US1887089A - Selective fuse plug shell - Google Patents

Description

Nov. 8, 1932. H. J. l.. FRANK sELEcTIvE FUSE PLUG SHELL Filed Feb. 14, 195o 3 sheetsheez 1 INVENTOR ATTORM Nov. 8, 1932. H. J, FRANK 1,887,089

SELECTIVE FUSE PLUG SHELL Filed Feb. 14. 1930 3 Sheets-Sheet 2 ez l 6/7 f/.f g x i i ii j INVENToR ATTORNEY Nov. 8, 1932. H. J. L. FRANK 1,887,089

sELEcTrvE FusE PLUG SHELL Filedfeb. 14. 1930 s sheets-sheet s INVENTOR ATTORNEY YPatented Nov. 8, 1932 UNITED STATES.

PATENT OFFICE HABBISQ'H J, L. FRANK, 0F HIGHLAND PARK, MICHIGAN, ASSIGNOB TO BULL DOG ELECTRl- PRODUCTS COMPANY, 0F HAMTBAMCX, MICHIGAN, .A CORPORATION OF WEST VIRGXNIA SELECTIVE FUSE PLUG SHELL .plicnton Med February 14, 133D. Serial No, 428,231.

etes to current take o is 'plug which may he 1 accommodate cartridge s engths and capacities.

Another object is e plug having a. use consealing shell which may be moved to expose one and only one7 ci the fuses, at any one time, whereby the exposed fuse may be removed and replaced Without disassembling the device, even in part.

A further object is a plug of the tye de-i scribed in the foregoing paragraph, w erein the shell is so interlocked with the receptacle with which it cooperates that movement of the shell for fuse exposure, is not possible unless and until the plug has been Withdrawn from the live receptacle, this feature preventing fuse manipulation whilethe fuse is aliveu L further object is a plug having grounding means whieh eectively grounds the plug to the distribution conduit, before the plug can be plugged into the receptacle7 until after i the the plug is Withdrawn from the receptacle,

i and all the While the plug is plugged in the receptacle.

A further object is a plug which has projecting contactsy readily convertible from the knife blade or male type, to the parallel leaf or female type.

further object is a plug made of a numloer of stock parts, assembled as desired, to create plugs of dilerent capacities.

. A further object is a plug having parts designed to afford maximum electrical insulation consistent with compactness.

Still further objects will readily occur to those skilled in the art upon reference to the following description and the accompanying drawings in which 'to Figs l and S7 it seen that the plug includes two complementary insulating por tions l@ and ils between which the fuses are disposed and from one oi which project the plug contacts, and to the other of which the current conductors are connected.

The portion i0 is made of molded insulation, such as a phenolic condensation product, and is molded around the contacts i2. Projecting down from its lower face, Figs. 4 and 6, is a central section 13 oi 'l' contour', and from each outer point of the T, barriers le project radially to denne peripherally spaced recesses l5, these containing ends of the contirets-l2.

Each or the ends is provided with a thread ed hole i6 into which may be threaded a screw 17 for securing a cartridge usevclip i8 to the Contact, the construction aording remorn ability to the fuse clips.

The portion il, complementary to the portion l0, is also made of molded insulation anf is molded around the connecting lugs 21, these having binding posts 22 to which may be conn nected ends o conductor 23, leading to a ma chine or other current consuming device.

Ill

' will serve to close electrical lines from contacts 12 to lugs 21 and conductors 23, and it will be seen that the electrical lines are relatively insulated by the complementary barriers 14 and 25.

Thevplug enclosure and details The portions 10 and 11, together with their fuses, clips etc. are enclosed in a hollow cylindrical shell 32 of insulation, the same being capped at the plug contactv end by a ring shaped annularly grooved casting' 33 and at the cable end by a plate casting 34 thru which the conductors 23 pass. The shell. 32 is rotatable between the castings and around the portions 10 and 11 and is provided with an opening 35 (Fig. 6) adapted to be registered with a selected one of the recesses, as desired, or with none of them, as desired. The casting 33 is provided with a friction leaf spring 36 (Fig. 4) to engage the shell, thereby restraining its rotation, although not absolutely preventing rotation.

If desired, a knob 37 on the leaf may be provided to engage in a depression in the shell, the engagement alining the shell with the casting, so that the shell opening is normally in registry with one of the barriers 14-25.

