US3522403A - Illuminated pushbutton switch device - Google Patents

Description

Aug. 4, 1970 M. D. FULLER ILLUMINATED PUSHBUTTON SWITCH DEVICE Filed 0013. 14, 1968 wuavroz (is Maw/4E .0. Fuzz-E A rraewa f United States Patent 3,522,403 ILLUMINATED PUSHBUTTON SWITCH DEVICE Maurice D. Fuller, Mercer Island, Wash., assignor to Korry Manufacturing Co., Seattle, Wash., 21 corporation of Washington Filed Oct. 14, 1968, Ser. No. 767,299 Int. Cl. H01h 9/18 US. Cl. 200-167 14 Claims ABSTRACT OF THE DISCLOSURE A generally tubular outer casing supports and encloses sets of electrical contactor elements and associated actuator elements for a switch unit aflixed in one end of the casing and for a relampable illuminated pushbutton unit socketed in the opposite end of the casing, with said sets of elements occupying longitudinally overlapping positions normally established by stops and a return spring reacting from a support bushing located intermediate the ends of the casing. The support bushing carries lamp base terminal contact elements and serves as a base for a pushbutton return spring. This bushing is apertured to permit passage longitudinally through it of salient extensions of a pusher element for the pushbutton unit. These extensions engage a switch-actuating shuttle through the medium of a relatively stifr" pusher spring so as to exert switch actuation force on the shuttle through the interposed spring. Conducitve terminal strips for the lamp base terminal contacts are brought out of the switch unit end of the casing through apertures in insulative segments which center the switch unit within the end of the casing and serve as spaced supports for the bushing. The pusher spring is precompressed between the switchengaging end of the shuttle and lugs on the ends of the salient extensions of the pusher member, which lugs are held captive by spring force between the adjacent end of the pusher spring and stop elements on the shuttle engaged behind such lugs by longitudinal insertion between the extensions followed by relative rotational displacement.

This invention relates to improvements in push-toactuate illuminated pushbutton switch devices such as are suitable for panel mount installations wherein a high degree of reliability and a compact construction are important design considerations. The invention is herein illustratively described by reference to the presently preferred embodiment thereof; however it will be recognized that certain modifications and changes with respect to details may be made without departing from the essential features involved.

A broad further object of this invention is to provide a switch device of the nature indicated wherein the parts and components are mounted and enclosed in a unitary casing of relatively short length and small cross section while accommodating a switch unit of commercially available or suitable design and frontally accessible relampable pushbutton elements compatible with most if not all instrument panel mounting requirements. Ease of manufacture and assembly of components with positive spacing of elements to be electrically insulated are also important objectives.

A related object is to fulfill these purposes and particularly that of achieving shortness of length of the total assembly while incorporating separate pusher spring means for actuating the switch unit without damage thereto due to bottoming before completion of the actuation movement of the pushbutton, and an independent relatively light return spring for the pushbutton assembly.

An important feature of the device resides in the provision of salient longitudinal extensions on a pusher element designed for passage through openings in a bushing fixed intermediate the ends of the outer casing to support lamp base contact elements and provide a base for one end of a pushbutton return spring. As a related feature, the projecting ends of the salient extensions engage a relatively stiff push spring as a transmitter of actuation force and displacement to a switch actuation shuttle when the pushbutton is depressed, the spring being initially precompressed between one end of the shuttle and shuttle-retaining lugs formed on the salient extensions so as to hold the shuttle captive to the pusher extensions.

Thus, in effect, the pusher elements and associated components for actuating the switch occupy longitudinally extending space within the casing which is also occupied by the pushbutton lamp contact elements and return spring assembly, while accommodating terminal connection strips for the lamp contacts so as to minimize the total required length and bulk of the device.

These and other features, objects and advantages of the invention will become more fully evident from the following description thereof by reference to the accompanying drawings.

