US2617903A - Electric switch - Google Patents

Description

NOV. 11, 1952 KQENIG 2,617,903

ELECTRIC SWITCH Filed Feb. 12, 1949 4 Sheets-Sheet l M. F. KOENIG ELECTRIC SWITCH Nov. 11, 1952 4 Sheets-Sheet 2 Filed Feb. 12, 1949 as a6 2,6 as

M. F. KOENIG ELECTRIC SWITCH Nov. 11, 1952 4 Sheets-Sheet 3 Filed Feb. 12, 1949 NOV. 11, 1952 KAOENIG 4 2,617,903

ELECTRIC S WITCH Filed Feb. 12, 1949 4 Sheets-Sheet 4 Patented Nov. 11, 1952- ELECTRIC SWITCH Martin F. Koenig, Milwaukee, Wis., assignor to Cutler-Hammer, Inc., Milwaukee, Wis., a corporation of Delaware Application February 12, 1949, Serial No. 76,150

9 Claims.

This invention relates to improvements in electric switches, and more particularly to improvements in enclosed, quick make and break switches of the front-side operated type.

A primary objective of the invention is to generally improve the details of construction and assembly of the parts and the operation of switches of the aforementioned character.

Another object is to provide a compact switch of the aforementioned character wherein the fuses are mounted over the switch parts thus tending to reduce the size of the switch and make it more compact.

Another object is to provide a switch of the front-side operated type wherein a rotary motion of a snap action operating mechanism is translated through a cam surface to move a contact carrying plunger in reciprocal movement at a right angle to the plane of rotary motion.

Another object is to provide a plunger type switch wherein a plurality of switch units may be placed in tandem for joint operation through interconnection of their respective plungers.

Another object is to provide an improved type of individual switch unit in which arcing of the contacts is confined to a substantially enclosed chamber.

Other objects and advantages of the invention will hereinafter appear. v

The accompanying drawings illustrate a preferred embodiment of the invention, it being understood that the embodiment illustrated is susceptible of modification in respect of certain structural detailsthereof without departing from the spirit'and scope of the invention as defined by the appended claims.

In the drawings,

Figure 1 is a somewhat reduced top plan View of a three-pole, front-side operated switch of the fused type; the switch being shown in the off position and with a fragment of the open covertwo of the fuses, an insulating cover of one of the switch units, and a cover of one of the complementary fuse clamp assemblies being omitted for clarity of illustration of the parts of the switch.

Fig. 2 is a sectional view on the broken line 2-2 of Fig. 1, with the cover closed, and fixed stops shown in dotted lines.

Fig. 3 is a somewhat reduced side elevation of the guard for the operating mechanism with the movable stops shown in dotted lines.

Fig. 4 is a sectional view similar to Fig. 2, but with the switch operating parts in the on position.

Fig. 5 is a sectional view on the broken line 55 of Fig. 4, the switch operating parts being shown in the on position.

Fig. 6 is a fragmentary elevation view of the details of the switch operating mechanism, similar to that shown in Fig. 5, but with the parts shown in the off position.

Fig. '7 is a top plan view of the one of the switch units adjacent the switch operating mechanism, the cover being omitted but with certain of the depending portions of the cover being shown in section, and the switch parts being shown in the on positiona developed view of the cam portion of the switch operating mecha nism also being shown in dotted lines, and a fragment of the next adjacent switch unit being shown to illustrate the interrelation of the switch units.

v Fi 8 is a sectional view on the broken line 8-8 of Fig. '1, but with the switch unit cover and fuse clamp in place and a portion of the mounting plate and back wall of the casing being shown; the cam portion of the switch operating mechanism being shown in dotted lines.

Fig. 9 is a sectional view on the broken line 9-9 of Fig. l, but with the switch Darts shown in the on position.

Fig. 10 is a sectional view on the broken line |0--Hl of Fig. '7, but with the cover member in assembled position, the fuse clamp being omitted.

Referring first to Figs. 1 to 6 inclusive, the numeral I0 designates the body portion of a sheet metal casing or enclosure of substantially the same construction as that illustrated in the patent to Millermaster et al. No. 2,325,697 to which reference is made for the details of construction thereof. Casing [0 may be provided with suitable knockouts as shown for example at H, and mounting holes as shown at l2. A cover I3 is removably hinged to casing I0 as for example at M in the manner disclosed in the aforementioned patent to Millermaster, the switch preferably embodying as a whole the ornamental design disclosed and claimed in Design Patent No. 126,465, granted April 8, 1941, to Millermaster and Stevens. A manually releasable cover latch I5 of the type disclosed in the aforementioned patent to Millermaster et al. No. 2,325,697 and more fully described therein is also provided.

