US2151910A

US2151910A - Electric switch

Info

Publication number: US2151910A
Application number: US35579A
Authority: US
Inventors: Herman G Graubner
Original assignee: Union Carbide and Carbon Corp
Current assignee: Union Carbide Corp
Priority date: 1935-08-10
Filing date: 1935-08-10
Publication date: 1939-03-28
Anticipated expiration: 1956-03-28

Description

March 28, 193 H. G. GRAUBNER ELECTRIC SWITCH Filed Aug. 10, 1935 4 SheetsSheet l INVENTOR HERMAN G. GRAUBNER ATTORNEY March 28, 1939. B R 2,151,910

ELECTRIC SWITCH Filed Aug. 10, 1935 4 Sheets-Sheet 2 INVENTOR HERMAN G. GRAUBNER F I BY ATTORN EY March 28, 1939. r GRAUBNER 2,151,910

ELECTRIC SWITCH fay [2 5 I 57 2/17 Filed Aug. 10, 1935 4 Sheets-Sheet 3 INVENTOR HERA IAN G. GRAUBNER ATTORNEY March 28, 1939.

H. G. GRAUBNER ELECTR IC' SWITCH Filed Aug. 10, 1935 4 Sheets-Sheet INVENTOR HERMAN G. GRAUBNER BY I 'ATTORNEY Patented Mar. 28, 1939 UliiThD STATES 2,151,9iii

PATENT OFFICE ELECTRIC SWITCH York Application August 10,

18 Claims.

The invention pertains to electric switches in general and more specifically to switches for controlling the low voltage electric circuits of selfcontained battery operated devices such as flashlights, hand lamps, lanterns, and the like.

Flashlights and the like usually include a lamp bulb. a battery, and suitable connections for conducting the battery current through a circuit including the lamp bulb. The conductors for the circuit may include the outer casing of the flashlight and also a conductor insulated from the casing. To control this circuit a suitable switch may be mounted upon the casing to bridge the gap between the casing and the insulated conductor at the will of an operator.

lViany switches have been proposed for this purpose but they are mostly unsatisfactory because they are hard to operate, easily damaged, intricate, fragile, and of poor quality. Therefore, the more important objects of the invention are to provide a switch that is convenient and easy to operate, rugged in structure, not easily damaged, simple in construction, and high in quality.

These and any other new and novel features will be more fully illustrated in the following description and the accompanying drawings, in which:

Fig. 1 is a vertical sectional View of a switch embodying the invention;

Fig. 2 is a sectional View along line 2-2 of Fig. 1;

Fig. 3 is a vertical sectional view of another switch embodying the invention;

Fig. i is a sectional view along line l4 of Fig. 3;

Fig. 5 is a vertical sectional view of another switch embodying the invention;

Fig. 6 is a sectional view along line 6-'6 of Fig. 5;

Fig. l is a plan view of another switch embodying the invention;

Fig. 8 is a sectional view along line 8-8 of Fig.

Fig. 9 is a sectional View along line 9--9 of Fig. '7;

Fig. 10 is a plan View of another switch embodying the invention;

Fig. 11 is a sectional view along line 11-11 of Fig. 10;

Fig. 12 is a sectional view along line 12-42 of Fig.

Figs. 13, 14 and 15 are detail views of part of the flngenpiece of the switch shown in Figs. 10, 11 and 12 in three different operating positions;

1935, Serial No. 35,579

Fig. 16 is a plan view of another switch embodying the invention;

Fig. 1'7 is a sectional view along line l'l-ll of Fig. 16;

Fig. 18 is a sectional view along line l8l8 of Fig. 1'7;

Fig. 19 is a plan View of another switch embodying the invention;

Fig. 20 is a sectional view along line 2020 of Fig. 19;

Fig. 21 is a sectional view along line 2l-2| of Fig. 20;

Fig. 22 is a vertical sectional View of another switch embodying the invention;

Fig. 23 is a plan view of another switch embodying the invention; and

Fig. 24 is a sectional View along line 2424 of Fi 23.

