US585171A - William t - Google Patents

Description

(No Model.)

W T ARNOLD -BURGLARALARM SYSTEM.

Patented June 29,1897.

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UNTTED STATES PATENT EErcE.

VILLIAM T. ARNOLD, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE CHICAGO ELECTRIC PROTECTIVE COMPANY, OF SAME PLACE.

BU'ReLARv-ALARM SYSTEM.

`SPECIFICATION forming part of Letters Patent No. 585,171, dated J une 29, 1897.

Application filed December l5, 1896. Serial No. 615,813. (No model.)

T @ZZ whom it muy concern:

Be it known that I, WILLIAM T. ARNOLD, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Burglar-Alarm Systems, (Case No. 1,) of which the following is afull, clear, concise, and exact description, reference beinghad to the accompanying drawings,

ro forming a part of this specification.

My invention relates to burglar-alarm systems in which openings or objects are protected by movable covers, and especially to those systems in which the openings or objects x 5 are protected by sliding covers.

In a patent issued to Alfred Stromberg, No. 530,975, dated December 18, 1894, is shown and described a burglar-alarm system of the class ment-ioned in which a circuitzo closer is employed comprising a plunger adapted to be depressed by the cover, asa window-sash, to make Contact with a circuitterminal and close the circuit, the plunger at the saine time making contact with a contact-terminal to complet-e the circuit. This device being located upon the window-sill is in a position to become rusted, thereby affording poor contact. Moreover, since the window-sill is subject to considerable dampness, 3o currents have leaked from this device to adjacent iron construction, thereby affording a path of low resistance which shunts the artificial resistance normally in circuit with the line, thereby causing a false indication or 3 5 alarm.

My invention has for one of its objects to overcome the defects in the Stromberg system above set forth.

My invention will be more readily under- 4o stood by reference to the accompanying drawings, in which- Figure 1 is a diagrammatic View of a burglar-alarm system equipped in accordance with my invention. Eig. 2 is a sectional plan View of a portion of the apparatus, taken on line 2 2 of Fig. 1.

Like letters refer to like parts in both views.

My invention is shown as being applied to an ordinary window-opening having a suit- 5o able casing a. Within the structure and before the opening are vertically disposed two guides b, of wire or other conducting material, anchored at b b. Vithin the guarded structure and before the Window-opening is placed a vertically-movable screen c, (in this instance serving to protect the lower half only of the window,) provided with conductors adapted to guard the opening, as will be set forth hereinafter. The screen is provided with eyes c d, which inclose the metallic 6o wires b b and guide the screen in its vertical travel.

Secured near the lower ends of the guides b h are two cone-shaped blocks of insulating material d d', supporting terminal plates d d, 65 which make contact with terminal springs e e, supported upon the screen c, when said screen is lowered in a position to protect the opening. The insulating-blocks d/ d extend slightly above the terminals CZ d, as shown. 7o When the screen is raised, springs e e are iirst brought into contact with the exposed portions of blocks d d and then in contact with guides h b, causing an alarm in each instance if the circuits are in condition to protect the opening, as will be hereinafter set forth. Two contact-terminals f fare mounted upon the window-casing and project over the guides b b in a position to make contact therewith if the screen should be pushed inwardly 8o from its normal vertical plane, as in the act of entering the guarded structure, whereby an alarm is sounded, as will be set forth.

The line g, extending from the central station II to the protected district, includes the 8 5 line instruments t c" of the central-office apparatus, which are grounded through a battery 2. Associated with magnet c' is an armature k, adapted to close circuit at 7c through asignal or alarm apparatus Z when 9o attracted. Associated-with magnet c" is an armature fm, adapted to close circuit at m', when unattracted, through signal apparatus n.

When the screen is lowered and the system is to be put in condition for protecting the window, switch o is thrown from the daybutton o to the position shown, whereby the continuity of the circuit from the centraloffice battery i2 is completed through to the roo ground p at the protected station, the current passing from line g, through the wire q, terminals e and (l upon the right of the screen, conductor r, terminals d and e upon the left of the screen, and resistance s, to ground. The resistance s serves to reduce the current emanating from battery 2.

A conductor t is united at t' to the line g, the plates ff constituting terminals of this conductor. A second conductor a is connected between the resistance s and ground and attached at uf n to the metal guides b b.

The magnets il i are wound to have similar magnetic strength. The armatures 7s and m are so adjusted that lnagnet fi will not attract its armature when resistance s is in circuit, while the armature of magnet t" will be attracted thereby. It circuit from battery @"2 is opened, armature on will fall, thereby closing circuit at m through the signal n. If the current from battery 2 be increased by shunting resistance s from the line, armature 7c will be attracted, thereby completing circuit at la through the signal l.

