US2247247A - Electric switch - Google Patents

Description

June 24, 1941. G, J, MEUER 2,247,247

ELECTRIC SWITCH Filed Oct. '7, 1938 2 Sheets-Sheet 1 .Fume 24, 19M. G. J. MEUER l ELECTRIC SWITCH Filved oct. '7, 1958 2 sheets-sheet 2 Ill:

, Patented JuneZ-l, 1941 UNITED STATES PATENT vOFFICE ELECTRIC SWITCH George J. Mener, Milwaukee, Wis., assignor to Cutler-Hammer, Inc., Milwaukee, Wis., a corporation of Delaware Application October '1, 1938, Serial No. 233,828

12 Claims.

This invention relates to improvements in electric switches. The invention relates more particularly to improvements in toggle operated snap switches of the tool-handle type.

A primary object of the invention is to provide a tool-handle snap switch of substantially dusttight construction.

Another object is to provide novel means affording substantial dust-tightness of tool-handle switches having various different forms of operating levers.

Another object is to improve the details of construction and facilitate assembly of the parts of switches of the aforementioned character.

Another object is to provide a switch operating lever having novel means for pivotally supporting and guiding the same whereby wobbling or lateral displacement of the lever is substantially prevented.

l Another object is to provide a tool-handle switch of the aforementioned character having combined contact and terminal members of novel form whereby peripheral dust-tightness of the molded insulating base is insured.

Another object is to provide a switch of the character last mentioned having novel means for insuring substantial dust-tightness of the operating elements of the switch.

Another and more specific object is to provide for utilization of a resilient, rubber-like material for rendering the switches substantially dust-tight without appreciably modifying the normal operative characteristics of the switch mechanism.

Other objects and advantages of the invention will hereinafter appear.

rThe accompanying drawings illustrate certain embodiments of the invention which will now be described, it being understood that the embodi- `ments illustrated are susceptibleof modification the tool-handle type, said switch having novel' means for mounting the same in a tool-handle or the like, and the same having elements applied thereto to render the same substantially dust-tight.

Fig. 2 isla sectional view (double-scale) on the line 2 2 oflFig. 1.

Fig. 3 is a sectional View, on the line 3-3 of Fig. l.

Fig. 4 is `a view (normal size), partly in side elevation and in vertical section, illustrating a switch generally similar to the switch of Figs, 1 to 3, but having mounting means of modified form applied thereto.

Fig. 5 is an end* elevation, partly in vertical section on the line 5-5 of Fig. 4.

Fig. 6 is a fragmentary vertical sectional view of the pivotal supporting and guiding means for the toggle lever shown in Figs. 1 to 5.

Fig. 7 is a view (normal size), partly in side elevation and partly in vertical section, of a switch having combined contact and terminal members of novel form; a novel form of lever attachment to provide a trigger or linger grip; and novel means for rendering the switch mechanism substantially dust-tight.

Fig. 8 is an end elevation, partly in section on the line 8--8 of Fig-7. I

Fig. 9 is a vertical section substantially on the line 9-9 of Fig. 8, parts of the insulating base of the switch being shown in elevation.

Fig. 10 is a side elevation (normal size) of a switch having a modified form of operating lever associated therewith, a portion of the rubberlike cap being broken away to illustrate the supporting frame for the lever.

Fig. 11 is a view, partly in end elevation and partly in vertical section on the line l l-ll of Fig. 10, a fragment of the flush mounting plate being shown in position, and

Fig. 12 is a fragmentary view, partly in elevaprior patents, No. 1,889,259, dated Nov. 29, 1932;

No. 1,977,078, dated Oct. 16, 1934; and No. 2,089,- 032, dated Aug. 3, 1937; reference being had to said prior patents for a detailed description of certain of the switch parts.

Here, as in said prior patents, I provide a molded insulating base, designated in general by the numeral l5, said base having a recess i6 (Fig. 2) yopening to the upper surface thereof. Base I5 is provided with a rib whose flat surface il (Fig. 2) is offset upwardly from the bottom wall of recess it. Slidable upon surface Il is a flat punched insulating plate i8 which carries a pair of like contactors arranged on opposite sides of said rib.V One of said contactors is shown at i9 as comprising a metal trip'bent to substantially U-shape, whereby the arms thereofare exposed on the upper and lower surfaces of plate I8. Said contactors are rigidly .and permanently secured to plate I8 as by means of rivets, one of which is shown at 20. A pair of upper and lowerv resilient stationary contacts 2| and 22 isl positioned on each side of the aforementioned rib within recess IB, the respective contacts being secured to ledges oiset downwardly from the upper surface of base I as by means of a corresponding number of internally threaded eyelet members which provide for bottom wiring of the switch, in the manne-r illustrated in Fig. 4, of my aforementioned Patent No. 2,089,032. Two of the wiring terminal screws are shown herein at 23 in Fig. 3.

