US3753192A

US3753192A - Protector for electric circuits

Info

Publication number: US3753192A
Application number: US00200711A
Authority: US
Inventors: A Urani
Original assignee: MCGROW EDISON CO
Current assignee: Cooper Industries LLC
Priority date: 1969-02-04
Filing date: 1971-11-22
Publication date: 1973-08-14
Anticipated expiration: 1990-08-14
Also published as: US3518600A

Abstract

A female connector is connected to a conductor and normally telescopes over a male connector on one end of a fuseholder, but is will respond to a separating force, smaller than the elastic limit of that fuseholder, to release that male connector; and a sleeve of insulating material normally encases and insulates the connection between that male connector and that female connector.

Description

United States Patent 1191 111 3,753,192 Urani Aug. 14, 1973 [54] PROTECTOR FOR ELECTRIC CIRCUITS 3,356,806 12/196; Urani 3,417,359 12 196 Urani... l [75] Invent: i 3,518,600 6/1970 Urani 337/192 x [73] Assignee: McGraw-Edlson Company, Elgin, 111.

[22] Filed: No 22 1971 Primary Examiner-Bernard A. Gilheany Assistant Examiner-F. E. Bell [211 App]. No.: 200,711 AtmMey Rey Eilers Related U.S. Application Data I [60] Continuation of Ser. No. 871,233, Nov. 3, 1969,

which is a division Of Sci. NO. 796,520, Feb. 4, 1969, 7 ABSTRACT A female connector is connected to a conductor and normally telescopes over a male connector on one end (gl. 337l2llllll3h3gls of a fuseholder, but is will respond to a separating 58] Fieid "5 201, force, smaller than the elastic limit of that fuseholder, 21 1 to release that male connector; and a sleeve of insulating material normally encases and insulates the connection between that male connector and that female con- [5 6] References Cited necton UNITED STATES PATENTS 3,085,138 4/1963 Brown et a1. 337/192 4 Claims, 7 Drawing Figures PROTECTOR FOR ELECTRIC CIRCUITS This is a continuation of application Ser. No. 871,233 filed Nov. 3, 1969, which was a division of application Ser. No. 796,520 filed Feb. 4, 1969 now US. Pat. No. 3,518,600.

This invention relates to improvements in Protectors For Electric Circuits. More particularly, this invention relates to improvements in fuseholders and in separable connectors used therewith.

It is, therefore, an object of the present invention to provide an improved fuseholder and. an improved separable connector used therewith.

It is desirable to interpose fuseholders between the sockets for street lamps and the power lines connected to. those sockets; because the fuses within those fuseholders can provide important electrical protection. That electrical protection can be impaired and those fuseholderscan be damaged, when vehicles strike and break off those street lamps; because the conductors within those street lamps can, as those street lamps are broken off, applydestructive' tensile forces to the fuseholders andto the connectionsbetween those fuseholders and the powerlines- It would be desirable toequip a fuseholder, to be. interposed between the socket of 'a street lamp. and the. power; line. connected to that socket, with a separable connector which would respond to forces smaller than the elastic limit of that fuseholder toseparate}. from: that fuseholder; and it wouldbe desirabletoprovide that separableconnector with insulation which: would? remain with that separable connector as;it isseparatedifrom thatfuse-hold'er. Such a separable connector and the. insulation therefor would keepz that fuseholder from being subjected'to dc-- present. invention; to equip. a fuseholder, to be interposedbetween the socket of a street lamp and the powerline connected to: that socket, withia separable connector whichwill respond to forcessmaller than theelastic limit of that. fuseholder. to separate from that" fuseholder, andto provide: that separable connector with insulation: which: will. remainwith that. separable connector as it is separated from that fuseholder.

Other andfurther objects and advantages of the present invention should become? apparent from anexamination of the drawing'and accompanying: description.

In t the drawingandaccompanying description several preferred embodiments ofthe present invention are shown and described-butsit isto beunderstood that 'the drawing and accompanying description are for the pur pose of illustration only andd'o not'limit the invention and that the invention wilhbe' defined by-the' appended claims.