Formed integrally with one side wall of casing I0 and bent inwardly at a right angle thereto is a flange portion 16, having an opening I6 Said opening l6 is of elongated rectangular contour to accommodate and to provide oscilvabovementioned latory clearance for a flat, substantially circular plate-like portion Il (Fig. 2' and Fig. 4) of a die cast metal operating lever I1, said lever having a handle or hand grip portion 17 preferably of the type described in the aforementioned Millermaster Patent No. 2,325,697. As best illustrated in Fig. 1, there is rigidly attached, as by spot welding, to the one side wall of casing H), a metal member having a portion l3 and integral portions lB and 18 bent inwardly at a right angle to portion I8 and an integral intermediate portion [8 offset slightly inwardly from and extending upwardly in a plane parallel to said portion I8 Portion lt is provided with two merging circular openings I 8 (Fig. 2) for cooperation with a peripheral notch l l in platelike portion I! of operating lever l7 thereby to accommodate the hasps of padlocks for locking the switch in the off position. Portion lt is also provided with a circular opening I 8 (Fig. 5) for registration with. circular openings H and H (Figs.v 2 and 4) in plate-like portion llto enable padlocking of the operating lever in the on and off positions respectively.

Plate-like portion H also has a peripheral, arcuate; ca-m like extension H (Figs. 2 and. 4) for engagement with a latch member 19 of. the type disclosed in the aforementionedMillermaster Patent No. 2,325,697 to which reference is made for the. details of construction andoperation thereof. Latch member I9 is adapted to hook a lug li on cover 13. The arrangement of portion [1 and latch member. I9 is such. that. the switch operating lever ll cannot be moved to the on. position when the cover: !3 is open, nor can the cover l3 be opened unless. the operating lever H- is in. the oiT position. However order to provide for manual release of the aforedescribed cover interlock afiorded by member. I.9- when the switch is in the on. position, said member is preferably provided with a substantially rec.- tangular opening. or slot 19* (adapted to. accommodate the. end. of screw driver or the like), the side wallv of easing Hi being provided with a registering opening as shown in dotted lines in Figs. 2. and 4, the operation of saidmanual release being more particularly described inthe Millermaster Patent No. 2,325,697.

Lever ll (Fig. 5-) is piv-otally supported upon the inner surfacev of the side. wall of casing it as by means of a pin 29,. one end of which has. a

flange portion 29 said pin having a relatively ,long intermediate shank portion 23 a reduced intermediate shank portion. 2 9. for insertion through a correspondingly shaped opening in lever I7, and a still further reduced portion 29.

for insertion through a correspondingly shaped opening in the side wall of easing E9, pin 28. be.- ing upset over the outer-surface of said side wall as: at 25 The flange portion 25* abuts the inner surface of a sheet metal housing member or guard 21 which substantially encloses all of the pin 29. Lever i7 is provided with a. substantially circular portion H offset slightly outward for insertion with aclose fit through. a. corresponding opening in spring washer 22 to support the latter when in assembled relation.

The aforementioned guard member 2! (Fig. 3) has flanges 2| and 2| c at opposite ends thereof which are rigidly attached to the side wall of casing id, as by means of rivets 23 (Figs. 2 and 3). Guard 2! extends from the bottom wall of easing H] to substantially meet the inner edge of flange it of casing Ill. Guard 2| is further provided with 2. preferably rectangular opening 2 i and an outwardly extending lug 2 l e the purposes of which will be. hereinafter described. Guard member 2! is also provided with two pairs of stops 2i, ZI 2t and 2i the purposes of which will become apparent hereinafter, said stops being formed by punching and forming inwardly portions of guard 2| to form a cup shaped structure as shown best in Fig. 3.

Intermediate shank portion 28 of pin 20 is fitted with a sleeve-like bearing 24 (Fig. 5) one end of which is flanged as at 24 said flange. abutting flange portion 25* of pin. 2%). The outer end of bearing 24 is reduced as at 24 for insertion through a corresponding opening in a fiat. sheet metal cam operating member 25, and isspun over the outer surface of the latter to rigidly secure the parts together. A shallow annular recess 11* is formed in. plate-like portion I l of. lever. H to provide clearance for the spunover. end. 24 of bearing 24.

Said cam operating member. 25 is generally of arcuate form and has an armor extension 25 to which is pivotally connected one end. of a plunger 25, as by means of a rivet or pin 27 The other end 26* of plunger 2b is afiorded sliding and. oscillatory clearance. (Figs. 2 and 4). by a slot 2 l in guard 2 l. Plunger Z6 is provided with a slot 6. which is adapted to accommodate the Shani-sofa pin 28 which penetratesalined openings. in the side wall of casing It and guard. 2t (Fig. 1 and is headed at each end to'retain the sameirrposition. Pin 28 thus acts to perrnit both reciprocatory and oscillatory movement of plunger 26. with respect to slot 2H.

Plunger 26 is surrounded by a relatively heavy compression. spring 29, one end of which abuts pin 28 and the other end of which abuts shoulders 25 formed on said'plunger 2t; wherefore upon'going over center spring 29 acts to efiect snap movement of cam operating member 25 to one or the other of its extreme positions, respectively shown in Figs. 2 and 4. Said member 25 is provided with a pair of angularly spaced integral lugs' 25' and 25, bent inwardly at substantially right angles to the plane of the major portion thereof; the inner edges of which are adaptedfor alternate engage.- ment with the side edges of a cam. member 3D to provide a lost motion connection between members 25 and St for a purpose that will hereinafter appear, while the outer edges of said lugs are adapted to alternately engage fixed stops 2 N and Zl of guard 25 respectively. (Said fixed stops are shown in dotted lines in Figs. 2 and 4- to indicate the aforedescribed relationship of the same with. said lugs 25 and 25.)

