Coupling device for a skid steer

Information

  • Patent Grant
  • 6238130
  • Patent Number
    6,238,130
  • Date Filed
    Friday, January 15, 1999
    26 years ago
  • Date Issued
    Tuesday, May 29, 2001
    23 years ago
Abstract
A coupling device is provided for interconnecting an attachment tool to the loader arm of the skid steer. The coupling device includes handles which are pivotable between unlocking and locking positions. The handles control coupling pins which diverge from each other and which move between a retracted position and an extended position to capture the attachment tool on the coupling device.
Description




BACKGROUND AND SUMMARY OF THE INVENTION




This invention relates generally to skid steers, and in particular, to a coupling device for interconnecting the loader arms of the skid steer to an attachment tool such as a bucket or the like.




As is known, skid steers are used in wide variety of applications. In order to perform such applications, various types of attachment tools are mounted to the loader arms at the front end of the skid steer. Typically, a coupling device is used to interconnect the loader arms of the skid steer to the attachment tool. It is highly desirable to provide a coupling device which securely interconnects the loader arms of the skid steer to the attachment tool. It is also highly desirable to provide a coupling device which allows a user to quickly and securely substitute one attachment tool for another.




Heretofore, the coupling device was pivotally mounted to the loader arms of the skid steer by pivot pins. Thereafter, the skid steer was interconnected to the attachment tool necessary to perform the task to be undertaken. In order to interconnect the coupling device to the desired attachment tool, the loader arms of the skid steer are such that the coupling device engages mounting shoes extending from the rearward surface of the attachment. The attachment tool is then manipulated in order to align one or more holes on the back thereof with corresponding holes extending through the coupling device. Pins are manually inserted through the coupling device and the attachment tool in order to interconnect the attachment tool to the skid steer.




While manual insertion of pins to interconnect the attachment tool to the skid steer is functional, such manual insertion technique is often difficult and time consuming. The time involved in substituting one attachment tool for another results in significant down time for the skid steer which, in turn, increases the cost of operating the skid steer and reduces the productivity thereof.




In the alternative, the coupling device may include vertical pins which may be inserted into corresponding openings in the attachment tool which are spaced an industry standard distance apart. A complex arrangement of linkages allow a user to insert and remove the vertical pins from their corresponding openings. In addition to the expense associated with providing such linkages, these types of linkages tend to become packed with debris during use of the skid steer rendering them inoperative thereafter.




Therefore, it is a primary object and feature of the present invention to provide a coupling device which securely interconnects an attachment tool to the loader arms of a skid steer.




It is a further object and feature of the present invention to provide a coupling device which quickly and easily interconnects an attachment tool to the loader arms of a skid steer.




It is a still further object and feature of the present invention to provide a coupling device which allows a user to easily interchange a wide variety of attachments on the loader arms of skid steer.




It is a still further object and feature of the present invention to provide a coupling device which is easy to assemble and more durable than prior devices.




In accordance with the present invention, a coupling device is provided for interconnecting an attachment tool to the loader arms of a skid steer. The coupling device includes a frame extending along an axis and mountable on the loader arms of the skid steer. A pivotable handle is mounted to the frame. The handle is moveable between a first unlocking position and a second locking position. A coupling pin extending at an angle to the axis of the frame is connected to the handle and is moveable between a first retracted position and a second extended position in response to movement of the handle between the unlocking position and the locking position.




It is contemplated that the coupling device further include a support bracket interconnected to the frame for supporting an upper portion of the attachment tool. A second support bracket is laterally spaced from the first support bracket and also supports an upper portion of the attachment tool.




A pivotable, second handle may also be mounted to the frame. The second handle is moveable between the first unlocking position and a second locking position. A second coupling pin extending at an angle to the axis of the frame is connected to the second handle and is moveable between a first retracted position and a second extended position in response to movement of the second handle between the unlocking and locking positions. It is contemplated that the first and second coupling pins diverge from each other at a predetermined angle. In order to prevent debris and the like from hampering movement of the coupling pins, shrouds are provided to partially surround corresponding coupling pins.




The frame of the coupling device may include first and second connection elements which define a loader arm receipt cavity. The loader arm receipt cavity is dimensioned to receive an end of a corresponding loader arm. A connection pin extends through the connection elements and the end of the corresponding loader arm to pivotally interconnect the frame of the coupling device to the corresponding loader arm.




