US2921159A - Push button control device - Google Patents

Description

n 1960 R.,W. ELDERTON ETAL 2,921,159

. PUSH BUTTON CONTROL DEVICE Filed Oct. 13, 1958 United States Patent 2,921,159 PUSH nU'i'roN CONTROL DEVICE Robert W. Elderton, Bloomington, Ill., and Robert J.

Wodtke, Columbus, Ohio, assignors to Robertshaw- Fulton Controls Company, Richmond, Va., 2 corporation of Delaware Application October 13, 1958, Serial No. 766,982 2 Claims. (Cl. 200-83 This invention relates to fluid pressure responsive devices for controlling the head of a body of liquid and more particularly to an adjustment means therefor.

In devices such as washing machines, it is desirable to automatically control the level of water in the machine. This is generally accomplished by a pressure responsive electrical switch. Also, since it is desirable to vary the amount of water depending upon the size of the washing load, manual adjustment means have been provided for this purpose.

It is an object of this invention to adjust a level of liquid by means of a push button apparatus.

It is another object of this invention to provide a push button apparatus which is simple in construction and positive in operation.

In the preferred embodiment of this invention, a casing .is provided with a first contact and a diaphragm mounted therein. The diaphragm has a second contact connected thereto and is movable in response to the level of liquid in a washing machine or the like. The movement of the diaphragm opens or closes the contacts to operate a solenoid valve provided in the liquid supply line. A push button apparatus having a pivotally mounted pressure plate or lever thereon is connected to said casing. Resilient means is disposed between the pressure plate and the diaphragm. The push buttons are operable to engage the pressure plate and compress the resilient means to vary the amount of pressure required to move the diaphragm, thereby controlling the liquid level in the washing machine.

Other objects and advantages of this invention will become apparent from the following detailed description taken in connection with the accompanying drawings wherein:

Fig. 1 is a perspective view of the control device embodying this invention;

- Fig. 2 is a cross-sectional view of the device shown in Fig. 1; and

Fig. 3 is an end view of the device shown in Fig. 1.

Referring more particularly to the drawing, a casing is provided which consists of a cup-shaped shell 12 and a cover 14 secured thereto. The shell 12 is of electrical insulating material and is preferably formed of molded plastic insulation. The cover 14 may be a metal stamping having a circular flange 1 6 enclosing the flange 18 of the shell 12 with a portion 20 of the flange 16 crimped over the edge of the flange 18 to lock the parts together. The flange 18 of the shell 12 also serves to clamp the marginal edge portion 22 of a pressure sensitive diaphragm 24. The diaphragm 24 is preferably provided with an extremely thin flexible annular edge portion 26 which is sufliciently limp so that the diaphragm 24 is responsive to the extremely minute changes in pressure within the chamber. As shown, the diaphragm 24 includes a relatively stifi metal disc 28 which maintains a central portion of the diaphragm relatively flat.

The cover 14 is formed to provide a pressure chamber 30 on the outer surface of the diaphragm 24 and a pres sure fitting '32 is soldered or welded to the cover so that a flexible tube or hose connection may be applied to the tube to transmit pressure through the port 34 to the chamber 30.

The shell 12 is provided with an internal cavity 36 in which a switch mechanism 38 and its actuating device 40 are enclosed. The moving part of the switch 38 is an overcenter leaf spring toggle having contacts 42 on each side so that it acts 'as a single-pole, double-throw unit. The leaf spring of the toggle comprises a double spring blade having an end portion secured to a boss on the shell 12 as by a rivet 44. As shown, this rivet extends through the wall of the housing shell.

The contacts 42 are positioned for engagement with a contact 48 which is mounted on the shell 12 or contact 50- which is provided opposite the contact 48 and is attached to the shell 12 by an offset mounting strip.

The details of the switch mechanism '38 do not form a part of this invention and it will be suflicient to say that the switch arm has two acting positions; that is, a reset position when the contacts 42-48 are closed and an actuating position when the contacts 4250 are closed. With the present engagement, the switch contact 42 will snap into engagement with the contact 48 when the outer end 52 of the blade moves downwardly into the plane of the contact arm in its actuating position, and the arm will reverse its position and snap the contact 42 against the contact 50 when the outer end 52 of the blade is raised into the plane of the arm in its reset position. These two positions may be termed the reset and actuating positions of the switch, since they are the two different points at which the arm will snap from the one position to the other. Between these positions, there will be an intermediate zone through which the outer end 52 of the blade may swing without actuating the contact arm.

