GB408900A - Lathes or like machine-tools having air-operated chucks - Google Patents

Abstract

408,900. Fluid - actuated valves. HERBERT, SIR A., and LLOYD, A. H., c/o Herbert, Ltd., Canal Road, Edgwick, Coventry. Nov. 10, 1933, No. 31355. [Class 135.] In a control valve for the air supply to a fluid-operated chuck, such as that described in Specification 383,234, [Group XXII], a supply pipe 11 leads to a filtering chamber 14 provided with a drain plug 15 and thence to a handoperated control valve 18. In the position shown, air passes to a lightly loaded reducing valve 24 which supplies air at a slightly reduced pressure to the outlet 29 for giving a high gripping pressure to the chuck. In the other position of the valve 18, air passes through a plug 21 and one or more of the bleed-ducts 23 to a heavily loaded reducing valve 25 which supplies air at a greatly reduced pressure to the outlet 29 for causing the chuck to grip lightly, such as for finished work &c. Both valves 24, 25 are adjustable by screws 26 and the light gripping pressure may be finely adjusted to compensate for variations in the supply pressure by screwing the plug 21 in or out and thus altering the number of ducts 23 in use. A pressure gauge is mounted in the space 27<1> between the valves 24, 25 to indicate the pressure of flow through either of these valves, the space being momentarily exhausted through a passage 30 each time the valve 18 is moved from one position to the other. The outlet 29 leads to a distributing valve 33 communicating with opposite ends of the chuck cylinder.