US1793305A - Fuse and cut-out - Google Patents

Description

C. W. COWLES FUSE AND CUT-OUT Filed Jan. 21, 1927 2 Sheets-Sheet 1 Feb. 17, 1931.

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Patented Feb. 17, 1931 UNITED STATES PATENT OFFICE CLIFFORD W. COWLES, OF NEW BRITAIN, CONNECTICUT, ASSIGNOR OF ONE-HALF TO FREDERICK L. BENZON, OF PLAINVILLE, CONNECTICUT FUSE AND CUT-OUT Application filed January 21, 1927- Scrial No. 162,456.

This invention relates to fuses and cut-outs and comprises all the features of novelty herein disclosed.

In a very common type of fuse and cut-' shell is in electrical connection through the.

fuse wire with a center contact arranged to m engage a'second contact piece or screw at the bottom of the socket. These fuses are made in several ampere capacities intended for different circuits, the illuminating circuit being frequently designed for amperes and 15 no larger capacity fuse should be or safely can be used in such a circuit. Since all these fuse plugs of different capacities are of the same size, there is nothing to prevent overfusing and indeed, through ignorance, recklessness or abuse, it is rather common to dispense with fuse protection altogether in branch circuits as by inserting a thin disc or coin into the cut-out or socket to connect the socket shell directly with the center con tact.- And this may be easily concealed by screwing down over it a blown out or small capacity fuse plug. Again, a careless or ignorant person changing fuses can often receive a shock because it is easy to make con tact with both terminals within the comparatively large open socket. Such practices are obviously dangerous. Other. proposed cutouts are more diliicult to overfuse but all known to me can be more or less easily shunted.

An object of the invention is to provide an improved fuse and cut-out which will eliminate the above and other dangers and disadvantages as by making it practically impossible to shunt the terminals of the cutout. Another object is to provide a type of plug fuse and cut-out which will prevent over-fusing as by making different sized parts for different capacity circuits. Another objectis to provide an adapter to render my fuse plug available for standard cut-outs.

To these ends and to improve generally upon devices of this general character, my invention consists in the various matters herein after described and claimed.

The invention is not necessarily limited, in its broader aspects, to the specific form shown merely for illustrative purposes in the accompanying drawings in which, Figures 1 and 2 are central sections showing, respectively, the plug ready to enter the cut-out and seated in said cut-out. Figure 2A is a view similar to Figure 1 of a fuse and cut-out of different capacity. Figures 3, 4 and 5 are perspectiveviews of detail parts. Figure 6 is a central section of a fuse adapter construction drawn to smaller scale than Figures 1 and 2. Figure 7 is a plan viewof the adapter of Figure 6 and Figure 8 is a central section of a lamp adapter construction.

The numeral 10 indicates a suitable insulating base, such as porcelain, having a depressed or cut-away portion for a contact plate 12 fastened by a screw 14 which is in electrical communication with the usual circuit wire. Another contact plate 16 is fastened at one end in a recess or cut-out portion of the base by-a screw 18 which is in electrical communication with the other wire of the circuit. The contact plate 16 extends into a communicating '75 recess 20 extending up into the base leaving a ledge or shelf 22 of insulating material between the contact plate and other instrumentalities mounted on the base.

Fastened rigidly to the base by screw bolts 24 and 26 is a flanged insulating member or block 28, one screw bolt 24 passing through and also holding the 'plate 12 and engaging a' nut 30 in a recess or hole'in the base. The other screw bolt 26 is passed through the block and the plate 16 and also holds the latter in position. The block 28 has a recess 32, preferably circular, with an inwardly extending flange or stop shoulder 34 near the top. lVithin the recess is a floating block 36 of insulating material, preferably circular, so as to be capable of rotating, and having an annular edge recess 87 formed by an outwardly extending flange or shoulder 88 near the bottom. The flange 38 is herein shown as enclosed by a contact member in the form of a circular metal plate 40 bent of pressed around it, the lower annular flange 42 of the plate being in line with the end portion of the contact plate 12 and adapted to engage it when 10 the fuse is in operative position. The upper flange or bent-over portion 44. of the plate T0 is of sufiicient radial extent to engage the stop shoulder 34 when the floating block 36 is elevated and to also form the bottom of the annular recess 37 which is surrounded by the shoulder or flange 34 at the top of block 28. As will later appear, a fuse terminal member of tubular form is pressed into this recess to make contact with the plate 40.- A coiled expansion spring 46 rests on the insulatingshelf 22 and bears against the top wall of a recess in the bottom of the floating block and tends to hold the block in raised or circuit breaking position as indicated in Figure 1.

