US2683784A - Burglar alarm mat - Google Patents

Description

July 13, 1954 w. A. RECTOR BURGLAR ALARM MAT Filed April 12, 1952 I III a FIG. I

q I 1 I I I J FIG. 6 I INVENTOR.

WILLIAM A. RECTOR FIG. 4

ATTORNEYS Patented July 13, 1954 UNITED STATES PATENT OFFICE BURGLAR ALARM MAT William A. Rector, Akron, Ohio Application April 12, 1952, Serial No. 282,007

6 Claims. 1

This invention relates to burglar alarms and particularly to burglar alarm mats that can be set to actuate an alarm system when any person steps upon the mat.

Heretofore there have been various types of alarm systems proposed for actuation when a burglar enters a premise in an unauthorized manner and some of such systems have comprised the use of mats that activated an alarm by a person stepping thereon. All of such types of apparatus using mats, insofar as are known to me, have involved the use of a relatively complicated alarm system, or else they have been of such vertical height as to be quite noticeable and therefore objectionable, or they have not continued the alarm after the person steps off the mat, or they have been otherwise objectionable.

It is desirable that alarm systems of this gen eral type should be of positive action and should be of very small vertical height so as to resemble an ordinary floor mat or pad. Also, the apparatus should be so connected that it will continually actuate an alarm signal even after a person has stepped onto the burglar alarm mat and then off the mat.

The general object of the present invention is to provide a new and novel alarm mat of the type described, which alarm mat is characterized by its low over-all height and by the positive and continued actuation of the burglar alarm by a person stepping thereon.

Another object of the invention is to provide a burglar alarm system of relatively uncomplicated construction which has mechanical means for positively retaining the burglar alarm in closed or actuated condition when a trigger mechanism therein is once released.

Another object of the invention is-to provide a burglar alarm mat the movable portion of which can be easily reset and wherein the operative components of the alarm system are of sturdy construction and are relatively easily assembled.

The foregoing and other objects and advantages will be made more apparent as the specification proceeds.

For a better understanding of the present invention, one currently preferred embodiment of the invention is completely shown in the attached drawings, wherein:

Fig. 1 is a plan of the burglar alarm mat of the invention with a portion of the mat removed to show the base member of the mat;

Fig. 2 is a longitudinal vertical section taken on line II-II of Fig. 1;

Fig. 3 is a fragmentary vertical section taken on the line III-III of Fig. 2;

Fig. 4 is a fragmentary enlarged plan of the trigger and contact means of the alarm mat;

Fig. 5 is an enlarged vertical section of a modification of the mat of the invention; and

Fig. 6 is a simplified wiring diagram of an alarm system of the invention.

In general, the apparatus of the present invention relates to a burglar alarm comprising a flat base, an arm secured to the base, resilient means positioning a portion of the arm above the base, and normally spaced electric contact means on the base and being movable into contact closing relation. Special means are provided that urge the contact means into engagement whereas trigl;- ger means are associated with these last named means to retain such means in position with the contact means out of engagement but being adapted to be released by the trigger means when the arm is depressed.

The novel burglar alarm mat of the invention is indicated as a whole by the numeral l and it includes a base member 2 that usually is in the form of a flat metal sheet which may have a reinforcing bead 3 formed around the edge thereof. Usually a cover 4 is provided for the mat l and this cover 4 is formed from suitable resilient material, such as rubber or rubber-like material, which has a large, centrally positioned recess 5 provided in its lower surface. The base member 2 and all of the elements carried thereby are snugly received within the recess 5 without any appreciable increase in thickness of the cover 4 because of the base member being received thereunder.

As an important portion of the control means for the alarm mat of the invention, an arm 6 is shown carried by the base member 2 and being secured thereto by suitable means, such as rivets '5 at one end of the arm 6. One end of the arm 6 is depressibly supported above the base member 2 by suitable spring means, such as a leaf spring 8. This leaf spring 3 is usually secured to the free end of the arm 6 by a rivet 9 with such leaf spring normally positioning the free end of the arm appreciably vertically above the base memher but free for movement downwardly to the base member.

