US2752441A - Electric switches - Google Patents

Description

June 26, 1956 s. L. FRANK 2,752,441

ELECTRIC SWITCHES Original Filed Sept. 9, 1947 2 Sheets-Sheet 1 Fig.l.

I I92 I90 I86 WITNESSES: |NVENTOR r 22 Stonle L Frank. gf B Y I ATTORN EY June 26, 1956 s. FRANK 2,752,441

ELECTRIC SWITCHES Original Filed Sept. 9, 1947 2 Sheets-Sheet 2 WITNESSES: INVENTOR gzonley L.Fronk.

ATTORN EY United States ELECTRIC SWITCHES Stanley L. Frank, Beaver, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., 21 corporation of Pennsylvania Claims. (Cl. 200-44) This application is a division of my copending application, Serial No. 772,938, filed September 9, 1947, now Patent Number 2,669,616.

This invention relates generally to electric switches, and more particularly to such switches as are commonly employed in circuits for controlling electrical apparatus.

Electric switches of the type described generally take the form of pushbutton switches, or they may be of the rotary selector switch type. Each type of switch is often used in locations where a liquid, such as the oil used as lubricant or coolant for machine tools may be splashed against the switches, and one object of this invention is to provide a novel switch design of this type which is moisture-proof.

A more specific object of this invention is to provide a novel attachment for a switch of the type described for locking the switch in a predetermined position.

Still another object of this invention is to provide a novel rotary locking means for a pushbutton type of switch.

These and other objects of this invention will become more apparent upon consideration of the following detailed description of preferred embodiments thereof, when taken in connection with the attached drawings, in which:

Figure 1 is a view, in side elevation, of a switch constructed in accordance with this invention with the operating unit and locking arrangement thereof shown in section, and with the cover plate for the switch unit removed;

Fig. 2 is a top plan view of the switch shown in Fig. l with the locking arrangement secured thereto; and

Fig. 3 is a view, in elevation, of the operating unit shown in Fig. 1.

In Fig. l of the drawing, an operating unit 2 is shown as being assembled with a switch unit 4 in a manner which will be hereinafter described. The operating unit 2 includes a tubular supporting sleeve 6, preferably of a cast metal, and having a flange 8 at the inner end thereof adapted to engage the inner side of a supporting panel 11. The panel 11 may be open at the rear, or enclosed, in which case panel 11 forms the front wall of a switch box. Preferably, flange 8 of supporting sleeve 6 has a positioning pin 10 secured thereto which is adapted to be received in a recess provided at a predetermined position on the inner side of panel 11. A sealing disc 12 of any desirable moisture-proof compressible sealing material, such as rubber or the like, is interposed between,

flange 8 of the supporting sleeve and the inner surface of supporting panel 11. The outer end of supporting sleeve 6 is threaded for threadedly receiving a clamping ring 14 which is adapted to secure the sleeve to panel 11 when the clamping ring is drawn up tightly.

If desired, a washer 16 having an extended portion at one side may be provided between clamping ring 14 and panel 11. This washer may carry suitable indicia for proper identification of the switch, and for operative positions of the switch. Indicator washer 16 preferably atent O 2,752,441 Patented June 26, 1956 is provided with key projections adapted to be received in external grooves 15 in sleeve 6 to properly position washer 16 on the sleeve and prevent relative angular movement.

Supporting sleeve 6 of the switch operating unit is interiorly provided intermediate its ends with a transversely extending web 18 which is centrally apertured for slidably receiving an operating rod 20. A pushbutton 22, preferably of a molded insulating material, is illustrated as being secured to the outer end of operating rod 20, preferably by being molded thereon. Pushbutton 22 is provided with an annular skirt 23 which is engageable with the outer surface of web 18 to determine the extent of inward movement of pushbutton 22. A coil compression spring 24 is interposed between pushbutton 22 and a retainer disc 26 seated on web 18, to normally bias the pushbutton to the outer limit of its movement. The part of retainer disc 26 which seats on web 18 is adapted to engage a sealing disc 28, also of a moisture-proof resilient material such as rubber, for sealing any space between operating rod 20 and the opening through web 18. The portion of retainer disc 26 which is engaged by spring 24 is offset into an annular drain recess 34 provided in web 18, and this recess communicates with the exterior of supporting sleeve 6 by means of a plurality of radially extending drain openings 36 (only one of which is shown). In order to permit drainage of liquid through drain openings 36, clamping ring 14 is provided with a plurality of notches 38 in the inner edge thereof, and it will be observed that the extreme inner end of clamping ring 14 is not threaded, but is actually spaced from the outer surface of supporting sleeve 6 to form a drain channel 39 therebetween, so that it is not necessary that a notch 38 be lined up opposite each drain opening 36.

