US2325697A

US2325697A - Electric switch

Info

Publication number: US2325697A
Application number: US417106A
Authority: US
Inventors: Ralph A Millermaster; Alex A Writzmann
Original assignee: Cutler Hammer Inc
Current assignee: Cutler Hammer Inc
Priority date: 1941-10-30
Filing date: 1941-10-30
Publication date: 1943-08-03
Anticipated expiration: 1960-08-03

Description

g- 3, 1943- R. A. MILLERMASTER ET AL 2,325,697

ELECTRIC SWITCH Filed Oct. 30, 1941 4 Sheets-Sheet 1 g- 1943- R. A. MILLERMASTER ET AL 2,325,697

ELECTRIC SWITCH ,Fild Oct. 50, 1941 4 Sheets-Sheet 2 & o ws- 6 1y dRwQWM WZ A 5% My 4 g- 1943- R. A. MILLERMASTER ETAL 2,325,697

ELECTRIC SWITCH Filed Oct. 30, 1941 4 Sheets-Sheet 5 Aug. 1943- R. A. MILLERMASTER ET AL 2,325,697

ELECTRIC SWITCH Filed Oct. 30, 1941 4 Sheets-Sheet 4 Patented Aug. 3, 1943 ELECTRIC SWITCH Ralph A. Millermaster and Alex A. Writzmann, Milwaukee, Wis., assignors to Cutler-Hammer, Inc., Milwaukee, -Wis.,' a corporation of Delaware . Application October 30, 1941, serial No. 417,106

a Claims. (01. 209-40) This invention relates to improvements inelectric switches, and more particularly to improvements in electric switches, and more particularly to improvements in enclosed, snap make and break switches of the frontside operated type.-

Aprimary object 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 simple bail-type operating element for the movable contacts of the switch--said operating element and the snap-actuating means therefor being supported by the metal housing or casing within the boundaries of the opposite side walls thereof, independentlyof the stationary and movable contact elements of the switch-41. cooperative interlock ing connection being provided between the bailtype operating element and the movable contact elements of the switch.

Another object is to provide novel and simple means for insuring adequate current controlling capacity of the switch.

Another object is to provide a hinge connection between the switch casing and the cover therefor, whereby the latter may be readily assembled or disassembled with respect to the former.

Another object is to provide improved means affording an interlocking connection between the snap operating. mechanism and the casing cover, whereby normally,'the cover cannctbe opened while the switch is in on position, and the switch cannot be moved to its on position while the cover is open.

Another object is to provide novel, simple and inconspicuous means for rendering saidin'terlocking connection ineifective, to provide for proper examination and testing of the switch parts when in use. I 7

Another object is to provide aswitch operating lever having a novel, non-'arcuate arrangement of the openings in each of a plurality of groupsthe casing having an associated part provided with openings for cooperation with certain or all openings of each; group selectively, to accommodate the hasp's of one or' more padlocks; the arrangement being such that the padlock hasps maybe applied only in the full on or full of! position of the switch mechanism. 7

Another object is to provide improved and simplified arc-'snuffmg means for association with switches of the, aforementioned character, whereby the current controlling capacity thereof is substantially'increased.

novel form of Another object is to provide improved and simplified fuse clamps adapted for use'with switches of the aforementioned character.

Another object is to provide novel means for insulating the live parts of the switch when the latter is in off position with the cover open.

Another object is to provide novel and simple means for insuring a good electrical connection between each oscillatable switch contactor and the terminal member associated therewith.

Other objects and advantages of the invention will hereinafter appear.

The accompanying drawings illustrate a preferred embodiment of the invention, and modifications of certain structural details thereof; it

. being understood that the embodiment illustrated is susceptible of modification in respect of other structural details thereof without departing from the spirit and scope of the invention as defined by the appended claims.

In the drawings, Figure l is a top plan view of a three-pole, front-side operated safety switch of the fused type; the switch being shown in its off position with a fragment of the open cover-one of the arc snuifers and two oi the fuses being omitted, andthe insulating shield being broken away, for clarity of illustration of other parts of the switch.

Fig. 2 is a sectional View, on the line 2-2 of Fig. 1, with the cover closed.

Fig. 3 is a sectional view similar to Fig. 2, but with certain additional parts shown in elevation, and with the switch in its on position.

Fig. 4 is a fragmentary sectional view, on the line 4--l of Fig.- 1.-

Fig. 5 is a fragmentary side elevational view of the switch in its on position-portions of the cover and casing being broken away, and portions of the interlocking elements being shown in full lines and in dotted lines.-

Fig. 6 is a fragmentary sectional view, on the line 9- 5 of Fig. 4. V

Fig. 6 is aside elevational view of one of the two like molded insulating arc-snuffmg elements shown in Fig. 6.

Fig. 7 is a fragmentary sectional View, on the line l'--1 of Fig. 5.

Fig. 8 is a top plan view or" a stationary switch contact having a pair of flat, punched insulating arc snn'fling elements retained in assembled re= lation'ship' thereto by a spring clip.

Fig. 9 is a side elevational view of the device shown in Fig. 8, showing the manner in which the same is supported independently of the insulating base.

i is 'a elevational view of a further d form of arc snuiiing ievicethe same .pted for use in conjunction with a stationar switch contact having a metal reiniorc- I or sack-up member of special form associated therewith.

Fig, 11 isa vertical sectional view, on the line i 1-! I of Fig. 10,.

Fig. 12 is a side elevation'al view of a novel form of clamp or support for the blade type terminal of acartridge fuseportions of the insulating supporting base and the fuse being broken away.

