US2172397A

US2172397A - Electric switch

Info

Publication number: US2172397A
Application number: US145318A
Authority: US
Inventors: George J Meuer
Original assignee: Cutler Hammer Inc
Current assignee: Cutler Hammer Inc
Priority date: 1937-05-28
Filing date: 1937-05-28
Publication date: 1939-09-12
Anticipated expiration: 1956-09-12

Description

Sept. l2, 1939. G. J, MEUER I ELECTRIC SWITCH Filed May 28, 1957 2 Sheets-Sheet l Sept. 12, 1939. Q MEUER 2,172,397

ELECTRIC SWITCH Filed May 28, 1937 2 Sheets-Sheet 2 E" .11 :zo lzt' 129 m5 m7 f las uz :07d

L* los /04 -lzo /zz Patented Sept. 12, 1939 UNITED STATES PATENT CFFICE ELECTRIC SWITCH poration of Delaware Application May 28, 1937, Serial No. 145,318

14 Claims.

' This invention relates to improvements in electric switches, and the invention relates more particularly to rotary switches of the slow-make,

slow-break type.

' 5 A primary object of the invention is to simplify the construction and improve the operation of switches of the aforementioned character.

Another object is to provide a single form of molded insulating base which may be employed in constructing switches having various different circuit controlling characteristics.

Another object is to minimize the number of different parts required for construction of switches having such different electrical control characteristics.

Another and more specific object is to provide a switch having a set or sets of contacts which are normally biased to open-circuit position, together with simple and efficient means for effecting control of such contacts.

Another object is to provide a switch having a contact actuating cam consisting of a flat punched plate of insulating material.

- Another object is to provide an alternating eurrent controlling switch of the aforementioned character which is particularly well adapted for use in conjunction with relatively small size radio rheostats and the like.

Various 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 in respect of certain structural details thereof without departing from the spirit and scope of Ymy invention as defined in the appended claims.

In the drawings, p

Figure 1 is a. top pla'n view (double-scale) of a double pole, slowake, slow-break switch as constructed in accor/dance with my invention.

Fig. 2 is a pers ctive View, in 'separated relation, of the part of the switch shown in Fig. 1.

Fig.,3 is a view, partly in elevation and partly in vertical section, illustrating the switch of Figs. 1 and 2 as combined with arradio rheostat or potentiometer.

Fig. 4 is a sectional view on the irregular line 4 4 of Fig. l, the cam plate being shown in a controlled circuit.

Fig. 5 is a view similar to Fig. 1,-but illustrating a modified arrangement of contacts adapted to provide a switch of. the .sc-called three-way type.

rotary position to provide for interruption of the 6 6 0f Fig. 5.

Fig. '7 is a bottom plan view of a switch generally similar to that shown in Fig. 1,-but involving use of a bus member so connected as to provide 5 a switch of the so-called three-wire type.

Fig. 8 is an elevational View of a device having a pair of switches mounted in tandem relation to a radio rheostat or the like,-certain parts being broken away to illustrate the rotatable operating l0 means common to the rheostat and the switches. Fig. 9 is a top plan View (actual size) of a modied form of double pole slow-make, slow-break switch as constructed in accordance with my invention.

Fig. 10 is an enlarged view similar to Fig. 9, but with a portion of the metal casing cut away and with the insulating actuating plate omitted for purposes of illustration.

Fig. 11 is a fragmentary view, partly inv eleva- 20 tion and partly in vertical section, illustrating the manner of attaching the switch of Figs. 9 and 10 to the metal casing or housing of a radio rheo. stat or the like.

Fig. 12 is a bottom plan view of the switch 25 shown in Figs. 9 to 11.

Fig. 13 is an enlarged top plan view of a modified form of slow-make, slow-break switch.ofitheA single pole type.

Fig. 14 is a view similar to Fig. 13, but with a 30 portion of the metal casing cut away and with the insulating actuating plate omitted for purposes of illustration.

Fig. 15 is a View, partly in elevation and partly in Vertical section, of the switch shown in Figs.Y 35 13 and 14,-the switch contacts being shown 1n open-circuit position, and

Fig. 16 is a bottom plan view, actual size, of the switch shown in Figs. 13 to 15.