Cam operating member 25 is further provided with. a rigidly attached outwardly extending pin 25 which pin extends into an arcuate slot ll in plate-like portion l'i of lever I? to provide a lost motion connection therewith. Member 25 is alsoprovided with a pair of arcuate slots25 and 25 (Figs. 2 and 4) in each of which is seated a ball bearing, 3 l and 31 respectively; said bearings being confined within slots 25 and 25 be ing trapped between the inner surface of cam member 33 and a bearing plate 32 (Fig. 5). Bearing plate '32 is preferably a relatively thin sheet metal member having an annular portion 32 (shown in doted lines in Figs. 2 and 4) and a wing-like arcuate extension 32, the whole of said heating plate being closely fitted into a shallow recess H of corresponding shape in plate-like portion 11* of lever ll. Said bearing plate 32 provides a bearing surface for ball bearings 3| and 3| thus to facilitate substantially frictionless movement of cam member 30.

Cam member 30 comprises a fiat metal member of the contour best illustrated in Figs. 2 and 4, having a body portion 30 and an arcuate winglike" extension 30 the latter providing a cam surface as will hereinafter be described. The body portion 30 has a circular opening having annpstanding collar 33 (Fig. 5), pin 20 and sleeve bearing 24 being inserted through the aforementioned circular opening to provide pivotal support for cam member 30, collar closely fitting bearing 24, the outer edge of collar 30 abutting the inner surface of flange 24 of bearing24. Body portion 30 is further provided with anintegral arcuate lug 3|! bent outwardly at approximately a right angle to the body portion bathe former being in substantially the same I plane as body portion 3|] (Fig. 6), while the latter lies in a plane parallel to but offset inwaiidly from that of body portion 30* (Fig. 5), andan-intermediate sloping portion 30 connectingsurface 30 to surface 3|) and extension 30 thdrelationship of the foregoing portions being such as-to present an inclined cam surface to a roller 34 of plunger 33 as cam member 30 is moved from one to the other of its extreme positio'ns, this relationship being best illustrated in Figfi'l wherein the dotted lines represent a developed view of the cam surface of member 30. A slight upstanding ridge 30 the purpose of which will hereinafter be described, is also provided at the'juncture of surfaces 3|! and 30% Contact actuator or plunger 33 is preferably a substantially rectangular bar of insulating material and is notched at one end as at 33- to provide clearance for a metal roller 34, which is mentioned notch 33 and through a centrally located opening in roller 34, said pin being headed on"both ends, thereby to retain the same in assembled relation with plunger 33. Said plunger 33jis biased by means to be hereinafter described to j' extend through a clearance opening 2| in guard member 2| to maintain roller 34 in contact at all times with the cam surface of cam member 30, lug 2| affording an alinement bearfor plunger 33.

The operation of the aforedescribed snap action switch operating mechanism is as follows: Assuming the parts to be in the off position as illustrated in Fig. 2, raising of handle of lever |lf results in counter-clockwise rotation of platelike portion l1, it being pivotally supported on the side wall of casing In by pin 20. A certain amount of lost motion between portions l'!" and cam operating member 25 being afforded by the interconnection provided by pin 25 and slot cam operating member 25 is not actuated until pin 25 engages the end of slot I! in lever IT. The lost motion having been taken up, further upward movement of handle and hence further counter-clockwise movement of portion IT'- causes cam operating member 25 to similarly move in a. counter-clockwise direction, it also being pivotally supported by pin 20. Movement of cam operating member 25 is against the biasing afforded by compression spring 29 and causes an upward and clockwise movement of plunger 26 relative to its pivotal support, pin 28. A second increment of lost motion occurs before lug 25 engages notch 33 of cam member 30. This second increment of lost motion having been taken up, further upward movement of handle causes further counter-clockwise movement of portion ll of lever ll, cam operating member 25, and cam member 3|! simultaneously, the last mentioned movement resulting in downward passage of surface 30 of cam 30 relative to plunger 33, its roller 34 having rolled alon surface 30 Upward movement of handle thus far has not resulted in lateral displacement of contact plunger 33 until roller 34 engages ridge 30 on cam member 30, the latter being provided to prevent further downward movement of cam 30 by virtue of its own weight. At this moment plunger 26 is carried over center, lever I1 is disengaged from the other moving parts by virtue of the aforementioned lost motion connection, pin 25 and slot H while compression spring 23 propels cam operating member 25, lug 25 of which in turn carries cam member 30, in further counter-clockwise movement at great speed, cam surfaces 3|] and 30 passing rapidly by roller 34, the offset surface 30 permitting plunger 33 and its roller 34 to be laterally displaced outwardly with great rapidity. Movement of cam operating member 25 is ultimately halted by engagement of lug 25 with fixed stop 2| on guard 2|, the aforementioned lost motion connection permitting further movement of cam 30, the latter being stopped ultimately by virtue of lug 3|) engaging fixed stop 2| Finally the movement of lever I1 is stopped when handle portion engages member |8 on casing 0.

