US2582034A - Snap action switch - Google Patents

Description

Jan. 8, 1952 G. M. HAUSLER 2,582,034

SNAP ACTION SWITCH 7 Filed Jan. 8, 1949 ruwulnhuinwul Inventor:

Geor' e M. .Hausler,

by wJ/M His Attorney.

Patented Jan. 8, 1952 SNAP ACTION SWITCH George M. Hausler, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Application January 8, 1949, Serial No. 39,922

Claims.

This invention relates to electrical switches and more particularly to an improved snap action switch providing positive contact pressure until the moment of operation.

Such switches are used for pressure, float, temperature, and other applications where the operating means travels slowly but the contacts must snap quickly and positively.

It is an object of this invention to provide an improved snap action switch having the characteristics outlined above.

It is a further object to provide such a switch with a minimum of operating parts readily adapted to low cost manufacturing methods.

In general, my invention comprises a unitary, flat, resilient actuated member in a snap action switch which member provides the switch with positive contact pressure until the moment of operation.

For a complete understanding of this invention, reference should be had to the following specification and the accompanying drawing in which likeelements are given the same reference character throughout the several views.

In this drawing, Fig. 1 is a side elevation partly in section of a switch illustrative of my invention; Fig. 2 is a sectional view taken on line 2--2 of the Fig. 1; Fig. 3 is a plan view with cover removed of Fig. 1; Fig. 4 is a side elevation showing the contacts in open position; Fig. 5 is a side elevation partly in section of a single contact switch in accordance with my invention; Fig. 6 is a sectional view taken on line 6-6 of Fig. 5; and Fig. 7 is a plan view with cover removed of Fig. 5.

Referring to the drawing, my improved switch I comprises a unitary, fiat, resilient actuated member 2 biased against and supported by a resilient, u-shaped support member 3 by means of a flat, L-shaped, resilient spring member 4 actuated by an actuating member 5. Actuated member 2 comprises an integral strip of thin material slotted longitudinally to form two tension arms 43 and 44, two pivot compression arms 28 and 29, and an actuated compression arm 23, all of the arms being substantially parallel, as shown in Fig. 3. Actuated member 2 is further provided with a projection 32 centrally located at one end of actuated member 2, as shown in Fig. 3. Each of the tension arms 43 and 44 has its ends connected to opposite ends of the actuated member 2. Each of the pivot arms 28 and 29 has one end inwardly disposed and its other end connected to end 33 of the actuated member 2. The actuated compression arm 23 has one end inwardly disposed and its other end connected to the opposite end of actuated member 2 from end 33. I have found that to provide a proper snap action of actuated member 2, it is preferable that the inwardly disposed ends of pivot compression arms 28 and 29 extend some distance beyond the inwardly disposed end of actuated compression arm 23. This snap action will be described in detail later. One or more contacts 6 are secured to end 33 of actuated member 2, as shown in Fig. 3. Fig. 1 shows the contacts 6 in closed position. As the actuating member 5 is depressed, positive contact pressure is maintained until the actuated member 2 snaps to the position shown in Fig. 4 and the contacts 6 are thereby opened. When pressure on the actuating member 5 is released, the reverse action takes place.

For a complete understanding of the structure of switch I, attention is now directed to Figs. 1 and 3 wherein it may be seen that I provide a rectangular mounting plate I on the outer surfaceof which are secured terminals 9 and Ill. Terminals 9 and ID are located adjacent to the sides at one end of mounting plate 1. Each of the terminals 9 and I9 is provided with an aperture to accommodate terminal screws l2. In order to provide space for the threaded end of terminal screws l2 when secured in terminals 9 and I0, U-shaped notches l3 are provided at the sides of mounting plate I, as shown in Fig. 4.

To secure support member 3 to mounting plate I a rivet l4 and screw I5 pass through suitable aligned apertures in mounting plate I and support member 3. A recess 8 is provided in the face of support member 1 adjacent to support member 3 and screw l5, as shown in Fig. 1. The reason for this recess will be explained in detail later.

