed gas system that utilizes a rotary valve assembly uses less gas than a constant flow compressed gas system and is quieter than a compressed gas system that uses valves. The rotary valve is a disk-like body having an opening therethrough. The rotary valve body is disposed within a housing assembly wherein gas may only flow through the housing when the rotary valve body is properly aligned with a space on one side of the rotary valve body.
BRIEF DESCRIPTION OF THE DRAWINGS
A full understanding of the invention can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which:
FIG. 1 is a partial cross-sectional view of a cupper.
FIG. 2 is a schematic view of a pressurized gas system 20 with one embodiment of the rotary valve assembly.
FIG. 3 is a front view of one embodiment of a rotary valve.
FIG. 4A is a front view of another embodiment of a rotary valve. FIG. 4B is a front view of another embodiment of a rotary valve.
FIGS. 5A and 5B are front views of another embodiment of a rotary valve. FIG. 5C shows the combination of the cooperative rotary valve bodies shown in FIGS. 5A and 5B .
FIGS. 6A and 6B are front views of another embodiment of cooperative rotary valve bodies. FIG. 6C shows the combination of the cooperative rotary valve bodies shown in FIGS. 6A and 6B . FIGS. 6D and 6E are front views of another embodiment of cooperative rotary valve bodies. FIG. 6F shows the combination of the cooperative rotary valve bodies shown in FIGS. 6D and 6E .
FIG. 7 is a schematic view of a pressurized gas system with another embodiment of the rotary valve assembly.
FIG. 8 is a schematic view of a pressurized gas system with another embodiment of the rotary valve assembly.
FIG. 9 is a schematic cross-sectional view of a rotary valve assembly.
FIG. 10 is a front view of another embodiment of a rotary valve.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Generally, and as shown partially in FIG. 1 , a cupper 10 includes at least one movable, elongated ram 12 and a corresponding die 14 . The ram 12 has a concave distal end 16 and an axial ram ejection conduit 18 that is yin fluid communication with the ram distal end 16 . An operating mechanism (not shown) moves the ram 12 axially toward, and into, the die 14 . A work piece (not shown), which may be a circular blank or a sheet of metal from which a circular blank is cut, is disposed between the ram 12 and the die 14 . As the ram 12 moves into the die 14 , the work piece is formed into a cup 2 . As the ram 12 withdraws from the die 14 , the cup 2 remains disposed over the end of the ram 12 . The ram 12 is coupled to, and in fluid communication with, a pressurized gas system 20 . The pressurized gas system 20 is structured to deliver a volume of gas to the ram distal end 16 via the axial ram ejection conduit 18 . When the volume of gas is introduced at the ram distal end 16 , the cup 2 will be ejected from the ram 12 .
Further, it is known to operate a plurality of rams 12 with a single operating mechanism. For example, a single operating mechanism may operate multiple rams 12 at substantially the same time. It is noted that the discussion below identifies four rams 12 as an example; the disclosed concept is not limited to a specific number of rams 12 . As such, multiple cups 2 will be ejected at substantially the same time. Accordingly, the pressurized gas system 20 is structured to deliver a sufficient volume of gas so as to eject a plurality of cups 2 at substantially the same time. It is noted that the plurality of rams 12 may form the cups 2 in a staggered manner. That is, the cups are formed at slightly different times so as to reduce impact forces on the operating mechanism. In such a system, the cups 2 may be ejected from the ram 12 at substantially the same time, or, the cups 2 may be ejected from the ram 12 in a staggered fashion, i.e., the cups 2 are ejected at slightly different times. For example, the cupper 10 that forms cups 2 in a staggered manner may be structured to eject all the cups 2 at a specific, single time during the cycle of the operating mechanism, or, the cups may be ejected when the ram 12 is at a certain distance from the die 14 . In the former example, the cups 2 will be ejected at substantially the same time and, in the latter example, the cups 2 are ejected at slightly different times.
As shown in FIGS. 2, 7 and 8 , the pressurized gas system 20 includes a source of pressurized gas 22 (shown schematically), a surge tank 24 , an optional controlled valve 26 , a control unit 28 , a motor 30 , at least one downstream pressure conduit 32 and a rotary valve assembly 40 . The source of pressurized gas 22 is, in one embodiment, a compressor, but any known source for pressurized gas may be used. The surge tank 24 is structured to contain a quantity of gas at a pressure between about 10 psi and 70 psi, and in one exemplary embodiment about 18 psi. The surge tank 24 includes an inlet 34 and an outlet 36 . The source of pressurized gas 22 and the surge tank 24 are coupled and in fluid communication via the surge tank inlet 34 . As is known, a plurality of conduits and valves (none shown), such as but not limited to relief valves, are used to couple the source of pressurized gas 22 and the surge tank 24 .
A tank conduit 38 is coupled to, and in fluid communication with, surge tank outlet 36 as well as rotary valve assembly housing assembly at least one inlet passage 48 (described below). Controlled valve 26 may be disposed anywhere on tank conduit 38 . The controlled valve 26 is structured to be selectively configured. That is, the controlled valve 26 may be in a first closed configuration, a second fully open configuration, or any number of partially open configurations therebetween. The controlled valve 26 may be controlled mechanically but, in a preferred embodiment, the controlled valve 26 is structured to be selectively configured electronically. Accordingly, control unit 28 is structured to provide an electronic valve configuration command, i.e., the control unit 28 is coupled to, and in electronic communication with, the controlled valve 26 . The controlled valve 26 is structured to place itself in a selected configuration in response to the electronic valve configuration command. That is, the control unit 28 is structured to configure the controlled valve 26 .
The motor 30 includes at least one drive shaft 31 having a distal end 33 . The motor 30 is structured to rotate the drive shaft 31 at a selected speed. In one embodiment, the drive shaft 31 rotates at between about 25 rpm and 425 rpm and in one exemplary embodiment between about 100 to 250 rpm. The speed of the motor 30 may be adjusted while in use. Thus, the motor 30 is structured to adjust its speed in response to an electronic motor command. Further, the control unit 28 is structured to provide an electronic motor command. Further, the motor may be started and stopped in selected orientations. For example, if operation of the cupper 10 is stopped, the motor 30 may be stopped with the rotary valve assembly 40 in a closed configuration, discussed below. Alternatively, if desired, the rotary valve assembly 40 may be stopped in an open configuration whereby fluid passes through the rotary valve assembly 40 . The control unit 28 is coupled to, and in electronic communication with, the motor 30 . Thus, the control unit 28 is structured to control the speed of the motor 30 .
The control unit 28 may also include one or more sensors 29 (one shown schematically) such as, but not limited to, a pressure sensor disposed on tank conduit 38 or at least one downstream pressure conduit 32 . The sensors 29 are in electronic communication with the control unit 28 and provide data thereto. The control unit 28 may also include a processor, memory, and programming (none shown) structured to automatically adjust the configuration of the controlled valve 26 and the speed of motor 30 in response to the sensor 29 data.
Rotary valve assembly 40 includes a housing assembly 42 and a rotary valve 44 . The rotary valve assembly housing assembly 42 defines an enclosed space 46 and has at least one inlet passage 48 , at least one outlet passage 50 , and a drive shaft passage 52 . Each of the inlet passage (s) 48 , outlet passage(s) 50 , and drive shaft passage 52 are in fluid communication with said enclosed space 46 . The rotary valve 44 is disposed in the enclosed space 46 and effectively divides the enclosed space 46 into an upstream enclosed space 54 and a downstream enclosed space 56 . As described below, the rotary valve 44 includes a rotary valve body assembly 70 (discussed below) with at least one opening 71 . The rotary valve at least one opening 71 is structured to allow selective passage of a gas from the upstream enclosed space 54 to the downstream enclosed space 56 . That is, the rotary valve at least one axial opening 71 is only in fluid communication with both the upstream enclosed space 54 and the downstream enclosed space 56 intermittently. To accomplish this, the rotary valve at least one opening 71 is intermittently in fluid communication with at least one aligned portion 58 of the upstream enclosed space 54 and at least one aligned portion 59 the downstream enclosed space 56 . As used herein, the at least one “aligned portion 58 ” of the upstream enclosed space 54 and the downstream enclosed space 56 means the portion of the enclosed space 46 wherein an upstream enclosed space 54 and a downstream enclosed space 56 exist on each side of the rotary valve 44 in a direction generally parallel to the axis of rotation of the rotary valve 44 . That is, to prevent constant fluid communication through the rotary valve 44 , the enclosed space 46 includes a substantially sealed portion 60 wherein the rotary valve assembly housing assembly 42 is very close, and may abut, at least one side of the rotary valve body assembly 70 . As there is no space between the rotary valve 44 and the rotary valve assembly housing assembly 42 in the substantially sealed portion 60 , there is no enclosed space 54 , 56 to be an “aligned portion 58 ” of the upstream enclosed space 54 or the downstream enclosed space 56 .
In the enclosed space substantially sealed portion 60 the nearness of the rotary valve assembly housing assembly 42 to the rotary valve body assembly 70 substantially prevents fluid from passing through the rotary valve at least one opening 71 . A discussion of various embodiments of the rotary valve assembly housing assembly 42 with different embodiments of the enclosed space 46 follow the discussion of the rotary valve 44 .
As shown in FIG. 3 , the rotary valve 44 includes a substantially disk shaped body assembly 70 having at least one axial opening 71 therethrough. As used herein, “disk shaped” may include an axially elongated disk or cylinder. Further, as used herein, “axial opening” means the opening 71 extends parallel to the axis of the disk shaped body assembly 70 and does not mean that the opening is disposed on the axis of the disk shaped body assembly 70 . In one embodiment, the rotary valve body assembly 70 is a substantially circular, planar body 72 having an opening 71 therethrough. The rotary valve body assembly opening 71 may be any shape, but is, as shown, preferably arcuate. Further, as shown, the rotary valve body assembly opening 71 extends over an arc of about 180 degrees; it is understood that the rotary valve body assembly opening 71 may extend over a longer or shorter arc as needed.
In another embodiment, shown in FIG. 4A , the rotary valve body assembly 70 is, again, a substantially circular, planar body 72 having a plurality of openings 71 A, 71 B, 71 C, 71 D therethrough. Each rotary valve body assembly opening 71 A, 71 B, 71 C, 71 D is disposed at a different radial distance from the center of the rotary valve body assembly body 72 . The center-point of the rotary valve body assembly openings 71 A, 71 B, 71 C, 71 D, i.e., not the mathematical “center” of the arcs which is the center of the rotary valve body assembly body 72 , may be disposed substantially on a single radius, i.e., along a single radial line r, as shown in FIG. 4A . In an alternate embodiment, shown in FIG. 4B , the rotary valve body assembly openings 71 A, 71 B, 71 C, 71 D may be staggered. That is, the center-point of each rotary valve body assembly openings 71 A, 71 B, 71 C, 71 D is disposed on a different radial line R A , R B , R C , R D . It is noted that FIGS. 4A and 4B each disclose four rotary valve body assembly openings 71 A, 71 B, 71 C, 71 D and such a rotary valve body assembly 70 could be used, with a cupper having four rams 12 . It is again noted, however, that the disclosed concept is not limited to a cupper 10 having a specific number of rams 12 . It is understood that if the cupper 10 has a different number of rams 12 the rotary valve body assembly 70 , or multiple rotary valve body assemblies 70 , will have a corresponding number of rotary valve body assembly openings 71 .
In another embodiment, shown in FIGS. 5A and 5B the rotary valve body assembly 70 includes two substantially circular, planar bodies 74 , 76 that are, preferably, about the same size and may be placed in alignment as indicated in FIG. 5A . Each rotary valve body assembly planar body 74 , 76 has at least one axial opening 75 , 77 , respectively, therethrough. Each rotary valve body assembly first and second planar body at least one axial opening 75 , 77 is disposed at a similar radius so as to at least partially overlap when the rotary valve body assembly first and second planar bodies 74 , 76 are disposed on a common axis and the rotary valve body assembly first and second planar body at least one axial opening 75 , 77 are at least partially aligned, as shown in FIG. 5B . Preferably, the rotary valve body assembly first and second planar bodies 74 , 76 are disposed on drive shaft distal end 33 . In this configuration, the rotary valve body assembly first planar body at least one axial opening 75 may move relative to said rotary valve body assembly second planar body at least one axial opening 77 between a first position, wherein the rotary valve body assembly first and second planar body at least one axial openings 75 , 77 are substantially aligned, and a second position wherein the rotary valve body assembly first and second planar body at least one axial openings 75 , 77 are partially aligned.
Further, the two rotary valve body assembly bodies 74 , 76 substantially abut each other. That is, the two rotary valve body assembly bodies 74 , 76 contact each other over one axial face so that there is, essentially, no gap therebetween. A localized gap may exist if the abutting axial faces of the two rotary valve body assembly bodies 74 , 76 are not perfectly smooth, but such a gap does not form a path for fluid communication from one side of the rotary valve body assembly 70 to the other. The rotary valve body assembly openings 75 , 77 are, preferably, arcuate and extend over an arc of about 180 degrees. In this configuration, the two rotary valve body assembly bodies 74 , 76 may be rotated relative to each other so as to adjust the size of the rotary valve at least one axial opening 71 . That is, if the two rotary valve body assembly bodies 74 , 76 are positioned so that the rotary valve body assembly openings 75 , 77 are substantially aligned, the rotary valve at least one axial opening 71 will extend over an arc of about 180 degrees. If, the two rotary valve body assembly bodies 74 , 76 are positioned so that the rotary valve body assembly openings 75 , 77 are 50% aligned, as shown, the rotary valve at least one axial opening 71 will extend over an arc of about 90 degrees. Thus, by selectively positioning the two rotary valve body assembly bodies 74 , 76 relative to each other, the size of the rotary valve at least one axial opening 71 may be adjusted.
In another embodiment shown in FIGS. 6A and 6B , and as with the embodiment wherein the rotary valve body assembly 70 includes a single circular, planar body 72 , the rotary valve body assembly 70 having two substantially circular, planar bodies 74 , 76 may also include a plurality of rotary valve body assembly openings 75 A, 77 A, 75 B, 77 B, 75 C, 77 C, 75 D, 77 D, respectively. The rotary valve body assembly openings 75 A, 77 A, 75 B, 77 B, 75 C, 77 C, 75 D, 77 D on each of the two rotary valve body assembly bodies 74 , 76 are each disposed at a different radial distance from the center of the associated rotary valve body assembly body 74 , 76 . The rotary valve body assembly openings 75 A, 77 A, 75 B, 77 B, 75 C, 77 C, 75 D, 77 D on different rotary valve body assembly bodies 74 , 76 , however, are at substantially the same radial distance from the center of the associated rotary valve body assembly body 74 , 76 . That is, for example, rotary valve body assembly openings 75 A, 77 A are each at substantially the same radial distance from the center of the associated rotary valve body assembly body 74 , 76 . In this configuration, each pair of the rotary valve body assembly openings at substantially the same radial distance, e.g., rotary valve body assembly openings 75 A, 77 A, may be aligned to create a rotary valve axial opening 71 A, as shown in FIG. 6B . Further, the rotary valve body assembly openings 75 A, 77 A, 75 B, 77 B, 75 C, 77 C, 75 D, 77 D are, preferably, arcuate so that the size of the rotary valve axial openings 71 A, 71 B, 71 C, 71 D may be adjusted as described above.
Also, as with the embodiment wherein the rotary valve body assembly 70 includes a single circular, planar body 72 , the rotary valve body assembly openings 75 A, 77 A, 75 B, 77 B, 75 C, 77 C, 75 D, 77 D may be positioned on the rotary valve body assembly body 74 , 76 so that the center-point of the resulting rotary valve axial openings 71 A, 71 B, 71 C, 71 D may be disposed substantially on a single radius, i.e., along a single radial line, or, may be staggered, i.e., disposed along different radial lines. Alternatively, as shown in FIGS. 6D-6F , the rotary valve body assembly openings 75 A, 77 A, 75 B, 77 B, 75 C, 77 C, 75 D, 77 D may be staggered. In this configuration, when rotary valve body assembly body 74 , 76 are joined the center-point of each rotary valve body assembly openings 71 A, 71 B, 71 C, 71 D is disposed on a different radial line R A , R B , R C , R D . It is noted that FIGS. 6A-6F each disclose four rotary valve body assembly openings 71 A, 71 B, 71 C, 71 D and such a rotary valve body assembly 70 could be used with a cupper having four rams 12 . It is again noted, however, that the disclosed concept is not limited to a cupper 10 having a specific number of rams 12 . It is understood that if the cupper 10 has a different number of rams 12 , the rotary valve body assembly 70 , or multiple rotary valve body assemblies 70 , will have a corresponding number of rotary valve body assembly openings 71 .
It is further noted that the rotary valve at least one axial opening 71 maybe shaped so as to produce a specific pressure profile through the rotary valve assembly 40 . For example, an arcuate rotary valve at least one axial opening 71 may have a narrow radial width at the beginning of the arcuate rotary valve at least one axial opening 71 , and a wider radial width at the end of the arcuate rotary valve at least one axial opening 71 . That is, the at least one axial opening 71 may be shaped as an arcuate “teardrop.” Other shapes for the at least one axial opening 71 may be used as well. As used herein, a “shaped” axial opening 71 is an axial opening 71 wherein the opposing edges of the opening are not substantially parallel.
The rotary valve 44 , i.e., the rotary valve body assembly 70 , is coupled to the drive shaft distal end 33 . It is noted that a single motor 30 may be used to drive more than one rotary valve 44 . For example, a single drive shaft 31 may be coupled to more than one rotary valve assembly 40 . In such a configuration, the “drive shaft distal end 33 ” shall mean any part of the drive shaft 31 that is spaced from the motor 30 . Alternatively, as shown in FIG. 7 , the motor 30 may include more than one drive shaft 31 , 31 ′, each of which is coupled to a rotary valve assembly 40 .
The at least one downstream pressure conduit 32 has an inlet 25 and an outlet 27 is coupled to, and in fluid communication with, the rotary valve assembly housing assembly at least one outlet passage 50 . The at least one downstream pressure conduit 32 is also coupled to, and in fluid communication with, the axial ram ejection conduit 18 . In a cupper 10 with a single ram 12 , the at least one downstream pressure conduit 32 may be a single downstream pressure conduit 32 . As shown in FIG. 2 , in a cupper with a plurality of rams 12 , the at least one downstream pressure conduit 32 may include, and be in fluid communication with, a manifold 90 having a manifold inlet 91 and a plurality of manifold outlet conduits 92 each coupled to, and in fluid communication with, one of the rams 12 in the plurality of rams 12 . Alternatively, in a cupper 10 with a plurality of rams 12 , the at least one downstream pressure conduit 32 may include a plurality of downstream pressure conduits 32 A, 32 B, 32 C, 32 D each coupled to, and in fluid communication with, one of the rams 12 in the plurality of rams 12 . It is noted that, for this example, it is assumed that there are four rams 12 in the plurality of rams 12 . If there are more than four rams 12 , there is a downstream pressure conduit 32 N for each ram 12 . Further, the pressurized gas system 20 may be structured to operate with more than one plurality of rams 12 . That is, the cupper 10 may have a first plurality of rams 12 operating on a first cycle and a second plurality of rams 12 operating on a second cycle. In this configuration, the at least one downstream pressure conduit 32 may include two downstream pressure conduits 32 X, 32 Y each coupled to a manifold 90 X, 90 Y, as shown in FIG. 7 , each having a plurality of manifold conduits 92 each coupled to, and in fluid communication with, one of the rams 12 in both plurality of rams 12 . Further, the at least one downstream pressure conduit 32 may include an individual conduit 32 N coupled to, and in fluid communication with, each ram 12 in both plurality of rams 12 . Further, as shown in FIG. 7 , if the motor 30 includes more than one drive shaft 31 , 31 ′, as discussed above, each drive shaft 31 , 31 ′ is coupled to a rotary valve assembly 40 , 40 ′ each of which is in fluid communication with one or more manifolds 90 X, 90 Y, 90 X′, 90 Y′. It is noted that the rotary valve 44 in each rotary valve assembly 40 , 40 ′ may be radially offset relative to each other. That is, the rotary valve assemblies 40 , 40 ′ may be structured to be open at different times.
Generally, when assembled, the drive shaft distal end 33 extends through the rotary valve assembly housing assembly drive shaft passage 52 . The rotary valve 44 , i.e., the rotary valve body assembly 70 , is coupled to the drive shaft distal end 33 within the rotary valve assembly housing assembly enclosed space 46 , thereby dividing the rotary valve assembly housing assembly enclosed space 46 into the upstream enclosed space 54 and a downstream enclosed space 56 described above. A discussion of the “aligned portion” of the upstream enclosed space 54 and the downstream enclosed space 56 may be more easily understood by providing examples. Accordingly, and as shown in FIG. 2 , in one embodiment, the rotary valve assembly housing assembly at least one inlet passage 48 and at least one outlet passage 50 are each a single passage 48 A, 50 A, respectively. Further, the rotary valve assembly housing assembly inlet passage 48 A and outlet passage 50 A are coextensive with the upstream enclosed space 54 and the downstream enclosed space 56 , respectively. Further, the rotary valve assembly housing assembly inlet passage 48 A and outlet passage 50 A are substantially aligned. Thus, the rotary valve assembly housing assembly inlet passage 48 A and outlet passage 50 A are the at least one “aligned portion” of the upstream enclosed space 54 and the downstream enclosed space 56 . Other than the portions of the rotary valve assembly housing assembly 42 that accommodate the drive shaft distal end 33 , the remaining portions of the rotary valve assembly housing assembly enclosed space 46 are disposed very close, and may abut, both sides of the rotary valve body assembly 70 . That is, other than the space defined by the rotary valve assembly housing assembly inlet passage 48 A and outlet passage 50 A, the rotary valve assembly housing assembly enclosed space 46 is a substantially sealed portion 60 . Thus, the rotation of the rotary valve body selectively provides fluid communication between aligned portions of the upstream enclosed space 54 and the downstream enclosed space 56 via the rotary valve body assembly at least one opening 71 when the rotary valve at least one axial opening 71 is in fluid communication with the at least one aligned portion 58 of the upstream enclosed space 54 and the downstream enclosed space 56 .
This embodiment operates as follows. Pressurized gas from the surge tank 24 is communicated via the tank conduit 38 to the rotary valve assembly housing assembly at least one inlet passage 48 . When the rotary valve at least one axial opening 71 is disposed within the rotary valve assembly housing assembly substantially sealed portion 60 , there is no passage for fluid communication through the rotary valve assembly 40 . In this configuration the rotary valve assembly 40 is “closed.” As the drive shaft 31 rotates, the rotary valve at least one axial opening 71 is brought into alignment with the rotary valve assembly housing assembly inlet passage 48 A and outlet passage 50 A, i.e. into alignment with the aligned portions of the upstream enclosed space 54 and the downstream enclosed space 56 . In this configuration the rotary valve assembly 40 is “open.” That is, when the rotary valve at least one axial opening 71 is brought into alignment with the rotary valve assembly housing assembly inlet passage 48 A and outlet passage 50 A gas may pass through the rotary valve assembly 40 . Thus, the gas is communicated to the at least one downstream pressure conduit 32 and then to the axial ram ejection conduit 18 whereby a cup 2 is ejected from the ram 12 . As the rotary valve at least one axial opening 71 is moved out of alignment with the rotary valve assembly housing assembly inlet passage 48 A and outlet passage 50 A, gas does not pass through the rotary valve assembly 40 . During this time, the ram 12 is actuated to form another cup.
In another embodiment, shown in FIG. 8 , the rotary valve assembly housing assembly 42 includes a space 100 on one side of the rotary valve 44 . For this example, it will be assumed that the rotary valve assembly housing assembly space 100 is disposed on the upstream side of the rotary valve body assembly 70 . That is, in this embodiment, the rotary valve assembly housing assembly 42 may be spaced from the upstream side of the rotary valve body assembly 70 . Rotary valve assembly housing assembly at least one inlet passage 48 is in fluid communication with the rotary valve assembly housing assembly space 100 . Thus, the upstream enclosed space 54 extends over the entire upstream side of the rotary valve 44 and is coextensive with space 100 . Similar to the embodiment described above, the rotary valve assembly housing assembly 42 on the downstream side of the rotary valve body assembly 70 includes an outlet passage 50 A and a portion disposed very close to, and which may abut, the downstream side of the rotary valve body assembly 70 , i.e., the substantially sealed portion 60 . Thus, the portion of the upstream enclosed space 54 on the opposite side of the rotary valve body assembly 70 from the outlet passage 50 A is the at least one aligned portion 58 of the upstream enclosed space 54 and the downstream enclosed space 56 .
This embodiment operates as follows. Pressurized gas from the surge tank 24 is communicated via the tank conduit 38 to the rotary valve assembly housing assembly at least one inlet passage 48 and into rotary valve assembly housing assembly space 100 . When the rotary valve at least one axial opening 71 is disposed within the rotary valve assembly housing assembly substantially sealed portion 60 , there is no passage for fluid communication through the rotary valve assembly 40 . As the drive shaft 31 rotates, the rotary valve at least one axial opening 71 is brought into alignment with the rotary valve assembly housing assembly outlet passage 50 A, i.e., into alignment with the aligned portion 58 of the upstream enclosed space 54 and the downstream enclosed space 56 . When the rotary valve at least one axial opening 71 is brought into alignment with the rotary valve assembly housing assembly outlet passage 50 A gas may pass through the rotary valve assembly 40 . Thus, the gas is communicated to the at least one downstream pressure conduit 32 and then to the axial ram ejection conduit 18 whereby a cup 2 is ejected from the ram 12 . As the rotary valve at least one axial opening 71 is moved out of alignment with the rotary valve assembly housing assembly outlet passage 50 A, gas does not pass through the rotary valve assembly 40 . During this time, the ram 12 is actuated to form another cup.
It is noted that the configuration described above may be reversed, i.e., the rotary valve assembly housing assembly space 100 may be disposed on the downstream side of the rotary valve body assembly 70 .
Cupper 10 may include multiple rams 12 acting in cooperation, i.e., utilizing one drive mechanism. Either embodiment described above may be configured to operate with a manifold 90 , also described above. In an exemplary embodiment having four rams, the at least one downstream pressure conduit 32 may include a manifold 90 having four outlet conduits 94 , wherein each manifold outlet conduit 94 is in fluid communication with one of the four rams 12 . Thus, rather than ejecting a single cup 2 from a single ram 12 , four cups 2 are ejected from four rams 12 simultaneously. It is understood that in an embodiment having more than four rams 12 , the manifold 90 has more than four outlet conduits 94 , i.e., one outlet conduit 94 for each ram. Alternatively, there may be more than one manifold 90 as shown in FIG. 7 and discussed above.
The embodiment, shown in FIG. 8 , is also structured to eject four cups 2 from four rams 12 , but without using a manifold 90 . In this embodiment, the housing assembly at least one outlet passage 50 includes four housing assembly outlet passages 50 A, SOB, 50 C, 50 D. Each housing assembly outlet passage 50 A, 50 B, 50 C, 50 D is coupled to and in fluid communication with one of the four rams 12 . That is, there are also four downstream pressure conduits 32 A, 32 B, 32 C, 32 D, each coupled to and extending between each housing assembly outlet passage 50 A, SOB, 50 C, SOD and one of the four rams 12 . Moreover, each housing assembly outlet passage 50 A, 50 B, 50 C, SOD is separate from each other. There may also be housing assembly four inlet passages 48 (not shown), but as shown, there is one housing assembly four inlet passage 48 and a space 100 on one side of the upstream side of the rotary valve 44 . In this configuration, there are four aligned portions 58 A, 58 B, 58 C, 58 D of the upstream enclosed space 54 and the four aligned portions 59 A, 59 B, 59 C, 59 D downstream enclosed space 56 . Further, there are four each of the rotary valve body assembly at least one axial openings 71 A, 71 B, 71 C, 71 D. Each of the four rotary valve body assembly axial openings 71 A, 71 B, 71 C, 71 D is structured to provide selective fluid communication between the upstream enclosed space 54 and one of the four housing assembly outlet passage 50 A, SOB, 50 C, SOD. Although axial openings 71 A, 71 B, 71 C, 71 D are shown in the figures as having a similar width, the axial openings 71 A, 71 B, 71 C, 71 D would typically be thinner near the perimeter of rotary valve body assembly 70 and thicker near the center of rotary valve body assembly 70 . By selecting the thickness of the axial openings 71 A, 71 B, 71 C, 71 D, the volume of fluid passing through each axial opening 71 A, 71 B, 71 C, 71 D may be balanced.
In this configuration, pressurized gas from the surge tank 24 is communicated via the tank conduit 38 to the rotary valve assembly housing assembly at least one inlet passage 48 and into rotary valve assembly housing assembly space 100 . When each rotary valve at least one axial opening 71 A, 71 B, 71 C, 71 D is disposed within the rotary valve assembly housing assembly substantially sealed portion 60 , there is no passage for fluid communication through the rotary valve assembly 40 . As the drive shaft 31 rotates, each rotary valve at least one axial opening 71 A, 71 B, 71 C, 71 D is brought into alignment with one rotary valve assembly housing assembly outlet passage 50 A, 50 B, 50 C, SOD, i.e., into alignment with the aligned portion 58 of the upstream enclosed space 54 and the downstream enclosed space 56 . When the rotary valve at least one axial opening 71 is brought into alignment with the rotary valve assembly housing assembly outlet passage 50 A, SOB, 50 C, SOD, gas may pass through the rotary valve assembly 40 . Thus, the gas is communicated to the each downstream pressure conduits 32 A, 32 B, 32 C, 32 D and then to one of the four the axial ram ejection conduits 18 whereby a cup 2 is ejected from each ram 12 . As the rotary valve axial openings 71 A, 71 B, 71 C, 71 D are moved out of alignment with the rotary valve assembly housing assembly outlet passages 50 A, 50 B, 50 C, 50 D, gas does not pass through the rotary valve assembly 40 .
Further, this embodiment may be structured to allow for the ejection of the cups to be staggered. That is, the four rotary valve axial openings 71 A, 71 B, 71 C, 71 D may be disposed in a staggered configuration, i.e., disposed along different radial lines, as described above. In this configuration, and assuming the rotary valve assembly housing assembly outlet passages 50 A, 50 B, 50 C, 50 D are disposed along a single radial line, each rotary valve axial opening 71 A, 71 B, 71 C, 71 D enters the four aligned portions 58 A, 58 B, 58 C, 58 D of the upstream enclosed space 54 and the downstream enclosed space 56 at a slightly different time, thus providing for the gas to pass through the rotary valve 44 at slightly different times. This, in turn, causes the ejection of the cups 2 to be slightly staggered. Alternatively, the four rotary valve axial openings 71 A, 71 B, 71 C, 71 D may be disposed along the same radial line and the rotary valve assembly housing assembly outlet passages 50 A, 50 B, 50 C, SOD may be disposed along different radial lines. This means that the four aligned portions 58 A, 58 B, 58 C, 58 D of the upstream enclosed space 54 and the downstream enclosed space 56 are staggered and that the four rotary valve axial openings 71 A, 71 B, 71 C, 71 D will enter the four aligned portions 58 A, 58 B, 58 C, 58 D of the upstream enclosed space 54 and the downstream enclosed space 56 at slightly different times. The end result is the same; the gas passes through the rotary valve 44 at slightly different times and this, in turn, causes the ejection of the cups 2 to be slightly staggered.
In the examples above, it was assumed that there were four rams 12 operating on the cupper 10 . There may, however, be any number of rains 12 on the cupper 10 . Thus, in an embodiment without a manifold 90 as part of the at least one downstream pressure conduit 32 , there is at least one downstream pressure conduit 32 per ram 12 . That is, in such an embodiment the number of relevant components correspond to the number of rams 12 on the cupper 10 . Thus, the housing assembly at least one outlet passage 50 includes a plurality of housing assembly outlet passages 50 , the number of housing assembly outlet passages 50 correspond to the number of the downstream pressure conduits 32 . Further, each housing assembly outlet passage 50 is coupled to, and in fluid communication with, one of the downstream pressure conduits 32 . Further, the rotary valve body assembly at least one axial opening 71 includes a plurality of axial openings 71 , the number of axial openings also corresponding to the number of downstream pressure conduits 32 . Thus, each rotary valve body assembly axial opening 71 is structured to provide selective fluid communication between the upstream enclosed space 56 and one of the housing assembly outlet passages 50 .
While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of invention which is to be given the full breadth of the claims appended and any and all equivalents thereof. | The disclosed and claimed compressed gas system provides for the use of a rotary valve assembly in association with a cupper. A compressed gas system that utilizes a rotary valve assembly uses less gas than a constant flow compressed gas system and is quieter than a compressed gas system that uses valves. The rotary valve is a disk-like body having an opening therethrough. The rotary valve body is disposed within a housing assembly wherein gas may only flow through the housing when the rotary valve body is properly aligned with a space on one side of the rotary valve body. | 5 |
RELATED APPLICATIONS
This application claims the benefit of U.S. Design patent application Ser. No. 29/263,127, filed 17 Jul. 2006, which is a continuation of U.S. Design patent application Ser. No. 29/216,331, filed 1 Nov. 2004.
BACKGROUND OF THE INVENTION
This invention relates to flexible ties and, more particularly, to a normal entry low profile locking tie head having a reduced cross-section sidewall thickness for use with a flexible tie.
Flexible ties for use in bundling elongated members such as wires, cables, etc. are well known. Typically, such ties include an elongated flexible strap made of suitable material. The tie usually has a free end (tail) and a locking head at the opposite end. The strap is flexible; the free end (tail) is capable of being looped 270 degrees around back toward itself and inserted into the locking head after which the diameter of the loop formed by the strap can be adjusted to fit in the desired manner over the intended bundle.
A normal entry tie head is a tie head wherein the insertion of the strap into the locking head and then its extension through the locking head is generally normal, perpendicular, or oblique to the strap, while the strap is in an unfastened, or generally planar orientation.
Various constructions of normal entry tie heads have been proposed. Primarily, such tie heads have been relatively bulky, thereby leading to at least three problems. First, processing cycle times of flexible straps having a locking head are driven by the cure time of the tie heads. That is, in any molded plastic product, the minimum cycle time is determined by the cure time of the most volumetric portion of the product. Therefore, it would be desirable to have a normal entry tie head having a reduced cure time, which would, in turn, decrease cycle time and increase the number of units produced in a given amount of time.
Second, previous tie head bulk provided undesirable obstruction in a variety of applications. Such heads would not allow passage of bundled items through wire looms, frame rails and channels. Furthermore, due to their protrusion from a bundle, such heads could cause injury to persons installing bundles or maintaining equipment containing the bundles. Finally, obstruction of previous tie heads affected the wire density in a given routing location. That is, since prior tie heads were bulky, the obvious protrusion of the head from the bundle would consume valuable routing space, which would otherwise be filled with wires or cables. Thus, it would be desirable to have a tie head that does not generally provide undesirable obstruction.
Third, previous tie heads comprised a significant amount of material. It would, therefore, be desirable to have a tie head that reduces the amount of material used, thereby leading to material cost savings.
SUMMARY OF THE INVENTION
The invention herein described provides all of the desirable features indicated in the Background of the Invention.
To achieve the desired characteristics, the low profile locking tie head of the present invention comprises a reduced amount of wall thickness while maintaining desired structural integrity. The reduction of the wall thickness allows for the shortening of production cycle time and further allows for material savings and desirable installation and maintenance characteristics.
The reduction of wall thickness and material is achieved by using a reinforcement rib, which is integrally formed with the low profile locking tie head wall. The reinforcement rib can be used alone or in connection with clamping rails on the underside of the tie head. Clamping rails allow an even greater reduction in head height, thereby reducing even further the protrusion from the surface of a bundle of objects.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a perspective view of a prior art locking tie head.
FIG. 1B is a cross-section view of the prior art tie head taken along line 1 B- 1 B of FIG. 1A .
FIG. 2A is a perspective view of a first embodiment of the present invention.
FIG. 2B is a first cross-section view taken along line 2 B- 2 B of FIG. 2A .
FIG. 2C is a front elevation view of the embodiment of FIG. 2A .
FIG. 2D is a perspective view showing the embodiment of FIG. 2A in use.
FIG. 2E is a first alternate cross-section view taken along line 2 B- 2 B of FIG. 2A .
FIG. 2F is a second alternate cross-section view taken along line 2 B- 2 B of FIG. 2A .
FIG. 3 is a front elevation view of an alternate first embodiment of the present invention showing an enhanced reinforcement rib.
FIG. 4A is a perspective view of a second embodiment of the present invention.
FIG. 4B is a front elevation view of the embodiment of FIG. 4A .
FIG. 4C is a perspective view showing the embodiment of FIG. 4A in use.
FIG. 4D is a cross-section view taken along line 4 D- 4 D of FIG. 4A .
FIG. 5A is a perspective view of a third embodiment of the present invention.
FIG. 5B is a front elevation view of the embodiment of FIG. 5A .
FIG. 5C is a perspective view showing the embodiment of FIG. 5A in use.
FIG. 5D is a cross-section view taken along line 5 D- 5 D of FIG. 5A .
FIG. 6A is a perspective view of a fourth embodiment of the present invention.
FIG. 6B is a front elevation view of the embodiment of FIG. 6A .
FIG. 6C is a perspective view showing the embodiment of FIG. 6A in use.
FIG. 6D is a cross-section view taken along line 6 D- 6 D of FIG. 6A .
FIG. 7A is a perspective view of a fifth embodiment of the present invention.
FIG. 7B is a front elevation view of the embodiment of FIG. 7A .
FIG. 7C is a perspective view showing the embodiment of FIG. 7A in use.
FIG. 7D is a cross-section view taken along line 7 D- 7 D of FIG. 7A .
FIG. 8A is a perspective view of a sixth embodiment of the present invention.
FIG. 8B is a front elevation view of the embodiment of FIG. 8A .
FIG. 8C is a perspective view showing the embodiment of FIG. 8A in use.
FIG. 8D is a cross-section view taken along line 8 D- 8 D of FIG. 8A .
FIG. 9A is a perspective view of a seventh embodiment of the present invention.
FIG. 9B is a front elevation view of the embodiment of FIG. 9A .
FIG. 9C is a perspective view showing the embodiment of FIG. 9A in use.
FIG. 9D is a cross-section view taken along line 9 D- 9 D of FIG. 9A .
FIG. 10A is a perspective view of an eighth embodiment of the present invention.
FIG. 10B is a front elevation view of the embodiment of FIG. 10A .
FIG. 10C is a perspective view showing the embodiment of FIG. 10A in use.
FIG. 10D is a cross-section view taken along line 10 D- 10 D of FIG. 10A .
FIG. 10E is a cross-section view of a first alternate tie element having a locking tie head for a head retainer, similar to that shown in FIG. 10D .
FIG. 10F is a cross-section view of a second alternate tie element having a locking tie head for a head retainer, similar to that shown in FIG. 10E .
FIG. 11A is the cross-section view of the prior art tie head of FIG. 11B , further including an inserted strap at a first position.
FIG. 11B is the cross-section view of FIG. 11A , wherein the strap is in a second position.
FIG. 12A is the cross-section view of FIG. 2B , further including an inserted strap in a first position.
FIG. 12B is the cross-section view of FIG. 12A , wherein the strap is in a second position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1A and 1B , a previous locking tie head 10 is shown. The relative mass of the tie head 10 is especially evident with reference to the solid molded sections 11 . As previously described, such bulk adds cost in both raw material and processing time.
Referring to FIGS. 2A-D , a first embodiment of the invention includes a tie head 100 having a wall 101 , a reinforcement rib 102 , and a pawl 103 . The wall 101 has a reduced cross section, an outer wall surface 109 and an inner wall surface 108 , which circumferentially forms an opening 105 having an entrance 106 and an exit 107 . Generally, the reinforcement rib 102 is attached to, or disposed on, the wall 101 outer surface 109 , and the pawl 103 is attached to the wall 101 inner surface 108 and is disposed at least partially in the opening 105 adapted to receive a free end 905 of a retaining strap 901 . More specifically referring to FIG. 2B , the reinforcement rib 102 preferably encircles the wall 101 , is preferably molded integrally with the wall 101 , protruding from the wall outer surface 109 proximate the entrance 106 to the opening 105 . In addition to integral molding with the wall 101 , the reinforcement rib 102 further may be molded, merged and aligned with the tie strap 901 . In this case, aligning the reinforcement rib 102 with the tie strap 901 provides 360 degrees of structural rib reinforcement encircling the tie head 100 which provides increased hoop strength around the tie head 100 . This alignment also simplifies the mold cavity profile by eliminating the need for any cross slides in the molding process.
The head 100 is also preferably provided with clamping rails 104 near the entrance 106 to the opening 105 . The rails 104 are adapted to interface to the bundled objects 900 . When the strap 901 is sufficiently pulled through and tensioned the curved surface of the clamping rails 104 are drawn onto the bundle surface, filling in the 90 degree transition between inserted strap 901 and tie head entrance 106 that creates a contact gap, and thereby providing substantially 360 degrees of clamping force around the bundle's surface. While providing a complete clamping surface, the use of clamping rails 104 also allows the pawl 103 to be positioned closer to the entrance 106 to the opening 105 , thereby allowing more material to be removed from the height of the walls 101 which subsequently lowers the overall profile of the entire tie head 100 . When clamping rails 104 are used, it is preferable that the reinforcement rib 102 be placed proximate the entrance 106 of the opening 105 formed by the wall 101 thereby providing reinforcement for the clamping stresses.
FIG. 2E depicts an alternate clamping bottom surface lacking the clamping rails 104 shown in FIG. 2B . Rather, this embodiment includes only a ridge 115 directed towards the bundled object.
FIG. 2F shows a second alternate embodiment having neither a ridge 115 as in FIG. 2E nor clamping rails 104 as shown in FIG. 2B .
Where clamping forces are generally high, the reinforcement rib 102 may, itself, require additional support at rib locations expected to deflect under higher forces. Reinforcement may come by way of a shouldered or thickened rib 102 . That is, the rib 102 may be supplied with a reinforced rib section 116 to provide such additional support, as seen in FIG. 3 . While the required thickness of the reinforced rib section 116 may depend upon a particular application, an increase of thickness by 25-50%, as compared to the thickness of the strap 901 , has proven to add significant strength to the reinforcement rib 102 and ultimately the tie head 100 .
Turning now to FIGS. 4A-4D , a second embodiment of the invention includes a locking tie head 100 having a similar wall 101 and reinforcement rib 102 structure to the first embodiment. This embodiment further includes a head retainer 110 in the form of a stud receiver 111 . The stud receiver 111 may be formed with at least one pawl, but preferably two opposing pawls 114 adapted to engage threads or other ridges on a support stud 902 . The head retainer 110 is preferably attached to, or formed integrally with, an extended portion 112 of the reinforcement rib 102 at a retainer attachment point 113 .
The retainer attachment point 113 is generally either flexile or robust, depending upon the particular application. While the second embodiment of FIGS. 4A-4D provides a flexile connection 113 , a third embodiment pictured in FIGS. 5A-5D has a robust retainer attachment point 123 between the stud receiver 111 and the reinforcement rib 102 . While a flexile connection 113 could be formed of any desirable shape, the preferred connection 113 is a latitudinal groove formed on at least one surface of the extended portion 112 . The groove preferably has a substantially semi-rectangular cross-section. Such a cross-section provides many flex points, thereby eliminating the focus of flex stress from a single point as may occur if the groove had a semi-circular cross-section. A purpose of a flexile attachment point 113 is that the head retainer mechanism may be used in a greater variety of situations. For example, referring back to FIG. 4C , if the retaining stud 902 did not have the lower standoff portion and the retainer 111 needed to be positioned nearer the support structure, the flexile connection 113 would allow placement of a large bundle close to the support structure, and would further allow slight movement in the head to allow insertion of the strap into the opening.
A fourth embodiment of the present invention is shown in FIGS. 6A-6D . This embodiment includes a locking tie head 100 having a similar wall 101 and reinforcement rib 102 structure to the first embodiment. This embodiment, like the second and third embodiments, has a head retainer 110 , in the form of a stud receiver 121 . This stud receiver 121 , however, lacks the pawls of the other embodiments, and instead has a bore 124 adapted to engage a smooth or welding stud 906 . Similar to the second embodiment, this embodiment has a flexile retainer attachment point 113 , which connects the head retainer 110 to the extended portion 112 of the reinforcement rib 102 .
A fifth embodiment is depicted in FIGS. 7A-7D . This embodiment includes a locking tie head 100 having a similar wall 101 and reinforcement rib 102 structure to the first embodiment. Further, this embodiment has a similar head retainer 110 to the fourth embodiment. However, this embodiment includes a robust retainer attachment point 123 .
Now referring to FIGS. 8A-8D , a sixth embodiment of the invention includes a locking tie head 100 having a similar wall 101 and reinforcement rib 102 structure to the first embodiment. Similar to the second and third embodiments, this embodiment includes a head retainer 110 . However, this embodiment provides retention by mounting into a hole or slot 903 , rather than on a support stud 902 . To provide retention into a hole or slot 903 , the head retainer 110 is in the form of a supporting snap structure or arrowhead 131 which is generally known in the art.
A seventh embodiment of the present invention is depicted in FIGS. 9A-9D . This embodiment includes a locking tie head 100 having a similar wall 101 and reinforcement rib 102 structure to the first embodiment. Similar to the sixth embodiment, the head retainer 110 allows support through a hole or slot 903 . However, this embodiment utilizes a fir tree structure 141 for the head retainer 110 . The fir tree structure 141 is generally known in the art.
Another embodiment is disclosed in FIGS. 10A-10D , which incorporates as a head retainer 110 a second locking tie head 151 . The second tie head 151 is preferably of the same general structural design as described herein, having a wall 201 circumferentially defining an opening 205 , a reinforcement rib 202 disposed on the wall 201 and a pawl 203 disposed at least partially within the opening 205 . Such a head retainer 110 allows a secured bundle 900 to be secured to an anchor or miscellaneous object (not shown) that does not provide a standard support stud 902 or slot 903 . The second tie head 151 is preferably inverted with respect to the first tie head 101 . In this manner, it is possible to utilize a single flexible tie to wrap around a first object 900 , through the first tie head 101 , around a second object 900 , and through the second tie head. This embodiment provides separation and spacing between parallel and nearly parallel bundles.
A cross-section view of a first alternate embodiment having a second locking tie head 161 for a head retainer 110 is shown in FIG. 10E . In this embodiment, the second tie head 161 is generally of a similar construction to the first tie head 100 . The second tie head 161 is provided with a reverse pawl 203 similar to that in FIG. 10D , however, the reinforcement rib 202 of the second tie head 161 is positioned near the exit of the opening 205 .
FIG. 10F depicts a second alternate embodiment having a second locking tie head 171 for a head retainer 110 . In this embodiment, however, the reinforcement rib 202 of the second tie head 171 may extend into a second flexible strap 901 b for placement around an anchor, supporting structure, or second bundle.
The invention may be made from any methods and materials now known or developed hereafter. Standard methods for manufacture of such devices are generally known in the art and include, for example, resin molding.
To use the tie head 100 , the head 100 is first supplied, or formed integrally, with a tie strap 901 . The strap 901 is placed around an elongate object 900 to be held by the strap 901 . The free end 905 of the strap 901 is inserted into the entrance 106 of the opening 105 and pulled through exit 107 of the tie head 100 . If the tie head 100 is provided with clamping rails 104 , and when the strap 901 is sufficiently pulled through and tensioned, the curved surface of the clamping rails 104 is drawn onto the bundle surface, filling in the 90 degree transition between inserted flexible strap 901 and tie head entrance 106 that creates a contact gap, thereby providing substantially 360 degrees of clamping force around the bundle's surface. When the rails 104 contact the elongate object 900 the force of the strapping action is distributed along the rails 104 and throughout the wall 101 and reinforcement rib 102 . Then, if a head retainer 110 is provided, the head retainer 110 can be placed into or over the proper support structure; however, the head retainer 110 does not have to be applied last—it can be the first step in the installation followed by the insertion of the strap 901 into the tie head 100 .
FIGS. 11A and 11B depict, in cross section, a performance issue with the prior art tie head 10 with strap 901 inserted. In FIG. 11A , the strap 901 is engaged with the pawl 13 and an average load 20 is applied to bundle 900 resulting in the strap 901 attempting withdrawal from the tie head 10 while the wedged pawl 13 presses strap 901 against inner wall surface 108 . Note the positioning of the pawl 13 pressing against the strap 901 with the average load 20 applied to bundle 900 and strap 901 in FIG. 11A . On the other hand, note the positioning of pawl 13 as shown in FIG. 11B ; when an increased force 22 is applied to the strap 901 , the wall 11 fails by bowing outward 24 . This undesirable wall deformation 24 allows the withdrawing strap 901 to slide between the pawl 13 and the bowed wall 11 , thereby releasing a previously fastened bundle 900 .
The aforementioned increased loading 22 of bundles 900 commonly occurs in but is not limited to bundles on heavy equipment and trucks bouncing in transit resulting in bundled harnesses jostling up and down applying shaking impact loads to all mounted and bundled flexible ties, bundles of large pulsating hydraulic lines, and bundles of expanding soft flexible pressurized hoses.
If, in attempting to achieve a reduction in material usage and cure time with the prior art locking tie head 10 , the thickness of the wall 11 is reduced, deformation 24 is only exacerbated.
FIGS. 12A and 12B show operation of an embodiment of a tie head 100 according to the present invention in positions similar to those of FIGS. 11A and 11B . FIG. 12A depicts a strap 901 engaged with a pawl 103 with moderate or average clamping force 20 . FIG. 12B shows the new tie head 100 under the same increased force 22 as that applied in FIG. 11B to a prior art head 10 . Note that wall deformation or bowing 24 is significantly reduced and may be eliminated by using the reinforcement rib 102 , which may be further aided by the clamping rails 104 . Not only does the new tie head 100 prevent the aforementioned problem with bowed walls, but the head 100 is formed with walls 101 having a decreased cross-section. Therefore, the new tie head 100 allows a reduction in tie head material, thereby decreasing cure time and lowering production cost while providing a tie head having increased strength over prior art heads.
The foregoing is considered as illustrative only of the principles of the invention. Furthermore, 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. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims. | A low profile locking tie head having a reduced wall thickness is provided for use in conjunction with a flexible strap. The low profile head comprises a wall, which circumferentially defines an opening, a reinforcement rib attached to the wall, and a pawl mechanism disposed at least partially inside the opening. A pair of clamping rails preferably provides a complete clamping surface, lowers the required tie head height, and assists in the transfer of force to the reinforcement rib. Further, a tie head retainer is provided to allow secure connection to a predetermined support structure. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image data storing method and image data storing device applicable for various display devices such as liquid crystal displays, and particularly to those which can achieve downsizing, and are preferably applied to two-dimensional or three-dimensional graphics.
2. Description of Related Art
As is well known, a screen of a liquid crystal display consists of a lot of pixels arrayed in a matrix. Such a liquid crystal display generates a picture by controlling the transmittivity (reflectivity) of all the pixels by sequentially applying voltages corresponding to pixel data to liquid crystal elements mounted for individual pixels.
An image data storing device used in such a display device adopts various design ideas because it is necessary for a great number of pixel data to be read within a certain limited time to prevent screen flickering.
FIG. 6 is a block diagram showing a layout of an image data storing integrated circuit considering such an image read time. In FIG. 6, reference numerals 51, 52, 53, 54 and 55 each designate a physical bank, a repetition unit of a memory area in the memory layout; 8s designate memory buses, each of which has a bus width of m corresponding to the pixel data, and p (=4, in FIG. 6) of which are each connected to the physical banks 51, 52, 53, 54 and 55; and 61, 62, 63 and 64 each designate a memory group, each of which corresponds to one pixel, and consists of a plurality of memory elements connected to one of the memory buses 8. Reference numerals 71, 72, 73 and 74 each designate a group of n address decoders, each of which is provided for one of the memory groups for selecting a memory element for outputting one pixel data. Thus, the total number of address decoders amounts to p×n. The reference numeral 9 designates a selector for selecting n (=5 in FIG. 6) memory buses 8 from among the plurality of memory buses 8 to output the image data on the selected memory buses 8. Incidentally, the bus width (the number of lines of each bus) m of each memory bus 8 is determined in accordance with the number of gray levels of a pixel, and when the number of bits needed for the pixel is m bits, the bus width is also set at m in general.
Next, the image data storing method of the conventional image data storing integrated circuit will be described.
In the foregoing image data storing integrated circuit, pixels constituting a display picture are divided into pixel groups, each of which consists of p×n pixels. Then, the pixel data (1,1), (1,2), . . . , and (1,n) in the first row are stored in the (1,1) memory group 61, (1,2) memory group 61, . . . , and (1,n) memory group 61, respectively. Likewise, the pixel data (2,1), (2,2), . . . , and (2,n) in the second row are stored in the memory group 62, followed by storing the third row and onward in the same manner. Finally, the pixel data (p,1), (p,2), . . . , and (p,n) in the p-th row are stored in the memory group 64.
Next, the read operation of the conventional device will be described.
In a common image display mode, the pixel data corresponding to the pixels in the first row are successively read on an every n pixel basis by actuating the n address decoders 71, . . . , 71 while setting the selector 9 such that it outputs the data of the memory groups 61, . . . , 61 in the first row, thereby completing the first row. Likewise, the pixel data corresponding to the pixels in the second row are successively read on an every n pixel basis by actuating the n address decoders 72, . . . , 72 while setting the selector 9 such that it outputs the data of the memory groups 62, . . . , 62 in the second row, thereby completing the second row. Thus, all the pixel data of the following rows are read one after the other.
According to the image data storing integrated circuit, since the pixel data can be read in groups of n pixels, the time taken to display a picture is reduced by a factor of n. This enables the pixel data to be read in a time that can prevent the flickering of the picture.
In another operation mode of the image data storing integrated circuit, in which 3-D (three-dimensional) graphics or the like are carried out, pixel data are sometimes rewritten column by column at a location in which a displayed picture changes. In such a case, the p (=4) pixel data in each column can be read by actuating the four address decoders 71, 72, 73 and 74 corresponding to the physical bank 51 (52, 53, 54 or 55), after setting the selector 9 such that it outputs the pixel data in the physical bank 51 (52, 53, 54 or 55).
The conventional image data storing integrated circuit with the foregoing configuration must possess p sets of memory buses for each physical bank. As a result, the number of lines needed for reading the pixel data from each of the physical banks becomes m×p, amounting to m×n×p lines for the entire memory. This presents a problem of hindering downsizing of the memory when handling a large scale, high gray level display image.
SUMMARY OF THE INVENTION
The present invention is implemented to solve the foregoing problem. It is therefore an object of the present invention to provide an image data storing method and an image data storing device capable of handling a large scale, high gradation images with reducing the number of lines of the buses and the size of the memory.
According to a first aspect of the present invention, there is provided an image data storing device comprising: a plurality of physical banks, each of which forms a repetition unit of a memory area, and has a storage capacity that can store a plurality of pixels in each of a plurality of pixel groups formed by dividing a display image; and a plurality of memory buses provided in one to one correspondence with the plurality of physical banks, each of the memory buses having a bus width needed for conveying pixel data associated with at least one of the pixels, wherein the pixel data stored in the plurality of physical banks are simultaneously output through the memory buses to be displayed.
Here, each of the pixel groups may consist of p×n pixels of the display image, and each of the plurality of physical banks can store at least p pixels, wherein p and n are natural numbers.
The natural number p may equal n.
The image data storing device may further comprise a selector for selecting memory buses from among the plurality of memory buses, wherein the selector may simultaneously output one of a set of p pixel data and a set of n pixel data supplied from the plurality of physical banks through the memory buses.
The image data storing device may further comprise p address decoders for selecting memory elements of the plurality of physical banks in parallel, the memory elements each storing at least one of the pixel data.
The image data storing device may further comprise an image data control circuit for controlling such that each of the plurality of physical banks stores pixels with their rows and columns different from each other.
The image data storing device may be formed in an integrated circuit.
According to a second aspect of the present invention, there is provided an image data storing method comprising the steps of: dividing an image data to be displayed into a plurality of pixels groups, each of which consists of p×n pixel data, where p and n are natural numbers; and storing into each of physical banks a set of p pixel data of each of the pixel groups, the p pixel data having different rows and columns from each other.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a configuration of an embodiment 1 of an image data storing device in accordance with the present invention, and its neighboring devices;
FIG. 2 is a block diagram showing a layout of an image data memory circuit of the embodiment 1;
FIG. 3 is a diagram showing a matrix of pixels in a liquid crystal display device associated with the embodiment 1;
FIG. 4 is a block diagram showing a layout of an image data memory circuit of an embodiment 2 in accordance with the present invention;
FIG. 5 is a diagram showing a matrix of pixels in a liquid crystal display device associated with the embodiment 2; and
FIG. 6 is a block diagram showing a layout of a conventional image data storing integrated circuit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention will now be described with reference to the accompanying drawings.
Embodiment 1
FIG. 1 is a block diagram showing a configuration of an embodiment 1 of an image data storing device in accordance with the present invention, and its neighboring circuits. In FIG. 1, the reference numeral 1 designates an image data memory control circuit for accepting image data sequentially input thereto, and for outputting them in groups consisting of a predetermined number of pixel data; 2 designates an image data memory circuit for storing the pixel data; 3 designates an image data read control circuit for reading from the image data memory circuit 2 the image data in groups consisting of a predetermined number of pixel data; and 4 designates a liquid crystal device for carrying out display based on the image. The image data memory control circuit 1, image data memory circuit 2 and image data read control circuit 3 are implemented as an integrated circuit.
FIG. 2 is a block diagram showing an layout of the image data memory circuit 2. In FIG. 2, reference numerals 51, 52, 53, 54 and 55 designate n physical banks, each of which constitutes a repetition unit of a storage area in the memory layout. Reference numerals 8s designate memory buses, each of which has a bus width of m corresponding to the pixel data, and is connected to one of the physical banks 51, 52, 53, 54 and 55. Reference numerals 61, 62, 63 and 64 each designate a memory group, each of which corresponds to one pixel, and consists of a plurality of memory elements. Each physical bank includes four memory groups 61, 62, 63 and 64. Reference numerals 71, 72, 73 and 74 designate four address decoders for supplying the memory groups 61, 62, 63 and 64 in the physical banks 51, 52, 53, 54 and 55 with control signals for selecting the memory elements for outputting the pixel data. The reference numeral 9 designates a selector for selecting designated memory buses 8 from among the n memory buses 8 to output the image data on the selected memory buses 8.
Next, the operation of the present embodiment 1 will be described.
Receiving image data, the image data memory control circuit 1 supplies the image data memory circuit 2 with every five pixel data. The image data memory circuit 2 supplies the five image data in parallel to the physical banks 51, 52, 53, 54 and 55 so that they are stored in the memory elements designated by the address decoders 71, 72, 73 and 74. Once the pixel data have been stored in the physical banks 51, 52, 53, 54 and 55 in this way, the image data read control circuit 3 reads the pixel data therefrom, and outputs voltage information based on the pixel data. The liquid crystal device 4 applies the voltages in response to the voltage information to the liquid crystal elements to have them display an image formed as a distribution of their transmittivity (reflectivity).
Next, the storing operation of the present embodiment 1 will be described.
FIG. 3 is a diagram illustrating the pixel matrix in the liquid crystal device 4, in which a plurality of pixels are arranged in s rows by r columns. In the present embodiment 1, it is assumed that the pixel data are input to the image data memory control circuit 1 in such a manner that the pixel data of the first row are successively input from (1,1) in the first column to (1,r) in the r-th column, followed by the input of the pixel data (2,1)-(2,r) in the second row, the pixel data (3,1)-(3,r) in the third row, . . . , and finally the pixel data (s,1)-(s,r) in the s-th row.
In such an input condition, the image data memory control circuit 1 successively supplies the image data memory circuit 2 with the pixel data of each row in groups of every five pixel data.
In the course of this, the image data memory control circuit 1 changes the destination of the output pixel data for each row. More specifically, as clearly seen by comparing FIG. 2 with FIG. 3, the destination of the pixel data are switched such that the first physical bank 51 stores the pixel data (1,1) of the first column of the first row in the pixel group, the pixel data (2,2) of the second column of the second row in the pixel group, the pixel data (3,3) of the third column of the third row in the pixel group, the pixel data (4,4) of the fourth column of the fourth row in the pixel group, and again the pixel data (1,1) of the first column of the fifth row in the pixel group.
Thus, the pixel data on a display screen is divided into pixel groups each consisting of 4 rows by 5 columns to be stored as shown in FIGS. 2 and 3, and each physical bank stores the pixel data of a different column and a different row in the pixel group when storing the pixel data.
Next, the read operation of the present embodiment 1 will be described.
First, in an operation mode in which the pixel data are read row by row, the five pixel data corresponding to the pixels (1,1)-(1,5) of the first row are read from the physical banks 51, 52, 53, 54 and 55 by actuating the first address decoder 71. This operation is repeated until the pixel data of the first row are completed. Subsequently, the five pixel data corresponding to the pixels (2,1)-(2,5) of the second row are read from the physical banks 51, 52, 53, 54 and 55 by actuating the second address decoder 72, and this operation is repeated until the pixel data of the second row are completed. Repeating such operations with the entire rows enables the image data necessary for generating a picture to be supplied to the liquid crystal device 4.
Second, in an operation mode in which the pixel data are read column by column, all the address decoders 71, 72, 73 and 74 are actuated so that four pixel data of the same column such as (1,1)-(4,1) are read from the physical banks 51, 52, 53, 54 and 55, followed by the repetition of the read operation until all the pixel data in the column are read. The read operation is carried out for the required number of columns. This enables a part of the display image to be rewritten to form a new picture.
As described above, the present embodiment 1 comprises n (=5) physical banks each including p (=4) memory groups, n memory buses each provided for one of the physical banks, and the selector for selecting a predetermined number (=5 or 4) of memory buses from among the n memory buses to output the image data therefrom. This makes it possible to reduce the number of buses to the number of the physical banks. Therefore, the number of the lines of the memory buses reduces by a factor of p as compared with that of the conventional image data storing integrated circuit, and the scale of the selector also reduces by the factor of p, accordingly. As a result, the present embodiment 1 can achieve a large scale, high gradation display with reducing the size of the image data storing integrated circuit and image data storing device.
Furthermore, since all the physical banks are provided in common with address decoders for selecting the memory elements that output the pixel data to the memory buses, it is not necessary to prepare the address decoders for respective memory groups as in the conventional image data storing integrated circuit as shown in FIG. 6. This enables the number of address decoders to be reduced by a factor n, thereby making it possible to achieve the large scale, high gradation display with reducing the size of the memory.
According to the present embodiment 1, a display image is divided into a plurality of pixel groups, each of which consists of n×p pixels, and each of the physical banks stores the pixel data of a different column and a different row in each pixel group. This makes it possible to simultaneously read not only a plurality of consecutive pixels in the row, but also a plurality of consecutive pixels in the column. Thus, even the device with its size reduced can rewrite, in groups of every p pixels, only columns associated with a location in which an image changes.
Embodiment 2
FIG. 4 is a block diagram showing a layout of the image data memory circuit in an embodiment 2 of the image data storing device in accordance with the present invention. The embodiment 2 differs from the embodiment 1 in that it comprises four physical banks 51, 52, 53 and 54, and that the selector 4 is removed. Since the remaining portion is the same as that of the embodiment 1, the description thereof is omitted here by designating the corresponding portions by the same reference numerals.
Next, the operation of the embodiment 2 will be described.
In this embodiment, the pixel groups, each of which consists of four rows by four columns, are formed, and the pixel data stored in the memory groups 61, 62, 63 and 64 vary as shown in FIG. 4. The image data memory control circuit 1 outputs a group of four pixel data at the same time, and they are input directly to the physical banks 51, 52, 53 and 54 to be stored. The pixel data output from the physical banks 51, 52, 53 and 54 are directly supplied to the image data read control circuit 3. Since the remaining operation is the same as that of the embodiment 1, the description thereof is omitted here.
Thus, the embodiment 2 can reduce, besides the effect and advantages of the embodiment 1, the number of the buses to that of the physical banks, that is, can reduce the total number of bus lines by a factor of p as compared with the conventional image data memory. This is because the display image is divided into a plurality of pixel groups, each of which consists of n rows by n columns, where n=4 in FIG. 4, the physical banks each have a storage capacity capable of storing at least n pixel data in the pixel group, and the memory buses, each of which has a bus width needed for conveying the pixel data, are provided in one to one correspondence with the physical banks. Furthermore, the selector can be obviated because the number of lines of the memory buses equals the number of lines required for simultaneous reading of the pixel data. As a result, the large size, high gray-scale can be achieved with reducing the image data storage. | An image data storing device capable of solving a problem involved in a conventional device in that an increasing number of memory bus lines are required which are used for simultaneously reading pixel data from memory elements as the dimension of a screen increases, and that this hinders the device from being integrated. The present image data storing device includes n (a positive integer) physical banks, to which memory buses are connected in one to one correspondence with them. Each physical bank stores image data with their rows and columns different from each other. | 6 |
BACKGROUND AND SUMMARY OF THE INVENTION
In the field of handling of molten metals, the problem of discharging the molten metals from crucibles or similar containers has necessitated the use of very expensive materials for forming such valved outlets so that the outlets can safely be used and withstand the extremely high temperatures that result from the materials being handled and passed through the outlet. In general, the outlets have been subject to leakages due to rapid expansion upon exposure to the molten liquids and then rapid contraction when the valve closure is shut or the container emptied. It has previously been known to employ a bottom plate which surrounds the outlet channel of the vessel or crucible and a similarly shaped valve plate which is movable relative to the bottom plate so that these plates can be interchangeable thus reducing the costs of replacing one or the other plates when such plates become worn or cracked due to use over a period of time.
Such interchangeable plates are provided with apertures through which the molten metal passes when the apertures are aligned by moving one plate, the valve plate, relative to the bottom plate of the vessel. It has been the practice to provide on such a plate a key of some form, for example, a projection which would cooperate with a groove on another part of the assembly such as the perforated stone casing or the discharge casing. It has been the accepted practice to provide the projection or key so that it extends in the direction of flow of the molten liquid metal. However, with interchangeable plates, where the key is provided on the casing, then the key must run in a groove formed on the valve plate so that, at least with the valve plate, the key portion will extend counter to the direction of flow which is undesirable. Of course, whenever on the other hand, the key has been provided on the plates, then the key will extend in the wrong direction, that is, counter to the direction of liquid flow, at least on the side of the bottom plate of the vessel which faces away from the identically shaped valve plate.
With these previously employed embodiments, whenever a deviation from the accepted practice as mentioned above must be employed, it has been preferred to use the arrangement where the key surface or projection has been provided on the casing for the reason that the accepted practice would be followed in a critical area of the sliding closure,namely, at the groove and key connection lying above the sealing surface of the plates. This is important since the highest liquid pressure occurring in the sliding valve closure exists at the sealing surfaces for every position of the valve. In addition to the departure from the accepted practice with regard to the groove and key connection lying below the sealing plane, this embodiment has two other severe disadvantages. Firstly, the plate or plates are considerably weakened as a result of the indentation which provides the groove at a critical point of the plate, namely, immediately around the aperture defining a portion of the flow passage, and, secondly, the expansion or butt joints of the groove and key connections on both sides of the sealing surface will be disposed where the flow turbulence is always the greatest in a circumstance where the valve plate is not completely open.
In another known embodiment, where the key surface is provided on the surface of the plate, there will be, of course, no weakening of the structural integrity of the plate and, in addition, the joints of the groove and key connection are also located away from the area of greatest flow turbulence. However, a serious drawback still exists due to the fact that the greatest thickness which consists of the thickness of the plate plus the height of the key which projects from the plate and the area where the greatest temperature elevation is experienced on the plate coincide. It is well known, of course, that the absolute measure of the degree of expansion results from a consideration of the dimension of the element and the temperature of the element at the place being observed. Assuming the usual case where a sufficient pretension or strengthening as by hardening of the sealing surfaces is provided, the expansion of the thickness of the plates can occur only in a direction which extends away from the sealing surfaces. Extensive experiments have been conducted and the results reported concerning the fact that such expansions, due to the fact that they cannot be freely absorbed in the system of these elements, result in considerable pressure loads on the edges defined by the passage and by the sealing surfaces. As a result, where relative movement of the plates takes place, cracking or breaking of the plates occurs. Moreover, there is the danger that the plate will be broken at the point the key projection is connected to the plate due to internal stresses that exist.
Of course, when the pretensioning forces of the sealing surfaces is less than the force created by the heat expansion in the area of the flow passage, the plates will be able to easily expand in the direction extending toward the sealing surfaces but, in so doing, a critically undesirable formation of a gap between the sealing surfaces of the bottom plate and valve plate will result in the areas of the plate remote from the sealing surfaces. The portions of the plates that are thus exposed as a result of the formations of the gap can easily break away resulting in a dangerous outflow of the liquid metal through any gaps that develop.
It is an object of the present invention to avoid the foregoing difficulties by providing interchangeable plates with an improved groove and key connection which can still be used to cooperate with the adjacent casings of the vessel and discharge outlet.
More specifically, the present invention provides means for the formation of a groove and key connection in the form of a bead projecting from the side of the plate which faces away from the sealing surface of the plate with the bead having two flanks which are in the form of annular surfaces concentric about themselves, the straight generatrices of which surfaces run at a slant in opposite directions relative to the axis of the flow passage and the base of the bead and the inside flank of the bead lies on a diameter which is greater than the diameter of the passage.
With the structure of the present invention, it will be possible to dimension the thickness of the plate immediately adjacent the passage independently of the dimensioning practices relating to the formation of a groove and key connection so that, as a result, the usual condition, on the one hand, relating to the expansion of the elements and, on the other hand, relating to the distance of the butt joints from the sealing surfaces of the plate will be optimally satisfied. Moreover, the two flanks of the bead forming the key are situated and shaped so that it will be possible to use the plate either as a part forming a groove or a key so that the plate can perform both of these functions simultaneously.
Further, by the use of the present invention, it will be possible, perhaps without deviating from the accepted practice relating to the orientation of the groove with reference to the direction of flow of the liquid metal, to operate with plates of the same shape and dimensions so that the plates can be interchangeably employed. Also, advantageously, the bead will be disposed in an area of lesser temperature differences as a result of its being disposed at a distance from the flow passage thus minimizing or entirely eliminating the danger of cracks due to tension. It will also be noted that the disposition of the bead away from the flow passage will still impart a desired reinforcement to the plates to prevent or at least minimize bending in the area where the plate is supported to a lesser degree by the surrounding housing structure.
The foregoing and other advantages will become apparent as further consideration is given to the following detailed description together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view perpendicular to the flow passage of the elements of the present invention showing a groove and key connection of a two plate closure; and,
FIG. 2 is a view similar to that of FIG. 1 but showing a groove and key connection of a three plate sliding valve.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawing, wherein like numerals designate corresponding parts, in FIG. 1 there is shown a fixed bottom plate 10, a perforated stone casing 11 which is situated in the bottom of a vessel partially shown in dotted lines at 11', a longitudinally movable valve plate 12 and an outlet casing 13. The apparatus for moving plate 12 is conventional and is thus not shown. Both plates 10 and 12 have a bead 17, 17' disposed concentrically in relation to the apertures 16 and 16' formed therein, respectively, with the beads 17 and 17' being formed on the sides 15 and 15', respectively, which face away from the abutting sealing surfaces 14 and 14'. The cross sections of the beads 17 and 17' which are in the form of projections extending away from the uniform thickness indicated 18 and 18', are in the form of identical trapezoidal cross sections each with two flanks, the inner one 19 and the outer one 20. The flanks are inclined at an angle of about 10° to 15° in the form of concentric, annular surfaces. The inner flank 19 has its base disposed at a diameter which is larger than the diameter of the apertures 16 and 16'. Both the bottom plate 10 and the valve plate 12 thus form a groove and key connection in the area of the flow passages 16 and 16' either in relation to the stone casing 11 or the outlet casing 13, respectively. In particular, the flank 19 of the beads 17 and 17' define the groove forming portion. The edges of the adjacent parts of the vessel and support structure are indicated in dotted lines at 23, 23' and 21 and 21' which are not illustrated in more detail as these are standard elements which together with the casing surface of the stone casing 11 and the adjacent surfaces of the bottom plate 10 and the jacket surface of the outlet casing 13 respectively, form a joint. Also, the outside diameter of the bead defined by the flank 20 functions as a key forming portion of the connection relative to the parts or surfaces lying directly adjacent to it.
As a matter of practice, the groove and key connection are sealed by means of mortar placed in the gap that exists between them. The butt joints 22 and 22', in the past, have been particularly susceptible to the danger of being washed out, particularly, whenever the joints lie near the sealing surfaces 14 and 14' where, as previously noted, the greatest turbulences occur. The possibility of having the mortar washed out between the butt joints 20 and 22 is minimized by having a flush surface contact or gapless joint provided between these parts of the plates and the casings.
According to the present invention, by way of example, the beads 17 and 17' of the bottom plate 10 and the valve plate 12, respectively, are of the same shape and of the same dimensions so that the plates and the beads can be used with a complimentarily shaped casing either to form a groove or a key forming portion as will be described more fully in connection with FIG. 2. Of course, other portions of the plates 10 and 12 may be of different dimensions and shape depending on considerations which need not be taken into account here. Clearly, however, the advantages of the present invention reside in the fact that the shape and dimensions of the molds of the plate required for the formation of the groove and key connection is independent of the thickness of the plate in the vicinity of the flow apertures. As a result, the positioning of the butt joints 22 and 22' and the problem of manufacturing the plates with the proper thickness in the vicinity of the flow aperture 16 and 16' can be effected in th conventionally simple manner. Also, it should be noted that the beads 17 and 17' are located at a distance from the zone of highest temperature and of the greatest temperature gradient which is the location where changes in the thickness of the plate usually occur therefore, the danger of cracks or fissures occurring which lead to failure of the sealing functions of these elements is greatly minimized if not entirely eliminated.
In FIG. 2, another embodiment of the present invention is illustrated which is substantially similar to that of FIG. 1 so that only the essential differences will be described below.
FIG. 2 illustrates a three plate sliding closure which is used, for example, on intermediate crucibles or containers in continuous casting installations. Such arrangements use, in general, a base plate 30, a perforated stone casing 31, an outlet plate 32, an outlet casing 33 as well as the usual valve plate 34 which is disposed to be longitudinally movable between the base plate 30 and the outlet plate 32.
In the field of liquid metal handling, three plate sliding closures have the advantage that the emerging jet or stream of liquid metal does not move about relative to the axis of the flow passages and thus spattering is minimized when the valve plate 34 is moved between its open and closed position. According to the present invention, the base plate 30 and the outlet plate 32 have basically the same shape and dimensions. The thickness 39 and 39' of these plates in the area of flow apertures 35 and 35' and the inside flanks 36 and 36' of the beads 37 and 37' respectively, are larger than the basic thickness indicated at 38 and 38' of the plates 30 and 32. With this arrangement, the location of the butt joint 41 will be spaced at a greater distance from the sealing surface 40 without the width of the thick portion 39, 39' reaching a dimension which would be critical as a result of the above mentioned consequences of heat expansion. The dimensions of the thicknesses 39 and 39' and of the base thicknesses 38 and 38' can, of course, be adapted to the requirements of specific situations so that only a minimum of material expenditure will be needed compared to the conventional thicknesses of such plates thus resulting in a saving of material costs.
The embodiment illustrated in FIG. 2 demonstrates clearly the advantage stemming from the fact that the beads 37 and 37' can be used both as a groove as well as a key forming position. Specifically, relative to the perforated stone casing 31, the bead or key portion 37, on its interior, defines a groove for the complimentarily formed part of the casing 31 whereas the bead 37' functions as a key relative to the complimentarily shaped portion of the outlet casing 33. Thus, according to the accepted practice in which the key cooperating with the groove should be disposed in the direction of flow of the liquid metal, this feature is advantageously retained together with the additional advantage that the two plates 30 and 32 are interchangeable as they can be shaped identically.
The use of the bead 37' as a key functioning portion of the connection with the outlet casing 33 is of particular advantage whenever the outlet casing serves as an immersion outlet, that is to say, whenever the casing has a pipe shaped extension which extends below the surface of the bath level as in a continuous casting process. Such immersion outlets must be capable of being quickly installed and disassembled and, as is conventional, they are attached without mortar on the outlet plate 32 or on its housing indicated in broken lines about the plate 32. With this arrangement, the funnel portion 42 could be constructed with a key forming portion without difficulty which would prevent leakages due to the absence of mortar in the vicinity of the connection.
While the foregoing has been a description of the preferred embodiments, it will be understood that variations of the invention will be apparent to those skilled in the art without departing from the scope of the invention as defined in the appended claims. | The disclosure embraces a structure for plates provided on a sliding closure of an outlet or spout of a container for liquid metal, one side of each plate serving as a sealing surface which cooperates with the other, relatively movable plate of the closure; the plates have a passage running approximately perpendicularly relative to the sealing surface or surfaces with the other sides of the plate facing away from the sealing surfaces having annular grooves or keys for cooperating with complimentary shaped portions of either an outlet casing or a stone casing of the container. | 1 |
BACKGROUND OF THE INVENTION
This application is a continuation-in-part of U.S. Ser. No. 07/734,157, filed Jul. 22, 1991 now abandoned. U.S. Ser. No. 07/734,157 is hereby incorporated by reference in its entirety.
The present invention relates to a multilayer polypropylene film which has been produced by coextrusion and which has improved barrier properties with respect to permeability to water vapor and oxygen and simultaneously possesses favorable slip properties and low shrink values, in order to ensure good machine running properties.
EP-A-0,247,898 (=U.S. Pat. No. 4,921,749) describes a special polypropylene film which is claimed to possess, in particular, high-strength sealed seams and improved barrier properties.
DE-A-35 35 472 (=U.S. Pat. No. 4,786,533) is directed to polypropylene films where a certain amount of resin is incorporated in the base layer. However the films disclosed therein possess, in particular, inadequate barrier properties towards water vapor, so that there has been a need for films having improved properties in this respect.
DE-A-38 14 942 describes polypropylene films containing a resin proportion of 5 to 40% by weight in their base layers, the resins having a softening point in the range of 80° to 125° C. These films are used as shrink-on labels, but exhibit disadvantages with respect to the barrier properties towards water vapor and oxygen.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a polypropylene film having improved barrier properties with respect to permeability to water vapor and oxygen, while at the same time having favorable slip properties and low shrink values.
Another object of the present invention is to provide a process for producing the improved film.
In accomplishing the foregoing objectives, there has been provided, in accordance with one aspect of the present invention, a sealable film comprising (i) a base layer comprising polypropylene and a hydrocarbon resin having a softening point of at least 140° C. and (ii) at least one top layer comprising (a) an ethylene/propylene copolymer having an ethylene content of not more than about 10% by weight, (b) a propylene/1-butene copolymer, (c) a propylene/ethylene/alpha-olefin terpolymer, or (d) a blend of two or more of (a), (b) and (c), wherein said top layer contains an anti-blocking agent.
In another embodiment of the invention, the hydrocarbon resins has a softening point of less than 140° C., preferably from about 100° to 138° C.
In accordance with another aspect of the present invention there is provided a process for producing the foregoing film comprising the steps of: producing by coextrusion through a slot die a cast film comprising said base layer and at least one said top layer; chilling said cast film on a chill roll; and then orienting said film by biaxial stretching in the longitudinal and transverse directions.
In accordance with still another aspect of the present invention there is provided a process for producing a multilayer sealable film comprising the step of incorporating in at least one layer of said film a resin having a softening point of at least 140° C. or less than 140° C.
Other objects, features and advantages of the present invention will become apparent to those skilled in the art from the following detailed description. It is to be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration and not limitation. Many changes and modifications within the scope of the present invention may be made without departing from the spirit thereof, and the invention includes all such modifications.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In comparison to the films according to DE-A-38 14 942, the films according to the present invention display reduced deposits on the rollers.
Compared to the film disclosed in that publication, the film of the instant invention is distinguished by improved processability, in particular with respect to machine running properties on high-speed packaging machines and to thermal blocking. The term "machine running properties" refers to the ease of processing on high-speed packaging machines. For this purpose, the film must be neither too smooth nor too rough, for this might cause jams during the slitting operation. The stiffness of a film is also important in this respect. The term "thermal blocking" relates to the mutual adhesion of film-packaged goods, which is, above all, caused by the action of heat. The lower this mutual adhesion between two adjoining film layers under the action of heat is, the better is the thermal blocking behavior.
In comparison to the films according to DE-A-38 14 942, the films according to the present invention display reduced deposits on the rollers.
The terpolymer described under (c) above is preferably comprised of about 93.2 to 99.0% by weight of propylene, about 0.5 to 1.9% by weight of ethylene and about 0.5 to 4.9% by weight of the alpha-olefin, the percentages relating to the total weight of the terpolymer.
The base layer of the multilayer film is comprised of a propylene polymer having a melting point in the range of about 162° to 168° C. Isotactic polypropylene having an n-heptane-soluble fraction of 6% or less is preferably used. The polypropylene of the base layer in general has a melt flow index of about 1.5 to 5 g/10 min, measured under a load of 21.6N and at a temperature of 230° C., according to DlN 53 735.
The base layer preferably has a modulus of elasticity in the longitudinal direction of less than 3000 N/mm 2 , more preferably less than 2800 N/mm 2 , most preferably 2200 to 2800 N/mm 2 . The modulus of elasticity in the transverse direction is preferably less than 5200 N/mm 2 , more preferably in the range from 4000 to 5100 N/mm 2 . The modulus of elasticity is determined according to DIN 53,457 or ASTM-D 882, respectively.
The low-molecular weight resin contained in the base layer is a natural or synthetic resin having a softening point of ≧140° C. or a softening point of <140° C., such as from 100° to 138° C., determined according to DIN 1995-U4, corresponding to ASTM E-28, and it is present in an amount of about 5 to 30% by weight, preferably of about 5 to 20% by weight, most preferably 5 to 10% by weight, relative to the total weight of the base layer. Surprisingly, it was found that as a result of incorporating a resin having a softening point in the range specified above into the polypropylene, the barrier properties of the films towards water vapor are substantially improved, and that at the same time the optical properties and also the shrink behavior of the film are favorably influenced. Moreover, the films according to this invention do not lead to deposits on rollers, e.g., during the longitudinal stretching. It has also been shown that as a result of their particular slip properties, the films of this invention are especially well-suited for use on high-speed packaging machines. The film surface is smooth enough to avoid so-called `slip-stick` effects, i.e., irregular running speeds. On the other hand, the roughness of the film surface is sufficiently high to avoid jams prior to the actual slitting operation.
From among the numerous low-molecular weight resins, preference is given to the hydrocarbon resins, in particular to the petroleum resins, styrene resins, cyclopentadiene resins and terpene resins (these resins are described in detail in `Ullmanns Enzyklopadie der Technischen Chemie` (Ullmann's Encyclopedia of Technical Chemistry), 4th edition, vol. 2, pp. 539-553). The term `petroleum resins` defines hydrocarbon resins produced by polymerization of deep-decomposed petroleum components in the presence of a catalyst. These petroleum materials usually contain a mixture of resin-forming substances, such as styrene, methylstyrene, vinyltoluene, indene, methylindene, butadiene, isoprene, piperylene and pentylene. The styrene resins are low-molecular weight styrene homopolymers or copolymers of styrene and other monomers, such as alpha-methylstyrene, vinyltoluene and butadiene. The cyclopentadiene resins are cyclopentadiene homopolymers or cyclopentadiene copolymers obtained from coal tar distillates and fractionated petroleum gas. The resins are produced by subjecting the cyclopentadiene-containing materials to high temperatures over a prolonged period of time. Depending on the reaction temperature, dimers, trimers or oligomers are obtained.
The terpene resins include polymers of terpenes, i.e., hydrocarbons of the formula C 10 H 16 , which are present in practically all etherial oils or oil-containing vegetal resins, and also phenol-modified terpene resins. Specific examples of suitable terpenes include alpha-pinene, beta-pinene, dipentene, limonene, myrcene, camphene and similar terpenes. The hydrocarbon resins may also be chosen from among the so-called modified hydrocarbon resins. Modification is generally performed by reacting the raw materials prior to polymerization, by introducing special monomers or by reacting the polymerized product, whereby preference is given to hydrogenations or partial hydrogenations.
Suitable hydrocarbon resins also include styrene homopolymers, styrene copolymers, cyclopentadiene homopolymers, cyclopentadiene copolymers and/or terpene polymers, which in each case have a softening point of ≧140° C. (among the unsaturated polymers, preference is given to the hydrogenated products). Particularly preferably, the cyclopentadiene homopolymers having a softening point of ≧140° C. are employed in the base layer.
If the top layer(s), too, are to contain a hydrocarbon resin, the resins listed above in the listed amounts for the base layer can be used. In this case, it is, also possible to employ hydrocarbon resins having a softening point of ≧140° C. such as between 100° C. and 183° C.
In order to further improve certain properties of the film according to this invention, effective amounts of suitable additives may be incorporated both in the base layer and in the top layer(s). Preferred additives include antistatic agents and/or antioxidants.
Straight-chain and saturated, aliphatic, tertiary amines, which possess a C 10 to C 20 aliphatic radical and two 2-hydroxy-(C 2 -C 4 )alkyl groups are preferred antioxidants. N-(C 10 -C 20 )-, and especially N-(C 12 -C 18 )alkyl-N',N"-bis-(2-hydroxyethyl)-amines are employed particularly preferably.
The antioxidants employed preferably are so-called primary antioxidants, i.e., sterically hindered phenols or secondary amines, but it is also possible to use secondary antioxidants, such as, for example, thioethers or phosphites or phosphonites, or synergistic mixtures of primary and secondary anitoxidants. Antioxidants of this generic type are described, for example, in Gachter/Muller: Kunststoff-Additive (Plastics Additives), Carl Hanser Verlag, 2nd edition (1983). Below, the structural formulae of a number of suitable compounds are given: ##STR1##
Preferred lubricants include carboxylic acid amides, such as erucic acid amide and stearic acid amide, or polydiorganylsiloxanes.
Suitable anti-blocking agents include, for example, organic polymers which are incompatible with the raw material employed for the top layer(s), such as polyamides, polyesters, polycarbonates and the like, or inorganic substances such as silicates, silicon dioxide and calcium carbonate. Inorganic substances, in particular silicon dioxide, with an average particle size of 1 to 6 μm, have found to be most suitable. These anti-blocking agents are added in amounts of about 0.1 to 1% by weight, preferably of about 0.15 to 0.5% by weight, relative to the weight of the top layer(s).
The thickness of the top layer(s) preferably varies between about 0.4 and 1.0 μm.
The parameters for producing the films according to this invention are expediently selected such that stretching in the longitudinal direction is performed at a temperature between about 100° and 130° C., preferably between about 105° and 120° C., and at a stretch ratio between about 1:4 and 1:6. Stretching in the transverse direction is performed at a temperature between about 120° and 160° C., preferably between about 130° and 150° C. The stretching ratio in the transverse direction is higher than about 1:7.5, and preferably it is in the range of about 1:8 to 1:11. Following the stretching state in the transverse direction, the film is heat-set. During this treatment the film is conveyed in the tenter frame, optionally in a slightly converging manner, at a temperature which is about 5° to 50° C. below the stretching temperature. Preferably, a convergence range of about 5 to 15% is set for the heat-setting treatment. Ready printability of the film is achieved by subjecting the film to one of the conventional treatments prior to winding, such as, for example, to a flame treatment or electrical corona treatment. Corona treatment by means of any of the known methods is expediently performed such that the film is passed between two conductor elements which serve as electrodes, whereby a voltage which is high enough to cause spray or corona discharges is applied between the electrodes. This usually is an alternating voltage of about 10,000 V and a frequency of about 10,000 Hz. As a result of these spray or corona discharges, the air above the film is ionized and reacts with the molecules of the film surface, so that polar inclusions are obtained in the essentially non-polar polymer matrix. The treatment intensities are within the usual range; preferably they are between 38 and 42 mN/m.
The invention will be illustrated in greater detail by way of the Examples which follow. A comparative survey is given in Table 1.
EXAMPLE 1
A three-layered, transparent film having a total thickness of 20 μm was produced by coextrusion and subsequent orientation by biaxial stretching. The film had the layer build-up ABA, `A` denoting the top layers and `B` denoting the base layer. Each of the top layers was 0.6 μm thick.
The base layer was comprised of polypropylene to which 10% by weight of resin (ESCOREZ® ECR 356, supplied by Exxon, Darien, Conn., USA; softening point of the resin: 140° C.), relative to the total weight of the blend, had been added. The polypropylene had a melt flow viscosity of 3.5 g/10 min, determined according to DIN 53 735, under a load of 2.16 kg.
