US3681554A

US3681554A - Electrical switch actuating assembly

Info

Publication number: US3681554A
Application number: US97210A
Authority: US
Inventors: Ronald H Arthur
Original assignee: Unimax Switch Corp
Current assignee: Unimax Switch Corp
Priority date: 1970-12-11
Filing date: 1970-12-11
Publication date: 1972-08-01
Anticipated expiration: 1989-08-01

Abstract

A switch actuating assembly includes a switch body, and a switch operating plunger extending through one side of the switch body. A generally cruciform shaped operating lever has cross arms pivotally mounted in apertures in ears on the cover of the switch body, the lever being positioned to cooperate with the plunger in operation of the switch. The apertures, which may be polygonal, are sufficiently large to permit assembly of the operating lever by rotation about its longitudinal axis, and the lever has a bifurcated end which can be spread to urge the pivots of the lever further into the apertures to inhibit removal.

Description

[451 Aug. 1, 1972 United States Patent Arthur [54] ELECTRICAL SWITCH ACTUAT'ING Primary Exdminer-H. 0. Jones Attorney-None & Nolte ASSEMBLY [72] Inventor: Ronald H. Arthur, Wolcott, Conn.

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5 Claim, 7 Drawing Figures UNITED STATES PATENTS 3,336,458 8/1967 Hadley......................200/172A PATENTEmus 1 1912 3,681,554

F1620 FIGZb F1620 INVENTOR. RDI'ALD b! ARTHUR ATTORNEYS ELECTRICAL SWITCII ACTUAIING ASSEMBLY This invention relates to switches, and is particularly directed to the form of switch in which the switch mechanism is enclosed within a switch body, and is operable by means of a lever pivotally mounted on the switch cover and cooperates with a plunger extending through the switch body to the switch mechanism.

In one form of conventional switch, the electrical switch mechanism is enclosed within a switch body of molded insulation, with switch terminals extending from one external surface of the switch body to the switch mechanism. A switch operating plunger extends through the cover of the switch body to permit operation of the switch mechanism by an external force. This form of switch is frequently designed to be operated by extremely light force and minimum displacement of the plunger, and, when designed with these criteria in mind, such switches are commonly known as microswitches.

In order to adapt such switches to operation under various conditions, a switch actuating lever is frequently pivotally mounted on the switch, the lever being arranged to cooperate with the plunger for operating the switch.

In the past, various arrangements have been provided for pivotally mounting the actuating lever to the switch. For example, various brackets have been designed for mounting on the switch body to hold the lever in position, and, alternatively, the switch body cover has been molded in various configurations to permit assembly of the lever in cooperative relationship with the plunger.

In many applications it is desirable that the entire switch assembly be of minimum size, such that the position of external brackets for the operating levers undesirably enlarge the dimensions of the assembly. Such brackets are also difficult to manufacture and assemble when the size of the switch is to be minimized, and the number of components involved diminishes the attractiveness of such design from the standpoint of economy. Furthermore, in switches of this type in which the covers of the switch body were moded to accomodate the switch operating lever, complex molding configurations were required, and in some cases it was necessary to permit access to the inside of the cover for assembling the lever on the cover.

While these disadvantages are particularly important with respect to miniaturized switches, it is of course apparent that they are also undesirable features in switches of larger size.

It is, therefore, an object of this invention to provide a switch and switch operating mechanism that overcomes the above stated disadvantages.

It is a further object of this invention to provide a switch of the type having an external pivoted operating lever, in which the mounting of the switch operating lever is simple and economical, and readily adaptable to miniaturized switches.

According to the invention, a switch assembly is provided comprising a switch body enclosing a switch mechanism. A switch operating plunger extends through the cover of the switch body to permit external actuation of the switch mechanism. The switch body cover is provided with a pair of cover ears having aligned apertures, the apertures preferable, although not necessarily being polygonal. A switch operating lever of generally cruciform shape is mounted on the cover with the cross arms of the lever forming pivot trunnions and extending into the apertures, so that another arm of the lever cooperates with the plunger in operation of the switch. The apertures are of sufficient size that the pivot trunnions can be inserted therein by slight rotation of the pivot lever about the longitudinal axis of the lever. The other arm of the lever is bifurcated to a sufiicient depth that expansion of the bifurcations in the plane of the lever forces the pivot trunnions deeper into the apertures, to prevent removal of the lever.

In order to enable a clearer understanding of the invention, the invention will now be explained in greater detail, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a preferred embodiment of a switch according to the invention, with portions of the operating lever and one cover ear being removed to clarify the illustration;

FIGS. 20, 2b and 2c are partially cross-sectional end views of the switch of FIG. I, with FIG. 2a illustrating the manner of assembly of the operating lever in the switch, FIG. 2b illustrating the operating lever assembled in the switch, and FIG. 2c illustrating the final position of the operating lever in the switch subsequent expansion of the end of the operation lever;

FIG. 3 is a plan view of the operating lever of the switch of FIG. I prior to assembly;

FIG. 4 is a plan view of the operating lever of the switch of FIG. 1 after assembly; and

FIG. 5 is a partial side view of the switch of FIG. 1, illustrating in greater detail the aperture in the cover ears.

