US2982900A - Timing device - Google Patents

Description

May 2, 1961 E. LJNDER EI'AL TIMING DEVICE 3 Sheets-Sheet 1 Filed May 22, 1956 INVENTORS Eduard L1 and AWeber WMW ATTO RNEY TIMING DEVICE 3 Sheets-Sheet 2 Filed May 22, 1956 Ill-Ill =====:--HQIIIIIIIIIIIll-Ill:

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INVENTORS fduard Llgg .6

May 2, 1961 E. LINDER EI'AL TIMING DEVICE 3 Sheets-Sheet 3 Filed May 22, 1956 FIG .7

ill! I I E FIGS INVENTORS Eduard gg ggr and RH weber I I L W ATTORNEY United States Patent ()fiice TIMING DEVICE Eduard Linder, Muntelier, near Murten, and Artur Weber, Mlll'l, near Bern, Switzerland, assignors to Sara A.G., Murten, Switzerland Filed May 22, 1956, Ser. No. 586,555 Claims priority, application Switzerland Oct. 11, 1955 4 Claims. (Cl. 318-257) This invention relates to a timing device for automatic control of operating cycles of a machine and more particularly of an automatic washing machine, the timing device having one or more cam discs controlling switch contacts otf1i electric circuits supervising the operation of the mac me.

For automatic washing machines having a rotatable washing drum it is usual to rotate this drum at a relatively low speed for washing and rinsing the laundry,

the rotating direction of the drum being periodically respeed, whereby one single driving motor is provided for all operating conditions for keeping the costs of the machine down. This motor shall be able, without changeable gear between it and the drum, to drive this drum at a relatively low speed in both directions and at a relatively high speed in at least one direction.

In conventional timing devices for washing machines two kinds of individually driven cam discs were provided for controlling the driving motor of the washing drum, the one kind of cam discs serving for reversing the driving motor for Washing and rinsing whereas the other kind of cam discs control the whole operating cycle of the washing machine and particularly changing over from reversing to centrifuging. Due to the independent and individual drive for the above two kinds of cam discs it is impossible to determine with the necessary accuracy whether at the moment of the changing over from reversing to centrifuging or vice versa, the reversing contacts are in the one or other of their control positions, and therefore it is necessary to disconnect the driving motor for a minimum time between the end of the one operating condition and the beginning of the other operating condition in order to be sure that the driving motor and the washing drum are at rest and that, therefore, starting up of the driving motor in the one direction while the motor is still rotating in the other direction may certainly be avoided. This rupture of operation required at every change from one operating condition to another causes a loss of time by which the duration of the washing cycle is increased and, therefore, rendered more expensive.

It is a first object of this invention to avoid this disadvantage of prior art timing devices particularly for washing machines, by driving the said cam discs at different speeds and by provision of positive transmission means between cam discs providing for forced motion between cam discs driven at different speeds. By this means it is possible to effect the said change from reversing to centrifuging or vice versa in a washing machine at a moment in which the said reversing contacts and the cam discs controlling the same are in a predetermined-position,

that is at a moment in which the driving motor of the washing drum isdriven or will be driven in a predeter- 2,982,900 Patented May 2, 1961 mined direction. In order to provide for the said positive or forced motion between diiferent kinds of cam discs, cam discs may be provided rotating at a relatively high speed for controlling the reversing contacts and a stepping device is driven at the same speed as the reversing cam discs for stepwise advance of at least one cam disc at a low speed, the stepwise advance being always effected for a predetermined position of the reversing cam discs.

Timing devices of the kind referred to in the foregoing normally have driving means for driving the said cam discs and means for automatically deenergizing the said driving means and stopping the cam means in an end position at the end of each operating cycle, thereby stopping the machine. If another operating cycle of the machine shall be started up manual control is necessary for rendering the said deenergizing means inoperative. Up to now this was done by turning the control knob of the machine from an end position at which the driving means for the cam discs were deenergized to a start position in which the deenergizing means may be rendered inoperative. But it was found to be undesirable that the operator has to put the control knob to the start or zero position and since the timing device may also be started up when the start position is overpassed or not accurately adjusted the machine may as well be started up but its operating cycle will not properly be controlled. If the operator notices that he was overpassed the start position he cannot return the control knob because in most timing devices there is a ratchet mechanism allowing rotation of the cam discs and of the control knob connected to the same in one direction only.

