US1003145A - Electric contacts under carpets and the like for alarm-signals and other purposes. - Google Patents

Description

F. MARMION.

ELEGTRIG CONTACTS UNDER GARPETS AND THE LIKE FOR ALARM SIGNALS AND OTHER PURPOSES.

' APPLICATION FILED JUNE 24, 1910v 1,'003,'145. Patented Sept. 12,1911.

COLUMBIA PLANDGRAPM 60.,WASHINOTON, n. c.

UNITED STATES PATENT OFFICE.

FERNAND MARMION, 0F PARIS, FRANCE.

ELECTRIC CONTACTS UNDER CARPETS AND THE LIKE FOR ALABIVLSIGNALS AND OTHER PURPOSES.

Specification of Letters Patent.

Patented Sept. 12, 1911.

Application filed June 24, 1910. Serial No. 568,662.

To all whom it may concern:

Be it known that I, FERNAND MARMIoN, of Paris, France, have invented a new and useful Improvement in Electric Contacts under Carpets and the Like for Alarm-Signals and other Purposes, which invention is fully set forth in the following specification.

Electric interrupters placed underneath the carpet are usually operated by the pressure of the foot, which closes a spring contact and completes the electric circuit of a bell or other device. The practical drawback to this plan lies in the fact that the foot must be placed directly over the electric interrupter. The present invention obviates this drawback by an arrangement of the interrupter which will act wherever the foot is placed.

The advantages are obvious since the arrangement will indicate with certainty the presence of any one on the carpet and the invention can be applied to stair carpets, at the doors of rooms and in particular to oflices, banks and shops. It is also clear that the same arrangement may be applied not only to a circuit for ringing bells but also to electric lights or to any kind of control circuit.

The following description and accompanying drawings will explain the operation of the invention.

Figure 1 is a view of the upper side of the arrangement Fig. 2 of the lower side of the arrangement Fig. 3 is an end view Fig. 4 is a transverse view of one of the contact pieces in its off position Fig. 5 shows the same when the contact is made.

The method of carrying out the invention is as follows: Contact pieces C, of copper or any other conducting metal, are as shown in section. in Figs. 4 and 5, fixed in rubber washers B which are placed in an insulator A, which follows practically the form and extent of the carpet and is hidden below the latter. This insulating material may be card-board, or better presspahn, asbestos sheet etc and its thickness at is shown in Figs. 4 and 5. The head Z) of the contact piece C is above the level of the insulating sheet and the end of the part c of the contact piece terminates in the washer just above the lower part of the latter. A thin sheet of paper or other insulator of this kind, is pasted all overthe lower surface of the insulating sheet and of the rubber washers. It is only provided with apertures (Z to allow the shank 0 of the contact piece to project through when pressed from above. All the preceding parts, the insulating sheet with the rubber washers and the contact pieces rest simply on a metallic conducting surface, of wire gauze, network of wires etc E, while a second sheet of metal F rests on the top of the whole.

The system acts as follows :The conducting surfaces E and F are inserted in an electric circuit 0 7; for example in series in a circuit containing an electric bell and a battery. An ordinary carpet covers the sys tem and when the pressure of the foot is applied to the carpet, one or more of the contact pieces C assumes the position shown in Fig. 5, and come into contact with the metallic sheet E. As the pressure has been applied to the heads of the cont-act pieces of the top metallic sheet F, the contact pieces will connect the two sheets, that is will close the battery circuit and ring the bell. As soon as the pressure on the carpet ceases, the clasticity of the rubber, which has been compressed until then, will lift the contact pieces, break the connection and open the circuit, and the bell will cease to ring. So that, contrary to previously proposed arrangements, the system of the present invention insures an alarm signal being given, so long as, and this is very easy to provide, there is at least one contact piece under the foot, wherever it may be placed. This must occur if the contact pieces are so disposed, that their distance apart is less than the smallest dimension of an average boot.

The preceding arrangement has been described by way of example and can be varied indefinitely as regards the form, number and disposition of the contact pieces. Figs. 1 and 2 show two sets of contact pieces, which differ in the size of the caoutchouc washers. For these latter could also be substituted springs or their equivalents. Also the system which has been supposed, by way of example applied to ringing bells, can be extended to other purposes; thus the insulating sheets with the contact pieces between two metallic surfaces could be placed under the stair carpets, so as to light up incandescent lamps when any one mounted the staircase at night.

Having thus particularly described and ascertained the nature of my invention, and

the best means I know of carrying the same into practical effect, I claim 1. In combination, a source of electric current, a pair of conducting surfaces connected therewith, a body of insulating material interposed between said surfaces, a resilient insulating element carried in said material, a conducting member projecting into said resilient element and adapted to close an electric circuit through said conducting surfaces.

2. In combination, a source of electric current, a pair of conducting surfaces connected therewith, a body of insulating material interposed between said surfaces, a plurality of resilient insulating elements carried by said insulating material, a conducting member projecting into each resilient element and adapted to contact with said conducting surfaces to close an electric circuit therethrough.

3. In combination, a source of electric current, a pair of conducting surfaces connected therewith, a body of insulating material interposed between said surfaces, a sheet of paper secured to the under surface thereof, a plurality of rubber washers carried by said insulating material, and a conducting member projecting into each washer and adapted to contact with said conducting sur faces to close an electric circuit therethrough.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

FERNAND MARMION. Vitnesses:

H. C. COXE,

GABRIEL BELLIARD.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. G.

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