US2248361A - Electric switch - Google Patents

Description

July 8, 1941. A. w; KRIEGER ELECTRIC SWITCH Filed July 7', 1939 3 Sheets-Sheet 1 y A. w. KRIEGER 1 2,248,361

ELECTRIC SWITCH Filed July '7, 1959 3 Sheets-Sheet 2 (/1. E5 lull/"I'll y 8, 1941- A. w. KRIEGER 2,248,361

ELECTRIC SWITCH Filed July 7, 1939 5 Sheets-Sheet 3 Patented July 8, 1941 ELECTRIC SWITCH Alvin W. Krieger, Milwaukee, Wis., assignor to Cutler-Hammer, In poration of Delaware 0., Milwaukee, Wis., a cor- Application July '1, 1939, Serial No. 283,175

9 Claims. (01. 200-68) This invention relates to improvements in electric switches. The invention relates more particularly to manually operable multi-pole switches for control of airplane signal lights and the like.

A primary object is to provide a switch of the aforementioned character which is extremely simple in construction and reliable in operation.

Another object is to provide a minimum number of switch parts, including like parts, which may be combined in selected groups to provide switches having substantially difierent electrical characteristics.

Another object is to provide novel forms of contacts, terminals and contactors, and novel actuating means for the latter.

Another object is to provide switches of the aforementioned character having a relatively high current controlling capacity.

Another object is to provide switches of the aforementioned character of the double-throw type.

Another object is to provide double-throw switches, having novel means for insuring good electrical connections between the tiltable contactors and the terminal elements which support the latter.

Another object is to provide improved means for pivotally supporting and guiding the operating lever of the switch..

Another object is to provide a switch having novel spring means associated therewith to normally bias the contactors thereof from one or the other of their extreme positions.

Another object is to provide a double-throw switch mechanism having such spring means to bias the contactors from both of their extreme on positions to an intermediate ofi" position.

Other objects and advantages of the invention will hereinafter appear.

The accompanying drawings illustrate certain embodiments of the invention which will now be described; it being understood that the embodiments illustrated are susceptible of modification of Figs. 1 and 2 in assembled relation,--with the binding screws in assembled relation.

Fig. 4 is a central vertical section through the switch shown in Figs. 1 to 3, in the plane of oscillation' of the operating lever. which is shown in elevation,the movable switch parts being shown in their intermediate, or "oiP position.

Fig. 5 is a partial central vertical section. in a plane at right angles to the section of Fig. 4,- portions of certain of the switch elements being shown in elevation. t.

Fig. 6 is a sectional view similar to but to one side of the section of Fig. 4, showing the movable switch parts in one of their extreme "on positions.

Fig. '1 is a view similar to Fig. 3, but showing the addition of a pair of bus members for electrically connecting the end terminal members of each set, whereby (see Fig. 4) the movable switch parts will be biased out of one extreme position upon release of the operating lever, for momentary completion of a circuit, or will-be permitted to remain in their other extreme-position upon releaseof said lever for maintenance of the switch parts in circuit completing position, Hal-'1.

Fig. 8 is a perspective view of one of the-bus members shown in Fig. "l.

Fig. 9 is a fragmentary view, partly in side: elevation and partly in vertical section, of a doublepole, double-throw switch without an intermediate oif position,-the form of the contactors. which are slightly difierent from those sh'wn in Figs. 1 to 6, insuring this characteristic 1 Fig. 10 is a perspective view of 'the' modifled form of contactor shown in Fig. 9.

Fig. 11 is a fragmentary view similar t Fig but with stationary and movable contact sparts adapted to provide a multi-pole switch iofthe Fig. 13 is a-view similar to Fig. 11,- but having a modified form of contactorand a modified form of pivotal support and wiring terminaMor the latter.

Fig. 14 is a perspective view of the zcontact or -12 and the'pivotal support therefor shown Fig. 13, and Fig. 15 is a perspective view of a slightly in fled form of stationary contact tip"-:of'- *ob1ong form which may be substituted for the cii'cular contact tips shown in the other figures.

