US3858018A

US3858018A - Electrical switch with removable driving means

Info

Publication number: US3858018A
Application number: US00444884A
Authority: US
Inventors: J Walley
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1974-02-22
Filing date: 1974-02-22
Publication date: 1974-12-31
Anticipated expiration: 1991-12-31

Abstract

An electrical switch has a housing, and means is provided in the housing for access thereinto. Means is movable in the housing for completing a circuit therethrough, and means for actuating the circuit completing means is shiftable between at least two positions in the housing. Means is engaged with the actuating means in one position thereof for closing the access means, and means removable from the housing is insertable through the access means to conjointly drive the closing means from the access means and shift the actuating means to its other position to actuate the circuit completing means.

Description

United States Patent [191 Walley [451 Dec. 31, 1974 ELECTRICAL SWITCH WITH REMOVABLE DRIVING MEANS [75] Inventor: Joseph M. Walley, Morrison, Ill.

[73] Assignee: General Electric Company, Fort Wayne, Ind. [22] Filed: Feb. 22, 1974 [21] Appl. No.: 444,884

[52] US. Cl. 200/153 LA, 200/42 R, 200/5 EB [51] Int. Cl. H0lh 9/24, I-IOlh 27/00 [58] Field of Search 200/42 R, 5 EB, 153 LA,

[56] References Cited UNITED STATES PATENTS 2,947,825 8/1960 Woodward 200/5 EB 3,183,315 5/1965 Kiely 200/5 EB 3,600,529 8/l971 Gartland, .lr 200/5 EB 3,714,383 1/1973 Leonard et al. 200/44 Primary Examiner-Robert K. Schaefer Assistant Examiner-William J. Smith [57] ABSTRACT An electrical switch has a housing, and means is provided in the housing for access thereinto. Means is movable in the housing for completing a circuit therethrough, and means for actuating the circuit completing means is shiftable between at least two positions in the housing. Means is engaged with the actuating means in one position thereof for closing the access means, and means removable from the housing is insertable through the access means to conjointly drive the closing means from the access means and shift the actuating means to its other position to actuate the circuit completing means.

16 Claims, 10 Drawing Figures ELECTRICAL SWITCH WITH REMOVABLE DRIVING MEANS BACKGROUND OF THE INVENTION This invention relates in general to electrical switches for use with appliances or the like and in particular to such electrical switches operated by means removable therefrom for preventing unauthorized operation.

In the past, various electrical switches have been operated by a removable key which was selectively inserted through an opening in the electrical switch housing to effect actuation of the electrical switch component parts for making or breaking an electrical circuit. In some of the past electrical switches, a removable key was selectively insertable through a plurality of openings in the electrical switch housing for effecting actuating of the electrical switch component parts to make or break a plurality of electrical circuits. Some of the key receiving openings provided in the past key operated electrical switches were provided with particular or peculiar shapes in an attempt to prevent the entry of unauthorized keys or foreign tools, such as screwdrivers, nails, hairpins, knife blades, pencils, etc. One of the disadvantageous features of this type of past electrical switch was that irrespective of the particular shape of the key receiving opening utilized, some unauthorized key or foreign tool undoubtedly could be inserted thereinto. In other past electrical switches, the key receiving opening was restricted, i.e. made very narrow or slot-like, in an attempt to prevent the insertion of unauthorized keys or foreign tools; however, generally the same disadvantageous feature was applicable to such narrow key receiving openings as discussed above with respect to those having peculiar shapes. Of course, other disadvantageous features with respect to electrical safety and deformation of component parts of the past electrical switches are ancillary to the aforementioned disadvantageous feature with respect to the insertion of unauthorized keys or foreign tools into the past key operated type electrical switches.

SUMMARY OF THE INVENTION Among the several objects of the present invention may be noted the provision of an electrical switch adapted to be operated by means removable therefrom which overcomes the disadvantageous or undesirable features discussed hereinbefore, as well as others, with respect to the prior art electrical switches; the provision of such electrical switch which is positively blocked against the entry of unauthorized means for the operation thereof; the provision of such electrical switch having means internally thereof for blocking the entry of unauthorized keys or foreign tools or the like; the provision of such electrical switch in which the blocking means is effective to actuate other components of the electrical switch; the provision of such electrical switch in which the blocking means is displaced upon the insertion of an authorized means for operating the electrical switch and automatically returned to its blocking position upon removal of the authorized means for operating the electrical switch; the provision of such electrical switch which may be selectively momentarily actuated; and the provision of such electrical switch which is simplistic in design, economically manufactured, and easily assembled. Other objects and advantageous features will in part be apparent and in part pointed out hereinafter.

