US2687518A - Automatic burglar alarm for automobiles - Google Patents

Description

Aug.

V. HELMAN AUTOMATIC BURGLAR ALARM FOR AUTOMOBILES Filed Nov. 2, 1951 Patented Aug. 24, 1954 AUTOMATIC BURGLAR ALARM FOR AUTOMOBILES Victor Holman, Cleveland, Ohio Application November 2, 1951, Serial No. 254,492

1 Claim.

The present invention relates to improvements in automobile theft preventing devices and has for an object to provide an improved system which provides for the sounding of the horn whenever the doors, hood or trunk of the protected vehicle are opened without authority.

Another object is to provide an alarm which will be sounded when any movable part of the automobile is shifted by an unauthorized person, it being impossible to stop the sounding of the alarm until the owner or driver of the car can reset a concealed button. for the purpose of breaking the electrical circuit of the alarm.

A further object is to provide a device of this character adapted to be placed inside the glove compartment of the automobile where it cannot be reached except by opening a. body door, it being intended to connect switches to the body doors so that when a door is opened by an unauthorized person after the alarm has been set the alarm will be sounded and remain in operation until the separately locked door of the glove compartment is opened to permit the circuit reset button to be reached and depressed.

Still other objects are to provide a device of the type stated that is positive in action, simple in structure and economical to manufacture and install in either new or old automobiles.

These and other objects of the invention will become apparent from a reading of the following specification and claim, together with the accompanying drawing wherein:

Figure l is a top plan view of the control box, partly in section, the control elements being shown interposed in a plurality of electrical circuits which are shown in diagrammatic form;

Figure 2 is a perspective view of the control box; and

Figure 3 is a side elevation, on a reduced scale, of an automobile and showing the location of the control box in the glove compartment.

Referring to the drawing by characters, reference l designates a sheet metal control box or housing adapted to be secured in the glove compartment 32 where it cannot be reached without unlocking and opening the door thereof. In this housing is arranged a dielectric base [8 having spaced and bored bearing blocks l9. A shaft or slide member I is slidably mounted in the bearing block holes and is protected against vibratory movement by a friction leaf spring 3? which bears against the surface of the shaft i5.

The shaft l5 may be made of dielectric material or metal as desired. However, if it is made of insulating material the contact button M must be made of metal and attached to the end of the shaft.

Reference character 56 indicates an operating collar of larger diameter than the shaft l5 located intermediate the ends thereof. A reset button [.1 is located on the shaft end opposite to that of the contact button l G. The reset button I! is centered in a hole 9 in the face of the housing I 0 as shown in the Figures 1 and 2. The outer face of the reset button ll being normally flush with the face of the housing ii. A pair of flexible contact fingers it having the plane of their contact faces intersected by that of the contact button it, but normally out of engagement therewith, are mounted on an insulating block 8.

Reference numeral l i indicates an electromagnet which is mounted on the inner side of the front wall of the case it parallel to the shaft l5..

An armature 12 having a head 7 adapted to bear against the operating collar is is arranged in spring loaded hinged relation to the electromagnet i l, in theconventional manner.

Reference numeral 23 indicates the car battery having the usual positive and negative poles. As shown in the Figure l, the negative pole of the battery 2t is connected thru circuit 3i to one terminal of the horn 3%}. The positive pole of the battery is connected thru circuit 29 to one of the contact fingers 13 while the other contact finger is connected to the second terminal of the horn '35 The negative pole of the battery is also con nected by means of circuit 23 to one terminal of the electromagnet it thru the master switch 2|. The positive pole of the battery is connected th-ru circuit 26 to the normally open door switches 22 and 23, the trunk switch 24 and the hood switch 25. All of these switches are connected in par allel through circuit 2? to the second terminal of the electromagnet H. The master switch 21 is key operated and is located somewhere on the outer face of the body where it can be reached and operated from the outside of the car.

While protection has been illustrated only with reference to the car doors, trunk and hood, it is to be understood that any movable or removable part of the car may be protected by the suitable arrangement of a switch therewith.