FIG. 1 is an isometric rear view of the assembled switch device for panel mount applications;

FIG. 2 is an exploded isometric rear view of the device;

FIG. 3 is a longitudinal section taken on line 33 in FIG. 1; and

FIG. 4 is an isometric front view of the switch device subassemb'ly with parts broken away and the actuator shuttle shown separated therefrom, and FIG. 5 is a sectional view on line 55.

As shown, the improved switch device comprises a generally tubular outer casing 10 having an exteriorly threaded end portion 10a of reduced outside diameter adapted to pass through a mounting aperture in a panel P and to accommodate washers 12 and 14 and nuts 16 and 18 between which the panel is to be clamped. Thus mounted, the switch device body projects transversely inward from one face of the panel and presents electric lamp terminals 20 and 22 as well as electric switch terminals 24, 26 and 28 for wiring purposes at its projecting inner end. Its outer end, presented at the opposite panel face, presents an illuminable pushbutton 29 for actuating the electrical switch within the device, and through appropriate energizing circuits wired to the lamp and switch terminals, for lighting the electric lamp within the pushbutton when an external energizing circuit (not shown) is closed by switch actuation.

In the example, electrical switch unit 30 is of a commercially available form comprising an insulative body of six-sided generally rectangular proportions presenting the exposed contacts 24, 26 and 28 at one end, and a push-to-actuate switch actuation plunger 30a at its opposite end. This miniature switch unit is held within the projecting inner end of casing 10 by insulative complementally formed tubular segments 32 and 34 having closed ends 32 and 34 which together clamp the switch body between them in a three-part sandwich assembly filling out a circular outline which fits within the end of the casing and may be appropriately staked therein to hold the parts rigidly in place. Positioning posts 32a and 34a on the inner clamping faces of the end portions of these segments fit in sockets 30b formed in opposite lateral faces of the switch body so as to locate the switch body and hold it against sliding out of registry with the segments in mounted position. The switch unit 30 is thus protectively and securely held in the end of outer casing .10 which the switch unit actuation plunger directed inwardly of the casing parallel to the latters longitudinal axis.

Longitudinal apertures 32'a and 34'a in the ends of segments 32 and 34 are provided in order to pass the elongated conductor strips 22 and 20 respectively which extend from contacts adapted to engage the lamp base terminals. Separated by the thickness of switch body 30, the segments 32 and 34 have inner faces 32b and 34/) which together form a guide way for a switch actuation shuttle now to be described.

In order to actuate the switch unit a shuttle 36 is slidably received within the casing 10 with one end of the shuttle facing the tip of plunger 30a to press against the same for actuation purposes. The same end of the shuttle is provided with laterally extending wings 36a slidably received or accommodated in the aforementioned guide way to prevent rotational depositioning of the shuttle once the parts are assembled in the manner disclosed. The opposite end of shuttle 36 also carries wings 36b of shorter radial extent which serve as stops. A relatively stiff helical spring 38 surrounds the shuttles intermediate shank portion, terminated by the sets of end wings aforementioned. This spring is normally held precompressed between the wings 36a and internal lugs 40b formed in the ends of salient extensions 40a of tubular pusher member 40. Such extensions, in turn, are formed by notching tubular member 40. The notches are wide enough cir-' cumferentially so as to permit endwise insertion of the shuttle wings 36 between the extensions in order to compress the spring 38 against lugs 40b (FIGS. 4 and whereupon rotation of the shuttle 36 relative to the tubular pusher member 40 through an angle of 90 (FIG. 3) captivates the wings 36b behind the lugs with the spring 38 held in compression and with the shuttle projecting out of the end of the space formed between the pusher tubes salient extensions 40a. As previously stated the guide way between segments 32 and 34 prevents rotation of the shuttle, hence dislodgement of the shuttle from pusher extensions 40a.