Although the fuses 30 tend to hold portions 10 and 11 to each other, in the shell, other and more reliable means may be provided, if desired, to attain this result, and such means are shown best in Fig. 3. The means includes long bolts 38 passed thru .the portions and threaded at one end, into lugs 39 on the casting 33, and at the other end, provided with nuts, one of which 40 holds the portions 10 and 11 together, and the other of which 41 holds the casting 34 in place. The bolts pass thru the barriers .14-25 on the portions 10 and 11, and are surrounded by insulating tubes 42, which not only insulate the bolts from the spaces between the portions, but also serve to space the portions l0 and 11 at/ desired distances.

It will be observed that the length of the vertical space between the portions, and consequently the length of the shell 32, the bolts 38, and the tubes 42, depends upon the length of the fuses 30. Accordingly, when the plug is to accommodate low voltage or short fuses, short ones of the parts above mentioned will be chosen, but'when'the plug is to be used for` high voltage or with long fuses, long ones of the parts will be selected. It will' further be seen that to change a plug from onelength'to another, is a veryV simple matter, only certain, inexpensive, parts being substituted.

It will also be observed that plugs of large current carrying capacity will beprovided with large fuse clips easily mounted in the tapered recesses 154-26, whereas lower amperage plugs will contain smaller fuse clips.'V`

ccordingly, the creation and reconstruction of plugs, for various electrical demands, is a simple and inexpensive matter.

In order to isolate respective contacts 12 and respective binding posts 22, and to reduce creepage, etc., barriers are formed on the top surface of the portion 10 (Fig. 2) and barriers 46 are formed on the bottom surface of the portion 11 (Fig. 7). Contacts l2 are further isolated from each other, when live, by the walls 47 between the various outlet oles 48 on the outlet block 49 (Fig. 4) of the uct.

Further, while contacts 12 are shown as being of the blade or make type, to cooperate.

with leaf or female contacts 50 in the outlet block 49, they might well be of the leaf or female type, to cooperate with bare bus bars or with blade or male contacts, accessible thru or in the block.

It will be observed that one set of the barriers, 14-25 namely the one forming the legs of the T (Fig.'6) is extended peripherally so as to be of greater arcuate length than the opening 35 in the shell.` Further, this barrier is provided with recesses 56 in which are seated nuts 57 thru which pass screws 58 for holding an arcuate insulating plate 59 against the barriers. The plate 59 bridges the space isters with-the plate 59. The latter may bemade of a different color than the portions l0 and 11 so as to indicate its location by color contrast, and is made of the same colorA as the shell so as to make the plugin normal use, more attractive than would otherwise be the case. Y

The mounting, polm'iez'ng, interlocking and grounding details In prior art plug devices, the' friction and spring pressure between the plug and receptaclev contacts is relied upon to maintain the plug and receptacle in conjunction. This practice is perhaps satisfactory, in some cases, but is not as reliable as might be desired. Accordingly, plug mounting means, which may be dispensed with, if desired, have been disclosed and the same will now be described, in connection with parts provided on the duct.

The lduct 60 is provided on its lower surface with an opening around which is mounted a centrally apertured outlet plate 61, the

' latter having headed pins 62 passing upwardly-thru slots 63 in parallel locking plates 64, there being coiled springs 65 for pressing the locking plates against the plate 61. The out? let plate, further has holes 66 in registry.

with vlocking plate keyhole slots 67, these.

holes' and slots receiving the headed pins 68` on the plug ring casting 33. Wien the plug is plugged into the receptacle 49, the plug pins 68 pass thru the holes 66 and the large parts of the keyholer slots 67, after which the locking plates are shifted to cause the small parts of the keyhole slots 67 to line up with the holes 66, thus locking the plug to the outlet plate.

prevent access to lier use renewal 'lor when the plug is v interlock means, i such qm un en the plug is g i he duct outlet, however, and is live, tue plunger 1s retract-ed and the i in 'il is disposed in the slot l5, preventing the shell from being rotated. Furtner. tue 'lfv'n il n i Mm" w slo.-J lo, shell opening ou plunge; l() aie so located with respect to each other, that -the slot 73 must be in line with plunger pin 7l, and opening 35 must be in registry with insulating plate 59, before the plunger can be retracted to permit pluggingin ofthe plug. Accordingly, it is impossible to plug-in While any fuse or line in the plug "is exposed.

Further, the plunger 70 projects beyond the contacts l2, and must therefore be retracted by its engagement with the duct bcfore the contacts l2 can malle with the outlet contacts 50. Accordingly, the plug enclosure is grounded to the grounded duct before Athe plug is made live. As a corollary, the plug enclosure is grounded to the duct all the while the plug is live., and even shortly after the plug is pulled out of the receptacle.