In accordance with a still further aspect of the present invention, a coupling device is provided for interconnecting a loader arm of a skid steer to an attachment tool having a mounting bracket and a mounting plate with an aperture therethrough. The coupling device includes a frame extending along an axis which is pivotally connected to the end of the loader arm. The frame has upper and lower opposite sides. A support bracket is mounted to the upper side of the frame for engaging and supporting the mounting bracket of the attachment tool. A coupling pin is slidably supported by the frame at an angle to the axis of the frame and has a coupling end. The pin is moveable between a first extended position wherein the coupling of the pin extends through the aperture in the mounting plate of the attachment tool and a second retracted position. A handle controls movement of the coupling pin between the extended and retracted positions. A locking structure is provided for maintaining the coupling pin in the extended position. It is contemplated that the coupling pin be tapered in order to compensate for variations in the size and location of the pin-receiving aperture in the mounting plate of the attachment tool. In addition, a shroud may be interconnected to the frame in order to partially surround the coupling pin and prevent debris or the like from hindering movement thereof.




It is further contemplated that the support bracket be generally L-shaped and include a resilient engagement element for engaging the mounting bracket of the attachment tool.




The frame may include first and second connection elements which define a loader arm receipt cavity in the frame. The loader arm receipt cavity is adapted for receiving an end of a corresponding loader arm. A connection pin extends through the connection elements and the end of the corresponding loader arms to pivotally interconnect the frame to the corresponding loader arm.











BRIEF DESCRIPTION OF THE DRAWINGS




The drawings furnished herewith illustrate a preferred construction of the present invention in which the above advantages and features are clearly disclosed, as well as others which will be readily understood from the following description of the illustrated embodiment.




In the drawings





FIG. 1

is an isometric view of a skid steer incorporating the coupling device of the present invention.





FIG. 2

is an isometric view of the coupling device of the present invention.





FIG. 3

is a front elevational view of the coupling device of the present invention showing the coupling pins in a retracted position.





FIG. 4

is a front elevational view, similar to

FIG. 3

, showing the coupling pins in an extended position.





FIG. 5

is a cross-sectional view showing the coupling device of the present invention with the coupling pins in the extended position in order to interconnect the loader arms of the skid steer to an attachment tool.





FIG. 6

is a cross-sectional view, similar to

FIG. 5

, showing the coupling device of the present invention with the coupling pins in the retracted position in order to disengage the loader arms of the skid steer from the attachment tool.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT




Referring to

FIG. 2

, a coupling device in accordance with the present invention is generally designated by the reference numeral


10


. As best seen in

FIG. 1

, coupling device


10


is intended to interconnect the loader arms


12




a


and


12




b


of a skid steer


14


to an attachment tool such as bucket


16


. However, it is contemplated as being within the scope of the present invention that coupling device


10


be used for interconnecting bucket


16


to other types of vehicles, such as front-end loading tractors or the like. Further, it is contemplated as being within the scope of the present invention that coupling device


10


be used to interconnect other types of attachment tools to skid steer


14


. As such, bucket


16


is provided only as an example and is not intended to limit the type of attachment tool which may be coupled to skid steer


14


by coupling device


10


.




As is conventional, skid steer


14


includes a support frame


20


supported by four independently driven wheels


18


. Support frame


20


of skid steer


14


includes a loader assembly


22


on the upper portion thereof. Loader assembly


22


includes left and right support arms


24


and


26


, respectively. Support arms


24


and


26


include first ends


28


and


30


, respectively, pivotally mounted to corresponding supporting members


32


and


34


of support frame


20


. As is conventional, pivotal movement of support arms


24


and


26


is controlled by corresponding hydraulic cylinders (not shown).




Loader assembly


22


further includes corresponding left and right loader arms


12




a


and


12




b,


respectively. Loader arm


12




a


includes a first end


36




a


pivotally mounted to second, terminal end


40


of support arm


24


. Similarly, a first end


38




a


of loader arm


12




b


is pivotally mounted to second, terminal end


42


of support arm


26


.




In order to provide strength and stability to loader arms


12




a


and


12




b,


loader arms


12




a


and


12




b


are braced by a support assembly


50


. Support assembly


50


includes first and second parallel support members


52


and


54


, respectively, extending along the length of corresponding loader arms


12




a


and


12




b,


respectively. Support members


52


and


54


are interconnected by first and second cross supports


56


and


58


, respectively. A first end of support member


52


is pivotally mounted to terminal end


40


of support arm


24


through pivot point


60


so as to capture end


36




a


of loader arm


12




a


therebetween. Similarly, a first end of support member


54


is pivotally mounted at pivot point


64


to terminal end


42


of support arm


26


so as to capture first end


38




a


of support arm


12




b


therebetween.