The pressure sensitive diaphragm 24 is directly coupled to the outer end 52 of the switch blade so that the switch is actuated in response to changes of pressure in the charm ber 30. This is accomplished by an actuating pin 54 having an end in engagement through a hole in the center of the metal pressure disc 28. The pin 54 has an annular groove into which the outer end 52 of the switch mechanism extends. The parts are connected to cause movement as a unit at all times. The pin 54 includes a reduced portion 58 which extends into an aperture 60 in shell 12 and a reduced pilot portion 62 which extends through a central aperture 64 of a shiftable spring base 66.

A shoulder 70 on the pin is positioned to contact the underside of the spring base 66. A spring 72 is mounted on the upper side of the spring base 66 whereby base 66 and shell 12 provide a limit stop to limit the downward expansion of spring 72. Spring 72 extends upwardly and is restrained and the bias thereof is controlled by a manually operable adjustment means.

The adjustment means provided for varying the bias of spring 72 comprises a bracket 74 having the lower portion thereof secured to the shell 12 by the rivets 46 and 76. The bracket 74 has sides 78 and 80 which terminate in a horizontal top member 82.

A channel-shaped latch bar 84, a guide plate 86, and a pressure plate or lever 88 are mounted on the bracket 74 and extend between the sides 78 and 80 thereof. Latch bar 84 and guide plate 86 are each provided with a plurality of apertures therein which are adapted to receive a plurality of push rods 90, 92, and 94, respectively. The apertures are arranged in overlying pairs with apertures 85, 87 receiving push rod 90, apertures 89, 91 receiving push rod 92, and apertures 93, receiving push rod 94. Each of the push rods 90, 92, and 94 is provided with a rectangular opening 96 in the upper portion thereof.

- The push rods are slidably mounted in the top member 82 of bracket 74. Coil springs 98 are disposed one ineach of the openings 96 and compressed between a bossltlt) formed on top member 82 and a projection 1E2 formed on each push rod 90, 92, and 94 adjacent the upper portion of the openings '96. The bias of coil springs '98 tends to urge the push rods 90, 92, and 94 to an extended position whereby a shoulder or limit stop 104 formed on each push rod respectively engages the top member 82. The push rods 90, 92, and 94 are provided with buttons 1%, 108, and =11), respectively, to facilitate manual operation thereof.

The channel-shaped latch bar '84 is provided with a tongue 112 on each end thereof. The tongues 112 are slidably received in slots 114 formed in sides 73 and 80 of bracket 74, respectively. A small coil spring 116 is provided around tongue '112 and is compressed between an abutment on the channel-shaped portion 84 and the adjacent side 8t) to urge the latch bar 84toward'side 78. One wall of each aperture 85, 89, 93 is punched or otherwise formed to provide detents 118 which are adapted to cooperate with the notches 120 formed on each of'the push rods 90, 92, and 94 to lock the push rods: upon manual operation thereof to the depressed position.

Means are provided to effect release of a previously operated push button upon operation of a presently selected one.

120; Depression of one of the push rods will cause-cam surface 122. to move the latch bar 84 against the bias of spring. 116 to release a detent118; from thenotch 120 of i a:.. previously operated push rod. The guide plate=-86 being fixedly mounted to bracket 74 below the latch bar 84 with the apertures S '91, 95 serving to restrict the path of travel ofpush rods- 90, 92, and 94 to a rectilinear movement.

The pressure plate or lever 88 is pivotally' mounted onside 78 and movement of the other end thereof is restricted by an opening 124 formed in side 80. Attached to the medial portion of the pressure plate 88' is a stud 126 having a head: portion 128 extending on the upper side ofpressure plate 88. A knurled nut 130 is threaded on stud 126 and acts as a retainer and adjustment-for coil spring 72. A look nut 134 also threaded on stud 126 serves to restrain vibration of the nut 130'. The head portion 128: of stud 126 is positioned immediatelybelow push rod '92 and is adapted for engagement therewith. Also, a punch projection'1-32 of pressureplate 88'is positioned immediatelyv belowpush rod94 andextends upwardly at right angles to the pressure plate 83 for engagement therewith. V

In operation, assuming no button ,has been previously depressed, whenpush button 105, the low button, is depressed, the cam surface.122,of the pushrod 90, moves latch bar '84 towards side 80 until-thepush rod-90;,has been v depressed sufficiently to .permitthe detents-118 on the latch bar 84 to. align with the notch 120 in push: r o d9l). Then, under the bias of coil spring-116, the latch bar 8'4 moves towardsside 78-. causing the detent 118 to enter the notch 120 of the latch bard-4. At this point, the push rod 90 islockediin, position- However, this particular push rod, when in depressed position, does not touch the pressure plate 88 so that the.position thereof and the compression of the. coil spring '72 remains unchanged. This provides the lowest possible level ofwater in the washer. In. this position, pressure plateSS is in its uppermost position and is restrained by engagement of the punched. projection 132 with push rod'94.. V

