US2205482A - Electric switch - Google Patents

Description

June 25, 1940. A. w. KRIEGER ELECTRIC SWITCH Filed Sept. 27, 1938 3 Sheets-Sheet 1 a a 5 d 2,4 Z;7 2.6 2 7 3 June 25, 1940. A. w. KRIEGER ELECTRIC SWITCH Filed Sept. 27, 1938 3 Sheets-Sheet 2 1 n m M z a f I June 25, 1940. A. w. KRIEGER 2,205,482

ELECTRIC SWITCH Filed Sept. 27, 1938 3 Sheets-Sheet 3 Patented June 25, 1940 ELECTRIC SWITCH Alvin W. Krieger, Milwaukee, Wis., assignor to Cutler-Hammer, Inc., Milwaukee, Wis., a corporation of Delaware Application September 27, 1938, Serial No. 231,940

15 Claims.

This invention relates to improvements in electric switches. Although not limited thereto, the invention relates more particularly to improvements in the structural details and operative characteristics oi switches of the so-called ian duty type. V

An object oi the invention is to minimize the cost and iacilitate assembly of the parts oi switches oi the aforementioned character.

Another object is to minimize the number oi diiierent parts required ior construction oi switches having various diiierent circuit controlling characteristics.

Another object is to provide a rotary switch adapted for alternative use for control of alternating current or direct current circuits.

Another and more specific object is to provide a switch having simple and eflicient means ior snufling or smothering any arcs formed incident to interruption of a circuit controlled by the switch, thus increasing the current control ling capacity oi the latter.

Another object is to provide stationary and movable switch contact elements oi novel iorm.

Another object is to provide a novel iorm of metal supporting irame or housing ior the switch.

Another object is to provide a single novel means ior insuring both a double make and/or break oi the controlled circuit in each instance and positive positioning oi the movable contact elements oi the switch.

Other objects and advantages oi the invention will hereinaiter appear.

. The accompanying drawings illustrate certain 35 embodiments oi the invention which will now be described, it being understood that the embodiments illustrated are susceptible oi modification in respect oi certain details of construction thereoi without departing irom the scope oithe appended claims.

In the drawings, Figure 1 is a side elevation oi a three-speed, iour-position ian switch. constructed in accordance with my invention, the switch parts being shown in "oil" position.

Fig. 2 is a top plan view oi the switch, with the operating knob or handle and the mounting nuts removed ior purposes oi illustration.

-Fig. 3 is a bottom plan view oi the switch shown in Figs. 1 and 2.

Fig. 4 is an exploded perspective view oi certain oi the stationary and movable parts oi the switch, said parts being in relative positions corresponding to second speed of the ian motor or the like (not shown).

Fig. 5 is a top plan view oi the insulating base of the switch, with the combined stationary contact and terminal members attached thereto, the contour of the insulating plate to be superimposed thereon, and the openings in said plate as well as the cross sectional contour of the operating shait, being illustrated in dotted lines.

Fig. 6 is a vertical sectional view of the switch, with the parts thereof in off position as shown in Fig. 1, said view being taken on the line 66 01 Fig. 3. 10

Fig. '7 is a vertical sectional view, on the line l-i oi Fig. 6.

Fig. 8 is a horizontal section, on the line 88 of Fig. 7.

Fig. 9 is a top plan view of a switch base like that shown in Fig. 5, but with one of the combinedstationary contact and terminal members omitted, to provide a two-speed, three-position ian switch.

Fig. 10 is a fragmentary view, partly in section on a line corresponding to 8-8 in Fig. 7, showing a modified iorm oi stop plate (as compared with Fig. 8, for instance), and illustrating the manner in which the same cooperates with the stop lugs formed upon the supporting frame or housing.

Fig. 11 is a vertical sectional view oi a switch which is functionally similar to that .shown in Figs. 1 to 8, but difl'ers from the latter in respect of certain structural details.

Fig. 12 is a sectional view on the line l2--l2 oi Fig. 11.

,Fig. 13 is a bottom plan view of the switch shown in Figs. 11 and 12.

Fig. 14 is a top plan view of the insulating base oi the switch shown in Figs. 11 to 13, the stationary combined contact and terminal members being shown attached thereto.

Fig. 15 is a side elevational view oi a switch quite similar to that shown in Figs. 11 to 14, but modified to provide means for insuring movement oi the movable switch parts to one or another 01 their desired positions upon manual release oi the operating knob, one oi the frame legs being broken away to show the octagonal iorm oi the operating shait, and v Fig. 16 is a horizontal section on the line ll-IO oi Fig. 15, looking in the direction oi the arrows.

Reierring first to Figs. 1 to 8, inclusive, the 50 numeral 2| designates the substantially circular top portion oi a punched and stamped sheet metal supporting irame or housing, said top pore tion preierably having formed integrally therewith three leg portions II, 22 and 23 which are 55 substantially in the form of an arc.

bent downwardly at substantially right angles thereto. Said legs are respectively provided at the lower ends thereof with reduced portions 2|", 21 22, 22 and 23, 23", the reduced portions 2|, 22 and 23 providing pairs of horizontal shoulders which engage the upper surface of a fiat punched insulating base 24 to insure against upward displacement of the latter with respect to the top portion 20 of the metal frame; said reduced portions 2H, 22* and 23 also providing pairs of vertical shoulders which fit rather closely between the side walls of the equally spaced peripheral notches 24 24 and 24 of like dimensions formed in base 24 to restrain the latter against rotary displacement relatively to the frame.

The aforementioned reduced portions 2U, 22 and 23 serve as lugs which are bendable inwardly over the lower surface of base 24 to positively retain the latter in assembled relation to the frame.

As best illustrated in Fig. 5, there are attached to base 24 three combined contact and terminal members of identical form, the contact portions 25 of said members being seated flatwise upon the upper surface of the base and being attached thereto as by means of pairs of lugs 25 which penetrate pairs of openings in the base and are bent inwardly toward each other in the manner illustrated in Fig. 3. Formed integrally with contact portions 25, and bent downwardly at substantially right angles thereto, are the wiring terminal lugs 25, which are respectively accommodated by a corresponding number of substantially rectangular openings formed in the base. Lugs 25 are provided with the usual openings or perforations (see Fig. 1) to facilitate attachment of the bared ends of circuit wires thereto as by soldering or brazing.

As will be apparent from 'Fig. 5 the adjacent ends of the three contact portions are arranged Diametrically opposed to the three contact portions 25 is a flat contact portion 26 of arcuate contour, said contact portion 26 having three lugs 26*, 26 and 26 which penetrate correspondingly located openings in base 24 and are bent inwardly over the lower surface of the latter, as shown in Fig. 3. Formed integrally with contact portion 26, and bent downwardly at substantially a right angle thereto, is a wiring terminal lug 26 which is accommodated by a substantially rectangular opening formed in base 24.