Referring now to the drawings, and more particularly to FIG. 1, a switch asembly according to one embodiment of the invention is comprised of a switch body 10 having a cover 11 affixed to a base I2. The switch body I0 has a hollow interior for enclosing a suitable switch contact assembly of conventional nature, and it is hence believed unnecessary to illustrate and describe in detail the contact assembly. The contacts of the switch contact assembly are internally connected to terminals I3, in conventional manner, extending through the bottom of the base I2. The switch body cover 11 and base 12 are preferably molded from an insulating material, and may be held together by any suitable means, such as by a cement.

The cover 11 of the switch body is provided with a suitable guide aperture 14 through which a plunger 15 extends. The plunger 15, which is preferably made from an insulating material, is adapted to engage the switch contact assembly in conventional manner so that the contacts can be actuated externally of the switch body by axial movement of the plunger.

The portion of the switch above described is conventional in nature, and may be modified according to known practice without departing from the invention.

The cover II is provided with a pair of upstanding ears 20 adjacent one end of the cover, the ears 20 being in alignment on opposite sides of the center line of the cover. Each ear 20 has a polygonal aperture 21 extending transversely of the center line of the cover, with the apertures 21 also being mutually aligned. The ears 20 are preferably molded as integral parts of the cover 11.

The operating lever 24 for the switch assembly according to the invention, is a generally cruciform shaped flat member, preferably of a metallic material. Referring specifically to FIG. 3, the operating lever has a pair of aligned oppositely extending projections 25 which form pivot trunnions for the lever. The operating portion 26 of the lever extends in one direction from the projections 25, and is adapted to engage the plunger at a point 27 along its center line, and to extend therebeyond for a distance determined by the particular application of the switch. The other end 28 of the lever 24 is bifurcated, with the bifurcation extending from the end 28 past the projections 25, but preferably not extending as far as the point 27. As can be seen in FIG. 3, prior to assembly in the switch, the edges of the lever 24 opposite the slot 36 are generally tapered inwardly toward the end 28. Notches 30 may be provided in the edges of the lever 24, for example, adjacent the point 27, to permit expansion of the end 28 of the lever without deformation, as will be explained in more detail .in the following paragraphs.

The lever 24 as illustrated in FIG. 3 is adapted to be inserted in the switch assembly with the pivot trunnions 25 extending into the polygonal apertures 21. For this purpose, the apertures 21 are made sufficiently large in the vertical direction that the pivot trunnions can be inserted therein by rotating the lever 24 about its longitudinal axis so that the trunnions fit between the projecting cars as shown in FIG. 20. When the lever 24 is rotated back to a position parallel to the cover II the pivot trunnions will extend into the apertures 21 as shown in FIG. 2b. After the lever has been thus inserted in the cover, the bifurcated ends of the lever is expanded (to the form illustrated in FIG. 4) in the plane of the lever until the edges 29 of the lever extend generally parallel to the center line as shown in FIG. 2c. When the lever is thus expanded, it cannot be removed from the cover without deformation.

When the bifurcated end of the operating lever is expanded, as more clearly seen in FIG. 4, it is to be noted that the projections extend transversely of the longitudinal axis of the lever. It is preferred that the projections have this form in the final assembly, to provide better pivoting action in the apertures 21, and hence the initially formed projections 25, as seen in FIG. 3, extend backwardly at a small angle with respect to the longitudinal axis of the lever.

Referring again to FIG. 1, when the switch is fully assembled, the plunger I5, which is normally spring biased, urges the lever 24 upwardly. In order to limit the movement of the lever in this direction, the end 28 of the lever is adapted to engage the top of the cover II. For this purpose, a bridge 31 may be provided molded between the cars 20 at the end of the cover, with the end 28 of the lever being adapted to engage the bridge 31. The upper edges of the apertures 21 are preferably formed to conform to the upper surface of the lever in this position, i.e., the unactuated position of the switch. Downward movement of the portion 26 of the lever in operation then effects a rotational movement of the lever about a pivot axis 34 which is generally at the rear upper edge of the pivot trunnions 25 (as shown in FIG. 5). In order to permit free move ment of the lever about its pivotable axis, the rear edges 35 of the apertures 21 preferably extend downwardly from the pivot axis 34 at a small angle toward the left edge of the switch (as shown in FIGS. I and 5) with respect to the perpendicular to the cover.

The lower edges of the apertures 21, as above stated, are spaced from the upper edges thereof a sufficient distance to permit assembly of the lever 24 by the technique illustrated in FIG. 2a, and are preferably parallel to the cover 11. The front edges of the apertures 21 are also shaped to permit assembly of the operating lever24, as well as to maintain the lever 24 from excessive back and forth movement in the plane of the lever, and these edges are preferably normal to the plane of the top of the cover 11. It will be obvious, of course, that other configurations may be employed for the apertures 21 than that illustrated in the above example, as long as the apertures have sufiicient depth in the direction normal to the cover surface to permit assembly, while permitting the desired pivotal movement in operation, and restraining the lever from excessive movement in the plane of the lever. It is further ap parent, that the extension of height of the apertures to permit assembly of the operating lever need not be the same for each aperture 21, although a symmetrical arrangement is preferred so that the lever can be inserted by angular displacement in either direction.