The toggle snap action mechanism for the switch comprises a wire yoke member 24 pivotally supported above base I5 but depending into the recess I6; a toggle operating lever 25 pivotally supported above yoke 24; a flat punched insulating plate 26 pivotally supported by said yoke, the lower end of plate 26 projecting into a slot or opening Isa in plate I8 to provide a lost motion driving connection between said plates. A coiled spring 2l is interposed under compression between the lower end of lever 25 and plate 26, a portion of which telescopes into the lower end of said spring. Spring 21 carries at its upper end a metal cup 28 for engagement 'by said lower end of lever 25.

A at metal plate 29 is superimposed upon the upper surface of base I5, aiiat punched or sheared plate or piece of resilient, rubber-like material 30 being interposed between plate 29 and the upper surface of base I5. Plates 29 and 30 are provided with alined centrally located openings 29a, 3l)a (Fig. 2) which provide oscillating clearance for yoke 24 and the aforementioned parts associated therewith. Superimposed upon plate 23 is a sheet metal top plate the peripheral ange portion of which is designated by the numeral 3| in Figs. 2 and 3, said top plate having a centrally located portion 3| of substantially dome-shape. tion 3|a is provided at its upper end with a relatively narrow opening or slot 3|h extending in a direction longitudinally of base I5, opening 3|b having a width to rather closely accommodate lever 25 comprising a flat sheet metal punching, and the length of opening 3|b being such as to provide a rather close oscillating clearance for the arc-shaped portions 25b forming an enlargement of said lever. Opening 3|J thus serves to guide lever 25 `for oscillatory movement in a single plane, whereas said portions 25b of the lever insure substantial closure of said opening 3|b under all conditions. Y

Dome-shaped portion 3|EL is provided adjacent to the lower end thereof with alined openings v3|, 3Il (Fig, 3) into one of which an outwardly bent end of one arm of yoke 24 is freely insertable, the bent end of the other arm of said yoke being insertable into the other" opening by temporarily bending the yoke arms toward each other. Portion 3| is provided adjacent to the upper end thereof with alined openings 3Ie, 3|f which are respectively vertically alined with openings 3|c and 3Id. Openings 3Ie, 3|f are adapted to receive a pin 32 of circular form in transverse cross section, said pin having a head 32a engaging the exterior of one sidewall of porytion 3|a and a hollow shank end 32b which is upset over the exterior of the other side wall of said portion 3Ia. Pin 32 freely penetrates the Dome-shaped porpassage of corresponding circular form in transverse cross section provided in a relatively long metal member 33 to provide a relatively wide area of bearing engagement between the latter and said pin. Member 33 is provided at its midlength with a portion 33a of exteriorly polygonal form (preferably square, as best shown in Fig. 2) in transverse cross section. Lever 25 is provided with an opening 25c to accommodate, with a rather close sliding iit, Athe portion 33a, said portion 33a extending beyond each side of lever 25, and the material of said portion being upset against opposite sides of lever 25, as shown at 33D and 33c in Figs. 3 and 6, to rigidly and permanently secure said parts in assembled relation.

In practice the pin 32 is free to oscillate or rotate within the aforementioned .openings 3Ie, 3| (Fig. 6) but pivotal movement of lever 25 is afforded primarily by the bearing engagement of tubular member 33 with pin 32. By reason of the rigid connection between lever 25 and member 33 and the relatively wide area of bearing engagement of the latter with pin 32 lateral tilting or Wobbling of said lever is prevented. Also as aforedescribed the walls of opening 3|b in dome-shaped portion 3|a cooperate with lever 25 to limit the same to oscillatory movement in a single plane. This insures against accidenal lateral displacement of the lower end of lever 25 from the cup or abutment 28 at the upper end of spring 21.

Many portable tools (such as grinders, polishers or drills) are used under conditions involving the presence of metal dust, stone dust, or other particles in the surrounding air; and if such dust particles have access to the switch chamber they, of course, tend to run the switch mechanism and to greatly reduce the useful life of the latter. It is accordingly a primary. object of my invention to render the switch chamber substantially dust-tight, and this object is attained in the device of Figs. l to 3 by providing a relatively thin walled, dome-shaped insulating member 34 molded from a resilient, rubber-like material. Member 34 and the aforementioned plate 30 may be and preferably are composedY of identical resilient, rubber-like material, a` preferred form of such material being made and sold commercially under the trade-name of Neoprene Such material is extremely live and resilient (or elastic) and is further characterized by its resistance to deterioration under the influence of, or in the presence of, oil or grease.

As best shown in Figs. 2 and 3 member 34 is provided with a slot or opening 34a which it is to be understood is relatively narrower than the thickness of lever 25 and relatively shorter than the width of the enlarged portion (comprising arcuate portions 25h) of said lever. Therefore the walls of said opening 3l!a will be biased by the resiliency of the rubber-like material into close engagement with the sides and edges of lever 25 in all'positions of the latter, the resiliency or elasticity of member 34 being such as to permit bodily deformation or distortion thereof as an incident to oscillatory movement of said lever while maintaining said close connection of member 34 with the latter.