In general, an electrical switch in one form of the invention has a housing and means in the housing for access into an interior portion thereof. Means is movable in the housing for completing a circuit therethrough, and means for actuating the circuit completing means is shiftable between at least two positions in the housing. Means is engaged with the actuating means for generally closing the access means with the actuating means is in one position thereof, and means removable from the housing is insertable through the access means for driving the closing means to conjointly displace it away from the access means and drivingly shift the actuating means to its other position to actuate the circuit completing means.

Also in general, the electrical switch in one form of the invention may also additionally include means for momentarily operating the circuit completing means, and the operating means is adapted to both drive the closing means and be driven by it. The operating means is driven by the closing means, in response to the driving thereof by the driving means, toward an operative position in the housing effecting actuation of the circuit completing means, and resilient means returns the operating means from its operative position toward an original position in the housing to effect de-actuation of the circuit completing means upon the removal of the driving means from the housing. The operating means drives the closing means to its position for closing the access means upon the return of the operating means to its original position.

Further in general and in one form of the invention, an electrical switch has a housing with a contact therein, and a contact blade is movably supported in the housing for making and breaking engagement with the contact. A slider is shiftable in the housing relative to the contact blade, and a pair of opposite edges are provided on the slider. A cam surface in one of the opposite edges drives the contact blade to effect the making and breaking engagement thereof with the contact when the slider is in the one position and the other position thereof, respectively, and a pair of inclined surfaces are provided in the other of the opposite edges. A generally stationary plate is disposed in the housing adjacent the slide and includes an edge portion having a pair of guide slots therein for transverse alignment, at least a part, with the inclined surfaces, respectively. A pair of openings in the housing are generally vertically aligned with the guide slots, and a push button actuator is generally reciprocably movable in the housing extending through one of the openings. Extension means on the push button actuator engages with the housing to prevent displacement therefrom of the push button actuator and extends between the slider and plate for guiding engagement in one of the guide slots and both driving and driven engagement with one of the inclined surfaces. The push button actuator is movable in response to an applied force thereon to move the extension means within the one guide slot and drive the one inclined surface to shift the slider from its one position to the other position thereof. A rod extends between the slider and the plate for guiding engagement in the other of the guide slots and both driving and driven engagement with the other of the inclined surfaces, and the rod is driven by the other inclined surface generally upwardly in the other guide slot toward a position in seating engagement with the housing generally about the other of the openings to block it when the slider is shifted to its other position. A key, which is removable from the housing, has a shank with a configuration closely conforming to that of the other opening for selective insertion therethrough into driving engagement with the rod, and the rod is driven, upon the driving engagement of the shank therewith, generally downwardly in the other guide slot away from its blocking position thereby to drive the other inclined surface and effect return shifting of the slider from its other position to the one position thereof.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 2;

FIGS. 4, 5 and 6 are plan views of the stationary plate and sliders of the electrical switch of FIG. 1;

FIG. 7 is a side elevational view of a key for operating the electrical switch of FIG. 1;

FIG. 8 is a side elevational view of an alternative key for operating the electrical switch of FIG. 1;

FIG. 9 is a plan view of a cover which may be employed with the electrical switch of FIG. 1 which is also embodied in one form of the present invention; and

FIG. 10 is a bottom elevational view of the cover of FIG. 9.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

The following examples illustrate the invention and are not to be construed as limiting in any manner.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings in general, there is shown at 1 an electrical switch having a housing 3, and means, such as at least an opening 5, is provided in the housing for access into an interior portion, such as a chamber 7, thereof (FIGS. 1 and 2). Means, such as a contact or switch blade 9 or the like, is movable in housing 3 for completing a circuit (not shown) therethrough, and means, such as an elongate slider 11, for actuating the switch blade is shiftable between at least two positions in the housing. Means, such as a rod 13 or the like, is engaged with slider 11 for generally closing openings 5 when the slider is in one position thereof, and means, such as a key 15 or the like (FIG. 7), which is removable from housing 3, is selectively insertable through the opening for driving the rod to conjointly displace it away from the opening and drivingly shift the slider to its other position to actuate the switch blade.

