US3219766A

US3219766A - Push button switch

Info

Publication number: US3219766A
Application number: US180495A
Authority: US
Inventors: John W Sayward; Jr Bernard C Westgate
Original assignee: Ark Les Electronic Products Corp
Current assignee: Ark Les Electronic Products Corp
Priority date: 1962-03-19
Filing date: 1962-03-19
Publication date: 1965-11-23
Anticipated expiration: 1982-11-23

Description

Nov. 23, 1965 J. w. SAYWARD ETAL 3,219,766

PUSH BUTTON SWITCH Filed March 19, 1962 2 Sheets-Sheet l H gEu u mfg 1965 J. w. SAYWARD ETAL 3,219,756

2 Sheets-Sheet 2 Filed March 19. 1962 J2 Ill/will?! United States Patent 3,219,766 PUSH BUTTON SWITCH John W. Sayward, Stow, and Bernard C. Westgate, J12,

Cambridge, Mass., assignors to Ark-Les Switch Corporation, Watertown, Mass., a corporation of Massachusetts Filed Mar. 19, 1962, Ser. No. 180,495 7 Claims. (Cl. 200-) This invention relates to what are sometimes called multiple push button switches, that is, push button switches in which several circuit contacts are controlled by the operation of more than two push buttons. Such switches are used in controlling appliances such as electric ranges and similar devices. More particularly the present invention relates to multiple push button switches of the type having movable contact controlling slides, each slide provided with a series of cam surfaces that are acted upon and moved by the push buttons, the slides having other cam surfaces which in turn open or close contacts as the slides are moved by the push button.

One object of the present invention is to provide improved constructions to facilitate the manufacture of push button switches of the type above noted. Another object is to provide improved performance in these switches. A further object is to reduce the number of parts required in a switch of the character described and at the same time to simplify the fabrication and assembly of the necessary parts. A specifically important object is to provide an improved detenting arrangement for the push buttons in such switches whereby each push button will be held reliably in a definite extended or depressed position at any single time during operation of the switch.

The objects of the invention are met generally by forming the interior active parts of the switch from flat sheet metal and insulating sheet stock and so shaping the parts that they may be simply slipped or slid into grooves or sockets within a molded insulating housing from a single direction, all interior parts being held in place within the housing by the application of a cover or closure secured thereto which completes the assembly of the switch. The push button detent arrangement in particular consists of a single element in the form of a flat strip common to' all of the push button plungers in the switch, this strip, like the other interior parts of the switch, being slipped into place in a slot in the housing and held in place within the housing by the application of the housing closure, this element having resilient detenting arms integral therewith cooperating with the ends of the push button plungers to hold the plungers in and out of their depressed positions.

Other objects and further details of that which is believed to be novel and included in this invention will be clear from the following description and claims, taken with the accompanying drawings in which is illustrated an example of push button switch embodying the present invention and incorporating the improved constructions and arrangements outlined above.

In the drawings:

FIG. 1 is a top outside plan view of a preferred form of a completed push button switch according to this invention;

FIG. 2 is a side elevational view of this switch;

FIG. 3 is a horizontal sectional view on the line 33 of FIG. 2 showing, on an enlarged scale, a top plan view of part of the inside of the switch;

FIG. 4 is a longitudinal vertical sectional view of this part of the switch as taken on the line 4-4 of FIG. 3;

FIG. 5 is a transverse vertical sectional view through the switch as on the line 5-5 of FIGS. 3 and 4;

FIG. 6 is another transverse vertical sectional view but on line 6-6 of FIGS. 3 and 4;

FIG. 7 is a perspective view of a preferred form of terminal spring member serving as an electrical bridging strip or bus within the switch;

FIG. 8 is a perspective view of a preferred form of push button holder or detent element used in a switch according to this invention, and

FIG. 9 is a perspective view of a preferred form of push button plunger element for the switch.

