US3073934A

US3073934A - Push button switch

Info

Publication number: US3073934A
Application number: US8268A
Authority: US
Inventors: Albert S Oakman; Michael J Sakatos
Original assignee: Allied Control Co Inc
Current assignee: Allied Control Co Inc
Priority date: 1960-02-12
Filing date: 1960-02-12
Publication date: 1963-01-15
Anticipated expiration: 1980-01-15

Description

Jan. 15, 1963 A. s. OAKMAN EI'AL PUSH BUTTON SWITCH 2 Sheets-Sheet 1 Filed Feb. 12, 1960 25' 3| INVENTORS ALBERT s. OAKMAN MICHAE J.SAKATOS ATTORNEY Jan. 15, 1963 A. s. OAKMAN ETAL 3,073,934

PUSH BUTTON SWITCH Filed Feb. 12, 1960 2 Sheets-Sheet 2 INVENTORS ALBERT $.OAKMAN MICHAEL J. SAKATOS ATTORNEY United States Patent 3,073,934 PUSH BUTTON SWTTQH Albert S. Qakrnan, Flushing, N.Y., and Michael 5. Salsatos, Union, N..l., assignors to Allied Control Company, End, New York, N.Y., a corporation of New York Filed Feb. 12, 1950, Scr. No. 8,268 4 (Ilaims. (Ci. 2tllll59) This invention relates to the art of switches and, more particularly, to an electrical switch of the push button type, i.e. a switch which makes or breaks electric contact only during the interval of time that a push button opera- Lively associated with switch contacts is depressed.

One important object of this invention is to provide a simplified multi-pole push button switch having improved structural features and operational characteristics.

Another important object of the invention is to provide a multi-pole push button switch which is adapted to be conveniently made in various sizes, including miniature and sub-miniature sizes, and which is capable of rendering eificient and dependable service over extended periods of time.

A further object of the invention is to provide a switch of the character indicated that is simple, compact and light-weight in design; that is durable in construction; that is reasonable in manufacturing cost; and that is capable of performing its intended functions in an entirely satisfactory and trouble-free manner.

To the end that the foregoing objects may be attained, a preferred and recommended push button switch according to this invention comprises a base member which carries a plurality of spaced fixed electrical contacts and a like plurality of spaced, parallel, leaf spring contacts, each of the latter including a stationary end part which is anchored to the base member and a free end part extending over and above the base member and disposed in operative alignment with a corresponding fixed contact. A housing is positioned on and extends above the base member. The housing and base member define a compartment into which the leaf spring contacts project. The housing has a through passage which communicates with the compartment.

The switch includes a push button unit comprising a body member which extends through and is slidable in the housing passage, an actuating bar which is secured to the inner end of the body member and a pair of spaced guide pins which are afiixed to the lower face of the actuating bar and register with openings in the base member. The actuating bar is positioned wholly within the compartment in a position over and transverse of the leaf spring contacts and intermediate the ends of these contacts. The parts are so constructed and arranged that the positions of the free end parts of the leaf spring contacts relative to the fixed contacts may be. changed simultaneously by merely depressing the push button unit. The connections between the guide pins and the base member prevent angular movement of the actuating bar relative to the leaf spring contacts in use. This insures proper movement of the push button unit and maintains the actuating bar in correct position relative to the leaf spring contacts at the time of actuation, whereby the leaf springs are all positively actuated in unison.

The above-mentioned push button unit constitutes principal features of this invention. This unit is of one-piece construction and its parts, namely, the body member, the actuating bar and the guide pins, are so arranged that the actuating bar is normal to the body member and the guide pins are positioned to the side of the actuating bar remote from the body member, are parallel to each other and to the body member and are normal to the actuating 3,7333% Federated Jan. 15, 1963 2 The guide pins register with and are slidable in The guide bar. corresponding openings in the base member. pins serve a number of functions including:

(1) They maintain the actuating bar in a predetermined angular position relative to the leaf spring contacts at all times and thereby prevent rotation of the bar with respect to such contacts in use.

(2) They are positioned between successive leaf spring contacts and prevent those contacts from contacting each other in the event such contacts are deformed or their connecting rivets become loosened.