Referring first to Figs. 1 to 4, inclusive, the 40 numeral 25 designates a molded insulating base of substantially cylindrical form,-said base having a substantially cylindrical recess 26 formed therein and opening to the upper surface thereof. Positioned centrally of recess 26 and formed in- 45 tegrally with the bottom wall thereof is an annular raised portion 21 having a fiat upper surface 28 located a predetermined distance below the upper surface of base 25, as best illustrated in Fig. 3. Extending radially from raised portion 21 50 is a rib 29 having a fiat upper surface 30 located in the planeof surface 28. Also extending radially from raised portion 2l is a rib 3| arranged in Ldlametrical alinement with rib 29. The upper isurface 32 of rib 3| is preferably located ina 55 after described in connection with Figs. and 6.'

accommodate a contact member employed to provide a switch of the three-way type, as hereinnecting portion of member 34. Adapted to seat upon the bottom wall of recess 26 (Figs. 1 and 4) on opposite sides of rib 3i, and in closely adjacent relationship to the latter, is a pair of one piece combined contact and wiring terminal members 3l of identical form,-said members having openings 38 to accommodate the upwardly extending hollow shanks of rivets 35 which are upset over said members to rigidly secure the same to the bottom wall of recess 26. Members 3l are preferably provided with arcuate wings which are oset upwardly from the bottom wall of recess 26 to provide the pair of stationary contacts for the switch. Members 3l are provided with wiring terminal portions 6l extending radially from lthe contact portions 60, and then downwardly at substantially right angles thereto.

Base 25 is provided with auxiliary recesses i2 and i3 and with rectangular openings 66 and 55 to accommodate said terminal portions (il, whereby the latter are exposed below the lower surface of base 25,-said terminal portions having the usual openings to facilitate attachment of circuit wires. Secured to the bottom Wall of recess 26 in substantially diametrically opposed relationship to members 5l are the fiat portions 66 and 6l of a second pair of one-piece combined contact and wiring terminal memberssaid flat portions having openings to accommodate the hollow Shanks of a pair of rivets 66, which are upset thereover as shown in Fig. 1.

Bentupwardly at an angle to the respective flat portions 66 and il are oppositely curved arcuate resilient arms 69 and v56, the free ends 5i and 52 of which respectively overlle the aforementioned contact portions ll and the pair of members 3l.

Arms

69 and 56 are sheared or slit at

corresponding points

53 and 55 in the length thereof, but at different points with-respect to the arcuate center lines thereof respectively. The relatively Y narrower portion at the outside of slit 53 is bent or deformed to provide an upwardly converging double-inclined cam portion 55; and the relatively narrower portion at the inside of slit 56 is bent or deformed'to provide an upwardly converging double-inclined cam recess 51 to accommodate a lateral extension 56 of flat portion 66,-and projecting downwardly recess 63 to accommodate a lateral extension 66` of at portion dlr-and projecting downwardly at a right angle to extension 65 is a Wiring tel'- -plane below the plane of

surfaces

28 and 30, to

minal portion 65; base 25 being provided with a substantially rectangular opening 66 to accommodate wiring terminal portion 65, whereby the perforated lower end portion of the latter is exposed below the lower surface of base 25. Base 25 is also preferably provided with a recess 6l to accommodate a lug 68 extending laterally from fiat portion 4l to assist in preventing movement of the latter relatively to the base.

As will be apparent from the foregoing description and the drawings, the combined contact and terminal members, including the respective portions 66 and 61, are merely bent in opposite directions from identical blanks, after shearing thereof to provide the

respective slits

53 and 56, to provide right-hand and left-hand members. By this arrangement only two forms of metal blanks are required for constructing a. double pole switch, thus reducing the cost thereof.

Positioned within recess 26 and adapted to seat upon the

fiat surfaces

28 and 30 in a relation substantially ush with the upper surface of base 25 is a fiat punched insulating plate 69 of substantially circular contour. Plate 69 is provided with a centrally located rectangular opening l0, which is adapted to accommodate with a fairly close fit the downwardly extending arms of actuatingv member 36 (Fig. 3) ,-it being understood that for this purpose opening 'i6 is of slightly greater length than breadth. Plate 69 is provided with an opening or peripheral notch 1i preferably positioned radially of opening 7U, and with the walls of said notch arranged in parallel relation to the walls of opening lil. Notch 'H is adapted in one rotary position of plate 69 to accommodate the double-inclined cam portion 55, whereby arm i9 by its own resiliency is adapted to raise the free end portion 5l thereof out of engagement with the stationary contact portion 65' associated therewith, as-best illustrated in Fig. 4.

Angularly spaced in a clockwise direction from notch li in plate 69 (with reference to Fig. 2) is a rectangular opening l2 which is adapted to accommodate the double-inclined cam portion 56 in the aforementioned rotary position of plate 69, whereby arm 56 by its own resiliency is adapted to raise the free end portion 52 thereof out of Vengagement with the stationary contact portion l@ associated therewith (see Fig. 4). The arrangement is such that cam 55 will not enter opening l2 and cam 56 will not enter notch li in any rotary position of plate 69.