- In the drawing;

FIG; 1 is a partially sectioned. view-ofv afuseholder, ofa'separable. connector used'with that fuseholder; of. a sleeve'ofrinsulatingmaterial used with that separable connector, and of two'boots of insulating material used with thatfuseholder and with'th'at'separable connector,

FIG. 2isa cross-sectional view that is-taken along the plane-indicated by; the line. 2 -2"- in' FIG 1,

1 FIG. 3" is. a. partially: broken-away, side elevational view of one ofthe-boots-ofinsulatingmaterial shown in'FIG. 1,

FIG; 4 isa-partially sectionedside view showingthe fuseholder of F165 1 assembledwith a different separa;

- ble connector,

FIG. 5 is a partially sectioned view of the different boot shown in FIG. 4,

FIG. 6 is a sectional view through the different boot shown in FIG. 4, and it'is taken along the plane indicated by the line 6-6 in FIG. 5, and

FIG. 7 is a partially sectioned view of a different fuseholder and of a boot of insulating material therefor.

Referring to the drawing in detail, the numeral 20 generally denotes a fuseholder of the type shown in my US. Pat. No. 3,356,806 for Protectors For Electric Circuit which was granted Dec. 5, i967; and that fuseholder has a body portion 21 and a body portion 23. The body portion 23 has an external thread 25 at the left-hand end thereof, has a hexagonal wrenchreceiving surface 27 adjacent that thread, and has a male connector 22 projecting outwardly beyond the right-hand end thereof. The male connector 22 has an enlarged diameter portion 24 that abuts the body portion 23. The body portion 21 has a nut 26 with an internal thread rotatably mounted on the right-hand end thereof and has a terminal 76, with an elongated recess in the shank thereof, projecting outwardly beyond the left-hand end thereof. The

body portions

21 and 23 are hollow; and they coact to form a recess which will accomodate a cartrid'getype electric fuse, all in the manner shown by my said patent.

The numeral 28 generally denotes a separable connector of tubular configuration; and that separable connector has a continuous and unbroken sleeve-like portion30 at the right-hand'thereof, and'h'as elongated, flexible."

fingers

34 ,36, 38and 40 at the left-hand end thereofwhich define an elongated recess 32, The fingers 34', 36, 38'and40 have radially'extending flanges" at'thefree-ends thereofi and the inner surfaces of those fingers can be spread'far'enough-apart to accommodate the: male connector 22 on'the body portion" 23 of the fusehold'er20. As a result, the

fingers

34, 36, 38 and 40 enable the separable'connector 28 to act as a female connector. However,- a split ring 42 of resilient mate'- rial, such as spring steel, encircles the free ends of the

fingers

34, 36,. 38 and 40; and that split ring biases those free ends-into a position wherein they define an openingwithadiameter smaller than the diameterof the" male connector 22 on the body portion 23. This means that the male connector 22 must distend that split ring as it is moved into the elongatedrecess 32 defined by the fingers 34', 36,-38 and 40. After that-male connector hasbeen moved into the elongated recess 32, the force which the split ring 42 applies to the

fingers

34, 36,38'and 40will hold those fingers in intimate engagement with the male connector 22, thereby providing good mechanical securement and-good electricalcontact between thosefingers andthat male connector.

The numeral 44 denotes a-sleeve of insulating material,isuch as neopreneyand the inner diameter of the right-hand'end 'of that'sleeve is slightly smaller than the diameter of the separable connector 28. As a result, thatright-hand endof that sleeve hasapress fit-with that separable connector. An annular recess 46 is provided in thesleeve 44; andthat recess is dimensioned to accommodate the split ring 42. A further annular recess 481s provided in the sleeve 44; and that recess is dimensioned to accommodate the radially directed flanges at the free ends of the

fingers

34', 36, 38 and 40 of the separable connector 28. A larger diameter recess 50 is provided in the left-hand of the sleeve 44; and the inner diameter of that sleeve is slightly smaller than the diameter of the body portion 23 of the fuseholder 20. As a result, the recess 50 will provide a close fit with that body portion when the left-hand end of the sleeve 44 is telescoped over that body portion. A shoulder 52 is provided in the sleeve 44 between the annular recess 48 and the larger diameter recess 50; and that shoulder will help prevent accidental separation of that sleeve from the separable connector 28.

The numeral 54 denotes an insulated conductor which has the right-hand end thereof freed of insulation; and that right-hand end is telescoped within the elongated recess in the shank of the terminal 76 of the body portion 21 of the fuseholder 20. Once that end of that conductor has been telescoped within that recess, the terminal 76 will be crimped, staked, or otherwise deformed to provide a permanent electrical and mechanical connection between that terminal and that end of that conductor. The numeral 56 denotes an insulated conductor which has the left-hand end thereof freed of insulation; and that left-hand end is telescoped within the continuous and unbroken sleeve-like portion 30 at the right-hand end of the separable connector 28.