In moving from the on position as illustrated in Fig. 4 to the off position illustrated in Fig. 2 the operation is substantially the reverse. Downward movement of handle of lever results in clockwise rotation of plate-like portion H Upon traversing the distance afforded by the lost motion connection, slot I1 and pin 25, cam operating member 25 is picked up and likewise rotated in a clockwise direction, lug 25 finally engaging notch 3|] of cam member 30 to cause the latter also to rotate in a clockwise direction. This latter motion results in passage of surface 30 along roller 34 of plunger 33. Plunger 26 having reached center lever 11 is disengaged from the other moving parts, and spring 29 suddenly and with great force propels cam operating member 25, lug 25 in turn carrying cam 30, in further clockwise rotation at great speed. The rapid movement of cam 33 along roller 34 results in a sudden lateral displacement of plunger 33 to the left as roller 34 rides up onto surface 3|) of cam 3|]. Movement of cam 30 is finally halted when lug 3|] engages fixed stop 2| on guard 2| while movement of cam operating member '25 ceases-when lug 25 strikes fixed stop 2], and lever l? is stopped when its handle li engages member I 8 on casing l0.

It. will be apparent that the operation just described affords a snap action, quick make and break operation that is substantially immune to "teasing inasmuch as all manual control over the moving parts is lost the moment plunger 26 and its spring 29 go over center.

Having described the snap action mechanism reference will now be made to Fig. 1 wherein is illustrated a switch having three individual switch units 36, though it is to be understood that any number of said units might be employed. Each of the switch units 36 has a separate complementary fuse clamp assembly 31 each of the latter including an insulating base properly alined with switch units 36 and spaced therefrom, this arrangement minimizing the cost and weight thereof, though it is to be understood that if desired a single integral base of proper size might be employed. The fuse clamp assemblies 37 are identical, as also are the three switch units 35 except as to their contact carrying plungers as will hereinafter appear. The switch units 36 and complementary fuse clamp assemblies 3? are individually removably attached to a common mounting plate 38 as by screws 39.-

Mounting plate 38 is formed of sheet metal and is provided with flanged portions 35 at opposite side edges thereof, said flanges being adapted to engage the back wall of easing i5 and provide for removable attachment of mounting plate 3.8 to said back wall of casing It as will hereinafter be described. Flange portions 38 are provided with a pair of edge notches 33 to accommodate respectively a pair of positioning lugs formed integrally with and extending upwardly from the back wall of casing Ill. One of flange portions 38 is further provided with a pair of edge notches 38 to accommodate a pair of screws 40 for removably attaching said flange portion to the back wall of casing Hi; while the opposite flange portion 38 is provided with a pair of humps 4| formed integrally therewith, each of which has an opening to accommodate a selfretaining screw 42 of well known structure for removably attaching said flange portion of mounting plate 38 to the back wall of casing it. From the foregoing it will be apparent that the entire switch mechanism may be readily and easily removed from the casing i by merely loosening screws 45 and 42 and lifting mounting plate 38 from the casing, all the other switch parts being being attached to mounting plate Baby screws 44.

Referring primarly to Figs. '7 to inclusive, the individual switch units 86 include a substantially rectangular base 45 molded from insulating, arc resisting material. Insulating base 65 is provided at opposite ends thereof with a pair '1 of integrally formed substantially circular peripheral projections i5 which projections extend upwardly from the bottom plane of said base, said proections 45 being countersunk to accommodate screws 39 for attachment of the base to mounting plate 38 .as hereinbefore described" integrally formed preferably circular positioning lug (Fig. 8) adapted to cooperate with a core responding opening in plate 38 is provided on the bottom surface of base 45. Base 45 is also pro,- vided at opposite ends thereof witha pair of smaller, semicircular, integrally formed projections 45 which extend downwardly a substantial distance from the plane of the top surface of the aforementioned base, said last mentioned projections each being provided with an internally threaded metal insert 45 rigidly attached thereto for accommodating a cover screw, as will hereinafter be described.

Insulating base 45 is further provided withja pair of recesses 45, 45*, of the contour best 11-; lustrated in Fig. 7, extending downwardly a sub-e stantial distance from the top surface thereof, said recesses 45 45 serving as contact chambers, as will hereinafter become apparent. Oriel side wall. of each of the recesses 45, 45 has opening into the same a smaller substantially rectangular recess 45 (Fig. 1 and-Fig. 10) extending downwardly from the top surface of base 45, the rounded bottom walls of said recesses 45 each serving to support the end of a spring as'will hereinafter appear. 2 Within each of the recesses 45, 45 and-extending upwardly from the bottom wall and outwardly from the aforementioned side wall thereof is an integrally formed shoulder 41 of the contour best illustrated in Figs. 7 and 10; said shoul ders being formed to cooperate with a depend,- ing portion of a cover member to be hereinafter described to afford rather close clearance for a bridging contactor 48 as the switch is moved to the "ofi position. Provision of said shoulder 41 and its aforementioned mating member reduces the size of the contact chamber and tends to confine any are which may be present on opening or closure of the contacts as will hereinafter be described.