E3i3 of Fig. 12, and

Fig. 13 is a vertical sectional View, on the line Fig. 14 is an end elevational view of a clip for a fuse-having ferrule type termina1sa resilient metal reinforcing or backing member-being aseociated therewith.

eferring first to Figs. 1 to 7, inclusivawherein is illustrated a switch of the aiorer'nentioned characterhavinga ratingof 6i] amperes at575 volts; Figs. 1 to 5 and 6 are drawn to one half of full scale, and Figs. 6 and '7 are drawn to full scale. .In these figures the numeral desig nates the body portion of a sheet metal casing-'- said body portion having a'bottom wall 5 5 opposite end walls #5 and IE andopposite side walls le and i5 certain or all of said walls being provided with suitable knockouts, as shown, for

' example, at Hi 5 and 5 in said bottom wall 55* (Fig. 1). Saidbody portion I5 is preferably formed from a single punched sheet metal piecethe end'walls Ni and i5 having inwardly bent flanges formed thereon as shown, against which the inner surfaces of the'respective side walls 5 5 and 55 are adapted to abut-said side walls being spot-welded or otherwise rigidly and permanently attached to said end Wall flanges.

Formed integrally with the side wall I5 and bent inwardlyat a right angle thereto is a flange dent to blanking of the sheet metal member from whichthe body portion i5 is produced.

Gpeningiii is of elongated rectangular contour, to accommodate and to'provide oscillatory clearance forthe fiat, plate-like portion I6 of arcuate contour, of a die-cast metal lever it.

ng a pluralityof 'openings,. 5 55 i5 and 15 formed therein as an incimeans of a pin 28 whose head overlies a portion of the extension 58* formed on member i9the shank of which pin penetrates thearcuate slot is in said extension and is rigidly attached to said end of lever 17. L

Member i9 is provided with an armor extension lQ to which is pivotally connected one end of a plunger 2|, as by meansfof a rivet or pin 22.

;The other end Zi of plunger 2| is aiforded slid- 10 ing and oscillatory clearance by a slot 23 (Fig. 2) formed in a sheet metal housing member 23 which substantially encloses all of the snap actuating elements of the switch. Member 23 has flanges 23 and at opposite ends thereof. which are rigidly-attached to side wall 55 as by means of rivets 2 5 As shown in Figs; 2 and 3,

,memberlZB extends from the bottom wall W to a line spaced inwardly only slightly from therupper edge of said side wall M Member 23 is, provided'in its upper edge intermediate the length thereof with an approximately' rectangular notch, indicated in dotted lines fat23 in Fig 3, to provide clearance for that end portion of a bail member Ziwhich is 7 associated with the snap actuatingmechanism;

, member 2-3 having a lug 23 (Figs. 1 and 3) formed integrally with the lower edge of said notch 23 to limit oscillatory movement of bail 2d a direction to effect closure of the switch. Oscillatory movementof said bail rnember 2d inthe reverse direction'is limited byapin'ZS (Figs;

2 and 3) which has one end thereof riveted to 1 the side wall :5 as shown at 25 in'F-ig. 5.the

The handle or hand-grip portion W of said lever is preferably of increasing thickness toward the U outer endth'ereof, as shown'at EE and le in Fig. l, to iacilitate gripping thereof-said portions I5 and Mi being of convex form; Portion iiiis formed with an opening or cut-awayrpor tion His, to minimizethe weight andto improve the appearance thereof, while also improving the functioningthereof as a hand-grip. Portion 15 of said lever is inserted downwardly through opening i5 said portion having a segmentalnotch id iormed therein to permit 'such'dowlm ward insertion, to minimize the total weight or mass of the lever, and to provide proper clearance between the same and a'lever H (see Fig. 2).

Porticn iof said lever is provided with a perforated extension ifi of reduced thickness as'indicated in'dotted lines at ifi in Fig. 2-the perforation in said extension being adapted to have alined therewith theperforation (not shown) in the laterally onset end portion li of the afor inentionedlever H; a headed rivet or pin 53 penetrating. said perforations'an'd havingits shank end upset to pivotally connect said parts to each 7 other. The other end of lever H has a pivotallost. motion driving connection with a. punched and stamped sheet metal member l9as by other end of said pin being adapted to seat in an opening or notch formed in member 23 adjacent to the upper edge thereofsaid upper edge being cutaway, as indicated in dotted lines at 23 in Fig. 3, to permit abutment of bail member 24 against saidpin25.

Plunger 2| is provided with a slotZl which is adapted-to accommodate the shank of' aipin 26 which penetrates alined openings'in side wall IE and member 23 and is headed at each end thereof to retain the sam in position. Pin 25 thus acts to permit both reciprocator-y and oscillatory movementof plunger 2} with respect to slot 23 (Fig. 2). Plunger 2| is surrounded by a relatively-heavy bias the latter to one-or the other of its extreme positions (Figs..2 and 3).

Member 19' hasan inwardly offset, flat, circu- .lar portion l9? which is spot-welded or otherwise rigidly secured, in a predetermined rotary or angular relationship, to a fiat sheet metal cam member 28, the latter having a main cam portion 28 adapted for cooperation with the tail portion 23 of a latch member 29 ,to normally provide for locking the casing cover 30 in closed positionwhen the switch is closed. 'Cover 39 has spot Welded or otherwise rigidly attached to the inner surface thereof a sheet metal member 3 i-thelatter having a right angled inwardly extending perforated f lug portion ti for cooperation with the latch end 29* of member, 29, in a well known manner. 7 r

Member 29 is pivotally attached to the side Wall Pi as by means of a headed rivet or pin 32, the shank of which is accommodated by a slot 29, as shown in Figs. 2 and 3. A coiled tension spring 38 has one end attached to side wall 15c and the other end attached to member 29, in the manner illustrated in Figs. 2 and 3, whereby member 29 is biased to the position illustrated in Fig. 2 by closure of cover 30, whentheswitch is open; whereas the cam portion" of member 28 acts upon member 29, and against the bias of spring 33, to. effect locking of cover 30 in closed position upon closure of the switch, as shown in Fig. 3.

