US3284598A

US3284598A - Cartridge fuse pull-out switch

Info

Publication number: US3284598A
Application number: US423680A
Authority: US
Inventors: Melvin J George; Harris I Stanback
Original assignee: Square D Co
Current assignee: Schneider Electric USA Inc
Priority date: 1965-01-06
Filing date: 1965-01-06
Publication date: 1966-11-08
Anticipated expiration: 1983-11-08
Also published as: GB1089069A

Description

1966 M. J. GEORGE ETAL 3, 84,598

' CARTRIDGE FUSE PULL-OUT SWITCH Filed Jan. 6, 1965 5 Sheets-Sheet 1 |1 l UM 55c Z6 iVeZwm JGeor e ii, l J 9 ,i/a 7 1 1617? (522272 ac/ 54a 3k 7 0W2 4. M

8, 1956 M. .1. GEORGE ETAL 3, 84,598

CARTRIDGE FUSE PULL-OUT SWITCH Filed Jan. 6, 1965 3 Sheets-Sheet 5m 56 3% 56a, 355 385 flc Nov. 8, 39% J. GEORGE ETAL 3,284,598

CARTRiDGE FUSE PULL-OUT SWITCH Filed Jan. 6, 1965 5 Sheets-Sheet 3 United States Patent l 3,284,598 CARTRIDGE FUSE PULL-OUT SWITCH Melvin J. George, Ferndale, Mich, and Harris I. Stanback, Lexington, Ky., assignors to Square D Company, Park Ridge, Ill., a corporation of Michigan Filed Jan. 6, 1965, Ser. No. 423,680 8 Claims. (Cl. 200133) This invention relates generally to cartridge fuse pullout switches, and more particularly to a cartridge fuse pu'l-l-out switch adapted to be plugged into an electrical panelboard.

An object of the invention is to provide a cartridge fuse pull-out switch including a casing and an elongated fuse holder removably insertable therein axially of a cartridge fuse held by the fuse holder, the fuse holder including a pair of generally flat contact blades disposed at right angles to each other on adjacent longitudinal sides to perm-it over-lapping of the contact blades axially of the fuse and thus provide :sufiicient resiliency in the contact blades on fuse holders for short fuses.

Another object is to provide a fuse holder for such a cartridge fuse pull-out switch, the fuse holder having a body formed of electrically insulating material and including an integral port-ion preventing contact between a fuse clip secured to the fuse holder and a terminal strap in the casing when the switch is electrically energized and the fuse holder is inserted in the casing by a workman while he is inadvertently touching the fuse.

A further object is to provide a fuse holder for such a cartridge fuse pull-out switch, the fuse holder including a body portion formed of electrically insulating material and a bracket member secured to the body portion and carrying a separate insulating member for preventing contact between a fuse clip secured to the body portion and a terminal strap in the casing when the switch is electrically energized and the fuse holder is inserted in the casing by a workman while he is inadvertently touching the fuse.

Still another object is to provide a fuse holder for such a cartridge fuse pull-out switch, the fuse holder having a body formed of electrically insulating material and including an otherwise solid side wall portion having a slot therethr-ough for accommodating a tool for prying a fuse out of a pair of fuse clips secured to the body.

Other objects will appear when the following specification is considered along with the accompanying drawings in which:

FIG. 1 is a side elevational view of a cartridge fuse pullout switch constructed in accordance with the invention;

FIG. 2 is an end elevational view of the switch of FIG. 1;

FIG. 3 is a top view of the switch of FIG. 1;

FIG. 4 is an enlarged sectional view of the switch of FIG. 1 taken generally along the line 4-4 of FIG. 8;

FIG. 5 is a perspective view of one of the fuse holders of the switch of FIG. 1;

FIG. 6 is a perspective view of the line terminal strap and plug-in line terminal assembly of the switch of FIG. 1;

FIG. 7 is an enlarged sectional view of the switch of FIG. 1 taken generally along the line 7-7 of FIG. 8;

