US3912310A

US3912310A - Door lock

Info

Publication number: US3912310A
Application number: US453585A
Authority: US
Inventors: Thomas J Dugan
Original assignee: Individual
Current assignee: Individual
Priority date: 1974-03-22
Filing date: 1974-03-22
Publication date: 1975-10-14
Anticipated expiration: 1992-10-14

Abstract

A tamper-proof door lock having a beveled latch bolt which is extended by spring pressure for latching engagement with a keeper plate on the door jamb upon closing of the door and is retractable by rotation of the door handle to open the door. The lock embodies locking means, releasible by door handle rotation, for locking the latch bolt against retraction by insertion of a shim or blade between the door edge and keeper plate. The latch bolt of the described lock is locked in its extended latching position by extension of a locking member carried by the bolt to a locking position behind the keeper plate. Rotation of the door handle to open the door effects initial retraction of the locking member and then retraction of the latch bolt.

Description

' Unite States [4 1 Oct. 14, 1975 DOOR LOCK Thomas J. Dugan, 2501 S. El Camino Real No. 206, San

Clemente, Calif. 92672 22 Filed: Mar. 22, 1974 [21] Appl. No.: 453,585

[76] Inventor:

[56] References Cited UNITED STATES PATENTS 5/1902 Fogel 292/169.l4 12/1955 Gresham et al 292/192 X Primary Examiner-Richard E. Moore Attorney, Agent, or FirmBoniard I. Brown [5 7] ABSTRACT A tamper-proof door lock having a beveled latch bolt which is extended by spring pressure for latching engagement with a keeper plate on the door jamb upon closing of the door and is retractable by rotation of the door handle to open the door. The lock embodies locking means, releasible by door handle rotation, for locking the latch bolt against retraction by insertion of a shim or blade between the door edge and keeper plate. The latch bolt of the described lock is locked in its extended latching position by extension of a locking member carried by the bolt to a locking position behind the keeper plate. Rotation of the door handle to open the door effects initial retraction of the locking member and then retraction of the latch bolt.

11 Claims, 8 Drawing Figures US, Patent ot.14,1975 sheetzof 3,912,310

US. Patsnt Oct. 14, 1975 Sheet 3 of3 3,912,310

DOOR LOCK BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to door locks and more particularly to a burglarproof lock for swinging entry doors.

2. Discussion of the Prior Art Generally speaking this invention relates to door locking devices of the kind which comprise a door lock proper and a keeper plate and are used on entry doors that are hinged along one vertical edge for swinging between open and closed positions. When closed, the opposite or outer door edge is situated in closed confronting relation to a door jamb which mounts the keeper plate. This door jamb may be either a fixed upright member of the door frame or, in the case of double hinger doors, the vertical outer edge of a second hinged door that is normally secured in closed position by means of slide bolts on the door entering sockets in the upper and lower portions of the frame.

The door lock proper is installed in a recess in the door along its outer edge and includes a beveled latch bolt which is normally extended by spring pressure beyond the edge. When the door closes, the beveled outer end of the bolt engages the keeper plate on the door jamb in such a way that the plate retracts the bolt against its spring bias sufficiently to allow the bolt to ride over the plate. Upon arrival of the door at the fully closed position, the bolt enters an opening in the keeper plate to secure the door in closed position. Retraction of the latch bolt to open the door is accomplished by rotation of the door handle. In the case of entry doors of the type with which this invention is concerned, the outside door handle is equipped with a key lock which normally locks the handle against turning to open the door.

Existing door locking devices of this kind are deficient in that an intruder may quite easily gain entrance by simply inserting an implement, such as a shim or blade, between the door and jamb and against the beveled end of the latch bolt to force thr latter from the keeper plate against the spring pressure on the bolt, thereby permitting the door to be opened. This shortcoming of the locking devices, of course, has been recognized in the past and has been avoided by the use of dead bolt locks, night chains, and the like. These methods of preventing entry b an intruder are not totally satisfactory, however, since they require the use of two separate locking devices and, in the case of a night chain, can only be used from the inside.

