US3437775A

US3437775A - Illuminated pushbutton switch and method of assembling same

Info

Publication number: US3437775A
Application number: US604707A
Authority: US
Inventors: Earl T Piber
Original assignee: Cutler Hammer Inc
Current assignee: Cutler Hammer Inc
Priority date: 1966-12-27
Filing date: 1966-12-27
Publication date: 1969-04-08
Anticipated expiration: 1986-04-08
Also published as: GB1147549A

Description

April 8, 1969 E. T. PlBE IR 3,

ILLUMINATED FUSHBUTTON SWITCH AND METHOD OF ASSEMBLING SAME Filed Dec. 27, 1966 1 Sheet of 4 NIH I93 Zia April 8, 1969 E. 1 FEB? 3,

ILLUMINATED PUSHBUTTON SWITCH AND METHOD OF ASSEMBLING SAME Filed Dec. 27. 1966 I Sheet i April 8, 1969 E. 1'. FIBER 3,

ILLUMINATED PUSHBUTTQN SWITCH AND METHOD OF ASSEMBLING SAME Filed Dec. 27, 1966 v Sheet .5 M4

6| as a H 1O 1 v A. A '2 gate BS /W79 72 l? e wbrmg April 8, 1969 'r. FIBER 3,437,775 I ILLUMINATED PUSHBUTTON SWITCH AND METHOD OF ASSEMBLING SAME Sheet 4 014 Filed Dec. 27, 1966 53 54 56 9 sz 34 4 626 63 67 a7 a l 55 35 36 I9 I88 9a m.

United States Patent ILLUMINATED PUSHBUTTON SWITCH AND METHOD OF ASSEMBLING SAME Earl T. Fiber, Ocenomowoc, Wis., assignor to Cutler- Hamrner, Inc., Milwaukee, Wis., a corporation of Delaware Filed Dec. 27, 1966, Ser. No. 604,707

Int. Cl. H01h 9/18 U.S. Cl. 200-167 13 Claims ABSTRACT OF THE DISCLOSURE A pushbutton switch having a cylindrical outer shell and a flexible insulating liner. Before assembly the liner is initially planar with various functional surfaces molded therein. The liner is rolled and inserted into the outer shell where the molded functional surfaces cooperate with various movable parts of the switch. The inserted liner also serves to support various stationary parts such as a conductor strip which is retained between the liner and shell and insulated from the aluminum shell by an anodized layer.

Background 0 the invention This invention relates to pushbutton electrical switches and more particularly to miniature pushbutton switches and the method of assembly thereof.

It is not uncommon in the manufacture of pushbutton switches to construct the switch housing with a variety of camming or latching surfaces or similar operating elements formed or molded on the inside of the housing. The manufacture of such switches, particularly in miniature sizes, can understandably be relatively costly because the construction of complicated elements in the confines of the housing may require complicated molding dies or other intricate manufacturing equipment. Also, the assembly of illuminating elements or conductors within the housing may be dilficult.

Summary of the invention It is an object of this invention to provide means and a method for the rapid and economical assembly of electrical switch mechanisms.

The objects of this invention are accomplished primarily by molding various functional operating shapes or the like on the surfaces of a flexible flat liner member and then rolling the flexible members to a cylindrical shape and further inserting the cylindrical member into a switch housing. The complicated functional surfaces can thereby be formed in relatively simply generally planar dies. Further, the molded surfaces need not be provided with relief clearances for the dies which clearances might tbe required if the molded surfaces were molded in the final cylindrical shape. The rolled flexible member is also used to secure electrical conductors and other elements within the housing and these may be assembled within the housing simultaneously with the insertion of the flexible member. A complete reading of this specification will more clearly demonstrate how this construction and method of assembly also makes possible an extremely compact device and provides for the incorporation of other unique details of construction.

Brief description 0 the drawing In the drawings:

FIGURE 1 is a sectional view taken through the axial centerline of an illuminated pushbutton switch embodying the principles of the present invention;

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

FIG. 3 is a fragmentary sectional view taken on line 3-3 of FIG. 1;

3,437,775 Patented Apr. 8, 1969 FIG. 4 is an elevational view of one of the unassembled elements of the device illustrated in FIG. 1;

FIG. 5 is a sectional view taken on line 5-5 of FIG. 4;

FIG. 6 is an elevational view of another unassembled element of the device illustrated in FIG. 1;

FIG. 7 is a sectional view taken on line 7--7 of FIG. 6;

FIG. 8 is a fragmentary sectional view taken on line 8-8 of FIG. 6;

FIG. 9 is a bottom view of the device shown in FIG. 1;

FIG. 10 is an enlarged fragmentary sectional view taken on line 10-10 of FIG. 9;

FIG. 11 is an exploded isometric view of certain elements of the device shown in FIG. 1;

FIG. 12 is an isometric view of certain elements of the device shown in FIG 1; and

FIG. 13 is a sectional view taken on line 13-13 of FIG. 9.