It is a further object of this invention to allow very easy handling of the timing device and particularly to bring the control knob to its start position without any difiiculty. This result is obtained by providing stop means for the said cam means and means for advancing the cam means from the said end position to a start position determined by the said stop means and by further providing means for rendering the said means for deenergizing the driving means for the cams inoperative, the said driving means being started up when the cam means have been brought into the said start position and the said stop means have been rendered inoperative.

It is another object of this invention to provide for improved and simplier construction and manufacture of the cam disc assembly and for securing the relative position of the cam discs on the cam shaft. To this end the cam shaft has a non-circular cross section and the cam discs have fixing openings having a shape similar to the cross section of the cam shaft so that the cam discs cannot turn on the cam shaft, and the axial position of the cam discs being determined by spring means such as spring washers or cup spring inserted between adjacent cam discs. There is no need for screw fastening of the cam discs on the cam shaft and once the cam contours are accurately shaped in the required relationship to the fixing opening of the cam discs the cams need only be slid onto the cam shaft and will immediately take the correct angular position without further adjustment.

Other objects and advantages of the invention will be apparent from the following description and of the attached drawings in which-- Fig. 1 is a top View of a first embodiment of the timing device having portions shown in section for better illustration,

Fig. 2 is a section on the line II-II in Fig. 1,

,Figs. 3 and 4 are partial sections of the timing device of Figs. 1 and 2,

Fig. 5 is an electrical diagram of the first embodiment of the timing device,

Fig. 6 shows a possible variation of the circuit of Fig. 5.

Fig. 7 is a sectional view on the line VII-VII in Fig. 8

of a second embodiment of the timing device according to this invention and Fig. 8 is a section on the line VIII-VIII in Fig. 7..

The timing device illustrated in Figs. lto has a oasing comprising two side plates 1 and 2. A hollow shaft 3 is pivoted in the side plate 1, to which a control knob 4 is fixedly secured at the outer end and a driving disc 5 is fixedly secured at the inner end. The hollow shaft 3 has two axially staggered circumferential grooves 6 constituting a rest mechanism together with a spring wire 7 secured between the side plate 1 and a plate 1 screwed to the-plate 1, th hollow shaft 3 being held in two difier- .ent axial positions according to whether the spring wire 7 engages the one or other of the grooves 6. In the outer axial position shown in Fig. 1 of the hollow shaft 3 a coupling pin 8 of a stepping wheel 9 engages one hole of a rim of holes 10 of the driving disc 5, whereby the stepping wheel 9 is coupled with the driving disc 5 and cannot be turned relatively to the latter. The number of teeth of the stepping wheel 9 is equal to the number of holes 10 of the driving disc 5 there being 90 teeth and holes respectively. The stepping wheel 9 may be rotated but not axially displaced on the bearing sleeve of the hollow shaft 3.

A shaft 11 is rotatably inserted in the hollow shat3 to which are fixedly connected a control knob 12 at the outer end and a control arm 13 at the inner end. A

spring washer 14 is provided between the hub of the conby means of a driving pin 17 so that all the cam discs will always follow the motion of the driving disc 5. Thedriving pin 17 is axially displaceable in a sleeve 18 of the The driving disc 5 and the adjacent foremost cam disc 16 'are coupled first cam disc 16. A ratchet wheel 19 is fixed on the 7 rear end of shaft 15 adjacent plate 2, the said ratchet wheel being adapted for cooperation with a spring loaded ratchet 20 thereby allowing rotation of the shaft 15 and of the cam discs respectively in clockwise direction only in Fig. 2. Each of the cam discs :16 is'in operative en- -gagen1ent with a switch contact 21 of which only the rearmost is shown in the drawing for convenience of illustration.