Referring first to the switch shown in Figs. 1

to 6, inclusive, the numeral 20 designates a supporting base preferably comprising a flat punched plate of insulating material. Base 23 is of approximately square form with rounded corners, the same being provided with rectangular notches 2| arranged in alined pairs at two of the parallel edges of the base and said notches being arranged singly, centrally and in alinement with each other at the other parallel edges of said base. Base 20 is provided with substantially circular small openings 22 arranged in four pairs in the manner best illustrated in Fig. 2.

Said pairs of openings 22 are adapted to accom-,

modate the reduced ends 23 of the parallel arms 2t of four like wiring terminal members 23,- the connecting portions 23 of which are angled upwardly, and said terminal members being assembled with respect to base 29 and with respect to each other as shown in Figs. 2 and 3 to facilitate attachment of circuit wires thereto while minimizing the over-all depth of the switch. Thus, as shown in Fig. 2, each connecting portion 23 is provided with a tapped opening 23 to accommodate the shank of a binding screw 24,- the heads of said screws being arranged in opposed pairs in downwardly divergent relationship to each other, as illustrated in Figs. 3, 4 and 6. The shoulders formed on arms 23 by the reduced ends 23 are adapted to abut the lower surface of base 20.

The four stationary contacts of the switch of tiltable contactors 30; and the side edges of .which notches prevent lateral displacement of said contactors. The mid-portions of contactors 30 are provided with lateral extensions 30', 30

which fit between the arms 29, 29 of members 29 to prevent substantial displacement of said contactors in either direction with respect to the length of the latter, as best illustrated in Figs. 4 and 6. p

I preferably interpose between the top surface of base and the flat portion 29 of each member 23 the perforated flat portion 3| of a member 3| formed of phosphor bronze, or a similar resilient metal of good electrical conductivity. Each member 3| includes an integral arm 3| which is bent to provide for positioning thereof between the arms 29 and 29 of one of the members 29,-and the free end 3l of each arm is of upwardly convex form in transverse cross section (Figs. 4 and 6) and biased upwardly against the mid-portion of the contactor 35 associated therewith. By this means a good electrical connection between each contactor comprise flat punched metal plates 25 each havrigid and permanent connection of members 23 and plates 25 to each other and to base 23. In practice the plates 25 are formed of brass or other good conducting metal, and to provide a good contacting area thereon I prefer to attach to each plate 25, as by welding, a relatively thin disk or button 26 of fine silver, or similar contact metal. To facilitate such welding of disks 26 I prefer to provide each of the latter with a small integral nib or stud 26 (see Fig. 1), which will act to localize the welding current, with resultant fusion of said stud without fusion of or damage to the main body of the disk.

Base 20 is further provided with a pair of rectangular openings 21, arranged as shown in Fig. 2, to accommodate the reduced upper ends 26' of a pair of flat punched sheet metal terminal members 28,-the shoulders formed by said ends 29 being curved outwardly and upwardly to provide a pair of sharp edges or teeth 23 which are pressed into the lower surface of base 29 to assist in retaining the respective members 28 in the planes thereof illustrated in Figs. 3 and 6. Each reduced end 28 extends upwardly through a correspondingly shaped opening 29 in the flat bottom portion 29" of a punched and stamped U-shaped sheet metal member 29- (Fig. 2), and said ends are upset or riveted as shown in Figs. 2 and 6 to retain members 28 and 29 in assembled relation to each other and to base 29. I

Each member 29 is provided with a pair of upstanding parallel arms 29 and 29 which are provided with upwardly opening notches 29 and 29 the bottom edges of which notches are respectively adapted to provide pivot bearings for the opposite upwardly angled arms 35, 30

and its support 29 and terminal 29 is insured at all times. As shown in Fig. 2, each terminal member 23 is provided with a tapped opening to accommodate the shank of a binding screw 24,-the shanks of said screws extending inwardly through members 23 toward each other, as shown in Fig. 3.

