US1187982A - Fire-alarm. - Google Patents

Description

UNITED STATES PATENT OFFICE.

CHARLES B. EASTMAN 'AND 'MINOT C. EASTMAN, OF GEORGETOWN, MASSACHUSETTS.

FIRE-ALARM.

Specification of Letters Patent..

Patented June 20, 1916.

Application led April 7, 1915. Serial 110.19380.

chusetts, have invented certain new and use-v ful Improvements in Fire-Alarms; Aand. We do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to new and useful improvements in automatic'fire alarms.

The principal object of the invention is to provide means to indicate fire in any part of a building by means of electric connections.

Another object of our invention is to provide a device of the above character which may be connected to signal in several different places at the same time, should a fire occur in any part of a building.

Another object of our invention is to provide a casing having a source of electrical supply and the contact points therein, thus forming a compact device which may be located at any desirable point.

With the above and other objects in view,

we will now proceed to describe our invention i'n the following specification and accompanying drawings, in which,

Figure 1 is a front view in elevation of the casing and interiormechanism for the alarm with the cover removed, Fig. 2 is a vertical sectional View through the circuit closing section of the casing, illustrating the detail 1construction of the circuit closer, Fig. 3 is an enlarged` transverse sectional view through the casing, Fig. 4 is a detail view in elevation of one of the pulleys used in connection with the device, and Fig. 5 is an edge view of said pulley.

Referringto the drawings by characters of reference, 1 indicates generally the casing forming the main part of our improved fire alarm. This casing preferably comprises the end walls 2, the side walls 3, the bottom 4 and the cover 5. Intermediate the side walls, we preferably provide a division wall 6, which separates the battery section from the contact section. This wall 6 eX- tends longitudinally through the middle of the box and throughout its entire length.

A source of electricalsupply, preferably batteries indicated at 7 and 8, respectively,

sliding block 13.

is provided and the current from this source of supply passes through the switch indicated generally at 9, which may be of any preferred type.

The circuit closing mechanism of our improved fre alarm preferably comprises a longitudinally slidable membervlO which iso provided at each extremity with the "L- l shaped portions 11, these portions 11 being adapted tolimit the longitudinal movement of the slide 10 by coming in contact with the transverse strips 12 secured to the bottom 4 ofthe box. A sliding block 13 is fixedly mounted upon the slide 10 and is provided upon its upper side with a cam surface .14 preferably segmental in contour and provided with a metallic plate 15. Each metallic plate 15 is adapted'to Contact at either end with a spring 16, through which the current on its way through the circuit closer passes. Each spring 1 6 coperates with a plate 17, against which the finger 18 of the spring is pressed, by means of the metallic plate 15 carried on the sliding block 13. The ends of the sliding block are preferably recessed, as clearly illustrated at 19 and adapted to receive the ends 20 of the springs 21.

, A suitable pin 22 passes transversely througheach recess 19 and is adapted to extend slightly beyond the extremity of the block 13 and into an aperture formed in the sliding member 10 as clearly illustrated 1n Fig. 2. This pin 22 is adapted to be surrounded by the end 20 of the `spring 21 and hold the spring in operative relation to the The end of the spring 2 1 opposite the end 20 is preferably provided with an eye 23 which is adapted to receive the end of the cord 24, by means of which the .device is actuated. The cords 24 extend out of the box, as is clearly illustrated, and pass over the pulleys, indicated generally at 25, these cords being adapted to enter different parts of the building and have weights attached to their ends, by means of which they are kept at all times taut, so that at any time, should any cord extending from the springs 21, pulling against the tension of the weights be burned, said cord will be released and cause the sliding block of the circuit closer to press the spring fingers of the member 16 forward and into contact with the plate 17, thereby completing the circuit to cause the alarm bell to ring. The pulleys referred to enerally as 25, are clearly illustrated in ' igs 4 and 5, and preferably comprise the body portion 26, havingformed at one extremity thereof` a point 27 which is adapted to be driven into the wall of a building. The opposite terminal of the body portion 26 is bent back upon itself, as clearly illustrated at 28, and forms a U-shaped member, as clearly shown in Fig. 5, between which the pulley 29 is rotatably mounted on its axle 30'. A suitable aperture 31 is provided in the portion 28 and is ada ted to receive a nail or tack, by means of W ich the device is more securely held in place.

In use, the box l is placed at any desired point in a building and the cords 24 pass outwardly therefrom, these cords 24 being carried along the ceiling by means 0f.,the pulleys 25, and are provided at their terminals with suitable weights not shown which will keep thecords taut at all times and also keep the springs 21 extended. It will beA clearly seen that, should a fire break out in any part of the building and the cord burn through, the springs Will cause the cord to be pulled, thereby causing the cam face of the sliding block 13 to force one of the fingers 18 of the spring 16 forward and in contact with the plate 17, thus completing a circuit through thel alarm bell and giving an alarm through the building. I

It is to be understood that while we have shown and described a specific form of pulleyv adapted for use in connection with our fire alarm, we desire to retain the right to use any preferred type of pulley Without departing from the spirit and scope of thek invention.

The cords 24 are so treated with a suit able chemical or may be formed of a suitable composition which will enable them to readily burn, but which will prevent the fire from traveling along the cord and causing another part 0f the building to be ignited.

While in the foregoing we have shown and described the preferred embodiment of our invention, we wish to have it understood that we may chan the specific arrangements of parts wit out in any way departing from the spirit and scope of'our invention.

Having thus fully described our invention, what We claim is:

1. A device of the class described comprising a casing having openings in each end, slides slidable longitudinally through the casing, cams on the upper sides of the slldes, contact plates extending across the slides near each end and spaced upwardly therefrom,'contact springs to engage the plates to close an electric circuit, and springs normally under tension connected to each end o f the slides to hold the slides centrally of lthe casing until the tension of one of the springs is released.

2. A device of the class described comprising a casing having openings in each end, slides slidable longitudinally through the casing, cams on the upper sides of the slides,

contact plates extending across the slides near each end and spaced upwardly therefrom, contact springs to engage the plates to close an electric circuit, springs normally under tension connected to each end of the slides to hold the slides centrally of the casing, and flexible members of a readily combustible material connected to the springs and extending to different parts of a building, said flexible members holding the springs under tension., g

In testlmony whereof we affix ourv signatures in presence of two witnesses.

CHARLES B. EASTMAN. MINOT C. EASTMAN.

Witnesses:

MARY A. EASTMAN, IRA A. EAs'rMAN.

Images