Description of the preferred embodiment Referring to the drawings, FIG. 1 illustrates a complete switch assembled within a tubular housing 2 which is preferably made of aluminum. Housing 2 has an anodized finish for improved appearance and for an electrical insulating function as later described. The upper portion of housing 2 is threaded to accommodate a plurality of mounting nuts (not shown).

A manually depressible cylindrical pushbutton 3 extends from the upper end of housing 2. Pushbutton 3 is preferably made of resilient insulating plastic material. A light transmitting lens cap 4 made of a thermoplastic material is placed over and fused to a peripheral flange 5 of pushbutton 3.

A lamp bulb 6 is mounted within the axial bore of pushbuttorn 3 to illuminate lens 4 when energized. A metallic lip 7 formed at the base of bulb 6 engages a step 8 in the bore of pushbutton 3 to position bulb 6 and restrain bulb 6 from movement toward lens 4. Lip 7 also serves as one of the two terminals through which the bulb 6 is powered. As shown best in FIG. 13, electrical power is delivered to bulb 6 through conductor strips 9 and 10. Conductor strips 9 and 10 are insulated from housing 2 by an anodized coating 11 on the inner surface of housing 2 as shown in FIG. 10. Referring again to FIG. 13, conductor strip 9 extends from the base of the switch to form a terminal 9a. At its upper end strip 9 is bent horizontally to the central axis of the switch and then bent upwardly to form a spring holder portion 9b for the lower end of a compression spring 12. Spring 12 serves as the electrical connection between strip 9 and a center terminal .13 of lamp 6 and urges the lip 7 of lamp 6 against step 8 to thereby hold lamp 6 in place. The other conductor strip 10 similarly extends from the base of the switch to form a terminal 10a. At its upper end, strip 10 is bent inwardly to form a contact portion 10b which is resiliently urged against lip 7 of lamp 6 to make sliding contact therewith during the full reciprocal movement of lamp 6.

Two

liners

14 and 15, molded of resilient plastic such as nylon, are retained within the tubular housing 2.

Liners

14 and 15 in their relaxed state before assembly within housing 2 are substantially flat as shown in FIGS. 4, 5, 6 and 7. When rolled to a cylindrical shape and inserted into the housing, the

liners

14 and 15 conform to the cylindrical shape of the inside of housing 2 and cover nearly the entire inner surface thereof. The resiliency of

liners

14 and 15 causes them to press outwardly and fit tightly against the interior of housing 2. With reference to FIGS. 1 and 13, liner 14 occupies approximately the upper half of the housing. Liner 15 is inserted into the lower half. The lower end of housing 2 is crimped by forming four indentations 16 shown in FIG. 9 to hold the

liners

14 and 15 within housing 2. The more detailed features of these liners and their cooperation with other parts will be described later.

A base 17 made of molded electrical insulating material is held within housing 2 at the lower end thereof by liner 15. Six upstanding stationary contacts 18 through 23 are mounted in base 17. Contacts 18 through 23 extend through base 17 and the lower ends thereof form terminals 18a through 23a, respectively.

Contacts

19 and 22 are normally closed contacts,

contacts

20 and 21 are normally open and

contacts

18 and 23 are common contacts.

An axial cylindrical aperture 24 in the center of the upper surface of base 17 serves to hold the lower end of a compression return spring 25.

A pair of

movable bridging contacts

26 and 27 are supported by a contact carrier 28 made of resilient electrically insulating material such as nylon. FIG. 11 best illustrates the contact carrier 28 as having a generally cylindrical upper portion 29 and a depending wall 30. A freely rotatable collar 31 surrounds the cylindrical portion 29 and is held loosely thereon by a peripheral ridge 32 on portion 29 and a pair of stepped edges 33 formed on opposite edges of wall 30. Three equally spaced lugs 34 extend radially from collar 31. A pair of integral roughly L-shaped resilient detent members 35 extend radially from the opposite edges of wall 30. A cylindrical axial spring holder portion 36 is formed in the center of wall 30 and receives the upper end of spring 25. A pair of contact holding recesses 37 are formed in the lower surface of cylindrical portion 29 on opposite sides of wall 30.

