US2979593A - Push to test pilot light - Google Patents

Description

April 11, 1961 P. F. WHITE 2,979,593

PUSH To TEsT PILOT LIGHT 2 Sheets-Sheet 1 Filed Oct. 14, 1958 wm. 8 y /9 3/ ummm im 0 l i mL i; i5@ 35 I /f Il 1/ 7/ i 5 l; 1 J i 4 77 7 /T'ITJT I 65 34 F76 7 46 INVENTQR. j Pau! F Wfl/@ TEW M mi @7' April l1, 1961 P. F. wHxTE PUSH TO TEST PILOT LIGHT 2 Sheets-Sheet 2 Filed Oct. 14, 1958 INVENTOR. Paul F Wfl/f6 lfinitrd,States.,f12F96@'0w i@ 2,979,593 u u i l PUSH To TEST PILOT .LIGHT Paul F. White, Glen Ellyn, Ill.,-assignor to Furnas Electric Company, Batavia, Ill., a corporation of Delaware Filed oef. 14, 195s, ser. Np. 767,193 4 claims. (cl. 290'1s9) The invention relates to electric switch structure and has reference in particular to a push to test pilot light of the type having a translucent push button andiwhich is illuminated when the enclosed bulb is energized inV -either of the two operative positions of the push button.

In switch structure of the character described the housing of the device contains a transformer and a plurality of fixed contacts are provided in associated relation with movable contact bars. The movable bars are actuated by movement of the push button to connect the electric bulb across respective circuitsras thefbars are caused to engage vwith certain of the fixed contacts. Accordingly the device can -be employed for testing the main circuit to an electric motor or the like in the event a failure is indicated in the supply of current toA the' motor by the auxiliary or control circuit. The invention therefore has for its primary object to providesuch a push to test pilot light of improved design, whereinthe various parts will be comp-actly arranged in the switchehousing although capable of etiicient operation over long periods of time without requiring any attention on the part of theV operator. v

Another object of the invention is to provide a push to test pilot light which will incorporate a cover plate having a snap-on attachment to one of the housing members so that the parts can be readily assembled or disassembled andwhich when assembled will comprise a v unitary part of the complete switch device. Y

Another object is to provide apilot light as described which will incorporate a snap-on cover platefor one of the two housings of the device, the said housing con- 2,979,593 Patented Apr. 11,1961

' manner of attaching the snap-on cover;

taining the transformer and the spring-energized pusher c v member for the pushv button.

A further object is to provide a pilot light of the character described which will incorporate a snap-on cover plate for the housing containing the transformer,

and wherein the cover plate providesa support for the light bulb, the said plate having the socket for the bulb iixedly secured thereto. Y

With these and various other objects in view, the invention may consist of certain novel features of construction and operation, as will be more fully described and particularly pointed out in the specification, drawings and claims appended thereto.

In the drawings which illustrate an embodiment of the invention and wherein like reference characters are used to designate like partsf Figure l is an elevational view of a push to test pilot switch, the same embodying the improvements of the present invention;

Figure 2 is an exploded view of the switch of Figure l showing the various parts thereof in their relation -to one another `when assembled;

Figure 3 is an elevational view on an enlarged scale of the cover side of the transformer housing of the switch structure showing the same with the cover removed;

Figure 4 is a side elevational view of the transformer Figure 5 is a fragmentary, vertical,` sectional view on the same enlarged scale `as Figure 3 ,andwhich illustrates the structural details of the operating parts of the present switch;

Figure 6 is an elevational View ofthe cover side of the transformer housing similar to VFigure 3 'but lwith, the parts being drawn onthe same scale as used forpFigures Yl Aand 2, and which shows the complete switch in assembled relation; Y Y l Figure 7 is a front elevational ',viewAof the plunger housing for vthe switch with the plunger're'taining plate removed; and

Figure 8 is an enlarged view `of the rear side of the4 plunger ion the enlarged scale lof Figure 5. ,l