If an attempt be made to gain access to the interior by thrusting the screen aside, either or both of the plates f f will be brought into contact with either or both of the metal guides l) l), thereby establishing a shunt-circuit from t about the resistance s, thus @arising signal t to respond. Terminals ff and guides l) h thus form a circuit closing or changing device adapted to be operated by the screen as it is thrust aside. If the screen be raised, springs c c will rst be removed from contact with plates d d and brought into contact with the exposed portions of blocks d d', thereby opening the circuit, including battery t'causing the operation of signal n. As the screen is still further raised the springs c c will be brought into contact with wires b b, thus establishing a shunt-circuit about resistance s,

thereby causing the operation of signal Z. This shunt-circuit may be traced from the point through conductor Q, terminal c and wire Z1 upon the right or left of the screen, and conductora, to ground. If desired, one of the guides l) may be made of other material than metal, in which ease one of the terminals f may be dispensed with.

The conductors q are inclosed in incasing strips of wood, securedto the trame of the screen, which are placed close enough together to prevent access between them.

My invention is susceptible of modifications which lnay be readily made by those skilled in the art and may be applied to the protection of objeetsas well as openings. I do not therefore desire to be limited to the precise construction shown; but,

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

l. In a burglar-alarm system the combination of a sliding cover adapted to be placed over an opening or object, and having a mounting or support which permits of its ready removal from its normal plane, with a circuit closing or changing device adapted to be operated by said cover when the cover is shifted from its normal plane, a burglaralarm circuit including a signal or alarm apparatus adapted to be actuated by the burglaralarm circuit when altered by the operation of said circuit closing or changing device, substantially as described.

2. In a burglar-alarm system the combination of a sliding cover adapted to be placed over an opening or object, with a burglaralarm circuit having one terminal mounted upon said cover and a second terminal stationarily supported with relation to said cover adapted to be brought into contact with the aforesaid terminal by the cover when it is shifted from its normal plane whereby the condition of said circuit is altered, and a signaling or alarm apparatus adapted to be actuated by the burglar-alarm circuit when thus altered, substantially as described.

In a burglar-alarm system the combination of a sliding cover adapted to be placed over an opening or object, and having a mounting or support which permits of its ready removal from its normal plane, with a burglar-alarm circuit including alarm or signal apparatus and an artificial resistance, a circuit changing or closing device adapted to be operated by said cover when the cover is shifted from its normal plane, and a shuntcircuit about said resistance adapted to be closed by said circuit changing or closing dcvice when thus operated, said signal apparatus being adapted to be operated by the bur glar-alarm circuit when thus altered, substantially as described.

4. In a burglar-alarm system the combination of a sliding cover adapted to be placed over an opening or object, and a metallic guide b adapted to direct said cover in its travel, with a plate f stationarily supported and adapted to be brought into contact with guide l) by said cover when it is shifted from its normal plane, a burglar-alarm circuit in cluding alarm orsignal apparatus and an artiicial resistance and a normally open shunt circuitabout said resistance having its terminals in guide b and plate f, substantially as and for the purpose described.

5. In a burglar-alarm system the combination of a sliding cover adapted to be placed over an opening or object, with a metallic guide Z1 to direct said cover in its travel, terminal d supported upon but insulated from said guide, terminal c carried upon the cover, a burglar-alarm circuit normally completed through terminals d c said guide Z2 being connected with said circuit, alarm or signal apparatus included in said circuit, said terminal c being adapted to be removed from contact with terminal d to open the circuit, and then brought into contact with conductor ZJ to alter the circuit when the cover is being moved said signal apparatus being adapted to respond when the circuit is opened and altered, substantially as described.

G. In a burglar-alarm system the combina- IOO TIO

tion of a sliding cover adapted to be placed over an opening or object, with a metal guide b to direct said cover in its travel, terminal d supported upon but insulated from said lguide, terminal e carried upon the cover, a burglar-alarm circuit including alarm apparatus and an artificial resistance normally completed through said terminals d e, said guide b and terminal e constituting terminals of a normally open path of low resistance about said artificial resistance, said terminal e being adapted to be removed from terminal d and brought into contact With conductor b as the cover is moved to rst open the circuit WILLIAM T. ARNOLD. I

Witnesses:

ALBERT LYNN LAWRENCE, GEORGE L. CRAGG.

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