Contacts

26 and 27, when inserted in recesses 37 are held therein by the engagement of

barbs

38 and 39 with the resilient material of contact carrier 28.

Each of the

movable contacts

26 and 27 is made of spring-like electrically conductive metallic sheet and is folded at its upper barbed end. At the lower ends of each of

contact member

26 and 27, there are formed wider portions 40 through 43 which are bent to form the contact making surfaces. Contact making portions 40 and 41 are formed on the lower ends of contact member 26 and

contact making portions

42 and 43 are formed on the lower ends of contact member 27.

A spring support 44 is interposed between the upper surface of contact carrier 28 and the lower end of lamp 6. Support 44 is substantially cup-shaped with an open top and one open side as shown in FIGS. 2 and 13. Spring holder portion 9b is in close proximity to the lower inner surface of support 44 when the switch mechanism is in its normal position as shown in FIG. 13. When pushbutton 3 is depressed lamp 6 contacts the upper end of support 44 and support 44 then moves to transmit the operating force to the upper surface of contact carrier 28.

The upper liner 14 is made of an insulating plastic, preferably nylon, and is molded in the substantially planar form shown in FIG. 4. The outer surface of liner 14 has, as shown in FIG. 2, parallel grooves 45 to facilitate the bending of liner 14 to its cylindrical assembled form.

The overall appearance of the inner surface of liner 14 is best illustrated in FIG. 4. The surface has a plurality of ridges which form functional surfaces and serve to outline certain functional areas. A ridge 46 is formed across the greater part of the upper edge of liner 14 and has a plurality of notches 47 to facilitate bending of the liner. A similar ridge 48 is molded on the lower edge of liner 14. A series of raised ridges are arranged to form a stepped groove 49 and a similar but wider groove 50. When liner 14 is rolled to assembled

cylindrical shape grooves

49 and 50 are positioned on opposite sides of the central cavity of the switch and cooperate with the corresponding

lugs

51 and 52 to form a bayonet type socket for retaining pushbutton 3 within the switch. As pushbutton 3 is inserted into the switch, lugs 51 and 52 enter the open upper ends of

grooves

49 and 50, respectively. When pushbutton 3 is inserted sufficiently a clockwise turning of pushbutton 3 causes lugs 51 and 52 to enter the lower portions 49a and 50a of

grooves

49 and 50. The upper edges 4% and 50b of portions 49a and 513a then serve to retain pushbutton 3 within the switch against the pressure of spring 12 by limiting the upward movement of

lugs

51 and 52 as they are moved reciprocally within portions 49a and 50a dur ing normal operation of the switch.

The lower edge of liner 14 has a relief opening 53 to provide clearance for conductor strip 9. Similarly, the opposite side of liner 14 has a relief opening 54 with a sloping upper edge 54a to provide clearance for conductor strip 10.

The lower liner 15 is also molded in a substantially planar shape as shown in FIG. 6. The outer surface of liner 15 is formed with a plurality of spaced parallel grooves 55 shown in FIG. 9 to facilitate the bending of liner 15 to its assembled cylindrical shape. A notched ridge 56 similar to ridge 46 is formed on the upper edge of liner 15. Another ridge 57 on the lower edge of liner 15 serves to hold base 17 within the assembled switch in the manner shown in FIGS. 3, 10 and 13. A pair of recessed

areas

58 and 59 are molded in the outer surface of liner 15 to accommodate conductor strips 9 and 10, respectively. In the centers of

areas

58 and 59 there are elongated raised

portions

60 and 61, respectively.

Portions

60 and 61 fit tightly within a pair of similarly shaped

apertures

62 and 63 in conductor strips 9 and 10, respectively, to retain strips 9 and 19 in the assembled switch. During assembly conductors 9 and 10 are placed within recessed

areas

58 and 59 prior to the insertion of liner 15 within housing 2. After insertion of liner 15, the conductor strips 9 and 10 are held in place between liner 15 and housing 2. Longitudinal movement of conductors 9 and 10 is prevented by raised

portions

60 and 61. As previously explained conductors 9 and 10 are electrically insulated from housing 2 by the anodized layer 11.

The inner surface of liner 15 is furnished with a groove or track 64 which cooperates with lugs 34 on collar 31 to provide a push-push operating mechanism. The upper edge of track 64 is defined by a continuous ridge 65. The lower edge is defined by a discontinuous ridge made of

separate ridges

66, 67, 68 and 69. The three gaps between

ridges

66, 67, 68 and 69 are furnished to permit insertion of the corresponding three lugs 34 into track 64 when collar 31 is inserted from the lower end of the switch when liner .15 is in its assembled cylindrical form.

