US1524666A - Burglar alarm - Google Patents

Description

Feb. 3. 1925.

G. MARSHALL BURGLAR ALARM Filed Oct. 21, 1924 INVENTOR':

Patented Feb. 3, 1925.

BU-RG LAR ALARM;

Application. filed October 21, 1924. Serial N'o.v 744,871.

To all whom it may concern:

Be it known that I, Gnonon MARSHA L,

a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented a certain new and useful Burglar Alarm,

of which the following is a specification:

This invention, generally stated, relates to signals. or alarms. and has more especial relation to a device for a-udibly announcing A further object resides in the providing.

of general arrangement, construction and connection of parts for attaining-the results sought by the leading object. 7,

Other and further objects not at this time ap caring will. be hereinafter more specifical y referred to.

The invention consists of the novel construction hereinafter described and finally laimed.

The nature, characteristic features and scope of the invention will be more fully understood from the following description aken in connection with the accompanying drawings forming part hereof, and inwhich:

Fig. 1, is a fragmentary view, partly sectioned, of a window frame and complemental sash showing my burglar alarm operatively arranged with respect to the lower sash.

Fig. 2, is a view in elevation of the burglar alarm detached.

Fig. 3, is anend view of Fig. 2, and

Fig. 4, is a top or plan view of Fig. 2.

For the purpose of illustrating my invention I have shown in the accompanying drawings one form thereof which is at present preferred by me, since the same has been found in practice to give satisfactory and reliable results, although it is to be understood that the various instrumentalities of which my invention consists can be mentalities as herein! shown and described;

Referring to the drawings in detail the reference numeral 1' designates a plate of rectangular configuration. This plate 1 is provided with openings 2 for screw accommodation whereby the plate may be secured to the frame 3 of a window as clearly shown in Fig. 1. y The. plate 1 has. preferably formed integral therewith at its top a lateral extension a terminating at its; top ina hearing 5, which bearing including said; lateral: extension. has averticalv openinggor passage 6 extended entirely therethrough for a purpose to presently appear. Preferably formed integral with the lower part of'plate- 1 andextended laterally therefrom is an. extension 7 having a. screw threaded: opening arranged vertically theret-hrough to. receive the screw threaded end: of a spring" barrel 8 containing a coiled. spring: 9,. Also carried by a plate 1, arranged intermediate the extensions 4.- and- 7 and provided with aniape'rture in alignment with the opening through extensiond: and the opening in; springbarrel 8 is a lateral extension: 10 forming a. bearing for avertically disposed: plunger 11.. The: plunger 11: isshowlr asbeing cylindrical in form, has its lower end engaging in a loose fit with the interior of spring barrel 8, and is provided at its upper end with a nib 12. This nib in the operation of the burglar alarm is adapted to strike the head of a percussion cap and cartridge 13 positioned in the opening through extension 4. and bearing 5. The plunger 11 is provided with a slotted portion 14. Having pivotal relation as at 15 with an extension 16 of plate 1 is a trip lever 17. This trip lever 17 is provided at its inner end with a bevelled portion 18 adapted to engage the slotted portion let of plunger 11, as clearly shown in Fig. 2.

A description will now be given of the mode of operation of the above described device: To set the burglar alarm the lower sash 19 of a window in closed position is adapted to have rested upon the top thereof the end 20 of the pivotal lever 17. The bevelled end 18 of which lever is positioned within the slot 14 of plunger 11. In this position of parts no tension is being exerted upon spring 9. Upon an unauthorized person raising the window sash 19 the pivotal lever 17 is moved from the position shown in full lines to that shown in dotted lines, during which movement plunger 11 has been depressed to compress spring 9. As the window sash 19 is continued to be raised the bevelled end 18 of lever 17 disengages from the slot of plunger 11 whereupon spring 9 forces plunger 11 forward- 1y so that the nib 12 is impelled against the percussion cap of cartridge 13 and exploding same to notifv the occupants of the building that unauthorized entry is being attempted. The bevelled end 18 of lever 17 is maintained in a normal horizontal position by means of stop 20 carried by plate 1.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a device of the character stated, a plate provided at its lower portion with a barrel containing a coiled spring, a slotted plunger capable of vertical movement with respect to said plate, the lower end of which plunger is loosely fitted within said barrel upon said spring, a lever pivoted to said plate, one end of said lever being adapted to engage within said plunger slot, which lever when tripped being adapted to cause compression of said spring, means carried by said plate for limiting the movementof said lever and plunger and a percussion cap carried by the upper part of said plate in register with said plunger.

2. In a device of the character stated, a plate adapted for attachment to a window frame provided at its lower portion with a barrel containing a coiled spring, a slotted plunger capable of vertical movement with respect to said plate, the lower end of Which plunger is loosely fitted within said barrel upon said spring, means carried by the plate to guide said plunger, a lever pivoted to said plate, one end of said lever being adapted to engage within said plunger slot, which lever when tripped being adapted to cause compression of said sprin the end of said lever engaging said slot being bevelled so as to disengage from said slot during downward movement of said bevelled end, means carried by said plate for limiting the movement of said lever and plunger and a percussion cap carried by the upper part of said plate in register with said plunger.

3. In combination a window frame, a window sash, a plate secured to the window frame, a barrel containing a coiled spring carried by the lower end of said plate, a slotted plunger paralleling said plate and having its lower end loosely fitted Within said barrel upon said spring, a lever pivoted to said plate, one end of said lever engaging said slot and the other end of said lever lying in the path of travel of said window sash, whereby upon raising of said sash said lever is moved about its pivoted point to cause compression of said spring, means carried by said plate for limiting the movement of said lever and plunger and a percussion cap arranged in alignment with said plunger and carried by the top of said plate.

In testimony whereof, I have hereunto signed my name.

GEORGE MARSHALL.

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