US970565A - Burglar-alarm. - Google Patents

Description

C. H. SMITH. BURGLAR ALARM.

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0. H. SMITH. BUBGLAR ALARM.

APPLICATION FILED 001. 6, 1909.

Patented Sept. 20, 1910.

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CALVIN H. SMITH, OF BESSEMER, ALABAMA.

BURGLAR-ALARM.

Specification of Letters Patent.

Patented Sept. 20, 1910.

Application filed October 5, 1909. Serial No. 521,039.

To all whom it may concern:

Be it known that I, CALVIN H. SMrrI-I,

' citizen of the United States, residing at Bessemer, in the county of Jefferson and State of Alabama, have invented certain new and useful Improvements in Burglar- Alarms, of which the following is a specification.

This invention relates to burglar alarms and refers to a mechanical device which is adapted to be set into operation by walking upon a platform which is positioned within the floor.

An object of this invention is to provide an improved alarm of this nature which is especially applicable to store-houses and the like, where it is desired to set a sounding device into motion which is located in an adjacent room or chamber to that in which the burglar enters.

The invention has for a further object the provision of a mechanism for sounding an alarm which is of simple construction, so that the same can be readily positioned within the floor of a building and one which can be easily set and which is positive in its operation when tripped.

For a full understanding of the invention and the merits thereof and also to acquire a knowledge of the details of construction, reference is to be had to the following description and accompanying drawings, in which:

Figure 1 is a perspective view of a building partially in section, disclosing the improved alarm applied thereto; Fig. 2 is a sectional view through the sounding device; and, Fig. 3 is a longitudinal vertical section through the tripping mechanism.

Corresponding and like parts are referred to in the following description and indicated in all the views of the drawings by the same reference characters.

Referring to the drawings, the numeral 10 designates the flooring beneath which the improved trip mechanism is located. Disposed beneath the flooring is a base 11 which is suitably supported beneath the same and which is provided with guides 12 which are disposed in spaced relation and in longitudinal alinement upon the base 11 and which are provided with central slots 13 arranged vertically therein for the accommodation of a rack 14. The rack .14 is formed of a longitudinal bar, preferably of metal, although any material may be used, which carries a plurality of teeth 15 in its upper edge into which is engaged the lower extremity of a tripping lever 16 which is pivotally mounted through the upper end of the guide .12. The tripping lever 16 is retained in engagement with the teeth 15 by the provision of a spring 17 which is secured at its opposite extremities against the under side of the floor 10 and to the upper arm of the tripping lever 16. A tripping pin 18 is carried by the upper arm of the lever 16 and extends through an aperture 19 formed in the floor 10. For the purpose of depressing the upper end of the tripping lever or trip 16, a platform 20 is employed which is hingedly disposed upon the uoper face of the floor 10 and is so positioned as to engage its under face against the upper extremity of the trip pin 18. The sprmg 17 is of such a strength as to normally hold the pin 18 upwardly to hold the platform slightly above the upper face of the floor 10 and is adapted to yield upon the weight of a person who steps upon the platform.

The rear end of the rack 14L is connected to a cable 21 which extends beneath the floor 10 to a wall 22 or the like, where the cable 21 is passed over a pulley 23 in order to change the direction of the cable. As is disclosed in Fig. 1, the cable is extended upwardly against the wall 22 through an upper floor 24: and is engaged over a second pulley .25 which supports the cable 21 in such a manner that it is extended to the sounding device, indicated as 26.

For the purpose of drawing the rack 14: forward, the same is provided with a cord 27 which extends outwardly from the rack 14: and is engaged over a roller 28 from which the cord 27 is extended upwardly and through a small aperture 29 formed in the floor 10. The upper extremity of the cord 27 carries a ring 30 or the like, to prevent the cord 27 from passing downwardly through the floor 10, and also for the purpose of forming a hand hold, whereby the operator is capable of drawing the cord 27 upwardly and to thereby set the rack 14-. The sounding device which is indicated by the numeral 26 in Fig. 1, includes a casing 31, as is disclosed in Fig. 2, within which is mounted a bell 32. A frame 33 is mounted in the casing 31 and against one of the sides thereof, which supports a spring actuated mechanism 34 for vibrating a clapper 35. The spring mechanism 34 is provided with an escapement 36 which is controlled by an arm 37, the arm 37 being extended upwardly toward the upper end of the casing 31. The cable 21 is extended into one end of the easing 31 and is connected to a link 38 which in turn carries the outer extremity of a spring 39. The spring 39 is secured to an eye bolt 40 which is carried upon the oppo site end of the casing 31 and normally draws the cable 21 inwardly of the casing 31. The link 38 is provided with an abutment 41 which is engaged against the arm 37 in order to hold the escapement 36 from operation and to thereby prevent the vibration of the clapper 35 against the bell 32 when the spring mechanism 34 is wound.

In the operation of the device when it is desired to set the same, the operator grasps the ring 30 and draws the cord 27 upwardly through the floor 10. This action causes the rack 14 to move forwardly toward the roller 28 and permits the tripping lever 16 to ride over the teeth 15 until the abutment 41 is engaged closely against the arm 37 to prevent the vibration of the same. As the escapement mechanism is thus held from move: ment, the spring mechanism 34 is wound and the alarm is thus set.

hen the platform 20 is stepped upon,

the Weight of the person throws the platform 20 downwardly and depresses the trip pin 18, whereby the upper end of the lever 16 is depressed to cause the lower end of the lever 16 to be raised from the teeth 15 and to permit of the sliding of the rack 14: backwardly through the guides 12. The spring 39 is connected to the cable 21, as

hereinbefore set forth, whereby a tension is exerted upon the cable 21 to draw the same inwardly of the casing 31 upon the release of the tripping lever 16. WVhen the rack 14c is therefore released, the spring 39 draws the cable 21 inwardly of the casing 31 and carries the link 38 and abutment 41 back wardly therewith, whereby the arm 37 is released and the escapement 36 is permitted to operate. The spring mechanism 34 now operates the clapper 35 to strike the bell or gong 32, thus sounding the alarm.

Having thus described the invention what is claimed as new is:

An alarm including a base, spaced guides disposed on said base, a rack slidably disposed between said guides and having the teeth thereof in the upper edge, a tripping lever carried by one of said guides, a tripping pin carried by said lever and extended upwardly through the floor, a platform disposed upon the floor over said tripping pin, a cord extended from the forward end of said rack and through said fioo-r, a ring carried by said cord for engagement with the hand of the operator to move said rack forwardly, a cable carried upon the rear end of said rack, a spring connected to said cable to hold said rack normally in a backward. position and a sounding device connected to the rear end of said cable.

In testimony whereof I aflix my signature in presence of two witnesses.

CALVIN H. SMITH. [11. s.]

WVitnesses:

J. A. Es'rns, W. P. GUNN.

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