SUMMARY OF THE INVENTION This invention provides an improved lock for door locking devices of the class described which prevents intrusive entry in the manner explained above. To this end, the door lock is equipped with means for locking the latch bolt in its extended position of latching engagement with the keeper plate in such a way that the bolt cannot be forced out of engagement with the plate until released from the inside of the door.

In the particular door lock described, the bolt locking means comprises a locking member carried by the outer end of the latch bolt. This locking member is mormally retracted flush with the bolt to prevent entrance of the bolt into the keeper plate opening. The

locking member is then extendable laterally of the bolt,

by an actuating member at the inside of the door, to a locking position behind the keeper plate wherein the member locks the bolt against retraction from the plate opening. The locking member is retracted to release the latch bolt for retraction by rotating the inner door handle through an initial angle; continued rotation of the handle retracts the bolt from the keeper plate to permit opening of the door.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a section through a door lock according to the invention;

FIG. 2 is a section taken on line 22 in FIG. 1;

FIG. 3 is a section taken on line 33 in FIG. 1;

FIG. 4 is a section taken on line 4-4 in FIG. 1;

FIG. 5 is a section taken on line 55 in FIG. 1;

FIG. 6 is a section taken on line 66 in FIG. 1;

FIG. 7 is a section similar to FIG. 1 showing the latch bolt locked in extended position; and

FIG. 8 is an exploded perspective view of the lock.

DESCRIPTION OF THE PREFERRED EMBODIMENT The drawings illustrate a lock 10 according to the invention installed in a recess 12 in the outer edge 13 of a hinged door 14 for cooperation with a keeper plate 16 (FIG. 7) on the door jamb 18 to lock the door in closed position. As noted earlier, this door jamb may be a fixed upright member of the door frame or, in the case of double doors, the outer edge of a second, normally locked door.

Generally speaking, the lock 10 includes a housing 20 containing a latch bolt 22 which is movable longitudinally of the housing between its extended position of FIGS. 1, 2 and 7 and a retracted position. In its extended position, the outer end of the latch bolt projects beyond the adjacent end of the housing 20 and the outer door edge 13 for engagement in a bolt receiving opening 24 in the keeper plate 16 to latch the door closed. Accordingly, the extended position of the latch bolt is its latching position. When retracted, the outer end of the latch bolt is substantially flush with the door edge and the door is free to open and close.

Latch bolt 22 is urged to its extended latching position by spring means 26 acting between the bolt and housing 20. The door has knobs or handles 28 (only one shown) which are operatively connected to the latch bolt to retract the latter against spring pressure upon rotation of either handle. One handle, generally the outside handle, embodies a key lock for locking the handle against turning to retract the latch bolt until released by the proper key. The other or inside handle is freely rotatable to open the door. This latter handle 28 is shown in phantom lines in FIGS. 1 and 6.

The outer end of the latch bolt 22 is beveled or rounded in the usual way, as shown at 30 in FIG. 2. In the event the door 14 is closed without retraction of the bolt by door handle rotation, the beveled surface 30 of the bolt engages an edge of the keeper plate 16 as the door approaches closed position. The plate produces on the bolt a camming force which retracts the bolt against spring pressure sufficiently to enable the bolt to ride over the plate. Upon the door reaching fully closed position, the bolt snaps into the keeper plate opening 24 to latch the door closed.

As noted earlier, with conventional door locks of this general type, it is a fairly easy task for an intruder to gain entrance by inserting a blade-like implement between the outer door edge and door jamb and urging the implement against the beveled end of the latch bolt to retract the latter from the keeper plate. According to a primary feature of this invention, the lock is provided with locking means 32 for locking the latch bolt 22 against retraction from the keeper plate 16 by such an implement and thereby preventing intrusive entry in the manner explained. This bolt locking means includes an actuator 34 for setting the locking means in its locking condition and means 36 for releasing the locking means. In the particular lock shown, the bolt locking means 32 comprises a locking member 38 carried by the outer end of the latch bolt 22 and extendable by the actuator 34 to a locking position (FIG. 7) behind the keeper plate 16. The lock releasing means 36 is operable by initial rotation of either door handle 28 to retract the locking memeber 38 to its position of FIG. 1, wherein the latch bolt is free to retract from the keeper plate 16. Continued rotation of the door handle retracts the bolt from the keeper plate to permit opening of the door 14.