The operating unit 2 described above is thus adapted to be secured to a supporting panel 11 or the like, in a manner to prevent the passage of moisture from one side of the panel to the other, and it embodies a pushbutton 22 normally biased to an outer position defined by an operating disc 30 secured on the reduced inner end of operating rod 20, as by riveting over the outer end of the rod as at 32. The opening through which the operating rod moves is also sealed against the passage of moisture from the front to the rear, and any moisture which may accumulate within operating sleeve 6, particularly when the latter is mounted in a horizontal position such as that shown in Figure 1, will drain from the interior of the sleeve through the drain passages provided, irrespective of the relative angular position of clamping ring 14 and sleeve 6.

The switch unit 4 which is utilized with operating unit 2 includes a base 40 of insulating material, preferably a molded insulating material. Switch base 40 is provided with opposed recessed projections 41 and 43 at one side thereof, and has on the same side another pair of opposed projections 42. All of the projections 41, 42 and 43 are spaced apart so as to provide in effect a recessed space 44 between the inner ends of the several projections. Projection 41 has a recess 46 extending throughout the length of the projection and having an outer reduced portion forming an internal shoulder, and projection 43 has a recess 47, the outer end of which is closed. Projections 42 are spaced from opposite sides of projections 41 and 43 to form spaces 48 therebetween. Spaced contact receiving slots 52 are provided at the inner side of each projection 42 for receiving one edge of a straight contact strip 54, with the opposite edge being received in a recess provided in the adjacent corner of projection 41. As illustrated in Figure 1, straight contact strips 54 are secured in the lower set of slots 52 in each space 48 on base 40, and gernerally U-sh aped contact strips 62 are steamed iri'the" upper 'slots52'." The U-shap'ed contacts 62 each have one leg carrying a contact button 64 which is adapted to have one side received in a slot 52, with theothr side 'the'reof resting in the recess provided in adjacent corner of projection 41. Thebight portion of eachcontact 62 is adapted to engage base 49, with the other leg of each contact strip 62 extending beyond projections '42 resting againstanadjacent flange 70 integral with each projection 42. Such other leg of each contact strip 62, as well as the outer ends or contact strips b'ljar'e provided with terminal screws 66 for the purpose cf securing" conductors thereto. It is apparent that contiici strips '54'and 62 are maintained against withdrawl from slots 52 by engagement of a cover (not shown).

erab'ly, the cover 'is secured in position by any desired means, such as screws or the like, engaged in open- Tprovided in opposite sides of the base 40 of ta s the swit h nnit;

ille' switcl i unit further includes an operating member' of insulating material, preferably a molded insulatmaterial, adaptedto be received in the recess 46 of ba'seprojection"4 1, and having a reduced operating extension '7'4extending'through the reduced recess opening at the out'er end'of projection 41, to provide a shoulder 7.6 around three sides of operating member-'72 which is engageable with the shoulder adjacent the outer end of to limit the extent of outward movement of theoperatin'gmember. A contact supporting strip 75 is secured to the inner end of operating member 72, preferably by beingcemented therein, and it is adapted to have a bridging contact bar 78 slidably mounted thereon; Bridging contact bar 73 is provided with contact buttons 800:1 opposite sides'thereof at each end of the-bar, for cooperation with the respective contact but tons of contact strips 54 and 62. Contact supporting strip 75fhas a' reduced extension 82 on which is slipped a spring supporting sleeve 84, also preferably of an insulating material. A coil compression spring 86 is adapted to bereceived in recess 47 of base projection 43, and to react between the closed end of this recess and sleeve 84 to nor'inally bias operating member 72 to its outerniost position, where the contact buttons of bridging contactbar 7sengage'the upper contacts 64 mounted'on the base. A coil compression s pring 87*which is weak relative to spring 86 is provided on-contact supporting strip 75"and."reac-t s betweenopcrating member 72 andthe Contact bridging bar. Preferably, a' notch 89 extends across the space between opposed pairs: of contacts for the purpose of increasing the 'creepage'distance between eachpair of contacts;

