GB217366A - An automatic scotch for preventing vehicles running back on gradients - Google Patents

Abstract

217,366. Thomas, W., and Thomas, W. P. April 7, 1923. Scotch blocks and scotching-appliances; skid.-One or more shoes are each freely suspended on a link and one arm of a bellcrank lever, the other arm of which supports a slidable rod having a roller adapted to rest on the ground when the device is in use and pointed ends adapted to engage the ground when the vehicle moves backwards so as to turn the bell-crank lever and insert the shoe. or shoes between the ground and the back of the wheel. Each shoe 1 is carried by the lower end of a link 2, the upper slotted end 3 of which is pivoted to the vehicle frame, and by the slotted end 7 of one arm 8 of a bell-crank lever mounted on a transverse shaft 9. The other arm 13 of the lever 8 carries a weight 13<a> and also a pivoted bracket 14, through which slides the upper end of a rod 15 surrounded by a spring and provided at the lower end with a forked extension 16 in which is mounted a roller 18 provided with a ratchet so that it turns in one direction only. The, ends of the forked extension are spear-shaped and are slotted to take the roller spindle 19, which is connected at the ends by hooked rods 22 to pivoted levers 24 connected in turn to a rod 26 supported by a strap on the pivot of the bracket 14. Cords 30, 32 are attached to the rod 15 and to the end of the arm 13 respectively and serve to lift the device clear of the ground. When the device is lowered and the vehicle is going up hill the roller will trail and support the shoe, as shown in Fig. 1. If the vehicle reverses, the roller slides up in the slots and the sharpened ends 13 of the rod dig into the ground. Further backward movement causes the rod to slide in the bracket 14 and the shoe to engage the wheel.