Patent GB-333536-A (GB)
Title: Improvements in lifeguards or obstruction-removers for motor road and other vehicles
IPC: B60R21/34
Filed: 1929-05-13
Abstract: 333,536. Clifford, V. J. May 13, 1929. Obstruction-removers and safety appliances. - In a lift-guard or obstructionremover for motor and other vehicles of the type in which an elevated roller carried in a frame in front of the vehicle is adapted to be lowered and rotated in an opposite direction to that of the road wheels when the roller itself or some projection comes into contact with an obstruction, the release of the frame is effected either bv the driver or bv an eccentric or like means mounted on the roller or roller shaft and actuating frame-supporting catch members through rods or the like so that in the first revolution of the roller under the action of a motor, springs, or other means set into operation by the rearward movement of the roller, the frame is released, permitting the roller to fall into the lower operative position where rotation is maintained. In the construction shown the roller spindle 19 is carried by the front end of a frame 11 pivoted to brackets on the chassis and a transverse stay rod 20 of the frame extends through slots in stirrups 23 and carries pivoted plates 35 connected by a latch pin which engages a slot 43 in one stirrup. When the roller is struck, the bearings 27 of the roller spindle move in a rearward direction against the action of compression springs 28 to an extent sufficient to force a rod 46, Fig. 3, connected with an eccentric 49 on the spindle 19, to bear against one arm of a lever 38 so as to close the switch 37, 39 of an electric motor which drives the roller 24. During the first rotation the eccentric pushes the rod 46 against a pin 47 on the plate 35 and releases the latch-pin 42 from the slot 43 so that the whole device falls to the bottom of the stirrup. A projection at the lower end of the stirrup 23 cooperates with a cam surface on the back-plate 35 so as to turn the latch gear away from the end of the reciprocating rod 46 when the device is falling. The other arm of the lever 38 normally engages a recessed collar 54 on the stay rod 20, so as to hold the latch gear against displacement. Preferably the roller 24 is driven from the motor through flexible shafting 32 actuating bevel gearing or worm gearing, but it may be driven from the road wheels or other moving part of the vehicle. The switch 37, 39, the driver's switch and the engine switch are so connected that the apparatus is ready for action when the vehicle engine is running and the latter cannot be started without completing the circuit to the life-guard motor. In returning the mechanism to the normal position a spring 66 may be used to assist the latch pin 42 to engage the slot 43. Springs may also be employed to give when released an initial rotation to the roller before the drive from the motor becomes effective. Shields or guards may be provided in conjunction with the roller which may be formed in sections and constructed of corrugated aluminium sheet, &c. The driving motor may be associated with the frame, in which case the flexible driving shaft may be dispensed with. Specification 280,344 is referred to.