US971776A - Burglar-alarm. - Google Patents

Description

L. MYERS.

BURGLAR ALARM.

APPLICATION FILED NOV. 9, 1909.

Patented Oct. 4, 1910.

2 BHEETB-SHBET 1.

L. MYERS.

BUBGLAB. ALARM. APPLIOATIQH FILED NOV. 9, 1909.

971,776. Patented 0013.4,1910.

2 QHEETS-BHEET 2.

WWW! K Maw UNITED STATES PATENT oEEicE.

LEWIS MYERS, OF NEWARK, MICHIGAN.

BURGLAR-ALARM.

To all whom it may concern:

Be it known that I, LEwis MYERS, a citizen of the United States, residing at Newark, in the county of Oakland and State of Michigan, have invented a new and useful BurglanAlarm, of which the following is a specification.

This invention has reference to improvements in burglar alarms and is designed to provide a means whereby an unauthorized person entering the protected area will set an alarm into operation by engaging with an attenuated strand of sufiicient strength to cause the movement of the alarm to active position even though the force operating on the strand be sufficient to break the latter.

By the present invention a room or an entire building may be protected against entrance or approach of unauthorized persons and the alarm be set into operation without the intruder being aware of having encountered the strand.

The invention will be best understood from a consideration of the following detail descripticn taken in connection with the accompanying drawings forming a part of this specification, in which drawings,

Figure 1 is a partially diagrammatic and partially structural view of the alarm mechanism to be actuated by the strand with the parts in the inoperative position. Fig. 2 is a similar view with the parts in the operative position. Fig. 3 is a diagram illustrating the application of the device to the pro tection of a room. Fig. 4 is a diagram showing the arrangement of the device for the protection of a building against the approach of intruders.

Referring to the drawings and more particularly to Figs. 1 and 2 there is shown a pivoted arm 1 with its ends oppositely bent and at their extremities carrying rock arms 2, 3 respectively, projecting equally on opposite sides of their pivot connections with the arm 1. The free ends of each arm 2 and 3, which arms as well as the arm 1 may be made of flat bars, are turned at right angles to the body portions of the said arms 2 and 3 and there carry insulated studs 4 of conducting material projecting beyond one face of the arms 2 and 8 and at the other ends formed with means for the attaching of conductors 5 electrically connecting the conducting studs a in such manner that the stud e at one end of the arm 2 is connected to the stud 4 at the corresponding end of the arm 3 Specification of Letters Patent.

Application filed November 9, 1909.

- is connected by a conductor 10 to Patented Oct. 1, 1910. Serial No. 527,092.

and the studs at the other ends of these arms are also connected by a conductor In the path of each stud at is an elastic conducting finger 6 mounted on a suitable block 7. One stud 1 is connected by a conductor 8 to one side of a battery 9 or other source of electric current while the other side of this battery the other finger 6 engaged by the stud on the opposite end of the arm 2. The fingers 6 in the path of the studs 1 on the arm 3 are connected one by a conductor 11 to one side of a bell 12 and the other by a conductor 13 on the other side of the bell 12.

The arm 1 with the parts carried thereby as well as the battery 9 are all housed in a suitable box 1% which may be located in any desired position and the bell 12 may be exterior to this box. One of the conductors, say the conductor 11 includes a switch 15 so that the apparatus may be cut out of service whenever desired. Pivotally mounted within the box 14 is a lever 16 having one end connected by a link 17 to one side of the arm 1 while the other end of the lever is bent into a quarter turn, the lever being made of a flat bar and traversed by a rod 17 surrounded by a spring 18 and extending through a bracket 19, the action of the spring 18 being to move the lever in' a direction to cause the studs t to engage the fingers 6. The lever 16 may be locked against the action of the spring 18 with the latter under tension by a bell crank lever 20 suitably mounted in the box 1a and having one end 21 extending therebeyond. This end 21 receives one end of a strand 22 which may extend to various points liable to be entered by an intruder, its direction being diverted where necessary by pulleys 23. In Fig. 3 the strand 22 is shown as traversing doors and windows, and on each side of the latter the strand may pass through eyes 21 and the strand at one side of either the door or window or both may have its continuity broken so that the ends of the strand at such point may be coupled together as by hook and eye or other suitable means and when the device is not to be operated the portion of the strand traversing the door or window or both may be unhooked from the main portion of the strand and temporarily suspended from an eye 25 at one side of the door or window. This will not interfere with the circuit closing mechanism of Figs. 1 and 2 and which is housed in the box 14: since the lever 16 is positively locked by the bell crank lever 20 and it is only a pull on the arm 21 that will cause the lever 20 to move to a position releasing the lever 16. If an intruder attempts to enter through a door or a window across which the strand 22 is extended, the strand will be engaged by the intruder and moved longitudinally to a sufficient extent to pull the lever 20 so that it releases the lever 16 when the spring 18 will act to move the lever 16 and through the link 17 the lever 1 into a position where the studs 1 will engage the fingers 6 and so close the circuit. The strand 22 may be highly attenuated but strong enough to cause the movement of the lever 20 even though the strand be ultimately broken.

In Fig. 4 the strand 22 is shown as mount ed upon short posts 26 and extending for a sufiicient distance to include a considerable area about a building 27. If now an intruder approached the building then the strand 22 will be engaged since it is lodged but a short distance above the ground but at such a height as to be surely engaged by the intruder and the alarm will be caused as before, the said alarm being maintained until the lever 1 is again locked in the inactive position.

A burglar alarm to be efficient must be positively operative at all times and faulty connections or faulty conducting members cannot be tolerated. It will be observed that in the circuit closing mechanism shown in Figs. 1 and 2 the circuit at no point traverses any pivot, but the circuit is completed through spring fingers along which the conducting studs 1 move so tha whenever the circuit is closed there is a rubbing contact which at all times positively insures good electrical conductivity.

Vhat is claimed is 1. In a burglar alarm a pivoted arm carrying contact members at each end electrically connected independent of the arm, elastic contact fingers in the paths of the contact members on the pivoted arm, an electric circuit completed through the said contact members and elastic fingers, an actuating member for the pivoted arm, a lock for the actuating member for holding the pivoted arm in the inactive position, and a strand extending from the lock to the point to be protected.

2. In a burglar alarm a pivoted arm having at each end pivoted arms carrying contact members at each end, electric conductors independent of the pivoted arm and connecting the contacts at the end of the first named arm, elastic circuit terminals in the path of the contacts on the ends of the arms carried by the first named arm, a spring controlled lever connected to the first named arm for moving the same, a latch member for holding the spring controlled member against its normal tendency, and a strand extending from the lock or latch member to the point to be protected.

In testimony that I claim the foregoing as my own, I have hereto atfixed my signature in the presence of two witnesses.

LEl/VIS MYERS.

"Witnesses WILLIAM P. Hicks, IVILLIAM A. PATTERSON.

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