Implement and power take off attachment system

A quick attaching coupler is mounted to a tractor three point hitch, with a first actuator linked to latches on both sides of the hitch. The first actuator may be moved by a seated operator between a first position wherein both latches are unlatched and a second position wherein both latches are latched. A quick PTO coupler is mounted to the quick attaching coupler, and has a sleeve carrying a first end of a tractor PTO shaft. The sleeve pivots independently of the latches between a first PTO disengaged position and a second PTO engaged position. A second actuator linked to the sleeve may be moved by the seated operator between a first position wherein the PTO is disengaged and a second position wherein the PTO is engaged.

FIELD OF THE INVENTION

This invention relates generally to coupling devices for connecting a tractor or other similar vehicle to a rear mounted implement, and more specifically to latching a quick attaching coupler and engaging a power take off from a tractor to a rear mounted implement.

BACKGROUND OF THE INVENTION

Quick attaching couplers have been developed to allow faster attachment of three point hitches to rear mounted implements. A quick attaching coupler may be an inverted U-shape arch that is attached to the conventional three points of a tractor hitch. The frame of a quick attaching coupler may have an upper hook with a long, tapered point and two lower coupling hooks or jaws with a latching and unlatching arrangement to hold the implement hitch pins. To hook up the quick attaching coupler to an implement, the hitch may be lowered and the tractor or similar vehicle backed into place near the implement. Then the hitch may be raised with the hydraulic system so that the upper hook engages the upper pin on the implement. Further lifting causes the weight of the implement to force the lower hitch pins to enter the lower hooks.

The tractor operator then may lock each of the latches to secure the implement hitch pins to the hooks. The latches may be spring loaded to the locked or latched position. To lock each latch to the implement, the operator must dismount the operator station or tractor seat to manually operate two locking mechanisms for the two hitch pins of the implement.

Similarly, to unhitch an implement from a quick attach coupler, the tractor operator must leave the operator station or tractor seat to manually release the spring loaded latches. Once the latches are released, the hitch may be lowered until the implement is on the ground. Then, after the hitch is lowered further, the two lower hooks and the upper hook disengage from the implement and the tractor can be driven away.

Tractors may be equipped with a power take off (PTO) drive that provides a means for transmitting rotary power from the engine to implements that are coupled to a tractor. The most common location for the PTO shaft is at the rear of the tractor, but some tractors have auxiliary PTO shafts at other locations. The direction of rotation, rotational speed, approximate location and exact dimensions of the PTO shaft are standardized to provide ability to interchange between power shafts on various implements made by different manufacturers. PTO shafts typically rotate at 540 rpm, 1000 rpm, or both speeds.

To engage the PTO shaft to the power shaft of a rear mounted implement, the, the PTO shaft may have the ability to telescope. After the tractor is in proper position, the tractor operator may manually extend the telescoping PTO shaft and employ various locking devices to engage the PTO shaft to the implement power shaft. This requires getting down off the seat or operator station of the tractor, and it can be quite difficult and time consuming to engage the power take off.

A need exists for an apparatus and method for latching a quick attach coupler from the operator seat of the tractor. A need also exists for engaging a power take off on a tractor to a rear mounted implement, while seated on the tractor. There is a need for an apparatus and method that may be used for a variety of different implements having power shafts at different locations relative to the tractor PTO. There is a need for an apparatus and method that will allow a tractor to be hooked up to non-PTO powered Category 1 implements without removing the quick attach coupler or hitch from the tractor. There is a need for an apparatus and method that will allow hooking up a tractor to PTO driven rear mounted implements without requiring the operator to leave the tractor seat. There is a need for an apparatus and method to hook up, from the seat of the tractor, both PTO powered and non-PTO powered implements. There is a need for greater operator safety and ease of use when hooking up a tractor to a rear mounted implement.

SUMMARY OF THE INVENTION

A quick attaching coupler may be mounted to a tractor three point hitch, the quick attaching coupler having a frame, a hook on each side of the frame, each hook having a latch that pivots between a first unlatched position and a second latched position. A first handle linked to both latches may be moved between a first forward position wherein both latches are unlatched and a second rearward position wherein both latches are latched.

A quick PTO coupler also may be mounted to the quick attaching coupler, the quick PTO coupler having a sleeve carrying a first end of a tractor PTO shaft. The sleeve pivots independently of the latches between a first PTO disengaged position and a second PTO engaged position. A second handle linked to the sleeve may be moved between a first forward position wherein the PTO is disengaged and a second rearward position wherein the PTO is engaged.