In carrying out the objects of this invention, in one embodiment thereof a molded insulating base or housing 10 is provided with an interior cavity 12 opening to one side of the housing, in this case the top, this open side being closed as by a cover 14. The cover 14 is shown as made of sheet metal, but it is insulated from the interior parts of the switch as by a flat insulating sheet 16. For some purposes the closure for the housing might be made of insulating material entirely but in that case attachment details for the closure would be altered from those shown. These consist of extended tabs 18 at the corners of the cover and other tabs 20 along the sides of the cover which are bent down along the outside of the housing and hooked inwardly under appropriate shoulders on the housing as indicated, thus securing the metal cover 14 and the insulating sheet 16 in place. If desired, threaded holes 22 may be provided in the closure or in the housing to mount the switch body in place by screws in a conventional fashion.

Within the cavity 12 in the housing various slots, holes or grooves are provided to receive and guide the active parts of the switch during assembly and in use. These slots, grooves and holes all open to the same side of the switch housing as the interior cavity 12, this not only assisting in the molding of the piece but also facilitating assembly of the switch by the simple dropping or sliding of the parts into place from one side, the open side of the housing. For example, a lengthwise channel or groove 24 is provided within the cavity of the insulating housing to receive the slidable flat insulating cam pieces 26. These contact actuating slides have upper cam surfaces 28 which control the position of the movable contacts within the switch as explained later, and the positions of these pieces are governed in turn by engagement of the cylindrical end 30 of each push button plunger 32 with other portions of the cam surfaces 28 in a manner well understood in the construction of switches of this general character.

Vertically extending guiding grooves 34 in the cavity transverse to the groove 24 slidably receive the edges of the push button plungers 32 for straight up and down movement. The push button plungers preferably are made from fiat sheet metal stock and are curled or rolled centrally at their ends to provide the cylindrical portions 30. Extended fiat edge portions 31 on either side of each cylindrical end may be provided to ride in the transverse grooves 34 to guide each plunger.

The lengthwise channel 24 also receives the push button detent element 36 of this invention, this element extending lengthwise for the entire length of the interior cavity of the housing and having ends 38 which extend for the entire depth of the cavity and of the channel 24. A preferred shape of this element is shown most clearly in FIG. 8 and it will be seen that it may be formed of a single piece of relatively stiff but resilient sheet material cut or blanked into appropriate contour. This contour includes not only the extended element-positioning ends 38 above noted but also a series of reguarly spaced pairs of opposed resilient arms 40, each pair of arms having between them a slot 42 leading to a slightly enlarged circular end recess 44. Each end recess 44 is precisely positioned an'd dimensioned to receive and hold therein the cylindrical end 30 of a push button plunger, and the slot 42 leading to this recess is made only slightly less in width than the diameter of the cylindrical push button plunger end. Therefore, and because the construction of this type of switch is based upon this kind of action, whenever a push button is manually depressed it will move one or more of the cam slides 26 longitudinally and push button plungers other than the one depressed will be carnmed outwardly by the moving cam surface 28 if not already in extended position. The push button detenting arrangement is designed to hold a depressed push button in proper position and also to allow previously depressed push buttons to be cammed outwardly by the slides 26, the detent element holding these push buttons in their outer position after they have been moved thereto. The slight overhang of the resilient arms will hold the cylindrical end 30 of a push button plunger in the circular recess 44 when a push button has been depressed. However, when another button is depressed and this push button plunger is pushed outwardly by action of a moving cam slide 26, the resilient arms 48 will engage and be spread by the sides of the cylindrical end 30 as it is forced outwardly, holding the plunger in place frictionally in extended position. The entrance of each slot 42 may be rounded or tapered, as shown. Insulating or conducting material may be used for this detent element because the current-carrying switch parts are all separated from each other and from the push button plungers by the insulating slides 26 and the detent strip does not touch any current-carrying parts.