(3) They prevent undesirable cocking of the push but-ton unit as a whole in use.

The enumerated objects and other objects, together with the advantages of this invention, will be readily understood by persons trained in the art from the following detailed description and the accompanying drawings which describe and illustrate a preferred form of push button switch embodying the invention.

In the drawings, wherein like reference numerals denote corresponding parts throughout the several views:

FIG. 1 is a top plan view of a multi-pole push button switch of this invention;

FIG. 2 is a view taken along line 22 of FIG. 1;

FIG. 3 is a view taken along line 33 of FIG. 2;

FIG. 4 is a bottom plan view of FIG. 3;

FIG. 5 is a view taken along line 5-5 of FIG. 2;

FIG. 6 is an enlarged isometric view of the push button unit which is also shown in other views;

FIG. 7 is a view taken along line 7-7 of FIG. 5;

FIG. 8 is a view taken along line 8--8 of FIG. 7;

FIG. 9 is a top plan view of the base member of the switch;

FIG. 10 is a view taken along staggered line 1010 of FIG. 9; and

FIG. 11 is a view taken along line l111 of FIG. 9.

Referring initially to FIGS. 1, 2 and 3, there is shown a switch comprising a base member 15 which carries a plurality of electrical contacts, a housing 16 which is rnounted on the base, a push button unit 17 which is slidable in the housing and engages leaf spring contacts that are carried by the base, and a positioning nut 18 and a locking nut 19 which are provided to position and secure the switch on, for example, a panel board (not shown).

The base member 15 is best shown in FIGS. 9, 10 and 11 and is made of a suitable insulating material, such as a thermosetting melamine formaldehyde resinous composition, available under the trademark Melmac, or a thermosetting phenol formaldehyde resinous composition, available under the trademark Bakelite. The base member is recessed along its sides, as indicated at 20, and is provided with pairs of oppositely disposed slots 21. :Formed in the base member are two rows of spaced through

openings

22 and 23 of similar configuration.

. It will be observed that there are three openings 22 and a like number of openings 23 (FIG. 9). A pair of spaced parallel blind bores 24 are formed in the base member. These bores are intermediate and preferably equi-distant from the rows of

openings

22 and 23.

The base member carries a plurality, namely three, of fixed electrical contacts 25, each of which registers with an opening 23 and is electrically and mechanically connected at its lower end to a corresponding fixed contact terminal 26. The base member also carries three electrically conductive rivet elements 27, each of which registers with an opening 22 and is electrically and mechanically connectedv at its lower end to a corresponding fixed contact terminal 28.

Provided for cooperation with each fixed contact 25 r is a generally J-shaped leaf spring contact 30 consisting 53 of a rectilinear arm or part 31 and an arcuate part 32. which is anchored to the base member by a corresponding rivet element 27. The free end portion of each arm 31 is equipped with a contact button 33 which is disposed in operative alignment with a corresponding fixed contact 25 so that it will, upon predetermined downward movement, engage its contact 25 and make electrical connection therewith.

Housing 16 includes a tubular wall 34 which is open at its lower end to receive and engage the recessed portion of the base member and make a snug fit therewith. Tubuwall 34 is depressed to define dimples 35 which register with corresponding base slot 21 (FIGS. 2 and 4) whereby to securely join the housing to the base member. The housing also includes an externally threaded tubular connector 36 which extends through a central opening in wall 34 and which is bent over, as indicated at 37, to effect firm engagement with that wall.

Reference is next had to FIGS. 2, 3, and 6 which best show the construction, configuration and relative position of the parts of push button unit 17. This unit is of onepiece construction and is formed of a suitable insulating material, preferably an appropriate synthetic resin, such as molded nylon. The push button unit consists of a cylindrical body member or plunger 40 which is freely slidable in housing connector 36, an actuat ng bar 41 which is normal to the longitudinal axis of the body member and which is formed with an arcuate contact surface 42, and a pair of guide pins 43 which are disposed equi-distantly to opposite sides of the axis of the body member. Pins 43 are parallel to each other and to the body member and normal to the actuating bar. As is best shown in FIGS. 2 and 3, each guide pin registers with and is slidable in a corresponding blind bore 24. The guide pins are rounded at their lower ends to facilitate initial entry in the blind bores.