To secure terminals 9 and ID to mounting plate I, I bend portions l8 and I1 respectively of terminals 9 and I0 into opposed U-shapes, one leg of each U-shaped portion lying against the outside surface and one leg of each against the inside surface of mounting plate I. Screws It or other suitable means are passed through aligned apertures in the legs of U-shaped portions 16 and I1 and the mounting plate I. The heads of screws l8 are suitably plated to form contact buttons l9 electrically connected to terminals 9 and II].

In order to open and close a circuit connected to terminals 9 and I0, actuated member 2 s biased against the shorter leg 20 of support member 3 by means of spring member 4. To accomplish this, spring member 4 has its end 2! bent downward at approximately a right angle, as shown in Fig. 1, and its end 22 bent in a concave manner with respect to actuated compression arm 23 of actuated member 2, also as shown in Fig. 1. To provide stability in actuated member 2 and spring member 4, a notch 24 is provided in the longer leg 25 of support member 3, and a notch 26 is provided in the inwardly disposed end o1 actuated compression arm 23 of actuated member 2. Notches 24 and 26 respectively receive the ends 2| and 22 of spring member 4, as shown in Fig. 3. Also leg 20 of support member 3 is formed with pivot bends 21 to receive the inwardly disposed ends of pivot compression arms 28 and 23 of actuated member 2. Spring member 4 is tapered in order that ends 2| and 22 will fit in respective slots 24 and 26.

The recess 8 adjacent to support member 3 is provided in order that the bends 21 of short leg 20 of support member 3 may be adjusted by means of screw I5 to a position nearer to or farther from the longer leg 25 of the same member. For example, by tightening screw l5, bends 21 of support member 3 are moved in the direction of long leg 25, while loosening screw I5 moves bends 21 in the opposite direction. Thus a proper bias between spring member 4 and actuated member 2 is attained.

Actuated member 2 is formed in one integral piece and, in order to provide space for operation of the same, leg 20 of support member 3 is provided with a recess 30, as shown in Fig. 3. Leg 25 of support member 3 is provided with a rectangular aperture 3| to receive a projection 32 of actuated vmember 2 and to limit the movement of projection 32 within the vertical dimension of aperture 3| when the actuated member 2 is operated. Movement of end 33 of actuated member 2 is limited by contact buttons l3 and a stop 34 which stop is made of suitable insulating material and secured to a recessed housing 35, also of any suitable insulating material. Stop 34 is positioned in the path of end 33 of actuated member 2 at a proper distance from contact buttons l3 to provide satisfactory operation of actuated member 2.

Housing 35 is provided with a projecting portion 33 aligned above the curved portion 31 of spring member 4. Portion 36 oi. housing 35 is provided with a cylindrical aperture or sleeve 38 which acts as a guide for actuating member 5. The lower portion 39 of actuating member 5 is made larger in diameter than the portion which slides in the aperture 38 in order that the inner surface of housing 35 may act as a stop limiting the upward motion of actuating member 5.-

Housing 35 is secured to mounting plate I by nuts 40 and bolts 4| passing through aligned apertures in the mounting plate and housing or by any other suitable means.

To show the manner of operation of switch attention is directed to Figs. 1, 2 and 4 in order. In Figs. 1 and 2, contacts 6 are closed upon contact buttons l9 and the circuit between terminals 3 and I is closed. As actuating member is depressed, end 22 of spring member 4 is pressed downward carrying the end of leg 23 of the actuated member 2 downward also.