The stationary contacting and conducting parts of the switch are also of designs compatible with the objects of this invention and are mounted in slots or holes 46 along one side of the interior cavity 12. The holes 46 frictionally receive stationary line terminals 48 each formed of conducting material, preferably from a flat piece of copper or bronze, a central tab 50 being blanked out at one end and bent at right angles to the body of the terminal piece as seen most clearly in FIG. 5. The end of this tab may be provided with a contact button 52 of silver or other good conducting material in a manner well understood. On the sides of the line terminal piece, next to the portion where the tab 50 is blanked and bent out, vertical posts 54 remain which extend from the tab 50, where it rests on the bottom of the interior cavity, upward to the top of the cavity so that each line terminal member 48 is held in place by the cover when the switch is completely assembled and closed. The bottom end of each terminal piece 48 extends downwardly into and is frictionally received by the hole 46, a dimple 56 on each terminal piece being provided for a tight friction fit. One or more of the terminal pieces 48 is extended through its hole 46 to the outside of the insulating housing It as indicated at the right hand side of FIG. 5. This extended end is used as a tab type connector in establishing electrical connection with cooperating contacts in an electrical receptacle not here shown because of a type well known in the art.

Because there is no need to supply more than one of the terminals 48 with the tab connection when several are to receive power from the same source, the present invention provides for an electrical bridging strip or bus 58 which is used to connect several of the line terminals 48 together inside of the housing. As shown in FIG. 7 this bus preferably is made in the form of a fiat ribbon or resilient conducting material with flat contacting sections 60 separated by slightly bowed spring connecting sections 62. When the terminal pieces 48 are inserted in the holes 46, the bridging strip 58 is forced into a shallow groove 64 in the side of the cavity above the holes 46 and is thus compressed between the posts 54 of the terminals and the side wall of the groove in the cavity. The flat sections 60 are opposite these extended ends of the terminals 48 and the spring sections 62 extend between each of the terminal locations and press the bridging strip into good electrical contact with the terminal elements. This bridging strip is, like the other parts, held in place by the cover when the cavity of the housing is closed.

The load terminal elements are preferably for-med as integral parts with the movable contacts of the switch. These are the elements 66 located on the side of the housing cavity opposite the line terminals 48, each element consisting of a main terminal portion 68 bent upon itself and extending through a mounting slot or hole 70 at the edge of the cavity in the housing and projecting outwardly in back of the housing to serve as a tab contact element adapted to be received within a cooperating receptacle or load connector in a conventional fashion. The free end of each element 66 extends upwardly within the housing to the top of the interior cavity and the cover of the housing will hold the element in place after assembly in a manner readily understood. A bridging strip (not shown) like the bus 58 may be used to connect any terminal element 66 to one or more adjacent elements 66, if desired, in the same manner as connections between terminals 48, described above.

When a load terminal element is in place in the mounting hole 70 the other end of the reversely bent portion extends as a switch contact arm into the cavity 12 and over the switch operating slides 26, with a contact button 72 at its end positioned to cooperate with the contact button 52 on a line terminal 48 to close or open a circuit across the switch. The elements 66, like the elements 48, are each made from a single piece of thin resilient electrically conducting material such as copper or bronze strip stock and are simply blanked to the required shape and then bent to the desired form. The portion of this element which serves as the moving contact arm may be cut away as at 74 in order to obtain increased flexibility of the element at this point. The portion 76 which extends above and across the slides 26 is preferably bent intoa V-channel form as shown, both to stiffen this portion of the element and to provide a smooth contour for proper cooperation with the cam surfaces 28 on the slides. As is customary in switches of the general character here described, when no cam surface lifts the contact arm 76 of a particular element 66, the element is forced by its own resiliency into a position where its contact button completes a circuit with a contact button on an opposite line terminal. In other conditions, determined by the position of one or more of the cam slides, a cam peak will ride under the contact arm portion 76 of the element, flexing it at the cutaway portion 74 so that the contact button in this pole of the switch will be lifted and the circuit opened.

