Patent GB-512078-A (GB)
Title: Improvements in or relating to automatic controls for washing, dry-cleaning, bleaching, dyeing and the like machines
IPC: D06F33/04
Filed: 1938-05-06
Abstract: 512,078. Fluid-pressure servomotor-control systems. ELVERSTON, G. May 6, 1938, No. 13527. [Class 135] [Also in Group VIII] An automatic control arrangement for washing, dry-cleaning, bleaching, dyeing and like machines of the kind in which the supply and discharge of various substances used in the process is controlled by fluid-pressure operated main valves actuated automatically at predetermined times comprises a uniformly rotated master member and a control member oscillated by a float and provided with cams which open normally closed control valves controlling the supply of fluid under pressure to the pistons or the like operating the main valves. The invention is shown applied to a washing machine having a float chamber 1 in open communication with the bottom of the washing cylinder 2. A float 7 is connected by a rack or chain 5 and a toothed wheel 4 with a shaft 3 carrying a sleeve 9 which rotates with the shaft 3 but is axially slidable thereon. The sleeve 9 carries axially and angularly adjustable cams 8 for operating compressed air valves 12, 26 which respectively control the closing of the hot and cold water supply valves. By means of two arms 10, the sleeve 9 also carries a spindle 14 bearing roller cams 11 which operate further compressed air valves 13, 27 controlling the opening of the hot and cold water valves. The number of cams 8, 11 correspond to the number of times the hot and cold water valves have to be actuated in a particular process. These cams may be duplicated or triplicated, each set being differently adjusted and corresponding to a different process. A sleeve 30 with sets of diametrically opposite lugs 31 is lose on a parallel rod 29 and is connected to the sleeve 9 by a crosshead 32. A cable 33 is connected to the crosshead 32 and passes over a pulley 34 for connection to a counterweight 35. Axial movement of the sleeves 9, 30 by the weight 35 is prevented by a pallet 86 mounted on a rock shaft 36 and having two prongs 37, Fig. 3, which co-operate with the pairs of lugs 31. Rotation of the pallet 86 to free the engaged lug and allow axial movement of the sleeves to the next pair of lugs is accomplished by a trip arm 38 which is actuated by a finger 39 on the sprocket wheel 4 as the float sinks. A spring 40 automatically returns the pallet to its initial position. After a process has been completed the sleeves 9, 30 may be returned to their initial positions by turning the sleeve 30 through 90 degrees by means of a handle 41 so that all its lugs 31 miss the prongs 37. To prevent the rollers 11 fouling the compressed air valves whilst the sleeves are being re-set, a hand lever 79 pivoted at 80 co-operates with a lug 82 on the wheel 4 to raise the rollers 11. A stationary bracket 83 is engaged by one of the arms 10 if it is omitted to raise the lever 79. To change from one process to another, the sleeves 9, 30 are relatively adjusted axially by means of a spring-pressed bolt 56 mounted in the crosshead and engageable with either of two axially spaced slots in the sleeve 30. The compressed air valves 12, 13, 26, 27 are of the automatically closing type and are operated through levers 76, those of the valves 12, 26 carrying rollers 78. The hot and cold water valves 20, Fig. 6, are similar and are actuated by a cam-ended lever 18 which may be operated manually in case of emergency. The piston 17 of a pivoted valve opening cylinder 15 is connected to the lever 18 whilst the piston 21 of a trip cylinder operates on an extension 25 of the lever to close the valve 20, the cam surface 19 being selfholding in the two positions. The master control member comprises a disc 42 carrying a series of angularly adjustable cams 43 and is driven at a slow constant speed for example through reduction gearing 84. The number of such cams 43 depends on the number of times the washing cylinder is to be emptied during a particular process. Each cam 43 operates to open a single compressed air valve 46, Fig. 5, controlling the opening of the main discharge valve 44. The latter is closed by gravity and its operating piston acts on the usual pedal lever (not shown). Air escapes from the operating cylinder past grooves 50 in the valve stem when the valve 46 closes. A dashpot may be provided to delay the final fall of the float until the discharge valve is closed, but as shown such closure is ensured at the time the hot and cold valves are opened by an operating piston 51 which is supplied with compressed air through either or both the valves 13, 27 and moves the casing of the valve 46 bodily out of the path of the cams 43. A steam valve similar to the hot water valve 20 is provided and its opening is controlled by a further compressed air valve actuated by a further cam or cams on the disc 42 and receiving its supply through either or both of the valves 13, 27 so that the steam valve cannot be opened before liquid is supplied to the washing cylinder. The steam valve is closed under the control of the valve 46. The operation of the master control disc 42 may be suspended at the start of any particular charging operation by a removable projection 67 on the respective cam 43. The projection 67 actuates a compressed air valve 66 controlling an operating plunger 69 which through a hand lever 70 declutches a driving pulley 72. The lever 70 also operates a switch 75 controlling a signal bell or light. The disc 42 may be temporarily disconnected from the gear 84 and turned by a knob 85 for the purpose of adjusting the cams 43. The cams may be provided on a drum instead of a disc, and to change from one process to another, interchangeable discs with pre-set cams may be used or a two master disc slidable on the shaft 45. The cams 8, 11 may be replaced by cams mounted on a slidable drum. The step-wise movement of the sleeve 9 may be effected by a pawl and a ratchetwheel or rack. According to the Provisional Specification the hot and cold water valves, the steam valve and the discharge valve are operated by single spring-pressed pistons. Means are also described for controlling valves which supply soap, soda, bleaching, dyeing and like solutions to the machine. Such means may comprise a float-operated drum which works in conjunction with the cam drum for the hot and cold water valves or additional cams on the latter drum may control two-way cocks for supplying soda, and soap, these cocks also being controlled by floats in measuring tanks for the two solutions.