Base 24 may, if desired, be provided with a centrally located circular opening 24* to accommodate a reduced lower end portion of shaft 11 to assist in centering the latter. As best illustrated in Figs. 6 and 7, however, the shaft I1 is provided with a fiat lower end which is positioned in a plane slightly above the upper surface of base 24, said shaft being supported and centered by means independent of base 24, as hereinafter described. Pressed or extruded upwardly from base 24 at diametrically opposite points 24 24 (Figs. 3 and 6), are a pair of substantially cylindrical bosses 24, 24 (Figs. 5 and 6), the flat upper surfaces of which are preferably located in a plane slightly above the plane of the aforementioned contacts 25 and 26.

Superimposed upon base 24 and adapted to seat upon the contacts 25 and 26 is a relatively thin, flat, punched plate 21 of insulation-said plate having a circularly arranged series of eight equally spaced openings-one diametrically opposed pair of said openings being designated 21*, 21*;

and the three other diametrically opposed pairs of openings beingrespectively designated 21, 21 21 21 and 21, 21. Plate 21 is provided with three equally spaced peripheral notches 21 21 and 21 which are respectively adapted to register with the relatively smaller notches 24 24 and 24, in base 24, as best illustrated in dotted lines in Fig, 5. Said peripheral notches in plate 21 are respectively adapted to accommodate the aforementioned leg portions 22, 23 and 2| of the metal frame (as best illustrated at 2|, 21 in Fig. l) to prevent rotary displacement of plate 21 relatively to the metal frame and base 24.

Plate 21 may be provided with an indicating notch as shown in dotted lines at 21 in Fig. 4 to facilitate proper positioning thereof with respect to base 24. However, for purposes of assembly it is suflicient to note that notch 21 is the only one having a pair of openings (21 21 definitely alined and centered with respect thereto, it being understood that plate 21 must be so positioned as to bring notch 21 into alinement with notch 24 in base 24 (Fig. 5). This will insure positioning of the openings 21 21 in alinement with the cylindrical extrusions or bosses 24 24 and one series of openings 21*, 21 and 21 will be alined with the arcuate contact 26, as illustrated in dotted lines in Fig. 5, the other series of openings 21 21 and 21 being alined with the three contacts 25.

To insure against substantial upward displacement of plate 21, I preferably shear and bend inwardly from the respective frame legs 2 I, 22 and 23 tongues 2l, 22 and 23, the lower ends of which tongues closely overlie the upper surface of plate 21, in the manner best illustrated at 22 in Fig. 6.

Superimposed upon plate 21, for rotation with respect thereto, is a relatively thick punched insulating plate 28, of a size sufficiently large to overlie the aforementioned circularv series of openings in plate 21, as best illustrated in Fig. 8, but small enough to provide ample clearance between the same and frame legs. Plate 28 is provided with a centrally located square opening 28 to accommodate with a sliding fit the lower portion of shaft I1 of corre onding form in cross section, to provide for rotation of said plate by said shaft. Plate 28 is provided with a pair of diametrically opposed circular openings 28 and 28, said openings being arranged in a line at right angles to two of the sides of opening 28 (see Fig. 4). Loosely positioned within openingsZB 28 are a pair of spherical metal contactors or balls 29, of a diameter substantially greater than the thickness of plate 28. The arrangement is such that the openings 28*, 28 and the balls 29 located therewithin will be alined with one or another of the pairs of diametrically opposed openings in plate 21 in the several operative positions of the switch parts, as hereinafter described. In practice I prefer to provide plate 28 with cut away portions, as indicated by the straight sides 28 and 28, primarily to reduce the amount of insulation required, with consequent reduction in the weight or inertia of this part.

' Superimposed upon plate 28, and adapted to seat against the portions of balls 29 which project above said plate, is a punched sheet metal conductor or plate 30 of annular form. Plate 30 is provided with a relativelylarge centrally located circular opening 38 which aifords ample electrical clearance between said plate and shaft l1. In a line at right angles to the line of en:

gagement of plate 38 with balls 29 are a pair of 75 diametrically opposed, upwardly projecting, hemispherical bosses 33 and 30 formed integrally with said plate. Superimposed upon plate 30 is a flat punched insulating plate 3| of substantially the same contour as plate 28, but preferably relatively thinner than the latter. Plate 3| is provided with a centrally located square opening 3| (like the opening 28 in plate 28) to accommodate shaft I1 and to provide for driving of the former by the latter. Plate 3| is also provided with a diametrically opposed pair of circular openings 3| and 3| which are adapted to accommodate the respective bosses 30 and 30 formed on conductor plate 33, to constrain the latter to rotate in either direction with the former. I also prefer to provide plate 3| with cut away portions, as indicated by the straight sides 3|, 3|.

As illustrated in Fig. 4, the plates 28, 30 and 3| are so assembled that the fiat sides 3|, 3| of plate 3| are angularly displaced substantially 90 degrees with respect to the flat sides 28 28 of plate 28. Inasmuch as plates 28, 30 and 3| are restrained against rotary displacement relatively to each other, it will be apparent that the flat lower surface of plate 30 is adapted to engage the projecting upper ends of balls 29 at points on the former spaced substantially 90 degrees from the respective bosses 33 and'30.

Shaft I1 is provided at an intermediate point in its length with a reduced portion |1 of circular form in transversev cross-section, the groove required to form said reduced portion providing a pair of spaced horizontal shoulders, as best illustrated in Figs. 6, 7 and 8. Insertable into said groove with a rather close fit is a horseshoe-shaped metal washer 32 which has its adjacent end portions bent toward each other, as shown in Fig. 8, to substantially entirely surround the reduced portion H of the shaft and to resist accidental displacement of said washer.

Strung upon the lower end of shaft l1, in a relation to other of the switch parts as illustrated in Fig. 4, is a flat sheet metal stop plate 33 having a square opening 33 to accommodatethe shaft |1 whereby the former is driven by the latter. Also strung upon shaft I1 and interposed between the lower surface of stopplate 33 and the upper surface of insulating plate 3| is a coiled compression spring 34, the upper and lower end coils of which spring are preferably arranged in parallel horizontal planes by the winding operation, as shown in Fig. 4. Stop plate 33 is formed as shown in Figs. 4 and 8 to provide a pair of spaced radial shoulders 33 and 33, the shoulder 33 being engageable with an integral lug'20 struck downwardly-from the top portion 23 of the metal frame, to limit the degree of clockwise movement of shaft l1 and its associated parts; and the shoulder 33 being engageable with a second integral lug 2|) struck downwardly from top portion 20, to limit the degree of counterclockwise movement of the shaft.