Positioned above contactors 30 is a molded member or block 32 of Bakelite or other suitable insulating material, said member being of substantially cruciform in horizontal cross section (see Fig. 1) ,two of the arms of member 32 overlying the respective contactors 30, and each of said arms having a downwardly opening substantially cylindrical recess 32 which is adapted to accommodate with a free sliding fit a substantially cylindrical molded insulating plunger 33. Plungers 33 have lower ends 33 of rounded or hemispherical form adapted for continuous engagement with the respective contactors 30. Each plunger 33 is provided with an upwardly opening cylindrical recess 33" (Figs. 1 and 5) to accommodate and provide an abutment for the lower end of a coiled compression spring 34 the upper end of which abuts the end wall of one of the recesses 32. The end wall of each recess 32 is provided with a projection or boss 32 (Fig. 5) to be surrounded by the upper end coils of spring 35 to retain the latter in centered relation, whereby fouling of the spring by its associated plunger 33 is prevented.

Member 32 is provided with a centrally located cylindrical opening or passage 32 which is adapted to provide for downward insertion of the reduced cylindrical lower end 35 of a metal lever 35 (preferably machined), said lower end having a hollow portion which is spun or upset over the lower surface of member 32 (Figs. 4 and 5) to rigidly secure said parts to each other. Member 32 is provided at its upper end with a flat surface 32 (Fig. 1) against which the flat surface 35 of the intermediate enlarged portion 35 of said lever is adapted to abut, said enlarged intermediate portion having parallel fiat sides 35 and 35. The lower portions of said flat sides 35 and 35 are adapted to fit rather closely between the parallel vertical walls 32 and 32 arranged on opposite sides of the flat surface 32 aforementioned, whereby relative rotation of member 32 and lever 35 is prevented.

The enlarged portion 35 of lever 35 is provided with a passage 35 of circular cross section extending transversely therethrough in a plane at right angles to the flat sides 35, 35. Freely insertable through passage 35 and projecting from opposite sides of lever 35 is a pivot pin 38, the ends of which are adapted toseat within the upwardly opening bearings 31, 31 formed in the flat upper surface 31 of a stamped sheet metal housing member 31 of substantially inverted cup shape, and of substantially rectangular contour to conform to the shape of base 28. Said upper surface 31 of the housing is provided between the bearings 31, 31 with a substantially rectangular opening 31 (Fig. 1) which is adapted to rather closely accommodate the enlarged intermediate portion 35 of lever 35 to assist in restricting the latter to oscillatory movement in a single plane.

Superimposed upon the flat surface 31'- of the housing is a substantially flat metal plate 38 of relatively larger dimensions than said flat surface. Plate 38 is provided centrally thereof with an approximately rectangular opening 38 to accommodate the intermediate enlarged portion 35 of lever 35, and with a pair of downwardly opening bearings 38, 38, complementary to the bearings 31*, 31 aforementioned to properly accommodate the opposite ends of pivot pin 36 (see Fig, 5). The top surface 31 of housing 31 is provided at diagonally opposite points with relatively large countersinks or recesses 31 and 31',- the bottom walls of said recesses having openings 31, 31 respectively formed therein. In like manner, plate 31 is provided with relatively smaller countersinks 38 and 38 having openings 38 and 38 formed in the respective bottom walls thereof. Said countersunk portions are telescoped or nested in the manner best illustrated at 31, 38 in Fig. 6. Rivets 33 have their heads positioned within countersinks 38, 33*- their shanks 39 penetrating the aforementioned openings and being'upset over the inner side of the surface 31 of thecasing (Fig. 6) to rigidly and permanently secure the casing and supporting plate to each other. I

As illustrated in Fig. 1, disksor buttons 28, preferably composed of fine silver, ,are welded or otherwise rigidly attached to therlower surfaces of the arms 30 of each contactor 38, for cooperative engagement with the disks attached to the stationary contact plates 25.