Also as best shown in Figs. 2 and 3 member 34 is provided at its lower end with a flange portion 34b which overlies the aforementioned top plate 3|, said flange portion 34b being. provided with a downwardly'extending edge portion or peripheral rib 34c which surrounds the peripheral edge of top plate 3| and engages the aforementioned metal plate 29. superimposed upon flange portion 34b is a metal plate 35 having a relatively large centrally located opening- 35a to accommodate said dome-shaped member 34. Plate 35 has associated therewith a pair of nuts here shown as substantially cylindrical elements 36 having threaded passages 36a extending therethrough. Elements 36 are provided at their lower ends with reduced portions 36b adapted to extend downwardly through correspondingly shaped openings in plate 35, the material of said reduced portions being upset over the lower surface of plate 35, as shown at 36, to rigidly and permanently secure said nuts to said plate. Elements 36 are provided withfurther reduced portions 36d projecting downwardly through corresponding openings in flange portion 34b and metal top plate 3| to afford a proper degree of engagement of elements 36 with the threaded shanks of a pair of bolts 31 extending upwardly from the bottom surface of base I5.

The fiat upper ends of elements 36 are adapted to abut the inner surface of the wall of a cavity provided in a tool-handle or'the like (not shown), said wall having openings formed therein to provide clearance for the shanks of mounting screws or bolts which take into the upper ends of the respective threaded passages 36a. Said cavity wall will of course be provided with a suitable opening to afford oscillating clearance for the upper end portion of lever 25. As shown in dotted lines in Fig. 2 lever 25 is provided at its upper end with a reduced portion 25d which is adapted for a drive t within a recess provided 'in a spherical knob member 25e. As will be understood, knob 25e is applied to lever 25 after upward insertion of the latter through the vaforementioned opening 3 lb in portion 3|a of the top plate. The walls of opening 34"- in the dust-proofing cap 34 are sufliciently elastic to permit downward passage of said cap over knob 25e and the intermediate portion of said lever.

In the modification shown in Figs. 4 and 5 most of the'switch parts are identical with those aforedescribed and have been given corresponding numerals of reference. AInstead of the plate 35 and nuts 36 aforedescribed, the switch is provided with a plate 38, preferably of die cast aluminum,

the opposite'ends of plate 38 extending beyond the respective ends of base I5 and having openings 38, 38b to accommodate the Shanks of securing screws (not shown) which take into suitable tapped openings in the wall of a portable tool housing or handle. Plate 38 is provided with a central opening 38 to accommodate the domeshaped dust-proofing cap 34 and the operating lever 39 extending upwardly through the latter, lever 39 having a spherical knob 394 attached thereto with a drive lit in the manner aforedescribed.

Formed integrally with plate 38 and extending upwardly at substantially right angles thereto adjacent the opposite longitudinally spaced sides of opening 38c are a pair of transverse ribs 38d and38e, said lugs having segmental notches or concavities 381, 38g formed in the upper` edges thereof and allned with each other. Notches 38f, 384` provide ample clearance to enable thumb operation of lever 39 in either direction, whereas the high portions of ribs 38d, 38 serve to prevent accidental operation of lever 39 or injury thereto in the event of rough or careless usage of the tool to which the switch may be attached. The

switch base I5 and its associa/ted parts are attached to plate 38 as by means of a pair of relatively long bolts 49 which penetrate tapped openings providedin the aforementioned ribs 38d, 38e, the upper ends of said bolts being upset, as shown at 49E, to permanently secure the parts in assembled relation.

'Ihe switches illustrated in Figs. 1 to 6, inclusive, have a rated capacity of l0 amperes at 250 volts, whereas the modified form of switch shown in Figs. 7 to 9, inclusive, has a rated capacity of 20 amperes at 250 volts. In Figs. 7 to 9, the numeral 4l designates a molded insulating base having a recess 42 formed therein and opening to the upper surface thereof. Recess 42 is provided in its bottom wall with an integral rib upon the flat upper surface 43 of which (Fig. 9) the insulating plate 44 is sl-idably movable. Plate 44 has attached thereto a pair of bridging contactors, one of which is shown at 45 in Fig. 7. Located within recess 42 are two identical pairs of upper and lower resilient contacts, one pair of said contacts being shown at 46 and 41 in Figs.-

7 and 9. Each contact has rigidly and permanently attached thereto a terminal member 448 (Figs. 7 and 8). Each member 48 comprises an outer end portion 43a providing a flange of square contour; an intermediate portion 48b of cylindrical form; and a reduced inner `end of cylindrical form which penetrates a circular opening provided adjacent to the upper end of its associated contact, and is upset over the latter as shown at 48c in Fig. 7 to rigidly unite said parts.