It will be observed that the switch unit is pre-formed to have the various projections, recesses and notches described; so that all, of the switch contacts and operating parts may be assembled with the base'merely by laying them in their appropriate recesses or slots. Thus contacts 54 and 62 can be merely laid into notches 52, and the entire movable contact assembly comprises parts which are unsecured together, being merely mounted in telescoping relation and held assembled by biasing spring 86." Moreover, the contacts including the movable contact bridging bar and operating elements therefore are all held againstrernoval from base 40, and against movement from their operative positions relative to the base merely by a cover.

It will be apparent that the operating member 72 for the switch unit may be depressed by exerting pressure on the outer end of operating extension 74 to be moved from the position illustrated on the drawings wherein the contact buttons or bridging bar 78 engage the upper set of stationary contact strips, to a position where they engage the lower set of stationary contactjstrips, and

extension '74may be moved'beyond this position due to the slidable mounting'of the bridging contact baron contact supporting strip 75, with such "movement acting to compress spring 87 as Well as spring 86. As soon as operating extension 74i's released, spring 87 will return the parts to the position illustrated in the drawings wherein bridging contact bar 78 has its contacts in engagement with the upper set of stationary contacts on base 40. i'

The switch and operating units are preferably assernbled in operative relatjpn by screws 90 extending through openings provided at opposite ends of base 40 of switch unit 2. The switch unit may be'positioned so that screws 99 may engage in either pair of opposed pairs of threaded sockets 91 provided in the flange 8 of operating unit sleeve 6, as may be convenient. l'tis immaterial insofar as the operating unit is concerned at what angular position the switch unit is secured thereto, because at any position operating disc 30 of the operating unit will engage operating extension 74 of the switch unit to dep e s he l tter wh pushbuttc s ep d and he eby op te the, on acts. o he switch Imit- It is often desirable, particularly with pushbutton switches of the type shown in Fig. 1, to have provision o ki e nshbutto num r at a p es p tion- 0 s o a mpli hin this. with n Operating unit 2 of the type shown in Fig. 1 is illustrated in Figs. 2 an 3 s n at a hmen r su h a p t n i This locking attachment comprises, a mounting ring 181 d pted to b s cure n e u s end of pp rt sleeve 6, as by setscrews 183 at one side of the mountns. in A1 n e ral extens n 8 is P de at one side of mounting ring 181 with an aperture 187, for a purpose to be described. A locking ring is provided with inwardly extending pins 1&2 adapted to be received in inclined grooves 184,*provided in opposite sides of ntin t n hen. he lo ki ring is c pe ye he m ntina ins- Lo k ring is prov with an inwardly extending flange 1 88 at one side adapted to be received in an inclined cutout portion 189, of; the assum n ring, a d w th n oppos longer e.v 186 ad t d tn ex en o er a si la uto por 1 1 in hs p g e e. i mou t n sleev L Fl ge 186 is ad p o e ten ver. pu hbut cn 22 for p pose t be described. Locking ring; 180 is provided with a bore 0. ope n e at flan e 8.6fm receiving a i compression spring 192 which urges a ball detent 194 downwardly into engagement with the upper surface of mounting ring 181. Locking ring 180 is provided with insg l sxt nsip i 1 .6. h ch. is pc ured as at 197 s milar to he xtensips. .8.5, t mounti ring 1 1 It W l e. pa en that ock ng in 180 m y. be. rotated relative to mounting ring 181 by grasping extension fll sqfnd, mqyin t to e c t p r i y slots 18 4 in which pins lfizam received. The parts are li tr tl. n Fi 2 nd. 3 a he. nn r o p i of oc in in 9 where t pinsl z, are ec in h nnerm st nds. t r ws. f: mou g ng 81- Atthis point ball detent 124; is receiyed in a, recess 198 for dei iningjthe locking position of ring 180 wherein flange 186 holds pu shbutton22 at av depressed position, forexample, a position wherein the contacts of bridging contact bar 78 -are iritermediatefthe, fixed contacts of the was a t- Ati s PPs t sm. o o k n s 189,the o ening 197 in its extension 196 is alignedwith the ns .31m. he sait nsi n i amm n i i t Pa -lessor imil oc g mem r. m y

