Patent GB-368730-A (GB)
Title: Improvements in or relating to timing mechanisms, particularly for washing or dry cleaning machines
IPC: D06F33/06
Filed: 1930-12-01
Abstract: A timing mechanism for controlling the timing of the valves of dry-cleaning machines comprises a time-controlled element and a position-controlled element, the former comprising a perforated, slotted, notched or otherwise recessed travelling belt, disc, plate, rod or like member and a reciprocating feeler operating in conjunction therewith to constitute a hit and miss device.  The operation of the position-controlled element is dependent on the correct functioning of the machine and may include a float-controlled drum actuated by the level of liquid in the machine.  When the feeler passes through a perforation &c. it actuates a lever which controls the opening of a valve, the lever remaining in its operative position until released by the position-controlled element.  In Fig. 1 the time-element comprises a ratchet drum 3 on to which a perforated record strip 1 is wound from a drum 2.  A vertically reciprocating feeler 17 coacts with the record strip <PICT:0368730/III/1> <PICT:0368730/III/2> and, on passing through a perforation therein, engages and rocks a pawl 21 so that a notch 21a therein is engaged by the upper end of a lever 11 secured to a shaft 24 which is constantly rocked from the driving-shaft of the machine.  The pawl is pivoted to a lever 23 which is loose on the shaft 24 and is connected by a cable 25 with a valve or other member to be operated.  When the notch 21a is engaged by the lever 11 the lever 23 is rotated counterclockwise and opens the valve and is held in this operative position by the engagement of a roller 28 carried by a plate 29 pivoted at b with another notch 21e in the pawl 21.  The lower end of the lever 11 is cam-shaped and engages rollers 9, 12 to operate two linkages of which one--8 . . 6--rotates the ratchet drum 3 through a pawl 4 and the other--13 . . 15--reciprocates the sleeve 16 in which the feeler 17 is yieldingly housed.  The lower end of the lever 23 also is cam-shaped and, when the lever is swung to its operating position by the engagement of the lever 11 with the pawl 21, engages the roller 9 and moves it out of the path of the lower end of the lever 11, simultaneously advancing the ratchet drum by several teeth so that the record strip is advanced sufficiently to move the edge of the perforation therein out of the path of the feeler 17.  When the lever 23 is held in its operating position, by the engagement of the roller 28 with the notch 21e in the pawl 21, its cam-shaped end continues to hold the roller 9 out of the path of the lower end of the lever 11 so that the ratchet drum remains stationary whilst the valve, opened by the cable 25, remains open.  A drum 33 which comprises the position-element and is rotated by the movement of a float in the machine is formed with a portion 30 having an aperture 31 in its cylindrical surface.  During the continued rocking of the lever 11 a spring-pressed feeler 11b carried thereby inoperatively contacts with the cylindrical surface of the portion 30 until the drum has been rotated by the float sufficiently to bring the aperture 31 into its path.  At the next forward movement of the rocking lever the feeler 11b passes through the aperture and contacts with a projection 32 on the plate 29 to lower it against its spring.  The roller 28 is thereby freed from the notch 21e in the pawl 21 whereby the lever 23 is restored by a spring to its inoperative position thereby closing the valve and restoring the roller 9 into the path of the cam 10 to render the time-element again operative.  A set of time and position elements is provided for each valve requiring operation.  In Fig. 2 the operating lever 17 connected to the valve &c. by a rod or cable 20 comprises one of a pair of toggle links 13, 17 which are moved to the position 13<1>, 17<1> beyond the dead centre when a pawl 12 pivoted to the link 13 is engaged by an arm 15 on a rocking shaft 6. The pawl is spring loaded away from the arm and is moved into the path of the arm by the limb 27 of a bell-crank lever pivoted at f which is rotated clockwise by a feeler 9 when the latter passes through a perforation in the record strip 1.  The feeler is reciprocated by a lever 11 which is operated by another arm 10 on the rocking shaft 6 and the record strip is moved by the engagement of a projection 7 on the rocking shaft with a bell-crank lever 5 which operates the ratchet 4 rotating the feed drum 3.  A lever 23 having a catch 23a at one end and a cam 23b at the other is pivoted on a rocking arm 21 and a lever 25 is pivoted at d and is provided with a notch 24 which is normally out of the path of the catch 23a so that on the forward stroke of the arm 21 the cam 23b contacts with the toggle links 13, 17 in the position 13<1>, 17<1> with insufficient pressure to break the toggle joint.  A removable link 29 is provided between the lever 25 and the bell-crank lever 27, 28 whereby, when the link is in position, the lever 25 is rotated counterclockwise whenever the feeler passes through a perforation in the record strip. When this next occurs, therefore, the notch 24 in the lever 25 engages and holds the catch 23a.  On the next forward movement of the arm 21 the cam 23b forcibly engages the link 13 and breaks the toggle joint, the p  links moving to the position 13<11>, 17<11> from which they are restored to their original inoperative position by a spring and the valve is consequently closed.  The link 29 may be removed and a stop 43 provided on the lever 13 to contact with the bell-crank lever 5 for imparting an increased travel to the record strip and suspending the operation of the feed mechanism, the release of the valve-operating levers 13, 17 from the position 13<1>, 17<1> being effected by the position control which is arranged to operate at different predetermined levels of the float and comprises a float drum 33 gearing with a pinion 35.  A crank 36 is keyed to the axle of the pinion and a sleeve 37 carrying a weighted arm 38 and an arm 39 provided with a roller 40, is loosely mounted on the axle.  When the crank 36 engages the weighted arm 38 and lifts it to tumbling position and the sleeve 37 completes the rotation due to the weight, the roller 40 engages a recess 41 in the lever 25 to swing the latter counterclockwise and to cause the recess 24 therein to engage the catch 23a of the lever 23, the subsequent release of the toggle links being effected as when the link 29 is in position.  The engagement of the catch 23a in the recess 24 and the movement of the arm 21 swings the lever 25 and allows the roller 40 to pass out of the recess 41 and down a guide tail-piece 42 to disconnect the position element from the operating lever 17.  The lever 27, 28 is restored by the engagement of a stop 32 with a portion 30 thereof. Two sets of time elements may be provided for each valve, one with a link 29 for time control only and the other without the link but with a position element.