Base 4I is provided at each end thereof with two upwardly opening notches (preferably of rectangular contour) against the bottom walls of which the respective cylindrical portions 481 of the terminal members are adapted to seat, as shown at 49 and 50 in Fig. 1. The arrangement is such that flanges 48a overlap the bottom and side walls of the respective notches and extend to a plane substantially flush with the upper surface of base 4l (Figs. '7 and 8), said flanges being positioned rather closely against the exterior surfaces of the end walls of the base, whereas the respective contacts are positioned closely against the inner surfaces of said end walls, as shown in Fig. 7; the combined contact Y and terminal members being insertable with a and alined with the aforementioned rib 43 are` barriers 5l and 52 which cooperate with the respective side walls of recess 42 to assist in retain- `ing the upper and lower contacts of the respective pairs in proper alinement with each other, while assisting in insulating said pairs of contacts from each other. Also formed integrally with the respective end walls of base 4| and interposed between the terminal members 48 of the respective pairs are verti ally extending barriers 53 and 54 (Figs. 8 and to properly insulate said terminal members and the circuit wires to be attached thereto. Each member 48 is provided with a centrally located threaded passage to accommodate a binding screw 55.

superimposed upon the upper surface of base 4l is a sheet'or plate 56 `of the aforementioned resilient, rubber-like material, which overlies the aforementioned terminal members and screws 55 (Fig. 7) superimposed upon plate 56 is a metal top plate 51, the latter being slightly shorter ends 'of the arms of yoke member 65, as shown in to a suitable support. Super-imposed upon 'top plate 61 is a metal plate 58of approximately diamond shape, plate 58 having a centrallylocated bulge or dome-shaped portion 58 which is provided with a centrally located circular opening to accommodate the reduced lower end of a hollow metal member or bushing 59, said reduced lower end of the bushing being upset over the inner surface of portion 58a, as shown at 59l (Figs. '1 and 8) to rigidly'secure said parts in assembled relation.

Pivotally supported within bushing 59, as by means of a pin 68 permanently attached thereto, is a lever having a cylindrical upper end portion 6|; a reduced cylindrical portion 6|@ located above pin 68, and a convex lower end 6| which serves as a spring abutment. End 6|b of said lever engages a concavity or recess formed in the upper end of a substantially cylindrical metal -member 62, the latter being adapted to telescope into the upper end of a. coiled compression spring 63 (Fig. 9) and having a flange to seat against Kthe upper end coil of said spring. Member |52 is provided in'its lower end with a recess 62a to telescopically accommodate the reduced upper end 64a of a flat punched insulating plate 66 which is pivotally supported by the U- shaped wire yoke member 65, the latter being pivotally attached to portion 58a of plate 58 in the manner illustrated in Figs. 8 and 9. Member 68 is provided with shoulders which serve as an abutment for the lower end of spring 63, and the substantially triangular lower end portion of member 64 is adapted for cooperation with an opening provided in the contactorY supporting plate 44 to provide a lost motion driving connection between the former and the latter.

Positioned within recess 42 beneath yoke 65 but above the tips of the respective pairs of contacts is a flat punched insulating plate 66 (Figs.

'1 and 9), said plate having' a central slot ory opening 66B (Fig. 9) to provide oscillating clearance for member 64. Insertable vertically into recess 42 prior to insertion of the upper contacts (one of which is shown at 46) of the respective pairs is a flat punched insulating plate 61 which is interlocked with vertical grooves (not shown) at opposite sides of the aforementioned barrier 5| to prevent lateral displacement of said plate. For practical reasons barrier 52 is provided with like vertical grooves. As b est illustrated in '1, plate 61 is interposed between each contactor (45) Iand the upper contact (46) in the oi posiswitch parts in assembled relation. To render the switch chamber (recess 42) substantially dust-tight I provide a molded hollow cap member 69 formed of the aforementioned resilient,

rubber-like material, said cap as shown being preferably inthe form of a frustum of a cone. 'I'he base of cap 69 is provided with an inwardly extending annular flange which is adapt-ed to closely surround or hug the aforementioned dome-shaped portion 58a of plate 58, and to underlie and engage with the outwardly projecting Fig; 8, to assist in retaining said cap in proper position. The fiat upper end of cap 69 is provided with a centrally located circular opening of smaller size than the cross sectionalarea of the reduced portion 6| of lever 6I, whereby the wall of said opening closely surrounds or hugs said reduced portion 6|a of the lever. It is to be understood that the material of cap 59 is sufficiently elastic or stretchable to permit forcing of the aforementioned opening downwardly over the cylindrical upper end portion 6| of said lever after pivotal attachment of the latter to bushing 59 by pin 60. Moreover, the arrangement is such that cap 69 is bodily deformable to permit the necessary oscillatory movement of reduced portion 6|!a of the lever as an incident to operation of the switch, without destroying the seal or dust-tight grip of the aforementioned A wall of the opening about said portion 6|.