Referring

FIG. 2

, coupling device


10


includes first and second mounting shoes


70


and


72


, respectively, dimensioned for receiving the terminal ends


36




b


and


38




b


of loader arms


12




a


and


12




b,


respectively. Mounting shoes


70


and


72


are defined by generally parallel outer plates


74


and


76


, respectively, and generally parallel inner plates


75


and


78


, respectively.




Inner surface


80


of outer plate


74


and inner surface


82


of inner plate


75


define loader arm receipt cavity


84


therebetween in mounting shoe


70


. Similarly, the inner surface


86


of outer plate


76


and the inner surface


88


of inner plate


78


define loader arm receipt cavity


90


therebetween in mounting shoe


72


. The outer surface


92


of inner plate


75


of mounting shoe


70


is interconnected to the outer surface


94


of inner plate


78


of mounting shoe


72


by first and second, parallel cross braces


96


and


98


, respectively. Cross braces


96


and


98


provide strength and stability to coupling device


10


and prevent lateral movement of mounting shoes


70


and


72


.




Outer surfaces


92


and


94


of inner plates


76


and


78


, respectively, further include handle support walls


100


and


102


, respectively, lying in a common plane and extending toward each other. First and second handles


106


and


108


, respectively, are pivotably mounted to corresponding handle support walls


100


and


102


, respectively. Handles


106


and


108


include gripping portions


110




a


and


112




a,


respectively, and body portions


110




b


and


112




b,


respectively. Plates


114


and


116


are rigidly mounted to corresponding body portions


110




b


and


112




b,


respectively, of handles


106


and


108


, respectively, by mounting elements


118


and


120


, respectively. Handles


106


and


108


are pivotally mounted to corresponding handle support walls


100


and


102


, respectively, by mounting pins


122


, thereby allowing handles


106


and


108


to pivot thereon between a first pin retracted position,

FIG. 3

, and a second coupling pin extended position, FIG.


4


.




Plate


114


includes an aperture


124


which is axially aligned with a corresponding aperture (not shown) in the body portion


110




b


of handle


106


. Trunnion


126


is pivotably supported and extends through aperture


124


and the aperture in handle


106


. Referring to

FIGS. 3-4

, threaded end


130


of rod


128


extends through a central opening in trunnion


126


and is adapted for receiving a nut


132


thereon. Spring


134


is captured between first and second washers


136


and


138


, respectively, which are slidably received on rod


128


Washer


136


abuts trunnion


126


for slidable movement therewith along rod


128


. Washer


138


abuts a shoulder in rod


128


to prevent movement of washer


138


away from threaded end


130


along rod


128


.




End


140


of rod


128


is pivotally mounted to a first end


142


of coupling pin


144


by pivot pin


146


. Coupling pin


144


includes first and second sides


145


and


147


and a second, opposite end


148


which terminates at generally flat end surface


150


. A generally tapered surface


152


extends from and interconnects end surface


150


with first side


145


. A shroud


151


partially surrounds coupling pin


144


and is secured to outer and inner plates


74


and


75


, respectively, of mounting shoe


70


so as to isolate coupling pin


144


from the external environment and to prevent debris or the like from hampering movement of coupling pin


144


in response to the pivoting of handle


106


.




Referring to

FIG. 3

, with handle


106


in the pin retracted position, spring


134


provides a biasing force on trunnion


126


which maintains handle


106


in such position. As handle


106


is pivoted counterclockwise by a user to overcome the biasing force of spring


134


, the position of trunnion


126


is translated over center of the pivot point of handle


106


at mounting pin


122


such that the biasing force provided on trunnion


126


by spring


134


urges handle


106


counterclockwise. Referring to

FIG. 4

, with handle


106


in the pin extended position, spring


134


provides a biasing force on trunnion


126


such that handle


106


is maintained in such position.