The top layers were comprised of a propylene/ethylene copolymer having an ethylene content of 4.8% by weight, to which 0.8% by weight of polydimethylsiloxane, 0.13% by weight of a phenolic stabilizer (Antioxidant 330, supplied by Ethyl Corp., Brussels, Belgium, and Baton Rouge, La., USA), 0.075% by weight of calcium stearate and 0.33% by weight of SiO 2 having an average particle size of 2 μm, had been added. The polydimethylsiloxane had a kinematic viscosity of 30,000 mm 2 /sec; the propylene/ethylene copolymer had a melt flow viscosity of 6.0 g/10 min, measured according to DIN 53 735, under a load of 2.16 kg.
EXAMPLE 2
A film was produced as described in Example 1, except that the resin content of the base layer was 20% by weight (same resin as in Example 1).
EXAMPLE 3
A film was produced as described in Example 1, except that the resin content of the base layer was 30% by weight (same resin as in Example 1).
EXAMPLE 4
A film was produced as described in Example 2, except that the layer build-up was ABC. Top layer `A` had been corona-treated and did not contain any polydimethylsiloxane, whereas in top layer `C` the polydimethylsiloxane content had been doubled. Layer B was the base layer.
EXAMPLE 5
A film was produced as described in Example 2, except that the layer build-up was ABC. Top layer `C` was comprised of a blend comprising an ethylene/propylene copolymer with an addition of 10% by weight of the resin employed in Example 1.
EXAMPLE 6
A film was produced as described in Example 1 except that the resin was REGALITE® R101 (Hercules) having a softening point of 100° C.
EXAMPLE 7
A film was produced as described in Example 1 except that the resin was REGALREZ® 1128 (Hercules) having a softening point of 130° C.
COMPARATIVE EXAMPLE 1 (C1)
A film was produced as described in Example 1, but without the addition of the resin.
COMPARATIVE EXAMPLE 2 (C2)
A film was produced as described in Example 1, except that a resin having a softening point of 85 ° C. was employed (ESCOREZ® 5380, supplied by Exxon).
COMPARATIVE EXAMPLE 3 (C3)
A film was produced as described in Example 2, except that no SiO 2 was contained in the top layers.
In Table 1 below, the properties of the films described in the Examples and Comparative Examples are expressed in numerical values or rated as follows:
++=very good or no resin deposition on the rollers
+=good or hardly any resin deposition on the rollers
-=poor or noticeable resin deposition on the rollers
--=unacceptable or severe resin deposition on the rollers
Determination of Thermal Blocking
To determine the thermal blocking properties, two wooden blocks (72 mm×41 mm×13 mm), to one surface of which a piece of felt had been glued, are wrapped into a sample of the film to be tested and sealed. The two blocks are stacked on top of one another, with the felt-clad surfaces facing each other, and loaded with a weight of 200 g. This arrangement is put in an oven preheated to 70° C. and left there for two hours. Then the temperature is reduced to room temperature (21° C.) for 30 minutes and the weight is lifted off from the wooden blocks. By means of a mechanical appliance the upper block is removed from the lower block. Evaluation is performed over the course of 4 individual measurements, from which the maximum take-down force (measured in N) is determined.
The requirements of the specification are fulfilled if none of the individual measurements exceeds 5N.
Determination of Haze
The haze of the film is determined by a method similar to ASTM-D 1003-52, whereby a 1° slot aperture is used instead of the 4° round aperture, and the haze is indicated for four superimposed films, because in this way measurement can be performed within the optimum range. Haze is evaluated as follows:
up to 15%: very good
15 to 25%: moderate
over 25%: unsatisfactory
Determination of Gloss
The gloss of the films is determined according to DIN 67 530. The reflector value is measured as an optical quantity for the surface of a film. In accordance with the ASTM-D 523-78 and ISO 2813 standards, the angle of radiation incidence is adjusted to 20°. A light beam hits the planar test surface at the set angle of incidence and is reflected or scattered by the test surface. The light beams incident on the photoelectronic receiver are indicated as a proportional electrical quantity. The measured value is dimensionless and must be given with the angle of incidence. The gloss (angle of incidence 20°) is evaluated using the following ratings:
down to 115: very good
115 to 100: moderate, and
less than 100: poor
Determination of Modulus of Elasticity
The modulus of elasticity is determined according to DIN 53,457 or ASTM-D 882.
Determination of Shrink
The shrink of a film is defined as the percental change in length (l o -l/l o ). Square film samples having a side length of 10 cm (l o ) are heated to a temperature of 120° C. for five minutes. Then the remaining length (1) is measured.
Determination of Permeability to Water Vapor and Oxygen
The permeability to water vapor is determined in accordance with DIN 53 122, part 2.
The barrier effect towards oxygen is measured according to draft standard DlN 53 380, part 3, at an atmospheric moisture content of 53%.
The Table shows that with regard to the desired combination of properties, the films according to the present invention are superior to the films according to the Comparative Examples.
TABLE 1__________________________________________________________________________ Shrink 120° C. O.sub.2 -Perm. 5 min in % OpticalWVP (g/m.sup.2 · d) (cm.sup.3 /m.sup.2 · d · bar) longit./ Friction Thermal Properties Resin Depos. MachineExamplein % in % transv. DIN 53375 Blocking (N) Haze/Gloss on Rollers Runnability__________________________________________________________________________1 0.88 1080 5/2 0.35 1 19/130 + ++2 0.79 770 7/3 0.35 1 18/125 + ++3 0.66 750 10/3 0.35 1 15/130 + ++4 0.79 770 7/3 0.35 1 19/125 + ++5 0.70 760 7/3 0.35 0.8 17/130 + ++6 0.93 1050 7/2 0.35 1 17/125 + ++7 0.95 1100 6/3 0.35 1 18/128 + ++C1 1.40 1800 3/1 0.35 1 25/115 ++ ++C2 0.85 1200 10/5 0.35 1 21/120 - ++C3 0.79 1150 7/3 0.45 5 20/130 ++ -__________________________________________________________________________ WVP: Permeability to water vapor O.sub.2Perm.: Permeability to oxygen Friction: Determined according to DIN 53 375 Resin deposition on the rollers and machine runnability were evaluated by subjective visual inspection. | A sealable film is disclosed comprising (i) a base layer comprising polypropylene and a hydrocarbon resin and (ii) at least one top layer comprising (a) an ethylene/propylene copolymer having an ethylene content of not more than about 10% by weight, (b) a propylene/1-butene copolymer, (c) a propylene/ethylene/alpha-olefin terpolymer, or (d) a blend of two or more of (a), (b) and (c), wherein at least one of said base layer and said at least one top layer contains an anti-blocking agent or lubricant. The film possesses improved barrier properties with respect to permeability to water vapor and oxygen, and which at the same time exhibits favorable slip properties and low shrink values. | 8 |
This invention relates to an improved process for the preparation of polybenzimidazoles, wherein the starting material is polymerized smoothly to high molecular weight in a manner so that the product is obtained in the form of small particles.
BACKGROUND OF THE INVENTION
Polybenzimidazoles are a class of polymers characterized by a high degree of thermal stability.
The preparation of poly[2,5(6)-benzimidazole], ##STR1## by heating phenyl 3,4-diaminobenzoate has been described by Marvel et al. in Example 1 of U.S. Pat. No. 3,174,947 (Reissue 26,065). This reference also describes the preparation of other polybenzimidazoles from various o-diaminocarboxylic acids in the form of their phenyl esters, as well as from mixtures of monomers in which one compound contains a pair of o-diaminoaryl substituents and the other compound is a diphenyl ester of an aromatic dicarboxylic acid.
Japanese Patent Application No. 18,352/67, describes a process for preparing poly[2,5(6)-benzimidazole] by heating 3,4-diaminobenzoic acid in the presence of polyphosphoric acid. Although it is desirable from a commercial viewpoint to prepare the polymer directly from 3,4-diaminobenzoic acid, rather than from its phenyl ester, it has been found difficult to reduce the bulk polymer so prepared to the small particles required for dissolution. It would be desirable for the polymeric product to be prepared in the form of small particles so that polyphosphoric acid and other impurities could be easily removed and the particles easily dissolved to low solutions suitable for extrusion into shaped articles. A further problem is that the reaction mass employed in this process is quite corrosive towards conventional steel reaction vessels, and a less corrosive process would be desirable.
Polybenzimidazoles may be prepared in the form of fibers and other shaped articles which are flame resistant and which can be used for many purposes in high-temperature environments. For instance, polybenzimidazole fibers are suitable for use in making filter bags for removal of particles from hot stack gases, owing to the stability of the fibers in hot acidic environments.
BRIEF DESCRIPTION OF THE INVENTION
This invention provides a process for the preparation of polybenzimidazoles in the form of small particles from aromatic compounds selected from the group consisting of:
(A) a bis(o-diamino) substituted compound and a dicarboxylic acid compound, and
(B) an o-diamino-substituted carboxylic acid compound,
compounds (A) if used being present in approximately equimolar amounts, by reaction in the presence of polyphosphoric acid wherein compounds (A) and/or (B) are combined in an inert, nonsolvent, liquid medium with polyphosphoric acid and heated to 120°-230° C. with stirring for 1-4 hours, cooled to room temperature with continued stirring, filtered to remove polybenzimidazole and washed to remove impurities. Preferably the inert, nonsolvent, liquid medium is mineral oil. Preferably a surface active agent is present in the reaction mixture. Preferably aromatic compounds of type (B) are used. Most preferably the aromatic compound is 3,4-diaminobenzoic acid. Preferably the reaction is carried out at 120°-200° C. for two hours.
DETAILED DESCRIPTION OF THE INVENTION
The reactants (A) and/or (B) are heated and agitated in the liquid inert medium with polyphosphoric acid to keep the finely divided mixture suspended until reactants (A) and/or (B) are polymerized to a polybenzimidazole. The reaction mixture is cooled with continued stirring and the polybenzimidazole is separated in the form of small particles from the liquid inert medium. The orthodiamino substituent comprises two amino groups attached on an aromatic nucleus in an ortho relationship and is counted as a single substituent. Thus, the aromatic compounds may comprise (a) a mixture of at least one aryldicarboxylic acid compound or anhydride thereof with at least one bis(o-diamino) compound, (b) a single o-diaminoarylcarboxylic acid compound or (c) a mixture containing compounds from both (a) and (b). Compounds (b) if used are present in approximately equimolar amounts.
In a preferred embodiment of the invention, a mixture of polyphosphoric acid and 3,4-diaminobenzoic acid is physically suspended in an inert, nonsolvent, liquid medium and heated and agitated until the mixture is suspended as a finely divided mixture in the liquid medium; heated with continued agitation until the 3,4-diaminobenzoic acid is converted to poly[2,5(6)benzimidazole] the liquid inert medium is cooled; and the poly[2,5(6)-benzimidazole] is separated in the form of small particles from the liquid inert medium.
When the polymerization is completed, agitation of the liquid inert medium should be continued while the medium is being cooled. The liquid inert medium is preferably a mineral oil. A surface active agent may also be included in the reaction mixture.
By polyphosphoric acid is meant approximately 115% orthophosphoric acid, i.e, orthophosphoric having a P 2 O 5 content of approximately 83% by weight.
When the polymerization is carried out using mineral oil, after removal of polybenzimidazole by filtration, the polybenzimidazole particles may be washed with a low-boiling hydrocarbon solvent to remove residual mineral oil and then dissolved in 90-100%, preferably 100%, orthophosphoric acid to form a solution suitable for spinning into fibers or coating into film. Alternatively, 98-100% sulfuric acid may be used to form solutions suitable for forming shaped articles.
The inherent viscosity of the polymer is determined by obtaining viscosimeter flow times at 25.0°±0.1° C. for concentrated sulfuric acid (95-98%) and for a solution of the polymer in the concentrated sulfuric acid at a concentration of 0.5 gram per 100 milliliters of solution. The relative viscosity is calculated by dividing the flow time of the solution by the flow time of the concentrated sulfuric acid. The inherent viscosity of the polymer is then calculated as 2 times the natural logarithm of the relative viscosity.
The following examples illustrate the invention.
EXAMPLE 1
To a clean, dry, nitrogen-swept, 3-necked, 200-ml glass flask equipped with a mechanical stirrer are added:
13.0 g of 3,4-diaminobenzoic acid
100 ml of white mineral oil
1 g of an amine dodecylbenzenesulfonate surface-active agent.
The mixture is stirred well and 55.4 g of polyphosphoric acid is added with stirring. It is observed that a large lump is formed in the flask. The flask is heated slowly, and it is observed that at about 120° C. the lump breaks up into small particles. The mixture is then heated further to 200° C., and held at this temperature for two hours with continued stirring, forming a grayish-black product. When the mixture is cooled, most of the product is in the form of small beads, which are readily removed from the mixture by filtration. The beads, which are hard and tough, are designated as part A of the product. The remainder of the product, designated as part B, is in the form of material stuck to the sides of the flask. Both parts of the product are separately extracted with water, neutralized with sodium bicarbonate, filtered, washed with water and then with acetone, and finally dried 7 hours at 110° C. in a vacuum oven. Part A of the product weighs 16.32 g and has an inherent viscosity of 1.37. Part B of the product weighs 1.09 g and has an inherent viscosity of 1.60.
A 5.0 g portion of the beads of part A of the product is placed in a 50-ml portion of 100% sulfuric acid and the mixture is heated and stirred, whereupon a solution is obtained. The solution is poured slowly into 500 ml of water and the resulting solid removed by filtration, suspended in water, neutralized with sodium bicarbonate, removed by filtration, washed many times with water, washed with acetone, dried over a steam bath, and finally further dried in a vacuum oven at 110° C. The dry weight of the recovered solid product is 3.0 g, and its inherent viscosity is 1.90.
EXAMPLE 2
Using the equipment described in Example 1, the following ingredients are added to the flask:
6.5 g of 3,4-diaminobenzoic acid
27.7 g (13.8 ml) of polyphosphoric acid
100 ml of white mineral oil
1 g of an amine dodecylbenzenesulfonate surface-active agent.
The reaction is initiated by heating the mixture slowly to 130° C. with rapid stirring. The mixture is heated further to 200° C. and held at this temperature for 2 hours with continued stirring. The mixture is cooled and the product removed by filtration and washed with hexane. This portion of the product, which is in the form of small beads which are very hard and tough, is designated as part A. A small additional quantity of product at the top of the flask is removed, washed with hexane, and designated as part B. Both parts are suspended in water, neutralized with sodium bicarbonate, removed by filtration, washed with water and then with acetone, and finally dried at 110° C. in a vacuum oven. Part A of the product, comprising 5.18 g (70.3% of the total) consists of small beads and has an inherent viscosity of 1.52. Part B of the product, comprising 2.20 g (29.7% of the total) is in the form of powder and has an inherent viscosity of 1.84.
EXAMPLE 3
A higher concentration of the surface-active agent is employed in this example. The equipment used is the same as that used in Example 1. The following ingredients are added to the flask:
6.5 g of 3,4-diaminobenzoic acid
100 ml of white mineral oil
1.5 g of an amine dodecylbenzenesulfonate surface-active agent.
The mixture is stirred well and 27.7 g of polyphosphoric acid is added in small portions. The mixture is then heated to a temperature of 200°-210° C. with stirring, and held for 2 hours at that temperature. When the mixture is cooled, it is observed that the product is in the form of particles larger than those observed in Example 1. The product is removed by filtration and placed in a beaker. The small amount of solid remaining in the flask is dissolved in 14 ml of hot 100% sulfuric acid and poured into the beaker over the solid product already there, after which the mixture is allowed to stand overnight. It is observed that additional mineral oil has separated, and this is decanted from the very viscous acid solution. The acid solution is then heated and an additional 25 ml of 100% sulfuric acid is added. The solution is then poured slowly into water and the precipitated polymer removed by filtration, washed with water and dried. The dry weight of the product is 6.44 g having an inherent viscosity of 1.25.
EXAMPLE 4
The work reported in this example, in which no surface-active agent is added to the reaction mixture, is carried out in the equipment used in Example 1. The following ingredients are added to the flask:
13.0 g of 3,4-diaminobenzoic acid
100 ml of white mineral oil.
To the well-stirred mixture is added, drop-wise from a small dropping pipette, 60 g of polyphosphoric acid, the reaction mixture is heated slowly to 200° C., whereupon a large mass surrounded by clear fluid is formed. The mass breaks into flat chips ranging in size from small flat particles to chips of about 1 cm long. After 2 hours, the mixture is cooled to room temperature with continued stirring and the solid particles are removed by filtration and washed with hexane. The product weighs 17.58 g and has an inherent viscosity of 1.32. An additional 1.36 g of product is obtained from the walls of the flask, washed well with water and then acetone and then dried under vaccum at 110° C. The additional product has an inherent viscosity of 1.96.
A 6.18 g portion of the product in the form of loose chips is dried for 2 days at 125° C. under high vacuum. The dried product weighs 5.95 g, thus showing little weight loss. Another 11.29 g portion of this product is dissolved in 75 ml of 100% sulfuric acid, and then precipitated in 400 ml of water, filtered, washed with water until the filtrate is free of acid, washed with acetone, and dried at 125° C. under high vacuum for 16 hours. The weight of dry product is 6.62 g and is believed to be free of phosphoric acid. The inherent viscosity of the reprecipitated product is 2.07. | Polybenzimidazoles are prepared in the form of small particles by reaction of bis(o-diamine) substituted compounds with dicarboxylic acids or of o-diamino-substituted carboxylic acids in the presence of an inert, nonsolvent, liquid medium and polyphosphoric acid. | 2 |
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates generally to a wheel and belt or track driven device, and more particularly to a suspension system, positive hydraulical four wheel disc braking system, positive drive belt system, and belt tensioning device for wheel and belt devices.
DESCRIPTION OF THE RELATED ART
[0002] The popularity and nearly universal acceptance of wheel propulsion systems rather than track systems in agricultural use has stemmed primarily from the past track system's “rough ride,” relatively higher noise levels, higher initial cost, lower maximum travel speed and inability to transport itself on improved road surfaces without inflicting damage thereto.
[0003] Present day track systems have overcome the majority of these objections by utilizing a propulsion system in which a continuous rubber belt encompasses a pair of wheels. Problems encountered in actually reducing such belt systems to practice include how to drive such belt with the entrained wheels, how to maintain structural integrity of the belt and wheels, how to encompass the belt in lateral alignment with the wheels when the wheels are subjected to large lateral loads, how to provide long life for the belt and wheels, how to accommodate debris ingested between the wheels and belt while maintaining the driving relationship therebetween without damaging either, how to preclude the belt from coming off the wheels, how to brake the belt and wheel systems, how to preclude the belt from coming off of the wheels during braking, and how to maintain proper belt tension during braking and turning.
[0004] Elastomeric belt systems have been used but they operate such that the elastomeric belt needs to be highly tensioned about a pair of wheels to provide frictional engagement with the wheels. Interposed between the wheels is a roller support system for distributing a portion of the weight and load imposed on the machine frame to the belt. The roller support system includes a mounting structure, which is pivotally connected to the machine frame and, therefore, free to rotate relative to the machine frame to accommodate undulations in the terrain surface while maintaining uniform ground pressure.
[0005] The frictional elastomeric drive belt system requires a higher belt tension than is required for a positive drive belt system. This higher belt tension causes premature failure of the belt. Further, the elastomeric suspension system only provides for a limited amount of suspension travel. This allows for an exorbitant amount of force being transferred to the frame and operator cabin when crossing rough terrain. Friction drive technology has many disadvantages. For example, track failure is common in wet and rocky conditions, and the track tends to fall off during braking and turning.
[0006] Current positive drive belt systems usually have only one wheel positively engaged with the belt causing premature wear when braking occurs. Further, known positive drive belt systems provide insufficient recoil to allow foreign material to escape from the belt system.
[0007] In addition, track driven systems are “hard” riding. Specifically, track driven systems lack suspension systems entirely or have primitive suspension systems resulting in a rough ride.
[0008] The present invention is directed to overcome one or more of the problems as set forth above.
SUMMARY OF THE INVENTION
[0009] The present invention includes a novel independent suspension for use in conjunction with a positive drive belt system, belt tensioner adapted for use with a positive drive belt system, drive wheel for use in conjunction with a positive drive belt system, and positive braking system for use with a positive drive belt system.
[0010] There present invention also includes a plurality of middle rollers for use with a positive drive belt system, wherein the group of middle rollers aid in the support of the wheel and belt device and provides a low ground pressure distribution.
[0011] The present invention further includes an independent suspension system, a positive drive system, and a belt tensioner system for use on a track system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] These and other features and advantages of the present invention will be better understood by reading the following detailed description, taken together with the drawings wherein:
[0013] [0013]FIG. 1 is a side view of a lower section of a track driven device having a suspension system, belt tensioner system, positive braking system and positive drive system thereon according to the present invention;
[0014] [0014]FIG. 2 is a side view according to FIG. 1 but with phantom lines illustrating hidden components of the track driven device;
[0015] [0015]FIG. 3 is a front view of a wheel for the track driven device shown in FIGS. 1 and 2;
[0016] [0016]FIG. 4 is a side view of the wheel shown in FIG. 3 for the track driven device;
[0017] [0017]FIG. 5 is an exploded, side view of one side of the track driven device having the suspension system, belt tensioner system, positive braking system and positive drive system thereon according to FIG. 1;
[0018] [0018]FIG. 6 is an exploded, top view of one side of the track driven device having the suspension system, belt tensioner system, positive braking system and positive drive system thereon according to FIG. 1;
[0019] [0019]FIG. 7 is a front view of one side of the track driven device having the suspension system, belt tensioner system, positive braking system and positive drive system thereon according to FIG. 1;
[0020] [0020]FIG. 8 is a front view of one side of the track driven device having the suspension system, belt tensioner system, positive braking system and positive drive system thereon according to FIG. 5 but with phantom lines illustrating hidden components of the track driven device;
[0021] [0021]FIG. 9 is a top view of one side of the track driven device having the suspension system, belt tensioner system, positive braking system and positive drive system thereon according to FIG. 1;
[0022] [0022]FIG. 10 is a top view of one side of the track driven device having the suspension system, belt tensioner system, positive braking system and positive drive system thereon according to FIG. 9 but with phantom lines illustrating hidden components of the track driven device;
[0023] [0023]FIG. 11 is a side view of the lower section of the track driven device with cutouts showing a hydraulically operated four-wheel disc braking system thereon;
[0024] [0024]FIG. 12 is a side view according to FIG. 11 but with phantom lines illustrating hidden components of the track driven device;
[0025] [0025]FIG. 13 is a top view of one side of the braking system according to FIG. 9 with cross-sections through the wheels;
[0026] [0026]FIG. 14 is a top view according to FIG. 13 but with phantom lines illustrating hidden components of the track driven device; and
[0027] [0027]FIG. 15 is a top view according to FIG. 12 isolating one of the disc brakes.
DETAILED DESCRIPTION OF THE INVENTION
[0028] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. Additionally, the present invention contemplates that one or more of the various features of the present invention may be utilized alone or in combination with one or more of the other features of the present invention.
[0029] Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, FIGS. 1 & 2 show a lower section 11 of a track driven device 10 . The track driven device 10 has two belts 13 each encompassing an idler wheel 14 and a drive wheel 15 . The drive wheels 15 drive the belts 13 . The drive wheels 15 are powered by an engine, a transmission system, and other components substantially similar to a Caterpillar® brand Challenger system.
[0030] Referring now to FIGS. 3 & 4, the idler wheels 14 and the drive wheels 15 are shown. In the preferred embodiment, the idler wheels 14 are 26 inches in width by 41.05 inches in diameter, and the drive wheels 15 are 29 inches in width by 41.05 inches in diameter, although such dimensions are not a limtation of the present invention. The idler wheels 14 and the drive wheels 15 have front windows or openings 16 in the circumference. In an alternative embodiment, side windows (not shown) are provided in the side of the wheels 14 , 15 . The windows 16 allow snow, ice, soil, rocks and other foreign matter to pass freely during operation. In addition, the front windows 16 are used to receive lugs 18 on belts 13 , best shown in FIGS. 1 & 2. The lugs 18 enter the front windows 16 in much the same way that meshing gears interact with one another. As the drive wheels 15 rotate, the lugs 18 mate with the front windows 16 , and the belts 13 are positively driven by the drive wheels 15 . In an alternative embodiment, there are no windows 16 in the wheels 14 , 15 ; rather, the wheels 14 , 15 and the lugs 18 mate in much the same way as two gears mesh.
[0031] A suspension system 12 is operatively mounted to each side of the lower sections 11 of the track driven device 10 . The suspension systems 12 provide independent suspension for the belts 13 . The suspension systems 12 absorb load stresses and allows the idler wheel 14 to move vertically when an object is encountered providing a more comfortable, controlled and safe ride while prolonging the life of the track driven device 10 .
[0032] Although it is understood that the track driven device 10 has two belts 13 and two suspension systems 12 , the description that follows describes one side of the track driven device 10 . Referring in combination to FIGS. 1 & 2, the suspension system 12 has a lower suspension bracket 19 . The lower suspension bracket 19 has front ends 23 that are operatively connected to a frame 20 of the track driven device 10 via a suspension cylinder 21 and upper suspension bracket 22 . The suspension cylinder 21 has a first end 50 operatively attached to the lower suspension bracket 19 and a second end 51 operatively attached to the upper suspension bracket 22 . The upper suspension bracket 22 is operatively attached to the frame 20 .
[0033] [0033]FIGS. 5 and 6 show the idler wheel 14 rotatably mounted between a first side 28 and a second side 29 of the lower suspension bracket 19 via an axle 30 . The lower suspension bracket 19 has distal ends 24 operatively attached to a main frame 25 . The main frame 25 is pivotally mounted to a track frame pivot 26 . The track frame pivot 26 is operatively attached to the main frame 25 . The track frame pivot 26 extends from one side of the main frame 25 to the other side for each suspension system 12 . The track frame pivot 26 is operatively connected to the main frame 25 via a bearing cup 38 and a bearing cap 39 . Ends of the track frame pivot 26 ride in the bearing cup 38 and the bearing cap 39 . To hold the track frame pivot 26 in place, the bearing cap 39 is bolted over the track frame pivot 26 to the bearing cup 38 . In the preferred embodiment, the bearing cap 39 and the bearing cup 38 are lined with neoprene rubber. The track frame pivot 26 is preferably a steel bar but other materials could be substituted.
[0034] The suspension cylinder 21 is generally readily available and one such cylinder is made by Caterpillar Industrial Products, Inc. in Peoria, Ill. under Part No. 151-1179. The suspension cylinder 21 is hydraulically connected to an accumulator 27 via a suspension pressure line 49 to provide suspension travel and load support. Preferably, the accumulator 27 is a high capacity nitrogen accumulator. The accumulator 27 is available over-the-counter and one such accumulator is made by Caterpillar Industrial Products, Inc. in Peoria, Ill. under Part No. 7U5050. It is obvious to those with ordinary skill in the art that other cylinders and accumulators could be substituted for these specific cylinders and accumulators.
[0035] When the idler wheel 14 encounters an object, the idler wheel 14 moves upwardly and the suspension cylinder 21 absorbs the initial shock of the object. During this upward movement, the suspension system 12 pivots about the track frame pivot 26 . On the downward movement, the suspension cylinder 21 precludes a rapid descent for a smooth ride. FIGS. 9 and 10 show a roller bearing or side thrust bearing 52 operatively attached between the lower suspension bracket 19 and an inside support 53 to prevent side bearing thrust movement. The side thrust bearing 52 allows the lower suspension bracket 19 to move up and down pivoting about the track frame pivot 26 . The side thrust bearing 52 moves up and down and keeps the track frame from moving.
[0036] Referring now to FIGS. 1, 2, 9 and 10 , a track belt tensioner 31 is used to maintain tension on the belt 13 between the idler wheel 14 and the drive wheel 15 . The amount of tension in the belt 13 is determined by the horizontal distance between the idler wheel 14 and the drive wheel 15 . The drive wheel 15 is rotatably mounted about a powered axle 54 , and the idler wheel 14 is rotatably mounted to a yoke 80 via the axle 30 .
[0037] Referring now to FIGS. 5 & 6, the yoke 80 includes a first axle bracket 81 and a second axle bracket 82 for supporting the rotating axle 30 . A yoke housing 83 is operatively attached to the first and second axle brackets 81 , 82 . The yoke 80 has guide member 84 moveably mounted to a top surface of the main frame 25 , and the yoke 80 moves horizontally along the main frame 25 when urged by a track tension cylinder 32 . The yoke 80 has a first track guide 85 and a second track guide 86 that surrounds the main frame 25 . The first and second track guides 85 , 86 are attached to the first and second axle brackets 81 , 82 and the yoke housing 83 , and the first and second track guides 85 , 86 keep the yoke 80 on the main frame 25 during the back and forth horizontal movement. The idler wheel 14 and the yoke 80 move along a horizontal axis via the track tension cylinder 32 .
[0038] A piston rod 90 from the track tension cylinder 32 extends moving the idler wheel 14 and the yoke 80 backward and forward, thereby adding tension on the belt 13 . When the piston rod 90 is retracted, the idler wheel 14 and the yoke 80 are moved closer to the drive wheel 15 , thereby reducing the tension on the belt 13 . The idler wheel 14 is encapsulated in the lower suspension bracket 19 , and the lower suspension bracket 19 keeps the belt 13 from falling off of the wheels 15 , 15 . During the extension and retraction of the piston rod 90 from the track tension cylinder 32 , the yoke 80 slides on the track frame 20 . Once again, the position of the yoke 80 along with the idler wheel 14 is adjusted horizontally via the track tension cylinder 32 to adjust the belt 13 tension. In addition to adjusting the horizontal position of the yoke 80 to adjust the belt 13 tension, the lower suspension bracket 19 pivots in the vertical direction as previously described. The lower suspension bracket 19 pivots about the track frame pivot 26 but does not move horizontally with the yoke 80 .
[0039] The combination of the suspension cylinder 21 and the track tension cylinder 32 absorbs the shock placed on the idler wheel 14 . This shock absorption prevents the belt 13 from tearing and falling off the idler wheel 14 and the drive wheel 15 and also provides a smooth ride.
[0040] The track belt tensioner 31 has the track tension cylinder 32 . The track belt tensioner 31 is operatively mounted to the frame 20 via a cylinder bracket 33 . The cylinder bracket 33 is welded to the lower suspension bracket 19 . A first end of the track tension cylinder 32 is pinned to the cylinder bracket 33 . A second end of the track tension cylinder 32 has the piston rod 90 for adjusting the yoke 80 and the idler wheel 14 in the horizontal direction. The piston rod 90 is operatively mounted to a piston cylinder bracket 34 . In the preferred embodiment, the piston cylinder bracket 34 is triangular as viewed from the side and welded to the frame 20 . The track tension cylinder 32 is hydraulically connected to a tension accumulator 35 to provide belt 13 tensioning and a smooth ride. The tension accumulator 35 is preferably mounted above the track tension cylinder 32 . It is important to note that in the preferred embodiment, there is one tension accumulator 35 and one track tension cylinder 32 per belt 13 ; however, the track tension cylinders 32 could be connected to one accumulator. In yet another embodiment, the track tension cylinders 32 and the suspension cylinder 21 are connected to one accumulator.
[0041] The tension accumulator 35 is hydraulically connected to the track tension cylinder 32 via a hose 36 . The track tension cylinder 32 is, preferably, a tow large-bore, long-stroke cylinder to provide excellent cushioning and dampening. J. R. Schneider Company, is located at 849 Jackson Street, Benicia, Calif., 94510 and provides a suitable cylinder under the name BAILEY330™ Part No. 216-141. Preferably, the tension accumulator 35 is a high capacity nitrogen accumulator. The tension accumulator 35 can be purchased from DYNA TECH, A Neff Company, located at 1275 Brume Elk Grove Village, Ill., 60007, and provides a suitable accumulator under Part No. A2-30E-OSG-BTY-MIO. It is obvious to those with ordinary skill in the art that other cylinders and accumulators could be substituted for these specific cylinders and accumulators.
[0042] The tension on the belt 13 needs to be set after the belt 13 is assembled on the idler wheel 14 and the drive wheel 15 . To set the tension, hydraulic fluid is added to the track belt tensioner 31 until the gauge on the track tension cylinder 32 reads 10,000 pound per square inch. The tension accumulator 35 is pre-charged at 600 pounds per square inch with nitrogen.
[0043] The combination of the suspension system 12 and the track belt tensioner 31 provides independent track suspension. When an object is encountered by the idler wheel 14 , the idler wheel 14 is allowed to move vertically and horizontally because of the suspension system 12 and the track bolt tensioner 31 , respectively.
[0044] Referring now to FIGS. 1, 2 and 5 , middle rollers 40 are shown. The middle rollers 40 are rotatably mounted to the frame 20 and fixed; the middle rollers 40 are not capable of moving up and down or back and forth. In the preferred embodiment, there are eight middle rollers 40 per belt 13 . There are four middle rollers 40 along the outside of the belt 13 , and there are four middle rollers 40 along the inside of the belt 13 . The eight middle rollers 40 are weight bearing and, thus, provide a low ground pressure design and are load bearing rollers. The middle rollers 40 , preferably, are 21 inches in diameter by 2-5 inches in width fork truck wheels press on wheels. Suitable middle rollers 40 are available through Caterpillar Industrial Products, Inc. under Part No. 120-5746. In arctic use, the ground contacting surfaces of the middle rollers 40 are coated with rubber. Normally, the middle rollers 40 are made with solid rubber. The middle rollers 40 are beveled on one side to match the bevel of the cog of the rubber track.
[0045] Referring now to FIGS. 11 - 15 , a braking system 41 for positive braking is shown. The braking system 41 has calipers 42 , preferably four. The calipers 42 are used on each of the four wheels 14 , 15 .
[0046] There are two calipers 42 for each belt 13 system (i.e., one caliper 42 for the idler wheel 14 and one caliper 42 for the drive wheel 15 ). The two calipers 42 operatively controlling the two idler wheels 14 are operatively mounted to the yoke 80 . The two calipers 42 operatively controlling the two drive wheels 15 are mounted to the main frame 25 . Large diameter discs 43 are operatively mounted to the idler wheels 14 and the drive wheels 15 . The calipers 42 act on or contact the discs 43 causing the track driven device 10 to slow or stop. Dust covers 44 enclose the calipers 42 . The braking system 41 results in positive braking due to the combination of lugs 18 on the belts 13 mating with the idler wheels 14 and the drive wheels 15 . The lugs 18 enter the front windows 16 of the idler wheels 14 and the drive wheels 15 in much the same way that meshing gears interact with one another. As the calipers 42 work on the discs 43 , the idler wheels 14 and the drive wheels 15 are slowed as a result of the front windows 16 acting on the lugs 18 thereby positively slowing or stopping the belts 13 from rotating about the idler wheels 14 and the drive wheels 15 .
[0047] In the braking system 41 , hydraulic pumps 47 supply hydraulic fluid to a master cylinder 46 via brake lines 45 . The hydraulic pump 47 is a mechanically driven hydraulic pump. Supply lines 48 provide pressurized hydraulic fluid from the master cylinder 46 to the calipers 42 . The operation of the braking system 41 is readily apparent by the elements previously described.
[0048] Modifications and substitutions by one of ordinary skill in the art are considered to be within the scope of the present invention, which is not limited except by the following claims. | A track driven device having a suspension system, positive hydraulic braking system, positive drive belt system and belt tensioning system for an improved ride, reducing belt wear and belt failure. | 1 |
This is a continuation-in-part application of U.S. patent application Ser. No. 410,635, filed Sept. 21, 1989, now abandoned.
FIELD OF THE INVENTION
This invention is drawn to single-sided cling stretch wrap films of high tensile strength having an A/B/C film structure, wherein the A surface exhibits cling properties, the B layer is primarily responsible for the high tensile strength of the film structure and the C layer is substantially cling free. In addition, layer C has a slide property when its surfaces are in contact with relative motion with a second layer of C.
BACKGROUND OF THE INVENTION
One of the problem areas in the packaging industry concerns the overwrap packaging of goods, particularly the unitization of pallet loads. Ideally, an overwrap material should have high strength, be resistant to tear and puncture, and exhibit single-sided cling properties. In particular, single-sided cling properties are required in order to prevent individual pallets from clinging to each other and being torn or destroyed when being separated from each other.
Development of single-sided cling has, generally, been directed toward surface modifying one side of an A/B film. For example, U.S. Pat. No. 4,820,589 discloses an A/B film structure, wherein the A layer has a comparatively high cling force to layer B and layer B has substantially less cling force to a layer of itself. The B layer contains nylon. Further, single and two-layer film structures are further disclosed in U.S. Pat. Nos. 4,518,654 and 4,833,017, herein incorporated by reference. In U.S. Pat. No. 4,518,654, the "non-cling" B layer is a polyolefin with an anti-cling additive such as crystalline or amorphous silica, sodium aluminum silicate, diatomaceous earth, and talc. It is not possible to obtain a zero cling force for the B layer, however, since the additive must be present in minimal quantities in order to prevent tearing or fracturing of the film. Further, the coefficient of friction of such films is greater than 2.0 which indicates an unfavorable slideability property of the B layer. Also further, the minimum stretch capability of such films is approximately 50%. Thus, such films neither exhibit a truly cling-free layer or the maximum tensile strength and minimum stretch capability which is commercially demanded.
In order to prevent the tearing or loosening of the wrapping on stacked overwrapped pallet loads, it would be highly desirable to have a tough film exhibiting high tensile strength and greater elongation with good cling properties on one side to engage the contained load and little or no cling properties on the other side to avoid clinging to neighboring stacked, wrapped loads.
SUMMARY OF THE INVENTION
The invention comprises novel stretch wrap films and an improved process for preparing such films. In particular, the stretch wrap films of this invention are (1) exhibit high tensile strength and an improved minimum stretch capability, (2) are tear and puncture resistant, and (3) have single sided cling. Such films are ideally suited for use in overwrapping of packages and pallet loads.
The stretch wrap film of this invention comprises a thermoplastic A/B/C film structure of differential cling wherein layer A has a high cling force to layer B, layer B is a core layer with high tensile strength, and layer C has little, if any, cling properties.
The stretch wrap film is prepared as a co-extrusion product of the A/B/C layers.
DETAILED DESCRIPTION OF THE INVENTION
The invention comprises a single-sided cling stretch wrap film. In order to achieve the desired single-sided cling properties a co-extruded A/B/C film structure was utilized. Layer B is bonded through the co-extrusion process to layers A and C. Layer B is characterized by a high tensile strength and is chiefly responsible for rendering high tensile strength to the film structure of this invention. The thermoplastic film structure of this invention exhibits a machine directional tensile strength between about 4,000 to about 12,000 psi, as measured by ASTM D 882. In addition, the film structure of this invention has a minimum stretch capability of about 200%, and a maximum stretch capability of about 600%, preferably between 350 and 450%, as measured by ASTM D4649 (A1.2.2). Such minimum stretch capability is needed due to the continuous stretching of the film roll caused by the braking tension applied to the roll after the film is laid about the girth of the pallet platform during overwrapping. The surface of the C layer is cling-free.
The cling force of the A surface of the film structure of this invention to the A surface of a like A/B/C film (of identical composition) is between about 150 g to about 400 g. (Cling force measurements referred to herein are in accordance with ASTM D4649 wherein the surfaces of the films are in a stretched condition.) The cling force of the A surface to the C surface of a like A/B/C film is between about 100 g to about 350 g. The cling force of the C surface of the film structure of this invention to the C surface of a like A/B/C film is negligible and ideally is not detectable. Further, layer C is characterized by a slide property when it is in contact with a layer of itself with relative motion therebetween. The coefficient of friction of the C surface to the C surface of a second (like) film is between about 0.2 to about 2.0, and most preferably is less than 1.0, as measured by ASTM 1894.
The film should have an A to B to C weight ratio of from about 5:90:5 to about 30:40:30, most preferably about 10:80:10. The film will have an overall thickness ranging from about 0.3 mil to about 3.0 mil, preferably 0.8 mil. In general, the thickness of the A layer is between about 0.025 to about 0.9 mils. The thickness of the B layer is between about 0.020 to about 2.7 mils and the thickness of the C layer is between about 0.025 to about 0.9 mils.
The A layer for use in the present invention is fabricated from a resin possessing an inherent cling property and/or a cling property resulting from the incorporation of a cling additive. Examples of such resin film-forming compositions are polyolefins such as polyethylene, polypropylene, copolymers of ethylene and propylene, and polymers obtained from ethylene and/or propylene copolymerized with relatively minor amounts of an ethylenically unsaturated monomer such as a mono-olefin, preferably a C 4 -C 12 mono-olefin, such as butene-1 and isobutylene, acrylic acid, methacrylic acid, esters of acrylic acids, vinyl acetate, styrene and combinations thereof. Preferred is polyethylene, including high and low molecular weight polyethylene and copolymers thereof.
Particularly preferred for the cling film portion of the stretch wrap film of the present invention are those resin-forming systems which do not exhibit a fairly high level of cling without the addition of a cling additive such as linear low density polyethylene (LLDPE). LLDPE is defined as having a maximum density ranging from about 0.890 g/cc to about 0.930 g/cc, preferably about 0.917 g/cc. LLDPE, characteristically has a melt flow value (ASTM D 1238 Cond. E) ranging from about 0.3 to about 10.0, preferably about 2.3, and is a copolymer of ethylene with a C 4 -C 10 olefin, for example, butene-1; 1,3-dimethyl-butene-1; 1,3-dimethyl-pentene-1; hexene-1; 4-methyl-penetene-1; 3-methyl-hexene-1; octene-1; or decene-1. The alpha-olefin is usually between 1 to 20 weight percent of the copolymer. Further, ultra low density polyethylene (ULDPE) is also particularly preferred. ULDPE is defined as having a maximum density ranging from about 0.890 g/cc to about 0.915 g/cc, preferably about 0.912 g/cc and contains a higher percentage of the C 4 -C 10 olefin.
Resins not inherently possessing cling properties can nevertheless be used in this invention by incorporating with the resin a cling additive.
The resin film-forming film of the A layer may contain any known cling agent which will be effective in maintaining the A layer in cling contact with the surface of the C layer of a second A/B/C film of like composition while both are in the stretched condition. Non-limiting examples of cling additives include, for example, such tackifiers as polybutene and low molecular weight polyisobutylene, preferably between 200-3000, most preferably 200-300. Other suitable tackifers include polyterpenes, amorphous polypropylene, ethylene vinyl acetate copolymers, microcrystalline wax, alkali metal sulfosuccinates, and mono- and di- glycerides of fatty acids, such as glycerol monostearate, glycerol monooleate, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate and sorbitan monooleate. Preferably, the tackifier is polybutene. Most preferably the butene is admixed with LLDPE such that from about 20 weight percent to about 70 weight percent, preferably about 50 weight percent, of the admixture is polybutene.
The cling additive can be present in the A layer in any concentration which will permit the A surface to cling to the C surface of a second A/B/C film of like composition or other surfaces, while in its stretched condition. A preferred concentration can range from about 0.1 to 20% by weight of the A layer, most preferably between 0.25 to 6.0 weight percent.
The B layer exhibits a minimum machine directional tensile strength value ranging from about 4,000 psi to about 12,000 psi, preferably about 7,000 psi, as measured by ASTM D882. Suitable as the resin film-forming composition for the B layer for use in this invention are polyolefins such as polyethylene, polypropylene, copolymers of ethylene and/or propylene and a minor amount of a C 4 -C 12 mono-olefinic monomer such as butene-1 and isobutylene. Especially preferred is LLDPE, as defined herein. The B layer is most preferably chemically distinct from the film-forming resins of layers A and C, i.e. the film-forming resins of layers A and C are not identical to the film-forming resin of layer B. In the most preferred embodiment of the invention the film is fabricated from three chemically distinct resin film-forming systems.
The film-forming component of the C layer imparts to the film structure a noncling-slip surface. While any thermoplastic film can be employed which will render a noncling-slip surface, most preferred are polyolefins. Particularly desirous results are obtained with polypropylene. As explained more fully below, a resin film-forming comprising polypropylene and between 10 to about 50 weight percent high density polyethylene (HDPE) is especially preferred. A HDPE has a maximum density greater than or equal to 0.940 g/cc and is a homopolymer of ethylene.
In addition to polypropylene, styrene-butadiene as well as other polyolefins can be employed as the resin film-forming system of the C (skin) layer. Such polyolefins include ultra low density polyethylene (ULDPE), LLDPE, low density polyethylene and copolymers thereof also including medium density polyethylene (MDPE) These materials are defined as having a density ranging from about 0.890 to about 0.980 g/cc and a melt index ranging from about 0.4 to about 20. MDPE is defined as having a minimum density ranging from about 0.925 to about 0.940, preferably about 0.935. ULDPE and MDPE are copolymers of ethylene and at least one of the C 4 -C 10 olefins recited above. (It is well recognized in the art that LLDPE, MDPE and ULDPE are copolymers of ethylene and an alpha olefin comonomer and that the density of the copolymer decreases as the amount of comonomer increases.) When such polymers are employed, however, it is often necessary to use an antiblock agent in order to obtain a A/C and C/C cling force within the desired limitations as stated herein. Suitable antiblock agents include those containing silicon such as calcium silicate, silicon dioxide (most preferably 0.5 to 10 wt. % SiO 2 in. LLDPE) as well as such crystalline and amorphous silicates as Na 2 O·Al 2 O 3 ·SiO 2 ·4H 2 O, bentonite, diatomaceous earth, clay and talc. In addition, such organic materials, as starches, preferably those having an average particle size from about 10 to about 200 millimicrons, can be employed. Such antiblock agents should be evenly distributed and should be added in such quantities as to impart to the film structure as undetectable C/C cling force. Normally, the presence of an antiblock agent in excess of 2.0 weight percent is undesirable since greater amounts initiate tear and/or fracture thereby compromising the tear and puncture resistant properties of the total film structure.
The stretch wrap films of this invention are formed by conventional techniques of coextrusion to assemble the composite structure, such as by the simultaneous coextrusion of resin film-forming layers A, B and C. The A layer is preferably between 5 and 15 weight % of the overall film thickness; the B layer is between 70 and 90% of the overall film thickness; and the C layer is between 5 and 15% of the overall film thickness. The melt temperature for each extruder is independently selected such that the viscosity of the different film components is matched. In such co-extrusion processes, the three extruders should be operating simultaneously to produce the coextruded film. Thus, the output capacity for each of the three extruders should be close to equivalent. For example, to produce a 10:80:10 (w/w) A/B/C film structure, if the core (center) extruder for layer B is relatively small (1.5 inch diameter, 24:1 L:D) then the satellite extruders for layers A and C must be proportionately smaller. If on the other hand the core extruder is relatively large (6 inch diameter, 30/1 L/D) then the size of the satellite extruders must be increased in order for the film layer ratios to remain relatively constant. In addition, the melt viscosity of all three components must be approximately the same. Generally, the viscosity of the resin forming systems of layers A and C are matched to the viscosity of the resin film-forming system of layer B. Thus, if the viscosity of the resin in the A or C extruder is lower than that of the core layer at any given temperature, then its melt temperature must be reduced to increase its viscosity. If the viscosity of the resin in the A or C extruder is higher than that of the resin film-forming system of the B layer, then its melt temperature must be increased to decrease its viscosity. Since each extruder of the film-forming system B operates at a separate melt temperature, the temperature profile of the zones in each extruder will likewise differ.
In preparing the A/B/C extrudate of the present invention, the resin film-forming systems of layers A/B/C, if any, are fed into the feed hopper of a conventional rotating screw extruder. The polypropylene is melted by working it in the compression zone of the extruder. The molten polypropylene is continuously advanced through the metering zone to the mixing zone of the extruder.
It is readily recognized in the art that the production of thicker extrudates either requires an operator to increase the speed of the extruder or decrease the line speed, i.e. the rate the extrudate is removed from the dye. Modern extrusion apparatus naturally have maximum speeds and minimum line speeds that can complicate the process. As previously stated the viscosity of the resin film-forming system of the layers of the film structures of this invention are approximately the same during co-extrusion. The melt viscosity of polypropylene, the preferred resin film-forming system of the C layer, rapidly decreases with an increase in temperature. The inventor discovered that the addition of between about 10 to about 50 weight percent (based on total weight percent of resin film-forming system) of high density polyethylene to polypropylene dramatically reduced the extruder speed. In addition, the viscosity of the resin film-forming system containing the high density polyethylene/polypropylene blend is similar to that of the resin film-forming compositions which do not contain high density polyethylene. Thus, high density polyethylene serves as an invaluable processing aid to molten extrudates of polypropylene. Most preferably the resin film-forming system comprises approximately 30 weight percent of high density polyethylene. While the use of high density polyethylene with polypropylene is preferably realized in the fabrication of the C layer of the A/B/C film structure of this invention, it is also within the scope of this invention to provide a single film or A/B film structure or even a laminate with such composition. Thus, the use of the high density polyethylene/polypropylene blend is not restricted to the production of layer C of an A/B/C film structure but is equally applicable to the cling-free layer of an A/B film structure such as those disclosed in the prior art cited and discussed herein. Thus, in the fabrication of an A/B stretch wrap film wherein layer B is the cling-free layer comprising polypropylene, the high density polyethylene in the quantities stated above can be admixed with the polypropylene. Likewise, the processing aid can be used in the fabrication of single layer films of polypropylene in the stated quantities.
EXAMPLES
General Procedure
In preparing the A/B/C extrudates of the present invention any known prior art technique for coextrusion can be employed. The resin film-forming composition of each layer is fed into the feed hopper of a conventional rotating screw extruder. The extruder screw employed can have approximately a 5 inch diameter and a length to diameter, L/D, ratio of about 30:1. Satellite extruders are used for the coextrusion of the resin film-forming compositions A and C. The satellite extruders comprise a conventional extruder having an extruder screw with about a 2.5 inch diameter and a L/D ratio of about 30:1. Molten resin from the satellite extruders are fed into the case film die affixed to the end of the B extruder through an adapter specifically designed to join polymer streams A and C from the satellite extrudates to the molten B polymer stream so that it effectively interfaces with the molten surface of the B layer. The slots coextrudant film had a gauge of ˜5 mil at a melt temperature of approximately 420° F. (A layer), 510° F. (B layer), and 480° F. (C layer).
Glossary
As used herein, the materials recited in these Examples are commercially available. In the examples the actual material used is indicated by reference to the corresponding glossary number.
__________________________________________________________________________ COMMERCIALLYMATERIAL DENSITY MELT FLOW AVAILABLE AS SOURCE__________________________________________________________________________ Polypropylene 3014 Exxon Chemical Co. Polypropylene 5A08 Shell Oil Co. Polypropylene 7C49 Shell Oil Co. Polypropylene 4062 Exxon Chemical Co. Polypropylene HGX-030 Philips Pet. Co. Polypropylene RMN-020 Philips Pet. Co. Polypropylene 2104 Soltex, Inc. Polypropylene 4207 Soltex, Inc. Polypropylene 6C44 Shell Oil Co.20. LLDPE 0.917 2.3 2047 Dow Chemical Co. LLDPE 0.935 2.5 2036A Dow Chemical Co. LLDPE 0.926 2.0 2032 Dow Chemical Co. LLDPE 0.912 3.3 4004 Dow Chemical Co.30. Tackifier (52% of polybutene Santech Co. in LLDPE) Styrene-Butadiene KR-10 Phillips Pet. Co. Copolymer40. Methacrylic acid copolymer (MMA) - a copolymer of ethylene and approximately 20-30 wt. % methacrylic acid, commercially known as XC-102.sup.40 and XC-101.sup.41 from Exxon Chemical__________________________________________________________________________ Company.
Example 1
Film 1 has a composition as follows: Layer A (15% by weight of total film) is LLDPE 23 with 6% tackifier 30 ; Layer B is LLDPE 20 (approximately 70% by weight of total film); and Layer C (15%) is LLDPE 20 with 0.5% silicon dioxide. The cling properties are presented in Table 1.
Example 2
Film 2 has the same composition as Film 1, except that Layer C is LLDPE. The cling properties are presented in Table 1.
Example 3
Film 3 has the same composition as Film 1, except that Layer C is MDPE 20 . The cling properties are presented in Table 1.
Example 4
Film 4 has the same composition as Film 1, except that Layer C is a polypropylene homopolymer 2 .
TABLE I______________________________________ CLING (g)Example A/A C/C______________________________________1 325 252 230 1703 270 704 325 (NA)*______________________________________
Table 1 is illustrative of some of various approaches taken in the past concerning the non-cling surface of single-sided cling film. Example 2 shows that LLDPE is not a preferred material due to its substantial cling to itself. Example 1 shows that addition of non-cling additives provide enhancement of the desired non-cling property. Example 3 shows that an increase in the density has limited enhancement of non-cling properties. Example 4, on the other hand, shows true non-cling properties. The standard test for cling (ASTM D4649) cannot be used to quantitate the cling properties of this material, as a result a more sensitive test to measure the coefficient of friction (ASTM D1894) was employed.
Comparative Examples 5-8 and Examples 9-10
Resin film-forming compositions were prepared as extrudates in accordance with the General Procedure above. The thickness of layers A, B, and C were the same as recited in Example 1. Percentages are weight percentages. The speed of the extruder is indicated. Table II reports the cling data ASTM D4649, Standard Guide for Selection of Stretch Wrap Materials:
______________________________________ COMP COMP COMP COMP EXEX 1 EX 5 EX 6 EX 7 EX 8 EX 9 10______________________________________A layer, 10 5 10 15 20 5 10MMA.sup.40,wt %B layer, 80 85 80 75 70 85 80LLDPE,wt %C layer, 10 0 0 0 0 5 5Polypropy-lene wt %C layer, 0 10 10 10 10 5 5HDPE, wtExtruder A 35.8 30 30 30 30 30 30rpmExtruder B 47.8 30 30 30 30 30 30rpmExtruder C 111.9 30 30 30 30 30 30rpmCast Roll, 746 380 380 380 380 371 311Ft. permin.______________________________________
TABLE II______________________________________ % STRETCHEXAMPLE 100 150 200______________________________________5 Poor None --6 Fair Poor None7 Fair None --8 Fair Poor None9 Fair Fair Fair10 Fair Fair Fair______________________________________
Examples 11-19
The films were prepared in accordance with the procedures of Comp. Exs. 5-8 and Examples 9-10 above. 10% of the film comprised layers A and C and 80% layer B. Respective cling forces are compiled in Table III. Data for coefficient of friction is compiled in Table IV.
______________________________________EX. A LAYER B LAYER C LAYER______________________________________11 Methacrylic Acid Co- LLDPE.sup.20 LLDPE.sup.11polymer.sup.4112 Methacrylic Acid Co- LLDPE.sup.20 Styrene-butadiene.sup.35polymer.sup.4213 94% LDPE.sup.23 LLDPE.sup.20 Polypropylene.sup.76% polybutene.sup.3014 94% LDPE.sup.23 LLDPE.sup.20 Polypropylene.sup.86% polybutene.sup.3015 94% LDPE.sup.23 LLDPE.sup.20 Polypropylene.sup.26% polybutene.sup.3016 94% LDPE.sup.23 LLDPE.sup.20 Polypropylene.sup.36% polybutene.sup.3017 94% LDPE.sup.23 LLDPE.sup.20 Polypropylene.sup.16% polybutene.sup.3018 94% LDPE.sup.23 LLDPE.sup.20 Polypropylene.sup.46% polybutene.sup.3019 94% LDPE.sup.23 LLDPE.sup.20 Polypropylene.sup.56% polybutene.sup.30______________________________________
TABLE III______________________________________EX. A/A A/C C/C______________________________________11 364 ± 96 225 ± 42 NA12 35 40 NA13 280 ± 51 143 ± 39 NA14 176 ± 28 157 ± 16 NA15 324 ± 72 198 ± 66 NA16 513 ± 55 NA NA17 347 ± 50 191 ± 28 NA18 217 ± 11 124 ± 24 NA19 442 ± 20 192 ± 81 NA______________________________________
TABLE IV______________________________________ EX.______________________________________ 11 0.55 14 0.59 15 0.49 16 0.70 17 >2.0 18 0.65 19 0.51______________________________________
Example 20-22
The number of breaks a 1500 foot roll of 20/30 inches wide of the film structure prepared in Example 10 having a total thickness of 0.8 mils was determined by using a pallet wrapper commercially available from Lamtech, Inc. of Louisville, Ky. The film was prestretched 225% by making the second prestretch roller run 21/4 times the rpm of the first roller. Minimal relaxation was permitted. The number of breaks in every 1500 feet of film was determined, ASTM 4649.
______________________________________ Example* Example Example 20 21 22______________________________________% stretch 210 220 210(measuredon pallet)width of 20 30/20** 30/20**roll/inchesNo. of breaks 0 0 0______________________________________ *4 rolls tested **3 rolls tested 2 at 30 inches; 1 at 20 inches
The invention has been described with reference to its preferred embodiments. From this description, a person of ordinary skill in the art may appreciate changes that could be made in the invention which do not depart from the scope and spirit of the invention as described above and claimed hereafter. | This invention relates to a single-sided cling stretch wrap film having an A/B/C structure. The surface of the A layer exhibits a high cling force to the surface of the B layer which has a high tensile strength. The surface of the C layer is cling-free. Pallet loads overwrapped with the film are neither torn or destroyed when separated from each other. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to a DC motor having field poles each including a magnet pole of a permanent magnet and an auxiliary pole of a magnetizable material of high permeability such as soft steel.
As disclosed, for example, in Japanese patent publication No. 48-35721 published on Oct. 30, 1973, a DC electric motor having field poles of a permanent magnet is known in which the permanent magnet of each pole is partially replaced by an auxiliary pole of a magnetizable material of high permeability, such as soft steel to thereby provide the DC motor with series-wound characteristics. In the DC motor of this type, each auxiliary pole is disposed at the side of the associated field pole on which the armature reaction acts to produce magnetization effect, i.e. to increase the magnetic fluxes flowing therethrough, or in other words each auxiliary pole is disposed at the entry side of the associated field pole in the direction of rotation of the motor. Therefore, when the motor is reversely rotated, each auxiliary pole is disposed at the side of the associated field pole on which the armature reaction acts to produce demagnetization effect, i.e. to decrease the magnetic fluxes flowing therethrough so that the torque produced by the motor becomes smaller as the armature current becomes higher. Accordingly, the motor of this type is practically used for rotation only in one direction.
The above Japanese patent publication No. 48-35721 discloses a specific example in which the auxiliary pole is disposed at the side of the associated field pole on which the armature reaction acts to provide the demagnetization effect. However, this example is relating to a DC generator to be used as an electric power source for welding and aimed at providing the DC generator with a drooping characteristic of its voltage with respect to its load current, unlike the DC motor of the present invention having series-wound characteristics.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a DC electric motor having field poles of permanent magnets, which is normally used to rotate in one forward direction and can be used, if desired, to rotate in the reverse direction, while it provides series-wound characteristics when it rotates in either direction.
The DC electric motor according to the present invention comprises: a rotor having an armature core, an armature winding and a commutator; a stator having a yoke and a plurality of field poles formed on the inner circumference of the yoke; sets of brushes arranged to slidably contact with the commutator so as to make electrical conduction therebetween, each of the field poles being constituted of a permanent magnet and an auxiliary pole, the auxiliary pole being disposed at the side of the associated field pole on which the armature reaction acts to give demagnetization effect in the rotation of forward direction or in other words each auxiliary pole is disposed at the exit side of the associated field pole in the direction of forward rotation, each of the brushes being mounted so as to be movable between a position near to a geometrically neutral point of a pair of adjacent field poles and another position spaced by an electrical angle of 90 degrees or less from the geometrically neutral point in the direction of reverse rotation.
In this specification, the term "geometrical" is used in the meaning of "dimensionally" regardless of electromagnetic characteristics, and therefore the words "a geometrically neutral point of a pair of adjacent field poles" means "a dimensional center of a gap between a pair of adjacent field poles". The term "an electrical angle" means "an angle measured by a scale in which a circumferential angle covering a pair of adjacent field poles, i.e. N and S poles is scaled by 360 degrees". For example, in the case of a four-pole motor, a geometrical angle of 90 degrees is equivalent to an electrical angle of 180 degrees. In this specification, an electrical angle is referred to as "an electrical angle" as it is, while a geometrical angle is referred to merely as "an angle".
In a DC electric motor having field poles of permanent magnets, if each auxiliary pole is disposed at the side of the associated field pole where the armature reaction acts to reduce the magnetic fluxes by the field pole, the flux distribution of each field pole receives a demagnetization effect on the auxiliary poles due to the armature reaction. Assume now that a permanent magnet A and an auxiliary pole A constitute one field pole A in a manner as described above. If the direction of flux generated by the permanent magnet A is forward, the flux generated through the auxiliary pole A due to the armature current is in the reverse direction. However, if consideration is made with respect to another field pole B adjacent to the field pole A in the direction of reverse rotation, the flux generated through the auxiliary pole B due to the armature current is in the forward direction. In short, the auxiliary pole B generates flux in the same direction as that generated by the permanent magnet A.
Thus, with respect to each of the field poles, the direction of flux generated by the permanent magnet is reverse to the direction of flux generated through the auxiliary pole by the armature reaction, and a position where the direction of resultant flux by the permanent magnet and the auxiliary pole changes is at the electrically neutral axis. Accordingly, it is preferable to dispose each brush at this position, that is, the electrically neutral axis. However, the electrically neutral axis changes with a load current because the flux generated by the auxiliary pole changes with the load current. Generally, the brush is disposed at a position shifted by a predetermined angle in the direction of reverse rotation from a radially extending geometrical boundary between the permanent magnet and the auxiliary pole. The angle to be shifted varies depending on the electrical characteristics of the motor and the load current. The geometrical boundary between the permanent magnet and the auxiliary pole is clearly determined in the case where they are in side-to-side contact in a plane extending radially. However, in the case where they are not simple in shape, the geometrical boundary cannot be determined clearly. In practice, the positions of respective brushes are experimentally determined so as to make the torque as produced maximum and the degree of sparks as less as possible.
When each of the brushes is disposed in the vicinity of the electrically neutral point in such a manner as described above, the currents in the armature coils connected between positive and negative brushes are in the same direction, and the flux effective to generate a torque by the electromagnetic action in cooperation with those coil currents is the sum of the flux due to the permanent magnet of the field pole and the flux through the auxiliary pole of another field pole adjacent to the above-mentioned field pole due to the armature reaction. Since these fluxes are in the same direction, they act additively in torque generation. The flux through the auxiliary pole increases in proportion to increase in the armature current. Accordingly, the torque increases with increase of the armature current to thereby provide series-wound characteristics enough to generate large torque with a large current.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are cross sections showing the structure of an embodiment of the DC electric motor according to the present invention, and respectively being taken along the line I--I in FIG. 2 and the line II--II in FIG. 1;
FIG. 3 is a diagram showing the distribution of field pole flux density acting on armature coils when the DC electric motor of FIG. 1 embodiment is operated in the forward direction comparatively in the case where each of brushes is disposed at a position shifted in the direction of reverse rotation from a geometrically neutral point between a pair of field poles according to the invention and in the case where each of brushes is disposed at a geometrically neutral point like the prior art;
FIG. 4 is a graph showing the relation of an armature current and a quantity of flux acting on the armature coils;
FIG. 5 is a graph showing the relation of the shifted angle of each brush and the generated torque in the DC electric motor of FIG. 1; and
FIGS. 6, 7 and 8 are views showing various modifications of the embodiment of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a radially sectional view of a four-pole electric motor of a permanent-magnet field system provided with auxiliary poles, and FIG. 2 is an axially sectional view of the same. In FIG. 2, a rotor is provided with a rotary shaft 1, a commutator 2 formed on the shaft 1, and an armature constituted by an armature core 3 mounted on the shaft 1 and a winding 4 wound on the armature core 3. The rotor is supported at the opposite ends of the shaft 1 by end brackets 6a and 6b of a stator through bearings 5a and 5b respectively. The end brackets 6a and 6b are fixed to a cylindrical yoke 7. Four field poles are formed on the inner circumference of the cylindrical yoke 7. The four field poles are respectively provided with auxiliary poles 8a-8d, generally designated by reference numeral 8, of magnetizable material, such as for example soft steel, and permanent magnet poles 9a-9d, generally designated by reference numeral 9, disposed circumferentially adjacently to the respective auxiliary poles 8a-8d.
The four auxiliary poles 8a, 8b, 8c and 8d are circumferentially equidistantly disposed. θ 1 represents the circumferential angular width of each auxiliary pole as shown in FIG. 1 with respect to the auxiliary pole 8a by way of example.
The four permanent magnet poles 9a, 9b, 9c and 9d are circumferentially equidistantly disposed. θ 2 represents the circumferential angular width of each permanent magnet pole as shown in FIG. 1 with respect to the permanent magnet pole 9a by way of example.
The auxiliary pole and the permanent magnet in each of the field poles are in contact with each other on an interface or boundary 30 included in a plane containing the rotation axis O of the rotor and extending in the radial direction.
In FIG. 1, an arrow 10 indicates the direction of normal or forward rotation of the rotor of the motor in this embodiment, and 11 shows an illustrative position of each brush relative to the armature coil directly connected to the commutator segment with which the brush is in contact. Thus, it should be noted that 11 does not show the geometrical position of each brush shown in FIG. 2, but rather indicates a position of the armature coil to which each brush is electrically connected through the commutator segment just into contact with that brush. Each of brushes is located at a position corresponding to an angular position 11 circumferentially shifted by an angle of θ B in the direction of reverse rotation from a geometrically neutral point between a pair of adjacent field poles. In FIG. 1, the angle θ B that is an angle between the geometrically neutral point between the field pole including the auxiliary pole 8d and the permanent magnet 9d and the adjacent field pole including the auxiliary pole 8a and the permanent magnet 9a indicates a position which is shifted from the geometrical neutral point beyond a circumferentially boundary f where the auxiliary pole 8a and the permanent magnet 9a contact with each other and toward a position on the geometrical center line O-O' of the field pole including the auxiliary pole 8a and the permanent magnet 9a.
In the following, the position of the brush and the flux density distribution under the field pole, which are the important features of the present invention, are described in detail. FIG. 3 shows the flux density distribution patterns on the surface of the armature core in the loaded condition when each of brushes is disposed at a geometrically neutral axis between a pair of field poles and when disposed at an electrically neutral point, respectively.
The upper half and the lower half of FIG. 3 commonly use the abscissa to represent a circumferential position on the armature surface. The upper half shows the development of field poles and the direction of current noted thereon, and the lower half shows the flux density distribution patterns in each case.
The vertical line n in the upper half represents a geometrically neutral point between a pair of adjacent field poles, and the line f represents a boundary between the permanent magnet pole and the auxiliary pole in each field pole.
If each of the brushes is disposed at a position corresponding to the aforementioned neutral point n like in the prior art, the current in each of coils 4a to 4g is directed from the front of the paper to the rear thereof ( ○ direction) in the case where the auxiliary pole has a demagnetization action due to the armature reaction. Accordingly, the generated armature reaction serves as a demagnetization action or in other words the direction of the generated armature reaction is reversed to the direction of magnetization by the permanent magnet 9a. Accordingly, the flux density under the auxiliary pole 8a in the field pole is distributed in a negative direction. The flux quantity of the field pole distributed within the armature coils 4a to 4g relating to torque generation is the sum of the flux quantity of the auxiliary pole 8a and the flux quantity of the permanent magnet 9a. Consequently, as shown by the broken line in the lower half of FIG. 3, the resulting flux quantity decreases in proportion to the armature current so that series winding characteristics cannot be attained.
In this embodiment of the present invention, each of the brushes is disposed at a position corresponding to an angular position shifted from the neutral point n by an angle θ B . More particularly, each brush is disposed at a position corresponding to an electrically neutral point which is shifted from the geometrically neutral point n between a pair of adjacent field poles by the angle θ B in the direction of reverse rotation beyond the boundary f where the auxiliary pole 8a and the permanent magnet 9a circumferentially contact with each other. As the result, the armature coils corresponding to one pole contributing to torque generation are composed of coils 4d, 4e, 4f and 4g facing or near to the permanent magnet of one field pole and coils 4h and 4i facing or near to the auxiliary pole of adjacent field pole as shown in FIG. 3. The current direction in each of these coils 4d-4i is from the front of the paper to the rear thereof. Accordingly, the flux quantity acting on those coils 4d to 4i is the sum of the flux quantity of the permanent magnet 9a of the one field pole and the flux quantity of the auxiliary pole 8b of the adjacent field pole. The flux of the permanent magnet 9a slightly decreases due to the demagnetization effect of the armature reaction, but the flux density distribution is positive. Because the current in each of the coils 4d to 4i is directed from the front of the paper to the rear thereof, the flux quantity of the auxiliary pole 8b increases in proportion to the armature current due to the armature reaction and the flux direction thereof is the same as that of the permanent magnet 9a.
FIG. 4 shows the relation of the flux quantity (ordinate) at various parts of the field versus the armature current (abscissa). In FIG. 4, the broken line expresses the prior art, and the solid line expresses the embodiment of the present invention.
In the motor of FIG. 1, each of the brush positions 11 is shifted from a position corresponding to the geometrically neutral point, so that, for example, the permanent magnet 9a and the auxiliary pole 8b act on the armature coils corresponding to one pole. Accordingly, the flux quantity Φ M of the permanent magnet 9a decreases as the armature current increases due to the armature reaction On the other hand, the flux quantity of the auxiliary pole 8b increases proportionally to Φ A of the auxiliary pole 8b increases proportionally to the armature current due to the armature reaction. As the result, the total flux quantity Φ P (extending through the armature coils 4d to 4i), which is the sum of the flux quantity Φ M of the permanent magnet 9a and the flux quantity Φ A of the auxiliary pole 8b, has a finite value when the armature current is zero. The total flux quantity Φ P increases as the armature current increases correspondingly. However, if each brush is disposed at a position corresponding to the geometrically neutral point like in the prior art, the auxiliary pole 8a and the permanent magnet 9a act on the armature coils extending over one field pole. As shown by the broken line in FIG. 4, the flux Φ A , of the auxiliary pole 8a has a negative value, reverse to the flux of the permanent magnet 9a. Accordingly, the total flux quantity Φ P , distributed over the armature coil 4a to 4g, which is the sum of the flux quantity Φ M , of the permanent magnet 9a and the flux quantity Φ A , of the auxiliary pole 8a, decreases as the armature current increases.
FIG. 5 shows a motor torque in the case where the four-pole motor of the field-pole construction of the present invention, in which the circumferential angular width θ 1 of each auxiliary pole is 18 degrees (36 degrees in electrical angle) and the circumferential angular width θ 2 of each permanent magnet is 52 degrees (104 degrees in electrical angle), is used as a starter motor and each of the brush positions is shifted in the direction of reverse rotation. In the drawing, the abscissa expresses the geometrical angle by which the brush is shifted in the direction of reverse rotation. When the brush position is shifted in the direction of reverse rotation by 35 degrees (70 degrees in electrical angle), the maximum motor torque can be attained. The maximum motor torque becomes two or more times as large as that in the case where θ B is zero or in other words the brush is disposed at a position corresponding to the geometrically neutral point.
Although the aforementioned embodiment has shown the case where the invention is applied to a four-pole motor, it will be understood that the invention may be applied to any other multi-pole motor such as a two-pole motor, a six-pole motor, an eight-pole motor and the like. Further, the material for the permanent magnet is not limited specifically, but the magnet may be any of a ferrite magnet, a rare-earth magnet such as a samarium-cobalt magnet, a cerium-cobalt magnet and a neodymium-magnet, an iron-boron magnet, and a ferrite or rare-earth plastic magnet, etc. Although the embodiment of FIG. 1 has shown the case where the brush position is shifted by an angle θ B =θ B1 where torque becomes maximum as shown in FIG. 5, a satisfactorily large motor torque can be attained even by shifting the brush position by any angle within a range of from θ B2 to θ B3 as shown in FIG. 5. That is, when the shift angle θ b is selected to be a value within a range of from 25 to 45 degrees (50 to 90 degrees in electrical angle), torque increases practically usefully, compared to that in the case the angle θ B is zero. However, if the angle θ B is selected to be smaller than 25 degrees (50 degrees in electrical angle) or larger than 45 degrees (90 degrees in electrical angle), torque does not increase sufficiently.
Although the above description has been made of the case where the DC electric motor is operated in the normally-used or forward direction of rotation, each of the brushes is moved to a position shifted by a few or 2 to 7 degrees in the direction of reverse rotation from the geometrically neutral point between a pair of adjacent field poles like in the prior art, if the motor is to be operated in the reverse direction of rotation. In this case, the auxiliary pole in each field pole is placed on the entry side of the field pole in the direction of rotation. Accordingly, in the viewpoint of armature reaction, the motor becomes equivalent to a conventional permanent magnet field DC electric motor with auxiliary poles, so that series-wound characteristics can be obtained.
To shift brushes, any known brush shifting mechanism may be used. The direction of rotation of the DC motor according to the present invention varies depending on the situation where the motor is used. In the case where the direction of rotation is not changed from the initial setting which is determined according to the specific use of the motor, it is sufficient to adjust the position of each brush once before the motor is set in the location where the motor is used, and therefore the brush shifting mechanism may be simple in construction as shown in FIG. 2. In FIG. 2, each brush 22 is held by a holder 21 fixed to an arm 23. The arm 23 is fixed to a ring 20 rotatably supported by a hub 27 integrally formed on the end bracket 6b at the inside thereof. A bolt 26 is provided so as to project from the ring 20 to extend to the outside of the bracket 6b through an arc-like slot 25 formed in the bracket 6b. The bolt 26 can be externally moved in the arc-like slot 25 so as to rotate the ring 20 to thereby adjust the position of the brush 22. After the adjustment of the brush position, the bolt 26 is fixed at that position by a nut 24. It is a matter of course that any suitable means other than the aforementioned brush shifting mechanism may be used in the invention. For example, the brush holder may be fixed to the end bracket which is made to be circumferentially movable relative to the yoke 7.
The shape in section of each of the auxiliary poles is not limited to such a trapezoid as shown in FIG. 1. For example, as shown in FIG. 6, the auxiliary pole may be L-shaped in section so that the auxiliary pole 8a' 8d' and the permanent magnet 9a', 9d', respectively are in contact with each other at a step-like boundary 31. Alternatively, as shown in FIG. 7, the auxiliary pole 8a", 8d", may be shaped like an irregular quadrilateral or triangle in section so that the auxiliary pole and the permanent magnet 9a", 9d", respectively are in contact with each other at a boundary 32 having a certain angle relative to the radial direction. In either case, the same effects as those in the foregoing embodiment can be obtained.
If each field pole is formed by arranging the end surface 33 of the auxiliary pole to face the end surface 34 of the permanent magnet circumferentially through a gap 12 as shown in FIG. 8, the range where the flux density is zero increases so that a well commutation characteristic can be obtained. | A DC electric motor which comprises: a reversibly rotatable rotor having an armature core, an armature winding and a commutator; a stator having a yoke and a plurality of field poles provided on an inner circumference of the yoke and each having a permanent magnet and an auxiliary pole; and brush means including a plurality of brushes arranged to be slidably electrically conductively in contact with the commutator; in which the auxiliary pole of each of the field poles is disposed at an exit side of the field pole in the normal foward rotating direction of the rotor; each of the brushes is held movably between a first position corresponding to a position near a geometrically neutral point between a pair of adjacent field poles and a second position corresponding to a position separated at the maximum by an electrical angle of 90 degrees from the geometrically neutral point reversely to the normal rotating direction, and each of the brushes is fixed in the vicinity of the second position in normal use. | 7 |
CROSS REFERENCE TO RELATED APPLICATION
This application claims the priority of German Application No. 198 39 885.9 filed Sep. 2, 1998, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
This invention pertains to a draw frame for textile slivers and is more particularly directed to a method and a device for pressing down the upper rolls onto the respective lower rolls of the drawing unit which is composed of serially arranged roll pairs formed of upper and lower rolls. During operation the upper rolls are pressed against the respective lower rolls by loaded pressing elements in pressing arms. In the inoperative state the upper rolls are relieved of pressure by the pressing arms.
During operation, the pressing arms are closed and the pressing devices press the upper rolls onto the associated lower rolls of the drawing unit. In case the drawing frame is at a standstill particularly for a longer time period, the pressing arms are opened to thus release the upper rolls from the pressing forces for protecting the roundness of the rolls and their elastic coating against deformation. In a known arrangement the pressing arms are pivoted open manually while the upper rolls remain stationarily positioned on the lower rolls. In such an arrangement the upper rolls exert a pressure on the lower rolls by their weight. Since the slivers are positioned between the upper and lower rolls, the upper rolls, in their idle state, exert a pressure on the slivers. During operation, particularly at high sliver speeds of 1,000 m/min and above, the rolls heat up substantially. Frequently the fibers contain substances which become sticky when heated, for example, honeydew in cotton and reviving agents in chemical fibers. Occasionally the draw frame is at a standstill for a period which is longer than, for example, the time required for coiler can replacements at the output end of the draw frame. Such longer periods may occur, for example, in case of sliver rupture or in case of coiler can replacements at the input end of the draw frame, during operational disturbances and the like. During such longer standstill periods, particularly as the upper output roll (or rolls) press against the sliver situated between the roll pair the earlier noted substances become sticky by heating. As a disadvantageous result, the slivers adhere firmly mostly to the upper rolls and, when operation resumes, the slivers are entrained in a circular path by the rotating roll and are thus wound thereon. This is a highly undesirable phenomenon which results in substantial operational disturbances since the draw frame must be immediately stopped and the wound sliver manually removed from the roll. Such a defect may often not be immediately eliminated which leads to significant delays and thus to downtimes in the production.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved method and apparatus of the above-outlined type which avoid the above-discussed disadvantages and by means of which an undesired winding of the sliver around the drawing rolls is eliminated or significantly reduced in a simple manner.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the method is performed on a draw frame which includes a plurality of serially arranged roll pairs each defining a nip through which a fiber sliver passes from roll pair to roll pair. Each roll pair is formed of an upper roll and a lower roll. A pressing arm carries the upper rolls and pressing devices are accommodated in the pressing arm for pressing each upper roll against a respective lower roll. The method comprises the following steps: during the working state of the draw frame, passing the sliver consecutively through the roll pair nips while the pressing devices press the upper rolls against respective lower rolls, and during an interruption of the working state the upper output roll is relieved of pressing forces to an extent that at the most only an insubstantial pressure is exerted by the upper output roll on the sliver situated in the nip between the upper output roll and the lower output roll.
By providing that the pressure of the upper rolls is absent and, in particular that the upper roll is only slightly contacting the fiber material or is in no contact with it at all, a heating of the potentially sticky substances in the fiber material and thus an adhesive effect are avoided. As a result, the slivers are prevented from adhering to the rolls and therefore the disadvantageous winding of the fiber material about the rolls upon restarting of the draw frame operation will not take place.
The invention has the following additional advantageous features:
The relief of pressure exerted by the upper roll is effected automatically.
Upon resumption of operation, the pressure exerted by the upper roll is re-applied automatically.
In a drawing frame having a 4-over-3 drawing unit the upper roll closest to the outlet of the drawing unit may be relieved of pressure.
The upper roll is a deflecting roll.
The relief of pressure by the upper roll is effected by lifting at least one upper output roll off the respective lower roll.
A clearance between the upper output roll or the upper output rolls and the slivers is provided when the pressure exerted by the upper roll or upper rolls is relieved.
In an apparatus in which the upper rolls are pneumatically loaded, a separately controllable pneumatic valve is provided for the pneumatic cylinder for lifting the upper output roll or rolls.
The pneumatic cylinder is associated with a settable carrier lever for the upper output roll.
The relief of the pressure exerted by the upper roll output is effected by a magnet or a controllable electromagnet.
Upon stoppage of the drawing frame at least one roll is automatically disengaged from the fiber material.
The last upper roll, as viewed in the direction of material advance, may be moved automatically out of contact with the sliver and, upon resumption of the operation, such lifted roll is automatically again brought into pressure contact with the fiber material.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a drawing unit incorporating the invention.
FIG. 2a is a sectional view taken along line IIa--IIa of FIG. 1.
FIG. 2b is a view similar to FIG. 2a, showing the upper roll in a raised position.
FIG. 3a is a front elevational view illustrating the device according to the invention, showing a downwardly pivoted pressing arm and a carrier element illustrated out of engagement with the upper roll.
FIG. 3b is a view similar to FIG. 3a showing the pressing arm in an inwardly pivoted position, while the carrier element is in an engaged state and the upper roll is in a lowered position.
FIG. 3c is a view similar to FIG. 3a showing the pressing arm in an inwardly pivoted position, while the carrier element is in an engaged state and the upper roll is in a raised position.
FIG. 4a is a side elevational view of the drawing unit shown in operation with loaded upper rolls.
FIG. 4b is a side elevational view of the drawing unit shown in an idling state with a raised upper outlet roll (deflecting roll).
FIG. 5 is a front elevational view showing details of one part of a preferred embodiment of the invention.
FIG. 6a is a schematic side elevational view of a pneumatic 5/2-way valve forming part of the structure according to the invention.
FIG. 6b is a symbolic representation of the pneumatic 5/2-way valve shown in FIG. 6a.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a drawing unit forming part, for example, of an HS-model drawing frame manufactured by Trutzschler GmbH & Co. KG, Monchengladbach, Germany. The drawing unit is of the "4-over-3" type, that is, it is formed of three lower rolls I (lower output roll), II (lower middle roll) and III (lower input roll) and four upper rolls 1, 2, 3 and 4. With the lower output roll I two pressure-relievable upper output rolls 1 and 2 are associated. The last upper output roll 1--as viewed in the direction of sliver run C--operates as a deflecting roll. The drawing unit drafts the sliver bundle 5 formed of a plurality of slivers and advancing through the drawing unit in the direction of the arrow C. The roll pairs formed of rolls 4 and III as well as 3 and II constitute a pre-drafting field while the roll pair formed of rolls 3 and II and the roll assembly formed of rolls 1, 2 and I constitute the principal drawing field.
The lower output roll I is driven by a non-illustrated principal motor which determines the output speed. The lower input roll III and the lower middle roll II are driven by a non-illustrated regulating motor. The upper rolls 1-4 are pressed against the respective lower rolls I, II, III by pressing devices 6, 7, 8 and 9 positioned in pressing arms 11 (only one is visible) rotatable in the direction of arrows A and B about a bearing 10. The upper rolls 1-4 are driven by the respective lower rolls I, II and III by frictional contact.
Also referring to FIGS. 2a and 2b, the lower rolls I, II and III are supported in bearing blocks 13 mounted on the machine frame 35. The pressing arms 11 also serve for shiftably receiving two pressing roll holders 14 for accommodating the upper rolls 1-4. Each upper roll holder 14 is composed of an upper part 15 and a lower part 16. The upper part 15 forms a cylinder unit having a cylinder chamber 17 in which a piston 18 is slidably received. A piston rod (pressure rod) 19 is attached to the piston 18 and is guided in a bore 20 of the upper part 15 and in a bore 21 of the lower part 16. The stub shaft 1a of the upper roll 1 projects through an opening of a holding plate 24a and is received in a bearing 22 which extends in a space 23 between the pressing roll holder 14 and the roll stub shaft of the lower roll I.
A diaphragm 25 which is in engagement with the face of the piston 18 divides the cylinder chamber 17 into an upper work chamber 17a and a lower work chamber 17b which may be selectively vented or charged with compressed air.
In operation, after a sliver bundle 5 has been positioned over the lower rolls I, II and III, the pressing arms 11 are pivoted inwardly (downwardly) into the working position illustrated in FIG. 1 and immobilized therein so that the upper rolls 1, 2, 3 and 4 may press the sliver bundle 5 against the lower rolls I, II and III. Such a pressing force is exerted by the weight of the pressure rods on the bearings 22 and by the pressurization of the upper work chamber 17a of each pressing device 6-9. As a result, the respective pressure rod 19--displaceable in the direction of the arrows D and E--presses down on the associated bearing 22 to generate the earlier noted pressure between the upper roll 1 and the lower roll I.
A carrier element formed as a slide pin 26 is mounted at an angle of 90° to the pressing rod 19 by a securing screw 28 and is shiftable in the direction of the arrows F and G relative to the pressing rod 19 by virtue of a slot 27 which is provided in the slide pin 26 and through which the securing screw 28 extends. The slide pin 26 is, at one end, supported in a bearing housing 29 which is shiftable in the direction of the arrows H, I and in which a non-illustrated driving device is accommodated for shifting the slide pin 26. The holding plate 24a has a throughgoing opening 30 in alignment with the slide pin 26. By shifting the slide pin 26 in the direction of the arrow G, it may form-fittingly project through the opening 30.
In FIG. 3a the pressing arm 12a is shown in an inwardly pivoted, upright state, and the pressing rod 19 of the pneumatic pressing device 9 presses on the bearing 22. The slide pin 26 is out of engagement with the holding plate 24a. The pressing arm 12a is rotatable in the direction of the arrows K, L about a rotary bearing 32 which is supported by the machine frame 35. According to FIG. 3b the slide pin 26 has been shifted in the direction of the arrow G and thus extends into the holding plate 24a through the aperture 30. Thereafter the pressing rod 19 is shifted upwardly in the direction of the arrow E. Also referring to FIGS. 2a and 2b, since the slide pin 26 is connected to the pressing rod 19 by means of the screw 28 (see FIGS. 2a and 2b), the holding plate 24a, together with the upper roll 1 is also lifted in the direction E to the same extent as the pressing rod 19, as illustrated in FIG. 3c. At the same time, the attachment 22 1 of the bearing 22 is lifted out of the supporting extension 13a of the stand 13. Also at the same time, the housing 29 too, which is shiftably supported by a slide bearing 33 at the pressing arm 11a, is displaced in the direction of the arrow N through the same extent as the pressing rod 19. As a result, the upper roll 1 is relieved of pressure. Subsequently, since the slide pin 26 is in a form-locking relationship with the holding plate 24a, the upper roll 1 is also shifted further in the direction N and is thus lifted off the lower roll.
As shown in FIG. 4a, the upper output rolls 1 and 2 lie, in operation, with pressure on the lower output roll I and the fiber material 5 runs between the upper output rolls 1 and 2 and the lower output roll I. In case of an extended disturbance--which is detected by the non-illustrated electronic control and regulating device for the roll drive motors--the upper output roll 1 is relieved of pressure and is immediately lifted off the fiber material 5, that is, it is lifted off the lower output roll 1 by a distance a. This occurrence prevents the fiber material from sticking to the upper output roll 1 since no pressure prevails which forces any sticking substance of the fiber material 5 against the upper output roll 1. By virtue of the fact that the upper output roll 2 is relieved of the additional external pressure, but remains in place by gravity, the fiber material 5 remains firmly clamped between the upper output roll 2 and the lower output roll I and may, upon restart, be guided without difficulty by the upper output roll 1 and the lower output roll I.
Turning now to FIG. 5, the lever 34 constituting a carrier element is at one end 34 1 rotatably jointed for pivotal motions in the direction of the arrows O, P to a rotary bearing 35 which is secured to the lateral column 12' of the pressing arm 12. The lever 34 is a single lever crank, whose two arms are oriented at an obtuse angle to one another. The other end 34 2 of the lever 34 terminates in a fork 34' through which extends a pin 28 secured to an intermediate element 36 which, in turn, is mounted on the pressing rod 19. One tine of the fork 34' has a carrier attachment (carrier element) 34" which may project into the opening 30 of the holding plate 24a (not shown in FIG. 5). If the pressing rod 19 is shifted in the direction of the arrow E, the carrier element 34 pivots about the bearing 35 in the direction P and the carrier attachment 34" is shifted in the direction E in a circular path about the center of the bearing 35. At the same time the lever 34 rotates in the direction of the arrow P and the opening 34' moves in the direction of the pin 28 so that the carrier attachment 34" projects beyond the pin 28 as the latter slides inwardly into the fork 34'. In this manner, the carrier attachment 34" is placed in a position in which it may project into the opening of the non-illustrated holding plate for the upper roll 1 (also not shown in FIG. 5). If the pressing rod 19 is shifted in the direction of the arrow D, all motions occur in the opposite direction.
The pneumatic control of the loading (pressure-applying) device of the drawing unit is effected by means of two 5/2-way valves as shown in FIGS. 6a and 6b. For loading the upper output roll 1 an own (dedicated), separately controllable 5/2-way valve is provided with which the following three switching states may be obtained:
A. The piston 18 is, in its lower dead center, charged with compressed air, that is, the upper rolls 1-4 are loaded. In this arrangement the loading force for each upper roll 1-4 may be individually regulated by pressure regulators. Further, for safety reasons, the pressure is monitored by pressure switches.