Two

detent areas

70 and 71 are preferably formed on the inner surface of liner 15 to provide a snap action as the contact carrier 28 moves downwardly. These detent areas have stepped cross sectional shapes as shown best in FIG. 8. FIG. 8 illustrates area 71 which comprises two levels 71a and 71b.

Detent areas

70 and 71 cooperate with detent member 35 on contact carrier 28 to provide a detent action as carrier 28 is moved downwardly from the position shown in FIG. 1 and detent members 35 are forced over the steps and bent inwardly against their outward resilient bias. The edges of

areas

70 and 71 also cooperate with detent members 35 to prevent rotation of contact carrier 28.

The steps in the assembly of the switch will now be reviewed. The top liner 14 is rolled to a cylindrical shape and inserted into the bottom end of housing 2. The lower liner 15 is then rolled to a cylindrical shape and terminal conductor strips 9 and 10 are positioned on the outer surface thereof with

apertures

62 and 63 over raised

portions

60 and 61. The longer conductor strip 10 is alined with the beveled relief 54 in the top liner 14. The lower liner .15 together with strips 9 and 10 is partially inserted into the lower end of housing 2. As liner 15 is inserted, liner 14 is further pushed toward the upper end of housing 2. With liner 15 partially inserted, spring guide 44 is inserted from the lower end of the switch and positioned as best shown in FIG. 13, with strip 9 extending through the open side of guide 44.

The

movable contact members

26 and 27 are inserted into carrier 28. Latch ring 31 is placed over the cylindrical portion 29. It is to be noted that ring 31 may be omitted if a momentary switch action is desired. The contact carrier and contact assembly is inserted from the lower end of the switch. As carrier 28 is inserted, lugs 34 of latch ring 31 pass through the gaps between

ridges

66, 67, 68 and 69. The return spring 25 is positioned in the aperture 24 of base 17. Base 17 with contacts 18 through 23 mounted therein is positioned in the lower end of liner and the upper end of spring is simultaneously inserted into the spring retainer 36 on carrier 28. As base 17 is inserted, carrier 28 and base 17 must be alined so that wall is positioned with contacts .19 and 20 on one side and

contacts

21 and 22 on the other. Contact member 26 must be placed in operating position between

contacts

18, 19 and 20. Similarly contact member 27 must be placed between

contacts

21, 22 and 23. Base 17 is then pressed all the way into its final position.

Liners

14 and 15 are as a result simultaneously pushed into housing 2 until liner 14 abuts the constricted upper end of housing 2. The lower end of housing 2 is then clenched as shown in FIG. 9 by forming indentations 16.

The lamp contact spring 12 is then placed on the end 9b of strip 9 through the upper end of the switch. Lamp 6 is inserted in the pushbutton 3 with lens 4 assembled thereto. Pushbutton 3 is inserted into its bayonet-type socket. The assembly is then complete.

It can be seen that

contacts

18 and 23 are common contacts in the sense that they are in continual contact with movable contact making portions 40 and 43 of

contact members

26 and 27, respectively, during the full movement of the contact carrier 28.

Contacts

19 and 22 are normally closed contacts since

contact making portions

41 and 42, respectively, are in contact with hooked upper ends 19b and 22b of contacts .19 and 22 when contact carrier 28 is in its normal upper position.

Contacts

20 and 21 are normally open and become closed when carrier 28 is depressed and

contact making portions

41 and 42, respectively, contact the stepped portions 2% and 21b of

contacts

20 and 21 immediately above base 17.

The push-push latching mechanism operates in the manner best illustrated in FIG. 6 where the path of one of lugs 34 is illustrated. The other two of lugs 34 simultaneously travel in similar paths in the two other similar portions of track 64. When lug 34 is in position A as shown in FIG. 6, carrier 28 is in its normal upper position. As pushbutton 3 is depressed and carrier 28 is forced downwardly, lug 34 travels straight down until it contacts ridge 67. At that point latch ring 31 begins to rotate and lug 34 travels downwardly at an angle to fully depressed position B. When the manual pressure is removed from pushbutton 3, lug 34 moves due to the force of spring 25 from position B straight up until it hits ridge 65. Lug 34 then angles upwardly to position C. The mechanism is then latched in its depressed position. The mechanism is released by again pressing pushbutton 3 to move lug 34 to position D. As pressure on pushbutton 3 is released, lug 34 moves to position E where the mechanism again assumes its fully released normal position. The process then may be repeated by again pushing the pushbutton 3.