Likewise, in order to return handle


106


to the pin retracted position, handle


106


is pivoted clockwise by a user to overcome the biasing force of the spring


134


. As handle


106


is pivoted on its pivot point at mounting pin


122


, the position of trunnion


126


is translated over the center of the pivot point such that the biasing force provided on trunnion


126


by spring


134


urges handle


106


clockwise. As previously described, with handle


106


in the pin retracted position, spring


134


provides a biasing force on trunnion


126


which maintains handle


106


in such position.




Similarly, plate


116


of handle


108


includes an aperture


156


which is axially aligned with a corresponding aperture (not shown) in handle


108


. Trunnion


158


is pivotably supported by extends through aperture


156


and the aperture in handle


108


. Threaded end


162


of rod


160


extends through a central opening in trunnion


158


and is adapted for receiving a nut


164


thereon. Spring


166


is captured between first and second washers


168


and


170


, respectively, which are slidably received on rod


162


. Washer


168


abuts trunnion


158


and is urged thereagainst by the biasing force of spring


134


. Washer


170


abuts shoulder


172


in rod


162


to prevent movement of washer


170


away from threaded end


130


along rod


162


.




End


174


of rod


160


is pivotally mounted to a first end


176


of coupling pin


178


by pivot pin


180


. Coupling pin


178


includes first and second sides


181


and


183


and a second, opposite end


182


which terminates at an end surface


184


. A generally tapered surface


186


extends from and interconnects end surface


184


with first side


181


of coupling pin


178


.




As best seen in

FIGS. 3 and 4

, coupling pins


144


and


178


diverge from each other at a predetermined angle. As heretofore described, by providing each coupling pin


144


and


178


at a predetermined angle to vertical, the complexity of the linkage needed to move the coupling pins


144


and


178


between the retracted position,

FIG. 3

, and the extended position,

FIG. 4

, is greatly reduced.




End surface


150


of coupling pin


144


and end surface


184


of coupling pin


178


are separated by a predetermined distance corresponding to an industry standard width between pin-receiving apertures provided in various attachment tools such as bucket


16


which are designed for attachment to the loader arms


12




a


and


12




b


of a skid steer


14


. Further, tapered surface


152


of coupling pin


144


and tapered surface


186


of coupling pin


178


are provided to compensate for possible variances in the distance between pin-receiving apertures in various attachment tools to be mounted on skid steer


14


.




It is also contemplated to provided a taper


144




a


and (not shown) in the forward face of corresponding coupling pins


144


and


178


, respectively, to compensate for variances in the size and location of pin-receiving apertures in various attachment tools to be mounted on skid steer


14


.




A shroud


190


partially surrounds coupling pin


178


and is secured to the outer and inner plates


76


and


78


, respectively, of mounting shoe


72


so as to isolate coupling pin


178


from the external environment and to prevent debris or the like from hampering movement of coupling pin


178


in response to the pivoting of handle


108


.




Referring to

FIG. 3

, with handle


108


in the pin retracted position, spring


166


provides a biasing force on trunnion


158


thereby maintaining handle


108


in such position. As handle


108


is pivoted clockwise by a user to overcome the biasing force of spring


166


, the position of trunnion


158


is translated over center of the pivot point of handle


108


and mounting pin


122


such that the biasing force provided on trunnion


158


by spring


166


urges handle


108


clockwise. Referring to

FIG. 4

, with handle


108


in the pin extended position, spring


166


provides a biasing force on trunnion


158


such that handle


108


is maintained in such position.




In order to return handle


108


to the pin retracted position, handle


108


is pivoted clockwise by a user to overcome the biasing force of the spring


166


. As handle


108


is pivoted on its pivot point at mounting pin


122


, the position of trunnion


158


is translated over the center of the pivot point such that the biasing force provided trunnion


158


by spring


166


urges handle


108


clockwise. As previously described, with handle


108


in the pin retracted position, spring


166


provides a biasing force on trunnion


156


which maintains handle


108


in such position.




Coupling device


10


further includes first and second upper support brackets


200


and


202


, respectively, mounted on corresponding mounting shoes


70


and


72


, respectively. Support bracket


200


includes a horizontal base


204


having an underside


206


affixed to the upper edges of plates


74


and


75


of mounting shoe


70


. A gusset


208


extends between the outer surface


210


of outer plate


74


and the underside


206


of horizontal base


204


in order to provide added support to support bracket


200


. Support bracket


200


further includes a connection bracket


212


which extends from horizontal base


204


. Connection bracket


211


includes a leg first


212


which extends vertically from horizontal base


204


and a second leg


214


which extends from first leg


212


. First and second legs


212


and


214


, respectively, form a resilient connector which dimensioned for receipt in a corresponding connector receipt cavity formed in the rearward surface of bucket


16


, as hereinafter described.




