Patent Application
20070052207
This invention is in the field of towed vehicles, such as trailers and agricultural implements, and in particular hitch mechanisms for attaching such towed vehicles to a towing vehicle.
Connecting mechanisms for towed vehicles take a variety of forms, such as ball and socket mechanisms, clevis and tongue mechanisms, pintle hook and ring mechanisms, and the like. A common problem with clevis and tongue connections is that the draw pin holes in the upper and lower clevis members and the draw pin hole in the tongue extending between them are very often of different sizes.
For example in agricultural, an implement is typically hitched to a tractor drawbar by a clevis and tongue connection. The clevis provides an upper and lower clevis members each defining a draw pin hole, and the tongue defines a draw pin hole and is inserted between the clevis members to align the draw pin holes such that a draw pin can be inserted through them and thereby connect the clevis and tongue. Where the draw pin holes are the same size, a corresponding size of draw pin can be inserted to connect the clevis and tongue in the preferred manner such that there is only minimal movement at the connection.
The clevis may be mounted to the tractor drawbar and the tongue mounted to the implement hitch, or vice versa. Tractors come in a wide variety of sizes, and the draw pin hole is typically sized for a pin of sufficient strength to match the power of the tractor. Implements also come in a wide variety, and similarly have a hitch with a draw pin hole that is sized for a pin of sufficient strength to match the power requirement of the implement. Since there are typically a limited number of tractors on a farm that are required to tow a wide variety of implements, often the draw pin holes are of different sizes, and a draw pin that fits through the smaller of the holes must be used. The implement and tractor are thus connected by a loose fitting connection that allows significant movement. Control of the implement is thus reduced, and undesirable shock forces are exerted on the draw pin, implement hitch, and tractor drawbar during use, causing excessive wear.
Similarly trailers are commonly attached to a towing vehicle by a pintle hook and ring mechanism. The pintle hook is typically mounted to the towing vehicle, and a ring member is attached to the trailer hitch and drops over the ring member onto the pintle hook to connect the trailer and towing vehicle. The ring member defines a pintle hook aperture into which the pintle hook must fit. Similar to the clevis and tongue mechanism, it is desirable to have the pintle hook aperture fit the pintle hook quite closely.
This problem has been addressed for example in U.S. Pat. No. 5,671,938 to the present inventor Olson. The disclosed implement hitch provides a hitch member defining a draw pin hole that is adjustable by moving a back portion of the hitch member forward and rearward by securing a variety of spacers in the hitch member, or by securing in the hitch member an auxiliary member that defines a smaller draw pin hole. The disclosed hitch requires considerable machining to make, and as well it also requires a significant amount of time to change the size of the draw pin hole.
It is an object of the present invention to provide mechanism for connecting a towed vehicle to a towing vehicle that overcomes problems in the prior art.
The present invention provides, in a first embodiment, a hitch apparatus comprising a hitch member defining a draw pin hole extending substantially vertically therethrough. A hole adjusting member is movably attached to the hitch member such that a front end of the hole adjusting member can be moved forward and rearward. A threaded actuator is operative, when rotated in a first direction, to move the front end of the hole adjusting member forward to decrease a distance between a front edge of the pin hole and the front end of the hole adjusting member, and is operative, when rotated in a second direction, to move the front end of the hole adjusting member rearward to increase the distance between the front edge of the pin hole and the front end of the hole adjusting member.
The present invention provides, in a second embodiment, a hitch apparatus comprising a hitch member defining a draw pin hole extending substantially vertically therethrough. A hole adjusting member is movably attached to the hitch member and slopes upward and rear ward from the draw pin hole to an upright face of the hitch member. A threaded actuator bolt extends substantially vertically through a rear portion of the hole adjusting member, and a threaded end of the threaded actuator bolt is engaged in a threaded aperture. Rotating the threaded actuator in a first direction moves the rear end of the hole adjusting member down along the upright face and moves the front end of the hole adjusting member forward to decrease a distance between a front edge of the pin hole and the front end of the hole adjusting member, and rotating the threaded actuator in a second direction moves the rear end of the hole adjusting member up along the upright face and moves the front end of the hole adjusting member rearward to decrease the distance between the front edge of the pin hole and the front end of the hole adjusting member.
Thus the draw pin hole is adjusted by moving the hole adjusting member forward and rearward into or out of the hole to decrease and increase the distance between the front edge and the front end of the hole adjusting member, which then acts as the rear edge of the pin hole.
When an undersize draw pin is used, the front end of the hole adjusting member is moved forward to decrease the distance between the front edge and the rear edge of the pin hole and thus restrict movement of the draw pin in the draw pin hole. When a larger draw pin is used, the front end of the hole adjusting member is moved rearward to increase the distance between the front edge and the rear edge of the pin hole and thus allow the larger pin to be inserted. The hole adjusting member will typically be positioned such that the pin just fits between the front edge of the hole and the front end of the hole adjusting member, thereby restricting movement of the draw pin in the draw pin hole.