The quick attach coupler and quick PTO coupler may both be operated from the seat of the tractor. As a result, latching the quick attach coupler and engaging the PTO to a rear mounted implement is safer and easier.

DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown inFIG. 1, quick attaching coupler10may be connected to a three point hitch on a tractor or similar vehicle. Additionally, in one embodiment, quick PTO coupler11also may be attached to the quick attaching coupler. As described below in more detail, the quick attaching coupler may be latched to a rear mounted implement, and/or the quick PTO coupler may be engaged to a power shaft of a rear mounted implement.

In one embodiment, quick attaching coupler10may be an inverted U-shaped arch having left hand leg13and right hand leg14extending downward from cross member12. Each of the left and right legs may be provided with lower hooks15and16which are rearward projecting and upward opening. Each of lower hooks15,16may have a pivoting latch43,46to latch or lock in place hitch pins of a rear mounted implement. Upward opening central hook18may be positioned on cross member12at or near a midpoint between legs13and14. Quick attaching coupler10may be secured to the hooks of a three point hitch by pin45through clevis19on cross member12, and pins42,52extending outward from legs13and14.

FIG. 5shows a typical rear mounted mowing implement100that may be hooked up to quick attaching coupler10and/or quick PTO coupler11. Quick attaching coupler10may be hooked up to a rear mounted implement by lowering the hitch and backing up the tractor and/or moving the implement into a position where lower hooks15,16are under the left and right hitch pins101,102of the implement, and upper hook18is under the upper hitch pin103of the implement. After the tractor and implement are properly positioned, the tractor operator may raise the quick attaching coupler sufficiently for the hitch pins to enter hooks15,16,18. The operator may raise the quick attaching coupler by use of a hydraulic system for the tractor's three point hitch, preferably with controls that are accessible from the tractor operator station.

In one embodiment, a method and apparatus are provided for a tractor operator to latch or lock quick attaching coupler10to a rear mounted implement after the hitch pins enter hooks15,16,18. Additionally, in one embodiment, a method and apparatus are provided for a tractor operator to engage tractor PTO50to implement PTO104after the quick attaching coupler is latched or locked to a rear mounted implement. The present invention provides a mechanism for the tractor operator to do either or both of these tasks without getting down off the tractor.

In one embodiment, as shown in detailFIG. 4, quick attaching coupler10may be latched or locked to an implement using a first actuator such as first handle20connected to cross bar17. Alternative actuators such as hydraulic or electric actuators may be used instead of or in addition to first handle20to rotate cross bar17and lock or latch the quick attaching coupler to implement hitch pins. First handle20may be manually operated and located on the tractor or other vehicle so that it is accessible to a seated operator, preferably less about 4 feet from the operator seat. First handle20may have a generally vertical alignment or be generally vertically oriented. A tractor operator may pull the first handle20in a forward direction to a first position toward the front of the tractor to unlock latches43,46from the implement, or in a rearward direction to a second position toward the rear of the tractor to latch or lock the latches to the implement. The operator may move or pivot the first handle between the first position and second position such that the upper portion of the first handle travels a distance of between about 6 inches and about 24 inches to lock or unlock the latches. By moving the first handle in a forward or rearward direction, a tractor operator may rotate cross bar17on its longitudinal axis between about 10 degrees and about 60 degrees.

In one embodiment, each of the two ends of cross bar17may be linked to latches43,46that latch and unlatch the hitch pins of a rear mounted implement. Cross bar17may be a hollow tube having first and second ends, with pin(s)41inserted into the first and second ends and through projections70,71on left and right legs13,14. The pins and projections support the cross bar and allow the cross bar to turn or rotate between about 10 degrees and about 60 degrees on its longitudinal axis to lock or unlock the latches. The first and second ends of cross bar17may be affixed by welds or other means to the first or lower ends of arms21,22which may have a generally inverted L-shape. The second or upper ends of arms21,22may be connected to links76,77by pins72,73that ride in slots74,75. In one embodiment, when the operator pushes first handle20to the second position toward the rear of the tractor, cross bar17and arms21,22turn or rotate and urge links76,77to move and/or pivot in a generally downward direction.