The fuse plug 50, as shown best in Figures 1 and 2, is essentially cup-shaped with a body portion of moulded insulating material having a side opening 52 for a fusible element 54: and having a bottom opening for a fuse terminal member in the form of a screw56 to which the fusible element is attached. Surrounding the lower portion of the plug and projecting beyond it is a fuse terminal 1 member in the form of a sleeve or tube '58 arranged to enter the recess 37 above mentioned. The tube may be attached by rolling its uper edge into a groove in the plug and the fusible element 54 is attached at the side opening 52. The bottom of the plug is shown with an insulating extension 60 of annular form surrounding the screw 56' and projecting down through and fitting a central open1ng62 in the floating block. This is to prevent the possibllity of shunting the fuse circuit as by a fine wire. The tube surrounds the extension 60 and should project below the bottom 'tube 58 is pushed into the recess 37 against the contact member or plate 40 and the plug is turned to cause the contact screw to screwinto the tapped opening. thereby depresseth compressing the spring 46, until the plate =20 or its flange 42 makes contact with the end of plate 12. The floating block is free to rotate relatively to both the tube 58 and the plate 12. the tendency being to keep the metal parts bright for good electrical contact. It will be noted that the circuit terminals are not connected until the fuse plug is way down and the floating block depressed and, if the plug is partly unscrewed, the block immediately rises. The opening 62 is so small and the recess 3? so narrow that the circuit terminals practically cannot be The floating block is shunted especially with. the floating block ele-- vated as it will be whenever the fuse-plug is out. The upper end of the fuse plug may be closed in any suitable known way and the. other parts enclosed'by an insulating cover.

For circuits of different current capacityone procedure is to make my fusesand cutouts of different sizes or dimensions so that one fuse plug will not fit another cut=out,ythus avoiding overfusing However, to avoid the necessity of making all or most ofthe. parts. for the different capacity-fuses and cut-outs of difierentdimensions, and to get the same results more simply and cheaply, I propose to change only the length of the tube 58 and the depth of the recess 37 "as indicated in Figure 2A where the fuse is of smaller Ca V pacity thanthat of Figure 2. The tube 58A is longer than tube 58, and the recess 37A-is deeper than recess 37 This plug A could be used in the cut-out ofFigure- 2-, with no" harmful results but the plug of Figure 2. could not be used i'nthe cut-out of Figure 2A becauseits tube f 58 is too short toreach the bottom of recess' 37A. The insulating pro jection 60, since it fitsthe hole in the floating block, will in every case preventishunting of.

' theterminalsofa blown out fuse, There may:

be any desired number of fus'es,.the depthof the recess in the fioating' block and the cor responding, amount of projection ofthe tube being progressively greater for the fuses ofsmaller capacity.

Although myplug fuse and: cuti-outjare particularly intended for new installations I have made theinvention adaptable to the common form of plugcut-out as indicated in Figure 6. .Here, the common cut-out or socket 66 has the usual threaded shell 68 and a center'contact screw 70. My adapter comprises a block 72 of insulating material hav-- ing an outer threaded metal shell 40B. The block is cut at opposite portions of'its periphcry to enablethe top edge of the: shell to" be electrically connected to thin plate members 44:13 which lie in the bottom of a narrow I annular recess 37B corresponding to the re-- cess 37 in Figure 2. This adapter block has a central recess 6213 to receive the projecting portion of the plug fuse 50 and there is av threaded opening in the bottom of the block, reinforced by a nut 6413, to receive the screw 56. The nut 6413 makes contact with the corn tact screw in the cut-out. The recess- 3713 may be made in various depths like the recesses 87 and 37A of Figures 2 and 2A to fit corresponding fuse plug projections. The use ofthis adapter will enable my plug fuseto be used in present day cut-outs and bridge the gap until such time as present day cutcuts are replaced by the cut-out designed especially for; the improved fuse plug. Any suitable known form. of. thread lock maybe used to lock the threaded shell 68 to the responding to the tube 58 of Fig. 2. The tube has an extension or connection 86 carried up through the bottom of an enlarged cupped portion 88 to make contact with an internally threaded shell 90 in the cup, this shell receiving the screw base of the lamp. This lamp adapter will of course also fit in the adapter of Fig. 6. The projection 58C may be made in various lengths like the projections 58 and 58A of Figs. 2 and 2A to fit correspondingly deep recesses.