B. The piston 18 is vented, at its lower dead center, that is, the upper roll loading device may be pivoted upwardly without the upper rolls 1-4 since the latter are not fixed to the device, as shown in FIG. 5. Such a state is effected automatically when the machine is at standstill. This arrangement ensures that the coatings provided on the upper rolls as well as the fiber material are not exposed to unnecessary stresses.
C. The piston 18 is, at its upper dead center, charged with pressurized air, that is, the upper roll 1 is raised, as shown in FIG. 4b.
Turning to FIG. 6a, in the pneumatic valve 38 a solenoid 40 is operating a 5/2-way valve 39 which has a supply air inlet nipple 39a, a first venting nipple 39b, a second venting nipple 39c, a work nipple 39d (way 1) and a work nipple 39e (way 2). The arrows show the direction of the air flow. FIG. 6b is a symbolic representation of the operation of the 5/2-way valve 39. Dependent upon the state and direction of pressurization through the work nipple 39d three switching states may be obtained. The additional work nipple 39e may be blocked or may be utilized, for example, for a pneumatic control of the slide pin 26 (shown in FIGS. 2a, 2b and 3a-3c). The arrows indicate the directions of the air flow.
It is noted that relieving an upper roll 1-4 of pressure according to the invention may be effected automatically after stoppage of the draw frame. For this purpose, for example, a motion sensor may be provided which applies a signal to a timer as the draw frame stops, and the timer, in turn, applies a signal--after a predetermined delay--to actuate the valve 38. Upon restarting the draw frame the motion sensor may apply a signal directly to the valve 38 to effect re-pressurization of the upper roll or rolls.
The invention was described in connection with pneumatic pressure elements as an example. It will be understood that mechanical, hydraulic or electric pressure elements may also be used for loading the upper rolls 1-4.
In practice, in the absence of the invention many loops appear about the deflecting roll 1, particularly because reviving agents and adhesive particles are present in the fiber. As an operational disturbance in the machine occurs, such as sliver rupture, coiler can replacement or the like, frequently the machine attendants are not capable of immediately eliminating such disturbances. The drawing unit is relieved of pressure after a malfunction appears, but the hot deflecting roll 1 continues to lie on the fibers 5 by gravity. In case such a state persists for an extended period, the sticky fibers 5 are glued to the deflecting roll 1 and upon machine restart, the sticky fibers 5 are wound about the deflecting roll 1. According to the invention, it is feasible to lift the deflecting roll 1 by means of a separate valve upon occurrence of a disturbance. By lifting the deflecting roll 1 the fibers 5 cannot stick to the roll and the pressure on the lower roll I is reduced whereby the tendency of looping (winding of fiber about the roll) significantly diminishes. Such a reduction in the looping tendency significantly increases the efficiency of the drawing frame in case sticky fibers are processed because the delays involved with operational disturbances and their elimination are substantially reduced or avoided.
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims. | A method of operating a draw frame including a plurality of serially arranged roll pairs each defining a nip through which a fiber sliver passes from roll pair to roll pair. Each roll pair is formed of an upper roll and a lower roll. A pressing arm carries the upper rolls, and pressing devices are accommodated in the pressing arm for pressing each upper roll against a respective lower roll. The method comprises the following steps: during the working state of the draw frame, passing the sliver consecutively through the roll pair nips while the pressing devices press the upper rolls against respective lower rolls, and during an interruption of the working state the upper output roll is relieved of pressing forces to an extent that at the most only an insubstantial pressure is exerted by the upper output roll on the sliver situated in the nip between the upper output roll and the lower output roll. | 3 |
BACKGROUND
1. Technical Field
The present disclosure is directed to electrosurgery and, in particular, to circuitry for measuring or sensing the contact resistance or impedance between the patient and pairs of RF return pad contacts or electrodes employed in such surgery.
2. Description of the Related Art
One potential risk involved in electrosurgery is the possibility of stray electrical currents causing excess heating proximate the RF return pad contacts or patient return electrodes. The most common conditions which are thought to lead to excess heating include:
(1) Tenting: Lifting of the return electrode from the patient due to patient movement or improper application. This situation may lead to excess heating if the area of electrode-patient contact is significantly reduced;
(2) Incorrect Application Site: Application of a return electrode over a highly resistive body location (e.g., excessive adipose tissue, scar tissue, erythema or lesions, excessive hair) will lead to a greater, more rapid temperature increase. Or, if the electrode is not applied to the patient (i.e. electrode hangs freely or is attached to another surface), the current may seek an alternate return path such as the table or monitoring electrodes; and
(3) Gel drying either due to premature opening of the electrode pouch or use of an electrode which has exceeded the recommended shelf life.
Many monitor or detection systems have been developed in the past, but most cannot directly guard against all three of the above listed situations. In order to protect against these potentially hazardous situations, the contact resistance or impedance between the return electrode and the patient should be monitored in addition to the continuity of the patient return circuit.
Safety circuitry is known whereby split (or double) patient electrodes are employed and a DC current (see German Pat. No. 1,139,927, published Nov. 22, 1962) or an AC current (see U.S. Pat. Nos. 3,933,157 and 4,200,104) is passed between the split electrodes to sense the contact resistance or impedance between the patient and the electrodes. U.S. Pat. No. 3,913,583 discloses circuitry for reducing the current passing through the patient depending upon the area of contact of the patient with a solid, patient plate. A saturable reactor is included in the output circuit, the impedance of which varies depending upon the sensed impedance of the contact area.
The above systems are subject to at least one or more of the following shortcomings: (a) lack of sensitivity or adaptiveness to different physiological characteristics of patients and (b) susceptibility to electrosurgical current interference when monitoring is continued during electrosurgical activation.
U.S. Pat. Nos. 4,416,276 and 4,416,277 describe a split-patient return electrode monitoring system which is adaptive to different physiological characteristics of patients, and a return electrode monitoring system which has little, if any, susceptibility to electrosurgical current interference when monitoring is continued during electrosurgical activation. The entire contents of both U.S. Pat. Nos. 4,416,276 and 4,416,277 are incorporated herein by reference.
Still a need exists for a detection or monitoring system, which is: 1) adaptive to different physiological characteristics of patients; 2) has little, if any, susceptibility to electrosurgical current interference, (including interference or measurement interaction between components of the detection system); 3) can measure or sense the contact resistance or impedance between the patient and pairs of RF return pads or electrodes where multiple pairs of RF return pads are utilized due to the high current frequently needed during electrosurgery, such as during tissue ablation; and 4) eliminates or minimizes the risk of measurement interaction between the RF return pad pairs.
Therefore, it is an aspect of the invention to provide a multiple RF return pad contact detection system for use during electrosurgical activation which achieves the above objectives.
SUMMARY
A multiple RF return pad contact detection system is disclosed which is adaptive to different physiological characteristics of patients, without being susceptible to electrosurgical current interference. The detection system includes interference or measurement interaction between components of the detection system which can measure or sense the contact resistance or impedance between the patient and pairs of RF return pads or electrodes when multiple pairs of RF return pads are utilized. Due to the high current frequently needed during electrosurgery, such as during tissue ablation, the detection system eliminates or minimizes the risk of measurement interaction between the RF return pad pairs.
The circuitry of the multiple RF return pad contact detection system is preferably provided within an electrosurgical generator for controlling the generator according to various measurements, such as the contact resistance or impedance between the patient and pairs of RF return pads or return electrodes. The system allows for the independent and simultaneous measurement of the pad contact impedance for each pair of RF return pads. If the impedance of any pad pair is above a predetermined limit, the system turns off or reduces the electrosurgical output of the electrosurgical generator to prevent excess heating.
The system eliminates or minimizes interference or measurement interaction between the pad pairs by providing a different signal source frequency for each pad contact pair, but a frequency which matches an associated series resonant network frequency. The current that flows in the series resonant network is a direct reflection or function of the pad impedance of the corresponding pad pair. Since the two resonant networks are tuned to different frequencies, there is minimal interaction, if any, within the system, thus reducing the chances of inaccurate measurements.
The system could be modified by providing a multiplexer to multiplex the measurements corresponding to each pad contact pair to eliminate or minimize measurement interaction and also minimize hardware resources.
Further features of the multiple RF return pad contact detection system of the invention will become more readily apparent to those skilled in the art from the following detailed description of the apparatus taken in conjunction with the drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
Various embodiments of the invention will be described herein below with reference to the drawings wherein:
FIG. 1 is a schematic diagram of the multiple RF return pad contact detection system in accordance with a preferred embodiment of the invention; and
FIG. 2 is a graph illustrating the operation of the pad contact impedance measurement subsystem of FIG. 1 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Reference should be made to the drawings where like reference numerals refer to similar elements. Referring to FIG. 1 , there is shown a schematic diagram of the multiple RF return pad contact detection system 100 of the present invention wherein electrosurgical generator 10 includes known circuitry such as a radio frequency oscillator 12 and an output amplifier 14 which generate an electrosurgical current. This current is applied to a patient (not shown) via an active electrode 16 . The electrosurgical current is returned to the generator 10 via pad contact pairs or return electrode pairs 18 a , 18 b having pads or electrodes 20 a , 20 b and 22 a , 22 b and a corresponding two conductor patient cable 24 a , 24 b having leads 26 and 28 . Two capacitors 32 and 34 are connected across each of the secondary windings 40 a , 40 b of transformer 38 a , 38 b.
Each primary winding 36 a , 36 b is connected to a corresponding a.c. signal source 42 a , 42 b and a series resonant network 44 a , 44 b . The purpose of each series resonant network 44 a , 44 b is to produce a current (i.e., left and right current senses) which is a function of the impedance between pads or electrodes 20 a , 20 b and 22 a , 22 b.
The system 100 eliminates or minimizes interference or measurement interaction between the pads 20 a , 20 b and 22 a , 22 b , while allowing for the independent and simultaneous measurement of the pad contact impedance for each pair of RF return pads by having each a.c. signal source 42 a , 42 b provide a different signal source frequency for its corresponding pad contact pair. The frequency of each series resonant network 44 a , 44 b is tuned to match the frequency of the current produced by its associated a.c. signal source 42 a , 42 b.
Accordingly, the frequency of one of the series resonant networks 44 a is different from the frequency of the other series resonant network 44 b . Hence, there is minimal interaction, if any, between the left and right circuitry of the system 100 , especially the two contact pad pairs 18 a , 18 b . This essentially eliminates inaccurate or confusing measurements.
Additionally, the frequency of the electrosurgical current produced by the electrosurgical generator 10 is substantially different from that of the current produced by the a.c. signal sources 42 a , 42 b.
The current that flows in each series resonant network 44 a , 44 b , i.e., left and right current senses, is a direct reflection or function of the pad impedance of the corresponding pad contact pair 18 a , 18 b according to the physics of a series resonant network. Each series resonant network 44 a , 44 b is an RCL network or a combination of R (resistance), L (inductance) and C (capacitance). In a preferred embodiment of the series resonant networks 44 a , 44 b , the inductive component for each network is integrated into the respective transformer 38 a , 38 b.
The frequency response of a series resonant network has a maximum resonant frequency f R . At the resonant frequency, the series resonant network has the minimum impedance, as opposed to a parallel resonant network which has the maximum impedance at the resonant frequency, and the phase angle is equal to zero degrees. The total impedance of a series resonant network is Z T +jX L −jX C =R+j(X L −X C ). At resonance: X L =X C , f R= 1/(2πsqrtLC), Z T =R, and V L =V C . The resonance of a series resonant network occurs when the inductive and capacitive reactances are equal in magnitude but cancel each other because they are 180 degrees apart in phase.
The left and right current senses are applied to pad contact impedance measurement subsystem 46 which determines whether the impedance measurements between pads or return electrodes 20 a , 20 b and 22 a , 22 b are within a desired range. The range is preferably adaptable to the physiological characteristics of the patient. If at least one of the impedance measurements is not within a desired range, an inhibit signal is applied over a line 48 to internally disable the electrosurgical generator 10 (or reduce the RF output therefrom) to prevent excess heating.
U.S. Pat. Nos. 4,416,276 and 4,416,277 describe a method for determining the desired range according to the physiological characteristics of the patient, the entire contents of these patents is incorporated herein by reference.
Preferably, the desired range for which the impedance must fall between return electrodes 20 a , 20 b and 22 a , 22 b is about 20 to about 144 ohms. If not, the electrosurgical generator 10 is disabled. Thus, in one method of operation of the present invention, the lower limit is fixed at the nominal value of 20 ohms, thus reducing the onset of patient injury as a result of stray current paths which may surface if a contact pad or electrode is applied to a surface other than the patient. The upper limit is set to avoid such problems as those mentioned hereinbefore, i.e., tenting, incorrect application site, gel drying, etc.
In accordance with an important aspect of the invention, the upper limit is adjustable from the absolute maximum (typically about 144 ohms) downward to as low as typically 20 ohms to thereby provide for automatic adaptiveness to the physiological characteristics of the patient. This provides the multiple RF return pad contact detection system 100 of the present invention with significantly more control over the integrity of the RF pad contact or electrode connections without limiting the range of patient types with which the multiple RF return pad contact detection system 100 may be used or burdening the operator with additional concerns.
That is, the physiological characteristics can vary significantly from patient to patient and from one location site for the pad pairs to another. Thus, patients may vary in their respective amounts of adipose tissue (which is one determining factor in the impedance measurement between the various pads) without effecting the detection system. Further, for a particular patient, one location site may be more fatty, hairy or scarred than another. Again, this does not reduce the effectiveness of the system, i.e., all of these factors typically affect the impedance measured between pads 20 a , 20 b and 22 a , 22 b and thus concern the operator as to which site is optimal for a particular patient. Such concerns are eliminated in accordance with the present invention by providing for automatic adaptability to the physiological characteristics of the patient.
Reference should now be made to FIG. 2 which is a graph illustrating the operation of pad contact impedance measurement subsystem 46 .
During operation, the desired impedance range (that is, the acceptable range of the impedance detected between pads 20 a , 20 b and 22 a , 22 b ) is preset when the power is turned on to an upper limit of, for example, 120 ohms and a lower limit of, for example, 20 ohms as can be seen at time T=0 seconds in FIG. 2 . If the monitored impedance for any pad contact pair is determined to be outside of this range (T=A seconds) by comparing the current sense signal (or a signal derived there from) with a reference signal (e.g., a signal equal to 120 ohms or 20 ohms) using comparator circuitry (e.g., when a pad pair or any single contact pad is not affixed to the patient) an alert will be asserted and the electrosurgical generator 10 will be disabled over line 48 .
The impedance between two contact pads of a contact pad pair at any instant is designated the return RF electrode monitor (REM) Instantaneous Value (RIV) in FIG. 2 . When the REM impedance enters the range (T=B seconds) bounded by the Upper Limit (UL) and the Lower Limit (LL), a timing sequence begins. If after five seconds the RIV is still within range (T=C seconds), the alert condition will cease and the REM impedance value is stored in memory. This is designated as REM Nominal Value (RNV). The upper limit is then reestablished as 120% of this amount. The 80 ohm RIV shown in FIG. 2 causes the upper limit to be at 96 ohms. This feature of the invention is particularly important because it is at this time (T=C seconds) that adaptation is initially made to the physiological characteristics of the patient. Note if the RIV were to exceed 96 ohms at a time between T=C and T=F seconds (while the upper limit is 96 ohms), the alert will be asserted and the electrosurgical generator 10 disabled.
However, if the upper limit had not been adjusted to 96 ohms, the alert would not have been asserted until after the RIV exceeded the initial 120 ohms upper limit as determined by the comparator circuitry, thus possibly heating one or both of the pads 20 a , 20 b and 22 a , 22 b . This situation is of course exacerbated if the patient's initial RIV within the preset 20 to 120 ohm range is 30 ohms.
An initial RIV of 10 ohms within the preset range of 20 to 120 ohms sets an upper limit of 144 ohms.
In accordance with another aspect of the invention, it has been observed that the impedance between contact pads of contact pad pairs decreases over a relatively long period, such as a number of hours. Since many surgical procedures can extend a number of hours, this effect is also taken into consideration in the present invention. Accordingly, RIV is continuously monitored and any minima in REM impedance (e.g., a downward trend followed by a constant or upward trend in REM impedance) initiates a new five second timing interval (T=E seconds) at the end of which the RNV is updated to the RIV if the RIV is lower (T=F seconds). The REM upper limit of 120% of RNV is re-established at this time. The five second interval causes any temporary negative change in REM impedance (T=D seconds) to be disregarded. Operation will continue in this manner provided RIV does not exceed the upper limit of 120% RNV or drop below the lower limit of 20 ohms. Exceeding the upper limit (T=G seconds) causes an alert and the electrosurgical generator 10 is disabled. It will remain in alert until the RIV drops to 115% of RNV or less (T=H seconds) or until the system 100 is reinitialized. RIV dropping to less than 20 ohms (T=I seconds) causes a similar alert which continues until either the RIV exceeds 24 ohms (T=J seconds) or the system 100 is reinitialized. The hysteresis in the limits of the REM range (that is, the changing of the upper limit to 115% of RNV and the lower limit to 24 ohms in the previous examples) prevents erratic alerting when RIV is marginal.
It should be noted in the example of FIG. 2 that the alert actually does not turn off when RIV returns to a value greater than 24 ohms because the pad pairs are removed before 5 seconds after T=J seconds elapse. Thus, the alarm stays on due to the removal of the pad contact pairs 18 a , 18 b.
Removing the pad contact pairs 18 a , 18 b from the patient or unplugging the cables 26 , 28 from the electrosurgical generator 10 (T=K seconds) for more than one second causes the system 100 to be reinitialized to the original limits of 120 and 20 ohms. This permits a pad to be relocated or replaced (T=L seconds) without switching the electrosurgical generator 10 off. The RIV at the new location is 110 ohms and 120% RNV is 132 ohms. Thus, as described above, this is the one time (whenever RIV enters the 20 to 120 ohms range (either as preset during power on or as reinitialized as at T=K seconds) for the first time) that the upper limit can be raised during the normal REM cycle. Otherwise, it is continually decreased to adapt to the decreasing RIV impedance with the passage of time.
The preferred implementation of the foregoing FIG. 2 operation of the pad contact impedance measurement subsystem 46 is effected by a set of programmable instructions configured for execution by a microprocessor.
The system 100 could be modified by providing a multiplexer to multiplex the measurements corresponding to each pad contact pair 18 a , 18 b to eliminate or minimize measurement interaction and also minimize hardware resources.
Other pad contact pair arrangements can be provided in the system 100 of the present invention besides the pad pair arrangements shown in FIG. 1 . For example, ten pad contact pairs 18 can be provided and connected to electrosurgical generator 10 by cables 26 and 28 , where the corresponding a.c. signal source 42 and series resonant network 44 corresponding to each pad contact pair 18 are tuned to the same frequency which is different from the frequency of the other a.c. signal sources 42 and series resonant networks 44 .
It is provided that the system 100 of the present invention allows for impedance comparisons to be performed between pad pairs. Therefore, if the pad pairs are placed symmetrically on the patient, i.e., left leg and right leg, comparison of the contact impedance can provide another degree of detection and safety.
Although the subject apparatus has been described with respect to preferred embodiments, it will be readily apparent to those having ordinary skill in the art to which it appertains that changes and modifications may be made thereto without departing from the spirit or scope of the subject apparatus. | A multiple RF return pad contact detection system is provided which is adaptive to different physiological characteristics of patients without being susceptible to electrosurgical current interference (e.g., interference or measurement interaction between components of the detection system). The detection system can measure or sense the contact resistance or impedance between the patient and pairs of RF return pads or return electrodes where multiple pairs of RF return pads are utilized due to the high current frequently needed during electrosurgery while eliminating or minimizing the risk of measurement interaction between the RF return pad pairs. The system allows for the independent and simultaneous measurement of the pad contact impedance for each pair of RF return pads. If the impedance of any pad pair is above a predetermined limit, the system turns off or reduces the electrosurgical output of the electrosurgical generator to prevent excess heating. The system eliminates or minimizes interference or measurement interaction between the pad pairs by providing a different signal source frequency for each pad contact pair, but a frequency which matches an associated series resonant network frequency. The current that flows in the series resonant network is a direct reflection or function of the pad impedance of the corresponding pad pair. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of International Application No. PCT/EP03/13962 filed Dec. 9, 2003, the disclosures of which are incorporated herein by reference, and which claimed priority to German Patent Application No. 102 58 790.6 filed Dec. 16, 2002, the disclosures of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to a piston with a valve arrangement for a vehicle hydraulic brake system comprising a piston channel penetrating the piston, a valve seat formed around an opening of the piston channel, and a valve element, which is displaceable relative to the piston and for sealing the piston channel is positionable in a fluid-tight manner against the valve seat, wherein the sealing seat takes the form of an annular projection on a sealing component, which comprises an elastic sealing element and a support element, which stabilizes the sealing element.
Such a piston is known from EP 0 607 370 B2, and corresponding U.S. Pat. No. 5,473,896 which is incorporated by reference herein, and according to this background art is installed in a master brake cylinder of a vehicle brake system. The piston together with the master brake cylinder encloses a pressure chamber. In a ready position prior to a brake actuation, the valve arrangement is in an open position, in which the pressure chamber communicates with a hydraulic fluid reservoir. When a driver of the vehicle initiates a braking operation, the piston is displaced inside the master brake cylinder. In said case, the valve arrangement closes in that the valve element positions itself in a fluid-tight manner against the sealing seat, thereby interrupting the fluidic connection between the pressure chamber and the hydraulic fluid reservoir. Consequently, a high hydraulic pressure builds up in the pressure chamber and leads to actuation of the vehicle brake circuit and to activation of the vehicle brakes. On completion of the braking operation, the piston is moved back into its ready position, wherein the valve arrangement opens and the pressure in the pressure chamber reduces.
In modern vehicle brake systems, in addition to the previously described braking-induced pressure increase, considerable pressure increases moreover arise in the pressure chamber when automatic brake pressure generating systems, such as e.g. a vehicle traction control system or a vehicle stability control system, are activated. Such automatic brake pressure generating systems are used for selective actuation of a brake circuit independently of an active braking operation by the driver in order to activate individual wheel brakes for increased vehicle safety. The pressure increase in the pressure chamber is effected, for example, by means of an additional hydraulic pump. The pressure thus increased then has to be reduced by opening the valve arrangement.
It has been shown that the elastic sealing element according to the background art in the region, in which it is exposed to the pressurized hydraulic fluid in the pressure chamber, has a tendency to deform elastically and, especially given high hydraulic pressures, to “flow”. If, given high hydraulic pressure in the pressure chamber, the piston is moved back into its ready position, then, as the valve arrangement starts to open, i.e. as the valve element starts to move, the sealing element deforms in the region of the sealing seat under the action of the hydraulic pressure in such a way that the sealing seat expands and moves, for part of the lift of the valve element, together with this valve element. Allowance has to be made for this behaviour of the sealing element when designing the valve arrangement. It is therefore necessary to provide a large enough lift to guarantee reliable opening of the valve arrangement despite the pressure-related deformation of the valve seat. The valve element however has to complete this lift also during initiation of a braking operation, thereby delaying the response of the brake system.
In order to prevent such pressure-induced deformations at the sealing element, it is further known from EP 0 607 370 B2 to provide an additional valve, which during a pressure build-up separates the pressure chamber from the valve arrangement and therefore prevents high hydraulic pressures at the valve arrangement. This solution is however considerably more costly to manufacture and more susceptible to faults when in operation.
DE 39 32 248 A1 and U.S. Pat. No. 2,136,835 each disclose a piston with valve arrangement, in which piston the valve element during a pressure build-up is pressed by an annular bead into the sealing element. These solutions are susceptible to wear owing to the high mechanical loads acting upon the sealing element.
BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to provide a piston of the initially described type which, while being of a simple design and highly resistant to wear, allows a rapid pressure build-up in the pressure chamber.
This object is achieved according to the invention by a piston with a valve arrangement for a vehicle hydraulic brake system, wherein the piston comprises a piston channel penetrating the piston, a valve seat formed around an opening of the piston channel, and a valve element, which is displaceable relative to the piston and, for sealing the piston channel, is positionable in a fluid-tight manner against the valve seat, wherein the sealing seat takes the form of an annular projection on a sealing component, which comprises an elastic sealing element and a support element, which stabilizes the sealing element. To achieve the previously stated object, according to the invention it is further provided that the support element is designed in a region close to the sealing projection with a corresponding annular recess.
The purpose of the annular recess is to receive the material of the sealing element that is deformed under high pressure in the region of the sealing seat and hence to direct the deformation towards the support element. This is achieved in particular also in that the surface of the support element in the region of the annular recess effects a better stabilization of the material of the sealing element and keeps it dimensionally more stable than is the case with the previously described background art. A better reinforcement of the elastic material of the sealing element is achieved by the enlargement of the surface of the support element by means of the annular recess than is the case with the background art.
A further increase of the dimensional stability of the sealing element is achievable according to the invention in that the sealing element is connected adhesively to the support element. This further reduces the deformability of the sealing element and stabilizes the sealing element as a whole. The adhesive connection may be effected by glueing or by vulcanizing the sealing element onto the support element.
In a development of the invention, it is provided that the annular sealing projection, viewed in cross section, has a round contour with a shallow flank trailing in the direction of the pressure chamber. The round and continuous run of the cross-sectional contour of the sealing projection prevents pressure peaks from occurring at the sealing projection and leading to locally concentrated extreme mechanical stress. The shallow trailing flank, precisely in the region subject to high pressure, ensures a well-balanced pressure distribution over a relatively large area and therefore leads to a reduction of the deformation.
In order to distribute pressure- and deformation-induced mechanical loads as uniformly as possible in the material of the sealing element also by means of the configuration of the annular recess, in a development of the invention it is provided that the annular recess, viewed in cross section, has a round, preferably circular-segment-round, contour.
Alternatively, it may however be provided that the annular recess, viewed in cross section, has a polygonal, preferably trapezoidal, contour. In the latter case, the sides serve as mechanical resistance to a deformation or flowing of the elastic sealing element material.
It was explained above that by means of the shape of the annular recess the deformation- and flow behaviour of the material of the sealing element may be influenced. As a further measure for purposefully controlling the deformation of the sealing element under pressure load, in a development of the invention it is provided that the annular recess is disposed, in relation to the sealing projection, closer to the opening of the piston channel. In other words, this means that the sealing projection lies, in relation to the annular recess, closer to the pressure chamber. If there is a high pressure in the pressure chamber, then a relatively high pressure difference exists at the sealing element between pressure chamber and piston channel. This pressure difference leads to a deformation of the material of the valve element in the region of the sealing projection in the direction of the piston channel. By virtue of the offset arrangement of sealing projection and annular recess, the material of the sealing projection is pressed initially in radial direction into the annular recess, so that an undesirable lift-increasing deformation of the sealing element in axial direction—as is the case with the background art—may be prevented.
With regard to the valve arrangement, in a development of the invention it is provided that the valve element comprises a valve tappet, which is guided in a guide element, and a valve disc, which interacts with the sealing seat. It may further be provided that the guide element is disposed in a receiving channel provided in the sealing component and that the valve disc has a substantially flat surface, which interacts with the sealing seat. Thus, the valve element and the sealing component, while being highly functional, are of a simple design and inexpensive to manufacture. With regard to the detailed construction of the guide element, in a development of the invention it is provided that the guide element comprises a guide bush, which guides the valve tappet, wherein the guide bush is held, preferably centrally, in the sealing component by means of at least one retaining web and wherein a fluid channel is formed between the guide bush and the sealing component.
To guarantee reliable and rapid closing of the valve arrangement during a braking operation, according to the invention it may further be provided that the valve element is biased by biasing means into a sealing position, in which it lies in a fluid-tight manner against the valve seat. In the ready position of the piston the valve element is then displaced out of its sealing position, so that the valve arrangement opens. The valve element is held in this open position until the piston is moved for the pressure build-up in the pressure chamber. The biasing means then effect a transfer of the valve element to the sealing position, simultaneously reducing the risk of jamming or blocking.
According to the invention, the sealing element may be formed from a flexible plastics material, in particular from an elastomer, and the support element may be formed from a material that is harder than the flexible plastics material, in particular from a metal material.
The invention further relates to a master brake cylinder arrangement comprising a master cylinder, a piston of the previously described type guided displaceably in the master cylinder, stop means defining a predetermined normal position of the piston, and biasing means biasing the piston into the normal position, wherein the piston together with the master cylinder encloses a pressure chamber, wherein moreover in the normal position the valve element is lifted off the sealing seat and the pressure chamber is connected by the piston channel fluidically to the fluid reservoir and wherein, upon displacement of the piston from its normal position counter to the action of the biasing means, the valve element positions itself against the sealing seat and a brake pressure builds up in the pressure chamber.
Other advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described below by way of example with reference to the accompanying drawings. The drawings show:
FIG. 1 an axis-containing partial section of a master cylinder arrangement according to the invention;
FIG. 2 a plan view of the piston from the left, and
FIG. 3 an enlarged detail view of the valve element denoted by III in FIG. 1 .
FIG. 4 an enlarged detail view of an alternate embodiment of the valve element.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1 , a piston according to the invention is illustrated in an axis-containing part-sectional view and generally denoted by 10 . The piston 10 is guided movably in the direction of the axis A in a cylinder housing 12 of a master cylinder. The piston 10 is designed with a stepped piston channel 14 , which penetrates the piston axially. A sealing component 16 , comprising a sealing element 18 and a support element 20 , is installed with press fit adhesion in the piston channel 14 . The design of the sealing component 16 is additionally described in detail below.
The sealing component 16 is designed likewise with a central stepped through-channel 22 , in which a guide element 24 is received and press-fitted such as to be locked against displacement. In the guide element 24 a valve element 26 is guided in an axially displaceable manner. The valve element 26 comprises a valve tappet 28 and a valve disc 30 . For guiding the valve element 26 in the guide element 24 , the valve tappet 28 is accommodated with slight play in a corresponding guide bush 32 of the guide element 24 (see FIG. 2 ). The guide bush 32 is pressed into and held axially in the through-channel 22 of the sealing component 16 by means of retaining webs 34 . By means of a restoring spring 35 , which is disposed between the guide bush 32 and the free end of the valve tappet 28 that is provided with a lock washer 37 , the valve element 26 is biased in such a way that the valve disc 30 is pressed with its underside 36 into abutment on a valve seat 38 on the end 40 facing the valve disc 30 .
For a closer description of the sealing component 16 , reference is made to FIG. 3 , which is an enlarged view of the partial detail of FIG. 1 denoted by III. The sealing component 16 comprises the sealing element 18 and the support element 20 . Both are connected adhesively to one another at their common contact surface 42 , e.g. by vulcanizing the sealing element 18 onto the support element 20 or by glueing them to one another.
The sealing element 18 on its end face 40 has the valve seat 38 in the form of an annular sealing projection. Its contour—viewed in the axis-containing cross section—from the radially inner side facing the through-channel 22 extends substantially in the shape of a segment of a circle and then tapers off with a sloping flank in the region denoted by 46 . The sealing element 18 on its outer peripheral surface 44 further comprises a plurality of bead-shaped sealing projections 48 running round in peripheral direction as well as a bead-shaped support projection 50 running round in peripheral direction and disposed close to the valve seat. The sealing projections 48 are used to enable the sealing component 16 to be pressed with a press fit and in a fluid-tight manner into the piston 10 , as shown in FIG. 1 . The support projection 50 additionally stabilizes the region of the end 40 of the sealing element 18 by being supported against the inner wall of the piston channel 14 .
The support element 20 in its end region 52 facing the end 40 has an annular recess 54 extending in peripheral direction around the axis. The annular recess 54 —viewed in the axis-containing cross section—possesses, for the most part, a contour that is round like a segment of a circle with harmonically rounded-off transitions. Alternatively, as shown in FIG. 4 . it may however be provided that the annular recess 54 ′, viewed in cross section, has a polygonal, preferably trapezoidal, contour. In the latter case, the sides serve as mechanical resistance to a deformation or flowing of the elastic sealing element material. The annular recess 54 is filled up with elastic material of the sealing element 18 . In its radially outer region, the support element 20 has a circumferential stabilizing edge 56 , which stabilizes the radially outer region of the sealing element 18 . In the radially inner region of the sealing component 16 , an end face portion 58 of the support element 20 is not covered by the material of the sealing element 18 .
Returning to FIG. 1 , it may be seen that the piston 10 is accommodated in a cylindrical cavity 60 of the cylinder housing 12 , which is closed at one end, and together with the cylinder housing 12 encloses a pressure chamber 61 filled with hydraulic fluid. The piston 10 is biased by a spring 62 in FIG. 1 to the right into its ready position shown in FIG. 1 and is therefore applied under bias against a stop bolt 64 , which extends transversely through the cylinder housing 12 and is fixed therein. In the cylinder housing 12 a connection port 66 is provided, by which the cavity 60 communicates with a non-illustrated fluid reservoir. The cylinder housing 12 further comprises a non-illustrated further connection port, by which the pressure chamber 61 is connected to the brake circuit of a motor vehicle.
At the outer periphery of the piston 10 a fluid seal 68 is provided, which prevents a flow of fluid along the outer periphery of the piston 10 upon axial movement of the piston 10 in the cylinder housing 12 and hence allows fluid-tight guidance of the piston in the cylinder.
The arrangement according to FIG. 1 operates as follows. Prior to initiation of a braking operation by the driver, the piston 10 is situated in its ready position shown in FIG. 1 . In this ready position, the piston 10 is pressed by the spring 62 against the stop bolt 64 . In said case, the valve tappet 28 presses with its free end against the stop bolt 64 . The spring force of the spring 62 exceeds the spring force of the restoring spring 35 , so that the valve element 26 occupies its open position shown in FIG. 1 , in which the valve disc 30 is lifted off the valve seat 38 . The pressure chamber 61 is therefore fluidically connected to the end of the piston channel 14 remote from the pressure chamber.
Upon an actuation of the brake, the piston 10 is displaced in FIG. 1 according to arrow P 1 to the left. In said case, the valve disc 30 moves closer and closer to the valve seat 38 until finally they both come into contact. From then on, upon further piston movement in the direction of arrow P 1 , an above-atmospheric pressure builds up in the pressure chamber 61 and is transmitted to the brake circuit. On completion of the braking operation, the piston 10 moves according to arrow P 2 back into its normal position shown in FIG. 1 . In said case, the valve element 26 again occupies its open position shown in FIG. 1 .
Under the growing hydraulic pressure the valve element 26 , or more precisely its valve disc 30 , is pressed with increasing strength onto the valve seat 38 , with the result that the valve seat 38 deforms under this pressure. The hydraulic fluid under the above-atmospheric pressure moreover acts upon the flank region 46 , which is in contact with this hydraulic fluid and therefore likewise deforms. Given very high hydraulic pressures, a flowing of the material of the sealing element 18 may even occur in this region.
Because of the shape of the flank region 46 and the end region 52 of the support element 20 , the previously mentioned deformation does not however lead to the effect whereby upon lifting of the valve disc 30 off the sealing seat 38 under high pressure in the pressure chamber 61 the sealing seat 38 deforms in axial direction according to arrow P 1 and because of this axially directed deformation prevents a rapid disengagement of valve disc underside 36 and sealing seat 38 for the purpose of a rapid pressure reduction in the pressure chamber 61 . Instead of this, the material of the sealing element 18 deforms under the pressure of the hydraulic pressure in the pressure chamber 61 in such a way that it penetrates into the annular recess 54 and is displaced by it further in a radially inward direction. The shallow course of the flank 46 moreover brings about a rapid disengagement of valve disc underside 36 and valve seat 38 . Thus, even given high hydraulic pressures in the pressure chamber 61 , the invention guarantees a rapid lifting of the valve disc 30 off the valve seat 38 also with a small lift of the valve element 26 . In this way, the response characteristic of the brake system may be improved.
The invention discloses a simple yet effective way of designing the piston plus central valve for a vehicle brake system that, even given high hydraulic pressures in the pressure chamber—optionally caused by an automatic system such as e.g. a traction control system or a stability program, guarantees a rapid pressure reduction on completion of the braking operation. This is achieved in particular by measures relating to the shape of the valve seat, so that an unwanted hydraulic-pressure-related deformation of the valve seat may be extensively suppressed.
In accordance with the provisions of the patent statutes, the principle and mode of operation of this invention have been explained and illustrated in its preferred embodiments. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope. | The invention relates to a piston having a valve arrangement for a vehicle hydraulic brake system comprising a piston channel penetrating the piston, a valve seat formed around an opening of the piston channel, and a valve element, which is displaceable relative to the piston and which for sealing the piston channel is positionable in a fluid-tight manner against the valve seat, wherein the valve seat takes the form of an annular projection on a sealing component, which comprises an elastic sealing element and a support element, which stabilizes the sealing element, and wherein the support element is designed in a region close to the sealing projection with a corresponding annular recess. | 1 |
CROSS-REFERENCE TO PATENT OFFICE DISCLOSURE DOCUMENT
This application is related to disclosure document No. 412,663 filed Feb. 10, 1997 at the U.S. Patent Office. It is respectfully requested that this disclosure document be transferred to the file of the present application.
BACKGROUND OF THE INVENTION
The invention relates to hammers, and more specifically to a hammer having structure for releasably holding a nail in a forward-oriented position to assist in starting a nail.
Most carpenters have experienced injury to fingers or thumbs caused by missing a nail while holding the nail to initially drive or start the nail into the desired material.
Furthermore, hammering or driving nails while in difficult positions, such as perched on a ladder, can be even more difficult when both hands are needed, one to hold a nail and the other to hold the hammer. As can be attested to by many in the field, this is a long-standing problem which needs a solution.
A large number of attempts have been made to provide a solution to this problem. A number of patents disclose various structures for holding a nail on the hammer for making the initial impact with the material in which the nail is to be driven so as to start the nail with a swing of the hammer and without needing the nail to be held in place. These disclosures are characterized, however, by a number of disadvantages. These disadvantages include structure which interferes with or detracts from the striking surface of the hammer, structure which includes magnets having a tendency to de-magnetize, structure which requires awkward movement to insert and release nails, and the lack of a good striking anvil for making the initial drive of the nail.
Thus, the need clearly remains for a hammer including a nail-holding attachment which overcomes the aforesaid disadvantages.
It is therefore the primary object of the present invention to provide a hammer having a nail-holding attachment which does not interfere with the striking surface or head of the hammer.
It is a further object of the present invention to provide such an apparatus wherein the nail-holding attachment mechanically holds the nail, without the need for a magnet, and which firmly holds the nail in place in a position wherein the nail is easily placed in the attachment, and released through a smooth and ergonometric motion after the nail has been started.
It is still another object of the present invention to provide an apparatus as described wherein the attachment has a good striking anvil for the nail.
Other objects and advantages of the invention will appear hereinbelow.
SUMMARY OF THE INVENTION
In accordance with the present invention, the foregoing objects and advantages are readily attained.
In accordance with the invention, a hammer is provided having a nail-holding structure, which comprises a hammer head having a forward nail striking surface; and means for releasably holding a nail having a point, a head and a body portion therebetween, wherein said means for releasably holding holds said nail with said point facing forward, said means for holding comprising a notch for receiving said body portion and a striking anvil for contacting said head with said body portion in said notch.
In further accordance with the invention, the means for releasably holding is preferably an integral portion of the hammer head.
In accordance with another aspect of the present invention, the nail-holding hammer which is provided comprises a hammer head having a forward nail striking surface; and means for releasably holding a nail in an engaged position wherein said nail is engaged against longitudinal movement, wherein said means for releasably holding receives a nail in said engaged position through upward pivot of a head of said nail relative to a point of said nail, and said nail is released from said engaged position through downward pivot of said head relative to said point.
BRIEF DESCRIPTION OF THE DRAWINGS
A detailed description of preferred embodiments of the present invention follows, with reference to the attached drawings, wherein:
FIG. 1 is a side view of a hammer including a nail-holding structure in accordance with the invention;
FIG. 2 shows a perspective view of a portion of the nail-holding structure of FIG. 1;
FIG. 2a is a partially sectional view of an alternative embodiment of a nail-holding structure;
FIG. 3 shows an alternative embodiment of the structure of FIG. 1;
FIG. 4 shows an alternative embodiment of the present invention wherein the nail-holding structure is mounted to the top of the hammer head;
FIG. 5 is a front view of the embodiment of FIG. 4;
FIG. 6 further illustrates the structure of another portion of the nail-holding feature of the present invention;
FIG. 7a illustrates the placement of a nail in a nail-holding attachment in accordance with the present invention; and
FIG. 7b illustrates disengagement of a nail from a nail-holding attachment of the present invention after the nail has been started.
DETAILED DESCRIPTION
The invention relates to a hammer having a nail-holding structure whereby a nail can be readily and easily engaged to the head of the hammer for driving or starting the nail without requiring the nail to be held in place by the user of the hammer.
Referring to FIG. 1, a hammer including a nail-holding structure in accordance with the present invention is generally referred to by reference numeral 10. As shown, hammer 10 includes hammer head 12, a handle 14 depending downwardly therefrom, and structure 16 for holding a nail 18 oriented facing forward for starting with a single-handed and routine swing of hammer 10.
As shown, hammer head 12 has a striking surface 20 for striking nails to be hammered into a surface as is well known in the art. Hammer head 12 may suitably have any desired shape or structure, and may be typical claw hammer as shown in FIG. 1, for example, or any other type of hammer having different shape or other features as desired.
Nail-holding structure 16 preferably includes a notch structure 22 (see also FIG. 2) which includes a substantially upwardly opening groove 24 for receiving a body portion 26 of nail 18. Structure 16 in accordance with the invention also includes a striking anvil portion 28 against which a head 30 of nail 18 rests or abuts when nail 18 is held by nail-holding structure 16. As shown in FIG. 1, a nail 18 held or engaged within nail-holding structure 16 is arranged with a point 32 oriented facing forward, in the same direction as striking surface 20, such that a nail held within nail-holding structure 16 can advantageously be started with the same motion or swing of hammer 10 as is used during subsequent hammering with the nail already partially driven into the desired surface or structure.
Referring to FIG. 2, additional detail of notch structure 22 in accordance with the present invention is illustrated. As shown, in one embodiment, notch structure 22 preferably includes groove 24 formed having a series of ramps 34 positioned on arms 36 which define groove 24. Also, as shown, arms 36 preferably extend gradually further away from each other so as to define a groove having an upwardly increasing width as shown. This advantageously allows groove 24 to receive nails 18 of various different diameter.
Referring now to FIG. 3, an alternative embodiment of notch structure 22 is illustrated. As shown, notch structure 22 may suitably be provided having nylon or other compressible or flexible wiper members 38 which advantageously deflect upon insertion of nail 18 into groove 24 so as to frictionally engage nails 18 of wide variety in diameter. Furthermore, in accordance with this embodiment of the invention, notch structure 22 may suitably be provided as a generally upwardly open sleeve structure 40 into which replaceable wipers 38 can be inserted and removed.
According to still another embodiment, notch structure 22 may be provided having a detent member 56 (FIG. 2a) biased outwardly to extend beyond an inner surface 58 of one or both arms 36 and into notch 24. Detent member 56 preferably has an at least partially spherical profile at the extending portion 60 thereof, and may suitably be outwardly biased by a spring 62 or any other member so as to allow a nail 18 to be pushed into notch 24 past detent member 56 so as to be releasably but firmly held or engaged in place by detent member 56.
Referring back to FIG. 1, striking anvil portion 28 of nail-holding structure 16 preferably includes a substantially flat anvil surface 42 against which head 30 of nail 18 rests in an engaged position of nail 18 as shown in FIG. 1. In accordance with the invention, and advantageously, anvil surface 42 is provided having sufficient area to contact substantially the entire area of head 30 of nail 18 so as to provide a firm striking surface from which nails held within nail-holding structure 16 can be started or driven. In further accordance with the invention, anvil portion 28 also preferably further includes a projection member 44 extending laterally from anvil surface 42, preferably positioned at an upper portion of anvil surface 42 as shown, so as to prevent upward sliding of head 30 relative to anvil surface 42 when nail 18 is in the engaged position. Furthermore, striking anvil portion 28 may also preferably include a lip member 46 preferably downwardly extending from projection member 44, for example as shown in FIG. 1, so that head 30 of nail 18, when in the engaged position, has the striking portion 48 resting against anvil surface 42, and lip member 46 extends at least partially over the opposed portion 50 of head 30, thereby holding nail 18 within nail-holding structure 16 and against longitudinal movement of nail 18 along the axis thereof.
This structure advantageously allows for nails 18 to be readily positioned and engaged within nail-holding structure 16 for driving or starting in a material as desired, and further allows nail 18 to be readily released from this position through an ergonometric and natural movement of hammer 10 as will be further discussed and illustrated below.
Still referring to FIG. 1, nail-holding structure 16 may suitably be positioned relative to hammer head 12 such that nail 18 extends in proximity to striking surface 20 of hammer head 12, but preferably without interfering with striking surface 20. As shown in FIG. 1, notch structure 22 and striking anvil portion 28 may suitably be positioned so as to hold a nail 18 along a side portion of hammer head 12, with nail 18 substantially vertically centered as shown. Referring to FIG. 4, notch structure 22 and striking anvil portion 28 may alternatively be positioned at a top region of hammer head 12 as shown, with nail 18 centered substantially laterally with respect to striking surface 20 of hammer head 12 (see FIG. 5). Alignment of nail 18 centered either vertically or laterally advantageously helps to allow a user of hammer 10 to start nails at a desired location.
As shown in FIG. 5, placement of nail-holding structure 16 advantageously allows for holding nail 18 as desired for starting, without interfering with perimeter 52 of striking surface 20 of hammer head 12. Thus, after nail 18 has been started, a normal hammering action can be used without concern for striking nail 18 with an incomplete portion of striking surface 20. It should of course be noted that while FIG. 5 shows nail 18 held at a top portion of striking surface 20 and outside of perimeter 52, the embodiment of FIG. 1 would result in nail 18 being held to the side of striking surface 20 and outside of perimeter 52 in similar fashion.
Referring now to FIG. 6, the preferred structure of nail-holding structure 16 in accordance with the present invention will be further illustrated. As shown, structure 16 may suitably be provided having a body portion 54 connected between notch structure 22 and striking anvil portion 28. Body portion 54 serves advantageously to strengthen the structure and enhance the durability of striking anvil portion 28 so as resist bending or other damage due to repeated use. For example, as shown in FIG. 6, notch structure 22, body portion 54 and striking anvil portion 28 may suitably be provided as an integral member, and may further preferably be provided as an integral portion of hammer head 12, for example by casting, so as to provide a sturdy and reliable structure in accordance with the present invention.
Referring now to FIGS. 7a and 7b, the use of hammer 10 in accordance with the present invention is illustrated. As shown, a nail may suitably be positioned within nail-holding structure 16 by starting with the nail in position as shown by solid lines, and then downwardly pivoting a point 32 of nail 18 relative to head 30 so as to rest body portion 26 of nail 18 within groove 24 of notch structure 22 with head 30 of nail 18 engaged by striking anvil portion 28 in an engaged position as shown by dashed lines in FIG. 7a. In this position, and advantageously, nail 18 is firmly engaged or held within nail-holding structure 16 and will remain there during a conventional swing of hammer 10 so as to drive nail 18 into a suitable structure 56 (see FIG. 7b), as desired.
Referring to FIG. 7b, once nail 18 is started in structure 56, hammer 10 may suitably be pivoted in a natural motion as illustrated by arrow X so as to provide relative downward pivot of head 30 of nail 18 relative to point 32 of nail 18, thereby releasing head 30 from striking anvil portion 28 and preferably at least partially removing body portion 26 of nail 18 from notch structure 22. After such pivot, hammer 10 can readily be pulled back from nail 18, with nail 18 released, and hammer 10 can then be used to conventionally finish driving nail 18 into structure 56 as desired.
It should readily be recognized that hammer 10 in accordance with the present invention provides for holding a nail to start same, without interfering with striking surface 20 of hammer head 12, and without conventionally used magnets which de-magnetize, and further without including any moving parts and the like which are undesirable to conventional users and which increase the cost and potential for breaking of apparatus 10. Furthermore, nails are easily placed within structure 16 for holding of same, and are also readily released from structure 16 after being driven into structure 56 as desired in accordance with the invention.
Furthermore, the striking anvil portion 28 of structure 16 in accordance with the invention provides for a full surface to strike the head 30 of a nail 18 being started, and thereby substantially prevents the possibility of destruction or deformation of head 30 during starting of nail 18.
As set forth above, structure 16 is preferably casted or otherwise provided as an integral portion of hammer head 12 so as to provide structural strength. Alternatively, structure 16 could be fixed in any suitable matter to hammer head 12, so long as sufficient strength is provided to withstand repeated use of same.
It should also be noted that several portions of this description refer to top or upper areas or features of the invention, and that these features are to be considered with hammer 10 oriented as illustrated for example in FIG. 1.
It is to be understood that the invention is not limited to the illustrations described and shown herein, which are deemed to be merely illustrative of the best modes of carrying out the invention, and which are susceptible of modification of form, size, arrangement of parts and details of operation. The invention rather is intended to encompass all such modifications which are within its spirit and scope as defined by the claims. | A nail holding hammer includes a hammer head having a forward nail striking surface; and a nail holding structure for releasably holding a nail having a point, a head and a body portion therebetween wherein the nail holding structure holds the nail with the point facing forward, the nail holding structure including a notch for receiving the body portion and a striking anvil for contacting the head with the body portion in the notch. | 1 |
FIELD OF THE INVENTION
The present invention relates to pulp screens in general and to pulp screens used for de-trashing pulp from recycled paper in particular.
BACKGROUND OF THE INVENTION
In a typical modern office waste paper is separated from other wastes and collected for recycling. Nevertheless, paper suitable for recycling is rarely completely separated from other wastes which cannot be recycled as paper. Paper for recycling is often contaminated with plastic bags, transparent overhead view-foils, X-Ray film, envelope windows, and paper with high wet strain such as Express Mail envelopes and bible papers. Heavy contaminants such as metal and rock may also be present.
Because the cost of sorting recycled paper by hand is generally prohibitive, all the trash which is collected as recyclable paper is commonly placed in a pulping device where it is mixed with water and chemicals and made into a pumpable slurry. The slurry thus produced is about 12 to 18 percent pulp by weight. The slurry is diluted with water to about 4 percent fiber dry weight as it is allowed to flow to a de-trashing unit. A typical de-trashing unit consists of a cylindrical tank with one end forming a screen through which the slurry is drawn by a pump. To aid the passage of the slurry through the screen a three bladed impeller is mounted adjacent to the screen and caused to rotate.
Unfortunately, with existing de-trashing units the impeller blades shred the non-pulping contaminants such as plastic bags, view-foils, envelope windows, etc. The shredded material then passes through the screen in the de-trasher and must be removed by additional processing steps. Inevitably the pumps between the additional pieces of processing equipment shred the contaminants into ever smaller particles so that a certain portion of the contaminants end up in the finished paper. Removal is possible but involves considerable additional cost. Contaminants which are not removed result in a final product which is of lower quality and value.
In addition to shredding the contaminants, the rotor in existing de-trashing units becomes laden with a buildup of contaminants such as plastic bags which wrap around the impeller. This buildup of contaminants increases the power required for operating the de-trashing unit and requires cleaning of the unit every eight hours.
What is needed is an improved de-trashing unit which can separate trash without significantly shredding lightweight plastic and without becoming clogged with trash.
SUMMARY OF THE INVENTION
The de-trashing unit of this invention employs a rotor which is fabricated from an integral stainless steel blank. The rotor has two swept blades which have blunt leading edges and a trailing edge which is relieved. The blade is driven to rotate over a trash screen with holes of between one-quarter and one-half inch in diameter. The blade is positioned to have a clearance between the blade and the screen of between 0.005 and 0.010 inches. The relieved portion of the blade faces the screen with the result that the trailing edge of the blade is tapered between 18 and 30 degrees away from the screen surface. The blade taper creates a strong negative pressure pulse which keeps the screen clear. Holes drilled through the relieved portion of the blade allow fluid circulation through the blade into the region of low pressure generated by the relieved portion passing over the screen. The circulation holes create micro turbulence which keeps a slurry of water and paper fibers fluidized.
The advantages of the improved rotor may be employed in a cylindrical screen where foils are moved over the screen surface to create a negative pressure pulse whereby the screen is prevented from clogging. The advantages of the rotor are incorporated by adding holes which pass through the foils to create micro turbulence which aides the cleaning of the screen surface and maintains the stock in a fluidized state.
It is a feature of the present invention to provide a pulp de-trasher which does not shred plastic which is mixed with pulp.
It is a further feature of the present invention to provide a pulp de-trasher which allows pulp to be passed through a screen more rapidly.
It is another feature of the present invention to provide a blade for a pulp de-trasher which reduces shredding of plastic film contained in pulped office waste paper.
Further objects, features and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a bottom plan view of the rotor of this invention.
FIG. 2 is a schematic cross-sectional view of the rotor of FIG. 1 taken along section line 2--2 and shown in relation to the screen over which the rotor passes.
FIG. 3 is a schematic view of a pulper and a de-trasher which employs the rotor of FIG. 1.
FIG. 4 is a top cross-sectional view of a cylindrical screen with foils employing the advantages of the rotor of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring more particularly to FIGS. 1-4, wherein like numbers refer to similar parts, a rotor 20 is mounted in a de-trasher 22 as shown in FIG. 2. The de-trasher 22 is supplied with a slurry of paper fiber stock from a pulper 24, as shown in FIG. 3. Waste paper collected from offices which is intended for recycling is typically contaminated with items of trash such as staples, paper clips, plastic bags, view foils, envelope windows, and various plastic films. This flow of mixed paper and trash is supplied to the pulper 24. Water is added in proportion to the dry office waste paper so that the final pulp will consist of twelve to eighteen percent fiber. The pulper 24 is typically operated in a batch mode, but may be operated in a continuous mode. The water, various chemical aids to pulping, and recycled office waste is processed in the pulper 24 until a slurry of water and paper fibers is formed. An agitator 26 mixes the water and paper waste causing the waste paper to be defibered. The contents of the pulper vessel 28 is then dumped from the pulper 24 through a pipe 30. Flow into the pipe 30 is controlled by a gate valve 32. Water 34 is added to the stock as it flows into the de-trasher vessel 36 to dilute the stock to a fiber dry weight content of between three and five percent.
The de-trasher vessel 36 is divided by a screen 38 which has a multiplicity of openings 39. The openings 39 in the screen 38 are typically round and have a uniform diameter which is typically between one-quarter and one-half inch. The rotor 20 is mounted on a shaft 40 which is driven by a motor 42.
A vacuum is drawn on the portion 44 of the vessel 36 formed by the screen 38. Vacuum is supplied by a pump 46. The rotor 20 is positioned with the bottom surface 48 of the rotor 20, as shown in FIG. 1, adjacent the surface 50 of the screen 38. The spacing between the rotor surface 48 and the screen surface 50 is preferably between 0.005 and 0.010 inches. The motor 44 drives the rotor 20 so that it has a tip speed of about 5,000 feet per minute, which for a forty-four inch rotor corresponds to a rotation rate of approximately 450 rpm.
In a typical sequence of operations, the de-trasher 22, the pump 46 and motor 42 are started and the contents of the pulper 24 are diluted by water supply 34 and allowed to flow thru pipe 30 into the de-trasher 22. The pump 46 draws the paper stock through the screen 38. The rotor 20 operates to keep the paper stock fluid and to prevent clogging of the screen 38. As the level of paper stock falls in the de-trasher vessel 36 the rotor splashes the stock excessively and the motor 42 and pump 46 are shut down. The chamber is then filled with water and the pump and motor are again activated. After the majority of stock has been removed from the vessel 36 the remaining water and trash are drained through a first valve 54 and a second valve 56 to a disposal unit 58. During drainage of the remaining water and trash a valve 60 can be used to isolate the vessel 36 from the stock drain pipe 62. If required, depending on the amount of trash in the waste paper, the cycle and be repeated. The valves 54 and 56 can be used to form a chamber for emptying trash while the de-trasher is processing stock.
The arrangement of the pulper 24 and de-trasher 22 is conventional. The improvement consists of using a rotor 20. A conventional rotor has been found to shred plastic bags and other plastic films so they pass through the screen and must be removed at greater expense downstream of the de-trasher. Furthermore, conventional rotors have been found to be prone to the wrapping of plastic, particularly plastic bags, around the blades of the rotor. The wrapped bags build up on the rotor and increasing the mass being rotated, thus increasing resistance to motion through the stock so that power consumption is increased.
The rotor 20 overcome this limitations of existing rotors by employing blades 52 forming the rotor 20 having a unique shape. The rotor 20 is also more closely spaced from the screen 38 then is typical in an existing de-trasher.
The shape of the rotor 20 and blades 52 is shown in FIG. 1 and FIG. 2. The rotor 20 is forty-four inches in diameter and is one inch thick, and has a central portion 63 with a central opening 64 which has a diameter of eight and one-quarter inches. A hub (not shown) mounted to the shaft 40 protrudes through the central opening 64. The central portion 63 is counter-bored on a fourteen inch diameter to a thickness of about 0.56 inches so the entire central portion 63 is relieved below the level of the blades. Bolt holes 67 extend through the central portion 63 and allow bolts to pass into the hub (not shown) which attaches attach the rotor 20 to the shaft 40.
The rotor 20 has two blades 52 which extend from the central portion 63. The blades sweep away from the direction of motion of the rotor 20 as indicated by arrows 66 in FIG. 1. The blades 52 have blunt leading edges 68, and trailing edges 70 which are cut away to form an eighteen degree bevel surface 72. The relieved portions of each blade define five holes 75 positioned upstream of the trailing edge 70. The holes are formed perpendicular to the beveled surfaces 72. The relieved portions adjacent the trailing edges 70 create low pressure pulses as the blades 52 move over the surface 50 of the screen 38. The rapid increase in volume between the screen 38 and the blade 52 cause by the movement of the beveled surfaces 72 of the blades over the portion of the screen previously covered by the flat surface 48 of the blade 52 draws liquid into the space created between the surface 50 of the screen and the beveled surfaces 72. Responding to the decreased pressure opposite the beveled surfaces 72 liquid moves through the screen openings 39 towards the rotor 20 removing any blockage of the openings 39. At the same time liquid flows through the holes 75 into the low pressure volume created by the beveled surface 72 the mixture of liquid flowing through the blades 52 and through the screen 38 in combination with the trailing edges 70 create micro turbulence which fluidizes the stock.
The rotor is typically fabricated of hardenable metal, for example 17-4PH stainless steel or stainless steel type 410 and hardened to 42 to 46 Rockwell C hardness. The rotor may be cut from a steel blank with an abrasive water jet and finished, machined or ground to its final shape.
Close positioning of the rotor 20 to the screen 38, sometimes referred to as a barrier plate, is critical to developing the pressure pulse which cleans the screen 38 and to preventing plastic bags from becoming wrapped around the blades. The spacing between the rotor surface 48 and the screen surface 50 is preferably between 0.005 and 0.010 inches, a gap of greater than 0.125 would probably be totally ineffectual.
Obtaining the fine gap between the rotor 20 and the barrier screen 38 can require careful shimming between the rotor 20 and the hub (not shown). A better solution which allows adjustment of the plane defined by the surface 50 of the screen 38 is to mount the screen 38 so it can be adjusted. If the screen 38 is bolted to a circumferential flange 76, a series of circumferentially positioned set screws (not shown) may be positioned to extend from the screen and engage the flange to hold the screen away from the flange and thus position the screen 38 with respect to the rotor 20. Once the screen is aligned to be parallel with the surfaces 48 of the rotor 20, bolts (not shown) can be used to lock the screen 38 to the flange 76.
Tests Performed with Water
A prior art rotor and the rotor 20 of this invention have been tested on both water and pulp. For the water test, two barrel liners and one trash bag, which is a lighter weight plastic than the barrel liners, were placed in the de-trasher. Water was added to the pulper and the de-trasher was run for 10 minutes in recirculation mode, so that whatever passed through the screen came back into the pulper and was then passed back into the de-trasher. Following 10 minutes, the de-trasher was flushed using the water in the pulper. A gauge was set up to read the number of amps drawn by the motor driving the rotor.
For the run with the improved rotor 20, the clearance was 0.005" to 0.010" between the rotor 20 and the screen 38. After 10 minutes with the improved rotor, the three plastic bags came out in the de-trasher dump. Although the new rotor did tear the bags in some places, the bags were mostly intact and the torn parts were still large. Two of those pieces were trapped behind the rotor. The de-trasher pulled 11.5 amps in no load and 13.75 amps during operation.
The prior art rotor was run at both a tight clearance (0.005" and 0.010") and a normal clearance (0.200"). The tight clearance caused severe ripping of the plastic. The water being recirculated back to the pulper was full of plastic, meaning that the plastic was reduced in size enough to pass through the grate. All that was left were confetti like pieces of plastic. Also, there was more plastic trapped behind the rotor than there was with the new rotor. At this clearance the amps were 12 in no load and 23 in operation.
At the larger clearance with the prior art rotor, there was no shredding, but all three bags were wrapped tightly around the rotor. The no load was 11.6 amps and in operation the de-trasher pulled 20 amps.
TABLE 1______________________________________Summary of De-Trasher Rotor Results on Water AmpsRotorClearance (in.) No Load Operating Comments______________________________________New 0.005-0.010 11.5 13.75 Some tearing; no shreddingOld 0.005-0.010 12 23 Massive shreddingOld 0.200 11.6 20 No tearing or shredding; plastic wound on rotor______________________________________
Tests Performed with Pulp
Batches of 1,000 air dry pounds of a mixture of 70 percent ONP and 30 percent OMG were pulped at a target consistency of 14 percent for 20 minutes with a Maule rotor. The target temperature was 120° F. As in the water trials, the de-trashing units were seeded with two barrel liners and one trash bag to simulate a worst case scenario. After pulping was complete, the batch was dumped through the de-trasher and into the pulper dump chest. The dump time was measured and recorded and the amps used by the de-trasher was recorded from the gauge current gauge.
The prior art rotor was run first. Its clearance was 0.200 inches. The pulp dumped extremely slowly. The rotational speed of the pulper rotor was varied from 200 rpm to 275 rpm depending on the amount of stock that was being thrown by the rotor and how quickly stock was being dumped into the dump chest. For the most part, the speed was 250 rpm and higher. Also, the pump was stopped and started twice to try to speed up the dump. But, the total dumping time was 83 minutes. At 75 minutes, water was added underneath the prior art impeller to speed up dumping. Following the completion of the dump, the de-trasher was flushed. Very little plastic was in the trash box under the de-trasher. Opening the de-trasher revealed that all three bags had been wound around the rotor very tightly. During operation, the de-trasher pulled 21.5 amps.
The prior art rotor was pulled out and the newly designed rotor 20 was put in. A clearance of 0.005" to 0.010" was requested, but checking the clearance afterward showed that the clearance was between 0.010" and 0.030". Dumping was much quicker with the new rotor. As in the first batch, the pulper rotor speed was kept over 200, in this case between 225 and 250 until the pulper rotor began to throw stock as the level in the pulper decreased, which necessitated slowing the rotor down to prevent the stock from being thrown. After 31.25 minutes, the dump was completed. The de-trasher flush discharged the two barrel liners--mostly intact--into the trash box, along with some larger pieces that had been torn from the barrel liner and trash bag. When the de-trasher was opened, it was noticed that the majority of the trash bag had wrapped around the rotor, but it had not been shredded, only torn. Compared to the old rotor, the new rotor was wrapped much less severely. Running the new rotor at the closer clearance should prevent the plastic from wrapping around the rotor.
The temperature when dumping started was 15° F. higher for the new rotor than it was for the old rotor. The temperature difference contributed to the lower dump time, but is not likely responsible for decreasing the dump time by over 60 minutes.
The new rotor pulled 12.8 amps during operation, which was unexpected because it pulled 13.57 while running with water. Table 2 shows the changes in pulper speed and the points at which the pump was turned off and then on during the dump for both runs. Table 3 is a summary of the dump results for the two batches, including the consistency and the defibering index, as measured on a 0.010" slotted Valley Flat Screen.
TABLE 2______________________________________Changes in Operation During the Dump CycleOld Rotor New RotorTime Time(minutes) Change (minutes) Change______________________________________0 speed at 225 0 speed at 2255.5 speed at 250 5.5 speed at 25010 speed at 275 20 speed at 200 - tossing stock12 speed at 250 - vibration 23 speed at 150 - tossing at 275 stock22.5 speed at 225 - tossing 25 speed at 75 - tossing stock stock24.25 speed at 200 - tossing 25.75 speed at 50 - tossing stock stock25 speed at 275 - stopped 30 pump stopped, then stock tossing started32.5 pump stopped, then 31.25 dumping completed started60 speed at 250 - throwing stock64 pump stopped, then started66.5 speed at 175 throwing stock75 began adding water under the Maule83 dumping completed______________________________________
TABLE 3______________________________________Summary of Rotor ResultsClearance Csy. DefiberingRotor(in.) Amps (%) Index (%) Comments______________________________________Old 0.200 21.5 6.3 99.7 Plastic wound on rotorNew 0.010-0.030 12.8 6.0 100 some tearing; no shredding______________________________________
A pulp cleaning screen 120 of the type employing a cylindrical screen 122 with a concentric rotor 124 is shown in FIG. 3. The rotor 124 is shown with four arms 126 which are typically employed with a twenty-four inch diameter screen. Typically screens employ pulsation generating devices such as foils which are moved over the screen surface to create negative and positive pressure pulses to keep the screen from clogging. The improved foil 128 for a twenty-four inch diameter screen is about three and one-half inches long in a circumferential direction and about one and one-half into thick at the leading edge 130 tapering to a thickness of one-half inch at the trailing edge 132. The foil 128 will typically be one to several feet tall parallel to the cylindrical axis defined by the screen. A bottom surface 133 of the screen is flat and angled slightly away from the screen 122 so that the gap between the screen 122 and the foil 128 increases from the leading edge 130 to the trailing edge 132. This increasing gap causes fluid to be drawn through holes 137 in the screen 122. Holes 134 adjacent to the leading edge 130 of the foil 128 aid in creating microturbulence. Holes 136 may also be used in connection with the holes 134 to improve the performance of the screen 120.
It should be understood that the rotor 20 may have a diameter of between 24 and 60 inches depending on the size of the de-trasher. As the diameter of the blade varies the optimal angle of the bevel surface 72 will change.
It is understood that the invention is not limited to the particular construction and arrangement of parts herein illustrated and described, but embraces such modified forms thereof as come within the scope of the following claims. | A de-trashing unit has a rotor fabricated from steel blank. The rotor has two swept blades with blunt leading edges and relieved trailing edges. The rotor is driven to rotate over a trash screen with holes of between one-quarter and one-half inch in diameter. The blade is positioned with a clearance between the blade and the screen of between 0.005 and 0.010 inches. The relieved portions of the blades face the screen while the trailing edges of the blade are tapered between 18 and 30 degrees away from the screen surface. The blade taper creates a strong negative pressure pulse which keeps the screen clear. Holes drilled through the relieved portion of the blade allow circulation through the blade into the region of low pressure generated by the relieved portions passing over the screen. The circulation created by the holes creates microturbulence which keeps a water and paper fiber slurry fluidized. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to and all the benefits of U.S. Provisional Application No. 62/054,023, filed on Sep. 23, 2014, and entitled “Turbocharger With Integrated Actuator.”
BACKGROUND
[0002] Advantages of turbocharging include increased power output, lower fuel consumption, and reduced pollutant emissions. The turbocharging of engines is no longer primarily seen from a high-power performance perspective, but is rather viewed as a means of reducing fuel consumption and environmental pollution on account of lower carbon dioxide (CO 2 ) emissions. Currently, a primary reason for turbocharging is using exhaust gas energy to reduce fuel consumption and emissions. In turbocharged engines, combustion air is pre-compressed before being supplied to the engine. The engine aspirates the same volume of air-fuel mixture as a naturally aspirated engine, but due to the higher pressure, thus higher density, more air and fuel mass is supplied into a combustion chamber in a controlled manner. Consequently, more fuel can be burned, so that the engine's power output increases relative to the speed and swept volume.
[0003] In exhaust gas turbocharging, some of the exhaust gas energy, which would normally be wasted, is used to drive a turbine. The turbine includes a turbine wheel that is mounted on a shaft and is rotatably driven by exhaust gas flow. The turbocharger returns some of this normally wasted exhaust gas energy back into the engine, contributing to the efficiency of the engine and saving fuel. This is achieved via a compressor, which is driven by the turbine and draws in filtered ambient air, compresses the air, and then supplies the compressed air to the engine. The compressor includes a compressor wheel that is mounted on the same shaft so that rotation of the turbine wheel causes rotation of the compressor wheel.
[0004] Turbochargers typically include a turbine housing connected to the exhaust manifold of the engine, a compressor housing connected to the intake manifold of the engine, and a center bearing housing coupling the turbine and compressor housings together. The turbine housing defines a volute that surrounds the turbine wheel and that receives exhaust gas from the engine. The turbine wheel in the turbine housing is rotatably driven by a controlled inflow of exhaust gas supplied from the exhaust manifold via the volute.
SUMMARY
[0005] In some aspects, a variable turbine geometry (VTG) turbocharger includes a turbine wheel, a turbine housing that surrounds the turbine wheel and a VTG device disposed in the turbine housing adjacent to the turbine wheel. The VTG device is configured to selectively control the amount of exhaust gas delivered to the turbine wheel. The turbocharger includes a bearing housing defining a shaft-receiving bore and an actuating mechanism configured to connect the VTG device to an actuator. The actuating mechanism includes an actuation pivot shaft that is disposed in the shaft-receiving bore and connected to the VTG device, and at least a portion of the actuating mechanism is disposed externally of the bearing housing. The turbocharger includes the actuator and a cover that surrounds the actuator and the actuating mechanism. The cover forms a sealed connection with the bearing housing such that exhaust gas passing into the shaft-receiving bore is prevented from escaping to the atmosphere.
[0006] The turbocharger includes one or more of the following features: The cover comprises an air inlet connected to a source of pressurized air, whereby gas within the area surrounded by the cover is at a higher pressure than atmospheric pressure. The source of pressurized air comprises an air outlet of a compressor section of the turbocharger. The bearing housing comprises a passage that connects the shaft-receiving bore to a lubrication oil drain, whereby pressurized air from within the cover exits the turbocharger via the passage and the oil drain. The shaft-receiving bore includes a first end adjacent the actuating mechanism and a second end adjacent the VTG device, the bearing housing includes a lubrication oil drain and a passage that connects the shaft-receiving bore to the lubrication oil drain, and the passage communicates with the shaft-receiving bore at a location between the first end and the second end. The turbocharger includes piston rings disposed between the actuation pivot shaft and the shaft-receiving bore, and wherein the passage communicates with the shaft-receiving bore at a location between adjacent piston rings. The actuating mechanism comprises interconnecting elements configured to transmit a rotational motion provided by the actuator into a rotational motion of the actuation pivot shaft, and each element of the actuating mechanism comprises a gear-toothed surface, and each element is connected to an adjoining interconnecting element via its respective gear-toothed surface. The cover comprises an air inlet connected to a source of pressurized air, and the turbocharger comprises an air cooler configured to cool air from the source of pressurized air prior to reaching the air inlet, whereby gas within an area surrounded by the cover can be made cooler than an ambient temperature outside the cover.
[0007] In some aspects, an actuating assembly is mounted on an outer surface of a housing and is configured to actuate a device located within the housing. The actuating assembly includes an actuator and an actuation pivot shaft that extends through a shaft-receiving bore in the housing. The actuation pivot shaft includes a first end that is disposed on an outside of the housing and is connected to the actuator and a second end disposed on an inside of the housing and connected to the device. The actuating assembly includes an actuating mechanism that connects the actuation pivot shaft to the actuator, and a cover that cooperates with a portion of the outer surface of the housing to form a sealed enclosure that encloses the actuator, the actuating mechanism and the actuation pivot shaft first end.
[0008] The actuating assembly includes one or more of the following features: Gas within the sealed enclosure is at a pressure higher than atmospheric pressure. The cover includes an air inlet connected to a source of pressurized air, whereby gas within the sealed enclosure is at a higher pressure than atmospheric pressure. The housing further includes a sink passage formed therein, the sink passage defining a fluid flow path between the shaft-receiving bore and a drain opening formed in the housing at a location not enclosed by the cover. The actuating assembly includes a first seal and a second seal. The first seal includes piston rings disposed between the actuation pivot shaft and the shaft-receiving bore, and the second seal includes a region of relatively low pressure at a location corresponding to a sink passage in the housing, and regions of high pressure provided on opposed sides of the region of relatively low pressure. The actuating mechanism comprises interconnecting elements configured to transmit a rotational motion provided by the actuator into a rotational motion of the actuation pivot shaft, and each element of the actuating mechanism comprises a gear-toothed surface, and each element is connected to an adjoining interconnecting element via its respective gear-toothed surface. The cover comprises an air inlet connected to a source of cooled air, whereby gas within the sealed enclosure is at a cooler temperature than ambient temperature.
[0009] VTG turbochargers allow a turbine flow cross-section leading to the turbine wheel to be varied in accordance with engine operating points. This allows the entire exhaust gas energy to be utilized and the turbine flow cross-section to be set optimally for each operating point. As a result, the efficiency of the turbocharger and hence that of the engine can be higher than that achieved with bypass control of a wastegate valve assembly.
[0010] In some VTG turbochargers, adjustable guide vanes in the turbine are used to control pressure build-up behavior and, therefore, the turbocharger power output. The adjustable guide vanes are pivotally connected to a lower ring and an upper vane ring, including various possible rings, and/or nozzle wall. The angular position of the guide vanes is adjusted to control exhaust gas backpressure and turbocharger speed by modulating the exhaust gas flow to the turbine wheel. The guide vanes can be pivoted by vane levers, which can be located above the upper vane ring. Performance and flow to the turbine are influenced by changes of the flow angle to the turbine wheel by pivoting the guide vanes.
[0011] One goal of VTG turbochargers is to expand the usable flow rate range in practical applications while maintaining a high level of efficiency. To accomplish this, the turbine output is regulated by changing an inflow angle and inflow speed of the exhaust gas flow at a turbine wheel inlet. With VTG turbochargers, this is achieved using guide vanes in front of the turbine wheel that change their angle of attack with exhaust gas flow speed. This reduces lag at slow speeds while opening to prevent exhaust gas backpressure at higher speeds.
[0012] With VTG, turbocharger ratios can be altered as conditions change. When the guide vanes are in a closed position, the high circumferential components of the flow speed and a steep enthalpy gradient lead to a high turbine output and therefore to a high charging pressure. When the guide vanes are in a fully open position, the turbine reaches its maximum flow rate and the velocity vector of the flow has a large centripetal component. An advantage of this type of output control over bypass control is that the entire exhaust gas flow is always directed through the turbine and can be converted to output. Adjustments of the guide vanes can be controlled by various pneumatic or electrical actuators.
[0013] A VTG turbocharger may have an actuation pivot shaft with a VTG lever to help control the movement of the guide vanes. A VTG actuation pivot shaft is typically not fitted directly to a bore in the turbine housing, but more often to a stationary bearing in a bore in the turbine housing. The actuation pivot shaft is often radially located in a bearing, which can be located either in a bore, with a centerline within the turbine housing, or directly in the bearing housing depending on the design.
[0014] The actuation pivot shaft system typically needs sealing between turbine gas pressure and atmospheric pressure. A VTG actuation pivot shaft system is difficult to seal in part because of the clearance between the shaft and bushings. This clearance is necessary with the bushing design to prevent binding, but it creates misalignment of the shaft to the bushing/housing.
[0015] The VTG turbocharger includes a VTG device disposed in the turbine housing between the turbine volute and the turbine wheel. The VTG device is configured to selectively control the amount of exhaust gas delivered to the turbine wheel. The VTG device is connected to an actuator disposed outside the turbocharger housing via an actuating mechanism. The actuating mechanism includes an actuation pivot shaft that is rotatably disposed in a shaft-receiving bore formed in the bearing housing. At least a portion of the actuating mechanism is disposed externally of the bearing housing. The turbocharger includes a cover that surrounds the actuator and the actuating mechanism, and forms a sealed connection with the bearing housing such that exhaust gas passing into the shaft-receiving bore is prevented from escaping to the atmosphere.
[0016] The VTG actuator and actuating mechanism for the turbocharger are sealed within one or more covers that serve to prevent exhaust gas leakage from the turbocharger housing via the shaft-receiving bore.
[0017] The area enclosed by the cover defines an enclosure that is pressurized, for example by using a portion of the charged air generated in the turbocharger compressor. By providing a pressurized enclosure, a flow of air is forced into the joint between the actuation pivot shaft and the bushing that supports the actuation pivot shaft, preventing the pressurized exhaust gas from exiting the turbocharger housing at this location.
[0018] The pressurized air delivered to the cover is conditioned using an air-to-air cooler, a filter and/or a pressure regulator. The cooled air cools the actuator, the VTG actuating mechanism and the turbine end of the bearing housing, minimizing heat related damage to these parts and coking at the turbine end. In this regard, when the actuator includes electronics, such electronics can be sensitive to high temperatures, whereby cooling the actuator can improve actuator accuracy and durability.
[0019] An exhaust gas passage is formed in the bearing housing. One end of the exhaust gas passage opens facing the actuation pivot shaft, and an opposed end of the exhaust gas passage opens to a drain for lubrication oil. The drain returns oil to the engine crankcase, where the leakage enters the engine air inlet and is burned. Thus by retaining the leaked exhaust gas within the bearing housing and using pressure to direct the leaked exhaust gas to the engine crankcase via the exhaust passage and drain, leakage from the actuation pivot shaft is minimized or eliminated.
[0020] The exhaust passage includes radially-extending through holes formed in the sidewall of the bushing that supports the actuation pivot shaft within the housing, and a radial bore formed in the bearing housing, the radial bore providing fluid communication between the radial bores of the bushing and the drain via a half-moon shaped sump formed in the bore.
[0021] The actuator is disposed outside the turbocharger and includes a geared output shaft. In addition, the VTG actuating mechanism may include a series of gears that connect the geared output shaft of the actuator to a geared actuation pivot shaft connected to the VTG device. The geared connection between the actuator and the VTG device advantageously decreases hysteresis, improves accuracy of the kinematics, and reduces wear.
[0022] This configuration addresses many problems associated with some conventional turbocharger VTG actuating mechanisms in which the actuator is connected to the VTG device via a lever arm and linkages. For example, when assembling a conventional VTG lever arm to the actuation pivot shaft, in some cases the actuator is manually rotated in order to tighten a pinch bolt through a small “window,” whereby the actuator can be damaged during assembly. In another example, although the actuation pivot shaft may have piston rings to reduce soot leakage from the shaft-receiving bore, some exhaust gas is still vented to the atmosphere via the shaft-receiving bore. In another example, forming the connection between the actuator and the actuator lever arm is often done in a swaging (e.g., cold forging) process, but this process can create cracks in the actuator lever arm and/or damage the actuator. In another example, the fork-style actuation pivot shaft used in some conventional VTG actuating mechanisms moves a block attached to a pin. This combination of components accrues tolerances, reducing accuracy. In another example, in order to address customer requirements including tolerance of higher temperatures and reduction in turbocharger size, the materials used to form the race of the conventional linkage are relatively expensive. In still another example, the conventional linkage is assembled using a hex tool on the back side of a ball stud, which can difficult to perform in the tight spaces provided. By providing a geared actuator that rotates a series of gears attached to a geared actuation pivot shaft, use of an expensive linkage is avoided and assembly is simplified. In addition, the geared VTG actuating mechanism is capable of tolerating higher temperatures, and results in lower vane angle tolerances, reduced wear, and lower hysteresis relative to some conventional VTG actuating mechanisms.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Advantages of the present disclosure will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
[0024] FIG. 1 is a cross sectional view of a VTG turbocharger;
[0025] FIG. 2 is a side perspective view of the VTG turbocharger of FIG. 1 with the turbine housing and cover omitted for clarity;
[0026] FIG. 3 is a schematic diagram of fluid flow within an engine system that includes the VTG turbocharger of FIG. 1 ;
[0027] FIG. 4 is an enlargement of a portion of the cross sectional view of the VTG turbocharger shown in FIG. 1 ;
[0028] FIG. 5 is a cross-sectional view of the VTG turbocharger as seen along line 5 - 5 of FIG. 4 ;
[0029] FIG. 6 is a side perspective view of a VTG turbocharger including an alternative actuation mechanism, with a portion of the cover removed to show the alternative actuation mechanism, and the turbine housing removed for clarity;
[0030] FIG. 7 is a side perspective view of the VTG turbocharger of FIG. 5 with the cover in place over the alternative actuation mechanism; and
[0031] FIG. 8 illustrates an alternative cover configuration.
DETAILED DESCRIPTION
[0032] Referring to FIGS. 1-3 , an exhaust gas turbocharger 1 includes a turbine section 2 , a compressor section 3 , and a center bearing housing 8 disposed between and connecting the compressor section 3 to the turbine section 2 . The turbine section 2 includes a turbine housing 11 that defines an exhaust gas inlet (not shown), an exhaust gas outlet 10 , and a turbine volute 9 disposed in the fluid path between the exhaust gas inlet and exhaust gas outlet 10 . A VTG device 20 including adjustable guide vanes 21 is located inside a radially-extending throat 7 of the turbine volute 9 . A turbine wheel 4 is disposed in the turbine housing 11 between the throat 7 and the exhaust gas outlet 10 .
[0033] The compressor section 3 includes a compressor housing 12 that defines the air inlet 16 , an air outlet (not shown), and a compressor volute 14 . A compressor wheel 5 is disposed in the compressor housing 12 between the air inlet 16 and the compressor volute 14 . The compressor wheel 5 is connected to the turbine wheel 4 via a main shaft 6 .
[0034] The main shaft 6 is supported for rotation about a rotational axis R within an axially-extending bore 15 in the bearing housing 8 via a pair of axially spaced journal bearings 18 . In addition, a thrust bearing assembly 19 is disposed in the bearing housing 8 so as to provide axial support for the main shaft 6 .
[0035] In use, the turbine wheel 4 in the turbine housing 11 is rotatably driven by an inflow of exhaust gas supplied from an exhaust manifold 38 of an engine 34 ( FIG. 3 ). Since the main shaft 6 is rotatably supported in the center bearing housing 8 and connects the turbine wheel 4 to the compressor wheel 5 in the compressor housing 12 , the rotation of the turbine wheel 4 causes rotation of the compressor wheel 5 . As the compressor wheel 5 rotates, the air mass flow rate increases, airflow density and air pressure delivered to the cylinders 36 of the engine 34 via an outflow from the compressor air outlet (not shown), which is connected to an air intake manifold 37 of the engine 34 .
[0036] The VTG device 20 includes guide vanes 21 that are pivotably supported between an upper vane ring 22 and lower vane ring 23 , which are spaced apart by spacers 24 . The guide vanes 21 are adjustable through an actuator 30 which actuates an adjustment ring 26 . A rotary motion of the adjustment ring 26 about the rotational axis R with respect to the upper vane ring 22 is transmitted onto the guide vanes 21 , which by this device can be adjusted within a pre-determined range between the open and closed positions. The spacing between the guide vanes 21 defines the flow channels of the circular throat 7 in which the exhaust gas radially flows toward the turbine wheel 4 . The flow channels are adjustable through variation of the angular position of the guide vanes 21 .
[0037] More specifically, the guide vanes 21 are mounted to the upper vane ring 22 by means of vane shafts 27 , which penetrate the upper vane ring 22 and which carry a vane arm 28 on the end opposing the guide vanes 21 . The adjustment ring 26 is located in a vacancy between the bearing housing 8 and the turbine housing 11 so as to be disposed within the axial plane of the circularly-arranged vane arms 28 . The adjustment ring 26 engages each of the vane arms 28 such that during rotation of the adjustment ring 26 with respect to the upper vane ring 22 , all vane arms 28 , and therewith the guide vanes 21 , are simultaneously rotated.
[0038] As illustrated in FIG. 4 , the adjustment ring 26 is connected to the actuator 30 via an actuating mechanism 140 that transfers a rotational motion output from the actuator 30 to the adjustment ring 26 . The actuator 30 that drives the VTG device 20 is secured to an outer surface of the bearing housing 8 , for example via a bracket (not shown). The actuating mechanism 140 includes an actuation pivot shaft 54 that enables the adjustment of the adjustment ring 26 from outside of the bearing housing 8 . To this end, the actuation pivot shaft 54 is rotatably supported and radially located within a shaft-receiving bore 25 formed in the bearing housing 8 via a bushing 90 that is press fit into the shaft-receiving bore 25 . In the illustrated embodiment, the actuation pivot shaft 54 and the bushing 90 are disposed in the shaft-receiving bore 25 . The shaft-receiving bore 25 extends through a wall portion of the bearing housing 8 and includes first and second bore openings 25 a , 25 b , respectively. In some turbocharger designs, the shaft-receiving bore 25 may be formed at least partially within the turbine housing 11 .
[0039] The actuation pivot shaft 54 protrudes through the first and second bore openings 25 a , 25 b in the bearing housing 8 so that a first end 56 of the actuation pivot shaft 54 engages the VTG actuating mechanism 140 on an outside of the bearing housing 8 at a location that, in some conventional turbocharger designs, is at atmospheric pressure. In addition, an opposed, second end 58 of the actuation pivot shaft 54 engages the VTG device 20 within the bearing housing 8 at location that is at a relatively high pressure corresponding to the pressure of the exhaust gas.
[0040] Three seals 75 , 102 and 120 can be used individually, or in combination, to address leakage of exhaust gas out of the bearing housing 8 via the shaft-receiving bore 25 . For example, a first seal, such as a labyrinth seal 102 , may be disposed between the actuation pivot shaft 54 and the bushing 90 . The labyrinth seal 102 includes piston rings 104 , which are received in corresponding axially-spaced circumferential grooves 64 formed in an outer surface of the actuation pivot shaft 54 . Four piston rings 104 are employed between the actuation pivot shaft 54 and the bushing 90 . The piston rings 104 are arranged in two piston ring pairs 104 a , 104 b.
[0041] A second seal can surround a portion of the outside of the bearing housing 8 in the vicinity of the first bore opening 25 a of the shaft-receiving bore 25 to the outside. The second seal may be, for example, a cover 75 that prevents the escape of exhaust gas from the exhaust ( 70 ) into the environment. The cover 75 is sealed to, and cooperates with, a portion of the outer surface of the bearing housing 8 to form a sealed enclosure 76 that encloses the actuator 30 , the actuating mechanism 140 and the actuation pivot shaft first end 56 . This configuration minimizes or eliminates leakage of exhaust gas out of the bearing housing 8 via the shaft-receiving bore 25 .
[0042] In the illustrated embodiment, the cover 75 includes two cover portions 75 a , 75 b that are bolted together along a sealed joint ( 77 ) and cooperate with, and are sealed to, the bearing housing 8 to form the sealed enclosure 76 . The cover 75 includes a cover air inlet 78 connected to a source of pressurized air, whereby gas within the sealed enclosure 76 is at a higher pressure than atmospheric pressure. In the illustrated embodiment, the source of pressurized air is pressurized air generated in the compressor section 3 of the turbocharger 1 , but the source is not limited to this.
[0043] Referring to FIG. 3 , the air delivered to the enclosure 76 may be conditioned. For example, prior to reaching the cover air inlet 78 ( FIG. 1 ), the air may pass through an air-to-air cooler 74 located downstream of a conventional charged air cooler 71 , an air filter 72 and/or a pressure regulator 73 . As a result, the air delivered to the enclosure 76 is clean, cooled and at a pre-determined pressure that is greater than atmospheric pressure. The air-to-air cooler 74 is configured to cool the delivered air prior to reaching the cover air inlet 78 , whereby the air within the enclosure 76 is cooled. For example, the air within the enclosure 76 can be made cooler than the ambient temperature (e.g, the air temperature outside the cover 75 ). The pressure regulator 73 controls the air pressure within the enclosure 76 . Pressure in the enclosure 76 will vary depending on the application. For example, the pressure in the enclosure 76 may be set between 1.05 to 3.0 atmospheres. In some embodiments, the air delivered to the enclosure 76 may be set to be at least seventy-five percent of the exhaust gas pressure within the turbine volute 9 . For example, when the exhaust gas pressure within the turbine volute 9 is 4 atmospheres, the pressure regulator 73 provides air to the enclosure 76 at a pressure of 3 atmospheres. Pressurization of the enclosure 76 may also reduce or prevent fouling of the actuator 30 and the actuating mechanism 40 due to exhaust gas leakage from the shaft-receiving bore 25 .
