Patent GB-937811-A (GB)
Title: Improvements in or relating to machines organised for applying pressure to shoe bottom parts
Inventor: KESTELL THOMAS AUBREY
IPC: A43D25/06
Filed: 1958-07-09
Abstract: 937,811. Shoe bottom presses. BRITISH UNITED SHOE MACHINERY CO. Ltd. Oct. 8, 1959 [July 9, 1958], No. 21965/58. Addition to 702,282. Class 17 (1). A machine for applying pressure to shoe bottoms has a pair of operating stations each including a pair of devices 2a, 4, 2b, 4, movable relatively to each other to apply pressure therebetween, power-operated means to effect such movement through mechanical connections to one of the devices 2a, 2b at each station, and yieldable means arranged to yield when the poweroperated means applies a predetermined pressure to the work and comprising an hydraulic device so interconnected with the poweroperated means as to enable it to yield whenever the means operates either of the devices connected therewith. The connections including a toggle T1, T2 for each station and these toggles being interconnected so that the two pair of devices may both be in operative position simultaneously and when one pair is in inoperative position the other pair is in operative position. Toggles T1, T2 are interconnected by levers 26a, 38a, 42 pivoted to the yielding device 10, 38b and 26b, and levers 26a, 26b are also pivoted to lugs 34a, 34b on hydraulic locking devices L1, L2. The toggles are operated by means of drive shaft 44 acting via crank 43, links 48a, 48b, levers 50a, 50b and links 58a, 58b. Lugs 34a, 34b form part of pistons 68 which move in the hydraulic cylinders 60a of locking devices L1, L2, a ball valve 80 controlling flow of fluid through the piston head. In Fig. 1, valve 80 is shown held in the open position by actuating rod 100 which is depressed by a rocker arm 118, the latter being locked in this position by engagement of a latch member 130a with a projection 128a on a lever 124a connected to the rocker. When this latching engagement is released, by engagement of a cam member 138a on the moving lever 50a with an arm 136a of latch member 130a, rod 100 is raised by spring 112, and valve 80 closed by spring 90. Movement of piston 68, and hence of device 2a is permitted when valve 80 is open, but resisted when the valve is closed. The yielding device 10 is similar to that shown in the parent Specification, having a cylinder 101, piston 111, and a valve 129 operated by a rod 163 which is normally urged downwardly by spring 161 but may be lifted by lever 171 controlled by cam 240. When compressed the device yields, if valve 129 is open, but becomes virtually solid if the valve is closed, the valve being adjustable by hand wheel 159, associated with a visual indicator to determine the pressure at which it will yield. To prevent fluttering a counteracting inertia mass 163a is loosely mounted on the rod. An outersleeve 185, providing a channel 193, and non-return valve 207 facilitate more speedy return of fluid between operations. Shaft 44 controlling crank 43 is driven via reduction gearing, including a gear-wheel 228 carrying cam discs 238, 240, and a clutch 208, 202a by a driven pulley 202. The clutch, which is normally urged to engaged position by spring 210, is controlled by cam 238 acting via roll 242, lever 244, latch member 250, and lever 212 to disengage the clutch at successive stages of the operation, and to engage element 208 with braking disc 226. The clutch is then reengaged to initiate the next stage by depression of a treadle which acts via rod 252, lever 256, and latch clearing member 260 to withdraw latch 250 from lever 212, springs 210 then moving member 208 to engage member 202a. As pad 2a or 2b attains raised position the respective lever 26a, 26b operates a microswitch MS1, MS2 which operates timing device T10, T20 and lights lamp L10, L20. De-illumination of lamp L10 or L20 indicates that the treadle should be operated to release the shoe. Alternatively, pad 2a or 2b may be withdrawn automatically by means of a solenoid S energized by the timing device T10, T20 and then actuating the clutch tripper lever 256. The clutch tripping means are inter-linked so as to prevent operation of the treadle when solenoid S is to be operated. The sequence of operations is as follows, with movement of the toggles controlled by crank 43 and operation of valve 129 controlled by earn 240. In the condition shown in Fig. 1, toggle T1 is collapsed and pad 2a lowered, latch 130a locks device L1 in open position, and device 10 is lightly closed. When the clutch is tripped crank 43 is rotated through 90 degrees, toggles T1, T2 are nearly straightened, and the reaction pressure set up via 38a &c., is balanced by the pressure exerted on a shoe on pad 2b or by engagement of lever 26b with stop 29b. The pressure applied through pad 2a, as determined by the setting of hand wheel 159, becomes effective just before pad 2a reaches the raised position (Fig. 2, not shown). Cam 138a actuates arm 136a to close device L1, in order to sustain the pressure on pad 2a when the balance of pressure through lever 38a &c. is removed by subsequent lowering of pad 2b. Toggle T2 is broken and pin 200b brings lever 124b into a position in which it is locked by latch 130b, thus securing device L2 in unlocked condition (i.e. as L1 is shown in Fig. 1). Toggle T1 is moved into and beyond the fully straightened position, imparting a positive squeezing upon the shoe on pad 2a. Subsequently toggle T2 straightens, raising pad 2b, and toggle T1 again passes into and beyond the extreme position and squeezes the shoe. Reaction pressure is again set up through lever 38b &c. and cam 138b. actuates arm 136b to lock device L2 in locking condition. As a safety measure cam 238 is shaped so as to disengage the clutch, after initial operation of the treadle, before the shoe is fully engaged with supports 4a, 4b to permit withdrawal of the hand of the operator, without injury, if it should be caught. Further depression of the treadle is then necessary to raise the pad fully.