US307660A - Burglar-alarm - Google Patents

Burglar-alarm Download PDF


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US307660A US307660DA US307660A US 307660 A US307660 A US 307660A US 307660D A US307660D A US 307660DA US 307660 A US307660 A US 307660A
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    • G08B13/00Burglar, theft or intruder alarms
    • G08B13/02Mechanical actuation
    • G08B13/08Mechanical actuation by opening, e.g. of door, of window, of drawer, of shutter, of curtain, of blind


(No Model.)
No. 307,660. tgd Nov. 4, 1884.
L6. 45. Q fi I mcw@ NiTnn ETnTns.
PATENT @rrncn...
SPECIFECATION forming part of Letters Patent No. 307,660, dated November 4, 1884.
(No model.)
To tbZZ whom it may concern.-
Be it known that 1, PETER KEFFER, a citizen of the United States, residing at the city of Reading, county of Berks, State of Pennsylvania, have invented a new and useful Improvement in Burglar-Alarms, of which the following is a specification.
This improvement relates to that class of burglar-alarms which are adjusted each time they are desired to operate as an alarm, and at all other times are not affected by the opening of the article to which they are attached.
The object of the invention is to place within the means of all a cheap and effective burglar-alarm, which may be attached to doors, windows, and transoms, and so adjusted relative thereto that the opening of the same shall fire off a cap and ring a bell with noise enough to wakcn all ordinary sleepers.
The drawings herewith forming a part of this specification are detailed sufliciently for an expert to grasp the idea, similar letters of reference indicating similar parts throughout.
Figure 1 is a front view of the alarm as applied to adoor, and. as represented, would not cause any alarmupon the opening of the door. Fig. 2 is a plan, looking down on the same as secured to the door. Fig. 3 represents the alarm as set. The opening of the door will release the catch and sound the alarm. Fig. 4 is a view of the alarm applied to a windowsash. Fig. 5 represents it as applied toadoorpull.
A represents the door; 13, the door-frame; G, the bolt keeper plate; 0, lap-recesses on opposite sides of the case; 0, securing-holes;
D, bolt-case; D, slot in the same; D bolt-apertures; D, anvil for explosive; D, spiral spring; E, bolt; E, locking-recess; E, spade handle head, within which the bell-spring is loosely held; F, thumb-piece; F, nipple adjusting screw; F", nipple for exploding caps placed in the anvil; G, reversible arm supporting the alarm-bell; G, head to the same; H, bell-spring; I, a clamp; I, clamping-screw to secure bell-spring; J, the alarm-bell; K, catch-bracket, K, jaws to same; K fulcrum tt'orcat-ch; K securing-holes; L, catch; L, bifurcated end to grasp the bolt in the recess or neck J, and IF thumb end of same.
A modified form of application of the invention is shown in Figs. at and 5, in which M is the side of a window-frame, N, the sash; O, a hole in the end of the bolt in lieu of recess E when used for a door-pull; l, leading-pulley; Q, bell-wire, and R door-pull.
I am aware that burglar-alarms of this class are not uncommon; but I believe that I have by my arrangement and adaptation of parts secured an alarm so cheaply constructed and so easily applied that its use will become universal.
The construction is so fully shown in Figs. 1 and 2 that little remains for explanation. The keeper-plate is cut down or recessed at the bell end on both sides of the bolt-case. This adapts the plate and apparatus to either a right or left hand door, the bell-arm fitting within the recess upon either side of the boltcase. The locking-catch in the same way is adapted to retain the bolt upon either side of the door. \Vhen placed in windows, a simple knee will be screwed against the sash, which will have its projected end turned slightly down to catch in the recess E, and when the sash is raised it will carry the knee-piece along, thus releasing the bolt and giving the alarm. \Vhen used as a doorbell, the catch is not required, and a hole will be drilled in the end of the bolt, in which the wire will be secured that is led to the bell-pull or to any rooms in the house by sheaves and bell-cranks, in the usual manner. The anvil D is bored to suit an ordinary pistol cap or cartridge, and the adjusting nipple screw F is projected through the thumb-piece, and has its forward end of the proper shape to explode the cartridge on coming in violent contact therewith. The spring D, I prefer to make of springsteel. It is sprung over the bolt E, and confined between the thUll'llf-PlCCG F and the end of the bolt-case.
The operation is easily understood. The keeper-plate is secured to the inner face of the door on the lock side, and when in position the 5 bolt E is drawn out toward the frame and the position of the recess E marked thereon. The
catch-plate is then secured to the frame in such position that the bifurcated end of the catch will be in line with the mark indicating the recess E of the bolt E. This being done, the bolt is again drawn or shoved toward the catch, which is caught in the recess, and will so remain as long as the door is unopened. While in this position, a cartridge is inserted in the anvil D". will be released from the catch, and the resistance of the compressed spring D will throw the bolt toward the anvil D, and the nipple striking the cartridge, it will explode. At the same time the bell, being set free, will ring for some time, and the operations of burglars will thus be foiled.
Having shown my improvement, its construction and advantages, I desire to secure by Letters Patent the following claims thereon:
1. In combination with a burglaralarm spring-bolt adapted to explode a percussion cap or cartridge, the bolt-case D, thumb-piece F, provided with an adjustable screw-nipple, F F-,-the anvil D" of the boltcase, recess E of the bolt E, spring D, and reversible catch Now, on opening the door, the bolt I with its adjustable nipple F F anvil D re- L, the whole arranged and combined as shown, and for the purpose set forth.
2. In combination with a burglar alarm bolt, as described, the seat or recess 0 of the bolt keeper plate, the reversible arm G, provided with head G, clamp I, and clampingscrew 1, the spade handle head E of the bolt E, bell-spring H and bell J, recess E, and catch L, all combined and adapted to be operated as and for the purpose specified.
3. In combination with a burglar-alarm spring-bolt, as described, the thumb-piece F,
35 eess E, catch L, reversible arm G, and bell J,
suspended from reversible arm G, its vibrating spring H being loosely held in the spade handle head E", as and for the purpose substantially shown and set forth.
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