US1619640A - Explosionproof fuse - Google Patents

Description

1,619,640 W. W. SLOANE EXPLOSIONPROOF FUSE Filed June 24. 1920 2 Sheets-Sheet 'L /v V z 57 i March l 1927.

W. W. SLOANE EXPLOSIONPROOF FUSE Filed June 24, 1920 March 1 1927.

2*-Sheets-/Sheet 2 n i Ewan/of? JZOa/ze, (Jfyf @mu/@ my Patented Mar. 1, 1927.-

unirse stares A'EENT QFFEQE.

XVILLIAIiIvV/. SLOANE, OF CHICAGO, ELLNCS, ALSSGNCR TO GOGDMAN MANUFACTUR- ING COMQANY, GF ClrCAsrO,l ILLNCvI-S, A CORPORATION OF ILLINOIS;

EXPLOSON? Application filed'iunc 24,

This invention relates to improvements in cxplosioi'i-prootl electrical .tuses or cutouts, and has for its principal object to provid-e a satety fuse for use in gaseous mines, or under similar conditions inA which explosions maybe caused by the arcing o' exposed fuse connect-ions. Y

To` this end, I provide an improved construction con'iprisino a renevzble Vtuse element and a casing therefor, in which the fuse isenclosed in the casing` and-cannot be removed therefrom Without first breaking the electric circuit.

A further object of this invention is to provide a construction in which it is practically impossible to insert a substitute l'or the fuse element between the fuse connections.

Further objects Will appear from the following description, reference being' had to the accompanying' drawings, in which Figure l is a' vertical cross-section ot my improved. device,` showing' the fuse element in locked position in the. casing.

Figure 2 is an end vienT ot the casing.

Figure 3 is a vertical cross-section ot" the casingl and fuse element taken on line 3 3 oi Figure l.

Figure el is a vertical cross-section olf' the fuse element, removed from the casing.

Figure 5 is a detail.

Referring nouv to the details ot the construction, my device comprises two main elements, namely; an outer casing l, and a removable fuse element 2 adapted to be inserted at one end of the casinan l, and locked therein, so as to provide a practicallyY airtight enclosure.

T he outer casing l comprises a cylindrical body 3, preferably ot metal, enclosed at one end by a thr aded plug Ll and at the opposite end by the t'use element 2 already re- 'lerred to. A pair ot metallic connecting,` members 9'and l() are separatel from each other in the casing, and encircle the chamber adjacent the outer Wall 3 of the casing, but are insulated therefrom by means or suitable insulation pieces l1 and l2,.respective ly. Connecting. members 9 and l0 each comprise a springmember 9a, and a contiguous conductingmember, or shunt 9b. The springmember 9e is preferably of phosphor bronze, or other material suitable tor use as a spring, While the conducting member, or shunt7 9", is preferably made up ot a ROOF FUSE.

1929. Serial No. 391,393.

pliu'alityoi thin copper plates, oit high rela tive conductivity`r so as to carry most of the current. This arrangement is provided so that the tensional properties ot the spring member 9a are not atliected by heating'.V ffs shown in Figure 3, the connecting' members 9 and 19' are preferably constructer in the form of rings, and arranged eccentril:l with respect to the casing rl`hey are connected to the outside terminals 5 and G bv means ot studs 7 and 8, having heads i3 and lei'. The4 studs are inserted thru suitable holes in the rings 9 and l0. and secure the said connecting' rings by threaded nuts l5 and NS on the terminals. Contact shoes i7 and i9 arenttaclied'to the upper portions otA the rings 9 and l0 respectively, andare adapted to provide contact With corresponding' contact members 19 and 29 carried by the fuse ele- .ment 2.