I claim:

1. In an electrical switch comprising:

a housing having a substantially cylindrical interior portion;

a flexible liner in said housing for lining said interior portion having an initial substantially planar form before insertion in said housing with functional surfaces formed thereon and substantially cylindrical form when rolled and inserted in .said housing;

movable switching means inside said interior portion and comprising a reciprocally movable contact can ner;

said functional surfaces comprising guiding surfaces alined in the direction of movement of said contact carrier; and

said contact carrier having means interengaging with said guiding surfaces to prevent rotation thereof during reciprocal movement.

2. The invention as defined in claim 1 wherein said functional surfaces and said contact carrier have interengaging detent means for providing a detent action during reciprocal movement of said contact carrier.

3. The invention as defined in claim 1 in which:

said switching means additionally comprises reciprocally movable pushbutton means; and

said functional surfaces and said pushbutton means comprise interengaging groove and lug means together forming a bayonet type socket for removably holding said pushbutton means within said liner while allowing limited reciprocatory normal operating movement of said pushbutton means.

4. The invention as defined in claim 1 in which:

said contact carrier has a normal first position and a second position; and

said functional surfaces and said contact carrier have latching means for releasably maintaining said contact carrier in said second position.

5. The invention as defined in claim 4 in which:

said functional surfaces comprise a groove; and

said contact carrier has a rotatable latch ring with radially extending lug means for engaging said groove.

6. An illuminated electrical device comprising:

a housing formed of anodized coated aluminum and having a substantially cylindrical interior portion; electrically powered lamp means within said housing for illuminating said device;

electrical conductor means for conducting electrical power to said lamp means; and a flexible liner in said housing for lining said interior portion, said liner being made of resilient insulating material and having an initial substantially planar form and a substantially cylindrical form when rolled and inserted into said interior portion of said housing;

said conductor means having a portion thereof between said liner and said housing and being held in .place by the resilient outward pressure of said liner and insulated from said housing by the anodized coat on the latter.

7. The method of assembling an electrical switch device which comprises the steps of:

providing a housing having an interior cavity with an opening to the exterior thereof;

providing switching means for assembly within said cavity;

forming a flexible liner for lining said cavity, said liner being formed in an unrolled form with functional surfacesthereon for cooperating with said switching means;

rolling said liner to a substantially cylindrical form and inserting said liner into said cavity;

inserting said switching means into said cavity and within said liner in cooperative engagement with said functional surfaces.

8. The method as defined in claim 7 in which:

said switching means comprises a reciprocally movable contact carrier; and

said functional surfaces comprise guiding surfaces alined in the direction of movement of said contact carrier for preventing rotation of said contact carrier during reciprocal movement thereof.

9. The method as defined in claim 7 in which:

said switching means includes detent means; and

said functional surfaces comprise means for engaging said detent means for providing a detent action during reciprocal movement of said switching means.

10. The method as defined in claim 7 in which:

said switching means comprises reciprocally movable pushbutton means with retainer means thereon; and said functional surfaces together with said retainer means comprise interengaging groove and lug means forming a bayonet type socket for removably holding providing electrical conductor means for conducting electrical power to illuminating lamp means within said housing;

providing a flexible resilient liner for lining said interior said pushbutton means within said liner while allow- 5 portion, said liner being initially in an unrolled form; ing limited reciprocal normal operating movement of rolling said liner to a substantially cylindrical form; and said pushbutton means. inserting said liner into said interior portion with said 11. The method as defined in claim 7 in which: conductor means between said housing and said liner said switching means has a normal first operating posito a position wherein the resilience of said liner causes tion and a second operating position; said liner to press outwardly to retain said conductor said switching means includes latching means; and means in position within said housing. said functional surfaces engage said latching means to References Cit d releasably maintain said switching means. e 12. The method as defined in claim 11 in which: UNITED STATES PATENTS said functional surfaces comprise a groove; 15 2 723 339 11 1955 Hanerberg et 1 said latching means comprises a rotatable latch ring 2 957 0 2 10 19 0 Rigel with radially extending lug means which is assembled 2 244 8/1966 Schultz to said switching means before said switching means is inserted into said cavity; and

said lug means engage said groove after said switching means is inserted into said cavity.

13. The method of assembling an illuminated electrical ROBERT K. SCHAEFER, Primary Examiner.

H. O. JONES, Assistant Examiner.

US. Cl. X.R.

device which comprises the steps of:

providing a housing having a substantially cylindrical interior portion;