US2563727A - Door lock with alarm device - Google Patents

Description

g- 1951 H. H. KEMPF DOOR LOCK WITH ALARM DEVICE 2 Sheets-Sheet 1 Filed Nov. 29, 1949 I 'INVENTOR. flfFM/I/V fi Aim/PF ATTO/Q/VEV 7, 1951 H. H. KEMPF 2,563,727

DOOR LOCK WITH ALARM DEVICE Filed Nov. 29, 1949 2 Sheets-Sheet 2 I N V EN TOR. fife/14A /v ,6. Ai /w;

Patented Aug. 7, 1951 UNITED STATES PATENT OFFICE noon LOCK WITH ALARM DEVICE Herman H. Kempf, Garden City, N. Y., assignor to Abe April Fine Furs, Incorporated, New York, N. Y., a corporation of New York Application November 29, 1949, Serial No. 129,971

8 Claims. 1

Doors with spring extended latches are frequently opened by burglars by inserting a tool between the door and the frame to push back the latch bolt.

I propose to provide such latch mechanism with an alarm device which will attract attention in case the latch bolt is retracted by unauthorized action of the bolt but in which the door can be opened by manual retraction of the bolt by a knob or finger lever in the proper manner or by a proper key without actuating the alarm.

One object is to provide a simple construction which is applicable to a conventional type of lock.

Accordingly I have provided alarm mechanism which can be combined with a door lock to sound an audible alarm mechanically.

In carrying out the invention, I provide a push button type of alarm bell which is actuated when the latch bolt is pushed in by a tool inserted from outside the door. Retraction of the bolt by a knob or finger lever at the inside of the door however disconnects the alarm device. Insertion of a proper key from outside the door also disables the alarm.

Fig. l is a front view of a lock and alarm device embodying one form of my invention showing it as mounted on the inside of a fragment of a door.

Fig. 2 is a vertical sectional view of the same, the section being taken on the general plane of the line 2-2 of Fig. 1.

Fig. 2a is a rear view of the supporting plate for the cylinder lock of Fig. 2.

Fig. 3 is a rear view of the device, the. back plate of the lock unit being broken away.

Fig. 4 is a fragmentary horizontal section of a lock device, the section being taken on the plane of the line 4-4of Fig. 3,

Fig. 5 is an enlarged perspective view of parts of the bolt retracting mechanism and the cam for initiating an alarm.

Fig. 6 is an enlarged perspective view of a part shown in Fig. 5, the view being taken at a different angle.

The lock case or housing 8 is adapted to be attached by screws 9 to a door I and supports the spring-pressed latch bolt I l which is adapted to be retracted manually by a lever [2 or a key l4. The back plate l of the case is secured in place by a screw IS.

The latch bolt is slidably guided in one end of the case and has two rods ll, H which are slidable in a saddle l8 which is supported in the guide IS in the case. The springs 29, 20 on these 2 rods bias the bolt to a protruded latching position.

At the inner ends of the rods ll are abutment plates 2| and 22. Finger lever l2 extends through a slot in the case and is pivoted at 22' to plate 22. The arm 23 is hinged on stud 24 which is secured in plate 2|. This arm extends through a slot in the case and carries at its upper end an inclined cam 25 which coacts with a spring-pressed button 26 of a spring-driven alarm bell 21 which may be suitably mounted on or may be adjacent the lock case. A leaf spring 28 is secured at one end to arm 23 and presses at the other end against the wall of the case to press the upper end of arm 23 and its cam 25 toward the rear of the case where the camis in alinement with the alarm button 26.

The rear of arm 23 has a shoulder 29 which is engaged by a hook..3ll on the inner end of finger lever l2 so that when the finger piece is moved to the right (Fig. 1) or left in Fig. 3, the upper end of arm 23 and cam 25 will be moved forward and out of alinement with the alarm button. Continued movement of the lever retracts the entire bolt unit without moving the alarm button.

If the bolt and its unit are pushed inward, the cam 25 engages the alarm button and releases the alarm.

To retract the latch bolt from the outside of the door, I provide a cylinder type lock having a roll back 3| which is rotatably carried by the back plate l5 and has arms which engage the abutment plates 2| and 22. The cylinder body 32 has the pin carrying plug 33. The support 34 is secured to the door by screws or brads 35. The cylinder 32 is secured by screws 35, 36 to support 34. The rear ring 31 is secured to the pin plug 33 by screws 38, 38. A blade 39 has an enlarged end 48 slidably mounted in the inner end of the key slot of the pin plug 33. The blade 39 extends through a slot in ring 3! and through the central slot in the roll back 3| so that the bolt unit can be retracted by rotation of a key in the cylinder lock. When a key of ordinary length is inserted into the lock cylinder, the associated alarm parts are not disturbed and remain set so that rotation of the key will retract the bolt and sound the alarm. However, insertion of a special key of extra length will engage the end 43 of the blade 39 and push the blade against the arm 23 and tilt the arm thereby retracting the cam 25 from alinement with the alarm button 26 so that subsequent rotation of the key will retract the bolt to open the lock Without sounding the alarm.