. b n te h gl h. tii niass lq e Pushbutt n tthisp c n: psnt qa i si sl k n r n lfiucountercloc'kwise from the position shown in Fig 2, it will befappare'ntthatits ISZ'riding in slots 184 will cause the lo'ck i'nglringto moveoutwardly relativejto mounting ring 1811during suchjro'tativemoyeinent sothat when its extension 1916 i s' atth'je broken line position, shown in Fig. X ma intain pushbutton 22 I t r, ,1 tatthis positiondue to P QBQBQll Qfl bi 5i... 94 -hi O d epression 20011: the"upper"'dge' of mounting ring 181; i

Having described preferred embodiments of this invention in accordance with the patent statutes, it is desired that the invention be not limited to these particular devices inasmuch as it will be apparent that many changes and modifications may be made therein without departing from the broad spirit and scope of this invention. Accordingly, it is desired that the invention be interpreted as broadly as possible and that it be limited only as required by the prior art.

I claim as my invention: v

1. Switch structure adapted to be mounted an opening through a support, comprising, an operating unit including a sleeve member adapted to extend through said support opening and having a flange at one end adapted to engage the inner side of said support, a clamping ring threaded on said sleeve to engage the outer side of said support when drawn tight to secure said sleeve member in said opening, a switch operating member movably mounted in said sleeve; a switch unit comprising a base having stationary contacts and a movable contact carrying member mounted thereon; and means for securing said switch unit to said sleeve member at the inner side of said support and at a position such that movement of said operating member will cause movement of said contact carrying member to actuate contact means carried thereby into and out of engagement with said stationary contacts; a lock unit comprising a supporting ring having a locking ring mounted thereon for rotative and axial movement in substantially a spiral path, said locking ring having a radially inwardly extending operating part; and means for mounting said lock unit comprising securing means on said supporting ring for removably securing it on said sleeve member at the outer side of said support with said operating part on the locking ring overlying the outer end of said switch operating member.

2. A pushbutton switch comprising, separable contacts, a mounting sleeve in which a pushbutton operator for said contacts is slidably mounted, a locking ring rotatably mounted on said sleeve for movement in a substantially spiral path when rotated and having a part overlying said pushbutton, whereby when said ring is moved in one di- ;rection said part will move said pushbutton inwardly to one predetermined position, and means on said ring for :receiving lock means to retain the ring at a locking po- :sition.

3. A pushbutton switch comprising, separable contacts, :a mounting sleeve in which a pushbutton operator for :said contacts is slidably mounted, a locking ring mounted (on said sleeve for movement in a substantially spiral path :and having a part overlying said pushbutton, whereby when said ring is moved in one direction said part will move said pushbutton inwardly to one predetermined position, detent means for releasably retaining said ring at least at one predetermined position thereof, and means on said ring for receiving lock means to retain the ring at a locking position.

4. A pushbutton switch comprising, separable contacts, a mounting sleeve in which a pushbutton operator for said contacts is slidably mounted, a locking attachment for said switch comprising a mounting ring secured to said sleeve and a locking ring rotatably mounted on said mounting ring for movement in a substantially spiral path when rotated and having a part overlying said pushbutton, whereby when said locking ring is moved in one direction said part will move said pushbutton inwardly to one predetermined position, and said rings having aligned openings therein for receiving lock means to retain the looking ring at a locking position.