. Once that end of that conductor has been telescoped within that portion, that portion will be crimped, staked or otherwise deformed to provide a permanent electrical and mechanical connection between'that conductor and the separable connector 28.

While the separable connector 28 will be permanently connected to the conductor 56 by the crimping, staking, or other deforming of the sleeve-like portion 30, that separable connector will have only a frictional engagement with the male connector 22 of the body portion 23 of the fuseholder 20. That frictional engagement will provide holding forces which are strong enough to prevent accidental separation of the separable connector 28 from the male connector 22, and which are strong enough to provide a low resistance electrical connection between that separable connector and that male connector; but those forces will be smaller than the elastic limit of the fuseholder 20. This is important; because it enables the separable connector 28 to release the male connector 22 before the fuseholder 20 can be subjected to potentially hurtful forces. Also, the separable nature of the

connectors

22 and 28 is important in rendering a broken-off street lamp electrically dead so persons coming incontact with that street lamp will not receive an electrical shock.

The numeral 58 generally denotes a boot of insulat: ing material, such as neoprene; and that boot has a frusto-conical left-hand end 60 and a cylindrical right-hand end 62. Annular ribs 64 are provided at the exterior of the frusto-conical end 60, and annular ribs 66 are provided at the interior of the cylindrical end 62. The unstressed diameters of the annular ribs 66 at the interior of the cylindrical end 62 are slightly smaller than the diameter of the body portion 21, and hence those annular ribs will provide a close fit with that body portion on that conductor, as that left-hand end is distended to permit that conductor to be passed through it.

FIG. 3 shows the configuration of the boot 58 a s that boot is sold; and it will be noted that the boot 58 in FIG. 1 has bad part of the left-hand end 60 thereof cut off. That part was cut off because the insulation on the conductor 54 has a diameter which is appreciably larger than the inner diameter of the smallest diameter portion of the left-hand end 60 of the boot 58, as that boot is sold. Specifically, it will be noted that there are eight ribs 64 at the exterior of the left-hand end 60 of the boot 58 shown in FIG. 3, but there are only seven ribs 64 at the exterior of the boot 58 shown in FIG. 1 the left-handmost rib 64 and the portion of the left-hand end 60 between that first rib and the second rib having been cut off.

In determining where the frusto-conical left-hand end 60 of the boot 58 should be cut, one end of the insulated conductor 54 will be telescoped through the cylindrical end 62 of the boot 58 and moved into engagement with the inner surface of the frusto-conical lefthand end 60. When a light pressure on the conductor 54 is unable to cause the left-hand end of that conductor to move any further through the frusto-conical lefthand end 60 of the boot 58, the portion of that frustoconical left-hand end into which the insulated conductor 54 did not extend will be cut off, by appropriate use of a knife, scissors or the like. The cut will be made to the left of the right-handmost annular rib 64 through which the end of the insulated conductor 54 did not extend; and hence that rib and the part of the frustoconical left-hand end 60 which is adjacent to, and slightly to the right of, that rib will have to be distended as the conductor 54 is subsequently pressed through that frusto-conical left-hand end. After the frustoconical left-hand end 60 of the boot 58 has been cut, the insulated conductor 54 will be introduced into that boot by first passing it through the frusto-conical lefthand end 60 and then moving it through the cylindrical end 62. At such time, the bared end of that conductor will be telescoped into the terminal 76 of the body portion 21 of the fuseholder 20 and then that terminal will be crimped, staked or otherwise deformed to provide a permanent electrical and mechanical connection between that conductor and that terminal. Thereafter, the boot 58 will be shifted to the right, relative to the conductor 54, until the cylindrical end 62 telescopes onto the body portion 21 of the fuseholder 20.

The engagement between the frusto-conical end 60 of the boot 58 and the insulation on the conductor 54 will be snug and will be water-resistant. Similarly, the engagement between the annular ribs 66 at the inner surface of the cylindrical end 62 of that boot and the body portion 21 of the fuseholder 20 will be snug. Those annular ribs will coact with that body portion to provide a plurality of spaced seals; and those seals will effectively resist the entry of water into the joint between the boot 58 and the fuseholder 20. I

The numeral 68 generally denotes a boot which can be identical to the boot 58.'The annular ribs 69 within the cylindrical, left-hand end 70 of the boot 68 will be distended to telescope over the right-hand end of the sleeve 44; and those ribs will coact with that sleeve to provide a plurality of spaced seals. The frusto-conical right-hand end 72 of the boot 68 will be cut to provide a snug and intimate engagement with the insulation on the conductor 56; and, as with the boot 58, there are just seven annular ribs 74 at the exterior of the righthand end 72 of the boot 68. The boot 68 will coact with the sleeve 44 on the separable connector 28 and with the insulation on the conductor 56 to provide waterresistant joints on opposite sides of the electrical connection between that conductor and that separable connector.