Inside ot the ring-shaped connectors 9 and 19 is inserted an insulating` member 2l which extends practically the. entire length ot the casing, and is held in place by insu* lating,l dii-lts 23, 241 and'25 supported by the casing- Wall 3. Said insulating member (shown in detail in nigure 5)' is so proportioned in cross-section as to receive the fuse element 2 therein, and includes a depending wall portion 26 extending the full length thereof. which receives the contact members 19 and'20 ot said tusefelemcnt Whenvthe Jfuse element is inserted in its inverted position, as willihcreinatter be more fully describedz Referring now particularly to the tuse ele mentY 2, l prefer to utilize a so-called` removable link fuse in connection with my device, details of which are shown in Figure et. The inner contacty member 2() of the fuse element extends laterally trom the inner end ot an insulator tube 27, and preferably` has a circular portion 28 enclosing one end ot said tube. Anend portion 27l ot the tube extends flush with the outer tace ot the disl 28 excepting adjacent the contact member, for a purpose which u'ill hereinafter be described. rlhe opposite, or outer end ot the tube 27 is detachably connected to a cap member 29. preterzblv having' threaded engagement 30 in a collar 8l which is rotatably mounted at the inner face of the'cap member 29 and secured thereto by means ot a plate The collar 3lA is linurled shown in Figure l so that the tube may be readiliv screwed and unscreived by hand, to assemble or disassemble the fuse element. A' slot 33 extends longitudinally from the outer end Y of the tube 27, toward the center thereof.

Y against by a spacing collar 40 which abuts the inner end of the disk 32 when the fuse element is assembled. The opposite terminal for the fuse link comprises a terminal piece 41 having an enlarged flange 42, and a spindle 43 which extends thru the end disk 28 on the inner end of the fuse element. The

spindle 43 has a threaded portion V44 adja' cent the outer face of the end disk 28, and is provided with a nut 45 which clamps the terminal member to said disk. rlhe fuse link 35 is detachably connected between the link terminals 37 and 41 in any suitable manner, as for instance by bolts 56, 56.

The end of the spindle is adapted to t in a recessed bushing 46, formed inthe plug 4, but insulated therefromV by insulating bushing 47. Y

The outer end of the fuse element comprises the plug 29 having an annular body portion 49 adapted to fit tiglitly in the neck 50 of the casing, and has a longbearing surface therein, so as to provide an explosionproof joint, in which any flame from an arc, or an explosion caused thereby, within the casing, cannot reach the outer air. The fuse element 2 is provided with a handle 51, and is adapted to be locked in the casing by means of a segmental flange 52 which is adapted to engage a corresponding lip 53 on the casing.

The operation of my device is as follows: The fuse element 2 is inserted in the casing with the Contact members 19 and 2O Vin their inverted, lor downward position, so as to register with the insulating tube 21 and the downwardly extending portion 26 thereof, hereinbefore described. 1When the fuse element,` is inserted to its farthest limit, the pin 43 seats in the recess 46. The entire fuse element is then turned a half turn by means of the handle 51 so that the locking flange 52 on the fuse element engages with the lip 53 to lock the fuse element firmly in place, as shown in Figure 1. As the fuse element is thus rotated, the contact members 19 and 29 are also removed from the inverted, or downward position. Two segmental slots 54 and 55 (shown in Figure 5) are providedV in the insulating tube 21, with which the contact members 19 and 2O are adapted to register,` so that they may be turned from their in verted, or downward position to a second position indicated in Figure 1, where they engage with the contact shoes 17 and 18, respectively. In this position, therefore, the fuse element is locked in the casing and the circuit thru the fuse is closed. It will now be clear that in order to unlock the fuse element and casing, it is necessary to vreverse the above described action, by rotating the fuse element so as to move the contact inembers 19 and 2O out of engagement with Vtheir respective contact shoes 17 and 18, before the locking flange 52 can be unlocked, `and the fuse element withdrawn from the casing.

prefer to make the slot 54 and contact member 19 somewhat shorter than the'contact member 20, so that the latter cannot be accidently engaged with the contact shoe 17. Otherwise, if it were possible to insert the fuse element part way into the casing, and then rotate it to contact the member 20 and shoe 17, a short-oircuiU might be formed thru the fuse and contact member 19 to the casing 3.V The possibility of such a short-circuit is eliminated, however, by constructing the shoes and slots of dierent lengths, as described.

