US3705421A

US3705421A - Chain lock with signal for door

Info

Publication number: US3705421A
Application number: US122654A
Authority: US
Inventors: Fredic B Vanderveer
Original assignee: LEIGH PROD Inc
Current assignee: HARROW SECURITIES Inc A CORP OF; Harrow Products LLC
Priority date: 1971-03-01
Filing date: 1971-03-01
Publication date: 1972-12-05
Anticipated expiration: 1989-12-05

Abstract

A metal base plate has a keyhole anchor for a door chain and is carried by a mounting plate. A signal lever on the base plate has a flexible ear positioned to be engaged by the anchor knob on the end of the chain. An on-off lever on the base plate selectively locks the signal lever against movement, so that unauthorized movement of the chain and its anchor end either moves the signal lever to complete an alarm circuit, or bends the flexible ear on the signal lever without releasing the chain anchor. The mounting plate carries retainers and contacts for batteries that are connected in circuit with an audio signal on the base plate and a fixed switch contact on the base which coacts with the signal lever.

Description

United States Patent I Vand erveer CHAIN LOCK WITH SIGNAL FOR DOOR Inventor:

Appl. No.: 122,654

Int. Cl. .......G08b 13/08 Field of Search ...340/274, 282, 276; ZOO/61.93,

ZOO/61.68; 116/14 [5 6] References Cited UNITED STATES PATENTS 3,585,625 6/1971 Prinsky et a] ..340/274 3,569,950 3/197l Betz ..340/274 3,406,386 10/1968 Hawkins ..340/276 Assignee: Leigh Products, Inc., Coopersville,

US. Cl. ..340/274, ZOO/61.93, 340/276 [151 3,705,421 [451 Dec.5 1972 Primary Examiner-John W. Caldwell Assistant Examiner-Glen R. Swann, ll] Attorney-Austin A. Webb [5 7] ABSTRACT A metal base plate has a keyhole anchor for a door chain and is carried by a mounting plate. A signal lever on the base plate has a flexible ear positioned to be engaged by the anchor knob on the end of the chain. An on-off lever on the base plate selectively locks the signal lever against movement, so that unauthorized movement of the chain and its anchor end either moves the signal lever to complete an alarm circuit, or bends the flexible ear on the signal lever without releasing the chain anchor. The mounting plate carries retainers and contacts for batteries that are connected in circuit with an audio signal on the base plate and a fixed switch contact on the base which coacts with the signal lever.

7 Claims, 5 Drawing Figures PATENTEDMB 5 m2 sum 1 0F 2 FREDRIC INVENTOR.

E .V ANDERVEER BY I M ATTORNEY PAIENTEDnEc 5 m2 mm 2 or z INVENTOK FREDRIC B. VANDERVEER a ATTORNEY CHAIN LOCK WITH SIGNAL FOR DOOR PRIOR ART Safety chain locks to limit the opening motion of doors have been provided with battery operated signals and switching devices to sound an alarm when a door secured by the chain starts to open. These devices have operated on the principal that movement of the door relative to the end of the chain causes the end of the chain to touch a terminal and complete the alarm circuit through the end of the chain or through the movable anchor which secures the chain to the door.

OUTLINE or INVENTION The present invention provides an arrangement in which movement of the anchor button on the end of the chain relative to its retaining anchor on the door functions to mechanically shift a switch member of a signal unit on the door, completing an alarm circuit. Thus the coacting anchor part on the door and the chain function directly to secure the door for limited opening movement. The electrical switch and circuit parts associated with the signal carry no mechanical loads for securing the door, and can be of lighter construction.

Further, the invention provides a yieldable drive connection between the anchor on the end of the chain and the switch lever, which enablesthe switch lever to be separately and selectively locked in open position without interfering with the door securing function of the chain and the anchor on the door. Thus, the chain lock assembly can be selectively adjusted to sound the alarm, or not, when the door is opened to the limit permitted by the chain.

Additional desirable features of the lock and signal permit the use of economical parts and retaining structure for the battery, alarm, and their circuit connections, and easy assembly into the complete lock and signal as will be described. 1

DESCRIPTION The drawings, of which there are two sheets, illustrate a preferred form of the invention.

FIG. 1 is a fragmentary elevational view of the lock and signal, in operative position on a door and door frame.

FIG. 2 is an elevational view of the door anchor and signal as mounted on the door with the cover removed.

FIG. 3 is a fragmentary vertical cross sectional view taken along the planeof the line 3-3 in FIG. 1.

FIG. 4 is an enlarged front elevational view of the door anchor, switch lever, on-off lever and the related retaining parts for the battery, circuit connections and mounting structure, with the selective signal control in on position.

FIG. 5 is a fragmentary front elevational view of the switch lever and the selective on-off lever in of position.