, The push to test pilot-light as shown in the drawings comprises in generale, unitary base -10y which is provided with an upstanding cylindrical portion 11 threaded exteriorly at 12 for-a partof its height. The base 10 is formed with a central interior bore 13 and the said base is further characterized by an intermediate inwardly directedange 14l and an outwardly directed bottom flange Y15.V u The push button gener-ally indicated by numeral 18, and which is associated with the base 10, includes the adapter 19 and the lens 20. Whereas the base and adapter may be formed of anyl suitable material such as metal, plastic or the like, -the lens 20- is formed of translucent material so that the light from the bulb within the samewill be visible to the operator. Thelens 20'is provided with a reduced portion at its base, which `portion is threaded fas at 21.,v The adapter 19'is also locatedV within the bore 13Wof-the base 10 andin the position as shown insaid figures,y the reduced 'end 220i the adapteris located within the opening formed by the flange 14. A guide washer 27 is located below ange 1'4 and said washer additionally has contact with the bottom surfacevof the adapter.` TheV distortable sealing ring 28 hasl location within groove 23 and `said ring completes the mounting ofthe push button within" the base in Va manner wherein the button may be moved axially within the bore 13' ofthe said base. Should it be desired to'A mount the base and associated switch structure on a mounting panel, the same can be readily secured `to the panel, as shown in Figure 6, by employing the mounting washer 30 and locking ring 31, said ring being interiorly threaded at 32 for threaded engagement with the threads 12 located on the cylindrical portion of the base.

The switch structure for the present device is contained within av pair of housings ,-34 and 35, the former housing containing a plunger and switch contacts, whereas the latter housing contains a transformer and a pusher member. More particularly, housing` 35 is provided with a disposed at right angles to the said extensions. When the pusher plate is associated with the housing the base portion 44 is located under the'intermediate partition wall 39 and the parts are normally maintained in contact by the coil spring 45 contined'between the bottom wall 46 of the housing and the said base portion 44. Asa result of this structure the extensions 43 are maintained in projected position above the top wall 37 and the same have contact with push button 18 to resiliently maintain the same in extended position. The pusher plate 42 is held in operative association with the housing 35 byv means of the cover plate generally indicated by numeral 48, see Figure 4. Both ends 49 and 50 of the cover plate are bent at right angles thereto and the top end 49 is provided with the support flange 51, the same being formed by being cut out from the main body portion of the cover plate. In accordance with the invention the support flange 51 supports the socket 52 and the electric light bulb 53. The socket 52 is ixedly secured to the ange and the same locates the bulb within the lens of the push button. In forming the support flange 51 by cutting out some of the material from the body portion of the cover plate, opening 57 is formed in the cover plate and provision is made for the extensions 43 of the push plate to extend through said opening.

An additional feature in connection with the cover plate 48 resides in the snap-on attachment which the cover plate has with the housing 35. For this purpose the bottom wall 46 of the housing is formed with the locking ledge 47 and the bottom end 50 is provided with the upwardly bent locking liange 54. Also the top end 49 is formed with a pair of openings such as 55 which are adapted to coact with the positioning pins 56 projecting upwardly from the top wall 37 of the housing `35. Figure 4 illustrates the manner of attaching the cover plate 48 to the housing, which requires that the openings 55 and positioning pin 56 be brought into coacting relation with each other as shown, and then the bottom end 50 can be snapped under the bottom wall of the housing whereby the locking ange 54 will interengage with the ledge v47 to releasably retain the cover in place.

The base 10 and housing 35 are releasably/secured to each other by means of the clamping screws such as 58, adapted to have location within ,the longitudinally extending grooves 59. 'I'he base 10 on its undersurface is formed with recesses 60 for receiving the positioning pins 56 which properly locate'the base l10 with respect to the housing 35. The'threaded ends of the clamping screws 58 enter vthe opening 61 and upon tightening of the screws the base 10 is connected tothe housing 35with the end 49 of the cover plate being clamped between the parts, thus preventing any displacement of the cover plate with the parts in assembled relation.

The housing 34 is provided with the longitudinally ex- -tending channel 64 for receiving the plunger 65. A central cavity 66 is also formed in the housing 34 and within said cavity the stationary iixed contacts and the movable contact bars are located. Considering iirst the stationary fixed contacts, it will be seen from Figures v and 7 that a pair of upper contacts 67 are supported by said housing so as to extend forwardly toward the front of the housing, and in a similar manner a pair of lower contacts-68 are supported bythe housing. The said contacts Vextend through the plunger retaining plate 70 torproject beyond the same and the said projectingends are provided with terminal screws 71 for theupper pair of stationary contacts and terminal screws 72 for the bottom pair-ofstationary contacts. The movable contact bars 73 and 74 extend transversely of the plunger 65, for which purpose the plunger is provided with an intermediate transversely extending opening 75, Figures 5 and 8. The movable contact bars 73 and 74 are held in spaced relation by the coil vspring 76. The plunger 65 is additionally-characterized by the provision of a stop shoulder 77 which -is adapted to contact the ledge'78 provided by the'housing to limit the upward movement of the plunger. Said plunger is resiliently biased upwardly to maintain the stop shoulder in contact with the ledge by means of the coil spring 80, whichy is conned between the bottom wall 81 provided by the housing 34 and the ledge 82 of the plunger. With the plunger being resiliently biased into its upward projecting position, it will be seen that its upper end projects beyond the top Wall of the housing for contact with the push button so that actuation of the push button in a downward direction will result in similar movement ybeing imparted to plunger 65.