5. A pushbutton switch comprising, separable contacts, a mounting sleeve in which a pushbutton operator for said contacts is slidably mounted, a locking attachment for said switch comprising a mounting ring removably secured to said sleeve and a locking ring mounted on said mounting ring for movement in a substantially spiral path 6 and having a part overlying said pushbutton, whereby when said ring is moved in one direction said part'will move said pushbutton inwardly to one'predetermined position, and said locking ring when at its locking position covering the means securing said mounting ring on said sleeve. to prevent removal of the mounting ring from the sleeve, and said'r'ings having aligned openings therein for receiving lock means toretain the locking ring in its locking position.

6. Switch structure comprising, a supporting sleeve member adapted to be mounted in an opening provided in a supporting plate member, an operating member movably mounted in said sleeve member and having an operating handle on its outer end and a switch operating member at its inner end, separable contacts at the inner end of said sleeve member for actuation by said switch operating member, locking means comprising a supporting ring having a locking ring mounted thereon for rotative and axial movement in substantially a spiral path, said locking ring having a radially inwardly extending operating part, and means on said supporting ring for removably securing it on said sleeve member at the outer side of said supporting plate with said operating part overlying the outer end of said switch operating member.

7. Switch structure comprising, a supporting sleeve adapted to be mounted in an opening in a supporting member, an operating member movably mounted in said sleeve and having an operating handle on its outer end and a switch operating member at its inner end, separable contacts at the inner end of said sleeve for actuation by said switch operating member, locking means comprising a supporting ring removably attached to said sleeve at the outer side of the supporting member, a locking ring mounted on the supporting ring for rotative and axial movement, said locking ring having an inwardly extending operating part therein, and projections on the looking ring engaging the supporting ring to retain said operating part in engagement with said operating handle when the locking ring is rotated.

8. Switch structure comprising, a supporting sleeve adapted to be mounted in an opening in a supporting member, an operating member movably mounted in said sleeve and having an operating handle on its outer end and a switch operating member at its inner end, separable contacts at the inner end of said sleeve for actuation by said switch operating member, locking means comprising a supporting ring removably attached to said sleeve at the outer side of the supporting member, a locking ring mounted on the supporting ring for rotative and, axial movement, said locking ring having an inwardly extending operating part therein, and projections on the locking ring engaging the supporting ring to move the locking ring axially when it is rotated thereby engaging the operating handle with said operating part on the locking ring.

9. Switch structure comprising, a supporting sleeve adapted to be mounted in an opening in a supporting member, an operating member movably mounted in said sleeve and having an operating handle on its outer end and a switch operating member at its inner end, separable contacts at the inner end of said sleeve for actuation by said switch operating member, locking means comprising a supporting ring removably attached to said sleeve at the outer side of the supporting member, a locking ring mounted on the supporting ring for rotative and axial movement, said locking ring having an inwardly extending operating part therein, an inclined groove in the supporting ring, and a projection on the locking ring disposed in said groove to move the locking ring axially when it is rotated to a predetermined position thereby engaging said operating handle with said operating part on the locking ring.

10. Switch structure comprising, a supporting sleeve, an operating member movably mounted in said sleeve and ha n an infla ing gn lc n its outer ggd and a swi h waning-11mm m cr nd, fiepq rgb le ntas a at the iQ lQI- gnd f ai slewe to: acguagiqn by said sw t h om' t ng membgn, c ing means c mprisin a limming r ng havi g a locki ng mou fi cmn f9: qtative and i l movs me said lo k r n h v n at; wardly x gndi Onerating Pa h in an indium. qqv c. umm n ring, a p i tion 611 the locking ring disposed in said ggpoyc tq mpve hsz lp k n r n i lywhen, t is ro atsd to a predet ine b sit q i fim y a in s d operating handlfi wi h sa om tin p 01 he o ki ga and m- ,889,115 Evans NQY- 29, .32

2,506,5Q5 i rey a May 2, 19.50

2,673,259 Appleton et a1. Mgr. 23, 1 9;?4

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