In practice the side walls of casing 31 are lined or covered by an insulating strip, which is preferably in the form of a section 48 of wound paper tubing, rather closely conforming to the inside contour of said casing and insertable bodily into the latter. By this means grounding or jumping of any arcs, to the casing from the sets of stationary contacts and contactors is efiectually prevented. Plate 38 is preferably provided with a pair of openings 38 and 38 adjacent the respective ends thereof to provide for attachment of the switch as a whole, by screws or bolts (not shown), to a panel or other suitable support.

With respect to Figs. 1 to 6, and with particular reference to Fig. 4, it will be noted that due to the trough formation at the mid-point of each contactor 30, a definite intermediate oil! position is provided for the contactors,the operating lever being retained in its intermediate or vertical position by the coaction or cooperation of the switch contactors and the operating elements therefor. As shown in full lines in Fig. 4 a bolt II is positioned within a recess 32 formed in block 32 and opening to the upper surface of diameter to freely accommodate a coiled compression spring I: which surrounds the shank of bolt II and underlies the rounded or hemispherical head ll' thereof to bias said head against the inner side of the flat top surface 31 of the casing,said surface 31 preferably having lugs 31 and 31 partially sheared therefrom and bent inwardly at an angle thereto for cooperation with a bolt head at either or both sides of the pivotal center of the lever 35.

The bottom wall of recess 32 is provided with an opening to afford sliding clearance for bolt lL-the lower end of the bolt shank being upset or riveted as shown to limit the degree of upward displacement of the bolt. Thus, assuming use of a single bolt 4| as shown in full-lines in Fig. 4, it will be apparent that upon clockwise pivotal movement of lever 35 the contactors will engage the left hand stationary contacts only so long as lever 35 is manually held against the bias of the aforementioned spring 42,--whereas upon manual release of lever 35 the same and the other movable switch parts will assume the intermediate or v 011" positions thereof illustrated.

the latter,-said recess being of suiiiciently large In the absence of the bolt 4| and spring 42 shown in dotted lines in Fig. 4, it will be understood that upon counterclockwise operation of lever 35 the contactors will be engaged with the cooperating contacts at the right and will be maintained in such engagement by the action of the aforementioned plunger springs 34 pending manual operation of lever 35 in a clockwise direction. With such an arrangement, it is obvious that if the right hand and left hand contacts are provided with a common circuit connection-as by use of a pair of conductors or bus members 43 (Figs. 7 and 8), the circuit or circuits to be controlled may be completed temporarily (or only so long as lever 35 is manually held) upon clockwise movement of said lever from its intermediate position; whereas the circuit or circuits may be completed upon counterclockwise movement of said lever from its mid-position, and will remain completed upon manual release of the lever. Manifestly such function, or a similar function, may be obtained by omitting the bus members 43 and by providing different circuit connections for the left hand and right hand contacts of the respective sets.

As aforeindicated, block 32 is likewise provided at the right hand side of the pivotal center of lever 35*with a recess 32 which accommodates a bolt ll and a spring 42 (dotted lines) like the corresponding parts aforedescribed, whereby the contactors will be automatically biased to their intermediate off position upon release of lever 35 after counterclockwise movement of the latter. Under the last mentioned conditions, if the left hand bolt II and spring 42 are omitted, the switch will function in the reverse manner from that aforedescribed. That is to say, upon counterclockwise movement of lever 35 from its midposition the contactors will be biased out of engagement with the right hand contacts upon manual release of the lever; whereas upon manual clockwise movement of the lever from its midposition the contactors will be permitted to remain in engagement with the left hand contacts (under the bias of plunger springs 34) pending manual operation of lever 35 in a counterclockwise direction.

In certain installations it may be desirable to provide for automatic return of the contactors to their intermediate off position upon release of lever 35 after operation thereof in either direction,in which case it is of course only necessary to employ both of the bolts 4l and the springs 42 shown in full lines and in dotted lines in Fig. 4.