In order to provide for, manual release of the cover interlock afforded by member 29 when the switch is closed, said member is preferably provided with a substantially rectangular opening or slot 29 (adapted to accommodate the end of a screwdriver or similar. tool), the side wall l5 being provided with a registering opening or slot l5 of substantially the same length as slot 2!! but ofsubstantially greater width than the latter, as shownin full lines in Fig. 5 and in dotted lines in- Figs- 2 and 3. With reference to Fig. 3, it is to be understood that upon insertion of a screwdriver lnto slot 29 from the exterior of the casing the screwdriver may be rotated or pressed downwardly to effect bodily lateral and downward movement of member 29 to efiect disengagement of hook portion 29 of member 25 from lu ill the point of engagement of tail portion 29 with cam portion 28 forming a fulcrum for such movement, and the slot 29 being arranged at the proper angle to permit such movement of member 29 relatively to pivot pin 32.

The rigidly connected members l9 and 28 are pivotally supported as by means of a metal member having an intermediate shank portion, represented by the circular dotted line 34 in Fig. 2, which freely penetrates alined openings in said members, and an adjacent end shank portion of reduced diameter which penetrates an opening of corresponding, size in side wall li and is upset over the outer surface of the latter, as shown at 34 in Fig. 5. Said pivotal supporting member is provided with a disk-like header flange 34 (Figs. 2 and 3) which overlies a. part of the flat portion I 9 of member l9 to retain the latter and member 28 in pivotally assembled relation to side wall l5". Located centrally of head 34, and formed integrally therewith, is a. substantially cylindrical stud portion 34 which is adapted to act as a pivotal support for the flattened and perforated end portion 24- of bail member 24 (Figs. 2 and 3).

In assembling bail member 24 with respect to the main portion 15 of the casing, the straight left-hand end portion 24* thereof is extended or projected outwardly a substantial distance beyond the side Wall lo' through a suitable bearing opening [5 (Fig. 1) provided in the latter. This permits the pivot opening provided in the other, or flattened, end 24* of the bail member to be brought intoregistry with the stud portion 35 (Figs. 2 and 3), whereupon the bail member may be moved bodily toward the right (Fig. l) to provide proper pivotal engagement oibail end 2 with stud 34 while maintaining proper pivotal engagement of the end 24 thereof with the pivot opening I5 in side wall 15 In practice a resilient sheet metal clip 35 (Fig. 1) of greater than semicircular length or area is then snapped onto the end portion of said bail member, interiorly of the casing, to retain the right-hand end 24 in pivotal engagement with said stud 3*.

Prior to forming of ,bail member '24 a pretion by any other'operator.

formed seamless tube 36 (Fig. 1) 0! suitable insulating material, such as impregnated and wound sheet fiber, is loosely slid thereonto-said bail member being then pinched, or otherwise slightlydeformedas shown at 24 a d o P vent substantial endwise displacement of tube 36 in eitherl direction. As hereinafter described in detail, tube 8 is adapted for cooperative driving engagement with the walls of open slots formed in insulating members which are in turn rigidly attached to the movable oontactors of the switch.

As, best illustrated in Figs. 1 and 5, there is rigidly attached to the side wall H as by spot welding, a metal member having a portion 3! corresponding in width to the width of the flange 30' of cover member 3il-said member having

integral portions

31 and 31 bent inwardly at a right angl to portion 31 and an integral intermediate portion 3! slightly ofiset inwardly from and extending upwardly in a plane parallel to said portion 37*. Portion 31 (Fig. 5) is provided with three equally spaced

circular openings

31, 31 and Sl' which are arranged in a straight line as shown. When lever I6 is in the position shown in Fig. 2 (corresponding 'topfi positioning of the switch mechanism) the openings l6, l6 and lfi inporticn It of said lever are respectively adapted to register with said

opening

31, 31 and 31* in portion 3'! (Fig. 5) whereby (as indicated in Fig. 2) from one to three workmen or operators may apply and lock the hasps of their individual padlocks, to positively lock the switch against closure pendingremoval of all of said padlocks. As aforementioned, the openings I6 l6 and lB are arranged in a straight line to jointly aline with the openings 31, 3'! and 3? only when lever 16 is in its lower extreme position shown in Fig. 2.

Portion N5 of lever I6 is further provided with a pair of openings I5 and W which are likewise arranged in a straight line for cooperation jointly with therespective openings 31, 31 (Fig. 5) when lever i6 is in its upper extreme position (Figs. 3 and 5) corresponding to on position of the switch mechanism. With particular reference to Fig. 3, it should be noted that the arrangement of parts is preferably such that handle portion IE may be moved downwardly to a sufficient degree to permit the opening 15 to register with opening 31, without in anywise affecting the full on. positioning of the switch mechanism. This result may be attained by reason of the lost motion afforded between the walls of the slot IS in member 29 and the pin 20 attached to lever 11. From the foregoing it is apparent that-a single operator may apply a padlock to retain the switch in on position pending removal of such padlock-whlle insuring against simultaneous locking of the switch in on posi- The advantages of this novel arrangement, from the viewpoint of safety, are believed to be apparent.

Lever I6 is pivotally supported upon the inner surface of casing wall Hi as by means of a pin the head of which is designated by numeral 38 (Figs. 2 and 7); said pin having a relatively long intermediate shank portion 38 of relatively large diameter which is adapted to freely penetrate a correspondingly shaped opening 16 (Fig. '7) in portion Hi of said lever; said pin also having a reduced end or shank portion which penetrates an opening of corresponding size in wall I5 and is upset over the outer surface of the latter, as shown at 38' in Fig. "7. As shown in Figs. 5 and 7 the portion 3'! of the aforementioned metal arm of spring 63 7 otherwise. rigidly attached thereto."

o-f latch A8 to a position mits free outward or opening movement of cover large molded insulating base 45, adapted to support the switch proper and one group of fuse clamps,and a relatively smallmolded insulating member, has been attached .to the casing. Also,

as best illustrated inFig. 7, apair of like bowedspring

metal strip members

39, 39 are arranged with their end'portions engagedthe interme'-' 'diate portions thereof being perforated tota'ccommodate the shank .portion 38 of pin 33.-

' Said springs are jointly interposed between the head ofpin 38 and the portion I6 of lever it under a predetermined degree of compressionwhereby the central raised portion or projection l6 (Fig. .7) is biased into bearing engagement with the inner surface of wall 5 The upper edges of springs 39 are locatedadjacent to the lower surfaceof flange I 5 (see Fig.2) to prevent I rotary displacement of the former. As shown in Figs. 1 to-3, the space between portions 3? and 37 of the aforementioned metal member cooperates with the opening in flange 15 to base id-properly alined therewith and spaced therefrom to support the other group of fuse clamps and their, associated .wiring terminals. It

afford oscillatory clearance for portion I b of V,

lever 15.

