US3553721A

US3553721A - Door locking system

Info

Publication number: US3553721A
Application number: US623419A
Authority: US
Inventors: Paul Maddison Hawkins
Original assignee: General Alarm Corp
Current assignee: General Alarm Corp
Priority date: 1967-03-15
Filing date: 1967-03-15
Publication date: 1971-01-05
Anticipated expiration: 1988-01-05
Also published as: DE1653999A1; GB1227852A; BE712253A; CH471303A; DE1653999B2; FR1556158A

Abstract

DOOR LOCK ARRANGEMENTS INCLUDING STRIKE HOUSING WHICH IS RESILIENTLY MOUNTED TO PIVOT IN RESPONSE TO FORCING PRESSURES, APPLIED VIA A BOLT OR LOCKING CHAIN, TO ACTUATE AN ENCLOSED ALARM SWITCH, AND AN ADJUSTABLE CHAIN ANCHOR COMPRISING A WALL WITH A CROSS SHAPED OPENING AND A RECESS IN THE SURFACE OF THE WALL OF ACCOMMODATING A CHAIN LINK LYING FLATWISE THERIN ADJACENT THE OPENING.

Description

Jan. 5, 1971 I P. M. HAWKINS 3,553,721

DOOR LOCKING SYSTEM Filed March L5, 1967 3 Sheets-Sheet 1 /4- II Z\ 74' L 70. 30 30 g 306 A I I fHT H' 51, 21 4 30 I 1 P. M. HAWKINS DOOR LOCKING SYSTEM Jan. 5, 1971 Filed March L5, 1967 3 Sheets-Sheet 2 Q WEE M m mfm Jan. 5, 1971 P. M. HAWKINS noon LOCKING SYSTEM Filed March L5, 1967 3 Sheets-Sheet 5 H HM. 94

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United States Patent US. Cl. ZOO-61.64 14 Claims ABSTRACT OF THE DISCLOSURE Door lock arrangements including strike housing which is resiliently mounted to pivot in response to forcing pressures, applied via a bolt or locking chain, to actuate an enclosed alarm switch; and an adjustable chain anchor comprising a wall with a cross shaped opening and a recess in the surface of the wall for accommodating a chain link lying flatwise therein adjacent the opening.

This is a continuation-in-part of copending application Ser. No. 492,455 filed Oct. 4, 1965 now US. Pat. 3,406,386 and Ser. No. 596,841, filed Nov. 25, 1966 now US. Pat. 3,471,188.

This invention relates to locking systems and more particularly it concerns door lock arrangements suitable for surface mounting on presently existing door arrangements.

In one of its aspects the present invention involves the provision of novel lock element receptacles which may be mounted on a door frame to receive a lock bolt, a locking chain or both. These receptacles include a casing formed with one or more lock element receiving recesses therein to receive a lock element such as a door bolt or chain. The casing is mounted, preferably on a door frame with means which permit limited movement out away from the frame under a predetermined amount of force applied via the bolt or chain. A switch is carried by the casing and is arranged to be actuated in response to movements of the casing away from the door frame. The switch may be connected to a remote alarm for actuation thereof when the door is forced open.

An important feature of the arrangement of the present invention lies in the fact that the switch and casing are arranged such that any attempt to remove the casing away from its mounted position so as to free it from the locking member (i.e. the bolt or chain) inherently produces actuation of the switch and consequent sounding of the alarm. Thus, even though the device is surface mounted and therefore is relatively easy for accomplished lockbreakers to penetrate, nevertheless the lock device of the present invention carries its own protection against such penetration in that it produces an alarm upon the occurence of any attempted penetration.

According to a second aspect of the present invention there is provided a novel adjustable chain anchor arrangement for conventional link chains used as auxiliary door locks. This novel chain anchor arrangement is specially designed to permit positive securing of a door chain at any of several link positions while at the same time allowing convenient adjustment of the chain to be secured to the anchor at a new position. This new chain anchor arrangement moreover is exceptionally sturdy and is capable of withstanding considerable shaking without becoming unsecured. Yet it provides an unimposing, actually pleasing external apperance.