The range of 'rotary movement thus provided for shaft I1 is such as to provide four definite operative positions for the switch parts. That is to say, from an "off position wherein the ball contactors 23 are engaged with the respective bosses 24 and 24*, the parts may be rotated clockwise (Fig. 5) to three other operative positions, wherein one of the ball contactors 29 sequentially assumes positions alined with the openings in plate 21, as represented by the dotted lines 21, 21 and 21 upon the contact 26 in Fig. 5, while the other ball contactor 29 is simultaneously moved to sequentially assume positions aligned with other openings in plate 21, as represented by the dotted lines 21, 21 and 21 upon the three contacts 25 in Fig. 5. Assuming proper connection of the switch terminals in the circuit of a fan motor, the arrangement is such that the motor circuit may be interrupted, or the motor circuitmay be commutated (through the medium of suitable resistances, not shown) to provide for high, medium or low speed operation of the motor.

As best illustrated in Figs. 6 and '7 the top portion 20 of the frame is provided with a centrally located circular opening 20 which is adapted to accommodate the reduced lower end 35 of an externally threaded hollow metal bushing 35, said reduced end 35 being upset over the lower surface of top portion 2|] to rigidly and non-rotatably attach said parts to each other. The circular wall of opening 35 is preferably notched in a well known manner to provide a better interlock with the upset end 35 of the bushing.

The lower end portion of bushing 35 is preferably provided with an annular recess 35 to accommodate and provide a bearing for the aforementioned washer 32, to limitthe degree of upward'displacement of shaft l1. Shaft l1 extends upwardly beyond bushing 35, and said shaft is provided with a second groove or reduced portion |1 which is adapted to accommodate a relatively thin sheet metal washer 3B of horseshoe shape. The free ends of washer 36 are bent toward each other, or clinched, to prevent accidental displacement thereof from shaft l1. Washer 36 bears upon the upper end of bushing 35 to restrain shaft l1 against substantial downward displacement. As best illustrated in Fig. 7, the relatively thick washer rotatably bears within the annular recess 35 to maintain shaft H in properly centered relation to bushing 35; the diameter of the opening or passage 35 in bushing 35 being such as to provide a rotatable bearing for shaft l1 at the four vertical comers or edges of the latter, to further insure centering of said shaft.

Shaft I1 is provided at its upper end with a tapped recess |1 (Fig. 6). A molded insulating knob or handle 31 is provided. The knob as shown is of the form illustrated in Design Patent No. 108,723, granted March 8, 1938, to C. B. Stevens. A knob of any other suitable form may of course be employed if desired. Knob 31 is provided with a recess 31* of square form in transverse cross section to non-rotatably rethe shank 39 of which penetrates an opening 31 leading from recess 31 to recess 31, said shank taking into the aforementioned tapped recess |1 .in shaft l1 to retain knob 31 in assembled relation to shaft H. A known form of split lock washer 40 preferably underlies the head 3 9 of the fastening screw to prevent accidental loosening of the latter.

Prior to attachment of handle 31 to the switch, the latter is mounted upon asuitable casing or panel provided with a single mounting hole, the upper clamping nut 4| being temporarily removed and the nut 42 being adjusted to the desired position, depending upon the thickness of the panel or casing. Preferably the mounting is such that the upper surface of nut 4| when in clamping position against the panel is substantially flush with the upper end of bushing 35. In practice I prefer to provide the switch frame with integral struts or indentations 2| 22 and 23 at the points of juncture of the leg portions 2|, 22 and 23 with the top portion 20 to strengthen the frame as a whole and to prevent accidental bending or deformation of said leg portions after assembly of the switch parts.

With particular reference to Fig. 8, it will be understood that although I have described a four-position switch having asingle off position and three on positions, wherein the direction of rotation of the shaft must be reversed upon attainment of each extreme rotary position thereof, it is possible by a slight modification of one of the parts to provide a switch mechanism having two alternative off positions, and to provide for rotation of the movable switch parts in either direction from any given rotary position thereof to another. Such modification merely involves the provision of a plate 33 having the outer or laterally extending portion thereof removed, as indicated by the dotted line 33 in Fig. 8, whereby the stop shoulders 33 and 33 are eliminated.

Also as shown in Figs. 9 and 10 a two-speed, three-position fan switch may be provided by substituting for the metal stop plate 33 aforedescribed a metal stop plate 43 wherein the radial stop shoulders 43 and 43 for engagement with the respective stop lugs 20 and 20 are less widely spaced, angularly, than are the aforedescribed stop shoulders 33 and 33 of stop plate 33. For this purpose, one of the combined stationary contact and terminal members 25 (the left-hand contact and terminal member of Fig. 5) is preferably omitted, as shown in Fig. 9, the insulating base plate 24 being identical with that aforedescribed. Such modified switch mechanism may be in all other respects exactly like that aforedescribed.

From the foregoing description it will be apparent that the conductor plate 30 which is at all times biased into engagement with the ball contactors 29 acts as a connecting bus member for the latter. Due to the fact that insulating plate 21 is maintained stationary it is to be noted that upon rotation of plate 28 by shaft I! the ball contactors 29 are obliged to ride upwardly over the walls of each diametrically opposed pair of openings 21 21 21 21, etc., and are carried by plate 28 into alinement with the next succeeding diametrically opposed pair of such openings. As the ball contactors 29 fall into each pair of openings a definite feel or position indication of the switch mechanism is provided.

As will be apparent from consideration of Figs. 6 and 7, upon movement of ball contactors 29 from each on position thereof, a double break of the controlled circuit is provided. At the same time the movable plate 28 cooperates with the stationary plate 21 to close the gaps resulting from movement of ball contactors 29 outwardly tacts and contactors, thereby increasing the life of the switch.

In practice the bushing 35 is provided with a pair of parallel sides 35, 35 (Figs. 1 and 2), the opening in the casing or panel having corresponding flat sides for cooperation therewith to prevent relative rotation of the bushing within said opening. Also in practice a suitable indicating plate (not shown) is non-rotatably mounted upon bushing 35 and clamped in position by nut 4|, said indicating plate having suitable legends for cooperation with knob 31 to indicate the electrical condition of the circuit or circuits controlled by the switch.