More particularly with reference to FIGS. 1 and 2, housing 3, which is formed from a dielectric material as well known in the art, is provided with a base wall 17 within chamber 7, and opening 5 extends generally vertically through the housing intersecting with the base wall. Another opening 19, in which a push button actuator, such as an off-key 21, is reciprocally movable, as discussed hereinafter, also extends generally vertically through housing 3 intersecting with base wall l7, and a recess 23, in which is disposed a spring loaded detent 25, as discussed hereinafter, is provided in chamber 7 intersecting with the base wall between

openings

5, 19. A closure member or cover 27, which is also formed from a dielectric material, is removably secured to housing 3 by suitable means, such as a plurality of screws (not shown), and

terminal pairs

29, 31 and 33, 35 are molded or otherwise fixedly disposed in the housing for connection in the electrical circuit (not shown).

As shown in FIGS. 2 and 3, contact blade 9 and another switch or contact blade 37 are pivotally movable and supported in housing 3 in electrical connection with

terminals

29, 31 in a manner well known to the art, and the switch blades are formed from a resilient, current conductive metal or metal alloy. Switch blade 37 along with switch blade 9 may also constitute the aforementioned circuit completing means.

Contacts

39, 41 are disposed on switch blades 9, 37 for making and breaking engagement with a pair of mating or stationary contacts (not shown) carried on a pair of generally

stationary busses

43, 45 or the like therefor within housing chamber 9 which are electrically connected with

terminals

31, 35, respectively.

Guiding means, such as an elongate stationary plate 47, is disposed in housing chamber 7 and interposed generally in side-by-side guiding relation between slider 11 and means, such as another elongate slider 49, for momentarily operating the circuit completing means, as discussed hereinafter, and the plate and sliders are also shown in FIGS. 46. Engagement of sliders ll, 47 with the side walls of housing chamber 7 predeterminately limits transverse displacement of the sliders from the general side-by-side guiding relation with plate 47. Plate 47 has upper and

lower edges

51, 53, and a pair of generally vertical or perpendicularly extending

guide slots

55, 57 are provided through the upper edge.

Guide slots

55, 57 are positioned generally in vertical alignment with

openings

5, 39 of housing 3. Upper edge 51 of plate 47 has a notch 59 therein in which is received spring loaded detent 25 disposed in housing recess 23 thereby to maintain the plate generally stationary or against generally longitudinal or end-wise sliding or shifting movement with sliders ll, 49, as discussed hereinafter. A pair of spaced tabs 61 are integrally formed on plate 47 depending from lower edge 53 thereof in abutment with cover 27 wherein the lower edge generally transversely spans the switch blades 9,

Slider 11 has upper and lower edges 63, 65 in which a pair of oppositely disposed

inclined surfaces

67, 69 are provided, and the inclined surfaces are generally, at least in part, transversely aligned with

guide slots

55, 57 of plate 47 for overlaying or overlapping relation therewith upon shifting movement of the slider in housing chamber 7, as discussed hereinafter. A camming surface or portion 71 is provided on lower edge 65 of slider 11 for actuating engagement with switch blade 9, and a pair of spaced tabs 73 are also integrally formed in slider 11 depending from the lower edge thereof in sliding or shifting engagement with cover 27 for movement generally in the longitudinal or left-right end-wise direction (as seen in FIGS. 2 and 3). Tabs 73 space lower edge 65 from cover 27 so that the lower edge spans switch blades 11, 37.

Slider 49 has upper and

lower edges

75, 77, and an inclined surface 79 is provided on the upper edge generally in a transverse alignment, at least in part, with guide slot 55 of plate 47 and inclined surface 69 of slider 11 for overlaying or overlapping relation therewith upon the shifting or sliding movement of slider 49 in housing chamber 7, as discussed hereinafter. Slot 81 is also provided in slider 49 through upper edge 75 thereof generally spanning the overlaying or overlap pingrelation of guide slot 57 in plate 47 and inclined surface 67 of sliderll. Another camming surface or portion 83 is provided on lower edge 77 of slider 49 for momentary actuating engagement with switch blade 37, and a pair of spaced tabs 85 are also integrally formed on the slider depending from the lower edge thereof in sliding or shifting engagement with cover 27 for movement generally in the longitudinal or left-right end-wise direction(as seen in FIGS; 2 and 3). Tabs 83 space lower edge 77 from cover 27 so that the lower edge spans switch blades 11, 37. A retaining notch is provided in the slider at 87 for retainengagement with resilient means, such as a spring 89, which is biased between slider 49 and housing 3 within housing chamber 7 urging the slider rightwardly (as seen in FIG. 2) at all times.