The invention shown by the drawings may be embodied in a switch comprising an insulated conductor and a grounded conductor operably mounted in a housing, and a rockable element for moving one of said conductors into contact with the other.

One of the conductors may be a resilient switch arm or blade, and the rockable element or finger-piece may extend outwardly through a suitable opening in the housing into an exposed position suitable for manual operation. The fingerpiece may be mounted so that it is free to move through a complete revolution or through only a part of a revolution, and the switch may be provided with means for rendering it either wholly or partially inoperative so that it will not be closed by pressure accidentally applied to the finger-piece. Furthermore, the finger-piece may be mounted so that either a depressing movement, a rocking movement, or both, will close the circuit, and the housing may be provided with a base or bottom that may be secured to the inner surface of .a flashlight casing opposite the outer surface to which the housing is secured. In addition to the features described above, the switch may be provided with means for preventing the parts from becoming injured when pressure in excess of that required to operate the switch is applied to the finger-piece.

In the example shown in Figs. 1 and 2 the invention may be embodied in a switch comprising conductive contacts l0 and I2 normally in open circuit relation, and means such as a fingerpiece I l for moving one of the contacts into engagement with the other to close the circuit. One of the contacts, such as the movable contact it, may be a resilient switch blade, and the other contact, such as the normally stationary contact l2, may occupy a position in the path of the switch blade although this normally stationary Contact may be movable out of the path of the switch blade to render the switch inoperative to close the circuit.

The contacts [0 and i 2 may be inclosed in a suitable housing i5 which may be mounted upon the outer surface of a flashlight casing I 8 over a suitable opening 20, and this housing may be provided with a suitable base 22 which may be mounted upon the inner surface of the casing H3 over the opening 20 opposite the housing 16. The housing 16 and the base 22 may be secured to the casing I8 by an appropriate fastening such as a suitable number of rivets 24 each located in suitably aligned openings in the housing, casing, and base.

One of the contacts such as the resilient switch blade l0 may be electrically insulated from the housing l6 by a suitable covering of insulating material 26, and the other contact such as the stationary contact l2 may be in conductive relation with the housing. The switch blade H] may be secured to the base 22 by appropriate means such as a suitable number of overturned ears 28, and the other contact l2 may be secured to the housing IS in cooperative relation with the free or movable and of the switch blade by a suitable rivet 30 which may be fixed to the contact It with which it may be moved longitudinally of the switch blade in a suitable opening 32 in the housing [6 by manual manipulation of a suitable head or operating button 34 located in, an exposed position outside of the housing.

The finger-piece (4 may be mounted in a suitably exposed position within the upper portion of the housing IS in operative relation with the switch blade l0, and the finger-piece may be resiliently supported in this position against the inner surface of the housing by the switch blade in such a manner that it is rockable about its to move the switch blade into closed position, and also so that it is bodily movable, depressible, or translatable, to move the switch blade into closed position in engagement with contact l2. The finger-piece may also be of any suitable form, shape, or outline, such as circular, and it may be provided with one or more semicircular or arcuate portions which engage the inner surface of the housing and provide a bearing upon which the finger-piece turns, and also provide a means for limiting the rocking movement to a range which is suitable for moving the switch blade into engagement with the stationary conductor.

The central portion 36 of the finger-piece K may be of a generally circular outline, and the outer portion may extend or project upwardly into a suitable operating or engageable position through a suitable opening in the upper portion of the housing 15, while the inner portion may be in operative engagement with the switch blade H3. t each side of the central portion 36 the finger-piece may be provided with a suitable arcuate portion 40 that engages the inner surface of the housing [6 and provides a bearing upon which the finger-piece turns, and also limits the rocking movement to a suitable range of substantially '10 degrees. To provide suitable support for the finger-piece when it is bodily depressed or translated, each end of the opening 38 in the housing 16 may be provided with a suitable ear 42, and these cars may be substantially parallel and extend into the housing toward the switch blade. Also, to facilitate manual inovenrient the outer surface periphery of the finger-piece may be provided with a suitable roughened portion such as a linurl.