[0044] Referring again to FIG. 4 , and as illustrated in FIG. 5 , a third seal may be disposed in the shaft-receiving bore 25 between the bushing 90 and a surface of the shaft-receiving bore 25 (e.g., the bearing housing 8 ). The third seal may be, for example, a sink seal 120 that prevents exhaust gas from entering the enclosure 76 , and instead directs exhaust gas passing through the shaft-receiving bore 25 to the crankcase 35 (not shown) of the engine 34 via an oil lubrication passageway 17 (shown in FIGS. 1 and 3 ) of the bearing housing 8 and corresponding oil lubrication drain line 13 (shown in FIGS. 1 and 3 ). The sink seal 120 includes a sump 122 formed in a surface of the shaft-receiving bore 25 at a location spaced apart from the first and second bore openings 25 a , 25 b . In the illustrated embodiment, the sump 122 is disposed between two pairs of piston rings 104 a , 104 b , such that a labyrinth seal is provided between the sump 122 and each first or second bore opening 25 a , 25 b , respectively. In the illustrated embodiment, the sump 122 is a hemispherical depression disposed on a downward-facing side of the shaft-receiving bore 25 . In other embodiments, the sump 122 may be a circumferentially-extending channel that surrounds the outer surface of the bushing 90 .
[0045] As illustrated in FIG. 5 , the bushing 90 includes radially-extending cross-drilled through-holes 84 which allow the pressurized air from the enclosure 76 to mix with the pressurized exhaust gas leaking from the turbine housing 11 . The through-holes 84 are equidistantly spaced about a circumference of the bushing 90 , and are axially positioned so as to communicate with the sump 122 , where the pressurized air and exhaust gas mix further. In the illustrated embodiment, there are four through-holes 84 arranged to lie in a common plane, but the through-holes are not limited to this number or arrangement.
[0046] The sink seal 120 also includes a generally radially-extending sink passageway 124 formed in the bearing housing 8 having one end that communicates with the sump 122 , and an opposed end that communicates with the oil lubrication passageway 17 of the bearing housing 8 . This arrangement permits the mixed air and exhaust gas within the sump 122 to “drain” into the turbocharger oil lubrication drain line 13 .
[0047] As used herein, the term “sink seal” refers to the condition in which the sink passageway 124 , the oil lubrication passageway 17 and oil lubrication drain line 13 are at substantially atmospheric pressure, and in which this region of atmospheric pressure is disposed between the first relatively higher pressure region (e.g. greater than atmospheric pressure) within the enclosure 76 at the first bore opening 25 a , and the second relatively higher pressure region (e.g. greater than atmospheric pressure) within the turbine housing 11 at the second bore opening 25 b . By locating the sump 122 and sink passageway 124 between the regions of higher pressure, the mixed air and exhaust gas within the sump 122 is directed to the oil lubrication drain line 13 , and then ultimately to the engine crankcase 35 (not shown) where it is burned within the engine cylinders 36 . Thus the sink seal 120 directs leaked exhaust gas to the engine before it can exit from the second bore opening 25 a.
[0048] Referring to FIGS. 2 and 6 , although the actuator 30 may be connected to the VTG device 20 via a conventional actuating mechanism 140 that includes a VTG lever arm 47 , a linkage 43 and an actuation lever arm 41 ( FIG. 2 ), the turbocharger 1 can optionally include an improved geared actuating mechanism 40 . The geared actuating mechanism 40 consists of a series of interconnecting elements 42 , 48 , 94 that are configured to transmit a rotational motion provided by the actuator 30 into a rotational motion of the adjustment ring 26 of the VTG device 20 .
[0049] In particular, each interconnecting element 42 , 48 , 94 of the geared actuating mechanism 40 includes a gear-toothed surface, whereby adjacent interconnecting elements 42 , 48 , 94 are connected to an adjoining interconnecting element 42 , 48 , 94 via its respective gear-toothed surface. To this end, the outer surface of an output shaft 32 of the actuator 30 is formed having gear teeth 33 , whereby the output shaft 32 serves as a drive gear for the geared actuating mechanism 40 . One interconnecting element of the geared actuating mechanism 40 may include a first idler gear 42 rotatably supported on a first axle 44 . The first idler gear 42 includes both internal and external gear teeth. For example, the first idler gear 42 has inner gear teeth 45 a (not shown) formed on a radially inward-facing edge thereof that engage the gear teeth 33 of the output shaft 32 of the actuator 30 , whereby the first idler gear 42 is driven by the actuator 30 . In addition, the first idler gear 42 has outer gear teeth 45 b formed on a radially outward-facing edge thereof. Another interconnecting element of the geared actuating mechanism 40 may include a second idler gear 48 rotatably supported on a second axle 50 and having gear teeth 51 formed on an outer peripheral edge thereof. The gear teeth 51 of the second idler gear 48 engages the outer gear teeth 45 b of the first idler gear 42 , whereby the second idler gear 48 is driven by the first idler gear 42 . Gear teeth 51 of the second idler gear 48 engages gear teeth 62 formed on an outer surface of the remaining interconnecting element 94 , whereby the remaining interconnecting element 94 is driven by the second idler gear 48 . Interconnecting element 94 , may also be, for example, an actuation pivot shaft 94 . The only difference between actuation pivot shaft 94 and actuation pivot shaft 54 is that actuation pivot shaft 94 may include gear teeth 62 . Gear teeth 62 of the actuation pivot shaft 94 engage teeth 63 formed on an outer portion of the adjustment ring 26 to drive the adjustment ring 26 . The rotational axis 31 of the actuator output shaft 32 , the rotational axis 46 of the first axle 44 , the rotational axis 52 of the second axle 50 , and the rotational axis 60 of the actuation pivot shaft 94 are each parallel to the rotational axis R of the main shaft 6 .
[0050] By providing a geared actuator 30 that drives a series of idler gears 42 , 48 attached to the geared actuation pivot shaft 94 , the cost of manufacturing the actuating mechanism 40 is reduced and assembly is simplified relative to some conventional configurations. In addition, the geared actuating mechanism 40 is capable of tolerating higher temperatures, and results in lower vane angle tolerances, reduced wear, and lower hysteresis relative to some conventional actuating mechanisms.
[0051] Referring to FIG. 6 , although the geared actuating mechanism 40 can be used without the cover 75 , it is contemplated that the geared actuating mechanism 40 will be enclosed within the cover 75 to minimize or eliminate leakage of exhaust gas out of the bearing housing 8 via the shaft-receiving bore 25 . As previously described, the cover 75 is sealed to, and cooperates with, a portion of the outer surface of the bearing housing 8 to form the sealed enclosure 76 that encloses the actuator 30 , the actuating mechanism 40 and the actuation pivot shaft first end 56 . This configuration minimizes or eliminates leakage of exhaust gas out of the bearing housing 8 via the shaft-receiving bore 25 .
[0052] Referring to FIG. 8 , in another embodiment, an alternative cover 175 is sealed to, and cooperates with, a portion of the outer surface of the bearing housing 8 to form a sealed enclosure 176 (not shown) that encloses the actuating mechanism 40 and the actuation pivot shaft first end 56 . In this embodiment, the actuator 30 is provided in a sealed housing 39 , which is then joined in a sealed manner to an outside surface of the alternative cover 175 .
[0053] Selected illustrative embodiments are described above in some detail. It should be understood that only structures considered necessary for clarifying the illustrative embodiments have been described herein. Other conventional structures, and those of ancillary and auxiliary components of the system, are assumed to be known and understood by those skilled in the art. Moreover, while working examples have been described above, the present disclosure is not limited to the working examples described above, and various design alterations may be carried out without departing from the disclosure as set forth in the claims. | A turbocharger ( 1 ) includes a variable turbine geometry (VTG) device ( 20 ) disposed in the turbine housing ( 11 ) adjacent to the turbine wheel ( 4 ) and configured to selectively control the amount of exhaust gas delivered to the turbine wheel ( 4 ). A geared actuating mechanism ( 40 ) connects the VTG device ( 20 ) to an actuator ( 30 ) disposed outside the turbocharger bearing housing ( 8 ). The geared actuating mechanism ( 40 ) includes an actuation pivot shaft ( 94 ) that is rotatably supported in a shaft-receiving bore ( 25 ) and connected to the VTG device ( 20 ) such that at least a portion of the geared actuating mechanism ( 40 ) is disposed externally of the housing ( 8 ). A cover ( 75 ) surrounds the actuator ( 30 ) and the geared actuating mechanism ( 40 ), and forms a sealed connection with the housing ( 8 ) such that exhaust gas passing into the shaft-receiving bore ( 25 ) is prevented from escaping to the atmosphere. | 5 |
RELATED APPLICATIONS
[0001] This application is a non-provisional application that claims priority benefit of U.S. Provisional Patent Application No. 61 / 413 , 757 , filed Nov. 15, 2010, the entirety of which is hereby incorporated by reference herein.
BACKGROUND
[0002] 1. Field of the Disclosure
[0003] The invention generally relates to metered pump stands for metered pumps that periodically pump measured amounts of chemical or biological material into septic or sewage systems.
[0004] 2. Related Technology
[0005] Certain systems require periodic additions of chemical or biological material to keep the systems running smoothly. For example, boiler systems, cooling towers, septic tanks, or other sewage systems, may require periodic additions of chemical or biological material to break down sewage in the system, or to clean fouling substances from pipes, so that the system continues to run smoothly. Similarly, plumbing systems, in particular drains in plumbing systems, may require periodic additions of chemical or biological materials to clear drains of blockages or build-ups.
[0006] Pumps and pumping devices have been developed that periodically meter a set amount of chemical or biological material into drains or sumps of septic or sewage systems. These pumps are connected to a supply of chemical or biological material. The pumps generally include an internal timer, a power source (e.g., battery or A/C power from an outlet), a processor, and an input device (such as a keyboard, a touchscreen, an input button, a data port, etc.). A user may program the pump with a material addition schedule by which the pump periodically or regularly adds chemical or biological material to the septic or sewage system. One example of such a pumping system is the United 757 NEEM-BAC Gelled Drain Treatment System produced by United Laboratories Inc. The United 757 NEEM-BAC system injects several bacterial strains and Neem oil in a gelled formulation that provides the bacteria sufficient surface contact time to implant into build-up found in drains. The bacteria work to eliminate the build-up by degrading organic solids, proteins, starch, cellulose and grease.
[0007] Known pumps or pumping devices are usually permanently mounted to a wall or other structure in a conventional way, such as by using fasteners, wall anchors, etc. An input of the pump is then connected to a source of chemical or biological material and an output of the pump is connected to a drain, sump, or pipe in a septic or sewage system. Because the pump is permanently mounted in a specific location, the source of chemical or biological material must be located in proximity to the pump. Known sources of chemical or biological material are usually stored in bulk containers, such as deltangular containers, which come in many sizes, for example six gallon sizes.
[0008] Permanently mounted pumps are not easy to relocate. The permanently mounted pump must first be removed from the wall or other support. Next, new holes must be drilled in the new location. Additional mounting hardware may also be required.
[0009] Recently, pumps have been mounted directly to the bulk containers of the chemical or biological material to save space. Pumps mounted to the bulk container often result in a pump/container configuration that is large or awkwardly shaped. In other words, the container mounted pumps often do not fit well into locations near drains or sumps, which are often spatially limited.
SUMMARY OF THE DISCLOSURE
[0010] A metered pump system includes a metered pump stand having a main panel with first and second sides, a top edge, a bottom edge, and a pair of side edges. A pair of feet extends from the first side of the main panel near the bottom edge. An upper flange extends from the second side of the main panel near the top edge. A metered pump may be attached to the first side of the main panel. A material container for supplying chemical or biological material to the metered pump may be located proximate the second surface of the main panel. The disclosed metered pump system is customizable by interchanging components while using the same metered pump stand.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Objects, features, and advantages of the present invention will become apparent upon reading the following description in conjunction with the drawing figures, in which:
[0012] FIG. 1 is a perspective view of a metered pump system installed near a typical septic system sump, the metered pump system including a metered pump stand, a metered pump, and a material container.
[0013] FIG. 2 is a perspective view of the metered pump stand of FIG. 1 .
[0014] FIG. 3 is a side elevational view of the metered pump stand of FIG. 1 .
[0015] FIG. 4 is a front view of the metered pump stand of FIG. 1 .
[0016] FIG. 5 is a perspective view of the metered pump stand of FIG. 1 with a metered pump attached to a front surface of the metered pump stand.
[0017] FIG. 6 is a perspective view of the metered pump stand of FIG. 5 including a container proximate a back surface of the metered pump stand.
DETAILED DESCRIPTION
[0018] FIG. 1 illustrates a metered pump system 10 connected to a sump 100 of a septic system. The metered pump system 10 includes a metered pump stand 20 , a metered pump 60 , and a material container 80 . An input 61 of the metered pump 60 is connected to a chemical or biological material within the material container 80 while an output 63 of the metered pump 60 is connected to the sump 100 . The metered pump 60 periodically pumps a measured amount of chemical or biological material from the material container 80 into the sump 100 . An empty container 80 may be quickly and easily replaced with a full container 80 . Other plumbing fixtures, such as a sink 110 , for example, may be located in proximity to the sump 100 and connected to the sump 100 via one or more drain pipes 112 . The metered pump system 10 advantageously fits underneath the sink 110 to save space. Moreover, the metered pump system 10 is easily movable and may be repositioned based upon special considerations or other factors. Furthermore, the metered pump system 10 may be connected to the drain pipe 112 in addition to the septic sump 100 , if desired.
[0019] FIGS. 2-4 illustrate the metered pump stand 20 in more detail. The metered pump stand 20 includes a main panel 22 having a front or first surface 24 and a back or second surface 26 opposite the first surface 24 . The main panel 22 may also includes a bottom edge 25 , a top edge 27 , and a pair of side edges 29 . In the embodiment of FIGS. 2-4 , the main panel 22 takes on a roughly rectangular shape. However, other embodiments may have other shapes, such as, for example, square, circular, triangular, oval, polygonal, etc., based on spatial considerations or other factors.
[0020] The metered pump stand 20 has a pair of feet 28 extending outwardly from the first surface 24 , near the bottom edge 25 . Other embodiments may have more or less than two feet. For example, other embodiments may have one, three, four, five, or more feet. The feet 28 in this embodiment are generally rectangular in shape having a length that is greater than a height. However, other embodiments of the metered pump stand 20 may have feet 28 with other shapes, or other relative dimensions. For example, other embodiments may have feet 28 that have a height that is greater than a length, or the feet 28 may be triangular in shape. Regardless of size or shape, the feet 28 stabilize the metered pump stand and counter any moment created by the weight of the metered pump 60 when the metered pump 60 is mounted on the first surface 24 , as illustrated in FIG. 1 .
[0021] A pair of guide rails 30 extends outwardly from the first surface 24 along the side edges 29 . The guide rails 30 may be integral with the feet 28 , as in the embodiment illustrated in FIGS. 2-4 . However, other embodiments may include guide rails 30 that are separated from the feet 28 . Still other embodiments may not have guide rails 30 . Regardless, the guide rails 30 of the embodiment illustrated in FIGS. 2-4 help position the metered pump 60 on the first surface 24 by guiding the metered pump 60 into a correct mounting position. Additionally, the guide rails 30 may at least partially protect the metered pump 60 from impact damage, especially when moving the metered pump stand 20 , or when changing the material container 80 . In the embodiment of FIGS. 2-4 , the guide rails 30 do not extend completely to the upper edge 27 of the main panel 22 . However, other embodiments may include guide rails 30 that extend completely to the upper edge 27 , or the guide rails 30 may terminate at any point between the feet 28 and the upper edge 27 .
[0022] An upper flange 32 extends outwardly from the second surface 26 near the upper edge 27 of the main panel 22 . The upper flange 32 may include an opening 34 that is sized to receive a spout or mouth 86 (see FIG. 6 ) of the material container 80 . When the metered pump stand 20 is attached to a material container 80 , the mouth 86 of the material container 80 extends through the opening 34 and the opening 34 stabilizes the metered pump stand 20 with respect to the material container 80 while allowing an input of the metered pump 60 to access material in the material container 80 through the mouth 86 of the material container 80 . The moment created by the weight of the upper flange 32 when the metered pump stand 20 is standing freely is countered by the moment created by the feet 28 . The feet 28 extend outwardly farther from the first surface 24 than the upper flange extends outwardly from the rear surface 26 . In the embodiment of FIGS. 2-4 , the feet 28 extend approximately twice as far from the first surface 24 as the upper flange 32 extends from the second surface 26 . In other embodiments, a single foot may extend outwardly from the first surface 24 at the bottom edge 25 in a mirror image of the upper flange 32 .
[0023] The first surface 24 also includes one or more mounting structures, such as a mounting pin 36 . The mounting pin 36 may fit into a complementary recess in a rear side of the metered pump 60 when the metered pump 60 is mounted on the metered pump stand 20 . Other mounting structures are possible in other embodiments of the metered pump stand 20 . For example, other embodiments may use mounting shelves, mounting fasteners, mounting hooks, etc. However, the mounting structures should releasably secure the metered pump 60 to the first surface 24 .
[0024] Turning now to FIG. 5 , a metered pump 60 is illustrated attached to the metered pump stand 20 . The metered pump 60 includes a pump body 62 having a front surface 64 , a back surface 66 , a top surface 68 , a bottom surface 70 , and two side surfaces 72 . The pump body 62 in this embodiment takes on a cubic shape. Other embodiments may have pump bodies of different shapes. For example, other embodiments may have pump bodies 62 that are rectangular cubes, circular, oval, and irregular shapes.
[0025] The metered pump 60 also includes an input device, such as a timer 74 , by which a user may program a specific pumping schedule. For example, a user may set the timer 74 to pump a metered amount of material into the septic system every two days. Other pumping schedules are possible depending on the needs of the particular system. The pump body 62 also includes a power switch 76 to turn the metered pump 60 on or off. A material input/output hose 78 is connected to a source of material in the material container 80 at one end, and the sump 100 or drain 112 at the other end. The metered pump 60 draws chemical or biological material in from the material container 80 through an input hose and pumps the chemical or biological material into the sump or drain through an output hose. The input and output hoses may be flexible hoses made of plastic or rubber, or the input and output hoses may be more rigid hoses made of PVC or metal, for example.
[0026] FIG. 6 illustrates a metered pump system comprising a metered pump stand 20 with a metered pump 60 mounted on the first surface 24 and a material container 80 located proximate the second surface 26 . The material container 80 includes a container body 82 , a handle 84 , and an opening or spout 86 . The container body 28 may be generally cube-shaped in this embodiment. However, other shapes are possible in other embodiments. For example, other embodiments may have cylindrical, spherical, pyramid, cone, or parallelepiped shaped container bodies 82 . Regardless, the upper flange 32 of the metered pump stand 20 may rest on top of a ledge 88 in the material container. The spout 86 of the material container may extend through the opening 34 in the upper flange 32 to further stabilize and support the metered pump stand 20 . Although not illustrated in FIG. 6 , a securing nut may be threadably engaged with the spout 86 to sandwich the flange 32 between the securing nut and the ledge 88 if desired.
[0027] The disclosed metered pump stands and systems advantageously provide greater spatial flexibility and portability over prior art metered pump systems. Moreover, the disclosed metered pump stands and systems may be easily customized to particular septic or sewer systems. For example, different metered pumps and/or material containers may be interchanged with one another to provide different capabilities while using a common metered pump stand.
[0028] Although certain metered pump stands and metered pump systems have been described herein in accordance with the teachings of the present disclosure, the scope of the appended claims is not limited thereto. On the contrary, the claims cover all embodiments of the teachings of this disclosure that fairly fall within the scope of permissible equivalents. | A metered pump system periodically pumps measured amounts of chemical or biological material into a septic or sewage system. The metered pump system includes a metered pump stand having a main panel with first and second sides, a top edge, a bottom edge, and a pair of side edges. A pair of feet extends from the first side of the main panel near the bottom edge. An upper flange extends from the second side of the main panel near the top edge. A metered pump may be attached to the first side of the main panel. The upper flange of the metered pump stand is disposed above a portion of a material container that supplies chemical or biological material to the metered pump. The disclosed metered pump system is customizable by interchanging components while using the same metered pump stand. | 5 |
TECHNICAL FIELD
[0001] The present invention generally relates to a method of constructing a supporting architectural structure, or structural frame, having the form of an arch. The invention is generically applicable to arch structures in lattice or shell form, in which the main structural forces are resolved into compressive forces, in particular to arch bridges, (e.g. supported deck arch bridges, suspended deck arch bridges, tied arch bridges, etc.) to large arched buildings, tunnels, galleries and temporary supporting structures.
BACKGROUND
[0002] For the purposes of the present, the terms “supporting structure” and “structural frame” designate the load-resisting sub-system of a construction (architectural structure), i.e. the part of the construction that transfers and possibly absorbs the main load through interconnected structural components or members.
[0003] Supporting arch structures, in particular of arch bridges, belong to the oldest engineered forms of construction and have played a fundamental role in the development of all advanced societies. For many centuries, arch bridges were constructed from masonry, which conditioned the manner and methods of construction to such an extent that, even with the advent of the industrial revolution, the first iron bridges were constructed as arch (i.e. compressive load-carrying) structures. The introduction of modern materials permitted the adaptation of arch bridges for longer spans. The development of high-strength tensile steel in the twentieth century made it possible to construct arch bridges with spans of hundreds of meters especially by means of transferring the reaction forces away from the abutments to the bridge deck itself (tied arch bridges).
[0004] The traditional construction materials for structural components are concrete, steel and—nowadays to a lesser extent—wood. In the second half of the twentieth century, a new class of materials, fibre-reinforced polymers or plastics (FRP), slowly began to be considered as potential candidates as construction materials for addressing the limitations of concrete, wood and steel structures. These composite materials are most interesting for the construction industry due to their high strength, low weight and high corrosion resistance. Nevertheless, in spite of the continual reduction in their prime material cost, FRPs still remain relatively expensive in general, even when this handicap is offset on the long term by generally low life cycle cost.
[0005] The use of FRP in bridge construction has produced a number of interesting solutions for deck systems, described, for instance, in patents U.S. Pat. No. 6,108,998, U.S. Pat. No. 6,170,105 and U.S. Pat. No. 6,455,131. However, although the potential (in terms of their mechanical properties) for the use of FRPs materials in long-span bridges is very high, the current material prices and the lack of production methods capable of producing the large components at acceptable market prices has restricted the spreading of such materials in bridge construction, particularly for single spans in excess of ten meters. Although, in principle, the use of cheaper FRPs (such glass-fibre reinforced composites, GFRC) is an acceptable option for short spans or long pedestrian bridges, GFRCs have a rather low specific modulus which precludes them from use in stiffness-dominated bridge applications whenever spans in excess of a tens meters are called for. Of course, long bridges made from FRPs are viable if they are multiply supported; however, in certain locations, multiple supports are not always physically possible or are too expensive to implement. For these reasons, current construction and installation practice has only resulted in medium-length multi-span or short, single-span, beam bridges.
[0006] In civil engineering applications, there is a need for cost-efficient construction methods for erecting supporting structures, in particular with medium and long spans.
[0007] WO 90/13715 A1 discloses a method of constructing an arched building structure that uses lightweight elongate frames, pivotally connected to each other at one end, wherein the frames are lifted simultaneously so that the pivotal connection forms a ridge of the building structure. The free ends of the frames are anchored at abutments while the frames are held in the lifted position to form a three-pin arch frame building structure. U.S. Pat. No. 4,143,502 describes another method of constructing an arched building structure, wherein an elongate structural frame is bent into parabolic shape by lifting the medial portion thereof and fixing the opposed ends of the structural frame on abutments. When the ends are fixed, the flexed frame supports itself thanks to the abutments.
BRIEF SUMMARY
[0008] to the invention provides an alternative cost-efficient construction method for erecting an arched supporting structure.
[0009] According to the invention, in a method of constructing a supporting structure (of an architectural construction such as e.g. a bridge or the roof of a building) in arched form, an initially straight or pre-curved frame structure, having a first end and a second end opposite to the first end, is pivotally supported at the first and second ends, whereupon the first and second ends are pushed towards one another to achieve a displacement of the first and second ends relative to one another. The reduction of the distance between the first and second ends causes them to pivot and the frame structure to progressively and flexibly bend, against its resiliency, into a final arched form. The displacement of the first and second ends relative to one another is chosen to amount to at least 1% of the initial distance between the first and second ends. The first and second ends are then fixed relative to one another in their displaced position so as to preserve the final arched form of the frame structure. The arched supporting structure is kept in place by suitable containments of the arch reaction forces, either at the abutments (or building foundations), or in case of a tied arch, by tension in a structural component (e.g. the deck in case of a tied arch bridge) linking the first and second end of the frame structure. An arched supporting structure erected according to the present method may be considered a “deployable” supporting structure in the sense that its constituent structural components generate an arch upon the application of a force provided by an actuated mechanism. The frame structure is preferably configured such that its bending takes place over substantially the entire length between the ends of the frame structure.
[0010] It should be noted that the term “frame structure”, as used herein, is intended to cover, among others, a girder, a girder assembly, a beam, a beam assembly, or whichever structure that is to able to serve as a load-carrying structure when bent into an arched form as described above.
[0011] It should also be noted that the arched supporting structure achievable with the present invention might be part of the final construction or building. However, it is also possible that the supporting structure is only temporarily used during the construction stage, e.g. as a falsework.
[0012] According to a preferred variant of the method, there are at least two frame structures (hereinafter referred to as the first and second, possibly third, etc. frame structures), which are bent into arch shape. In this variant, each of the first and second frame structures comprises an extrados surface (i.e. a surface lying radially outward when the frame structure is bent) and an intrados surface (i.e. a surface lying radially inward when the frame structure is bent). The second frame structure is caused to progressively bend concomitantly with the first frame structure in such a way that one of the intrados and extrados surfaces of the first frame structure contacts the other of the intrados and extrados surfaces of the second frame structure at the latest when the first frame structure is in its final arched form. The second frame structure is then fixed to the first frame structure at the meeting surfaces so as to prevent relative movement between them. Such fixing of the second to the first frame structure is preferably achieved by gluing and/or with flanges. The second frame structure is preferably of the same configuration as the first frame structure. Accordingly, if reference is made hereinafter to a frame structure without that it is specified which one of the at least two frame structures is meant, the statement applies to any or all of the at least two frame structures, unless something different follows from the context. As those skilled will appreciate, by using relatively shallow frame structures, which are joined together, it is possible to reach significantly higher buckling capacities. On the other hand, by using a single frame structure having the dimensions of several shallow frame structures joined together, the material will fail much earlier for the bending strains at the intrados and/or extrados sides exceeding the tolerances.
[0013] According to a preferred embodiment of this variant of the invention, prior to bending, the first and second frame structures are arranged such that one of the intrados and extrados surfaces of the first frame structure is adjacent the other of the intrados and extrados surfaces of the second frame structure, a layer of glue being arranged between the adjacent surfaces. The progressive bending is carried out while the glue has not set so that the first and second frame structures are allowed to slide along their lengths while they bend. The fixing of the second frame structure to the first frame structure comprises letting the layer of glue set while keeping the first and second frame structures immobile with respect to one another when the first frame structure is in its final arched form.
[0014] According to a preferred embodiment of the method, the frame structure comprises fibre-reinforced polymer elements extending from the first end to the second end. Compared to other construction materials, FRPs exhibit very high strain-to-failure limits. In the case of glass-fibre-reinforced composites (GFRC) such FRPs come even with a competitive price. Those skilled will appreciate that other materials may be chosen, provided that such materials are able to withstand the considerable bending stresses occurring in the frame structure when it is bent into its arched shape. The FRP elements can be made using a variety of techniques, but the most attractive (and cheapest) solution is to use tubes or prismatic profiles that can be easily manufactured using filament-winding or pultrusion techniques, respectively. It is also possible to form the frame structure from sandwich panels, which are assembled flat on the construction site, cross-raced, and then bent into the desired curvature.
[0015] Experimental and analytical calculations have revealed that a curved FRP arch member would support working strain well in excess of the limits of steel or reinforced concrete members. For example, curved arch members made from FRP can be subject to an unloaded strain of the order of 0.2 to 0.3% just from the imposed curvature, whereas construction steel would yield at approximately 0.1% strain, making it impossible to generate the desired curvature without generating plastic deformations. It is expected that, under full load, the supporting structure could have a service strain of the order of 0.3 to 0.4% and a failure strain in excess of 1%, which is considered an adequate safety margin.
[0016] If a pre-curved frame structure is to be used, it could be made from a plurality of segments of uniform curvature fabricated by means of the same mould. The segments could be joined on the construction site to form the initially pre-curved frame structure. By using an initially arched frame structure, one may arrive at more pronounced arch heights than with an initially straight frame structure. It should be noted that the initial distance between the ends of the supporting structure would be measured along the straight segment between the ends (not along the initial arch).
[0017] Given that FRP supporting structures are, in principle, much lighter than such structures made from traditional materials like concrete, steel or wood, FRP supporting structures have the potential to substantially reduce construction costs and to be applicable to soil conditions where standard construction would otherwise require more extensive, and expensive, soil foundation.
[0018] Joining of FRP elements to form the frame structure could be carried out e.g. by using a vacuum-assisted resin-transfer moulding (VARTM) technique or in the case of profiles by connecting the pultruded profiles using standard joining techniques known to practitioners skilled in the art.
[0019] In a particularly advantageous variant of the invention, the frame structure is provided as a hollow fibre-reinforced polymer formwork for concrete or high-strength mortar. When the first and second ends are fixed relative to one another in their displaced position, concrete may be poured into the formwork. As the concrete sets, it increases the overall capacity and stability of the arched supporting structure. This variant addresses, in particular, applications in which the supporting structure has to carry high loads. There has been some concern over the safety of tied-arch bridges because the ties can be classified as fracture-critical members. A fracture-critical member is one that would cause collapse of the bridge if it fractured. Since its tie resists the horizontal thrust of a tied-arch, most tied arches would collapse if the tie were lost. One solution to mitigate the possibility of this type of collapse with the arch bridge system is to increase the overall capacity and stability of the arch by using e.g. hollow tubular elements as formwork that is filled with poured concrete. It should be noted that the formwork may remain in place after the concrete or mortar has set (in which case the resulting supporting structure comprises both the set concrete or mortar and the formwork), or, alternatively, be removed so as to leave only the concrete structure.
[0020] According to a preferred embodiment of this variant of the invention, the frame structure comprises steel and/or fibre-reinforced polymer rebar within the formwork. The formwork and the reinforcement placed therein, are subjected to bending at the same time. The reinforcement, being confined inside the formwork follows the curvature during the raising stage of the method. Once the arch has been erected and fixed, the formwork may be filled with concrete or high strength mortar. Again, the formwork may be removed after the concrete or mortar has cured, or remain in place.
[0021] The first and second ends are preferably pivotally supported about a first and a second pivot axis, respectively, these pivot axes being substantially parallel to one another and substantially perpendicular to the displacement of the first and second ends relative to one another. In such configuration, the bending of the frame structure takes place parallel to a plane that is perpendicular to the pivot axes. It should be noted that the pivot axes may be horizontal (resulting in a vertical arch) but may also be inclined with respect to the horizontal plane (in which case the arch will be inclined with respect to the vertical plane containing the first and second end of the frame structure). Preferably, the forces exerted on the first and second ends to push them towards one another are transferred to the frame structure via the pivot axes.
[0022] Preferably, the first end is pivotally supported by a first stationary swivel provided as part of a first abutment while the second end is pivotally supported with an actuatable swivel and pushing the first and second ends towards one another is carried out by the actuatable swivel pushing the second end and said stationary swivel exerting an opposite reaction force on the first end. Actuators suitable for actuating the actuatable swivel are e.g. actuators currently used in the push-forward bridge launching technique. Preferably, the actuatable swivel is guided on rails (fixed to the ground). When the second end has reached its desired position, the actuatable swivel is preferably fixed in a stationary position so as to become part of a second abutment, opposed to the first abutment.
[0023] Preferably, the displacement of the first and second ends relative to one another amounts to at least 2%, preferably at least 3%, more preferably at least 5%, possibly even at least 10% or at least 15%, of the initial distance between the first and second ends. Most preferably, the relative displacement amounts to around 5%, e.g. from 2% to 8% of the initial distance between the ends. To give an idea about the resulting arch heights, the following table summarizes the raise of the centre of the frame structure caused by such displacements of the ends relative to one another in case of an initially straight, horizontal frame structure in case of a perfectly parabolic shape when bent.
[0000]
Displacement in % of
Arch height in %
arch length
arch length
1
6.12
2
8.65
3
10.59
5
13.65
10
19.24
15
23.46
[0024] Hence, given an initially straight, horizontal frame structure having a length of 100 m between the points of application of the compressive forces at the ends and assuming a perfectly parabolic shape of the resulting arch, a relative displacement of the ends toward one another of about 5 m will lift the centre of the frame structure by about 14 m. Of course, the flexibility of the material of the frame structure has to be chosen in accordance with the desired bending to avoid failure of the material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Further details and advantages of the present invention will be apparent from the following detailed description of several not limiting embodiments with reference to the attached drawings, wherein:
[0026] FIG. 1 is a lateral view of a straight beam before it is bent into an arched form;
[0027] FIG. 2 is a lateral view of the beam of FIG. 1 when bent into the arched form;
[0028] FIG. 3 is an illustration of the method according to the present invention applied to a braced structure;
[0029] FIG. 4 is a perspective view close-up of a T-joint of the braced structure of FIG. 3 ;
[0030] FIG. 5 is an exploded perspective view of the T-joint of FIG. 4 ;
[0031] FIG. 6 is a perspective view of a swivel for fixing an end of the frame structure to be bent into arched form;
[0032] FIG. 7 is perspective view of a modular composite deck system made from FRP beams and slotted FRP sandwich panels;
[0033] FIG. 8 is an illustration of the filling of an FRP formwork with concrete; and
[0034] FIG. 9 is a schematic illustration of the bending of a layered assembly of plural frame structures into an arched form;
[0035] FIG. 10 is a side view of an FRP I-beam as may be used in a frame structure to be bent according to the invention;
[0036] FIG. 11 is a side view of the I-beam of FIG. 10 when bent;
[0037] FIG. 12 is a perspective view of a bolted joint connecting two I-beam elements.
DETAILED DESCRIPTION
[0038] FIGS. 1 and 2 illustrates the general concept underlying the method of constructing an arched supporting structure. An initially straight beam 10 of tubular (rectangular, round, trapezoidal or other) cross section is mounted pivotally supported at its ends 12 , 14 . The pivot axes 16 are parallel to one another and perpendicular to the longitudinal axis 18 of the beam. ( FIGS. 1 and 2 show the longitudinal axis 18 and the pivot axes 16 to be horizontal; however, this is not necessary in general.) A stationary swivel 20 pivotally supports the first end 12 of the beam 10 . The stationary swivel 20 is firmly anchored in the ground so as to form a first abutment of the arched supporting structure to be constructed. The second end 14 of the beam 10 is pivotally supported by a movable swivel 22 , guided on rails (not shown in FIGS. 1 and 2 ) extending along the direction of the longitudinal axis 18 of the beam. An actuator 24 (e.g. a hydraulic or other actuator as commonly used in incremental bridge launching technique) is arranged to push the movable swivel 22 into the direction of the stationary swivel 20 at the first end 12 of the beam 10 .
[0039] Before pushing the movable swivel 22 , a small initial curvature (if not already present) is generated in the beam 10 . The initial curvature is chosen such that the bending goes into the desired direction. When the actuator 24 pushes the movable swivel 22 into the direction of the stationary swivel 20 and thus the second end 14 towards the first end 12 of the beam 10 , the distance between the ends 12 , 14 decreases. As the beam length remains substantially the same, the beam 10 bends under the applied load and assumes an arched form. The distance between the first and second ends 12 , 14 is measured between the pivot axes 16 . The displacement of the first and second ends 12 , 14 relative to one another is calculated beforehand, in accordance with the desired span and arch height and the static requirements. It is emphasized that the relative displacement of the ends 12 , 14 is significant in the sense that it is not merely a displacement that leads to a pre-stressing of the beam 10 , as commonly used e.g. on arched concrete structures to compensate for sagging moments, but one that results in a significant displacement of the beam centre off the longitudinal axis 18 . In particular, the relative displacement of the ends amounts to at least 1% of the initial distance between the first and second ends 12 , 14 . The process of displacing the first and second end 12 , 14 toward one another may be done in steps if the desired displacement is larger than the stroke length of the piston: the movable swivel 22 is then temporarily anchored in the ground or otherwise held in position, while the actuator 24 is brought closer. The next pushing step is then carried out essentially in the same way as the previous one after the movable swivel 22 has again been released.
[0040] When the desired arch curvature is reached, the movable swivel 22 is fixed in a stationary position relative to the swivel 20 at the other end of the beam 10 . This may be achieved by fixing the movable swivel 22 to a previously prepared foundation, a socle or other support firmly anchored in the ground. Additionally or alternatively, the swivels 20 , 22 may be tied to one another (as in case of a tied arch bridge) e.g. via a tie beam extending along the straight line between the ends of the arched beam. In case of a tied arch, the outward-directed horizontal forces of the arch, are at least partially borne as tension by the tie beam, rather than by the ground, the foundations or other supports the arched supporting structure rests upon.
[0041] The frame structure (in the above example: the tubular beam) is preferably made from fibre-reinforced polymer (FRP) elements, such as e.g. elements made of glass, carbon or aramid fibre reinforced composites, In the case of an arch being formed in the manner of the variant using intrados/extrados concommittant surfaces, it could also be possible to use high-strength aluminium or steel alloys or any material that could accommodate the bending strains.
[0042] FIG. 3 illustrates a variant of the method according to the invention, wherein the frame structure comprises a braced structure 30 with two initially straight longitudinal beams 32 arranged in parallel one to the other and a plurality of transverse beams 34 linking the longitudinal beams 32 . The framework is completed by diagonal steel bars, rods, or cables 36 , which make the framework more resistant against longitudinal shear stress. As the different views of FIG. 3 show, the frame structure is bent into arch shape in essentially the same way as the beam of FIGS. 1 and 2 . The first end of each longitudinal beam 32 is pivotally mounted on a stationary swivel 38 , whereas the second end of each longitudinal beam 32 is mounted on a movable swivel 40 , guided on a rail 42 . By progressively increasing the loads (illustrated by arrows 44 ) on the second end of each longitudinal beam 32 , the initially slightly curved longitudinal beams 32 bend upwards until the frame structure finally reaches its planned curvature.
[0043] Instead of a tubular beam 10 as in FIGS. 1 and 2 or a braced structure 30 as in FIG. 3 , the frame structure could also comprise a cutout panel or shell. The tubular elements of the longitudinal and transverse beams 32 , 34 in FIG. 3 could be made using a filament winding process, or with arbitrary-shaped profile sections that could possibly be made using, for example, pultrusion techniques.
[0044] Preferably, the beam elements are made to a length that is acceptable for transport and are joined on the construction site using, for example, vacuum-assisted resin transfer moulding or slot-in connectors 46 (as shown in FIGS. 4 and 5 ). In the case of the tubular beam elements being slotted into the T connectors, the structural strength of the resulting joint can be increased by applying adhesive between the overlapping surfaces of the connector elements and the beam elements. Once joined, the beam and connector elements form the flexible frame structure that is then placed over the span to be bridged and locked into abutments on either side.
[0045] FIG. 6 shows an example of a swivel 50 for fixing the frame structure at its ends, usable as the stationary or the movable swivel. The swivel 50 comprises a base 52 and a sleeve portion 54 , which is pivotally fixed to the base 52 . The sleeve portion 54 is dimensioned such that the first or the second end of the supporting frame may be inserted into it. The base 52 is fixed to a foundation (if it is used as the stationary swivel) or a sliding train (if it is used as the actuatable swivel). Once the frame structure has reached the final curvature and required span, the rotation about the pivot axes of the first and second ends is fixed by blocking the sleeve portion 54 with linchpins 56 and the movable swivel is also fixed to a foundation, e.g. with bolts.
[0046] FIG. 7 shows a modular composite deck assembly 60 made from FRP beams 62 and slotted FRP sandwich panels 64 . When the supporting structure is in place, the deck assembly 60 may be suspended from it by means of cables. Another possibility is to suspend a light deck from the supporting structure before the latter is raised, so that when the arch forms, the deck is automatically lifted into position. Given that the buckling load of an arch depends non-linearly on arch curvature, the arch will initially only be capable of supporting a small fraction of the ultimate buckling load. Therefore, in this case the deck is preferably initially made from a lightweight composite box-beam, which is fitted with the heavy road-surface stratification once the final shape of the arch has been reached.
[0047] To increase the overall capacity and stability of the supporting structure, the support frame is preferably configured as a hollow formwork, into which concrete may be poured and allowed to set. Such a support frame is illustrated in FIG. 8 . The support frame comprises tubular formwork elements 70 having arranged in their interior a steel or fibre-reinforced polymer rebar and stirrups 72 . When the support frame is bent during the raising stage, the steel or FRP rebar 72 is forced to follow the curvature of the arch being generated. After the arch has been erected and fixed, the formwork is filled through openings 74 , provided in the formwork shell, with concrete 76 or high-strength mortar. Once the concrete 76 or mortar has set, the supporting structure is capable of supporting much higher loads than before. To further enhance the capacity of the supporting structure, a hogging moment may be induced in the set concrete or mortar by a further displacement of the ends of the supporting structure towards one another. However, such further displacement would be much smaller than 1% of the initial distance between the ends because the concrete or mortar would fail otherwise. Filling the formwork with reinforced concrete could increase its buckling capacity by a factor of about 2 to 3, depending on the quality of the concrete or mortar used.
[0048] As shown in FIG. 9 , it is also possible to compose the supporting structure from a plurality of sequential overlapping frame structures (e.g. flat tubes/profiles). Each of the frame structures has a relatively shallow section in the bending direction, so that the distance from the intrados and extrados surfaces to the respective neutral axis are small. Assume that one bends a square-section tube or profile with a height of 1 m in bending direction in such a way that the height-curvature imposes a strain of 3000 microstrain. If one bends a shallower tube or profile having a height of ⅓ m in bending direction to the same curvature, the resulting bending strains are approximately three times smaller. If three such shallow tubes or profiles 80 , 82 , 84 are placed on top of one another and bent up to the same arch height as the tube of 1 m height, whilst they are allowed to slide along their lengths as they rise up, the buckling capacity of the assembly would only be given by the individual shallow tube or profile sections (which is much smaller than the buckling capacity of the 1 m square section tube). If however, the shallow tubes or profiles are joined along their meeting surfaces after they have reached their final shape, the buckling capacity of the assembly becomes approximately the same as that of the 1 m square section tube or profile.
[0049] The shallow tubes or profiles have each an intrados surface and an extrados surface. As they are progressively bent concomitantly with one another, the intrados surfaces are compressed while the extrados surfaces are stretched, which locally results in relative movement between meeting surfaces, i.e. between the intrados surface 90 of the middle tube or profile and the extrados surface 88 of the lower tube or profile as well as between the extrados surface 92 of the middle tube or profile and the intrados surface 94 of the upper tube or profile. Once the tubes or profiles have reached their final positions, they are fixed to one another by gluing and/or with bolted flanges. Preferably, layers of glue are applied between adjacent meeting surfaces when the shallow tubes or profiles 80 , 82 , 84 still have their initial shape and the bending is carried out while the glue has not yet set and allows the meeting surfaces to locally slide one with respect to another while they bend. In this case, the layers of glue are simply let set while the shallow tubes or profiles 80 , 82 , 84 are kept immobile with respect to one another when they have reached their final arched form. Additionally, flanges may be used to bond and bolt the shallow tubes or profiles 80 , 82 , 84 together. Of course, the assembly of shallow tubes or profiles 80 , 82 , 84 might serve as a formwork for concrete or mortar, depending on the application.
[0050] As illustrated in FIGS. 10-12 , the frame structure to be bent into arch form according to the method of the present invention may be assembled from FRP I-beam elements 98 (sometimes also referred to as H- or double-T-beam elements), assembled together with bolted joints 100 . The use of such profiles instead of hollow tubular profiles may be advantageous in case the frame structure of the construction needs not be filled with concrete or mortar. | In a method of constructing a supporting structure (e.g. of a bridge or the roof of a building) in arched form, an initially straight or pre-curved frame structure, having a first end and a second end opposite to the first end, is pivotally supported at the first and second ends, whereupon the first and second ends are pushed towards one another to achieve a displacement of the first and second ends relative to one another, where the reduction of the distance between the first and second ends causes them to pivot and the frame structure to progressively and flexibly bend, against its resiliency, into a final arched form, the displacement of the first and second ends relative to one another is chosen to amount to at least 1% of the initial distance between the first and second ends, where the first and second ends are then fixed relative to one another in their displaced position so as to preserve the final arched form of the frame structure. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Benefit is hereby claimed to U.S. provisional application Ser. No. 62/074,676, filed Nov. 4, 2014, the contents of which are incorporated herein by reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The instant invention relates to systems of variable light-transmitting coverings for building exteriors which will permit selective visibility from inside the building while rejecting solar heat and while minimizing the amount of heat that is radiated into the building by the solar heat rejecting apparatus. Additionally, the instant system will provide a blanket covering the building, thus, providing a thermal blanket as well as a shell for security purposes.
[0004] 2. Description of the Related Art
[0005] Louvered panel systems for cladding an outside wall are known in the art. For example, WO2013036112 relates to an outside wall cladding element. The outside wall cladding element comprises a structure of a panel-shaped material and fastening elements to be mounted on the outside wall, in which the panel-shaped material comprises a zigzag or wave-shaped element, and is provided with a side comprising a light-absorbing layer and another side comprises a light-reflecting layer.
[0006] U.S. Patent No. 20110214712 teaches a solar window shade which includes a frame for supporting louvers for shading at least one window of a building. Preferably, the frame is pivotally connected to the building above the window, and a frame drive system selectively pivots the frame upwardly or downwardly in accordance with the elevation of the sun. A louver drive system rotates the louvers within the frame to track east-to-west movements of the sun. The louvers are preferably provided as outer and inner louvers interlaced with each other, and such louvers nest with one another when the sun is hidden, or approaches from an acute angle, to maximize passage of indirect light rays to light the interior, while minimizing obstruction of the view through the window. The device is modular and is easily applied to aligned rows of windows and/or windows on multi-story buildings, with central control of the associated frame drive and louver drive systems.
[0007] U.S. Pat. No. 8,342,224 shows an architectural louver shade assembly comprising a shade canopy mounted to a rotatable central axle tube that supports a rod rib assembly to which the shade canopy is attached by adjustable tensioners that mechanically stretch and tension the fabric element of the shade canopy to remove wrinkles and sags. A wax cylinder piston attached by elements of a wax piston pressure system that changes the pitch of the shade canopy in response to temperature with a gas spring unit that returns the shade canopy to its default, horizontal orientation with decreasing temperatures. An optional manual/mechanical system that, through use of control cables, changes the pitch of the shade canopy with a gas spring unit that returns it to a default orientation. A camber cable assembly that maintains an equal compression load on the rib arm units that directly support the shade canopy, and carrier brackets that support the central axle tube and connect the louver shade assembly to a building wall.
[0008] U.S. Patent Publication No. 20110214712 describes methods, apparatus, and systems relating to the use and design of specially shaped, rotating reflective louvers to provide cost effective harvesting of electricity, heat, and/or lighting are described. In an embodiment, the reflected and concentrated direct light is focused on the neighboring louver photovoltaic cells to generate electricity and an integral cooling channel allows heat collection. A skylight embodiment permits the indirect light to pass between the louvers and through a transparent backing providing high quality natural light inside while allowing artificial lights to be dimmed or turned off saving energy. In some embodiments, control systems (that may be computer controlled) can modulate the louver position to improve the light transmitted into the build-ing when appropriate to maximize the net energy saved or generated depending on the situation. Moreover, the devices can be retrofitted into existing buildings or integrated into new building construction.
SUMMARY
[0009] In general, what is described herein is a system of building cladding which incorporates specially-designed louvers and/or roll-down shutters, and which accomplishes the goals of providing excellent solar heat rejection and night-time building insulation value and security while presenting a new and desirable building aesthetic.
[0010] It is the objective of the instant invention to provide an improvement on existing louver systems by providing a modular unit which can be installed as a unit or in an array, covering a complete wall if desired. These modules can be installed over either existing or new curtainwall or other acceptable building structures.
[0011] It is further an objective to provide modules designed to operate either manually or electrically, in both cases being controlled from inside the building.
[0012] It is further an objective to provide an assembly of louver blades which can swing away from the underlying glass to expose the glass for cleaning, repair, or replacement. In one embodiment the module is connected to the vertical support mullion by way of a hinge. As a result the module can be swung away from the vertical support mullion, thereby exposing the underlying glass.
[0013] Accordingly, described is a building envelope, comprising a vertical support mullion on one side of a building structure; a module attached to the vertical support mullion using a hinge, wherein the module is adapted to swing away from the vertical support mullion; a drive means including a gear system housed within the module and a drive shaft connected through the building structure; one or more cladding elements connected to and operable by the drive means; and, wherein the cladding elements can rotate in a vertical plane, and the complete module can swing away from the vertical support mullion to expose or cover an underlying glass surface. The cladding is coupled to the drive means using a coupling assembly which is biased by a spring and which includes a coupling groove in which a blade shaft within the module can seat to thereby rotate in response to the drive means, thus moving a worm gear assembly which then moves the louver blades (cladding elements) of the system.
[0014] The cladding can be a roll-down shutter or louver (cladding elements) system, and each louver can be coated with a heat-reflective coating material. Additionally, each louver blade can rotate around a y-axis while the module in which the louver is fixed can swing in an XY plane away from the vertical support mullion to partially expose or cover the underlying glass surface, as further described.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 shows an elevation view of the instant system.
[0016] FIG. 2 shows a top plan view of three modules with one of the modules shown rotated, or swung, on its hinges into an open, locked position to allow access to the glass wall.
[0017] FIG. 3 shows a top plan view of a typical glass curtainwall mullion, the vertical support mullion of the new system, the main frames of the modules, the cladding elements or louvers, the inside and outside drive shafting and the geared mechanisms which rotate the cladding elements.
[0018] FIG. 4 shows a top plan view of an array of cladding with the vertical support mullion, portions of three modules (one shown in the open [locked] position) and a sub-figure shows a rotating clip means for securing a module in the open (locked) position.
[0019] FIG. 5 shows a cross-sectional view of the louver blades including an alternate contact method.
[0020] FIG. 6 shows a cross-sectional view of alternative embodiments of the louver blade contact method.
[0021] FIG. 7 shows a vertical section through an array of gears and a toothed belt the slave gears of which each are connected to and drive a louver blade.
[0022] FIG. 8 shows a section through the vertical plane of an alternate embodiment using roll down shutters in lieu of louvers.
[0023] FIG. 9 is a rendering in perspective illustrating how the modules, as described herein, may appear as an array covering an entire building.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] With reference then to FIG. 1 , shown are six modules of potentially many of the instant building envelope, including one typical module 6 which is a perimeter frame that captures an array of cladding elements 8 , here louver blades 26 . These are modular units for installation over either existing or new curtainwall or other acceptable building structures. As an example only, these modules (units) are typically 3′-5′ wide, which is the width of common curtainwalls, and 10-ft. to 12-ft. high, similar to floor-to-floor height of most commercial buildings, although other dimensions are likely. Shown in FIG. 1 is an array of cladding elements 8 of modules 6 clad with either an array of multiple louver blades 26 , or roller shutters 25 (or shades), thus “building envelope” means one or more of any of the cladding elements 8 , arrays or arrangements therefor. Additionally, as it relates to all components, “a” as used in the claims means one or more. Each module 6 would cover an exterior wall/underlying surface. The underlying surface 11 in this example is glass. The frame of the module 6 is typically aluminum. The louver blade array 8 and the roller shutters 25 are typically aluminum or painted steel. Both the louver blade array 8 and the roller shade 25 units can be coated on the outer-facing surfaces with a coating material, typically paints, which reject or reflect solar energy. The coating on the interior-facing surfaces is a material which tends to not reflect heat, thus, saving the building from “feeling” the heat radiated from the louver blades themselves.
[0025] Referencing now FIGS. 2-4 , the building envelope is shown in part, being comprised of curtain wall mullions 1 and vertical support mullions 2 . The frames 2 a and 2 b of module 6 hold louver blades 26 and are attached to vertical mullion 2 by hinge(s) 7 . They may be installed as individual units or in arrays. The curtain wall mullion 1 would be on the interior side of the building structure 5 and would aesthetically house a driving mechanism, as further described. In this example, the building structure 5 is a curtain wall, although any wall or building structure 5 is intended and by this definition also encompasses pre-existing or newly fabricated walls. The vertical support mullion 2 would be on one side, here the opposing, exterior side of the building structure 5 which is used to support most of the components of the building envelope. Since the system can be installed over building structures 5 , either new or existing, vertical support mullion 2 is either fabricated or pre-existing. In this embodiment vertical support mullion 2 is generally L-shaped as shown. It fastens to the curtain wall mullion 1 but then extends outward to hold the hinge(s) 7 which then hold the framing module(s) 6 .
[0026] The module framing would have a top and bottom framing member and a left and right side framing member, in particular left vertical frame 2 a and right vertical frame 2 b. Such side designations are based on observing a complete module 6 from the outside. Positioned at and connected to each right vertical frame 2 b would be hinge 7 . At both left vertical frame 2 a and right vertical frame 2 b the modules 6 are structurally similar, but at one of the sides, modules 6 act as a housing for drive components, whereas on the other side, module 6 simply houses the pivots for the left end(s) of the louver blades 26 . Shown here, right vertical frame 2 b is attached to the vertical support mullion 2 using hinge(s) 7 . As a result, the module 6 is adapted to swing away from the vertical support mullion 2 .
[0027] Still with reference at right vertical frame 2 b, a drive means (for moving the cladding 8 ) includes a worm gear assembly 23 housed within this frame 2 b and a drive shaft 12 which connects through building structure 5 . The worm gear assembly 23 is operable by drive shaft 12 . Drive shaft 12 has an inner shaft end 13 and an outer shaft end 14 . A crank 20 for hand-operating the drive means can be attached to inner shaft end 13 , or the drive means can be operated electrically by providing any type of drive motor. FIG. 1 shows a typical motor location 21 for a drive motor (typical position shown in FIG. 1 ). The connection of the motor to the gear assembly is not shown but this method is well known in the industry.
[0028] Outer shaft end 14 is engaged to a coupling assembly 15 . Thus, coupling assembly 15 is disposed between the module frame 2 b and the building structure 5 as shown. Coupling assembly 15 includes a coupling 16 . The coupling 16 can slide along outer shaft end 14 , constrained by spring 18 which rests against washer 19 . A coupling groove 17 is defined within coupling 16 .
[0029] A worm and sprocket gear assembly, or gear system 21 a, is housed on gear shaft 22 . Although a variety of gears and arrangements can be employed, shown here is a gear system 21 a which is driven by gear shaft 22 . Gear shaft 22 incorporates a blade end which is shaped to fit within coupling groove 17 of coupling 16 . The worm gear assembly 23 via blade shaft 23 a operates sprocket assembly 24 rotationally. Sprocket assembly 24 drives connected louver blade 26 via blade shaft 23 a in a rotational fashion. Thus, as motor 21 (See FIG. 1 ) or crank 20 operates drive shaft 12 , louver blade 26 can be rotated completely up to 360 degrees and beyond. Of note is that as a result of the above configuration, the blade shaft 12 is essentially spring-loaded so it will only drive gear shaft 22 upon fitting into coupling groove 17 . Movement of shaft 12 in the inner direction is possible if spring 18 is compressed. Such compression will occur if module 6 is swung closed via hinge 7 and when nearly in the closed position the blade end of gear shaft 22 encounters the sloped surface of coupling 16 and forces coupling 16 and drive shaft 12 inward. This will allow the closing of a unit even if the gear shaft 22 and coupling groove 17 do not align. At a later point in time, a person inside the building can simply turn the crank 20 and the gear shaft 22 will snap into the coupling groove 17 when they are aligned.
[0030] Now, with continued reference to FIGS. 3 and 4 but now at left vertical frame 2 a, a stop 3 extends from vertical support mullion 2 . Stop 3 positions left vertical frame 2 a (of module) when left vertical frame 2 a is rotated on hinge 7 to the closed position. A cushion 4 is adhered to stop 3 , to reduce the impact when frame 2 a is returned to its closed position. A typical module 6 , if not locked, is free to rotate on hinge 7 with vertical frame 2 a separating away from stop 3 . Recall that the same module 6 is hingedly attached to vertical support mullion 2 . The entire module 6 and thus vertical frame 2 a can easily be released and rotated (move away from vertical support mullion 2 ) through the X-Y plane constrained by hinge 7 . As such, the underlying glass surface 11 can be at least partially exposed (partially or entirely) accessed for repair, replacement, or cleaning. More particularly, each louver blade 26 has a right end 9 engaged to the drive means at the right vertical frame 2 b wherein the louver blade 26 can rotate around a Y-axis that passes through the blade shaft 23 a and the sprocket assembly 24 parallel to building structure 5 , i.e. the worm gear assembly 23 to drive shaft 22 . Each louver blade 26 has a left end 10 opposite its right end 9 which is adapted to swing away from and towards the stop 3 . Thus, vertical frame 2 b rotates on hinge 7 , while the other vertical frame 2 a also rotates but moves a greater distance circumferentially because it is located farther from the hinge point. Therefore, each louver blade 26 can both rotate (around the Y-axis of blade shaft 23 a ) and can swing (180° through X-Y plane).
[0031] Locking clip(s) 30 can be employed, for example on the left side of a typical module 6 , where security latching is made to the adjoining vertical support mullion 2 via clip 30 to secure that left side such that the unit cannot swing open on its hinges. See FIG. 4 for example. Means for maintaining the cladding in an aligned position includes any type of clip 30 that can latch on to and mate with a neighboring clip, post, or anchor.
[0032] Referencing now FIGS. 5-8 , in the case of the cladding/units which are comprised of louver blades 26 , in one embodiment the blades 26 are designed with an elastomeric seal 27 , i.e. weather-stripping or gasket, on one edge of each louver blade 26 . When the louvers are in an aligned position, the elastomeric seal 27 on one louver blade 26 is compressed slightly when touching the adjoining edge 28 of the adjacent louver blade 26 . That adjoining edge 28 is rounded so as to allow the elastomeric seal gasket to move into the compressed position easily when the alignment of the louver blades 26 is desired (see option 1 of FIG. 5 ).
[0033] An alternate configuration for the louver blades 26 is one in which each blade 26 overlaps the other slightly. In those cases, a similar elastomeric seal 27 is attached to one end of one louver blade 26 where it makes contact with the adjoining louver blade (see option 2 of FIG. 5 ).
[0034] Still another embodiment is one in which the edges of the louver blades 26 , where they adjoin, are designed in a “hook” fashion, thereby forming a hook-shaped edge 29 so that the edge of one blade 26 grips the edge of the other blade 26 in the event of an impact to one or both of the blades (see option #3 of FIG. 6 ).
[0035] Still another embodiment is one in which any of the blades 26 has its cavity filled with foam insulation 33 (see option #4 of FIG. 6 ). This is of particular value when the outer face of the louver blade becomes heated, for example, due to sunlight, and the desire is to not transfer that heat to the other side of the louver blade 26 . Foam insulation is also advantageous for purposes of creating a thermal blanket for the building when the louver blades 26 are completely closed with blade edges 31 overlapped, for example, at night and is further advantageous for strengthening the louver blade array of cladding elements 8 .
[0036] Referencing now FIGS. 7 and 8 , shown is a section through the vertical plane of the sprocket assembly 24 and showing one method for driving multiple louver blades 26 using a toothed belt 32 . In this instance, the sprocket assembly 24 is simply a number of sprockets which are driven by a worm gear assembly 23 . FIG. 8 shows a section through the vertical plane of an embodiment with roll down shutters 25 in lieu of louvers, so here “drum 34 ” is a rotating drum that will extend or retract roller shutters 25 . The rotating drum 34 is driven by a mechanism such as worm gear assembly 23 and is contained within a top housing 21 b (see also FIG. 1 ).
[0037] The system offers aesthetic value, for example, to an architect. If used in an array, it presents a façade which is different from more common facades and, further, which can be dynamic to the extent that the appearance of the building may change on any given day, depending on the extent to which various louvers are closed or rotated into a non-closed position or, in another embodiment, roller shutters are positioned at differing levels. Even more dramatic is a case where the louver blades 26 are painted a different color on each side. In that case, the color of the side of the building changes in each localized area, depending on which way the louvers are oriented.
[0038] In yet another embodiment, electric lighting fixtures 35 may be positioned between the module(s) and the building structure 5 , typically supported by vertical mullion 2 . See FIG. 3 . The lighting has the advantage of providing light penetrating the underlying glass 11 which relates the lighting to the penetration of natural lighting from the atmosphere, an aesthetically pleasing feature. The location of the lighting, when viewed from the exterior of the building, will cause the entire building to glow in various amounts in various places, depending on how the louver blade arrays 8 are set.
[0039] FIG. 9 is a rendering illustrating how the modules, as described herein, may appear as an array covering an entire building, thus providing partial shading, as desired, by module, plus a thermal overcoat and an aesthetically desirable appearance. As illustrated in FIG. 9 , the top row of modules are roller shades, as described above, whereas the remainder of the building is clad with louvered modules also as described above. | A building envelope or cladding system which permits selective visibility from inside the building while rejecting solar heat and providing an optional insulative envelope. A vertical support mullion is on one side of a building structure. A module is attached to the mullion using a hinge, wherein the module is adapted to flip away from the mullion. A drive means includes a gear system housed within the module and a drive shaft connected through the building structure. One or more cladding elements is connected to and operable by the drive means. As a result, the cladding elements can both rotate and flip away to expose or cover an underlying glass surface. Each module is coupled to the drive means using a coupling assembly which is spring-biased to thereby rotate the cladding elements, thus modifying the effects of the sun and other ambient factors on the state of the building. | 4 |
[0001] Priority is claimed to German Patent Application No. 100 64 521.6-43, which is hereby incorporated by reference herein.
BACKGROUND INFORMATION
[0002] The present invention relates to plastic films having color effects for treating everyday objects, in particular, for the surface coating of vehicle bodies and building facades, as well as a method for manufacturing them.
[0003] The paint finish of a motor vehicle and of other objects represents an important sign of quality. In addition to the technical requirements of corrosion protection and mechanical stability, the choice of color and the optical quality of the paint finish are intended to convey individuality, prestige, and design aspects.
[0004] However, the technical possibilities for producing specific effects are very limited. In addition to standard paint finishes, so-called metallic finishes are available today which contain finely distributed metal particles and which as a result yield a shinier finish.
[0005] Further possibilities arise if, instead of the simple metal flakes, coloring particles are embedded. One familiar approach is to provide plate-shaped particles made of glass or glimmer (mica) with interference-capable layers and therefore to achieve a direction-dependent color impression. Products of this type have been offered for years by the companies Merck and BASF, among others, and have established themselves above all in the application areas of cosmetics, packing products, advertising, design, etc. In the vehicle area as well, these developments have led to interesting results, which can be seen again and again at professional fair exhibits or which are manufactured in limited numbers, but which heretofore have not been introduced as a mass- produced paint finish. The main reasons for this are the relatively high costs for manufacturing the interference layer and preparing it as pigment. Further typical disadvantages are the color fidelity and reproducibility of these methods. It should be noted in general that the manufacturing costs of the pigment rise sharply as quality and reliability improve and that they rapidly reach prohibitive levels in large-surface applications.
SUMMARY OF THE INVENTION
[0006] An objective of the present invention is to provide high-quality surface coatings, which make it possible to produce novel color impressions and designer effects and which are suitable for rational production methods of large surfaces.
[0007] The present invention provides a decorative plastic film for the surface treatment, in particular of vehicle bodies and building facades, wherein the film has a micro- or nano-scale structure, micro- or nano-scale particles ( 4 ) being introduced in uniform shape, size, and orientation into a transparent polymer substrate ( 3 ), and the optically perceptible effect is produced exclusively or substantially by optical effects in the collective arrangement of the particles ( 4 ).
[0008] The solution according to the present invention lies in generating the color effect, in particular, direction-dependent colorings, or a direction-dependent darkening of a clear film substrate solely or largely using structural effects. Known methods employ conventional color pigments, i.e., substances for which a typical color, a specific degree of reflection, or an interference effect can be assigned to the individual particle on the basis of its size (in particular, much larger than the length of a lightwave) and its chemical composition. In contrast to this, the present invention is based on optical effects in nano-scale or micro-scale particles, which have no inherent color due to their dimensions (comparable or smaller than the length of the lightwave, i.e., specifically, smaller than one micrometer or in the order of magnitude of one micrometer), but which only produce the desired effect on the basis of their collective arrangement. Examples of color impressions of this type, which are mainly generated by the form and size of particles and less as a result of their material qualities, are the dispersion in the smallest particles having minimal extinction (the blue of the sky), the dispersion in larger particles having greater extinction (intensive colors of gold colloids), interference in combined layered media, and birefringence and dichroism in oriented rod-shaped particles.
[0009] If the present discussion involves nano-scale or micro-scale particles or structures, it should be understood thereby that at least one structural dimension of these particles or structures lies in the nano- or micrometer range, and below, for simplicity's sake, will be termed “microstructures.”
[0010] Although the aforementioned classical phenomena are generally known, they are not technically available for decorative coatings of larger objects because it has heretofore not seemed possible to introduce the particles into a paint layer or plastic film in a simple and controllable manner in a suitable size, form, concentration, and orientation.
[0011] One advantage of the present invention can also be seen in the fact that the surface treatment is achieved by applying a prefabricated film, this film being manufactured on the basis of semifinished films, film-like paint layers, polymer or paint layers applied to substrate films, or similar configurations. It is easy to see that an automated manufacturing process of a film makes possible an incomparably greater degree of color homogeneity and reproducibility than an individual dipping or injection method, especially if complex solid pigments having a defined orientation and concentration are to be embedded. Especially in vehicle construction, cost advantages and greater flexibility with regard to future ecological requirements are possible using prefabricated films in place of conventional vehicle painting.
[0012] The methods for manufacturing the color-effect films according to present invention include a plurality of steps, involving both transfer techniques as well as application techniques. The first step concerns the production of a suitable micro- or nano-scale structure on an auxiliary surface or a master (matrix). Subsequently, the transfer of the structural elements onto a film-like polymer substrate takes place (transfer) or, alternatively, only the structural information is applied to a polymer substrate (replication). Further optional method steps can be carried out for strengthening the optical effects and for the secondary treatment and further processing of the polymer substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The various method steps are described in greater detail below by way of example and on the basis of schematic drawings. The following are the contents:
[0014] [0014]FIG. 1 a replication method for manufacturing the color-effect film according to the present invention in five method steps:
[0015] a: aluminum layer 1 having porous oxide 2
[0016] b: shaping a mold 4 having rod-shaped surface 5
[0017] c: hot stamping a polymer substrate 3
[0018] d: removing the polymer substrate having pore-like recesses 7
[0019] e: embedding color particles 4 .
[0020] [0020]FIG. 2 a transfer method for manufacturing the color-effect film according to the present invention, having the method steps:
[0021] a: aluminum film 1 having porous oxide 2
[0022] b: embedding particles 4
[0023] c: partial removal of oxide layer 2
[0024] d: bonding to polymer substrate 3
[0025] e: removing aluminum film 1 together with the residual oxide layer.
DETAILED DESCRIPTION
[0026] According to the replication method depicted in FIG. 1, in step a, a uniform surface structure is produced. In principle, for generating the finest uniform structures, the known lithographic structuring methods can be used on the basis of x-ray and electron beam irradiation. However, methods that are based on self-organizing mechanisms may be more suitable for the present objective; these mechanisms generally do not yield strictly ordered structures, but they can be applied in a cost-effective manner to larger and more complexly shaped surfaces. As a preferred example, the generally known anodic oxidation of aluminum (aluminum layer 1 in step a) and other metals should be mentioned. By appropriately choosing the electrolyte and the other anodizing parameters, an oxide layer 2 having very regular cylindrical pores 6 can be produced. The attainable structural dimensions, i.e., the separation and the diameter of the pores, are between roughly 10 nm and 1 micrometer, i.e., in the wavelength range in which the cited optical effects occur.
[0027] Subsequently (FIG. 1, b), the structural information of the aluminum oxide layer is transferred to a mold suitable for the subsequent production steps, i.e., a press roll or a tool mold 8 . This occurs in accordance with known molding techniques, e.g., electroforming, it being advisable to observe the methods and measures customary in this specialized area with respect to material selection, pre- and post-processing, surface coating, etc., although they are not further mentioned here. From the pore-like surface of the starting layer, a rod-shaped negative image 5 arises in the mold surface.
[0028] For transferring the microstructure of the mold onto a polymer substrate, a plurality of possibilities can be considered:
[0029] hot stamping a film in continuous operation (FIG. 1, step c);
[0030] injecting into a mold, which carries the micro-structured surface, having a thermoplast;
[0031] filling a micro-structured mold or a calender using a monomer or partially cross-linked polymer and subsequent polymerization using chemical, thermal, or UV starters, as well as combinations;
[0032] transferring the microstructure in a press or stamping process. The structured mold surface, in this context, functions as a roll-shaped pressure matrix so as to apply a liquid or pasty substance to the polymer substrate, which subsequently is brought into contact with a monomer. Depending on the material pairing of polymer substrate and monomer, the substance to be imprinted is selected so as to have either strongly cross-linking (adhesive agents) or strongly decross-linking properties (release agents). On the basis of the surface effects, droplet-like structures are created, which are polymerized in accordance with known methods, and in this way a 3-dimensional replication or negative form of the matrix arises.
[0033] Differing variants and combinations of these basic methods, generally known from plastics technology, are also applicable.
[0034] Well-suited as materials for the polymer substrate, on account of their processability, optical properties (transparence), and stability, are especially plastics such as PMMA (polymethyl methacrylate) and PU (polyurethane), but also polymers such as PE (polyethylene), PP (polypropylene), PVC (polyvinyl chloride), PC (polycarbonate), PET (polyethylene terephthalate), PVDF (polyvinylidene floride), polyester, ABS (acrylonitrile-butadien-styrene), ASA (acrylonitrile-styrene-acrylester). Copolymers of these compounds also can be considered.
[0035] In the next treatment step, after being removed from the tool mold (FIG. 1, d), the surface structure embedded in the polymer substrate is used to form the actual coloring particles, for which purpose there are also a multiplicity of approaches available. On the basis of substrates that are available in film form, suitable for this process step are, for example, vacuum coating methods, i.e., vapor deposition or cathode sputtering, which yield very cost-effective and uniform coatings in continuous operation. In this context, it is important to introduce substances whose refractive index n deviates significantly from that of polymer substrate matrix 3 , i.e., preferably highly-refractive oxidic, semiconducting or metallic materials, it being important that absorption coefficient k (the imaginary part of refractive index) not lie at too high a level, to avoid excessive light absorption in the coating. As a result of the choice of material and of the coating thickness, the most varied color tones and effects can be achieved, the optical effect beginning even in metals in the form of very thin films of a few atom layers. Rare metals, in particular gold, yield very strong color effects due to their special optical constants that are coupled to electrical conductivity, but the method is in no way limited to these classes of material. Suitable above all are transparent metal oxides having a higher refractive index such as Al 2 O 3 , Bi 2 O 3 , CeO 2 , Fe 2 O 3 , In 2 O 3 , SnO 2 , Ta 2 O 5 , TiO 2 . The oxides can be used directly as starting materials for the coating process, but it is often more expedient from the process engineering point of view to vaporize or to sputter the corresponding metals and subsequently to oxidize them in the gas phase or after the deposition. In the case of some metals and at lower coating thicknesses, this occurs spontaneously in response to the presence of air. Similarly well suited as a starting material for coloring particles are semiconductors such as Si and Ge due to their favorable optical constants (high n/k ratio) and advantages in the area of coating engineering.
[0036] The aforementioned powerful absorption effect of metals can also be exploited in the meaning of the present invention. This effect arises most of all when metals in the form of fine fibers and having small numerical density are embedded, which succeeds as a result of the controlled adjustment of the aluminum oxide matrix (large pore distances) and of the vaporizing of small material quantities (slightly diagonal with respect to the pore axis). Structures of this type, viewed vertically, demonstrate no particular color effect, but they darken in response to an increasingly planar angle. In connection with a standard color paint coating underneath, interesting optical effects are also generated, in particular in response to directed incident light or solar radiation (colored-hueless-transition).
[0037] As a process-engineering variant for vacuum coating, a special form of the chemical deposition of metals can be used (step e). As is customary in the electroplating of plastics, first the surface to be coated is activated using an ionogenic or colloidal solution containing palladium. On activated palladium seeds it is possible subsequently to deposit larger metal particles 4 chemically, i.e., without current. These methods are particularly effective in the meaning of the present invention for depositing isolated structural elements, because the germination in the recesses of the molded nano-structured surface can be processed in a very controlled and uniform manner because of capillary forces. Further steps such as reducing and fixing the palladium seeds, surface rinsing, re-etching the deposited metal particles, inter alia, can be used to influence the shape, size, and number of the embedments and thus to modify the resulting color impressions. For the technical applications of the currentless metallization, metals such as copper and nickel are generally used. In addition, the solution according to the present invention can also have recourse to other metals that can be chemically deposited, because only small quantities of material and short process times are necessary in these cases, for example rare metals or elements from the above-mentioned material groups such as indium and tin, and their subsequent conversion into the corresponding oxides.
[0038] Alternatively to the coating of a molded polymer substrate, it is also possible according to the present invention to use other methods. If, for example, the structured surface is filled out with or joined to a second transparent polymer substance and the substance possesses a higher refraction index than the substrate film, then, similarly, color effects are created on the regularly arranged border areas as a result of interference. A similar effect is achieved by an arrangement in which the structured film is directly bonded to a planar base, so that regular nano-scale air pockets arise. The color contrasts that can be achieved in this way are not as intensive as when metals or oxides are used, but they are well suited for emphasizing or setting off conventional colors and finishes, which can be used in lower layers.
[0039] Further possibilities arise if the color-determining elements are produced not on the pre-structured plastic substrate but rather already on the auxiliary substrate, and subsequently are embedded in the polymer substrate in collective form (transfer method). An exemplary method in this regard is depicted in FIG. 2. Initially, as was described above, a nano-structured auxiliary layer is produced (step a) preferably using anodic oxidation of thin aluminum film 1 or of an aluminized plastic film. Then metal needles, e.g. made of nickel, tin, indium, or zinc, are embedded in the pores of oxide layer 2 using electroplating methods (step b). Rare metals such as gold, platinum, silver, inter alia, are also suitable, it being possible for them to undergo epitaxial growth in the form of thin-wall tubes if the process is managed appropriately. The deposition process is terminated as soon as the metal needles or tubes extend substantially (roughly 100 nm or more) beyond the surface of the oxide mask, but before they grow together into a solid layer. This is not successful in the case of all metals or the case of very fine pores; in these cases, the oxide mask after the metal deposition can be partially etched away chemically (step c), so that a layer composed of free-standing metal particles also arises. Optionally, a partial or complete transfer of the metal particles into the oxide phase can be carried out (in the case of very fine structures, this occurs under certain circumstances spontaneously in the air), e.g., using a subsequent anodic oxidation or a plasma treatment in an oxidizing atmosphere. The auxiliary substrate then is bonded to transparent polymer substrate 3 by gluing, melting, welding, laminating, etc., techniques (step d), and subsequently (step e) the aluminum film including the (residual) oxide skin is mechanically separated or chemically etched away.
[0040] In accordance with the rules of optics, it is necessary in designing the color-producing structures to observe specific boundary conditions. In using very small particles (in comparison to the wavelength of visible light), the particles in the polymer matrix form a so-called composite medium, i.e., a layer zone, to which a homogeneous effective refraction index can be assigned. This effective refraction index results, in accordance with known mixing formulas, from the optical constants of the partners; in metal embedments the result in this manner is a relatively high refraction index and absorption coefficient, in the case of oxides and semiconductors, it is an average one, and in the case a purely organic mixed structures or air pockets, it is an especially small refraction index. In one medium of this type, it is possible to produce a color effect by interference, if the layer density in relation to the wavelength takes on specific values that are a function of the effective refraction index. Depending on the type and density of the embedments, the layer must therefore be set at a specific density that is capable of generating interference. In replication methods, this takes place via the density of the aluminum oxide matrix, i.e., the pore depth, or the height of structure in the mold, and in transfer methods, it takes place via the height of the free-standing structural elements. In the case of larger particles, dispersion effects increasingly come to the fore, overriding the interference effect.
[0041] The polymer substrate provided with color-determining structures through replication or using a transferred layer is subsequently further processed and applied in accordance with customary methods such as deep drawing, back spraying, laminating, gluing, heat treating, radiation curing, etc., which cannot be described here in detail. Because the color effects according to the present invention are primarily brought about by dispersion and interference, suitable bases are above all black or dark finishes or surfaces. Brighter backgrounds send back a greater light component, which overrides the dispersed and reflected light beams from the embedded particles and weakens the color contrast. In the case of finely distributed metal structures, which tend to produce a direction-dependent shadow effect, the color of the background is not so important, and here bright colors can also be used.
[0042] Because the color effects described are linked to the collective arrangement of the embedded particles, the result is a further important feature of the present invention, which can be observed especially in the case of very small structural dimensions. As was mentioned above, the volume concentration of small particles is codeterminative for the effective refraction index of the composite medium, i.e., via the particle density it is also possible to control the spectral position and therefore the color of an interference layer, in contrast to conventional finishes. This becomes noticeable in biaxially curved surfaces, because as a result of the deformation a thinning of the material necessarily takes place. In addition to the aforementioned direction-dependent color effects, the result in this context is an additional form-dependent color and brightness shift on curved surfaces, which can be exploited very effectively, for example, in paint finishes of vehicle bodies. On the one hand, in the case of a discreet adjustment of the effect, an interesting emphasis of the vehicle shape (plasticity) is produced, and on the other hand, powerful contemporary color effects are also possible. As the particle size increases, the dispersion effects on the individual particles predominate over the collective effect of the medium, so that the percentage of the various phenomena as a result of the structural size can gradually be adjusted to the specific object and the desired overall decorative effect. | The present invention relates to a decorative plastic film for the surface treatment, in particular, of vehicle bodies and building facades. It has a micro- or nano-scale structure, in which micro-or nano-scale particles ( 4 ) are introduced in uniform shape, size, and orientation into a transparent polymer substrate ( 3 ), so that the optically perceptible effect is produced exclusively or largely by optical effects in the collective arrangement of the particles ( 4 ). | 1 |
FIELD AND BACKGROUND OF THE INVENTION
The invention relates to a mechanised longwall system for mining.
Mechanised longwall systems for mining are known of the kind including face roof support units disposed adjacent to each other along the longwall and connected via hydraulic advancing cyclinders to a face transport track laid along the length of the longwall, each unit comprising a floor element and a roof element supported on hydraulic props, the system further including a drift transport track arranged at and perpendicular to that end of the face transport track so as to extend into the drift in the conveying direction.
In these known mechanical longwall systems all the roof support units over the entire length of the longwall are of the same construction, and the working area formed at the junction between the face and the drift is timbered out with a large number of individual props made of wood or steel or with individual hydraulic props. This solution is not only very cumbersome and laborious, but it is also unfavourable from the safety point of view.
The mechanised supporting of the junction between the coal face and the drift is not only desirable for reasons of safety, but also to improve the air supply at the said location, to increase the cutting speed for the longwall and thus its productivity, to ensure the protection of the transfer and take-over sections of the face transport and drift transport devices, and to make possible the continuous advance of the cutter in the vicinity of the transfer section without additional fixing measures and supplementary means. The force which arises when cutting tends to lift the transfer section upwards, and this is commonly prevented by inserting props at each cut. This solution is laborious and unprofitable since a step, which is generally 70-80 cm long depending on the hardness of the coal, can only be cut with 4 to 5 cuts and repeated propping up.
SUMMARY OF THE INVENTION
An object of the invention is to provide a mechanised longwall system for mining, in which the junction between the mining face and the drift is provided with mechanised support units which can be moved together with the drive and reversing station of the face transport device in the same way as the longwall support units.
According to the invention, a mechanised longwall system for mining of the kind referred to above is characterized in that at least two drift supporting units are provided to be arranged in the drift adjacent to each other, in the said drift supporting units each have a supplementary floor element connected via a linkage to the front end of its floor element, in that a supplementary prop is connected via linkages between the supplementary floor element and the front end of the roof element, and in that the floor element and supplementary floor element of the outermost drift supporting unit (i.e. that unit of the two adjacent drift supporting units lying further from the face) are constructed so as to accommodate a take-over section and a reversing unit of the drift transport track, a transfer unit of the face transport track being arranged to project over the take-over section of the drift transport track, whilst the supplementary floor element of the outermost drift supporting unit accommodates a guide system for guiding the transfer unit in the longitudinal direction of the drift transport track, and a fluid operated advancing cylinder, one end of which is hinged onto the transfer unit while the other end is connected to the floor element and/or to the supplementary floor element of said outermost drift supporting unit.
In one preferred embodiment of the longwall system according to the invention the system which guides the transfer unit in the longitudinal direction of the drift transport track consists of a rail equipped with a head part, and a guide groove which accommodates the head part of the rail, and the rail is expediently constructed on the supplementary floor element of the outermost drift supporting unit.
According to a preferred feature of the invention, the transfer unit has a sliding carriage-type bearing member which bridges over the supplementary floor element of at least two drift supporting units, and the guide groove is defined in this bearing member.
In a further preferred feature according to the invention the bearing member has a guide attachment which fits that side of the supplementary floor element of said other drift supporting unit which is nearer to the mining face.
According to another advantageous feature the transfer unit is hinged onto the floor element and/or onto the supplementary floor element of said other drift supporting unit via an advancing cylinder.
Conveniently, the floor element and supplementary floor element of each of the drift supporting units are connected to each other via a connecting component which is constructed with articulations at both its ends. Thus, with a mechanised longwall system for mining according to the invention, the junction between the drift and the mining face is also equipped with mechanised supporting which is suitable for accommodating and anchoring or moving the drive head of the face transport track and the cutter in such a way that the cutter can be operated continuously during movement of the drive head without any danger of the drive head and the face transport track being drawn together. The entire gallery roof is clad above the drive motors. Behind the drift supporting units the gallery roof can be broken out in the normal way with a face supporting unit, and it is not necessary to leave behind a clad section of drift and subsequently to recover the cladding assembly. By using a system according to the invention the safety and productivity of the longwall are significantly increased.
In order that the invention will be readily understood, one preferred embodiment will now be described, with reference to the accompanying drawings in which:
FIG. 1 is a plan view showing two of the face supporting units of the longwall system and two adjacent drift supporting units which adjoin these face supporting units and are located in the drift,
FIG. 2 is a side view of the outermost drift supporting unit of the system shown in FIG. 1,
FIG. 3 is a perspective view of the two adjacent drift supporting units of the system shown in FIG. 1,
FIG. 4 is a section on line IV--IV of part of the outer face supporting unit and the two drift supporting units of the system shown in FIG. 1, and
FIGS. 5a-5e are a series of schematic plan views showing the separate phases of a preferred movement arranged for the system.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The system shown consits of conventional mechanised coal free supporting units 20 disposed adjacent to each other along the longwall 11 and connected via hydraulic advancing cylinders 12 (see FIG. 5) to a face transport track 10 which is laid over the length of the longwall 11. The supporting units 20 have a floor element 14 (see FIG. 4) and a roof element 18 supported by hydraulic props 16. The hydraulic props 16 are connected by their lower end to the floor element 14. The face supporting units 20 in this instance are generally of normal construction and, at the rear end of the floor element 14 of each unit a rear support element 15 is attached, on which a shield back 17 is hinged. The upper ends of the hydraulic props 16 and the roof element 18 are similarly hinged onto the shield back 17.
At the outer end of the face transport track 10 and perpendicular thereto a drift transport track 22 is arranged which extends along the drift 21. A takeover section 54 of said drift transport track is arranged partly underneath a transfer unit 55 formed at the end of the face transport track 10. A reversing unit 56 for the drift transport track 22 and also a drive 57 for the face transport track 10 are provided in line with the longwall 11. In this instance, the drive 57 is constructed as a front-end drive.
In the drift 21, two drift supporting units 24, 26 are arranged adjacent to each other and they adjoin the face supporting units 20. The inner space (i.e. the space defined within) of the drift supporting unit 24 is substantially clear, only the transport track 10 running through this inner space. The drive 57 and the transfer unit 55 of the face transport track 10, and also the take-over section 54 and the reversing unit 56 of the drift transport track 22 are arranged in the inner space of the outermost drift supporting unit 26 (i.e. that supporting unit which lies further from the mining face 11).
The rear part of each supporting unit 24, 26 is of a normal shield construction (in this embodiment, it will be appreciated that supporting units 20 are also constructed in this way), but the roof element 18 adjoining the shield back 17 is significantly longer than normal, and the roof element 18 is connected in the vicinity of its front end 28 via a linkage 30 to the upper end 34 of a supplementary hydraulic prop 32. Also at the front end 36 of their respective floor elements 14, a supplementary floor element 38 is connected via a connecting component 76, which latter is constructed with articulations at both its ends.
The rear end 40 of each supplementary floor element 38 is connected via a linkage 42 to its connecting element 76. A linkage 48, to which the lower end of each supplementary hydraulic prop 32 is connected, is constructed in the vicinity of the front end 44 of its respective supplementary floor element 38.
The floor element 14 and the supplementary floor element 38 of the outermost drift supporting unit 26 accommodate the take-over section 54 of the drift transport track 22, this being effecfted in such a way that the longitudinal axis of the take-over section 54 is parallel to the longitudinal axis of the floor elements 14, 38. The transfer section 55 of the face transport track 10 is disposed projecting out over the take-over section 54 of the drift transport track 22, and the drive 57 is disposed in between the props 16 and 32 with its drive axis projecting in the longitudinal direction.
The transfer unit 55 is arranged in the inner space of the drift supporting units 24, 26 in such a way that, above the supplementary floor elements 38 of the drift supporting units 24, 26, a bearing member 68 (see FIG. 4) constructed as a sliding carriage is disposed, having a guide system 58 on the supplementary floor element 38 of the outermost drift supporting unit 26 and a guide attachment 72 which fits on the nearer mining face side of the supplementary floor element 38 of supporting unit 24.
The guide system 58 which guides the bearing member 68 of the transfer unit 55 consists of the supplementary floor element 38 of the supporting unit 26, a rail 62 projecting upwardly from the parallel to the longitudinal axis of said supplementary floor element, and a guide groove 66 extending into the lower plate 70 of the bearing member 68. The rail 62 has a head part 64 and the guide groove 66 is constructed with a cross-section in the form of an inverted "L" so that the transfer unit 55 cannot be lifted off the rail 62. By means of the guide attachment 72 on the bearing member 68, the supplementary floor elements 38 of both supporting units 24, 26 are simultaneously prevented from moving away from each other and their parallel position is thus assured.
Between the transfer unit 55 and the supplementary floor element 38 of the outermost drift supporting unit 26 a hydraulic advancing cylinder 60 is inserted (see FIG. 3 and FIG. 5). Similarly, front and rear hydraulic advancing cylinders 74 (see particularly FIG. 5) are arranged between the supplementary floor element 38 and the transfer unit 55 and between said transfer unit and the floor element 14 respectively of the drift supporting unit 24.
In FIGS. 5a, 5b, 5c, 5d and 5e, the separate phase of the movement of the described system with respect to a coal face are illustrated.
In the phase shown in FIG. 5a the hydraulic advancing cylinders 12 of the face supporting units 20 are retracted. The transfer unit 55 of the face transport track 10 connected to the hydraulic advancing cylinders 12 is thus in its retracted position (in its rear location), within the inner space of the drift supporting units 24, 26. Also the rear one of the hydraulic advancing cylinders 74 of the drift supporting unit 24 (i.e. that lying nearer the coal face) is in its retracted position, whilst the front one is in its extended position, and the hydraulic advancing cylinder 60 located between the supplementary floor element 38 and the transfer unit 55 of the outermost drift supporting unit 26 is also in the extended position.
In the phase shown in FIG. 5b, the face transport track 10 has been moved forwards by extending the advancing cylinders 12. In this case the transfer unit 55 of the face transport track 10 inside the drift supporting units 24, 26 is in its advance position (in its front location), the front advancing cylinder 74 of the supporting unit 24 and the advancing cylinder 60 of the supporting unit 26 are in their retracted positions, while the rear advancing cylinder 74 of the supporting unit 24 is in its extended position.
In the phase shown in FIG. 5c the face supporting units 20 are moved forwards individually to the face transport track 10 by retracting the advancing cylinder 12, while the position of the drift supporting units 24, 26 remains unchanged.
In the phase shown in FIG. 5d, by extending the front advancing cylinder 74 and by retracting the rear advancing cylinder 74, the drift supporting unit 24 (lying nearer the face) is moved into alignment with the coal face supporting units 20, so that the transfer unit 55 is set to its rear position relative to the supporting unit 24, the position of the outermost drift supporting unit 26 remaining unchanged.