A stepping lever 22 is pivoted on the hub of the stepping wheel 9, the stepping lever projecting into the path of a control pin 23 of a cam disc 25 fixed on a shaft 24. A spring loaded stepping latch 26 operativ'ely engaging the stepping wheel 9 is pivoted on the stepping lever 22. -In the rest position of the stepping lever 22 as illustrated in Fig. 2 the lever '22 is pulled upwardly by a strong spring 27 whereby the stepping latch 26 is tightly jammed between a stop pin 28 and the stepping wheel 9, so that the latch 26 prevents any rotation of the stepping wheel 9. Above the stepping latch 26 a spring loaded latching dog 29 is pivoted on the plate 1, the latching dog 29 being under control of a latching lever 31 having an adjusting screw 32. V The adjusting screw 32 of the latching lever is soadjusted that the lug 33 -of the latching lever 31 applies without play on the circular portion of the control edge of the cam disc 25 thereby preventing any 'rota tion of the lever 31 and of the latching dog. 29 except for the time during which the lug 33 is over a notch 34 of the cam disc 25.

Shaft 24 carries two other cam discs 35 and 36 ofinsui :lating material cooperating each with the movable 'contact spring of control switches 37 and 38 respectively.

4 The shaft 24 is driven by a synchron motor 42 in clockwise direction in Fig; 2 'at'a speedof say one rotation per minute.

At the outer end of the control arm 13 a spring loaded latch 39 is pivoted on a shaft 40. This latch 39 is urged against a stop pin 41 in its rest position so that it projects outwardly in ra-dialdirectionr The latch 39 may be turned in clockwise direction as indicated in Fig. 2 when a suitable force acts on its end projecting from the outer end of arm 13 but the latch 39 cannot be turned in anticlockwise direction due to the stop pin 41.

Between the driving disc 5 and the first cam disc 16 a switch lever 43 of insulating material is pivoted at 44, this switch lever projecting with its free end below the movable contact spring of switch 45. The switch lever 43 has a control member 46 projecting downwardly into the path of latch 3-9 as well as into the path of the cou- ,pling pin 17, the switch lever 43 being lifted against the action of the-contact spring of switch 45 when the coupling pin 17 or the latch 39 abuts against the control member 46 from the leftlin Fig. 2. The switch lever 43 also has an inclined lateral control face 47 adapted for cooperation with the driving disc 5 in. a manner ex- .plained later on. I a

Fig. 5 illustrates in a .schematical manner the synchon motor 42, the cam discs 35 and 36 driven by the synchron motor, and the switches 37 and 38 controlled by the cam discs 35 and 36. Fig. 5 further illustrates the switch 45 supervising all the other control circuits and the synchron motor. A switch 48 supervising the control switches 37 and 38 and another switch 49 are illustrated of which each is controlled by one of the cam discs 16. The switches 37 and 38 control each .a contactor 50 and 51 respectively schematically shown in Fig. 5 and the motor 54 of the washing drum is connected to a three phase circuit 52 in opposite phase sequence according to whether the one or other contactor "50 or 51 is closed. The switch 49 controls the circuit of another contactor 53 adapted to connect the motor .54 to the three phase circuit 52 with the same phase sequence as contactor 50 but at lower number of poles.

The timing device described in the above description operates as follows:

Fig. 2 illustrates the initial position of the timing device at the beginning of 1a washing process. The switch .45 is'closed .and'the synchron motor 42 drives the shaft 24- for instance at a speed of one rotation per minute in clockwisedirection in Fig. 2. Towards the end of the first rotation of this shaft the control pin 23 of the .cam-disc-25 presses the stepping lever 22 downwardly against the action of spring 27, whereby the stepping latch 26 is put back by one tooth. During this motion the lug 33' of the latching lever 31 still slides on the circular portion of the rim of cam disc 25 and therefore secures the latch 29 in the position illustratedso that rocation of the stepping wheel 9 during the said backward :motion of the stepping latch 26 is prevented. Shortly before the pin 23 leaves the free end of the stepping lever 22 the notch 34 of the cam disc 25 moves below the lug 33 Off-he latching lever 31 so that the latter is free. to move downwards. Immediately afterwards the pin 23 leaves the stepping lever 22 which will jump back into the position illustrated under the pull of spring 27 .thereby advancing the wheel 9 by one tooth and latches .thesame againin itsnewposition. Thernotions described above .reoccur "for everyrotation of the cam shaft 24, that; is for instance every minute; so that the stepping wheel v9, the driving disc 5 coupled to the same and the cam discsv 16 coupled with the driving disc 5 are stepviliseadvanced-in clockwise direction inFig. 2. Thereby the switch-contacts controlled by the carn disc 16 are operated for controlling the. washing 'machine in accordaneewithadesired program. i Asvsetout ip the'Ioregoing-the:washingdrum shall be reversed dmingi'washing and rinsingthat Tis'the re fitting direction of the washing drum shall be reversed periodically for instance at the end of each half minute, this reversing condition being controlled by closure of switch 48 by the corresponding cam disc 16. For the condition of the circuit illustrated in Fig. 5 the contactor 50 is energized over switches 48 and 37 so that the driving motor 54 of the washing drum rotates at a relatively low speed in one given direction. From Fig. 2 it is seen that the control faces of the cam disc 35 and 36 overlap each other in such a way that at any time both switches 37 and 38 are opened or one of these switches only is closed. It will also be seen from Fig. 2 that after a certain time the switch 37 which is illustrated in closed position in Fig. 5 is opened and switch 38 which was closed also remains open for a short time. Therefore the contactor 50 is deenergized and the motor 54 comes at rest some time later. Thereafter the switch 38 is closed as may be seen from Fig. 2 so that contactor 51 is closed and the motor 54 is fed in opposite phase sequence so that the washing drum will be driven in opposite direction.

When, for instance at the "end of a rinsing process, during which the washing drum was reversed in the manner described above the washing drum shall be accelerated to higher speed in order to centrifuge the laundry the switch 48 is opened and the switch 49 is closed. This change over of switch positions can only take place at the same instant as the cam discs 16 are advanced by one step in the manner described in the foregoing. As may be seen from Fig. 2 which shows the position of the timing device immediately after the stepping wheel has been advanced both switches 37 and 38 are opened at this moment so that both contactors 50 and 51 are deenergized. Moreover the switch 37 was closed and the contactor 50 energized prior to each advancing step of the cam discs 16, and consequently the motor 54 has been driven in a predetermined direction prior to each advance of cam discs 16. If, therefore, a change over takes place in the manner explained above from reversing to centrifuging the contactor 53 is closed over switch 49 and'the motor 54 is fed at the same phase sequence but at a lower number of poles than immediately before with switch 37 and contactor 50 closed, and the motor 54 will be accelerated to a higher speed at the same rotating direction. Therefore it is possible to change over from reversing to centrifuging practically without loss of time, that is without allowing the motor 54 and the washing drum to come at rest and therefore the motor must not be accelerated from rest to the high centrifuging speed whereby the starting current in the motor is held down and there is very little loss of time and energy for accelerating the motor and washing drum.

When changing over in the opposite sense, that is from centrifuging to reversing the rotating direction first occurring in the reversing state will be opposite to the rotating direction in the centrifuging state and therefore a time of at least one minute will be required to let the motor 54 and the washing drum run down to rest before being started up at the lower speed for reversing.

If this interval of for instance one minute is not desired for reasons of the machine operation advancing of the cam discs 16 might also be efiected approximately in the middle of the closing period of switch 37, so that independently of the direction of change over either from reversing to centrifuging or vice versa the motor 54 may immediately rotate on at a different speed. In order to obtain this result the circuit of Fig. 5 should be changed as shown in Fig. 6 in which the operating coils of contactors 5t), 51 and 53 are designatedwith same reference numerals as corresponding contactors in Fig. 5. As shown in Fig. 6 contactors 50 and 53 have each an auxiliary rest contact 50' and 53 respectively connected in the control circuit of contactors 53 and 50 respectively. Therefore contactor 50 cannot be operated as long as contactor 53 is closed because rest contact 53 connected into the operating circuit of contactor 50 is opened and on the other hand contactor 53 cannot be operated as long as contactor 50 is operative because the control circuit of contactor 53 is broken at rest contact 50 of contactor 50. Therefore it is impossible that both contactors 50 or 53 are closed at the same time and there is no danger of short circuits occurring at the terminals of motor 54. As pointed out above, for this arrangement switch 37 shall be in closed state whenever the cam discs 16 are advanced by one step. With this circuit there is no loss of time whatever.