It will be understood that many other variations of the disclosed embodiment are possible without departing from the spirit and scope of the invention, such as variations in the shape of the operating lever and switch cover, and it is intended herein to cover all such variations as fall within the true spirit and scope of the invention.

What is claimed is:

I. In a switch assembly of the type having a switch body and a switch operating plunger extending through one surface of said body, and a switch operating lever pivotally mounted on said body in operative alignment with said plunger, the improvement wherein said operating lever has a generally cruciform configuration with a pair of opposite-arms forming pivot trunnions, and means for pivotally holding said pivot trunnions with respect to said switch body for holding a third arm of said lever in operative relationship with respect to said plunger, said holding means comprising a pair of projections extending from said surface and having aligned apertures engaging said pivot trunnions, said apertures having continuous peripheral edges and having dimensions normal to said surface adequate to permit insertion of said pivot trunnions therein by rotation of said lever about its longitudinal axis with respect to said third arm, the fourth end of said operating lever, opposite said third end, having a slot extending therefrom toward said third end and past said pivot trunnions, whereby the opposite sides of said slot may be deformed when said lever is assembled on said switch assembly, to urge said pivot trunnions further into their respective apertures.

2. The switch assembly of claim 1 wherein said apertures are polygonal shaped.

3. An operating assembly for an electric switch of the type having a switch body enclosing a switch contact and an operating plunger extending through one surface of said body for externally actuating said contact assembly: said operating assembly comprising a pair of aligned projections extending from said surface and separately defining a pair of aligned apertures having continuous peripheral edges, a flat operating lever assembled in position between said projections and having one end extending operative relationship with said plunger, said lever having a pair of opposed trunnions extending transversely of the lever intermediate its ends and in the plane thereof, said trunnions extending into said apertures to form rotational pivots for said lever, said lever further having a slot extending from said other end towards said one end and pass said trunnions, whereby deformation of the portion of lever on said other end defining the sides of said slots affects the relative spacing of the trunnions in the plane of said lever, said slot being sufficiently long that the trunnions may be drawn together to a first position by deformation of said other end of said lever to permit assembly 5. The assembly of claim 3 wherein said apertures are polygonal shaped and have upper edges extending at an angle through said surface corresponding to the angular displacement of said lever when said lever is rotated away from said plunger.

a m y: s

Claims

1. In a switch assembly of the type having a switch body and a switch operating plunger extending through one surface of said body, and a switch operating lever pivotally mounted on said body in operative alignment with said plunger, the improvement wherein said operating lever has a generally cruciform configuration with a pair of opposite arms forming pivot trunnions, and means for pivotally holding said pivot trunnions with respect to said switch body for holding a third arm of said lever in operative relationship with respect to said plunger, said holding means comprising a pair of projections extending from said surface and having aligned apertures engaging said pivot trunnions, said apertures having continuous peripheral edges and having dimensions normal to said surface adequate to permit insertion of said pivot trunnions therein by rotation of said lever about its longitudinal axis with respect to said third arm, the fourth end of said operating lever, opposite said third end, having a slot extending therefrom toward said third end and past said pivot trunnions, whereby the opposite sides of said slot may be deformed when said lever is assembled on said switch assembly, to urge said pivot trunnions further into their respective apertures.

2. The switch assembly of claim 1 wherein said apertures are polygonal shaped.

3. An operating assembly for an electric switch of the type having a switch body enclosing a switch contact and an operating plunger extending through one surface of said body for externally actuating said contact assembly: said operating assembly comprising a pair of aligned projections extending from said surface and separately defining a pair of aligned apertures having continuous peripheral edges, a flat operating lever assembled in position between said projections and having one end extending operative relationship with said plunger, said lever having a pair of opposed trunnions extending transversely of the lever intermediate its ends and in the plane thereof, said trunnions extending into said apertures to form rotational pivots for said lever, said lever further having a slot extending from said other end towards said one end and pass said trunnions, whereby deformation of the portion of lever on said other end defining the sides of said slots affects the relative spacing of the trunnions in the plane of said lever, said slot being sufficiently long that the trunnions may be drawn together to a first position by deformation of said other end of said lever to permit assembly and disassembly of the trunnions in the apertures by rotation of the lever about its longitudinal axis, and may be spread apart to a second position in which the removal of the trunnions from the apertures is prevented.

4. The assembly of claim 3 further comprising means on said surface positioned to inhibit rotation of said lever away from said plunger by engagement with the other end of said lever.

5. The assembly of claim 3 wherein said apertures are polygonal shaped and have upper edges extending at an angle through said surface corresponding to the angular displacement of said lever when said lever is rotated away from sAid plunger.