US2831078A - Sequence switch arrangement for cycle timers - Google Patents

Description

April 15, 1958 H. GREENWALD 2,831,073

SEQUENCE SWITCH ARRANGEMENT FOR CYCLE TIMERS I Filed 001;. 3; 1956 INVENTOR.

Harry Greenwald ATTORNEY United States Patent SEQUENCE SWITCH ARRANGEMENT FOR CYCLE TIMERS Harry Greenwald, Blauvelt, N. Y., assignor to H. Greenwald Co., Inc., Maspeth, N. Y., a corporation Application October 3, 1956, Serial No. 613,696.

8 Claims. (Cl. 200-37) This invention relates to cycle timers for electric appliances, such as automatic washers and driers, and more particularly to a novel sequentially operated switch arrangement for a coin slide controlled cycle timer.

Conventional cycle timers include a motor driving a shaft operating one or more wafer or disk type switches which initiate, control and terminate the several functions of an appliance during an operating cycle. Initiation of the cycle is effected by turning the shaft to a start position at which the timer'motor is energized to drive the shaft. When the shaft reaches the stop or off position, the timer motor is automatically deenergized to terminate the cycle, and re-starting can be effected only by again turning the shaft to the start position.

It is frequently desirable, particularly in the case of coin-controlled appliances, that a certain function be initiated only after a pre-set time delay following initiation of another function. For example, in the case of a coincontrolled washer or laundry machine, it is sometimes desirable that the supply of hot water to the washer be delayed until a pre-set time after the cycle has been started, rather than have the hot water supplied immediately at the start of the cycle.

Such special sequence of operation can, of course, be fairly easily incorporated in the timer during manufacture or assembly of the later, for example by blanking off, with dielectric material, the initial part of the wafer switch contacts controlling the initiation and duration of the function to be delayed. I

However, timers with this special sequence are nonstandard, and must be ordered special. In the more usual case, the standard timer furnished with an appliance must be altered in the field to provide the desired delayed sequence. This is not only difficult to effect, due to the close clearances between the timer switches, but also frequently requires dismantling of the timer. Not only is the operation time consuming and costly, but also it is difficult to the point of impossibility to obtain the desired accurately timed relation between the starts of the two sequential functions.

A further factor, characteristic of both factory and field alteration or modification of the timer, is that the blanking out of part of the switch contacts with dielectric, reduces the throw" of the switches to an extent where a clean and sharp make or break of the contacts cannot be obtained, with resultant relatively rapid deterioration of the contacts due to sparking.

In accordance with the present invention, the foregoing difficulties are obviated and either factory or field modification of a timer, to provide a delayed sequence, is effected in a simple, inexpensive manner and with resultant accurate setting of the time delay. More specifically, a pair of jack type switches are mounted on the timer and arranged to be sequentially operated by a rotary cam adjustably secured to the timer shaft. This cam has a sector shaped projection extending from its other wise circular surface, arranged to engage operating arms on the two switches.

The switches are arranged so that the operating arm of one switch extends beyond that of the other, in the direction of cam rotation, by a predetermined amount. The arcuate length of the cam projection is accurately selected, with respect to the spacing of the operating arms of the switches, so as to delay the operation of the second switch for the desired preset time after operation of the first switch. Furthermore, the radial projection of the cam sector is made sufficiently great to effect a large throw of the switch contacts, thus providing a clean make and break. The switches may be connected in series with the usual timer switches controlling the two functions so that, with the cam operated switches normally open, the usual switches are ineffective to initiate the functions until closure of the cam switches. Alternatively, the cam switches could be normally closed and connected in shunting relation to the usual timer switches.

For an understanding of the invention principles, reference is made to the following description of a typical embodiment thereof as illustrated in the accompanying drawing. In the drawing:

Fig. l is an elevation view of a cycle timer and a coin controlled slide for initiating operation thereof, the timer including the sequentially operated switch arrangement of the invention; and

Figs. 2, 3 and 4 are plan views of the switch arrangement, illustrating three operating positions thereof.

Referring to Fig. 1, a conventional cycle timer 10 is illustrated as including a driving motor 311 for operating wafer type cycle controlling switches 12 on a rotatable shaft 13 driven by motor 11 when the latter is energized. To start the timer, shaft 13 is manually operated to the start position wherein motor 11 is energized to rotate shaft 13. The motor continues to rotate shaft 13 until the shaft reaches the stop position at which motor 11 is automatically deenergized. During rotation of shaft 13, switches 12 effect the desired sequence of operations such as, for example, filling a washer with Water, washing the clothes, rinsing, and spin drying. The switches also shut off motor 11 at the stop position.

The timer If) is arranged to be moved to the start position by a coin controlled slide 15 carrying a roller 16 engageable with a cam 17 on the upper end of shaft 13. When a coin 0f the proper denomination is inserted in slide 15, the slide may be pushed in to engage roller 16 with cam 17 to rotate shaft 13 to the start position.