Referring with particularity again to FIGS. 2 and 3, off-key 21, which is shown in its in or off position, has ashank orshaft 91 reciprocally movable through housing opening 19, and a generally transversely extending rod 93 is fixedly connected by suitable means (not shown) to the interior end of the shaft. Rod 93 is engagable with base wall 17 of housing chamber 7 generally about opening 19 to prevent displacement of offkey 21 from housing 3, and the rod is also guidably and slidably received in guide slot 57 of plate 47 and disposed for both driving and driven engagement with inclined surface 67 of slider 11. Closing means or rod 13 extends transversely of plate 47 and sliders 11, 49, and the rod is generally floatably movable in guide slot 55 of the plate in sliding and guiding engagement therewith and disposed for both driving and driven engagement with

inclined surfaces

69, 79 of sliders 11, 49, respectively. A seat, indicated at 95, is provided on base wall 17 of housing chamber 7 generally about opening 13 therein, and as seen in FIG. 2, rod 13 is urged by both

inclined surfaces

69, 79 of sliders 11, 49 generally upwardly in guide slot 55 of plate 47 toward engagement with seat 95 thereby to block housing opening 5.

Removable key 15, FIGS. 7 and 8, is provided with a generally flat shank 97 having a pair of opposite prongs or tines 99, and the configurations of the tines closely conform to those of housing openings 5 through which the tines may be manually inserted for driving engagement with rod 13 to effect actuation of electrical switch 1, as described hereinafter. It is understood that other shapes for housing opening 5 and key may be utilized within the scope of the invention.

OPERATION In the operation of electrical switch 1, it will be recalled that sliders ll, 49 are shiftable or translatable in housing chamber 7 relative to stationary plate 47 in a generally left-right or end-wise direction (as seen in FIG. 2). When slider 11 is in its one or leftward translated position, camming surface 71 thereof is engaged with switch blade 9 depressing it toward cover 27to disengage contact 39 from buss 43 and interrupt the circuit through housing 3 between

terminals

29, 31. The compressive forceof spring 89 urges slider 49 toward its one or'rightward translated position (as seen in FIG. 2), and with slider 49 so urged to its rightward translated position, camming surface 83 is engaged with switch blade 37 depressing it toward cover 27 to disengage contact 41 from buss 45 and interrupt the circuit through housing 3 between

terminals

33, 35. In the following discussion with respect to function of the various components of electrical switch 1, the operation of slider 11 will be considered separately prior to that of slider 49 for the sake of clarity albeit understood that sliders 11, 49 may be in some instances simulta neously operable.

To initiate the operation of electrical switch 1, an authorized operator initially inserts tines 99 of removable key 15 through generally mating housing opening 5 therefor to drivingly engage the free ends of the tines with rod 13 which is urged by sliders 11, 49 toward its blocking position with respect to the opening in engagement with seat 95. Thereafter, a manual force applied by the operator onto key 15 drives rod 13 generally vertically downwardly (as seen in FIG. 2) within guide slot 55 of plate 47 so as to displace the rod away from its seat and its blocking position with respect to housing opening 5. When slider 11 is in its one or leftward translated position interrupting the circuit through housing 3 between

terminals

29, 31, as previously mentioned,

inclined surfaces

67, 69 of the slider are disposed, at least in part, in transverse overlaying relation with respect to guide

slots

55, 57 of plate 47; therefore, the applied force downward movement of rod 13 in guide slot 55 causes the rod to drive on inclined surface 69. This driving engagement between rod 13 and inclined surface 69 translates or shiftably moves or slides slider 11 from its original or leftward translated position in the righward direction (as seen in FIG. 2) toward its other opposite or rightward translated or actuating position to effect actuation of switch blade 9. This rightward translatory movement of slider 11 toward its other or rightward translated position in housing 3 disengages camming surface 71 from switch blade 9, and the inherent resiliency of the switch blade moves it upwardly toward a circuit making position engaging contact 39 with buss 43 and completing the circuit through the housing between