FIG. 8 is an enlarged view of the switch of FIG. 1, with half of the casing removed and with the fuse holders shown in section;

FIG. 9 is an enlarged sectional view of the switch FIG. 1 taken generally along the line 99 of FIG. 8;

FIG. 10 is a view of the fuse holder shown in FIG. 9 taken from the left of the fuse holder as shown in FIG. 9 and omitting the casing;

FIG. 11 is a view of the 'fuse holder taken from the left of FIG. 10;

FIG. 12 is a fragmentary view similar to the fuse holder 3,284,598 Fatented Nov. 8, 1966 of the switch of FIG. 1 as shown in FIG. 9, but showing a modified fuse holder;

FIG. 13 is a fragmentary view of the modified fuse holder taken from the left of FIG. 12;

FIG. 14 is a perspective view of a portion of the modiiied fuse holder of FIGS. 12 and 13; and

FIG. 15 is a fragmentary view of a dual fuse holder usable in a double switch unit such as would be formed by securing two switches like the switch of FIG. 1 together.

FIGS. l3 show a cartridge fuse pu l-out switch 20 constructed in accordance with the invention and includ ing a casing 22 and a pair of fuse holders 24 removably insertable therein selectively in ON and OFF positions.

' e casing 22 is molded of electrically insulating material and includes two generally

symmetrical halves

22a and 22b held together preferably by a plurality of rivets 23 and provided with appropriate internal projections and pockets for securing various parts of the switch in proper position and for removably receiving the fuse holders 24.

FIG. 8 shows an enlarged view of the switch 20 with the casing half 22a removed. Various parts of the switch trapped between the

casing halves

22a and 22b include a line terminal strap and plug-in line terminal assembly 26 (best shown in FIG. 6), a pair of lamps 28 for indicating blown fuses, a pair of generally U-shaped spring members 30 electrically connected respectively to the indicating lamps 28, each spring member 30 having a pair of leg portions disposed on opposite sides of the associated indicating lamp 28 and a bight portion from which a yieldable stationary contact portion 32 depends, a pair of resistors 34 electrically connected respectively to the indicating lamps 28, a pair of load terminal straps 37 and 38, and a pair of spring members 40 eooperable respectively with the load terminal straps 37 and 38 to provide load terminals. Also trapped between the

casing halves

22a and 22b and around one of the rivets 23 is a mounting clip 42.

The terminal assembly 26 (FIG. 6) includes a line minal strap portion 26a which might be described as generally L-shaped with a long leg portion 26b fiatwise offset in one direction and a short leg portion 260 flatwise offset in an opposite direction. The leg portion 26b is provided with raised stationary contact portions 26d and 26a for cooperation respectively with the fuse holders 24, as hereinafter described, and with a bent tang portion 26 which aids in anchoring the assembly 26 in the casing 22. A pair of

spring jaws

26g and 26h are riveted or otherwise secured to the leg portion 260 to provide a plug-in type line terminal.

Each of the indicating lamps 28 is provided with a lead wire 44 electrically connected in any suitable manner to the associated spring member 30 and with a lead wire 46 electrically connected through the respective resistor 34 to the respective one of the load terminal straps 37 and 38. Inner end portions 37a and 38a of the load terminal straps form stationary contacts for cooperation respectively with the fuse holders 44, as hereinafter set forth. Outer end portions 371) and 38b'of the load terminal straps are grooved respectively at 37c and 380 (FIG. 4) to receive a pair of load wires (not shown) insertable respectively through a pair of openings 39 provided in the casing 22. The spring members 40 cooperate respectively with the outer end portions 37b and 38b to form load terminals, in a manner more fully set forth in US. Patent No. 3,133,999.