The illustrated door lock 10 will now be described in greater detail. The lock housing comprises a sleeve 40 joined at its outer end to a flange 42 and face plate 44 with mounting screw holes 46 and closed at its inner end by a wall 48. Face plate 44 has a rectangular opening 50 aligned on the axis of the housing sleeve 40. Latch bolt 22 is movable through this face plate opening and has an inner flange 52 which is engageable with the inner side of the face plate to limit extension of the bolt through the opening to the bolt position of FIGS. 1 and 2.

Latch bolt 22 is supported for extension and retraction in the lock housing 20 by slide means 54 including a pair of bearing posts 56 on the bolt, a generally yokeshaped slide frame 58 and a slide plate 60. Bearing posts 56 are rigidly joined to the inner end of the latch bolt 22 and extend inwardly or rearwardly through the housing 20 parallel to its longitudinal axis. Slide frame 58 is movable longitudinally in the housing and includes a plate 62 at the outer end of the frame in a transverse plane of the housing. This plate is sized to slide in the housing and has bores 63 slidably receiving the latch bolt bearing posts 56. Posts 56 extend beyond the rear side of the plate and mount snap rings 56a which retain the plate against rearward movement from the posts. Integrally joined to and extending rearwardly from the plate 62 are a pair of legs 64 parallel to the longitudinal axis of the housing. These legs slide in slots 66 in the slide plate 60. Slide plate 60 is also sized to slide in the lock housing. As shown best in FIGS. 2 and 8, opposite sides of the inner or rear end of the housing 20 are inset to form forwardly or outwardly facing stop shoulders 68 against which the slide plate 60 normally seats to position the plate longitudinally in the housing.

As noted earlier, latch bolt 22 is urged to its extended latching position by spring means 26. These spring means include a first set of springs 70 and a second set of springs 72. Springs 70 surround the latch bolt bearing posts 56 and seat at their outer ends against the latch bolt and at their inner ends against the slide frame plate 62. Springs 72 are located between and seat against the latter plate and slide plate 60. The outer ends of these latter springs fit over the projecting inner ends of the posts 56. The inner ends of the springs engage over positioning dimples 74 formed on the slide plate 60.

From the description to this point, it is apparent that the

springs

70, 72 urge the latch bolt 22 outwardly to its extended position of FIG. 2, the slide frame 58 outwardly toward the latch bolt to the frame position shown in the latter figure, and the slide plate 60 inwardly into seating engagement with the lock housing shoulders 68. The latch bolt and slide frame are movable inwardly relative to the housing against the pressure of the springs, and the slide plate is movable outwardly relative to the housing, also against the spring pressure. The latch bolt 22 normally occupies its extended position. When the door 14 is closed, the beveled or rounded surface 30 of the bolt initially engages the leading edge of the keeper plate 16 and is cammed inwardly by the plate to retracted position to permit the bolt to ride over the keeper plate. When the door reaches fully closed position, the latch bolt is urged by spring pressure into the keeper plate opening 24 to lock the door closed.

As noted earlier, the latch bolt 22 is retracted against spring pressure to open the door 14 by rotation of the door handles 28. To this end, the inner handle (shown) is fixed, to a shaft 76 which extends through the rear or inner end of the lock housing 20, transverse to its longitudinal axis. The shaft is rotatably supported in the usual way to turn on its longitudinal axis. The outer door handle 28 is coupled to the shaft, also in the usual way, such that the latter handle may be locked against turning by its key lock without preventing rotation of the inner handle. When the outer handle is unlocked, it may be turned to rotate the shaft 76.

Fixed to the handle shaft 76 within the housing 20 is a collar 78 having a pair of integral radial projections or

lobes

80 and 82 with generally circularly rounded outer ends. The purpose of lobe 80 will be explained presently. Lobe 82 projects through a longitudinal slot 84 in the upper leg 64 (as viewed in FIG. 1) of the slide frame 58. The rear edge of this slot is turned upwardly to form a seating surface 86 for engagement by the lobe. Clockwise rotation of the shaft 76 from its position of FIG. 1 by rotation of either door handle urges the lobe 82 against the slide frame surface 86 to move the slide frame 58 and thereby the latch bolt 22 inwardly or rearwardly (i.e., to the right in FIG. 1) relative to the lock housing 20. Theus, clockwise rotation of the handles retracts the latch bolt to permit opening of the door 14. Release of the handles effects return of the parts to their positions of FIG. 1 by spring pressure.