The novel chain anchor arrangement of the present invention comprises a block having a cross shaped passage extending therethrough for allowing passage of a chain. One of the surfaces onto which the cross shaped passage extends is recessed so that at one end it closely accommodates a chain 'link lying flatwise therein. The recess is arranged with this one end lying over one of the arms of the cross shaped passage and near its center. The chain passes through the passage and then bends at right angles so that the link adjacent the one in the passage lies in the recess. The chain is thus essentially flush mounted in the block while the end walls of the recess provide a very positive securing action to hold the chain from being pulled through the passage.

There has thus been outlined rather broadly the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject of the claims appended hereto. Those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of the invention. It is important, therefore, that the claims be regarded as including such equivalent constructions as do not depart from the spirit and scope of the invention.

Specific embodiments of the invention have been chosen for purposes of illustration and description, and is shown in the accompanying drawings forming a part of the specification, wherein:

FIG. 1 is a front elevation view showing a door lock arrangement constituting a first embodiment of the present invention;

FIG. 2 is a view taken along line 22 of FIG. 1, and showing the door lock arrangement in normal locked condition;

FIG. 3 is a section view taken along line 33 of FIG. 2;

FIG. 4 is a view similar to FIG. 2, but partially broken away and showing the door lock arrangement in bolt forcing condition;

FIG. 5 is a view similar to FIG. 4, but showing the door lock in chain forcing condition;

FIG. 6 is an exploded fragmentary perspective view showing a strike assembly forming one portion of the lock arrangement of FIG. 1;

FIG. 7 is a side elevational view of the strike assembly of FIG. 6;

FIG. 8 is a front elevational View showing a door lock arrangement constituting a second embodiment of the present invention;

FIG. 9 is a view taken along line 9-9 of FIG. 8, and showing the door lock arrangement in normal locked condition; and

FIG. 10 is a view similar to FIG. 9 but showing the door lock in chain forcing condition.

The door lock arrangement shown in FIGS. 1 and 2 comprises a lock casing 10 fastened by means of screws 12 to the surface of a door 14, and a strike assembly 16 secured to the surface of a door frame 18.

The lock casing 10 is provided with a thumb turn 20 which may be used to project a bolt 22 into the strike assembly 16. A lock cylinder 24 (FIG. 2) is provided to project through the door 14 for key operation of the lock from outside the door. There is also provided a chain anchor recess 26 in the surface of the lock casing 10 which is engageable by an anchor 28 at one end of a locking chain 30. The locking chain 30 is adjustably secured to the strike assembly 30 in a manner to be described.

The strike assembly 16, as shown in FIG. 2, comprises a mounting plate 32 and a strike casing 34. The mounting plate 32 is an essentially flat member which lies flush against the surface of the frame 18. An extension 36 bends around the frame 18 and is covered by the edge of the door 14 when it is closed. The mounting plate 32 is secured to the frame 18 by means of screws 38 which pass through the extension 36 and into the frame. It will be noted that these screws are covered by the edge of the door 14 when it is in its closed condition as shown in FIG. 2. This prevents the use of a screwdriver or other tool to remove the anchor plate 32 and break through the lock. Additional screws 40 pass directly through the main portion of the anchor plate 32 and into the door frame 18 to more securely hold it in place. These additional screws are also protected from tampering in a manner to be described.

Along the edge of the anchor plate 32 opposite the extension 36, there is provided an upstanding ridge 42. Two holes or recesses 44 extend crossways through the ridge in a direction generally parallel to the plate 32 itself. These holes or recesses act as guides for the strike casing 34.

The strike casing 34, as shown in FIG. 3 and 4, is of hollow construction, and is formed with lower and

upper portions

46 and 48. The lower portion 46 is of greater width than the upper portion. A bolt receiving recess 50 opens out onto the front of the upper portion as shown in FIG. 3. Also, toward the front of the lower portion on either side of the upper portion 48 there are provided downwardly extending openings 52 which terminate at bottom floors 54. Force adjustment bolts 56 are located within the openings 52 and pass through the floors 54 to the anchor plate 32 where they are threaded in place. Coil compression springs 58 are provided in each of the openings 52 between the floors 54 and the heads of the adjustment bolts 56. This arrangement secures the strike casing 34 to the anchor plate 32 in such a manner that the casing cannot be pulled up off the anchor plate 32 except by a force greater than that exerted by the springs 58. Moreover, once the springs become fully compressed, the bolts 56 prevent further movement of the casing. The amount of force needed to be overcome in order to produce initial movement of the strike casing 34 can easily be adjusted simply by turning the adjustment bolts 56 into the anchor plate 32 so as to move their heads further down against the springs 58.