Similar control circuits might be designed for operation with one phase alternating current or with direct current.

The whole operating cycle of the washing machine is controlled while the stepping wheel 9, the driving disc 5 and the cam discs 16 coupled thereto execute one full rotation. When the driving disc 5 has been advanced by 89 steps from its starting position illustrated in Fig. 2 the coupling pin 17 engages the control member 46 of switch lever 43 and lifts the latter thereby opening switch 45. As is clearly seen from Fig. 5 the synchronous motor 42 and all the control circuits of contactors 50, 51 and 53 are disconnected. At the same time all the other control circuits of the washing machine not illustrated in the drawings, which are without interest in connection with this invention, are broken and the washing machine is set to rest. The laundry may be removed and the machine may be charged again for starting a new washing cycle to which end the control knob 4 together with the hollow shaft 3 and the driving disc 5 is pushed to the inner axial position. Thereby the driving disc 5 moves from the position shown in Fig. 3 into that illustrated in Fig. 4 and engages the inclined control face 47 of the switch lever 43 which is thereby held in a position in which the switch 45 remains open. The driving disc 5 which is now disengaged from the stepping wheel 9 may be turned in clockwise direction by any desired angle the cam discs 16 being advanced by the same angle. If another full washing cycle is to be started the driving disc 5 is advanced by one step only whereupon the control knob 4 with the hollow shaft 3 and with the driving disc 5 is pushed into the outer axial rest position. By this displacement the coupling pin 17 has left the control member 46 and the driving disc 5 has released the inclined face 47 and therefore all the parts of the timing device have returned to the initial position illustrated in Fig. 2 from which the device starts to run for controlling another washing cycle.

If one or more parts of the operating cycle of the washing machine, for instance one or more rinsing operations at the end of the cycle or preliminary washing at the beginning of the washing cycle are to be repeated, the control knob 4 is pressed inwardly into its inner axial rest position in the manner described above, whereby the timing device and the washing machine are shut down by the opening of switch 45. The driving disc 5 which is disengaged from the stepping wheel 9 by the axial displacement and the cam discs 16 may now be rotated in clockwise direction (Fig. 2) until a pointer secured to the control knob 4 points to the place on a scale (not shown) illustrating the washing program, from which the washing operation shall be restarted. The control knob 4 is now pulled back into its outer rest position whereby the switch 45 is closed again and the driving disc 5' is coupled with the stepping wheel 9 so that the timing device starts its control motion as described from the desired place of the washing cycle. In a similar way a portion of the washing cycle might he jumped or left out if desired by pressing the control knob 4 inwardly at a desired place of the washing cycle and advancing the driving disc 5 and cam discs 16 to the place where the cycle is to be restarted and then pulling control knob outwardly to start up the timing device.

If the end of the washing cycle shall be shifted to any desired time before the 89th minute, the control arm 13 is turned into the position corresponding to the time at which the cycle is to be ended, to which end the control knob 12 is turned relatively to the control knob 4 until a sign of the control knob 12 points to aplace of a scale comprising 90 divisions traced on the control knob 4, corresponding to the desired time at which the cycle is to be ended. When now the driving disc 5 is stepwise advanced-in the manner described this rotation is transmitted to the control arm 13 by spring washer 14 and the latch 39 projecting radially outwards will engage the control member 46 of the switch lever 43 before the 89th minute of the washing cycle thereby causing rupture of the switch 45 and thereby shut down of the timing device and of the washing machine in the preselected moment. If, for instance, the next washing cycle shall again be carried out normally the driving disc 5 is first disengaged from the stepping wheel '9 in the manner described and is advanced-into the starting position illustrated in Fig. 2 and coupled again with the stepping wheel 9. By this operation the timing device is started up for controlling another operating cycle of the machine and the control arm 13 is to be reset into the zero position illustrated in Fig. 2 in which the latch 39 is held in inclined position below the coupling pin 17 and therefore is inefltective'that is cannot shut down the timing device.