From the earlier discussion, it will be recalled that a primary feature of the invention resides in locking means 32 for releasably locking the latch bolt 22 in its extended latching position to prevent intrusive entry. Locking means 32 comprises the locking member 38 carried by the outer end of the bolt for movement to and from a locking position behind the keeper plate 16. This locking member is a cylindrical pin which slides in a normally vertical transverse bore 88 in the latch bolt 22. Associated with this lock pin is a telescoping arm 90 including a pair of slidably interfitting

arm members

92, 94. The outer arm member 92 has a flat blade portion 96 rigidly joined at its front end to a collar 98. Collar 98 seats coaxially on the upper end of and is firmly attached by a screw 100 to the lock pin 38. The blade portion 98 of the arm member 92 extends laterally inward from the lock pin 38 and slidably through a slot 102 in the lock bolt 22 in the plane of the axis of the pin bore 88. Projecting laterally from the inner end of the blade portion 96 are ribs 104 located in a plane normal to the plane of and containing the longitudinal axis of the blade portion. Blade portion 96 extends inwardly through a vertical slot 106 in the front plate 62 of the slide frame 58.

The inner member 94 of the telescoping arm 90 has an outer flat blade-like portion 108 with a vertical longitudinal slot 110 which slidably receives the blade portion 96 of arm member 92 and laterally opening slots 112 which slidably receive the ribs 104 on the latter member. Thus, the

arm members

92, 94 are slidably keyed to one another for relative longitudinal extension and retraction. On the inner end of the inner arm member 94 is an enlarged integral block-like head 114 which fits within a vertical slot 1 16 in the slide plate 60. Entering opposite sides of the head 114 are grooves 118 which slidably receive the vertical edges of the plate slot 1 16. From this description, it is apparent that the telescoping arm 90 and the lock pin 38 are slidably supported by the slide plate 60 for movement as a unit in the axial direction of the pin. The lock bolt 22, lock pin 38, and outer member 92 of the telescoping arm 90 are movable as a unit relative to the inner arm member 94 in the longitudinal direction of the latter member and the lock housing 20.

Projecting from opposite sides of the telescoping arm inner head 114 are

extensions

120, 122. Extension 120 is engaged by a wire spring 124 which is secured to the inner side of the slide plate 60 and fits in a slot 126 in the extension. This spring urges the telescoping arm 90 upwardly in the slide plate slot 116 to the position of FIG. 1 wherein the lock pin is fully retracted into the latch bolt 22. The telescoping arm and lock pin are movable downwardly against the bias of the spring 124 to the position of FIG. 7, wherein the lock pin projects below the underside of the latch bolt.

The telescoping arm 96 and lock pin 38 are moved from the retracted position of FIG. 1 to the extended position of FIG. 7 by the lock actuator 34. This lock actuator comprises a lever 128 having a central transverse journal 130 which is rotatable in a bracket 132 fastened by screws to the inner side of a cover plate 134 for the inner door handle 28. This cover plate seats against the inner side of the door 14 and is fixed to the door in the usual way. Handle shaft 76 extends rotatably through the plate for connection to the inner door handle. Extending outwardly from the journal 130, through an opening 136 in the cover plate 134 is a lever arm 138. Extending inwardly through an opening 140 in the lock housing is a lever arm 142. The inner end of the latter arm has a rounded portion 144 for engaging the inner lateral extension 122 on the telescoping arm 90.

The actuator lever 128 is mounted by the bracket 132 to pivot on an axis parallel to the longitudinal axis of the lock housing 20. Upward rotation of the outer arm 138 of the lever rotates the inner lever arm 142 downwardly against the extension 122 of the telescoping arm 90, thereby moving the arm and the latch bolt lock pin 38 downwardly against the action of spring 124. Thus, the lock pin is movable to its extended position of FIG. 7 by rotating the outer arm 138 of the actuator lever 128 upwardly.