The major parts of the lock consist of a casing 1, attached to the frame 2 of a door, a fixed anchor 3 attached to the casing 4 of the doorway, and a chain 5 permanently secured to the fixed anchor and having a releasable anchor 6 in the form of a headed stud on its free end. The releasable chain anchor 6 is selectively engageable in a keyhole slot 7 in a door anchor 8 or in a storage hole 9 in the fixed anchor The casing 1 consists of a rear mounting plate 10, which is conveniently made of molded plastic. Ribs 11 along the sides of the mounting plate have detents 12 which springably engage the edges of the molded cover 13. The upper wall of the cover is cut away as at 14 exposing the door anchor 8 and the keyhole slot 7. Wlthin the casing and behind the cover 13, the mounting plate has integral forwardly projecting vertical side ribs 15 with opposed dovetailed slots 16. therein. See FIG. 4.

The slots slidably receive and retain folded

metal contact elements

17, 18 and 19 in position to engage the ends of

batteries

20 and 21. Vertically spaced converging flexible ears 22 formed integrally on the mounting plate retain the upper and lower sides of the two batteries in the casing.

The anchor 8 is formed as a forwardly and downwardly inclined flange on the upper crosspiece of a generally T-shaped base plate 23. The plate 23 is of sturdy metal construction to withstand the pull of the chain 5 and the movable anchor 6 thereon, and is secured to the frame of the door by screws 24 that pass through the mounting plate 10. Other screws or bolts 25 secure the base plate to the mounting plate prior to installation of the lock on the door. Note that the mounting can be reversed to mount the casing 1 on the doorway casing and the anchor 3 on the frame of the door.

The vertical stem 26 of the T-shaped base plate is lapped flush with the mounting plate, between the ribs 15 and behind the batteries to a forwardly offset pad end 27 (See FIG. 3) which constitutes a mounting connection for an audio signal device 28 such as a buzzer. The connection of the signal to the pad constitutes an electrical connection from one side of the signal to the base plate. A wire 29 connected electrically to the other side of the signal extends to the terminal clip 17 to form a series connection between the signal and the batteries and the base plate. The other end of the series is the terminal 19 which has a contact flange 30 located forwardly of one side of the cross bar of the T-shaped base plate.

Secured to the base plate 23 in lapped relation to its upper end is a switch lever 31, held rockably in pace by a rivet 32. One arm 33 (See FIG. 4) of the lever has a forwardly turned contact flange 34 in opposed coacting relation to contact flange '30. An opposite arm 35 of the switch lever projects to underneath an on-off lever 36 to be described. The center of the switch lever extends upwardly in an arm 37 with a forwardly and downwardly inclined flange 38 on its upper end. Extending laterally from the flange 38 is an upwardly inclined finger 39 with a tab 40 on its upper end in closely spaced relation below the flange 8 and slot 7. The finger and tab are thus in the path of movement of the movable anchor 6 along the slot, and tension on the chain 5 can force the switch lever and its contact flange 34 into engagement with the terminal 30, to complete the circuit to the alarm signal 28.

The on-off lever 36 permits the safety chain lock to be used without sounding the alarm signal. It also turns off the alarm. The lever is secured in lapped relation to the cross piece of the base plate by a rivet 41. An actuating finger piece 42 projects through a notch in the cover'l3 to be exposed on the outside of the casing; while a forwardly turned stop flange 43 overlies the arm 35 of the switch lever in blocking relation thereto when the lever 36 is in off" position. Whenever the lever 36 and its flange 43 are in blocking relation to the switch lever, the movable anchor 6 on the chain can still slide along the slot 7 by deflecting the arm 39 downwardly as shown by the dotted line position in FIG. 5. Similarly, the switch lever 31 and its contact flange 34 can be moved to off position while the safety chain is extended and the anchor 6 is in engagement with the finger 39. This action is made possible by flexing of the relatively narrow finger 39 and its corresponding narrow connection to the flange 38 f the switch lever. It is thus possible for the householder to turn off the alarm while leaving the safety chain in place while he identifies the person who opened the door and sounded the alarm in the first place.

What is claimed as new is:

l. A safety chain lock and alarm for doors and including a chain with a movable anchor comprising a casing having a battery and an electrical signal connected in series therein,

a metal base plate secured in said casing and having a flange at one end bent forwardly and defining a keyhole slot exposed through one wall of said casing and adapted to removably receive said movable anchor,

one side of said signal being electrically connected to said base plate,

a switch lever pivotally and electrically connected to said base and having a contact swingable with the lever into electrical contact with the opposite side of said battery from said signal,

and an actuating arm on said switch lever eccentric to the pivot of the lever and extending to adjacent said flange on said base plate and in the path of said movable anchor when said anchor moves along said keyhole slot.

2. A chain lock and alarm as defined in claim 1 in which said switch lever has another arm formed thereon,

and a signal interrupting lever pivoted on said base plate and having a stop arm movable into blocking relation to said switch lever to hold the contact of the latter open,

said interrupting lever having an operating arm projecting through the side of said casing,

said actuating arm being springable relative to the remainder of said switch lever to permit passage of of said battery one of said clips having a portion forming the contact engageable with the contact portion of said switch lever,

and another of said clips having alarm electrical connection connected to the opposite side of said signal from said base plate.

