US1336424A - Testing device - Google Patents

Description

M. w. DAVIS.

TESTING DEVICE.

APPLICATION FILED APR. I4, 1919.

Patented Apr. 13, 1920.

EEK/[Davis I N VEN TOR ITED STAES OFFICE MAXWELL WM. DAVIS, OF WEST HAVEN, CONNECTICUT.

TESTING DEVICE.

Specification of Letters Patent.

Patented Apr. 13., igi fid.

Application filed April 14, 15519. Serial No. 290,058.

To all whom it may concern:

Be it known that I, MAXWELL WM. DAvis,

a citizen of the United States, residing at West Haven, in the county of New Haven 1 and State of Connecticut, have invented new and useful Improvements in Testing Devices, of which the following is a specification.

This invention comprehends the provision of a testing device, designed for use by electricians, for testing spark plugs, fuses, motor trouble and electric light wiring. and in general all trouble work.

The invention aims to provide a simple device which can be carried about the per son finding a use for the same and embodies among other features, a casing closed by an insulated contact plate, the latter carrying an electric bulb adapted to project light rays through an opening in the casing, when the circuit is closed through batteries disposed within the casing.

One of the chief characteristics ofthe invention resides in the use of a resilient element of novel construction, designed for association with the electric light bulb and used to maintain a plurality of dry batteries fixed relatively end to end within the casing and spaced from the walls of the latter.

Another object of importance resides in giving the contact plate a smaller diameter than the insulated member therefor whereby the latter projects beyond the major portion of the edge of the plate to protect the same; and shaping the plate to provide the latter with'a contact projection which is cut away to accommodate itself to various parts to be tested. p

The nature and advantages of the invention will be better understood when the following detailed description is read in connection with the accompanying drawings, the invention residing in the construction, combination and arrangement of parts as claimed. I

In the drawings forming part of this specification like numerals of reference indicate similar parts of the several views and wherein Figure 1 is a perspective view of the device.

Fig. 2 is a longitudinal sectional view therethrough.

Fig. 3 is a detail view of the contact plate or cover.

Fig. i is a similar view of the insulating plug.

Fig. 5 is a detail view of the resilient element for holding the batteriesfixed relatively within the casing.

A device constructed in accordance with my invention essentially embodies a tubular casing 10 constructed from suitable material, and of any desired dimension. One end of the casing is closed by a screw cap 11 which carries a binding post 12 havin a portion disposed within the casing when the cap is associated therewith. the major portion of the binding post projecting outwardly from the bottom to accommodate a clamping screw 13 of usual construction. The screw is adapted to clamp one end or" the wire or cord 14 to the binding post. A plurality of dry batteries '15 are inserted within the casing through the opposite end thereof, the batteries being arranged in end to end contact with the lowermost battery resting upon the binding post 12 and thus held spaced from the bottom cap 11. As shown, the batteries are slightly smaller in diameter than the similar dimension of the casing 10 and consequently the batteries are spaced from the walls of the latter. If desired the batteries 15 may be wrapped in an adhesive sheet of suitable material 16 which will serve to insulate the upper cell from shorting with the case 10.

A plug 17 of suitable insulating material such as fiber or the like is inserted within the open or upper end of'the casing 10, the plug having an annular flange 18 which re poses upon the upper edge of the casing 10. and a' threadedbore 19 which receives the threaded stem 20 of an electric light bulb 21. The bore 19 is open at both ends of the plug to permit the terminal of the bulb 21 to engage the metallic contacting plate or disk 23 which is secured to the plug 17 in any suitable manner. such as for instance by removable fastening elements 24. The

contacting plate or disk 23 is smaller in diwith certain parts of a circuit when testing said parts, and the projection 25 is cut away or indented as at 26 to permit the contact plate to accommodate itself to said parts. For instance, in testing a spark plug or the like, the binding post thereof would be received within the cut away portion 26 of the disk 23 thus allowing the latter to rest upon the binding screw with which binding posts are generally provided. It is of course manifest that the plug 17 can be readily separated from the casing 10 when it is desired to replace either the electric light bulb 21 or the batteries 15.

\Vith a view of maintaining the batteries 15 fixed relatively in a given position within the casing 10, I employ a ring 27 which receives the stem 21 of the electric light bulb whereby the latter provides a support for said ring. Projecting from the periphery of the ring 27 is a resilient finger 28 Which is curved throughout its length to conform to the curvature of the bulb 21, the finger 28 terminating beneath the bulb and adapted to engage the end of the adjacent battery'lo. The inner end of the plug 17 provides a bearing surface for the ring 27, and with the resilient finger 28 bearing against the adjacent battery 15, the said batteries are, held under tension in their given position within the casing 10. If desired, the flexible element 14 may be provided with a springclip at one end to be readily attached to any article to be tested. It is of course to bennderstood that any part of the casing 10 When closed with the contacting plate or disk 23 will illuminate the bulb 21, and the rays therefrom will be projected through an opening 29 in the casing 10 in the vicinity of the bulb. The device is not very large and can be conveniently carried in the vest pocket or about the person finding use for the same, and the device cannot be short circuited and the batteries run down because the batteries are designed to fit within the casing 10 in the manner shown, and because the case and batteries are of the same polarity. The light rays from the miniature bulb 21 shows up very clear at a reasonably good distance,-and gives instant results when seeking the source of trouble in electrical systems.

, While I have shown and described what I consider the preferred embodiment of the invention, I desire to have it understood that the same is merely illustrative, and that I do not limit myself to the exact construction and arrangement disclosed, and that such changes may be resorted to when desired as fall within the scope of what is claimed.

\Vhat I claim is 1. A device of the class described comprising a casing, a binding post at one end of the casing, an insulated contact plate at the opposite end thereof, a plurality of dry batteries arranged end to end within the casing, and spaced from the walls thereof, an electric lightbulb carried by said plate, an annulus surrounding said bulb and a spring finger carried by the annulus and engaging one of said batteries to hold the latter fixed relatively within the casing.

2. A device of the class described comprising a casing, a binding post at one end of the casing, an insulated contacting disk at the opposite end of the casing, the insulating material projecting beyond the periphery of the disk for the major portion of its circumference, the remaining portion of the circumference of the disk projecting beyond said insulating material to provide a contacting projection, an electric light bulb carried by the insulated plate, and a battery arranged within the casing.

In testimony whereof I aflix my signature.

MAXWELL WM. DAVIS.

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