Patent ID: 7540524

Claim:
A device for detecting a support load between a trailer vehicle and a tractor vehicle, comprising: said trailer vehicle having a forwardly projecting tongue; a horizontal, transverse pivot shaft being fixed to said tongue; a fore-and-aft extending first coupling element having a location intermediate front and rear ends of said coupling element pivotably coupled to said pivot shaft such as to be pivotable about said pivot shaft; a sensor arranged between the rear end of said first coupling element and the tongue to detect a vertical force component acting therebetween; a second coupling element mounted to a rear end of said tractor vehicle configured to be detachably connected to the front end of said first coupling element such that the first coupling element is movable about an axis running parallel to the pivot shaft, wherein the axis and the pivot shaft are both at least approximately located within a common horizontal plane; said rear end of said first coupling element having a downwardly facing surface; a fore-and-aft extending third element having a forward end disposed beneath, and including an upwardly facing surface disposed in confronting relationship to said downwardly facing surface of said first coupling element; said sensor being one of a force measuring cell or a wire strain gauge located between said downwardly and upwardly facing surfaces and having top and bottom surfaces respectively fixed to said downwardly and upwardly facing surfaces; and said tongue being provided with vertically spaced, lower and upper stops respectively located above and below a rear end of said third element, with said rear end of said third element being located between, and free of, said stops when said trailer vehicle exerts a support load of approximately zero on said second coupling element, and with the third element resting on the lower stop in the case of downwardly directed support loads being imposed on said second coupling element by said trailer.