GB764908A - Improvements in or relating to portable internal combustion ramming tools - Google Patents

Abstract

764,908. Direct-acting engines, carburetters, starting. WAMPACH, A. N. April 21, 1953 [April 23, 1952], No. 10883/53. Classes 7 (2), 7 (3) and 7 (5). In a portable ramming-tool in which the suction of the fuel mixture, the ramming stroke and the evacuation of the exhaust gases are carried out by a single piston 1, a tension spring 5 for effecting the recoil of the piston is housed in a tubular rod 6 slidable in a tubular percussion bar 2. The lower end of the spring 5 is attached at 7 to the lower end of the rod 6 and the upper end of the spring is anchored as by a pin 5a to the upper end of the bar 2. As shown, the foot 14 of the tool incorporates vibration - absorbing, rubber rings 32 and is secured by a pin 13 to the bar 2, that pin also anchoring the lower end of a tension spring 12 disposed within the bar. A tank 20 is provided for liquid fuel which is vaporized along the surface of wicks 26 suspended from a plate 27. Primary air is admitted through an opening 28 closable by a plate 29, the air circulating between the wicks 26 and the resulting fuel-air mixture passing along a pipe 23, through an admission valve 24 and to a combustion chamber 22. There is an adjustable valve 25 for secondary air in the pipe 23, and ignition of the fuel-air mixture is by means of a sparking plug 18 and a magneto, the electrical circuit being controlled by a lever 19 mounted on an operating stirrup 8. Secured to the stirrup 8 is a push rod 3 comprising parts 3a, 4, the part 4 being spring- loaded and slidable in the part 3a and having a conical face co-operating with a spring- loaded catch 9 engageable under the lower end 10 of the part 3a. The catch 9 prevents the stirrup 8 being inadvertently moved downwards until the piston 1 has been completely pushed back toward the head 16 and to release the catch by contact with the part 4. In operation, the piston 1, together with the bar 6, is pushed downwards by the rod 3 to suck in fuel-air mixture through the valve 24, the mixture being ignited and the effect of the resulting explosion throwing the whole body of the tool upwards whereby the piston 1 and the bar 2 move downwards until ports 30 are uncovered by the piston to allow the exhaust gases to escape from the cylinder 21. During the upward movement of the tool the bar 2 and the foot 14 leave the body of the tool to stretch the spring 12 which returns the bar and foot before the tool falls back to the ground. Simultaneously, the spring 5 returns the piston 1 towards the head 16 and to force residual exhaust gases through orifices 11 in the part 4.