Patent GB-320102-A (GB)
Title: Improvements in or relating to washing, bleaching and like machines
IPC: D06F37/36
Filed: 1928-07-03
Abstract: 320,102. British Launderers' Research Association, Parker, R. G., Jackman, D. N., and Hampson, R. E. V. July 3, 1928. Stopping or reversing machinery by movement of guards.-The drive to the rotary clothes container of a washing or like machine which is automatically reversed at predetermined intervals is automatically and periodically interrupted at predetermined times for periods of substantial length so that during periods the articles under treatment lie quietly in the treating fluid. The " rest periods " are additional to the momentary pauses occurring at the time of reversal the effect of the preserc mechanism being superimposed upon that of the automatically-reversed driving- gear. A " est period " may be provided either between each reversal or after several reversals. The mechanism for producing the " rest periods " is mechanically connected with the door of the stationary casing in which the clothes container rotates so that, if the door is opened during the operation of the machine. the mechanism is thrown out of action. In the form shown in Figs. 2 and 3, the shaft of the receptacle rotated within the stationary casing 10, Fig. 2, is geared to a shaft 13 having a fast pulley 15 and loose pulleys 16, 17 engaged by open and crossed belts 18, 19. The pulley 17 constantly drives a worm wheel 25 having a crank pin 24 engaging a slot in a lever 21 pivoted at 22 and provided with a pin 34 loosely engaging a recess 33 in a member 32, which is fast on a slidable rod 20 which carries the belt-shifter 30, A disc 38, having an upstanding cam 39 which engages under an extension 42 of the member 32, is removably secured to a ratchet disc 37 which is rotated by a pawl 44, Fig. 3, pivoted to a link 43 which is connected to the lever 21 by an adjustable lostmotion connection 45, 46, 47, Fig. 2, the length. of the aperture 45 in which the pin 46 on the lever 21 engages being variable by securing the plate 47 at different points along the link 43, thereby providing an adjustable drive to the ratchet disc 37 with consequent variation in the time of lifting of the member 32 by the cam 39. When such lifting occurs, the member 32 becomes disengaged from the pin 34 on the lever 21, and the spring 35, Fig. 2. moves the member 32, and consequently the rod 20 and belt-shifter 30, to neutral position, where it remains until, by the continued rotation of the ratchet and cam discs 37, 38, the cam 39 frees the extension 42 of the member 32, thereby permitting it to reengage the pin 34. Reverse rotation of the ratchet disc is prevented by a spring-pressed detent 40 housed in the cam disc and engaging a serrated plate 41 fast on the pin 36, around which the ratchet and cam discs are rotated. The pawl 44 is retracted from driving engagement with the ratchet disc 37 when the door of the stationary casing is opened, by the engagement of a rib 50 on the door with a lever 49 connected by a Bowden cable 48, Fig. 3, with the pawl, so that, if when the door is opened the belt shipper is in neutral position, it remains so. In a modification, Figs. 5 and 6, the pawl 44 is pivoted on a plate 51, Fig. 6, freely rotatable around the pin 36 and provided with a depending lug, not shown, engaged between two adjustable, pins 55, 56 on the link 43, whereby the drive to the ratchet discs 37 may be adjusted. The pawl is provided with a tail 60 which is engaged by the internal cam surface of a segmental plate 57 pivoted at 58. A spring 62 tends to swing the plate 57 to disconnect the pawl from the ratchet wheel, but a bell-crank lever 65, Fig. 5, connected to the door of the casing by a cable 68 and engaging a hole 63, Fig. 6, in the plate, normally prevents the spring from functioning. In addition to the adjustment permitted by the pins 55, 56, the amount of engagement between the pawl and ratchet teeth is controlled by the position of the plate 57. which is determined by the bell-crank lever 65, the maximum engagement being controlled by the position of an eccentric 70, Fig. 5, which engages the bell-crank. When the casing door is opened and tension on the cable 68 released, the spring 62 moves the segmental plate 57 clockwise to free the pawl 44 and disconnect the drive to the ratchet and cam discs 37, 38. In the form shown in Fig. 7, the rod 20 