60 It will iurther be noted that upper casting 33 completelyT closes the receptacle opening when the plug is in circuit, thus sealing the live parts of the plug in the plug shell and the duct.

l Now having described the invention and The outlet plate and receptacle as a unit,

' scctioi the preferred embodiment thereof, it is to be understood that the said invention is to be limited, not to the specific details herein set forth but only by the scope of the claims which follow.

What I claim is:

l. In a fused plug adapted for operative connection with a bus bar structure a central space-enclosing cap provided with means for detachably engagin the bus har structure, thereby to hold the plug in place,

a peripherally recessed, intermediate section oi' insulating material, pairs of relatively spaced Contact members in 'recesses of said intermediate section, each e ed with a fuse clip, one of eati contact members acted at one enc, the other one o" tact members g plug' contact which project rounded enclosed by s f `cap, longitudine ing the parts rotate ly mounted rial surrounding said and .Xie-ving aperto? tercd Tenth selected one o Lize .ecesses said intermediate section to i thereto *for inspection or replacement of fuse 'therein positioned.,

:2. n a fused plug, a pair o 'rininal caps, one oi' which is provided s peripheral flange de.,A lng a central protective recess and with periplierally disposed for detachably engaging parts -of a bus bar structure, means for oetacliably holding said caps in l deslred spaced relation, an intermediate member of insulating inaleriai having a plurality of peripherally spaced and peripherally accessible recesses wherein fuses may be positioned in isolation from one another, a pair of spaced' fuse clips positioned in each of said recesses, one of said clips being provided with a binding post positioned at one end of said intermediate member, the other of said clips being provided with a plug contact which projects into and is surrounded by the 'peripheral liange of the adjacent one of said caps, and a rotatably mounted insulating shell surrounding said intermediate member and Aadapted to protect said fuseliousing recesses from external access, said shell having an aperture adapted to he moved into registry with selected ones of said recesses as the shell is rotated.

3. In a fused ico plug, a. peripheral body of L insulating' material having peripheral re'- vided with a fuse clip, one of each pair of terminal members having its end contoured to binding post form, the end of its companion member projecting from the opposite end of said insulating body and formed as a plug contact,terminal plates positioned at the ends of and secured to said body'of insulating material, that one of said plates adjacent said projecting plug contacts having a peripheral skirting which forms a protective recess into which said plug contacts project, means appurtenant said last mentioned terminal plate for detachably connecting it and accordingly, the body to a bus bar structure and thereby effecting an electrical contact between said projecting plug contacts and the busl bar structure, and a rotatably mounted insulating shell surrounding said peripherally recessed body and adapted to protect the fuses positioned in the several recesses'against external access, said shell having an aperlure adapted to be moved into registry with selected ones of said recesses as the shell is rotated.v

4. In a fused plug adapted for operative connection with a bus bar structure, a plate provided with means for detachably engaging the bus bar structure, means for preventing the complete connection of said plug and bus bar structure until a` ground connection therebetween has first been made, said plate also having a centrally located recessed portion, a peripherally recessed body of insulating material having one end engagihg said plate, a pair of circuit terminals spacedly disposed in each of the recesses of said insulating body, one of each pair of said terminals having end portions in the form of plug contacts which project into the central recess of said plate, the other of the terminals in each recess projecting beyond the opposite end of said insulating body t provide a conc luctor binding portion, a second plate forming a cap over'the last mentioned end of the insulating body, a fuse clip carried by each of said terminals in said recesses, and a rotatably mounted, insulating shell surround: mg said recessed insulating body and having an aperture adapted to afford access to selected ones of said recesses and to the fuse positioned therein only when the shell is ro- .tated to such position that its aperture registers With the recess.

5. A fused plug comprising an intermediate insulating block provided with a plurality of peripherally accessible recesses, a pair of relatively spaced fuse clips positioned 1n each of said recesses, each pair being adapted to be connected by and/detachably support a fuse positioned in said recess, a protective frame for said block comprising end plates and connecting rods, one of said plates being formed for'detachable connection with a bus bar structure when properly positioned thereon, and. a protective insulating shell rotatably positioned about said insulating block and provided with an access aperture Whereby access to any of said recesses is permitted only when the aperture is registered therewith, and plug terminals projecting from one of each pair of fuse clips.

6.' Means for detachably and accessibly 'supporting a plurality of fuses in insulated and normally protected position, comprising al cylindrical block of insulation having spaced peripherally accessible recesses, a rotatably mounted protective shell surrounding the block and having an aperture thru which access to selected ones of said recesses is permitted when the aperture is in registry therewith, a pair of spaced fuse clips positioned in each of said recesses, a plug contact extending from one of each pair of clips beyond the end of said block, and structurally connected protective plates positioned at the ends of said block, one of said plateshaving a skirt adaptf vthrough one end of said body, a frame for said body and its supported elements and for protecting said plug contacts, means on said frame for detachably securing said plug in operative relation to current-carrying elements, and a shell rotatably supported by said frame to conceal said recesses, said shell having an aperture thru which may be had access to selected ones of said recesses, when the aperture is in registry with any one thereof.