Thus with the switch parts in the open-circuit position thereof shown in Fig. 4 it will be apparent that upon initialclockwise rotation of plate 69 (the latter being restrained against upward displacement by the means hereinafter described) portion 56. Basev 25 is provided with an auxiliary one end wall of notch ll will coabt with cam 55 and one end wall of opening l2 will coact with cam 56 to effect movement of the free ends 5i and 52 into engagement with the stationary contacts respectively associated therewith; and engagement of the movable and stationary contact elements will be maintained during further clockwise movement ,of plate 65, throughout the range of movement provided for shaft 35. As set forth in my application Serial No. 144,891, led May 26, 1937, for electric switches of the slow-make, slowbreak type, it is customary to provide means of known form for limiting the rotary movement of the rheostat shaft to less than 360 degrees.

However, it will be apparent to those skilled in the art, and I desire to have it understood, that the switch mechanism herein disclosed is adapted Aim if desired the length of notch 1I and of opening 12 might be substantially increased, to provide for interruption of the controlled circuit in other rotary positions of plate 59, or'during a greater portion of the rotary movement of the latter. It will be understood that in any event the longitudinal walls of notch 1| and opening 12 may be in the form of arcs parallel to the periphery of plate 59. y Base 25 is preferably provided with a recess 13 concentric with and of smaller diameter than recess 33,-the bottom surface of the base being provided with a countersink or recess 14 (Fig. 3) concentric and commensurate with recess 13, whereby a relatively thin diaphragm 15 is provided. Said diaphragm may be readily removed by broaching to provide rotary clearance for an extension of the switch actuating member,-as shown, for instance, in Fig. 8. Where a single switch is associated with a rheostat 16, asshown in Fig. 3, the diaphragm 15 is permitted to remain intact. In Fig. 3 the rheostat 16 is shown as provided with a stamped sheet metal shell 11 having arms 18 and 19 of arcuate form in cross section which lit into suitable grooves in the base of rheostat 11 and in grooves 80 and 8| in the periphery of base 2.5.

Interposed between rheostat base 16 and switch base 25 is an annular sheet metal member 82, the same having upwardly bent lugs 83 and 8l to engage, and said lugs having openings to accommodate, the aforementioned arms Il and 19. Arranged on opposite sides of member 82 are annular insulating members 85 and 86,-the latter overlying a portion of plate 89 to restrain the same against upward displacement. Arm 80 is provided with a pair of lugs 81 and 88 (Fig. 7) and arm 8l is provided with a lug 89,--said lugs being bent inwardly into corresponding recesses provided in the bottom surface oi' base 25, as indicated in Figs. 3 and 7, to retain the rheostat and switch in assembled relation.

As shown in Fig. 3, an externally threaded hol low metal bushing 98 is attached to shell" to provide for one-hole mounting of the complete device to a panel or the like, as by means of a clamping nut (not shown),-shell 11 being preferably'provided with upstanding lugs 9| and 92 l formed integrally therewith to assist in maintaining parallelism between said shell and the panel to which it is'attached.

The aioredescribed arrangement of the switchparts and theloperating means therefor is such that a slow-make and a slow-break of the controlled circuit is provided upon operation of the rheostat in the usual manner. The aforedescribed switch has a rating or current controlling capacity of 3 amperes at 125 volts A. C.; 1 ampere at 250 volts A. C.; or an alternative rating of 15 amperes at l2 volts D. C.

In the three-way switch illustrated in Figs. 5 and 6 certain o1* the identical parts aforedescribed are employed, and such parts have been given corresponding numerals of reference. However, the pair otcontacts shown at the left-hand side of the insulating base in Fig.' 1 have been omitted dierent form of combined contact from the base of Fig. 5. Within recess 26 at thev lower left-,hand side thereof (Fig. 5) I position a and wiring terminal member,-the latter having a ilat portion 93 which is secured by a rivet 39. Extending upwardly at a right angle to at portion 93 is a portion 94, and extending from the latter in a plane adapted to clear the upper surface 32 of rib 3| (see Fig. 6) is-a hat contact portion 95 which overlies the aforedescribed contact portion 5|. Extending downwardly at a right angle to flat portion 93 is a wiring terminal portion 98, which is perforated as shown to facilitate attachment of a circuit wire. Located in the plane of tlat portion 93 is a lug 91 which assists in preventingV rotary displacement of this combinedcontact and terminal member with respect to base 25.

An insulating cam plate 69 identical with that aforedescribed may be employed in the switch of Figs. 5 and 6, it being understood that only the notch 1l of plate 69 is adapted to function. As shown in Fig. 6, the arrangement is such that in a given rotary position of plate 69, wherein the notch 1| accommodates the double-inclined cam 55, the contact portion 5I is moved upwardly, by the resiliency of arm 49, into engagement with the contact portion 95, whereby a circuit connection is provided between the lower left-hand terminal member of Fig. 5 and the upper right-hand terminal member of this gure. Upon clockwise rotation of plate 69, the end wall of notch 1I cooperates with one side of cam to depress the with stationary contact portion 40, whereby a circuit connection is provided between the two terminal members at the right-hand side of the base in Fig. 5. Such last mentioned circuit con'- nection will of course be maintained throughout the remainder of the clockwise movement of plate 69 by the rheostat shaft, as aforedes'c'iibed, and pending counterclockwise movement of plate 69 to the rotary position thereof illustrated in Fig. 6.

