Patent GB-403084-A (GB)
Title: Improvements in or relating to starting and stopping mechanism of power driven machines
IPC: B30B15/28
Filed: 1932-06-11
Abstract: 403,084. Cutting - out presses. BRITISH UNITED SHOE MACHINERY CO., Ltd., and KEALL, F. B., Belgrave Road, Leicester. June 11, 1932, No. 16528. [Class 31 (i).] In a cutting-out press or like power-driven machine started by depressing a treadle 32 and stopped at the end of a revolution by the automatic disengagement of a clutch and application of a brake-band 26, the application of the brake is effected by a member 44 which partakes of the motion of the crosshead 16 and also has a component of movement transverse thereto so that the member continues to move to apply the brake further after the beam 10, which is connected to the crosshead, has passed its desired stopping position. The clutch is engaged through linkage 104, 106, Fig. 1, by a spring 70 held in tension by a pivoted latch 36, Fig. 2, retaining an arm 30 on a rock-shaft 34 to which the clutch linkage is connected through a vertical rod 103 and an arm 102 rigid with the arm 30. Depression of the treadle 32, which is freely mounted on the rock-shaft, acts through a bar 54 pivoted on an arm secured to the treadle to trip the latch 36 and allow the clutch to engage. The latch 36 is connected through linkage 40, 42, 46, 48 with the pin 44 which is mounted on one side of the eccentric-strap 18 which reciprocates the crosshead 16, and is so caused to move downwards to pick up the clutch-and-brake arm 30 which it subsequently lifts to disengage the clutch and apply the brake, this operation being assisted by the transverse component of the elliptical motion of the pin 44. The latch 36 is pressed towards the clutch arm 30 by a tension spring 50 connected to an arm 52 rigid with the trip-rod 54, the spring 50 also serving to hold this trip-rod up against a pin 56 on the cross-head 16. The pin 56 serves to depress the end of the trip-rod 54 to a position out of alignment with an abutment-face 63 associated with the latch 36 which face it must engage to trip the latch, so that the machine cannot perform another revolution unless the treadle is fully released and again depressed. If, through maladjustment of the brake, the machine repeatedly stops beyond the desired position, the trip-rod 54 is finally pushed so low by the cross-head pin 56 that it is out of alignment with the latch abutment-face 63 and the machine cannot then be restarted until the brake band has been adjusted by means of nuts 88. The abutment-face 63 is carried on a rod 74 which has a pin-and-slot engagement 66 with the latch 36 and is held up by a spring- pulled rod 16. The rod 74 has a handle 90 and can be moved by the operator into a lower notch 77 in a guide-plate to pivot it about the pin 66 and move its abutment-face 63 to a " safe position out of alignment with the trip-rod 54 and so prevent restarting of the machine. The handle 90 also permits of pulling out the abutment-face 63 to allow restarting of the machine after it has been rendered inoperative due to excessive overrun. In order positively to move the hook 72 of the latch 36 under the clutch arm 30 if the spring 50 fails, a wedge part 60 rotating with the driving-shaft 22 strikes an incline 62 on the latch. A further safety device which positively prevents the descent of an overrunning beam beyond a safe limit comprises a lateral wedging surface 82, Fig. 3, on the brake drum 24 cooperating with a similar surface 80 on a pivoted lever 78 moved out of the path of the wedge 82 during the operative stroke by connection through links 84, 85 with the toggle mechanism 31, 29, 28 for operating the brake. Means are also provided for disengaging the clutch at any desired point before and independent of the brake actuation, such means comprising a cam 108, Fig. 1, on the main-shaft 22, acting through a pivoted lever 109 on a vertical rod 110, Fig. 2, attached loosely to the clutchoperating arm 102. The lifting effect of the cam on the arm is only sufficient to disengage the clutch without affecting the brake. In a modification the spring 50 is arranged between the latch 36 and the clutch-arm 30, the triprod 54 having an inclined slot connecting it with the cross-head pin 56. Specifications 14413/11, 5896/12, and 4833/13, [all in Class 103 (i), Brakes &c.], are referred to.