I claim:

1. In a device of the character described, a fuse having a body portion of insulating material with an extension,.a fuse terminal member on the outside of and projecting beyond the end of thebody portion, the fuse terminal member surrounding said extension and having connection with a fusible element, a block of insulating material having a norrow recess in line with and arranged to receive the projecting fuse terminal member, a contact member confined to the bottom of the recess, the projecting terminal member substantially filling the recess and engaging the contact member therein, a contact plate under the block, and a second fuse terminal member having connection with the fusible element and extending through an opening in the block to make contact with the contact plate; substantially as described.

2. In a device of the character described, a fuse having a body portion of insulating material, a fuse terminal member projecting beyond the body portion and having connecv tion with a fusible element, a block of insulating material having a narrow recess in line' with andarranged to receive the pro ecting fuse terminal, a contact member in the reccss, a contact plate under the block, the body portion of the fuse having a projection of insulating material extending into and lit ting an opening in the block, and a second fuse terminal member having connection with the fusible element and extending through said insulating projection to make contact with the contact plate; substantially as described.

3. In a device of the character described, a fuse having a body portion of insulating material, a fuse terminal member projecting beyond the body portion and having connection with a fusible element, a block of insulating material having a narrow recess of the same depth as the projection of the fuse terminal member beyond the body portion and arranged to closely fit the latter, a contact member forming the bottom of the recess, a contact plate under the block, and a second fuse terminal member having connection with the fusible element and extending through a small opening in the block to make contact with the contact plate; substantially as described.

4. In a device of the character described, r

a fuse having a body portion of insulating material a fuse terminal member of tubular form projecting beyond the body portion and having connection with a fusible element, a circular block of insulating material having a narrow annular recess of the same depth as the projection of the fuse terminal member beyond the body portion, a contact member in the recess, a contact plate under the block, and a second fuse terminal member having connection with the fusible element and extending through a central opening in the block to make contact with the contact plate;

substantially as described.

5. In a device of the character described, a fuse having a circular body portion of insulating material, a fuse terminal member of tubular form surrounding and projecting beyond the body portion and having connection with a fusible element, a circular block of insulating material having a narrow annular recess, of the same depth as the projection of the fuse terminal member beyond the body portion, a circular contact member forming the bottom of the recess, a contact plate under the block, and a second fuse terminal member having connection with the fusible element and extending through a central opening in the block to make contact with the contact plate; sub stantially as described.

6. In a device of the character described, a fuse having a body portion of insulating material, a fuse terminal member projecting beyond the body portion and having connection with a fusible element, a block of insulating material having a narrow annular recess of the same depth as the projection of the fuse terminal member beyond the body portion, a circular contact member forming the bottom of the recess, the body portion of the fuse having a projection of insulating material extending through and fitting an opening in the block, a contact plate under the block, and

a second fuse terminal member having connection with the fusible element and extending through said insulating projection to make the contact with the contact plate; substantially as described. v

7. In a device of the character described, a fuse having a body portion of insulating material, a fuse terminal member having connection with a fusible element, a floating block of insulating material carrying a contact member in line with the fuse terminal member, a contact plate in line with and adapted to be engaged by the contact member on the floating block, a'second contact plate under the block, and. a second fuse terminal member having connection with the fusibleelement and arranged to engage the second contact plate; substantially as described.

8. In a device of the character described, a fuse having a body portion of insulating material, a fuse terminal member having connection with a fusible element, a floating block of insulating material carrying a contact member in line with the fuse terminal memher, a contact plate in line with and adapted to be engaged by the contact member on the floating block, a spring for moving the floating block'to separate the contact member from the contact plate, a second contact plate, and a second fuse terminal member having connection with the fusible element and extending through said floating block to en gage thesecond contact plate; substantially as described.

9. In a device of the character described, a fuse having a body portion of insulating material, a fuse terminal member having connection with a fusible element, a floating block of insulating material carrying a contact member in line with the fuse terminal member, a contact plate in line with and adapted to be engaged by the contact memher on the floating block, a spring for moving the floating block in one direction, a second contact plate, a second fuse terminal member having connection with the fusible element and extending through said floating block, said second fuse terminal member and said second contact plate having cooperating threaded portions to hold the fuse and floating block seated against the tension of the spring; substantially as described.