Pusher tube 40 fits slidably within an insulative sleeve 42 retained within the casing and enlarged at one end, 42a, so as to stop the sleeve against a shoulder formed in the inside wall of the outer casing by an abrupt increase in internal diameter thereof. The projecting end of pusher tube 40, opposite the salient extensions 40a, carries pushbutton unit 29 and it also carries Within itself a relatively light pushbutton return spring 44 of helical form which at one end bears against an internal sleeve 46 retained in the pusher tube by a groove-seated split ring 48 of resilient material. At its opposite end the light return spring 44 bears against a transverse annular terminus of terminal strip which in turn bears against the inner end face of a stationary bushing 46 mounted within the outer casing at a location intermediate the ends thereof. Thus, pushing inwardly on pushbutton 29 longitudinally advances the pusher tube 40, and through the stiff spring 38, advances the shuttle 36 against switch plunger a in order to actuate the switch. Spring 38 accommodates overtravel of the pushbutton in this motion when the switch plunger 30a bottoms out in the switch unit 30, and thereby prevents damage to delicate switch parts inasmuch as the spring 38 permits the pushbutton to continue its actuation motion even though the switch plunger has stopped. However the concept per se of actuating a switch through a transmission opening is not original with the present disclosure. Pushbutton return spring 40 is compressed against bushing 46 by such switch actuation movement of the pushbutton assembly and returns the latter to its normal position when the pushbutton is released.

An electrical lamp L is socketed in the pushbutton assembly by insertion of a bulb L1 and base L2 into the tubular metal fitting 29b carrying a translucent pushbutton enclosure 29a surrounding the bulb and usually suitably engraved or painted on its exposed face for indication purposes. Base L2 conventionally h a t i l 4 flange which in this case seats against the inner end of fitting 2%. A central contact L3 on the lamp base serves as one lamp terminal whereas the conductive lamp base L2 slidably inserted in tubular member 2% serves as the lamps opposite terminal. The latter makes electrical connection with terminal strip annulus 20a through sleeve 40 and spring 38. For this purpose the lamp base is tightly, though slidably, fitted within the metal sleeve 29b. A locating notch 40d in the adjacent end of sleeve 40 accommodates a corresponding finger 29c on pushbutton sleeve 2% so as to rotatably orient the pushbutton with the device appropriately installed in a panel P. The lamp base button terminal L3 makes contact with the springactuated plunger 50. The latter is provided with an enlargement 50a slidably accommodated with its return spring 52 within the hollow rivet member 54 extending through a central aperture in the stationary bushing 46 and flanged over at its opposite end to capture and electrically engage the annulus 20a formed on the inner end of terminal conductor strip 20. Sleeve-rivet 54 has an annular formation near its inner end which receives an internal rivet in the bushing 46 so as to fix the rivet against endwise movement in the bushing. The bushing has an enlarged base fitted snugly within the outer casing 10 and is pressed to a seat against the flanged end of sleeve 42 by the inner ends of segments 32 and 34 and is thereby fixedly held in the casing.

Arcuately formed apertures 46a in the transverse web 46b in the base portion of bushing 46 form through-ways for longitudinal traversal by the salient extensions 40a of pusher tube 40. This permits the lamp base contact elements carried by the bushing to be positioned immediately adjacent the lamp base whereas the switch elements and actuator shuttle therefore may in turn be located closely adjacent the base of the bushing opposite from the lamp and still be accessible by the elements of the pushbutton assembly for actuation of the switch protectively housed within the same outer casing. Such an arrangement, whereby the switch actuation parts and the lamp actuation and contact parts occupy the same longitudinally extending region within the outer casing 10 achieves a degree of compactness and an orderly positive positioning of parts not heretofore provided in illuminated pushbutton switch assemblies intended for similar applications. It further provides related economies in manufacture by a reduction in the number of parts through multiple functions of same, such as the apertured bushing member 46 and the pusher means including salient extensions for actuating the switch and a tubular socketing arrangement also for the relampable pushbutton unit.