It is to be understood that a plate like 59 (Fig. 2) but omitting the opening 12 therefrommight be employed for the three-way switch of Figs. 5 and 6. For purposes of economy in manufacture, however, I prefer to employ the particular f orm of plate 69 shown in Fig. 2 for each of the various forms of switches illustrated in Figs. 1 to 8, inelusive. In this connection, it may be noted that a single pole on and olf switch may be provided by merely vomitting the contact and

terminal members

95, 96 from the switch of Figs. 5 and 6. Similarly, a single pole switch may be provided by omitting the pair of contact and terminal members from either the left-hand side or the right-hand side of Fig. A1. Withreference to Figs. 1, 2, 5 and 7 it will be noted that I provide base 25 with a pair of diametri'cally opposed

openingsl

98 and 99 which are adapted to accommodate the Shanks of headed rivets or bolts (not shown) aifording an alternative means for attaching the switch base 25 to a suitable support.

In Fig. 7', I have illustrated a so-called threewire switch which is structurally like the double pole switch of Figs. 1 to 4, inclusive,-with the exception that a bus member or conductive strip |09 is secured in position by the rivets 48, whereby the terminal portions of the two movable contact elements of the switch are continuously electrically connected with each other. Inasmlich as only one Wiring terminal portion is requii'ecl for the pair of movable contacts in Fig. 7, I also prefer to shear or cut off that part of. one terminal portion which would project below the lower surface of base 25,-as indicated at 55a in Fig 7. In Fig. 7 I have shown the three wiring terminal .latter to effect engagement of contact portion 5l portions" 59, 4|, 4| bent radially outward within suitable grooves provided in the lower surface of base 25, and in a relationship substantially flush with the latter.

In Fig. 8 I have shown a rheostat 'I6 having a pair of

switch bases

25, 25 mounted in tandem relationship thereto, said parts being retained in assembled relation-as by means of a metal shell l1, having a pair oi arms, one of which is shown at 18a, of the required lengthy and having lugs, such as the

lugs

8i, 80 and 89 aforedescribed, formed integrally with the lower ends thereof. The switch mechanisms carried by the two bases 25 in Fig. 8 may have any desired circuit controlling characteristics,-but for present purposes it may be assumed that the switch 25 adjacent to the rheostat 10 is of the double pole type illustrated in Figs. 1 to 4; whereas the lower switch 25 may be assumed to be of the three-Wire type illustrated in Fig. 7. The cam plate 69 of the upper switch in Fig. 8 is adapted to be driven by the U- shaped metal member 3d aforedescribed,where as the cam member 69 of the lower switch is adapted to be driven by a member of rectangular form in cross section which telescopes into the U-shaped member 3S. I have shown a relatively thin insulating plate |02 interposed between the switch bases 25,-but this insulating plate may' be omitted if desired. Shell 'Ila is also preferably provided with the diametrically opposed upstandingspacing lugs, one of which is shown at 9 laf-and an externally threaded hollow metal bushing 90 is non-rotatably attached to said shell.

In Figs. 9 to 12, inclusive, I have illustrated a modified form of double pole switch, which is of substantially smaller size than that shown in Figs. 1 to 4, inclusive,-as indicated by the actualsize showing in Fig. 9. This modified form of switch comprises a substantially cylindrical insulating base |03 having a substantially cylindrical recess |04 formed therein and opening to the upper surface thereof. Formed integrally with the bottom and side walls of recess |04' and |08, and arranged in said recess on the left-hand side of rib |05 is a second pair of one-piece combined contact and wiring terminal members |09- Members`|0`| and |09 are formed and ||0. rightand left-hand from blanks of identical form; and members |08 and ||0 are likewise formed rightand left-hand from blanks of identical form. Four rivets I of identical form are employed to secure the four combined contact and terminal members to base |03. 4 'Ihe wiring terminal portions |01, |00', |09 and H0 of said members penetrate correspondingly shaped openings in base |03 and are exposed below the lower surface of the latter to facilitate attachment of circuit wires.