The operation of the protective device is as follows: All of the doors, trunk and hood of the car are closed which opens thesecondary switches 22, 23, 24 and 25. The authorized person then closes the master switch 2| by means of a key. The car can be re-entered without causing an alarm by any authorized person having a key adapted to open the switch 2|. This must be done before any of the protected elements of the car are moved.

In case a door, trunk or hood is opened by an unauthorized person, the particular secondary switch, 22, 23, 24 or 25 connected thereto will be closed. This completes circuits 26 and 21 to the magnet I l and circuit 28 thru the closed master switch 2| back to the battery. This causes the electromagnet II to become energized and draw the armature I2 toward it, or to the right, as indicated by the alternate position of the armature designated by reference numeral [2a in the Figure l. The head i of the armature bears against the operating collar I6 sliding it and the shaft IE to their alternate positions indicated by reference numerals Ilia and [a respectively. The contact button [A is also moved to the position designated by Ma which causes the flexible fingers l3 to ride on the periphery of the metallic contact button I4. This causes the horn circuits 29 and 3| to be closed thru the flexible finger l3 and the button [4 which energizes the horn 30, thereby causing it to blow. At the same time, the reset button I! is moved to its alternate position lla wherein it protrudes thru the face of the housing l0. If the shifted part of the car should be restored to its original position, such as closing of the door, the electromagnet circuit would be de-energized and the armature 12 returned to its original position. However, since the shaft I5 is not spring loaded it will remain in its alternate position [5a and the horn 30 will continue to blow. Neither will the opening of the master switch 2| alone cause the horn to stop blowing. The horn will continue blowing until both the master switch 2| is opened and the glove compartment is unlocked so that the reset button I! may be reached and manually pushed inward to its original position which causes the contact between the fingers I3 and the button 14 to be broken, as shown in solid outline in the Figure 1. As soon as the reset button H is pushed inward the device is set and ready to protect the car as outlined originally.

The secondary or operating switches 22 and 23 are located in the door jambs so as to be operable by the opening and closing of the doors, while the trunk and hood switches, 24 and 25 respectively, are located in the rims of these openings so as to be engaged by the edge of the hood and trunk covers 33 and 35 respectively.

These switches are connected to the device through a four wire cable as shown in the Figure 2. It is possible to make the control mechanism quite compact so that the control box will occupy only a small section of the average glove compartment, leaving the balance of it free for its usual uses.

It will now be clear that there is provided a device which accomplishes the objectives heretofore set forth. While the invention has been disclosed in its preferred form, it is to be understood that the specific embodiment thereof as described and illustrated herein is not to be considered in a limited sense as there may be other forms or modifications of the invention which should also be construed to come within the scope of the appended claim.

I claim:

The combination with an automobile, of a housing secured to the dash, a base mounted within the housing; a dielectric shaft mounted on the base and slidable longitudinally thereof between a first and a second position, the said shaft having an electrically conductive button at one end thereof and a collar of larger diameter than the shaft located intermediate the ends thereof; a leaf spring mounted on the base and having its free end pressed against the shaft; a pair of contact fingers mounted on the base, positioned adjacent said contact button on diametrically opposite sides thereof and out of contact therewith when the shaft is in its first position; electromagnetic means, including an armature having a head normally spaced from said collar and engageable therewith, when energized, to slide said collar and shaft to their second position; an audible signal device; a source of electrical energy connected thereto electrically through a first circuit including said contact fingers; and a second circuit electrically connecting the source of electrical energy to the electromagnetic means, including a master switch and a secondary switch for closing the second circuit thereby to energize the electromagnetic means to move said armature head against the shaft collar, thereby to slide the shaft and conductive button to their second position to bring the button into electrical engagement with the fingers to complete the first circuit to the audible signal independently of the subsequent operation of the secondary switch, the said shaft being maintained in its second position by the aforesaid leaf-spring upon the opening of the second circuit.

References Cited in the file of this patent UNITED STATES PATENTS

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