To provide means for closing the switch when the finger-piece is rocked, the inner portion of the finger-piece in engagement with the switch blade may be provided with a suitable camrned contour such as a depression or recess 44, and the switch blade may be provided with an appropriate raised portion it extending therein. The recess Mr and the raised portion 45 may extend laterally across the finger-piece and the switch blade respectively, and the engaging surfaces nay be arcnate, or suitably rounded to iacilitate disengagement when the finger-piece is rocked. Also, to hold the switch blade against movement into engagement with the base 22 of the housing it when the contact i2 is in inoperative position out of the path of the switch blade, and thereby prevent the circuit from being closed, since the base 2 and contact I2 are in conductive relation, the portion of the base 22 in the path of the switch blade may be provided with a suitable covering of dielectric material such as the insulation $8, which may be secured to the base by a suitable fastening such as a rivet 5t.

Normal operation of the switch may be eifected by bodily depressing or translating the finger- I piece with respect to the housing until the switch blade engages the stationary contact, or by rocking the finger-piece with respect to the housing thereby moving the switch blade into engagement with. the stationary contact. During the movement of the finger-piece while it is being translated, the ears maintain the finger-piece in correct relation with the housing and prevent longitudinal wandering. When the finger-piece is rocked, the raised portion 46 of switch blade iii moves downwardly from the recess 44 to the periphery of the finger-piece thereby moving the free end of the switch blade into engagement with the conductor i2, and the arcuate portions 40 limit the rocking movement of the fingerpiece to that suitable for closing the switch and prevent excess or useless travel.

To prevent accidental movement of the fingerpiece from closing the circuit at times when the switch is not intentionally operated, the switch may be placed in inoperative position by moving the button 34 to the rear of its range of travel thereby moving conductor 52 out of the path or out of operative relation with the switch blade. Then when the finger-piece is moved or operated the switch blade engages the dielectric it and he circuit is not closed or completed.

When the switch in inoperative position and a user manipulates the finger-pies in an at tempt to close the switch, considcraltile pressure be exerted in excess of that required for normal operation. To prevent this sure from injuring the switch or bending the resilient switch blade, the base 22 be provided with a longitudinal groove Eli! in which the dielectric 48 and suitable portions of the switch blade If! and conductor l2 are disposed. Then when excess pressure is applied to the finger" piece the switch blade IE! will be depressed into this groove and the arcuate port ons 4! of the finger-piece M will engage the edges 54 01' this groove and thereby prevent injury to the switch. To obtain this result the groove 52 may be somewhat less in width than the finger-piece I4, and the switch blade ii] may be somewhat less in width than the groove 52. Also, the opening in the casing 18 may be of suflicient size to provide space for the free and normal operation of the switch elements.

In the embodiment of the invention incorporated in the switch shown in Figs. 3 and 4 the construction is generally similar to that shown in Figs. 1 and 2 although some of the operating functions are secured in a diiierent way.

In this switch the stationary contact 55 may be the insulated conductor, and the grounded contact 56 may be the resilient switch blade. The finger-piece 5'? may be similar to that shown in Figs. 1 and 2 with the exception that the cammed portion may be provided with two recesses 58 and 59 of which one may have a greater depth than the other. Also, the switch blade so may be provided with a relatively high raised portion to having a rounded upper surface corresponding in shape with the recesses 58 and 59 into which it extends.