l provide another safety feature in the construction of the inner end of the fuse element, in which the insulation 27a extends flush with the end portion 28 of the contact member 20, as already described.l I Yhave found that it is possible to insert the fuse element at such an angle that Ythe forward edge 27au of the fuse element Vmay extend thru the slot 54 and engage with the contact shoe 17. As this forward edge 27a is insulated however, the possibility of shortcircuit 'from this cause is eliminated.l

A further feature of my invention is a construction which makes it practically impossible for a careless operator to insert a substitute for the fuse element'so as to close the circuit within the casing while the casing is unlocked. It is well known to those familiar with the operation of safety devices of this character, that in spite of all warnings as to the danger of overloading a circuit, and of explosions caused by open fuse contacts, yet

a large proportion of operators will ignore all provisions for their own welfare by attempting to contrivev some method of defeating the purpose of the safety'device.` One of the common practices is to connect the ordinary fuse terminals with fuse w're, and in fact Common wire, and many other articles, are used for this purpose. lt will be seen, however, that with my improved construction, it is practically impossible to reach the Contact shoes 17 and 1S for the purpose of connecting these ter ninals with any substitute for the fuse element in the manner above suggested. lVhile it may be possible to insert fuse wire or other substitute Yfor Vthe fuse link 35, yet when this is done, theentire ico lao

fuse element 2 must be inserted and locked before proper contact ot the fuse device can be made.

Having described my invention What I claim as new and desire to cover by Letters Patent, is:

l. In a device ot the class described, a casing, a removable fuse element having a portion thereof adapted to form a closure ttor said casing, electrical contacts tor said Vfuse element Within said casing, contact members associated with said fuse element adapted to engage said contacts, and means independent ot' said contacts tor locking said closure in all positions of engagement between said contacts and contact members.

2. In a device ot the class described'.v a crising, a removable inse element having a porti-on thereoft adapted to form a closure tor said casing, electrical contacts Within `said casing, contact members on said fuse element adapted to engage the tirst named contacts, and means independent ot said contacts permitting insertion and removal ot said 'fuse element only when said inse contact members are ont of engagement with said contacts.

3. In a device of the class described, a cylindrical casing, a rotatable fuse element having an annular portion thereof adapted to torni a closure tor said casing, electrical contacts tor said fuse element- Within said casing, mea-ns pern'iitting longitudinal movement of said 'fuse element within said casing When said fuse contacts are out otI longitudinal alignment with said casing contacts, and means permitting rotation ot said 't'nse element in said casing only when said annular portion is in fully closed position in said casing.

4. In a device ot the class described, a casing, a removable fuse element having a portion thereof adapted to torni a closure tor said casing, a pair of contacts tor said fuse element in said casing, contact members on said fuse element, means permitting insertion and removal ot said fuse element in one position with said fuse contact members removed trom said casing contacts; means attording movement ot said t'nse element in a second position With .said fuse contact members in engagement with said casing contacts, and means operable to lock said closure against longitudinal movement, in a position intermediate the tivo tirst mentioned positions of said fuse element.

5. In a device ot the class described, a casing, a rotatable fuse element having an annular portion thereof adapted to form a closure for said casing, and having a pair orn laterally extending contact members. a pair of contacts in said casing for said inse contact members, said casing having a passageway affording entrance ot the fuse element in an axial direction with the respective fuse and casing contacts maintained at a distance t'rom each other, and means whereby the fuse element may be rotated to engage the resprctive fuse and casing contacts only when said tese element is in closed position in said casing.

6. In a device of the class described, casing, a rotatable fuse element adapted to be inserted in said casing to form a closure therefor, said fuse element having a pair ot' laterally extending contact members and a lock, contacts in said casing 'for said tnse Contact members, said casing having a passageway attordine entrance ot the frise element in an axial direction with the respective tnse and casing contacts removed -trom each other, and means independent ot said contacts whereby the fuse element may be rotated to locl said tnse element against. axial movement, and to engage the respective inse and casing contacts, said fuse elementbeing iocked at all times that said t'nse and casing contacts are engaged.