As stated, it is frequently desirable that a certain time-controlled function, such as turning on the hot water, be not initiated simultaneously with starting of the timer, or with another function, but at a predetermined interval thereafter. This sequence has previously been effected by covering, with dielectric material, part of the circuit controlling contacts of wafer switches 12.

This can be effectively accomplished as a factory operation during manufacture or assembly of the timer. However, such special sequence arrangements are not usually provided for in the timers as installed at the factory but require alteration of the timer in the field. Due to the compactness and close spacing of wafer switches 12, incorporation of the special sequence arrangements is a difficult operation to perform in the field without complete dismantling of the timer. This is not only a time consuming and costly operation but, furthermore, it is difficult to time the sequence precisely. In addition, both in factory installed and field modified special sequence arrangements involving alteration of wafer switch 12, the clearance problems are such that clean making and breaking of the switch contacts cannot be attained, with resultant arcing and rapid deterioration of the contacts.

The special switch arrangement of the invention avoids these dificulties and provides a simple and simply adjusted special switching sequence with clean making and breaking of the switch contacts. In accordance with the invention, a special cam is adjustably secured to shaft 13 and arranged to sequentially operate a pair of jack type switches and mounted on mounting bracket 14 of liner 10.

Switch 25 includes spring arms 21, 22 carrying contacts 23, 24 respectively. Arm 22 extends beyond arm 21 and has a bent operating end 26 for coaction with cam 21). The spring arms are secured in a dielectric mounting base 27 which also mounts the spring arms 31, 32, of switch 361, carrying contacts 33, 34 respectively. It will be noted that spring arm 32 extends somewhat beyond arm 22 of switch 25 and has a somewhat longer bent operating arm 36.

Cam 20 has a sector shaped projection 35 extending into the path of switch operators 26 and 36. The arcuate length of projection 35 is selected in accordance with the desired time interval between operation of switches 25 and 30.

Fig. 2 illustrates the stop position of the timer. Both switches 25 and 30 are closed but the washer motor circuit has been opened by a wafer switch 12, switch 25 also controlling operation of the washer motor. Switch 30, in the illustrative example, controls the flow of hot water. in one typical cycle, as slide 15 is operated to start the cycle, roller 16 engages cam or finger 17 to rotate shaft 13 to the start position energizing timer motor 11. In the start position, projection 35 opens both switches 25 and 3%. After an interval, finger 26 rides ofi projection 35 to close switch 25 starting the washer motor, as illustrated in Fig. 3. A pre-set time interval thereafter, finger 36 rides 01f projection 35 starting the fiow of hot water, as shown in Fig. 4. The timer continues to operate until the stop position of Fig. 2 is reached, at which time a wafer switch 12 opens the circuit of timer motor 11 in the usual manner.

It will be noted that the throw of switches 25 and 30 is such as to effect a clean make and break of the contacts. The arrangement is easily incorporated in a timer and easily adjusted for precise timing.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the invention principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

l. In a timer controlled electric appliance having a cycle timer including a timer motor energized upon movement of the timer to a start position, a shaft rotated by said timer motor, and function control switch means operated by rotation of said shaft; means for delaying the initiation of a selected function for a predetermined time interval after initiation of another selected function, said means comprising a cam adjustably secured to said shaft for rotation therewith and having a generally circular periphery concentric with the axis of said shaft; and a pair of switches mounted on said timer and each, when operated, controlling initiation of a different function; each switch having an operator cooperable with said cam, and the operators being spaced a pre-set distance apart circumferentially of said cam; said cam having a switch operating interruption in its periphery having an arcuate extent corresponding to such predetermined time interval to operate one switch such predetermined time interval after operation of the other switch.

2. Means as claimed in claim 1 in which said switches are normally closed switches opened when the switch operators engage said interruption in the cam periphery and released to close when the operators leave the trailing end of said interruption.

3. Means as claimed in claim 1 in which said peripheral interruption comprises a sector shaped lobe projecting from the circular periphery of said cam.

4. Means as claimed in claim 1 in which said peripheral interruption comprises a sector shaped lobe projecting from the circular periphery of said cam; and said switches are normally closed switches opened when the switch operators engage said lobe and released to close when the operators leave the trailing end of said lobe.

5. Means as claimed in claim 4 in which said switches are jack type switches each having a pair of contact carrying spring arms.

6. Means as claimed in claim 4 .in which said switches are jack type switches in a common mounting each having .a pair of contact carrying spring arms; said operators each comprising a bent end on one switch arm extending toward said cam.

7. Means as claimed in claim 6 in which the throw of said lobe is sufiicient to provide a clean and pronounced make and break of the switch contacts.

8. Means as claimed in claim 1 in which said switches are in overriding circuit relation with said switch means.

References Cited in the file of this patent UNITED STATES PATENTS 2,044,617 Leonard June 16, 1936 2,073,756 Osten-Sacken Mar. 16, 1937 2,215,414 Wilcox Sept. 17, 1940 2,302,626 Gallagher et al. Nov. 17, 1942 2,487,573 Meier Nov. 8, 1949

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