The lever 33 is preferably provided with a' luminous tip 44 comprising an inverted hollow glass or lens the inner surface of which is provided with a coating or layer of luminous paint 44' or similar substance. Lens 44 is freely insertable into a recess 33' provided in the upper,

end of the lever,-a soft fiber or paper disk being interposed between the bottom wall of said recess and the open end of lens 44 to provide a seal for the latter and to provide a cushion therefor to accommodate the pressure thereon incident to inward spinning or upsetting of the upper edge of the peripheral wall 33 of said recess, whereby the lens is permanently attached to the lever.

In Fig. 9 all of the parts employed, except the contactors may be identical with those aforedescribed, and the same have been given corresponding numerals of reference,--it being understood that Fig. 9 is likewise intended to illustrate a switch of the double-pole, double-throw type, but without an o position. In Fig. 9 each contactor 43 is provided between its pair of arms 43', 43' with a straight or horizontal portion 43', which functions to insure against intermediate oiT positioning of the contactors. As will be apparent from Fig. 9, each contactor 43 is at all times fulcrumedupon one or the other of the edges 29' or 29 provided in the arms 29 and 29 of its supporting element 29. Moreover, the horizontal portion 43 of each contactor prevents engagement of the lower end 33" of its associated plunger 33 therewith in a manner to apply equal degrees of pressure to the fulcrum points thereof, as distinguished from the effect provided by the trough or groove formation provided at the midpoints of contactors 30 in Figs. 1 to 6.

In a device like that illustrated in Fig. 9, I may, if desired, utilize a single bolt 4i and spring 42 like those aforedescribed, and arranged at one side or the other of the pivotal center of the aforementioned lever 33, whereby the lever and the contactors are normally biased to one extreme position for completing a circuit or circuits controlled thereby. In such a device as that disclosed in Fig. 9, two of the spring-pressed bolts 4i would not be employed, because of the lack of an intermediate "off" position, as will be obvious. Thus Fig. 9 discloses a double-pole, double-throw switch having two alternative "on positions,--as distinguished from the three-position switch (two alternative on positions and an intermediate 011" position) shown in Figs.

Fig. 11 illustrates a modified form of switch of the double-pole, single-throw type. Most of the parts aforedescribed are employed in a switch like that illustrated in Fig. 11, and the like parts illustrated have been given corresponding numerals of reference. Fig, 11 provides a single on"-position and a sinthat one stationary contact (left hand) of each of the sets aforedescribed is omitted. The insulating base 43, although of the same size and contour as base 20 aforedescribed, is provided with a pair of rectangular openings, one of which is shown at 43, to provide for downward insertion of the wiring terminal ends 41 of a pair of members 41 each having a flat portion 41" superimposed upon the upper surface of base 43, and a vertically extending arm 4'I having an upwardly opening notch 41 which provides a sin- Inasmuch as the switch of .gle off position for the contactors, it follows gle fulcrum for its associated contactor. The

flat portion 41 of each member 41 is provided with an opening 41 alined with an opening 43'' in base 43, a headed rivet 49 having its shank extending upwardly through said openings and being upset over the upper surface of the base.

Each contactor 49 in the switch of Fig. 11 consists of a punched and stamped sheet metal member provided at one end with an arm 49, to the lower surface of which a fine silver contact disk or tip 23 is attached in the manner aforedescribed. Member 49 is provided at opposite sides thereof with sets of spaced lateral extensions 49 and 49, (Fig. 12) which sets accommodate therebetween the respective portions of arm H at opposite sides of the notch 41 in. the latter. The pivotal connection between each contactor 49 and its associated supporting and wiring terminal member is illustrated in Fig. 11,-it being understood that relative lateral and longitudinal movement of the contactor with respect to its support is substantially prevented. The rear end portion of each contactor 49 is curved upwardly from the pivot point, as shown at 49, and the end thereof is bent downwardly, as shown at 49, to form a-stop or abutment for engagement with the upper surface of base 43 to limit the degree of opening movement of the contactor. The end 41 of each member is provided with a tapped opening 41' to accommodate the shank of a binding screw 24, as shown in Fig. 11. The single stationary contact and terminal unit 23, 23 of each set is identical with the corresponding units aforedescribed.