The fuseholder 20 has a water-tight seal between the body portion 21 and the terminal 76 thereof, has a water-tight seal between the body portion 23 and the male connector 22 thereof, and will provide a water-resistant seal between the

body portions

21 and 23 thereof. The boot 58 will coact with the body portion 21 and with the insulation on the conductor 54 to keep water away from the electrical connection between that conductor and the terminal 76; and the sleeve 44 of insulating material and the boot 68 will coact with the body portion 23 and with the insulation on the conductor 56 to keep water away from the electrical connection between that conductor and the separable connector 28 and away from the electrical connection between that separable connector and the male connector 22. As a result, the fuse within the fuseholder 20 and the connections between that fuseholder and the

conductors

54 and 56 are protected against moisture and water.

The conductor 56 will be connected to the line side of the circuit, and the conductor 54 will be connected to the load side of the circuit. The male connector 22 will thus be the load connector and the female connector 28 will thus be the line connector of 30 the connection provided by those two connectors; and this is important, because that male connector will be exposed whereas that female connector will be protected whenever that connection is interrupted. Specifically, the portion'of the sleeve 44 of insulating material which defines the recess 50 will project outwardly beyond the left-hand end of the female connector 28, and will thus keep that female connector from contacting any nearby objects or the ground as that female connector and the male connector 22 are separated. Further, that portion of the sleeve 44 of insulating material will keep a repairman from being shocked as he picks up the line connector of the connection provided by the male connector 22 and the female connector 28.

It should also be noted that the boot 68 will remain in engagement with the conductor 56 and with the sleeve 44' of insulating material whenever the connection provided by the male connector 22 and the female connector 28 is interrupted. Specifically, the annular ribs 69 at the interior of the cylindrical portion 70 of that boot will continue to remain in engagement with the exterior of the right-hand portion of the sleeve 44 of insulating material, and the small diameterrighthand end 72 of that boot will remain in engagement with the insulation on the conductor 56. As a result, that boot will continue to encase and to insulate the connection between the conductor 56 and the female connector 28 whenever the connection between that female connector and the male connector 22 is interrupted. The overall result is that the female connector 28 will continue to be protected and shielded and the connection between that female connector and the conductor 56 will continue to be encased and shielded whenever the connection provided by the male connecto'r 2 2 and the female connector 28 is interrupted.

To restore the connection provided by the male connector 22 and the female connector 28 the repairman will grip the cylindrical end 62 of the boot 58, will grip the cylindrical portion of the boot 68,- and will guide the tapered tip of the male connector 22 into the re male connector 28. Thereafter, that repairman will apply relatively strong telescoping forces to the body portion 21 of the fuseholder 20 and to the female connector 28 to effect full telescoping of the male connector 22 into that female connector. Because the split ring 42 will cause the ends of the

fingers

34, 36, 38 and 40 to strongly resist the telescoping of the male connector 22 into the female connector 28, the repairman may want to press against the left-hand end of the body portion 21 of the fuseholder 20 and to grip the sleeve-like portion 30 of the female connector 28; and the walls of the

boots

58 and 68 will be made thin enough to enable that repairman to do so. Consequently, although the connection provided by the male connector 22 and the female connector 28 is a blind connection, the

boots

58 and 68 will enable the repairman to make that connection and to sense that the connection has been made.

Where the walls of the

boots

58 and 68 are made quite thin, the frusto-conical ends of those boots can tend to tear as those frus'to-conical ends are telescoped over, and are then slid along, the insulation on the

conductors

54 and 56. The walls of the

boots

58 and 68 can be made quite thin, and yet the frusto-conical ends of those boots can be made very resistant to tearing, by providing the

annular ribs

64 and 74, respectively, at the exteriors of the frusto-conical ends 60 and 72 of the

boots

58 and 68.

Referring to FIG. 4, the numeral 82 denotes a conductor which can be identical to the conductor 54, and which will be electrically and mechanically connected to the terminal, not shown, on the left-hand body portion of the fuseholder 20. The junction between that conductor and that terminal will be encased and insulated by a boot 58 which can be identical to the boot 58 shown in FIGS. 1 and 3. The numeral 84 denotes a female connector with a rod-like projection 86 at the righthand end thereof and with four circumferentially spaced fingers adjacent the left-hand thereof. Because FIG. 4 is a side view, only two of those fingers, namely the

fingers

88 and 90, are shown. The female connector 84 of FIG. 4 will closely resemble the separable connector 28 in FIGS. 1 and 2, except for the fact that the female connector 84 has a rod-like projection 86 at the right-hand end thereof whereas the separable connector 28 has a sleeve-like portion 30 at the right-hand end thereof.