In Figs. 11 to 14, inclusive, I have shown a modified form of three-speed, four-position fan switch. Thus I provide a flat, punched insulating base or plate 44 of substantially circular contour, plate 44 having three equally spaced peripheral notches 44, 44 and 44 formed therein to accommodate .the reduced lower ends 45*, 46 and 4'1 of the respective frame arms, two of which are shown at 46 and 41 (Figs. 11 and 12). Said frame arms are provided at opposite sides of the reduced end portions thereof with horizontal shoulders which are adapted to seat upon the upper surface of base 44, and said end portions 45, 46 and 4'! are bent inwardly over the lower surface of base 44 to secure the frame and the base in assembled relation. Said arms are formed integrally with and bent downwardly at right angles to the plane of the fiat top portion 48 of the frame.

As shown in Figs. 13 and 14, there is superimposed upon the upper surface of base 44 the arcuate portion 49 (Fig. 14) of a punched sheet metal member, the integral wiring terminal portion 49* of which is bent downwardly at substantially a right angle to said arcuate portion and penetrates an opening provided in base 44 for exposure below the lower surface of the latter (Figs. 12 and 13). Arcuate portion 49 and base 44 are provided with three sets of alined openings arranged in equally spaced arcuate relationship to each other, said sets of openings being respectively adapted to accommodate the shanks of three rivets the heads 50 of which clampingly engage said arcuate portion 49 and the hollow shanks 50 of which are upset over the lower surface of base 44 to rigidly secure said parts in assembled relation.

Arranged in diametrically opposed relationship to arcuate portion 49 is an arcuately arranged series of three punched sheet metal members 5| of like form, said members having integral terminal portions 5| bent downwardly with respect thereto and penetrating suitable openings provided in base 44 for exposure below the lower surface of the latter. Another series of three rivets have their heads 50 superimposed upon said portions 5|, the hollow shanks 50 of said rivets penetrating alined openings provided in the respective portions 5| and in base 44, and said shanks being upset over the lower surface of base 44 (Figs. 12 and 13) to rigidly secure said parts in assembled relation. The terminal portions 49 and 5| are provided with the usual openings 49 and 5| to facilitate looping attachment and soldering of the circuit wires (not shown).

Pressed or extruded from base 44 and projecting a substantial distance above the upper surface thereof is a pair of diametrically opposed substantially cylindrical bosses 44 and 44 which are respectively positioned between the adjacent ends of the two arcuate series of rivet heads 50 (Fig. 14). Superimposed upon base 44 and of corresponding circular contour is a flat punched insulating plate 52, which is preferably of less thickness than said base (Figs. 11 and 12). Plate 52 is provided with a circularly arranged series of eight equally spaced circular openings, certain of which are shown at 52 in Figs. 11 and 12;

said plate being adapted to seat upon the portions 49 and 5| of the aforementioned sheet metal members, and said openings being adapted to accommodate and rather closely surround the six rivet heads 50 and the bosses 44 and 44 (Fig. 14). The arrangement is such that the flat upper surfaces of the rivet heads 55 (Fig. 12) and the flat upper surfaces of bosses 44 and 44 (Fig. 11) are offset downwardly to a substantial degree with respect to the upper surface of plate 52.

Plate 52 is provided with three equally spaced peripheral notches to accommodate the relatively wide portions of the frame arms, one of said notches being shown at 52 (Fig. 11) in assembled relation with arm 45. The straight side walls of the respective notches cooperate with the side edges of the frame arms to restrain plate 52 against rotation relatively to base 44 and the switch frame. Plate 52 is also provided with a centrally located circular opening 52 (Figs. 11 and 12) which provides rotatable clearance for the lower end of the operating shaft 53, which, as indicated in Figs. 11 and 12, is of substantially square form in transverse cross section.

The fiat upper portion 45 of the switch frame is provided with a centrally located opening 48 (Figs. 11 and. 12) which is adapted to receive the reduced lower end of an externally threaded hollow metal bushing -which may be identical with the corresponding bushing aforedescribed said reduced lower end being upset over the lower surface of frame portion 45, as shown at 35' in Figs. 11 and 12, to rigidly and non-rotatably secure said parts to each other. Shaft 53 is provided at an intermediate point in its length with a peripheral groove 53, within which a horseshoe-shaped washer 54 is loosely inserted. The lower end of bushing 35 is provided with an annular recess 35 the peripheral wall of which accommodates washer 54, whereby lateral displacement of said washer from shaft 53 is prevented. The flat upper end wall of recess 35 also cooperates with washer 54 to prevent substantial upward displacement of shaft 53. In practice the flat lower end of shaft 53 is adapted tobear against or closely approach the upper surface of base 44. Also it is to be understood that the opening or passage 35 in bushing 35 is of such circular size in transverse cross section as to provide a rotatable bearing for the shaft 53 at the four transverse corners of the latter, whereby proper positioning or centering of the shaft is insured.

Strung upon the lower end of shaft 53 and adapted to bear against the upset end 35' of bushing 35 is a flat punched metal plate 33, which may be identical with the correspondingly designated part aforedescribed. Plate 33 is associated with shaft 53 for positive rotation by the latter, and said plate is provided with a pair of angularly spaced radial shoulders adapted for cooperation with a pair of spaced integral lugs struck downwardly from frame portion (one of said lugs being shown at 48* in Fig. 11) to limit the degree of rotary movement of shaft 53 in each direction, as described in connection with the device of Figs. 1 to 8, inclusive.

Strung upon the lower end of shaft 53 and adapted to be centered by the latter is an annular metal washer or plate 55 which abuts plate 33, and also strung thereon is an annular insulating washer 55 of a shape and size similar to washer 55 and underlying the latter. It is to be understood that a second insulating annulus like 55 may be substituted for the metal washer 55, or a single insulating annulus corresponding in thickness or depth to the combined thicknesses of washers 55 and 55 may be employed.

Also strung upon the lower end of shaft 53 and underlying insulating washer 55 is a fiat punched insulating plate 51 which is preferably of substantially circular contour and of a size to at least partially overlie the aforementioned arcuately arranged groups of rivet heads 50 which form the stationary contacts of the switch. The substantially square opening in plate 51 cooperates with shaft 53 to provide for positive rotation of the former with the latter. Underlying plate 51 is a bridging contact member 55, which is preferably of substantially annular form and is composed of a suitable resilient conducting metal or alloy, such as phosphor bronze.

Member 58 is so formed that diametrically opposed portions 58 and 58 thereof are adapted to abut the lower surface of plate 51, said plate having a pair of openings 51- and 51 formed therein (Fig. 12), and member 55 having lugs 53 and 58 formed integrally therewith and extending upwardly through said openings 51* and 51 lugs 55 and 55 being bent outwardly over plate 51- to positively unite member 58 to plate 51 for rotation with the latter. Member 55 is bent or deformed to provide a pair of diametrically opposed low points angularly displaced substantially 90 degrees from the respective portions 53 and 55 thereof, said low points being further deformed, as shown at 58 and 58 in Figs. 11 and 12, to provide downwardly convexed movable contact portions. Upon complete assembly of the switch parts as shown in Figs. 11 and 12 the bridging contact member 53 is compressed or dis-- torted to a predetermined degree.