terminals

29, 31. It may be noted that rod 13 is not only utilized to block opening 5 when'electrical switch 1 is de-energized or de-actuated but is also responsive to the operator applied force exerted thereon by key 15 to effect actuation of slider 11 for completing the circuit through the housing. The positive or predetermined blocking effect of rod 13 with respect to housing opening 13 prevents the entry of foreign tools of the type previously mentioned thereby to obviate deformation of component parts of electrical switch 1 and the possibility of such foreign tools contacting an electrically hot part of the electrical switch. As previously mentioned, in the in" or off position of push button actuator 21 (as seen in FIG. 2), rod 93 thereof and inclined surface 67 of slider 11 are engaged; therefore, the rightward translatory movement of the slider causes inclined surface 67 to drive on rod 93. This driving engagement between inclined surface 67 and rod 93 drives or moves the rod generally vertically upwardly in guide slot 57 of plate 47, and push button actuator 21 is, of course, displaced along with its rod to the *out" or inoperative position thereof. When slider 11 in its rightward translated position completing the circuit through housing 3, as above described, key 15 may be removed from the housing for sake keeping, if desired.

When it is desired to de-actuate or de-energize electrical switch 1, the operator applies a manual force onto push button actuator 21 moving it from its out position toward the in position thereof. This applied force movement of push button actuator 21 conjointly drives rod 93 generally vertically downwardly (as seen in H6. 2) within guide slot 57 of plate causing the rod to drive on inclined surface 67 of slider l 1. This driving engagement between rod 93 and inclined surface 67 translates or shiftably moves slider 11 from its rightward translated position in the leftwardly direction back toward its original or leftwardly translated position to effect de-actuation of switch blade 9. This leftward or return translatory of slider 11 toward its original leftward position in housing 3 re-engages camming surface 71 with switch blade 9 to depress it toward its breaking position disengaging contact 39 from buss 43 and again interrupting the circuit through the housing between

terminals

29, 31. Since rod 13 and inclined surface 69 of slider 11 are engaged, as previously mentioned, the leftward translatory movement of the slider causes inclined surface 69 to drive on rod 13. This driving engagement between inclined surface 69 and rod 13 drives or moves the rod generally vertically upwardly in guide slot 55 of plate 47 returning the rod to its blocking position in engagement with seat 95. It may be noted that upon de-actuation of electrical switch 1, as described above, rod 13 is automatically returned to its blocking position with respect to housing opening 5. Such automatic return movement of rod 13 will drive key 15 to, at least in part, effect ejection thereof from opening if the key is in the opening.

Turning now to the function of the momentarily operating slider 49, it will be recalled that this operating aspect of electrical switch 1 is separately discussed only for the purpose of clarity, and it is understood that if momentary energization of the electrical switch is not desired, slider 49 and its associated component parts for completing the circuit through housing 3 between

terminals

33, 35 may be omitted from electrical switch 1. A typical application for an electrical switch in which momentary energization is desirable is for starting an electric motor (not shown). In this electric motor application, it may be desirable to effect the closure of a pair of contacts, such as

contacts

39, 41 for instance, in order to accommodate the initial in-rush of current which occurs when the motor is initially energized; however, thereafter it may be desirable to maintain only one contact, such as contact 39 for instance, closed during the normal running of the motor after the starting thereof.

When slider 11 is in its original or leftward position, the applied force movement of rod 13 by key downwardly in guide slot 55 of plate 47 not only effects the rightward translation of slider 11 to its rightward translated position to complete the circuit through housing 3 between

terminals

29, 31, as previously described, but also effects the simultaneous actuation of momentarily actuated slider 49. Since the compressive force of spring 89 normally biases slider 49 toward an original or rightward position in housing 3 engaging inclined surface 79 of the slider with rod 13, the applied force movement of the rod downwardly in plate guide slot 55 causes'the rod to drive on inclined surface 79. This driving engagement between rod 13 and inclined surface 79 translates or shiftably moves or slides slider 49 from its original position in housing 3 in the leftward direction (as seen in FIG. 2) against the compressive force of spring 89 toward a leftward translated or actuating position to effect actuation of switch blade 37 generally simultaneously with the actuation of switch blade 9 by the rightward translatory movement of slider 11, as previously described. This leftward translatory movement of slider 49 toward its leftward translated positions in housing 3 disengages camming surface 83 from switch blade 37, and the inherent resiliency of the switch blade moves it upwardly toward a making position engaging contact 41 thereof with buss 45 and completing the circuit through the housing between

temrinals

33, 35 generally at the same time the circuit is also completed between

terminals

29, 31, as previously described.

