GB205136A - Improvements in hydraulic pressure controlling and reversing mechanism for grinding machines and the like - Google Patents

Abstract

205,136. Bloxam, A. G., (Heald Machine Co.). June 9, 1922. Hydraulic transmission of power; speedvarying mechanism; liquid-pressure engines. -In hydraulic mechanism for reciprocating the tables of grinding machines or other machine parts, comprising a pump, cylinder and control valve, the latter is normally operated from the table &c. but may also be operated by hand; means are also pro vided for controlling the speed of the table, and for allowing the table to be withdrawn from working position at maximum speed irrespect.ve of the setting of the speed controlling means. The table is provided with adjustable dogs 22, 23, Fig. 2, adapted to rock a segment 21 pivoted at 17, Fig. 3, and having at its lower end a notch 15 normally engaged by a pin on a spring-pressed lever 11, which is trunnioned on the end of the control valve shaft 2. The shaft 2 has a depending projection 5 operating dash-pot plungers 7, and the segment is provided with a slideway for a spring- controlled pin 18, Fig. 4, having a triangular end to provide flattened surfaces cooperating with similar surfaces of a stationary member 19. The speed of the table is controlled by a throttle valve q with an operating lever s. Manual control of the table is obtained bv moving the lever 11 against the action of its spring until its pin is disengaged from the notch 15, after which the lever may be moved to stop or reverse the table. When the table is to be withdrawn from working position, the lever is moved into disengaged position, the stop 23 passes the segment without operating the valve, and a stop 24 finally forces the segment over and causes a pin 27 to force the lever into its neutral position. In order to effect this movement at maximum speed, the stop 23 is provided with a bar 28, which acts through a lever 29 and connections to move a plunger 35 to open a by-pass around the throttle valve.