Shaft 53 is provided at its upper end with a tapped recess 53 (Fig. 11) to accommodate a securing screw (such as the screw 33, Figs. 6 and 7) employed for attaching a knob or handle, such as the lmob 31 aforedescribed. The plate 52 is adapted for assembly in only one rotary relationship to base 44 (as pointed out in the description of plate 21 and base 24 of Figs. 4 and 5). The bushing 35 of Figs. 11 and 12 may be provided with clamping nuts 4|, 42, as shown in Fig. 6, to provide for one-hole mounting of the switch to a panel or other suitable support. As shown in Fig. 11 the top portion of 45 of the metal frame has an integral lug 45 bent downwardly at substantially a right anglethereto and in dlametrically opposed relationship to the frame arm 45, said lug 43 having utility only in conjunction with the modified form of switch niechanism shown in Figs. 15 and 16.

With reference to Fig. 11, wherein the portions 53' and 53 are engaged with the insulating bosses orprojections 44 and 44 to provide for of! or circuit interrupting positioning of the switch parts, it will be understood that upon clockwise rotation of the shaft 53 the convex lower surfaces of the movable contact portions 58 and 58 will first ride upwardly, with a camlike action, over one side wall of each of the respective openings 52 in plate 52, thus further stressing the downwardly bent portions of the annular bridging contact member 58, and upon continued clockwise rotation of shaft 53 said convex contact portions 58 and 58 will move with a similar, but reverse, cam-like action into bridging engagement with the first succeeding diametrically opposed pair of rivet head stationary contacts 50. Due to the temporary increase of the degree of compression of member 58 and the subsequent release of such additional pressure (upon attainment of another operative position of the switch parts) a definite feel is provided, to indicate to the switch operator that such operative position :has been attained.

Moreover, as best illustrated in Fig. 12, upon movement of the portions 58 58 of the bridging contactor 58 out of circuit completing engagement with one pair of diametrically opposed rivet head contacts 50, said portions are obliged to move upwardly over the walls of a pair of openings 52 in plate 52 and then laterally away from said openings, thus providing a relatively large gap across insulating surfaces which assists in cooling and snuffing any arcs formed incident to interruption of the circuit or circuits controlled by the switch.

The modified form of switch illustrated in Figs. 15 and 16 is in many respects like that shown in Figs. 11 to 14, inclusive, and like parts in the two devices have been given corresponding numerals of reference. In Figs. 15 and 16, however, the top portion 48 of the switch frame has been modified to provide a second pair of downwardly bent integral lugs 48 and 48 which are alined with the respective lugs 48 and 48 ,it being noted that lugs 48 and 4Bare spaced farther from the center of portion 48 than are the lugs 48 and 48*, whereby the former provide rotatable clearance for the stop plate 59. Stop plate 59 is substantially like the stop plate 33 aforedescribed, and is provided with radial shoulders 59 and 59 for engagement with the respective lugs 48 and 48 to limit the degree of rotation of the switch shaft 60, which in this case is of octagonal form in transverse cross section. Accordingly the stop plate 59 is provided with an octagonal opening 59 (Fig. 16) to accommodate said shaft whereby a positive driving connection between saidparts is provided.

As shown in Fig. 16 a pairof leaf springs BI is provided, one of said springs engaging one side of shaft 60 and having portions adjacent to the respective ends thereof engaged under tension with the alined lugs 48 and 48. The other spring 6| is engaged with the other side of shaft 60 and has portions adjacent to the respective ends thereof engaged under tension with the alined lugs 48 and 48 The springs 6| thus act to resiliently bias shaft 50, and the switch parts controlled thereby, to the nearest one of its various predetermined positions (within the range provided by the shape of stop plate 59) upon release of the knob or handle. Springs 61 likewise cooperate with shaft 60 to provide a predetermined degree of resistance to rotation thereof within its range, such resistance to rotation being cumulative with respect to the resistance to turning of said shaft afforded by the aforementioned resilient cam action of contact portions 58 and 58 with respect to the walls of openings 52 in plate 52.

As shown in Figs. 15 and 16, the frame arm 46 serves as an abutment to prevent endwise displacement of springs 6| in one direction, and downwardly extending lug 48 serves as an abutment to prevent endwise displacement of said springs in the opposite direction. Loosely strung upon shaft 60 is a relatively thin punched plate 63 (Fig. 15) of insulating material, said plate providing a suitable barrier between the springs BI and the lugs 58 and 58 by which "bridging contact member 58 is attached to plate 51; and plate 63 likewise prevents downward displacement of springs 6|. Interposed between insulating plates 63 and 51 is an annular insulating disk or washer 64 of smaller diameter and less thickness than plate 51, said washer serving to insure proper clearance between plate 63 and the aforementioned lugs (one of which is shown at 58 in Fig. 15).

The knob 62 as shown in Fig. 15 comprises a lower cylindrical portion 62 of relatively large diameter and an upper substantially cylindrical portion 62 of relatively smaller diameter. An integral portion 62 tapers laterally toward the periphery of portion I52 and another integral portion 62 flares laterally and extends beyond the portion 62 to provide a handle or lever to facilitate operation of the switch. A passage (not shown) extends upwardly through portions 62 and 62 of knob 62, the lower portion of said passage being of octagonal form in transverse cross section to non-rotatably accommodate the upper end of shaft 60, the upper portion of said passage being adapted to accommodate the head and shank of a securing screw which takes into a tapped opening (not shown) in the upper end of said shaft. Knob 62 may be provided with a countersink or recess opening to its upper surface to accommodate an insulating disk or the like to conceal the screw head and thus provide a more finished appearance to the knob, in the manner illustrated in Figs. 6 and 7. It will be understood that a knob like that shown in Figs. 6 and '1 may be employed in lieu of that shown in Figs. 15 and 16, provided that the knob is furnished with an octagonal recess of proper size opening to the lower surface thereof.

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

1. In an electric switch, in combination, an insulating base, a plurality of combined contact and terminal members having contactportions superimposed upon said base and having wiring terminal portions penetrating said base and exposed below the lower surface of the latter, certain of said contact portions being common to one of said wiring terminal portions, a flat punched insulating plate superimposed upon said base and restrained against transverse movement relatively thereto, said plate having a plurality of groups of openings forming opposed pairs, certain openings of one group overlying the contact portions common to said one wiring terminal portion to thereby provide for exposure of restricted areas of said contact portions, other of said contact portions being individual to their respective wiring terminal portions, certain openings of another group overlying the in- 'dividual contact portions last mentioned to provide for exposure of restricted areas of the latter, an opposed pair of openings located adjacent to one end of each of the respective groups being adapted to overlie only the material of said in- 76 sulating base, a bridging contactor having a pair of convex end portions movable jointly into and out of alinement with the respective pairs of opposed openings in said plate to provide for circuit interruption or for completion of a plurality of difierent circuit connections in sequence, and an insulating member associated with said bridging contactor for guiding and controlling such movements of the latter.