'I'he contact portions of members |0`| and |09 comprise resilient arms |01", |09b, the tips |01 -and |09c of which respectively overlie' and are biased outv of engagement with the stationary contact portions of members |08 and ||0. The outer portion of arm |01b is bent upwardly to provide a double-inclined cam |0'|d; and the inner portion of arm |09b is bent upwardly to provide a double-.inclined cam |09". Rotatabl/y positioned within recess |00 is'a at punched cam plate I I2 of circular form; said plate having a notch I3 to accommodate cam |0'ld in one rotary position of said plate, and an opening H4 to accommodate cam |09d in said one rotary position of the plate, as shown in Fig. 9, whereby the contact tips |0'lc and |09c are disengaged from the stationary contacts |08 and ||0.

Base |03, with the switch parts assembled with respect thereto is inserted upwardly into a cylindrical metal shell ||5 having an inwardly extending fiange I |6 which partly overlies the cam plate ||2 to prevent substantial upward displacement of the latter. Flange I I6 is prefer- -ably cut away at two diametrically opposed points, as shown at and ||8y in Fig. 9, to insure proper electrical clearance between the same and cam |01d upon assembly of base |03 in one or the other of two diametrically opposite rotary relationships.

As indicated in Fig. 12 (and as illustrated in the similar arrangement of Fig. 15), the shell ||5 is of slightly less depth than base |03, to provide for lateral bending of the terminal portions trical contact between the same and said shell. Base |03 is provided in its lower surface with a pair of diametrically opposed recesses I|9 and into which the lugs |2| and |22 may be bent, in one or the other of two diametrically opposite rotary positions of. said base and shell, whereby all of the parts are retained in assembled relation.

Shell I I5 is also provided at its upper end with a pair of diametrically opposed upstanding lugs |23 and |23, said lugs being adapted to be accommodated within an opening I 25 (Fig. 11) in the bottom wall |26 of a sheet metal shell |21 adapted to house a rheostat of suitable form,-the switch shell ||5 and the rheostat shell |21 being preferably of substantially the same diameter. Said lugs |23 and |24 are bent outwardly over the bottom wall |26 of the rheostat shell to retain the latter and the switch shell against roltary and longitudinal displacement relatively to each other. Cam plate ||2 is provided (Figs. 9 and 11) with an opening |28 to receive an extension |29 of the operating shaft of the rheostat 'to provide for positive driving of the former by the latter.

The single pole switch illustrated in Figs. 13 to 16 is in general quite similar to the double pole switch of Figs. 9 to 12. Fig. 16 shows the actual size of this single pole switch. In Figs. 13 to 16 the numeral |30 designates a molded insulating base of substantially cylindrical form, said base vhaving a substantially cylindrical recess |3I formed therein and opening to the upper surface thereof. Secured to the bottom wall of re'- cess, as by means of a pair of rivets |32 is a pair of one-piece combined contact and wiring terminal members |33 and |34, member |33 having a relatively long resilient arm |335 of arcuate form the tip |33b of which overlies and is biased away from the relatively short arcuate arm |34a of member |36 which forms the stationary contact of the switch.

Member |33 is provided with a perforated wiring terminal portion |33, and member |34 is provided with a perforated wiring terminal portion IME- said wiring terminal portions being exposed below the lower surface of base |30, as shown in Figs. 15 and 16, and the same being bendable outwardly over said lower surface, to reduce the over-al1 depth of the switch. Arm

|33EL is provided intermediate the length thereof with an upward deformation to provide a doubleinclined cam |33d. The portion of the area of. recess |3| not occupied by members |33 and |34 is in the form of a ledge |35 of irregular contour, said ledge providing a at bearing surface fora cam plate |36, whereby the latter is positioned substantially flush with the upper surface of base |30. Plate |36 is provided with a peripheral notch |36a which is adapted infone rotary position thereof to accommodate cam |33d (Figs. 13 and 15) to permit disengagement of `contact portion |33b from stationary contact portion |34,-said plate |36 acting in all other rotary positions thereof to effect engagement of contactportion |33b with contact portion |34.

Plate |36 is provided with an opening |36b to receive the extension of a rheostat shaft or the like, whereby said plate is positively driven. Because of the symmetrical arrangement of notch |36 with respect to opening |36", it will be understood that plate |36 may be Aassembled with either face thereof. turned toward'recess |3|. Base |30 with the parts thereof in position is inserted upwardly into a cylindrical shell |31,- the latter being provided at its upper end with an inwardly extending flange |31a which overlies an annular portion of plate |36 to prevent substantial upward displacement of the latter. \As shown in Fig. 15, the shell |31 is 'of slightly less depth than base |30, to insure electrical clearance between said shell and the terminal por-- tions |33c and |34b'upon outward bending of the latter.