In the phase shown in FIG. 5e the outermost drift supporting unit 26 is moved into alignment with the face supporting units 20 and the drift supporting unit 24 by extending the advancing cylinder 60, while the transfer unit 55 is set to its rear position relative to the supporting unit 26, and the situation shown in FIG. 5a again prevails, except that the whole system has moved one step forwards.
The drift transport track 22 is constructed as a bridging transport device, and the section of it which is connected to the drift supporting unit 26 slides during the advancing movement on that section of it which lies in the drift 21, which latter section can e shortened according to requirements during the course of the advance. | A mechanized longwall system for mines is provided which includes face roof supporting units disposed along the longwall and connected to a face support track by hydraulic advancing cylinders, each unit including a floor and roof element, a drift transport track mounted perpendicularly to one end of the face transport track, including two drift supporting units coupled with hydraulic linkages to the face supporting units, a guide system arranged on one of the floor elements of the drift supporting units and guiding a transfer unit in the longitudinal direction of the drift transport track, the arrangement being such that shifting of a drift supporting unit is accompanied by a simultaneous shifting of the face conveyor apparatus. | 4 |
This application claims priority from U.S. Provisional Patent application ser. no. 60/937,309, filed Jun. 27, 2007.
The invention disclosed and claimed herein is a gasifier and gasifier system based on the gasifier, which contains as a major component, a novel feed system for feeding organic materials into the burn pile of the gasifier.
The invention is useful for gasifying solid organic materials and using such gasified products for conversion to thermal energy.
Materials that can be gasified using this invention include, among other materials, biomass materials, such as forestry and agricultural residues, industrial waste materials, such as saw mill pulp and paper products, hydrocarbon based products and plastics, and the like.
BACKGROUND OF THE INVENTION
It has been known in the art for a long time to use industrial and agricultural solid organic by-products, such as forestry an agricultural residue and the like, as potential sources of large amount of chemical energy. Such organic materials are frequently referred to as “biomass” materials. There is a large library of patents and other publications dealing with gasifiers (retorts) and associated systems for creating energy from biomass materials.
Patents dealing with such systems are for example, U.S. Pat. No. 4,971,599 that issued to Cordell on Nov. 20, 1990; U.S. Pat. No. 4,691,846 that issued to Cordell, et al. on Sep. 8, 1987; U.S. Pat. No. 4,593,629 that issued to Pedersen, et al. on Jun. 10, 1986; U.S. Pat. No. 4,430,948 that issued to Schafer, et al. on Feb. 14, 1984; U.S. Pat. No. 4,321,877 that issued to Schmidt, et al. on Mar. 30, 1982; U.S. Pat. No. 4,312,278 that issued to Smith, et al. on Jan. 26, 1982; U.S. Pat. No. 4,184,436 that issued to Palm, et al. on Jan. 22, 1980, and U.S. Pat. No. 5,138,957 that issued to Morey, et al. on Aug. 18, 1992.
However, none of these patents deal with a horizontal auger system to deliver feed material to a discharge elbow that discharges directly to a burn pile in the gasifier. The prior art deals with vertical auger units and most of them deal with a double vertical auger system. The disadvantage to the use of vertical augers is that the inside vertical auger cannot be repaired while the system is on-line, and they have a tendency to burn up at the tip when dry fuels are fired, or when there is an upset in the system. This problem has been completely eliminated by the use of a single, horizontal auger firing into a ceramic discharge elbow for discharging directly into the burn pile.
The gasifier of the instant invention is less costly to build and operate, easier to maintain, has fewer moving parts and contains nearly 100% ceramic internals to prevent warping and contortion of metal parts that are used in the prior art devices.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a low cost to build, low cost to operate, easier to maintain, and relatively simple gasifier and system. The gasifier is used in a gasification system to provide recovery of energy from feed stock of forestry and agricultural residues, such as industrial waste materials such a pulp and paper products, hydrocarbon based products, such as plastic and the like, by gasification of such materials with the inventive gasifier and employment of the inventive system disclosed herein.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a full side view of a gasifier of this invention.
FIG. 2 is a partial cross sectional side view of a portion of the gasifier of FIG. 1 , through line 2 - 2 of FIG. 4 .
FIG. 3 is a cross sectional view of a portion of the gasifier of FIG. 1 , through line 3 - 3 of FIG. 4 .
FIG. 4 is a full top view of a gasifier system of this invention.
THE INVENTION
Thus, in more detail, there is an improved gasifier system for pyrolizing organic material, the gasifier system comprising a gasifier having a cylindrical housing. The cylindrical housing has a steel sidewall and the sidewall is completely lined with a refractory material. The sidewall has a top and a bottom.
The top of the sidewall is closed and sealed with a monolithic dome, the dome comprising a steel-walled hemi-elliptical section. The hemi-elliptical section comprises a height to diameter ratio of at least 1 to 2 and the dome has a top and is completely lined with a refractory material. The dome has a syngas exit duct centered at the top and the bottom of the sidewall is fixed to a furnace bed.
There is a refractory lined ash removal system comprised of an air-locked ash removal auger, an ash lift conveyer and, an enclosed ash dumpster.
There is a refractory lined combustion system comprised of a tuyere plenum, a segmented ceramic combustion hearth contained in a refractory lined hopper, a tuyere manifold, a plurality of tuyeres leading from the tuyere manifold through the tuyere plenum to a burn pile area.
There is a retractable, all-ceramic lance ignition burner projecting from the outside of the tuyere plenum and through the tuyere plenum and into the segmented ceramic combustion hearth and above the burn pile area.
There is a refractory lined upper housing comprising the burn pile area and a feed system for feeding organic materials to the burn pile area. The feed system comprises a hopper for organic material, a conveyor for conveying organic materials to the feed hopper, and a horizontal auger contained in an auger housing for conveying organic material through a ceramic discharge elbow and into the burn pile area.
The auger housing connects the hopper and the discharge ceramic elbow, and the auger housing has a control valve associated with it to control air flow through the auger housing.
There is an air cooling system for the ceramic elbow and auger housing, and the air cooling system comprises an electrical fan and an air feed system, the air feed system comprising an air feed duct housed in a refractory lined housing.
The upper housing of the upper segment contains a burn pile height detector.
In addition to that Supra, there is contemplated within the scope of this invention to use a grate over the air-locked ash removal auger. Preferably this grate is a ceramic grate, and most especially, the ceramic grate is an oscillating ceramic grate system.
One of the major features of this invention is the gasifier feed system which is a horizontal auger driven feed system that feeds directly into the bottom without having to auger the feed through significant vertical elevations.
DETAILED DESCRIPTION OF THE INVENTION
Turning now to FIG. 1 wherein there is shown a full front view of a gasifier system 1 of this invention showing a refractory lined combustion chamber 2 having a cylindrical housing 29 wherein the cylindrical housing has sidewalls 30 ( FIG. 2 ) that are completely lined with a refractory material 27 ( FIG. 2 ), a feed hopper 3 , a litter feed conveyor 24 , a tuyere air manifold 4 , an oscillating ceramic grate 5 , an ash auger 6 , an ash lift conveyor 7 , an enclosed ash dumpster 8 , a tuyere plenum 9 , a lance ignition burner 10 , a combustion air fan 11 , a feed tube 12 ( FIG. 4 ), a feed tube housing 13 ( FIG. 4 ), a pile control detector 14 , a syngas exit duct 15 , and a control valve 16 . The cylindrical housing 29 has a top 31 and a bottom 32 , the top 31 being surmounted by a monolithic dome 33 having the syngas exit duct 15 mounted thereon (See FIG. 1 ).
The dome 33 has a hemi-elliptical section comprising a height to diameter ratio of at least 1 to 2 and the dome 33 is also completely lined with a refractory material (not shown).
FIG. 4 is a full top view of the gasifier system 1 of this invention wherein like numbers indicate like components, and FIG. 2 is a full cross sectional view through lines 2 - 2 of FIG. 4 .
The bottom 32 of the sidewall 30 of the cylindrical housing 29 of the combustion chamber 2 is fixed to a furnace bed, generally 34 , the furnace bed 34 comprises an upper segment 35 , a middle segment 36 , and a lower segment 37 .
As shown in FIG. 4 , the lower segment 37 is a refractory lined ash removal system comprising an air-locked ash removal auger 6 and an ash auger housing 17 for the ash auger 6 and a flange 18 that permits the retention and removal of the auger 6 from the ash auger housing for replacement or repair, an ash lift conveyer 7 , and an enclosed ash dumpster 8 .
In FIG. 2 , there is shown the components of the middle segment 36 which shows a fixed ceramic hearth 19 constructed of replaceable segments and a plurality of oscillating ceramic ash removal plates 20 located above the fixed ceramic hearth 19 . Situated above the oscillating ceramic ash removal plates 20 is the tuyere plenum 9 having side wall 21 , wherein there is located the retractable ignition burner 10 . Multiple tuyeres 23 are inserted through the side walls 21 and lead to a burn pile area, generally 40 in FIGS. 2 and 3 and the tuyeres 23 are fed air or other gas from the tuyere manifold 4 located on the outside of the furnace 34 . The tuyeres 23 can be changeable inside diameter tuyeres and can be zoned, manifolded or single plenum, as shown herein, to inject air or flue gas into the tuyere plenum 9 as required by pulsing, steady or varying flow of the burning mass described infra.
The housing for the tuyere plenum 9 the burning chamber 22 is constructed of insulated wear/temperature lining 26 , retained with stainless steel alloy “Y” anchors as shown at 25 and is line with insulated fire brick lining 27 . It should be noted in FIG. 2 that the combustion chamber 2 is constructed such that there is built into the walls thereof, a stabilizing reflective arch 28 . In addition, there is a retractable, all-ceramic lance ignition burner 10 projecting from the outside of the tuyere plenum 9 and through the tuyere plenum 9 and into the segmented ceramic combustion hearth and above the burn pile area 40 .
The novelty and essence of this invention is the delivery system for the burnable biomass material 41 . The upper segment 35 comprises a refractory lined upper housing 42 containing the burn pile area 40 . The upper housing 42 of the upper segment 35 contains a burn pile height detector 14 .
The feed system 43 , generally, comprises a system for feeding organic materials (biomass, litter, etc.) to the burn pile area 40 . The system comprises a hopper 3 for the biomass material 41 , a biomass material conveyor 24 for conveying the biomass 41 to the feed hopper 3 , an auger system 38 comprising a horizontal auger 44 contained in an auger housing 39 .
The auger housing 39 terminates inside of the furnace 34 in a ceramic feed elbow 45 that is directed upwardly from the terminal end of the auger housing 39 and allows the biomass material 41 to overflow and descend to the burn pile area 40 . The horizontal feed system 43 is possible because of the ceramic elbow 45 . It should be noted that the ceramic elbow 45 is preferred to be wider at the top 46 than at the bottom 47 to enhance the flow of biomass material 41 through the ceramic elbow 45 .
FIG. 3 also shows the accumulation of ash 48 and the general distillates 49 that are generated by the burning pile of biomass material 41 .
As can be observed from FIG. 1 , in addition to the tuyeres 23 , air is introduced into the furnace 34 through a duct 50 using an auxiliary fan 11 to enhance the burning activity in the furnace 34 . This provide for an air cooling system for the ceramic elbow 45 and auger housing 39 . This system is comprised of an electrical fan and an air feed system that is integrated and controlled by the gasifier. | A gasifier and gasifier system based on the gasifier, which contains as a major component, a novel feed system for feeding organic materials into the burn pile of the gasifier. The gasifier feed system is a horizontal auger driven feed system that feeds directly through a ceramic elbow into the furnace without having to auger the feed through significant vertical elevations. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is the U.S. national stage of PCT/EP2014/076914 filed Dec. 8, 2014, which claims priority of German Patent Application 10 2013 225 063.0 filed Dec. 6, 2013.
FIELD OF THE INVENTION
[0002] The invention relates to a connecting rod for a reciprocating piston internal combustion engine (also called an internal combustion engine (ICE) in the following text). In the case of said connecting rod, the gudgeon pin is mounted eccentrically in the small connecting rod eye. A variable compression ratio is also abbreviated in the following text as VCR; accordingly, the connecting rod according to the invention is also called a VCR connecting rod. Otherwise, the terms “conrod” and “connecting rod” are used synonymously in conjunction with the invention.
[0003] The main motivation for a variable compression ratio is a reduction in the fuel consumption. There are various alternatives for realizing a VRC. Important aspects during the selection of a suitable alternative are the required structural amendments to a conventional internal combustion engine and the costs.
BACKGROUND OF THE INVENTION
[0004] VCR conrods for realizing a variable compression in internal combustion engines belong to the prior art. DE-A-10 2005 055 199 describes a VCR conrod, in which the effective conrod length is brought about by way of rotation of an eccentric which is mounted in the small connecting rod eye. Here, the eccentric rotation is firstly brought about by the forces which act on the gudgeon pin during the operation of the internal combustion engine and secondly hydraulic forces on a supporting mechanism.
[0005] Said supporting mechanism limits the rotating speed of the eccentric and prevents undesired rotating back of the eccentric. The supporting mechanism which is known from DE-A-10 2005 055 199 consists of a pair of slider crank mechanisms on both sides of the eccentric, the pistons of which are supported in each case on fluid-filled supporting chambers. By way of a corresponding hydraulic connection of said supporting chambers, the desired reverse rotation lock and the desired braking action are realized.
[0006] One disadvantage of said VCR conrod is the increase in the (oscillating) mass in comparison with a conventional conrod. Moreover, the supporting mechanism, in particular the lever which is connected to the eccentric, requires a corresponding clearance in the interior space of the piston.
[0007] An adjustment toward high compression requires upwardly directed forces on the gudgeon pin, as occur during the phase of the gas exchange. That part of said gudgeon pin force which is caused by the centrifugal force increases as the square of the rotational speed. Conversely, the result of this is that the force which is available is reduced by the square of the rotational speed. As a consequence, the adjusting time increases greatly at low rotational speeds, as a result of which the thermodynamic potential of the variable compression can be used only incompletely in transient operation.
[0008] Moreover, DE-A-10 2005 055 199 discloses a reciprocating piston internal combustion engine having an adjustable variable compression ratio in a reciprocating piston by means of an actuating unit. The actuating unit is actuated by way of an adjusting mechanism, the adjusting mechanism having a rack and pinion drive. Here, the actuating unit and the adjusting mechanism are arranged outside a conrod of the reciprocating piston internal combustion engine. An arrangement of this type is very expensive and therefore requires a large amount of installation space in the internal region of the piston.
[0009] Furthermore, EP-B-1 496 219 describes an internal combustion engine with a variable compression ratio and DE-A-10 2012 014 917 describes a pressure pulse actuation means for a device for adjusting a variable compression ratio.
SUMMARY OF THE INVENTION
[0010] The object on which the invention is based consists in providing a VCR conrod which avoids the abovementioned disadvantages completely or at least partially.
[0011] According to the invention, this object is achieved in a connecting rod for an internal combustion engine comprising a large connecting rod eye, a small connecting rod eye, an eccentric with a bearing bore which is arranged eccentrically with respect to its external diameter for a gudgeon pin being configured in the small connecting rod eye, and means for supporting the eccentric in order to prevent a rotational movement of the eccentric relative to the connecting rod being provided, by virtue of the fact that the means for supporting comprise a rack and pinion drive and a double acting hydraulic cylinder which is coupled to the rack and pinion drive, the rack and pinion drive and the hydraulic cylinder being an integral part of the connecting rod.
[0012] The VCR conrod according to the invention has the following advantages over the prior art:
[0013] A merely low increase in the conrod mass, in particular in the oscillating mass; a lower installation space requirement, in particular in the internal region of the piston; lower mechanical loads of the supporting mechanisms; lower production costs and virtually constant adjusting times, even at low engine rotational speeds.
[0014] In one advantageous refinement of the invention, the eccentric has a toothing system which is concentric with respect to its external diameter and meshes directly or indirectly via an intermediate gear with a rack of the rack and pinion drive.
[0015] As a result, it is possible to integrate the actuating travel of the rack into the connecting rod in an optimum manner with a minimum installation space requirement and to adapt it to various applications.
[0016] By way of the intermediate gear, the rack can be displaced further in the direction of the large connecting rod eye, with the result that, in the case of the conrod according to the invention, the rack protrudes only a little beyond the conrod main body even in its extended end position.
[0017] In order that the engagement between the rack and the gearwheel or the external toothing system of the eccentric takes place precisely and without play, a guide face which interacts with a complementary groove in the connecting rod is configured on the rack.
[0018] As a result, a linear guide of the rack is configured in the connecting rod in a simple way, which linear guide is resilient and durable.
[0019] It is provided in one refinement according to the invention that a cylinder bore of the hydraulic cylinder is arranged in the connecting rod and is particularly preferably configured in the form of a precisely machined bore in the connecting rod. As a result, the material costs are saved and the installation space requirement for the double acting cylinder is minimized.
[0020] The cylinder has a piston rod with a piston, the piston rod being coupled at one end to the rack, with the result that, via the locking action of the piston in a desired position, the eccentric is therefore also at the same time locked or supported in the upper connecting rod eye. The actuating forces for rotating the eccentric do not have to be applied by the cylinder. Rather, it is the case that the mass forces which occur during operation of the internal combustion engine provide the energy which is required for rotating the eccentric. The cylinder serves via the rack and pinion drive merely to support the eccentric in such a way that it maintains the position which is provided by the engine controller.
[0021] The double acting cylinder is divided by way of the piston into an upper supporting chamber and a lower supporting chamber, the upper supporting chamber being sealed by way of a piston bushing, and the piston rod being guided sealingly through the piston bushing.
[0022] Here, in principle, every design known from the prior art of a double acting cylinder with a single or double piston rod can be used or can be adapted correspondingly to the application.
[0023] Furthermore, in one refinement according to the invention of the connecting rod, a first duct for supplying the upper supporting chamber with a hydraulic fluid and a second duct for supplying the lower supporting chamber are configured in said connecting rod.
[0024] In accordance with the requirements and other boundary conditions during the manufacture and construction of the connecting rod, said ducts can be configured as bores in the connecting rod. However, it is also possible in the case of screwed conrods that the fastening bore of the connecting rod is configured as a stepped bore and has a greater diameter at least in regions than the shank of the connecting rod screw. An annular duct section is then produced between the shank of the connecting rod screw and the bore.
[0025] Furthermore, it is of course also possible to configure said ducts in the form of grooves which are milled into the connecting rod.
[0026] In a further advantageous refinement of the invention, a supply groove which serves to supply the two ducts with lubricating oil is configured in the lower half of the large connecting rod eye. It is to be noted in this regard that the plain bearing of the large connecting rod eye is continuously supplied with pressurized oil via the oil pump of the internal combustion engine. According to the invention, part of said oil quantity is always branched off and is guided into one of the two supporting chambers of the double acting cylinder when the eccentric is to perform a rotational movement. Here, the oil flows via the supply groove into a directional valve and from there into the first duct or the second duct. Depending on which of the two ducts is supplied via the supply groove and the directional valve with lubricating oil from the oil circuit of the internal combustion engine, the lower supporting chamber or the upper supporting chamber is enlarged and, as a consequence thereof, the piston moves in the direction of the small connecting rod eye or in the direction of the large connecting rod eye.
[0027] In other words: by way of the actuation of the directional valve between the supply groove and the ducts, the piston of the cylinder can move in one or the other direction and makes the rotational movement of the eccentric possible as a result.
[0028] If the eccentric is to be locked in its position, the directional valve is switched in such a way that, for example, the oil in the lower supporting chamber cannot flow out of the latter. As a consequence thereof, the oil in the lower supporting chamber serves to a certain extent as a stop for the piston which in this way supports the eccentric in the small connecting rod eye in a first position and prevents it from rotating.
[0029] If the eccentric is to assume the opposite second position, the upper supporting space is filled with oil and, when the directional valve is closed, assumes the function of a stop for the piston, with the result that the eccentric is also locked in said position.
[0030] It goes without saying that there are various designs of directional valve which are suitable in principle for the use according to the invention. It has proven particularly advantageous if the directional valve is configured as a slide valve with two switching positions, and the slide of the directional valve is arranged parallel to the crankshaft longitudinal axis or to the rotational axis of the connecting rod eyes. It is then possible namely to move the slide from the one position into the other position by way of an actuating element which is arranged fixedly in the crankcase. This can be achieved, for example, by way of a fork-shaped actuating element which can be displaced in the direction of the longitudinal axis of the crankshaft. During every revolution of the crankshaft, the valve member dips into the fork of the actuating element, which fork is arranged displaceably on the crankcase, and is held in the desired position as a result or is moved into a new position.
[0031] In order that the valve member is not in permanent contact with the adjusting element after a change in the position has been carried out, a spring-loaded ball is arranged in the directional valve, which spring-loaded ball engages into a correspondingly positioned depression of the valve member when the latter assumes its first and/or its second switching position.
[0032] Further advantages and advantageous refinements of the invention can be gathered from the following drawings and the description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] Various views of one exemplary embodiment of a VCR conrod according to the invention, in which:
[0034] FIG. 1 shows a perspective illustration of the conrod with a directional valve,
[0035] FIG. 2 shows a front view of the conrod,
[0036] FIG. 3 shows a side view of the conrod from FIG. 1 ,
[0037] FIG. 4 shows a sectional view of the conrod along the sectional line A-A in FIG. 4 ,
[0038] FIG. 5 shows a sectional view of the conrod along the sectional line B-B in FIG. 2 ,
[0039] FIG. 6 shows a sectional view of the conrod along the sectional line C-C in FIG. 1 ,
[0040] FIG. 7 shows a perspective illustration of the essential components of the supporting system,
[0041] FIG. 8 shows a perspective illustration of the directional valve,
[0042] FIG. 9 shows a plan view of the directional valve,
[0043] FIG. 10 shows a sectional view along the sectional line D-D in FIG. 9 ,
[0044] FIG. 11 shows a sectional view of the conrod in an eccentric position close to the minimum compression, and
[0045] FIG. 12 shows a sectional view of the conrod in an eccentric position close to the maximum compression.
DETAILED DESCRIPTION OF THE INVENTION
[0046] FIGS. 1 to 12 show one and the same exemplary embodiment, with the result that it goes without saying that the designations in various figures in each case have the same meaning, and swapping is carried out between the various figures in order to explain the invention.
[0047] FIG. 1 shows a perspective view of a connecting rod 1 according to the invention, the small connecting rod eye 21 being arranged at the top in FIG. 1 and the large connecting rod eye 22 being arranged at the bottom in FIG. 1 . Both the small connecting rod eye 21 and the large connecting rod eye 22 are part of a connecting rod main body 1 . 1 . An eccentric 2 . 1 is arranged in the small connecting rod eye 21 , which eccentric 2 . 1 has a cylindrical external diameter 2 . 1 . 3 and a bearing bore 2 . 1 . 4 which is arranged eccentrically with respect to the external diameter 2 . 1 . 3 . The gudgeon pin (not shown) of a piston of the internal combustion engine is mounted in a manner known per se in the bearing bore 2 . 1 . 4 .
[0048] If the eccentric 2 . 1 is then rotated relative to the connecting rod main body 1 . 1 , the spacing of the bearing bore 2 . 1 . 4 from the large connecting rod eye 22 changes. As a consequence thereof, the effective length of the connecting rod 1 and the compression ratio of the internal combustion engine also change.
[0049] At the lower end (in FIG. 1 ) of the connecting rod 1 , a connecting rod bearing cap 1 . 2 and a directional valve 10 are screwed to the connecting rod main body 1 . 1 with the aid of the connecting rod screws 1 . 3 .
[0050] In the exemplary embodiment which is shown, the bearing shell of the large connecting rod eye 22 is split in two; it comprises an upper connecting rod bearing shell 1 . 4 and a lower connecting rod bearing shell 1 . 5 .
[0051] A supply groove 13 is configured in the lower connecting rod bearing shell 1 . 5 . An inlet of the directional valve 10 is supplied with oil via said supply groove 13 . The oil is conveyed by the oil pump of the internal combustion engine through the crankshaft (not shown) to the large connecting rod eye 22 .
[0052] A part of an external toothing system 2 . 1 . 1 on the eccentric 2 . 1 can be seen in the upper part of FIG. 1 . It can be seen, furthermore, that a profiled groove 1 . 1 . 1 is configured in the connecting rod main body 1 . 1 , in which profiled groove 1 . 1 . 1 a rack 2 . 2 is guided displaceably by way of its guide faces 2 . 2 . 2 . The guide faces cannot be seen in FIG. 1 . In FIG. 7 , for example, the guide faces 2 . 2 . 2 are shown cut free and are clearly visible. The linear guide which is formed from guide faces 2 . 2 . 2 and the groove 1 . 1 . 1 can be seen very clearly in FIG. 6 .
[0053] As arises from FIG. 4 which shows a longitudinal section through the connecting rod 1 according to the invention along the line A-A in FIG. 3 , the rack 2 . 2 is coupled to a piston rod 2 . 3 which in turn bears a (supporting) piston 2 . 3 . 1 . The (supporting) piston 2 . 3 . 1 serves to support the eccentric 2 . 1 via the rack 2 . 2 and the gearwheel 2 . 4 in a defined position which is predetermined by the controller of the internal combustion engine. The piston 2 . 3 . 1 is therefore partially also called a supporting piston. It does not have to perform work, as is the function in conventional hydraulic cylinders, and to actively rotate the rack and, as a consequence, also the eccentric 2 . 1 via the piston rod 2 . 3 . The energy which is required to rotate the eccentric 2 . 1 is provided at least partially via the mass forces which act on the eccentric 2 . 1 during operation of the internal combustion engine.
[0054] The cylinder according to the invention has two functions: firstly, supporting of the eccentric moments which come from the force at the gudgeon pin; secondly, the pressure difference at the double acting piston is also to be utilized, in order to “push” the eccentric out of its end positions because the eccentric moment is low in the end positions. In the extreme case, the eccentric moment is even zero. This is the case as a rule when a rotational angle of 180° is realized.
[0055] The piston 2 . 3 . 1 and the piston rod 2 . 3 are part of a double acting cylinder 23 , the cylinder bore 24 of which is drilled directly into the main body 1 . 3 of the connecting rod 1 and is subsequently precision machined.
[0056] The piston bushing 2 . 6 is sealed with respect to the cylinder bore 24 by means of an O-ring 2 . 6 . 1 and is fixed in the cylinder bore 24 or the main body 1 . 1 with the aid of a wire ring or another securing element 2 . 6 . 2 .
[0057] Like every double acting cylinder, the supporting spaces 1 . 1 . 3 and 1 . 1 . 4 have in each case one connector to the oil supply.
[0058] In the case of the upper supporting space 1 . 1 . 3 , the oil supply takes place via a first duct 15 which is formed from a plurality of sections, in the upper part from a transverse bore 15 . 1 , a bore 15 . 2 parallel to the cylinder 23 , a circular segment-shaped cutout 15 . 3 and finally an annular gap 15 . 4 between the left-hand (in FIG. 4 ) connecting rod screw 1 . 3 and the bore 26 of the connecting rod bearing cap 1 . 2 or the connecting rod main body 1 . 1 .
[0059] In a similar way, the second duct 12 which connects the lower supporting space 1 . 1 . 4 to the directional valve 10 hydraulically consists of a bore section 12 . 1 and an annular gap 12 . 2 between the right-hand (in FIG. 4 ) connecting rod screw 1 . 3 and the connecting rod bearing cap 1 . 2 and the connecting rod main body 1 . 1 . 1 . The way in which the ducts 15 and 12 are routed is determined predominantly by manufacturing aspects. The routing of the ducts 15 and 12 within the connecting rod main body 1 . 1 is of minor significance for the function of the invention.
[0060] In the exemplary embodiment which is shown, both ducts 12 and 15 open into the valve 10 at the bottom on the underside of the connecting rod bearing cap 1 . 2 .
[0061] As has already been explained, the lubricating oil is present at an inlet of the directional valve 10 at the pressure which is provided by the oil supply of the internal combustion engine.
[0062] The directional valve 10 can be switched to and fro between two switching positions when the engine is running, with the result that either oil is guided into the lower supporting chamber 1 . 1 . 4 or oil is conducted into the upper supporting chamber 1 . 1 . 3 .
[0063] The hydraulic force which results from the oil pressure in one of the two supporting chambers 1 . 1 . 3 and 1 . 1 . 4 is sufficient to move the piston into one of the two end positions and to hold it there, with the result that the oil which is situated in the relevant supporting chamber serves as a stop for the supporting piston 2 . 3 . 1 and therefore a rotation of the eccentric 2 . 1 is prevented. The maintaining of the eccentric position is made possible by way of the check valve in the feed line. However, the “pushing” from the end positions which is triggered and/or assisted by the oil pressure in the relevant supporting chamber and the assistance of the moments in the respective direction which result from the gudgeon pin forces are important. The eccentric 2 . 1 itself has no end stops. The hydraulic piston acts as a travel limiting means. Said hydraulic piston can rest at the bottom on the inside or can bear against the piston bushing at the top.
[0064] The construction of the directional valve 3 which is shown by way of example will be described in somewhat more detail using FIGS. 8 to 10 .
[0065] There are two through bores 10 . 2 and 10 . 3 in a main body 3 . 1 of the directional valve 10 . The connecting rod screws 1 . 3 protrude through the bores 10 . 2 and 10 . 3 when the directional valve 10 is screwed onto the connecting rod bearing cap 1 . 2 from below. Here, the diameter of the bores 10 . 2 and 10 . 3 is somewhat greater than the diameter of the shank of the connecting rod screws 1 . 3 , with the result that an annular duct is also formed there, which annular duct extends the ducts 15 and 12 in the connecting rod main body 1 . 1 . 1 .
[0066] Two grooves 10 . 4 and 10 . 5 are configured on the upper (in FIG. 8 ) surface/top side of the main body 3 . 1 , one of the grooves 10 . 4 and 10 . 5 ending in a bore 10 . 2 and 10 . 3 , respectively. By way of said grooves 10 . 4 and 10 . 5 , the bores 10 . 2 and 10 . 3 are connected to two outlets of the directional valve 10 .
[0067] A third groove 10 . 6 is machined approximately in the center of the valve body 10 . 2 , which third groove 10 . 6 is connected hydraulically to the supply groove 13 in the assembled state of the directional valve 10 . The groove 10 . 6 provides the inlet of the directional valve 10 .
[0068] FIG. 10 shows the valve body 3 . 1 along the line D from FIG. 9 .
[0069] The slide 3 . 2 can be seen clearly in FIG. 10 , which slide 3 . 2 connects the groove 10 . 6 (inlet of the directional valve 10 ) to the groove 10 . 5 in the switching position which is shown. The inlet of the directional valve 10 is therefore connected hydraulically to the lower supporting space 1 . 1 . 4 via the second duct 12 with the sections 12 . 2 and 12 . 1 .
[0070] The groove 10 . 4 is not visible in the left-hand part of FIG. 1 because it lies “in front of” the sectional plane. It can be seen clearly, however, that the bore 10 . 7 which is connected to the groove 10 . 4 is connected to the surroundings in the switching position of the slide 3 . 2 which is shown. This means that the upper supporting space 1 . 1 . 3 is pressureless.
[0071] If the slide 3 . 2 in FIG. 10 is then displaced to the left relative to the valve housing 3 . 1 , the slide 3 . 2 connects the inlet of the directional valve 10 (=the groove 10 . 6 ) to the outlet 10 . 7 which is in turn connected hydraulically to the first duct 15 and therefore fills the upper supporting space 1 . 1 . 3 with oil.
[0072] At the same time, the lower supporting space 1 . 1 . 4 is switched to pressureless or is connected hydraulically to the surroundings, that is to say the interior of the crankcase.
[0073] The ends of the slide 3 . 2 are of crowned configuration. In order that the slide 3 . 2 can be moved while the engine is running, there is an actuating element in the crankcase, which actuating element can be configured, for example, as a fork 28 , the slide 3 . 2 being received between the two prongs of the fork 28 . FIG. 10 shows a fork 28 of this type diagrammatically. If the fork 28 is then moved to the left when the internal combustion engine is running, the right-hand crowned end of the directional valve 10 runs on the right-hand prongs of the fork 28 and is moved to the left by the latter. In the reverse direction, the actuating movement takes place from the second switching position (not shown) into the switching position which is shown in FIG. 10 if the fork 28 is displaced from the left-hand end position (not shown) into the right-hand end position.
[0074] In order that the slide 3 . 2 maintains its switching position, a spring-loaded ball 30 is provided which latches into a corresponding depression of the slide 3 . 2 when the latter has reached one of its switching positions (see FIG. 4 ).
[0075] FIG. 7 shows the components which serve for the supporting function. In the refinement which is shown, a toothing system 2 . 1 . 1 is machined centrally onto the external diameter 2 . 1 . 3 of the eccentric 2 . 1 . Said toothing system meshes with the gearwheel 2 . 4 . The gearwheel 2 . 4 is mounted rotatably and with as little friction as possible in the connecting rod main body 1 . 1 via an axle 2 . 5 . The rack 2 . 2 meshes with the gearwheel 2 . 4 . In this way, there is a kinematic coupling between the rotation of the eccentric 2 . 1 and the lifting movement of the rack 2 . 2 . The rack 2 . 2 is attached rigidly to the piston rod 2 . 3 in the stroke direction, as a result of which the stroke movements of the rack 2 . 2 and the piston rod are identical. The rack 2 . 2 is guided via the guide faces 2 . 2 . 2 in the profiled groove 1 . 1 . 1 in the connecting rod main body 1 . 1 . By way of this type of linear guide, the radial force which is induced at the rack 2 . 2 is supported in the connecting rod main body 1 . 1 .
[0076] FIG. 4 shows the conrod in the eccentric center position. The rack 2 . 2 is situated at half its adjustment travel.
[0077] FIG. 11 shows the conrod in a position close to the position “minimum compression”.
[0078] FIG. 12 shows the conrod in a position close to the position “maximum compression”. The force which acts on the rack 2 . 2 in the movement direction acts on the piston rod 2 . 3 . The piston 2 . 3 . 1 separates the upper supporting chamber 1 . 1 . 3 from the lower supporting chamber 1 . 1 . 4 . The two supporting chambers are part of a double acting cylinder 23 . The upper supporting chamber 1 . 1 . 3 is sealed via the piston bushing 2 . 6 with respect to the surroundings of the conrod. Here, the piston bushing 2 . 6 is sealed, for example, via an O-ring 2 . 6 . 1 with respect to the connecting rod main body 1 . 1 and is fixed by way of a securing ring 2 . 6 . 2 .
[0079] As has already been explained, the two supporting chambers 1 . 1 . 3 and 1 . 1 . 4 can be connected hydraulically to the surroundings of the conrod 1 , that is to say the crankcase of the engine. As an alternative, the fluidic connection can be established with the connecting rod bearing of the large connecting rod eye 22 . A connection according to FIG. 10 is provided in the refinement which is shown here.
[0080] Here, for example, a 4/2-way valve 10 is used. The directional valve has two switching positions and four connectors. The connectors are: tank (connection to the crankcase axially in the slide), pump (supply groove), working connector 1 (connection to the supporting chamber 1 ), working connector 2 (connection to the supporting chamber 2 ). Although the exemplary embodiment has five connectors, the two outlets into the crankcase can be counted as one connector, since they after all open into the same space. This is done merely for reasons of installation space. A bore 10 . 1 establishes a connection between a supply groove 13 and the directional valve 10 . A check valve 11 (see FIG. 4 ) is situated in the bore 10 . 1 , which check valve 11 prevents a return flow of oil into the supply groove 13 . The check valve 11 serves, above all, to prevent a reverse rotation of the eccentric under the influence of large moments. Apart from pronounced low load and low rotational speed points, the moment on account of the supply oil pressure is considerably lower than the moment which is caused by way of the gudgeon pin forces. In a first switching position of the 4/2-way valve, the lower supporting chamber 1 . 1 . 4 is loaded with oil pressure. Here, the upper chamber 1 . 1 . 3 is ventilated via the first duct 15 , that is to say is connected to the crankcase.
[0081] Since the oil pressure which prevails in the supply groove is always greater than the pressure which prevails in the crankcase, the resulting fluidic force acts in the direction of the rack 2 . 2 . In the other switching position of the directional valve, the resulting fluidic force acts in the opposite direction. However, the magnitude of said fluidic force at the same oil pressure in the supply groove 13 is lower than in the first valve switching position if the active piston faces, as configured in FIG. 13 , are of different size.
[0082] Said fluidic force brings about a corresponding first torque on the eccentric via the mechanism which is shown in FIG. 7 . A second torque is produced as a consequence of the forces which act on the gudgeon pin, which second torque is superimposed with the first torque. Depending on the instantaneous oil pressure in the supply groove and the instantaneous force on the gudgeon pin, a corresponding resulting torque is produced on the eccentric. The resulting torque on the eccentric causes the eccentric 2 . 1 to rotate into its end positions and, as a consequence thereof, the VCR to assume two different values.
ADVANTAGES OF THE INVENTION
[0083] Slight increase in the connecting rod mass, in particular of the oscillating mass. An eccentric 2 . 1 can be rotated by up to 180° by way of the use of a rack. As a result, a lower eccentricity is required to produce a defined variation range of the connecting rod length.
[0084] The eccentric moment to be supported is also reduced as a result. As a consequence thereof, the supporting mechanism can be of weaker dimensions, which is ultimately also reflected in a lower component mass. If the possible eccentric rotational range is utilized completely, that is to say a rotational angle of 180° in the extreme case, a further advantage can also be realized: in theory, no more eccentric moment at all has to be supported in the eccentric end positions, since the gudgeon pin then lies precisely on the connecting line between the large and the small connecting rod eye 22 , 21 (see FIGS. 11 and 12 ). The gudgeon pin force is therefore introduced into the connecting rod main body 1 . 1 on a direct path, with the result that the conrod has a similarly great tensile and compressive stiffness as a conventional conrod.
[0085] As a consequence of the lower eccentricity, the external diameter 2 . 1 . 3 of the eccentric 2 . 1 can also be of small configuration. This in turn has the consequence that the connecting rod head also has smaller dimensions. It is due to said effects together that there is correspondingly less mass in the vicinity of the small connecting rod eye 21 , which has a favorable effect on the oscillating mass.
[0086] The rack 2 . 2 and the gearwheel 2 . 4 are situated below the small connecting rod eye 21 and are therefore incorporated into the oscillating mass to a less pronounced extent.
[0087] The installation space requirement, in particular in the internal region of the piston, is very low. In the solution which is proposed here, the rack 2 . 2 protrudes only a little beyond the silhouette of the connecting rod main body 1 . 1 , as can be seen in FIG. 12 .
[0088] In FIG. 12 , the eccentric 2 . 1 is situated in the position “high compression”. Here, the rack 2 . 2 is extended to its maximum. This favorable circumstance was made possible by another gearwheel 2 . 4 having been introduced between the eccentric 2 . 1 and the rack 2 . 2 . In this way, the rack engagement point is at a lower location than in the case of a direct engagement, that is to say if the rack 2 . 2 meshed directly with the eccentric. Direct meshing is possible, but is not to be recommended as a general rule on account of the installation space requirement. If, in contrast, there are no installation space restrictions in this region, for example in the case of a piston with a comparatively great compression height, direct meshing (that is to say, without an intermediate gear) would be advantageous because the number of parts could be reduced as a result.
[0089] The low installation space requirement of the present solution is very important with regard to the universal usability of the VCR conrod for different engines, since there is a similarly great design freedom in this case as in the case of a conventional conrod.
[0090] On account of the relatively simple construction and because only a few functional faces with low tolerances have to be manufactured, the VCR conrod according to the invention can be manufactured inexpensively. The machining operations on the connecting rod main body which are to be added in comparison with a conventional conrod are substantially the following.
[0091] The pocket for receiving the gearwheel 2 . 4 can be manufactured with a comparatively large slide milling cutter, which is very favorable with regard to machining time and tool wear.
[0092] The parts of the supporting mechanism, namely the rack 2 . 2 and the gearwheel 2 . 4 , can be manufactured by way of inexpensive sintering technology.
[0093] The groove 1 . 1 . 1 in the connecting rod main body 1 . 1 can be manufactured easily by means of an end mill which runs perpendicularly with respect thereto.
[0094] Reduction of the undesired effect of the increase in the adjusting times toward low engine rotational speeds.
[0095] This negative effect manifests itself to a less pronounced extent in this construction. Thanks to the hydraulic connection which is shown in FIG. 10 , in each case one side of the double acting supporting cylinder is ventilated, that is to say is brought into fluidic connection with the crankcase. As a result, the oil pressure which acts on the respectively other piston side causes a piston force which acts on the eccentric 2 . 1 via the rack 2 . 2 . This force is active even if only low centrifugal forces act on the power unit at low engine rotational speeds. The undesired increase in the adjusting time toward “high compression” at low engine rotational speeds therefore manifests itself more weakly.
[0096] In the present invention, an intake of air into the supporting chambers 1 . 1 . 3 and 1 . 1 . 4 is not critical, since the eccentric 2 . 1 is theoretically moment-free in the end position, and therefore an inclusion of air in the hydraulic support is without further consequences. This insensitivity to the inclusion of air has the great advantage that the oil supply may be interrupted, and that a higher transfer speed of the piston 2 . 3 . 1 can be permitted.
[0097] It is therefore also possible that the supply groove 13 in the connecting rod bearing shell has to extend only over an angle of approximately 180°. As a result, the connecting rod bearing is impaired to a correspondingly lesser extent in terms of its load-bearing behavior. Secondly, the adjusting speed can be increased as a consequence of the higher permissible transfer speed. | A connecting rod for an internal combustion engine having an adjustable length between a first connecting rod eye and a second connecting rod eye. An eccentric member having a bearing bore which is positioned eccentrically to an outer diameter is rotated to adjust the length. The eccentric member is rotated by a rack and pinion drive and a double acting hydraulic cylinder. | 5 |
The invention described herein was made by employees of the United States Government and may be manufactured and used by or for the Government for Government purposes without the payment of any royalties thereon or therefor.
BACKGROUND OF THE INVENTION
This invention relates to lasers and in particular to lasers thermally pumped using rare earth selective emitters.
Selective emitters are devices for converting thermal energy into narrow band radiation. Most solid state materials have nearly a constant spectral emittance (gray body). The spectral emittance of a rare earth is characterized by several emission bands in the visible and near infrared region resulting from electronic transitions from the lowest excited states.
Selective emitters have been used in thermophotovoltaic energy conversion systems such as those described in U.S. Pat. Nos. 4,584,426 and 5,080,724.
Lasing in rare earths such as neodymium (Nd), holmium (Ho) and erbium (Er) in a host material such as yttrium aluminum garnet (YAG, Y 3 Al 5 O 12 ) has been achieved using flashlamp or laser diode pumping.
SUMMARY OF THE INVENTION
A laser includes an emitter having a selective energy emission band in response to applied thermal energy and a rare earth doped laser rod having an energy absorption band matching the emission band. The emitter and the rod are arranged to allow energy from the emitter to impinge on the rod.
Using a selective emitter allows thermal energy to be used as the input for the rare earth ion laser. Not only does using a selective emitter allow thermal energy to be the input, but it also results in higher laser efficiency than flashlamp or diode laser pumped rare earth ion lasers. Both the flashlamp and diode laser pumping mechanisms are not as efficient at converting the input energy to radiation matched to the absorption band of the laser medium.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective schematic view of a laser according to one aspect of the invention.
FIG. 2 is a top plan view of a laser according to another aspect of the invention with portions cut away.
FIG. 3 is a front elevation view of the laser of FIG. 2 with portions cut away.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a laser 10 or optical amplifier includes a circular cylindrical laser rod 12 and a circular cylindrical selective emitter 14 . The rod 12 and the emitter 14 are located at respective foci of an elliptical cylindrical laser cavity 16 . The internal walls of the cavity 16 are reflective and in the preferred embodiment the cavity 16 is under a vacuum.
A resistive heater 18 is located at the axis of the emitter 14 . The heater 18 may be a refractory metal (e.g., molybdenum). The heater 18 preferably has a polished surface to minimize emittance from its surface. In the preferred embodiment, the emitter 14 is segmented into a series beads to minimize thermal stresses. As is known in the art, a mirror and window are provided at each end of the rod 12 .
The rod 12 is composed of a crystal doped with a rare earth element and may be, for example, two millimeters in diameter and may include an attached unshown cooling fin.
The emitter 14 is composed of a selective emitting material that has a selective energy emission band in response to applied thermal energy. The emitter 14 may be, for example, Tm-YAG (Tm x , Y 3-x Al 5 O 12 ), thulium aluminum garnet (Tm 3 Al 5 O 12 ) or thulium oxide (Tm 2 O 3 ). The material of the emitter 14 may be either polycrystalline or a single crystal.
In operation, an electrical current from an unshown source is passed through the heater 18 causing the emitter 14 to heat and emit in the selective energy emission band characteristic to the particular emitter material. Because of the elliptical shape of the cavity 16 , except for end losses, all or substantially all of the radiation that leaves the emitter 14 impinges upon the rod 12 .
The rod 12 is doped with a rare earth having an energy absorption band matching the emission band of the emitter 14 (e.g., the emitter 14 and the rod 12 contain the same rare earth, for example, thulium). The absorbed radiation will produce excited states in the rod 12 , producing a population inversion between an energy level in the first excited state manifold and an energy level in the ground state manifold, and thus lasing in the rod 12 . For a rod 12 doped with just a single rare earth such as thulium, the emitter 14 may have to be operated at a temperature of greater than 2500° K for the laser 10 to operate.
In the preferred embodiment, the rod 12 is doped with more than one rare earth. In this case, one rare earth serves as the energy absorber and corresponds to the emission band of the emitter 14 . A second rare earth is the laser species. The population inversion is produced by energy transfer from the absorber rare earth to the lasing rare earth. For example, the rod 12 may be composed of Tm-Ho-YAG (Tm x , Ho y , Y 3-x-y Al 5 O 12 ) or Tm-Ho-YLF (yttrium lithium fluoride) (Tm x , Ho y , Y 1-x-y LiF). The Tm doping level (x) should be large while the Ho doping level (y) should be low in order to produce a population inversion in the Ho for emitter 14 temperatures of approximately 2000° K.
In order to keep the lower laser level density low, the laser rod 12 must be kept relatively cool. This can be accomplished by a combination of the vacuum in the cavity 16 and a thermal connection such as an unshown longitudinal rib between the rod 12 and the cavity 16 which is in turn cooled by a suitable means.
Referring to FIGS. 2 and 3, an additional embodiment of the laser 10 ′ includes a laser rod 12 , and selective emitters 14 ′. The rod 12 is contained in an evacuated chamber 22 that allows energy from the emitters 14 ′ to impinge on the rod 12 . The chamber 22 may be, for example, composed of sapphire. A coolant line 24 is in thermal contact with the rod 12 . Planar combustors 26 are arranged adjacent to the emitters 14 ′.
The combustors 26 may be formed of a matrix of interspersed tubes carrying fuel 28 and oxidizer 30 (e.g., methane and oxygen).
In operation, the combustors 26 produce flame fronts 32 that heat the emitters 14 ′, which then emit in an energy band matching the rare earth absorber in the rod 12 , resulting in lasing in the rod 12 . To reduce the lower laser level density, a cooling fluid is passed through the line 24 (e.g., liquid nitrogen (77° K)).
It is also possible to surround the rod 12 with additional emitter/combustion pairs or to use an annular emitter with suitable external combustors.
It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. The invention is therefore not limited to particular details of this disclosure except to the extent that the following claims are necessarily so limited. | A selective emitter pumped rare earth laser provides an additional type of laser for use in many laser applications. Rare earth doped lasers exist which are pumped with flashtubes or laser diodes. The invention uses a rare earth emitter to transform thermal energy input to a spectral band matching the absorption band of a rare earth in the laser in order to produce lasing. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is related to co-pending and commonly assigned U.S. patent application Ser. No. 11/114,314 entitled “METHOD AND SYSTEM FOR COMPUTING AND DISPLAYING LOCATION INFORMATION FROM CROSS-CORRELATION DATA,” filed Apr. 25, 2005, and co-pending and commonly assigned U.S. patent application Ser. No. 11/114,759 entitled “METHOD AND SYSTEM FOR EVALUATING AND OPTIMIZING RF RECEIVER LOCATIONS IN A RECEIVER SYSTEM,” filed Apr. 2, 2005, all of the disclosures of which are hereby incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention is directed generally to superimposing data on images, and more particularly to superimposing probability density functions or power distributions on cartographic displays.
BACKGROUND OF THE INVENTION
[0003] In certain geolocation applications, it is often useful to superimpose data, such as a probability data, power distribution, density data, or other data, on a cartographic display, such as a map. This allows representation of the probability that a certain feature is present at certain locations represented by the map, the amount of power that is present at certain locations represented by the map, or the densities of some element at certain locations represented by the map.
[0004] When forming the display, there is a trade-off between the visibility of the superimposed data and the underlying map. The superposition will use an alpha or opacity factor to determine the relative transparency of the superimposed data. An opacity of 0.0 will result in the underlying map being completely visible and the superimposed data being invisible. An opacity of 1.0 will result in the underlying map being obscured and the superimposed data being completely visible.
[0005] If the opacity is set too low, the superimposed data will be difficult to see. If the opacity is set too high, the features in the underlying map will be difficult to discern. Previously, applications would use a single opacity value for the entire data set that provided a compromise between the visibility of the data and the underlying map. When such arrangements are used in power distributions superimposed on maps, for example, regions of the map with little to no power would be obscured by the superimposed data to the same extent as regions with maximum power.
[0006] Superimposing data on an image requires a number of steps. The data may often be represented using a color scheme, with a color scale selected to span the range of data values. The data also needs to be registered to the map, as the data will generally represent the values of some quantity at specific locations. When using a map, for example, the superimposed data should be aligned and scaled to coincide with the map so that the location represented by a specific superimposed data value corresponds to the same location as represented on the map at the point of overlay. To superimpose the data, the map image and the color scheme representing the data are combined. An opacity factor determines the relative weight by which the color representing the data obscures the map.
BRIEF SUMMARY OF THE INVENTION
[0007] Representative embodiments of the present invention provide for varying the opacity based upon variations in the numerical values of the data being superimposed on a chart. This allows for representing the superimposed data most prominently where the values are the highest, and viewing the underlying chart more prominently where the superimposed data values are the lowest. That is, the opacity may be higher for higher data values, and lower for lower data values. Such a variation allows for using a higher opacity to see clearly where data values are the highest, while still providing a clear view of the surrounding chart features. Other embodiments of the invention allow for an inverse relationship between opacity and data values, and/or non-linear relationships.
[0008] Representative embodiments of the present invention provide for varying the opacity based upon variations in the numerical values of the data to be overlaid. This allows for representing the power or probability most prominently where it is strongest, and viewing the underlying map more prominently where probability or power is weakest. That is, the opacity may be higher for higher data values, and lower for lower data values. Such a variation allows for using a higher opacity to see clearly where power or probability is strongest, while still providing a clear view of the surrounding landmarks and other map annotations. Other embodiments of the invention allow for an inverse relationship between opacity and data values, and/or non-linear relationships.
[0009] The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which:
[0011] FIG. 1 shows a plot of opacity versus normalized power/probability values;
[0012] FIG. 2 shows an alternative plot of opacity versus normalized power/probability values;
[0013] FIG. 3 shows an overlay of a map with a power density superimposed using a constant alpha or opacity of 0.95;
[0014] FIG. 4 shows an overlay of a map with a power density superimposed using a constant opacity of 0.35;
[0015] FIG. 5 shows an overlay of a map with a power density superimposed using a varying opacity ranging up to a maximum of 0.95;
[0016] FIG. 6 shows an overlay of a map with a power density superimposed using a varying opacity ranging up to a maximum of 0.60; and
[0017] FIG. 7 depicts a block diagram of a computer system which is adapted to use the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] It will be understood that the inventive concepts of the present invention may be adapted for use to superimpose data of any type related to an underlying chart or map. What follows will be understood to be specific embodiments, and the present invention need not be limited to only the embodiments described.
[0019] FIG. 3 shows overlay 300 of map 301 with power density 302 superimposed using a constant alpha or opacity of 0.95. Power density 302 is easily seen, however features of map 301 are obscured.
[0020] FIG. 4 shows overlay 400 of map 401 with power density 402 superimposed using a constant opacity of 0.35. The features of map 401 are easily seen, but the color intensity of power density 402 is compromised.
[0021] FIG. 1 shows plot 100 of opacity versus normalized power/probability values. Power/probability axis 101 shows values from 0.0 to 1.0, which represent the extremes of normalized data values. Alpha axis 102 shows values from 0.0 to 0.95 which represent the range from invisibility to near total obscuration by the superimposed data. Line 103 represents a constant opacity value of 0.95 as used in overlay 300 of FIG. 3 . Line 104 represents a constant opacity value of 0.35 as used in overlay 400 of FIG. 4 . Note than in lines 103 and 104 , opacity is constant for all values of power/probability.
[0022] Line 105 shows a variation of opacity with power/probability. Line 105 shows a linear variation starting at an opacity of 0.0 for power/probability of 0.0 and increasing to a maximum opacity of 0.95 for a power/probability of 1.0. Note that in FIG. 1 , the power/probability values are normalized to a minimum of 0.0 and a maximum of 1.0. Lines 106 and 107 show examples of non-linear alternatives for line 105 . The non-linear functional relationship between power/probability and opacity may be logarithmic, exponential, polynomial, discrete steps, Fibonacci, factorial, sinusoidal, or any other suitable function. As another example, line 108 shows a variation of opacity with power/probability up to a maximum opacity of 0.35. Lines 109 and 110 represent examples of non-linear alternatives to line 108 . In some situations, it may be desirable to use an inverse relationship between opacity and power/probability. Each of the different lines represents an example functional relationship between opacity and power/probability that can be used for determining opacity in an overlay.
[0023] FIG. 2 shows alternative plot 200 of opacity versus normalized power/probability values. Power/probability axis 101 shows values from 0.0 to 1.0, which represent the extremes of normalized data values. Alpha axis 102 shows values from 0.0 to 0.95 which represent the range from invisibility to near total obscuration by the superimposed data.
[0024] Line 201 represents a variable opacity with a minimum opacity above 0.0 when the power/probability is at a minimum value. Line 202 represents a stepped opacity, with a number of discrete values covering various ranges of power/probability. Line 203 represents an inverse relationship between opacity and power/probability, shown here as an exponential decay.
[0025] FIG. 5 shows overlay 500 of map 501 with power density 502 superimposed using a varying opacity ranging up to a maximum of 0.95. In FIG. 4 , both the highest regions of power density 502 are clearly visible, as well as the features of map 501 in the regions of lower power.
[0026] FIG. 6 shows overlay 600 of map 601 with power density 602 superimposed using a varying opacity ranging up to a maximum of 0.60. Not only can the functional relationship between opacity and power/probability be tailored, but the maximum and minimum opacity can also be adapted to maximize the clarity of the information in the display.
[0027] Note that any of the functions described herein may be implemented in hardware, software, and/or firmware, and/or any combination thereof. When implemented in software, the elements of the present invention are essentially the code segments to perform the necessary tasks. The program or code segments can be stored in a processor readable medium or transmitted by a computer data signal embodied in a carrier wave, or a signal modulated by a carrier, over a transmission medium. The “processor readable medium” may include any medium that can store or transfer information. Examples of the processor readable medium include an electronic circuit, a semiconductor memory device, a ROM, a flash memory, an erasable ROM (EROM), a floppy diskette, a compact disk CD-ROM, an optical disk, a hard disk, a fiber optic medium, a radio frequency (RF) link, etc. The computer data signal may include any signal that can propagate over a transmission medium such as electronic network channels, optical fibers, air, electromagnetic, RF links, etc. The code segments may be downloaded via computer networks such as the Internet, Intranet, etc.
[0028] FIG. 7 illustrates computer system 700 adapted to use the present invention. Central processing unit (CPU) 701 is coupled to system bus 702 . The CPU 701 may be any general purpose CPU, such as an HP PA-8500 or Intel Pentium processor. However, the present invention is not restricted by the architecture of CPU 701 as long as CPU 701 supports the inventive operations as described herein. Bfs 702 is coupled to random access memory (RAM) 703 , which may be SRAM, DRAM, or SDRAM. ROM 704 is also coupled to bus 702 , which may be PROM, EPROM, or EEPROM. RAM 703 and ROM 704 hold user and system data and programs as is well known in the art.
[0029] Bus 702 is also coupled to input/output (I/O) controller card 705 , communications adapter card 711 , user interface card 708 , and display card 709 . The I/O adapter card 705 connects to storage devices 706 , such as one or more of a hard drive, a CD drive, a floppy disk drive, a tape drive, to the computer system. The I/O adapter 705 is also connected to printer 714 , which would allow the system to print paper copies of information such as document, photographs, articles, etc. Note that the printer may a printer (e.g. dot matrix, laser, etc.), a fax machine, or a copier machine. Communications card 711 is adapted to couple the computer system 700 to a network 712 , which may be one or more of a telephone network, a local (LAN) and/or a wide-area (WAN) network, an Ethernet network, and/or the Internet network. User interface card 708 couples user input devices, such as keyboard 713 , pointing device 707 , and microphone 716 , to the computer system 700 . User interface card 708 also provides sound output to a user via speaker(s) 715 . The display card 709 is driven by CPU 701 to control the display on display device 710 .
[0030] The overlays may be viewed on a display, such as a computer display device 710 , or printed on any suitable medium. The color scale used for representing data values may either be true color or a grayscale. Examples of uses include display of the location of an emitter, such as a signal transmitter device, denoted by varying shades of color using the “Tentagram” display format as described in U.S. patent application Ser. No. 11/114,759 entitled “METHOD AND SYSTEM FOR COMPUTING AND DISPLAYING LOCATION INFORMATION FROM CROSS-CORRELATION DATA,” the disclosure of which is hereby incorporated herein by reference. Other examples of uses include, without limitation, displays of transmitter geolocation, transmitter power densities, acoustic sonar data, weather data, radiation distribution, particulate distribution, particle density, energy distribution, and lightning strike location.
[0031] The data to be superimposed may include multi-modal distributions which contain multiple regions of relatively high and low values, rather than just a single region of high values. Further, the shape of the distribution contours may be significantly different than circular, such as dog-bone shaped. The underlying image need not be a map, but may be any image suitable for an overlay of data. Examples include, without limitation, representations of objects, schematics of circuits, drawings of devices, photographs of scenes and medical images. The data may be supplied as a data file, or an attached system may furnish measurements. Likewise, the image may be supplied as a pre-existing image or may be collected using an attached system. The overlaying can be accomplished by merging two separate files on a computer or by maintaining two separate files and visually combining the files.
[0032] Although the present invention and its advantages have 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. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps. | A system and method are disclosed for superimposing data on an image using a variable opacity that is based upon variations in the numerical values of the data to be superimposed. This allows for representing data most prominently where it the values are higher, while still providing a clear view of the surrounding features. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a permanent whipstock for use downhole in a wellbore.
2. Prior Art
For many years whipstock assemblies have been used to deflect drillstrings around obstructions in a formation or in a previously completed casing. Whipstock have been used with great success, however, normally require several trips and a number of separate parts.
Generally, to employ a whipstock assembly to deflect a drillstring, the whipstock assembly must be supported. Supports for whipstocks are most commonly in the form of packers. Packers have been designed in many different ways over the years and have performed their intended function satisfactorily but most require they be run in the hole separately or that complex apparati and multiple steps be used to set the packer and whipstock on the same run-in of the workstring. Examples of such packers and whipstock/packer assemblies include Baker DW-1 packer/anchor and whipstock assembly.
While the above methods and apparati for supporting a whipstock are functional, they are expensive, either because of complexity or because of the need to remove the workstring. Therefore a need exists for a permanent whipstock assembly which does not require a packer and which can be fully and securely set in one run-in of the workstring.
SUMMARY OF THE INVENTION
The above-discussed and other drawbacks and deficiencies of the prior art are overcome or alleviated by the permanent self camming whipstock of the invention.
The permanent self camming whipstock of the present invention comprises a tapered face for diverting a drillstring, said face being held in desired position by diverging camming pivot arms positioned at the lower end thereof. The system has conventional electrically activated Pressure Setting Actuator (PSA) which allows the whipstock to be set anywhere in a cased hole environment. The system eliminates the need for a set down weight as a preset anchor as most prior art whipstock assemblies require. Essentially, the whipstock of the present invention is permanently settable in one trip downhole.
A setting sleeve and various connecting rods are advantageously positioned to pull the pivot arms into a set position, thus forcing a slip pad against a casing of a borehole and thereby cam the whipstock in place. Moreover, the various connecting rods are attached with screws, in a two piece shear block assembly, which are shearable a given tensile force. As the workstring pulls upward, it increasingly tightens the camming action of the pivot arms and consequently creates mounting tensile force on the screws. As the tensile capacity of the screws is surpassed, they shear off, thereby releasing the setting tool and workstring for tripping uphole. The whipstock is maintained in an "as set" position by the diverging angle of the pivot arms; camming in opposite directions makes the assembly extremely stable. The whipstock is then permanently set in the hole.
One of the important advantages of the arrangement is that due to the very narrow run-in cross section, the permanent whipstock of the invention can be run-in through a restricted bore and due to the large expansion capability of the device, can still be opened and set in a standard sized hole further downhole. Inflatable anchoring systems have been used but usually locate the deflection surface in a centralized position leaving unacceptable cavities around the whipstock in which a mill could become lodged.
The above-discussed and other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the following detailed description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS Referring now to the drawings wherein like elements are numbered alike in the several FIGURES:
FIG. 1 is an elevation view of the permanent whipstock assembly of the invention in the run-in position.
FIG. 1A is an elevation view of the permanent whipstock assembly in the set position.
FIG. 2 is a plan view of the slip pad housing and pivot arms.
FIG. 3 is a plan view of the whipstock shear block assembly upper setting bar adapter and setting sleeve of the invention.
FIG. 4 is a plan view of the shear block assembly of the invention in the run-in position.
FIG. 5 is a cross section view of FIG. 1 taken along section line 5--5.
FIG. 6 is a cross section view of FIG. 1 taken along section line 6--6.
FIG. 7 is a cross section view of FIG. 1 taken along section line 7--7.
FIG. 8 is a cross section view of FIG. 1 taken along section line 8--8.
FIG. 8A is a cross section view of FIG. 1 taken along section line 8A--8A.
FIG. 9 is a plan view of the slip pad, setting bar an lower shear block.
FIG. 10 is a partial cross-section view of FIG. 9 taken along section line 10--10.
FIGS. 11 and 12 are plan and side views, respectively, of the pivot arm wedge.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 1A, the permanent whipstock assembly is understood by one of skill in the art to be a whipstock housing 1 with a tapered whipstock 2 having pivot arms 15, 18 and 21 for setting and holding (by camming action) the whipstock housing 1 at a preselected position within a wellbore casing 9. Several particular arrangements make the disclosed whipstock extremely effective. The embodiment described in detail hereunder is particularly suited for a cased wellbore of a 6.25 inches inside dimension, however, clearly the invention is useable in other sized cased wellbores with minor modifications.
Whipstock housing 1, as seen in elevation view in FIG. 1, is tapered axially both uphole and downhole of a zone of attachment 6 between whipstock 2 and slip pad housing 4. As can be easily observed in drawing FIGS. 1 and 1 A, whipstock 2 steadily increases in elevational dimension from the uphole end of whipstock housing 1 to the zone of attachment 6 between whipstock 2 and slip pad housing 4. At this juncture, however, a taper begins again but in the opposite direction. More specifically, slip pad housing 4 steadily decreases in elevational dimension beginning at the zone of attachment 6 and extending to the downhole end of slip pad housing 4, which is also the downhole end of whipstock housing 1. The taper of slip pad housing 4 creates a lever action of the whipstock housing 1 such that as the downhole end of the assembly is pressed into contact with the one side borehole casing 9, the uphole end of the assembly is pressed into contact with the opposite side of the borehole casing 9. This is advantageous as it ensures that the uphole end of whipstock housing 1 does not allow for gaps in which the subsequently tripped drilling tool might become jammed.
Referring now to FIGS. 1, 1A, 2, 5-8A, 11 and 12, the whipstock housing 1 is supported in a preselected position within a borehole by a series of camming devices. In the most preferred embodiment, three camming pivot arms are contemplated. It will be understood that three arms is not critical, but is preferred for effective support and cost considerations. The most preferred embodiment includes a long pivot arm 15, a short pivot arm 18 and a pivot arm wedge 21. As is illustrated in the drawings long pivot arm 15 and short pivot arm 18 are both of a three piece construction. Each arm is severed into two similar pieces; each arm is then reassembled with the severed halves via a swiveling means. Preferably the swiveling means is a threaded insert. This ensures that arms 15, 18 will not bind upon encountering irregular forces downhole; rather they will swivel and continue to operate properly. Pivot arm wedge 21 is not so arranged as there is no need for it to swivel. Wedge 21 is connected to the apparatus of the invention at only one end and will find its own equilibrium against casing 9.
Long pivot arm 15 and short pivot arm 18 are pivotally mounted in the slip pad housing 4 on hinge pins 16 which preferably are of a 0.75 inch diameter, however a range of from about 0.25" to about 1.5" in diameter would be acceptable. Using these hinge pins 16 as a reference point, the long and short pivot arms 15, 18 extend from the hinge pins 16 in a generally downhole direction and in a direction generally opposed to the whipstock 2 taper. With one end of the subject pivot arms 15, 18 being connected to hinge pins 16, the other ends of these pivot arms are connected to slip pad assembly 5 via hinge pins 17 through clevis plates 19; clevis plates 19 are welded or otherwise fastened to slip pad 5. Hinge pins 17 may be in the range of about 0.25" to about 1.5" in diameter but are most preferably 0.50 inches in diameter. All hinge pins 16 and 17 are preferably welded in place but may be fixedly attached in other conventional arrangements.
It should also be noted that the hinge pin holes in clevis plates 19 are not circular but are of an elongated oval shape. This arrangement is beneficial to the strength of the assembly since it allows for all of the load in the pivot arms 15, 18 to be borne by slip pad 5; hinge pins 17 do not bear any significant load.
The third pivot arm, pivot arm wedge 21, is pivotally connected to slip pad housing 4 on a pin 16 in a manner similar to arms 15, 18, however, using this pin as a reference point, pivot arm wedge 21 extends generally in an uphole direction and away from the slip housing 5 taper. Pivot arm wedge 21 advantageously contains a means to engage one end of an extension spring 22 which then is connected on its other end to extension spring pin 36 on slip pad 5. On an end opposite hinge pin 16, pivot arm wedge 21 contains at least one carbide insert 30, and more preferably three carbide inserts 30, to provide frictional engagement with casing 9 when pivot arm wedge is in the set position (i.e., extending through an opening in slip pad 5).
Slip pad 5 as illustrated in FIGS. 9 and 10, comprises an elongated rectangular member with carbide inserts 30 for frictional engagement with the casing 9. The inserts 30 provide for greater frictional adhesion than the slip pad 5 itself. Individual inserts may be placed in any array desired. Slip pad 5 also includes a wedge opening 32 uphole from the inserts 30. Wedge opening 32 is positioned such that pivot arm wedge 21 may pass through the opening to contact casing 9. Included at the downhole most edge of wedge opening 32 is extension spring pin 36 which is fixedly attached to slip pad 5. Spring 22 is anchored between this pin and pivot arm wedge 21 to assist in moving pivot arm wedge into the set position.
Upon actuation of the setting process, slip pad 5 is pulled in an uphole direction. This movement causes long and short pivot arms 15, 18 to pivot outwardly from slip pad housing 4, effectively increasing the distance of slip pad 5 from slip pad housing 4; thus increasing the diametrical dimensions of the whipstock housing so that it will turn in the borehole. As this distance increases, the tapered side of slip pad housing 4 is forced into contact with casing 9. Consequently, because of the shape of the whipstock housing 1, the taper of slip housing 4 ensures that the uphole end of whipstock 2 is in firm contact with the opposite side of casing 9, generally diametrically opposed sides are indicated.
As slip pad 5 is pulled uphole and long and short pivot arms 15, 18 are pivoted into place, pivot arm wedge 21 is pivoted in a direction opposite arms 15, 18. This pivoting action of wedge 21 is augmented, as stated above, by an extension spring 22. Pivot arm wedge 21 continues to pivot from its run-in position shown in FIG. 1 to an extended position shown in FIG. 1A wherein the end of wedge 21 opposite hinge pin 16 is disposed within wedge opening 32. This provides pivot arm wedge 21 access to casing 9. The purpose of pivot arm wedge 21 is to maintain whipstock housing 1 in an "as set" position. This end is achieved because pivot arm wedge 21 is cammed in an opposed direction to long and short pivot arms 15, 18. Therefore the whipstock housing 1 cannot move uphole or downhole. Moreover, vibration does not loosen the pivot arms, rather it has been found that vibrations from workstrings and drillstrings tripped downhole actually cam the pivot arms more tightly. Indeed, experimental settings have actually revealed the carbide inserts 30 on slip pad 5 and on slip pad housing 4 to become embedded into casing 9 up to 1/16 of an inch.
At the uphole most portion of whipstock housing 1 a setting sleeve 40 is positioned. Setting sleeve 40 is adapted to be operatively connected at the uphole end to a conventional setting tool (not shown) and at the lower end to an adapter 42 and a lip 7 of whipstock 2. Adapter 42 is connected to an upper setting bar 44 which in turn is connected to an upper shear block 46. Upper shear block 46 is fastened to lower shear block 52 by any fastening means, but preferably is fastened by tack welding and machine screws 47. Lower shear block 52 is connected to lower setting bar 54 which is connected to slip pad 5.
As can be ascertained from FIGS. 1 and 3, setting sleeve 40 is axially aligned with whipstock housing 1. The centrally mounted adapter 42 and upper setting bar 44 are, therefore, located adjacent the tapered trough 11 in the whipstock 2. Since the slip pad 5 is located diametrically opposite the trough 11, the setting assembly preferably passes through whipstock 2. Provision is made therefore by shear block assembly opening 3, illustrated in FIGS. 4 and 4a. Opening 3 passes from trough 11 completely through whipstock 2 to whipstock/casing surface 8. The opening is dimensioned preferably in the shape of a rectangle closely approximating the lateral edge dimension of lower shear block 52 and providing for relatively extended movement in parallel with said lateral edges. Lower shear block 52 is oriented within the opening so the casing surface of block 52 is flush with the casing side 8 of whipstock 2; a channel 13 is provided in the casing side 8 of whipstock 2 opposite from trough 11, to receive lower setting bar 54. The channel 13 continues for the length of whipstock 2 beginning from shear block assembly opening 3 and ending at slip pad 5.
The setting motion of the above listed parts is initiated at a preselected time by a heat charge exploding within the setting tool. The charge heats oil contained in the setting tool and actuates a piston connected to the setting sleeve 40 of the invention. As tension in the components builds a shear pin 48, which previous to shearing extended from within lower shear block 52 to whipstock 2 to maintain the slip pad 5 and pivot arms 15, 18 and 21 in the run-in position, is sheared. Once shear pin 48 shears, the setting assembly begins moving in the uphole direction, slip pad 5 moves uphole with these components and moves laterally as well, against the casing 9, because of long and short pivot arms 15, 18. As the overall diameter of the slip pad housing 4 and slip pad 5 grows the whipstock housing 1 is firmly wedged within the cased wellbore at a predetermined location.
As long and short pivot arms 15, 18 pivot to a more perpendicular position relative to the axis of the whipstock housing 1, pivot arm wedge is drawn from the run-in position toward the extended slip pad 5. The drawing action is accomplished by extension spring 22 which, as noted above, is mounted on slip pad 5 at one end and on pivot arm wedge 21 at the other. As slip pad 5 is pushed away from slip pad housing 4, extension spring 22, attached on one end to pivot arm wedge 21 and on the other to slip pad 5, contracts. This assists the pivoting action of pivot arm wedge 21 to pivot into wedge opening 32 and into contact with casing 9. Further pulling in the uphole direction by the setting assembly sets pivot arm wedge 21 firming into casing 9. With long and short pivot arms 15, 18 and pivot arm wedge 21 in opposing frictional relationship with casing 9 the whipstock housing 1 is set.
The set position of whipstock housing 1 is ensured both by simple principles of physics and by mechanical assistance from lower shear block 52. Lower shear block 52 is equipped to maintain slip pad 5 in an "as set" position by incorporating in block 52 at least one, and preferably a pair of slip locks 49. Slip locks 49 include gripping means adapted to slide within shear block assembly opening 3 in the uphole direction and grip in the downhole direction. Slip locks 49 are equipped with biasing means 50 to bias the slip locks 49 toward engagement with the defining structure of shear block assembly opening 3. Upon engagement therein the lower shear block is prevented from moving in the downhole direction. Consequently slip pad 5 cannot move in the downhole direction and thus the whipstock housing remains in an "as set" position.
After whipstock housing 1 is set, the setting assembly desirably continues to pull uphole. That creates mounting tensile forces on all of the components. The predetermined "weak link" in the setting assembly of the preferred embodiment chain is machine screws 47. Machine screws 47 are engineering to hold safely under a tensile force of approximately 10 to 15 thousand pounds but will shear off between 17 and 18 thousand pounds. This is desirable in order to disconnect and retrieve setting sleeve 40, adapter 42, upper setting bar 44 and upper shear block 46. Once these parts are disconnected and tripped uphole, whipstock 2 provides a continuous virtually obstruction free (lower shear block 52 is flush with trough 11 ) tapered path to force a drillstring toward casing 9 for drilling a lateral or avoiding an obstruction.
While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation. | This invention relates to a permanent whipstock assembly which uses camming pivot arms to secure the whipstock at the desired location within a cased wellbore. Camming pivot arms are pivotally attached to the downhole end of a whipstock housing and are further attached to a slip pad. Intentionally induced relative movement of the slip pad and the whipstock housing causes the camming pivot arms to pivot in such a manner that slip pad housing 4 and slip pad 5 are forced away from each other and cammed into the cased borehole. The invention relates specifically to a device that is particularly adapted to be lowered through a small diameter and later to be activated and set in a much larger casing or hole diameter. | 4 |
BACKGROUND OF THE INVENTION
This invention is directed to portable heating equipment capable of directing energies of 1,000 to 20,000 watts or more in a path of predetermined configuration for such purposes as baking paint; curing thermosetting materials; rendering temporary comfort to outside or inside personnel areas exposed to severely cold temperatures; thawing out frozen equipment; or preheating aircraft, automotive, or other engines. For such uses, it is important and desirable to provide a dolly-type heating device capable of all manner of positions in respect to a support plane in order that the radiated energy may be most effectively applied.
Hence, it is a primary object of this invention to provide a dolly-type heater device of articulated construction and with such structural features as to afford a great range of adjustments of the heat radiating section relative to the base of the dolly, and further, to enable the device as a whole to assume a plurality of positions relative to a floor or other support surface.
It is a more specific object to provide a dolly-type heating device especially adapted for the radiation of heat energy from an elongate heater housing such as utilized in the construction of infra-red heating units.
SUMMARY OF THE INVENTION
The present invention achieves the above-mentioned and other objects in a manner not known to the inventor from the prior art in the provision of a dolly-type heating device comprising, as main components, a heater having an elongate housing provided with an open side for radiation, a dolly having a base and a tilt frame in pivotal relation with an upper portion of an upstanding mast of the base. The tilt frame directly supports the heater and thus renders it tiltable through a preselected angle relative to the base and securable to different positions by a releasable detent mechanism such as a link and clamp-screw connection between the mast and the tilt frame.
The geometry of the base, especially that of the mast and the tilt frame, and a strut handle attached to that portion of the tilt frame ordinarily in a radially outward position with its pivotal connection with the mast, is such as to enable tilting of the device as a whole about a tilting axis, e.g., through a pair of dolly wheels, to engage the strut handle with a supporting surface for the device. In this manner, the device utilizes alternate floor-engaging members in combination with other continuously floor engaging means such as coaxial dolly wheels.
DESCRIPTION OF THE DRAWING
FIG. 1 is a side view of a dolly-type heating device according to this invention as oriented in a normal upright position for radiating energy substantially horizontally in the direction of the arrows.
FIG. 2 is a side view of the device of FIG. 1 with the base positioned as shown in FIG. 1 but the heater and tilt frame thereof adjusted for directing radiation in an upwardly vertical direction.
FIG. 3 is a side view of the device of FIGS. 1 and 2 showing the device as adjusted in FIG. 2 tilted about the axis of its dolly wheels to allow a portion of its weight to be supported on a portion of the tilt frame, i.e., a handle strut.
FIG. 4 is a side view of the device of FIGS. 1, 2, and 3 illustrating the use of the handle strut as a floor-engaging means when the device is in a "prone" position for directing radiation vertically upward.
FIG. 5 is a fragmentary perspective view of a modified base for the device of the invention illustrating lateral floor-engaging supports which are adjustable with respect to the main portion of the base.
FIG. 6 is a fragmentary perspective elevation of portions of the mast of the base, the tilt frame, and the pivotal connection thereof.
FIG. 7 is a fragmentary cross section in elevation of portions of the tilt frame and heater housing of the embodiment of FIGS. 1 to 4.
FIG. 8 is a fragmentary perspective view of a modified tilt frame and heater arrangement illustrating pivotal structure for connecting the heater to the tilt frame along a pivotal axis extending in transverse relation to the axis for pivoting the tilt frame relative to the base.
FIG. 9 is a fragmentary view in cross section taken along line VIII--VIII of FIG. 8.
DESCRIPTION OF PREFERRED EMBODIMENTS
In the embodiment shown in FIGS. 1 to 4, 6 and 7, and dolly-type heating device 5 comprises in combination a heater 6 and a dolly 7. The heater comprises a housing 8, a reflector 9 and an electrode terminal box 11. Main elements of the dolly 7 are a base 14 and a tilt frame 15. The base 14 comprises parallel beams 17 and 18, a cross beam 19 connecting intermediate portions of the parallel beams, a shaft 20 mounting coaxial floor-engaging dolly wheels 21 and 22, and a mast 23. The shaft 20 is centered along the tilting axis N--N for the device 5 as a whole. The bars 17, 18 terminate at the ends opposite the wheels 21, 22 in floor-engaging down-turned pads or elements 24, 25 respectively. Such floor-engaging means of the device are arranged to locate the center of gravity of the device in intermediately overhead relationship .
In the form of the invention illustrated, the tilt frame comprises an elongate main member 26 extending lonitudinally approximately in a plane containing the mast 23 to which it is pivotally connected by a pivot joint 27 at axis M--M. The tilting axis M--M preferable extends in a direction parallel to axis N--N. As shown, the tilt frame is pivoted on the upper end portion of the mast approximately midway along the tilt frame length and terminates in end brackets 28, 29 rigidly attached to opposite ends of the main member 26.
The tilt frame further comprises the dual purpose handle strut 31 which is fixedly attached to that portion of the main member which can be rotated in longitudinally outwardly projecting relation with the upper or distal end of the mast 23. As shown, the handle strut 31 is aligned in a general plane perpendicular to axis M--M and containing the mast 23 and main tilting frame member 26. The handle strut 31 extends from its juncture with the main member at a divergent angle of, e.g., 30 to 45 degrees therewith, in a direction away from the heater 6 and away from the axis M--M approximately to or beyond a plane S--S (see FIG. 1). Plane S--S is parallel to axes N--N and M--M and extends through the more adjacent longitudinal extremity of the heater reflector 9 approximately perpendicularly to the plane 33 of the face of the heater. This geometric arrangement permits the use of the handle strut without engagement of any portion of the heater with a floor as shown in FIG. 3
Exemplary of structure for connecting the base or main mast with the tilt frame 15 is that shown in FIG. 6. A tubular bearing 35 is embedded as by welding within the end of the mast 23. A clamp screw 36 having a wing nut 37 extends through the mast with its axis parallel to that of the bearing 35 at a selected radius from the bearing, such as five to ten inches. Tie-means, such as a shaft element 38, welded to the main member 26 has a portion 39 rotatably received in the bearing 35 and secured therein by means, such as a cotter key 41 and washer 42.
Changes in angular positioning of the tilt frame relative to the base 14 about the first axis M--M is accomplished by quick-release adjustable detent means comprising the aforementioned clamp screw 36 and a slotted lever 45 pivoted on the main member at a radius from axis M--M similar to or suitably related to the aforenamed radius of the clamp screw from the axis M--M to enable efficient relative movement of the tilting frame and the mast. The lever 45 has slot 46 through which the screw 36 extends and a face surface 47 engaged by the nut 37 in the tightened condition of the detent means. The lever also has a shaft portion 48 extending at right angles to the length of the lever through a cylindrical bearing 49 fixed within and transversely through the main member 26 along an axis p--p parallel to axis M--M. Shaft portions 39 and 48 are preferably closely diametrically fitted to respective bearings 35 and 49 to eliminate looseness and wobble of the tilt frame relative to the dolly base. Axial movement within the bearing 49 of the lever 45 is limited by the washer 51 and cotter key 52 shown in FIG. 6 attached to portion 48.
FIGS. 8 and 9 depict a modification directed primarily to structure enabling the heater to be pivoted with respect to the tilting frame along an axis R--R which extends in parallel relation with the elongate direction of the heater. Parts in this modified device similar to those of the device of FIGS. 1 to 4, 6 and 7 are indicated by numerals ending in "a ". Exemplary of a mode for effecting such relative adjustment of the heater and tilting frame is structure comprising a tilting frame main member 26a, and end plate 28a of which two are fixed to opposite ends of the main member, and a swivel bracket 55 fixed to the heater housing 8 and pivoted on the end plate 28a by a bolt 56. Fixing of position in the changing from one angular position of the heater relative to the tilting frame to another is obtained in the use of an elongate lever 58 comprising a shaft portion 59 in journal-bearing relation with the swivel bracket 55 at a selected radius from axis R--R, and a clamp screw 61 anchored in the end plate 28 a. Similarly, as described above with respect to lever 45 and clamp 36, the lever 58 has an elongate slot 63 through which extends the screw 61. Fixing and releasing of position is obtained through tightening and loosening a wing nut 64. A position of the heater shown in dot-dash line 65 is illustrated at approximately 90 degrees with respect to the full line position shown in FIG. 8.
Employment of heater-tilting structure such as illustrated in FIGS. 8 and 9 results in shifts of gravity of the device giving rise to the possibility of capsizing. To overcome any such tendency, lateral support of the device may be increased by the provision of means, such as the adjustable lateral elongate legs or braces 71 and 72 shown. The braces 71, 72 are adjustable to positions outside a periphery of the base defined by straight lines extending progressively from one floor-engaging means to the next. In the mode illustrated, the cross beam 19 is tubular, thereby providing an internal passageway of uniform cross section for receiving straight shank portions of the braces 71, 72 in telescoping relationship. The braces may be ordinarily stored in retracted position within the cross member 19. They are secured in laterally extended position by set screws 73, 74 screwed within threaded bosses 75, 76, respectively, of the cross member 19 into engagement with the shanks of braces 71, 72. Each brace has a downturned pad portion 77, 78 for engaging the floor. This arrangement is merely illustrative of many other constructions for obtaining guide relation and securement of lateral braces with respect to the dolly base. | A heating device comprising, as portions, a heater and a dolly of which a tilt frame of the dolly is attached to, or fixed integrally with, the housing of the heater with such adjustability with respect to a base of the dolly to afford universality of position of the heater when taking into account the orientability of the device as a whole. The scope of positioning of the device is greatly amplified by use of a handle strut fixed to the tilt frame. | 5 |
FIELD OF THE INVENTION
The present invention relates to microfilament manufacturing method and manufacturing apparatus therefore and the nanofilament obtained. More specifically, the present inventions relate to microfilament manufacturing means that enables the microfilament to be attenuated until it is nanofilament by achieving a super high draw ratio by irradiating using an infrared light beam.
BACKGROUND OF THE INVENTION
Fibers with fiber diameters smaller than 1 μm, that is, nanometer sized (from several nanometers to several hundreds of nanometers) fibers have gained attention in recent years as revolutionary materials of the future in a broad range of applications such as IT, bio, environmental and other applications. The nanofibers have typically been prepared using an electro-spinning method (henceforth sometimes abbreviated to “ES method”). (See U.S. Pat. No. 1,975,504; You Y., et al Journal of Applied Polymer Science , Vol. 95, p. 193-200, 2005.) However, the ES method is a complicated manufacturing method since polymer needs to be dissolved in solvent and the solvent must be removed from the product obtained. In addition, molecules lack orientation in the filament obtained, and many quality problems such as the presence of small resin particles, referred to as balls and shots were encountered in the fiber aggregates obtained.
The inventors previously invented a means to obtain microfilaments and non-woven fabrics using a super high draw ratio that exceeded one thousand through molecular orientation conducted according to an infrared method. (See Japanese Patent Publication No 2003-166115 and 2004-107851; International Publication No. WO2005/083165A1; Akihiro Suzuki and one other “ Journal of Applied Polymer Science ”, Vol. 88, p. 3279-3283, 2003; Akihiro Suzuki and one other, “ Journal of Applied Polymer Science ”, Vol. 92, p. 1449-1453, 2004; Akihiro Suzuki and one other, “ Journal of Applied Polymer Science ”, Vol. 92, p. 1534-1539, 2004.) These are simple means, and microfilaments with molecular orientation and non-woven fabrics thereof were obtained. The present invention is a further development of the same theme and relates to a means that allows microfilaments to be manufactured continuously and consistently by enabling filaments to be attenuated into nanofilaments.
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
The present invention further develops the inventors' previous technology described above. The objective of the invention is to make it possible to readily obtain a filament comprising a microfilament that may be as small as a nanofilament and non-woven fabrics that is an aggregate thereof using a simple means without requiring a special high precision, high performance apparatus. Furthermore, the present invention relates to the nanofilaments obtained according to the manufacturing means of the present invention from large diameter filaments comprising polyesters such as poly(ethylene terephthalate), poly(ethylene naphthalate) and the like, biodegradable polymers such as poly(lactic acid), poly(glycolic acid) and the like, and fluorinated polymers such as tetrafluoroethylene.perfluoroalkyl vinyl ether copolymers (PFA) and the like and to present a non-woven fabrics used in diverse applications such as medical applications, filters and the like.
Means to Solve the Problem
The present invention presents a drawing method that draws an original filament and attenuates it into the nanofilament range and an apparatus therefore. The original filament in the present invention refers to a filament previously manufactured and wound on a reel and the like. In addition, a filament obtained by cooling a molten material or coagulating a dissolved material in a spinning step may become an original filament in the present invention subsequent to the spinning step. Here the filament refers to a basically continuous fiber and is distinguished from staple fiber that varies in length from several millimeters to several tens of millimeters. The original filament preferably exists individually, but several to several tens of filaments may be gathered and used.
The filaments drawn in the present invention are all referred to as filaments, and those characterized as nanofilament fibers mentioned above are also included. A filament drawn in the present invention is drawn for at least several minutes without breaking in most cases and can be considered a continuous filament with a small filament diameter, d. However, staple fibers characterized as nanofilament fibers mentioned above can be manufactured depending upon the conditions.
The filament of the present invention may be a single filament comprising one filament or a multi-filament comprising multiple filaments. As far as the tension and the like on one filament are concerned, it is reported as “per single yarn”. However, the expression signifies “per single filament” when one filament is involved and, when a multifilament is involved, signifies “per individual single filament” that constitutes the multi-filament.
A feature of the present invention is the fact that a filament with a high degree of molecular orientation of at least 50% measured by birefringence can be used, and the fact that such a original filament with a high degree of orientation can be drawn to a super high draw ratio such as several hundred differentiates the method from other drawing methods. When an original filament is highly oriented as in this case, the drawing is often initiated using an expanded section with a diameter greater than the original filament diameter.
Filaments comprising thermoplastic polymers, for example, polyesters such as poly(ethylene terephthalate), aliphatic polyesters and poly(ethylene naphthalate); polyamides such as nylon (includes nylon 6 and nylon 66); polyolefins such as polypropylene and polyethylene; poly(vinyl alcohol) type polymers; acrylonitrile type polymers; fluorinated polymers such as tetrafluoroethylene.perfluoroalkyl vinyl ether copolymers (PFA); vinyl chloride type polymers; styrene type polymers; polyoxymethylene; ether ester type polymers and the like may be used as the original filament in the present invention. Poly (ethylene terephthalate), nylon (including nylon 6 and nylon 66) and polypropylene are particularly suited for manufacturing the microfilament and the non-woven fabrics comprising the microfilament of the present invention since they have good drawing properties and molecular orientation. In addition, biodegradable polymers and polymers that are degraded and absorbed in vivo such as poly (lactic acid), poly (glycolic acid) and the like and high strength, high elasticity filaments and the like such as polyarylates, aramides and the like are stretched well in the present invention using infrared beams and are particularly suited for manufacturing microfilaments and micro non-woven fabrics of the present invention. Composite filaments such as core-sheath type filaments and the like comprising the polymers may be used in the original filament. Now, the polymers mentioned above are sometimes referred to as polyester “types” and as polymers with polyester as the “main component” when the polymer mentioned above is present in at least 85% (by weight %).
