US1174125A - Electrical burglar-alarm. - Google Patents

Description

F. E..CRAWFORD.

' ELECTRICAL BURGLAR ALARM.

A 'Fu'cATlpN FILED 0m. 7. 1901.

1,174,125. Patented 1M7, 1916.

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f/ fw a) 4 8? iv; 3 Q 1/ n //,".9/n1' F. E. CRAWFORD.

ELECTRICAL BURGLAR ALARM.

APPLICATION FILED opTJ, 1901.

1,174,125. Patented Mar. 7,1916.

ii?! IQ UNITED STATES PATENT @FFIGE.

FRANK E. CRAWFORD, OF IBGSTON, MASSACHUSETTS, ASSIGNGR T0 BANKERS ELECTRIC PROTECTIVE ASSOCIATION, OF BOSTON, MASSACHUSETTS, A CGRPOB-ATION OE MAS- SACHUSETTS.

ELECTRICAL BURGLAR-ALARM.

Application filed October 7, 1907.

To all whom it may concern: I

Be it known that I, FRANK E. CRAWFORD, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Electrical Burglar-Alarms, of which the following is a specification.

My invention relates to new and useful improvements in electrical burglar alarms for guarding and protecting a vault or the like, and its object is to pro 'ide a system having means adapted to be operated manually from the outside of an electrically guarded structure by the holder of the combination or the key and permit the opening of the door of the vault without sounding the alarm. In case the door is tampered with or opened without authority, an alarm will be sounded.

In the present application, I have shown my invention applied to a combination lock and time lock and when the lock is shot forward and the time lock set for a predetermined period there is a closed main circuit maintained through the door of the vault and through the electrically guarded structure; at the same time, an automatic switch controlling a shunt circuit is opened and held open while the lock maintains a locked position. When the predetermined time has elapsed, the party having the combination can operate same and withdraw the lock. Simultaneously with the withdrawing of the lock, the automatic switch controlling the shunt circuit is closed maintaining a circuit through both the main and shunt circuits, until the door has been opened, when the main circuit is broken and the shunt circuit remaining closed prevents the sounding'of the alarm. That is, only the person or persons having the combination can open the door after the predetermined time has elapsed. The combination lock and time lock are located within the guarded structure as shown in Figure l so that no access to the timing mechanism can be had without breaking the circuit and sounding the alarm. Means are also provided for pre venting the locking of the safe without setting the time lock, thereby protecting the safe at any time when in use.

In the accompanying drawings which illustrate a construction embodying my invention, Fig. 1 is a perspective view with part of the casing removed showing the com- Specification of Letters Patent.

.Tatented; Mar. 7, 1916. Serial No. 396,137.

bination lock and the time lock with the bolt withdrawn. Fig. 2 is a similar view with the bolt thrown forward and the time lock set for a predetermined period. Fig. 3 is a view similar to Fig. 1 with the time lock released and the bolt shot forward previous to opening the door. Fig. 4 is a diagrammatic view illustrating a safe and the electrical structure around the safe guarding it. Fig. 5 is a diagrammatic view illustrating the circuits.

Like letters of reference refer throughout the several views.

Referring to Figs. 4 and 5, the system comprises a guarded structure T which may be a compartment, vault or cabinet inclosing a safe Y, and Z represents the door thereof and adapted to be manually operated by the key or combination G, which combination may be controlled by a time lock or chronometer N located within the casing A within the guarded structure T (see Figs. 1, 2 and 3).

The conductors 1, 2, 3, and at and door Z indicate a closed main circuit through the battery X inclosing and guarding the struc ture T when the door Z is closed.

1, 5 and 6, switch 0, 7, 2, 3 and a represent a shunt circuit normally open when the door Z is locked, and which circuit is adapted to be closed, comprising the main circuit when the door Z is unlocked to permit the opening of said door without sounding an alarm.

3 represents a balance relay which may be located at headquarters controlling the alarm circuit 81O through the battery X and alarm Z for operating said alarm when any of the circuits through the guarded structure are broken.