Thus, with the applied force being exerted through key 15 onto rod 13, sliders ll, 49 are oppositely displaced or translated to their respective rightward and leftward translated positions. However, when the open ator removes key 15 from housing 3 through opening 5 thereby to eliminate the applied force, slider 11 remains in its rightward translated position maintaining the circuit through the housing completed between

terminals

29, 31, but the compressive force of spring 89 is effective to return slider 49 rightwardly in the housing toward its original position. This return translatory movement of slider 49 re-engages camming surface 83 thereof with switch blade 37 depressing it toward cover 27 and moving contact 41 to its breaking position disengaged from buss 45 and interrupting the circuit through housing 3 between

terminals

33, 35. It may be noted that the circuit through housing 3 between

terminals

29, 31 made by slider 11 in its rightward translated position remains completed and the circuit which was made between

terminals

33, 35 by the momentary actuation of slider 49 is interrupted. Since inclined surface 79 of slider 49 is drivingly engaged with rod 13, the compressive force of spring 89 causes inclined sur face 79 to drive on the rod during the return movement of the slider to its original rightward translated position. This driving engagement between inclined surface 79 and rod 13 drives or moves the rod generally typically upwardly in guide slot 55 of plate 47 returning the rod to its blocking position with respect to housing opening 5 in engagement with seat 95. It may be noted that the momentary actuation of slider 49 automatically returns rod 13 to its blocking position with respect to housing opening 3 when slider 11 is in its rightwardly translated position maintaining the circuit through the housing completed between

terminals

29, 31.

Referring now to FIG. 8, resilient means, such as spring 101, may be disposed about chank 97 of key 15, and upon insertion of the key into housing opening 5 to effect actuation of electrical switch 1, the spring is compressed between the key and housing 3. The compressive force of spring 101 will effect automatic ejection of key 15 from housing opening 5 when the applied force is removed from the key by the operator, as previously mentioned.

In FIGS. 9 and 10, there is shown in general means, such as a rotatable member 103, adapted to be disposed on housing 3 exteriorly thereof for normally blocking opening 5 and adapted to be rotatably displaced, and means, such as passage 105 generally complimentary to housing opening 5, in the blocking means for alignment with the housing. opening to permit the passage of key 15 therethrough into the housing opening when the blocking means is selectively displaced.

More particularly, a cover plate l07 is adapted to be mounted to or superposed over the face of housing 3 (as seen in FIG. 1) of electrical switch 1 by suitable means, such as a plurality of screws or the like (not shown). Cover platel07 is slotted at 109 to accommodate shank 91 of push button actuator 21 which extends therethrough, and a hole or aperture 111 is provided through the cover plate for disposition generally about opening in housing 3. Rotatable member 103 is positioned over aperture 111 on the underside of cover plate 107, as illustrated in FIG. 10, and is rotatably retained thereon by a plurality of integrally formed tabs 113 lanced from the cover plate in a manner well known to the art. A projection or finger 115 is provided on rotatablemember 103, and a spring 117 is biased between the finger and cover plate 107 so as to normally rotatably misalign complimentary passage 105 in the rotatable member from housing opening 5.

In order to insert key into housing opening 5 to effect actuation of electrical switch 1 when cover plate 107 is mounted thereto, tines 99 are inserted into passage 105 of rotatable member 103, and the key and rotatable member are conjointly rotated against the relatively light compressive force of spring 115 to a position aligning the passage with the housing opening. When housing opening 5 and passage 105 of rotatable member 103 are thus aligned, key 15 may be moved therethrough to effect actuation of electrical switch 1, as previously described. When key 15 is removed from housing opening 5 and rotatable member passage 105, the compressive force of spring 115 rotatably returns rotatable member 103 to its original position again effecting the misalignment between housing opening 5 and rotatable member passage 105. It may be noted that the predetermined positive misalignment of rotatable member passage 105 with housing opening 5 provides an additional safety feature to prevent insertion of foreign tools or the like directly into the housing opening.