8. In a fused plug, a frame provided with means for permitting the detachable operative installation of the plug on a distribution system, an insulating body Within said frame and provided With peripherally opening recesses, fuses in said recesses, a shell rotatably supported by said frame and surrounding said body, said shell having an aperture adapted to be registered With selected ones of said recesses and means for preventing rotative movement of said shell when the plug is connected to said distribution system.

Q. In a fused plug, a pair of spaced end sections, each containing a fuse clip, a fuse connecting and supported in said clips, cable connection means on one of said sections and plug contacts on the other, and means comprising elongated rods removably positioned in the sections and connecting them for maintaining them in assembly, the rods being insulated from the space between the sections.

10. In a fused plug having an end section provided with plug contacts and an apertured, rotatable, fuse-concealing shell, means llO on the end section for preventing rotation of the shell when the plug contacts are in engagement with cooperating contacts, the means also preventing the plug contacts from being engaged with cooperating contacts while the shell is not in fuseconcealing position.

11. Ina fused plug, spaced end sections of insulation having peripherally accessible fuse containing recesses separated by radially extending barrier walls of insulation, a rotatable insulating shell surrounding said end sections and having an aperture adapted to be registered with selected ones of the recesses and barriers, and an insulating plate connecting the adjacent radially projecting ends of one pair of barriers to conceal the space between that pair of barriers, and thereby between the sections at that barrier.

12. In a fused plug, a pair of spaced end sections, each containing a fuse clip, a fuse connecting and supported in said clips, cable connections means on one of said sections and plug contacts on the other, and means comprising elongated rods removably positioned in the sections and connecting them for maintaining them in assembly, the rods being insulated from the space between the sections by tubes of rigid, form-sustaining insulation whose ends engage the sections to separate them. Y

13. In a fused plug having an end section, plug contacts, and an apertured, rotatable, fuse-concealing shell, means on the end section for preventing rotation of the shell when the plug contacts are in engagement with cooperating contacts, the means also preventing the plug contacts from being engaged With cooperating contacts While the shell is not in fuse 'concealing position, the means also serving to ground the plug.'

14. In a fused plug having an end section provided with plug contacts and an apertured, rotatable, fuse-concealing shell, means on the end section for preventing rotation of the shell when'the plug contacts are in engagement with cooperating contacts the means also preventing the plug contacts from being engaged with cooperating contacts while the shell is not in fuse concealing posi# tion, the means also serving to ground the plug automatically, before, during the time that and shortly after, the plug contacts are engaged with their cooperating contacts.

15. In a fused plug, spaced end sections of insulation having peripherally accessible fuse containing recesses separated by radially extending barrier walls of insulation, a. rotatable insulating shell surrounding said end sections and having an aperture adapted to be registered withselected ones of the recesses and barriers, and an insulating plate connecting the adjacent radially projecting ends of one pair of barriers to conceal the space between that pair of barriers, and thereby between the sections at that barrier, the plate and the barrier ends when combined being of a greater arcuate length than that of the shell apertures.

16. In a fused plug, spaced end sections of insulation having peripherally accessible fuse I containing recesses separated by radially extending barrier walls of insulation, a rotatable insulating shell surrounding said end sections and having an aperture adapted to be registered with selected ones of the recesses and barriers, and an insulating plate connecting the adjacent radially projecting ends of one pair of barriers to conceal the space between that pair of barriers and thereby between the sections at that barrier, and means on the plug for normally insuring the registry of the shell aperture with the plate.

17. ln a fused plug, spaced end sections of insulation having peripherally accessible fuse containing recesses separated by radially eX- tending barrier walls of insulation, a rotatable insulating shell surrounding said end sections and having an aperture adapted to be registered with selected ones of the recesses and barriers, and an insulating plate connecting thc adjacent radially projecting ends of one pair of barriers to conceal the space between that pair of barriers and thereby between the sect-ions at that barrier, and means on the plug for normally insuring the registry of the shell aperture with the plate and for preventing movement of the shell from such registered position, when the plug is live.

18. In a fused plug having a shell and fuses therewithin, means for mounting the plug on and connecting it to a current distribution system, said shell being mounted so as not to be movable to fuse exposing position when the plug is in connection with said system, said shell, when in fuse exposing position, further preventing mounting said plug on and connecting it to said shell.

In testimony whereof I sign this specifica-

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