After the parts of the switch as above described have been slipped into place within the cavity in the switch housing, the insulating sheet 16 and cover 14 are applied and secured in place by bending over the

tabs

18 and 20, the push button plungers 32 extending through appropriate clearance holes to the outside of the switch assembly. Insulating push button knobs or heads 78 then may be suitably shipped and secured over the ends of the plungers in any desired fashion and the assembly is entirely complete.

Depending upon the service desired of the particular switch, one or more of the line terminals 48 may be eliminated as may one or more of the load terminal pieces 66. Furthermore, depending upon the service, a bridging strip or bus 58 may serve any one or more of the terminal elements 48, or the opposite terminal elements 66, or terminal elements on both sides, and the strip may be interrupted or discontinued at any desired point to isolate some particular terminal from the tab connection of switch contact of another.

These variations are well within the knowledge and understanding of the manufacturers of these switches and need not be further emphasized. However it is pointed out that because of the structures herein provided a standard switch of the character herein set forth can be used in the manufacture of a great variety of switches with different circuit arrangements by simple changes in the number and connection of parts during assembly.

Furthermore, it should be noted that in the assembly of the entire switch it is not necessary to use any screws, bolts, clips or clamps extraneous to the functional parts of the switch itself. Every mechanical and electrical connection is made by sliding or friction fit in a single direction during assembly, all the parts being held in place by the securing of the cover which closes the open side of the cavity in the housing.

As will be evident from the foregoing description, certain aspects of this invention are not limited to the particular details set forth as an example, and it is contemplated that various and other modifications and applications of the invention will occur to those skilled in the art. It is therefore intended that the appended claims shall cover such modifications and applications as do not depart from the true spirit and scope of the invention.

What is claimed as new and is desired to be secured by Letters Patent of the United States is:

1. In a multiple push-button switch of the type having longitudinally movable slides with contact actuating cam surfaces thereon,

a multiplicity of push-button plungers, each with an end movable in and out of a depressed position to move said slides, and

a housing having an internal cavity with one open side receiving the slides and guiding them in their longitudinal movement and receiving the push-button plungers and guiding them in their movement in and out of their depressed positions,

that improvement in switching means comprising the combination of,

a single fixed detent member extending the full length of the cavity opposite the ends of the push-button plungers,

resilient arms on said fixed detent member extending toward said push-button plungers, said arms being shaped frictionally to engage the ends of said pushbutton plungers and hold each plunger individually in its depressed position,

stationary electrical terminal elements in the cavity,

a terminal bridging strip in the cavity extending alongside a plurality of said stationary terminal elements,

resilient spring portions integral with said bridging strip urging said strip into electrical contact with said terminal elements,

movable electrical contact elements in the cavity moved by said slides for cooperative switching action with respect to said terminal elements,

said fixed detent member, said terminal elements, said bridging strip and said contact elements each being insertable through the open side of the housing into the cavity and having portions extending the full depth of the cavity and a cover secured to the housing, closing the open side and holding said detent member, terminal elements, bridging strip and contact elements within the cavity.

2. In a multiple push-button switch of the type having longitudinally movable slides with contact actuating cam surfaces thereon,

a multiplicity of push-button plungers, each with an end movable in and out of a depressed position to move said slides,

a housing having an internal cavity with one open side receiving said slides and guiding them in their longitudinal movement and receiving the ends of said push-button plungers and guiding them in their movement in and out of their depressed positions,

plunger detent means in the cavity opposite the ends of said push-button plungers engaging and holding each individually in its depressed position, and

stationary electrical terminal elements in the cavity and cooperating movable electrical contact elements 6 in the cavity moved by the slides for switching action with respect to said terminal elements,

that improvement in means connecting said stationary terminal elements together electrically, comprising a terminal strip of conducting material in the cavity extending alongside a plurality of said terminal elements and lying between said stationary terminal elements and an adjacent side of said cavity,

resilient bowed spring portions on said strip urging other portions of said strip into electrical contact with said terminal elements and into frictional contact with said adjacent cavity side,

said terminal strip being insertable through the open side of the housing into the cavity and a cover secured to the housing, closing the open side and holding said terminal strip in place in the cavity.