The, upper surface of base 45 is further provided with a shallow recess 45 to accommodate the substantially rectangular flat intermediate portion 49 of a combination stationary contact and terminal lug member 49, the terminal lug portion, 49 of said member being supported by a substantially rectangular integrally formed projection 45 extending upwardly a substantial distance from the bottom plane of base 45. The terminal lug illustrated is of the type disclosed in the patent to Millermaster No. 2,193,202" to which reference "is made forthe details of construction thereof. Said terminal lug includes a hollow metal member of substantially rec tangular form in transverse cross section, which member is provided with a relatively large tapped opening to accommodate the threaded shank of a screw 5|. Intermediate portion 49 serving as a strip metal conductor or bus is preferably rigidly attached to base 45 as by rivets 52. An integral portion 49 of member 49 is bent downwardly at approximately a right angle to inter-- mediate portion 49 to depend into recess 45, the lower end of said portion 49 being provided with a suitable contact surface 49 preferably circular, thus to serve as a stationary contact for the switch unit. 7 r

The aforementioned bridging contactor 413 com prises a flat, substantially rectangular metal bar having a pair of preferably circular contact surfaces 48 projecting forwardly therefrom at each end thereof, said contact surfaces being adapted to engage contact surfaceli) and another'stawhich it is adapted-to cooperate.

tionary contact to be hereinafter described respectively. The back surface of contactor 48 is provided near each end thereof with a preferably circular integrally formed lug 48, each for insertion into the end of a helical compression spring 53 for support thereof, the opposite end of each spring being supported by the bottom walls of recesses 45 respectively as hereinbefore described, said springs 53 thus serving to bias bridging contactor 48 to a closed position with respect to its cooperating stationary contacts.

Bridging contactor 48 is supported as a whole by the bottom wall of a rectangular notch 33 of plunger 33, said notch extending downwardly from the top surface of plunger 33, and being of suincient width to allow contactor 48 considerable play. The aforementioned bottom wall of notch 33 is provided with an integrally formed transverse rib or ridge 33 to interlock with a corresponding notch 48 formed in the bottom edge of contactor 48 as best shown in Figs. 9 and 10, said interlocking preventing lateral displace- .ment of contactor 48 relative to plunger 33.

Plunger 33 is adapted for sliding reciprocal movement in a substantially rectangular channel 45 extending through base 45 from side to side thereof, the bottom wall of said channel being provided with a substantially rectangular recess 45 (Figs. 8 and 9) for accommodating a helical compression spring 54. As best shown in Fig. 8, 9

erably of such dimensions as to closely fit within recess 45 for reciprocal movement therein. Spring 54 is positioned so that one end thereof abuts the end wall of recess 45 while the other end of said spring abuts a side edge of said lug 33 thus tending to bias plunger 33 to the closed position of the switch.

Switch unit 36 is also provided with a flat cover member 55 of arc resisting insulating material, said cover member being of substantially the same size and peripheral contour as that of base 45 with Extending outwardly from each end of cover member 55 are a pair of integrally formed semi-circular extensions 55* alined with and adapted to cooperate with the corresponding extensions 45 of base 45, said extensions 55 each having a centrally located, preferably circular opening 55 to accommodate a screw 56 for insertion therethrough and threading into the alined openings in metal inserts 46 hereinbefore described, thus to provide for removable attachment of cover member 55 to base 45.

As best shown in Fig. 10, cover member 55 is further provided with a pair of integrally formed depending portions 55 so proportioned and alined as to fit downwardly into recesses 45, 45 each to mate with shoulders 41 hereinbefore described and each having an integral extension 55 fitting into recess 45 (Fig. '7) to interlock cover member 55 with base 45 and prevent upward displacement of springs 53 within recesses 45 (Fig. The bottom surface of cover member 55 is also provided with an integrally formed substantially rectangular depending portion 55 extending the entire width thereof, said portion 55 being so proportioned and alined with respect to base 45 as to extend downwardly into channel 45 to form an upper wall thereof and being adapted to closely fit the upper surface of plunger 33 and prevent upward displacement of the latter. Said portion 55 and cover member 55 are recessed as at 55 to provide clearance for a pair of rivets 51, the shanks of which are inserted through corresponding and alined openings in cover member 55 and a bus or conducting member 58, said rivets being upset over the top surface of bus 58 to rigidly secure the same to the top surface of cover member 55.