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

1. In an electric switch, in combination, a molded insulating base having a recess formed therein and opening to the upper surface thereof, said base having a ledge formed integrally therewith and said ledge having a flat face offset upwardly from the bottom wall of said recess, a relatively thin flat insulating plate of substantially circularY contour positioned within said recess and adapted to seat against said flat face in a relation substantially ush with the upper surface of said base, means for restraining said plate against substantial upward displacement, a pair of contacts rigidly'secured to the bottom wall of said recess, one of said contacts comprising a resilient arm the free end of which overlies and is biased'out of engagement with the other contact, said arm having a cam-shaped boss formed upon the upper surface thereof, said plate having an opening formed therein to accommodate said boss in one rotary position of the former, said plate when rotated from said position cooperating with said boss to effect depression of said arm, whereby vthe free end of the latter is engaged with said other contact, and means for effecting rotation of said plate in opposite directions respectively.

2. In an electric switch, in combination, a molded insulating base having a recess formed therein and opening to the upper surface thereof, said base having a ledge formed integrally therewith and said ledge having a flat face offset upwardly from the bottom wall of said recess, a relatively thin flat insulating plate of substantially circular contour positioned within said recess and adapted to seat against said flat face in a relation substantially flush with the upper surface of said base, means comprising a metal supporting member for said-base, said supporting member having a Aflange for restraining said plate against substantial upward displacement, a pair of contacts rigidly secured to the bottom wall of said recess, one of said contacts comprising a resilient arm the free end of which overlies and is biased out of engagement with the other contact, said arm having a cam-shaped boss formed integrally therewith upon the upper surface thereof, said plate having an opening formed therein to accommodate said boss in one rotary position of the former, said plate when rotated from said position cooperating with said boss to effect depression of said arm, whereby the free end of the latter is engaged with said other contact, means for effecting rotation of said plate in opposite directions respectively from and to said one rotary position thereof, said last mentioned means comprising a shaft having a positive driving connection with said plate, and means for limiting rotation of said shaft to an angle of less than 360 degrees.

3. A relatively small slow-make, slow-break switch of the rotary type, said switch comprising a molded insulating base having a recess formed therein and opening to the upper surface thereof, said base having a ledge formed integrally therewith ,and said ledge having a flat face offset relatively thin flat plate of insulating material loosely tting into said recess and adapted to seat against said flat face in a relation substantially flush with the upper surface of said base, a metal shell surrounding said base and having a substantially annular flange overlying a portion of said insulating plate to retain the latter in assembled relation to said basa-said shell having means engaging the lower surface of said base to retain all of said parts in assembled relation, a pair of one-piece combined contact and wiring terminal members rigidly secured to the bottom Wall of said recess at one side of said ledge, each of said members having the wiring terminal portion thereof penetrating said bottom wall and exposed at the lower surface ofsaid base, the contact portion of one of said members comprising a resilient arm the tip of which overlies the contact portion of the other member, said arm having a cam portion formed integrally therewith and normally projecting above the plane of said flat face of the ledge, said insulating plate being provided with an opening 5to accommodate said cam portion in one rotary position of said plate, whereby said contact portions are separated from each other to interrupt the controlled circuit, said insulating plate being adapted when moved from said one position to cooperate with said cam portion and depress said resilient arm, whereby said contact portions are engaged with each other, and manually operable rotatable means having a positive driving engagement with said insulating plate.

4. A switch comprising a molded insulating base having a substantially cylindrical recess formed therein and opening to the upper surface thereof, said base having a ledge formed integrally therewith and said ledge having a flat said recess, a relatively thin at plate of insulating material loosely fitting into said recess and adapted to seat'against saidat face in a relation substantially flush with the upper surface of said base, a metal shell surrounding said base and having a substantially annular ange overlying a vportion of said insulating plate to retain the latter in assembled relation to said base, said shell having means engaging the lower surface of said base to retain all of said parts in assembled relation, a pair of combined contact and wiring terminal members secured to the bottom wall of said recess at one sideofsaid ledge, each of said members having the wiring terminal portion thereof penetrating said bottom Wall and exposed at the lower surface of said base, the contact portion of one of said members comprising a resilient arm the tip of which overlies the contact portion of the other member, said arm having a double-inclined cam portion formed integrally therewith and normally projecting vabove the plane of said at face of the ledge, said insulating plate being provided with an opening to accommodate said cam portion in -one rotary position of said plate, whereby said contact portions are separated from each other to interrupt the controlled circuit, said insulating Aplate being adapted when moved from said one position to cooperate with said cam portion and depress said resilient arm, whereby said contact portions are engaged with each other to complete the controlled circuit, and manually rotatable means having a positive driving engagement with said insulating plate, said last mentioned means including means for limiting the degree of rotation of said insulating plate.