This switch may be placed in inoperative condition by moving the finger-piece 5'! into a position where the raised portion Eii of the switch blade '55 is in recess 59 which is the deeper of the two. When the switch is in this position and the finger-piece Si! is depressed the lateral arcuate portions 5| engage the base 62 along the sides of groove 63 before the switch blade to engages the conductor 55 so that accidental depression of the finger-piece will not close the switch. By moving the finger-piece 5'! into a position where the raised portion 6Q is in the shallower recess 58, depression of the finger-piece may move the switch blade 56 into engagement with the conductor 55 and the switch may be closed. Also, by moving the finger-piece into a position where raised portion 65 engages the periphery of the finger-piece the switch blade may be held in contact with conductor 55 and the switch may be maintained in closed position.

in the embodiment of the invention incorporated in the switch shown in Figs. 5 and 6, the stationary conductor lil may be insulated from the switch and the switch blade 12 may be the grounded conductor. The switch blade may be secured to housing '54 by a stud it that is disposed in a suitable slot '53 in the housing and the stud may be provided with an enlarged head or operating button 83 at the outside of the housing. Also, the switch blade may be provided with a suitable opening 82, and a depending ear 84 in operative relation with conductor TE.

The finger-piece 85 may be provided with a circular central portion 88 that extends outwardly through a suitable opening in the housing and downwardly through the opening 82 in the switch blade. For support, the finger-piece may be provided with trunnions or pivots 95! at opposite sides of the central portion, and the housing i l may be provided with a vertical groove 92 in each side thereof in which the trunnions are respectively secured. Between the central portion and each of the trunnions the finger-piece may be provided with an elongated cammed portion or cam 5 5 having arcuate ends adapted to engage the switch blade at each side of the opening 82. Also, each of the arcuate ends may be provided with a rib at the portion most remote from and coaxial with the axis of the finger-piece, and the switch blade E2 may be provided with a transverse depression or groove 98 in the upper surface thereof vertical alignment with the axis of the fingerpicce. To provide the switch with an inoperative position the base [Bil may be provided with a ledge I02 over which the depending ear 84 may be disposed by moving the operating button 80 to its position nearest the finger-piece. When this button is in its position away from the fingerpiece the switch may be closed by depressing the finger-piece 86 thereby depressing the ear 84 of the switch blade into engagement with conductor iii. During this movement the trunnions may move downward in the grooves Q2, and when the pressure is removed from the finger-piece it may returned to its original position by the resilient switch blade. By rocking the finger-piece 86 in either direction until one of the ribs 96 at the end. of the elongated cam 94 is seated in the groove 5%, the cam will move the switch blade into engagement with conductor m thereby closing the switch, and the engagement between the rib and the groove will hold the switch closed until they are disengaged by further movement of the finger-piece.

In the embodiment of the invention incorporated in the switch shown in Figs. '7, 8 and 9, the finger-piece Mid may be provided with a cammed portion such as triangular cams I35 instead of the elongated cams 94 shown in Fig. 5, and. instead of internal grooves the housing may be provided with a support F38 having vertical slots lid in which the trunnions oi the finger-piece operate. The support Hi8 and the switch blade H2 may be rigidly secured to the housing by suitable means such as a rivet I I4, and the switch blade may be provided with a groove H6 that cooperates with the corners of cam 95 to detain the finger-piece in a position where the switch blade is in contact with conductor H8 and the switch is closed. The switch may also be closed by depressing the finger-piece, and at the end of this movement the trunnions may engage the bottom of slots iii! to prevent excess pressure from injuring the switch. To maintain the switch in inoperative condition the housing may be provided with a slide 52!! having operating ears 22 extending outwardly through suitable openings adjacent the sides of the housing, and interior supports I2 3 adapted to slide underneath the trunnions thereby preventing the finger-piece from being depressed.

In the embodiment of the invention shown in Figs, 10 to 15, the switch may be provided with a stationary insulated conductor I25, and a grounded conductor and resilient switch blade E26 rigidly secured to the housing I21 by a rivet 28 and provided with a downturned ear I in operative relation with conductor 125.

To operate the switch the housing may be provided with a finger-piece ltl having trunnions i32 operably secured in vertical grooves I36 in the housing lZl, cams !36 in operative relation with the switch blade E26, and bosses 138 in operative relation with suitable abutments MEI in fixed relation to the base M2 and housing I21. The cammed surface or cams E may have the shape or form of a diamond with the ends or points removed to provide flat surfaces somewhat smaller than the four side surfaces, and the bosses E38 may be disposed with respect to the cams so that they extend outwardly from two of the opposite fiat side surfaces although at points along the axis of the finger-piece between the cams and the central circular operating portion Hi l.

