| 摘要 |
<p>1,240,097. Controlling pneumatic balance hoists. INGERSOLL-RAND CO. 19 Feb., 1970 [10 April, 1969], No. 8038/70. Heading B8B. [Also in Division G3] A pendant control for a pneumatically operated balance hoist comprises an element 39, rotatable relative to the control casing 7 such that one of a plurality of pairs of balls 45 loaded by pre-set adjustable springs may be brought into loading engagement with diaphragm valves 16, 17 which regulate the pilot air bleed rate, and therefore the pressure in a pilot line 2 controlling the main balance pressure for the hoist, the valve 16 or 17, or an exhaust port 11 being connectable to the line 2 by manual movement of a cap valve 21. The latter, slidable within an exhaust chamber 10 of the control, comprises opposed telescoping caps 21, 23, spring biased apart, and the manual operating lever is spring biased away from its exhaust position. An exhaust passage 12 formed in the pendant handle communicates with the cap valve exhaust port 11 which includes a needle valve for adjusting the exhaust pressure, and an exhaust port 19 which through chamber 10 communicates with exhaust ports 18 from the regulator valves 16, 17. A latch piston is operated by the pilot pressure to lock the element 39 against rotation during operation.</p> |