2. In an electric switch, in combination, an insulating base, a plurality of combined contact and terminal members having portions thereof exposed at the upper surface of said base, said members having sheet metal terminal portions penetrating said base and exposed below the lower surface of the latter, a flat punched insulating plate superimposed upon said base and restrained against rotation relatively thereto, said plate having a circularly arranged series of equally spaced openings formed therein to provide access to limited areas of the exposed portions of said members at the upper surface of said base, said base having a diametrically opposed pair of bosses formed integrally with the upper surface thereof, one pair of said plate openings being alined with said bosses, a second insulating plate positioned above said plate first mentioned and rotatable relatively to the latter, and a diametrically opposed pair of convex contactor elements movable with said second plate and resiliently biased downwardly with respect thereto, said contactor elements being electrically connected with each other and the same being movable jointly into and out of alinement with respective diametrically opposed pairs of openings in said plate first mentioned, to thereby provide for circuit interruption or for completion of a plurality of different circuit connections in sequence.

3. In a rotary electric switch, in combination, a punched and stamped sheet metal frame having a flat top portion and a plurality of equally spaced arms bent downwardly at substantially right angles thereto, said arms having lower ends of reduced width, a punched insulating base having peripheral notches to accommodate said reduced ends of the arms, said reduced ends being bent inwardly over the lower surface of said base to retain said parts in assembled relation, a plurality of combined contact and terminal members having portions thereof exposed at the upper surface of said base, said membershaving sheet metal terminal portions penetrating said base and exposed below the lower surface of the latter, a flat punched insulating plate superimposed upon said base and restrained from rotation relatively to the latter, said plate'having a circularly arranged series of equally spaced openings formed therein to provide access to exposed portions of said members at the upper surface of said base, said base having a diametrically opposed pair of bosses formed integrally with the upper surface thereof, the upper ends of said bosses being located substantially in the plane of said contact portions, one pair of said plate openings being alined with said homes, a second insulating plate positioned above said plate first mentioned and rotatable relatively to the latter, a pair of diametrically opposed convex contactor elements movable with said second plate and resiliently biased downwardly with respect thereto, said contactor elements being electrically connected with each other and the same being movable jointly into and out of alinement with the respective diametrically opposed pairs of openings in said plate first mentioned, to thereby provide for circuit interruption or for completion of a plurality of different circuit connections in sequence, an externally threaded hollow metal bushing carried by said top portion of the frame, and a shaft of polygonal form in transverse cross section adapted to bear within said bushing, said shaft having a positive driving connection with said second insulating plate.

4. In a rotary electric switch, in combination,

a punched and stamped sheet metal frame having a flat top portion and a plurality of equally spaced arms bent downwardly at substantially right angles thereto, said arms having lower ends of reduced width, a punched insulating base having peripheral notches to accommodate said reduced ends of the arms, said reduced ends being bent inwardly over the lower surface of said base to retain said parts in assembled relation, a plurality of combined contact and terminal members having portions thereof exposed at the upper surface of said base, said members having sheet metal terminal portions penetrating said base and exposed below the lower surface of the latter, a flat punched insulating plate superimposed upon said base and restrained from rotation relatively to the latter, said plate having a circularly arranged series of equally spaced openings formed therein to provide access to exposed portions of said members at the upper surface of said base, said base having a diametrically opposed pair of bosses formed integrally with the upper surface thereof, one pair of said plate openings being alined with said bosses, a second insulating plate positioned above said plate first mentioned and rotatable relatively to the latter,

siliently biased downwardly with respect thereto,

said contactor elements being electrically connected with each other and the same being movable jointly into and out of alinement with the re, spective diametrically opposed pairs of openings in said plate first mentioned, to thereby provide for circuit interruption or for completion of a plurality of different circuit connections in sequence, an externally threaded ho low metal bushing carried by said top portion 0 the frame, a shaft of polygonal form in transverse cross section adapted to bear within said bushing, said shaft having a positive driving connection with said second insulating plate, a flat punched sheet metal plate with which said shaft has a positive driving connection, said metal plate having angularly spaced radial shoulders formed thereon, and a pair of spaced shoulders extending downwardly from said top portion of the frame and with which said radial shoulders are adapted to engage selectively to limit the degree of rotation of said shaft in each direction.

5. In a rotary electric switch, in combination, an insulating base, a flat punched insulating plate superimposed upon said base, said plate having a circularly arranged series of eight equally spaced openings formed therein, a plurality of combined contact and terminal members secured to said base, said members having diametrically opposed pairs of contact portions alined with and accessible through certain of said plate openings,

tive. rotation. a second insulating plate superi n- ,75

posed upon said plate first mentioned and rotatable with respect thereto, said second plate having a diametrically opposed pair of openings adapted for selective alinement with the pairs of openings in said first plate, a ball contactor positioned within each opening in said second plate, a metal plate superimposed upon said ball contactors to provide an electrical connection therebetween, spring means providing a continuous downward bias of said metal plate, and a rotatable shaft having a positive driving connection with said second insulating plate.

6. In a rotary electric switch, in combination, an insulating base, a fiat punched insulating plate superimposed upon said base, said plate having a circularly arranged series of eight equally spaced openings formed therein, a plurality of combined contact and terminal members secured to said base, said members having diametrically opposed pairs of contact portions alined with and accessible through certain of said plate openings, the terminal portions of said members extending downwardly through said base and being accessible below the lower surface of the latter, one diametrically opposed pair of said plate openings being free from contact portions, means for restraining said base and said plate against relative rotation, a second insulating plate superimposed upon said plate first mentioned and rotatable with respect thereto, said second plate having a diametrically opposed pair of openings adapted for selective alinement with the pairs of openings in said first plate, a ball contactor positioned within each opening in said second plate, a metal plate superimposed upon said ball contactors to provide an electrical connection therebetween, spring means providing a continuous downward bias of said metal plate, a rotatable shaft having a positive driving connection with said second insulating plate, a metal frame providing a bearing for said shaft, said frame having a pair of spaced shoulders formed integrally therewith and positioned therewithin, and a metal stop plate with which said shaft has a positive driving connection, said stop plate having angularly spaced radial shoulders respectively adapted for engagement with said frame shoulders to limit the range of rotary movement of said shaft.