'A-manually releasable cover latch-I19 is pivoted to side wall 55 j'and 5) riveted to the latter. 7 vided with an arcuate slot 49 (Fig.2) which accommodates'the shank of a a pinAiKFigSrZ Member ii] is pro-- as by means of headed rivet "52 attached to wall I5 the lower' end of said slot cooperating with: pin M toflimit the degree of upward movement of latchm'ember 45!; "Member 48 is provided at the other end of slot hi withanintegral lug: or hook 46* (Fig- 2) which is spring 43;

torsion V or' hairpin-type said spring 7 being'provided with at least one coil intermediate its ends and surrounding pin 4!. 'I'he other predetermined degree of stress with the pin l2 wherefore latch member 49 is'biased to its nor mal. or latching position shown in Figs. 1 to 3. As shown, member iflhas an end portion 33 (Figs..1 and 2) adapted to project outwardly through opening Hi andthe alin'ed openingiii .in cover 393 and overlying the'outer surface of the latter to retain the same in closed position;

Cover 39 is provided with a'finger hold or.

handle formed of a metal strip "54 (Figs. 3 and 5) one end of which is bent, as shown at 4B? in Fig. 3, for insertion through an opening 38 in said cover and adapted to lie flatwise against the inner surface of saidcoverbeing spot welded or 7 The other end dd (Fig. 3) of member 44 is spot welded or otherwise i'ig'idly'att'ached'to-the outer surface. of cover 39 at a point adjacent tobut in wardly Of'the opening (Fig. 2). The opening i5 inflange I5 (Figs. '1; andfi) is adapted to accommodate said end 44* of member A l.

As bestillustratedin Fig 3, handle 44 and latch 39 are soarranged as'to facilitate opening of cover 35 'by one hand; the index finger of the right hand being insertable inwardly through the'loop formed by memberM, and the thumb of the;

same hand being free to effect pivoted movement wherein the same per- The switch disclosed herein is of the fused type (see Figs. 1 and 5) and to minimize the 'cost and weight thereof we. prefer to employ arelativeiy is normally engaged under-a adapted to'be engaged by onefar'mfof a coiled I of which are shown at 15 55 and 55 56 in Fig.

4) to space the body portions of said bases a substantial distance upwardly from thebottom wall Eli o'f'the casing. In practice relatively thin fiat.- punch d insulating plates fland 49 are inter posed'between said insulating b-asesandsaid bottom wall 5 5 ,.to insure'against ing of any-of the live parts of the switch in the event of loosening of any of the screws .7. If. desired, the heads of screws :31 may be waxed in, to provide an additional safeguard. As shown in l the bases and' ifi are removably'at tachedto bottom wall l 5*, as by means of screws p t -the shanks of which penetrate openings in the bases, alined with the feet 45 dfi and 45 1' spectively, and corresponding openings in' ates i and d9. Said screws take into tapped openings (not shown) inbottom wall 1%. The fuse clamps 5! illustrated in Figs. 1 and 4 are preferably of the charact'erdisclosed in the patent of R. A. Millermaster, No. 2,194,667, dated March 26, 1940-to which i'eference'may be had member iid of operation thereofsaid fuse clamps being particularly adapted for use in conjunction with cartridge fuses having terminals" of the ferrule type. 7

The solderless wiring terminals 52 shown in Figshl and 4 are of the character disclosed in the-patent'of R. A. Millermaster; No. 2,193,202, dated'Marcn l2, 1940to which reference may be had for ad'etailed description of the construction and operation thereof 'As'best illustrated in Fig. 4, the screws 41 associated with base' ie each freely' penetrate an opening (not'shown) in a bus any suitable metal, such as copper, and take into a tapped opening in the base portion of the fuse clamp 5| (see Fig. 1); thestop members fil being spot weldedf or otherwise rigidly secured to said fuse clamps 51] If desired, the stop members (corresponding to 5% hereof) may be removably associated with clamps 5i, ina manner No.'-2,l94,667'in which event the screws All will preferably freely v penetrate passages. formed in clamps'lii and take into nuts (not shown) posisimiiar to that disclosed in said Pa'tent accidental-grounde, Y:

tioned'above the washer portions of thestop reducedlwidth intermediate its length to provide sets of spaced shoulders to accommodate and prevent endwise movement of the tubular element 52 of the associated wiring terminal device. As shown in Fig. 4, each fuse 'clampffi l on base .5 is secured in position by its associated screw 371, and in good electrically conducting relationship to one end portion of a bus member 54 of copper or the like ;'a second screw 41 being'adapted to secure to base 45, in good electrically con ducting relationship to the other end of member-54, a metal member 55, which acts in bus 1 conjunction with a pivot pin 56 and a sprin washer 51,. to provide a pivotal support-i0): one of the three movable contactors 58 of the switch. Also as shown in Fig. 4 each bus member is bent or deformed at a point intermediate its ends to provide a downwardly opening groove 54 which is adapted to accommodate one end 59 of a multiple strand flexible conductor wire or pigtail 53 said end 56 being spot welded, or otherwise rigidly and permanently secured within groove 54. The other end of wire 59 is spot welded or otherwise rigidly secured to the associated movable contactor 58 as indicated in dotted lines at 59'.