From the foregoing, it is now apparent than an electrical switch 1 has been provided meeting the objects and advantageous features therefor set out hereinbefore, as well as others, and that changes may be made with respect to the precise arrangements, shapes and details of the constructions set forth herein for purposes of illustration by those skilled in the art without departing from the spirit or the scope of the invention which is set out by the claims which follow.

What I claim as new and desire to secure by Letters Patent in the United States is:

1. An electrical switch comprising a housing, means in the housing for access into an interior portion thereof, means movable in the housing for completing a circuit therethrough, means for actuating the circuit completing means and shiftable between at least two positions in the housing, means engaged with the actuating means for generally closing the access means when the actuating means is in one position thereof effecting de-actuation of the circuit completing means, and means removable from the housing and selectively insertable through the access means for driving the closing means to conjointly displace it away from the access means and drivingly shift the actuating means to its other position to actuate the circuit completing means.

2. An electrical switch as set forth in claim 1, wherein the closing means comprisesmeans for seating engagement with the interior portion of the housing generally about the access means therein.

3. An electrical switch as set forth in claim 1, wherein the closing means comprises means for driving engagement with the actuating means to drivingly shift it to its other position when the closing means is driven by the driving means.

4. An electrical switch as set forth in claim 1, wherein the closing means comprises means for seating engagement with the housing generally about the access means therein and driving engagement with the actuating means in the one position thereof.

5. An electrical switch as set forth in claim 1, wherein the driving means is constituted by a key having a shank portion with a configuration conforming closely with that of the access means.

6. An electrical switch as set forth in claim 1, further comprising means movable through at least a portion of the housing and operable generally in response to a manually applied force thereon for shifting the actuating means from its other position to the one position thereof to de-actuate the circuit completing means.

7. An electrical switch as set forth in claim 6, wherein the shifting means includes means for engagement with the interior portion of the housing to prevent displacement therefrom of the shifting means.

8. An electrical switch as set forth in claim 6, wherein the actuating means includes means engaged with the closing means for driving it to a position in seating en gagement with at least a part of the interior portion of the housing about the access means when the actuating means is shifted to its one position.

9. An electrical switch as set forth in claim 1, further comprising means adapted to be engaged between the driving means and the housing exteriorly thereof for returning the driving means upon the insertion thereof through the access means.

10. An electrical switch as set forth in claim 1, further comprising means engaged with both the closing means and the actuating means for guiding the displacement and shifting movements thereof, respectively.

lll. An electrical switch as set forth in claim 10, further comprising means in the housing for engagement with at least a part of the guiding means to maintain it generally stationary in the housing.

12. An electrical switch as set forth in claim 1, further comprising means engaged with the closing means and driven generally conjointly therewith by the driving means for momentarily operating the circuit completing means when the actuating means is in its other position.

13. An electrical switch as set forth in claim 12, wherein the momentarily operating means includes resilient means for conjointlyreturning the momentarily operating means and closing means when the driving means is removed from the housing.

14. An electrical switch as set forth in claim 1, further comprising means for momentarily operating the circuit completing means and adapted to both drive the closing means and be driven by it, the operating means being driven by the closing means in response to the driving thereof by the driving means toward an operative position in the housing effecting actuation of the circuit completing means, and resilient means for returning the operating means from its operative position toward an original position in the housing to effect deactuation of the circuit completing means upon the removal of the driving means from the housing, the operating means driving the closing means to its position for closing the access means upon the return of the operating means to its original position.

15. An electrical switch as set forth in claim 1, further comprising means disposed on the housing exteriorly thereof for normally blocking the access means and adapted to be selectively displaced, and means in the blocking means for alignment with the access means to permit passage of the driving means therethrough into the access means when the blocking means is selectively displaced.

