US2154688A - Fuse - Google Patents

Description

AprilL 18, 1939- c. L.. MATTHEWS ET AL 2,154,588

FUSE

2 Sheets-Sheet 1 F I G2.

Filed Feb. l0, 1936 April 18, 1939- c.,| MATTHEWS ET A1. 2,154,688

FUSE

Filed Feb. lO, 1936 2 Sheets-Sheet 2 .5 Among the several Patented Apr. 18, 1939 PATENT oFElcE 2.15am I rusa cima l.. Matthews; si. Louis, carl E. Mosley,

Richmond Heigh St. Louis,- Mo.,

ts, and Theodore Birkenmaier, signers to W. N. Matthews Corporation, St. Louis, Mo., Missouri a corporation of Application February lo, 1936, serial Nn. 63,098`

7- Claims.

This invention relates to fuses, and with regard to certain more specic features, to fuses having means for separating the fuse ends upon blowing. I

objects of the invention may be noted the provision of a simple and eco-4 nonlical form of fuse cutout which is adapted to be connected between a transformer secondary or the like and adjacent apparatus without a l `special mount or enclosure; the provision of a device of the class described, which despite its lack of mounting or covering, is positively safe and reliable in opening the circuit, without the possibility of an accidental non-fused reclosure of the circuit through the burned fuse link; the provision of a vfuse cutout which may be universally used in connection with vvarious apparatus; and the provision of a device of the class described having a fuse-link terminal which prevents undesirable destructive action on the link when making a fastening. Other objects will. be in part obvious and in part pointed out hereirlafter.

The invention accordingly comprises the elements and combinations of elements, featuresy .of construction, and arrangements of parts which will be exemplified in the structures hereinafter described, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings, in whichis illustrated one of various possible embodiments of the invention, l Fig. 1 is a side elevationl showing one application of the device; 35 Fig. 2 ls an enlarged vertical section of one form of the invention;

Fig. 3 is a fragmentary right-side elevation of Fig. 1 but showing a fuse pulling device in open position and without a fuse link therein; Fig. 4 is a view similar to Fig. 1 showing the apparatus in blown condition;

Fig. 5 is a cross section taken on line 5-5 of Fig. 2;

Fig. 6 is a side elevation, parts being broken 45 away, and showing an alternative form and application of the invention; and,

Fig. 'l is a side elevation showing another application. Similar reference characters indicate corre- 50 spending parts throughout the several views of the drawings.

Referring now more particularly to Fig. l, there is shown at numeral I, for example, a secondary outlet tap of4 a transformer which it is desired,`

55 through-a fuse, to electrically connect with a (Cl. '20o-117) wire such as shown at 3. Itis to be understood that the `invention may be applied directly to the secondary transformer studs where taps are not used and to other connections than secondary taps or studs of transformers, and that it has general utility in the electrical field, both for high and low`=voltages. For instance, in Fig. 6, the device is shown attached to a transformer stud 2, and in Fig.7 it is shown electrically connecting line wire sections 4 and 6 which are mechanically joined by the strain insulator 8. In this" case an insert wire III may be used. As will be clear from the following speciiication, ous fuse links adaptable for primary and secondary applications. Other applications may be thought of with the above as examples.

-At numerals 5 and 9 are shown deformable conducting terminals composed of material such as heavy bendable (but in the drawings nonilexible) copper wires, which are initially made straight and so delivered to the user. The user .then bends and/or cuts off portions of .these terminals 5 and 9 to suit his needs, and, as illustrated in the drawings, they` have been bent to suitable positions. Thus an electrical connection may be made by means of a connector 1 of known type, to any size of conductor wire which is within the range of the connectors 1. As shown in Fig. 6, bending may not be necessary.

It is to be understood that the wires 5 and/or 9 may be flexible and that the term deformable is meant to be genericto the terms flexible and bendable".