Each contactor 58 as shown has attached thereto on opposite sides thereof a pair of like flat, punched insulating

elements

66, 66, as by means of a pair of

rivets

69, 60 It is to be understood that for switches of smaller size and lower current controlling capacity only one element corresponding to element 66 need be attached to each contactor-and only one of the 'rivets 66 need be employed, if the insulating plate is provided with one or more suitable openings, and if each contactor is provided with a corresponding number of extruded bosses or projections to interlock with such openings.

Each plate 66 is provided with a forwardly opening notch 66 of U-shape or contour-said notches being jointly adapted for cooperation with the insulating tube 36 and the bail member 24 surrounded by the latter. The are of movement of ball 24 is so related to the arc of movement of plates 66 as to insure proper driving engagement of the former with the latter in all positions.

As best illustrated in Figs. 4 and 6, each stationary contact 6! is of the well-known constricted U-shape in transverse cross section (Fig. 6) to accommodate the free end of its associated switch contactor 58; the contact having formed integrally therewith the bus portion 6l (Fig. 4) to accommodate the solderless wiring terminal device 52 aforedescribed-and a pair of screws 41 being employed, as shown to retain each 0011- tact and bus portion in assembled position. Interposed between the lower end of each contact 6| and the bottom wall of a recess 45 in the upper surface of base 45 is a combined reinforcing and interlocking member 62, likewise formed to constricted U-shape (Fig. 6) from suitable resilient sheet metal, such as steel. The arms of each member 62 are so shaped that the upper end portions thereof normally engage the arms of their associated contact 6i with a predetermined degree of pressure, as an incident to assembly of said parts with respect to the base. The resiliency of the arms of member 62 acts to assist in exerting the desired degree of pressure of the arms of the contact 6| against a contactor 68 inserted therebetween, and further insure return of the arms of the contact to the desired normal position upon withdrawal of the contactor. The arms of each member 62 are further provided with outwardly extending upper end portions 62 and 62 (Fig. 6) which serve as interlocking connections between the same and a pair of like molded insulating arc-snufling members 63, 63 (Figs. 4, 6 and 6).

Members

63, 63 are in general quite similar both structurally and functionally to the corresponding element disclosed in the patent to R. A. Millermaster, No. 2,090,764, dated August 24, 1937-to which reference may be had.

Members

63, 63 act to substantially fully enclose their associated stationary contact, while permitting snap movement of the'contactor 58 into and out of engagement with the latter. As shown in 6 each member 63 is provided with a pair of endwise alined groove (53 and 63 extending inwardly from opposite edges thereof to a centrally located ridge or abutment 63, which limits the degree of telescoping onto a pair of said members 6.3 of a sheet metal spring clip 54 (Figs. 1 and 4). said clip acting to retain members 63 in assembled relation to their respective contact while permitting separation of said members by the contactor during circuit closing movement of the latter.

Grooves

63 and 63 are providedat points adjacent to their inner ends with approximately hemispherical recesses 63 and 63 (Fig. 6) either of which is adapted to accommodate a correspondingly shaped boss (not shown) formed on the inner surface of each arm of clip 64. With the arrangement herein illustrated the clips 64 may be relatively shorter than those employed in the device of said Patent No. 2,090,764; and, in addition, the connecting portion of each U-shaped clip is spaced a substantial distance rearwardly of the associated pair of members 63 (see Figs. 1 and 4) to insure proper self adjusting movement of the latter by the contactor without any possibility of positive interference or resistance by any portion of the clip 66.

It is to be understood that the line terminas of the switch are those shown at the upDc of Fig. 1 and at the left-hand end of Fig. 4; and, for cooperation with the arc-snuiiing insulating elements 63, we prefer to provide a removable insulating cover or plate 65thus affording a substantially dead-front arrangement for the live parts when the switch is oil with the cover open. The forward edge of plate 65 is preferably of the contour best illustrated in dotted lines in Fig. 1--the same being provided with three notches 65-- to accommodate the several arcsnufiing devices aforedescribed.

Plate 65 is attached; as by means of a plurality of rivets 66, to a punched and stamped sheet metal plate 6'|-the latter having

opposite end portions

61 and 61 of reduced width which are adapted to seat upon the horizontal or shelf portions (see 69, Figs. 2 and 3) of a pair of

sheet metal brackets

68 and 69; the vertical portions of which brackets are spot welded or otherwise rigidly secured to the respectiv side walls l5 and 15. The shelf portions of

brackets

68 and 69 are respectively provided with opposed bent or hooked ends 68, 63 and 69, 66 (Figs. 1 to 3)-the

ends

66 and 66 being relatively higher than

hooks

68 and 69. Plate ends 67 and 61' are respectively provided with partiall sheared and upwardly offset lugs 61 and 61, which fit rather closely beneath the hooks 68 and 66 (as illustrated in Figs. 2 and 3) Plate 61 is assembled with respect to said brackets by tilting the same, to permit free sliding movement of

lugs

61 and 61 beneath

hooks

68 and 69, whereupon the plate ends may be seated upon the horizontal portions or shelves (see 69 Figs. 2 and 3), and said plate ends may then be slid in the opposite direction, to fit within hooks 68 and 69 (see Figs. 2 and 3). The insulating plate 65 will thus be held in proper covering relationship to the line terminals of the switch. In removing plate 67 (with its attaching insulating plate 65) from said supporting brackets, the former is first slid upwardly (Figs. 2 and 3) to

clear hooks

66 and 69 and then tilted outwardly and withdrawn from engagement with

hooks

68 and 66*, as will be obvious.

granted April 8,1941,

The cover 38 isfremovably hinged tofcaSinglfiin the novelmanner illustrated in Fig. 1.; 'Thus in practice a pair of sheet metal hinge members 'lil, it are spot welded or otherwise rigidly at-[ tached to the outer surface'of the side wall 55 of the casing at points such as those illustrated; and a second pair of sheet metal hinge members H, "H are spot welded or otherwise rigidly attached to the inner surface of the flange Ell of cover member 30. All of the four hinge members may be of'identical forinbut the hinge members l9, 19 each have rigidly'secured therewithin (as by spot welding, brazing or the like) and projecting upwardly therefrom a hinge pintleoneof which is shown at l2. The hinge pintles preferably project like distances upwardly from members Hi, 'll but, dueto the relative positions of hinge members l9, l6 and ll, H; the "upper hinge member H will firstbe brought downwardly to telescope onto and slightly engage the pintle carried by the upper hinge member 'll!whereupon the lower hinge member "H may be readily'alined manually with the hinge pintle 'lz carried by the lower hinge member it. "The advantages of the hinging mechanism for the'removable'cover 3E3 vd-ll be sembled to the casing-provided that one of the hinge pintles (preferably the upper one) is made to project upwardly a substantially greater distance than the lower .pintle. It is believeihOwever, that the appearance of the cover hinging arrangement illustratedis somewhat better than that last described; in which the end portion'of one of thehinge pintles will be exposed.