For the purpose of describing the operation of the illustrated embodiment of the invention, it is assumed that the switch has been assembled and that the parts are in the relative position shown in FIGS. 2 and 3. With the parts in this position, actuating bar 41 bears against the central portion of each leaf spring contact arm 31, each guide pin 43 is positioned between one of the leaf spring contacts and the next successive leaf spring contact and registers with the upper portion of the corresponding blind bore 24, and push button unit 17 is normally and yieldingly maintained at its extreme upper limit of travel by leaf spring contacts 30 and by engagement of actuating bar 41 with connector element 37. Also, contact buttons 33 are in raised position and out of contact with their contacts 25.

Upon depression of the push button unit, actuating bar 41 flexes the leaf spring contact arms downwardly and causes contact buttons 33 to engage corresponding fixed contacts 25, thereby closing corresponding circuits containing these contacts. The actuating bar is maintained at all times in its normal transverse relation to its leaf spring contacts by the sliding connection of the guide pins in the blind bores. Accordingly, electrical connection of all leaf spring contacts and fixed contacts is effected simultaneously; and successive contacting, which would occur if the push button unit were permitted to rotate so as to dispose the actuating bar at a different angle to the leaf spring contacts, is prevented. Moreover, the guide pin arrangement effectively eliminates any possibility of cocking of the actuating bar at the time the push button unit is depressed. Additionally, the location of the guide pins between corresponding pairs of leaf spring contacts prevents any such contact, which may be deformed or loosened, from contacting one of the other leaf spring contacts.

From the foregoing, it is believed that the objects, advantages, construction and operation of the present invention will be readily comprehended by persons skilled in the art, without further description. Although the invention has been herein shown and described as applied to a multipole normally open switch, by way of example, it will be appreciated that the invention is applicable to various other forms of switches including multi-pole normally closed switches and multi-pole multiple throw switches. It will also be appreciated that certain parts or elements disclosed herein are representative of other parts or elements which may be used in the same or a similar manner to accomplish the same or similar results. Therefore, it is to be understood that the invention is not to be limited to the exact details described herein but is to be accorded the full scope and protection of the appended claims.

We claim:

1. An electrical switch comprising a base member, a plurality of spaced fixed electrical contacts fixedly mounted on the base member, a pluralit of leaf spring contacts extending over the base member in spaced parallel relationship, each leaf spring contact including a stationary end part anchored to the base member and a free end part disposed in operative alignment with a corresponding fixed contact, a housing secured to and extending above the base member, the housing and the base member defining a compartment into which the leaf spring contacts project, said housing having a through passage which communicates with the compartment, a push button unit comprising a body member extending through and slidable in said passage, an actuating bar secured to one end of the body member and at least a pair of spaced guide pins secured to the actuating bar and registering with openings formed in the base member, each guide pin being disposed in the space between a corresponding pair of successive leaf spring contacts, said actuating bar being positioned in the compartment over and transversely of the leaf spring contacts intermediate the ends thereof whereby the positions of the free end parts of the leaf spring contacts relative to the fixed contacts may be changed simultaneously by depressing the push button unit, the connection between the guide pins and the base member ensuring rectilinear movement of the actuating bar and preventing angular movement thereof relative to the leaf spring contacts.

2. An electrical switch according to claim 1 wherein the push button unit is one-piece and whereln the actuating bar is normal to the body member and the guide pins are parallel to each other and to the body member and normal to the actuating bar, said guide pins being disposed to the side of the actuating bar remote from the body member, each guide pin being positioned between one of the leaf spring contacts and a next successive leaf spring contact.