4. A chain lock and alarm as defined in claim 3 in which said base plate is a T-shaped member with its stem secured in lapped relation to the front side of said flat back and between said retaining flanges,

the stem of said T-shaped member extending beyond said retaining flanges and having said signal electrically and mechanically connected to its lower end.

5. A chain lock and alarm as defined in claim 4 in which said casing has a removable cover having a snap engagement with the edges of said flat back.

6. A chain lock and alarm as defined in claim 1 in which said switch lever is a flat metal member with a rivet forming the pivotal connection between the midportion of the lever and the upper part of said base plate,

a forwardly turned flange on one end of said flat metal member forming the swingable contact on the switch lever,

and an upwardly extending coplaner arm near the center of said flat metal member,

said actuating arm being folded forwardly from the top of said coplaner arm with an upwardly and laterally inclined finger on one side of a forwardly folded portion extending to adjacent the slot in the flange on said base plate.

7. A chain lock and alarm as defined in claim 2 in which said switch lever is a flat metal member with a rivet forming the pivotal connection between the midportion of the lever and the upper part of said base plate,

UNITEDSTATES PATENT OFFICE CERTIFICATE OF CORRECTION i Patent No." ,705,421 Dated December 1972 l t Fredric B. Vanderveer It is certified that errorappears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the cover sheet [72] "Fredic" should read Fredric ,v

Signed and sealed this 8th day of May 1973.

(SEAL) Attest:

EDWARD M. FLETCHER, JR ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents F ORM PO-1050 (10-69) USCOMM-DC 60376-P69 w us GOVERNMENT PRINTING OFFICE: 1959 mass-334, l

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION P n N I 1 3, 705,421 I Dated December 5, 1972 InventQr( Fr ed-Tic CB. VandeIVeer It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the cover sheet [72] "Fredic" should read Fredric Signed and sealed this 8th day of May 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JRV. I I ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents FORM PO-1050 (10-69) U$COMM-DC 60376-P69 w us. GOVERNMENT PRINTING OFFICE I969 0-366-334,

Claims

1. A safety chain lock and alarm for doors and including a chain with a movable anchor comprising a casing having a battery and an electrical signal connected in series therein, a metal base plate secured in said casing and having a flange at one end bent forwardly and defining a keyhole slot exposed through one wall of said casing and adapted to removably receive said movable anchor, one side of said signal being electrically connected to said base plate, a switch lever pivotally and electrically connected to said base and having a contact swingable with the lever into electrical contact with the opposite side of said battery from said signal, and an actuating arm on said switch lever eccentric to the pivot of the lever and extending to adjacent said flange on said base plate and in the path of said movable anchor when said anchor moves along said keyhole slot.

2. A chain lock and alarm as defined in claim 1 in which said switch lever has another arm formed thereon, and a signal interrupting lever pivoted on said base plate and having a stop arm movable into blocking relation to said switch lever to hold the contact of the latter open, said interrupting lever having an operating arm projecting through the side of said casing, said actuating arm being springable relative to the remainder of said switch lever to permit passage of said movable anchor along said keyhole slot when movement of the switch lever is obstructed by said interrupting lever.

3. A chain lock and alarm as defined in claim 1 in which said casing has a flat back of insulating material to which said base plate is mechanically connected, aligned holes in said base plate and said flat back adapted to receive screws for fastening said casing to a part of a door, retaining flanges on said back arranged to receive and retain said battery, terminal supporting flanges on said back plate having dovetail slots formed therein in opposed laterally spaced and forwardly opening relation, and metal terminal clips retainingly received in said slots to electrically contact the electrical terminals of said battery, one of said clips having a portion forming the contact engageable with the contact portion of said switch lever, and another of said clips having alarm electrical connection connected to the opposite side of said signal from said base plate.

4. A chain lock and alarm as defined in claim 3 in which said base plate is a T-shaped member with its stem secured in lapped relation to the front side of said flat back and between said retaining flanges, the stem of said T-shaped member extending beyond said retaining flanges and having said signal electrically and mechanically connected to its lower end.

6. A chain lock and alarm as defined in claim 1 in which said switch lever is a flat metal member with a rivet forming the pivotal connection between the mid-portion of the lever and the upper part of said base plate, a forwardly turned flange on one end of said flat metal member forming the swingable contact on the switch lever, and an upwardly extending coplaner arm near the center of said flat metal member, said actuating arm being folded forwardly from the top of said coplaner arm with an upwardly and laterally inclined fInger on one side of a forwardly folded portion extending to adjacent the slot in the flange on said base plate.

7. A chain lock and alarm as defined in claim 2 in which said switch lever is a flat metal member with a rivet forming the pivotal connection between the mid-portion of the lever and the upper part of said base plate, a forwardly turned flange on one end of said flat metal member forming the swingable contact on the switch lever, and an upwardly extending coplaner arm near the center of said flat metal member, said actuating arm being folded forwardly from the top of said coplaner arm with an upwardly and laterally inclined finger on one side of a forwardly folded portion extending to adjacent the slot in the flange on said base plate.