The peculiar shape of the cams use may pro vide the finger-piece with three pairs of operating positions: two in which the switch is closed; two in which the switch may be closed by depressing the finger-piece; and two in which the finger-piece cannot be depressed and the switch is therefore in inoperative condition. For example, with the cams in the position shown in Figs. 11, 12 and 13, the bosses I38 engage the abutments I40 and support the finger-piece so that it cannot be depressed to move the switch blade I26 into contact with conductor I25 to close the switch. With the cams in the position shown in Fig. 14 the switch blade is in the position shown in Fig. 11 out of contact with the stationary conductor but the finger-piece may be depressed to move the switch blade into contact withthe conductor and thereby close the switch. With the cams in the position shown in Fig. 15 the end of the cam holds the switch blade in contact with the conductor and in this position the switch remains closed.

The embodiment shown in Figs. 16, 17 and 18 is of the same general construction as that shown in Figs. 10 to 15, but this switch is provided with the additional feature that it may be locked or latched in inoperative condition.

To provide this feature the finger-piece I46 may be provided with means that engage or in terflt with a portion of the switch blade I48, and means for moving the switch blade to disengage it from the finger-piece. This latching or locking of the switch may be obtained by providing the finger-piece I46 with a plurality of lugs I50 and the switch blade I48 with one or more notches or recesses I52 in which the lugs may be retained.

The lugs I50 may be of any suitable size and located in any suitable position, although lugs somewhat smaller than the bosses I38 with one located on the surface of the cam I36 adjacent, just outside of, and in axial alignment with each of the bosses I38 is preferred. Although four lugs are preferred, one or more may be adequate so long as they are located in the position shown.

Also, the notches or recesses I52 may be of any suitable form or shape and in any appropriate location, but one notch in each side of the opening I54 in vertical alignment below the axis of the finger-piece is preferred. As already explained the opening I54 is provided so that the manually engageable portion of the finger-piece may extend therethrough, and in this and the preceding switch the bosses I38 may also extend downwardly through this opening.

To unlatch or unlock the switch a manually operable actuator in operative engagement with the switch blade may be provided. This actuator or button I56 may be located adjacent but spaced an operable distance from the housing I58 to the rear of the finger-piece. The actuator may also conform with the shape of the housing and it may be secured thereto by a suitable fastening such as a rivet I60 that also joins the housing, switch blade, and flashlight casing I62.

To operate the switch blade the actuator may be provided with one or more ears or projections I64 extending inwardly through suitable openings in the housing and engaging the switch blade. When this switch is in the locked position shown in the drawings the bosses I38 hold the finger-piece against depression and the engagement between the lugs I50 and the notch-es I52 in the switch blade hold the finger-piece against rocking movement so that the switch cannot be accidentally closed. By depressing the actuator I56 the switch blade may be disengaged from the lugs I50 and then the switch may be operated the same as that shown in Figs. 10 to 15.

In the embodiment shown in Figs. 19, 20 and 21, a grounded conductor or resilient switch blade I66 may be moved into engagement with an exposed portion I68 of an insulated stationary conductor I10. The switch blade may be mounted in a housing I12 by a suitable fastening such as a rivet I14, the housing may be secured to a suitable base or flashlight case I16 by an appropriate fastening such as one or more rivets I18, and the conductor I10 may enter the switch through a suitable opening I in base I16 to which it may be secured by an appropriate number of overturned ears I82.

To move the switch blade into engagement with the stationary conductor the switch may be provided with a finger-piece I84 mounted in a l suitable opening I86 in the top of the housing upon a transverse shaft or pivot I88 rigidly secured to the housing I12.

To provide the switch with an inoperative position the housing I12 may be provided with an opening I86 that extends down the rear of the housing a sufficient distance to allow the elongated finger-piece to be folded down below the top of the housing so that only the end extends outside and to the rear of the housing. The finger-piece may have substantially parallel sides and when in inoperative position the pressure of the switch blade upon the lower side of the finger-piece may hold it against accidental movement.

