US2545727A - Burglar alarm switching system - Google Patents

Description

March 20, J. T DOQLEY BURGLAR ALARM SWITCHING SYSTEM Filed Aug. 10, 1946 \NVENTOR ATTORNEY Patented Mar. 20, 1951 UNITED STATES PATENT OFFICE BURGLAR ALARM SWITCHING SYSTEM John T. Dooley, Buffalo, N. Y.

Application August 10, 1946, Serial No. 689,647

4 Claims.

This invention relates generally to certain new and useful improvements in burglar alarms, but more particularly to an electrically-governed alarm for safeguarding the public against burglary, hold-ups, fire, kidnapping, and the like.

It has for one of its objects to provide a device of this character which is self-contained, which is sensitive and positive and reliable in operation, and which is simple, inexpensive and sturdy as well as fool-proof, in construction.

Another object of the invention is to provide an alarm or body-protecting device which is so designed and constructed as to be rendered operative to sound an alarm whenever one attempts unauthorized intrusion on or into the premises in which the device has been installed to protect.

Other features of the invention reside in the construction and arrangement of parts hereinafter described and particularly pointed out in the appended claims.

In the accompanying drawings Figure 1 is a front elevation of the burglar alarm device installed near the Window of .a room and being rendered operative by an intruder. Figure 2 is an enlarged sectional elevation thereof with the trapping cord in its retracted, inop erative position. Figure 3 is a cross section of the alarm device taken in the plane of line 3-3, Figure 4. Figure 4 is a longitudinal section of the alarm device taken on line l4, Figure 3. Figure 5 is a diagrammatic perspective view of the electric circuit and parts included therein.

Similar characters of reference indicate the corresponding parts throughout the several views.

The working parts of my alarm are housed in a casing or cabinet In providing a self-contained unit which can be placed where desired for protective use. In Figure 1, it is shown mounted on a chair with the actuating element or trapping cord H thereof extending adjacent a window 22 through which a burglar has partially entered and whose leg has contacted such cord and rendered the device operative to sound the alarm. The latter may be in the form of a bell 13 contained in the casing and deriving its power from a battery 14, also housed therein, as shown. If desired, however, other outside alarms may be included in the circuit or the device may be connected to the lighting circuit of ones home or building to cause all the lights in the house to go on when the alarm is rendered operative. The trapping cord II has an attaching eye 15 or like at its free end for, securing it in its extended position to some fixed point, such as l6.

Journaled in the casing I0 is a winding drum I! about which the trapping cord H is wound,

its free end extending through the casing and having a pendant weight l8 thereon, as shown in Figure 2, for preventing back lash thereof during rewinding. The drum-shaft H) has a pinion. 2!) thereon meshing with a driven gear 2! in driving engagement with a spring 22 fixed at its inner end to the gear-hub and at its outer end to a pin 23 fixed to a frame plate 24. This spring-driven mechanism constantly urges the cord to its retracted position, and, as will herein after appear, any motion transmitted to the drum from a disturbance of the extended cord is utilized to insure closing certain contacts to render the alarm operative.

The numeral 25 indicates a manually-actuated slide or circuit control bar guided for horizontal movement within the casing in and at right angles to but in the axial plane of the drum-shaft l9. At its outer end this bar is provided with a finger knob 26 and in the full line position thereof, shown in Figure 4, the alarm circuit is rendered inoperative while in the dotted line position of the bar the circuit is pre-set and in readiness to close when the trapping cord is in any way tampered with. At its inner end this control bar has a contact 21 thereon terminating in an offset contact lug 28 in operative relation to a notched or bifurcated reset contact arm '29 loosely mounted on the drum-shaft. This arm is yieldingly urged by a flat spring 30 or the like into lateral frictional engagement with the op.- posing cam face 3| of a collar 32 fixed on the drum-shaft I 9, so that during turning of the latter the reset arm is free to oscillate laterally and have as well a slight vertical rocking movement relative to the lug 28 to make. an on and ofi sliding contact therewith. In the projected or inoperative setting position of the slide bar, its offset lug extends into and latches the contact arm in a central or neutral position, so that when such bar is retracted to an operative setting position such lug is free from contact with the arm until such time as the cord H is disturbed, when the alarm is rendered operative. l

Disposed alongside the bar contact 2-! for circuit-closing engagement therewith in the re:- tracted, operative setting position of the control bar 25 is a yielding contact connected by a wire 34 to the coil of a magnet 35, the other side of the coil being connected by a Wire 36, to one of the contacts 31 of a distributing switch. The other contact 38 of this switch is connected by a wire 38 to the bell IS, the other terminal of the latter as well as the reset contact arm 29 being connected to the grounded side of the battery M. The other side of the battery is connected,v tofa fulcruming-like yieldabl switch blade lflfixed at of a lug 42 on the control bar 25, so that in the inoperative setting positions of the latter such armature assumes the displaced position-shown in Figure 5 and by full lines in Figure 4, wherein the switch blade 40 is closed across the contact 31 leading to the magnet coil.'5.-.In'= the retracted:

operative setting position of the control bar vits armature-engaging lugrecedes therefrom and the contacts 2'! and 33 are closed, with the armature remaining in its initial "position duejto its frictional edgewise engagement with the .'.offset portion 43 of the yieldable switch blade All. .It is this circuit-prepared:condition which the device assumes when it is set foruse and to promptly sound the alarm when the cord H is disturbed.