Bus or conducting member 58 is a flat metal plate of the size and shape best shown in Fig., 1, it being constructed so as to substantially cover the top surface of cover member 55, the latter being provided with an upstanding integrally formed positioning lug 55 for cooperation with the aforementioned rivets 51 in preventing lateral displacement of bus 58. Formed integrally with bus 58 is a depending portion 58 extending downwardly at substantially a right angle thereto through a corresponding opening in cover member 55 and into recess 45 of base 45 (Figs. 1 and 9). Said portion 58 is provided at its lower end with a preferably circular contact surface 58 thus forming a stationary contact for cooperation with one of the contact surfaces 48 on bridging contactor 48 as hereinbefore described (Fig, 7).

Rigidly attached to bus 58 as by means of a screw 59 is a fuse clamp 60, cover member 55 being suitably recessed as at 55 to provide clearance for the head of screw 59 (Fig. 9) Said fuse clamp 60 is illustrated as being of the knife blade type disclosed in the patent to Millermaster No. 2,213,284, though it is to be under stood that any other suitable type of fuse clamp might be employed.

Each of the ends of bus 58 are upturned throughout the width thereof as at 58 to preventrelative rotary movement of fuse clamp 60 and bus 58, the upturned end 58 being provided to perform that function should it be found desirable to position fuse clamp 60 adjacent there to to accommodate a different size fuse.

As will be apparent from the foregoing description, the inter-relation of base 45, cover member 55 and plunger 33 provides two substantially closed chambers as indicated by recesses 45 and 45 respectively, each containing a stationary contact 43 and 58 respectively to be bridged by bridging contactor 48 carried by plunger 33 as hereinbefore described. Each of the aforementioned contact chambers is further provided with an L-shaped metal member 6|, Gi respectively (Figs. 7 and 9) to serve as a blowout or means to aid extinguishing of any arc which may be developed on opening or closure of the contacts. Said blowouts are each adapted to abut the respective side walls of recesses 45, 45, respectively, and each are rigidly attached to the bottom wall of the respective recess as by means of rivets 62, 62, the bottom surface of base 45 being suitably recessed as at 63, 63, to provide access to said rivets, said recesses being subsequently filled with wax or other suitable insulating material as shown at 64*, 54 (Fig. 9). Base 45 is also provided with other irregularly shaped recesses extending upwardly from the bottom surface thereof, as for example at 45 and 45 (Figs. 9 and 10), the purpose of which is primarily to reduce the weight of base 45.

The operation of the switch units 35 is as follows: Assuming the parts to be in the closed position as shown in Fig. '7, electrical conductivity is afforded from terminal lug 50 and conducting strip 49 to stationary contact portion 49 thence through bridging contactor 48 to stationary contact 58 bus 58 to fuse clampBO. In this osition springs 53 hold bridging contactor 48 firmly against its cooperating stationary contact while spring .54 urges plunger 33 to its extreme right position. As hereinbefore described rotary move.- ment of cam member 30 results in .reciprocal linear movement of plunger 33:; that is, to :the left'from the assumed position, against the bias afforded by spring 54. Movement of plunger 33'to the left, after a certain amount of lost motion afforded by the play in the connection between bridging contactor .48 and plunger .33 due to :the width of notch 33 ,,results in movement of bridging :contactor 43 to the left against the bias of springs 53, thusbreaking the circuit at two'points i. e.,'where contact surfaces 28* contact stationary surfaces 49 and 158 respectively. Closure .of :the switch is accomplished in substantially .the reverse manner, rotary movement of cam member 30 permitting plunger .33 'to slide ito-theright in response :to the :bias afforded by springs .53 and 54, while contactor 48, due to the bias of springs 53, bridges the aforementioned .stationary .contacts, thus completing :the circuit.

As previously mentioned, the construction of each of the switch .units .36 is identical except as to thereciprocating plunger, which in the unit adjacent :to'the snap action mechanism takes the form :of plunger .33 to cooperate with cam :member 30. .In each of the other "Switch units :the plunger takes-the form best illustrated in Fig. ,1 at I33. .Plunger I33 is isimila-rin .construction'to plunger 33 except that one end thereof instead of being provided with a rolleris::reduced in size as at 1.33 to abut thebeveled-end ;of the plunger of the next adjacent switch'unit, this relationship being best-shown inFig. 7,. Said-reduced portion I33, is provided with a plurality ,of radially extendingrfins i133", the purpose of whichistoincrease :the over-surface electrical clearance between live partsof adjacent switch units. :It will be apparent from the foregoing that {the operation of :each of the switch units is similar, and furtherthat the switch :unitsare operatedgjointly by thesnap action mechanism hereinbefore ;described by virtueof the interconnection of the individual switch units through the 'alinjed :and substantially abutting end to :end relation of their respectiveplungers. It willialso-be'appaa ent that since each of the switchunits is individually removably attached :to mounting plate '38 and may be added orremovedwithout disturbance of the other unitsa high'degreeof flexibility in the number of poles provided in the switch is afforded. Moreover, it-wil1be observed from the aforedescribed structurethat the bridging contactors 48 and/or their associated plungers .may, upon removal of the cover member --55 of the particular switch unit, 'be removed and/or replaced without disturbing adjacent switchunits, the end to end abutting relationship .of the respective plungers and the aforedescribed removable attachment of such bridging contactor with its associated plunger permitting removalof suchcon- .tactors and/or such plungers while nevertheless rendering the aforedescribed snap action mechanism .common tolall of .theswitch units utilized.