, 10. In a device of the character described, a fuse having a body portion of insulating material, a fuse terminal member projecting beyond the body portion and having connection with a fusible element, a floating block of insulating material having a narrow recess in line with and fitting the projecting fuse terminal, a contact member secured to the floating block and forming the bottom of the recess. a contact plate in line with and adapted to be engaged by said contact member on the floating block, a spring for urging said block in a direction to disengage the contact member from the contact plate, a second contact plate, and a second fuse terminal memher having connection with the fusible element and arranged to engage the second contact plate; substantially described.

11. In a device of the character described, a fuse having a body portion of insulating material, a fuse terminal member projecting beyond the body portion and having connection with a fusible element, a floating-block of insulating material having a narrow recess at one edge formed by a projecting shoulder on the block, a contact member fitted to and surrounding the shoulder, a contact plate in line with and adapted to be engaged by said floating contact member, a housing surrounding the block and having an inwardly extending shoulder arranged to overhang said contact member on the block, a spring for urging the floating block in a direction to separate its contact member from the contact plate, a second contact plate, and a sec- 0nd fuse terminal member having connection with the fusible element and arranged to engage the second contact plate; substantially as described.

12. In a device of the character described, a fuse having a body portion of insulating material, a fuse terminal member projecting beyond the body portion and having connection With a fusible element, a floating block of insulating material having a narrow recess in line with and adapted to receive the project-ing fuse terminal, a contact member secured to the block and communicating with the bottom of the recess, a contact plate in line with and adapted to be engaged by said contact member on the floating block, a spring for moving the floating block to separate the contact member from the contact plate, a second contact plate, a second fuse terminal member having connection with the fusible element and extending through said floating block, said second fuse terminal member and said second contact plate having cooperating threaded portions to hold the fuse and fioating block seated; substantially as described.

13. In a device of the character described, a fuse having a body portion of insulating material, a fuse terminal member having connection with a fusible element, a circular block of insulating material having a circular contact member adapted to be engaged by the fuse terminal member, a contact plate adapted to be engaged by said circular contact member, means for rotatably confining the block, a second fuse terminal member connected to the fusible element, and a second contact plate in line with the second fuse terminal member to be engaged by the latter; substantially as described.

14. In a device of the character described, a

fuse having a body portion of insulating material, a fuse terminal member projecting beyond the body portion and having connection with a fusible element, a second fuse terminal member and a contact plate, a block of insulating material having a narrow recess of the same depth as the projection of the fuse terminal member beyond the body portion, a contact member in the recess, the depth of the recess and the corresponding amount of projection being progressively'greater for fuses of smaller capacity; substantially as described.

15. In a device of the character described, a member comprising a body portion of in- 5 aulating material, a straight terminal member of tubular form projecting beyond the body portion. the body portion bein Cupshaped and having a central annular extension of insulating material and a second terminal member in the cup and projecting through the bottom of the cup and through the annular extension; substantially as described.

16. In a device of the character described,

a fuse having a body portion of insulating material, a fuse terminal member projecting from the outer edge of the body portion and having connection with a fusible element, the fuse terminal member having its projecting and free and out of contact With the body por tion, and a second fuse terminal member projecting centrally from the body portion and having a screw threaded end portion for holding the fuse seated in a socket; substantially as described.

17. In a device of the character described, a fuse having a body portion of insulating material, a fuse terminal member projecting from the periphery of the body portion and having connnection with a fusible element, a

second fuse terminal member projecting centrally from the body portion, an insulating projection on the body portion surrounding a portion of the second fuse terminal member,

said first fuse terminal member comprising a tube arranged at the end of the body portion and surroundin the insulating projection; substantially as described.

18. In a device of the character described,

a block of insulating material having a narrow recess to receive and substantially fit a fuse terminal member, a contact member for connection With one terminal of an electric circuit and set down at the bottom of the recess for engagement thereat With the fuse terminal member, the block also having an opening therethrough, and a contact member entirely below the block for connection with the other terminal of the electric circuit and .56 having a contact portion inline with the opening to make contact with a second fuse terminal member passed through the opening; substantially as described.

In testimony whereof I hereunto afiix my signature.

CLIFFORD W. COWLES.

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