When the center or medium push rod 92 isfdepressed; the camgsurface.122thereof causes the latch bar 8410 n qve towards side 80 and therebyi releases the low puslr rod 90. This also causes push rod 92 to contact More particularly, a cam surface 122 is provided on each ofthe push rods. adjacent thenotches the head portion 128 of stud 126 and move the pressure plate 88 pivotally until the detent 118 on latch bar 84 moves into the notch 12s of the push rod 92. Likewise, when the push rod 94 or normal is depressed, the medium push rod 92 is released and the bottom of the norma push rod 94 engages the punched projection 132 and continued movement of the push rod 94 further depresses pressure plate $8 until-latch bar 84 locks in place in the push rod notch 120.

I The pressure plate 88 is pivoted to its maximum downward position when the normal push rod '94 is depressed. Depressing one of the other buttons releases the normal button r110. When the normal button is released, the pressure plate 88 moves upward to either the low or medium position depending upon which of the other buttons is depressed. This is caused by the spring 72 which acts upwardly as well as downwardly, forcing pressure plate 88 upwardly until it stops either against head portion128 of stud 1126 when the push rod 90-is depressed.

It is apparent that the bias of spring 72 increases with the depression of push rods 92 and 94, respectively;

Since the spring 72 is connected to the diaphragm 24 through shiftable base 66, and pin 54, this depression increases the head or the like (not shown) which is required, through a pressure build up in chamber'30, to

move diaphragm 24 to close the contacts 42, 50. Opening of contacts 42, 48 causes operation of a solenoid valve (not shown) to stop fluid flow into the washing;

pressure plate '88 may be modified to provide different. This will change the amount of'movem'ent of:

height. the pressure plate 8'8 and consequently the compression ofspring 72. Y

The control is adjusted at the high setting by adjusting.

the knurled nut toprovide the desired. springcompression which in turn biases the switching mechanism against the pressure acting on the diaphragm24;

While a single embodiment of thisinvention hasbeen shown and described, it is apparentthat there may bemany changes in structure and in operationlwithoutdeparting from the scope of this invention as defined by) the appended claims. We claim: 1. 'A control device comprising in combination a casing having a pressure sensitive diaphragm disposed therein, a first contact mounted in said casing,va:second contact operatively associated with said diaphragm, .a.bracket mounted on said casing, a plurality of push 'rods slidably supported in said bracket, resilient meansurging' eachiof said pushrods toward one end of a path of confined travel in said bracket, a latch bar havinga plurality of slots therein for receiving said push rods, said-"latch bar be ing slidably supported in said bracket, resili'ent'means urging said latch bar in one direction, a notch in each of said push rods for. cooperation with said latch bar to lock a push rod upon movement thereof to theother end of the path of confined travel, carrmeans on each of said push rods for shifting. said latchbaragairistthe action of said last-named resilient means toetfect release of a previously operated push rod, a pressure'platepivotally mounted on said bracket, biasing'meansoperatively connected between said plate and" said diaphragm, said push rods being selectively operative relative'to said pres sure plateand moving the same vertically'for controlling the pressure required to move said 'diaphragm'to close said contacts. p I 2." A control 'devicecomprising in" combination a'cas ing having a pressure sensitive diaphragm disposed therein, a first contact mounted in said casing, a second contact operatively connected to said diaphragm, a bracket disposed on said casing, a plurality of push rods slidably supported in said bracket, resilient means urging each of said push rods toward one end of a path of confined travel in said bracket, a latch bar having a plurality of slots therein for receiving said push rods, said latch bar being slidably supported in said bracket, resilient means urging said latch bar in one direction, means on each of said push rods for cooperation with said latch bar to lock a push rod upon movement thereof to the other end of the path of confined travel, cam means on each of said push rods for shifting said latch bar against the action of said last-named resilient means to effect release of a previously operated push rod, a pressure plate movably mounted on said bracket, biasing means operatively connected between said plate and said diaphragm, and means disposed on said pressure plate and being selectively engaged by said push rods for moving said pressure plate vertically to control the pressure required to move said diaphragm to close said contacts.

References Cited in the file of this patent UNITED STATES PATENTS 1,609,223 Trumbull Nov. 30, 1926 1,996,891 Van Valkenburg Apr. 9, 1935 2,417,161 Hanner Mar. 11, 1947 2,636,093 Clark et a1. Apr. 21, 1953 FOREIGN PATENTS 605,016 Great Britain July 14, 1948 968,852 France May 10, 1950

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