Between the terminals 5 and 9 is located the cutout per se, but it is to be understood that it and the terminals 5 and 9 form a unit when delivered to the customer, with the WiresA 5 and 9 preferably, though not necessarily straight and solid, but as above forecast they may be flexible wires. v

In the form of theinvention shown in Fig. 1, the upper terminal 5. forms a rigid extension from an upper terminal socket I3 within which is heldthe upper end of an insulating, expulsion tube I5. The terminal socket I3 has an upper inlet I1 which is in alinement with the opening I9 of the insulating tube I5. The element I3 is threaded about said opening Il to accommodate a cap 2I which may be removed to permit insertion of a fuse link 23, the .head`25 of which rests upon the upper end of the element I3 and which is clamped in place' by replacement of the cap 2|.

The lower end of the tube I5 passes through the device will accommodate vari 1n turn connected to a second conducting portion 3| which connects with The wires 5 and 9 may be said head 25. soldered or sweated in their sockets, as shown in Fig. 2, or be riveted,l

as shown in Fig. 6.

The socket member 24 extends, as shown at numeral 33, to form a support for a pin 35. The pin 35 serves as a pivot for an arm 31 which has an opening 39 therein for accommodating passage therethrough of the conducting portion 21 of thev link 29. The arm 31 may swing on the pin 35 from the position shown in Fig. 4 clockwise to that shown in Figs. 1 and 2, vin winch latter position said opening 39 is in Substantial alinement or adjacent to the opening I9 through the tube l5.

The underside of the arm 311s provided with a plurality of guiding lugs 4| for positioning the conductor 21 under and on the arm 31. The conductor is thus led around the rear end of the arm to a position over said extension 33. Here `the conductor 21 is wrapped about a stud and threaded (Fig. 2).

A thumb nut 45 is threadedto the upper threaded portion of the stud 43 and is provided with a round counterbore which clears the corners of the square base of said stud to form a skirt 41. This skirt is externally grooved as at 48. A washer 49 has ears 5| which are crimped into the groove 48.

is provided a rotatable nut 45 which is adapted to drive the washer 49 down on the end of the conductor 21 without rotation of the washer. 'I'he washer can slide onthe square shank but cannot rotate, while the nut c an both'rotate and move endwise. There is relative rotary motion during adjustment between the ears 5| and the ange 53 but no relative longitudinal motion. Thus there is provided means whereby the ends of the component wires in the iiexible wire 21 only compress upon making a juncture, rather than twist and fray.

A spring 51 is wound about the pin 35 and has one arm 59 reacting under the extension 33 and another arm 6| reacting over the lever 31, thus lto push the lever downwardly.

To prepare the device for operation, the cap 2| is unscrewed and the link 23 threaded through the opening I1. The cap 2| is then reapplied and the head 25 of the link thus'held in electrical contact with the socket |3.- The upper conductor 3| extends into the tube I5, the latter surrounding the fusible portion 29. The lower, flexible conducting element 21 extends downward, from the lower open mouth of the tube l5, and is threaded through the opening 39,`around the lever 31 and clamped by rotating the thumb screw 45. During this threading and clamping operation, the lever 31 is turned upwardly to the position shown in Figs. 1 and 2, thus tensioning the spring 51 and causing the lever 31 to tension the fuse link.

Upon blowing of the link 23, under heavy overfllsible portion 29,'

load conditions, the gases formed by the fusion at the fusible portion 2l will more or less violently eject the conductor 21. The lever 31 will move coimterclockwise' until the rear set of lugs 4| strikes the back of the extension 33, thus limiting the counterclockwise motion of to the position shown in Fig. 4. for the exible conductor 21 to whip upwardly through an arc, is limited to the small dotted-line circle B shown around center Y, that is it cannot whip upwardly and into contact with the live member 5, or parts associated therewith along the arc A on center The above construction is quite different from those heretofore employed, in which the means for whipping out the lower or flexible conducting element of the fuse have, in effect, had the conducting elements swing around a higher center somewhere near the center X (Fig. 4), thus also leaving a greater length of flexible whipping wire which could swing up on the higher center and reach the live portions of the circuit. In short, this invention provides a means for lowering the center of swing of the flexible, separatedv conducting portion of the link after blowing. It also reduces the length of the portion of 21 which swings. In Fig. 4, the radius of arc A is the old free length of swing on center X; and the radius of B is the new limited free length of swing on the lowered center Y.

It is to be understood that if the overload is of the so-called dragging variety,l lthen the expulsive feature may not come into operation and the-flexible link will merely be pulled downwardly by the arm 31, without any tendency in any event to again swing upwardly. swinging radius is still limited which is advantageous. It will be seen from this that the invention is serviceable, both in cases where overloads provide the expulsionaction and where they db not.