7. In a device ot the class desciibed, a casing, a fuse element having an end portion thereof adapted to form a closure tor said casing and provided with laterally extending contact members, electrical contacts in said casing, insulating means in said casing having a passageway atiording entrance or' said fuse element with said t'nse contact members maintained out ot' registering position with said casing contacts, said insulating means also pei itting rotation ot said 't'nse contacts into and ont ol engagement with said casing contacts When said casing is fully ciosed by said fase element. I

8. In a device ot the class described, a casing, a fuser element having an end portion thereot' adapted to torni a closure tor said casing and provided with laterally extending contact members, electrical contacts in said casing, insulating means in said casinghaving a passageway aitording entrance of said 'inse element with said fuse contact members maintained out ot' registering position with said casing contacts, said insulating means also permitting rotation ot said 'fuse contacts into and out ot engagement with the casingcontacts when said casing is closed by said end portion ot the vtuse element, and means independent ot said contacts for locling said fuse element against end\vise movement in said casing when the respective fuse and casing contacts are engaged with each other.

9. In a device ot the class described, a casing having'electrical contacts therein, a fuse element having longitudinally spaced,

members, insnlaterally extending contact lating means in said casing having a longitudinal passage permitting endivise entrance of said tnse element .vhen the fuse contacts are out ot registering position with respect 4casing having *electricalY contacts therein, a

t'use element having laterally7 extending contact members, insulating means in said casing having a lonofitudinal Vpassage permit- 'ting endivise entrance of said fuse element when the fuse contacts are ont o' registering position with respect to said casing contacts,

saidinsulating means also having a pair of Y, v

casing, a removable fuse element comprising slots aiording rotation of said contacts into and out o't` engagement with the casing con- Ytacts andV O'uidinc means coactino' between n a: n ,l :a 1

the inner end ot. said inse element and tne.

casing. y

lL'ln a device ot the class described, a casing, a pair of electrical contacts in said casing, spring devices securing said electrical contacts to the casing, a fuse element having laterally extending contact members, insulating means in said casing'liaving a passage permitting entrance of said fuse element when the fuse contacts aie ont ot` registering position With respect to said casing contacts,

and means affording rotation of said fuseV contacts into and out of engagement with the casing contacts. 1

12. ln a device of the class described, a

casing, a pair ot electrical contacts in saidV casing, spring devices securing said electrical contacts to the casing, conductor pieces associated With said spring devices, Va fuse ele ment having laterally extending contact members, insulating means in said casing having a longitudinalV passage affording endWise entrance ot said t'iise element when the fuse contacts are out of registering position with respect to said casing contacts,

i3. in a device of the class described, a

casino', a removable `fuse element comprising b I r an annular end portion adapted to torni a closure :tor said casing, and a detachable ,body portion having an insulating cover, a

pair ot' laterally disposedcontact member extending tlierethru, and a fusible piece connecting said Contact members, said contact members being adapted to engage ivith contact members in said casingivhen the fuse element is in closed position;` A f 1min a device of the class described, a

an annular end portion adapted to forma closure tor said casing, and a detachable body portion extending axially from said end portion having aninsulating cover, a j

`Vpair oi laterally disposed Contact members extending tliei'ethru, and a fusible piece connecting said Contact, said contact members being adapted to engage With contact ineinbers in said casing When the tuse element Y is in closed position.

l5. ln a device ot the class described, a casing, a removable fuse element'coniprising an annular end portion adapted to form a closure tor said casing, and a detachable body'portion having an insulating cover, a pair of laterally-disposed contact members extending tlierethru, a fusible piece connecting said contactinenibers, said contactmembers being adaptedto engage With Ycontact members in said casing When the fuse element is in closed position, and guiding means coacting between the inner end ot said fuse element and said casing. Y

Signed at Chicago, Illinois, this 22nd day ot June, A. D., 1920. Y

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