Patent GB-1263296-A (GB)
Title: Improvements in or relating to the firing of a fuel or a monofuel
Inventor: KAHN PETER BRUNO
IPC: F23Q1/06
Filed: 1968-04-04
Abstract: 1,263,296. Combustion apparatus. PLESSEY CO.Ltd. March 27, 1969 [April 4, 1968; Feb.27, 1969], Nos. 8345/69 and 10476/69. Heading F1L. The invention relates to a device for firing a monofuel or a fuel and gas mixture in which monofuel or fuel and gas mixture is supplied to a breech, the monofuel or fuel and gas mixture then being compressed by means of a spring-loaded firing pin to establish spontaneous firing conditions, the firing pin being released by trigger action and being moved back by the pressure developed in the breech consequent upon the firing. The device shown in Fig. 1 operates with monofuel such as isopropyl nitrate and comprises an operating piston 6. The device comprises a cylinder 1 which is divided by a partition 14 into a reaction chamber 17 and a chamber 5 in which the spring-loaded operating piston 6 is disposed. A passage 15 is formed in the partition 14 whereby gases from the chamber 17 may pass to the chamber 5 to drive the piston 6. A breech 16 is also formed in the partition 14 and communicates with the chamber 17. A piston 21 is disposed in the chamber 17 and comprises a rod 18 which constitutes a firing pin which is aligned with the breech 16. The piston 21 is held in the position shown by means of a detent wheel 22 which is releasable by a trigger 20. In the position shown the reaction chamber 17 and breech 16 are filled with monofuel. When the trigger is operated the piston 21 and firing pin move to the right under action of the spring 19, the firing pin enters the breech pressurizing the monofuel which fires, the resulting increase in pressure and temperature causing the firing pin and piston to move back against the action of the spring 19, the main charge of monofuel in the chamber 17 being fired by the gases from the breech 16. The resulting gases pass through passage 15 and drive the piston. Monofuel is supplied from reservoir 3 to the reaction chamber 17 and breech 16 by means of a plunger pump 4 which comprises a cylinder 25 and piston 26, the piston being pressed in manually against action of a spring 27 whereby monofuel flows through opening 28 into the cylinder space 25a. When the piston moves outwardly by action of the spring 27 monofuel flows through opening 29 and line 39 to the reaction chamber 17 and then through opening 29a and line 40 to the breech 16. Non-return valves 35, 37, 37a are provided at the openings 28, 29, 29a. The amount of monofuel supplied to the chamber 17 may be controlled by adjustment of a stop nut 38 which limits inward movement of the piston. In Fig. 2 the breech is indicated at 45 being formed in a partition member 14 as in the first embodiment but in this case being formed as a through-bore which is normally closed at its lower end by a boss 46 formed on the working piston 6. In this case the firing pin 18 is normally entered into the breech, the firing pin being integral with a rod 43 which is held in its cocked position by means of a spring-loaded trigger 32 which engages the lower side of spring abutment 42. Monofuel is supplied to the breech 45 through line 39 and to the main reaction chamber 9 through line 40, the chamber 9 being formed by an annular recess in the upper face of the working piston 6. When the trigger 32 is released the firing pin 18 moves rapidly into the breech 45 thus firing the monofuel, the resulting pressure returning the firing pin to its initial position where it is again held by the trigger, also acting on the boss 46 causing the piston 6 to move downwardly so that the decomposition gases act on the monofuel in the main reaction chamber 9 which is thus fired, the resulting gases driving the piston 6 downwardly for its working stroke against the action of the spring 7. The gases are released to atmosphere through port 65 and valve 67 at the end of the power stroke. The charging pump is shown in Fig. 3 and comprises a main piston 52 disposed in a bore in cylinder 4, an auxiliary piston 54 being mounted for axial movement within bore 53 of the main piston. Monofuel is supplied through inlet 35, and monofuel discharges through outlet 37 to the breech 45 and through outlet 37a to the main reaction chamber 9. Downward movement of the plunger 23 causes the auxiliary piston 54 to move into the bore 53 of the main piston until the shoulder 58 abuts the main piston thus causing monofuel to discharge through outlet 37. Continued movement of the plunger 23 causes the auxiliary piston 54 and main piston 52 to move together downwardly drawing monofuel into the space 59. Return movement of the pistons by the spring 27 causes monofuel to be discharged through outlet 37a also re-charging the bore 53 below the auxiliary piston 54.