I prefer to attach to lever 6| a finger member or trigger 16, the same preferably consisting of a die-cast piece of metal such as aluminum. Member 10 is provided with a, recess to accommodate portion 6I of the lever, these parts when assembled as shown being drilled to receive a headed pin or rivet 18, the shank of which is upset (Fig. 8) to rigidly and nonrotatably unite said parts to each other. Member 1U is provided with flat portions 10a and 1|]b adapted to alternatively abut the respective Opposite ends of plate 58, each of said at surfaces having recesses, as'shown in Fig. 9 to provide clearance between the same and the protruding shank ends of bolts 68 and 688. When the switch is provided with a trigger member 18 it is of course desirable to provide for biasing member 18 to one of its extreme positions. For this purpose member 18 is recessed as shown in Fig. 9 to accommodate a. coiled spring 1| which is interposed under a predetermined degree of compression between the inner end of said recess vand the upper surface of plate 58, bolt 68 being made suii'iciently long so that the lower end coils of spring 1| may be telescoped onto the exposed shank portion to restrain the spring against lateral displacement. As indicated in Figs. '7 and 9 the arrangement is such that the switch will be biased to circuit interrupting position.

As Will be obvious from Fig. 9 the switch may be modified to provide for normally biasing the sameV to circuit completing position by merely attaching member 10 to lever 6| in a position of the former degrees removed from that illustrated, the positions of bolts 68 and |58a being reversed rwith respect to base 4| to provide for cooperation of the shank of bolt 68 withspring 1| in the changed location of the latter.

In Figs. 10 to 12, inclusive, I have shown a tool-handleswitch having a rated capacity of 6v amperes at 250 volts; it being understood that the switch mechanism is in many respects quite similar to the switch mechanisms aforedescribed. In Figs. 10 to 12, however, I' provide a special form oflactuating lever and a special form of supporting and dust-'proofing elements. Thus, base 12 is provided with an upwardly opening recess withinwhich the stationary and movable contacts are positioned, the stationary contacts being provided with suitable end-wiring terminal elements, two of which are shown at 13 in Fig. 11. The exposed portions `of elements 13 extend downwardly from a plane substantially ush with the'upper surface of base 12, the lower end portions of said elements being provided with tapped openings to accommodate the shanks of binding screws 14.

Superimposed upon, and being substantially co-extensive with the upper surface of base 12 is a sheet or plate 15 formed of resilient, rubberlike material of the character aforementioned. A punched and stamped sheet metal top plate 1E of substantially the same width as base 12 is superimposed upon sheet 15, a pair of screws or bolts 11 extending upwardly through base 12 and sheet 15 and taking into tapped openings provided in plate 16. Flate 16 is provided with upward extrusions 18a and 16b surrounding said openings, and the threaded shanks of said bolts preferably project upwardly a substantial distance beyond said extrusions, as shown in Fig. 12. Plate 18 is provided with integral upwardly extending parallel -arms 18c and 16d at opposite ends thereof, and said arms are provided with integral horizontal extensions 18e and 16f having tapped openings formed therein to accommodate the shanks of screws 18 having countersunk heads to t into openings 19a, 19h, of corresponding shape, in a substantially flush relationship to the upper or outer surface of a hollow tool-handle casing or housing, a fragment of which is shown at 19,

Sheet 15 and plate 16 are provided with alined, centrally located openings (Figs. 11 and 12) which provide oscillating clearance for the upper end of a coiled compression spring 80 and the lever abutment 8la associated therewith, a sheet metal member 82 being positioned within the upper end of spring 8D for engagement by said abutment. Plate 16 has attached thereto on opposite longitudinal sides of the opening therein a pair of upstanding. parallel arms 83 and 84, said arms having integral lugs penetrating corresponding openings in said plate and being upset over the lower surface of the latter, as indicated in dotted lines at 84a and 84b in Fig. 12, and at 85a and 85h in Fig. 10. As best illustrated in Fig. 11, arms 83 and 84 are provided with alinedopenings for pivotal yengagement by the outwardly bent ends of the arms of the wire yoke member 85. Said arms 83 and 84 are providedv punched sheet metal lever 8l and through the teeter-bar or thumb lever 81, which is recessed to accommodate the upper end portion of lever 8l. In practice the thumb lever 81 consists of a die casting composed of `a zinc base metal, or a similar light weight metal adaptable for formation by die casting.k As shown in Fig. 11 the shank end 86B of` pin 86 is upset to retain the parts in assembled relation.