These and related aspects and advantages of the novel switch device hereina'bove disclosed will be evident to those skilled in the art having reference to this disclosure of its presently preferred embodiment.

I claim:

1. A push-to-actuate electrical switch device comprising a generally tubular outer casing, an electrical switch, means positioning the switch in one end of the casing including a bushing fixedly held within the casing intermediate the ends thereof and spacer means maintaining longitudinal spacing between the switch and the bushing, a switch-actuation shuttle received for longitudinal reciprocation in the space between the switch and bushing, to actuate and deactuate the switch, an elongated tubular member received for longitudinal reciprocation in the opposite end of said casing and having circumferentially spaced salient extensions projecting endwise from its inner end within the casing, said bushing formed to pass the salient extensions into said shuttle space, a relatively stiff pusher spring interengaged between said shuttle and said salient extensions to exert switch actuation force on the shuttle by inward longitudinal displacement of the tubular member, and a relatively light return spring received 'within the casing and reacting therefrom to resist inward displacement of the tubular member.

2. The switch device defined in claim 1, further comprising illuminated pushbutton means on the outer end of the tubular member and including means removably socketing a lamp therein, lamp terminal contact means carried by the bushing, said contact including a bushingmounted stationary element connected slidably with an outwardly spring-biased reciprocative element engaging a terminal of the lamp and yieldable inwardly with displacement of the tubular member to actuate the switch.

3. The switch device defined in claim 2, further comprising two lamp contact terminal strips of conductive material extending longitudinaly beyond the first end of the casing through apertures in the spacer means, the inner end of one such strip being connected to the bushingmounted contact means element, and the inner end of the other strip extending longitudinally through the bushing and terminating in a transversely disposed annulus interposed between the end of the bushing opposite the switch and one end of the return spring.

4. The switch device defined in claim 3, wherein the salient extensions have interior transverse lugs near the outer ends thereof, wherein the shuttles inner ends have exterior stop means thereon engageable behind the extension lugs to resist endwise separation of the shuttle from the tubular member, wherein the shuttles outer end has exterior stop means thereon, and wherein the relatively stiff spring surrounds the shuttle and is of an initial length causing it to be precompressed between said latter stop means and said salient extension interior lugs.

5. The switch device defined in claim 4, wherein the spacer means comprise tubular segmental bodies sandwiching the switch between them to form a tubular assembly fitted within the outer casing and the shuttles outer end stop means comprise salient lugs antirotationally retained and slidably received between said insulative bodies.

6. The switch device defined in claim 4, wherein the first-mentioned stop means comprise transverse exterior lugs of such relative circumferential spacing and width as to permit advancing the same longitudinally between the tubular member salient extensions to a point beyond the interior lugs on the latter, and in so doing to precompress the stiff spring, whereupon relative rotation of the shuttle and tubular member permits engagement of such first-mentioned exterior lugs behind the salient extension interior lugs.

7. The switch device defined in claim 1, wherein the salient extensions have interior transverse lugs near the outer ends thereof, wherein the shuttles inner ends have exterior stop means thereon engageable behind the extension lugs to resist endwise separation of the shuttle from the tubular member, wherein the shuttles outer end has exterior stop means thereon, and wherein the relatively stiff spring surrounds the shuttle and is of an initial length causing it to be precompressed between said latter stop means and said salient extension interior lugs.

8. The switch device defined in claim 7, wherein the first-mentioned stop means comprise transverse exterior lugs of such relative circumferential spacing and width as to permit advancing the same longitudinally between the tubular member salient extensions to a point beyond the interior lugs on the latter, and in so doing to precompress the stiff spring, whereupon relative rotation of the shuttle and tubular member permits engagement of such first-mentioned exterior lugs behind the salient extension interior lugs.