From the foregoing it is clear that the timing device is very simple in construction and attendance but allows for any desired variation of the washing program.

Of course the'synchronous motor 42 might be replaced by a suitable time-piece particularly when the washing machine is operated by direct current. With suflicient precision of the control cams 16 transmission of the motion from the cam shaft 24 to the cam shaft 15 might be effected by a normal reduction gear, for instance a worm gear instead of being efiected by means of a stepping device as described.

It was shown in the above description of the operation of the timing device illustrated in Figs. 1 to 6 that the driving disc'S must manually be turned to its initial position for restarting operation of another operating cycle of the timing device and the machine controlled by the same. This means that the operator has to set the control knob 4 exactly to a zero position indicated on the scale provided on the timing device. Since this resetting motion may only be etfected in one direction 'due to the ratchet wheel '19 fixed on the cam shaft 15 the control knob and driving disc cannot be turned back when the zero position is overpassed by inadvertance in which case a further full rotation of the control knob is necessary with the further possibility of overpassing the zero position once more. This is highly undesirable and a simplified form of the timing device according to this invention is shown in Figs. 7 and 8 comprising means for avoiding theforementioned drawbacks and to facilitate restarting of the timing device. Corresponding parts of the timing device shown in Figs. 7 and 8 have same reference numerals as in Figs. 1 to 6. The timing device of Figs. 7 and 8 basically differs from the'one shown in Figs. 1 to 6 in that the control knob 12 and the control arm 13 are omitted, there being no possibility for automatically stopping operation of the timing device at a desired time, so that the duration of the operating cycle 'is always the same. Therefore the control knob 4 is fixed on a full shaft 60 carrying the driving disc 5 and having a bore 61 :taking up a pivot pin 63 of the cam shaft 62. Cam shaft 62 corresponds in function to cam shaft 15 but is of square cross section, the cam discs 16 having square fixing holes through which the shaft 62 passes without play so that the cam discs 16 cannot possibly turn on the-cam shaft 62. Any suitable non-circular cross section of cam shaft 62 and of the fixing holes might "be used preventing rotation of the 8 cam discs on the cam shaft. The cam discs 16 are axially secured between the hub 64 of the ratchet wheel 19 and an end washer 65 screwed onto the opposite end of the cam shaft 62. The cam discs .16 are spaced from each other by cup springs 66 inserted between adjacent cam discs. By this arrangement manufacture ofthe cam discs and of the cam assembly on the cam shaft 62' is facilitated in that a great number of cam discs of 'the same shape may be manufactured by milling the notches of a number of cam discs keyed on a square shaft so that a correct angular position of the control notches is secured and will not be changed and must not be adjusted when putting the cams onto the cam shaft 62 'asis the case with cam shafts of circular cross section where the cam discs have to be angularly adjusted on the cam shaft.

The control knob 4, the shaft 60 and the driving disc 5 may axially be displaced as described. The driving disc 5 has a stop pin 67 adapted to cooperate with a stop lever 68 when the driving disc is in its inner axial position as shown in Fig. 8. The stop lever 68 is pivoted at 69 on the plate 1. An arm 70 of the stop lever 68 abuts against a stop pin 71 fixed on plate 1 and the stop lever 68 is normally held in the position illustrated in Fig. 7 by a torsion coil spring 72 of which one end rests against connecting tube 73 of plates 1 and 2 and the other end is secured on stop lever 68.