The switch illustrated in Figs. 13 and 14 is functionally identical with that shown in Figs. 11 and 12, and is structurally like the latter except for certain detail changes now to be pointed out. Thus in Fig. 13, I am able to employ wiring terminal elements 23 identical with those aforedescribed in connection with Figs. 1 to 6,-the supporting elements 33 for the respective contactors being quite similar to the elements 29 aforedescribed, except that elements 30 are provided with only one upstanding lug 30* which is notched as shown at 33" (Fig. 14) to accommodate a contactor such as that shown at 3 l Thus each contactor 3i is provided with an end portion 3i slightly offset downwardly from the main body thereof, and to the lower surface of which the aforementioned silver contact tip 23 may be attached. Contactor 3| is provided with sets of spaced laterally extending lugs 3|, 3l for cooperation with the portions of lug 39 at opposite sides of notch 39", whereby substantial lateral and longitudinal movement of contactor 3| is prevented.

Each contactor 3i is provided at the left hand side of its point of pivotal support with a relatively long curved portion 3i which terminates in a downwardly extending portion 3" which engages the upper surface of the insulating supporting base 32 to limit the degree of opening movement of the respective contactors. The stationary contact and terminal units 23, 2: of each set may be identical with the corresponding parts aforedeacribed.

In Fig. 15 I have shown a contact plate 23 identical with the contact plates aforedescribed. Plate 23 has attached to the upper surface thereof, between the openings 23', 23', a rectangular plate or tip 33 of a suitable silver alloy. Tips 33 may be substituted for the disks or tips 23 on the stationary contact plates '23 of each of the switches aforedescribed,-the tips 23 of the respective contactors oi the switches remaining the same. The material of which the tips 53 are formed is available commercially, and tips formedtherei'rom are characterized by an in-' creased resistance toward welding or freezing," as compared with tips formed of fine silver as ai'oredescribed. Thus, with switches of the aforementioned character employing fine sflver tips upon-the stationary contacts, the same are ratedat '20'amperes at 125 volts A. (3., whereas like switches having stationary contact tips formed oi said silver alloy material have a rating of 40amperes at 125 volts A. C. If desiredy'otcourse, the contact tips for both the stationary contacts and the contactors may comprise the aforementioned silver alloy material, wherebythe current controlling capacity of the switch will be still further increased. Obviouslyfall of the contact tips may be made of rectangular shape if desired.

- When'a switch of 40 ampere capacity is constructed I'prefer to increase the spacing of the respective sets 01' contactsand contactors and/or to provide suitable means (not shown) to assist in controlling any arcs formed during operation oi the'switch.

WhatI claim as new and desire to secure by Letters'Patent is:

1. 'In a multi-pole electric switch. in combinat on. an insulating base. a plurality of sets of spaced stationary contacts carried by sa d base, a. contactor loosely and tiltably s pported by one of the stationary contacts of each set and having an end portion overlying anoth r contact of such set. an oscillatable metal operating lever p votallv supported above sa d insulating bas a molded insulating block rig dly attached to a d movable with the lower end of said lever, said insulating block having a pluralitv oi downwardlv Opening recesses formed therein and resoectively alined with said contactors, an insulating plunger slidably mounted in each of said recesses, said plungers being arranged in parallel relationship to each other, a coiled compression spring interposed between the inner wall or each recess and its associated plunger to bias the latter toward its associated contactor, said plungers cooperating with said contactors to efiect tilting movements of the latter with a quick action into and out of engagement with the aforementioned other stationary contacts of said sets upon movements of said operating lever in opposite directions respectively, and each of said contacts having a wiring terminal element associatedtherewith and exposed at the lower surface-of said base.