5. A relatively small slow-make, slow-break switch of the rotary-type for control of an alternating current circuit, said switch comprising a molded insulating base having a substantially cylindrical main recess formed therein and opening to the upper surface thereof, said base having a ledge formed integrally with the bottom wall1 of said recess and extending diametrically across the latter to divide the same into a pair of relatively shallow recesses of segmental form, a pair of one-piece combined contact and wiring terminal members rigidly secured to the bottom wall of each segmental recess at opposite ends respectively of the latter, said members having the terminal portions thereof extending downwardly through the respective bottom walls and exposed upon the lower surface of said base, one contact portion of each pair comprising a resilient arm the tip of which overlies and is bent toward the other-contact portion of the pair, said arms being bent upwardly relatively to the bottom walls of the respective segmental recesses whereby said contact portions are normally biased out of engagement with each other, each *of said arms havin a double-inclined cam portion formed inte rally therewith and normally projecting above the plane of the upper surface of said ledge, a flat substantially circular insulating plate adapted torseat against the upper surface of said ledge and being thereby positioned within said main recess in a relation substantially cam portions in another rotary position of said plate whereby said pairs of contact portions are disengaged from each other under the bias of said resilient'arms, means for retaining said plate in rotatably assembled relationship to said base, and manually operable means for eiecting rotation of said plate.

6. A switch comprising a molded insulating base having a recess formed therein and opening to the upper surface thereof, said base having a ledge formed integrally with the bottom Wall of said recess and extending diametrically across the latter to divide the same into a pair of relatively shallow recesses of segmental form, a pair of combined contact and wiring terminal members secured to the bottom wall of each segmental recess at opposite ends respectively oi the latter, said members having the terminal portions thereof extending downwardly through the respective bottom walls and exposed upon the lower surface of said base, one contact portion of each pair comprising a resilient arm the tip of which overlies and is bent toward the other contact portion of the pair, said arms being bent upwardly relatively to the' bottom walls of the respective segmental recesses whereby said contact portions are normally biased out of engagement with each other, each of said arms having a double-inclined cam portion formed integrally therewith and normally projecting above the plane of the upper surface of said ledge, a at insulating plate adapted to seat against the upper surface of said ledge and being thereby positioned within said main recess in a relation substantially ush with the upper surface of said base, the lower surface of said plate being engageable with said cam portions to depress said cams whereby the respective pairs of contact portions are engaged with each other in certain rotary positions of said plate; the lower surface of said plate being interrupted at points spaced angularly from each other to accommodate said cam portions in another rotary position of said plate whereby said pairs of contact portions are disengaged from each other under the bias of said resilient arms, means comprising a metal supporting member for said base, said supporting member having a ange for retaining said plate in rotatably assembled relationship to said base, and means including a manually operable shaft having a positive driving connection with said plate for effecting rotation of the latter, said last mentioned means including means for limiting rotary movement of said plate to an angle .of less than three hundred and sixty degrees.

7. As an article of manufacture, a one-piece combined contact and wiring terminal member for electric switches of the slow-make, slowbreak type, said member consisting of a-punched and stamped sheet metal piece, said piece having a perforated intermediate portion to be rigidly secured atwise to a suitable insulating support, a`perforated wiring terminal portion bent downwardly at substantially a right angle to said intermediate portion for exposure of the former at the lower surface of the support, and a resilient arm of arcuate contour extending laterally and upwardly from said intermediate portion at a predetermined angle thereto, said arm having a slit formed therein intermediate the ends thereof, and a portion of said arm at one side of said slit being bent upwardly to provide a doubleinclined cam surface for cooperation with an actuating cam member of suitable form.

8. As an article of manufacture, a punched sheet metal blank adapted for formation thereof into a right-hand or a left-hand combined contact and wiring terminal member for a rotary electric switch of the slow-make, slow-break type, said blank comprising an arcuate portion one end of which is provided with an opening to accommodate a securing element of suitable form, a perforated lateral extension at said end which is bendable in one direction or the other at substantially a right angle thereto to provide a wiring terminal, said arcuate portion being bendable adjacent to said end thereof in a direction opposite to the direction of bending of said terminal portion, whereby an upwardly angled contact arm is provided upon securement of the member 'to a suitable support, said arm'having a longitudinally extending slit formed intermediate the ends thereof, and the material on one side or the other of the slit being bendable upwardly to provide a double-inclined cam.

9. As an article of manufacture, a punched sheet metal blank adapted for formation thereof into a right-hand or a left-hand combined contact and wiring terminal member for a rotary electric switch of the slow-make, slow-break type, said blank comprising an arcuate portion one end of which is provided with an opening to accommodate a securing element of suitable form, a perforated lateral extension at said end which is bendable in one direction or the other at substantially a right angle thereto to provide a wiring terminal, said arcuate portion being bendable adjacent to said end thereof` in a direction opposite to the direction of bending of said terminal portion, whereby an upwardly angled contact arm is provided upon securement of the member to a suitable support, said arm having a longitudinally extending slit formed intermediate the ends thereof, the material on one side or the other of the slit being bendable upwardly to provide a, double-inclined cam, and said blank having an integral positioning lug located in the plane of the rst mentioned end thereof for cooperation with shoulders formed on the aforementioned support. t