Operation of the timing device shown in Fig. 7 and 8 is easily understood if reference is also had to the operation of the timing device shown in Figs. 1 to 6. By the stepping device (not shown in Figs. 7 and 8) arranged between cam shaft 24 and stepping wheel 9 the stepping Wheel 9 is advanced in clockwise direction in Fig.7 so that the driving disc 5 and the cam discs 16 are driven when coupled to the stepping wheel 9, until at the end of the operating cycle the coupling pin 17 engages the control member 46 of the switch lever 43, whereby the switch 45 is opened and the timing device and the machine controlled by it are shut down. This position is illustrated in Fig. 7. In order to restart the timing device and the machine, the control knob 4 and the driving disc 5 are pushed inwardly into. the inner axial rest position as illustrated in Fig. 8 by which displacement of the driving disc 5 the stop pin 67 is brought into a positionin which it will engage the stop lever 68 when the driving disc is further advanced in clockwise direction in Fig. 7. If this is done the stop lever 68 is pivoted anticlockwise in Fig. 7 until its arm 70 abuts against the connecting tube 73 whereby further rotation of the stop lever 68 and of the driving disc 5 is prevented. The parts, particularly the stop lever 68 and its arm 70 are so designed that this end or stop position in which the driving disc 5 cannot be turned on exactly corresponds to the initial or starting position of the disc 5. Therefore the driving disc 5 may now be pulled back into its outer axial position in which it is engaged with the stepping wheel 9 and in which'its stop pin 67 has left the stop lever 68 which latter immediately returns to its rest. position illustrated in Fig. 7 under the action of spring 72. The stepping wheel -9, the driving disc 5 and cam discs 16 coupled therewith arenow advanced by the stepping device (not shown in Figs. 7 and 8) until the position illustrated in Fig. 7 is reached again in which the timing device is shut down and may be restarted in the manner described, whereby there is no possibility of overpassing the initial position and there is no need for looking for the initial position on a scale.

As soon as the driving disc 5 is reengaged with the stepping wheel 9 in its starting position and the stop lever 68 has returned to its rest position as set out above the driving disc 5 might again be disengaged from the stepping wheel and advanced to any desired angular position between its start and end position, when it is desired to jump the beginning of the operating cycle. Thisis possible becausethestop lever 68 immediately returns to its rest position when it is released by the stop pin 67 and does, therefore, no longer prevent advancing of the driving disc beyond the starting position. If there is no necessity of starting at another place of the operating cycle than at the normal starting point, the stop lever '68 might be replaced by a simple stop arm entering into the path of the stop pin 67 when the driving disc 5 is disengaged from-the stepping wheel 9. Of course the stop device as illustrated in Figs. 7 and 8 might also be used in the same manner in the timing device shown in Figs. 1 to 6.

While the invention has been described and illustrated with reference to specific embodiments thereof, it will be understood that other embodiments may be resorted to without departing from the invention. Therefore, the forms of the invention set out above should be considered as illustrative and not as limiting the scope of the following claims.

What we claim is:

1. A timing device for automatic control of the operating cycle of the driving motor of an automatic washing machine, the said operating cycle comprising running of the motor at a low speed and alternatively in opposite directions and running in one direction at a high speed, the timing device comprising first, second and third relay means operable for connecting the said driving motor to an electric source in a manner that the motor is driven at a low speed and in opposite direction when the said first and second relay means respectively is operable and the said driving motor is driven at a high speed when the said third relay means is operable, a first, second and third control circuit for each of the said first, second and third relay means respectively, a first cam shaft having two cam discs controlling each one of a first and second switch contact connected into the said first and second control circuits respectively, a second cam shaft, a rigid gearing between the said first and second cam shafts securing running of the said first and second cam shafts at a predetermined speed ratio, driving means for driving the said first and second cam shafts, two cam discs on the said second cam shaft controlling each one of a third and fourth switch contact respectively, the said first control circuit comprising the said first and third switch contacts connected in series, the said second control circuit comprising the said second and third switch contacts connected in series and the said third control circuit comprising the said fourth switch contact, closed periods for each of the said switch contacts and open periods for each of the said switch contacts, the closed periods of the said first and second switch contact and the closed periods of the said third and fourth switch contacts respectively being chronologically spaced from each other.