As pointed out above, the openings 52 for resiliently securing the strike casing 34 to the anchor plate 32 are located toward the front of the casing. At the rear of the casing there are provided a pair of protruding lugs 60 which fit loosely within the holes or recesses 44 in the ridge 42 of the anchor plate. The lugs 60 and holes or recesses 44 cooperate to provide a hinge like guidance which permits a slight pivoting action for the strike casing 34 when it is moved against the action of the springs 58.

An electrical switch 62 is mounted within a further recess 64 formed in the lower portion 46 of the strike casing 34 just behind one of the downwardly extending openings 52. The switch 62 is provided with a switch arm 66 which is biased against the strike casing to follow the movements thereof which take place when the casing is forced. The switch 62 is thus actuated by movements of the strike casing to indicate that the door 14 is being forced. The switch may be connected in any conventional manner to a remote alarm (not shown) to provide an alarm signal whenever the switch is actuated.

The upper portion 48 of the strike casing 34 is also of hollow construction and, as shown in FIGS. 1 and 3, it is provided with a laterally slanted, generally vertical front wall 70 having a round central opening 72 therein through which the chain 30 freely passes. A specially configured rear wall 74 is provided at the back of the upper portion 70. The rear wall 74 is also vertically disposed and is somewhat less laterally slanted than the front wall 70. The special configuration of the rear wall 74 serves to permit adjustment of the chain so that any desired link 75 thereof may be held by the strike casing to limit the extend to which the door 14 may be partially opened.

As shown in FIGS. 6 and 7, the specially configured rear Wall 74 is provided with a cross shaped opening 76 which permits free passage of the mutually orthogonally disposed adjacent links of the chain 30 when the chain is properly disposed both positionally and rotationally. The cross shaped opening 76 is disposed in substantially horizontal alignment with the round opening 72 in the front wall 70.

The rear wall 74 is also formed with extended vertically disposed recesses 78 which, at the inner ends thereof, conform closely to the outer shape of the individual chain links when they lie flat in the recess. The central portions of the inner ends of the recesses 78, it will be noted, overlay the tips of the vertically extended arms of the cross shaped opening 76, to define retaining walls 78a and 78b for locking the chain 30 in place.

In operation of the above described lock arrangement, the door 14 may be locked either by turning the thumb turn 20 or by operating the lock cylinder 24 to project the locking bolt 22 into the recess 50- in the strike casing 34. Additionally or alternatively, the chain 30 may be used to provide a lock limiting the door 14 to a partially opened position. The locking arrangement is thus set to the condition illustrated in FIG. .2.

If now, with the bolt 22 projected, one should attempt to force open the door 14, the bolt will bear outwardly against the lower portion 46 of the strike casing 34 forcing it up and away from the anchor plate 32. When the force applied through the bolt becomes sufficient to overcome the restraint of the coil springs 58, the casing will pivot upwardly a short distance, as illustrated in FIG. 4, to operate the switch 62 and sound a remote alarm. It will be noted that the slight upward movement of the strike casing 34 does not alfect the integrity of the lock; and the bolt 22 remains firmly engaged in the recess 50 of the strike casing 34.

Should the bolt 22 be withdrawn, the door 14 may be opened until it reaches a point established by the amount of the chain 30 between the upper portion 48 of the strike casing 34 and the door lock 10. When the door reaches this position, then, as illustrated in FIG. 5, any further forcing movement will tension the chain 30 and cause it to pull the front end of the strike casing away from the anchor plate 32. When the force of this pull exceeds the resistance of the coil compression springs 58, the strike casing will pivot slightly away from the anchor plate 32 and operate the switch 62 as above described.