Another feature of the invention, when used under any conditions, is that the position of the arm 31 provides a visible indication as to whether functioned, and saves time in the location of blown out fuses. For instance, in the case of Fig. 4, it is quite cle'ar that the fuse has blown. l

It is to be understood that although the invention is primarily useful for unenclosed'fuses, it is also useful in connection with box type or enclosed fuses, because it prevents any excessive length of fuse link from whipping out and swinging from the open lower end of contact with outside wires or the like.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As many changes could be-made in carrying out the above constructions without departing from the'scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

We claim:

1. A fuse comprising spaced contacts, a fuse link having a fusible portion andv including a portion electrically connected between said contacts and having a turned portion thereand means pivoted to one of said conbetween, tacts and having an opening through which said fuse link is passed at said turned portion and between its points of connection with said contacts,

However the freethe box and into said link being permanently attached to the fuse at a point below the fusible portion of the link,

2. A fuse comprising spaced contacts, a iuse link having a iiexible portion held to said con`- tacts and extending therebetween, an insulating tube between said contacts and surrounding a portion of said link, ysaid link extending from the tube, means pivoted to one of said contacts and having an opening adapted to be positioned adjacent the tube outlet in one position ci said pivoted means, the ilexible portion of said link being threaded therethrough, means normally tensioning said pivoted means to withdraw a portion of the fuse link from the tube upon blowing of the fuse, and limiting stop means between said pivoted member and the contact to which it is pivoted, whereby upon withdrawal ci' said ilexible portion, the center of whip of the same is moved away from the pivot contact.

3. A fuse comprising spaced upper and lower contacts, a fuse link having a exible portion electrically connecting said contacts, an insulating tube joining said upper and lower contacts and surrounding a portion of said link and having an opening below the lower contact, said link extending irom said lower opening, an arm pivoted to said lower contact and having an opening adapted to be swung adjacent to the lower opening in the tube, said link being threaded through said arm opening when connected to at least one of said contacts, spring reacting means between said arm and said lower contact adapted normally to tend to withdraw the fuse link from the tube, and stop means between said'arm and said lower contact adapted upon blowing of the fuse to maintain the substantialcenter of whip of the flexible portion of the link to a point substantially below the lower contact.

4. A fuse comprising spaced upper and lower contacts, a fuse link having a ilexible portion electrically connecting said. contacts. an insulating tube joining said upper and lower contacts and surrounding a portion oi said link and having an opening below the lower contact, said link extending from said lower opening. an arm pivoted to said lower contact and having an opening adapted to be swung adjacent to the lower opening in the tube, said link being threaded through said ann opening when connected to at least one of said contacts, spring reacting means between said arm and said lower contact adapted normally to tend to withdraw the fuse link from the tube, stop means between said arm and said lower contact adapted upon blowing of the fuse to maintain the substantial center of whip of the flexible portion of the link to a point substantially below tensions comprising cylindric conductors which are adapted to be bent and cut in the field but which are strong enough to support the fuse in the circuit, the spaced contacts, mechanism and extensions forming a rigid unit when mounted.

6. A fuse comprising spaced contacts, a fuse link held to said contacts and extending therebetween, said link having a flexible portion, an insulating tube between said contacts and surrounding a portion of said link, said link extending from the tube and being turned back externally, means pivoted to one of said contacts and having an opening adapted to be positioned adJacent the tube outlet in one position, said link passing through said opening adjacent the region where it is turned back, and means biasing said pivoted means to withdraw a portion of the fuse from the tube upon blowing'oi the fuse, said link being permanently attached to the contact which supports said pivoted means.

7. An expulsion-tube current interrupter comprising a tube of insulating material, a fuse link within the tube consisting of a small fusible portion and a larger ilexible portion, an arm hingedly mounted near one open end of the tube with a swinging end movable from closed-circuit position at the tube to open-circuit position away from the tube, and a ring opening at the swing end of the arm to receive the flexible conductor.

CLAUD L. MATTHEWS. CARL E. MOSLEY. THEODORE BIRKENMAIER.

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