When the housing 34 is assembled with the base 10, the positioning pins v83 have location inthe openings 84 formed in the base and the parts are releasably secured to each other by the clamping screws 85. Said screws extend through the longitudinal grooves 86 formed in the housing 34 and their threaded ends enter the openings 87 for threaded connection with the base.

AAs a result of the expandingaction exerted -by the coil springs 45 and 80 the pusher plate 42 and the plunger 65 are resiliently held in extended positions. It accordingly follows that the push button, which maintains contact at its base end with the pusher plate and plunger, is also located in projected position. In this projected position of the plunger 65 it will be seen that the movable contact bar 73 is in electrical contact with the upper contacts 67. When the push button is depressed both the plunger and the pusher plate are depressed to a similar extent and this movement of the members acts to compress the coil springs 45 and 80. Downward movement of the plunger 65 will separate the movable Contact bar 73 from the upper contact A67 and will cause electrical vcontact to take place between movable contact bar 74 and the `lower contact168. Upon release of the push button by the operator the springs 45 and will effect return of the-pusher plate, plunger and also the push button to their normal projected positions.

The present structure is unique in that two housings are employed, one for the transformer and which additionally supports the socket and bulb, and the other housing for the plunger and switch contacts. Although the housingsare independent, it will be seen that when they are in assembled relation with the base 10, the plunger supported by housing 34 and the pusher plate supported by housing 35 have operative and joint coaction with the pushbutton. The cover plate performs a dual function in that it retains the pusher lplate in operative relation with respect to housing 35 and also supports the socket and the light bulb. Additionally, the cover plate closes its side of the housing 34 and its attachment to the housing is materially facilitated by the snap-on structure pro vided by these parts.

The invention is not to be limited to or by details of construction of the particular embodiment thereof illustrated in the drawings, as various other forms of the device will of course be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.

What is claimed is:

1. Electrical switch structure of the character described, the combination with a'base member having a base flange and a central longitudinal bore, a hollow cylindrical push button located within the bore and adapted to reciprocate with respect to the base member7 a housing secured to the base flange, said housing mounting a pusher plate and which normally projects above the connection of the housing with the base ange to extend within the central bore for contact with the push button, resilient means for yieldingly forcing/the pusher plate into a projected position, a cover plate for the 'housing adapted to have a snap-on attachment to the housing, said .cover plate when in attached relation on the housing functioning to retain the pusher plate in operative supported relation on the housing, and an electric light bulb supported by the cover plate and positioned within the push button.

2. Electrical switch structure of the character described, the combination with a base member having a base flange and a central longitudinal bore,V a hollow cylindrical push button located within the bore and adapted to reciprocate with respect to the base member, a housing secured to the base ange, said housing mounting a pusher plate and which normally projects above the connection of the housing with the base llange to extend within the central bore for contact with the push button, resilient means confined between a wall of the housing andV the pusher plate for yieldingly forcing the pusher plate into a projected position, a cover plate for the housing and which provides a front wall for the same, said cover plate having a releasable attachment to the housing and when in attached relation functioning to retain the pusher plate in operative supported relation on the housing, a socket xed to the cover plate, an electric light bulb adapted to be retained by the socket and positioned within the push button, a second housing secured to the base ange, said second housing mounting a plunger also normally projecting above the connection of the housing with the base ange to extend into the central bore for contact with the push button, a plurality of stationary contacts supported by the last mentioned housing, and contact bars carried by the plunger for coaction therewith.

3. Electrical switch structure of the character as delined by claim 2, additionally including resilient means within the second housing for yieldingly forcing the plunger into a projected position.

4. Electrical switch structure providing a push to test pilot light, in combination, a base member having a base flange and a central longitudinal bore, a hollow eylindrical push button located within theV bore and adapted to reciprocate with respect to the base member, a housing secured to the base flange, said housing including side walls, a rear wall and top and bottom walls, a cover plate for the housing and which provides the front wall thereof, means on the housing for releasably attaching the cover plate to the same, a socket liXed to the cover plate to extend above the connection of the housing with the `base flange and within the bore, a second housing secured References Cited in the iile of this patent UNITED STATES PATENTS Hallerberg et al June 14, 1955 Johnson et al. July 12, 1955

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