When the free end of actuated arm 23 of actuated member 2 is brought into a line with tension arms 43 and 44 of actuated member 2 the position of end 32 of actuated member 2 becomes unstable and further movement of actuated arm 23 in a downward direction results in end 32 of actuated member 2 snapping upward. However,

the contacts 6 maintain positive pressure on contact buttons l8 until the end 32 of actuated member 2 passes through a point of alignment with the pivot point 21, which in the illustrated embodiment coincides substantially with the center of aperture 3|. At this time the movement of end 32 is uncontrolled and end 33 of actuated member 2 snaps upward thereby opening contacts 6. Movement of end 32 of actuated member 2 is limited by the rectangular aperture 3| in leg 25 of support member 3 and movement of end 33 of actuated member 2 is limited by stop 34. The operating mechanism of switch is then in the position shown in Fig. 4.

To close contacts 3, actuating member 5 is released and by bias of actuated member 2 moves upward thus allowing the inwardly disposed end of actuated compression arm 23 of actuated member 2 to move upward. When the end of arm 23 of actuated member 2 passes the central balance point again, the reverse action takes place and contacts 6 are returned to the closed position shown in Fig. 1.

To show the manner in which the switch may be adapted to a single break circuit, Figs. 5, 6 and '7 are provided. In this form of my invention, a single contact 6 is provided on the actuated member 2 and a terminal 42 carrying a single contact button I9 is secured to mounting plate 1 adjacent one end thereof. Centrally located in the opposite end of mounting plate I a terminal 45 is provided. Terminal 45 is apertured to accommodate a terminal screw I2, and mounting plate I has a U-shaped notch l3 to provide space for the threaded end of screw l2 when the latter is in serted in the aperture in terminal 45. I

In order to secure terminal 45 to mounting plate I, a rivet l4 and screw l5 or other suitable means are provided, as shown in Fig. 5. Rivet l4 and screw l5 pass through suitable aligned apertures in terminal 45, mounting plate I, and U-shaped support member 3 thus electrically connecting terminal 45 to support member 3 as well as securing both to the mounting plate I.

In other respects, the single break switch shown in Figs. 5 to 7 inclusive is the same as the double break switch shown in Figs. 1 to 4 inclusive except that stop 34 in the case of the single break switch is formed as a projection centrally located on the end wall of housing 35 and aligned in the path of end 33 of actuated member 2.

The switch may also be built as a single pole double throw switch by substituting another contact and terminal structure for stop 34.

From the above, it may be seen that I have provided a compact switch whose mechanism comprises only 4 parts, namely an actuating member 5, a spring member 4, an actuated member 2, and a support member 3, all readily manufactured at low cost and simple to assemble. Yet this switch provides positive contact pressure until the moment of operation and therefore is suitable for pressure, float, temperature and other applica tions where the operating means travels slowly but the contacts must snap quickly and positively to prevent arcing and destruction of the contacts or damage to a motor connected to the switch.

As many changes could be made in the above construction without departing from the'scope of the invention, it is intended that all matter contained in the above description be interpreted 'as illustrative and not in a limiting sense.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A snap action switch comprising a fixed contact and a movable contact cooperating therewith, a thin flat resilient member supporting said movable contact, said member having a plurality of longitudinal slots defining a plurality of compression arms, a plurality of tension arms each positioned between adjacent compression arms, said tension and compression arms being substantially parallel, and a pair of transverse end portions each connected respectively to a different end of said tension arms and connecting said tension arms to one end of each of said compression arms, a fixed support member engaging the other ends of a plurality of said compression arms, and a resilient movable member engaging said fixed support member and engaging the other end of another of said compression arms, said fixed and movable members coacting in establishing compression forces in said compression members, said end portions being movable between two positions responsive to movement of said movable member, and said movable contact being supported on one of said end portions.

2. A snap action switch comprising a fixed contact and a movable contact cooperating therewith, a thin flat resilient member supporting said movable contact, said member having a plurality of longitudinal slots defining a plurality of compression arms, a plurality of tension arms each positioned between adjacent compression arms, said tension and compression arms being substantially parallel, and a pair of transverse end portions each connected respectively to a different end of said tension arms and connecting said tension arms to one end of each of said compression arms, fixed members engaging the other ends of a plurality of said compression arms, and a movable member engaging the other end of another of said compression arms, said fixed and movable members establishing compression forces in said compression members, said end portions being movable between two positions responsive to movement of said movable member, and said movable contact being supported on one of said end portions.