As shown in Figs. l and' plate- EST may'have' a raised portion 61* formed thereon by a stamping op-eration'said portion E l serving as a finger abutment to facilitate sliding of plate 6'! within

brackets

68 and 69 toward the end wall l5 of the casing, and subsequent tilting of said plate as aforedescribed to pe mit removal thereof from said brackets.

The switch aforedescribed preferably embodies as a whole the ornamental designdisclosed and claimed in Design Patent No. 126,465, to Milleimaster and Stevens. I 1' n 7 In Figs. 8 and 9 there is illustrated'a simpler (not shown in Fight and 9)., with a rectangu lar notch l3,land with a substantially circular opening "53 located between the aforementioned notch 73 and opening 73 =l A substantially LJ-shaped resilient metal clip, preferably formed of spring wire, has its connecting'portion 'l' ipositioned within the notches.

in the device ofFigs. 8 and 9. However,- as will be apparent, the wire clip l inherently has a predetermined reinforcing effect upon the arms of the contact 6!, by reason of the pressure applied'by the former upon the plates it. As will be apparent'frorh consideration of Figs, 8 and 9, the plates 13 afford a definite cooling and snuffing. effect uponany arcs drawn as an incident to separation of the contactor from the contact. 'I'he numeral '55 in Fig. 9 designates a fragment of a suitable insulating supporting base for the switch parts. In Figs. 10 and 11 there is disclosed a further modified form 1 of arc-snuffing .device, wherein a stationary contact member 15 (which may be like the contact 6! aforedescri bed) has associated therewith a reinforcing orfbacking member ll of, any suitable resilient metal, such as steel.'-Member fil' has a connectin portion Ti underlying contact It and upwardly extending arms 'll andfil which quite closely conform with the shape or contour of the contact arms throughout'the major portion of the length of .the latteryas shown in dotted lines in Fig. 10 and in full lines in Fig. 11, Each arm T'l and Ti is provided intermediate the width thereof with a pair of parallel shear lines extending inwardly from the upper edge thereof to provide and less expensive arc snuiiing device which is 7 adapted for use in conjunction with a combinedstationary switch contact 61 and integral bus portion 6H like that aforedescribed. Ifhe device comprises essentially a pair of like fiat, punched insulating plates 73,- 73, of impregnated fiber or the like, preferablyhaving high heat resisting characteristics. Each plate is preferably provided at its lower edge with'a substantially rectangular notch 13 (Fig. 9) to accommodate the upwardly and inwardly angled in termediateportion of one arm of the contact, and with an approximately semi-elliptical opening 73 accommodate the flared upper end portion of such arm of the contact. Each plate 73 is also provided, at the side thereof remote from the hinge point of Vthe'swltch cont-actor resilient tongues which are bent to extend laterally and then upwardly in the manner best illustrated in Fig. 11. '1 A pair of like flat, punched insulating plates 18, 18 (0f the form best illustrated in Fig. 10) are attachable by a simple'yieldable interlocking connection thereof with contact is and member Tl. As will be apparent from consideration of Fig. 10, each plate 78 may be placed in assembled positionby inserting the lower or hooked end lfl thereof within the free space provided at the lower end offeach arm of the-contact; the lower edge 58 of the upper rectangular portion of the plate being thenpressed downwardly between the respectivetongue 'il or li and the upper end of the respective arm li or??? of member ll-each edge 18 being provided with a small downwardly opening rectangular notch 78 to facilitateproper assembling movement; of the plate, and to assist in preventing subsequent ac-,

1 cidental'displacement thereof. Each plateqlsi is also provided with a substantially semi-elliptical opening lt toacc-ommodate the outwardly flared upper end of its associated contact arm, and to further assist in preventing accidental displace-' ment of said plate, as will be apparent trombonra ion arena, 10 and 11. er s ay clip like I the cli 82 heretofore described is not employed be attached to a suitable insulating base. 19, as by means of a screw or bolt 80. Plates 18 may be readily removed from. assembled position for purposes of inspection or replacement, as will be apparent.

In Figs. 12 and 13 there is illustrated a novel and simple form of fuse clamp adapted for use in conjunction with fuses having blade-type ter minals. Said clamp comprises a pair of elements ill and 32 respectively stamped from blanks punched from copper strips of different widths. The horizontal portion 8| of element BI is provided with. an upwardly extruded and tapped opening 8l .the substantially vertical portion 8| of said element having a. pair of upper relatively widely spaced parallel vertical slits and a pair of lower relatively narrowly spaced parallel vertical slits, with transverse slits connecting the former With the latter. The material between said pairs of slits is then bent outwardly, as shown in'Fig. 13 to provide a. relatively wide downwardly angled cam surface Bi and a relatively narrow upwardly angled strut or reinforcing portion 81 formed integrally therewith. Said cam surface Si is preferably of concave form (not shown) in horizontal cross section, whereby the same is adapted to closely lit and guide the adjacent portion of a conical cam surface 83 lormed upon an operating nut 83 of the form illustrated. 7

