Patent GB-751384-A (GB)
Title: Improvements in or relating to multispeed drive mechanism
IPC: B30B1/26
Filed: 1954-02-19
Abstract: 751,384. Controlling change-speed gearing: friction clutches. U.S. INDUSTRIES, Inc. Feb. 19, 1954 [July 16, 1953], No. 4934/54. Class 80(2) [Also in Group XXXIV] Change-speed planetary gearing for a metal drawing press comprises a driving flywheel 10 fast with a sun gear 12, planet gears 39 on a carrier 34 fast with a driven shaft 4, and an internally toothed annulus 55, rotated solidly with the flywheel for direct drive when a pneumatically - operated clutch 1 is engagec and held stationary for reduced drive when s pneumatically - operated brake 2 is engaged. A pneumaticallyoperated brake 3 is engaged to hold the driven shaft 4, and the press slide which it drives, stationary when the clutch 1 and brake 2 are both disengaged. The clutch 1 comprises segment-shaped friction elements 52, on a flange of a member 42, engaged by the movement to the right of Fig. 1 of a ring 18 having projections 19 connected to a ring 21 in an annular cylinder to which compressed air is admitted through ducts (not shown). A flexible diaphragm 24 covers the ring 21. The clutch is normally biased to the disengaged position by springs (not shown) spaced between the projections 19 and bearing on the ring 21. The brake 2 is similarly pneumatically-operated, the member 42 having a flange 50 engaged by friction members 63, &c., in a non-rotating ring 58. The brake 3 is normally biased to the engaged position by springs and is disengaged by admitting compressed air to move a ring piston 76, &c. The compressed air for controlling the metal drawing press is fed from a pipe 88, Fig. 11, first to a tank 89, where a solenoid-actuated three way valve 100 controls the engagement of the annulus brake 2. The compressed air is fed from the tank 89 to a tank 91 where a similar three-way solenoid actuated valve 104 controls the engagement of the shaft brake 3. Compressed air is also fed from the pipe 88 to a tank 95, Fig. 10, whence a solenoid-actuated three-way valve 96 controls its supply to the annulus clutch 1. With the three valves 96, 100, 104 in the closed position, the annulus clutch 1 and brake 2 will be held disengaged by their respective springs and the brake 3 will be similarly engaged to hold the driven shaft 4 stationary. Assuming the press slide is in its uppermost position, the valves 104. 96 are opened to disengage the brake 3 and engage the annulus clutch 1. The shaft 4 is then directly driven by the driving flywheel 10 and the press slide moves rapidly downwards. As soon as the metal drawing operation begins, the valve 96 is operated to disengage the annulus clutch 1 and the valve 100 is operated to engage the annulus brake 2, so that the gearing gives a reduced drive. The press slide is therefore moved slowly to the bottom of its stroke while the drawing operation is performed. When the slide reaches the bottom of its stroke, the valves 96, 100 are again operated to engage direct drive and return the slide rapidly to its initial position, when the brake 3 is applied and the annulus clutch 1 and brake 2 are disengaged. The reduced speed may also be used for inching the press slide towards its bed.