Thumb lever 81 is provided with downwardly opening recesses 81a and 81D either of which is adapted to` 4accommodate the upper end portion of a coiled compression spring 88, the lower end coils of which surround one of the extrusions 16a or 1lib and the upwardly projecting shank end of one of the bolts 11. As shown in Fig. 12, spring 88 is interposed under a predetermined degree of compression between the inner end of recess81a and the upper surface of top plate 1B, which it is to be understood provides a normal bias of the switch mechanism to circuit interrupting position; it being obvious that upon transfer of spring 88 to recess 81b the switch mechanism will be normally biased to circuit completing position.

Thumb lever 81 is preferably provided with knobs or projections 81, 81d at its opposite ends to facilitate manual tilting thereof to effect operation of the switch mechanism.

As shown in Figs. 10 and 12 thumb lever 81 is provided with end surfaces 81e and 81t of arcuatey contour, said arcuate surfaces extending from knobs 81c and 81d to the lower surface of said thumb lever. This formation of thumb lever 81 is such as to insure a like contour of said lever in all positions thereof in a plane substantially flush with the outer surface of the housing or plate 19.

In order to insure substantial dust-tightness of the switch mechanism I prefer to provide a molded hollow cap vmember 89 having a lower portion 89E of substantially rectangular contour, the peripheral lower edge of said rectangular portion being adapted to seat against the upper surface of top plate 16, as shown in Figs. 11 and 12, said portion 89a being of a size to accommodate arms 83 yand 84 and the switch parts associated therewith, and to provide oscillating clearance for thumb lever 81. Cap member 89 is provided with an upper end portion 89b of a length corresponding to portion 89a (see Fig. 12) but of lesser width than said portion 89EL (see Fig. 11), said portion 89b being adapted to fit Within an opening 19c in housing 19 in a substantially flush relationship to the outer surface of the latter. Member 89 is provided at opposite ends thereof with integral lugs or extensions 8.8

and 89d which are adapted to be clamped between housing 19 and the respective lugs 16e, 16

(Fig, 12), said lugs being notched as indicated in Fig. 12 to provide clearance for the shanks of screws 18.

The inner wall surface of said upper portion 89b is formed at opposite ends thereof to provide -a close sliding fit with the arcuate surfaces 81e, 81f on member 81, as best shown in Fig. 12, and the opposite sides of said inner wall surface are formed to provide a close sliding t with the respective sides of member 81, as shown in Fig. 11.

) f Said upper portion 89b of member 89 is thus provided with an opening which permits oscillation of member 81, whereas the latter is entirely surrounded and closely engaged by the rubber-like material of member 89 to insure substantial dusttightness of the switch as a whole.

What I claim as new and desire to secure by Letters Patent is:

1. In an electric snap switch, in combination, an insulating base having a reces-s formed therein and opening to the upper surface thereof, stationary switch contacts located within and carried. by the walls of said recess, contactor means also located within said recess, operating means including a pivoted lever projecting from said base, said operating means being adapted to effect snap movement of said contactor means Vinto and out of bridging engagement with said contacts, a metal top plate secured to said base in sealing relation to the peripheral wall of said recess and having an opening to accommodate the projecting portion of said lever, and yieldable, resilient rubber-like means overlying the opening in said top plate and. attached. to the latter and acting by its own resiliency to closelyy tacts located within said recess and biased to-l ward each other, means comprising a iiat plate of4 insulating material continuously interposed between said contacts and movable relatively thereto, a contactar carried by said plate and movable thereby into and out of bridging engagement with said contacts, manual operating means comprising a lever the upper end of which projects from said base, spring means interposed between the lower end of said lever and said plate to effect the aforementioned movements of said contacter with a snap action, means comprising a metal top plate for substantially closing and sealing the upper end of -said recess and having anA opening providing oscillating clearance for the upper end of said lever, and a hood? formed of resilient, rubber-like material overlying said opening and interlocked with said` metal top plate to retain said hood in assembled relation, said hood having a relatively small opening formed therein, the wall of said opening being stretchable to accommodate said lever during assembly of said parts and to surround an intermediate portion of the lever with a close fit in all positions of the latter, whereby said recess is rendered substantially dust-tight.

3. As an article o f manufacture, a sealing device ior direct attachment to and support by otherwise complete electric snap switches of the toggle type, said device comprising a hollow, self-sustaining substantially dome-shaped member molded from a resilient, elastic rubber-like material, said member being formed to profvide a self-maintaining resilient interlocking connection between the same and the metal top plate of a switch, and said member having an opening formed in the upper end thereof, the wall of said opening being stretchable to accommodate a toggle lever of suitable form and to engage by its own resiliency with a close iit an intermediate portion of the lever, the material of said part around said opening being yieldable to accommodate the movements of said lever while maintaining said close fit around the intermediate portion of the latter solely by the elasticity of said material.