A terminal block it is suitably secured to the base member 2 and leads II and i2 connect thereto in a conventional manner. Usually one terminal or contact 13 extends from the block l0 and may be fixedly positioned with relation thereto. Such contact it may abut an insulating back-up block I 4 on the base member 2 to prevent undesired movement of this contact. A resilient, or movable contact I5 is connected to the other lead l2 and extends from the terminal block I I] and spaced from the contact I3 but movable with relation thereto so that the contacts I3 and I can be engaged when the contact I5 has a slight pressure exerted thereon urging it toward the contact I3.

As an important novel feature of the invention, a mechanical member, such as a plunger I6, is provided to engage the contact I5 and force it toward the contact I3. The plunger I6 is slidably carried by a sleeve I'I suitably secured to the base member 2 and extending therefrom at both ends with a laterally outer portion of the plunger Iii extending through a positioning hole in the bead 3 of the base. Thus the plunger I 5 is well positioned for reciprocating movement and a coil spring I8 is in telescoped engagement with the plunger I6 and engages a pin I9 extending through the plunger I6. Normally this spring I8 is compressed between the bead 3 and pin I9 so that it tends to move the plunger I6 laterally inwardly of the mat and bring contacts I3 and I5 into engagement. This operative positioning of the plunger and contacts can be prevented by means of a spring trigger 20, one end of which is usually secured to the insulating block I4 and the other end of which extends over to a position adjacent the sleeve I'I. Usually the sleeve IT has a longitudinally extending slot 2| provided in one portion thereof and a pin 22 carried by the plunger I6 is snugly received in the slot 2| for accurate positioning of the pin 22 circumferentially of the plunger as the plunger is reciprocated.

In order to set the alarm mat I for action, the pin 22 can be engaged with the end of the spring trigger by a slidable blocking contact to prevent movement of the plunger I5 axially to engage the contact I5 and press it against the contact I3. The spring trigger 29 is released by being pulled from engagement with the pin 22 by any deflection of the arm 5, and a flexible member, such as a cable 23, is connected between the free end of the arm 5 and an intermediate but movable part of the spring trigger 253. Thus upon any deflection downwardly of the arm 5, or even movement upwardly thereof, for any reason, it immediately pulls the spring trigger 26 out of its frictional engagement with the pin 22 and permits the spring I8 to snap the plunger I5 into operative position wherein the contacts I3 and I5 are retained in engagement until the alarm mat of the invention is positively reset. The mechanical means of the invention produce a continued closure of the alarm circuit connected to the mat I. Only when the cover 4 is removed can the plunger It be retracted and the trigger be engaged with the pin 22 to disconnect the alarm mat from its associated electrical circuit.

Normally the burglar mat of the invention would be used with an electrical alarm circuit although other means may be controlled thereby and a typical example of such means is a battery 24 that connects to a member 25 which may be a buzzer, horn or the like by a lead 26. The other terminals of the battery and of the member 25 connect to the leads II and I2 referred to hereinbefore so that the alarm can be operated when the mechanical means of the invention are actuated.

Fig. 2 of the drawings possibly best shows that all of the means of the alarm system are carried by the base member 2 and are very low in height in relation to the normal height of the cover 3. The operative components of the alarm system can be varied somewhat in size and shape, if

desired, and the length of the contacts I3 and I5 can be reduced to position such plunger I6 and associated means quite close to one end of the mat I. Likewise, the arm I5 could be secured adjacent the opposite end of the mat I and have a longer operative portion provided than is shown in the drawings. Thus a plurality of leaf or other springs could be associated with longitudinally spaced portions of the arm 5 to support it above the base. Any suitable means may connect the arm to the trigger 25 to actuate same upon movement of the arm 6, and the pin 22 and trigger 2 3 may engage in any suitable manner.

In some instances, it may be desirable to have a turnbuckle 3!] connecting to the cable 23 to aid in adjusting the position of the trigger 28.