An original filament transferred from a filament transportation device is drawn in the present invention. Various types of transportation device may be used as long as the transportation device can move a filament at a constant speed using a combination of nip rollers and several stages of drived rollers. In addition, when only a filament of constant length needs to be drawn, an original filament may be grasped with a chuck and may be supplied to an orifice after it travels downward at a constant rate.
The original filament moved by a filament transportation device is also allowed to pass through an orifice aided by a gas flow in the direction of the motion. The original filament is in an atmosphere maintained at P 1 pressure until the filament is transported into the orifice using the filament transporting device, and the space that is maintained at P 1 pressure is referred to as a filament supply chamber. Constant pressure does not particularly need to be maintained when P 1 is atmospheric pressure. An enclosure (a chamber) is needed to maintain the pressure when P 1 represents an added or reduced pressure, and a pressurizing pump or a pressure reducing pump is needed. The orifice entrance needs to be maintained at P 1 in the present invention, but the area in which the original filament is stored and the transportation section of the original filament do not necessarily have to maintain P 1 . However, maintaining both areas at the same pressure is preferred since installing separate chambers is complicated.
The section downstream from the orifice exit is maintained at P 2 and becomes a drawing chamber in which the original filament exiting the orifice is heated using an infrared light beam and is drawn. The original filament is moved inside the orifice by the air flow created by the pressure difference (P 1 −P 2 ) between the original filament supply chamber at P 1 and the drawing chamber maintained at P 2 . When P 2 is atmospheric pressure, the pressure does not need to be maintained at a constant level. When P 2 is an added pressure or reduced pressure, an enclosure (a chamber) is needed to maintain the pressure and a pressurizing pump or a pressure reducing pump is also needed.
The difference in P 1 and P 2 pressures is created when P 1 >P 2 . Based on the experimental results, P 1 ≧2P 2 is preferred. However, P 1 ≧3P 2 is more preferred, and P 1 ≧5P 2 is preferred most.
A particularly desirable way to conduct the present invention is for P 2 to be under reduced pressure (less than atmospheric pressure). By following this procedure, P 1 can be atmospheric pressure and the apparatus can be radically simplified. In addition, reducing the pressure is relatively simple to achieve. Furthermore, air that is ordinarily present at atmospheric pressure does not interfere with the air released from the orifice when it is released into an area of reduced pressure. This allows the released air and the filament accompanying it to be very stable. As a result, the drawing properties are stable, and the drawing can yield filaments with properties in the nanofilament category. In addition, when a high speed fluid is ejected from a nozzle, a large amount of accompanying flow occurs around the nozzle. Such accompanying flow is minimized under reduced pressure, and the filament flow exiting from the nozzle is not disturbed. These factors were thought to play a role in stabilizing the drawing process. A special feature of the present invention is that a filament characterized as a nano micron material is obtained using such a simple means.
Room temperature air is ordinarily used for P 1 and P 2 . However, heated air is used when a manufacturer wants to pre-heat an original filament or wants to heat treat a drawn filament. In addition, an inert gas such as nitrogen and the like is used to prevent filament oxidation and a gas containing water vapor or moisture is also used to prevent moisture loss.
The original filament supply chamber and the drawing chamber in the present invention are connected to the orifice. A high speed gas flow is created inside the orifice by the pressure difference, P 1 >P 2 , in the narrow space between an original filament and the internal diameter of the orifice. The internal diameter (D) of the orifice and the diameter (d) of the fiber should not be too different in order to generate a high speed gas flow. According to experimental results, a relative diameter range expressed as 1.2d<D<10d is acceptable. However, the range of 1.5d<D<7d is preferred, and the range of 2d<D<5d is most preferred. When the nozzle diameter is too large in comparison to the filament diameter, the gas flow through the nozzle is not very fast and the P 2 pressure is not sufficiently low. In addition, when the nozzle diameter is too close to the filament diameter, air flow resistance is generated, and the speed of the gas flowing through the nozzle does not rise. Furthermore, not only does the diameter of a drawn filament increase as the air flow exceeds the preferred range described above, but also the filament diameter becomes less consistent and lumps tend to form more readily.
The internal orifice diameter (D) refers to the diameter of the orifice exit section. However, the diameter (D) of the narrowest section is used when the orifice cross section is not circular. Similarly, the smallest diameter is used as (d) for a filament diameter when the cross section is not circular. The diameter is ordinarily measured at ten locations using the smallest cross section as the standard, and the mathematical average is used. The lower end of a vertically positioned orifice is designated as the exit since an original filament ordinarily passes from top to bottom. However, the upper exit from an orifice is designated as the exit when an original filament passes from the bottom to the top. Similarly, the exit is located to the side of an orifice when an orifice is positioned horizontally and an original filament passes horizontally.
An orifice interior structure that offers little resistance is preferred since a gas flows through the interior at high speed. The orifice in the present invention does not necessarily need to be cylindrical. Although the orifice cross section is preferably circular, an orifice with an elliptical or rectangular cross section may also be used when multiple numbers of filaments are allowed to pass or when a filament shape is elliptical or rectangular. In addition, the use of an orifice with a large entrance that allows easy access to an original filament in which the exit is the only narrow section is preferred since the resistance to the filament movement is low and the speed of the gas leaving the orifice exit is high.
The role of the orifice in the present invention is different from the role an air supply pipe plays prior to drawing in the previous inventions of the inventors and the like. The air supply pipe was previously used to aim a laser at a fixed position in a filament and played the role of transporting an original filament to the fixed position with as little resistance as possible. The present invention adds to the previous inventions and differs from them in that a high speed regulating gas flow is generated by the pressure difference between pressure P 1 in an original filament supply chamber and pressure P 2 in a drawing chamber. Now, tension is applied on a molten filament using an air sucker and the like in an ordinary spun bonded non-woven fabrics manufacturing process. However, the action mechanism and effects of the air sucker in spun bonded non-woven fabrics manufacturing process and the orifice in the present invention are completely different. In a spun bonded process, a molten filament is transported using a high speed fluid inside an air sucker and the filament diameter is attenuated almost completely inside the air sucker. In contrast, a solid original filament is transported by an orifice, and attenuating of the filament does not begin inside the orifice. In addition, a high speed fluid is generated by sending high pressure air into an air sucker in a spun bonded fabric production process. The present invention differs in that the high speed fluid inside the orifice is generated by the pressure differential between the chambers before and after the orifice. The effects are also different. The best filament diameter one can expect from the spun bonded fabric production process is about 10 μm, but a nanofilament obtained in the present invention is smaller in diameter than 1 μm making the present invention much more advantageous effectives.
In the present invention, the drawing is preferably conducted at a rate in the speed of sound region. The speed of air leaving an orifice is represented by the following equation (Graham's theorum) where ρ represents air density.
v={ 2( P 1 −P 2)/ρ} 1/2
Here, the results posted on Table 1 were calculated when P 1 was atmospheric pressure and P 2 was changed. Based on the results, the air speed (v) is in the speed of sound region (340-400 m/sec) when the reduced pressure zone P 2 was 30 kPa, 20 kPa and 6 kPa in the present invention. The results obtained by calculating the ratio (mach M) with the speed of sound are also posted to the table. A microfilament with a filament diameter in the nanometer range can be obtained using the present invention by raising the air speed (v) in a drawing chamber to the speed of sound range when the speed of sound range is defined as the area in which M is at least 0.98.
TABLE 1
The Air Speed
P2
V
M
kPa
(m/sec)
at 298.5° K
50
289
0.834
30
342
0.987
20
365
1.05
6
396
1.15
The air speed at the orifice exit by the pressure change of the drawing chamber (degree of vacuum)
P1: atmospheric pressure
The original filament released from an orifice is heated at the orifice exit using an infrared light beam and is drawn by the tension applied to the filament by the high speed fluid from the orifice. The position directly under the orifice, based on experimental results, refers to the position in which the center of an infrared light beam is located 30 mm or less from the orifice tip. However, 10 mm or less is preferred, and 5 mm or less is most preferred. When a filament leaves the orifice, the original filament vibrates, does not remain in a set position and is not stable enough to be exposed to an infrared light beam. In addition, the tension applied to the filament by the high speed gas released from the orifice becomes weaker as the filament moves away from the orifice. The stability is thought to decrease also.
A feature of the present invention is the heating and drawing of an original filament using an infrared light beam. The infrared rays are defined as radiation with wavelengths of from 0.78 μm to 1 mm. However, the absorption attributed to a C—C bond in polymeric compounds is centered around 3.5 μm, and absorption bands of from 0.78 μm to 20 μm are particularly preferred. The infrared radiation in this zone is focused into a spot or a line using a mirror or a lens, and a heater referred to as a spot heater or line heater that concentrates the heating zone to an original filament can be used. A line heater is ideal when multiple numbers of original filament are moving in parallel lines.
A laser beam is particularly preferred as the infrared light beam in the present invention. Among lasers, carbon dioxide gas lasers with wavelengths of 10.6 μm and YAG (yttrium, aluminum, garnet type) lasers with wavelengths of 1.06 μm are particularly preferred. A laser can narrow the radiation range (light beam) and focuses on a specific wavelength. Therefore, a laser uses energy efficiently. The power density of a carbon dioxide gas laser of the present invention is at least 50 W/cm 2 , but a power density of at least 100 W/cm 2 is preferred and at least 180 W/cm 2 is most preferred. The super high draw ratio of the present invention is made possible by the concentration of high density energy power on a narrow drawing zone.
Now, irradiation using an infrared light beam in this case is preferably conducted from multiple locations. The reason for this preference is the difficulties encountered in drawing due to asymmetric heating caused by the heating of a filament from only one side when the melting temperature of a polymer is high, when fusion is difficult to achieve and when a filament is difficult to draw under any condition. Such multiple site irradiations may be achieved by using multiple light sources composed of infrared light beams but may also be accomplished by reflecting the beam from a single light source using mirrors to irradiate multiple times along the passage of an original filament. The mirrors may be fixed mirrors, but a rotating mirror such as a polygon mirror may also be used.
An original filament may be irradiated from multiple locations using multiple light sources as another means of irradiating from multiple locations. Multiple stable low cost laser emitters that are relatively small scale laser beam sources may be used as high powered light sources.
The original filament of the present invention is heated to a temperature suitable for drawing using an infrared light beam irradiated by an infrared heating means (includes lasers). An original filament is heated by the infrared light beam in the present invention. However, the range that is heated to a temperature suited for drawing is preferably within 4 mm up and down (8 mm length) along the filament axis direction in the center of the filament. The range of 3 mm up and down is more preferred, and the range of 2 mm up and down is most preferred. The diameter of the beam is measured along the axis direction of a filament in motion. When multiple original filaments are used, a slit-shaped beam may also be used. In such a case, the narrowest section preferably coincides with the axis direction of the original filament. The present invention was able to draw a filament to a nano range with a high degree of attenuating by suddenly stretching the filament in a narrow zone and was able to minimize the breakage caused by stretching. Now, when the filament irradiated with the infrared light beam is a multi-filament, the center of the filament described above refers to the center of the multi-filament bundle.
A filament drawn according to the present invention may be accumulated in a drawing chamber and removed but can also be wound in terms of an aggregate or non-woven microfilament fabrics by stacking the filament on a moving conveyer. Non-woven fabrics comprising nanofilament can be manufactured in the manner described above. As the conveyer in the present invention, a net-like moving body is ordinarily used, but the filament also may be accumulated on a belt or a cylinder.
Now, a laminated material on a cloth may be manufactured by accumulating the microfilament drawn according to the present invention on a cloth-like material in motion. An accumulated material or non-woven fabrics comprising nanofilament is particularly difficult to handle since the constituting filament is very fine, but the handling is improved when laminated with a cloth-like material in the manner described. In some applications, the filament can be used in applications such as filters and the like without any further treatment when the filament is laminated on commercially available spun bonded non-woven fabrics and the like. As the cloth-like material, a woven material, knit material, non-woven fabrics, felt and the like are used. In addition, the filament may be accumulated on a film in motion.
A filament drawn according to the present invention may be subsequently continuously wound on a bobbin, cheese, hank and the like through guide rollers and the like to prepare a wound product.
The objective of the present invention is to manufacture a microfilament by drawing an original filament using a super high draw ratio. The microfilament in the present invention refers to attenuated filament obtained by drawing an original filament at a ratio of at least one hundred. Of the microfilaments, those with a filament diameter smaller than 1 μm are specifically referred to as nanofilaments. The present invention can yield a nanofilament even from an original filament having a diameter of at least 100 μm by drawing the original filament at a draw ratio of at least 10,000.
The draw ratio (λ) in the present invention is represented by the following equation using the diameter (do) of an original filament and the diameter (d) of the filament after drawing. In this case, the calculation is executed using a constant filament density. The filament diameter is measured using a scanning electron microscope (SEM). A photograph of an original filament was taken at a magnification of 350, and a photograph of a drawn filament was taken at a magnification of 1,000 or more. An average of one hundred sites was reported.
λ=( do/d ) 2
One feature of the drawn filament obtained according to the present invention is the uniformity of the filament diameter. The filament diameter distribution was calculated using one hundred measurements on the SEM photograph described above using measurement software. The standard deviation was calculated from the measurement values and was used as a measure of filament diameter distribution.
The molecules in a drawn filament of the present invention become oriented upon drawing, and the filament is thermally stable. The drawn filament of the present invention has a very small filament diameter, and the molecular orientation of the filament is measured with difficulty. The thermal analysis results indicated that the drawn filament of the present invention did not simply become thinner but underwent molecular orientation. The differential thermal analysis (DSC) of an original filament and drawn filament was measured at a heating rate of temperature rise of 10° C./min using a THEM PLUS2 DSC8230 manufactured by Rigaku Co.
Advantageous Effects of the Inventions
The ES method previously used to manufacture nanofibers is complex manufacturing method that requires dissolution of a polymer in a solvent and removal of the solvent from the finished product and contributes to a high manufacturing cost. In addition, the finished product also encounters quality problems such as the presence of resin pieces referred to as lumps and balls, a broad filament diameter distribution and the like. In addition, the fiber obtained was short (staple fiber), and the length ranged from several millimeters to at most several tens of millimeters. However, basically continuous filaments that are at least several meters long can be obtained by using the present invention.
The present invention does not need a special high performance apparatus that operates at high precision, and a microfilament with improved molecular orientation can be obtained readily using a simple means. In addition, a draw ratio of at least 10,000 can be achieved using almost all thermoplastic polymers, and a super fine filament with a diameter of less than 1 μm in the nanofilament range can be manufactured. Furthermore, a super fine filament with a very narrow filament diameter distribution reflected in a standard deviation of 0.1 or lower can be obtained even though the average filament diameter is in the nanofilament range.
The pressure difference upstream and downstream from an orifice is utilized as the means to generate a high speed gas flow that imparts the drawing tension in the super drawing method of the present invention involving an infrared light beam. The approach creates a very stable high speed gas flow and yields not only a nanofilament but also enables a stable continuous operation as far as productivity is concerned.
The drawing process of the present invention is particularly stable due to the reduced pressure in the drawing chamber, and a stable nanofilament manufacturing process can be realized. An air flow released at high speed is not disturbed under reduced pressure, and a stable air flow is thought to be achieved.
In addition, the present invention can present long fiber non-woven fabrics comprising super fine filaments with diameters in the nanofilament range. Furthermore, a laminated material is also obtained by laminating the filament on non-woven fabrics such as commercially available spun bonded non-woven fabrics and the like.
The present invention can yield a super fine filament with a diameter in the nanofilament range from a filament comprising biodegradable polymers used in regenerated medical materials such as poly(lactic acid) and poly(glycolic acid) and the like that ordinarily have poor drawing properties. The ES method previously used to manufacture nanofibers used a solvent such as chloroform and the like, and the method not only required dissolution step and solvent removal step but also used such toxic solvents. The use of such solvents made it difficult to use the filaments in regenerated medical treatment applications.
The nanofilaments obtained according to the present invention not only dramatically improve filter efficiencies in conventional air filter applications but also are adaptable as revolutionary materials with a broad range of applications in IT, bio and environmental fields. Another feature of the present invention is that microfilaments and nanofilaments can be easily obtained from filaments of high performance polymers such as polyarylate type polymers, poly(ethylene naphthalates), fluorinated polymers and the like, previously considered difficult to attenuate due to the narrow range of conditions amenable for spinning and drawing thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a conceptual process diagram for the production of a drawn filament of the present invention.
FIG. 2 is a conceptual diagram for an apparatus in which the original filament supply chamber of the present invention is at atmospheric pressure.
FIG. 3 is a conceptual diagram of an apparatus in which the original filament supply chamber is under added pressure and the drawing chamber is at atmospheric pressure.
FIG. 4 is a conceptual diagram of an orifice used in the present invention.
FIG. 5 is a conceptual diagram of an example of another orifice used in the present invention.
FIG. 6 is a conceptual diagram showing a case in which the infrared ray radiation of the present invention is reflected using a mirror.
FIG. 7 is a conceptual diagram displaying the state of a light beam when multiple infrared ray irradiation devices of the present invention are used.
FIG. 8 is a scanning electron microscope photograph (magnification: 10,000) of a poly(ethylene terephthalate) nanofilament drawn by the present invention.
FIG. 9 is a filament diameter distribution diagram for the nanofilament of the present invention shown in FIG. 8 .
FIG. 10 is a scanning electron microscope photograph (magnification: 3,000) of a poly(lactic acid) nanofilament drawn by the present invention.
FIG. 11 is a filament diameter distribution diagram for the nanofilament of the present invention shown in FIG. 10 .
FIG. 12 is a scanning electron microscope photograph (magnification: 5,000) of a PFA filament drawn by the present invention.
FIG. 13 is a scanning electron microscope photograph (magnification: 1,500) of a PEN filament drawn by the present invention.
FIG. 14 is a scanning electron microscope photograph (magnification: 3,000) of a PGA filament drawn by the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The execution modes of the present invention are described below based on the figures. FIG. 1 is a conceptual diagram that shows the fundamental basis for the production of microfilaments in the present invention, and a cross section of an apparatus is shown. An original filament 1 is supplied from a reel 11 on which the filament had been wound, the filament is supplied at a constant rate using nip rollers 13 a and 13 b through a comb 12 and led to an orifice 14 . In the steps up to this point, the original filament supply chamber 15 is maintained at pressure P 1 . The pressure P 1 is adjusted using a duct 16 connected to a pressurizing pump (not illustrated), a valve 17 that controls the degree of pressurization, the rate of rotation of the pressurization pump and the like. Now, when the supply chamber 15 of the original filament is under reduced pressure, a vacuum pump is used in place of the pressurizing pump. A pressure gauge 18 ) is installed in the original filament supply chamber 15 , and the pressure is controlled.
A drawing chamber 21 under P 2 pressure is located downstream from the orifice 14 exit. The original filament 1 exiting the orifice 14 is introduced into the drawing chamber 21 along with a high speed air flow induced by the pressure difference (P 1 −P 2 ) between the original filament supply chambers 15 and the drawing chamber. The original filament 1 transferred is irradiated directly under the orifice using a laser generating device 5 with a laser beam 6 in a heating zone M of a constant width to the moving original filament. The laser beam 6 may be irradiated from multiple locations as shown in FIG. 6 and FIG. 7 . A laser beam power meter 7 is installed where the laser beam 6 reaches, and the laser power is preferably controlled to a constant level. The original filament is drawn upon heating by the laser beam 6 due to the downward tension on the lower section of the filament applied by the high speed air flow induced by the P 1 −P 2 pressure difference, moves downward in the form of a stretched filament 22 and accumulates below. The pressure P 2 is controlled using a duct 23 leading to a vacuum pump (not illustrated), a valve 24 that controls the degree of pressurization, the rotation rate of the vacuum pump, the bypass valves and the like. A pressure gauge 25 is installed in the drawing chamber 21 . Now, when the drawing chamber 21 is a pressurized chamber, a pressurization pump is used in place of a vacuum pump.
FIG. 2 is a cross sectional diagram of an apparatus showing an example in which the pressure, P 1 , in an original filament supply chamber is atmospheric pressure. The original filament that exits an orifice 14 yields a drawn filament 32 in a drawing chamber 31 through the same steps shown in FIG. 1 .
FIG. 3 is an angled view of an apparatus seen from the side showing an example in which the original filament supply chamber 41 is a pressurized chamber and the drawing chamber is under atmospheric pressure. Many original filaments 1 are wound on reels 42 and are attached to a platform 43 (only three filaments are shown to avoid complicating the diagram). The original filaments 1 a , 1 b and 1 c are moved by the rotation of transfer nip rollers 45 a and 45 b through snail wires 44 a , 44 b and 44 c used as guiding tools and are led to orifices 46 a , 46 b and 46 c . A drawing chamber under P 2 pressure that is atmospheric pressure is downstream from the orifice 46 exit and a specific chamber does not need to be installed. The original filament 1 exiting the orifice 46 is transferred to a drawing chamber along with a high speed air flow induced by the pressure difference P 1 −P 2 between the original filament supply chamber 41 and the drawing chamber. The moving original filament 1 is irradiated directly under the orifice with a line of infrared light beams 48 in a heating zone N of a constant width using an infrared ray irradiation device 47 . The original filament 1 is drawn by the tension applied to the lower part of the filament by the high speed air flow induced by the P 1 −P 2 pressure difference and moves down in the form of drawn filaments 49 a , 49 b and 49 c . The angled lines show the range of the heating section N of the infrared light beam along the moving route of the original filament 1 . The light beam that passes through without being absorbed by the original filament 1 is reflected by the concave mirror 50 shown by the dotted lines and is returned to the heating section N to condense the light. The concave mirror 50 is located on the infrared ray irradiation device 47 side also (however, a window is open in the progression section for the light beam from the infrared ray irradiation device), but the illustration is omitted. The drawn filaments 49 a , 49 b and 49 c accumulate on a moving conveyer 51 and form a web 52 . Air is withdrawn in the direction of the arrow (p) from the back side of the conveyer 51 by negative pressure suction and contributes stability to the web 52 movement. The web 52 on the conveyer 51 is pressed or embossed as needed and is wound in the form of non-woven fabrics.
Now, as far as the orifice in FIG. 3 is concerned, cylindrical orifices 46 a , 46 b and 46 c are installed for each of the original filaments. The orifice shown in FIG. 5 b that can allow numerous original filaments to simultaneously move may also be used as these orifices.
A rolled cloth-like material 54 attached to a platform 53 in FIG. 3 may be transferred to a conveyer, laminated with a web 52 to form a laminated material made from a web comprising microfilaments and a cloth-like material.
FIG. 4 shows a cross sectional view of one example of the orifice used in the present invention. The figure shows an original filament 1 with a filament diameter d exiting a simple cylindrical orifice 56 . The internal orifice diameter is D 1 at the exit. The filament 1 exiting the orifice is irradiated with an infrared light beam M. The infrared light beam M is positioned so that the distance L from the orifice exit to the center of the infrared light beam M is as short as possible.
Another example of an orifice is shown in the orifice cross section view of FIG. 5 . A type of an orifice 57 that has a large orifice entrance with a narrowing exit with an internal diameter of D 2 is shown in Fig. (a). An example of an orifice 58 that sends out numerous filaments simultaneously is shown in Fig. (b) with a conceptual diagram of a partial cross section. The exit diameter D 3 in Fig. (b) is shown with a diameter in the thickness direction that is the direction of narrowest section.
The infrared light beam used in the present invention is shown in FIG. 6 using an example in which an original filament is irradiated from multiple locations. A view from above is shown in Fig. A, and a side view is shown in Fig. B. The infrared light beam 61 a radiated by an infrared light beam irradiation device through a zone P (shown using dotted lines in the figure), reaches a mirror 62 , becomes an infrared light beam 61 b upon reflection by the mirror 62 and is again converted into an infrared light beam 61 c upon reflection by a mirror 63 . The infrared light beam 61 c passes through the zone P and irradiates an original filament at a position one hundred twenty degrees from the initial original filament irradiation location. The infrared light beam that passed through zone P becomes an infrared light beam 61 e upon reflection by a mirror 65 . The infrared light beam 61 e moves through the zone P and irradiates the original filament 1 at a position one hundred twenty degrees removed from the initial original filament irradiation location for the infrared light beam 61 c . In the manner described above, an original filament 1 can be evenly heated from symmetrically located positions that are one hundred twenty degrees from each other by generating three infrared light beam 61 a , 61 b and 61 c.
Another example of using an infrared light beam of the present invention in which an original filament is irradiated from multiple locations is shown in FIG. 7 . An example in which multiple light sources are used is shown using a plain view. The infrared light beam 67 a radiated from an infrared ray irradiation device is radiated toward an original filament 1 . In addition, an infrared light beam 67 b radiated from a separate infrared ray irradiation device is also radiated toward the original filament 1 . In the manner described above, multiple inexpensive laser transmission devices that are stabilized with relatively small scale light sources may be used as a high power light source to provide radiation from multiple light sources. Now three light sources are shown in the figure, but two may also be used and four or more may also be used. The multiple light sources described above are particularly effective for drawing multiple filaments.
Example 1
An undrawn poly(ethylene terephthalate) (PET) filament (filament diameter 182 μm) was used and was drawn using the drawing apparatus shown in FIG. 2 . The laser the emitter used at this point was a carbon dioxide laser emitter with laser output of 8 W, and the beam diameter (light beam) was 2.0 mm. The type of orifice shown in FIG. 5 a was used as the orifice, and the orifice diameter D 2 was 0.5 mm. The degree of vacuum in the drawing chamber was adjusted to 8 KPa. The supply speed of the original filament was changed from 0.1 m/min to 0.2 m/min, 0.3 m/min and 0.4 m/min, and the filament diameters of the filaments obtained are shown in Table 2. In addition, the filament diameters when the laser output was changed from two watts to eight watts are also shown. According to the data in the table, a nanofiber with an average filament diameter of 0.313 μm (313 nanometers) was obtained when using eight watts of laser power and a supply speed of 0.1 m/min. The standard deviation for the filament diameter was 0.078 at that point indicating a very uniform filament diameter distribution. Electron microscope photographs (magnification 10,000) of the filaments obtained using these conditions are shown in FIG. 8 . The photographs were obtained for filaments prepared under conditions that included a laser output of eight watts and original filament transport rates of 0.1 m/min (a), 0.2 m/min (b), 0.3 m/min (c) and 0.4 m/min (d). Nanofilaments with a filament diameter of less than 1 μm were obtained under other conditions also. The draw ratio reached a factor of 338,100 (about 340,000 fold) since the diameter of the original filament was 180 μm and that of the filament obtained was 0.313 μm. The filament diameter distribution of the filaments obtained under these conditions is shown in FIG. 9 . The filament diameters were very even in all cases, and the data in Table 2 indicate that the standard deviation was often 0.3 or less. In good cases, the standard deviation was 0.2 or lower and, in some cases, was 0.1 or lower. Filaments with diameters smaller than 1 μm were obtained under most conditions, and the drawing factor was 33,000 or greater. In addition, the filaments drawn in the manner described above were subjected to DSC, and the results are shown in Table 3.
TABLE 2
PET
Power
Density
Supply Speed
Supply Speed
Supply Speed
Supply Speed
W/cm 2
0.1 m/min
0.2 m/min
0.3 m/min
0.4 m/min
256.6
max
0.57 μm
max
0.78 μm
max
1.45 μm
max
2.33 μm
(8 W)
min
0.18 μm
min
0.22 μm
min
0.17 μm
min
0.23 μm
av.
0.31 μm
av.
0.39 μm
av.
0.63 μm
av.
079 μm
S.D.
0.078
S.D.
0.113
S.D.
0.231
S.D.
0.307
191.0
max
1.27 μm
max
1.37 μm
Max
1.76 μm
max
1.48 μm
(6 W)
min
0.20 μm
min
0.16 μm
min
0.24 μm
min
0.21 μm
av.
0.54 μm
av.
0.47 μm
av.
0.77 μm
av.
0.73 μm
S.D.
0.191
S.D.
0.197
S.D.
0.278
S.D.
0.254
127.0
max
2.52 μm
max
2.28 μm
Max
2.18 μm
max
2.27 μm
(4 W)
min
0.28 μm
min
0.19 μm
min
0.52 μm
min
0.61 μm
av.
0.79 μm
av.
0.82 μm
av.
1.15 μm
av.
1.13 μm
S.D.
0.419
S.D.
0.368
S.D.
0.315
S.D.
0.304
63.7
max
2.44 μm
max
5.13 μm
Max
6.97 μm
max
9.46 μm
(2 W)
min
0.56 μm
min
1.37 μm
min
1.42 μm
min
2.54 μm
av.
1.20 μm
av.
2.81 μm
av.
2.96 μm
av.
4.61 μm
S.D.
0.395
S.D.
0.829
S.D.
0.954
S.D.
1.035
Original filament supply speed and filament diameter (μm)
P2: 8 kPa
S.D.: Standard Deviation
TABLE 3
PET DSC Measurements
Supply
Power
heat of
Speed
Density
m, p,
fusion
enthalpy
crystallinity
m/min
W/cm 2
° C.
J/g
J/g
%
0.4
256.6
257.7
−47.7
17.6
23.8
0.3
256.6
256.7
−57.6
12.8
35.4
0.2
256.6
256.9
−67.4
18.8
38.4
0.1
256.6
256.9
−54.2
10.7
34.4
0.1
191.0
257.7
−60.1
23.3
29.1
0.1
127.0
256.7
−71.1
30.4
32.2
0.1
63.7
257.5
−60.7
23.9
29.0
(Heating rate of temp. increase 10° C./min)
Example 2
The same undrawn poly(ethylene terephthalate) filament used in Example 1 was used as the original filament. The same drawing chamber and laser emitter used in Example 1 were used. The experiment was conducted using a filament supply speed of 0.1 m/min at different degrees of vacuum for the drawing chamber. When the degree of vacuum was 8 KPa, the average filament diameter was 0.31 μm as shown in Example 1. When the degree of vacuum was 6 KPa, the average filament diameter was 0.42 μm. When the degree of vacuum was 24 KPa, The average filament diameter was 0.82 μm. Filaments with filament diameters less than 1 μm were obtained even under these conditions.
Example 3
An undrawn poly(lactic acid) (PLLA) filament (filament diameter 75 μm) was used as the original filament and was drawn using the drawing apparatus of FIG. 2 . A carbon dioxide gas laser emitter with a laser output of eight watts was used for this case, and the beam diameter (light beam) was 2.0 mm. The type of orifice described in FIG. 5( a ) was used as the orifice, and the orifice diameter d 2 was 0.5 mm. The degree of vacuum in the drawing chamber was adjusted to 8 kPa. The original filament supply speed was changed from 0.1 m/min to 0.8 m/min, and the filament diameters of the filaments obtained are shown in Table 4. In addition, the filament diameters when the laser output was changed from two watts to eight watts are also shown in the table. According to the data in the table, a nanofiber with an average filament diameter of 0.13 μm (130 nanometer) was obtained when the laser power was eight watts (watt density 256.6 W/cm 2 ) and the supply speed was 0.1 m/min. The filament diameter standard deviation was 0.0356 in this case indicating a very uniform filament diameter distribution. The standard deviation for the drawn filament diameter was 0.2 or lower for most cases when the laser power density was high. Many samples had a standard deviation for the same of 0.1 or lower indicating that the filament diameter was very uniform. A scanning electron microscope photograph (magnification 3,000) of the nanofilament obtained under these conditions is shown in FIG. 10 . Nanofilaments with filament diameters less than 1 μm were also obtained under other conditions. The draw ratio reached 322,830 (about 320,000 fold) since the original filament was 75 μm and the filament obtained was 0.13 μm. The filament diameter distribution of the filament obtained under these conditions is shown in FIG. 11 . In addition, a filament with a filament diameter less than 1 μm was obtained under most conditions, and the ratio was at least 22,500 when the filament diameter was less than 0.5 μm.
TABLE 4
PLLA
Power
Density
Supply Speed
Supply Speed
Supply Speed
Supply Speed
W/cm 2
0.1 m/min
0.4 m/min
0.6 m/min
0.8 m/min
63.7
max
8.41 μm
max
7.39 μm
max
23.3 μm
max
40.0 μm
(2 W)
min
0.58 μm
min
2.54 μm
min
2.17 μm
min
5.10 μm
av.
1.54 μm
av.
5.59 μm
av.
7.52 μm
av.
13.7 μm
S.D.
0.842
S.D.
1.004
S.D.
2.35
S.D.
9.40
127.0
max
0.66 μm
max
0.64 μm
max
1.50 μm
max
1.72 μm
(4 W)
min
0.16 μm
min
0.30 μm
min
0.27 μm
min
0.29 μm
av.
0.27 μm
av.
0.45 μm
av.
0.48 μm
av.
0.69 μm
S.D.
0.069
S.D.
0.074
S.D.
0.140
S.D.
0.254
191.0
max
0.36 μm
max
0.73 μm
max
0.69 μm
max
0.66 μm
(6 W)
min
0.08 μm
min
0.15 μm
min
0.14 μm
min
0.15 μm
av.
0.21 μm
av.
0.36 μm
av.
0.36 μm
av.
0.36 μm
S.D.
0.058
S.D.
0.109
S.D.
0.109
S.D.
0.117
256.6
Max
0.23 μm
max
0.56 μm
max
1.05 μm
(8 W)
min
0.5 μm
min
0.11 μm
min
0.10 μm
av.
0.3 μm
av.
0.29 μm
av.
0.31 μm
S.D.
0.036
S.D.
0.098
S.D.
0.171
Original filament supply speed and filament diameter (μm)
P2: 8 kPa
S.D.: Standard Deviation
Example 4
A filament (filament diameter 100 μm) comprising an undrawn tetrafluoroethylene.perfluoroalkyl vinyl ether copolymer (PFA) was used as the original filament, and the drawing was conducted using the drawing apparatus of FIG. 2 to initially obtain a drawn filament with a diameter of 6 μm (filament after primary drawing, ratio 277.8 fold). A secondary drawing was conducted on the filament from the primary drawing using the apparatus shown in FIG. 2 . The laser emitter and the like used in this case were the same devices used in Example 1. The type of orifice described in FIG. 5( a ) was used as the orifice, and the orifice diameter d 2 was 0.5 mm. The degree of vacuum in the drawing chamber was adjusted to 6 kPa. The filament diameters and the standard deviations for the filament diameters for the filaments obtained when the supply speed for the primary drawn filament was changed from 0.1 m/min to 0.2 m/min, 0.3 m/min and 0.4 m/min are shown in Table 5. A drawn nanofiber with a filament diameter of less than one micron was obtained. The standard deviations for many of the filaments were 0.1 or lower indicating that the filament diameters were very uniform. In addition, the filament was drawn by a ratio of at least one hundred even when the secondary drawing only was used, and some filaments were drawn by a ratio of at least four thousand. In addition, the draw ratio was at least ten thousand (ratio of ten thousand) in terms of total draw ratio (primary draw ratio×secondary draw ratio), and some were drawn to a draw ratio of at least one million (multiple of one million). A scanning electron microscope photograph (magnification five thousand) of a drawn filament is shown in FIG. 12 . The DSC experimental results for the filaments listed in Table 6 are also shown. The fusion calories increased with the decreasing average filament diameter, and the melting point was found to rise slightly.
TABLE 5
PFA
Supply Speed m/min
0.1
0.2
0.3
0.4
max μm
0.67
0.69
0.72
0.71
min μm
0.067
0.099
0.19
0.22
av. μm
0.093
0.19
0.26
0.35
second draw
4,161
997
529
300
ratio
total draw
1,155,914
276,842
146,743
83,526
ratio
Standard
0.029
0.046
0.98
0.101
Deviation
Original filament supply speed and filament diameter (μm)
P2: 6 kPa
Power Density: 254.6 W/cm 2
first draw ratio: 227.8
TABLE 6
PFA DSC Measurements
Supply Speed
heat of fusion
m.p.
m/min
J/g
° C.
0.1
−17.7
304.6
0.2
−16.7
303.8
0.3
−15.3
303.5
0.4
−15.2
302.4
(Power Density: 254.6 W/cm 2 )
Example 5
The filament obtained after the primary drawing in Example 4 was used as the sample, and the apparatus shown in FIG. 1 was used. A pressurizing pump was used to raise the pressure (P 1 ) in the original filament supply chamber to 120 kPa. The pressure (P 2 ) in the drawing chamber was set at 44 kPa, 30 kPa and 26 kPa for experiments using a vacuum pump. The results are shown in Table 7. Other conditions used were the same as those used in Example 4. Nanofilaments with an average filament diameter of less than 1 μm were obtained in these experiments. The standard deviation for the filament diameters was 0.2 or lower while the filament diameter was 0.097 μm and the filament diameter standard deviation was 0.03 when the degree of vacuum was high for P 2 .
TABLE 7
PFA
P2
max filament
mini filament
av. filament
Standard
pressure
(μm)
(μm)
(μm)
Deviation
26 kPa
0.652
0.058
0.097
0.031
30 kPa
0.715
0.215
0.270
0.115
44 kPa
1.211
0.428
0.515
0.181
Original filament supply speed: 0.1 m/min
P1: 120 kPa
Power Density: 254.6 W/cm 2
Example 6
A filament (filament diameter 170 μm) comprising an undrawn poly(ethylene 2,6-naphthalate) (PEN) was used as the original filament, and the drawing was conducted using the drawing apparatus shown in FIG. 2 . The same laser emitter and the like used in Example 1 were used in this case. The beam diameter was 2.4 mm, and the beam was brought closer directly under the orifice so that the edge of the beam came in contact, and the center of the beam was used for irradiation 1.2 mm directly under the orifice. When the location at which the beam was used was moved 2 mm away while P 2 in Table 8 was 6 kPa, the average filament diameter was 0.295 μm and the standard deviation was 0.075. When the location was moved an additional 6 mm, the average filament diameter was 0.410 μm, and the standard deviation was 0.074, indicating the importance of irradiating an original filament with a beam extremely close to the orifice exit. The type of orifice shown in FIG. 5 a ) was used, and the orifice diameter (d 2 ) was 0.5 mm. Table 8 shows the experimental results when P 1 was atmospheric pressure and P 2 was changed. When P 2 was 30 kPa or lower, the average filament diameter was less than one micron. The filament standard deviation was 0.1 or lower indicating how very uniform the filament diameter was in spite of the fact that the filament obtained was such a fine nanofilament. When P 2 was 30 kPa or lower, the draw ratio was at least ten thousand and was found to be at least twenty-eight thousand. A scanning electron microscope photograph (magnification 1,500) of the filament obtained using the conditions shown in Table 8 are shown in FIG. 13 .
TABLE 8
PEN
max
mini
av.
P2
filament
filament
filament
draw
Standard
pressure
(μm)
(μm)
(μm)
ratio
Deviation
6 kPa
0.400
0.120
0.259
149,073
0.054
20 kPa
0.660
0.330
0.463
46,648
0.062
30 kPa
0.760
0.420
0.595
28,247
0.064
40 kPa
1.720
0.850
1.186
7,110
0.187
Original filament supply speed: 0.1 m/min
Original filament diameter: 100 μm
Power Density: 177 W/cm 2
Example 7
A filament (filament diameter 100 μm) comprising undrawn poly(glycolic acid) (PGA) was used as the original filament and was drawn using the drawing apparatus shown in FIG. 2 . The same laser emitter and the like used in Example 1 were used in this case. The laser power density was 177 W/cm 2 , and a beam with a beam diameter of 2.4 mm was used for the irradiation 1.2 mm directly below the orifice. The type of orifice shown in FIG. 5( a ) was used as the orifice, and the orifice diameter (d 2 ) was 0.5 mm. The degree of vacuum in the drawing chamber was adjusted to 6 kPa. The filament diameters of the filaments obtained when the original filament supply speeds were changed from 0.1 m/min to 0.4 m/min, 0.8 m/min and 1.2 m/min are shown in Table 9. The data in the table indicates that nanofilament with an average filament diameter of 0.388 μm (388 nanometer) was obtained when the supply speed was 0.1 m/min, and the standard deviation for the filament diameter at the time was 0.096 indicating a very uniform filament diameter distribution. The scanning electron microscope photograph (magnification 3,000) of the nanofilaments obtained under the conditions is shown in FIG. 14 . Nanofilaments with filament diameters less than 1 μm were obtained under other conditions. The original filament was 100 μm, and the filament obtained was 0.388 μm. Therefore, the draw ratio reached 66,418 (about 66,000). The filament diameters were also uniform under other conditions, and the standard deviation was 0.2 or lower. In addition, filaments smaller than 1 μm were obtained under all conditions, and the draw ratios were at least 10,000 but also could be at least 100,000.
TABLE 9
PGA
Supply Speed m/min
0.1
0.4
0.8
1.2
max μm
0.670
1.200
0.870
1.430
min μm
0.240
0.190
0.250
0.190
av. μm
0.388
0.464
0.482
0.537
draw ratio
191,951
134,234
124,396
100,218
Standard
0.096
0.123
0.137
0.172
Deviation
Original filament supply speed and filament diameter (μm)
P2: 6 kPa
Power Density: 177 W/cm 2
INDUSTRIAL APPLICABILITY
The microfilament of the present invention can not only be used in air filters and the like in which conventional microfilaments have been used, but also as a revolutionary material in a broad range of applications such as medical filters, IT performance materials and the like. | The objective of the present invention is to enable a microfilament that is a nanofilament to be manufactured continuously and consistently from all thermoplastic polymers without requiring a specialized high precision•high performance apparatus and also to present the nanofilament manufactured as described. The present invention comprises a microfilament in a nanofilament region and the manufacturing means thereof wherein a original filament transferred using a filament transfer means is supplied to an orifice under pressure P 1 and is heated and drawn using an infrared light beam directly under the orifice under pressure P 2 (P 1 >P 2 ). | 3 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the benefit of German patent application 100 45 918.8 filed Sep. 16, 2000, herein incorporated by reference and German patent application 101 29 132.9 filed Jun. 16, 2001.
FIELD OF THE INVENTION
[0002] The present invention relates to an open-end spinning arrangement and, more particularly, to an open-end spinning arrangement having a stationary spinning box housing arranged on the base frame of a textile machine for seating a high speed spinning rotor in a vacuum-charged rotor housing, having a sliver opening unit connected to the spinning box housing via a linear guide, and having a cover element for closing the rotor housing.
BACKGROUND OF THE INVENTION
[0003] Various embodiments of open-end spinning arrangements are known in connection with rotor spinning machines.
[0004] For example, German Patent Publication DE 43 23 213 A1 describes an open-end spinning arrangement with a support frame which has been fixed in place on the machine base frame of a spinning machine. The support frame has a support disk seating arrangement, an axial bearing, as well as a rotor housing, which can be closed by means of a pivotably seated cover element.
[0005] In this open-end spinning arrangement, a so-called conduit plate, a sliver draw-in cylinder, an opening roller, and a single-piece fiber guide conduit are arranged in the cover element.
[0006] The drive for the opening roller is provided in a customary way by means of a tangential belt, while the sliver draw-in cylinder is connected via a worm gear with a drive shaft extending over the length of the machine.
[0007] In the closed state of the rotor housing, a so-called conduit plate adapter is arranged on the conduit plate and projects into the spinning rotor. The conduit plate adapter carries a yarn-draw off nozzle and the mouth of the fiber guide conduit, so that the individual fibers exiting the mouth of the fiber guide conduit are directly fed to the fiber slide surface of the spinning rotor arranged immediately adjacent the fiber guide conduit.
[0008] In the course of producing high-quality open-end yarns, it is necessary to meet defined conditions regarding the mutual arrangement of the spinning elements, for example their distance and/or their size. Therefore, the pivotable arrangement of the cover element results limits the minimum diameter of the usable spinning rotor.
[0009] Thus, even with the arrangement of the pivot axis of the cover element almost vertically below the rotor opening, such as is described in German Patent Publication DE 43 23 213 A1, and with the relatively shallow pivot range thereby achieved, the employment of very small spinning rotors, for example of a diameter of <28 mm, in the known spinning arrangements is very problematical.
[0010] Therefore attempts have already been made in the past to construct open-end spinning machines whose rotor housing cannot be closed by means of a pivotably seated cover element, but which has a cover element which is connected via a linear guide device with a stationary part of the open-end spinning arrangements.
[0011] German Patent Publications DE-OS 23 27 347 and DE-OS 23 27 348 show and describe rotor spinning arrangements with such a linear guide.
[0012] As can be seen in particular from FIGS. 1 and 2 of the drawings of these patent applications, these open-end spinning arrangements each have a stationary bearing housing for receiving a spinning rotor revolving inside a rotor housing, as well as a cover element, which is connected with the stationary bearing housing to be displaceable by means of a linear guide.
[0013] Furthermore, as already known, a sliver draw-in cylinder, as well as an opening roller, are arranged inside the cover element.
[0014] In such arrangement, the drive of the opening roller and the sliver draw-in cylinder takes place via central drive mechanisms extending over the length of the machine and are arranged fixed in place in the area of the stationary spinning rotor bearing housing.
[0015] In the interest of the uniformity of the yarn count, the sliver draw-in cylinder in particular must be driven free of slippage. Therefore, the transfer of the drive energy from the stationary drive mechanisms extending over the length of the machine to the sliver feed and opening devices arranged in the displaceably seated cover element is overall quite complicated and elaborate.
[0016] Because of their relatively failure-prone construction as a whole, the above described open-end spinning arrangements were not well-received and have therefore not been accepted in practical use.
[0017] Open-end spinning arrangements are also known wherein a sliver opening roller driven by an individual motor and/or a sliver draw-in cylinder driven by an individual motor are each arranged within the pivotably seated cover element.
[0018] An open-end spinning arrangement designed in this manner is described in German Patent Publication DE 43 09 947 A1, for example.
[0019] However, in connection with the spinning arrangement in accordance with such German Patent Publication DE 43 09 947 A1 it is disadvantageous that the cover element is connected with the spinning rotor bearing housing by means of a relatively difficult-to-access pivot shaft which, as explained above, leads to a definite restriction of the minimum rotor diameter, as well as, for example, to difficulties in connection with possibly required repairs of these individual drives.
[0020] Thus, with these known spinning arrangements the sliver opening unit driven by the individual motor and the sliver draw-in cylinder driven by the individual motor, integrated into the cover element, are relatively difficult to remove.
SUMMARY OF THE INVENTION
[0021] In view of the above described state of the art, an object of the present invention is to provide an improved rotor spinning machine. A more particular object of the invention is to further increase the productivity of rotor spinning machines by means of raising the number of revolutions of the spinning rotor and also to assure that the spinning arrangements are easy to access and to repair when needed.
[0022] In accordance with the invention, this object is addressed by providing an open-end spinning arrangement which basically comprises a stationary spinning box housing adapted to be arranged on a base frame of a textile machine for seating a high speed spinning rotor in a vacuum-charged rotor housing, a sliver opening unit connected to the spinning box housing via a linear guide, and a cover element for closing the rotor housing. In accordance with the present invention, the sliver opening unit is connected releasably to a connecting bracket of the linear guide, and the sliver opening unit comprises an opening roller driven by an individual motor and a sliver draw-in cylinder driven by a step motor arranged inside the sliver opening unit.
[0023] Advantageously, the use of a linear guide for seating the sliver opening unit enables very small spinning rotors to be employed if needed.
[0024] In turn, the use of extremely small spinning rotors makes possible a considerable increase of the number of revolutions of the spinning rotor, while at the same time assuring that the conditions of compatibility required for producing high-quality yarn, for example in regard to the positioning of the conduit plate adapter of the cover element, can be exactly maintained.
[0025] In a preferred embodiment, a step motor is employed for driving the sliver draw-in cylinder, and the sliver opening roller is driven by an individual motor, which assures in a simple and cost-effective manner a uniform individual fiber feeding into the spinning rotor, and thereby assures the exact uniformity of the yarn count at any time during the spinning process.
[0026] Furthermore, by means of an easily releasable connection of the sliver opening unit to the connecting bracket of the linear guide, it is furthermore assured that not only all components, for example the spinning rotor, remain easily accessible, but also that, when needed, the entire sliver opening unit can be replaced without problems, for example so that its individual drive mechanisms can be checked, and repaired in a special shop, if needed.
[0027] Thus, the preferred embodiment of open-end spinning arrangement in accordance with the present invention not only leads to a noticeable improvement of the productivity of such textile machines, but is also distinguished by ease of repair.
[0028] Furthermore, essential spinning components can be rapidly and dependably exchanged, for example in case of a batch change.
[0029] In one embodiment, the sliver opening unit is connected to the connecting bracket of the linear guide by means of a pivot shaft and is secured by means of a locking device.
[0030] In this manner, following the release of the locking device, the sliver opening unit can be tilted without problems via the pivot shaft, so that the greatest access to the spinning rotor, for example, is provided.
[0031] Since the pivot shaft is fixed in place in bearing slots which are open toward the front side of the arrangement, the sliver opening unit can also be removed without problems when needed and can be exchanged for another sliver opening unit, for example.
[0032] It is also advantageously provided that the locking device comprises a locking bolt, on which a spring force acts and which is displaceably seated on the connecting bracket of the linear guide, and a corresponding connecting bore is provided in the area of the sliver opening unit.
[0033] Thus, during the spinning operation, the sliver opening unit is pivoted inwardly to be dependably secured by means of latching of the locking bolt in the connecting bore and, at the same time, it is possible by means of retracting the locking bolt, which is preferably manually performed, that the locking device can easily be removed from service and the sliver opening unit can then be pivoted forward without problems and can be removed, if required.
[0034] It is further preferred that the sliver opening unit is connected with the connecting bracket of the first linear guide by means of a second, short linear guide.
[0035] In this manner, guide bolts may be arranged on the connecting bracket of this first linear guide, which slide in corresponding guide bores of a connecting body of the sliver opening unit.
[0036] The guide bolts in the present invention may each have an arresting groove in the area of their free ends, which can be engaged by a corresponding latching element.
[0037] These latching elements are preferably embodied as locking levers, which can be manually operated.
[0038] Thus, in the assembled state, two pivotably seated locking levers, which are biased by a spring element in an inwardly pivoted direction, engage the arresting grooves of the guide bolts and thereby interlockingly fix the sliver opening unit on the connecting bracket of the first linear guide.
[0039] In the present invention, the sliver draw-in cylinder, as well as the sliver opening roller, are driven by individual motors.
[0040] In a preferred embodiment, the sliver opening roller is driven by means of an individual electric motor drive, for example a d.c. or a.c. motor.
[0041] In this case this individual drive mechanism is embodied as a compact external rotor motor.
[0042] In an advantageous embodiment, a coupling device is arranged in the area of the connecting bracket of the first linear guide, which allows the mechanical separation of the electrical and pneumatic supply lines leading to the sliver opening unit.
[0043] In this manner, if required, the individual drive mechanisms arranged inside the sliver opening unit may be connected by supply lines, which can be easily separated, to an energy supply and control device arranged, for example, in the area of the stationary bearing device of the spinning rotor.
[0044] In a preferred embodiment, the coupling device comprises a coupling plate arranged on the connecting bracket of the first linear guide which, in the operating position of the open-end spinning arrangement, works together with a correspondingly embodied coupling element at the connecting body of the sliver opening unit.
[0045] Thus, a coupling element which, for example, is arranged in the area of the sliver opening unit, is embodied as a so-called “mother element”, whose contact bushings are in contact with the individual drive mechanisms of the sliver opening unit.
[0046] In the locking position, contact pins which are arranged on the coupling plate, enter into these contact bushings and in this manner constitute an electrically and pneumatically continuous connection.
[0047] To assure the exact positioning of the sliver opening unit at any time, the connecting bracket of the first linear guide has a centering device on its rear side. Preferably, the centering device comprises two hardened fitting pins which, in the operating position, enter into corresponding centering bores of a stationary bearing block.
[0048] At least one of the centering elements of the centering device functions as a key switch. Thus, in the operating position of the sliver opening unit at least one of the fitting pins acts on an electrical switch such that this switch is kept in the closed position and therefore the supply line to the drive mechanisms of the sliver opening unit carries electrical current.
[0049] However, each relative movement between the sliver opening unit and the associated stationary bearing block immediately leads to the opening of the key switch and therefore to an interruption of the energy supply to the individual drive mechanisms.
[0050] Thus, the key switch assures in a simple manner that the releasable coupling device inserted into the supply lines for the individual drive mechanisms is always switched to be without electrical current or pressure prior to each separation.
[0051] Further details of the invention will be understood from the following description of an exemplary embodiment in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0052] [0052]FIG. 1 schematically depicts the spinning operation of an open-end spinning arrangement according to the present invention, having a stationary spinning box housing and a sliver opening unit displaceably connected thereto by means of a linear guide, with a pivot shaft and a locking device arranged on a connecting bracket of this linear guide,
[0053] [0053]FIG. 2 is a similar schematic illustration of the open-end spinning arrangement represented in FIG. 1 in a non-operating condition wherein the rotor housing is open because of a linear displacement of the sliver opening unit,
[0054] [0054]FIG. 3 is a schematic illustration of the open-end spinning arrangement in accordance with FIG. 2, wherein the sliver opening unit has been outwardly tilted around the pivot shaft in the area of the connecting bracket,
[0055] [0055]FIG. 4 is a top perspective view depicting a first embodiment of the connecting bracket of the first linear guide with a coupling plate of an electrical/pneumatic coupling device,
[0056] [0056]FIG. 5 is an elevational view, partially cross-sectioned, of a centering device arranged on the connecting bracket, which has a centering element acting on a key switch,
[0057] [0057]FIG. 6 is a schematic illustration of an open-end spinning arrangement in accordance with FIG. 1 with a second embodiment of a first linear guide,
[0058] [0058]FIG. 7 is a cross-sectional view, taken along section line VII-VII in FIG. 6, of a bearing block for receiving the linear guide represented in FIG. 6,
[0059] [0059]FIG. 8 is a schematic illustration of an open-end spinning arrangement with a linear guide in accordance with FIGS. 1 to 3 , wherein a second linear guide for the releasable connection of the sliver opening unit is arranged in the area of the connecting bracket for the linear guides,
[0060] [0060]FIG. 9 is a schematic illustration of the open-end spinning arrangement in accordance with FIG. 8, wherein the second linear guide is represented in a separated state,
[0061] [0061]FIG. 10 is a top perspective view of the connecting bracket of the first linear guide with the guide bolts of the second linear guide, as well as the coupling device, arranged in the area of the second linear guide, and
[0062] [0062]FIG. 11 is a detailed perspective view of an arresting lever for the second linear guide.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0063] Referring now to the accompanying drawings and initially to FIG. 1, an open-end spinning arrangement in accordance with the present invention is identified as a whole by the reference numeral 1 and is represented in its operating position, i.e. in the closed state.
[0064] In the exemplary embodiment represented, the open-end spinning arrangement 1 has a stationary spinning box housing 2 , as well as a sliver opening unit 4 , which is displaceably connected relative to the spinning box housing 2 by means of a linear guide 3 .
[0065] A bearing device 5 is arranged inside the spinning box housing 2 which receives an individual drive 6 for a spinning rotor 7 . As is customary, the spinning cup of the spinning rotor 7 revolves in a rotor housing 8 , which is connected via a pneumatic line 9 to a vacuum source 10 and can be closed by means of a seal 24 inserted into a cover element 23 of the sliver opening unit 4 .
[0066] As indicated, an energy supply and control device 25 , which is a part of the spinning unit, is also arranged inside the spinning box housing 2 .
[0067] As is customary, the sliver opening unit 4 has an opening roller housing 11 , in which rotates an opening roller 12 driven by an individual motor.
[0068] The sliver opening unit 4 also has a sliver draw-in cylinder 14 which is driven by a step motor 15 .
[0069] The opening roller 12 in the present exemplary embodiment is driven by a d.c. motor 13 embodied as an external rotor motor, and thereby separates a sliver 18 supplied from a sliver condenser 16 into individual fibers (not represented) in a known manner.
[0070] Thus, the sliver 18 , which is fed into the opening roller housing 11 between a feeding trough 17 of the sliver condenser 16 and the sliver draw-in cylinder 14 , is separated into individual fibers, which are thereafter pneumatically conducted to the spinning rotor 7 through a fiber guide conduit 19 , which terminates in a so-called conduit plate adapter 20 formed in the cover element 23 .
[0071] In the course of this operation, the individual fibers are directly fed through the mouth of the fiber guide conduit 19 in the conduit plate adapter 20 onto an oppositely located fiber slide surface of the spinning rotor 7 .
[0072] A yarn 21 created in the course of the spinning process in the spinning rotor 7 is removed through a small yarn removal tube 22 and is wound into a cheese (not represented).
[0073] As represented in FIG. 1, the rotor housing 8 charged with a vacuum is closed during the spinning operation via the seal 24 introduced into the cover element 23 arranged on the sliver opening unit 4 . The sliver opening unit 4 is fixed in place on a connecting bracket 30 of a first linear guide 3 and is pivotable and, if required, easily releasable.
[0074] The first linear guide 3 itself is essentially comprised of a stationary bearing block 26 , which is fixed in place on the spinning box housing 2 against removal, for example by a welded connection.
[0075] In accordance with the exemplary embodiment, for example of FIGS. 1 and 8, the bearing block 26 has guide bores 27 , in which elongated guide members, for example two cylindrical guide rods 28 , are slidingly guided.
[0076] The guide rods 28 of this first linear guide 3 are connected at their rearward ends by means of a spacer 29 , while their forward ends are fixedly seated in a connecting bracket 30 .
[0077] In accordance with the exemplary embodiment in FIG. 1, the connecting bracket 30 has a locking device 31 , a guide slot 32 for a pivot shaft 33 arranged on the sliver opening unit 4 , as well as a coupling plate 44 of an electric/pneumatic coupling device 34 , which will be explained hereinafter by way of example with the aid of FIG. 4.
[0078] Additionally, the open-end spinning arrangement 1 preferably has a pneumatic dirt removal device 40 . In the operating position of the open-end spinning arrangement indicated in FIG. 1 or FIG. 8, a dirt reception funnel 39 of this dirt removal device 40 is positioned exactly underneath the dirt outlet of the sliver opening unit 4 .
[0079] As indicated in the drawing figures, the dirt removal device 40 either has its own vacuum source 41 , or the dirt removal device 40 is connected directly to the vacuum system of the open-end spinning arrangements 1 , i.e. to the vacuum source 10 .
[0080] [0080]FIG. 2 shows the above described open-end spinning arrangement 1 in a position wherein the sliver opening device 4 has been horizontally displaced by means of the first linear guide 3 into a rear position, i.e. the rotor housing of the open-end spinning arrangement is open.
[0081] In this manner, the cover element 23 , or the seal 24 in the sliver opening unit 4 , have been separated from the rotor housing 8 , which is open toward the front of the arrangement, so that the spinning rotor 7 is already relatively easily accessible.
[0082] In the position represented in FIG. 2, the centering device 46 represented in greater detail in FIG. 5, is out of service, and the coupling device 34 is thus without electrical current and pressure.
[0083] More specifically, the centering bolts 55 , which as a rule are hardened, of the centering device 46 have been withdrawn from their associated centering bores 56 . In this case, at least one of these centering bolts 55 has released a pusher 57 on which a spring element 58 of a key switch 47 acts and in this manner has caused the interruption of the energy supply to the individual drive mechanisms 13 , 15 in the sliver opening unit 4 .
[0084] As indicated above, in the position represented in FIG. 2, the sliver opening unit 4 is still fixedly locked to the connecting bracket 30 of the first linear guide via the pivot shaft 33 , as well as the locking device 31 , while the electrical current supply has already been switched off by the key switch 47 .
[0085] By means of releasing the locking device 31 , i.e. following the retraction of the manually operable locking bolt 42 out of the connecting bore 43 in the sliver opening unit 4 , the sliver opening unit 4 can be tilted around the pivot shaft 33 , as indicated in FIG. 3, and can be removed without problems through the forwardly-open guide slots 32 , if required.
[0086] In the course of this tilting process, the electrical/pneumatic coupling device 34 , which is also without electrical current and pressure, is disconnected. Specifically, a coupling element 45 arranged on the sliver opening device 4 , whose electrical components have spring-loaded contact pins, for example, is pivoted backward together with the sliver opening unit 4 such that these contact pins lose their mechanical contact at the contacts 59 of the coupling plate 44 .
[0087] In the course of this pivoting movement of the sliver opening unit 4 , a pneumatic coupling 60 which is in contact with the pneumatic lines 35 , is also disconnected.
[0088] [0088]FIGS. 6 and 7 show a further possible embodiment of such a first linear guide 3 .
[0089] In such embodiment, a box-like hollow profiled element 52 is provided in place of cylindrical guide rods.
[0090] The hollow profiled element 52 is displaceably seated in a cutout 53 of a stationary bearing block 26 and preferably has sliding faces 61 , which are spaced apart from each other on its exterior, as can be seen in FIG. 7 in particular. These sliding faces 61 are guided in a bearing bushing 54 , which is fixed in place in the cutout 53 of the bearing block 26 and is made of brass, for example.
[0091] In this manner, the bearing bushing 54 , which may be made as one or two parts, guides the hollow profiled section 52 over large surfaces, so that a stable guide device is provided.
[0092] A conduit 62 arranged inside the hollow profiled section 52 can be used in this embodiment for receiving the supply lines 35 , 36 .
[0093] [0093]FIGS. 8, 9 and 10 show a further preferred embodiment of the invention.
[0094] As known from the embodiment in accordance with FIGS. 1 to 3 , the releasably arranged sliver opening unit 4 is displaceably connected with the stationary spinning box housing 2 by means of a first linear guide 3 .
[0095] However, here a second linear guide 70 is arranged in the area of the connecting bracket 30 of the first linear guide 3 , which is essentially comprised of relatively short guide bolts 63 fixed in place in the connecting bracket 30 , as well as guide bores 69 cut into the connecting body 71 of the sliver opening unit 4 .
[0096] In the area of their free ends, the guide bolts 63 each have an arresting groove 66 , which in the installed state is engaged by one of the locking levers 64 arranged on the connecting body 71 of the sliver opening unit 4 .
[0097] The locking levers 64 , which are shown in greater detail in FIGS. 10 and 11 in particular, are seated for limited rotatability around a pivot shaft 68 , in vertical guide slots 65 of the connecting body 71 .
[0098] In addition, the arresting levers 64 are acted upon, for example by a spring element 67 , in a manner such that in the installed state they automatically snap into the arresting grooves 66 at the guide bolts 63 and thereby fix the sliver opening unit 4 securely, but to be easily releasable at any time in case of need, in place on the connecting bracket 30 of the first linear guide 3 .
[0099] Furthermore, a coupling device 34 is arranged between the connecting bracket 30 of the first linear guide 3 and the connecting body 71 of the sliver opening unit 4 . This coupling device 34 , which can be released by a relative movement of the second linear guide 70 , has a coupling plate 44 , which is fixed in place on the connecting bracket 30 and has contact plugs, which work together with appropriate contact bushings of a coupling element 45 arranged on the contact body 71 of the sliver opening unit 4 , as indicated by way of example in FIG. 10.
[0100] It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of 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. | An open-end spinning arrangement ( 1 ) comprises a stationary spinning box housing ( 2 ) arranged on a base frame of a textile machine for seating a high speed spinning rotor ( 7 ) in a vacuum-charged rotor housing ( 8 ), a sliver opening unit ( 4 ) connected to the spinning box housing ( 2 ) via a linear guide ( 3 ), and a cover element ( 23 ) for closing the rotor housing ( 8 ). The sliver opening unit ( 4 ) is releasably connected to a connecting bracket ( 30 ) of the linear guide ( 3 ), and an opening roller ( 12 ) driven by an individual motor and a sliver draw-in cylinder ( 14 ) driven by a step motor ( 15 ) are arranged inside the sliver opening unit ( 4 ). | 3 |
BACKGROUND OF THE INVENTION
One of the significant problems in the underground implantation of utility elements, such as telephone lines and electric power lines, is the accurate and reliable marking of the location of these elements to prevent damage to the element by others disturbing the ground in the area and even damage in some cases caused by the utilities' own employess digging too close to the underground elements. This problem is magnified where the buried utility is fragile, such as in underground fiber optic telephone transmission lines.
The comon practice today is that before disturbing the ground in an area suspected to contain underground utilities, the contractor contacts the subject utility and someone from that utility responds by coming out to the area and temporarily marking the location of its buried elements with paint usually from a commmon paint spray can or temporary stakes and pennants. This procedure has many disadvantages, one being that it is costly for the utility to employ marker people for this purpose because such marking requests are very frequent. Furthermore, it is not always possible for the marking person to accurately mark the location of the buried element either because of his or her own errors or due to errors in the location drawing that he has used as a guide.
For these reasons it has for many years been desirable to design a utility marking system that is permanent, rather than temporary, since this permits accurate marking of the location of underground elements if the marker is installed at the time of original utility element ground implantation because its correct location is easily physically ascertainable then without resort to any locating maps. However, because these so-called "permanent" markers are subject to theft, vandalism and damage resulting from ground moving equipment, they have not proved permanent at all and, therefore, have not been used extensively by the utility companies.
It is a primary object of the present invention to provide a marker assembly that will ameliorate the problems noted above in marking underground utilities.
SUMMARY OF THE PRESENT INVENTION
In accordance with the present invention a permanent marker assembly is provided for indicating underground utility elements that includes a non-removable, hammer drivable plastic stake that holds a tamper-proof marker in position close to the ground surface.
Toward this end the present marker assembly includes a one-piece injection moldable high impact strength plastic stake having an integral hammer impacting head at one end and two integral plastic flexible barbs at its point end that prevent removal of the stake from the ground. The stake has a generally rectangular cross-section that prevents rotation of the stake relative to the ground.
The marker is a shallow cup-shaped one-piece plastic molding that has directional arrows molded on its upper surface that cannot be removed. This marker has relatively thin walls and is constructd of an elastomeric plastic having a Shore A durometer of approximately 90, so that if anyone attempts to pry the marker upwardly from the ground, it will simply bend over the top of the stake and spring back to its ground position when released. This not only prevents permanent damage to the marker but also prevents stake removal by prying on the marker.
The marker has a generally rectangular opening that slidably and non-rotatably receives the stake so that the direction of the arrows on the marker remain unchanged over time relative to the ground surface.
Prior to implantation, the stake is assembled to the marker by sliding the point of the stake through the rectangular marker slot which compresses the barbs on the stake inwardly. Then the stake is driven into the ground by hammering the head of the stake making certain to drive the stake into the ground at an angular orientation so that the utility indicating arrows point in the correct direction since the direction cannot be changed thereafter. The flexible barbs on the stake point prevent removal of the stake, and the head of the stake prevents removal of the marker from the stake. The low profile of the marker easily permits equipment to pass thereover, such as mowing equipment, without damaging the marker or the stake.
Other objects and advantages of the present invention will appear more clearly from the following detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the present marker assembly shown implanted in the ground;
FIG. 2 is an enlarged top view of the present marker assembly;
FIG. 3 is a front view of the marker assembly illustrated in FIGS. 1 and 2 with the marker shown in cross-section;
FIG. 4 is a side view of the marker assembly illustrated in FIG. 3;
FIG. 5 is a cross-section of the marker assembly illustrating the interconnection between the marker and the stake taken generally along line 5--5 of FIG. 3;
FIG. 6 is a cross-section of the marker shank taken generally along line 6--6 of FIG. 3;
FIG. 7 is a front view of the marker assembly illustrated in FIG. 3, showing the slidable relation between the marker sub-assembly and the stake;
FIG. 8 is a front view of the marker assembly illustrated in FIG. 3, showing ground implanted with a prying implement attempting to pry the underside of the marker sub-assembly;
FIG. 9 is a view of an implanted marker assembly according to the present invention with a lawn mower passing freely thereover;
FIG. 10 is a perspective view of a modified form of the present marker assembly adapted to receive a secondary vertical marker;
FIG. 11 is a fragmentary longitudinal section of the marker illustrated in FIG. 10; and
FIG. 12 is a cross-section showing the interconnection between the secondary marker and the stake taken generally along line 12--12 of FIG. 11.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings and particularly FIGS. 1 to 9, a marker assembly 10 is illustrated consisting generally of a one-piece plastic stake 11 that holds a one-piece plastic marker 11 permanently in position against ground upper surface 13, both axially and rotationally.
The stake 11 is a one-piece plastic molding constructed of either a high impact Delrin or Styrene. Stake 11 includes a straight shank portion 15, having a generally rectangular cross-section as shown in FIG. 6, with spaced flanges 17 and 18 interconnected by a web 19, with a central cross flange 21 extending parallel to the flanges 17 and 18. The flanges 17 and 18 converge slightly at the forward end of the stake beginning approximately at point 24, and terminate in a point 26, having a rectangular cross-section with forwardly converging walls 28 and 29. The point 26 has a pair of rearwardly extending flexible barbs 32 and 33, having straight rearwardly and outwardly directed flexible portions 35, each ending in an arcuate gripping portion 37.
The rear end of the stake 11 has an integral impact receiving cylindrical head 38 formed on top of a central solid rectangular web 39 and cross web 21 (See FIG. 5).
The stake 11 holds the marker 12 in position on ground surface 13, and the marker is a one-piece plastic molding, preferably constructed of a high impact flexible thermoplastic material such as a vinyl acetate with an elongation of 750% and a Shore A durometer of approximately 90. One such plastic that has been found suitable is Dupont Corporation's Elvax™ 460.
The marker 14 is shaped generally as a shallow cup and includes a relatively thin top wall 40 that curves into an annular peripheral wall 41 with a central boss 42, having a generally rectangular opening 44 therethrough that is complementary in shape to the cross-section of the stake shank portion 15 immediately beneath the head 38. This complementary relationship of the marker opening 44 and the stake 11 beneath the head 38 prevents relative angular movement between the stake and the marker.
The upper surface or face 45 of the marker 12 has molded directional arrows 46 and 47 therein, as well as warning and telephone information 49 formed by engraving directly into the mold cavities for the marker 12 so that they are permanent and cannot be removed by peeling labels or paint wearing off due to environmental conditions.
The axial length of the marker 12 is less than 3/4 inches so that, as seen in FIG. 9, when implanted against the ground by the stake 11, equipment such as lawn mowing equipment, may pass unobstructed thereover.
The marker assembly 10 is preferably ground implanted when the underground utility is originally installed to accurately locate the utility elements, such as buried cables. The assembly is installed by inserting stake point 26 through marker aperture 44 sliding the stake forwardly through the aperture. Aperture 44 cams the flexible barbs 32 and 33 radially inwardly during this movement so that they pass through aperture 44. After passing through aperture 44 the barbs 32 and 33 spring outwardly to the position illustrated in FIG. 7. With the marker assembled to the stake as shown in FIG. 7, a hammer is utilized to drive the stake into the ground by impacting stake head 38 until the head 38 seats itself in an annular counterbore 51 in the upper surface of marker boss 42.
As seen in FIG. 8, the shape of the flexible barbs 32 and 33 and particularly curved ends 37 tend to force the barbs radially outwardly to the dotted line positions illustraed upon attempted removal of the stake or marker 11, making removal more difficult, and thus the present marker is permenently implanted into the ground. The marker 12 has sufficient flexibility and sufficiently thin walls so that in the event anyone attempts to pry the marker upwardly with an implement such as prying implement 53 in FIG. 11, the marker 12 will simply bend harmlessly upwardly without breaking or pulling the stake 11 upwardly.
An alternate embodiment of the present invention is illustrated in FIGS. 10 to 12, and in this embodiment, a stake 111 is provided identical to stake 11 illustrated in FIGS. 1 to 9, except that head portion 138 extends upwardly approximately one inch above marker 112 and has a hexagonal socket 125 formed therein that releasably receives a hexagonal boss 126 formed integrally with a flexible staff 140 that holds a locating device such as a small pennant 142 illustrated in FIG. 10. The boss 126, staff 140 and pennant 142 form a secondary marker 45 that is adapted to be temporarily utilized to identify either the location of the marker assembly and/or the location of the underground utility element, particularly for distance sitings. | A marker assembly for permanently locating underground utility elements with a non-removable plastic stake and a tamper-proof marker held in place by the stake. | 4 |
RELATED APPLICATIONS
This application is related to the following copending commonly-assigned U.S. patent applications: METHOD AND SYSTEM FOR MAINTAINING STRONG ORDERING IN A COHERENT MEMORY SYSTEM Ser. No. 08/720,330; ERROR CONTAINMENT CLUSTER OF NODES Ser. No. 08/720,368; and ROUTING METHODS FOR A MULTINODE SCI COMPUTER SYSTEM Ser. No. 08/720,331; all filed concurrently with this application on Sep. 27, 1996, and hereby incorporated by reference herein.
TECHNICAL FIELD OF THE INVENTION
This invention relates generally to multi-processor systems, and specifically, to a method and system for synchronization of a multi-processor system.
BACKGROUND OF THE INVENTION
In order to synchronize a multi-node, multi-processor system, each processor clock in the system must be relatively synchronized with the other processor clocks. To accomplish this, the approximate time must be known at certain processing points, and the time needs to be approximately the same throughout the system.
In the system, each node has a clock counter and each processor on that node reads that clock counter. Unfortunately, each counter clock, and hence each node, in the system runs at a slightly different clock frequency. The difference in clock frequencies is because the crystals in each counter are not exactly identical. The different crystal frequencies allow the counters to drift apart in their time values. The physical differences in the crystals cannot be controlled.
The known prior art solves this drifting problem by using extra wires connected between each node. These wires provide separate signal paths for conveying synchronizing signals. After a time interval, which is defined by the hardware, a synchronization packet is distributed via the wire, and each node then receives that signal and changes its counter time appropriately.
The problem with the prior art solution is that it is expensive in terms of the costs to performance because of the extra signal paths. The prior art solution also added complexity to the system because the wires require additional connections which can introduce more problems and errors in the circuit, particularly with respect to grounding between the connections.
Therefore, there is a need in the art for a system and method for providing access to low skew clocks on different nodes that are synchronized with each other.
There is also a need in the art for a system and method to synchronize the clocks on the different nodes without introducing latencies during synchronization.
There is also a need in the art for a system and method to synchronize the clocks on the different nodes without reducing system performance.
SUMMARY OF THE INVENTION
The above and other needs are met by a system and method that provide multi-processor systems access to a low skew clock to synchronize processing events. This invention uses existing hardware, such as an SCI or scalable coherent interconnect network, to distribute a low skew signal to synchronize the time of century clocks on the different nodes. By periodically synchronizing these counters with a signal from a selected master counter, all nodes will maintain approximately equal counter values. A single bit in the SCI header of send, echo, and idle packets is routed to all nodes via a SCI ring. Since the bit is inserted in existing packets, or routine packets, the creation of a special synchronizing packet is not required. Moreover, since the bit travels over existing lines, additional signal paths or extra wire are not needed.
A technical advantage of the present invention is to use the SCI to send a synchronization ("sync") pulse to all of the clocks on the system.
Another technical advantage of the present invention is to use an existing data packet to carry the sync pulse.
A further technical advantage of the present invention is to place the sync pulse in the header of the existing data packet.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which forms the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
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 descriptions taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a schematic diagram of the multi-node, multi-processor system using a SCI network with the inventive synchronization arrangement;
FIG. 2 is a more detailed schematic diagram of the system of FIG. 1 showing a single node;
FIG. 3 is a schematic diagram of a 112 node system;
FIG. 4 is a schematic diagram showing the sync pulse distribution arrangement;
FIG. 5 is a block diagram of the time of century clock hardware;
FIG. 6 depicts the layout of a typical SCI data packet; and
FIG. 7 depicts the TAC TOC control and status register.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1, depicts a schematic overview of two nodes of a total of 112 possible nodes in the system, specifically nodes 0 and 1. FIG. 2 depicts the element arrangement of a single node. The different nodes may be partitioned into clusters to improve system survivability, which is discussed in the co-pending application entitled "ERROR CONTAINMENT CLUSTER OF NODES" filed on Sep. 27, 1996, Ser. No. 08/720,368 which is incorporated herein by reference.
The multiprocessor computer system may have two nodes, or it may have as many as 112 nodes. As shown in FIG. 3, in the 112 node system, the nodes 24 are organized as seven X-dimension rings 26 by four Y-dimension rings 27 forming a wall 23. Four of such walls are interconnected by four Z-dimension rings 28. A bridge node is used to connect a Y-dimension ring to a Z-dimension ring.
Up to two processors 10 may be connected to the processor agent 11, labeled PAC for processor agent chip. A single node may have up to eight PACs 11. Note that there are a large number of identical elements. For purposes of clarity, this discussion will refer to like elements with a single reference numeral. When distinction is made between two or more like elements, the distinct element will be given a new reference number.
The processor 10 is preferably a HEWTLETT-PACKARD PA-8000 processor. However, the present invention is not limited by processor type or architecture. The processors 10 are attached through a runway bus to the PAC 11. PAC 11 has an input/output (I/O) subsystem and is coupled to cross bar 12 and the core logic access bus. The core logic access bus is used primarily for system boot operations. The bus is a low bandwidth multi-drop bus which interfaces all PACs to erasable programmable read-only memory (EPROM), synchronous dynamic random access memory (SDRAM), a real time clock, and RS-232 and Ethernet interfaces. Additionally, a processor can write to control and status registers (CSRs) which are accessed using the bus to initialize and configure the cross bar.
The function of the PAC 11 is to transmit requests from the processors 10 through the cross bar 12 and to the memory access system 14 and then forward the responses back to the requesting processor 10. Inside each PAC 11 is a time of century counter 13 labelled TOC. Since each PAC handles two processors and there are up to 8 PACs in a node, each node may have up to 16 processors. FIG. 2 depicts four cross bars 12, however, each PAC communicates with two of the cross bars.
The PACs communicate with memory controllers 14 through cross bar 12 using four unidirectional data paths. The cross bars 12, labeled RAC for routing attachment chip, are routers that receive a packet from any of the agents 11 and then route it to any of the memory access controllers 14 labelled MAC. Each PAC has 16 32-bit wide unidirectional interconnects coupling each RAC to four PACs and four MACs. The cross bar does not have any CSRs of its own, but rather is initialized by writes to CSRs which reside on the core access logic bus. These CSRs control which ports are active as well as enabling error detection.
The MAC 14 controls access to coherent memory. The memory access controllers can number from 2 to 8, in multiples of 2, and each MAC supports up to 2 Gbytes in 4 banks, each bank 29 with 512 Mbytes. Thus, each node can access up to 16 Gbytes, and a 28 node system can access 448 Gbytes. The memory banks comprise SIMMs of synchronous DRAMs or SDRAMs. FIG. 2 depicts only 2 memory banks 29 for simplicity. The memory is used for node local memory, network caching, and messaging. A method for maintaining cache coherency is discussed in the co-pending application entitled "METHOD AND SYSTEM FOR MAINTAINING STRONG ORDERING IN A COHERENT MEMORY SYSTEM" filed on Sep. 27, 1996 Ser. No. 08/720,330, which is incorporated herein by reference.
When the processor 10 generates a request to access memory or other resource, PAC 11 will examine the request address to determine the proper MAC for handling the request, and then PAC 11 sends the request through the RAC 12 to the appropriate MAC 14. If the MAC 14 determines the node ID is not to a local memory address, then MAC 14 forwards the request to the ring interface controller 15, which is labelled TAC (also known as "toroidal access chip"). If the MAC 14 determines the request address on the local node, the MAC accesses the attached memory 29.
The TAC acts as an interface from the node to a SCI ring. The TAC communicates with the MAC using two unidirectional data paths. Each TAC interfaces to two SCI rings, an X-dimension ring and a Y-dimension ring. FIG. 1 only shows a single dimension for simplicity. FIG. 1 also shows one TAC 15 interfacing ring 16 and another TAC 17 interfacing ring 18.
TAC 15 is capable of operating a separate ring 16, and since there can be up to 8 MAC/TAC pairs, there can be a total of up to 8 SCI rings connecting sections of nodes in a single dimension, i.e. 8 X-dimension rings and 8 Y-dimension rings. The SCI interface rings are defined in the IEEE Standard for Scalable Coherent Interface (SCI), IEEE Std. 1596-1992 ISBN 1-55937-222-2, which is incorporated herein by reference. The TAC 15 receives non-local memory access requests from the MAC 14 and places the request into the SCI ring 16. In FIG. 1, the receiving TAG 19 receives the request from the sending TAG 18 and then forwards the request to its local MAC 20. If the memory access satisfies the request, then the response would retrace the path through TAG 19, ring 16, TAC 15, MAC 14, RAC 12, PAC 11, to processor 10.
Inside each PAC processor agent there is a logic arrangement that is called TOC 13 or the time of century counter. This counter counts according to the local clock frequency, and each processor attached to the PAC has access to this counter with relatively equal latency between the processors such that if the two different processors read the TOC at substantially the same time, each processor would be set to approximately the same value, or at least within an acceptable tolerance limit. Each node has a single crystal clock and the TOCs on the same node operate from that clock.
Problems occur in that each node has a different crystal so the time and century counter operating on the different nodes are running at slightly different frequencies. The TOC counting needs to be synchronized periodically, such that when a remote processor on a different node reads or accesses the memory or other device on the local node, each processor (local and remote) when reading its own TOC, read approximately the same value.
In each node there are 8 PACs, each PAC with its own time of century counter or TOC. A wire 21 connects all 8 of these PACs in the node. Periodically, a sync pulse is sent down the wire 21 causing each PAC to synchronize its TOC. Since all the TOCs on the same node are running on the same crystal, there is no drift between the TOCs on the same node.
The wire 21 that connects all PACs in the node is also connected to all TACs in the node. One of the TACs in one of the nodes is selected as the TOC master. The task of the TOC master is to send the sync pulse around the SCI ring to all of the nodes connected to that SCI ring. Since the sync pulse is inserted into either an idle symbol or a header symbol of an existing data packet, the sync pulse can get to the other nodes faster than by creating a data packet for the sole purpose of transmitting the sync pulse. Moreover, since the sync pulse is in the header of the packet, the sync pulse is acted on before the remainder of the data in the packet. Therefore, when a processor reads the TOC on another node, there is no perceived drift between the different TOCs because the TOC sync signal is faster than any other packet.
As shown in FIG. 4, a single node 30, usually node 0, is designated to be the master, and this master node generates the TOC sync signal, which is sent to the remaining nodes or slave nodes 31. One of the PACs on the master node is designated to be the master PAC 11, this master PAC 11 generates the TOC sync signal and sends the signal to the other non-master PACs on the master node 30. Simultaneously, the TOC sync signal is transferred onto the SCI ring 16 via the TAC 15 and then transferred to the slave nodes 31. On the slaves nodes, the TAC 19 receives the TOC sync signal and then sends that pulse on the wire 22 which is connected to all PACs on that node 31. Therefore, all of the PACs on the slave nodes will receive the TOC sync signal at approximately the same time.
The sync wire 21 connects all PACs and all TACs so that the TOC sync signal actually is transmitted to all 8 TACs in the master node. Only one TAC is actually used to transmit the sync signal to other slave nodes, but software can select which TAC is used, and therefore, if a hardware failure occurs, a backup TAC can be selected that uses a different ring and thus operations can continue without having to stop to fix the failure.
FlG. 5 depicts the hardware for the TOC. The TOC provides a mechanism for very low latency access to a system wide synchronized clock. The TOC can be used to generate time stamped trace data for later analysis. The time-stamped trace data from each node can be merged in a post processing step to provide an accurate global picture, with event sequences in the 5-10 microsecond range. The TOC also provides time stamp of transmitted messages. The receiver can determine the transmission time by subtracting the time stamp from the current time.
Each PAC in the system has a TOC sync pulse generator 32, even though the generator is only used in the master PAC on the master node. The master TOC sync generator is activated by the TOC sync master selector 33. The selectors in all remaining PACs deselects, or sets to off, their respective generators. Therefore, only one PAC will be generating a pulse and will distribute it to all other PACs in the system. The generator 32 sends the signal to the distribution logic 34, which includes the wire 21. The TOC sync signal goes to all local PACs, but also goes to all local TACs. One of the TACS, the master TAC, is selected to send that signal to all remote PACs via the SCI ring. The receiving TAC 19 receives the TOC sync pulse and distributes it to all 8 PACs on its node. Now as each PAC receives the pulse, the PAC uses it to resynchronize its TOC.
The crystal clock 35 and clock generator 36 on each node generates a 16 Mhz clock for the TOCs on each PAC. The PAC synchronizes the crystal clock to its own TOC every 7 or 8 TOC clocks. The master PAC generates a TOC sync pulse every 256 clocks or 16 μsec.
In general, the 16 Mhz clock 35 is scaled down by the pre-scale/synchronizer 37 and becomes the time of century counter register 38. This is the register that is read by the local processors located on this particular PAC. The checker logic 39 ensures that the TOC counter registers maintain synchronization within their specified resolution. The logic 34 checks to ensure the time between synchronization pulses is in the range of the synchronization period plus or minus one half the synchronization resolution. The resolution is set by the TOC sync resolution logic 40. Table I below shows the check range for some of the supported resolution.
TABLE I______________________________________ Check RangeResolution (16 μsec)______________________________________1 μsec 256 ± 72 μsec 256 ± 154 μsec 256 ± 31______________________________________
If the checker logic detects a pulse that is early or late, an interrupt is sent to one of the processors connected to this PAC.
The pre-scale logic 37 performs a divide by 16 on the clock 35 resulting in a 1 μsec period signal. This signal is used to enable incrementing of the TOC counter register 38. Synchronization of the register 38 is performed by rounding up or down the pre-scale value when a sync pulse arrives. The amount of rounding is a function of the TOC resolution 40.
SCI is a packet based protocol. Each packet essentially comprises a header and then 0-8 data symbols depending on the type of packet. The header has an additional bit which is labelled CLK. This bit is the TOC sync bit. FIG. 6 depicts a typical SCI packet with the CLK bit 41 in the header. When a PAC receives a TOC sync from its master PAC it will then locate the first available header that it can modify, and then set the CLK bit. As every other TAC on the ring receives this packet with the CLK bit, it will take the bit and forward the bit to its local PACs, and also forward that bit down the ring to the next TAC. Finally, the CLK bit is passed around the ring all the way back to the original, or master TAC, and the master TAC will take the bit out of the header and not forward it to its local PACs, nor will it pass the bit to the next TAC.
The CLK is not used in calculating the cycle redundancy code or CRC code that is included in each packet. This allows the CLK bit to be changed on the fly without having to recalculate the CRC. The CRC is defined in the SCI specification. The CRC is essentially a huge XOR of all bits in the packet, that has been saved in the last packet, and as the packet is received on each TAC, a new CRC is calculated and compared to the transmitted one. If the two CRCs differ, then an error has occurred. The CLK bit is added to any header. Therefore, very little latency occurs because, at most, the TAC has to wait for the current packet to finish before it finds the header of the next packet. Thus, a new packet does not have to be created and no packets are added to the ring for this bit.
Each TAC has a control status register CSR which governs how the sync pulse is propagated throughout the system. The CSR specifies the source for the incoming sync pulse. The CSR also specifies whether the sync pulse will be propagated to the SCI X-dimension ring or the Y-dimension ring.
As shown in FIG. 7, the TAC TOC configuration register has three fields. The source field 42 is a two-bit field that specifies which synchronization pulse input (sync signal, X-incoming link or Y-incoming link) should be propagated to the enabled synchronization pulse output. The two bits allow four choices, which are value 0: no solution or do nothing; value 1: take the signal from the PAC and distribute it; value 2: take the signal from the X input in the two dimensional ring structure and distribute it; and value 3: take the signal from the Y input and distribute it. The last two fields, 43 and 44, dictate how the bit is distributed. If there is one in the X-ring or the Y-ring bits, then the TOC sync signal will be disbursed on the first available header on that ring. The x-y layout is discussed in the co-pending application entitled "ROUTING METHODS FOR A MULTINODE SCI COMPUTER SYSTEM" filed on Sep. 27, 1996, Ser. No. 08/720,331, which is incorporated herein by reference.
Although the present invention and its advantages have 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. | A multi-processor multi-node system having access to a low skew clock to synchronize processing events. This system uses a SCI network to distribute a low skew signal to synchronize the time of century clock counters on the different nodes. These counters are periodically synchronized with a signal from a selected master counter, so that all nodes will maintain approximately equal counter values. A single bit in a SCI header of send, echo, or idle packet is routed to all nodes via a SCI ring. Since the bit is inserted in existing packets, the creation of a special synchronizing packet is not required. Moreover, since the bit travels over existing lines, additional signal paths or extra wire are not needed. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to light emissive materials incorporating quinolinolato metal complexes used as emissive materials in electroluminescent (EL) devices, and in particular organic light emitting devices (OLEDs). These devices have utility, for example, in flat panel displays.