4. In a toggle snap switch of the tool-handle type, in combination a molded insulating base having a recess formed therein and opening to the upper surface thereof, a metal top plate superimposed upon said base and directly rigidly attached thereto, a resilient, rubber-like gasket interposed between said top plate and the upper surface of said base to provide a substantially dust-tight seal for the entire peripheral upper edge of the wall of said recess, said top plate having an upwardly extending hollow projection, an operating lever pivotally supported within said projectionl and having a portion extending upwardly from the latter, a relatively thin--walled hollow molded member of resilient, elastic, rubber-like material directly attached to said top plate and extending above said projection, and saidy member having a relatively small opening formed in the upper end thereof to forcibly accommodate said lever to permit assembly of said parts and to provide a close t about an intermediate portion of said lever, the material of said member being yieldable to accommodate the movements of said lever while insuring selfmaintenance of the close lit aforementioned.

5. A substantially dust-tight snap switch of the tool-handle type comprising, in combination, a molded insulating base having a recess vformed therein and opening to the upper surface thereof, stationary and movable switch contact elements positioned within said recess and wiring terminal elements accessible from the exterior of said base, a flat metal plate superimposed upon said base and a at, rubber-like gasket interposed between said plate and the upper surface of said base, said gasket providing a substantially dust-tight seal around the peripheral upper edge of said recess, said plate and said gasket having alined substantially centrally located openings formed therein, a sheet metal member having a fiat portion seated upon said plate, said member having a centrally located portion oi substantially dome-shape, said domeshaped portion having a relatively narrow opening formed therein and extending longitudinally of said base, a ilat punched sheet metal lever positioned within said opening and pivotally supported with respect to said dome-shaped portion, a yoke member pivotally supported below s-aid lever, a coiled compression spring interposed between said lever and said yoke member, means associated with said yoke member for effecting snap movements of said switch operating elements upon movement of said lever in opposite directions respectively, a molded hollow cap member formed of resilient, rubber-like material overlying and engaging said dome-shaped porti-on, said cap having a relatively small opening formed therein to forcibly accommodate said lever and to closely engage the sides and edges of said lever in all positions of the latter, said cap having a peripheral ange, a perforated, flat punched sheet metal plate overlying said flange, a pair of nuts associated with said last mentioned plate, and a pair of bolts extending upwardly through said base and engaged with said nuts to retain said overlying parts in assembled relation.

6. In an electric switch of the snap action toggle type, in combination, a molded insulating base having a recess opening to the upper surface thereof, a top plate secured to said base in substantially dust-tight relation to the peripheral upper edge of the wall of said recess, stationary and movable contacts located within said recess, operating means for said, movable contacts comprising a pivoted lever having a portion thereof projecting upwardly beyond said base through an opening in said top plate and spring toggle snap action means associated with said lever at the lower end of the latter, and a hollow molded cap member of substantially dome-shape secured to said top plate and overlying the opening in the latter, said cap member comprising a yieldable, rubber-like material and the same having a relatively small opening formed in the upper end thereof to forcibly accommodate 4said* lever when assembled and to hug an intermediate portion of the latter, whereby said cap completes a substantially dust-tight seal for said recess and the switch parts located therewithin.

'7. In an electric snap switch of the tool handle type, in combinati-on, a. molded insulating base having a recess formed therein and opening to the upper surface thereof, a rib formed integrally with the bottom wall of said recess and having a flat surface located above said bottom wall, a pair of upper and lower resilient stationary contacts located on each side of said rib and respectively biased below and above the plane of said flat surface, a thin, punched insulating plate slidable upon said flat surface and interposed between the contacts of the respective pairs in all positions of said plate, said insulating member having a pair of strip metal contacts attached thereto and exposed upon the upper and lower surface thereof for movement 4thereby into and out of bridging engagement with said pairs of contacts,.each of said contacts having a machined metal terminal member rigidly attached thereto, said base having notches formed in the upper edge thereof to freely accommodate said terminal members in a plane substantially flush with the upper surface of said base, each of said terminal members having a tapped opening extending therethrough in a plane parallel to but offset downwardly from the upper surface of said base, binding screws the Shanks of which cooperatively engage said tapped openings, a metal top plate overlying the upper surface of said base and secured thereto, an insulating plate of resilient rubber-like material interposed between said top plate and said base, said insulating plate cooperating with said terminal members to retain the latter in assembled position and to provide a substantially dust-tighty seal around the peripheral upper edge of said recess, said top plate having an opening, `an oscillatable actuating lever positioned within said opening and extending upwardly from said base, and a molded resilient rubber member closely engaging the upper end portion of said lever and said topplate to alford a dust-tight closure for said opening in the latter.

8. In an electric snap switch of the tool-handle type, in combination, a molded insulating base having a recess formed therein and opening to the upper surface-thereof, a rib formed integrally with the bottom wall of said recess and having a at surface located above said bottom wall, a pair of upper and lower resilient stationary contacts located on each side of said rib and respectively biased below and above the plane of said dat surface, a thin, punched insulating plate slidable `upon said fiat surface and interposed Icap being yieldable to permit oscillatory movement of said lever while maintaining said close connection with the latter.