A split ring 92 encircles the free ends of the

fingers

88 and 90 plus the other two fingers of the female connector 84, in the same manner in which the split ring 42 encircles the free ends of the

fingers

34, 36, 38 and I 40 of the female connector 28. The split ring 92 will normally hold the free ends of the

fingers

88 and 90 and of the other two fingers ofthe female connector 84 closer together than the diameter of the male connector 22 on the body portion 23 of the fuseholder 20; but that split ring will yield to permit that male connector to be telescoped into position between the free ends of those fingers. The numeral 93 denotes a sleeve of insulating material which can be identical to the sleeve 44 of insulating material in FIGS. 1 and 2; and that sleeve of insulating material will enclose and insulate the

fingers

88 and 90 and the other two fingers of the female connector 84, will enclose and insulate the split ring 92,

and will enclose and insulate the body portion 23 of the fuseholder 20.

The numeral 94 denotes a connector which has a tubular projection 96 extending outwardly from the lefthand end thereof, which has a cylindrical socket 98in the right-hand end thereof, which has a cylindrical socket 100 in the right-hand end thereof, which has a set screw 102 communicating with the cylindrical socket 100, and which has a second set screw, not shown, communicating with the cylindrical socket 98. The tubular projection 96 is dimensioned to telescope freely over the rod-like projection 86 on the female connector 84; but that tubular projection will be crimped, staked or otherwise deformed into permanent engagement with that rod-like projection. Consequently, the connector 94 will, effectively, serve as part of the female connector 84. The socket 98 is dimensioned to accommodate the bared end of an insulated conductor 104, and the socket 100 is dimensioned to accommodate the bared end of an insulated conductor 106. The set screw 102 will be tightened to provide a good electrical and mechanical connection between the connector 94 and the conductor 106; and the second set screw, not shown, will be tightened to provide a good electrical and mechanical connection between the conductor 104 and the connector 94. The connector 94 and the female connector 84 are used where it is desirable to interconnect two conductors to the male connector 22 of the fuseholder 20.

The numeral 108 denotes a boot which has a cylindrical left-hand end with internal annular ribs 110, which has a cylindrical central portion with external annular ribs 112, and which has two frusto-

conical sections

114 and 116 at the right-hand end thereof. The diameters of the ribs 1 10 are slightly smaller than the outer diameter of the right-hand portion of the sleeve 93 of insulating material which encases the

fingers

88 and 90 plus the other two fingers of the female connector 84; and hence those ribs will be distended as they are telescoped over that portion of that sleeve. Thereafter, the restorative forces within those ribs and within the cylindrical left-hand end of the boot 108 will cause those ribs to provide a plurality of water-resistant seals with that portion of the sleeve 93 of insulating material.

The frusto-conical section 114 of the boot 108 will accommodate the conductor 104, which has the lefthand end there-of held within the socket 98 of the connector 94; and the frusto-conical section 116 of that boot will accommodate the conductor 106, which has the left-hand end thereof held within the socket 100 of that connector. The unstressed inner diameter of the outer end of each of the frusto-

conical sections

114 and 116 will be smaller than the diameter of the insulation of the

conductors

104 and 106; and hence those outer ends will be distended as the

conductors

104 and 106 are telescoped through those sections. Thereafter, the restorative forces within those outer ends will provide water-resistant seals between the boot 108 and the insulation on those conductors.

The sleeve 93 of insulating material will encase and insulate the connection between the male connector 22 and the female connector 84; and the boot 108 will encase and insulate the connection between that female connector and the connector 94, and also will encase and insulate the connection between the connector 94 and the

conductors

104 and 106. In the event a force is applied to the conductor 82 or to either of the

conductors

104 and 106 which causes the female connector 84 to move away from the male connector 22 on the body portion 23 of the fuseholder 20, the sleeve 93 will remain in engagement with that female connector, and the boot 108 will remain in engagement with that sleeve and with those conductors. As a result, the female connector 84, the connector 94, the connection between them, and the connection between the connector 94 and the

conductors

104 and 106 will continue to be encased and insulated after the female connector 84 has been separated from the male connector 22 on the body portion 23 of the fuse-holder 20.