3. An electrical switch comprising a base member, a plurality of spaced fixed electrical contacts fixedly mounted on the base member, a plurality of leaf spring contacts extending over the base member in spaced parallel relationship, each leaf spring contact including a stationary end part anchored to the base member and a free end part disposed in operative alignment with a corresponding fixed contact, said free end parts being normally spaced above the fixed contacts, a housing secured to and extending above the base member, the housing and the base member defining a compartment into which the leaf spring contacts project, said housing having a through passage which communicates with the compartment, a push button unit comprising a body member extending through and slidable in said passage, an actuating bar secured to one end of the body member and at least a pair of spaced guide pins secured to the actuating bar and registering with openings formed in the base member, each guide pin being disposed in the space between a corresponding pair of successive leaf spring contacts, said actuating bar being positioned in the compartment over and transversely of the leaf spring contacts and bearing against the leaf spring contacts intermediate their ends, said leaf spring contacts normally maintaining the push button unit in raised position relative to the base member, the parts being so constructed and arranged that, by depressing the push button unit, the leaf spring contacts are simultaneously flexed downwardly to thereby eifect electric contact between the free end part of each leaf spring contact and a corresponding fixed contact, the connection between the guide pins and the base member ensuring rectilinear movement of the actuating bar and preventing angular movement thereof relative to the leaf spring contacts.

4. An electrical switch according to claim 3 wherein the push button unit is one-piece and wherein the actuat- 1t] ing bar is normal to the body member and the guide pins are parallel to each other and to the body member and normal to the actuating bar, said guide pins being disposed to the side of the actuating bar remote from the body member, each guide pin being positioned between one of the leaf spring contacts and a next successive leaf spring contact.

References Cited in the file of this patent UNITED STATES PATENTS 374,036 Bosworth Nov. 29, 1887 1,314,524 Kunkle Sept. 2, 1919 1,423,306 Catlin July 18, 1922 1,567,947 Hemphill Dec. 29, 1925 2,692,920 Brown Oct. 26, 1954

Claims

1. AN ELECTRICAL SWITCH COMPRISING A BASE MEMBER, A PLURALITY OF SPACED FIXED ELECTRICAL CONTACTS FIXEDLY MOUNTED ON THE BASE MEMBER, A PLURALITY OF LEAF SPRING CONTACTS EXTENDING OVER THE BASE MEMBER IN SPACED PARALLEL RELATIONSHIP, EACH LEAF SPRING CONTACT INCLUDING A STATIONARY END PART ANCHORED TO THE BASE MEMBER AND A FREE END PART DISPOSED IN OPERATIVE ALIGNMENT WITH A CORRESPONDING FIXED CONTACT, A HOUSING SECURED TO AND EXTENDING ABOVE THE BASE MEMBER, THE HOUSING AND THE BASE MEMBER DEFINING A COMPARTMENT INTO WHICH THE LEAF SPRING CONTACTS PROJECTS, SAID HOUSING HAVING A THROUGH PASSAGE WHICH COMMUNICATES WITH THE COMPARTMENT, A PUSH BUTTON UNIT COMPRISING A BODY MEMBER EXTENDING THROUGH AND SLIDABLE IN SAID PASSAGE, AN ACTUATING BAR SECURED TO ONE END OF THE BODY MEMBER AND AT LEAST A PAIR OF SPACED GUIDE PINS SECURED TO THE ACTUATING BAR AND REGISTERING WITH OPENINGS FORMED IN THE BASE MEMBER, EACH GUIDE PIN BEING DISPOSED IN THE SPACE BETWEEN A CORRESPONDING PAIR OF SUCCESSIVE LEAF SPRING CONTACTS, SAID ACTUATING BAR BEING POSITIONED IN THE COMPARTMENT OVER AND TRANSVERSELY OF THE LEAF SPRING CONTACTS INTERMEDIATE THE ENDS THEREOF WHEREBY THE POSITIONS OF THE FREE END PARTS OF THE LEAF SPRING CONTACTS RELATIVE TO THE FIXED CONTACTS MAY BE CHANGED SIMULTANEOUSLY BY DEPRESSING THE PUSH BUTTON UNIT, THE CONNECTION BETWEEN THE GUIDE PINS AND THE BASE MEMBER ENSURING RECTILINEAR MOVEMENT OF THE ACTUATING BAR AND PREVENTING ANGULAR MOVEMENT THEREOF RELATIVE TO THE LEAF SPRING CONTACTS.