2. Description of the Related Art
OLEDs are typically comprised of at least a layer of emissive material sandwiched between an anode, typically comprised of a transparent conductor such as indium-tin oxide, and a cathode, typically a low work-function metal, such as magnesium, calcium, aluminum, or the alloys thereof. When a bias is applied across the electrodes, positive charges (holes) and negative charges (electrons) are respectively injected from the anode and cathode into the emissive layer. The holes and the electrons form excitons in the emissive layer which emit light. Hole transport layers and electron transport layers may also be added adjacent the respective electrodes to facilitate charge transfer. Depending upon whether hole transport or electron transport is favored, the light emissive layer may be located closer to the anode or the cathode. In some instances, the emissive layer is located within the hole transport or electron transport layer. Known arrangements of electrodes, hole transport layers, electron transport layers and emissive layers in multilayer structures are disclosed for example in B. R. Hsieh, Ed., “Organic Light Emitting Materials and Devices,” Macromolecular Symposia, 125, 1-48 (1997), which is incorporated herein by reference.
Tris(8-hydroxyquinoline)aluminum (AlQ 3 ) complex is a widely studied emissive aluminum complex having the following structure:
AlQ 3 which has a characteristic green emission with a wavelength of about 535 nm, may be doped with guest emitter compounds to prepare an emissive system having an emission spectrum close to that of the guest. The emitter is energized by direct excitation or by transfer from the AlQ 3 host. Examples of these systems are described in C. W. Tang, et al., J. Appl. Phys., 65, 3610 (1989), which is also incorporated herein by reference.
Conventional doping causes certain problems. For example, if the guest compounds do not disperse properly in the matrix, “aggregation” occurs, local areas of high concentration of the guest compound which in turn leads to “quenching,” a phenomenon in which the guest compound absorbs energy but fails to emit at its characteristic wavelength or desired intensity.
AlQ3 has also become the prototype for a class of photoemitting materials in which quinolinolato metal complexes are bonded to organic groups. Examples of this class of materials are disclosed in U.S. Pat. Nos. 5,466,392 and 5,294,869, which are also incorporated herein by reference. Some of these materials show promise for use as emissive layers in OLEDs, exhibiting properties such as good electron transport, photoemission, high thermal stability, solubility and ease of sublimation. However, these photoemitting materials do not luminesce at wavelengths characteristic of the organic groups bonded to the metal complexes. Instead the organic groups merely modify or shift the emission of the metal complex portion of the material. While some of the organic modifying groups disclosed in the aforesaid U.S. Pat. Nos. 5,466,392, and 5,294,869 may have weak emission spectra, most of them are not light emitting at all.
The inventors herein have discovered materials based on the bonding of modified quinolinolate ligands to light emitting arylates, which exhibit photoemissive and charge transport properties, and which can reduce or eliminate the necessity for doping to improve emission efficiency or color in an organic light emitting device. In preferred embodiments, these materials exhibit emission spectra close to the characteristic emission spectra of the contained light-emitting arylate. In these instances, the metal complex serves to activate the emission of the light-emitting arylate, without contributing substantially to emission.
SUMMARY OF THE INVENTION
The invention is a light emissive material suitable for use in an OLED with a structure (L 2 M) n —X wherein L is a 2-alkyl-8-quinolinolate or 2-phenyl-8-quinolinolate ligand, M is a trivalent metal atom complexed with the ligand to form a conjugated metal complex, and n is an integer between 1 and 12. When n is equal to 1 or 2, X comprises a monovalent or divalent arylate emitter, respectively, that contains at least one arylamine group, or which is conjugation-isolated from the metal complex. When 3≦n≦12, X is an n-valent light emitting arylate group.
In embodiments, when n is equal to 1 or 2, X is a light emitting group having an emission in the range of about 500 nm to about 750 nm. Emission at this wavelength is necessary to obtain energy transfer from the metal complex. Provided the emitter's characteristic wavelength of emission is high enough (between about 500 nm and about 750 nm), the characteristic emission of the combined complex-plus-emitter will be at the characteristic emission wavelength of the emitter. In other embodiments, the complexes according to the invention comprise an amine or alkane functionality isolating the conjugation of the arylate emitter from the conjugation of the metal complex.
The invention in a further aspect is embodied as a multivalent arylate emitter core bonding to 3 to 12 metal quinolinolate complexes according to the following structure:
where “M” is a trivalent metal and “core” is a multivalent moiety such as:
This brief summary has been provided so that the nature of the invention may be understood quickly. A more complete understanding of the invention can be obtained by reference to the following detailed description of the preferred embodiments thereof in connection with the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The ligands used in the present invention are 2-alkyl-8-quinolinolate or 2-phenyl-8-quinolinolate ligands having the following structure:
where R is substituted or unsubstituted branched or straight chain alkyl, such as, without limitation methyl, ethyl, propyl or butyl, or substituted or unsubstituted aryl, such as, without limitation, phenyl. The ligand(s) L are complexed with metal M bonded to light emitting group X according to the formula (L 2 M) n —X. Complexing of the metal atom takes place with the electron density associated with the nitrogen and oxygen atoms of the ligand (coordinate and covalent bonds respectively). Metal complexes of quinolinolate ligands generally emit in the green region of the spectrum.
M is a trivalent metal, preferably aluminum.
“Light emitting group” and “emitter” are used interchangeably herein to mean any group in the recited combination which exhibits fluorescent or phosphorescent emission in the visible spectrum upon relaxation from an excited state. Thus, in the formula (L 2 M) n —X, both L 2 M and X are capable of being emitters. In preferred embodiments, the metal complex L 2 M, although capable of emission, does not emit light upon relaxation from the excited state, but transfers energy to the arylate emitter X, and X is substantially the sole emitter. In other embodiments X is a very weak emitter, and is provided mainly as a core on which the quinolinolate complexes are attached. In these embodiments emission of the material is at a wave length of the metal complex.
The entire group X is referred to as the emitter, even though only a small portion of X contains the functional groups responsible for emissive transition. In every case X contains an arylate group whose oxygen atom is bonded to the metal. This structure is required to have a stable bond to the metal complex. X may also contain bridging groups between the arylate moiety bonded to the metal and the rest of the arylate emitter. Such bridging groups isolate the conjugation of the arylate emitter from the conjugation of the metal complex, causing the emissive material to emit at a characteristic wavelength of the arylate emitter. The arylate bonded to the metal and the bridging groups are not themselves emissive, nevertheless, they form a part of X, the entirety of which is referred to as the arylate emitter.
Examples of isolating groups include —CH 2 —, —CH 2 —CH 2 —, —ArOCH 2 —, —Ar 2 N—R 2 N—, —Si—CH 2 —, and the like.
In the formula (L 2 M) n —X, where n is equal to 1, arylate emitters may include the following:
While referred to as “emitters” in the context of this disclosure, the above arylates do not cause the emissive material (L 2 M) n —X to emit at a characteristic wavelength of these groups. These X groups serve as a core on which quinolinolate complexes are attached.
In the formula (L 2 M) n —X, where n is equal to 2, and divalent arylate emitters may comprise the following:
all of which have emission in the blue or blue-violet region of the visible spectrum.
Examples of an emissive material according to formula (L 2 M) n —X, where n equals 2 and X is an arylate emitter incorporating arylamine groups include the following:
The methyl groups on the modified quinolinolate ligands can be replaced by phenyl groups and still remain within the scope of the invention. Likewise, additional triarylamine groups can be added to the arylate emitter X without departing from the scope of the invention. In general, triarylamine is a weak emitter. Accordingly, in embodiments where the arylate emitter X consists essentially of one or more triarylamine groups, the function of the triarylamine group(s) is primarily to impart hole-transport capability to the emissive material. One of ordinary skill in the art will appreciate that AlQ 3 itself has electron-transport capability. The triarylamine group may also shift the wavelength of the emission of the metal complex, however, the emission of the emissive material will not be the characteristic triarylamine emission wavelength.
An example of preparing an emissive material according to formula (L 2 M) n —X, where n is equal to 2 and having amine bridging group isolating the conjugation of the metal complex from the conjugation of the arylate emitter, is given in Scheme 1 below.
Compound 1 is a quinacridone derivative, which can be prepared according to methods set forth by Pei-Hua Liu, et al., “Luminescence Properties of Novel Soluble Quinacridones,” Journal of Photochemistry and Photobiology A: Chemistry 137 (2000) 99-104, incorporated herein by reference. An appropriate Ullman Coupling reaction can be conducted according to Bryan E. Koene, et al., “Asymmetric Triaryldiamines as Thermally Stable Hole Transporting Layers for Organic Light Emitting Devices,” Chemistry of Materials, Vol. 10, No. 8 (1998), also incorporated herein by reference.
Compound 2 is added to a dry, nitrogen-flushed vessel. Anhydrous methylene chloride is added and mixture is stirred and cooled in an acetone, dry ice bath. Excess boron tribromide in a methylene chloride solution is added dropwise, and the solution is heated to room temperature and stirred overnight. Solution is then removed and washed three times with sodium bicarbonate solution. The aqueous wash is then washed with methylene chloride twice, which is then added to the initial organic solution. The resulting solution is dried over calcium chloride, and reduced to dryness by rotary vacuum. Compound 3 is the crude product.
After purification, Compound 3 is used in the final reaction. 0.005 mole of Aluminum isopropoxide and 0.005 mole of 2-methyl-quinolinol is placed in a beaker along with 50 mL of anhydrous toluene. The mixture is heated and stirred until the bulk of the solids are dissolved. Solution is removed from heat, filtered, and placed in a nitrogen-filled flask. A solution of compound 3 (0.0022) mole and 0.005 mole of 2-methyl-8-quinolinol, dissolved in hot anhydrous toluene, is added to the flask.
The entire mixture is refluxed for 5 hrs, then allowed to cool and stirred overnight. Precipitate is filtered off and washed with ethanol and ether. Product is then dried under vacuum.
In the product 4, an amine functionality is interposed between the arylate group bonded to the aluminum atom, and the remainder of the quinacridone. This amine functionality serves to isolate the conjugation of the metal complex from the conjugation of the quinacridone.
An example of preparing an emissive material according to formula (L 2 M) n —X, where n is equal to 3 is given in Scheme 2 below:
One equivalent of compound 1 is refluxed with 4 equivalents of 1,4-dihydroxybenzene, three equivalents of potassium carbonate, and about 0.1 equivalent of 18-Crown-6 ether in THF. After refluxing overnight, remaining salts can be removed by filtration, and the solution can be concentrated via rotary evaporation. The concentrated solution can be added to a solvent such as hexane, and the resulting precipitate is compound 2.
After purification, compound 2 is used in the final reaction. 0.005 mole of Aluminum isopropoxide and 0.005 mole of 2-methyl-quinolinol are placed in a beaker along with 50 mL of anhydrous toluene. The mixture is heated and stirred until the bulk of the solids are dissolved. Solution is removed from heat, filtered, and placed in a nitrogen-filled flask. A solution of compound 2 (0.0016) mole and 0.005 mole of 2-methyl-8-quinolinol, dissolved in hot, anhydrous toluene, is added to the flask.
The entire mixture is refluxed for five hours, then allowed to cool and stirred overnight. Precipitate is filtered off and washed with ethanol and ether. Product is then dried under vacuum.
The foregoing examples are for purposes of illustration only and are not to be deemed limiting of the invention which is defined by the following claims.
Compound 4 in Scheme 1 is expected to have the emission of the quinacridone branch, green or green-yellow.
Compound 4 in Scheme 2 is expected to have the emission of the aluminum quinolinolate complex, in the green-blue region. | Novel emissive materials suitable for organic light emitting devices are disclosed having a structure (L 2 M) n —X wherein L is a 2-alkyl-8-quinolinolate or 2-phenyl-8-quinolinolate ligand, M is a trivalent metal atom, n is an integer between 1 and 12. When n equals 1, X comprises a monovalent arylate emitter that contains at least one triarylamine group or a light emitting group with emission peak wavelength in the range of 500-750 nm. When n equals 2, X comprises a divalent arylate emitter that contains at least one triarylamine group or a light emitting group with emission peak wavelength in the range of 500-750 nm. When 3≦n≦12, X is an n-valent arylate group. | 8 |
[0001] This application claims the benefit of provisional application Ser. No. 60/880,928 filed Jan. 16, 2007.
TECHNICAL FIELD
[0002] The present application relates generally to archery equipment. More particularly, the application relates to aiming devices for bows.
BACKGROUND
[0003] A bow sight is used to assist an archer in aiming a bow. A typical bow sight includes a sight housing secured to the frame of a bow by one or more brackets. The sight housing often defines a viewing opening (i.e., a sight window) through which an archer can frame a target. The bow sight also typically includes at least one sighting member that projects into the viewing opening. The sighting member defines and supports a sight point. The sight point is the point the archer aligns with the target during aiming. In use, the archer draws the drawstring of the bow and adjusts the position of the bow so that the intended target is visible through the viewing opening. While continuing to peer through the viewing opening with the bowstring drawn, the archer adjusts the position of the bow so that the sight point aligns with the intended target from the archer's eye. Once the sight point is aligned with the intended target, the archer releases the bowstring to shoot the arrow.
[0004] Many bow sights are equipped with multiple sighting members. The sighting members are typically arranged so as to define a plurality of separately visible sight points positioned vertically one above the other. The vertical positions of the sight points are preferably set so that each sight point corresponds to a different target distance. The sighting members are generally arranged in either a vertically aligned orientation (e.g., see U.S. Pat. No. 6,418,633, which is hereby incorporated by reference), or a horizontal orientation (see U.S. Pat. No. 5,103,568).
[0005] Sight point visibility is an important consideration in bow sights. To increase sight point visibility, many bow sights use fiber optic members (e.g., scintillating optical fibers) to define sight points. Such fiber optic members are capable of collecting ambient light along their lengths. The collected light is internally reflected within each fiber optic member and emitted from an end of the fiber at the sight point. Longer fiber optic members are able to collect more ambient light and generate brighter sight points at their ends than shorter fiber optic members. To accommodate longer fiber optic members, various wrapping configurations have been developed (e.g., see U.S. Pat. Nos. 6,418,633 and 6,601,380).
SUMMARY
[0006] One aspect of the present disclosure relates to a pin and sight point shape configuration for enhancing sight point visibility.
[0007] Another aspect of the present disclosure relates to a pin configuration including a pin portion, an integral pin mounting portion, and an integral spool adapted to be positioned offset to one side of a bow sight.
[0008] Examples representative of a variety of inventive aspects are set forth in the description that follows. The inventive aspects relate to individual features as well as combinations of features. It is to be understood that both the forgoing general description and the following detailed description merely provide examples of how the inventive aspects may be put into practice, and are not intended to limit the broad spirit and scope of the inventive aspects.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a view of an archery bow with a bow sight having inventive aspects in accordance with the principles of the present disclosure;
[0010] FIG. 2 is a front view of a bow sight having inventive aspects in accordance with the principles of the present disclosure;
[0011] FIG. 3A is an enlarged view of the demarcation structure;
[0012] FIG. 3 is a rear view of the bow sight of FIG. 2 ;
[0013] FIG. 4 is a front, perspective view of the bow sight of FIG. 2 ;
[0014] FIG. 5 is a right, side view of the bow sight of FIG. 2 shown mounted to a bow;
[0015] FIG. 6 is a left, side view of the bow sight of FIG. 2 shown mounted to a bow;
[0016] FIG. 7 is a right side, perspective view of the bow sight of FIG. 2 shown mounted to a bow;
[0017] FIG. 8 is a cross-sectional view taken along section lines 8 - 8 of FIG. 2 ;
[0018] FIG. 9 is a front view of a sight pin used by the bow sight of FIG. 2 ;
[0019] FIG. 10 is a rear view of the sight pin of FIG. 9 ;
[0020] FIG. 11 is a right, side view of the pin of FIG. 9 ;
[0021] FIG. 12 is a left, side view of the pin of FIG. 9 ;
[0022] FIG. 13 is a bottom, perspective view of the sight pin of FIG. 9 ; and
[0023] FIG. 14 is a top, perspective view of the sight pin of FIG. 9 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0024] For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations, modifications, and further applications of the principles of the invention being contemplated as would normally occur to one skilled in the art to which the invention relates.
[0025] Embodiments of the present invention provide a sight pin and a sight pin structure useable to define a sight point for an archer. In some embodiments, the sight pin includes a sight point configuration to enhance use of the sight point. The pin preferably includes a fiber optic cable or strand to gather light and carry it to an end of the fiber optic cable arranged at the sight point. In certain embodiments, the pin includes a one piece shaft, central portion and spool which is mountable to the housing. Preferably the pin is vertically adjustable relative to the housing to allow an archer to sight the pin for a selected range. In certain preferred embodiments, multiple pins are mountable to the housing and independently adjustable to sight respective sight points for selected designated ranges.
[0026] FIG. 1 illustrates one example of a conventional single cam compound archery bow generally designated as 10 . When viewed from the perspective of an archer holding the bow 10 , it includes a riser 11 with a handle, an upper limb portion 12 , a lower limb portion 14 and a bowstring 15 . Rotational members forming one or two variable leverage units such as idler wheel 16 and eccentric cam 18 are supported at the limb tip sections for rotary movement about axles 17 and 19 . The upper and lower limbs can be solid or formed of pairs of parallel and symmetric limb portions sometimes called quad limbs. Idler wheel 16 is carried between the outer limb tip portions of upper limb 12 . The lower pulley is carried between the outer limb tip portions of lower limb 14 .
[0027] Bowstring 15 is arranged with upper and lower ends which are fed-out from idler wheel 16 and cam 18 when the bow is drawn. Bowstring 15 is mounted around idler wheel 16 and cam 18 as is known in the art. When the bowstring 15 is drawn, it causes idler wheel 16 and cam 18 at each end of the bow to rotate, feeding out cable and bending limb portions 12 and 14 inward, causing energy to be stored therein. When the bowstring 15 is released with an arrow engaged to the bowstring, the limb portions 12 and 14 return to their rest position, causing idler wheel 16 and cam 18 to rotate in the opposite direction, to take up the bowstring 15 and launch the arrow with an amount of energy proportional to the energy initially stored in the bow limbs.
[0028] Bow 10 is described for illustration and context and is not intended to be limiting. The present invention can be used with dual-cam compound bows, or can be used with single-cam bows as described for example in U.S. Pat. No. 5,368,006 to McPherson, hereby incorporated herein by reference. It can also be used with hybrid cam bows or recurve bows. The present invention can also be used in other types of bows, which are considered conventional for purposes of the present invention.
[0029] FIGS. 2-8 illustrate a bow sight 20 mountable on bow 10 having features that are examples of inventive aspects in accordance with the principles of the present disclosure. The bow sight 20 includes a sight housing 22 defining a viewing area such as a viewing opening 24 through which an archer peers when aiming a bow with the sight. The bow sight 20 also includes a plurality of upper sight pins 26 a - c having vertical portions 28 that project downwardly from the sight housing 22 into the viewing opening 24 . The upper sight pins 26 a - c are positioned one behind the other with the vertical portions 28 generally aligned along a vertical plane 30 that bisects the sight housing 22 . The bow sight 20 also includes lower sight pins 32 a - c, having vertical portions 28 that project upwardly into the viewing opening 24 . The lower sight pins 32 a - b are also positioned one behind the other with the vertical portions 28 associated with the lower sight pins 32 a - c generally aligned along the vertical plane 30 (shown as a dashed line in FIG. 2 ). The illustrated bow sight 20 further includes an optional level 34 positioned adjacent the viewing opening 24 adjacent to a front side of the bow sight 20 . As used herein, the term “front side” means the side of the bow sight that faces toward the archer when the archer is aiming a bow.
[0030] In a preferred embodiment, each of the sight pins 26 a - c and 32 a - c supports a separate fiber optic member 36 having a light-emitting end at a corresponding sight point 38 . For example, the sight pins 26 a - c preferably can each support separate fiber optic members 36 with the light-emitting ends at the sight points 38 . Similarly, the lower sight pins 32 a - b can each support separate fiber optic members 36 with the light-emitting ends of those fiber optic members 36 being supported at the sight points. The sight pins 26 a - c and 32 a - b preferably include structure adapted to better demarcate, identify or otherwise accentuate the visibility of the sight points 38 .
[0031] As shown in FIGS. 2 and 2A , each of the sight pins 26 a - c and 32 a - b includes a sight point demarcation structure, generally designated 40 , depicted as a first tick mark member 42 positioned to the left of the sight point 38 and a second tick mark member 44 positioned to the right of the sight point 38 . The tick mark members 42 , 44 project transversely outward from and preferably perpendicular to the vertical plane 30 . Each of the tick mark members 42 , 44 includes a pair of surfaces 46 a and 46 b that converge as the tick mark members 42 , 44 extend away from the sight point 38 . The converging surfaces 46 a, and 46 b meet at a point 48 . The points 48 of the first and second tick mark members 42 , 44 are preferably aligned along a horizontal line 51 (shown as a dashed line in FIG. 2A ) that bisects the corresponding sight point 38 .
[0032] In the depicted embodiment, the sight point 38 is defined by the light emitting end of the fiber optic member 36 held at the end of the sight pin projecting into the viewing opening. In alternative embodiments, the sight point 38 can be formed by any other type of structure such as an opening, a paint dot, a reflective dot, any other type of illuminating dot, or any point provided on the sight pin 26 . Additionally, while it is preferred to have two tick mark members 42 , 44 for each sight point 38 , in other embodiments, it may be desirable to have only one tick mark member per sight point 38 . Alternately, a sight pin could have three or more tick mark members radiating from the sight point.
[0033] As indicated previously, the sight pins 26 a - c and 32 a - c have vertical portions 28 that project into the viewing opening and which are aligned along the vertical plane 30 . Immediately adjacent the sight points 38 , the vertical portions 28 have defined widths W 1 . The sight point demarcation structures 40 preferably have widths W 2 that are greater than the width W 1 (see FIG. 2A ). It will be appreciated that the widths are preferably measured in a direction generally transverse to the vertical plane 30 . In certain embodiments, the sight point demarcation structures 40 define widths W 2 that are at least 25% greater than the width W 1 . In other embodiments, the sight point demarcation structures 40 define widths W 2 that are at least 50% greater than the width W 1 . In still other embodiments, the sight point demarcation structures 40 define widths W 2 that are at least 75% greater than the widths W 1 . It is not necessary, however, that the widths W 2 of the demarcation structures 40 be consistent as between the sight pins 26 a - c and 32 a - c in the bow sight 20 . For example, it may be advantageous to have the demarcation structure 40 associated with the sight pin 32 a corresponding to the longest target distance be smaller than the demarcation structure associated with the sight pin 26 a corresponding to the shortest target distance.
[0034] As shown in FIGS. 2 and 2A , each of the tick mark members 42 , 44 has a generally triangular shaped profile when viewed from the front side of the bow sight 20 . It will be appreciated that other projections having other shapes suitable for demarking or improving sight point visibility can also be used. Examples of other usable shapes include flat tick mark members or curved tick mark members with points aligned along horizontal line 51 that bisects the corresponding sight point.
[0035] Gravity will affect archery shots. For example, when two arrows are shot different distances at the same speed, the longer shot will fall a greater distance than the shorter shot. To compensate for the effect of gravity for different shot distances, the sight points 38 of the sight pins 26 a - c and 32 a - c can be positioned at different vertical elevations relative to one another. Preferably, the sight pins 26 a - c and 32 a - c can be vertically adjusted relative to one another to set the vertical positions of the sight points 38 . This allows an archer, through trial and error, to “sight in” a bow so that each sight point 38 is accurately associated with a particular target distance. The sight points 38 of the lower sight pins 32 a - c would typically correspond to the longer target distances with the lowest sight point 38 (e.g., the sight point 38 of sight pin 32 c ) corresponding to the longest target distance. The sight points 38 of the upper sight pins 26 a - c correspond to shorter target distances with the shortest upper sight pin 26 a (shown at FIG. 4 ) defining the sight point 38 corresponding to the shortest shot distance. The positioning of the sight points 38 can be adjusted to be customized to the shooting characteristics of a particular hunter using a particular bow. In the depicted embodiment of FIGS. 2-7 , three upper sight pins 26 a - c and three lower sight pins 32 a - c are provided. With a six-pin sight, it is common to set the sight points 38 to correspond to shooting distances such as 60, 50, 40, 30, 20 and 10 yards. However, other pin numbers and configurations can be used.
[0036] FIGS. 9-14 illustrate an example sight pin 26 a. While the sight pin is labeled “ 26 a ”, it will be appreciated that sight pins 26 b - c and 32 a - c have the same configuration, except the lengths of the vertical portions 28 can optionally vary. The vertical portions 28 may also extend upward or downward from the central portion depending on the desired mounting location.
[0037] Referring to FIG. 9 , sight pin 26 a has a body which includes a vertical pin portion 28 integrally connected to a horizontal central portion 50 . The horizontal portion 50 extends from the vertical portion 28 at one end to a spool portion 52 at an opposing end. The body can be formed of various appropriate materials such as plastic or metal and can be formed by machining, stamping, injection molding or other forming methods. In certain preferred embodiments, spool portion 52 has a central axis W substantially parallel to an axis S defined by the line through the sight point which an archer aligns with a target as the archer is aiming the bow.
[0038] A pin mounting portion 54 is positioned along the length of the horizontal portion 50 . Pin mounting portion 54 is an example of how sight pin 26 b can be mounted to housing 22 . In this embodiment the pin mounting portion 54 includes a central guide portion 56 to be received within a slot in housing 22 and shoulders 58 that project outwardly from the guide portion 56 to abut housing 22 (see FIG. 8 ). A bolt hole 60 , optionally threaded, extends through the pin mounting portion 54 in a direction generally parallel to the horizontal portion 50 .
[0039] The sight pin 26 a preferably includes the fiber optic member 36 which in this example defines the sight point 38 at a free end of the vertical portion 28 . The light emitting end of the fiber optic member 36 is mounted facing the archer in an opening located at the free or extending end of the vertical portion 28 of the sight pin 26 a. From the sight point 38 , the length of the fiber optic member 36 extends along the back side of the vertical portion 28 and passes through an opening 62 defined through the vertical portion 28 adjacent the horizontal portion 50 . After passing through the opening 62 , the fiber optic member 36 extends along the front side of the horizontal portion 50 and may pass through a passage 63 defined through the pin mounting portion 54 . In certain embodiments, vertical portion 28 and horizontal portion 50 define depths with radiused portions to minimize bends in the fiber optic member and grooves with sidewalls and a channel to receive and retain the diameter of the fiber optic member. A portion of the fiber optic member 36 is wrapped at least one revolution and preferably a plurality of times about the spool portion 52 . The fiber optic pin can be held to the horizontal portion and vertical portions via tension between secured ends, a friction fit into a groove or can be secured with fasteners such as clamps or adhesive.
[0040] In certain embodiments, the spool portion is offset from the pin portion with the spool portion spaced away from the pin portion, for example outside of the housing. In this type of embodiment the sight pin passes through a side wall of housing 22 and the fiber optic member extends from the interior to the exterior of the housing.
[0041] The fiber optic member 36 is adapted to collect light along its length and convey the light to exit out at the sight point 38 defined at the end of the fiber optic member 36 . It is desirable to maximize the brightness of the sight point 38 . Preferably the visible surface area of the fiber optic member is maximized to allow a greater collection of light.
[0042] By providing a longer fiber optic member 36 , the brightness of the sight point 38 can be increased. The spool portion 52 provides a mounting location for an extended length of optical fiber to be wrapped. The fiber optic member can be made in various colors, such as green, yellow or red. When multiple pins are used in a sight, multiple colors can be used to provide contrast between adjacent sight points.
[0043] Referring back to FIGS. 2-8 , the sight housing 22 includes a base plate 66 with plurality of vertical slots 64 adapted for use in mounting the sight pins 26 a - c and 32 a - c to the sight housing 22 . The vertical slots 64 includes an upper set of vertical slots 64 U and a lower set of vertical slots 64 L. The upper set of vertical slots 64 U have upper ends that are open (see FIG. 7 ) to allow the pin mounting portions 54 of the sight pins 26 a - c to be inserted into the slots. Similarly, the lower set of vertical slots 64 L have open lower ends for allowing the pin mounting portions 54 of the sight pins 32 a - c to be inserted into the lower set of vertical slots 64 L.
[0044] As illustrated in cross-section in FIG. 8 , When the sight pins 26 a - c, 32 a - c are mounted to the base plate 66 , the shoulders 58 of the mounting portions abut against a first side 68 of the base plate 66 and the guide portions 56 fit within the vertical slots 64 . Set screws 70 , for example with cap heads, are positioned with the cap heads on the opposite side of the base plate 66 from the mounting portions 54 and threaded into internal threading within bolt holes 60 . The set screw can be tightened to lock the sight pins 26 a - c, 32 a - c with their sight points 38 at a desired elevation. Optionally, the heads of the set screws 70 abut against washers/collars 72 that abut against a second side 74 of the base plate 66 . By tightening the set screw 70 , the base plate 66 is compressed between the shoulders 58 and the washer 72 thereby causing the sight pins 26 a - c, 32 a - c to be frictionally locked in place. By loosening the set screw 70 , the sight pins 26 a - c, 32 a - c can be slid up and down along the vertical slots 64 to change the elevation or height of the corresponding sight points 38 .
[0045] The base plate 66 can include one or more bosses, texture such as ribs or other structures for facilitating attaching one or more mounting brackets that are useful in securing the sight housing 22 to a bow and locking the sight points in place. In certain embodiments, the brackets or other connecting structures can have structures for adjusting the vertical position of the sight housing 22 relative to the bow and can also include structure for adjusting the lateral position of the sight housing relative to the bow to account for windage. Furthermore, the brackets or other structures may include structure that allows the sight housing 22 to be pivoted relative to the bow to account for bow torque.
[0046] While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. | One aspect of the present disclosure relates to a pin and sight point shape configuration for enhancing sight point visibility. Another aspect of the present disclosure relates to a pin configuration including a pin portion, an integral pin mounting portion, and an integral spool adapted to be positioned offset to one side of a bow sight. | 5 |
FIELD OF THE INVENTION
[0001] The invention relates to an apparatus operable to emit light, and, more specifically, the invention provides a flexible light assembly engageable with the brim of a hat.
BACKGROUND OF THE INVENTION
[0002] It can be desirable to position a light with respect to an operator's head to provide light along the operator's line of sight and adjacent the line of sight, as well as to free the operator's hands for the performance of various tasks. For example, light assemblies can be mounted with respect to motorcycle helmets, construction helmets, mining helmets, firefighter helmets and athletic helmets. Light assemblies are configured to engage a particular style of hat.
SUMMARY OF THE INVENTION
[0003] The present invention provides an apparatus operable to emit light and engageable with a hat brim or visor. As used herein, the term “hat” refers to any style headpiece including a brim or visor. The apparatus includes a flexible member. The flexible member defines a longitudinal axis and can bend about or along the longitudinal axis to conform to at least one surface defined by the hat. The flexible member can selectively conform to the surface such that the flexible member can be engaged with a plurality of differently configured surfaces. The flexible member can be resilient and formed from foam rubber.
[0004] The flexible member can engage a surface associated with the brim of the hat. For example, the surface can be an underside of the brim of the hat. The flexible member can be sized and/or shaped to be completely disposed under the brim of the hat. The thickness of the flexible member can be less than a distance defined between the underside of the brim of the hat and a sight line of a wearer of the hat. In other words, the flexible member can be sized to ensure that the flexible member does not obscure the operator's line of sight. An outer surface of the flexible member can be aligned with an edge of the brim of the hat. An inner surface of the flexible member can be aligned with a head of a wearer of the hat.
[0005] The invention can also include means for operably associating the flexible member with the hat. For example, the flexible member can be engaged to the hat with velcro, adhesive, or clips. The flexible member can be permanently engaged with the surface of the hat, or removable with respect to the hat.
[0006] The flexible member can support at least one light emitter or a plurality of light emitters. The flexible member can be bendable about a longitudinal-axis of the at least one light emitter. The invention can include a plurality of light emitters and the flexible member can be bendable about the longitudinal axis of each of the plurality of light emitters. The light emitters can be pointed in the same direction, or can be pointing in different directions.
[0007] Other applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:
[0009] FIG. 1 is a perspective view of a light assembly according to an embodiment of the invention;
[0010] FIG. 2 is a front plan view of a light assembly according to the invention engaged with respect to a hat; and
[0011] FIG. 3 is a perspective view of a light assembly according to the invention engaged with respect to a hat.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0012] Various embodiments of the invention are shown throughout the figures. The figures include common elements in different operating environments. Common elements are designated with a common base numeral and differentiated with an alphabetic designation.
[0013] Referring now to FIG. 1 , the invention provides a light assembly 10 operable to emit light and engageable with a hat including a flexible member 12 defining a longitudinal axis 18 and operable to selectively conform to at least one surface defined by the hat. The flexible member 12 can selectively conform to a plurality of different surfaces of a hat. The flexible member 12 can include a top surface 14 and a bottom surface 16 . The flexible member 12 can be engageable with respect to a hat adjacent either the top surface 14 or the bottom surface 16 . The flexible member 12 can also include a first or outwardly facing surface 20 and a second or inwardly-facing surface 22 . The surfaces 14 , 16 , 20 and 22 can cooperate to define a substantially U-shaped member 12 . The flexible member 12 can be shaped to correspond to the shape of at least one surface of a hat. For example, the flexible member 12 can be shaped by a user to correspond to the brim of a hat.
[0014] The flexible member 12 can be fabricated from a flexible material. The flexible member 12 can be formed from a resilient material. For example, the flexible member 12 can be conformed to the surface of a first hat, disengaged with respect to the first hat, and conformed to a second hat. The flexible member 12 can be bendable about the longitudinal axis 18 , such as along an angular path 24 . The flexible member can be bendable along the longitudinal axis 18 , such that the longitudinal axis 18 can be arched.
[0015] Referring now to FIGS. 2 and 3 , the light assembly 10 a can be engaged with a hat 26 . The flexible member 12 a can be operable to conform to at least one surface 30 of the hat 26 . The at least one surface can be defined by a brim 28 of the hat 26 . The at least one surface can be an underside surface 30 of the brim 28 . The flexible member 12 a can be completely disposed under the brim 28 of the hat 26 . For example, the first surface 20 a can be recessed with respect to a front edge 32 of the brim 28 . Alternatively, the first surface 20 a can be substantially aligned with the edge 32 of the brim 28 when the flexible member 12 a is conformed with respect to the surface 30 of the hat 26 . Alternatively, the first surface 20 a can project outwardly with respect to the edge 32 . The second surface 22 a can be substantially aligned with a head 34 of a wearer 36 of the hat 26 when the flexible member 12 is conformed with respect to the hat 26 and the hat 26 is worn by the wearer 36 . Alternatively, the surface 22 a can be spaced from the head 34 of the wearer 36 , best shown in FIG. 3 . The surface 22 a can be spaced to accommodate positioning of controls for a power source for a light emitter.
[0016] The surface 22 a can define an arcuate profile extending generally parallel to the head 34 of the wearer 36 . The first surface 20 a and the second surface 22 a can be, at least partially, substantially parallel to one another. The first surface 20 a can be spaced with respect to the second surface 22 a a predetermined distance substantially equal to a width of the brim 28 of the hat 26 .
[0017] The flexible member 12 can be sized such that the thickness T 1 of the flexible member 12 is substantially similar to the thickness T 2 of the brim 28 . The thickness T 1 of the flexible member can be determined to ensure that a sight line of the wearer 36 is not obstructed by the flexible member 12 a . Thus, the flexible member 12 a can be positioned between the underside surface 30 of the brim 28 and the sight line of the wearer 36 .
[0018] Referring now to FIGS. 1-3 the flexible member 12 can include means 38 for operably associating the flexible member 12 with respect to a hat. Means 32 can be velcro or adhesive. Means can also include at least one clip 50 . FIG. 2 shows a single clip 50 , however, more than one clip 50 can be positionable along the brim 28 to removably secure the flexible member 12 with respect to the brim 28 . Means 38 can be disposed at one position along either surface 14 or 16 , or can be disposed at a plurality of positions along either surface 14 or 16 . The flexible member 12 can be removably engageable with respect to a hat. For example, the flexible member 12 can be engaged with a first hat, removed with respect to the first hat, and engaged with a second, differently configured hat. The hat can be any configuration of hat, especially hats defining a brim.
[0019] Referring now to FIG. 1 , the light assembly 10 can also include at least one light emitter 40 . The light emitter 40 can be a light-emitting diode. The light emitter 40 can be operably supported by the flexible member 12 . The light emitter 40 can define a longitudinal axis and the flexible member 12 can be bendable about the longitudinal axis 42 of the light emitter 40 . The light assembly 10 can include a plurality of light emitters 40 , 40 a and 40 b . Each of the light emitters 40 , 40 a , and 40 b can define respective longitudinal axis 42 , 42 a and 42 b . One of more of the axis 42 , 42 a and 42 b can be parallel with respect to the axis 18 . The flexible member 12 can be selectively bendable about one or more of the axis 42 , 42 a and 42 b of the plurality of light emitters 40 , 40 a and 40 b . One or more of the axis 42 , 42 a and 42 b can be angled with respect to one another.
[0020] Flexible member 12 can be removably engageable with respect to a hat to selectively position the at least one light emitter 40 relative to the brim of the hat. In other words, the flexible member 12 can be positioned to direct light in any desired direction relative to the hat. Also, the flexible member 12 can be recessed with respect to an edge 32 of the brim 28 to limit light emitted in an upward direction. Alternatively, the member 12 can be positioned with respect to the hat 26 to extend past the brim 28 to maximize the light emitted in an upward direction. The at least one light emitter can be disposed in an aperture defined by the flexible member 12 .
[0021] Referring now to FIG. 1 , the light assembly can also include means 44 for powering the one or more light emitters 40 , 40 a and 40 b . Means 44 can include a battery in electric communication with the one or more light emitters 40 , 40 a and 40 b . Means such as wires 48 for communicating electrical power between the light emitters 40 , 40 a and 40 b and the means 44 can be disposed internal with respect to the flexible member 12 . The light assembly 10 can also include means 46 for controlling powering means 44 to selectively power to the one or more light emitters. Means 46 can be a push button switch. Means 46 can include a flexible circuit board. Means 44 can be at least partially disposed internal with respect to the flexible member 12 . Means 44 and means 46 can be positional with the flexible member 12 adjacent the underside 30 of the brim 28 . Means 46 can include a switch to selectively engage and disengage electrical communication between means 44 and the one or more light emitters 40 , 40 a and 40 b . Means 46 can be positional between the first surface 20 and the hat 34 of the wearer 36 .
[0022] While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law. | A flexible light assembly is provided. The flexible tight assembly is mountable with respect to the underside of the brim of the hat. The light assembly can be made of a flexible resilient material and be conformed to correspond to any configuration of brim. The light assembly 10 includes at least one light emitter, means for powering the light emitter, and means for controlling the emission of light. The light assembly can be completely positional under the brim of a hat. The light assembly can be removably associated with respect to a hat. | 5 |
BACKGROUND
I. Field of the Invention
The present invention relates generally to the field of produce gardening and more particularly to a gardening cage apparatus and system.
II. Description of the Related Art.
Gardening cages are used for a variety of crops such as pole beans, cucumbers or any blooming vine growers, including smaller plants such as peppers, bush beans and the like. A very popular use of cages is for tomato plants. Most tomato cages provide inadequate support for plants with heavy fruit. Present cages typically require significant tying and staking of vines to the cage. Tying and staking is not only time-consuming but can cut the vines thereby causing disease and insect infestation. Present irrigation techniques often result in the use of too much water since irrigation is not gradual. Therefore, water tends to puddle and run-off. In addition, present irrigation techniques can wet leaves and vines causing rot and detrimental growth such as mold and fungus. In addition, water on the leaves can cause tomato bacterial wilt, a major killer of tomato vines and tobacco masaic virus (TMV). These cages also tend to be flimsy and topple over or fall apart as they tomato vines grow.
SUMMARY
In general, the invention features a gardening cage having self-irrigating and self-fertilizing devices for use with a 11 types of blooming vine growing plants, particularly tomatoes. In a typical embodiment, the cage includes three panels having a frame that includes a plurality of horizontal and vertical rungs. The panels are connected so that rungs of respective panels cascade with respect to rungs of the adjacent panel. The cascading orientation provides structural advantages as well as the ability to be broken down and folded on itself for ease of storage and transport. Although several geometric arrangements are contemplated, a triangular arrangement of the panels is typical. The cage allows tomato vines to be trained as they grow within the cage, thereby providing good support. The self-irrigating features allow the vines to be watered inexpensively and with ease. In a typical embodiment, the bottom rungs of each panel include irrigating holes so that water injected into the rungs can flow out of the holes, nozzles or drippers along the base of the cage, thereby dispensing water around the periphery of the vines. The water is typically suppled to the cage by a hose that connects to a water inlet that feeds the holes. The cage is typically set around the tomato plant with the ground engaging the legs being placed in the ground for sturdy support. Several cages can be placed side by side and can be fitted with “T” fittings that branch off the supply hose and feed the individual cages via the water inlet fitting.
In general, in one aspect, the invention gardening cage apparatus, including a plurality of geometrically arranged panels connected by common corners and being in a cascaded arrangement, each of the panels having a plurality of horizontally and vertically arranged hollow rungs, a plurality of T-connectors connecting adjacent horizontal rungs, a second plurality of T-connectors connecting vertical rungs, wherein both plurality of connectors further connect vertical rungs and horizontal rungs to one another, thereby coupling the hollow interiors of all rungs creating an internal interconnected matrix, stakes connected to bottom horizontal rungs of each of the panels, a water inlet connected to one rung of one of the panels, the water inlet being coupled to the internal matrix and a plurality of irrigation orifices located on the bottom horizontal rungs, the orifices being coupled to the matrix.
In one implementation, the apparatus further includes an fertilization coupling connected to a rung adjacent the water inlet.
In another implementation, the rungs include deformable flanges.
In another implementation, the apparatus includes a button connected to one of the flanges.
In another implementation, the apparatus further includes one or more button holes located on the plurality of connectors.
In another implementation, the buttons align with the button holes when the rungs are inserted into the connectors, thereby creating a secure fit.
In still another implementation, the apparatus includes an elbow on each panel connecting a horizontal rung of one panel to a vertical rung of an adjacent panel.
In yet another implementation, the apparatus includes tips located on one end of the stakes.
In another implementation, the tips are oriented in a common plane.
In another aspect, the invention features a gardening cage kit, including a gardening cage having a plurality of geometrically arranged panels connected by common corners and being in a cascaded arrangement, each of the panels having a plurality of horizontally and vertically arranged hollow rungs, a plurality of T-connectors connecting adjacent horizontal rungs, a second plurality of T-connectors connecting vertical rungs, wherein both plurality of connectors further connect vertical rungs and horizontal rungs to one another, thereby coupling the hollow interiors of all rungs creating an internal interconnected matrix, stakes connected to bottom horizontal rungs of each of the panels, a water inlet connected to one rung of one of the panels, the water inlet being coupled to the internal matrix and a plurality of irrigation orifices located on the bottom horizontal rungs, the orifices being coupled to the matrix, wherein the panels are adapted to be connected and disconnected from each other.
In one implementation, the kit further includes a hose adapted to be connected to the water inlet.
In another implementation, the kit further includes a fertilizer coupling adapted to be connected to a rung of the cage.
In another implementation, the kit further includes a protective sheath adapted to fit over the cage.
In another implementation, the sheath is plastic.
In another implementation, the sheath is netting.
One advantage of the invention is that the cage provide support from being blown over in the wind.
Another advantage is that tomato vines can grow through the rungs without becoming overgrown upon itself.
Another advantage is that tying and staking is eliminated.
Another advantage of the invention is that the self-irrigating features allows uniform irrigation to the roots, but keeps water away from the leaves and stems thereby preventing rot and detrimental growth such as mold and fungus.
Another advantage is that the self-irrigating system allows gradual watering thereby allowing good absorption into the soil and roots and prevents puddling and water run-off.
Another advantage of the invention is that the cage can be folded and stored.
Another advantage of the invention is that several cages can be interconnected and provided with a single water source for self-irrigation of all cages.
Another advantage of the invention is that the triangular panel orientation forces vines to buttress and reinforce each other rather than expanding outward, thereby increasing self-support.
Another advantage of the invention is that due to increased structure and growth control more than one plant can be grown in an individual cage.
Another advantage of the invention is that the cage can be used on both even and uneven ground and even on patios and decks.
Other objects, advantages and capabilities of the invention will become apparent from the following description taken in conjunction with the accompanying drawings showing the preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a top view of an embodiment of a gardening cage;
FIG. 2 illustrates a bottom view of an embodiment of a gardening cage;
FIG. 3 illustrates a front view of an embodiment of a gardening cage;
FIG. 4 illustrates a rear view of an embodiment of a gardening cage;
FIG. 5 illustrates a left side view of an embodiment of a gardening cage;
FIG. 6 illustrates a right side view of an embodiment of a gardening cage;
FIG. 7 illustrates a close up view of an embodiment of a panel of a gardening cage;
FIG. 8 illustrates a front view of an embodiment of a single panel of an embodiment of a gardening cage; and
FIG. 9 illustrates a close up view of an embodiment of a connector and portion of a rung.
DETAILED DESCRIPTION
Referring to the drawings wherein like reference numerals designate corresponding parts throughout the several figures, reference is made first to FIG. 1 that illustrates a top view of an embodiment of a gardening cage 100 . The cage 100 typically includes several panels arranged geometrically. In a typical embodiment, three panels 130 , 150 , 180 are arranged in a triangular orientation, generally defining three corners A, B, C of the cage 100 . The triangular orientation of the panels 130 , 150 , 180 offers several advantages. One such advantage is that vine growing plants such as tomatoes, which normally tend to grow outward, now grows inward on itself, which encourages vines to buttress and reinforce each other. In addition, by growing inwards, the vines tend to grow through the panels and on through the rungs (see below), thereby obviating the need for staking and tying. The panels 130 , 150 , 180 include a plurality of horizontal rungs 135 , 155 , 185 and connectors 140 , 160 , 190 that connect the horizontal rungs 135 , 155 , 185 to one another. The panels 130 , 150 , 180 further include elbows 165 that interconnect the horizontal rungs 135 , 155 , 185 with vertical rungs (see below).
The cage 100 further includes a water inlet 105 that can include one or more barbed fittings 106 to receive a water source such as a hose and to connect to inlets on adjacent cages, if connected. The inlet 105 can include an extension 107 , if necessary, and a coupling 108 to the cage 100 . The cage 100 can further include a fertilizer coupling 110 . The fertilizer coupling 110 allows fertilizer to be added directly into the cage 100 .
In a typical embodiment, the horizontal rungs 135 , 155 , 185 and vertical rungs (as discussed further in the description below, are hollow tubular bodies. The connectors 140 , 160 , 190 and elbows 165 are also typically hollow and tubular. Therefore, all rungs of all panels 130 , 150 , 180 are coupled together creating a continuous water channel matrix throughout the cage. It is appreciated that when fertilizer is added to the fertilizer coupling 110 , the fertilizer can mix with the water injected into the cage 100 and mix within the entire matrix formed by the panels 130 , 150 , 180 . Therefore, any water injected into the inlet 105 fills the entire inner hollow space of the cage 100 , provided that the cage 100 has no exit for the water. It is appreciated in the descriptions below, particularly with respect to FIG. 2 , that the cage 100 does have an exit for the water.
FIG. 2 illustrates a bottom view of an embodiment of a gardening cage 100 . As described above, the cage 100 includes three panels 130 , 150 , 180 that are arranged in a triangular orientation. The triangular orientation of the panels 130 , 150 , 180 offers several advantages. The panels 130 , 150 , 180 include a plurality of horizontal rungs 135 , 155 , 185 and connectors 140 , 160 , 190 that connect the horizontal rungs 135 , 155 , 185 to one another.
The panels 130 , 150 , 180 further include elbows 165 that interconnect the horizontal rungs 135 , 155 , 185 with vertical rungs (see below). The cage 100 further includes a water inlet 105 that can include one or more barbed fittings 106 to receive a water source such as a hose and to connect to inlets on adjacent cages, if connected. The inlet 105 can include an extension 107 , if necessary, and a coupling 108 to the cage 100 . The cage 100 can further include a fertilizer coupling 110 .
As described above, all rungs of all panels 130 , 150 , 180 are coupled together creating a continuous water channel throughout the cage. Therefore, any water injected into the inlet 105 fills the entire inner hollow space of the cage 100 , provided that the cage 100 has no exit for the water. However, the bottom rungs of each of the panels 130 , 150 , 180 are irrigating rungs 137 , 157 , 187 , each having irrigating orifices 138 , 158 , 188 . The irrigating orifices 138 , 158 , 188 allow water that has been injected into the cage 100 to be released from the irrigating rungs 137 , 157 , 187 . It is appreciated that the orifices 138 , 158 , 188 can be simple holes or more complicated nozzles and drippers. Therefore, as water and fertilizer is mixed within the panels 130 , 150 , 180 , the resulting mixture is gradually released from the orifices 138 , 158 , 188 for controlled gradual watering and fertilizing of the plants within the cage 100 . It is further appreciated that with a predictable rate of release, water flow into the cage can be controlled and adjusted as needed. For example, the rate of the water into the cage can be slightly greater than the release rate in order to store water within the cage for release. With a set amount of water stored within the cage, the rate of water into the cage can then be matched with the release rate so that a set amount of water remains within the cage 100 . It is appreciated that several injection and release rates are possible.
FIG. 2 further illustrates a bottom view of cage stakes 115 . The cage stakes 115 are used to insert the cage into the soil of the garden, or alternatively as stands if the cage 100 is used on a solid surface such as a deck or patio. In a typical embodiment, the stakes have sharp ends so that they can be easily inserted into the ground. Furthermore, the stakes 115 are typically hollow tubes but are typically also isolated from the continuous water matrix as described above. In this way, too large a flow of water from the bottoms of the stakes 115 into the ground is prevented. In another embodiment, if deeper irrigation is desired, the hollow stakes 115 can be coupled to the water matrix so that additional water flows from the tips of the stakes 115 directly into the ground.
FIG. 3 illustrates a front view of an embodiment of a gardening cage 100 . As described above, the cage 100 includes three geometrically arranged panels 130 , 150 , 180 . The panels 130 , 150 , 180 include a plurality of horizontal rungs 135 , 155 , 185 and connectors 140 , 160 , 190 that connect the horizontal rungs 135 , 155 , 185 to one another. The panels 130 , 150 , 180 further include elbows 165 that interconnect the horizontal rungs 135 , 155 , 185 with the vertical rungs 136 , 156 , 186 . The panels 130 , 150 , 180 further include connectors 141 , 161 , 190 that connect the vertical rungs 136 , 156 , 186 to one another.
In a typical embodiment, the connectors 140 , 161 , 190 and the connectors 141 , 161 , 191 are of the same type, which are typically “T” type connectors. Both the connectors 140 , 161 , 190 and the connectors 141 , 161 , 191 are discussed in further detail in the description below.
The cascading arrangement of the panels 130 , 150 , 180 is illustrated in FIG. 3 . In the arrangement shown, the panel 130 is the “lowest” of the panels 130 , 150 , 180 . The panel 180 is the “middle” panel and the panel 150 is the “highest” panel. The relative terms of low, middle and high refer to the orientation of the top-most horizontal rungs 135 , 155 , 185 of each of the panels 130 , 150 , 180 . It us further illustrated that horizontal rungs 135 , 155 , 185 that are adjacent to each other at the corners A, B, C. are also cascaded with respect to each other. The pattern of this cascading arrangement is repeated throughout the matrix defined in the cage 100 , all the way to the bottom-most horizontal rungs 135 , 155 , 185 . IT is further appreciated that the vertical rungs 136 , 156 , 186 of the panels 130 , 150 , 180 are also relatively cascaded with respect to vertical rungs 136 , 156 , 186 of adjacent panels 130 , 150 , 180 . In a typical embodiment, the stakes 115 are arranged generally parallel to one another. It is further illustrated that the bottom most tips 116 of the stakes 115 generally share a common plane of orientation, which can typically be represented a deck or patio floor. In situations in which the cage 100 is used in gardens, the ground is uneven and does not generally define a plane of orientation. In these implementations, the stakes 115 are used to puncture the ground for securement. As such, the tips 116 are formed with points that allow for better insertion into the ground. Due to the cascading arrangement of the panels 130 , 150 , 180 , it is further appreciated that each stake 115 has two common adjacent panels 130 , 150 , 180 associated with it. In addition, due to the cascading arrangement. If stake 115 has a different length in order to accommodate both the cascading arrangement and ultimately the common planar arrangement of the tips 116 of the stakes 115 .
As described above, the cage 100 further includes the water inlet 105 including one or more barbed fittings 106 , the extension 107 , if necessary, and a coupling 108 to the cage 100 . The cage 100 can further include the fertilizer coupling 110 , which includes a connector 111 and an elbow 112 having an opening 113 , into which fertilizer can be added. In a typical embodiment, the fertilizer coupling 110 is located toward the lower-most portion of the cage 100 and connected to a vertical rung 136 adjacent the water inlet 105 , although it can be located at other locations along the cage. By being low and adjacent to the water inlet 105 , injected water can better mix the fertilizer upon entrance into the cage matrix.
FIG. 4 illustrates a rear view of an embodiment of a gardening cage 100 , FIG. 5 illustrates a right side view of an embodiment of a gardening cage 100 and FIG. 6 illustrates a left side view of an embodiment of a gardening cage 100 . These different perspectives give a further appreciation of the orientation of the panels 130 , 150 , 180 in a typical embodiment as discussed in further detail in the description above. Only a few of the horizontal rungs 135 , 155 , 185 , vertical rungs 136 , 156 , 186 , connectors 140 , 160 , 190 and connectors 141 , 161 , 191 have been labeled as representatives of each given panel 130 , 150 , 180 .
FIG. 7 illustrates a close up view of an embodiment of the panel 130 of a gardening cage 100 . This close up view illustrates the horizontal rungs 135 and vertical rungs 136 of panel 130 . The connectors 140 , 141 connecting horizontal rungs 135 and vertical rungs 136 are further illustrated. The corners A, B as well as a connector 161 and horizontal rung 155 for panel 150 and a connector 191 and horizontal rung 185 for panel 180 are also illustrated. It is thus appreciated that vertical rungs on the corners A, B of the cage are common to adjacent panels 130 , 150 and 130 , 180 . Thus, as illustrated, the corner vertical rungs are labeled vertical rungs 136 , 186 and vertical rungs 136 , 186 . A similar orientation is appreciated for corner C.
As described above, the cage 100 further includes the water inlet 105 including one or more barbed fittings 106 , the extension 107 , if necessary, and a coupling 108 to the cage 100 . The inlet 105 further optionally includes an elbow 109 connected between the coupling 108 and the extension 107 . In another embodiment, the extension or the fitting can be directly connected to the coupling 108 without the need for the elbow 109 . The cage 100 further includes the fertilizer coupling 110 , which includes a connector 111 and an elbow 112 having an opening 113 , into which fertilizer can be added.
FIG. 8 illustrates a front view of an embodiment of a single panel 150 of an embodiment of a gardening cage 100 . The isolated panel 150 is shown as representative of one of the panels of the cage 100 in order to illustrate the isolated details of a single panel.
FIG. 9 illustrates a close up view of an embodiment of a connector and portion of a rung. The portion of rung 130 is shown for illustrative purposes. One connector 141 is further shown for illustrative purposes. In a typical embodiment, the end of the rung 130 is split into several deformable flanges 130 a . One or more of he flanges can include a button 130 b . Correspondingly, the connector 141 has a hole 141 a adjacent each of its openings. As such, the flanges 130 a can be inserted into one of the openings of the connector 141 . During insertion, the button 130 b aligns with the hole 141 a and snaps into place thereby securing the rung 130 to the connector 141 . When the rung 130 is to be removed from the connector, the button 130 b can be depressed which clears it of the hole 141 a , thereby allowing the rung 130 to be removed from the connector 141 . When it is desired to disassemble the cage 100 , respective buttons on the various connectors can be depressed that allows the end of the rungs to be removed from respective connectors. It is appreciated that the cage 100 can be easily disassembled and stacked or folded upon itself.
It is appreciated that several modifications can be made including but not limited to the number of panels, rungs and connectors used in the cage.
Several additional cages can be connected to one another thereby allowing several adjacent plants and vines to be grown next to each other.
Additional apparatuses can be added to the cage 100 to create a cage kit and system. A plastic sheath that mimics the overall shape of the cage 100 can be added that fits over the cage 100 . The sheath can be zippered to allow the sheath to be easily placed and removed. The sheath can thereby provide protection from frost or other weather and optionally provide a greenhouse setting. Many plants, typically tomatoes grow faster with warm soil. The sheath can help to keep surrounding soil warm. Similarly a netted sheath can be added to the cage 100 to protect plants from borer insects, birds, squirrels and other pests, but allow pollinating insects to enter to reach the buds.
The foregoing is considered as illustrative only of the principles of the invention. Further, various modifications may be made of the invention without departing from the scope thereof and it is desired, therefore, that only such limitations shall be placed thereon as are imposed by the prior art and which are set forth in the appended claims. | A gardening cage having self-irrigating and self-fertilizing devices. In a typical embodiment, the cage includes panels having a frame that includes a plurality of horizontal and vertical rungs. The panels are connected so that rungs of respective panels cascade with respect to rungs of the adjacent panel. In a typical embodiment, the bottom rungs of each panel include irrigating holes so that water injected into the rungs can be dispensed around the periphery of the vines. The water is typically suppled to the cage by a hose that connects to a water inlet that feeds the holes. Several cages can be placed side by side and can be fitted with “T” fittings that branch off the supply hose and feed the individual cages via the water inlet fitting. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to a remote monitoring system transmitter for use in an underground utility vault and, more particularly, to a conversion kit whereby the type of transmitter can be changed without changing the existing transmitter cabling, even though the transmitter cable terminations are different.
The need for remote monitoring capability of operating conditions existing at individual transformers in an underground vault of an underground network power distribution system is well known in the art. Ideally, information such as three phase load currents on transformers, status of network protectors, oil temperatures of transformers in excess of specified limits, water levels, fuse status, and surrounding environmental concerns such as vault access, air temperatures, etc., are required so that critical decisions can be made regarding network switching, problem analysis, peak load analysis, contingency studies, etc.
For example, the Remote Monitoring System manufactured by BAE Systems is typical of the current approach to meeting these requirements. This apparatus is a power line carrier system designed specifically to use network distribution feeders as the communications medium between network distribution transformers, located in underground vaults, and the substation. The system consists of a transmitter and sensors installed at the distribution transformer to be monitored and a receiver located at the network substation. The sensors provide input data, such as transformer load currents and network protector position, to the transmitter, which periodically transmits the information, including vault identification, by power line carrier signal over the distribution feeder to the substation receiver. Coupling of the signal to the feeder is accomplished by direct connection to the low voltage side of the network distribution transformer. At the substation, the signal is magnetically detected from the feeder by means of a pick-up coil attached to the feeder cable. Direct electrical connection to the feeder is not required. The substation receiver decodes the signal information and stores the data for presentation on demand. The receiver is microprocessor controlled. In addition to cross referencing data to the actual vault identification, the receiver produces the data in numerous “by exception” formats controlled by command inputs. Network protector status and transformer loading prior to and following feeder outages, are available, thereby reducing the need for feeder patrols. Peak period transformer loading data is instantly available for the whole network simultaneously for more accurate planning than was previously possible with manual measurements, which are not concurrent. Monitoring of spot networks, local areas, and critical locations for maintenance work can be achieved remotely without the need for field crews to be on-site to check status.
Up to now, the above-described transmitter, identified as Model 2391, has been in the form of a sealed cylindrical tube, having connectors on a first end for connection to complementary terminations at a first end of an otherwise environmentally sealed cable harness. The cable harness is connected at its second end to the network distribution transformer in the vault. To protect the transmitter connectors and cable harness terminations from the environment in the vault, which may be wet, the cable harness is equipped with a boot at its first end. After the cable harness terminations are mated to the transmitter connectors, the boot is slipped over the first end of the cylindrical transmitter and environmentally sealed thereto by means of a large hose, or ribbon, clamp.
Due to technological advances and the need for additional monitoring features, the transmitter has been redesigned, and may be identified as Model 2777. With this redesign, the transmitter is no longer in the form of a cylindrical tube, but instead now has a generally rectilinear and boxlike configuration. Additionally, the connectors on the new transmitter are different from the connectors on the old transmitter. Thus, if an old transmitter is to be replaced by a new transmitter, the new transmitter cannot be connected directly to the existing cable harness. It would be desirable to be able to connect the new transmitter to the existing cable harness because this would obviate the need to change internal wiring of the associated transformer, an arduous and time consuming task.
The environment in the underground vault requires that the transmitter and its connections be environmentally sealed. Since the new transmitter design is boxlike instead of cylindrical, the old manner of sealing the transmitter/cable connections is not possible. It would therefore be desirable to be able to provide a sealed environment for the new transmitter design and the transmitter/cable connections.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a conversion kit for providing a sealed environment for containing a remote monitoring system transmitter and providing electrical connections between the transmitter and an existing environmentally sealed cable harness, wherein the existing cable harness is terminated by a boot adapted to surround a cylindrical structure for environmental sealing contact therewith. The conversion kit comprises an adaptor cable harness having at least one termination at a first end for connecting to the existing cable harness and having at least one termination at a second end for connecting to the transmitter. The conversion kit further comprises an enclosure for containing the transmitter, the enclosure having an open end formed as the cylindrical structure surroundable by the boot.
In accordance with an aspect of this invention, the enclosure includes a hollow structure sized to accept the transmitter therein and having first and second open ends, with the second open end of the hollow structure being formed as the cylindrical structure surroundable by the boot. A cover piece is adapted to seal the first open end of the hollow structure.
In accordance with another aspect of this invention, the kit further includes at least one spacer element adapted for insertion between the transmitter and the interior of the hollow structure.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing will be more readily apparent upon reading the following description in conjunction with the drawings in which like elements in different figures thereof are identified by the same reference numeral and wherein:
FIG. 1 is a perspective view of the prior art cylindrical tube transmitter, showing the connectors on one end;
FIG. 2 is a perspective view showing the transmitter of FIG. 1 connected to the environmentally sealed cable harness and having the transmitter/cable connections environmentally sealed by a boot which is part of the cable harness;
FIG. 3 is a perspective view showing the new transmitter design;
FIG. 4 is a perspective view showing an adaptor cable harness according to the present invention;
FIGS. 5A , 5 B and 5 C are perspective views showing exemplary pieces which may be utilized to together form an enclosure for the transmitter, according to the present invention;
FIG. 6 is a cross-sectional view showing an assembled exemplary enclosure formed from the pieces shown in FIGS. 5A , 5 B and 5 C; and
FIG. 7 is a perspective view showing the assembled enclosure with the transmitter, spacer elements and adaptor cable harness contained therein, with the adaptor cable harness connected between the transmitter and the existing cable harness and with the existing cable harness boot sealing the enclosure, according to the present invention, wherein the enclosure and the boot are shown in phantom (broken lines).
DETAILED DESCRIPTION
Referring to the drawings, FIG. 1 shows the Model 2778 cylindrical tube transmitter, designated generally by the reference numeral 10 , which is installable in an underground utility vault of an underground network power distribution system as part of a remote monitoring system. On the end 12 of the transmitter 10 are the connectors 14 and 16 , which connect to terminations 18 and 20 , respectively, ( FIG. 7 ) at a first end of the cable harness 22 ( FIG. 2 ). The cable harness is sealed against the environment by encasing its wires in an outer protective rubber or plastic covering. The other end (not shown) of the cable harness 22 is connected to the network distribution transformer in the vault and enters the transformer casing through a sealed opening, as is known in the art. The first end of the cable harness 22 is provided with a boot structure 24 surrounding the terminations 18 , 20 and sealingly connected to the outer protective covering of the cable harness 22 . As shown in FIG. 2 , the boot 24 is slipped over the end 12 of the transmitter 10 (after the cable terminations 18 , 20 are connected to the connectors 14 , 16 ) and is then securely attached thereto by means of the large hose, or ribbon, clamp 26 . This provides a protective sealed environment for the connectors 14 , 16 and the terminations 18 , 20 .
FIG. 3 shows a transmitter, designated generally by the reference numeral 30 , which was designed to replace the transmitter 10 . Instead of the cylindrical configuration of the original transmitter 10 , the replacement transmitter 30 is generally rectilinear, or boxlike. In addition, the connectors 32 and 34 of the replacement transmitter 30 are markedly different from the connectors 14 and 16 of the original transmitter 10 . It is therefore apparent that the existing cable harness 22 used with the original transmitter 10 cannot be used with the replacement transmitter 30 , either to make electrical connections thereto or to provide a sealed environment for the connectors 32 , 34 . As will be described in full detail hereinafter, according to this invention, there is provided a conversion kit which provides connections between the replacement transmitter 30 and the existing cable harness 22 and also provides a sealed environment for the replacement transmitter 30 . Because the existing cable harness 22 is not disturbed when the original transmitter 10 is replaced by the transmitter 30 and the inventive conversion kit is utilized, there is no need to perform any rewiring of the transformer to which the existing cable harness 22 is connected.
FIG. 4 shows an adaptor cable harness 36 which is part of the inventive conversion kit. At a first end of the adaptor cable harness 36 are terminations 38 , 40 for mating engagement with the terminations 18 , 20 , respectively, of the existing cable harness 22 . Thus, the termination 38 emulates the connector 14 of the original transmitter 10 and the termination 40 emulates the connector 16 of the original transmitter 10 . At the other end of the cable harness 36 are terminations 42 , 44 for mating engagement with the connectors 32 , 34 , respectively, of the replacement transmitter 30 . As will be described hereinafter, after installation, the adaptor cable harness 36 is within a sealed environment, so there is no need to provide it with its own outer protective covering, in contrast to the existing cable harness 22 .
FIGS. 5A , 5 B and 5 C show exemplary pieces which may be utilized to together form the enclosure of the inventive conversion kit. Illustratively, those pieces are PVC pipe fittings manufactured by Plastic Trends, Inc. of Shelby Township, Mich. Thus, the piece 46 is a reducer coupling, the piece 48 is a fitting cleanout adaptor and the piece 50 is a threaded plug. The sizes of the pieces 46 , 48 , 50 are determined by the size of the transmitter, which fits inside the pieces 46 , 48 , 50 when they are assembled to form an enclosure, as shown in FIG. 6 . The piece 48 is hollow and is generally cylindrical with first and second open ends 52 , 54 , respectively. Illustratively, the transmitter 30 , when viewed from its end 31 , is approximately 4⅝ inches wide and 5⅝ inches high, so the exemplary piece 48 is selected as Plastic Trends part number P1508 with an inner diameter of slightly more than nine inches.
The cover piece 50 is a generally planar disc having external peripheral threads 56 for engaging the internal threads 58 at the first open end 52 of the piece 48 . The cover piece 50 also has a central boss 60 with a plurality (illustratively four) of flat sides 62 which may be gripped by a wrench, or the like, to turn the cover piece 50 for attachment to the piece 48 . Illustratively, the exemplary cover piece 50 is selected as Plastic Trends part number P1158.
The piece 46 is a hollow piece with first and second open ends 64 , 66 , respectively, and is made up of three sections. The first section 68 includes the open end 64 and is generally cylindrical so that it can telescopically surround the open end 54 of the piece 48 , as best seen in FIG. 6 . The second section 70 includes the open end 66 and is also generally cylindrical. The diameter of the second section 70 is substantially the same as that of the original cylindrical transmitter 10 so that the boot 24 can be placed snugly thereover. The third section 72 is a transitional section between the first and second sections 68 , 70 and is therefore of frusto-conical shape to account for the diametric difference between the first and second sections 68 , 70 . Illustratively, the exemplary piece 46 is selected as Plastic Trends part number P608-4.
The inventive conversion kit also includes two spacer elements 74 , 76 ( FIG. 7 ) which are formed of resilient material, such as a urethane foam. The spacer elements 74 , 76 can be cut from a cylindrical piece of foam so that they each have a planar side which can contact a side of the transmitter 30 and an opposing side which conforms substantially to the interior of the enclosure piece 48 . Alternatively, each spacer element 74 , 76 can be a sheet of foam material which is rolled up and inserted between a respective side of the transmitter 30 and the interior of the enclosure piece 48 .
To use the inventive conversion kit to replace the original cylindrical transmitter 10 by the box transmitter 30 , first the end 64 of the enclosure section 46 is slid over the end 54 of the enclosure section 48 and the two sections are secured to each other by glue. Next, the clamp 26 is loosened, the boot 24 is removed from the end of the transmitter 10 and the cable terminations 18 , 20 are separated from the connectors 14 , 16 . The adaptor cable harness 36 is then connected to the box transmitter 30 by mating the cable terminations 42 , 44 to the transmitter connectors 32 , 34 . The assembly of the adaptor cable harness 36 and the box transmitter 30 is then placed inside the combined enclosure sections 46 , 48 . The spacer elements 74 , 76 are then inserted each between a respective opposed side of the box transmitter 30 and the interior of the enclosure section 48 . The spacer elements 74 , 76 help protect the box transmitter 30 from vibration and/or shock damage. Next, the free end of the adaptor cable harness 36 is routed through the open end 66 of the reduced diameter section 70 of the enclosure piece 46 and the terminations 38 , 40 at the free end of the adaptor cable harness 36 are mated to the cable terminations 18 , 20 , respectively, of the existing cable harness 22 . The boot 24 is then slid over the reduced diameter section 70 of the enclosure piece 46 and secured thereto by the clamp 26 . Anti-seizing compound is applied to the threads 56 of the cover piece 50 and to the threads of the enclosure piece 48 , and the cover piece 50 is screwed into the end 52 of the enclosure piece 48 . A wrench may be used to grip a pair of opposed flat sides 62 of the boss 60 in order tighten the connection of the cover piece 50 to the enclosure piece 48 . FIG. 7 shows the completed assembly.
Accordingly, there has been disclosed a conversion kit whereby a cylindrical transmitter can be replaced by a box transmitter while utilizing an existing cable harness and preserving environmental protection of the cable terminations and the transmitter connectors. While an illustrative embodiment of the present invention has been disclosed, it will be apparent to those of skill in the art that various adaptations and modifications of the described embodiment are possible. It is therefore intended that this invention be limited only by the scope of the appended claims. | A conversion kit for providing a sealed environment for containing a remote monitoring system transmitter and providing electrical connections between the transmitter and an existing environmentally sealed cable harness. The existing cable harness is terminated by a boot adapted to surround a cylindrical structure for environmental sealing contact therewith. The conversion kit includes an adaptor cable harness having terminations at a first end for mating with the terminations of the existing cable harness and terminations at a second end for mating with connectors of the transmitter. The conversion kit also includes an enclosure for containing the transmitter. The enclosure is formed with cylindrical structure at an open end thereof which is surroundable by the boot. | 7 |
[0001] This application claims priority to U.S. Provisional Patent Application No. 60/525,533, filed Nov. 26, 2003, the entire contents of which is incorporated by reference herein for all purposes.
FIELD OF THE PRESENT INVENTION
[0002] This present invention relates generally to calendars and/or journals that can be color coded by a user. More particularly, the present invention relates to user pre-defined color-codeable calendars and/or journals that may be used to track past actions and occurrences in a highly visible way.
BACKGROUND OF THE PRESENT INVENTION
[0003] A journal typically is used to record actions, thoughts, or occurrences in a timely fashion, for later review or analysis, often with the aim of acquiring insight that can be used to effect improvement. A calendar can be used with a journal to correlate the entries in the journal to actual days of the calendar year.
[0004] One common way to record information in a journal is through the use of words or numbers. Numbers may be tallied to provide objective, meaningful analysis on a periodic basis and to easily identify trends. Dialogue or entries written in words are not easily quantified, however. Thus, it may be time-consuming or difficult to objectively identify trends over time. This is because recorded words usually need to be assigned some relative value or measurable component in order to conduct an analysis and form an objective opinion. As such it can be difficult to identify trends by using words alone.
SUMMARY OF THE PRESENT INVENTION
[0005] The present invention provides color-codeable calendars/journals and systems that preferably include one or more of: (1) a daily module with pre-designated and undesignated subsections, (2) a color key correlating to the subsections of the daily module, (3) arrangement of seven of the daily modules into a weekly array of modules with a means of recording quantifiable weekly totals, (4) arrangement of four to six weekly arrays into a monthly calendar array or page with a means of recording quantifiable monthly totals, (5) arrangement of monthly calendar arrays or pages into an annual calendar array or booklet with a means of recording quantifiable annual totals and year-to-year totals.
[0006] In accordance with one aspect of the present invention, a calendar/journal preferably includes a collection of monthly calendar pages. Each day on the monthly calendar page preferably comprises a self-contained daily module with pre-designated and undesignated subsections capable of being filled in with color, and optionally, numbers or words. A designated sub-section might include a pre-printed date, for example. An undesignated subsection preferably comprises an area whose meaning and use the user can define via a monthly color key. The monthly color key preferably features an outline of the daily module with empty spaces next to it where the user can indicate which colors will be used in which subsections of the daily module to indicate user-defined actions or occurrences. Daily modules can be arranged in four to six rows of seven modules with an area at the end of each row for optionally tallying quantifiable data for the week. At the end of the month there can be an area for tallying quantifiable totals. Other areas on the page may contain written information, instructions, or other visual ways to quickly gauge progress or behavioral changes.
[0007] At the beginning of each month a user preferably populates a color key with colors that correlate user-selected subsections of the daily module with behavior change or other actions or occurrences that the user wishes to track and analyze in a visual manner using a variety of colors. On a more or less daily basis throughout the month, the user preferably colors or otherwise marks the sections of the daily modules to reflect daily activity as specified in the color key. Optionally, the user may also enter alphanumeric data for later quantification and analysis. At the end of the month the user can review the pattern and trends represented by the colors and alphanumeric data and preferably adjusts the color key for the following month, gathering and tracking data throughout the entire year and through subsequent years.
[0008] In accordance with other aspects of the present invention, a calendar of the present invention may be printed on paper in any commonly found calendar variations such as wall calendars, compact calendars, desk calendars, calendar blotters, planners, pocket calendars, cube calendars, poster calendars, or the like. Various components of the calendar may be printed and offered separately in other forms. For example, the daily modules may be printed separately on plain paper or repositionable note paper for later attachment or entry on a monthly calendar. Any number of daily modules such as a week of daily modules may be printed separately on plain paper or repositionable note paper for later attachment or entry on the monthly calendar. Alternatively, week or day modules can be provided as stickers that can be placed on an existing calendar. Certain months or portions of the year may be printed and bound separately. A calendar may be printed in card form with colorful sliding plastic doors that open or close to show an action or occurrence. A calendar may also be printed in two sheets with die-cut windows that may be opened after certain actions or occurrences. A calendar may be printed on plastic or other materials with erasable surfaces, if desired.
[0009] Any of the described paper calendar systems may be used alone or in combination with a wide variety of electronic systems and processes. More specifically, a tracking system of the present invention may be provided electronically either online, via computer software, by PDA, telephone, or some combination of any of these. Electronic delivery may be combined with use of printed versions of the calendars and may include electronic analysis of data originally collected on the printed calendars. A specially created or adapted graphics tablet may be used to simulate electronic “coloring in” of the modules for uploading to an electronic environment. Animated versions of the calendar and its components may be created and may include sound or other graphic or special effects. Online versions of the calendar may include extensive analysis and interactivity, including automated reminders and the opportunity to compete with others in individual or group challenges or the like. Three-dimensional forms of the calendar may be created with individual modules that are put together in a building block process or puzzle piece process to create a larger form.
[0010] The present invention provides many advantages. A color codeable calendar design of the present invention can make it easy to see accomplishments by quickly glancing at a particular page and noting the relative quantity of a particular color. Such calendars can also be beneficial to determine where more improvement is needed, and can even provide motivation to act in order to see less empty white space on the calendar. The calendars of the present invention can provide a convenient place to schedule future activities. The pleasurable activity of coloring in the modules provides an immediate reward and sense of recognition. If desired, additional rewards can be provided as goals are completed. Rewards, such as short-term rewards, can help motivate a user to make positive changes.
[0011] The calendars and systems of the present invention can also serve as a place to organize and keep track of actions and occurrences that are so small they might otherwise not be noted, but that are the building blocks for larger changes and improvement, and also important in establishing overall trends in order to determine where to effect improvement. Such calendars can make the user mindful of such actions, and helps the user internalize their locus of control over the actions and over the long-term results of those actions. By viewing the color and data which the user has personally entered, the user is more likely to trust the information and to be more objective and realistic about what has or hasn't been done, and what might need to be done.
[0012] Over time the user creates a permanent record of actions, data, occurrences and achievements that might otherwise have gone uncollected or unrecognized. This information can be important for many reasons. It provides the user with a sense of continuity through all their stages of change and a recognition that small daily actions do matter. In the case of health improvement, the user's perceived self-efficacy in making positive changes may be confirmed by looking back on past achievements and accomplishments, which may help motivate the user to continue improving or to attempt to make improvements or changes in other areas. The user may also look back and correlate health behaviors to life events, which could be useful in helping shape new responses to such events. The collected health data and health improvement information may also prove vitally useful to family and medical advisors in making medical decisions for or with the user.
[0013] Calendar systems and methods of the present invention can be used for individuals at any fitness level from beginners to elite athletes. Calendars can be customized for a particular user and/or class of users. For example, calendar systems may be customized for those who desire to quit smoking, lose weight, exercise more, drink less, and the like. The calendars and methods of the present invention can also include tips to get started and keep going for providing positive reinforcement, for example. Calendars and methods of the present invention can be used to visually show progress towards a goal, one day at a time, by using color to show what has been done. On a calendar of the present invention, a user can use color to show daily positive actions. Also, if desired, a user can use a predefined color to identify negative actions or the occurrence of some undesired event or the absence of performing some action. That is, what was actually accomplished as well as what was not accomplished can be illustrated, depending on the desires of a particular user. Calendars of the present invention can also include tips and instructions to help users get started and to help users continue toward their goals.
[0014] Over time, a user can create a colorful, one-of-a-kind mosaic that illustrates positive performance toward a goal. With just a quick glance back over such a colorful journal, a user can spot trends and see what worked on an individual basis. All that color can be like “a pat on the back” for the effort expended. Short-term rewards of this type can help motivate a user to make positive lifestyle changes.
[0015] A calendar in accordance with the present invention provides users with powerful behavioral support based on the processes of change used by people to move through the stages of change common to most health behaviors, as described in the Transtheoretical Model.
[0016] A calendar in accordance with the present invention helps trainers and advisors assess where users are in the health behavior change ‘stages of change’ model, in order to tailor communication and interaction with them for a more successful outcome. By assisting in consciousness raising, the calendar provides good support for people in the second stage of change (contemplation.)
[0017] In the preparation stage a person intends to take action within the next 30 days and has already taken some behavioral steps to do so. This stage is characterized by self-liberation, which includes a belief that they can change, and the commitment/recommitment to act on that belief, as typified by a New Year's resolution. With its monthly evaluation, goal and reward setting features, the calendar encourages users to make those commitments at any time of year and often throughout the year, as the small steps they take each day help them progress through many positive changes.
[0018] A calendar in accordance with the present invention provides reward mechanisms to support the action stage of the Transtheoretical Model of health behavior change, which lasts about six months, in which people are making improvements sufficient to reduce their risk of disease. The short-term and long-term rewards provides help support the contingency management aspect of successful health behavior change. Contingency management means that there will be consequences for actions. Most often rewards work better than punishments, and a calendar according to the present invention can provide daily, weekly, monthly and even longer term rewards.
[0019] Coloring in a calendar with that day's positive actions is an immediate reward. Unlike writing, which is a chore for many, coloring is associated with play and is considered a pleasant activity or reward. Coloring in each day on the calendar breaks any program down into small manageable steps, and gives people an immediate reward before they might notice it in their appearance or health. Seeing an accumulation of too many days without color provides a subtle ‘punishment’ that can motivate the person to take positive action.
[0020] The design of a daily module in accordance with the present invention makes it easy for a user to keep track of multiple health-related behaviors of their choosing, and improvement in one area may lead to a decision to try to improve in another. A calendar becomes a control panel for them to move through the stages of change in many behaviors and strengthen their sense of self-control.
[0021] In the maintenance stage, which lasts from roughly 6 months to 5 years, a user works to prevent relapse but is less tempted to relapse and increasingly confident of being able to maintain healthy behavior despite challenging situations (self-efficacy.) Contingency management and helping relationships of trainers and advisors who review such calendars are still important processes at this stage. Reviewing the calendar, which involves looking back over months and years of color that represents their positive actions to improve, is rewarding and can help bolster a user's confidence that they can continue to engage in healthy behavior.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate several aspects of the present invention and together with a description of the embodiments serve to explain the principles of the present invention. A brief description of the drawings is as follows:
[0023] FIG. 1 is a schematic view of an exemplary monthly calendar page of the present invention showing a color key and plural individual day modules;
[0024] FIG. 2 is a schematic view of an exemplary color key of the present invention;
[0025] FIG. 3 is a schematic view of an exemplary day module of the present invention;
[0026] FIG. 4 is a schematic view of the day module of FIG. 3 showing information that has been recorded in the day module;
[0027] FIG. 5 is a schematic view of plural day modules of the present invention arranged to form a week module and showing information that has been recorded in certain of the day modules; and
[0028] FIG. 6 is an exemplary calendar of the present invention that includes plural monthly pages.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] FIGS. 1-6 illustrate several examples of calendars and calendar features according to the present invention. These Figures show examples of how various components and features of the present invention may be arranged and used. It is contemplated that many variations may be made to the arrangements exemplified by the Figures, which are included within the scope of the present invention. In particular, FIG. 1 shows an exemplary monthly page 10 of a calendar of the present invention. As illustrated, the monthly page 10 preferably includes a monthly color key 12 and daily modules 14 . As shown the key is placed at the top of the page but may be located anywhere on the page and may be on a separate page if desired. The day modules are arranged into weeks, as shown, but may be arranged in any way desired. For example, each day module, plural day modules, a week or plural weeks may be provided on a separate page, if desired. A monthly page may also include a goal/reward area, optional weekly/monthly totals, and/or tips to get started and keep going. Twelve monthly pages may be used to form a yearly calendar. Any number of monthly pages can be combined to form a calendar of the present invention. Such monthly pages may be printed on paper or the like or may be provided for electronic display and interaction such as on a web page or the like. Preferably, the background color for a monthly page is chosen so that colors used for the color key are visible and have contrast with respect to the background color. For example, monochromatic colors can be used.
[0030] FIG. 2 shows an exemplary monthly color key 12 that can be used in accordance with the present invention. The color key can be provided in any way that allows a user to associate a color, symbol, or other graphical indicator or mark with an action or the like. The monthly color key 12 preferably includes a column of blank spaces or fields 15 that preferably correlate with an adjacent column of blank spaces of fields 16 in which a user can define certain actions or occurrences that can be tracked in the daily modules throughout the course of the month as described below. The placement of the blank spaces, 15 and 16 , preferably corresponds roughly (vertically, as shown) to main sections 20 and subsections 22 of a representative daily module 24 that is preferably positioned on the color key 12 . Because more than one color may be used in a section or subsection throughout the course of the month, an additional set of columns, 26 and 28 , similar to columns 15 and 16 is preferably included adjacent to columns 15 and 16 . Some of the fields, 15 and 16 , maybe predefined for the user in terms of activity or occurrences tracked, but most are user defined such as shown with color code 30 and action 32 . Optionally, the user may choose to specify the color key selections from the previous month by checking field 33 .
[0031] A daily module such as the daily module 14 shown in FIG. 3 preferably includes a pre-defined area 34 for the calendar date and an area or areas 36 to record or signify certain pre-defined actions or occurrences. For example, the areas 36 may be used to track how many glasses of water a user consumes for that particular day, where one area 36 would be filled in by the user after each glass of water is consumed. To provide the user with optimum flexibility to adapt and customize the daily module according to personal preferences, many discrete areas of the daily module are preferably left undefined such as areas 38 , 40 , and 42 , for example. Also a section 44 may be used in its entirety or in subsections 46 , 48 , 50 , and/or 52 as shown by dividing lines. Horizontal and/or vertical dividing lines may be used. Daily modules may be provided in any manner desired such that actions can be recorded with color. They can be any desired size and shape. They can be provided in paper or as an interactive electronic system. Any manner of providing color to the daily module may be used such as, marker, highlighters, pens, pencils, paints, inks, stickers, crayons, and the like. Also, electronic devices may be used such as those that can provide colored lights and the like to a daily module to indicate performance of an action in accordance with the present invention.
[0032] Preferably, the user enters colors or alphanumeric data into each daily module 14 throughout the course of the month to indicate occurrences or actions taken as shown in FIG. 4 , for example. In the case of fitness improvement as shown in FIG. 4 , the user can color the entire section 54 in a particular color to indicate an outdoor jog as is preferably specified in the color key and then can optionally add alphanumeric data indicating distance 56 and time 58 . Water consumption can be indicated in a different color in predefined areas 60 . Section 62 can be colored to indicate user performed resistance training on that day, and a symbol such as the letter “U” may be added to indicate upper body training, as other examples. The user may also define section 64 as an area in which to keep track of healthy food selections also indicated by various colors. Also, field 66 can be used to track weight or other desired parameter.
[0033] FIG. 5 shows an entire exemplary week 68 of daily modules 14 colored with various colors (indicated as cross-hatching or patterns) according to a user-defined color key and demonstrating customization by the user to indicate days with two different activities 70 (i.e., two different colors/cross-hatching), days with minimal activity 72 (i.e., days with a relatively large amount of “white space” or blank areas) and days with no exercise 74 which are readily apparent due to the lack of color. Optionally the user can tally weekly totals in spaces 76 provided at the end of each week.
[0034] All of the monthly pages can be bound into a calendar form 78 as shown in FIG. 6 , for example, and optionally year-end totals for user and subjective or objective data may be compared to previously collected baseline data for the user at the end of the calendar year or data collection period in a summary section 80 . The calendar 78 may be bound in any desired way such as by spiral binding of the like.
[0035] Methods of the present invention can include steps of determining a goal such as one related to habits to improve, setting up a monthly color key, and coloring a calendar to indicate performance toward such goals.
[0036] As an example, one may desire to improve certain exercise habits. Accordingly, an exercise goal may be determined and set. For better health, exercising for 30 minutes per day on average may be a goal. For weight loss, exercising for 60 minutes per day on average may be a goal. Preferably, a user picks something they enjoy as an action. As such, it may be more likely that a user will stick with it. Also, those starting a new exercise program or those already on an exercise program may use such methods and calendars. Many activities can be used to set such goals. For example walking, running, stair climbing, swimming, biking, dancing, kickboxing, weight training, aerobics, yoga, gardening, team sports/activities, and the like may be used. Preferably, a user starts at a safe level for their current fitness level and health, and increases regularly and in small increments. Preferably, such exercise challenges a user somewhat (e.g. walking briskly rather than dawdling along). A user may consult with a fitness professional who can help the user identify weak points, and develop a cross-training program to help balance them out.
[0037] As described above, a calendar of the present invention preferably includes a monthly key that comprises a goal area where a user can set weekly goals and decide on a reward for reaching them by the end of the month, if desired. Typical goals might be “Walk to work three times a week” or “Exercise for 210 minutes per week” or “Run 12 miles per week,” or whatever activity, distance or duration is desired. This can also include diet or other goals such as generally health-related goals.
[0038] There may also be an area where a user can decide on a reward for fulfilling certain goals, if desired. A user may, for instance, decide to put away the money saved each day by not eating a certain unhealthy food item. At the end of the month, that money could be used to buy something new to wear, or some other desired item.
[0039] As another example, one may desire to improve certain eating habits. Accordingly, an eating habit goal(s) may be determined and set. For example, goals such as a candy-free day, donut-free day, soda pop-free day, white flour-free day, sugar-free day, fast food-free day, junk food-free day, did not eat anything 2 hours before bedtime, ate oatmeal, ate salmon or other source of omega-3 fatty acids, ate the recommended number of servings of fruits and vegetables, drank green tea, took vitamins, and the like, may be used. Other habits in the areas of eating, exercising, smoking, stress management and alcohol consumption can also be used to set goals.
[0040] Preferably, goals/actions are set forth in a positive way. Several examples include: alcohol-free day, smoke-free day, drank less caffeine, meditated, got adequate sleep, flossed my teeth, wore my seatbelt, or anything one can do to improve habits, or reduce risk of injury or illness.
