US280506A - Fbedebigk peaece - Google Patents

Description

(Mode1.)

F. PEARCE & J. JONES.

- LOOK FOR FIRE ALARM BOXES.

1109280506. Patented July 3, 1883.

UNITED STATES PATENT Gr nch.

FREDERICK PEARCE, OF NEWV YORK, AND JAMES JONES, OF BROOKLYN, N. Y.

LOCK FOR FIRE-ALARM BOXES.

SPECIFICATION forming part of Letters Patent No. 280,506, dated July 3, 1888.

Application filed April 14. 1883; (Model) T0 at whom it may concern Be it known that we, FREDERICK PEARCE and JAMES J oNEs, citizens of the United States, residing, respectively, at New York, in the countyof New York, and Brooklyn, in the county of Kings, and State of New York, have invented certain new and useful Improvements in Locks for Fire-Alarm Boxes; and we do 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, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification.

This invention relates to a key -trapping mechanism for use in connection with firealarm boxes and in other situations in which the misuse of a key is suspected.

The invention consists in the combination, with a lock, of a trapping mechanism embodying a pivoted plate, one end of which is adapted to partially cover the k ey-h ole of the lock and prevent the removal of the key after the door has been unlocked and opened; and, further, in certain details of construction, as hereinafter more fully described and claimed.

In the annexed drawings, illustrating our invention, Figure l is an interior view of the lock with the principal key-hole covered, the parts being in the position into which they are moved by the act of opening the door and the hinged lid of the case.

trapping the key. Fig. 2 is a similar view, showing the trapping mechanism set for action. Fig. 3 is a vertical edge view of the lock. Fig. 4 is a view of the case in which the trapping mechanism is inclosed. Fig. 5 is also a view of the case inclosing the trapping mechanisnuthe hinged lid of the case being raised, so as to expose a pin or pins by which the trapping device is moved away from the principal key-hole, thereby uncovering the same and setting the mechanism for further use. Fig. 6 is a view of the under side of the case in which the trapping mechanism is inclosed, and shows a spring-catch for securing Fig. 7 is a detail.

Like letters designate like parts in the several views.

A represents a spring-lock of any ordinary or suitable construction, and B is a casing arranged beneath the casing of the lock A, and communicating therewith. In the casing B is arranged a trapping mechanism for catching a key inserted into the key-hole of the lock A to open the door to which said lock is attached.

The trapping mechanism consists, essentially, of a pivoted plate, 0, that is adapted to be moved by the act of opening the door, so as to partially cover thekeyw-hol e of the lock A and prevent the key being turned sufficiently to be removed or disengaged from thelock. The pivoted trapping-plate O is provided with a pin, a, that projects through a slot, 1), in the case B, as shown in Fig. 5. It also has alug, c, for engagement with alug, d, on a flat spring, D, by which the trappingplate is held away from the keyhole. The lower corner of the trappingplate nearest the jamb or casing of the door is provided with a wedgeshaped projection or lug, e, that is adapted to pass through an opening, f, in the side of the easing B, and by hearing on the inner edge of the door-jamb prevents the pressure of the same against the spring D from springing or releasing the trapping-plate C until the door is opened. To the rear side or edge of the trapping-plate0 is attached a spring, E, that bears against the lower end of said plate and forces its upper end over the keyhole, thereby trapping the key. The forward side or edge of the plate G is notched at g for engagement with a hooked dog, F, Figs. 1 and 2, that is actuated by a spring, h, and carries a pin, i, which projects through a slot, 70, in the casing B, as shown in Fig. 5, a stop-pin, m, Figs. 1 and 2, being arranged to prevent the dog F being forced out of position byits spring.

The case B, inclosing the trapping mechanism, is provided with slots b and for passage of the pins a t, as before mentioned. These pins are ordinarily concealed by a hinged lid, G, that covers the entire surface of the case, the under side of said lid being provided with a notched lug, 1), that passes through an opening, s, inthe case B, and is held by a springcatch, H, on the under side of the case. The hinged lid G is provided with an opening, 2, for the passage of a key into and through a key-hole, w, in the case B, by which the catch H may be disengaged from the lug p, thereby permitting the lid to be raised to give access to the pins by which the trapping-plate (,1 is witlnlrawn from. the principal key-hole.

The operation of the device is as follows: By inserting a key throughthe opening 1 and key-hole w the lid G may be unlocked and raised, thus exposing the pins a and i, which may then be forced back, so as to move the upper end of the plate C away from the keyhole of the look A, where it is held by the lug 0, bearing against the lug (Z on the spring I). The door K, to which the lock is attached, may now be closed, the spring-actuated bolt of the look A securing the door until it is necessary to be opened. The act of closing the door brings the end of the spring D in contact with a ledge or projection on the inner edge of the door-jamb and forces the spring back against the door, thereby disengaging the lugs c and d, permitting the lug e to drop into a beveled indentation in front of the lug d, and permitting the plate 0 to move sufficiently to luring its lug 0 against the inner edge of the doorjamb, in which position the trapping mechanism remains set until the door is opened. \Vhen it is desired to unlock and open the door, a key is inserted into the key-h ole ot' the look A to draw its bolt, and the act of opening the door by releasing the lug e from its pressure on the inner edge of the door-jamb enables the spring E to force the lower end of the trappingplate (l forward, thus causing the upper end of the said plate to move backward and cover the lower portion of the key-hole, so as to prevent the removal of the key. l'n order to remove the key, the hingedlid G of the case B will be unlocked, as before described, and the pin (I moved back to partially rotate the plate Uand uncover the principal keyhole, so that its key may be disengaged. \Vith the construction shown, before moving the pin (I it will benecessary to move the pin 1' to disengage the deg F from the notch g of thetrapping-plate; but, il'desired, the deg F may be dispensed with.

It will be seen that by this mechanism akey used to draw the bolt of the look A will be invariably trapped or detained in the look, its removal being impossible without previously unlocking the case 13 and setting the trapping mechanism back. thus be readily detected.

The device is applicable for use in connec tion with fire-alarm boxes, or in other situations where the misuse of a key is to be detected.

lit will be observed that the hinged lid G, when closed, conceals the screws by which the casing B is secured to the door K, so that after the door has been opened and the principal key trapped it will be impossibleto reach the screws for the purpose of removing the casing 13 without the possession of the auxiliary key for unlocking the lid or cover G of said casing.

Having thus described our invention, what we claim as new, and desire to secure by Letters Patent, is

1. The combination, with the lock A, of the casing B, having slots a k, the pivoted trap ping-plate 0, having notch g, pin a, and lugs c c, the spring-dog F, having pin '6, the spring E, and the spring D, provided with lug (1, substantially as shown and described.

2. The combination, with the look A, the door K, and its casing, of the slotted case B, having a lid, G, adapted to conceal, when closed, the screws by which the case B'is secured to the door, the pivoted trapping-plate 0, arranged to project into the case A, and to obstru ct the key-passage in said case, and having pin a. and lugs c c, the spring E, and the spring I), having lug (I, substantially as shown and described.

In testimony whereof we altix our signatures in presence of two witnesses.

FREDK. PEARCE. JAMES JONES;

\Vitnesses:

ANDREW 13 LA KE, (mom: n H. T MLvN.

The misuse of a key can

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