Fig. 5 shows a modified arm 3|, like the arm 6. This arm 3| is pivotally mounted on a base sheet 32 by a hinge connection with an arcuate edge bead 33 on the base sheet. The arm Si is supported at its other end by a spring like the spring 8 so that a long operative length is provided in such arm. A plastic mat 35 covers the sheet 32 and all members thereon like the cover 4 over the base 2.

In view of the foregoing, it is thought that a novel but sturdy type of an alarm mat has been provided and that the objects of the invention have been achieved.

While one complete embodiment of the invention has been disclosed herein, it will be appreciated that modification of this particular embodiment of the invention may be resorted to without departing from the scope of the invention as defined by the appended claims.

Having thus described my invention, what I claim is:

1. A burglar alarm comprising a thin base member having a reinforced edge portion, an elongate arm secured at one end to said base member, a leaf spring supporting the free end of said arm spaced above said base member, a pair of electric contacts, means supporting said contacts in spaced relation, said contacts being movable into engagement, a plunger, means slidably positionin said plunger on said base member adjacent said contacts for sliding movement, spring means urging said plunger toward said contacts to bring said contacts into engagement when said plunger is in its extended position, means for connecting said contacts in an alarm circuit, a spring trigger carried by said base member for engaging said plunger to retain it in retracted position, flexible means connecting the free end of said arm to said spring trigger to release it when said arm is depressed, and. resili nt mat means covering said base member and having a recess in which all articles on the base member are received, the base member and articles thereon being of less height than the mat means.

2. A burglar alarm comprising a thin flat base member, an elongated arm secured at one end to said base member, a spring supporting the free end of said arm spaced above said base member, a pair of electric contacts, means supporting said contacts and positioning them in spaced relation, said contacts being movable into en gagement, a plunger, means slidably positioning said plunger on said base member adjacent said contacts, spring means urging said plunger toward said contacts to bring said contacts into engagement when said plunger is in its spring extended position, a spring trigger carried by said base member for engaging said plunger to retain it in retracted position, means connecting the free end of said arm to said spring trigger to release it when said arm is depressed, all of the articles on said base member extending only a short distance above said base member, and resilient mat means covering said base member and all articles thereon.

3. A burglar alarm comprising a thin fiat base member, an elongate arm secured at one end to said base member, a leaf spring supporting the free end of said arm spaced above said base member, a pair of electric contacts, means supporting said contacts and positioning them in spaced relation, said contacts being movable into engagement, a plunger, means positioning said plunger on said base member adjacent said contacts for sliding movement, spring means urging said plunger toward said contacts to bring said contacts into engagement when said plunger is in its extended position, means for connecting said contacts in an alarm circuit, a spring trigger carried by said base member for engaging said plunger to retain it in retracted position, flexible means connecting the free end of said arm to said spring trigger to move and release it when said arm is depressed, and resilient mat means covering said base member and all articles thereon.

4. A burglar alarm mat including a flat base, an arm secured to the base, spring means resiliently positioning an end of the arm above the base, normally spaced contact means on said base movable into contacting relation, spring pressed means for urging the contact means into engagement, trigger means to position the spring pressed means sothe contact means are not engaged, means connecting the trigger means to the arm to release the trigger means when the arm is depressed, and cover means having a recessed lower surface positioned over the fiat base and all means thereon, the flat base being snugly positioned in the recess in the cover means, said trigger means operating on an axis parallel to the base and lying at least substantially within the cover means.

5. An alarm as in claim 1 wherein said plunger has a pin extending therefrom, said plunger pcsitioning means have a longitudinally extending slot in which said pin is snugly received to retain said plunger against rotation, and said pin is adapted to engage the end of said spring trigger.

6. An alarm as in claim 2 wherein said plunger is positioned at two longitudinally spaced places, and said plunger has means protruding therefrom for engaging the end of said spring trigger.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 348,456 Fairchild et al Aug. 31, 1886 1,411,167 Cutshall Mar. 28, 1922 1,891,751 Coyne Dec. 20, 1932 2,187,928 Barcroft Jan. 23, 19 10 2,493,157 Merralls et al Jan. 3, 1950

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