Similarly, support bracket


202


includes a horizontal base


220


having an underside


222


affixed to the upper edges of plates


76


and


78


of mounting shoe


72


. A gusset


224


extends between the outer surface


226


of outer plate


76


and the underside


222


of horizontal base


220


in order to provide added support to support bracket


200


. Support bracket


202


further includes a connection bracket


228


which extends from horizontal base


220


. Connection bracket


228


includes a leg first


230


which extends vertically from horizontal base


220


and a second leg


232


which extends from first leg


230


. First and second legs


230


and


232


, respectively, form a resilient connector which is dimensioned for receipt in a corresponding connector receipt cavity formed in the rearward surface of bucket


16


, as hereinafter described.




Mounting shoes


70


and


72


of coupling device


10


are interconnected to the terminal ends


36




b


and


38




b


of corresponding loader arms


12




a


and


12




b,


respectively by pivot pins


230


and


231


. Pivot pin


230


extends between outer and inner plates


74


and


75


of mounting shoe


70


and through terminal end


36




b


of loader arm


12




a


so as to pivotally interconnect loader arm


12




a


to coupling device


10


. Similarly, pivot pin


231


extends between outer and inner plates


76


and


78


of mounting shoe


70


and through terminal end


38




b


of loader arm


12




b


so as to pivotally interconnect loader arm


12




b


to coupling device


10


.




It is contemplated that coupling device


10


be further connected to skid steer


14


by hydraulic cylinders which extend between loader assembly


22


and mounting shoes


70


and


72


. Pivot pin


240


may extend between outer inner plates


74


and


75


of mounting shoe


70


so as to capture the terminal end of the shaft of such hydraulic cylinder thereon. Similarly, pivot pin


242


may extend between outer and inner plates


76


and


78


of mounting shoe


72


and so as to capture the terminal end of a shaft of a second of such hydraulic cylinders thereon. As is known, such types of hydraulic cylinders are used to control the pivotable movement of coupling device


10


with respect to loader arms


12




a


and


12




b


of skid steer


14


.




Referring to

FIGS. 4-5

, in order to interconnect bucket


16


to skid steer


14


, handles


106


and


108


of coupling device


10


are pivoted to the pin retracted position,

FIGS. 3 and 6

, as heretofore described. Coupling device


10


is aligned with the rearward surface of bucket


16


such that the resilient connector formed by legs


212


and


214


of upper support bracket


200


is positioned within a corresponding receiving cavity


248


formed in the rearward surface


246


of bucket


16


and such that the resilient connector formed by legs


230


and


232


of support bracket


202


is positioned within a corresponding second leg support cavity (not shown) formed in the rearward surface of bucket


16


. In addition, end surfaces


150


and


184


of coupling pins


144


and


178


, respectively, are axially aligned with corresponding pin-receiving apertures


250


formed in the rearward surface


246


of bucket


16


.




Handles


106


and


108


are pivoted to the pin extended position,

FIGS. 4-5

, such that end surfaces


150


and


184


of pins


144


and


178


, respectively, extend through corresponding pin-receiving apertures


250


formed in the rearward surface


246


of bucket


16


. Tapered surfaces


152


and


186


of coupling pins


144


and


178


, respectively, compensate for variances in the distance between pinreceiving apertures


250


in the rearward surface


246


of bucket


16


. With handles


106


and


108


in the coupling pin extended position,

FIGS. 4 and 5

, bucket


16


is interconnected to skid steer


14


and ready for use.




In order to disconnect bucket


16


from skid steer


14


, handles


106


and


108


are pivoted, as heretofore described, to the pin retracted position,

FIGS. 3 and 6

, such that coupling pins


144


and


178


are removed from corresponding pin-receiving apertures


250


in the rearward surface


246


of bucket


16


. The resilient connector formed by legs


212


and


214


of support bracket


200


is removed from the corresponding second leg receiving cavity formed in the rearward surface


246


of bucket


16


and the resilient connector formed by legs


230


and


232


of support bracket


202


is removed from the corresponding leg receiving cavity (now shown) formed in the rearward surface


246


of bucket


16


, thereby disengaging bucket


16


from skid steer


14


.




