US2111624A - Fuse construction - Google Patents

Description

March 22, 1938. R. A. HAMMACK FUSE CONSTRUCTION Filed NOV. 8, 1935 Patented Mar. 22, 1938 UNITED STATES PATENT OFFICE FUSE CONSTRUCTION Application November 8, 1935, Serial No. 48,837

3 Claims.

This invention relates to a fuse construction. Objects of this invention are to provide a very simple type of fuse construction which may be used in any capacity but is eminently suitable for use as a secondary fuse.

It is well known that where very small amperage primary link fuses are used when fusing a transformer for instance, that it is usually the practice to use nothing smaller than a 3-ampere 1O fuse for example, with the result that there is often over fusing of the smaller transformers, particularly of the 13,000 volt class, and secondary fuses are therefore necessary for overload protection. Additionally, it is advisable to use secondary fuses where there are grouped secondaries of the transformers to prevent outage of the entire group in case of failure of a single transformer.

This invention is designed to provide a simple type of fuse which may be used as a suspension fuse and therefore does not require any additional room on the cross arm of a pole, for example, but which may be employed as a suspension fuse directly in the secondary line so that the minimum space is required.

Further objects are to provide a novel form of suspension fuse construction in which a porcelain body portion is employed and is so joined to the line wires that the porcelain is placed under compression, and in which no strains are imposed on the fuse link or fuse member, such fuse member being held in spaced relation to the line wires and being so held that it may be very readily refused.

In some of the previous constructions of suspension fuses it has been the practice to provide a separate insulating block which acts as a mounting member for the fuse link. This invention, however, has for its further object the 4.0 provision of a suspension fuse in which the strain member also serves as a spacing member for the fuse link.

Further objects are to provide a construction which is easy to install, which is reliable in operation, and which may be placed in any position desired, either horizontally, vertically, or in an angular position.

An embodiment of the invention is shown in the accompanying drawing, in which:

Figure 1 is a side elevation with parts broken away showing the fuse construction.

Figure 2 is a plan view of the structure shown in Figure l.

55 Figure 3 is a sectional view through the porcelain insulator, such view corresponding to a section on the line 3-3 of Figure 1.

Referring to the drawing, it will be seen that the porcelain body portion has been indicated by the reference character I. This porcelain body portion is provided with a plurality of pairs of channels 2 -2, and 3-3 located in diametric relation to each other. The channels 3-3 communicate with an opening 4 extending transversely through the porcelain insulator and the 10 channels 22 communicate with an opening 5 extending transversely through the porcelain insulator and arranged at right angles to the opening. 4.

The line wire 6 is passed through the opening 15 5 and lies within the channels 2. It is looped back upon itself and twisted or otherwise locked in place, as indicated at l in Figures 1 and 2. The line wire 8 is passed through the opening 4 and lies within the channels 3. It is looped back upon itself similarly to the line wire 6 and is twisted or otherwise looked, as indicated at 9.

Bracket members 10 and II are bolted toopposite ends of the porcelain body portion l in any suitable way, as by means of bolts or screws cemented into the porcelain body portion as indicated in Figure l, and have outwardly turned terminal portions.

Any convenient means may be provided for bolting the bared ends of the line wires 6 and 8 to these terminal members and for clamping the fuse link hereinafter described in place. For example, screws I2 may pass through the members l0 and H and may be provided with nuts I3 and thumb nuts M.

The bared end of the line wire 6 is secured to the terminal member i0, suitable washers being positioned on opposite sides of the bared end of the line wire 6 and such end being clamped in place by the nut l3. The bared end of the line 40 wire 8 is similarly locked to the terminal member H.

A fuse link 15 is supported from the terminal members, preferably being held between washers and locked by the thumb nuts 14, as. indicated 4:" most clearly in Figure 1.

The fuse link 15 is thus spaced a considerable distance from the line wires and also is spaced from the porcelain member. It is not subjected to any mechanical strain whatsoever.

The member 2 is preferably of porcelain. or glass to prevent serious burning and carbonizing from the are when the fuse blows under heavy current. Also it is to be understood that if it is desired, the fuse link may be enclosed in a fiber or protective tube to prevent metallic deposit from the fuse link or any damage to the insulator when the fuse blows, though generally this is not found necessary.

It is obvious that these fuses may be placed in the most convenient location for refusing and that they do not require any space on a pole arm or cross bar. Also they employ very little material and are easy to produce so that they are very mexpensive.

In refusing it is apparent that unscrewing the nuts M will not loosen the line wires as they are clamped by the nuts l3. Consequently a new fuse link may be substituted for the blown fuse link with the utmost ease.

It is to be noted particularly that this invention provides a porcelain or other similar body portion which is preferably held in compression and which carries a fuse structure. The particular form of fuse construction may, of course, be varied without departing from the spirit of this invention.

It is to be understood that these suspension fuses may be placed horizontally, vertically or at an angle or in any desired position, and that the fuse link may be above, to the side, or below the porcelain body portion as desired.

Although the invention has been described in considerable detail, it is to be understood that the description is intended as illustrative rather than limiting, as the invention may be variously embodied and is to be interpreted as claimed.

I claim:

1. A fuse construction comprising a body portion formed of relatively brittle insulating material and having flat ends and having pairs of diametrically opposed, longitudinally extending grooves therein, said body portion having spaced holes extending transversely from one groove to the diametrically opposite groove and adapted to receive looped conductors with the loop of one conductor interlinking with the loop of the other conductor and spaced therefrom by the insulating body portion, whereby said insulating body portion is put under compression, metal terminal members carried by the ends of the body portion and secured against the end faces thereof and projecting outwardly therefrom and having means for receiving conductors, a fuse link extending from one terminal member to the other terminal member longitudinally of said body portion, and clamping means carried by said terminal members for removably clamping said fuse link.

2. A fuse construction comprising a body portion formed of relatively brittle insulating material and having pairs of diametrically opposed, longitudinally extending grooves therein, said body portion having spaced holes extending transversely from one groove to the diametrically opposite groove and adapted to receive looped conductors with the loop of one conductor interlinking with the loop of the other conductor and spaced therefrom by the insulating body portion, whereby said insulating body portion is put under compression, said body portion having fiat ends, metal terminal members secured to the flat ends of said body portion and projecting laterally therefrom, said terminal members being located within the loops of said conductors, clamping means carried by said terminal members for receiving the ends of conductors, a fuse link extending from one terminal member to the other terminal member and held in spaced relation to said body portion, and means for clamping the ends of the fuse link to the terminal members.

3. A fuse construction comprising a body portion formed of relatively brittle insulating material and having pairs of diametrically opposed, longitudinally extending grooves therein, said body portion having spaced holes extending transversely from one groove to the diametrically opposite groove and adapted to receive looped conductors with the loop of one conductor interlinking with the loop of the other conductor and spaced therefrom by the insulating body portion, whereby said insulating body portion is put under compression, said body portion having fiat ends, terminal members secured to the flat ends of said body portion and projecting outwardly therefrom and having means for receiving conductors, and fuse means normally electrically connecting said terminal members and located oppositely and paralleling a portion of said body between adjacent grooves.

RAMESIS ALFONSO HAMMACK.

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