To save space the opening I90 in the fingerpiece, through which the pivot I88 extends, may be near the inner end, and to provide suitable operative engagement between the finger-piece and the switch blade the inner end may be provided with a substantially flat cammed surface I92 at such an angle that when this surface is in engagement with the switch blade the fingerpiece stands at an angle toward the rear of the switch from vertical, and when the inner end I93 is in engagement with the switch blade I66 it will be held in contact with the exposed portion I68 of conductor I10 and the circuit will be closed. Also, to provide means for holding the switch closed by manual pressure, the fingerpiece may be provided with an opening I90 that is suitably elongated so that the finger-piece may be moved with respect to the axis of the pivot I88.

The inoperative position of the switch is shown in the drawings. In this position pressure upon the finger-piece cannot close the switch. To place the switch in operative position the outer end of the finger-piece may be moved upwardly until the face I92 engages the switch blade. In this position the switch may be closed by exerting suffi cient pressure on the outer end of the fingerpiece to move it downward with respect to the pivot I88 against the upward pressure of the resilient switch blade I66 until the switch blade engages the exposed portion I66 of insulated conductor I10. The switch may also be placed in position where it will remain closed by moving the outer end of the finger-piece into its forward upright position where the inner end I93 of the finger-piece engages the switch blade and holds It in closed position. In this position the fingerpiece may rest against the forward end of slot I86 which may serve as a forward stop.

The embodiment shown in Fig. 253 is of the general construction as that shown in Figs. 19, 20 and 21. In addition to the features shown in the previous switch, this switch may be provided with means for latching the finger-piece in inoperative position, and means for resiliently holding iii ill

the finger-piece in latched position and also in open position.

To latch the switch in inoperative position the finger-piece 193 may be provided with one or more lateral extensions or latches I94 of which two are preferred for symmetrical appearance. These latches may extend from any suitable portion of the finger-piece although a position adjacent the lower side of the outer end is preferred. To secure the latches the housing I96 may be provided with a similar number of ears I98 which may extend inwardly from the rear wall a suitable distance above the lower edge thereof. To maintain the finger-piece in latched position the housing may be provided with a spring 2M having one end thereof secured to the housing by an appropriate fastening such as a rivet 202, and an arouate portion disposed a substantially uniform distance from the pivot 2G4 upon which the fingerpiece is mounted, and the finger-piece may be provided with a laterally extending pin 285 in operative relation with the arcuate portion of spring 25E).

The switch is shown latched in inoperative position. To move the switch into operative position the finger-piece may be moved forward against the pressure of spring 20!] until the latch I94 is disengaged from ears I98, and then the outer end may be moved upwardly around pivot 204. In this position it may be operated in a manner similar to that of the preceding switch although when it is depressed it encounters the pressure of spring 220 in addition to that of switch blade 203.

The embodiment shown in Figs. 23 and 24 is of the same general construction as the switch shown in Fig. 22. In this switch however, the finger-piece Zlil extends outwardly at the rear of housing Zi2 farther than that shown in Fig. 22 when the switch is in inoperative position. To latch the switch in inoperative position the fingerpiece 2"] may be provided with one or more latches 2M, of which two are preferred, and these latches may extend laterally outward from the lower side or edge of the outer end of the fingerpiece. To secure the latches the housing 2i2 may be provided with a suitabe number of cars 2l6 overlying the latches 2| 4 when the finger-piece 21a is in inoperative position.

When the finger-piece is in inoperative position the latches 2M3 may be disposed outside and adjacent the rear end of housing H2, and the ears: 21% may extend outwardly from the rear of housmg 2i2 adjacent opening 2H8 therein in which finger-piece 2H3 is operably mounted. To maintain the finger-piece in latched position, it may be provided with a laterally extending boss or pin 220 in operative relation with a spring 222 rigidly secured to housing 2I2 by appropriate means such as a rivet 224. The spring 222 may extend upwardly within the housing in resilient engagement with the rear side of pin 220 in a position tending to move the finger-piece forwardly with respect to the housing.