2. A timing device for automatic control of cycles of a machine and more particularly of an automatic washing machine, comprising a first cam shaft and a second cam shaft, driving means for rotating the first cam shaft, cam discs on the said first and second cam shaft controlling switch contacts, a stepped switch gearing having a step switch gear wheel rotatably mounted on the said second cam shaft and a forward switch pawl operatively associated with the said step switch gear wheel for stepwise advancing it through a number of predetermined positions, the said first cam shaft having means operatively associated with the said switch pawl for periodically operating it for advancing the said switch gear wheel from one of its predetermined positions to the next one, a coupling member operatively connected to the said second cam shaft and engageable with the said switch gear wheel in a number of predetermined positions equal to the number of predetermined switching positions of the said switch gear wheel so that the said switch gear wheel and the said second cam shaft coupled therewith can only assume a number of predetermined operating positions, at least two electrical conrtol circuits for the said machine, comprising control switches actuated by cam discs of the said first c'arn shaft and at least one electrical control circuit for the said machine comprising a control switch actuated by a cam disc of the said second cam shaft, an operating range for the said first cam shaft for which operating range the said two electrical control circuits are ineffective and an operating position within the said operating range for the said first cam shaft for which the said switch pawl is operated, the said control switch actuated by a cam disc of the said second cam shaft being only actuated during the said operating range of the said first cam shaft for which operating range the said two control circuits are ineffective, an engaged and disengaged position of the said coupling member, a main switch operable by the coupling member and closed when the coupling member is in its engaged position, the said driving means and control circuits being deenergized and the said main switch being opened when the said coupling member is disengaged.

3. A timing device for automatic control of operating cycles of a machine and more particularly of an automatic washing machine, comprising a first and second cam shaft, a timing motor for driving the said first cam shaft, control circuits for controlling parts of the said machine, cam discs on the said first and second cam shaft controlling switch contacts inserted into the control circuits, a stepped switch gearing having a step switch gear wheel rotatably mounted on the said second cam shaft and a forward switch pawl operatively associated with the said step switch gear wheel for stepwise advancing it through a number of predetermined positions, means on the said first cam shaft for actuating the said pawl whenever the said first cam shaft arrives at a predetermined angular position when rotated by the said timing motor, the said step switch gear wheel being advanced by one step whenever the switch pawl is actuated, a coupling member operatively connected to the said second cam shaft and engageable with the said switch gear wheel in a number of predetermined positions equal to the number of predetermined positions of the said switch gear wheel so that the said second cam shaft can only be maintained in one of its said predetermined positions, the positions of the switch contacts controlled by the said second cam shaft being well determined for any of the said positions of the second cam shaft, an operative and inoperative condition for any of the switch contacts controllable by the said first cam shaft, the said switch contacts controllable by the first cam shaft being ineffective when the said first cam shaft is in its said predetermined angular position wherein the said switch pawl is operated for advancing the said second cam shaft, operation of switch contacts by advancing the said second cam shaft being thereby only effected when the switch contacts controlled by the said first cam shaft are ineffective, a main switch operable by the said coupling member and open when the said coupling member is disengaged and closed when the said coupling member is engaged, the said timing motor and switch contacts being energized through the said main switch when the said coupling member is engaged and the said timing motor and switch contacts being deenergized when the said coupling means are disengaged.

4. A timing device for automatic control of operating cycles of a machine, comprising first and second cam means, control circuits for controlling parts of the machine, switch contacts controllable by the said first and second cam means and inserted into the said control circuits, a rigid gearing between the said first and second cam means securing advance of the said first and second cam means at a predetermined speed ratio, coupling means between the said gearing and the said second cam means, the said coupling means engageable in a number of distinct positions thereby securing a predetermined relation between the positions of the said first and second cam means for any engaged position of the said coupling means, at least one of the said control circuits comprising switch contactscontrollable byreach of the'said first and second cam means, a main switch through which the said timing motor and control circuits may be 'fed, the 'said [main switch being operable by the said coupling means, the saidmain switch being closed for energizing the-said motor and control circuits respectively when the said .couplingis engaged and the said main switch being opened for deener'gizingthe said timing motor and eontr ol circuits respectively'when the said coupling means is disengaged, hand operating means formanually advancing the said second cam means, and means allowing manual-advance'of the said second cam means when the said coupling means is disengaged but opposing manual ad- V 112. a vance of the said second cam means when the said coupling means is engaged.

References Cited in the file of this patent UNITED STATES PATENTS Kintzing May 14, 1957 Ara may

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