At least partially enclosed by right leg14of the quick attaching coupler, link77may be connected to the first or upper end of vertically aligned or vertically oriented bar68by pin79through slot53. Bar68may extend through and be at least partially covered by right leg14. The second or lower end of bar68may be pivotally connected to the first end of latch46by pin95. In one embodiment, latch46may be an inverted L-shaped member that pivots on pin82. Coil spring69may be positioned around bars68to urge latch46toward the second, or locked, position.

The same or very similar structure may be at least partially enclosed by the left leg of the quick attaching coupler. Specifically, link76may be connected to the first or upper end of a vertically aligned bar (not shown) by pin78through a slot (not shown). The second or lower end of the bar may be pivotally connected to the first end of latch43by a pin. Latch43also may be an inverted L-shaped member that pivots on pin81. A coil spring (not shown) may be positioned around the bar in the left leg to urge latch43to the second, or locked position.

When the operator operates the first actuator, the bars in the left and right legs move downward and latches43,46pivot toward the latched or locked position. In one embodiment, when the operator pulls first handle20toward the front of the tractor, both of the bars move upward and latches43,46pivot toward the unlatched or unlocked position. The quick attaching coupler may be latched or unlatched from an implement by moving the first actuator such as first handle20rearward or forward, as the case may be, while the operator remains in the operator station of the tractor or other similar vehicle.

In one embodiment, quick PTO coupler11also may be engaged to a rear mounted implement. The quick PTO coupler may be operated by a second actuator that is easily accessible to an operator positioned in the operator station of the tractor. For example, the second actuator may be second handle37which preferably is less than about 4 feet from the tractor seat. Second handle37may be used to engage or disengage the first end of PTO50with an implement power shaft104. Alternatively, or in addition to the second handle, the second actuator for the quick PTO coupler may operate hydraulically or electronically.

Preferably, the second actuator for the quick PTO coupler may be positioned adjacent the first actuator for the quick attaching coupler. However, the first actuator and the second actuator work independently of each other. Thus, the quick attaching coupler may hook up and latch a rear mounted implement before or without engagement of the quick PTO coupler to the implement power shaft.

In one embodiment, second handle37may have a generally vertical alignment or be vertically oriented and may pivot on an axis at or near the first or lower end thereof. The axis may be pin38inserted through the first or lower end of second handle37, and through arm(s)49secured by welding or other attachment means to housing30or another rigid component of the quick PTO coupler.

In one embodiment, second handle37extends through slotted plate44which may be mounted to cross member12. Slot84serves to limit travel of the second handle. Slot84may have a stop or catch60at or adjacent the first or forward end thereof to hold and maintain second handle37in a first position in which the PTO shaft is disengaged from the implement power shaft. Slot84also may be dimensioned to have sufficient length for some variability in the travel of second handle37when it pivots toward the second end of the slot to a second position in which the PTO is engaged to an implement power shaft. The variability may allow the quick PTO coupler to engage implement power shafts having various different locations relative to the tractor PTO, so that the second or PTO engaged position may vary from implement to implement. In one embodiment, second handle37may pivot between about 10 degrees and about 60 degrees to move the quick PTO coupler between the first or disengaged position and the second or engaged position. Slot84may have a length of between about 6 inches and 24 inches, depending on the mounting position of slotted plate44relative to handle37.

In one embodiment, the quick PTO coupler includes a pair of yokes28,29that carry sleeve24through which the first end of PTO shaft50extends. The yokes may be used to suspend sleeve24under cross member12. When an operator pulls second handle37toward the front of the tractor, the yokes move sleeve24forward so that the first end of PTO shaft50moves out of engagement with implement power shaft104. When the operator pushes second handle37rearward, the yokes move sleeve24rearward so that the first end of PTO shaft50moves into engagement with implement power shaft104.

In one embodiment, quick PTO coupler11may include housing30bolted or otherwise secured to cross member12. The housing may be a generally box-like structure having one or more open surfaces or side panels. Housing30may provide one or more plates, braces and/or mountings for components of the quick PTO coupler. For example, plate62may be secured to housing30by threaded fasteners65and rubber isolators66,67. Additionally, plates47,48may be secured to plate62by welds or other securing means. Posts33,34also may be secured to housing30by welds or other securing means.

