초록 ▼

To help hold a (trailer) bed of a truck or trailer steady at a loading dock as the truck is being loaded or unloaded of its cargo, a yieldable vehicle brace exerts a substantial, but limited, reactive force upward against the trailer's rear impact guard to resist the trailer's downward movement. In

To help hold a (trailer) bed of a truck or trailer steady at a loading dock as the truck is being loaded or unloaded of its cargo, a yieldable vehicle brace exerts a substantial, but limited, reactive force upward against the trailer's rear impact guard to resist the trailer's downward movement. In some embodiments, the brace holds the trailer bed stationary up to a certain load limit and provides the trailer bed with a controlled or dampened descent when the load exceeds that limit. In some cases, the reactive upward force exerted by the brace increases with the downward velocity of the trailer bed. The reactive force can be created by one or more pressure relief valves, hydraulic fluid passing through a flow restriction, a brake, a spring, or various combination thereof. Some embodiments of the brace include provisions for accommodating horizontal movement of the rear impact guard.

대표청구항 ▼

We claim: 1. A method of operating a vehicle brace engagable adjacent a vehicle's rear edge as material handling equipment traverses the rear edge while accessing the vehicle, the method comprising: continuously exerting an upward biasing force on the vehicle brace by way of a first actuation syste

We claim: 1. A method of operating a vehicle brace engagable adjacent a vehicle's rear edge as material handling equipment traverses the rear edge while accessing the vehicle, the method comprising: continuously exerting an upward biasing force on the vehicle brace by way of a first actuation system, wherein the upward biasing force is greater than the weight of the vehicle brace such that the vehicle brace is continuously biased to a raised position but that the upward biasing force does not substantially influence vertical movement of the vehicle brace when the vehicle brace is being engaged by a vehicle; selectively causing, by way of a second actuation system, the vehicle brace to apply a reactive upward force separate from the upward biasing force and adjacent the vehicle's rear edge, wherein the reactive upward force substantially reduces downward movement of the vehicle's rear edge that would result from the applied weight of the material handling equipment in the absence of the reactive upward force; limiting the reactive upward force to a predetermined upper limit; and wherein the reactive upward force reduces downward movement of the vehicle's rear edge by being substantially equal to a downward force resulting from the weight of the material handling equipment until the reactive upward force reaches the predetermined upper limit. 2. The method of claim 1, further comprising allowing the brace to yield for a reactive upward force that exceeds the predetermined upper limit. 3. The method of claim 1, wherein the reactive upward force is created by preventing movement of the brace until the reactive upward force reaches the predetermined upper limit. 4. The method of claim 1, further comprising increasing the reactive upward force in response to an increase in a rate of descent of the vehicle's rear edge. 5. The method of claim 4, wherein increasing the reactive upward force is carried out by forcing fluid through a flow restriction. 6. The method of claim 1, wherein causing the vehicle brace to exert a reactive upward force is carried out by applying frictional drag. 7. The method of claim 1, further comprising sensing when the vehicle is about to be loaded or unloaded. 8. The method of claim 1, further comprising raising a vehicle restraining member to limit horizontal movement of the vehicle. 9. The method of claim 1, further comprising permitting the vehicle brace to be lowered to a preparatory position upon interaction with the vehicle, prior to selectively causing the vehicle brace to apply the reactive upward force. 10. The method of claim 1, wherein the first actuation system comprises a spring and the second actuation system comprises an actuator. 11. The method of claim 1, further comprising positioning nonmovably one end of each of the first and second actuation systems. 12. A method of operating a vehicle brace engagable adjacent a vehicle's rear edge as material handling equipment traverses the rear edge while accessing the vehicle, the method comprising: biasing the vehicle brace to a raised position by continuously exerting on the brace an upward biasing force that exceeds the weight of the vehicle brace; permitting the vehicle brace to be pushed down to a preparatory position by horizontal movement of the vehicle as the vehicle moves toward the loading dock and is in engagement with the vehicle brace; selectively causing the vehicle brace to apply a reactive upward force adjacent the vehicle's rear edge, wherein the reactive upward force is to reduce downward movement of the vehicle's rear edge that would result from the applied weight of the material handling equipment in the absence of the reactive upward force; limiting the reactive upward force to a predetermined upper limit; and wherein the reactive upward force is to reduce downward movement of the vehicle's rear edge by being substantially equal to a downward force resulting from the weight of the material handling equipment until the reactive upward force reaches the predetermined upper limit. 13. The method of claim 12, further comprising allowing the brace to yield for a reactive upward force that exceeds the predetermined upper limit. 14. The method of claim 12, wherein the reactive upward force is created by preventing movement of the brace until the reactive upward force reaches the predetermined upper limit. 15. The method of claim 12, further comprising increasing the reactive upward force in response to an increase in a rate of descent of the vehicle's rear edge. 16. The method of claim 15, wherein increasing the reactive upward force comprises forcing fluid through a flow restriction. 17. The method of claim 12, further comprising raising a vehicle restraining member to limit horizontal movement of the vehicle. 18. The method of claim 12, wherein engagement of the vehicle with a sloped guide surface of the vehicle brace during horizontal movement of the vehicle pushes the vehicle brace down to a preparatory position. 19. A method of operating a vehicle brace engagable adjacent a vehicle's rear edge as material handling equipment traverses the rear edge while accessing the vehicle, the method comprising: biasing, by way of a first actuation system, a support member to a raised position by continuously exerting on the support member an upward biasing force; selectively causing, by way of a variable length second actuation system, the support member to exert a reactive upward force against the vehicle's rear edge to appreciably and controllably slow the descent of the vehicle; controlling, by way of a control system, a magnitude of the reactive upward force; limiting the reactive upward force to a predetermined upper limit; and wherein the reactive upward force is to reduce downward movement of the vehicle's rear edge by being substantially equal to a downward force resulting from the weight of the material handling equipment until the reactive upward force reaches the predetermined upper limit. 20. The method of claim 19, further comprising allowing the support member to yield for a reactive upward force that exceeds the predetermined upper limit. 21. The method of claim 19, wherein the reactive upward force is created by preventing movement of the support member until the reactive upward force reaches the predetermined upper limit. 22. The method of claim 19, further comprising increasing the reactive upward force in response to an increase in a rate of descent of the vehicle's rear edge. 23. The method of claim 19, further comprising raising a vehicle restraining member to limit horizontal movement of the vehicle.