Should the cord bedisturbed', for example, as shown irr Figure 1', the drum I! is partially turned and inso doing' causes the reset contact "arm- 29mg make-contact with the contact-lug ill andmomentarily close the circuit through the magnet 35. The energizing of themagnet attracts its armatureand-in so doing the latter is released from the switch bladedfi and the latter is-automatically-urged in switch-closing relation to th contact 38 to render the alarm i2 zopcra- *tive; When the controlba-r is pushed inwardly the alarm circuit isopened and the parts assume the positionshown in Figure 5.

If'd'esired, a jack plugfittingM may-be applied torthe-casingl 0, and included in the control circuit ofthe devicc'for shuntingthe current to an outside source to sound another alarm or to cause the hous lighting circuit to be simultaneously closediwhen-the alarm circuit is rendered operative and result in completeillumination of the .house.

.i I claim as my invention:

. .1. .An alarm-actuating switch mechanism, comprising anmelectricwcircuit.including a .magnet having an. armature, a switch in said circuit in- .cluding a-yieldableblade. movable to one or the votheriof twopositions to establish the circuit of the magnetin one of such. positions, said arma- .ture being disposed in frictional contact with .said; blade for normally releasably retaining said switch ,in one iof its .two positions, an auxiliary switch insaid' circuit including on and off presetting contacts. and a third contact movable into circuit-closing relation with one of said on and Loff contacts, a manual control member on which control member having means thereon engageable with the armature for. shifting the latter. to its retracted normal position after it has been actuated to .an operative switch-releasing position, a cord-winding drumincluding means for normally urging it to turn in a wind-iup direction, and an operative connection between said drum and-the third movable contact of'said'auxiliary switch for actuatingsuch contact to an alarmcircuit establishing position Wheneverthe drum is caused toibejturned.

2. An alarm-actuating switch mechanism, comprising an electric circuit including a normallyopen switch including a yieldable blade, an auxiliary circuit including a second switch and magnet having an armature in endwise frictional engagement at one end with said yieldable blade for normally holding the...first-named switch open 'and-the arnrlaturev releasably retracted and causing the closing of such switch and the release of the armature when said magnet is energized, a pre-setting, manually-shiftable control member in governing relation to said second switch for causing its. closing in one position thereof and its opening in its other position an on and ,i'ofif' displaceablecontact arm in operative relationtoone of the elements of said second switch and" included in the auxiliary circuit thereof for governing th energization of said magnet, and a rotatable connection to said contact arm-ior causing'its displacement to a position toclose the auxiliary circuit and energize said magnet.

. 3.. Analarm-actuating switch mechanism, comprising an .electricncircuit.including a normally- .open switch; an auxiliary circuitincluding a second switch and-magnet having an. armature in governing relation to firstenamed' switch. for normally holding it open and causingitsclosing when said magnet issenergized; the. free rendof said armatureibeing in camming relation to such first switch-toxretain itopen and the :armature retracted, a presetting, .manually-shiftable .control: member in governing relation to said second switch for causingrits...closing in'one. position thereof andits opening inxits other positiongand an on and off, displaceable contact arm' inoperative: relation toaone of the elements of said second switch andincluded in the auxiliary .cir- :cuit athereoffor governing the energization of said magnet.

4. An alarm-actuatingswitch mechanism, comprising an electric" circuit including a normallyopen switch,-an auxiliary circuitincluding a second-switchand magnetthatving an armature in governing relation tofirst-named switch for normally holding"- it open and causing its closing when-saidmagnet is energized, the free'end of said armature being in cammingrel'ation to such first-switch to retain it open andthe armature rctracted, a presetting, manually-shiftable control member in governing relation to said second switch for causing its-closing in oneposition thereof and its-opening in its other position, said control member having a part thereon releasably engageable withsaid armature for shifting it to a retracted position when such member is shifted to aswitch-open-ing position, and an "on and off contact arm inoperative relation to one of the switchelements of said second switch and included in the auxiliary circuit thereof for governing the energization of said magnet.

' JOHN T. DOOLEY.

REFERENCES CITED The following. references are of record in the file'of' this patent:

UNITED STATES PATENTS Number Name Date 914,173 Norpoth Mar. 2,1902 1,814,255 Loeding July'l4,"l931 1,965,946 Pincus et a1. July 10, 1934 1,980,796 Golf Nov. 13, 1934 2,014,474 Hopkins Sept. 17, 1935 Y 2,339,750 Bartho1y Jan. 25, 1944

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