The apparatus is simple and economical, and can be adapted to a variety of hitching mechanisms and vehicles.
While the invention is claimed in the concluding portions hereof, preferred embodiments are provided in the accompanying detailed description which may be best understood in conjunction with the accompanying diagrams where like parts in each of the several diagrams are labeled with like numbers, and where:
The apparatus 1 comprises a hitch member 3 that defines a substantially vertical draw pin hole 5. A hole adjusting member 11 is movably attached to the hitch member 3 such that a front end 11F of the hole adjusting member 11 can be moved forward and rearward by rotating a threaded actuator, illustrated as bolt 15. The distance between the front edge of the pin hole 5 and the front end 11F of the hole adjusting member 11 is thus increased or decreased to accommodate draw pins of a variety of sizes.
In the embodiment of
In
In the illustrated embodiment the threaded actuator bolt 15 extends through a hole near the rear end 11R of the hole adjusting member 11 and down through a compression spring 17 and through another hole in the floor 13 of the recess 7A and into a nut 19. Alternatively a threaded hole could be provided in the floor 13. The configuration of the hole adjusting member 11 is such that the spring 17 biases the rear end 11R of the hole adjusting member 11 upward and also biases the front end 11F thereof downward. Conveniently, the bolt 15 could also be reversed so that the nut 19 was on top and the head of the bolt 15 could be a carriage head bolt recessed into the bottom of the hitch member 3 such that the nut 19, preferably a lock nut, could be turned to move the rear end 11R of the hole adjusting member 11 up or down without also requiring a wrench to be engaged on the bolt head.
The triangular configuration of the hole adjusting member 11, the face 8, and the floor 13 requires that as the rear end 11R of the hole adjusting member 11 moves down, the front end 11F thereof bears against the floor and is prevented from moving down, and so moves forward into the pin hole 5. Conversely, when the rear end 11R of the hole adjusting member 11 moves up, the front end 11F thereof moves rearward out of the hole 5.
While the hole adjusting member 11 is bent near each end, the actual distance between the front and rear ends 11F, 11R thereof is illustrated in
By turning the bolt 15 in the nut 19, the position of the front end 11F of the hole adjusting member 11 in the draw pin hole 5 can be adjusted, and effectively change the size of the draw pin hole 5. A draw pin that is somewhat smaller in diameter than the draw pin hole 5, is thus prevented from moving forward and rearward in the draw pin hole 5, reducing shock forces on the apparatus 1 and draw pin and increasing control of a towed vehicle.
When towing an implement, trailer, or like vehicle, the towing force is exerted in direction F against the front end of the draw pin hole 5 defined by the thick front portion 9 of the hitch member 3, and the hole adjusting member 11 is thus not subjected to significant forces during most operations. When operating in reverse, or during sharp turns, forces will be exerted on the front end 11F of the hole adjusting member 11, however such operations are usually done at lower speeds for only short periods of time. Also agricultural implements are not typically engaging the ground when moving in reverse, such that the reverse forces on the front end 11F of the hole adjusting member 11 are usually significantly less than forward towing forces. In any event the hole adjusting member and associated elements will be designed as required to provide the necessary service in the design application. The apparatus 1 can readily be scaled up or down as required for the particular application.
Alternate embodiments of the apparatus 101, 201 are illustrated in
The apparatus 101 illustrated in
The illustrated draw pin hole 105 is shown somewhat oblong, to allow for easier visibility and access to the carriage bolt 115, however it is contemplated that a circular draw pin hole could be used as well. It is contemplated that a flat headed bolt could be used instead of the illustrated carriage bolt 115 however the carriage bolt conveniently provides a rounded head 123 and a square shank that is available for engagement by a wrench for adjustment. A lock nut can be provided to more securely retain the carriage bolt 123, or like threaded member, in the threaded hole 119 at the desired location.
A threaded actuator, illustrated as a set screw 215, is threaded into each threaded hole 219 and has a head 223 that is shown extending into the rear portion of the draw pin hole 205 at an angle as illustrated. The set screw 215 has a hexagonal or like recess in the end of the head 223 for engaging with a wrench. By turning the set screws 215 into or out of the threaded holes 219, the position of the heads 223 in the draw pin hole 205 can be adjusted, and effectively change the size of the draw pin hole 205. The longitudinal axes of the first and second threaded holes 219 are oriented to intersect at a location inside the draw pin hole 205, such that the heads 223 bear against laterally spaced rear areas of the drawbar pin 225. Thus a draw pin 225, that is somewhat smaller in diameter than the draw pin hole 205, is prevented from moving forward and rearward in the draw pin hole 205, as in the embodiment of
The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous changes and modifications will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all such suitable changes or modifications in structure or operation which may be resorted to are intended to fall within the scope of the claimed invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2,538,765 | Mar 2006 | CA | national |
The present application claims priority to Canadian Patent Application Serial No. 2,538,765, filed Mar. 7, 2006, and to U.S. Provisional Application Ser. No. 60/709,441, filed Aug. 19, 2005, both which are hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60709441 | Aug 2005 | US |