9. The switch device defined in claim 1, further comprising two lamp contact terminal strips of conductive material extending longitudinally beyond the first end of the casing through apertures in the spacer means, the inner end of one such strip being connected to the bushingmounted contact means element, and the inner end of the other strip extending longitudinally through the bushing and terminating in a transversely disposed annulus interposed between the end of the bushing opposite the switch and one end of the return spring.

10. The switch device defined in claim 2, wherein the salient extensions have interior transverse lugs near the outer ends thereof, wherein the shuttles inner ends have exterior stop means thereon engageable behind the extension lugs to resist endwise separation of the shuttle from the tubular member, wherein the shuttles outer end has exterior stop means thereon, and wherein the relatively stiff spring surrounds the shuttle and is of an initial length causing it to be precompressed between said latter stop means and said salient extension interior lugs.

11. The switch device defied in claim 10, wherein the first-mentioned stop means comprise transverse exterior lugs of such relative circumferential spacing and width as to permit advancing the same longitudinally between the tubular member salient extensions to a point beyond the interior lugs on the latter, and in so doing to precompress the stiff spring, whereupon relative rotation of the shuttle and tubular member permits engagement of such first-mentioned exterior lugs behind the salient extension interior lugs.

12. A push-to-actuate electrical switch device comprising a generally tubular outer casing, an electrical switch means positioning the switch in one end of the casing including a bushing fixedly held within the casing intermediate the ends thereof and spacer means maintaining longitudinal spacing between the switch and the bushing, a switch-actuation shuttle member received for longitudinal reciprocation in the space between the switch and bushing, to actuate and deactuate the switch, an elongated pusher member received for longitudinal reciprocation in the opposite end of said casing, one of said members having circumferentially spaced salient extensions projecting endwise from its inner end within the casing, said bushing formed to pass the salient extensions for engagement thereof with the other member, a relatively stiff pusher spring interengaged between said members to exert switch actuation force on the shuttle member by inward longitudinal displacement of the pusher member, and a relatively light return spring received within the casing and reacting therefrom to resist inward displacement of the elongated pusher.

13. The switch device defined in claim 12, further comprising illuminated pushbutton means comprising a lamp socket on the outer end of the elongated pusher member and including means removably socketing a lamp therein, lamp terminal contact means carried by the bushing, said contact including a bushing-mounted stationary element connected slidably with an outwardly spring-biased reciprocative element engaging a terminal of the lamp and yieldable inwardly with displacement of the elongated pusher member to actuate the switch.

14. A push-to-actuate electrical switch device comprising a generally tubular outer casing; a switch operatively mounted in a first end of the casing; a generally tubular plunger received for axial reciprocation within the casing, illuminated pushbutton means forming a lamp socket removably mounted on the tubular plungers end at the second end of the casing; lamp contact means positioned Within the casing intermediate the ends thereof for engagement by a lamp in said lamp socket, said contact means including a body portion disposed transversely across the casing interior, and electric contact means engageable by the base terminals of a lamp in said lamp socket, said body portion having transversely spaced openings adjacent opposite sides thereof, and the tubular plungers second end having circumferentially spaced lon gitudinal extensions passed slidably through the respective openings toward the switch to permit plunger reciprocation; a relatively limber helical compression spring received within the tubular plunger and reacting between said body and a shoulder within the tubular plunger to return the tubular plunger following button-pushed switchactuating axial displacement thereof; and transfer means to engage and actuate the switch for actuation thereof by such tubular plunger displacement, including a relatively stiff helical spring interposed between the switch and tubular plunger with one end of the spring seated against the tubular plunger extensions, a switch-engaging plate interposed between the springs opposite end and the switch, a stop member interposed for axial movement between such extensions, stop shoulders inside the latter limiting the stop members movement toward the switch, and a rod Within the spring joining the stop member and plate in fixed relationship.

Ensign et al. Blomquist et al. Hallerberg. Ehrenfels et a1.

HERMAN O. JONES, Primary Examiner

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