Improvements in counter-balancing means for pivotally mounted ramps, doors, tailboards and the like

摘要

844,855. Springs. THORNE, I. J. Nov. 25, 1957 [Aug. 23, 1956], No. 25813/56. Class 108(3). [Also in Group XXV] A multiple spring arrangement has the resilient members arranged coaxially and in such a manner that they are brought into action successively. As applied to counter balancing means for the tailboard ramp 2 of a vehicle or container 1 the arrangement comprises two springs 7 and 8 which are disposed within a tubular casing 5 secured to the vehicle body. A plunger 13 rests on the lower spring 7 and is connected to the ramp by a folding link 16, 16a. The upper spring 8 is carried between an abutment 14 on the upper end of a rod 12 secured to the plunger and a sleeve 10 slidable both on the rod and, to a limited extent in the downward direction, within a collar 6 carried on the casing 5. As the ramp is lowered the plunger and the sleeve descend, compressing the spring 7, until a shoulder on the sleeve abuts the collar 6 to arrest the downward movement of the sleeve. Further lowering of the ramp compresses both springs.