[0041] A user can set up a monthly color key in any desired way. Users can decide where to use favorite colors. Preferably, color is used to show positive actions that a user can take, such as “walk around the lake” or “do my exercise video.” Preferably, a color key is not set up to show the outcomes/results actions (such as “lose 3 pounds”) because such results cannot generally be controlled each day. In months where a key is not changing, a user may just check a “same as last month” option, for example.
[0042] Calendars and systems of the present invention can be used in many different ways depending on a particular user. For example, a user can color a predetermined section of a daily module a bright yellow to show when the user took a walk outdoors. The user might also color a predetermined section green to show when the user took the stairs at work. And the user can keep track of eight-ounce glasses of water, perhaps in blue highlighter.
[0043] Users might want to keep track of weight such as by using a section right next to the date (See field 66 of the daily module 14 of FIG. 4 , for example.). A user may decide to use color in that section to show days where they have not eaten a certain food they are trying to avoid. A user may also use color to show they added a healthy food item, or vitamins as described below.
[0044] A user who does more than one activity per day, can specify a different color in the main section for each activity. At the end of each day, the user can color the entire main section using many colors to represent multiple activities performed that day, using the dividing lines to separate activities.
[0045] As another example, for users doing regular resistance training, such a user can use the small circle in the lower right, and write in “U” for upper or “L” for lower body workouts or other symbol, or the like. Rest/recovery days are also positive and could be colored in and coded with an “R” or other symbol, or the like.
[0046] Weight and positive nutrition choices could also be noted in the space next to the date or any other space within a daily module, and a user can color in a spot to show the taking of vitamins or supplements.
[0047] A user can write in exercise distances, duration, frequency, or other sport-specific statistics, and total them up at the end of each week and each month. These totals can appear at the bottom of the page, making them easy to flip through and review.
[0048] Calendars of the present invention may also include one or more fields or locations to write down certain health statistics such as BMI, cholesterol, blood pressure and/or other user-selected measures/statistics before starting and at the end of some time period for comparison. For example, a user can track desired parameters weekly, monthly, quarterly, or yearly or on any other desired schedule. Also a place for before and after photos or written comments may be provided, if desired.
[0049] The present invention has now been described with reference to certain specific embodiments. The foregoing detailed description has been given for clarity of understanding. Others may recognize that changes can be made in the described embodiments without departing from the scope and spirit of the present invention. Thus, the scope of the present invention should not be limited to the exact details and structures described herein. | The present invention provides color-codeable calendars/journals and systems. A calendar/journal system in accordance with the present invention includes a graphical color codeable key that can be used to visually associate a color with an act or event. The calendar/journal also includes a graphical module that represents a predetermined period of time. The graphical module can be color coded according to the color codeable key to indicated the occurrence of an act or event. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a sewing machine in which a sewing thread can automatically be released from a thread loop formed when a sewing needle is threaded, a threading control program and a recording medium on which the threading control program is recorded.
[0003] 2. Description of the Related Art
[0004] There have conventionally been proposed sewing machines provided with threading means for automatically threading a sewing needle. For example, JP-8-173676-A discloses a technique for catching a thread by a hook having been passed through an eye of the needle and returning the hook through the needle eye such that the needle thread is passed through the needle eye, while the thread is guided by thread guide grooves or the like and held by thread holders. JP-6-254279-A discloses thread drawing means for wiping a leading end of the cut thread off the cloth after a thread cutting operation such as in completion of sewing and introducing the thread end to an upper thread nipper.
[0005] In the sewing machine disclosed in JP-8-173676-A, however, the thread having been passed through the needle eye forms a loop between the needle eye and the hook. The thread loop is drawn with fingers of an operator so that a free end side part of the thread is pulled back through the needle eye, whereby the needle is threaded. JP-51-24353-A discloses a first nipper holding a thread cut during the sewing and a second nipper catching the thread held by the first nipper. The thread caught by the second nipper is passed through the needle eye by a thread extruder. The thread having been passed through the needle eye is caught by a third nipper, which is then moved upward so that the thread is completely passed through the needle eye. In the disclosed sewing machine, however, three nippers are provided for catching and pulling back the thread through the needle eye. Moreover, since the three nippers are moved individually, the structure of the sewing machine is complicated.
SUMMARY OF THE INVENTION
[0006] Therefore, an object of the present invention is to provide a sewing machine in which the thread can be released from the thread loop formed during the threading operation by thread drawing means so that the thread is passed through the needle eye and the structure of the sewing machine can be simplified.
[0007] The present invention provides a sewing machine comprising a threader including a threading hook for passing a thread through an eye of a needle and a thread drawer including a thread drawing member wiping the thread extending through the needle eye downward, the thread drawing member also drawing a looped thread having been passed through the needle eye by the threading hook.
[0008] The threading hook on which the operator has set the thread is pulled back through the needle eye, so that the thread is passed through the needle eye by the threading hook. The thread formed into a loop shape can be drawn by the thread drawing member of the thread drawer. Consequently, the thread can be passed through the needle eye so that the sewing can be initiated.
[0009] In the above-described construction, it is preferred that when the looped thread is drawn by the thread drawing member, the thread drawer draws the thread to a position where the thread is released from a looped state.
[0010] In another preferred form, a part of the thread between the needle and the threading hook is drawn by the thread drawing member while the threading hook in engagement with the thread is spaced away from the needle rearward.
[0011] Furthermore, the sewing machine further comprises a thread holding member holding an end of the thread caught on the threading hook before the thread is passed through the needle eye. In this case, the thread drawing member is engaged with the thread after the thread has been released from a held state by means of the thread holding member, thereby drawing the thread.
[0012] In further another preferred form, the thread drawing member draws a free end side of the looped thread formed by the threading hook. Furthermore, the thread drawing member preferably has a shorter distance of movement in a case of releasing the thread from the looped state than a distance of movement in a case of wiping the thread.
[0013] In further another preferred form, the thread drawing member has a distal end positioned higher in a case of releasing the thread from the looped state than in a case of wiping the thread. Further, the thread drawing member releases the thread from the looped state in a middle of a movement locus thereof in a case of wiping the thread.
[0014] Furthermore, the sewing machine is preferably a multi-needle sewing machine including a plurality of needle bars provided with needles respectively. Additionally, the thread drawing member preferably carries out a thread drawing operation while a distal end of the threading hook on which the thread is caught is located lower than the needle eye.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Other objects, features and advantages of the present invention will become clear upon reviewing the following description of the invention with reference to the accompanying drawings, in which:
[0016] FIG. 1 is a perspective view of a multi-head sewing machine in accordance with one embodiment of the present invention;
[0017] FIG. 2 is a front view of a needle bar case;
[0018] FIG. 3 is a partial left side view of an embroidery sewing machine;
[0019] FIG. 4 is a partial right side view of the embroidery sewing machine;
[0020] FIG. 5 is a partial front view of the embroidery sewing machine;
[0021] FIG. 6 is a partial plan view of the embroidery sewing machine;
[0022] FIG. 7 is a right side view of the embroidery sewing machine, showing a stage of a threading operation;
[0023] FIG. 8 is also a right side view of the embroidery sewing machine, showing another stage of the threading operation;
[0024] FIG. 9 is a longitudinal section of a sewing needle and its periphery in the threaded state;
[0025] FIG. 10 is a plan view of a sewing needle and its periphery in the threaded state;
[0026] FIG. 11 is a plan view of the sewing needle and its periphery with a thread loop being formed;
[0027] FIG. 12 is a schematic block diagram showing an electrical arrangement of a control unit; and
[0028] FIG. 13 is a flowchart showing a threading control program.
DETAILED DESCRIPTION OF THE INVENTION
[0029] One embodiment of the present invention will be described with reference to the drawings. In the embodiment, the invention is applied to an industrial or occupational multi-head sewing machine including three multi-needle embroidery sewing machines which can embroider three same embroidery patterns on respective caps at the same time.
[0030] The multi-head sewing machine M will first be described. Referring to FIG. 1 , the multi-head sewing machine M comprises an embroidering machine body frame 1 extending in the right-and-left direction, and a generally rectangular machine support plate 2 mounted on the rear top of the frame 1 so as to extend in the right-and-left direction. Three multi-needle embroidery sewing machines M 1 to M 3 are mounted on the support plate 2 so as to be juxtaposed in the right-and-left direction. The embroidery sewing machines M 1 to M 3 have the same structure.
[0031] Each of the embroidery sewing machines M 1 to M 3 includes an arm 3 having a distal end on which a sewing head 4 is mounted. The head 4 has a front end on which a needle bar case 5 is mounted so as to be moved in the right-and-left direction. Six needle bars 10 are supported on the needle bar case 5 so as to be vertically moved. A sewing needle 15 having a needle eye 15 a is fixed to each needle bar 10 . A stud 6 is continuous to the arm 3 and has a lower end to which a sewing bed body 7 is continuous. The sewing bed body 7 is fixed to the machine support plate 2 . The sewing bed body 7 has a front end from which a cylinder bed 8 extends forward. The cylinder bed 8 has a front end on which a thread loop taker (not shown) and the like are provided. The multi-head sewing machine M includes an operation panel 9 disposed at the right end thereof. An operator operates the operation panel 9 to enter various commands.
[0032] Referring now to FIGS. 3 and 4 , each head 4 includes the needle bar case 5 , a lift driving mechanism 30 transmitting a vertically driving force from a sewing machine motor 110 to the needle bar 10 and a needle bar releasing mechanism 31 cutting off transmission of driving force between the needle bar 10 and the lift driving mechanism 30 . Each head 4 further includes a thread drawing mechanism 32 further including a thread drawing member 62 and a threading mechanism 33 passing a thread through an eye 15 a of a sewing needle 15 by means of a threading hook 83 .
[0033] Referring to FIGS. 2 and 3 , each needle bar case 5 includes six vertically extending needle bars 10 , six needle thread take-up levers 11 located so as to correspond to the respective needle bars 10 and attached so as to be moved vertically. Each needle bar case 5 further includes first and second needle bar guiding members 12 and 13 both fixed to the needle bar case 5 to guide the needle bar 10 and a first thread holding member 14 extending in the right-and-left direction and supported on a fixing plate 17 having both ends secured to the needle bar case 5 . Each needle bar case 5 still further includes six second thread holding members 16 disposed so as to correspond to the respective needles 15 and six presser feet 24 disposed so as to correspond to the respective needles 15 .
[0034] A connecting member 18 is secured to a middle portion of each needle bar 10 . The connecting member 18 includes a connecting pin 18 a to which a driving force from the lift driving mechanism 30 is transmitted. A compression coil spring 19 is provided around the needle bar 10 between the connecting member 18 and the first needle bar guiding member 12 . The compression coil spring 19 biases the needle bar 10 upward. The needles 15 are attached to the lower ends of the respective needle bars 10 . An embroidering thread T is supplied from a thread spool 21 mounted on a spool holder base 20 to each of the six needles 15 .
[0035] The first thread holding member 14 holds the thread T drawn by the thread drawing mechanism 32 . The first thread holding member 14 includes a thread holding tape 14 a further including hook sides of two pieces of hook-type magic tape (registered trademark). The hook sides are superposed so as to confront each other. The first thread holding member 14 further includes a pair of reinforcing plates 14 b holding the thread holding tape 14 a therebetween.
[0036] Each second thread holding member 16 preliminarily holds a leading end of the thread T caught on the threading hook 83 before the thread T is passed through the needle eye 15 a . The second thread holding member 16 includes a holding portion 16 a holding the thread T cut by a blade 16 a and a guiding portion 16 chaving a forwardly protruding distal end and guiding the thread T to the holding portion 16 a . The operator passes the thread T from the right side to the rear of the guiding portion 1 c . When guided to the blade 16 a , the thread T is drawn downwardly forward so that the thread T is cut by the blade 16 a and held by the holding portion 16 b and the front of the needle bar case 5 therebetween. Thus, the leading end of the thread T is held.
[0037] Each needle bar case 5 is moved right and left so that a desired one of the needles 15 is switched into a sewing position corresponding to a needle hole (not shown) formed in the distal end of the cylinder bed 8 , whereby one of the needle bars 10 is selected. A rotating force developed by the motor 110 is transmitted via the driving shaft 22 , a V belt and the like to the lift driving mechanism 30 as a vertically driving force. The lift driving mechanism 30 is then driven vertically so that the needle bar 10 is vertically moved and accordingly, the corresponding needle thread take-up lever 11 is vertically swung. Further, stitches are formed using the thread T with a selected color by the cooperation of the needle 15 of the needle bar 10 and the thread loop taker.
[0038] Referring now to FIGS. 3, 5 and 6 , the lift driving mechanism 30 includes a base needle bar 35 disposed in parallel with the needle bar 10 and a driving member 36 mounted on the base needle bar 35 so as to be slidable and non-rotatable. The lift driving mechanism 30 further includes a transmitting member 37 mounted so as to be vertically driven together with the driving member 36 and so as to be rotatable relative to the base needle bar 35 . The lift driving mechanism 30 still further includes a first coil spring 38 having one of two ends abutting the driving member 36 and the other end abutting the transmitting member 37 so that the transmitting member 37 is biased to a transmitting position where the driving force is transmitted to the needle bar 10 .
[0039] The driving member 36 includes upper and lower driving members 36 a and 36 b both fitted with the base needle bar 35 and a connecting portion 36 c connecting the upper and lower driving members 36 a and 36 b . A first coil spring 38 is fitted with the upper driving member 36 a . A stopper 39 is secured to a left side of the lower driving member 36 b . The stopper 39 limits rotation of the transmitting member 37 to a predetermined angle. The transmitting member 37 is disposed between the upper and lower driving members 36 a and 36 b . The transmitting member 37 includes first and second engaging members 40 and 41 engaging the connecting pin 18 a and an abutment pillar 42 to which a rotating force from the needle bar releasing mechanism 31 is transmitted in order that the needle bar 10 may be released. The first engaging member 40 includes an inclined portion 40 a turning the transmitting member 37 in the direction of arrow A in FIG. 6 when the connecting pin 18 a in the released state abuts the first engaging member 40 .
[0040] The needle bar releasing mechanism 31 includes a driving motor 46 mounted on the fixing member 45 and comprising a pulse motor and a sector gear 47 in mesh engagement with an output shaft 46 a of the driving motor 46 . The needle bar releasing mechanism 31 further includes a guided plate 50 guided by guide pins 49 a and 49 b secured to the fixing member 48 so that the guided member is vertically moved. The needle bar releasing mechanism 31 still further includes a first linking member 51 having a lower end connected to a central portion of the guided plate 50 so that the lower end is swung and a second linking member 52 connected to an upper end of the first linking member 51 so as to be swung, an abutting member 53 swung with the second linking member 52 and a stopper 54 fixed to the fixing member 48 . The sector gear 47 has a front half further having a lower end abutting an abutment pin 55 secured to a lower end of the guided plate 50 . The fixing members 45 and 48 are fixed to a left-side sewing machine frame 56 .
[0041] The abutting member 53 includes a shaft 53 a rotatably mounted on the fixing member 48 and fixed to the second linking member 52 by a small screw 57 , a first abutting portion 53 b abutting the abutment pillar 42 of the transmitting member 37 and a second abutting portion 53 c abutting the stopper 54 . A second coil spring 59 is wound on a right end of the shaft 53 a . The second coil spring 59 has one end fixed to a screw 58 in thread engagement with the fixing member 48 . The abutting member 53 is biased in the direction of arrow C in FIG. 3 by the second coil spring 59 except when the needle bar 10 is jumped, whereupon the second abutting portion 53 c is in abutment with the stopper 54 .
[0042] In order that the needle bar 10 may be jumped to be released by the needle bar releasing mechanism 31 , the driving motor 46 is driven so that the sector gear 47 is rotated in the direction of arrow Din FIG. 3 , whereby the guided plate 50 is moved downward. The movement of the guided plate 50 further moves the lower end of the first linking member 51 downward. With the downward movement of the first linking member 51 , the second linking member 52 is rotated in the direction opposite arrow C about the shaft 53 a together with the abutting member 53 . By the rotation, the abutting member 53 presses the abutment pillar 42 of the transmitting member 37 which is further in abutment with the first abutting portion 53 b , so that the transmitting member 37 is rotated in the direction of arrow A in FIG. 6 until the abutment pillar 42 abuts the stopper 39 (see the abutment pillar 42 shown by two-dot chain line in FIG. 6 ). As the result of rotation of the transmitting member 37 , the first and second engaging members 40 and 41 are released from engagement with the connecting pin 18 a . Consequently, the needle bar 10 is biased by the compression coil spring 19 thereby to be caused to jump to an upper limit position, whereby the needle bar 10 is in a released state in which a lifting force of the lift driving mechanism 30 is prevented from being transmitted to the needle bar 10 .
[0043] On the other hand, in order that the needle bar 10 may be switched from the released state to a transmissible state in which the lift driving force of the lift driving mechanism 30 is transmissible to the needle bar 10 , the transmitting member 37 is moved upward by the sewing machine motor 110 so that the connecting pin 18 a abuts the inclined portion 40 a from above, whereby the transmitting member 37 is rotated in the direction of arrow A in FIG. 6 . Further, when moved upward so that the connecting pin 18 a is located between the first and second engaging members 40 and 41 , the transmitting member 37 is rotated in the direction of arrow B in FIG. 6 by the biasing force of the coil spring 38 , whereby the connecting pin 18 a engages the first and second engaging members 40 and 41 such that the needle bar 10 is in the transmissible state.
[0044] The thread drawing mechanism 32 wipes the thread T extending downward through the needle eye 15 a when the thread has been cut by a thread cutting mechanism (not shown) provided in the cylinder bed 8 at the time of completion of the sewing or needle change. The thread having been passed through the needle eye 15 a and having a loop L is released from a looped state by the thread drawing mechanism 32 and caught on the threading hook 83 .
[0045] Referring to FIGS. 3, 5 and 6 , the thread drawing mechanism 32 includes the driving motor 46 , the sector gear 47 formed with a detected portion 60 , a thread drawing member origin detector 61 for detecting the detected portion 60 , and a thread drawing member 62 . The thread drawing mechanism 32 further includes a coupling plate 63 having both ends coupled to the thread drawing member 62 and the sector gear 47 respectively so that the coupling plate 63 is swung. The thread drawing mechanism 32 still further includes a guiding member 64 guiding the thread drawing member 62 and a cover 65 for the guiding member 64 . The thread drawing member 62 includes a standing portion 62 a coupled to the coupling plate 63 so as to be swung and a hook 62 b for drawing the thread T. The thread drawing member 62 is held between the guiding member 64 and the cover 65 and supported in a guide groove 64 a formed in the guiding member 64 so that the thread drawing member 62 is slid. The origin detector 61 comprises a photo-interrupter including a light emitting element and a light detecting element. The origin detector 61 detects, as an origin, a position of the thread drawing member 62 when the lower edge of the detected portion 60 passes between the light emitting and detecting elements. The guide groove 64 guiding the thread drawing member 62 is formed so that the thread drawing member 62 is allowed to be moved rearward from a standby position as shown in FIGS. 4 and 6 when the driving motor 46 is driven to rotate in the direction of arrow D in FIG. 3 in order that the needle bar releasing mechanism 31 may be driven.
[0046] In wiping the thread, the sector gear 47 to which the driving force is transmitted from the driving motor 46 is rotated in the direction of arrow E in FIG. 3 . With the rotation of the motor 46 , the coupling plate 63 is moved downwardly forward so that the thread drawing member 62 coupled to the lower end of the coupling plate 63 passes through the first thread holding member 14 while being guided by the guide groove 64 a . Thus, the thread drawing member 62 is slid to the thread wiping position where the hook 62 b is located below the needle 15 . The hook 62 b is engaged with the thread T which extends downward after having been passed through the needle eye 15 a (see two-dot chain line in FIG. 3 ). When the thread drawing member 62 is returned to the standby position in the aforesaid state, the thread T in engagement with the thread drawing member 62 is held by the thread holding tape 14 a of the first thread holding member 14 when passing through the first holding member 14 .
[0047] Referring now to FIGS. 4 and 5 , the threading mechanism 33 includes a threading motor 70 comprising a pulse motor, a rack 71 meshed with an output shaft 70 a of the threading motor 70 and having a guide groove 71 a which is engaged with guide pins 72 a and 72 b fixed to the right machine frame 73 , and an extension spring 76 having two ends. One end of the extension spring 76 is connected to a connecting pin 74 fixed to a lower end of the rack 71 and the other end of the extension spring 76 is connected to a connecting protrusion 75 fixed to a guide frame 77 . As a result, the extension spring 76 biases the rack 71 upward. The threading mechanism 33 further includes the guide frame 77 fixed to the right machine frame 73 and formed with a guide groove 77 a , a crank plate 78 located on the right of the guide frame 77 and connected via the connecting pin 74 to a lower end of the rack 71 , and a link block 80 formed into the shape of a rectangular parallelepiped. A first guided pin 79 is engaged with a guide groove 77 a formed in a lower end of the crank plate 78 . The link block 80 is connected via the first guided pin 79 to a left side of the guide frame 77 so as to be moved. The threading mechanism 33 still further includes a pair of right and left thread catching members 81 and 82 fixed to a distal end of the link block 80 and having inclined portions 81 a and 82 a both guiding the thread T to the threading hook 83 . The threading hook 83 has a hook 83 a on which the thread T held between the thread catching members 81 and 82 is caught. A threading hook detector 111 (see FIG. 12 ) detects a position of the threading hook 83 .
[0048] A second guided pin 84 engaged with the guide groove 77 a is fixed to a middle portion of the link block 80 . The guide groove 77 a includes an inclined portion 77 b and a horizontal portion 77 c . In the threading operation, the link block 80 is firstly guided downwardly forward and horizontally forward subsequently.
[0049] A threading operation by the thread drawing mechanism 32 and the threading mechanism 33 will now be described. FIG. 7 illustrates the threading hook 83 and the thread drawing member 62 both of which are in the standby state. In this state, the threading motor 70 is driven to move the rack 71 downward while the rack 71 is being guided by the guide pins 72 a and 72 b . As a result, the crank plate 78 connected to the rack 71 and the link block 80 connected to the crank plate 78 are firstly moved downwardly forward along the inclined portion 77 b of the guide groove 77 a and subsequently horizontally forward along the horizontal portion 77 c . Further, the link block 80 is moved so that the hook portion 83 a of the threading hook 83 passes through the needle eye 15 a as shown in FIGS. 4 and 9 . The link block 80 is stopped at a thread catching position where the second guided pin 84 abuts the front end of the guide groove 77 a.
[0050] Referring to FIGS. 2 and 4 , the operator sets the thread T guided by the thread guides 85 and 86 and the like, on the thread catching members 81 and 82 from the right side. The thread T is then cut by the blade 16 a of the second thread holding member 16 . A free end of the thread T is held between the holding portion 16 b and front face of the needle bar case 5 , whereby the thread T is held. In this case, when the operator upwardly draws the thread T caught on the thread catching members 81 and 82 , the thread T is guided to the threading hook 83 by the inclined portions 81 a and 82 a of the respective thread catching members 81 and 82 to be caught on the hook portion 83 a , as shown in FIGS. 9 and 10 .
[0051] Subsequently, the threading motor 70 is driven to move the threading hook 83 rearward by a predetermined distance. The threading hook 83 is stopped at a thread releasing position located in the rear of the needle 15 . The driving motor 46 is then driven to move the hook portion 62 b of the thread drawing member 62 through a thread loop L to a thread drawing position located lower than the loop L on the same locus as that in the thread wiping operation, so that the free end side F of the thread loop L is engaged with the hook portion 62 b , as shown in FIG. 8 . This thread drawing position is located higher than the thread wiping position and a distance of the hook portion 62 b moved is shorter than that in the thread wiping. In this case, the free end of the thread T held by the second thread holding member 16 is released such that the thread T is loosened, and the thread loop L is in engagement with the threading hook 83 . Accordingly, the width of the thread loop L in the right-and-left direction is increased without the thread loop hanging down between the threading hook 83 and the needle eye 15 a , as shown in FIG. 11 . Further, since the hook 83 a is located lower than the needle eye 15 a , the thread loop L is substantially perpendicular to the thread drawing member 62 , as shown in FIG. 8 . Consequently, the thread drawing member 62 can reliably be passed through the loop L and engaged with the thread T.
[0052] Subsequently, when the thread drawing member 62 is returned to the standby position by the driving motor 46 , the free end side F of the thread loop L held between the threading hook 83 and the needle eye 15 a is drawn so that the thread loop L is pulled back through the needle eye 15 a and disengaged from the threading hook 83 . Consequently, the thread T forming the loop L is released from the looped state. Further, the thread T is held by the thread holding tape 14 a of the first thread holding member 14 when the thread drawing member 62 passes the first thread holding member 14 while drawing the free end side F of the thread T. Thus, the thread T is completely passed through the needle eye 15 a . Subsequently, the threading motor 70 is driven to return the threading hook 83 to the standby position, whereby the threading operation is completed.
[0053] On the other hand, the operation panel 9 is operated so that various commands concerning the sewing or the like are supplied. The operation panel 9 includes a display 90 , input means 91 including a threading switch 92 (see FIG. 12 ) and a flexible disc drive (FDD) 93 . The threading switch 92 is operated so that a command for operating the threading mechanism 33 is supplied and so that a command for operating the thread drawing mechanism 32 releasing the thread with the loop L from the looped state.
[0054] A control unit 100 including a computer 101 will be described with reference to FIG. 12 . The control unit 100 controls overall sections and mechanisms of the embroidery sewing machines M 3 to M 3 including the threading mechanism 33 and the thread drawing mechanism 32 . The control unit 100 includes the computer 101 further including CPU 102 , ROM 103 , RAM 104 and buses 105 connecting these devices. The control unit 100 further includes an input/output interface 106 for input into and output from the computer 101 , a drive circuit 107 connected to the input/output interface 106 to drive the sewing machine motor 110 , a drive circuit 108 for the driving motor 46 and a drive circuit 109 for the threading motor 70 .
[0055] To the input/output interface 106 are connected the thread drawing member origin detector 61 detecting the position of the thread drawing member 62 and the threading hook detector 111 detecting the position of the threading hook 83 . ROM 103 stores a threading control program for driving the motors 46 and 70 so that a threading operation is carried out. RAM 104 stores various data such as position data received from the thread drawing member origin detector 61 and the threading hook detector 111 .
[0056] FIG. 13 is a flowchart showing the threading control program executed by the computer 101 of the control unit 100 in order that a thread T may be passed through the eye 15 a of the needle 15 . The threading control program will now be described. Reference symbol Si (where i=10, 11, . . . ) designates an operation step.
[0057] The operator operates the threading switch 92 of the operation, panel 9 to enter a command (step S 10 ). The computer 101 delivers a command to the drive circuit 109 when the sewing machine is in the sewing stop state (YES at step S 1 ). As a result, the threading hook 83 is driven by the threading motor 70 , so that the threading hook 83 is moved toward the threading position while the position of the threading hook 83 is being detected by the threading hook detector 111 (step S 12 ). When the threading hook 83 has been moved to the threading position (YES at step 513 ), the threading motor 70 is stopped in a state where the threading hook 83 has been passed through the needle eye 15 a (step S 14 ).
[0058] Subsequently, when the thread T is caught on the thread hook 83 and the threading switch 92 is then re-operated so that a command is supplied (YES at step S 15 ), the computer 101 supplies a command to the drive circuit 109 in response to the command from the threading switch 92 . As a result, the threading motor 70 is driven so that the threading hook 83 is moved backward through the needle eye 15 a toward the thread releasing position while the position of the threading hook 83 is being detected by the threading hook detector 111 (step S 16 ). When the threading hook 83 has reached the thread releasing position after movement by a predetermined distance (YES at step S 17 ), threading the needle 15 is then carried out and the threading motor 70 is stopped (step S 18 ).
[0059] Subsequently, when the computer 101 delivers a command to the drive circuit 108 , the drive motor 46 is driven to rotate the sector gear 47 in the direction of arrow E in FIG. 3 so that the thread drawing member 62 is moved toward the origin (step S 19 ). Thereafter, when the origin of the thread drawing member 62 has been detected by the origin detector 61 (YES at step S 20 ), a predetermined number of pulses is supplied to the drive motor 46 at the origin so that the thread drawing member 62 is moved to the thread drawing position (step S 21 ). Consequently, the free end side F of the thread loop L extending from the hook 83 to the needle eye 15 a is engaged with the hook 62 b of the thread drawing member 62 and thereafter, the drive motor 40 is stopped. In this case, the drive motor 46 is driven in the opposite direction so that the thread drawing member 62 with which the thread loop L is in engagement is returned to the standby position, whereupon the thread T is released from the looped state (step S 22 ) and the threading motor 70 is driven to move the threading hook 83 to the standby position and subsequently, the threading control program is finished.
[0060] The following effects can be achieved from the above-described multi-head sewing machine M. The multi-head sewing machine is constructed so that the thread drawing member 62 of the thread wiper 32 for wiping the thread in the thread change or the like is moved to the thread drawing position, whereby the thread with the loop L between the needle eye 15 a and the threading hook 83 in the threading operation is released from the looped state. Consequently, the number of parts of the multi-head sewing machine M is reduced such that the structure thereof can be simplified. Further, the production cost of the multi-head sewing machine M can be reduced, whereas the thread T can reliably be passed through the needle eye 15 a . Accordingly, useless labor by the operator and a useless working time can be reduced.
[0061] Furthermore, when the thread drawing member 62 engages the thread loop L, the thread loop L is held between the needle eye 15 a and the threading hook 83 without hanging downward. Additionally, since the distal end of the threading hook 63 is located lower than the needle eye 15 a , the thread drawing member 62 becomes almost perpendicular to the thread loop L. Further, the thread drawing member 62 passes through the thread loop L while the thread T is released from the holding by the second thread holding member 16 such that the thread loop L is loosened into a spread state. Consequently, the thread drawing member 62 can reliably engage the thread loop L.
[0062] Furthermore, since the thread drawing member 62 engages and draws the free end side F of the thread loop L, the thread T can smoothly be pulled out through the needle eye 15 a without uselessly drawing out the thread from the thread spool 21 .
[0063] Furthermore, the distance by which the thread drawing member 62 is moved for release of the thread is shorter than that thereof for thread wiping. Further, the thread drawing position is located higher than the thread wiping position, the size of the drive motor 46 need not be increased for the purpose of release of the thread loop L. Additionally, the thread drawing member 62 is moved in the release of the looped thread along the same movement locus as in the thread wiping. Consequently, the structure of the multi-head sewing machine M can be simplified since no complicated mechanisms are required which moves the thread drawing member 62 along a complicated movement locus for the release of the thread T from the threaded loop L.
[0064] Modified forms of the foregoing embodiment will now be described. In the foregoing embodiment, the present invention is applied to the embroidery sewing machines M 1 to M 3 each of which is provided with the needle bar case 5 in which a plurality of needles 15 and needle bars 10 are mounted on the single head 4 . However, the invention may be applied to a sewing machine comprising a single head provided with a single sewing needle.
[0065] The invention is applied to the multi-head sewing machine M composed of three embroidery sewing machines M 1 to M 3 in the foregoing embodiment. However, the invention may be applied to a single-head sewing machine composed of a single sewing machine. Further, the invention is applied to the industrial or occupational multi-head sewing machine M in the foregoing embodiment. However, the invention may be applied to a household sewing machine for personal use.
[0066] The lift driving mechanism 30 and the driving force transmitting means are inseparable from the cloth moving mechanism in the foregoing embodiment. However, the cloth moving mechanism may be separable from the lift driving mechanism 30 and the driving force transmitting means as disclosed in Japanese Patent No. 3178022.
[0067] In the foregoing embodiment, the threading hook 83 and the thread drawing member 62 are located in the rear of the needle 15 . However, either one or both of the threading hook and thread drawing member may be disposed in front of the needle or side by side.
[0068] In the foregoing embodiment, the thread drawing member 62 passes through the thread loop L and then engages the thread T while the threading hook 83 and the thread T are in engagement with each other. However, the thread drawing member 62 may engage the thread loop while the threading hook and the thread are disengaged from each other.
[0069] The thread T is held between the thread holding tapes 14 a of the first thread holding member 14 in the foregoing embodiment. However, unless the thread is inadvertently moved or if the thread can be released from the holding by the first thread holding member upon sewing, the thread may merely be placed on a member thereby to be held. Further, upon start of sewing, the thread T is drawn by the needle 15 without operation of the first thread holding member 14 , so that the thread T is released from the held state. However, the first thread holder may comprise an actuator so that the thread is released in a positive manner, instead.
[0070] The thread drawing member 62 is reciprocally moved along a linear passage in the foregoing embodiment. However, the thread drawing member may reciprocally be moved along an arc passage or may be moved in one way along a passage. In the foregoing embodiment, the distance by which the thread drawing member 62 is moved for release of the thread loop L is shorter than that thereof for thread wiping. However, the thread drawing member 62 is moved along a linear passage both for the release of the thread loop L and for thread wiping. Two linear passages may be provided both for the release of the thread loop L and for thread wiping respectively.
[0071] In the foregoing embodiment, the invention is applied to the multi-head sewing machine M in which the operator is located in front of the sewing machine in the sewing as viewed in FIG. 1 . However, the invention may be applied to a single-head sewing machine or the like in which the operator is located on the right or left of the sewing machine. Since the position of the operator changes in this sewing machine, it is desirable that the threading hook and the thread drawing member a removed along a track differing from the one in the foregoing embodiment, for example, so that the tracks of the threading hook and the thread drawing member are moved toward the operator.
[0072] An article to be sewn is moved by a cylindrical cap frame in the above-described multi-head sewing machine M. However, the invention may be applied to a sewing machine in which an article to be sewn is moved by a flat embroidery frame. Further, the invention may be applied to a sewing machine which is not provided with any embroidery frame and an article to be sewn is moved by a feed dog, by a feed roller or manually.
[0073] The free end side F of the thread loop L is located on the left of the needle 15 in the foregoing embodiment as shown in FIG. 11 . Accordingly, the hook 62 b of the thread drawing member 62 is open to the left side. However, the free end side of the thread loop may be located on the right of the needle so that the hook of the thread drawing member is open to the right side, instead.
[0074] The pulse motor is used as the drive motor 46 in the foregoing embodiment. Another type of motor, a solenoid or an air cylinder may be used as the drive motor, instead. Further, a recording medium on which the threading control program is recorded should not be limited to ROM. A flexible disc or a CD-ROM may serve as the recording medium. Additionally, the above-described multi-head sewing machine M includes the sewing bed 7 having a cylinder bed 8 . However, the sewing bed may have a flat bed.
[0075] The foregoing description and drawings are merely illustrative of the principles of the present invention and are not to be construed in a limiting sense. Various changes and modifications will become apparent to those of ordinary skill in the art. All such changes and modifications are seen to fall within the scope of the invention as defined by the appended claims | A sewing machine includes a threader including a threading hook for passing a thread through an eye of a needle. The sewing machine includes a threader driver driving the threader so that the threading hook is advanced through or retreated through the eye of the needle. The sewing machine includes a thread drawer including a thread drawing member wiping the thread extending through the needle eye downward, the thread drawing member also drawing a looped thread having been passed through the needle eye by the threading hook. The sewing machine includes a thread drawer driver provided independent of the threader driver for moving the thread drawer so that the thread is wiped and a thread loop is released from a looped state. The sewing machine includes a control unit controlling the threader driver and the thread drawer driver. | 3 |
TECHNICAL FIELD
The present invention is directed to refractory tube blocks which protect metallic waterwall tubes from hot and highly corrosive furnace gases, while at the same time maintaining good heat conductivity.
BACKGROUND OF THE INVENTION
Municipal solid waste (MSW) facilities incinerate trash and garbage in furnaces at temperatures of up to about 2500 degrees F. In order to recover the valuable energy produced in these MSW plants, water is passed through metallic waterwall tubes adjacent to the furnace and converted to steam by the high temperatures. A conventional waterwall boiler tube assembly comprising metallic tubes T connected by membrane M is provided in FIG. 1. The steam produced in the tube assembly is then used to power a turbine-driven electrical generator. However, the MSW plant also produces gaseous products which, if allowed to contact the metal tubes, would chemically attack those tubes. To prevent direct attack of the tubes by the gaseous products and still allow the tubes to be sufficiently heated, a protective refractory lining is placed between the waterwall tubes and the furnace fireside.
Although these refractory linings help to minimize attack on the metallic tubes, their use inhibits the heat flow from the furnace fireside to the waterwall tubes. Maximum heat flow is critical to achieving boiler efficiency. If the refractory lining has insufficient heat transfer the fireside surface of the refractory becomes hotter than designed. As the temperature increases, ash from the fuel being burned will cling to the surface and form an insulating layer. Once this phenomenon begins, the layer gets increasingly thick until heat transfer becomes extremely poor. The "flue gas" above the combustion zone then increases in velocity and temperature, often above the design limits, and causes corrosion/erosion problems downstream in the furnace. In addition, the layer of ash/slag buildup may eventually break off as it grows and cause major damage to the stoker grate bar area of combustion zone. It is well known that the heat transfer efficiency of a refractory lining is inversely related to its thickness. For example, a refractory having a 2 inch thickness has only 50% of the heat transfer efficiency of the same barrier having a 1 inch depth. Accordingly, the industry has demanded to use refractory lining materials which minimize refractory lining thickness and favor refractory linings as thin as possible.
The metallic waterwall tubes and refractory linings are often installed by hanging them from the ceiling of the building housing the furnace. Since these waterwall tubes and refractory lining can often run about 100 feet tall, the weight of these hanging waterwall tubes and refractory linings presents a safety issue. Accordingly, safety considerations provide further motivation for making refractory barriers as thin as possible.
Although the industry has recognized the need for thin refractory barriers, it also recognizes it cannot reduce the depth of these barriers without usually degrading performance. In particular, it has been found that reducing the depth too much (i.e., down to about 1/2 inch) weakens the strength of the barrier to the point where it cannot withstand the stresses produced by the tubes at high temperatures. Accordingly, the industry routinely uses barriers whose depths are at least about 0.875 to 1.00 inches in minimum cross section.
The MSW industry has developed different types of refractory structures in an effort to simultaneously protect the metallic waterwall tubes while maintaining excellent heat transfer. One such refractory is known as a "monolithic" refractory. A monolithic refractory is produced by gunniting a ceramic material directly onto studded waterwall tubes. However, some monolithic refractories have been known to suffer from low thermal conductivity, low strength, and bonding difficulties which can lead to excessive slag accumulation hampering high thermal conductivity leading to poor efficiency.
Another type of commercial refractory is the "tube tile or block" design. FIG. 2 presents a conventional tube block design. Typically, the tube block is a square or rectangular refractory tile, (typically no more than 8-12 inches in height H by 8-12 inches in width W by 1 inch in depth D), modified on its back face with channels C and ridges R for fitting properly to the waterwall tube design. A refractory wall is built as these tube blocks are assembled in a manner similar to laying bricks, that is, a tube block is set in place, its periphery covered with mortar, and another block is set either atop or beside the first block. This building continues until the desired wall is constructed. The tube block and tube assembly are typically secured by adding a stud S to the membrane M or directly to the waterwall tube passing the stud through a hole H in a ridge R of the tube block, and tightening the stud S by a screw A. See FIG. 3. Typically, the channels of a tube block do not directly contact the metallic tubes they receive. Rather, the channel and tube are bonded together by a mortar interlayer (not shown). Although the mortar provides a good bond between the tubes and the tube block, its own thermal conductivity is poor and so it inhibits the flow of heat from the furnace to the tubes. In general, tube blocks provide the advantages of high strength, better bonding and a higher thermal conductivity than the monolithic designs.
When the conventional tube assembly comprises 3-inch diameter metallic tubes having centers spaced at 4 inch intervals, the single tube block typically has a height of about 77/8 inches, a width of about 77/8 inches, and a depth of 1 inch. This spacing provides an intimate fit between tube blocks (i.e., about 1/8 inch) which reduces the chances of developing an air gap that hinders heat flow between the tubes and the tube block assemblies.
One commercial refractory tube block is the design shown in FIG. 4. This design is similar to the conventional prior art design shown above, except for a groove around the periphery of the block. Although this design possesses the discussed advantages over monolithic barriers, it nonetheless has a depth of at least about 1 inch, and so provides poor heat flow and is heavy.
Another commercial tube block design is the ship-lap design. Originally utilized in circulating fluidized bed boilers, the ship-lap design, shown in FIG. 5, has an interlocking design which prevents small particles (such as sand) from infiltrating the gaps between adjacent tube blocks. However, the interlocking design makes manufacture of the ship-lap design very expensive. Moreover, the depth of a typical ship-lap block is at least about 0,875 inches. Although this generous depth provides insurance against cracks in the tube block, it also significantly inhibits heat flow through the refractory and makes for a very heavy block.
In an effort to improve the thermal conductivity of the tube block designs, U.S. Pat. No. 5,154,139 ("the Johnson patent"), assigned to the Norton Company, disclosed a tube block having a 1/2 inch depth with ribs in its channels. As shown in FIG. 6, when this ribbed tube block is placed against the tube assembly, the ribs contact the tube walls. This direct contact allows heat to bypass the low thermal conductivity mortar and so provides a higher thermal conductivity than the other conventional tube block designs. The slight (i.e., 1/2 inch) depth of this design also enhances its heat conductivity. However, commercial embodiments of the Johnson patent were found to fail in the field. In particular, cracks began to develop in the tube blocks at the point designated as "x" in FIG. 6.
Therefore, there is a need for a refractory tube block which is light and reliable, and has superior heat conductivity.
SUMMARY OF THE INVENTION
Referring now to FIG. 7, in accordance with the present invention, there is provided a waterwall heat transfer system comprising a tube block and an assembly, the assembly comprising a plurality of parallel tubes 91 connected therebetween by a membrane 92, wherein the tube block comprises:
a) a base section 1, and
b) a plurality of spaced ridges 2 extending upward from the base section 1, the upper surface of at least one of the spaced ridges 2 defining a generally horizontal surface 3, the ridges being spaced to define channels 4 therebetween, the height of at least one of spaced ridges 2 being such that the membrane 92 of the assembly seats thereon, said tube block containing a means for securing the tube block to the assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a conventional tube assembly.
FIG. 2 is a perspective view of the prior art generic tube block design. FIG. 3 is a side view of a tube assembly secured to a conventional tube block.
FIG. 4 is a perspective view of a prior art design.
FIG. 5 is a perspective view of the prior art ship-lap design.
FIG. 6 is a side view of the prior art Johnson patent design.
FIG. 7 is a side view of one embodiment of the present invention.
FIG. 8 is a cross-sectional view of one embodiment of the present invention secured to a tube assembly.
FIG. 9 is an embodiment of the present invention in which a collar is wrapped around the stud and a cap is placed upon the tube block hole accommodating the stud.
FIG. 10 is an embodiment of the present invention in which the central ridge does not run the length of the tube block.
DETAILED DESCRIPTION OF THE INVENTION
Without wishing to be tied to a theory, it is believed that the failures of the commercial embodiments of the Johnson patent were due to the large concentrations of stress at the contact points between the tube block and the metallic tubes. By raising the central ridge of the tube block so that the membrane of the tube assembly seats on the central ridge (thus preventing direct contact between the tube block and metallic tubes), it has been unexpectedly found that the above failures do not occur even when the tube block has a depth as thin as 0.750 inches.
Referring now to FIG. 8, as the tube block 50 is placed against the tube assembly 60, the horizontal plane 3 of the central ridge 2 is secured to the membrane 62 of the tube assembly 60 by a passing the assembly's threaded stud 63 through the hole 5 provided therefor in the central ridge 2. Because the height of the central ridge 2 (defined as the distance from the horizontal plane 3 to the front face of the tube block) exceeds the sum of the depth of the tube block 50 and the radius of the tube 61, the tubes 61 cannot intimately contact the channels 4. Preferably, the gap between the tubes 61 and the channels 4 is between about 1/8 and 3/8 inches. As threaded stud 63 is tightened, the mortar-filled (not shown) channels 4 of the tube block 50 are forced against the tube assembly 60, thereby eliminating air spaces. The mortar acts to hold the tube block 50 in contact with the tube assembly 60, should the attachment means, i.e. threaded stud 63 and bolt, corrode during prolonged use.
Although the size of the tube block will vary depending upon the end use application and the tube size of the furnace with which it is being used, individual tube blocks generally have dimensions of from about 6" to 12" width, 6" to 12" height and 0.625 to 0.750 inch depth. However, in some embodiments servicing tube assemblies having 3 inch diameter tubes with centers spaced at 4 inch intervals, the front face of the tube block is only about 73/4 by 73/4 inches. Without wishing to be tied to a theory, it is believed the conventional 77/8 by 77/8 inch design produces a 1/8 inch gap between tube blocks which does not leave enough room for thermal expansion of the blocks and so is prone to premature cracking. It is believed the reduced dimensions of this embodiment (i.e., blocks which provide a 1/4 inch gap therebetween) of the present invention will further relieve the stress upon the tube blocks. The depth 65 of the tube block 50 is typically between about 0.5 and 1.0 inches, preferably between about 0.5 and 0,750 inches. It is believed that this decreased depth provides for an approximate 33% gain in thermal conductivity over conventional 1 inch tube blocks. The decreased dimensions also decrease the weight of the tube block. In one embodiment in which a 73/4" by 73/4" by 0,750" tube block consists essentially of oxynitride or nitride-bonded silicon carbide, the weight of the tube block is only about 6.5 pounds.
In some embodiments having three spaced ridges, the central ridge extends farther than the lateral ridges. Typically, this extension is between 0.5 and 1.0 inches longer than the extension of the lateral ridges.
Due to the extremely high temperatures generated in the primary combustion zone (or first passage) in which the tube blocks are used, the tube block typically comprises silicon carbide, preferably an oxynitride, nitride-, or oxide-bonded silicon carbide. However, other suitable refractory materials such as alumina, zirconia, and carbon may be employed. In addition to the refractory material per se, the tube blocks will further contain a high thermal conductivity bonding system. A preferred tube block composition contains about 80 to about 95 parts silicon carbide, and about 5 to about 20 parts bonding agent such as a nitride or oxide based material. More preferably, the block will be made from any of CN-163, CN-183, CN-127 or CN-101, each of which is available from the Norton Company of Worcester, Mass., or comparable refractories.
Any conventional technique typically used in the manufacture of tubes blocks may be used to make the present invention. In preferred embodiments, a mixture comprising silicon carbide grain and binders is loaded into a dry press and pressed to form a green body, the green body is then dried and fired in a tunnel kiln having an oxygen or nitrogen atmosphere to produce a fired refractory.
The refractory mortar used with the present invention may be of any suitable composition and preferably of a composition which provides the highest thermal conductivity and heat transfer between the tube block and the waterwall tubes. Suitable mortar compositions are generally based upon silicon carbide and further contain a bonding agent that adheres strongly to the tube block and metal waterwall tubes. In preferred embodiments, the mortar contains copper metal and silicon carbide. More preferably, the mortar is MC-1015, a copper-containing mortar available from the Norton Company of Worcester, Mass.
Although not shown, additional tube blocks can be placed on adjacent portions of the tube assembly. Depending upon the size of the boiler, tube blocks will normally be placed above, below and on both sides of each other to cover most of the waterwall tubes in the primary combustion zone as required for protection. In a conventional MSW facility, these tube blocks would usually be used to cover all waterwall tubes subject to deterioration from the products of combustion.
In some embodiments of the present invention, a ceramic collar 10 is wrapped around the stud 63 which secures the tube block 50 to the tube assembly 60, and a cap 11 is placed upon the hole 5 in the tube block which accommodates the stud 63. See FIG. 9. It is believed these modifications will keep the stud relatively cool, thereby retarding its corrosion.
In some embodiments, the extended ridges 20 of the tube block do not run the length of the block, but rather extend only in the vicinity of hole 5. See FIG. 10. It is believed that this design is helpful in reducing stress on blocks used in large furnaces, wherein thermal expansion of long tubes creates an axially uneven force upon the blocks. In certain embodiments, the ridges run less than about 50% of the length of the base section.
In some embodiments, a conventional tube block refractory system is modified by placing a refractory strip (typically about 0.5 by 6.5 by 0.625 inches) upon the horizontal plane of the central ridge of a conventional tube block. It has been found that this modification also produces the desired result of lifting the refractory tube block slightly off the surface of the waterwall tubes which minimizes high stresses caused by significant expansion of the waterwall tubes and enhances the integrity of the tube block system. | A waterwall heat transfer system has a tube block secured to a tube assembly. The tube assembly includes a plurality of parallel tubes connected together by a membrane. The tube block has a base section and a plurality of spaced ridges extending upward from the base section, the upper surface of at least one of the spaced ridges defining a generally horizontal surface. The ridges are spaced to define channels therebetween with the height of at least one of the ridges selected to provide a seat for the membrane of the assembly. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority of Australian Provisional Application No. PR6793, which filed on Aug. 3, 2001.
BACKGROUND OF THE INVENTION
[0002] I. Field of the Invention
[0003] The present invention relates generally to decoding in communication systems and, in particular, to the calculation of branch metrics in logMAP turbo decoding in wireless communication systems.
[0004] II. Description of the Related Art
[0005] Turbo decoding utilizes interactive decoding and random interleaving to achieve an error performance close to the Shannon limit Consequently, turbo decoding is often employed in decoding for third generation (3G) wireless communications systems.
[0006] A trellis diagram represents the possible state changes of a convolutional encoder over time. Each state in the trellis is connected, via two associated branch metrics, to two separate states in the trellis in the next time period. When decoding received symbols, decoding algorithms typically traverse the trellis in a forward direction to determine the probabilities of the individual states and the associated branch metrics.
[0007] The logMAP algorithm differs from other decoding algorithms, such as the Viterbi algorithm, by performing both a forward and a backward recursion over a trellis. The algorithm can be partitioned to provide a Windowed LogMAP arrangement where the blocks are divided into smaller alpha and beta recursions. Alpha values, representing the probabilities of each state in the trellis, are determined in the forward recursion. Beta values, representing the probabilities of each state in the reverse direction, are determined during the backwards recursion.
[0008] The respective probabilities of each pair of branch metrics associated with any given state are the gamma values (γ). The gamma values are calculated during each of the forward and backwards recursions of the trellis. The logMAP branch metrics are calculated using the following equation:
γ k 1 =d 1 ( y s +Le )+ y p c 1,k (1)
[0009] where i represents the path (0 or 1), d and c are the expected data and parity bits, respectively, and y s , y p and L e represent the soft information for data, parity and extrinsic information, respectively, and k represents the current state in the trellis for which branch metrics are being calculated.
[0010] For any given rate 1/2 trellis code, each of the expected data and parity bits, d and c respectively, may take the values of +1 or −1. Consequently, there are four possible branch metric combinations for the given input variables:
[0011] (y s +L e +y p ) for d=+1, c=+1;
[0012] (y s +L e +y p ) for d=+1, c=−1;
[0013] (−y s −L e −y p ) for d=−1, c=−1;
[0014] (−y s −L e +y p ) for d=−1, c=+1.
[0015] When traversing the trellis in the forward recursion stage, both the input symbol and the extrinsic memory must be accessed to compute the gamma values. FIG. 1 shows a prior art arrangement 100 for calculating branch metrics for a rate 1/2 decoder. Data (y s ) 130 and parity (y p ) 140 are read from a first memory 120 . The time and power required for read accesses from the first memory 120 are proportional to the size of the first memory 120 . The first memory 120 must be sufficiently large to store data and parity information for the entire length of the block being decoded. The first memory 120 is typically of the order of −5 k words in size for mobile communications applications.
[0016] It is possible to store the data 130 and parity 140 in two distinct memory units, rather than the single first memory 120 . However, there does not appear to be any apparent advantage associated with such an implementation, as reading the required data 130 and parity 140 from separate memory units would require two memory address decodes in addition to the retrieval of the information. Such an implementation is not appreciably faster than a single memory unit implementation and requires more power.
[0017] A processor 150 receives the data 130 and parity 140 , along with extrinsic information (L e ) 115 that is read from a second memory 110 , to produce output branch metrics 155 corresponding to all paths in the trellis. The output branch metric 155 is presented to a trellis calculation module 160 that utilizes the output branch metric 155 to traverse the trellis.
[0018] When the backward recursion of the trellis commences to calculate the beta values, each of the four possible combinations for the branch metric computation must be regenerated. This requires a read access to the memory 120 storing data and parity information, and one read access to the second memory 110 storing extrinsic information, in addition to the cost of computation in the processor 150 . As noted above, the time and power consumption of each memory access is directly proportional to the number of memory cells and, consequently, each read access to either one of the first memory 120 and the second memory 110 is costly with respect to power consumption Therefore, reducing the number of read accesses to either one or both of the first memory 120 and the second memory 110 would be advantageous.
[0019] [0019]FIG. 2 shows a prior art arrangement 200 for calculating branch metrics for a rate 1/3 LogMAP decoder. The branch metric combinations are given by Equation 2 below, in which y p1 represents a first parity bit, y p2 represents a second parity bit, c 1 represents the expected first parity bit and c 2 represents the expected second parity bit
γ k 1 =d 1 ( y a +Le )+ y p1 c 1 1,k +y p2 c 2 1,k (2)
[0020] As each of d, c 1 and c 2 can be either +1 or −1, there are eight possible branch metric combinations for a rate 1/3 decoder.
[0021] A first memory 220 stores each of data (y s ) 230 , first parity (y p1 ) 240 and second parity (y p2 ) 245 . Each of the data (y s ) 230 , first parity (y p1 ) 240 and second parity (y p2 ) 245 is read from the first memory 220 and presented to a processor 250 . The processor 250 also receives extrinsic information (L e ) 215 that is read from a second memory 210 . The processor 250 calculates all the branch metrics 255 , and presents the branch metrics 255 to a trellis calculation module 260 .
[0022] Branch metrics calculated during the forward recursion of a decoding trellis are often stored in memory units so that the branch metrics can be reused during a backwards recursion of the decoding trellis. As all of the branch metrics calculated during the forward recursion are stored, the memory units utilized are necessarily large. As noted above, read accesses to such memory units are costly in respect of power consumption and time.
[0023] In UMTS and CDMA 2000 systems, approximately 40% of computation in baseband processing is in the turbo decoding process alone. A single component can dominate the power consumption of a low-power handset, or a large infrastructure product. Any amount of power savings translates into a substantial advantage in the handset market, where battery life is paramount, or in packaging for wireless infrastructure products, where heat dissipation is important
SUMMARY OF THE INVENTION
[0024] The present invention provides a method for generating at least two branch metrics. The method generates the branch metrics, each having an inverse polarity to the other.
[0025] In one embodiment of the present invention, at least one primary branch metric and at least one secondary branch metric are generated. The secondary branch metric is generated by negating the primary branch metric.
[0026] In one example of the present invention, a method provides for producing branch metrics in a LogMAP turbo decoding operation. The method comprises generating a branch metric for each primary combination of extrinsic, parity and information data, and storing the primary branch metrics to generate by negation the remaining secondary ones of the branch metrics, during a forward recursion of a trellis. During a backwards recursion of the trellis, the method comprises retrieving the stored primary branch metrics, and generating the secondary branch metrics by negating the retrieved primary branch metrics.
[0027] Other aspects of the present invention are also disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The present invention will be better understood from reading the following description of non-limiting embodiments, with reference to the attached drawings, wherein below:
[0029] [0029]FIG. 1 is a block diagram representation of a known arrangement for calculating branch metrics for a rate 1/2 decoder;
[0030] [0030]FIG. 2 is a block diagram representation of a known arrangement for calculating branch metrics for a rate 1/3 decoder;
[0031] [0031]FIG. 3 is a schematic block diagram representation of an arrangement for a rate 1/2 logMAP turbo decoder that utilizes a branch metric cache; and
[0032] [0032]FIG. 4 is a schematic block diagram representation of an arrangement for a rate 1/5 logMAP turbo decoder that utilizes a branch metric cache.
[0033] It should be emphasized that the drawings of the instant application are not to scale but are merely schematic representations, and thus are not intended to portray the specific dimensions of the invention, which may be determined by skilled artisans through examination of the disclosure herein.
DETAILED DESCRIPTION
[0034] Where reference is made in any one or more of the accompanying drawings to steps and/or features, which have the same reference numerals, those steps and/or features have for the purposes of this description the same function(s) or operation(s), unless the contrary intention appears.
[0035] [0035]FIG. 3 shows an arrangement 300 for rate 1/2 LogMAP turbo decoding that utilizes a branch metric cache 370 . During a forward recursion of a coding trellis, a read access from a first memory 320 is required to access data (y s ) 330 and parity (y p ) 340 , each typically described by 8 bits of information. Extrinsic information 315 is read from a second memory 310 . The memories 310 and 320 typically have a capacity of 5 kilobytes for mobile implementations. Each of the retrieved data 330 , parity 340 and extrinsic information 315 is presented to a first processor 350 . The first processor 350 calculates from the retrieved parity, extrinsic and information data, a predetermined half of the relevant combinations of the data, thus providing a set of primary branch metrics 355 . The set 355 is stored in the cache memory 370 and is also provided to each of a trellis calculation module 360 and a second processor 390 . The second processor 390 negates the set of primary branch metrics 355 to produce a set of secondary branch metrics 395 , which are provided to the trellis calculation module 360 .
[0036] Due to the symmetry of a trellis structure, for a rate 1/2 trellis decoder two of the four possible branch metric combinations may be generated from the other two possible combinations. Thus, (y s +L e +y p ) and (y s +L e −y p ) can be negated to produce (−y s −L e −y p ) and (−y s −L e +y p ), respectively. The branch metric combinations that are calculated are the primary branch metrics. The corresponding branch metric combinations that are derived by negating the primary branch metric combinations are the secondary branch metric combinations. Due to the storage of the set of primary branch metrics in the cache memory 370 , it is only necessary to access data and parity and the corresponding extrinsic information from the two memory units 310 and 320 , during the forward recursion of a trellis. The remaining two branch metrics are calculated by negating the first two calculated branch metrics. The negation is relatively inexpensive, both in terms of processing time and power consumption and is performed by the second processor 390 . All possible branch metric combinations are presented to the trellis calculation module 360 in the forward recursion to determine the alpha values.
[0037] As two of the branch metrics may be generated by negating the first two branch metrics, only the first two calculated branch metrics are stored in the branch metric cache 370 . Accordingly, the size of the branch metric cache need only be sufficiently large to store half of the possible set of branch metrics and thus the cache may be referred to as a reduced set branch metric cache.
[0038] When the backward recursion of the trellis commences to calculate required beta values, the trellis processor 360 sends a control signal 365 to retrieve from the reduced set branch metric cache 370 the primary branch metrics 355 that were stored during the forward trellis recursion, thus obviating memory accesses to each of the first memory 320 and the second memory 310 . Due to the relatively small size of the reduced set branch metric cache 370 , typically about the window size, any read access to retrieve required primary branch metrics from the reduced set branch metric cache 370 requires significantly less time and power than a comparable read access from either one of the first memory 320 and the second memory 310 . Furthermore, retrieving primary branch metrics 355 directly from the reduced set branch metric cache 370 allows the backward recursion of the trellis to omit calculations undertaken during the forward trellis traversal by the processor 350 . Thus, utilizing a reduced set branch metric cache 370 that is relatively small provides desirable time and power savings over prior art arrangements. The retrieved primary branch metrics 380 are presented to each of the trellis calculation module 360 and the second processor 390 . Negation of the retrieved primary branch metrics 380 is again performed by the second processor 390 to produce secondary branch metrics 385 to complete the set of branch metrics necessary for trellis calculation.
[0039] As the reduced set branch metric cache 370 is only required to store half of the possible branch metric combinations generated during the forward recursion of a decoding trellis, the reduced set branch metric cache 370 may be implemented using a small, dedicated memory unit The power consumption associated with a read access to any memory unit is dependent on the size of the memory unit being accessed. As the reduced set branch metric cache 370 is significantly smaller than memory units required to store all branch metric combinations calculated during a forward recursion of a decoding trellis, read accesses to the reduced set branch metric cache 370 are quicker and consume less power.
[0040] [0040]FIG. 4 shows an arrangement 400 for logMAP decoding for a rate 1/3 decoder. During a forward recursion of a coding trellis, data (y s ) 430 , first parity (y p1 ) 440 and second parity (y p2 ) 445 are obtained via read accesses from a first memory 420 . Extrinsic information (L e ) 415 is obtained via a read access from a second memory 410 . Each of the data (y s ) 430 , first parity (y p1 ) 440 , second parity (y p2 ) 445 and extrinsic information (L e ) 415 are presented to a first processor 450 . The first processor 450 produces four branch metric possibilities 455 from the input parameters and presents the branch metrics 455 to each of a reduced set branch metric cache 470 , a second processor 490 and a trellis calculation module 460 . Each of the branch metrics 455 is stored in the reduced set branch metric cache 470 . The remaining four possible combinations are then generated by the second processor 490 by negating the initial four branch metric combinations 455 to produce a secondary set of branch metrics 495 , which are presented to the trellis calculation module 460 .
[0041] During a backwards recursion of a trellis, the trellis calculation module 460 retrieves branch metrics 455 from the reduced set branch metric cache 470 without the need to recalculate the branch metrics, thus realizing significant power and time savings. The trellis calculation module sends a control signal 465 to the reduced set branch metric cache 470 . The branch metrics 455 that were stored during the forward recursion of the trellis are accessed and presented as retrieved branch metrics 480 to each of the trellis calculation module 460 and the second processor 490 . The second processor 490 negates the retrieved branch metrics 480 to generate secondary branch metrics 485 that are presented to the trellis calculation module 460 to complete the set of branch metrics necessary for trellis calculation.
[0042] Whilst a branch metric cache for a rate 1/3 decoding application is required to store more information than a branch metric cache for a rate 1/2 decoding application, and therefore must be larger in size, the memory units utilized in the rate 1/3 decoding application must be correspondingly larger than the memory units utilized in the rate 1/2 decoding. Consequently, the principle of utilizing a relatively small, dedicated branch metric cache may be extended to any combination of decoding rates.
[0043] The principles of the methods and arrangements described herein have general applicability to trellis decoding in telecommunications systems.
[0044] While the particular invention has been described with reference to illustrative embodiments, this description is not meant to be construed in a limiting sense. It is understood that although the present invention has been described, various modifications of the illustrative embodiments, as well as additional embodiments of the invention, will be apparent to one of ordinary skill in the art upon reference to this description without departing from the spirit of the invention, as recited in the claims appended hereto. Consequently, the method, system and portions thereof and of the described method and system may be implemented in different locations, such as a wireless unit, a base station, a base station controller, a mobile switching center and/or a radar system. Moreover, processing circuitry required to implement and use the described system may be implemented in application specific integrated circuits, software-driven processing circuitry, firmware, programmable logic devices, hardware, discrete components or arrangements of the above components as would be understood by one of ordinary skill in the art with the benefit of this disclosure. Those skilled in the art will readily recognize that these and various other modifications, arrangements and methods can be made to the present invention without strictly following the exemplary applications illustrated and described herein and without departing from the spirit and scope of the present invention It is therefore contemplated that the appended claims will cover any such modifications or embodiments as fall within the true scope of the invention. | A method and an apparatus for producing branch metrics in a LogMAP turbo decoding operation. During a forward recursion of a trellis, a set of primary branch metrics is generated. The primary branch metrics are stored in receiver form in a relatively small memory cache module ( 370 ) and corresponding secondary branch metrics are produced by negating the primary branch metrics. The primary branch metrics and said secondary branch metrics constitute all possible branch metrics for a given state in the trellis. During a backwards recursion of the trellis, the stored primary branch metrics are retrieved from the memory cache module ( 370 ) and the secondary branch metrics are regenerated by negating the retrieved primary branch metrics. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 60/662,424, filed on Mar. 16, 2005.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an automatic transmission in the form of a belt-driven conical-pulley transmission, as known for example from DE 10 2004 015 215 and other publications, as well as a method for producing it and a motor vehicle equipped with it.
[0004] 2. Description of the Related Art
[0005] Automatic transmissions in the broader sense are converters, whose momentary transmission ratio changes automatically, in steps or continuously, as a function of present or anticipated operating conditions, such as partial load and coasting, and environmental parameters, such as, for example, temperature, air pressure, and, humidity. They include converters that are based on an electrical, pneumatic, hydrodynamic, or hydrostatic principle, or on a principle which is a mixture of those principles.
[0006] The automation refers to a great variety of functions, such as start-up, choice of transmission ratio, or the type of transmission ratio change in various operating situations, where the type of transmission ratio change can mean, for example, shifting to different gear steps in sequence, skipping gear steps, and the speed of shifting.
[0007] The desire for convenience, safety, and reasonable construction expense determines the degree of automation, i.e., how many functions take place automatically.
[0008] As a rule, the driver can intervene manually in the automatic sequence, or can limit it for individual functions.
[0009] Automatic transmissions in the narrower sense, as they are used today primarily in the construction of motor vehicles, usually have the following structure:
[0010] On the input side of the transmission there is a start-up unit in the form of a regulatable clutch, for example a wet or dry friction clutch, a hydrodynamic clutch, or a hydrodynamic converter.
[0011] With a hydrodynamic converter or a hydraulic coupling, often a bridging clutch or lock-up clutch is connected parallel to the pump and turbine parts, which increases the efficiency by transferring the force directly and damps vibrations through defined slippage at critical rotational speeds.
[0012] The start-up unit drives a mechanical, continuously variable or stepped, multi-speed gearbox, which can include a forward/reverse driving unit, a main group, a range group, a split group, and/or a variable speed drive. Gearbox groups can be of intermediate gear or planetary design, with straight or helical tooth system, as a function of the requirements in terms of quietness of operation, space conditions, and transmitting options.
[0013] The output element of the mechanical transmission, a shaft or a gear, drives a differential directly or indirectly via intermediate shafts or an intermediate stage with constant transmission ratio, which can be configured as a separate gearbox or is an integral component of the automatic transmission. In principle, the transmission is suitable for longitudinal or transverse installation in the motor vehicle.
[0014] To adjust the transmission ratio in the mechanical transmission there are hydrostatic, pneumatic, and/or electrical actuators. A hydraulic pump, which operates on the displacement principle, supplies oil under pressure for the start-up unit, in particular the hydrodynamic unit, for the hydrostatic actuators of the mechanical transmission, and for lubricating and cooling the system. As a function of the necessary pressure and delivery volume, possibilities include gear pumps, screw pumps, vane pumps and piston pumps, the latter usually of radial design. In practice, gear pumps, vane pumps, and radial piston pumps have come to predominate for that purpose, with gear pumps and vane pumps offering advantages because they are less expensive to build, and the radial piston pump offering advantages because of its higher pressure level and better regulation ability.
[0015] The hydraulic pump can be located at any desired position in the transmission, on a main or a secondary shaft that is constantly driven by the drive unit.
[0016] Continuously variable automatic transmissions are known that consist of a start-up unit, a reversing planetary gearbox as the forward/reverse drive unit, a hydraulic pump, a variable speed drive, an intermediate shaft and a differential. The variable speed drive, in turn, consists of two pairs of conical disks and an endless torque-transmitting means. Each pair of conical disks includes a second conical disk that is movable in the axial direction. Between those pairs of conical disks passes the endless torque-transmitting means, for example a steel thrust belt, a tension chain, or a drive belt. Moving the second conical disk changes the running radius of the endless torque-transmitting means, and thus the transmission ratio of the continuously variable automatic transmission.
[0017] Continuously variable automatic transmissions (CVT) require a high level of pressure in order to be able to move the conical disks of the variable speed drive with the desired speed at all operating points, and also to transmit the torque with a sufficient base contact pressure with minimum wear.
[0018] In motor vehicles the need for comfort and convenience is generally very high, especially in regard to the noise level. The driver and passengers, especially in upscale vehicles, want there to be no disturbing noises coming from the operation of the vehicle's mechanical units. But the internal combustion engine, and also other mechanical units such as transmissions, does produce sounds, which can be widely perceived as disturbing. Thus, for example, in continuously variable transmissions where a plate-link chain is used there can be a sound, since such a plate-link chain, because of its construction with plate links and pins, produces a recurring impact due to the pins striking the conical disks of the transmission. In CVT transmissions, acoustic effects are generally attributed to the pin impact as the source. That acoustic excitation then produces resonances at the natural frequencies of the transmission housing (FE modes) or of the shafts (torsional modes, bending modes).
[0019] Another acoustic effect is produced by the CVT belt, the CVT band, or the CVT chain, which can vibrate on the tension side like a musical string; that can be suppressed for example by a slide bar. Torsional friction vibrations at frequencies of 10 Hz are known in clutches, for example, as grabbing. If the coefficient of friction gradient is such that the coefficient of friction decreases with increasing relative rotational speed or velocity, as the slippage changes, grabbing results. In automatic transmissions it is primarily the steel-to-paper coefficient of friction that is relevant.
SUMMARY OF THE INVENTION
[0020] Part of the purpose of the present invention is to improve the acoustics of such a transmission, and thus to improve the comfort—in particular the sound comfort —of a motor vehicle equipped with such a transmission. Another part of the purpose of the present invention is, after analyzing strong CVT vibrations and clarifying the associated operating mechanisms, to design appropriate countermeasures for minimizing—or if possible preventing—those vibrations, which lie for the most part in the acoustic range on the order of 400-600 Hz. Another part of the purpose of the present invention is to increase the endurance strength of components, and thus to prolong the operating life of such an automatic transmission. The reason for another part of the purpose of the present invention is to increase the torque transmission capability of such a transmission and to be able to transmit greater forces through the components of the transmission. Furthermore—hence that is another part of the purpose—it should be possible to economically produce such a transmission.
[0021] The parts of the problem are solved by the invention along with its refinements, presented in the claims and in the description, and are explained in connection with the drawing figures.
[0022] The analysis produces a simulation-based understanding of the nature of the vibration form, which involves a movement of the encircling chain coupled with a tipping or bending of the particular conical disk. The primary determinants of the frequency of the vibrations are the mass of the chain and the overall tipping and bending stiffness of the conical disks. That stiffness includes the inherent dishing of the disks, the tipping of the disks, the bending of the shafts as a result of their elasticity, and the tilt of the shafts as result of differences in bearing rigidities or bearing spacings. In addition, the coefficient of friction level and the gradient of the coefficient of friction, as well as the rotational speed and the transmission ratio, are determinants of the frequency.
[0023] Those findings are surprising, inasmuch as vibrations of the chain in the encircling arc, i.e., while it is being clamped in the disk set, have not been described before, and are also contrary to the view held heretofore that the frictional contact with the conical disks suppresses such vibrations in the arcs.
[0024] The influence of the CVT oil on such frictional vibrations has also not been described before, so that up until now those oils have been developed merely for friction that is high and is stable over time, as well as for low wear.
[0025] While it is known that with the movable CVT conical disks (movable disks) tilting play between the shaft and the movable disk has an effect on the efficiency, no vibrational bending, tilting, or wobbling motions of the movable disks have been described heretofore.
[0026] To solve that problem, it can therefore be necessary to consider more than one of the influenceable parameters, and thus, for example, to combine certain properties of the oil with certain mechanical configurations.
[0027] In accordance with the invention the problem is solved by a belt-driven conical-pulley transmission having pairs of conical disks on the input and output sides, each having a fixed disk and a movable disk, which are positioned in each case on shafts on the input side and on the output side, and are connectable by means of a endless torque-transmitting means for transmitting the torque, where at least one of the listed factors is optimized in terms of the acoustics of the transmission:
[0028] a viscous or hydraulic medium in the form of oil;
[0029] the surface quality of the contact regions between the conical disk and the endless torque-transmitting means;
[0030] the geometry of at least one conical disk;
[0031] the damping of at least one conical disk; and
[0032] the guidance of at least one conical disk.
[0033] It can be advantageous to use an oil having a coefficient of friction that is insensitive to the frictional speed. It can also be advantageous to optimize the contact surfaces between the conical disk and the endless torque-transmitting means, for example in regard to their topography.
[0034] Furthermore, it can be advantageous to provide at least one conical disk that is optimized for rigidity and/or at least one damped conical disk. It can also prove advantageous to integrate into the transmission at least one conical disk that is radially outwardly guided.
[0035] In addition, the present invention relates to a motor vehicle having a transmission in accordance with the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The structure, operation, and advantages of the present invention will become further apparent upon consideration of the following description, taken in conjunction with the accompanying drawings in which:
[0037] FIG. 1 is a partial view of a belt-driven conical-pulley transmission;
[0038] FIG. 2 is an illustration of another embodiment, corresponding essentially to
[0039] FIG. 1 ;
[0040] FIGS. 3 and 4 are graphs of correlations of coefficients of friction; and
[0041] FIGS. 5 and 6 are schematic configuration possibilities for movable disks.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0042] FIG. 1 shows only a part of a belt-driven conical-pulley transmission, namely the input side of the belt-driven conical-pulley transmission 1 , which is driven by a drive engine, for example an internal combustion engine. In a fully constructed belt-driven conical-pulley transmission, there is associated with the input-side part a complementarily designed output-side part of the continuously variable belt-driven conical-pulley transmission, the two parts being connected by an endless torque-transmitting means in the form of a plate-link chain 2 , for example for transferring torque. Belt-driven conical-pulley transmission 1 has a shaft 3 on its input side, which is designed in the illustrated exemplary embodiment in a single piece with a stationary conical disk or fixed disk 4 . In the axial longitudinal direction of shaft 3 , that axially fixed conical disk 4 is positioned close to and opposite an axially displaceable conical disk or movable disk 5 .
[0043] In the illustration according to FIG. 1 , plate-link chain 2 is shown in a radial outer position on disk pair 4 , 5 on the input side, resulting from the fact that the axially displaceable conical disk 5 is shifted toward the right in the drawing, and that shifting movement of axially displaceable conical disk 5 results in a movement of plate-link chain 2 in the radial outward direction, producing a change in the transmission ratio of the transmission toward greater speed.
[0044] Axially displaceable conical disk 5 can also be shifted to the left in the plane of the drawing in a known manner, where in that position plate-link chain 2 is in a radially inner position (which is given reference numeral 2 a ), producing a transmission ratio of belt-driven conical-pulley transmission 1 in the direction of a slower speed.
[0045] The torque provided by a drive engine, not shown in detail, is introduced into the input side part of the belt-driven conical-pulley transmission shown in FIG. 1 by way of a gear 6 mounted on shaft 3 . Gear 6 is supported on shaft 3 by means of a roller bearing in the form of a ball bearing 7 that absorbs axial and radial forces, and which is set on shaft 3 by means of a washer 8 and a shaft nut 9 . Between gear 6 and axially displaceable conical disk 5 is a torque sensor 10 , with which a spreader disk configuration 13 having an axially fixed spreader disk 11 and an axially displaceable spreader disk 12 is associated. Located between the two spreader disks 11 ′ 12 are roller elements, for example in the form of the illustrated balls 14 .
[0046] A torque introduced through gear 6 results in the formation of an angle of rotation between axially stationary spreader disk 11 and axially displaceable spreader disk 12 , which results in an axial displacement of spreader disk 12 because of start-up ramps located on the latter, onto which the balls 14 run up, thus causing an axial offset of the spreader disks with respect to each other.
[0047] Torque sensor 10 has two pressure chambers 15 , 16 , of which first pressure chamber 15 is intended to be charged with a pressure medium as a function of the torque introduced, and second pressure chamber 16 is supplied with pressure medium as a function of the transmission ratio of the transmission.
[0048] To produce the clamping force that is applied as a normal force to plate-link chain 2 between axially stationary disk 4 and axially displaceable disk 5 , a piston and cylinder unit 17 is provided which has two pressure chambers 18 , 19 . First pressure chamber 18 changes the pressure on plate-link chain 2 as a function of the transmission ratio, and second pressure chamber 19 serves in combination with torque-dependent pressure chamber 15 of torque sensor 10 to increase or reduce the clamping force that is applied to plate-link chain 2 between conical disks 4 , 5 .
[0049] To supply pressure medium, shaft 3 has three conduits 20 , through which pressure medium is fed into the pressure chambers from a pump, which is not shown. The pressure medium is able to drain from shaft 3 through a drain conduit 21 on the outlet side, and can be conducted back to the circuit.
[0050] Applying pressure to pressure chambers 15 , 16 , 18 , 19 results in a torque-dependent and ratio-dependent shifting of axially displaceable conical disk 5 on shaft 3 . To seat shiftable conical disk 5 , shaft 3 has centering surfaces 22 , which serve as a sliding fit for displaceable conical disk 5 .
[0051] As can be readily seen from FIG. 1 , in the bearing regions of conical disk 5 on shaft 3 , belt-driven conical-pulley transmission 1 has a respective sound damping device 23 . For that purpose the sound damping device can have a ring body and a damping insert, or it can consist only of a damping insert.
[0052] The reference numerals used in FIG. 1 also refer to the essentially comparable features of the other figures. Thus the figures are to be regarded as a unit in that respect. For the sake of clarity, only the reference numerals that go beyond those in FIG. 1 are used in the other figures.
[0053] In FIG. 2 , only the middle one of the three conduits 20 is configured in a form that is modified from FIG. 1 . It is evident that bore 24 , which forms the central conduit 20 , and which is produced as a blind bore from the side shown on the right in FIGS. 1 and 2 , is significantly shorter than in FIG. 1 . Such blind bores are complex and expensive to produce and require a very high degree of precision in manufacturing. The expense of production and the requirements in terms of process reliability increase disproportionately with the length. Thus shortening a bore of that sort has a favorable effect on, for example, the production costs.
[0054] In the area of the floor of that bore 24 the lateral bore 25 branches off; there can be a plurality of those arranged around the circumference. In the case shown, that lateral bore 25 is shown as a radial bore; however, it can also be produced at a different angle as an inclined bore. Bore 25 penetrates the outer surface of shaft 3 at a place which is independent of the operating state, i.e., for example independent of the transmission ratio setting, in an area which is always covered by movable disk 5 .
[0055] By shifting lateral bore 25 to the zone covered by movable disk 5 , shaft 3 can be made axially shorter, enabling construction space to be saved. In addition, shortening shaft 3 can also result in reduced strain.
[0056] The mouth of the conduit or lateral bore 25 can be located for example in the area of the groove 26 , which is adjacent to the centering surface 22 of the shaft. That can be particularly advantageous if the tooth system 27 , which connects movable disk 5 to shaft 3 so that it can be shifted axially but is rotationally fixed, is subjected to heavy loads, for example by the transmission of torque.
[0057] But in many cases the load on the tooth system 27 will not be the most critical design criterion, so that the mouth of bore 25 can be placed in the area of that tooth system, as shown in FIG. 2 . Placing lateral bore 25 within the toothed area 27 instead of in the groove 26 produces an advantage through the fact that a greater section modulus is present, which reduces the bending stress in the surface layer region. In addition, the polar moment of inertia is greater at that location, while the critical fiber, which is disturbed by lateral bore 25 , remains at an approximately constant radius. That results in a significant reduction of the tensions in the critical area around the mouth of lateral bore 25 between the teeth of tooth system 27 . The system of supplying with hydraulic fluid is identical in FIGS. 1 and 2 , since pressure chambers 15 and 19 are connected to each other and movable disk 5 has connecting bores 28 which connect the area of the tooth system 27 with pressure chamber 19 . In the figures, movable disk 5 is in its most extreme left position, which corresponds to the start-up transmission ratio or underdrive. If movable disk 5 is now shifted to the right in the direction of fixed disk 4 , there is always part of the hollow space or of chamber 29 over the mouth of the lateral bore or of conduit 25 , so that the necessary fluid supply is always ensured, just as in FIG. 1 . Also as in FIG. 1 , there are two shift states for pressure chamber 16 , which depend on the axial position of movable disk 5 . In the illustrated position the control bores 30 are free, so that the conduit 20 which is connected to them and is closed axially with a stopper 31 , and the pressure chamber 16 , which is connected to the latter through a conduit (not shown), are not pressurized or have only ambient pressure. If movable disk 5 is now moved toward fixed disk 4 , it passes over control bores 30 , so that starting at a certain distance chamber 29 comes to rest over the mouths of control bores 30 . In chamber 29 , however, a high pressure dependent on the torque prevails, which is then also conveyed through control bores 30 and conduit 20 into pressure chamber 16 , so that high pressure is also present there. In that way two shift states are realized, which control the clamping force as a function of the transmission ratio.
[0058] In addition, in the FIG. 2 embodiment there is provided a disk spring that moves movable disk 5 to a predetermined axial position when transmission 1 is not under pressure, enabling a transmission ratio of transmission 1 to be set which prevents excessive loads, for example when the motor vehicle is towed.
[0059] FIG. 3 includes two graphs that show the gradient of the coefficient of friction over a range of running or surface speed and as a function of the contact pressure. The running or surface speed is shown on the abscissa and the coefficient of friction on the ordinate. The dashed line is to be seen as a reference value, and represents a coefficient of friction, which can be, for example, μ=0.12. As can be seen from both figures, the coefficient of friction is a function of the running or surface speed, tending to decrease as the running or surface speed increases.
[0060] As explained earlier, with clutches, for example, a coefficient of friction that drops as the running or surface speed increases leads to grabbing, and hence to a decline in comfort. An effort should therefore be made to keep that decline in the coefficient of friction over the change of running or surface speed as small as possible.
[0061] The coefficient of friction gradient shown in FIG. 3 occurs at the place of contact between the rocker members of the chain and the contact surfaces of the disks that operate together with them. The chain, or endless torque-transmitting means, is under load both in the running direction, from the torque that is being transmitted, and also transversely to the running direction, primarily from the clamping force. That clamping force must be chosen so that the torque to be transmitted can be conveyed to the other set of disks with adequate reliability against slippage.
[0062] The spacing of the curves in the direction of the ordinate represents the scatter range of the coefficient of friction as a function of the clamping force or contact pressure. The bottom line represents a low contact pressure and the upper one in each case represents a higher contact pressure.
[0063] When comparing the former construction according to the upper graph and the embodiment according to the invention as shown in the lower graph, it is noticeable that at first the scatter range that is bounded by the two curves is smaller, resulting in a lesser dependence of the coefficient of friction on the contact pressure or clamping pressure existing at the time. Expressed in different terms, the embodiment according to the present invention (the lower graph) is less sensitive to changes in contact pressure.
[0064] It can also be seen from FIG. 3 that the curves in the lower graph are flatter, which means that the coefficient of friction is less dependent on the running or surface speed. Through that flatter, negative gradient of the coefficient of friction over the range of running or surface speed, a more stable behavior of the coefficient of friction is achieved. At the same time, it is less problematic if the curves are shifted quasi parallel from top to bottom or vice versa, than if their slope were to change, since any change in slope represents a greater dependency of the coefficient of friction on the running or surface speed.
[0065] Such a clearly defined pattern of the coefficient of friction over the range of running or surface speed and over the range of contact pressure, as shown in the lower graph of FIG. 3 , results in a suppression of the vibration that is caused by the variation of the coefficient of friction of the steel-to-steel contact between the belt or chain and the conical disks. The vibration can be offset at the place where it develops, through the use of an appropriate oil with such a coefficient of friction variation.
[0066] The graphs in FIG. 4 are organized essentially like those in FIG. 3 . They do not show the dependency on the oil used, but on the surface characteristics. What is shown in FIG. 3 with regard to interpretation and improvement also applies to FIG. 4 ; that is, the lower graph shows a significant improvement in the conditions.
[0067] The upper graph in FIG. 4 shows the conditions at a polished surface, while the lower graph in the figure shows the coefficient of friction as a function of the running or surface speed and the contact pressure with surface characteristic values according to the present invention. Those surface characteristic values are producible by a finishing process, for example, where the friction parameters have the correct variation and also retain it over a relatively long running time. For example, noise phenomena occur immediately with smoother surfaces, while with rougher surfaces they occur later, or in the most favorable case not at all. An improvement of that sort in regard to the noise behavior is also achievable by reducing the clamping force or contact pressure.
[0068] Investigations with simulations and measurements have shown that the vibration behavior, and hence the noise behavior, are influenced positively by an increased tilting stiffness of the axially movable disks, with that applying in particular, but not exclusively, in regard to the movable disk on the output side. In general it has turned out that an increased bending stiffness, whereby the opening of the conical disks when under load is reduced, especially of the set of conical disks on the output side, the vibration amplitude, which is significant in regard to the noise, is lessened. A comparable effect can be achieved through increased damping at that location.
[0069] FIGS. 5 and 6 each show a schematic profile of a movable disk, with only the upper half of the rotationally symmetrical profile being shown in each case.
[0070] FIG. 5 shows in each of the schematic exemplary embodiments a) through e) a stiffening of the disk itself. At the same time, FIGS. 5 and 6 each show schematically a part of the axially moving disk or movable disk 33 on the output side; comparable designs can also be carried over to the movable disk 5 on the input side.
[0071] The movable disk 33 shown in FIG. 5a has, in its area facing away from the endless torque-transmitting means 2 , a plurality of radially-extending stiffening ribs 34 distributed circumferentially, which reduces displacement of the radially-outwardly-extending part of disk 33 when under an axial force, or in the most favorable case prevents it; thus it counteracts an enlargement of the axial spacing of the pair of disks.
[0072] Movable disk 33 according to FIG. 5 b has a design in which the radially outwardly extending part of movable disk 33 is reinforced by having its wall thickness increase in the radially outward direction. That is achieved by an appropriate design of the contour of the disk facing away from endless torque-transmitting means 2 . The course of that contour, which is shown in the drawing as even, or a wall of constant thickness, can also be modified so that the wall thickness increases in several steps.
[0073] To stiffen movable disk 33 in the axial direction, a stiffening collar can also be applied radially at the outside, as shown in FIG. 5 c . FIG. 5 d shows, in addition to stiffening collar 35 located radially at the outside, an additional stiffening collar 36 that is located further radially inward and thus can in that case also serve as a partition between two pressure chambers.
[0074] In FIGS. 5 c and 5 d , stiffening collars 35 and 36 are shown as separate parts or circular rings, which have to be connected to movable disk 33 . FIG. 5 e shows a possibility for constructing stiffening collar 35 and/or stiffening collar 36 in a single piece with movable disk 33 , with the possibility of giving consideration to a production-friendly design in a beneficial way.
[0075] FIGS. 5 f and 5 g show a stiffening of the connection of the disk to the shaft. Here, first of all, hub 37 of movable disk 33 is connected to the radially outwardly extending part of movable disk 33 by means of a stiffening ring 38 , so that a deformation of that area is at least reduced. Furthermore, there are again radial stiffening ribs 34 , which are connected on one side to stiffening ring 38 and on the other side to hub 37 of movable disk 33 .
[0076] FIGS. 6 a through 6 e show the principles of damping possibilities for the axially moving disk or movable disk 33 on the output side, which are also applicable, however, to the axially moving disk or movable disk 5 on the input side.
[0077] FIG. 6 a shows first of all a subdivision of hub 37 into individual lamellae. That bundle of lamellae is pressed together by the clamping pressure that is applied through the hydraulic medium and thus produces a damping effect.
[0078] In FIG. 6 b , in addition, stiffening collar 35 is constructed as a bundle of lamellae, which is again pressed together by the clamping pressure. According to FIG. 6 c , stiffening collar 36 , which is located radially further inwardly, can also be constructed as a bundle of lamellae; that stiffening collar 36 can again be utilized as a partition between different pressure chambers. Alternatively, in an embodiment in accordance with FIG. 6 c the hub 37 can also be subdivided into individual lamellae.
[0079] FIGS. 6 d and 6 e both show springs 39 , which increase the friction between the individual cylinders of lamellae through additional radial clamping pressure, which simultaneously increases the damping effect. It would also be possible in FIG. 6 e to construct hub 37 as a bundle of lamellae.
[0080] FIGS. 6 f and 6 g show a different approach to a solution, which involves changing the direction of tilt of the movable disk. With the usual guidance of the movable disk by its radial inner region or by its hub 37 , the radial outer region of that movable disk shows the greatest deflection in the direction of tilting. To counter that, it is possible in principle to guide the movable disk at the outside, so that its radially outer regions lie against the outer guide 40 and hence cannot deflect there. Tilting would then occur at the radially inner region of movable disk 33 , against which countermeasures could again be taken as described above. In that case, care must be taken, however, to avoid jamming or clamping of movable disk 33 between the guides.
[0081] Although particular embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit of the present invention. It is therefore intended to encompass within the appended claims all such changes and modifications that fall within the scope of the present invention. | A belt-driven conical-pulley transmission having a pair of conical disks on a power input side and carried on an input shaft, and a pair of conical disks on an output side of the transmission and carried on an output shaft, each pair of conical disks including an axially fixed disk and an axially movable disk. An endless torque-transmitting means extends around and is in contact with the input side disks and the output side disks for transmitting torque between the pairs of disks. The transmission is optimized to minimize noise emitted by the transmission when it is in operation. | 5 |
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