Element 82 has a horizontal portion 82 underlying portion ill" of element 8| and projecting laterally therebeyond to a predetermined point, where it merges with the vertical portion 82 which extends upwardly in substantially parallel relation to portion BI -the upper end of portion 82 being preferably flared, as shown at 82" to facilitate insertion of the blade-type terminal 8 of a fuse between portions 8l and 82 Said horizontal portion 82 is preferably provided with an opening 82 (Fig, 13) afiording clearance for the shank of a bolt 85 which extends upwardly through a clearance passage 86* in an insulating base 86, and through a clearance opening 81 in a bus member 81 or the like, and takes into the aforementioned tapped openingai in portion 8W; a lock washer 88 being preferably interposed between the head 85 of said bolt and base 85 to prevent accidental loosening of the bolt. The shank l5 extends upwardly a relatively great distance beyond portion M for cooperation with the aforementioned adjustable cam nut 83-the latter having an internally threaded downward extension $3 to insure a sufficient area of threaded engagement with shank 85; and said nut having a cylindrical upper end portion 83 provided with a keif 83 to accommodate a screwdriver or other operating or adjusting tool.

As shown, element 82 is provided with integral flange portions which extend upwardly from the horizontal portion, as indicated at 82 and 62 and inwardly from the vertical portion 82*, as indicatedat 82 and 8 the

upper edges

82 and 82 of the latter serving as stops to limit the degree of downward insertion of a blade terminal a l between portions 8| and 82'. Also, as will be readily understood, said integrally connected flange portions 82, 8! and 82, 82 serve to substantially reinforce and rigidify the momber 82 and to resist outward bending of the vertical portion 82 thereof as an incident to clampins action of portion 8|, against a blade terminal upon downward adjustment of nut 83. In practice the horizontal portion N of element 8| is spot welded or otherwise rigidly secured to horizontal portion 82* of element 82 (preferably adjacent to the right-hand end of said elements, Fig. 13) to insure maintenance of said elements BI and 82 in properly assembled relationship and of unit form prior to mounting thereof upon base 83. A similar result could, of course, be obtained by shaping elements BI and 82 as integrally connected parts of a single metal blank and then bending or reflexing the parts, at the point of connection thereof, to the relative positions shown in Figs. l2'and 13. The arrangement just described has the disadvantage that a substantial amount of scrap would result from formation of thev part corresponding to element Bl illustrated.

In Fig. 14 there is illustrated a clip 89 for ferrule type fuse terminals, the base portion 89 of which overlies the flat connecting portion 90 of a resilient metal'reinforcing member 90 of substantially rectangular U-shape. Member 90 is preferably formed from a strip of phosphor bronze or similar metal of strength and resiliency. and good electrical conductivity-although steel may be employed if desired. The

arms

90 and 90 may be employed if desired. The arms 90* and 90 of member 90 extend upwardly and engagewith a predetermined degree of initial pressure the respective arms 89* and 89 of the fuse clip-such degree of pressure being substantially increased upon spreading of arms 89' and 89 as an incident to insertion of a ferruletype terminal therebetween. Member 96 as shown is superimposed upon a bus member 8! or the like, and said parts are attached to a suitable insulating base 92, as by means of a bolt 93, the shank of which takes into a nut 94.

We claim:

1. A front-side operated safety switch comprising a sheet metal housing having bottom, side and end walls and a hinged cover, quick make and break mechanism comprising elements supported upon the inner surface of one side wall of said housing and including a pivoted handle projecting upwardly beyond the upper edge of said side wall, a bail member having a straight end portion insertable outwardly a substantial distance beyond the opposite side wall of said housing through a bearing opening in the latter, the opposite end portion of said bail member having a bearing opem'ng formed therein and one element of said quick make and break mechanism having a stud for cooperation with said last mentioned bearing opening upon endwise bodily movement of said bail member in a reverse direction, associated means to retain said bail member in assembled position, a switch unit comprising an insulating base having at least one set of stationary and movable contacts attached thereto, each movable contact being pivotally supported upon said base, and the same having a notched insulating plate attached thereto for hooked engagement with the intermediate portion of said bail member 7 for operation by the latter into and out of eneasement with its associated stationary contact, said insulating base with its attached switch contacts being insertable into and removable from said housing independently of said bail memoer.

2. A front-side operatedsafety switch comprising a sheet metal housing having bottom, side and end walls and a hinged cover, quick make and break mechanism comprising elements supported upon the inner surface of one side wan or said. housing and including 'a, pivoted handle projecting upwardly beyond the upper edge straight end portion insertable outwardly a subof said sidewall, a bail-member having a stancedistancebeyond the opposite side wall of saidhousingthrough a bearing opening in thelatter, the opposite end portion of said bail member having a bearing opening formed there- 7 in and one element of said mechanism having a 'stud' for cooperation with said last mentioned bearing opening upon .enclwise bodily movement of said bail member in a reverse direction, a springcollar adapted to fit. upon. said straight end portion of said, bail member within thehous ing to retain the same 'in; assembled posiiton, a

switch unit comprising an insulating. base having at least one set of stationary and movable contacts attached thereto, each movable contact being gpivotally supported upon said base, the

same having a notched insulating plate attached thereto for hooked engagement 'withlthe intermediate portioniof said bail member for operation by. the latter into and out of engagement with'it's associated stationarycontact, 6 said insulatingbase with its attached switch contacts being insertable into and removable from said housing independently of said bail membenand said quick make and break'mechanism and said cover havingicooperating interlocking elements to normally insure against opening'of said cover whensaidswitch is in closed positionand to also normally insure against closure of said switch when said cover is inother than its closed positions q l .7 J l 3. A front-side operated. safety switch comprising a sheet metal housing having bottom,

1 side and end walls'and a hinged cover, quick make and break mechanism comprising elements supported upon the inner surface of" one side wall of said housing and including a pivoted handle projecting upwardly beyond the upper edge of said sidewall, a bail member having a straight end portion insertable outwardly a substantial distance beyond the opposite side wall of said housing through a bearing opening in the lattentheopposite end portion of said bail member having a bearing opening formed therein and said side wall having a stud attachedthereto and projecting inwardly there-' 7 from for cooperationwith said last mentioned bearing opening upon end'wise bodily movement of said bail member in a reverse direction, means associated with said-straight end portion of said bail member within the housing to retain the same in assembledposition, a switch unit comprising an insulating base having at least one set of stationary-and movable contacts attached thereto, each movable contact being pivotally supported upon' said base, the same having a notchedv insulating plate attached thereto for hooked engagement with the intermediate por-' tion of'said bail member for'operation by'the la ter-into and outer" engagement with its associated stationary contact, said insulating base with-its'attached switch contacts being insertabie into and removable from said housing independently of said bail member, said quick make and breakymechanismfand said cover having cooperating interlocking elements to normally in- 7 supported upon thefinner surface-of one side of said housing for temporarily interlocking elements inefiective.

