US2037120A - Socket for plug fuses - Google Patents

Description

April 14 19365 J. v, CUNNINGHAM 2,637,120

SOCKET FOR PLUG FUSES Filed Feb. 5, 1954 Patented Apr. 14, 1936 UNITED STATES PATENT OFFICE SOCKET FOR PLUG FUSES James Vernon Cunningham, St. John, New Brunswick, Canada 1 Claim.

This invention relates to improvements in sockets for plug fuses, and the objects of the invention are to limit the size of fuse which may be used with a given socket thereby preventing the over-fusing of branch circuits beyond the established limits, and to prevent the improper use of substitutes such as copper cents for the plug fuses. It consists essentially of a socket having a central contact on the base thereof with an insulating partition in advance of the contact having a restricted aperture therein designed to fit closely to the central contact of a plug fuse of given size, the arrangement being such that each size of a plug fuse will have an appropriate sized aperture in the insulating partition as hereinafter more fully set forth and described in the accompanying specification and drawing.

In the drawing Fig. 1 is a sectional elevation of a socket embodying the present invention.

Figs. 2 and 3 are front elevations showing sockets for two different sizes of plug fuses.

Figs. 4 and. 5 are side elevations of two different sizes of plug fuse designed to fit into the sockets shown in Figs. 2 and 3.

In the drawing like characters of reference indicate corresponding parts in all the figures.

Referring to the drawing, A represents a fuse plug socket having a cylindrical shell 9, said socket being preferably screw-threaded at Ill to receive the plug, and being formed at the base with a central contact I I insulated from the socket, this contact being connected to an electrical conductor l2, the other electrical contacts for the socket not being shown and not relating to the present invention.

According to the present invention there is provided in the socket A in advance of the contact II and spaced therefrom an insulating partition or washer I 3 of fibre or other convenient insulating material, supported in position by small screws I4 and I5 which may extend into the base I! formed of insulating material in which the socket A is set. When in place insulating partition I3 retains the cylinder shell 9 in its proper position since it rests on a turned in flange It at the inner end of said shell, as shown in Figure 1. The partition I3 is supported a short distance in advance of the base and is formed with a restricted aperture I6 in its center, preferably circular, immediately in front of the contact I I and designed to receive the central contact I8 of the fuse plug which should be of a special size and shape to fit closely to the aperture. The size of the apertures in each socket will correspond with the plug which it is designed to receive. For instance the socket shown in Fig. 2 has an aperture of a smaller size than that shown in Fig. 3, and might be designed to receive contacts from plugs up to 15 amperes, while the larger aperture shown in Fig. 3 might receive contacts from plugs of 30 ampere capacity.

Figs. 4. and 5 show the plugs C corresponding to the sockets in Figs. 2 and 3. The construction of the fuse plugs themselves does not form part of the present invention. As far as the present invention is concerned it is only necessary that the central contact IS on the plug should be of a size closely to fit the aperture in the insulating washer I3 of the socket which it is designed to fit. The plug for instance shown in Fig. 4 is designed to fit the aperture in the socket shown in Fig. 2, while that shown in Fig. 5 fits the aperture shown in Fig. 3.

With the arrangement described it will be possible to avoid the over-fusing of branch circuits beyond the limits set by the standard code, since the sockets for the lower capacity fuse plugs will not receive larger capacity fuse plugs, and further it will not be possible to use copper cents or other expedients in place of the fuse plugs, since the insulating washer will prevent their making the proper contact. The result will be a substantial reduction in fire loss, and as the consumers of an electrical system will not be able to overload their branch circuits they will be able to get better lighting and a more advantageous use of their various appliances.

Various modifications may be made in the invention without departing from the spirit thereof or the scope of the claim and, therefore, the exact forms shown are to be taken as illustrative only and not in a limiting sense, and I desire that only such limitations shall be placed thereon as are imposed by the prior art or are specifically set forth in the appended claim.

What I claim as my invention is:

A fuse plug socket having a cylindrical shell with 2. turned in flange at its inner end, said socket having a central contact at the base thereof and a partition formed of insulating material secured in advance of the contact and resting on the flange, said partition being adapted to hold said cylindrical shell in place and having a restricted aperture through which a contact on a fuse plug of given size may pass.

JAMES VERNON CUNNINGHAM.

Jill

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