10. As anarticle of manufacture, a punched sheet metal blank adapted for formation thereof into a right-hand or va left-hand combined contact and wiring terminal member for a rotary electric switch oi the slow-make, slow-break type, said blank comprising an arcuate portion one end of which is provided with an opening to accommodate a securing -element of suitable' form, a perforated lat`eral extension at said end one direction or the other at substantially a right angle thereto to provide a wiring terminal, said arcuate portion being bendable adjacent to said end thereof in a direction opposite to the direction of bending of said terminal portion, whereby an upwardly angled contact arm is provided upon securement of the member to a suitable support, said arm having a longitudinally extending slit formed intermediate the ends thereof, and the material on one side or the other of the slit being bendable upwardly to provide a double-inclined cam, the arrangement being such that said cams when formed for right-hand or left-hand members are spaced an appreciable distance from the arcuate center lines of the respective contact arms.

11. In a switch of the character described, in combination, a molded insulating base having a substantially cylindrical recess formed therein vand opening to the upper surface thereof, a pair of combined contact and wiring terminal memment with the contact portion of which the contact portion of said resilient arm is adapted to move under said bias, said resilient arm having a double-inclined cam upon the upper surface thereof, a relatively thin flat plate of insulating material positioned and retained within said recess in a relation substantially flush with the upper surface of the latter, said plate having a central angular opening to provide a positive driving connection between the same and a'rotatable operating member of suitable form, said plate having an eccentric opening formed therein to accommodate said cam in a given rotary position of said plate to provide for movement of said arm to one extreme position thereof under its bias, and said plate cooperating with said cam to effect movement of said resilient arm to and retention thereof in its other extreme position against its -bias upon rotary movement of said plate from the position thereof aforementioned. N

12. In combination, a rotatable shaft having an inverted U-shaped sheet metal extension member rigidly attached to the end thereof for rotation therewith, a switch mechanism comprising a rotatable cam member having a rectangular opening formedtherein to accommodate said extension for rotation thereby, a molded insulating base having a recess within which said cam member is rotatably seated, a second switch 0f the aforementioned character the insulating base of which is adapted to seat in tandem relation against said rst mentioned base, a member of rectangular cross section telescoped into the open end of said U-shaped member and having a positi' z driving connection with the cam member of said second switch, said switch bases having substantially identical peripheral dimensions, a stamped sheet metal housing member having opposed arms insertabledownwardly over said switch bases and interlocked with each of the same to prevent relative rotation thereof, said opposed arms having integral lugs bendable inwardly over the lower surface of said second switch base to retain all of said parts in amembled relation, each of said switches having at least one pair of contacts resiliently biased out of engagement with each other, and the cam members of said switches cooperating with said pairs of contacts to effect engagement and permit disengagement thereof in different rotary positions respectively of said shaft.

13. In an electric switch of the rotary type, in combination, an insulating base, a pair of combined contact and terminal members rigidly secured to said base, the contact portions of said members being positioned upon one surface of said base and the terminal portions of said members penetrating said base and being exposed at the opposite surface of the latter, the contact portion of one of said members comprising a resilient arm the free end of which overlies and is biased out of engagement with the contact portion of the other member, said arm having a double-inclined cam upon the upper surface thereof, a relatively thin flat insulating plate positioned in a plane below the normal plane of said c am, said plate having an opening formed therein to accommodate said cam in one rotary position of said plate, to permit disengagement of thefree end of said resilient arm from the contact portion of the other member, said plate when rotated from said position cooperating with said cam to eiect depression of said resilient arm, whereby the free end of the latter is engaged with the contact portion of the other member, means overlying said insulating plate to prevent substantial upward displacement of the latter,

l and-manually operable means, including a shaft having a driving connection with lsaid insulating plate, for eiecting rotation of the latter in a given direction from and in the opposite direction to said one rotary position thereof to respectively make and break the circuit controlled by the gagement with the walls of said opening, a plurality of pairs of contacts, one contact of each pair being biased by its own resiliency away from but forcibly movable into engagement with the other contact of said pair, each of said resilient movable contacts having a cam portion on the upper surface thereof, said plate being adapted to overlie said resilient movable contacts and being constrained to move in a given plane with respect to the latter, said plate having two arcuate openings formed therein concentric to and spaced different radial distances from said rst mentioned opening and located in angularly spaced relation to each other, said last mentioned openings being adapted to accommodate the cam portions on said resilient movable contacts in one rotary position of said plate to permit disengagement of said movable contacts from the other contacts aforementioned, and said plate in all other .rotary positions thereof acting against said cam portions to etect engagement of said movable contacts with the other contacts respectively.

GEORGE J. MEUER.