Patent GB-501100-A (GB)
Title: Improvements in and relating to automatic devices for supplying liquid under pressure
IPC: B64C25/22
Filed: 1938-03-31
Abstract: 501,100. Reciprocating pumps. BOYSSON, J. B. A. DE. March 31, 1938, No. 9844. [Class 102 (i)] [Also in Group XXIX] Fluid under pressure is automatically supplied by a device comprising a body containing a spring- pressed piston having beneath it an accumulator chamber connectible, 'for a given pressure, with the pressure fluid supply, the pressure existing in the chamber controlling directly the actuation of the pump supplying the pressure fluid and an automatically controlled connection being provided between the accumulator and a discharge device when the pressure in the accumulator exceeds a predetermined value to limit, by disengagement of the pump, the maximum pressure of the supplied fuel while the re-engagement of the pump is produced directly by the fluid from the accumulator. A pump supplying fluid to a pressure system is controlled by a valve device in a casing 8 to which it supplies fluid through a pipe 32. The fluid raises a spring-pressed valve 29 and enters an accumulator chamber 10 formed in a piston 9 which is thereby lifted in the casing 8, against the pressure of a spring or a resilient fluid in the space 12 above, the piston. In rising, the piston engages the head 15 of the stem 16 of a valve 17 and a collar 28 on the stern engages the valve 29 to keep it open. The stem 16 passes through a channel 22 and a sleeve 21 on a box 19 opening into a lower compartment 20 and urged downwards by a spring 23, the pressure fluid thus entering the compartment 20. This pressure in the box 19 holds on to its seat, over the end of an outlet pipe 26, a valve 24 having limited sliding movement through the base of the box 19. As the piston 9 lifts the valve 17, the valve engages a seat 18 at the top of the box 19 to cut off the chamber 20 from the channel 22 and chamber 10, and further movement of the piston lifts the box 19 until the box raises the valve 24 from its seat releasing the pressure in the compartment 20. A pipe 46 leads from this compartment to a cylinder in the pump and the pressure reduction in this cylinder permits a spring to disengage the clutch connecting the pump to its driving motor. As the pressure in the supply pipe 32 falls due to use of the fluid, the piston 9 descends, the valve 29 is held off its seat by the shoulder 28 on the stem 16. of the valve 17 until the shoulder descends below the seat of the valve, the box 19 is lowered permitting the valve 24 to seat itself and finally the valve 17 leaves its seat 18, putting the compartment 20 into communication with the pressure accumulator chamber 10. This pressure is communicated to a cylinder 43, Fig. 4, in a fixed bearing 36 in the pump and displaces outwardly a piston 42 solid with the inner member 41 of a cone clutch, the outer member 50 of which is rigid with the driving shaft 51. The pump comprises a block 35 integral with the clutch member 41 and carrying radial cylinders in which operate pistons 39. The piston heads are domed to engage a toric groove in an idle liner 54 forming the inner part of an eccentric roller bearing race secured by its outer member 40 to the pump casing and the engagement of the heads with the groove is such that the pistons are rotated in their cylinders as they turn bodily about the fixed support 36. At starting, a hand pump connected to the pipe 46 builds up pressure in the compartment 20.