3. A snap action switch comprising a fixed contact and a movable contact cooperating there with, a thin fiat resilient member supporting said movable contact, said member having a pair of longitudinal slots defining a pair of compression arms, a tension arm, and a pair of transverse end portions each connected respectively to a different end of said tension arm and connecting said tension arm to one end of each of said compression arms, an adjustable resilient support member engaging the other end of one of said compression arms, a movable member engaged by said support member and engaging the other end of the other of said compression arms, said other end of said other of said compression arms extending beyond the other end of said one compression arm, said support and movable members cooperating in establishing compression forces in said compression members, and means for adjusting said support member to vary the magnitude of said compression forces, said end portions being movable between two positions responsive to movement of said movable member, and said movable contact being supported on one of said end ortions.

4. A snap action switch comprising a fixed contact and a movable contact cooperating therewith, a thin fiat resilient actuated member supporting said movable contact, said actuated member having a plurality of longitudinal slots de- ,sion arms being substantially parallel, means supporting said actuated member comprising a U-shaped resilent support member positioned beneath said actuated member, one leg of said support member being located beneath and extending in the direction of said opposite end of said actuated member, said one leg having an aper-- ture therein, the second leg of said support member being located beneath and extending in the direction of the inwardly disposed ends of said pivot compression arms, a notch in said second leg to permit actuation of said actuated member, bends in said second leg of said support member arranged to engage the inwardly disposed ends of said pivot compression arms, a flat L-shaped resilient spring member, the ends of said spring member being bent one over the free end of said actuated compression arm and the other over the free end of said one leg of said support member to move said actuated arm overcenter with respect to the other arms of said actuated member thereby to cause the outer ends of said actuated member to move in a reverse direction with a snap action, means limiting the movement of both ends of said actuated member in both directions normal to the plane of said actuated member and between two fixed positions, said means comprising an outwardly disposed projection on said opposite end of said actuated member, said projection protruding through said aperture in said one leg of said support member, and stop means located adjacent both surfaces of said one end of said actuated member and in the path of movement of said one end, an actuating member engaging said spring member and arranged to move one end thereof toward the plane of said actuated member thereby depressing the inwardly disposed end of said actuated arm, and stop means limiting the reverse movement of said actuating member, whereby positive contact pressure is maintained until the moment of operation of said movable contact.

5. A snap action switch comprising a fixed contact and a movable contact cooperating therewith, a thin fiat unitary resilient member supporting said movable contact, said member hav-- ing at least one tension arm, and at least one actuated compression arm and a plurality of pivot compression arms formed integrally with said tension arm and substantially parallel thereto, each of said pivot compression arms having one end inwardly disposed and its other end joined to one end of said tension arm, said actuated compression arm having one end inwardly disposed and its other end joined to the other end of said tension arm, a fixed support member engaging the inwardly disposed ends of said pivot compression arms, and a resilient movable member engaging the inwardly disposed end of said actuated compression arm, said fixed support member and said resilient movable member cooperating in establishing compression forces in said compression arms and tension forces in said tension arm, said end ortions of said tension arm being movable between two positions responsive to movement or said movable member, mb and said movable contact being supported on one Re. 17 646 of said end portions of said tension arm. 2

GEORGE M. HAUSLER. 3:233:32: 2.508.040

REFERENCES CITED UNITED STATES PATENTS I Name Date Johnsson Apr. 22, 1930 Eaton Aug. 22, 1939 Johnson Jan. 14, 1941 Kaminky July 12, 1949 Ransome May 16, 1950 FOREIGN PATENTS Country Date Switzerland Nov. 16, 1939

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