As hereinbefor'e indicated, each of the switch units 36 has associated therewith a complementary fuse clamp assembly-designated generally by the referenceanumeral 31. Said assembly includes an-open--bottom insulating shell or base '65 .(Fig. .9) of the contour best illustrated in plan viewiin Figrl, Said base 65 .has at opposite ends thereof a pair of integrally formed extensions 112 65 .65 extending upwardly a substantial dis tance from the bottom planeathereof, said extensions each having a countersunk opening therein for accommodating screws 39 for removable .attachment-of the assembly to mounting plate :33. Adapted to overlie base 65 and rigidly attached to the upper surface thereof as by means of screws .66, is a bus or conducting member 5] similar to conductingmember 58 on cover member :55 of switch'unit 3,6. Said bus member 761 is :a flat metal member :of substantially rectangular contour as best shown in .Fig. -1. Said bus :member '6'! hasaportion 'iil at one end thereof servingas the base for a terminal lug 53* which ,iistsimilar to the terminallug shown on'the switch units :36 and is likewise'provided-with ascrew 5|? Said bus member 6! has rigidly attached thereto as bymeans of a screw 59 a :fuse clamp 1&0 similar to .fuse clamp to attached to bus member 58. .Base fifihas an opening ;65:in the upper surface thereof for clearance of said screw 5.9 Bus member 51 is also preferably provided with upturned portion -31 that each endthereof and extending the width of said member .61. Portion 61 incooperation with an :upstanding inte rall formed positioningflug 161 is adapted to prevent rotary displacement of fuse clamp 65 when -:in assembled relation as shown :in;Fig. 9. Portion 67 at the opposite -;end of member 161 :is provided in the event that iitli desired to attachxfnse clamp 60*- .at the opposite ends of member :61 toaccommodate a diiferentsizedfuse.

As is apparent from atheioregoing description, fuse clamps 6D and 60 are adapted to accommodate a fuse 63 .(Fig. .1), said fuse roviding electrical conductivityfrom fuse clamp 16B .-to;fuse clamp 66*, thencethrough :conductinglmember 16:1 to-terminal lug 50?. As will also be apparen in addition to the flexibility of positioning offlthe fuse clamps '63, 163*- on their respective conducting members :to accommodate different sizes of s. a still-greaterflexibility resides the fac that casing 10 and mountin pl te :38 mi ht. if desired, ,be elongated to permit further spacing ;of the fuse clam assemblies 13:1 from the switch units '36 to accommodate still larger g fuses, :the arrangement of the fuse Bil-above the switch .36 nevertheless afiording reater compactness. hencesaving of space.

I claim:

.Acom act switch comp isin combination, t l st one individual switch .unit havin an enclosed arcing chamber and;having a reetilinearly movable contact actuator, pr sm-ting means for said switch unit separate therefrom and comprising a cam movable transversely of said contact actuator, .said actuator being biased into cam following engagement awithasaid .carn,

and said switch :operatingrmeans furthencom- :prising .snap acting means "for oscillating said cam -:to impart lateral rectilinear :movements to said ,contactactuator against its aforementioned bias.

tact actuator and means for individually biasing said actuators in a.giv en direction, anoperating mechanism for said switch units separatetherefrom andcomprising a cammovable transversely of the contact actuatorof one ofssaid units, the

.contact actuator of said one unit having-ream following engagement with said cam under its aforementioned bias, the other of said individual switch units being arranged in tandem relation to said one unit with their actuators in longitudinal alinement and operatively connected to rene der said operating mechanism common to all of said individual switch units, said operating mechanism further comprising snap acting means for oscillating said cam to impart lateral rectilinear movements tosaid contact actuators conjointly against their aforementioned bias.

3. A compact switch affording flexibility in number of poles comprising in combination, individual switch units in numberdepending upon the number of poles desired in the switch, each individual unit having an enclosed arcing chamber and having a rectilinearly movable contact actuator biased in a given direction, an operating mechanism for said switch units separate therefrom and comprising a floating cam movable transversely of the contact actuator of one of said units, the contact actuator of said one'unit having cam followin engagement with said cam under its aforementioned bias, the other of said individual units being arranged in tandem relation to said one unit with their actuators in longitudinal alinement in end to end engagement under their aforementioned bias to render said operating mechanism common to all of said switch units, said operating mechanism further comprising a pivoted handle and snap lost motion connections between said handle and said floating cam for movement of the latter in reverse directions selectively as a function of reverse movements of said handle to impart lateral rectilinear movements to said contact actuators conjointly against their aforementioned bias.