The fuse holders 24 are constructed as shown in full view in FIGS. 5, 9, 10, and 11 and in section in FIGS. 4, 7, and 8. Each fuse holder 24 includes a body 52 molded of electrically insulating material and provided with an integral handle portion 52a, an inner combination fuse clip and movable contact blade member 54 secured to a wall terof the body 52 as by a rivet 55, and an outer combination fuse clip and movable contact blade member 56 secured to the same wall of the body 52 as by a rivet 57. Each member 54 includes a generally U-shaped fuse clip portion 540 as best shown in FIG. 4, and each member 56 includes a generally U-shaped fuse clip portion 56a as best shown in FIG. 7, the

fuse clip portions

54a and 56a of each fuse holder 24 being adapted to hold opposite end portions of a cartridge fuse 60 as best shown in FIG. 8.

Each member 54 includes a generally flat movable contact blade portion 54b extending from the bight portion of the generally U-shaped fuse clip portion 54a and engageable with one of the stationary contact portions 37a and 38a, as best shown in FIG. 8. Each member 56 includes a generally flat movable contact blade portion 56b extending from one of the leg portions of the generally U- shaped fuse clip portion 56a and engageable with one of the stationary contact portions 26d and 26a, as best shown in FIG. 9. Because each blade portion 54b extends from the bight portion of the respective fuse clip portion 54a while each blade portion 56b extends from one of the leg portions of the respective fuse clip portion 56a, the

blade portions

54b and 56b of each fuse holder 24 are generally at right angles to each other. Each blade portion 56b thus may be made to overlap a tongue portion 540 of the respective member 54 in the axial direction of a respective fuse 60. This overlapping effect enables the

blade portions

54b and 56b to be made longer, for greater resiliency, than they could be if they were on the same side of the respective fuse holder. The rivet 55 of each fuse holder. extends through the tongue portion 540 of the respective member 54, the tongue portion 540 in each instance extending from the bight portion of the fuse clip portion 54a oppositely from the respective blade portion 54b.

As shown best in FIG. 9, the body 52 of each fuse holder 24 includes an inner end portion 52b which extends laterally outward (toward the left as viewed in FIG. 9) farther than the fuse clip portion 54a and thus prevents the fuse clip portion 54a from contacting the respective stationary contact portion 260. or 26c as the fuse holder is inserted into the casing 22. Therefore, if a workman inserts a fuse holder 24 in the casing 22 while the stationary contact portions 26d and 26a are at line voltage and while he is inadvertently touching the respective member 56 or the outer end of the respective fuse 60, he will be protected.

As will be understood, a double unit may be produced by securing'two casings 22 together with longer rivets 23, and dual fuse holders 24a may be produced by molding two bodies 52 connected by a common handle portion 52s but spaced apart exclusively of the common handle portion sufficiently to accommodate adjacent wall portions of two connected casings 22, as indicated at 61 in FIG. 15. On such a dual fuse holder, one of the fuses 60 can be pried out of its respective

fuse clip portions

54a and 56a by prying between the

fuse clip portions

54a and 56a, as at 522 in FIG. 15, and the other of the fuses 60 can be pried out of its respective

fuse clip portions

54a and 56a by prying through a slot 52d provided in the respective body 52. The location 52c and slot 52d are shown more clearly in the single fuse holder 24 shown in FIG. 5, although the slot 52d is not necessary for a single fuse holder.

FIGS. l2, l3, and 14 show a modified fuse holder 24b which differs from the fuse holder 24 at the inner end portion. A molded body 62 of the fuse holder 24b is shorter than the body 52. of the fuse holder 24 and instead of an integral protective.portion such as portion 52b of the fuse holder 24, the fuse holder 24b is provided with a separate protective member 63 formed of insulating material and adapted to prevent contact between a fuse clip portion 64a of a combination fuse clip and movable contact blade member 64 and the respective