To facilitate operation of the switch the fingerpiece may be provided with means for moving it from inoperative to operative position. Such means may comprise a resilient member such as a spring operably secured to the housing and to the finger-piece to move it to its rear upright, normal operating, or open circuit position. This spring may be of any suitable type, such as a coiled or helical spring 225 encircling the fixed pivot 226 a suitable number of times, with a fixed end secured to a suitable projection 228 fixed to piece into its open circuit position 230 shown in dotted lines. In this position the finger-piece may be depressed to move the switch blade 232 into closed position in engagement with stationary conductor 234. The finger-piece may also be moved into closed circuit position 236 shown in dotted lines in which the end of the finger-piece maintains the switch closed in the manner described in connection with the switches shown in Figs. 19 to 22.

In the switches illustrated hereinbefore the component parts may be of diiierent form and in different relative position. Also, various similar and equivalent elements may be substituted without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. An electric switch comprising a normally stationary contact; a normally open springopened movable contact; a finger-piece; means supporting said finger-piece for rectilinear depression to force said movable contact into circuit-closing engagement with said stationary contact; said spring-opened movable contact normally acting to urge said finger-piece toward the initial extremity of such limited rectilinear movement; said means also supporting said finger-piece for rocking movement about a fixed axis while held in such extremity by said springopened movable contact; and cam means coacting with said movable contact for moving and retaining the same in circuit-closing engagement with said stationary contact when said fingerpiece is rocked through a predetermined arc. about said fixed axis.

2. An electric switch as claimed in claim 1, in which a housing encloses the entire assembly except an exposed portion of said finger-piece, said housing having an opening through which said finger-piece projects for smooth rocking movement about said fixed axis as well as smooth rectilinear movement without exposing the interior of said housing,

3. An electric switch comprising a housing, cooperative conductive contacts mounted in said housing in open circuit relation, and means independent of said contacts for moving one of said contacts into engagement with the other to close the circuit, said means comprising a fingerpiece, and means supporting said finger-piece for limited rectilinear movement exclusively in a plane perpendicular to said housing to temporarily move one contact into engagement with the other contact, said means also supporting said finger-piece for limited rocking movement, and means acting to move and secure one contact in engagement with the other when said fingerpiece is rocked.

4. An electric switch comprising a housing; cooperative conductive contacts operably mounted in said housing in open circuit relation; and means independent of said contacts for moving one of said contacts into engagement with the other to close the circuit, said means comprising a finger-piece that is both rocka-ble about an axis and bodily translatable, said housing being provided with a base, and said base being in conductive relation with said housing.

5. An electric switch comprising a housing provided with an opening therein; engageable contacts mounted in said housing; means for moving one of said contacts into engagement with the other comprising a translatable fingerpiece mounted in said housing and provided with a central portion projecting outwardly through said opening, and lateral portions in engagement with the inner surface of said housing and forming bearings upon which said finger-piece turns; said finger-piece being also provided with a recess and one of said contacts being provided with a raised portion extending into said recess for moving said contacts into engagement upon rocking said finger-piece; and means forming a portion of said housing for engaging said fingerpiece and limiting the translational movement thereof to a range that will not injure said contacts.

6. An electric switch as claimed in claim 5, in which said housing is provided with means for moving one of said contacts out of operative relation with the other to render the operative movement of said finger-piece inefiective.

7. An electric switch as claimed in claim 5, in which the finger-piece is also provided with a second recess of such depth that when the same raised portion is disposed therein the translational movement of said finger-piece will not move said contacts into engagement,

8. An electric switch comprising a housing provided with trunnion supports and an opening between said supports; engageable contacts mounted in said housing; means for moving one of said contacts into engagement with the other comprising a translatable finger-piece mounted in said housing and provided with trunnions disposed in said trunnion supports, a central portion projecting outwardly through said opening, and a cam between each of said trunnions and said central portion in engagement with one of said contacts.