3. In a multiple push-button switch of the type having longitudinally movable slides with contact actuating cam surfaces thereon,

a multiplicity of push-button plungers, each movable to a depressed position to move said slides,

a housing having an internal cavity for receiving the slides and guiding them in their longitudinal movement and receiving the push-button plungers and guiding them in their movement,

stationary electrical terminals at spaced locations along one side of the cavity and cooperating movable electrical contacts with corresponding terminals at spaced locations along the opposite side of the cavity,

said contacts being actuated by the slides for switching action with respect to stationary terminals,

that improvement in means connecting terminals on one side of said cavity together electrically, comprising a terminal bridging bus in the cavity extending along one side thereof next to a plurality of the terminals on that side between said terminals and the adjacent side of said cavity and bowed spring portions separated by contacting portions on said bus urging said bus into electrical connecting contact with said terminals and into frictional contact with said adjacent cavity side,

whereby said bus is held frictionally in said cavity alongside said terminals and in contact therewith. 4. In a multiple push-button switch of the type having longitudinally movable slides with contact actuating cam surfaces thereon,

a housing having an internal cavity for receiving the slides and guiding them in their longitudinal movement,

cooperating stationary electrical terminals and movable switch contacts in the cavity, said contacts being engaged and actuated for switching action by longitudinal movement of the cam surfaces on said slides, and

means for moving the slides longitudinally in the cavity,

that improvement wherein said means for moving the slides comprises a multiplicity of separate push-button plungers each movable in and out of a depressed position in the cavity in said housing,

each plunger having an end rolled into cylindrical form, engaging a cam surface on a slide and moving said slide longitudinally when said plunger is depressed and each plunger having fiat edge portions extending beyond said cylindrical formed end,

said housing cavity having grooves receiving said fiat edge portions and guiding said plunger thereby in movement of said plunger in and out of its depressed position.

5. In a multiple push-button switch of the type having movable slides with contact actuating cam surfaces thereon,

a multiplicity of push-button plungers, each movable in and out of a depressed position to move said slides,

a housing containing said slides and said plungers and guiding them in their movements,

stationary contacts in said housing and cooperating movable contacts in said housing adapted to be engaged and moved by said cam surfaces on said slides for switching action with respect to said stationary contacts,

each said movable contact serving as a switch terminal and comprising a single piece of flat resilient conducting material folded upon itself at one end to form a double thickness terminal tab portion projecting outside of said housing at one side thereof and an integral contact arm on said piece extending within said housing adjacent and across said slides for engagement and movement by said cam surfaces thereon, said contact arm having a free end positioned for switching cooperation with said stationary con tact on the opposite side of said slides.

6. In a multiple push-button switch of the type having longitudinally movable slides with contact actuating cam surfaces thereon,

stationary electrical contact elements in said housing and cooperating movable electrical contact elements in said housing adapted to be engaged and moved by said cam surfaces on said slides for switching action with respect to said stationary contact elements,

each said movable contact element serving as a switch terminal and comprising a single piece of resilient, electrically conducting material bent upon itself to form at one end a terminal tab projecting from said housing,

a contact arm integral therewith, extending from said tab within said housing across said longitudinal slides for engagement and movement by said cam surfaces thereon, said arm having a portion adapted for switching cooperation with a said stationary contact element and said contact arm, where it extends across said slides,

being formed into a channel shape providing a surface for engagement by said cam surfaces on said slides.

7. In a multiple push-button switch of the type having longitudinally movable slides with contact actuating cam surfaces thereon,

stationary electrical contact elements in said housing and cooperating movable electricalcontact elements in said housing adapted to be engaged and moved by said cam surfaces on said slides for switching action with respect to said stationary contact elements,

each said movable contact element serving as a switch terminal and comprising a single piece of thin, resilient, electrically conducting material bent upon itself at one end to form a double thickness terminal tab portion projecting outside of said housing at one side thereof,

a contact arm portion integral with said tab, extending at right angles therefrom within said housing and across said longitudinal slides for engagement and movement by said cam surfaces thereon, said arm portion having a free end for switching cooperation with a said stationary contact element on the other side of said slides,

said contact arm being cut away adjacent said tab for flexibility at that point and said contact arm, where it extends across said slides, being formed into a V-channel shape for stiffening and providing a surface for engagement by said cam surfaces on said slides.