stationary contact portion

26d or 26c as the fuse holder 24b is inserted into a casing 22. The member 64 includes a movable contact blade portion 64b similar to the movable contact blade portion 54b of the member 54 of the fuse holder 24, and a tongue portion 640 similar to the tongue portion 54c of the member 54. The member 64 is secured to the body 62 by a rivet 65 extending through the tongue portion 640. The rivet 65 also secures a longer leg portion 68a of a generally L-shaped bracket 68 to the body 62. The protective member 63 is secured to a shorter leg portion 68b of the bracket 68 by means of a rivet 69. Preferably the leg portion 68b is provided with a circular dished configuration as at 680 in order that the inner head of the rivet 69 may be recessed within the member 63. The leg portion 68a is provided with a humped portion 68d for receiving a center portion of a wire spring member 70 between the humped portion and the tongue portion 640 of the member 64. The opposite end portions of the spring member 70 embrace opposite legs of the fuse clip portion 64a, as best shown in FIG. 14, to impart added resilience thereto.

Various modifications may be made in the structure disclosed without departing from the spirit and scope of the invention as set forth in the appended claims.

We claim:

1. A cartridge fuse pull-out switch comprising a casing, a line terminal mounted adjacent one end of said casing, a terminal strap in said casing electrically connected to said line terminal, and a pair of separate elongated fuse holders disposed in said casing, each of said fuse holders being re-movably insertable in the casing longitudinally of the fuse holder and axially of a cartridge fuse when a cartridge fuse is mounted in the fuse holder, each of said fuse holders being removably insertable in the casing selectively in ON and OFF positions, and each of said fuse holders including a pair of generally fiat contact blades linearly displaced from each other along a longitudinal axis of the fuse holder and angularly displaced substantially ninety degrees from each other about the longitudinal axis of the fuse holder, and said terminal strap being engaged with a contact blade of each of said fuse holders when said fuse holders are in the ON position in said casing.

2. A cartridge fuse pull-out switch comprising a casing, a line terminal mounted adjacent one end of said casing, a terminal strap in said casing electrically connected tosaid line terminal, and an elongated fuse holder disposed in said casing, said fuse holder being rem-ovably insertable in said casing longitudinally of the fuse holder and axially of a cartridge fuse when a cartridge fuse is mounted in said fuse holder, said fuse holder including an elongated body formed of electrically insulating material and a pair of inner and outer fuse clips mounted thereon, said body including an integral portion disposed inwardly of said inner fuse clip and extending beyond said inner fuse clip in a direction perpendicular to a longitudinal axis of said body to prevent contact between said inner fuse clip and said terminal strap as said fuse holder is inserted into said casing.

3. A cartridge fuse pull-out switch comprising a casing, a line terminal mounted adjacent one end of said casing, a terminal strap in said casing electrically connected to said line terminal and an elongated fuse holder disposed in said casing, said fuse holder being removably insertable in said casing longitudinally of the fuse holder and axially of a cartridge fuse when a cartridge fuse is mounted in said fuse holder, said fuse holder including an elongated body formed of electrically insulating material and a pair of inner and outer fuse clips mounted thereon, a bracket secured to said body and having a portion disposed inwardly of said inner fuse clip, and an insulating member secured to said bracket portion inwardly of said inner fuse clip and extending beyond said inner fuse clip in a direction perpendicular to a longitudinal axis of said body to prevent contactbetween said inner fuse clip and said,

terminal strap as said fuse holder is inserted into said casing.

4. A dual fuse holder for a cartridge fuse pull-out switch, said fuse holder comprising a pair of elongated spaced apart body portions formed of electrically insulating material and joined solely adjacent one end by a common handle portion, each of said body portions having a pair of leg portions defining a generally L-shaped cross section correspondingly disposed tothe generally L- shaped cross section of the other body portion, each of said body portions having a pair of fuse clips mounted on one of its leg portions for receiving a cartridge fuse in a direction generally parallel to the other of its leg portions, and the one body portion having its said other leg portion disposed remotely from the other body portion having a slot through its said other leg portion to aid in removal of a cartridge fuse from the fuse clips of said one body portion.

5. A cartridge fuse pull-out switch as claimed in claim 1, wherein the contact blades of each of said fuse holders overlap each other longitudinally of the fuse holder.