The lock may be provided with a dead lock catch 4| so that after retracting the bolt by means of the lever 12 the bolt may be held retracted without sounding the alarm.

I claim:

1. In an alarm system, the combination of a door lock. casing containing a latching unit therein and having a spring-pressed slidable latch bolt member for locking the door and adapted to be slidably retracted into the casing, to unlocking position an alarm device including an actuating button, an alarm initiating member movably carried by said latching unit and adapted to coact with said button to initiate an alarm when the bolt is pushed into the casing, to unlocking position and manually operable means for retracting said bolt latching unit and retracting said alarm initiating member from coaction with said actuating button.

2. In an alarm system, the combination of a door lock casing containing a latching unit therein and having a spring-pressed slidable latch bolt member for locking the door and adapted to-be slidably retractedinto the casing to unlocking position, an alarm device including an actuating button, an alarm initiating cam member hinged to said latching unit and adapted to coact with said button to initiate an alarm when the bolt is pushed into the casing, and a finger actuated lever for retracting said bolt latching unit and retracting said alarm initiating cam member from enacting with said actuating button.

3.. A. door lock Witha casing and a normally protruding spring-pressed. sliding bolt unit for attachment to the inside of a door in combination. with a push button-actuated alarm device actuator, a cam movably connected to the bolt unit and slidable with the bolt unit to engage the push button actuator and initiate an alarm when the bolt is forced inwardly of the casing by an outside force, a manually operable lever connected to said cam at the inside of the door for disengaging said cam from said push button actuator when retracting said bolt unit from the inside, and means actuated by a key from outside the door for retracting said bolt unit.

4. A door lock with a casing and a springpressed sliding bolt unit in normal protruding locking position for attachment to the inside of a. door in combination with a push buttonactuated alarm device actuator, a cam movably connected to the bolt unit and slidable with the bolt unit to engage the push-button actuator and. initiate an alarm when the bolt is forced to unlocked position by a force outside the door, a manually operable lever connected to said cam at the inside of the door for disengaging said cam from said push button actuator when retracting said bolt unit from the inside, and means actuated by a key from outside the door for re tracting said cam and retracting said bolt unit.

5. A door lock for use with an alarm device comprising a lock casing, a bolt unit slidably mounted in said casing and having one end of the bolt protruding externally therefrom, a cam member connected to the bolt unit and normally projecting'ex-ternally of the casing for engagement with a projecting actuating part of an alarm device and adapted to slide in normal alarm releasing position when the bolt unit is moved by forcing the bolt longitudinally at its protruding end, and key actuated means for simultaneously retracting said bolt and retracting said cam from alarm releasing position.

6. A door lock with alarm attachment comprising a lock casing containing a latch bolt unit including means slidable in the casing, an alarm device including a projecting element for initiating action of the alarm device, means carried by the latch bolt for coacting with said projection to cause an alarm when said latch bolt is pushed into said casing, and manually operable means including a finger piece for retracting said latch bolt unit and simultaneously deflecting said bolt carried means from said projection and preventing it from coacting with said projection when said latch bolt unit is'retracted by said finger piece.

7. A door lock with alarm attachment comprising a lock casing containingalatching unit including a bolt and a roll back for retracting said bolt and having key actuated means at one face and manually actuated means at the opposite face, each of said means coacting with said roll back to retract said bolt, an alarm device having an operating button, a cam carried by said latching unit and slidable with said bolt, when the bolt is pushed in, for engaging said operating button to initiate the alarm action, and means adapted to be actuated either by the key actuating means or by said manually actuated means for disabling said cam and avoiding said alarm.

8. An alarm system comprising, in combination, a bell device having a protruding actuating member, and door locking mechanism including a lock casing, a spring-pressed locking bolt unit slidable therein and having a bolt normally protrudingfrom said casing in looking position, a hinged cam device in said casing and having a portion protruding from said casing and movable in the path of said actuating member, and means of connection between said cam device and said locking unitv whereby movement of the bolt locking unit by a force externally of the easing on the protruding bolt will carry the cam device along and move the protruding portion thereof over said actuating member for ringing the bell, said connecting means including plates carried by the sliding bolt and a stud carried by one of the plates for hingedly connecting the cam device to the locking unit.

HERMAN H. KEMPF.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 531,955 Larson Jan. 1, 1895 583,952 Sutton June 8-, 18-97 FOREIGN PATENTS Number Country Date 2,963 Great Britain Dec. 8', 1910

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