'7. In a rotary electric switch, in combination, an insulating base, a fiat punched insulating plate of corresponding contour superimposed upon said base, said plate having a plurality of pairs of diametrically opposed openings formed therein and arranged in a circular series in equally spaced relationship to each other, said base having a pair of substantially cylindrical bosses formed thereon and alined with one diametrically opposed pair of openings in said plate, a plurality of one-piece combined contact and terminal members each having a terminal portion penetrating said base and exposed below the lower surface of the latter, one of said members having a flat group contact portion underlying a plurality of openings in said plate at one side 'of said cylindrical bosses, other of said members having fiat individual contact portions underlying a plurality of other openings in said plate at the other side of said bosses and respectively diametrically opposed to said group of contact openings, a second punched insulating plate having a diametrically opposed pair of openings, a ball contactor positioned-within each opening last mentioned and of substantially greater diameter than the thickness-of said secend plate, a metal plate superimposed upon said ball contactors and adapted to provide an electrical connection therebetween, a third punched insulating plate superimposed upon said metal plate and having a positive driving and centering connection with the latter, a rotatable shaft of polygonal form in transverse cross section having a positive driving and centering connection with said second and third mentioned insulating plates, means comprising a metal frame for supporting said shaft in centered position independently of said base, and a coiled spring surrounding said shaft and engaged under compression with the upper surface of said third insulating plate.

8. In an electric switch, in combination, a fiat insulating base, a plurality of combined contact and wiring terminal members, each of said members comprising a flat sheet metal portion seated upon and secured to the upper surface of said base and an integral terminal portion penetrating said base and exposed below the lower surface of the latter, a fiat punched insulating plate superimposed upon said flat sheet metal portions, said plate having certain openings formed therein to provide for exposure of predetermined areas of said fiat sheet metal portions and other openings to provide for exposure of corresponding areas of said base, said openings being circularly arranged in equally spaced relationship to each other, means for retaining said base and said plate in substantially fixed relationship to each other, a second fiat punched insulating plate positioned above said first mentioned plate and rotatable with respect thereto, a bridgingcontactor associated with said second plate for rotation thereby, said contactor having diametrically opposed convex portions adapted for movement jointly into and out of alinement with the respective diametrically opposed openings in said first mentioned plate to provide for circuit interruption or for completion of a plurality of different circuit connections in sequence, and means for resiliently biasing said convex portions of said contactor toward said first mentioned plate.

9. In an electric switch, in combination, a flat punched insulating plate, a plurality of combined contact and wiring terminal members. each of said members comprising a flat sheet metal portion seated upon the upper surface of said plate and an integral terminal portion penetrating said plate and exposed below the lower surface of the latter, each of said flat sheet metal portions having a plurality of integral lugs penetrating said plate and bent over the lower surface of the latter to secure said parts in assembled relation, a second fiat punched insulating plate superimposed upon said fiat sheet metal portions, said second plate having certain openings formed therein to provide for exposure of predetermined areas of said flat sheet metal portions and other openings to provide for exposure of corresponding areas of said first mentioned plate, said openings being circularly arranged in predetermined spaced relationship to each other, means for retaining said plates in substantially fixed relationship to each other, a third fiat punched insulating plate positioned above said first mentioned plates and rotatable with respect thereto, a bridging contactor associated with said third plate for rotation thereby, said contactor having diametrically opposed convex portions adapted for movement jointly into and out of alinement with the respective diametrically opposed openings in said second mentioned plate to provide for circuit interruption or for completion of a plurality of different circuit connections in sequence, means for resiliently biasing said convex portions of said contactor toward said second mentioned plate, a shaft of parallelsided polygonal form in transverse cross section having a positive driving connection with said third plate, and a pair of flat spring members engaged under tension with said shaft at opposite sides of the latter, said spring members acting to insure positioning of said convex contactor portions in alinement with one or another of said pairs of diametrically opposed plate openings upon release of said shaft after a given degree of manual rotation of the latter.

10. In an electric switch, in combination, a metal frame having a top portion and a plurality of equally spaced downwardly extending arms formed integrally with said top portion, said top portion having a centrally located opening formed therein, an externally threaded,hollow metal bushing having a reduced lower end penetrating said opening and upset over the lower surface of said top portion to rigidly secure said parts in assembled relation, said top portion having a pair of lugs partially sheared therefrom and bent downwardly at substantially right angles thereto, said lugs being located in a common plane parallel to the plane of one of said arms, said bushing having a pair of parallel flat sides in planes at right angles to the plane of said lugs, a shaft of polygonal form in transverse cross section positioned within said bushing to be centered thereby and, extending beyond each end of the latter, said shaft having spaced peripheral grooves formed therein, washers insertable into the respective grooves and engaged with saidbushing at each end of the latter to prevent substantial endwise displacement of said shaft, an insulating base arranged in a given angular relation to said frame arms and rigidly attached thereto, said base having a diametrically opposed pair of bosses formed upon the upper surface thereof, a flat sheet metal member of arcuate form seated upon the upper surface of said base at one side of and in arcuate alinement with said bosses, said member having a plurality of integral lugs penetrating said base and bent over the lower surface of the latter, said member also having an integral lug penetrating said base to provide for attachment of a circuit wire, a plurality of fiat sheet metal members seated upon the upper surface of said base at the other side of and in arcuate alinement with said bosses, said last mentioned members each having a plurality of integral lugs penetrating said base and bent over the lower surface thereof and each also having an integral lug to provide for attachment of a circuit wire, a flat punched insulating plate superimposed upon said base in a given angular relation and engaged by the respective frame arms to restrain said plate against substantial rotary or upward displacement, said plate having a circular series of eight equally spaced openings one diametrically opposed pair of which is alined with said bosses, other of said openings being adapted to overlie said fiat sheet metal members to provide a plurality of diametrically opposed pairs of contact portions, a second punched insulating plate with which said shaft has a positive rotary driving engagement, said second plate having a diametrically opposed pair of openings, a ball contactor in each of said openings, said ball contactors being adapted for movement into alinement with the diametrically opposed pairs of openingsin said plate first mentioned, a metal member providing a continuous electrical connection between said contactors, spring means for biasing said contactors toward said first mentioned plate, and, a metal plate positively rotatable with said shaft, said metal plate having radial shoulders adapted for engagement with said frame lugs respectively to limit the range of rotary movement of said shaft.