It can be appreciated from the above description of the various alternate attachment tools may be quickly and securely mounted on a skid steer utilizing the coupling device of the present invention.




In addition, various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter regarded as the invention.



Claims
  • 1. A coupling device for interconnecting an attachment tool to loader arms of a skid steer, comprising:a frame extending along an axis and mountable on the loader arms of the skid steer; a handle mounted to the frame, the handle movable between a first unlocking position and a second location position; a first coupling pin operatively connected to the first handle at an angle to the axis and movable along a first pin axis between a first retracted position and a second extended position in response to movement of the first handle between the unlocking position and the locking position; a second handle mounted to the frame, the second handle movable between a first unlocking position and a second locking position; a second coupling pin operatively connected to the second handle and movable along a second pin axis between a first retracted position and a second extended position in response to movement of the second handle between the unlocking position and the locking position; and wherein the first and second pin axis diverge from each other at a predetermined angle greater than zero degrees.
  • 2. The coupling device of claim 1 further comprising a support bracket interconnected to the frame for supporting an upper portion of the attachment tool.
  • 3. The coupling device of claim 2 further comprising a second support bracket laterally spaced from the first support bracket for supporting an upper portion of the attachment tool.
  • 4. The coupling device of claim 1 further comprising a shroud interconnected to the frame and partially surrounding the insert coupling pin.
  • 5. The coupling device of claim 1 wherein the frame includes first and second connection elements defining a loader arm receipt cavity, the loader arm receipt cavity receiving an end of a corresponding loader arm.
  • 6. The coupling device of claim 5 further comprising a connection pin extending through the support elements and the end of the corresponding loader arm to pivotally interconnect the frame to the corresponding loader arm.
  • 7. The coupling device of claim 1 wherein the first coupling pin includes a tapered end.
  • 8. A coupling device for interconnecting a loader arm of a skid steer to an attachment tool having a mounting bracket and having first and second apertures in a rearward surface thereof extending therethrough, comprising:a frame extending along an axis and pivotally connectable to an end of the loader arm, the frame having first and second opposite sides; a support bracket mounted to the first side of the frame for engaging the mounting bracket of the attachment tool; a first pin slidably supported by the frame at an angle to the axis and having a coupling end, the first pin movable along a first pin axis between a first extended position wherein the coupling end of the first pin is extendable through the first aperture in the rearward surface of the attachment tool and a second retracted position; a first handle for controlling movement of the first pin between the extended and the retracted positions; a first locking element for maintaining the first pin in the extended position; a second pin slidably supported by the frame at an angle to the axis and having a coupling end, the second pin movable along a second pin axis between a first extended position wherein the coupling end of the second pin is extendable through the first aperture in the rearward surface of the attachment tool and a second retracted position; a second handle for controlling movement of the second pin between the extended and the retracted position; a second locking element for maintaining the second pin in the extended position; and wherein the first pin axis and the second pin axis diverge from each other at a predetermined angle greater than zero degrees.
  • 9. The coupling device of claim 8 wherein the ends of the pins are tapered.
  • 10. The coupling device of claim 8 wherein the support bracket includes a resilient engagement element for engaging the mounting bracket of the attachment tool.
  • 11. The coupling device of claim 8 further comprising a shroud interconnected to the frame and partially surrounding the first pin.
  • 12. The coupling device of claim 8 wherein the frame includes first and second connection elements defining a loader arm receipt cavity for receiving an end of a corresponding loader arm.
  • 13. The coupling device of claim 12 further comprising a connection pin extendable through the support elements and the end of the corresponding loader arm to pivotally interconnect the frame to the corresponding loader arm.
US Referenced Citations (12)
Number Name Date Kind
3089261 Flath May 1963
3220487 Pilch Nov 1965
4167247 Sons et al. Sep 1979
4538955 Langenfeld et al. Sep 1985
4545720 Cochran et al. Oct 1985
4621973 Langenfeld et al. Nov 1986
4812103 Cochran et al. Mar 1989
4846624 Hohn Jul 1989
4998590 Wells Mar 1991
5088881 Ball et al. Feb 1992
5098252 Sheesley et al. Mar 1992
5836734 Doering Nov 1998
Foreign Referenced Citations (1)
Number Date Country
1369935 Jun 1972 GB
Non-Patent Literature Citations (1)
Entry
Case Corporation Service Bulletin, dated Jan. 30, 1996, pp. 1-5.