6. A cartridge fuse pull-out switch as claimed in claim 3, including a spring member having a mounting portion held between said inner fuse clip and said bracket and having portions urging the legs of said inner fuse clip toward each other to increase the clamping pressure on an end portion of a fuse mounted therein.

7. A fuse holder for a cartridge fuse pull-out switch, said fuse holder comprising (a) an elongated body formed of electrically insulating material and including a mounting wall portion,

(b) a first electrically conductive combination fuse clip and contact blade member mounted on said mount ing wall portion and including (1) a generally U-shaped fuse clip having (a) a bight portion disposed on an inner side of said mounting wall portion and extending generally parallel to said mounting wall portion, and (b) a pair of spaced leg portions extending from said bight portion inwardly and away from said mounting wall portion and adapted to clampingly receive an end portion of a cartridge fuse therebetween, and

(2) a generally flat contact blade extending from one of said leg portions of the fuse clip of said first member generally longitudinally of said body in generally perpendicular relationship to said mounting wall portion, and

(c) a second electrically conductive combination fuse clip and contact blade member mounted on said mounting wall portion in spaced relationship to said first member longitudinally of said body and includmg (1) a generally U-shaped fuse clip having (a) a bight portion disposed on an outer side of said mounting wall portion and extending generally parallel to said mounting wall portion, and

(b) a pair of spaced leg portions extending from said bight portion inwardly past said mounting wall portion and adapted to clampingly receive the other end portion of a cartridge fuse therebetween, and

(2) a generally flat contact blade extending from the bight portion of the fuse clip of said second member generally longitudinally of said body in generally parallel relationship to said mounting Wall portion.

8. A fuse holder as claimed in claim 7, wherein said second member includes a generally flat mounting tongue extending from the bight portion of the fuse clip of said second member oppositely from said contact blade of said second member, and said mounting tongue extends longitudinally of said body into partially overlapping relationship with said contact blade of said first member on the opposite side of said mounting wall portion.

References Cited by the Examiner UNITED STATES PATENTS 1,966,716 7/1934 Green 200-114 2,581,308 1/1952 Smith 200-133 X 2,621,227 12/1952 McMahon 339-258 X 2,984,723 5/1961 Jacobs 200-113 BERNARD A. GILHEANY, Primary Examiner. H. B. GILSON, Assistant Examiner.

Claims

1. A CARTRIDGE FUSE PULL-OUT SWITCH COMPRISING A CASING, A LINE TERMINAL MOUNTED ADJACENT ONE END OF SAID CASING, A TERMINAL STRAP IN SAID CASING ELECTRICALLY CONNECTED TO SAID LINE TERMINAL, AND A PAIR OF SEPARATE ELONGATED FUSE HOLDERS DISPOSED IN SAID CASING, EACH OF SAID FUSE HOLDERS BEING REMOVABLY INSERTABLE IN THE CASING LONGITUDINALLY OF THE FUSE HOLDER AND AXIALLY OF A CARTRIDGE FUSE WHEN A CARTRIDGE FUSE IS MOUNTED IN THE FUSE HOLDER, EACH OF SAID FUSE HOLDERS BEING REMOVABLY INSERTABLE IN THE CASING SELECTIVELY IN ON AND OFF POSITIONS, AND EACH OF SAID FUSE HOLDERS INCLUDING A PAIR OF GENERALLY FLAT CONTACT BLADES LINEARLY DISPLACED FROM EACH OTHER ALONG A LONGITUDINAL AXIS OF THE FUSE HOLDER AND ANGULARLY DISPLACED SUBSTANTIALLY NINETY DEGREES FROM EACH OTHER ABOUT THE LONGITUDINAL AXIS OF THE FUSE HOLDER, AND SAID TERMINAL STRAP BEING ENGAGED WITH A CONTACT BLADE OF EACH OF SAID FUSE HOLDERS WHEN SAID FUSE HOLDERS ARE IN THE ON POSITION IN SAID CASING.