9. In an electric snap switch of the toggle type, a molded insulating base having a recess opening to the upper surface thereof, stationary and movable contact elements locatedA within said recess, an oscillatable operating lever, a

' sheet metal member superimposed upon said between the contacts of the respective pairs in of said terminal members having a tapped opening extending therethrough in a ,plane parallel to but offset downwardly from the upper surface of said base, binding screws the shanks of which cooperatively engage said tapped openings, a metal top plate overlying the upper surface of said base and secured thereto, an insulating plate interposed between said top plate and s aid base, said insulating plate cooperating with said terminal members to retain the latter in assembled position and to provide a substantially dust-tight seal around the peripheral upper 'edge of said recess, a'lever pivotally supported relatively to said top plate and having a portion projecting upwardly from the latter, means providing a toggle snap action connection between said lever and said insulating member. and means comprising a dome-shaped cap of resilient. rubberlike material engaged with and attached to said top plate, said cap having a relatively small opening formed in the upper end thereof to forcibly accommodate said lever and to closely surround an intermediate portion of the latter, said base and rigidly attached thereto, said sheet metal member being formed to provide a clearran'ce opening and a pivotal support for said lever, a yieldable, elastic insulating sheet interposed vbetween said sheet \metal member and shape in vertical cross sections at right angles to each other and having a peripheral lower edge affording a substantial dust-tight seal around said clearance opening, said hollow member having an opening formed in the upper end thereof to forcibly accommodate an intermediate portion of said lever, and to provide a substantially dusttight connection with the latter in all positions thereof, whereby substantially complete dusttightness of said recess is insured, and means associated with said -sheet metal member for clamping said hollow member in assembled relation thereto. m

10. In an electric snap switch of the toggle type, in combination, a molded insulating' base having a recess opening to the upper surface thereof, stationary and movable contact elements located within said recess, a yieldable, elastic insulating member superimposed directly upon said base and adapted to provide a substantially dust-tight seal for the peripheral upper end of said recess, exteriorly accessible wiring terminal elements penetrating the walls of said recess in a dust-tight relationship and elec- 1 trically connected with the stationary contact elements respectively, said` insulating member having a.' 'centrally located opening alined with v said base recess, an operating lever pivotally supported above said base and having a springtoggle snap action connection with said movable contact elements, a molded hollow member formed of elastic, rubber-like material, said hollow member having a .peripheral lower edge which is adapted tov provide a substantially dusttight seal around the opening in said insulating member, the upper end of said hollow member having an opening formed therein to provide a frictional, substantially dust-tight connection betweenthe same and said lever, and means associated with said baseto retain said insulating member and said hollow member in assembled relation to said base.

11. In an electric snap switch of the toggle type, incombination, a molded insulating base having a recess opening -to the upper surface thereof, a plurality of pairs of stationary switch contacts located within said recess. a movable insulating member positioned within said recess. a plurality of contacts carried by said insulating member and movable thereby into and out of bridging engagement with the respectivefpairs' of contacts, manual operating means ycomprising a pivoted lever the upper end ofk which projects from said base, spring means interposed between the lower end of said lever and said insulating member to effect the aforementioned movements of said contactors with a snap action, means carried by said base for substantially dusttightly closing the upper end of said recess at the periphery of the latter while providing insulating clearance for the upper end of said lever, and a hood formed of resilient rubber-like material having its lower end portion interlocked with said last mentioned means to retain said hood in assembled relation to said base, said hood having an opening formed therein to accommodate said lever and to surround an intermediate portion of the same with a close fit in all positions of the latter, whereby said recess is rendered substantially vdust-tight.

12. In an electric snap switch of the toggle type, in combination, a molded insulating base having a recess opening to the upper surface thereof, a plurality of pairsof stationary contacts located within said recess, wiring terminal elements associated with said contacts and eX- posed at the outer surface of said base, a movable insulating member positioned within said recess, a plurality of contactors carried by said insulating member and movable thereby into and out of bridging engagement with the respec.

tive pairs of contacts, manual operating means comprising a pivoted lever the upper end of which projects from said base, spring means interposed between the lower end of said lever and said insulating member to effect the aforementioned movements of said contactors with a snap action,'means including a metal top plate for substantially closing and sealing the upper end of said recess while providing oscillating clearance for the upper end of said lever, and a hood formedof resilient, elastic rubberllike material interlocked with and supported directly by -said metal top plate to retain said hood in assembled relation thereto, said hood having a relatively small opening formed therein, the wall of said opening being stretcliable to forcibly accommodate said lever to permit assembly of said parts and to surround an intermediate portion of said lever with a close t in all positions of the latter, whereby said upwardly op'ening base recess is rendered substantially dust-tight while providing4 for exposure of said wiring terminal elements.

GEORGE J. MEUER.

Images