2. In a multi-pole electric switch, in combination,- an insulating base, a plurality of sets of spaced stationary contacts carried by said base,

- a"*contact'or loosely and tiltably supported by one oi the stationary contacts of each set and having aneridportion overlyinganother contact of such set,-an 6scillatable metal operating lever pivotallysupp'orted above said insulating base, a molded-insulating block rigidly attached to and movable with the lower end of said lever, said.

insulating block having a plurality of downwardly opening recesses formed therein and respectively alined with said contactors, an insumung plunger slidably mounted in each of said recesses, said plungers being arranged in parallel relationship to each other, a coiled compression springinterposed between the inner wall of each recess 'andits associated plunger to bias the latter toward its associated contactor, said plungers ooperating with said contactors to effect tilting movement of the latter with a quick action into and out of engagement with the aforementioned other stationary contacts of said sets upon movements 01' said operating lever in opposite directions respectively, each of said contacts having a wiring terminal element associated therewith and exposed at the lower surface of said base, and said plungers cooperating with said lever and said contactors to normally retain the same in one or the other of their extreme positions.

3. In a manually operable multi-pole electric switch, in combination, an insulating base, a plu-' rality of sets of spaced stationary contacts carried by said base, a contactor loosely and tiltably supported by one of the stationary contacts oi. each set and having an end portion overlying another contact of such set, an oscillatable metal operating lever pivotally supported above said insulating base, a molded insulating block rigidly attached to and movable with the lower end of said lever, said insulating block having a plurality of downwardly opening recesses formed therein and respectively alined with said contactors, an insulating plunger slidably mounted in each oi. said recesses, said plungers being arranged in parallel relationship to each other, a

I coiled compression .spring interposed between the inner wall of each recess and its associated plunger to bias the latter toward its associated contactor, said plungers cooperating with said contactors to effect tilting movements of the latter with a quick action into and out of engagement with the aforementioned stationary contacts of said sets upon movements of said operating lever in opposite directions respectively, each of said contacts having a wiring terminal element associated therewith and exposed at the lower surface of said base, said plungers cooperating with said lever and said contactors and tending to normally retain the same in one or the other of their extreme positions, and means including a spring-pressed bolt associated with said insulating block and adapted to cooperate with a suitable abutment to bias said block, said lever and said contactors out of one of said extreme positions.

4. In a manually operable .multi-pole electric switch, in combination, a metal housing member, an insulating base attached to said housing member for support thereby, a plurality oi sets of spaced stationary contacts carried by said base, there being three contacts in each set, a contactor loosely and tiltably supported by the intermediate contact of each set, said contactors having opposite end portions overlying the end contacts of the respective sets, an oscillatable metal operating lever pivotally supported above said insulating base. a molded insulating block rigidly attached to and movable with the lower end of said lever, said insulating block having a plurality of downwardly opening substantially cylindrical recesses formed therein and respectively alined with said contactors, a substantially cylindrical insulating plunger slidably mounted in each of said recesses, said plungers being arranged in parallel relationship to each other, a coiled compression spring interposed between the inner wall of each recess and its associated plunger to bias the latter toward its associated contactor, said plungers cooperating with said contactors to effect t lting movements of the latter jointly in either direction with a quick action into and out of engagement with the opposite end contacts respectively upon movements of said lever toward its respective extreme positions, each of said contacts having a wiring terminal element associated therewith and exposed at the lower surface of said base, said plungers cooperating with said lever and said contactors and tending to normally retain the same in any one of a number of given positions thereof, a pair of headed bolts slidably carried by said block at opposite sides of the center of oscillation of the latter, and a pair of coiled compression springs interposed between the respective bolt heads and said block, whereby said bolt heads cooperate with said housing member to bias said block, said lever and said contactors out of their respective extreme positions.