4, A compact switch Whose size varies directly with the fusing capacity afforded, comprising in combination, at least one individual switch unit having an enclosed arcing chamber and having a rectilinearly movable contact actuator biased in a given direction, fuse holding means carried on the top of said switch unit, a separate complementary fuse holding assembly in alinement with said switch unit and spaced therefrom according to the size of fuse utilized, an operating mechanism for said switch unit separate therefrom and comprising a cam movable transversely of said contact actuator, said contact actuator being biased into cam following engagement with said cam, and said operating mechanism further comprising means for oscillating said cam to impart lateral rectilinear movements to said contact actuator against its aforementioned bias.

5. A compact switch affording flexibility in number of poles and fusing capacity, comprising in combination, individual switch units in number depending upon the number of poles desired in the switch, each individual unit having an enclosed arcing chamber and having a rectilinearly movable contact actuator biased in a given direction, fuse holding means carried on the top of each of said switch units, individual complementary fuse holdin assemblies for each of said switch units and variably spaceable therefrom according to the size of fuses utilized, and an operating mechanism for said switch units separate therefrom and comprising a cam movable transversely of the contact actuator of one of said units, the contact actuator of said one unit having a cam following engagement with said cam under its aforementioned bias, the other of said individual switch units being arranged in tandem relation to said one unit with their actuators in longitudinal alinement in end to end engagement under their aforementioned bias to ren der said operating mechanism common to all of said switch units, said operating mechanism further comprising means for oscillating said cam to impart lateral rectilinear movements to said contact actuators conjointly against their aforementioned bias.

6. A compact switch whose size varies directly with the fusing capacity afforded, comprising in combination, individual switch units in number corresponding to the number of switch poles desired and spaced as closely as their fusing permits, each individual switch unit having an enclosed arcing chamber and having a rectilinearly movable contact actuator biased in a given direction, said actuators being in longitudinal alinement and in end to end engagement under their aforementioned bias, an operating mechanism for said switch units separate therefrom but in engagement with the contact actuator of the end one of said switch units to impart to all of said units conjointly lateral rectilinear movements against their aforementioned bias, fuse holding means carried on top of each of said switch units, and individual complementary fuse holding assemblies for each of said switch units and variably spaceable therefrom according to the size of fuses utilized, said complementary assemblies being in alinement with their respective switch units and spaced from each other as closely as the size of fuses utilized permits, the space required by said switch units and their respective fuse holding assemblies therefore in aggregate corresponding substantially to the space requirements of the switch fusing.

7. A compact switch having an enclosure, comprising in combination, at least one individual switch unit having a rectilinearly movable contact actuator biased in a given direction, fuse holding means carried on top of said unit, a complementary fuse holding assembly for said unit, a switch operating mechanism carried by said enclosure and comprising a cam movable transversely of said contact actuator to impart lateral rectilinear movements to said actuator, the latter under its aforementioned bias having cam following engagement with said cam, and a plate carrying said switch unit and its complementary fuse holding assembly, the latter being spaced from said switch unit according to the size of fuse utilized, and said plate therefore be ing of dimensions corresponding to the fuse size, said plate also having removable connection with said enclosure to afford joint removal of said switch unit and its complementary fuse holding assembly as a unit leaving said operating mechanism undisturbed.

8. A compact switch having an enclosure, comprising in combination, individual switch units in number corresponding to the number of switch poles desired, each individual switch unit having an enclosed arcing chamber and having a rectilinearly movable contact actuator biased in a given direction, fuse holding means carried on top of each of said switch units, an individual complementary fuse holding assembly for each of said switch units, a plate upon which said switch units and their respective complementary fuse assemblies are carried, said switch units being spaced on said plate as closely as their fusing permits with their actuators in longitudinal alinement and in end to end engagement under their aforementioned bias, said complementary fuse holding assemblies being in alinement with their respective switch units and spaced therefrom on said plate according to the size of fusin utilized, the dimensions of said plate therefore corresponding to the size of the switch fusing. and an operating mechanism carried by said .enclosure in engagement with the end one of .said switch units to impart lateral rectilinear movements to all of said units conjointly against their aforementioned bias, said plate having removable connection with said enclosure to afiord removal of said switch units and their complementary fuse assemblies :as a unit leaving said operating mechanism, undisturbed.

9.. A compact switch affording flexibility in number of poles comprising in combination, individual switch units in number corresponding to the number of switch poles desired, each individual switch unit having a rectilinearly movable contactactuator biased in a given direction, an operating mechanism for said switch units separate therefrom comprising a floating cam movable transversely of the contact actuator of one of said units, the contact actuator of said one unit having cam following engagement with said cam under its aforementioned bias, theother REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS i Number Name Date 1,081,550 Myers Dec. 16, 1913 1,714,743 Vontobel May '28, 1929 1,863,523 Hammerly June 14, .1932 1,893,829 Hammerly Jan. 10, 1933 2,221,575 Clark Nov. 12,, 1940 2,297,090 Weaver Sept. 29,1942 2,325,697 Millermaster et a1. Aug. ,3, 1943 2,515,449 Hammerly July 18, 119,50

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