It will be noted that the strike casing 34 effectively covers the anchor plate mounting screws 40 when it is in place; and that the casing must therefore be removed in order to gain access to the screws 40 for removal thereof. Although the adjustment bolts 56 are readily accessable for removal of the casing 34, nevertheless it will be noted that any attempt to so remove the casing will result in operation of the switch 64 and sounding of an alarm. Thus, even though the strike assembly 16 is surface mounted with conventional screws, it is effectively rendered tamperproof by virtue of the arrangements of the present invention.

Adjustments of the chain distance between the strike casing 34 and the lock 10 are made by holding the chain 30 in a horizontal position so that it is aligned with both the round opening 72 in the front wall 70 and the cross shaped opening 76 in the rear wall 74. The chain 30 may then be moved back or forth though the strike casing 34 to any desired position. When the desired length of chain is provided between the strike casing 34 and the door lock 10, the portion of the chain which extends out from the rear wall 74 of the strike casing is hung down so that it lays in one of the recesses 78. Thus, as shown in FIGS. 1 and 7, a first link 30a extends out through the transverse or horizontal portion of the crossshaped opening 76 (i.e. that aligned crosswise of the recesses 78), while the next adjacent link 30b extends at least partially through the longitudinal portion of the cross-shaped opening and up into one of the recesses 78. The following link 300 then lays substantially flatly in the recess and is held from movement by the walk at the end of the recess.

The recesses 78 cooperate with the cross shaped opening 76 to secure the chain 30 solidly in position; and they prevent it from turning or freeing itself under shaking or vibrations. At the same time, the chain is arranged in flush mounted relationship to the strike casing 34 to provide a neat and presentable appearance. Moreover, the chain may be readjusted simply by lifting its free end to a position of alignment and moving it through the strike casing FIGS. 8, 9 and 10 show a modified lock arrangement according to the present invention wherein the locking bolt is omitted. In this modified arrangement there is provided on the door 14, a chain anchor housing 80 which is secured in place by means of screws 82. The chain anchor housing is provided with a chain anchor recess 84 in which the anchor 28 of the locking chain 30 is detachably engaged.

A strike arrangement 86 similar in construction to the strike plate arrangement 16 of the previous embodiment is secured in similar fashion to the door frame 18. The strike plate arrangement 86 differs from that of the previous embodiment in that it has a strike casing 88 which omits a bolt receiving recess; and in which the front and

rear walls

70 and 74 through which the chain 30 passes are lowered into the region occupied in the previous embodiment by the bolt receiving recess 50'.

Thus, as shown in FIGS. 8- and 9 the chain 30 may be engaged and adjusted just as in the prevous embodiment; and, as shown in FIG. 10, it operates to pull out on the strike casing 88 to operate the switch 62 when the door 14 is forced open.

Having thus described my invention With particular reference to the preferred forms thereof, it will be obvious to those skilled in the art to which the invention pertains, after understanding my invention, that various changes and modifications may be made therein without departing from the spirit and scope of my invention, as defined by the claims appended thereto,

What is claimed as new and desired to be secured by Letters Patent is:

1. In combination, a lock element carrier casing for mounting on a first cooperating closure member, a lock element receiving casing for mounting on a second cooperature closure member, means on one of said casings for resiliently securing same to its respective closure member in a manner permitting limited movement of said one casing away from its respective closure member in response to the application of predetermined forces thereto via said lock element, and an alarm actuating switch biased toward an alarm actuating position and carried within said one casing and normally held by said casing against said bias, said switch being arranged to be released to an alarm actuating condition upon such limited movement of said one casing away from its respective closure member to actuate an alarm.

2. A lock switch device comprising an outer casing having recess means formed therein for receiving a lock element from a cooperating lock member, means on said casing for resiliently mounting said casing to one of two cooperating closure members in a manner permitting limited movement of said casing away from said one closure member in response to a predetermined force applied via said recess from said lock element, and an alarm actuating switch biased toward an alarm actuating position and carried within said casing, and normally held by said casing against said bias, said switch being arranged to be released to an alarm actuating condition upon such limited movement of said casing away from its respective closure member to actuate an alarm.