16. In an electrical switch having a housing, a contact within the housing, a contact blade movably supported in the housing for making and breaking engagement with the contact, a slider shiftable in the housing relative to the contact blade at least between two positions, a pair of opposite edges on the slider, a cam surface on one of the opposite edges for driving the contact blade to effect the making and breaking engagement thereof with the contact when the slider is in its one position and the other position-thereof, respectively, a pair of inclined surfaces in the other of the opposite edges, a generally stationary plate disposed in the housing adjacent the slider including an edge portion having a pair of guide slots therein for transverse alignment with at least a part of the inclined surfaces, respectively, a pair of openings in the housing and generally vertically aligned with the guide slots, a push button actuator generally reciprocally movable in the housing and extending through one of the openings, extension means on the push button actuator for engagement with the housing to prevent displacement therefrom of the push button actuator and extending between the slider and plate for guiding engagement in one of the guide slots and both driving and driven engagement with one of the inclined surfaces, the push button actuator being movable in response to an applied force thereon to move the extension means within the one guide slot and drive the one inclined surface to shift the slider from its one position to the other position thereof; a rod extending between the slider and plate for guiding engagement in the other of the guide slots and both driving and driven engagement with the other of the inclined surfaces, the rod being driven by the other inclined surface generally upwardly in the other guide slot toward a position in seating engagement with the housing generally about the other of the openings to block it when the slider is shifted to its other position, and a key removable from the housing and having a shank with a configuration closely conforming to that of the other opening for selective insertion therethrough into driving engagement with the rod, the rod being driven upon the driving engagement of the shank therewith generally downwardly in the other guide slot away from its blocking position thereby to drive the other inclined surface and effect return shifting of the slider from its other position to the one position thereof.

Claims

1. An electrical switch comprising a housing, means in the housing for access into an interior portion thereof, means movable in the housing for completing a circuit therethrough, means for actuating the circuit completing means and shiftable between at least two positions in the housing, means engaged with the actuating means for generally closing the access means when the actuating means is in one position thereof effecting deactuation of the circuit completing means, and means removable from the housing and selectively insertable through the access means for driving the closing means to conjointly displace it away from the access means and drivingly shift the actuating means to its other position to actuate the circuit completing means.

2. An electrical switch as set forth in claim 1, wherein the closing means comprises means for seating engagement with the interior portion of the housing generally about the access means therein.

8. An electrical switch as set forth in claim 6, wherein the actuating means includes means engaged with the closing means for driving it to a position in seating engagement with at least a part of the interior portion of the housing about the access means when the actuating means is shifted to its one position.

11. An electrical switch as set forth in claim 10, further comprising means in the housing for engagement with at least a part of the guiding means to maintain it generally stationary in the housing.

13. An electrical switch as set forth in claim 12, wherein the momentarily operating means includes resilient means for conjointly returning the momentarily operating means and closing means when the driving means is removed from the housing.

14. An electrical switch as set forth in claim 1, further comprising means for momentarily operating the circuit completing means and adapted to both drive the closing means and be driven by it, the operating means being driven by the closing means in response to the driving thereof by the driving means toward an operative position in the housing effecting actuation of the circuit completing means, and resilient means for returning the operating means from its operative position toward an original position in the housing to effect de-actuation of the circuit completing means upon the removal of the driving means from the housing, the operating means driving the closing means to its position for closing The access means upon the return of the operating means to its original position.

16. In an electrical switch having a housing, a contact within the housing, a contact blade movably supported in the housing for making and breaking engagement with the contact, a slider shiftable in the housing relative to the contact blade at least between two positions, a pair of opposite edges on the slider, a cam surface on one of the opposite edges for driving the contact blade to effect the making and breaking engagement thereof with the contact when the slider is in its one position and the other position thereof, respectively, a pair of inclined surfaces in the other of the opposite edges, a generally stationary plate disposed in the housing adjacent the slider including an edge portion having a pair of guide slots therein for transverse alignment with at least a part of the inclined surfaces, respectively, a pair of openings in the housing and generally vertically aligned with the guide slots, a push button actuator generally reciprocally movable in the housing and extending through one of the openings, extension means on the push button actuator for engagement with the housing to prevent displacement therefrom of the push button actuator and extending between the slider and plate for guiding engagement in one of the guide slots and both driving and driven engagement with one of the inclined surfaces, the push button actuator being movable in response to an applied force thereon to move the extension means within the one guide slot and drive the one inclined surface to shift the slider from its one position to the other position thereof; a rod extending between the slider and plate for guiding engagement in the other of the guide slots and both driving and driven engagement with the other of the inclined surfaces, the rod being driven by the other inclined surface generally upwardly in the other guide slot toward a position in seating engagement with the housing generally about the other of the openings to block it when the slider is shifted to its other position, and a key removable from the housing and having a shank with a configuration closely conforming to that of the other opening for selective insertion therethrough into driving engagement with the rod, the rod being driven upon the driving engagement of the shank therewith generally downwardly in the other guide slot away from its blocking position thereby to drive the other inclined surface and effect return shifting of the slider from its other position to the one position thereof.