References Cited by the Examiner UNITED STATES PATENTS 2,060,431 11/1936 Spicer 2005 2,652,470 9/1953 Batcheller 2005 2,723,317 11/1955 Hutt 2005 2,885,499 5/1959 Bentzman 2005 2,908,775 10/1959 Gilbert 200166 2,914,629 11/1959 DAprile et al. 200--5 2,934,613 4/1960 Stoner et al. 2005 2,968,704 1/1961 Woodward et al 200-5 3,022,409 2/ 1962 Williams et al. 2005 BERNARD A. GILHEANY, Primary Examiner. ROBERT K. SCHAEFER, Examiner.

Claims

1. IN A MULTIPLE PUSH-BUTTON SWITCH OF THE TYPE HAVING LONGITUDINALLY MOVABLE SLIDES WITH CONTACT ACTUATING CAM SURFACES THEREON, A MULTIPLICITY OF PUSH-BUTTON PLUNGERS, EACH WITH AN END MOVABLE IN AND OUT OF A DEPRESSED POSITION TO MOVE SAID SLIDES, AND A HOUSING HAVING AN INTERNAL CAVITY WITH ONE OPEN SIDE RECEIVING THE SLIDES AND GUIDING THEM IN THEIR LONGITUDINAL MOVEMENT AND RECEIVING THE PUSH-BOTTOM PLUNGERS AND GUIDING THEM IN THEIR MOVEMENT IN AND OUT OF THEIR DEPRESSED POSITIONS, THAT IMPROVEMENT IN SWITCHING MEANS COMPRISING THE COMBINATION OF, A SINGLE FIXED DETENT MEMBER EXTENDING THE FULL LENGTH OF THE CAVITY OPPOSITE THE ENDS OF THE PUSH-BOTTOM PLUNGERS, RESILIENT ARMS ON SAID FIXRF DETENT MEMBER EXTENDING TOWARD SAID PUSH-BOTTON PLUNGERS, SAID ARMS BEING SHAPED FRICTIONALLY TO ENGAGE THE ENDS OF SAID PUSHBUTTON PLUNGERS AND HOLD EACH PLUNGER INDIVIDUALLY IN ITS DEPRESED POSITION, STATIONARY ELECTRICAL TERMINAL ELEMENTS IN THE CAVITY, A TERMINAL BRIDGING STRIP IN THE CAVITY EXTENDING ALONGSIDE A PLURALITY OF SAID STATIONARY TERMINAL ELEMENTS, RESILIENT SPRING PORTIONS INTEGRAL WITH SAID BRIDGING STRIP URGING SAID STRIP INTO ELECTRICAL CONTACT WITH SAID TERMINAL ELEMENTS, MOVABLE ELECTRICAL CONTACT ELEMENTS IN THE CAVITY MOVED BY SAID SLIDES FOR COOPERATIVE SWITCHING ACTION WITH RESPECT TO SAID TERMINAL ELEMENTS, SAID FIXED DETENT MEMBER, SAID TERMINAL ELEMENTS, SAID BRIDGING STRIP AND SAID CONTACT ELEMENTS EACH BEING INSERTABLE THROUGH THE OPEN SIDE OF THE HOUSING INTO THE CAVITY AND HAVING PORTIONS EXTENDING THE FULL DEPTH OF THE CAVITY AND A COVER SECURED TO THE HOUSING, CLOSING THE OPEN SIDE AND HOUSING SAID DETENT MEMBER, TERMINAL ELEMENTS, BRIDGING STRIP AND CONTACT ELEMENTS WITHIN THE CAVITY.