11. In an electric switch, in combination, a metal frame having a top portion and three equally spaced downwardly extending arms formed integrally with said top portion, said top portion having an opening formed therein, an externally threaded hollow metal bushing having a reduced lower end penetrating said opening and upset over the lower surface of said top portion to rigidly secure said parts in assembled relation, said top portion having a pair of lugs partially sheared and bent downwardly with respect thereto, said lugs being located in a common plane parallel to the plane of one of said arms, said bushing having a pair of parallel flat sides in planes at right angles to the plane of said lugs, a'shaft of polygonal form in transverse cross section positioned within said bushing and extending beyond each end of the latter, said shaft having spaced peripheral grooves formed therein, washers insertable into the respective grooves and engaged with said bushing to prevent substantial endwise displacement of said shaft, an insulating base arranged in a given angular relation to said frame arms and rigidly attached thereto, said base having a diametrically opposed pair of bosses formed upon the upper surface thereof, a metal member of arcuate form seated upon the upper surface of said base at one side of and in arcuate alinement with said bosses, said member having a plurality of integral lugs penetrating said base and bent over the lower surface of the latter, said member also having an integral lug penetrating said base to provide for attachment of a circuit wire, a plurality of metal members seated upon the upper surface of said base at the other side of and in arcuate alinement with said bosses, said last mentioned members each having a plurality of integral lugs penetrating said base and bent over the lower surface thereof and each also having an integral lug to provide for attachment of a circuit wire, an insulating plate superimposed upon said base in a given angular relation and engaged by the respective frame arms to restrain said plate against substantial rotary or upward displacement, said plate having a circular series of equally spaced openings one diametrically opposed pair of which is alined with said bosses, other of said openings being adapted to overlie said metal members to provide a plurality ofdiametrically opposed pairs of contact portions,'

with said frame lugs respectively to limit the 15 range of rotary movement of said shaft, an insulating operating knob rigidly but removably attached to the upper end of said shaft for positive rotation of the latter, said knob being attached in a predetermined angular relationship to said shaft, and said knob being shaped to cooperate with legends upon a suitable plate to indicate the circuit controlling positions of the switch parts.

12. In a manually operable rotary electric switch, in combination, a stamped sheet metal frame, a fiat insulating base carried by said frame, a plurality of stationary contact members superimposed upon said base, a fiat insulating plate superimposed upon said base, means independent of said contact members and including a multiplicity of cooperating shoulders on said frame and said plate for restraining the latter against transverse movement relatively to said base, said plate having a plurality of pairs of openings formed therein, certain of said openings overlying the respective contact members to provide for exposure of restricted areas of the latter below the upper surface of said plate, a rotatable bridging contactor having a pair of convex portions movable jointly in either direction into and out of alinement with and into the respective pairs of openings in said plate to provide for completion of a plurality of different circuit connections in sequence, the walls of said openings acting as insulating barriers between the convex portions of said contactor and said contacts upon disengagement of the former from the latter, and a second flat insulating plate associated with said bridging contactor to assist in controlling and. guiding such movements of the latter, said second insulating plate being rotatable relatively to said base in closely adjacent relationship to said first mentioned plate to substantially close the upper ends of each opposed pair of openings in said first mentioned plate after disengagement of the convex portions of said contactor from the respective pairs of contact members, for the purpose set forth.

13. In an electric switch, in combination, an insulating base, a plurality of combined contact and terminal members having contact portions superimposed upon said base, certain of said contact portions having a common wiring terminal, a flat punched insulating plate superimposed upon said base, means independent of said contact members for restraining said plate against transverse movement relatively to said vide for exposure of restricted areas of said contact portions below the upper surface of said plate, other of said contact portions being individual to their respective wiring terminals, certain openings of another group overlying the individual contact portions last mentioned to provide for exposure of restricted areas of the latter below the upper surface of said plate, a bridging contactor having a pair of convex end portions movable jointly into and out of alinement with and into the respective pairs of opposed openings in said plate to provide for completion of a plurality of different circuit connections in sequence, the walls of said openings acting as insulating barriers between the convex end portions of said contactor and said contacts upon disengagement of the former from the latter, for the purpose set forth, and an insulating member associated with said bridging contactor for controlling and guiding such movements of the latter, said insulating member being adapted to overlie and substantially close the upper ends of the respective pairs of opposed openings after disengagement of the convex end portions of said contactor from the stationary contacts associated with said openings.

14. In a rotary electric switch, in combination, a punched and stamped sheet metal frame having a substantially fiat top part and a plurality of arms formed integrally with said top part and bent downwardly at substantially right angles thereto, said top part having an opening formed therein, a hollow metal bushing having a reduced lower end penetrating said opening and upset over the lower surface of said top part to rigidly secure said elements in assembled relation, said top part having portions thereof partially sheared therefrom and bent downwardly at substantially right angles thereto to provide stop shoulders, a shaft of polygonal form in trans verse cross section positioned within said bushing to be centered thereby and extending beyond each end of the latter, said shaft having spaced peripheral grooves formed therein, washers insertable laterally into the respective grooves and engaged with said bushing at the respective ends of the latter to prevent substantial endwise displacement of said shaft, a metal plate having an opening of polygonal contour substantially corresponding to the cross sectional form of said shaft and slidable endwise onto the latter and positively engaged therewith for rotation thereby, means for retaining said metal plate in a given position longitudinally of said shaft, and said metal plate having radial shoulders formed thereon for engagement with the aforementioned stop shoulders respectively to positively limit the degree of rotary movement of said shaft in each direction.

15. In a rotary electric switch, in combination, a punched and stamped sheet metal frame having a substantially flat top part and a plurality of arms formed integrally with said top part and bent downwardly at substantially right angles thereto, said top part having an opening formed therein, a hollow metal bushing having a reduced lower end penetrating said opening and upset over the lower surface of said top part to rigidly secure said elements in assembled relation, said top part having portions thereof partially sheared therefrom and bent downwardly at substantially right angles thereto to provide stop shoulders, a shaft of polygonal form in transverse cross section positioned Within said bushing to be centered thereby and extending beyond each end of the latter said shaft having spaced peripheral grooves formed therein, washers insertable laterally into the respective grooves and engaged with said bushing at the respective ends of the latter to prevent substantial endwise displacement of said shaft, a metal plate having an opening of polygonal contour slidable endwise onto said shaft and engaged therewith for positive rotation thereby, said metal plate having radial shoulders formed thereon for engagement with the aforementioned stop shoulders respectively to positively limit the degree of rotary movement of said shaft in each direction, a fiat punched plate of insulating material to which the lower ends of said frame arms are rigidly attache or support by the latter, a plurality of contact members superimposed upon said plate and rigidly attached thereto, a second fiat punched insulating the respective pairs of opposed openings in said second plate to provide for completion of a plurality of different circuit connections in sequence, and an insulating member with which said shaft has a positive rotary driving engagement, said insulating member having a positive driving connection with said contactor.

ALVIN w. KRIEGER.

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