A front-side operatedsaiety switchncom prising a sheet metal housing having bottom, side and end walls and a hinged cover, quick make and break mechanism comprising elements rendering said wall of said housing and including a pivoted handle projecting upwardly.beyond the upper edge of. said; side walls, a bail member having a straight end portion insertable' outwardly a sub stantialidistance beyond the opposite side Wall of said housing through a bearing latten'the opposite end-portion of said bail mem berhaving a bearing opening formed thereihand one of said elements having a stud for cooperation wit said last mentioned bearingopening upon endwise'bodilylmovement of said bail member a reverse direction, associated means to retain'said bailimember in assembled position, a switch unit comprising an insulating base: having at. least one set of stationary-andmovable contacts attached thereto, each movable contact being pivotallysupported upon said base, the same having a notched insulating plate at- ,tached thereto for'hocked engagement with the intermediate portion of 'saidbail member for operation by the latter'into and out of engage ment with its associated stationary contact, said insulating base with its attached switch contacts being insertable into and removable from said housing independently of said bail member, said quick make and break mechanism and said cover associated meansaccessible from the exterior 75 having cooperating interlocking elements to normally'insure against opening of said cover when said switch is in closed position and to also normally insure against closure of said switch when said cover is in other'than its closed position, associated means accessible from the exterior of saidhousing for temporarily rendering said interlocking elements inefiective, said handlehaving an enlarged flat portion provided with two groups of openings the openings of each group being arranged in a straight line and'th lines of said groups being at substantially right angles to each other, said'hou sing having apart positioned in parallel relation to the enlarged portionof said h'a ndle, and said part having a plurality of openings formed therein and arranged "in a straight line, the arrangement being such that said groups of openings are respectively alined with certain or all of the plurality of openings in said part tive extreme positions of saidhandle, said openings when alined providing 'for positively lockingthe switch and cover in predetermined positions by use-of one or more padlocks.

5. In an electric switch, in combination, a a

, metal casing, an operating lever pivotally supported relatively to said casing, said lever having an enlarged portion of flat, segmental form adjacent to the point of pivotal support thereof; said enlarged portion having two groups of openings formed therein, the openings in each group being arranged in a straight line, and a metal member carried bysaid casing and arrangedin parallel relation to said enlarged portion of said lever, said member having a plurality of openings formed thereinand arranged in a straight line, the arrangement .beingsuch that the aforementioned groups of openings arranged in straight lines areselectively adaptedto register jointly the openings in said memwith certaian orall of beronly in the respective extreme on'or o1? positlons of said lever., 5 1

opening in the" in the respeca parallel relation to said enlarged portion of said lever, said member having a plurality of openings formed therein and arranged in a straight line, the arrangement being such that the aforementioned groups of openings arranged in straight lines are selectively adapted to register jointly with certain or all of the openings in said member only in the respective extreme on or off positions of said lever, and said lever being movable from its extreme on position to throw the corresponding group of openings in the flat portion thereof out of registry with all of the openings in said metal member and to bring only one of the openings of the other group into registry with one of the openings in said metal member, to thereby provide for looking a said lever in an on position by a single padlock While preventing attachment of an additional padlock or padlocks.

'7. In a front-side operated safety switch of the snap make and break type, in combination, a sheet metal housing having bottom, side and end walls and a movable cover, a die-cast metal operating lever pivotally supported upon the inner surface of one side wall of said housing, said lever having an enlarged portion of relatively thick, flat, segmental form adjacent to the point of pivotal support thereof, said enlarged portion having two groups of openings formed therein, the openings in each group being arranged in a straight line and said lines being arranged at substantially a right angle to each other, and a metal member carried by said side wall of the housing and arranged in parallel relation to said enlarged fiat portion of said lever, said member having a plurality of openings formed therein and arranged in a straight line substantially parallel to the upper portion of said side wall, the openings arranged in a straight line in one of said groups being adapted to register with all of the openings in said member in one angular position of said lever, and the openings arranged in a straight line in tne other of said groups being adapted to register with certain of the openings in said member in another angular position of said lever.

8. In a front-side o erated safety switch of the snap make and break type, in combination, a sheet metal housing having bottom, side and end walls and a movable cover, a die-cast metal operating lever pivotally supported upon the inner surface of one side wall of said housing, said lever having an enlarged portion of relatively thick, flat, segmental form adjacent to the point of pivotal support thereof, said enlarged portion having two groups of openings formed therein, the openings in each group being arranged in a straight line and said lines being arranged at substantially a right angle to each other, a metal member carried by said side wall of the housing and arranged in parallel relation to said enlarged flat portion of said lever, said member having a plurality of openings formed therein and arranged in a straight line substantially parallel to the upper portion of said side wall, the openings arranged in a straight line in one of said groups being adapted to register with all of the openings in said member in one angular position of said lever, and the openings arranged in a straight line in the other of said groups being adapted to register with certain of the openings in said member in another angular position of said lever, and said lever being movable from one of said angular positions thereof to throw the corresponding group of openings in the flat portion thereof out of registry with all of the openings in said metal member and to bring only one of the openings in the other group into registry with one of the openings in said metal member.

RALPH A. MILLERMASTER. ALEX A. WRITZMANN.