A represents a casing located within the door Z and which contains a number of tumblers B on the shaft C forming a combination lock. Fast on the shaft 0 is a cam provided with three pawls G, G G and cooperating with said cam D is a lock-operating lever E provided with latches F and G which are adapted to be engaged by said pawls G G, G during the different operations or the locking mechanism. Cooperating with said combination lock and located within the casing A is the time lock N of usual construction and adapted by means of the square shaft M to be set for a predeter mined period in the usual manner.

to like parts J is a latch lever projecting through a slot J and carrying a latch K on its lower end adapted to cooperate with a pin K when the time lock is set. This lever J has a cross arm K pivoted to arms K and K which arms are pivoted at their lower ends to casing A. A spring M is provided secured to the lever J to hold latch K in cooperation with pin K when the time lock is in operation.

K is a latch pivoted at L to an arm L projecting from the lever J and is normally held in a vertical position in relation to the said arm by a spring L and a stop L.

Assuming the door Z of the vault open with the combination in the position shown in Fig. 1 with the time lock N at Zero, the main circuit maintained through the automatic switch 0 and wires 5, 6 and 7, the operator to lock the vault,closes the door Z and setting the time lock N for a predetermined period, causes the lever J to be thrown over within the slot J, moving the stop K from above the lock-operating lever E, permitting the lock H to be shot forward; the handle C- is now turned, causing the pawls G and G to engage with the latches G and F, shooting the bolt forward, at the same time raising the lever E upward until the pin K is engaged by the latch K (see Fig. 2). In the meantime, the closing of the door Z has closed the circuit through said door by reason of said door engaging suitable contacts in the main circuit heretofore described and the shooting forward of bolt H has operated the switch 0, separating the contacts P and P and breaking the circuit through the shunt, thereby preventing an alarm from being sounded. The vault is now protected and inaccessible without the sounding of an alarm until the predetermined time has elapsed, when the lever J is automatically thrown back in the slot J, withdrawing the latch K from engagement with the pin K (see Fig. 2) when the bolt H may be withdrawn by properly operating the combination. WVhen the operator is ready to open the vault, the combination is operated and the lever E falls, the latches F and G engaging with pawls G and G and the bolt H is withdrawn; simultaneously with the withdrawing of the bolt H, the switch 0 is automatically closed, maintaining a circuit through the shunt, and the door Z may now be opened without sounding an alarm. After the bolt H has been withdrawn, the

Copies of this stop K assumes a position directly over the lever E, preventing the bolt H from being shot forward until the time lock has been properly set. This is to prevent the possibility of the operator locking the door Z without the added protection of the time lock.

Having thus described the nature of my invention and set forth a construction embodying the same, what I claim as new and desire to secure by Letters, Patent of the United States is:

1. The combination with an electrically guarded structure of a door adapted to permit access thereto, a main circuit surrounding said structure and comprising portion of a normally closed alarm circuit, said door comprising a part of said main circuit when closed, a shunt circuit around said door and adapted to maintain the circuit through said alarm when said door is open, means located within said structure adapted to be manually operated from outside said structure to establish a circuit through said shunt to permit the opening of said door without sounding the alarm, and time controlled means located within said structure co-acting with said manually operated means to prevent the operation of said manually operated means within a predetermined time.

2. The combination with an electrically guarded structure, of a door adapted to permit access thereto, a main circuit surrounding said structure, and comprising a portion of a normally closed alarm circuit, said door comprising a part of said main circuit when closed, a second circuit around said door and adapted to be actuated to maintain the circuit through said alarm when said door is open, means guarded by the main circuit and adapted to be manually operated from outside said structure, to establish a circuit 1.

around the door to permit the opening of L said door without sounding an alarm, and

time controlled means guarded by the main circuit and co-acting with said manually operated means to prevent the operation of said manually operated means within a predetermined time.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses, this twenty-fifth day of September A. D. 1907.

FRANK E. CRAWFORD. lVitnesses:

A. L. HURD, L. G. BARTLETT.

patent may be obtained for five cents each, by addressing the. Commissioner of Patents,

Washington, D. C.

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