Patent Application
20070169951
This invention relates generally to quick coupler hitches used for connecting tractors to rear mounted implements, and more specifically to quick coupler hitches that may be operated with a single handle.
Quick coupler hitches have been developed to allow faster attachment of tractor three point hitches to rear mounted implements. Quick coupler hitches may include an inverted U-shape frame attached to a conventional three point hitch. The frame of a quick coupler hitch may have an upper hook and two lower coupling hooks or jaws with a latching and unlatching arrangement to hold the implement hitch pins. To hook up a quick coupler hitch to an implement, the hitch may be lowered and the tractor backed into place near the implement. Then the hitch may be raised with the tractor's 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 implement's lower hitch pins to enter the lower hooks.
A tractor operator may lock each of the latches to secure the implement hitch pins to the lower hooks of a quick coupler hitch. The latches may be spring loaded to the locked or latched position. To lock each latch, the operator must dismount from the operator station or seat to manually operate each of the two locking mechanisms for the two hitch pins of the implement. Similarly, to unhitch an implement from a quick coupler hitch, the tractor operator must get down off the seat to manually release each of the spring loaded latches. Once the latches are released, the quick coupler 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.
Although quick coupler hitches have advantages over conventional three point hitches, an operator cannot reach the handles easily while seated on the tractor. Quick coupler hitches may have two separate handles to operate the latches. The operator must leave the operator station to actuate each handle separately. It is inherently more dangerous for the operator to lock or unlock the hitch if he or she is outside the operator's station. A need exists for a quick coupler hitch having a single point of actuation that an operator can latch or unlatch while seated. There is a need for an improved apparatus and method that will allow a tractor to be hooked up to non-PTO powered Category 1 and/or Category 2 implements.
Quick coupler hitches are cam actuated, requiring the operator to exert a substantial effort to provide the needed force. A need exists for a quick coupler hitch that is easier to operate and requires a lower force to latch or unlatch. There is a need for greater operator safety and ease of use when hooking up a tractor to a rear mounted implement.
Quick coupler hitches include inverted U-shaped frames with square, welded corners. The frames are costly to manufacture because the parts of the frame must be welded together. A need exists for a lower cost quick coupler hitch having fewer parts.
A quick coupler hitch having a curved tube frame may be mounted to a tractor three point hitch. The quick coupler hitch includes flexible linkages within the curved tube frame, the linkages extending between a central pivot mechanism and left and right lower locking latches or lugs. The central pivot mechanism includes a single handle that may be operated from the seat of the tractor.
As shown in
In one embodiment, quick coupler hitch 10 may include upper clevis 16 and left and right lower clevises 17, 18, each of which may be used to attach the quick coupler hitch to three point hitch 11a, 11b, 11c extending from or mounted to the rear of a tractor. Upper clevis 16 may include side-by-side steel plates 19, 20 or a single steel casting that may be generally vertically oriented and welded to the top portion 15 of curved tube frame 12. Lock pin 21 may be removably inserted horizontally through holes in each of plates 19, 20 to lock the upper clevis to the three point hitch. Lower clevises 17, 18 may be integral with curved tube frame 12 on left and right legs 13, 14. Left lower clevis 17 may include a pair of vertically aligned plates 22, 23 and right lower clevis 18 may include a pair of vertically aligned plates 24, 25. Lock pin 26 may be removably inserted horizontally through holes in plates 22, 23 to lock the left lower clevis to a three point hitch. Lock pin 27 may be removably inserted horizontally through holes in plates 24, 25 to lock the right lower clevis to a three point hitch.
In one embodiment, quick coupler hitch 10 may be attached to a rear mounted implement by lowering the hitch and backing up the tractor into place near the implement. Then the quick coupler hitch may be raised with the tractor's hydraulic system so that upper hook 28 engages the upper pin on the implement. Further lifting causes the weight of the implement to force the implement's lower hitch pins to enter lower hooks 29, 30. Upper hook 28 and lower hooks 29, 30 are rearward projecting and upward opening, and may provide load bearing points of attachment for an implement. Upper hook 28 may be welded to quick coupler hitch 10 at or near upper clevis 16, and left and right lower hooks 29, 30 may be welded to the left and right lower portions or legs of the quick coupler hitch.
In one embodiment, left and right lower hooks 29, 30 may be latched or unlatched simultaneously. Left and right lower latches or lugs 31, 32 may be pivotably mounted to each of the lower portions or legs of the quick coupler hitch. The left and right lower latches or lugs may pivot on generally horizontal axes 33, 34 to latch or unlatch the hooks.
In one embodiment, as shown in
In one embodiment, flexible links 40, 41 may be wire cables. Flexible link 40 may be inserted through curved tube frame 12 between the left leg 13 and the top 15 of the frame, and flexible link 41 may be inserted through the curved tube frame between the right leg 14 and the top 15 of the frame.
In one embodiment, central pivot mechanism 35 may be manually operated from a seated position on a tractor to simultaneously lock or unlock the left and right lower latches or lugs. Central pivot mechanism 35 may include a generally vertically oriented shaft member 42 and a handle 43 extending horizontally from the upper end of the shaft. Shaft member 42 may extend at least partially through the curved tube frame near the top 15 of the frame so that the shaft may pivot on its vertical axis, and one or more bearings may be included between the shaft and frame.
In one embodiment, central pivot mechanism 35 may include a pair of cranks 44, 45 extending radially from the axis of vertical shaft 42 adjacent the lower end of the shaft. Pins 46, 47 may connect the first ends of cables 40, 41 to the cranks, and pins 48, 49 may connect the second ends of the cables to the left and right lower latches or lugs 31, 32. When handle 43 is turned by the operator, cables 40, 41 may be retracted or extended to lock or unlock the left and right lower latches or lugs.
In one embodiment, quick hitch coupler may be operated by turning handle 43 to pivot shaft 42 on its vertical axis to simultaneously retract or extend the wire cables in the bent tube frame. For example, the handle may be rotated between about 45 degrees and about 120 degrees, and most preferably about sixty degrees, to move the lower latches or lugs between their locked and unlocked positions. Through the sixty degrees of rotation, cables 40, 41 may be equally retracted or extended by cranks 44, 45. As the cables are retracted or extended, the attached lower latches or lugs 31, 32 may be pivoted between their locked and unlocked positions.
In one embodiment, central pivot mechanism 35 may have a locking position at the end of the sixty degrees of rotation that allows lower latches or lugs 37, 38 to be held in their unlocked positions. Additionally, when handle 43 is released from the locked position, springs 52, 53 attached to the lower latches or lugs may return them to their locked positions.
Quick hitch coupler 10 may be hooked up to a rear mounted implement by lowering the coupler and backing up the tractor and/or moving the implement into a position where lower hooks 29, 30 are under the left and right hitch pins of the implement, and upper hook 28 is under the upper hitch pin of the implement. After the tractor and implement are properly positioned, the tractor operator may raise the quick attaching coupler sufficiently for the implement's hitch pins to enter hooks 28, 29, 30. 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, the present invention provides a method and apparatus for a tractor operator to use a single handle to latch or lock quick hitch coupler 10 to a rear mounted implement after the hitch pins enter hooks 28, 29, 30. The present invention provides a simplified quick hitch coupler that is relatively easy to operate and economical to manufacture.
Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.