As shown by FIG. 7, the boot 108 can be assembled with the body portion of a fuseholder which has a tubular terminal that is large enough to accommodate the ends of two conductors. Specifically, the boot 108 can have the internal annular ribs 110 at the cylindrical left-hand end thereof distended to telescope over the right-hand body portion of a fuseholder which has a tubular terminal 122 that is large enough to accommodate the bared ends of two

conductors

124 and 126. The frusto-

conical sections

114 and 116 at the righthand end of the boot 108 will snugly accommodate the insulation on the

conductors

124 and 126; and the bared ends of those conductors will be held by the crimped, staked or otherwise deformed tubular terminal 122.

The annular ribs 122 on the boot 108 strengthen the cylindrical central portion of that boot; but they permit that cylindrical central portion to be flexible. If desired, external annular ribs, similar to the

annular ribs

64 and 72 of FIG. 1 can be formed on the frusto-

conical sections

114 and 116 at the right-hand end of the boot 108.

While the fuseholders, separable connectors, insulating sleeves, and insulating boots of the present invention are very useful in street lighting circuits, they are useful elsewhere too. In fact, those fuseholders, separable connectors, insulating sleeves, and insulating boots are usable anywhere external forces can accidentally separate a fuseholder from the line or load side of a circuit.

The

boots

58, 68 and 108 and the

sleeves

44 and 93 will be made from material that is resilient as well as non-conductive as a result, those boots and those sleeves will be able to withstand blows and stresses when the street lamp or other power consuming device with which they are used is struck which rigid and brittle elements could not withstand. The overall result is that the fuseholders, separable connectors, insulating sleeves and insulating boots of the present invention I can minimize and largely eliminate the risk of electrical shocks when street lamps and other power consuming devices are struck.

Whereas the drawing and accompanying description have shown and described several preferred embodiments of the present invention it should be apparent to those skilled in the art that various changes may be made in the form of the invention without affecting the scope thereof.

What I claim is:

l. A combination which comprises:

an enclosed fuseholder which has a male body portion, a female body portion, and means to releasably interconnect said body portions,

said male body portion being hollow but having the outer end thereof closed, I

saidfemale body portion being hollow but having the outer end-thereof closed,

said male body portion and said female body portion and said-means coacting to releasably enclose and confine acartridge type electric fuse,

a metallic connector carried by and projecting outwardly from one end of one of said body portions,

a metallic terminal carried by and communicating with the exterior of the other of said body portions,

a-water-tight seal between said one body portion and said metallic connector,

a second'wat'entight seal between said other body portionand said metallic terminal, 1

saidmeans releasably holding the inner ends of said body portions-in intimate engagement with each otherto provide a-water-resistant seal between said body portions,

whereby said cartridge type electric fuse is normally held within'a water-resistant but readily openable enclosed fuse holder,

a metallic separable connector which is located exteriorly of said enclosed fuseholder and which normally has one end thereof in telescoped engagement withaportion of the first said metallic connectorand which has the other end thereof connectable to aconductor, and

a body of insulating material which is mounted on and directly engages a portion of said metallic separable connector and which moves with said metal lic separable connector whenever said metallic separable connector is separated from the first said met'allicconne'ctor,

the first said metallic connector and said metallic separable connector being dimensioned to provide a frictional securement therebetween which is strong enough to normally maintain a low resistance: electrical connection between said fuseholder and said metallic separable connector,

the first said metallic connector and said metallic separable connector being dimensioned so said frictional securement will automatically yield to permit the first said metallic connector and said metallic separable connector to separate from each other in response to a separating force which is smaller than the elastic limit of said fuseholder,

said metallic separable connector and said portion of said first metallic connector, which is in telescoped engagement with said metallic separable connector, being located wholly externally of said one body portion of said enclosed fuseholder,

whereby said metallic separable connector can be pulled away from said first metallic connector while said means holds said male body portion and said female body portion in assembled relation and while thestressapplied to said enclosed fuseholder is well below the elastic limit of said enclosed fuseholder,

whereby said enclosed fuseholder is protected against damage from tensile forces which are applied to it by conductors of the circuit that is protected by the cartridge typevelectric fuse within said enclosed fuseholder.

2. A combination as claimed in claim 1 wherein the first said metallic connector is a male connector and whereinsaid metallic separable connector is a female connector, and wherein said metallic separable connector is a sleeve that is slit at one end thereof to define fingers which can telescope over and tightly grip said first said metallic connector, said metallic separable connector having the other end thereof dimensioned to telescope over the hated end of said conductor.