In one embodiment, the upper portions of yokes28,29are hinged to the cross member of the quick attaching coupler or another fixed component on the rear of the tractor. For example, yokes28,29may be hinged to plates47,48by cross bolts35,36. As noted above, plates47,48are welded to plate62, which is then attached to housing30using bolts with rubber isolators. The lower portions of yokes28,29are hinged to sleeve24by threaded fasteners39,40. Yokes28,29are both hinged to sleeve24, so that both yokes swing together rearward to move PTO shaft50into engagement with an implement power shaft, or forward to move PTO shaft50out of engagement with an implement power shaft. Preferably, PTO shaft50extending through sleeve24should maintain a generally horizontal alignment in the engaged or disengaged positions.

In one embodiment, when sleeve24moves or swings PTO shaft50into engagement with an implement power shaft, the sleeve carrying the PTO shaft may move or swing between about 3 inches and about 24 inches forward or rearward horizontally. The span between the forward and rearward positions may depend on the location of the implement power shaft. As the sleeve swings the PTO shaft into or out of engagement with the implement power shaft, the sleeve may move slightly vertically, generally less than about 3 inches.

In one embodiment, link61connects second handle37to yoke28by pins63,64. Link61may extend through an opening in housing30. By moving or pivoting second handle37rearward, link61is pushed rearward, causing yokes28and29to swing rearward and move the PTO shaft into engagement with an implement power shaft. One or more coil springs31,32, or other biasing means, may extend between pin64and posts33,34. The coil springs may urge the quick PTO coupler toward the second or engaged position.

In one embodiment, coupler25may be connected to the end of PTO shaft50by cross bolt or pin87. Coupler25may be a generally circular plate having a diameter between about 3 inches and about 6 inches. A plurality of teeth54may project rearward from the plate surface to interengage corresponding teeth on an implement power shaft coupler. In one embodiment, each of six teeth may project rearward from the coupler surface between about ½ inch and about 2 inches. Each tooth may be generally wedge shaped and extend radially outward from a first radius to a second or outer radius of the coupler.

Additionally, coupler25may have a centering hub26to help guide engagement of the coupler with a corresponding coupler on the power shaft of the rear mounted implement. In one embodiment, centering hub26may be a generally conical or frustaconical projection that extends about ½ inch to about 2 inches from the face of the coupler.

As shown inFIGS. 5 and 6, implement power shaft104may have a coupler105attached to the end thereof. Coupler105may have generally the same or similar construction as coupler25. For example, coupler105may be connected to the end of implement power shaft104by cross bolt or pin106. Coupler105may be a generally circular plate with a plurality of teeth108projecting rearward from the plate surface, each tooth extending radially outward from a first radius to a second or outer radius of the coupler. Coupler105may have a centering recess107to help guide engagement of with coupler25. In one embodiment, centering recess107may be have a generally conical or frustaconical shape for receiving centering hub26therein. For other implements, such as a tiller, coupler105may be directly mounted to a gear box shaft instead of a power shaft. In another embodiment, the coupler on the end of the PTO shaft may be splined externally to engage a mating internally splined coupler on the implement power shaft.

PTO shaft50may telescope or extend sufficiently to accommodate the forward and rearward motion of sleeve24of the quick PTO coupler. PTO shaft50also may have one or more universal joints90,91. The universal joints may allow for desired movement, positioning and alignment of the PTO shaft. Similarly, implement power shaft may have one or more universal joints109,110which may help provide for desired movement, positioning and alignment of the implement power shaft.

In one embodiment, bumper27may extend rearward over sleeve24for deflecting implement power shaft104and coupler105before engagement. In one embodiment, bumper27projects rearward from sleeve24and extends over sleeve and extends at least partially over coupler25. In one embodiment, bumper27is integral with or affixed to sleeve24. Bumper27may have a downward sloping rear facing surface88. As the quick attaching coupler is raised to hook up the implement, the sloped surface88of bumper27may contact and deflect implement power shaft104and coupler105sufficiently to prevent those components from hanging up on or impacting the upper side of coupler25. The sloped surface88causes the implement power shaft to slide downward sufficiently for coupler105to face and align with coupler25, reaching the desired position for engagement.

In a second embodiment, the end of PTO shaft50may be carried by an inverted U-shaped bracket, instead of a pair of yokes and sleeve. A bumper may be integral with or attached to the bracket. A rod and pivoting linkage may connect between the second handle or second actuator and the bracket. When the operator moves the second actuator forward or rearward, the rod and pivoting linkage causes the end of the PTO shaft to telescope forward or rearward. The rod may have a generally horizontal alignment, and helps the end of the PTO shaft to maintain a generally horizontal alignment. For example, the rod may extend through one or more bearings or openings in plates attached to the quick PTO coupler.