5. In an electric switch of the multi-pole type, in combination, a casing including an inverted cup-shaped sheet metal member, a metal lever supported for pivotal movement relatively to said sheet metal member, an insulating base member rigidly attachedto said sheet metal member at the open end of the latter, a molded insulating block rigidly attached to said lever at the lower end of the latter for movement thereby, a plurality of separate insulating members carried in parallel relationship to each other by said block and -spring-biased downwardly with respect thereto, a corresponding number of sets of stationary and movable contacts carried by said base, each movable contact being tiltably supported by one stationary contact of each set, and said tionary contact of each set and having an upwardly angled end portion overlying another contact of such set, a molded insulating block'supported for oscillatory movement relatively to said insulating base, said insulating block having spring-pressed insulating means associated therewith and projecting downwardly therefrom in parallel relationship to each other, said means cooperating with said contactors to effect tilting movements of the latter into and out of engagement with the aforementioned other stationary contacts of said sets upon oscillatory movements of said insulating block in opposite directions respectively, and manually operable means including a pivofilly supported metal lever for eflecting such movements of said insulating block.

8. In a multi-pole electric switch, in combination, a sheet metal member, an insulating base attached to said sheet metal member for support by the latter, a plurality of sets of spaced stationary contacts carried by said base, a wiring terminal element associated with each of said contacts, a plurality of contactors each tiltably 7 supported by one stationary contact of each set movable contacts being continuously engaged by A the respective spring-biased insulating members for tilting movements by the latter with a quick action into and outer bridging engagement with other of the stationary contacts of said sets upon corresponding movements of said lever.

rality of transversely spaced sets of stationary contacts carried by said base, a wiring terminal element associated with each of said contacts and exposed at the lower surface of said base, a plurality of contactors each loosely and tiltably supported by one stationary contact of each set and having an upwardly angled end portion overlying another contact of such set, a molded insulating block supported for oscillatory movement relatively to said insulating base, said insulating block having a plurality of downwardly opening recesses formed therein and respectively alined with said contactors, an insulating plunger slidably mounted in each of said recesses, said plungers being arranged in parallel relationship to each other, a coiled compression spring interposed between the inner wall of each recess and its associated plunger to bias the latter toward its associated contactor, said plungers cooperating with said contactors to eifect tilting movements of the latter into and out of engagement with the aforementioned other stationary contacts of said and having an upwardly angled end portion overlying another contact of such set, a molded insulating blocksupported for oscillatory movement relatively to said insulating base, said insulating block having spring-pressed insulating means associated therewith and projecting downwardly therefrom at a right angle to the axis of oscillation thereof, said means cooperating with said contactors to effect tilting movement of the latter into and out of engagement with the aforementioned other stationary contacts of said sets upon oscillatory movements of said insulating block in opposite directions respectively, and manually operable means including an oscillatable metal lever engaged with said block for eilecting such movements of the latter.

9. In a multi-pole electric switch, in combination, a sheet metal member, an insulating base attached to said sheet metal member for support by the latter, a plurality of sets of spaced stationary contacts carried by said base, a contactor tiltably supported by one of the stationary contacts of each set and having an end portion overlying another contact of such set, an oscillatable metal operating lever pivotally supported relatively to said insulating base, a molded insulating block engaged with and movable by said lever, said block being recessed in its lower surface and having spring-pressed plunger means associated therewith and projecting downwardly therefrom at a right angle to the axis of oscillation of said lever, said plunger means cooperating with said contactors to effect tilting movement of the latter into and out of engagement with the aforementioned other stationary contacts of said sets upon movements of said operating lever in opposite directions respectively, each of said contactshaving a, wiring terminal element associated therewith, said plunger means cooperating with said lever and said contactors to normally retain the same in any one of a number of given positions thereof, and additional means including a coiled spring associated with said block and said lever and cooperating with said metal member to bias said block, said lever and said contactors out of one of said given positions.

ALVIN W. KRIEGER.

insulating

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