3. A combination which comprises: an enclosed fuseholder which has a male body portion, a female body portion, and means to releasably interconnect said body portions, said male body portion being hollow but having the outer end thereof closed, said female body being hollow but having the outer end thereof closed, said male body portion'and said female body portion and said means coacting to releasably enclose and confine a cartridge type electric fuse, metallic connector carried by and projecting outwardly from one end of one of said body portions, a metallic separable connector which is located exteriorly of said enclosed fuseholder and which normally has one end thereof in telescoped engagement with a portion of the first said metallic connector and which has the other end thereof connectable to a conductor, body of insulating material which is mounted on and directly engages a portion of said metallic separable connector and which moves with said metallic separable connector whenever said metallic separable connector is separated from the first said metallic connector, the first said metallic connector and said metallic separable connector being dimensioned to provide a frictional securement therebetween which is strong enough to normally maintain a low resistance electrical connection between said fuseholder and said metallic separable connector, the first said metallic connector and said metallic separable connector being dimensioned so said frictional securement will automatically yield to permit the first said metallic connector and said metallic separable connector to separate from each other in response to a separating force whichqis smaller'than the elastic limit of said'fuseholder, said metallic separable connector and said portion of said first metallic connector, which is in telescoped engagement with said metallic separable connector, being located wholly externally of said one body portion of said enclosed fuseholder, whereby said fuseholder is protected against damage from tensile forces which are applied to it by conductors of the circuit that is protected by the fuse within said fuseholder, said metallic separable connector being a sleeve with a plurality of fingers at said one end thereof. 4. A combination which comprises: an enclosedfuseholder which has a male body portion, a female body portion, and means to releasably interconnect said body portions, said male body portion being hollow but having the outer end thereof closed, said female body portion being hollow but having the outer end thereof closed, said male body portion and said female body portion and said means coacting to releasably enclose and confine a cartridge type electric fuse, a metallic connector carried by and projecting outwardly from one end of one of said bodyportions, a metallic separable connector which is located exteriorly of said enclosed fuseholder and which normally has one end thereof in telescoped engagement with a portion of the first said metallic connector and which has the other end thereof connectable to a conductor,

a body of insulating material which is mounted on and directly engages a portion of said metallic separable connector and which moves with said metallic separable connector whenever said metallic separable connector is separated from the first said metallic connector,

the first said metallic connector and said metallic separable connector being dimensioned to provide a frictional securement therebetween which is strong enough to normally maintain a low resistance electrical connection between said fuseholder and said metallic separable connector,

the first said metallic connector and said metallic separable connector being dimensioned so said frictional securement will automatically yield to permit the first said metallic connector and said metallic separable connector to separate from each other in response to a separating force which is smaller than the elastic limit of said fuseholder, said metallic separable connector and said portion of said first metallic connector, which is in telescoped engagement with said metallic separable connector, being located wholly externally of said one body portion of said enclosed fuseholder, whereby said fuseholder is protected against damage from tensile forces which are applied to it by conductors of the circuit that is protected by the fuse within said fuseholder, said metallic separable connector being a sleeve with a plurality of fingers at said one end thereof, and a split ring encircling said one end of said metallic separable connector to enable said one end of said metallic separable connector to apply a substantial pressure to the first said metallic connector.

i 0 I i l

Claims

1. A combination which comprises: an enclosed fuseholder which has a male body portion, a female body portion, and means to releasably interconnect said body portions, said male body portion being hollow but having the outer end thereof closed, said female body portion being hollow but having the outer end thereof closed, said male body portion and said female body portion and said means coacting to releasably enclose and confine a cartridge type electric fuse, a metallic connector carried by and projecting outwardly from one end of one of said body portions, a metallic terminal carried by and communicating with the exterior of the other of said body portions, a water-tight seal between said one body portion and said metallic connector, a second water-tight seal between said other body portion and said metallic terminal, said means releasably holding the inner ends of said body portions in intimate engagement with each other to provide a water-resistant seal between said body portions, whereby said cartridge type electric fuse is normally held within a water-resistant but readily openable enclosed fuseholder, a metallic separable connector which is located exteriorly of said enclosed fuseholder and which normally has one end thereof in telescoped engagement with a portion of the first said metallic connector and which has the other end thereof connectable to a conductor, and a body of insulating material which is mounted on and directly engages a portion of said metallic separable connector and which moves with said metallic separable connector whenever said metallic separable connector is separated from the first said metallic connector, the first said metallic connector and said metallic separable connector being dimensioned to provide a frictional securement therebetween which is strong enough to normally maintain a low resistance electrical connection between said fuse-holder and said metallic separable connector, the first said metallic connector and said metallic separable connector being dimensioned so said frictional securement will automatically yield to permit the first said metallic connector and said metallic separable connector to separate from each other in response to a separating force which is smaller than the elastic limit of said fuseholder, said metallic separable connector and said portion of said first metallic connector, which is in telescoped engagement with said metallic separable connector, being located wholly externally of said one body portion of said enclosed fuseholder, whereby said metallic separable connector can be pulled away from said first metallic connector while said means holds said male body portion and said female body portion in assembled relation and while the stress applied to said enclosed fuseholder is well below the elastic limit of said enclosed fuse-holder, whereby said enclosed fuseholder is protected against damage from tensile forces which are applied to it by conductors of the circuit that is protected by the cartridge type electric fuse within said enclosed fuseholder.