3. A lock switch device as in claim 2 wherein said recess means in said casing includes a recess formed to receive a locking bolt which projects thereinto in a direction transverse to the direction of movement of said casing away from its respective closure member.

4. A lock switch device as in claim 2 wherein said means for resiliently mounting said casing comprises a bolt extending through said casing and secured to said closure member and a spring operating between the head of said bolt and said casing.

5. A lock switch device as in claim 2 wherein said recess means in said casing includes an opening for permitting passage therethrough of a chain said opening being configured to lock said chain from longitudinal movement at any desired link.

6. A lock switch device as in claim 5 wherein said opening is a cross shaped opening formed through a generally vertical wall on said casing.

7. A lock switch device as in claim 6 wherein said wall is formed on one surface thereof with a recess contoured at one end to closely embrace one end of a chain link lying flatly therein said one end of said recess covering one of the arms of said cross-shaped opening, the other end of said recess opening out at the end of said wall.

8. An adjustable chain anchor for conventional link chains, said anchor having a wall with a cross-shaped passage extending therethrough and opening out onto opposite surfaces thereof for allowing passage of the orthogonally oriented adjacent links of a chain, said wall further being formed with a recess in one of said surfaces, said recess being shaped and dimensioned at one end thereof to closely accommodate a chain link lying flatwise therein, said recess being positioned with said one end lying over one of the arms of said cross-shaped passage, the opposite end of said recess opening out at the end of said wall.

9. An adjustable chain anchor as in claim 8 wherein said recess in said casing is formed to receive a locking chain extending from said housing.

10. An adjustable chain anchor as in claim 8 wherein said recess is formed to define retaining walls which secure a chain link, lying flatwise in said recess, from longitudinal movements toward the center of said cross-shaped openmg.

11. An adjustable chain anchor for conventional link chains, said anchor comprising a hollow housing having front and rear walls, said front wall being formed with a first opening therethrough for allowing free movement of a chain therethrough, said rear wall being formed with a cross-shaped opening in substantial horizontal alignment with said first opening, the arms of said cross-shaped opening being disposed vertically and horizontally, said rear wall being formed with at least one recess in the surface thereof facing away from said front wall, said recess being configured at one end to conform closely to the outer contour of a chain link lying flatly therein said one end of said recess overlying one of the vertical arms of said cross-shaped opening, the opposite end of said recess opening out at the end of said rear wall.

12. In combination, a conventional link chain, a first chain anchor, means on said chain for detachably securing one end thereof to said first chain anchor, said first chain anchor being adapted to be mounted on a closure member, a second chain anchor, said second chain anchor including means for securing same to a cooperating closure member, said second chain anchor having a wall disposed in generally vertical alignment when secured to said c0- operating closure member, said wall being formed with a cross-shaped opening whose orthogonal arms are vertically and horizontally disposed and through which said chain freely passes when horizontally extended and rotationally positioned, said wall being formed on the surface thereof facing away from said first chain anchor with at least one vertically extending recess, one end of which overlies the lowermost vertically extending arm of said cross-shaped opening, said one end being configured to closely embrace one end of one of the links of said chain lying flatly therein, the other end of said recess extending out from the end of said wall.

13. A combination as in claim 12 wherein said second chain anchor includes a second, generally vertically disposed wall having an opening therein permitting free movement therethrough of said chain, said opening being disposed in substantially horizontal alignment with said cross-shaped opening.

14. A combination as in claim 12 wherein said second chain anchor comprises a casing having said wall incorporated therein, an anchor plate adapted to be secured to said cooperating closure member means resiliently urging said casing against said anchor plate and switch means arranged to be operated in response to movements of said casing away from said anchor plate.

References Cited UNITED STATES PATENTS Linnard 292-264 Pidgeon 340274 Postal 292264 Unger 292264 Harry 200-61.64 Hawkins 3402.74 Martin r 109-32 MARVIN A. CHAMPION, Primary Examiner E. I. MCCARTHY, Assistant Examiner US. Cl. X.R.