carries a member 72 integral therewith and formed with a shoulder 73 against which a roller 82 abuts. The lower end of the slidable vertical rod 81 on which the roller is mounted is secured to an arcuate cam 83 with which an eccentrically mounted roller 80 on a worm wheel 79 coacts to raise the rod 81 and so to rotate the rod 20, disengage the member 32 from the lever 21, and permit the spring 35. to move the rod 20 to neutral position. The worm wheel is driven from a loose pulley 17 through a spring clutch 77 which grips a sleeve 74 integrab with the loose pulley. One end of the spring is anchored to the worm 76 and the other end to a toothed wheel 78. The toothed wheel is held stationary to cause the spring to uncoil and disconnect the drive to the worm wheel when a lever 87 is caused to engage in one of the teeth. The lever 87 is linked by a rod 89 to another lever which is provided with a lug engaged by an abutment on the door of the stationary casing whilst the door is closed. As soon as the door is opened, the abutment clears the lug, the rod 89 falls under its own weight and thrusts the lever 87 into engagement with the toothed wheel 78. The rod 20 and associated parts are returned by a spring 84 after the roller 80 has cleared the cam 83. The means for producing the rest periods may be provided in a separate unit embodied in a countershaft as shown in Fig. 9. The countershaft 93 driven by a, fast pulley 94 drives a worm wheel 104 constantly and a pulley 95 through a coil spring clutch 101 The pullev 95 carries open and crossed belts. One end of the spring 101 is secured to the sleeve 96 of the pulley 95 and the other end is secured to a toothed wheel 102 which normally rotates with the sleeve 99 against which the worm 100 abuts, the spring gripping the sleeves 96, 99. The worm wheel, through a crank pin 105, cam 106 on a push rod 107, bellcrank lever 110, and stop 111, periodically raises a rod 113 into engagement with the toothed wheel 102 to hold it stationary, thereby uncoiling the spring and disconnecting the drive to the pulley 95. The rod 113 returns under its own weight, its descent being limited,by a stop 112. The lower end of the rod is pivoted to a, lever having a lug which engages a depression in the door of the stationary casing. As the door is opened, the lug leaves the depression and so raises the lever and' rod 113. In the form shown in Fig. 12, a '' rest period " of variable length is provided between each reversal of the main drive to the agitator. In this form, the shifter rod is always in engagement with the lever 21, which is rocked about its pivot 22 by the engagement of the eccentric pin 24 on the constantly driven worm wheel, centred at 122, with a cam slot 23 in the lever. The cam slot is provided with two portions 119, 120, each of which is, in the position of the lever 21 when both belts are on the loose pulleys of the usual open and crossed belt and pulley driving gear, concentric with the centre of the worm wheel, so that whilst the pin 24 is engaging either of these portions of the cam, a. rest period is maintained. The other portions 118, 121 of the cam are concentric with the centre of the worm wheel during the time that the lever 21 is in position for imparting a forward or reverse drive respectively. In order to vary the " rest period " or to eliminate it entirely the portions 119, 120 may be more or less or entirely masked by simultaneously operated cams 123, 124 being swung, against springs 127 and about their pivots 125, 126, over these portions of the cam 23, so that the pin 24 coacts therewith instead of with the portions 119, 120.. The cams 123. 124 are operated by rotation of an annular disc 128 having lugs 129, 130 acting on the cams 123, 124, the disc being rotated by a Bowden cable 132 against springs 131. The other end of the Bowden cable is secured to a ratchet disc held in any position by a pawl, so that the cams 123, 124 may be maintained in the desired position. The ratchet disc is provided with a lug which projects into the path of a rib on the door of the stationary casing, so that, as thedoor is opened, the cable is drawn tight to put the masking cams fully into action, thereby entirely eliminating the ''rest period." Thus, if the door should be opened during a " rest period," the clothes container is immediately re-started and continues to rotate in the normal intermittently reversed directions.