2. A combination as claimed in claim 1 wherein the first said metallic connector is a male connector and wherein said metallic separable connector is a female conNector, and wherein said metallic separable connector is a sleeve that is slit at one end thereof to define fingers which can telescope over and tightly grip said first said metallic connector, said metallic separable connector having the other end thereof dimensioned to telescope over the bared end of said conductor.

3. A combination which comprises: an enclosed fuseholder which has a male body portion, a female body portion, and means to releasably interconnect said body portions, said male body portion being hollow but having the outer end thereof closed, said female body being hollow but having the outer end thereof closed, said male body portion and said female body portion and said means coacting to releasably enclose and confine a cartridge type electric fuse, a metallic connector carried by and projecting outwardly from one end of one of said body portions, a metallic separable connector which is located exteriorly of said enclosed fuseholder and which normally has one end thereof in telescoped engagement with a portion of the first said metallic connector and which has the other end thereof connectable to a conductor, a body of insulating material which is mounted on and directly engages a portion of said metallic separable connector and which moves with said metallic separable connector whenever said metallic separable connector is separated from the first said metallic connector, the first said metallic connector and said metallic separable connector being dimensioned to provide a frictional securement therebetween which is strong enough to normally maintain a low resistance electrical connection between said fuse-holder and said metallic separable connector, the first said metallic connector and said metallic separable connector being dimensioned so said frictional securement will automatically yield to permit the first said metallic connector and said metallic separable connector to separate from each other in response to a separating force which is smaller than the elastic limit of said fuseholder, said metallic separable connector and said portion of said first metallic connector, which is in telescoped engagement with said metallic separable connector, being located wholly externally of said one body portion of said enclosed fuseholder, whereby said fuseholder is protected against damage from tensile forces which are applied to it by conductors of the circuit that is protected by the fuse within said fuseholder, said metallic separable connector being a sleeve with a plurality of fingers at said one end thereof.

4. A combination which comprises: an enclosed fuseholder which has a male body portion, a female body portion, and means to releasably interconnect said body portions, said male body portion being hollow but having the outer end thereof closed, said female body portion being hollow but having the outer end thereof closed, said male body portion and said female body portion and said means coacting to releasably enclose and confine a cartridge type electric fuse, a metallic connector carried by and projecting outwardly from one end of one of said body portions, a metallic separable connector which is located exteriorly of said enclosed fuseholder and which normally has one end thereof in telescoped engagement with a portion of the first said metallic connector and which has the other end thereof connectable to a conductor, a body of insulating material which is mounted on and directly engages a portion of said metallic separable connector and which moves with said metallic separable connector whenever said metallic separable connector is separated from the first said metallic connector, the first said metallic connector and said metallic separable connector being dimensioned to provide a frictional securement therebetween which is strong enough to normally maintain a low resistance electrical connection between said fuse-holder and said metallic separable conneCtor, the first said metallic connector and said metallic separable connector being dimensioned so said frictional securement will automatically yield to permit the first said metallic connector and said metallic separable connector to separate from each other in response to a separating force which is smaller than the elastic limit of said fuseholder, said metallic separable connector and said portion of said first metallic connector, which is in telescoped engagement with said metallic separable connector, being located wholly externally of said one body portion of said enclosed fuseholder, whereby said fuseholder is protected against damage from tensile forces which are applied to it by conductors of the circuit that is protected by the fuse within said fuseholder, said metallic separable connector being a sleeve with a plurality of fingers at said one end thereof, and a split ring encircling said one end of said metallic separable connector to enable said one end of said metallic separable connector to apply a substantial pressure to the first said metallic connector.