9. An electric switch as claimed in claim 8, in which said housing is provided with means for moving one of said contacts out of operative relation with the other to render the operative movement of said finger-piece ineffective.

10. An electric switch as claimed in claim 8, in which said cams and one of said contacts are provided with cooperating portions for releasably holding said finger-piece against movement from closed circuit position.

11. An electric switch comprising a housing having an opening therein; cooperative conductive contacts operably mounted in said housing in open circuit relation; means mounted in said opening for causing engagement of said contacts to close the circuit, said means comprising a circular operating member formed with axial projections rockably engaging portions of said housing, the circular portion of said member completely closing said opening at all times; and interlocking portions formed on said means and one of said contacts to restrain said means against rocking movement.

12. An electric switch comprising a housing; cooperative conductive contactsoperably mounted in said housing in open circuit relation; means independent of said contacts for causing engagement of said contacts to close the circuit, said means comprising an operating member that is both rockable about an axis and bodily translatable, and said means being formed with axially projecting cam portions in engagement with the underside of said housing to limit rocking movement of said operating member.

13. An electric switch comprising a housing; cooperative conductive contacts operably mounted in said housing in open circuit relation; means for moving said contacts into engagement with each other to close the circuit; said means comprising a finger-piece that is both rockable about an axis and bodily translatable; means for limiting the translatory movement of said fingerpiece; a projection formed on one of said contacts; and depressions formed in the periphery of said finger-piece to engage said projection; one of said depressions being deeper than the others whereby when said projection is seated in said deeper depression translatory movement of said finger-piece will not cause engagement of said contacts.

14. An electric switch comprising a housing; a

base associated with said housing; a central depression in said base; a conductive contact mounted in said depression; a second conductive contact mounted to cooperate with said first conductive contact and normally in open circuit relation therewith; shoulders formed on either side of said depression; a finger-piece mounted in said housing independently of said contacts for rockable and vertical movement in said housing; said finger-piece having portions adapted to engage said shoulders to prevent excessive vertical movement of said finger-piece; and means formed on said finger-piece for at times causing engagement of said conductive contacts to close the circuit.

15. An electric switch comprising a housing; cooperative conductive contacts operably mounted in said housing in open circuit relation; means independent of said contacts for causing engagement between said contacts to close the circuit; and means secured to said housing and adapted to be at times interposed between said conductive contacts to prevent engagement thereof; said first-named means being rockable about an axis which is translatable in a plane perpendicular to l i said housing.

16. An electric switch comprising a housing having an opening therein; cooperative conductive contacts operably mounted in said housing in open circuit relation; means mounted in said opening for causing engagement of said contacts to close the circuit, said means comprising a circular finger-piece provided with axially projecting cam portions for engagement with one of said contacts and trunnion portions projecting axially from said cam portions, said circular finger-piece completely closing said opening at all times; and means formed in said housing to receive said trunnion portions for slidable and rotatable movement therein.

17. An electric switch comprising a housing; cooperative conductive contacts operably mounted in said housing in open circuit relation; means independent of said contacts for causing engagement of said contacts to close the circuit; a depression formed in one of said contacts; and transversely projecting cam portions formed on said means for engagement with said depression to restrain rotation of said means about trunnions integral therewith and engaging in guide means formed in said housing in which said trunnions are both rotatable and movable vertically toward and away from said conductive contacts.

18. An electric switch comprising a housing, including vertical walls and a top portion having Ill) an opening therein; cooperative conductive contacts operably mounted in said housing in open circuit relation, one of said contacts having an opening formed therein; means independent of said contacts for causing engagement of said contacts to close the circuit, said means projecting through both said openings and being rotatable therein; axially projecting cam portions formed on said means and adapted to engage said contact to depress the same; and trunnions projecting from said means and engaging vertically extending guides formed in the vertical Walls of said housing for translatable and rotat- 5 able movement in said guides.

HERMAN G. GRAUBNER.