Fixed to the inner head 1 14 of the telescoping arm 90 and projecting below the head is a resilient catch 146 having a locking shoulder 148. During downward extension movement of the telescoping arm and the lock pin 38 to their extended position of FIG. 7 by the actuator lever 128, in the manner just explained, catch" 146 enters an opening 150 in the lower leg 64 of the slide frame 58, and the catch shoulder 148 snaps under the edge of the opening, as shown in FIG. 7, to latch the lock pin and telescoping arm in their lower extended position. The lower end of catch 146 is beveled, as shown, such that the catch is deflected into opening and then snaps into latching engagement under the edge of the opening.

As noted earlier, the handle shaft collar 78 has a lobe 80. When the telescoping arm 90 and lock pin 38 occupy their upper retracted positions of FIG. 1 and the handle shaft 76 occupies its position of the latch figure, lobe extends longitudinally of the lock housing 20 into an inwardly and upwardly opening recess 152 in the inner end head 114 of the telescoping arm and is located above the horizontal longitudinal plane P of the housing which contains the shaft axis. Recess 152 has laterally and longitudinally facing

walls

154, 156. Handle shaft 76 is urged counter-clockwise by a spring (not shown) which retains lobe 80 in seating contact with recess wall 154. The

springs

70, 72 retain the recess wall 156 in seating contact with the lobe 80. It should be noted here that in the position of the lock parts shown in FIG. 1, the slide plate 60 is spaced a slight distance outwardly of the lock housing 20 from the housing shoulders 68. Accordingly the

springs

70, 72 retain the recess wall 156 in contact with the lobe 80, as just stated. When the lock actuator lever 128 is rotated to depress the telescoping arm 90 and extend the lock pin 38 below the latch 22, the handle shaft spring urges the handle shaft 76 counterclockwise to the position of FIG. 7 to retain the lobe 80 in contact with the recess wall 154 and the

springs

70, 72 urge the slide plate 60 inwardly to the housing shoulders 68 to retain the recess wall 156 in contact with the lobe.

Referring to FIG. 7, it will be seen that in the illustrated position of the lobe 80, the latter is located below the plane P of the handle shaft axis. Accordingly, during clockwise rotation of the handle shaft 76 from the position of FIG. 7, the initial rotational motion of the lobe 80 has a vertical upward component toward the plane P and an outward horizontal component toward the recess wall 156. This horizontal component presses the lobe against the latter recess wall to move the rear member 94 of the telescoping arm 90 and the slide plate 60 outwardly toward the outer end of the lock housing 20. Such outward movement of the arm member and plate occurs relative to the slide frame 58 and releases the shoulder 148 of the telescoping arm latch 146 from the lower slide frame leg 64. The spring 124 then moves the telescoping arm 90 and lock pin 38 upwardly to their retracted positions of FIG. 1 and rotates the handle shaft 76 to its position of the latter figure, against the bias of the handle spring.

The operation of the lock 10 will now be explained, assuming the lock parts are initially in their positions of FIG. 1 and the door 14 is open. When the door is closed, the latch bolt 22 rides over the keeper plate 16 and then snaps into the keeper plate opening 24 to latch the door closed. The latch bolt is retracted to open the door by rotating either door handle 28 clockwise in FIG. 1 to retract the slide frame 58 to the right against the pressure of springs 72 by pressure of the on the latch bolt bearing posts 56.

The latch bolt 22 is locked in its extended position of engagement with the keeper plate 16 by rotating the lock actuator lever 128 in a direction to depress the telescoping arm 90 to its lower position of FIG. 7. This action extends the lock pin 38 behind the keeper plate to lock the latch bolt against retraction, as shown in FIG. 7. It will be understood that a clearance space for the lock pin is provided behind the keeper plate. The lock pin is latched in its extended position by latching engagement of the telescoping arm catch 146 in the lower leg opening 150 of the slide frame 58.

Release of the latch bolt 22 for retraction to open the door 14 is accomplished by clockwise rotation of the door handles from the position of FIG. 1. This handle rotation initially releases the catch 146 from the slide frame 58 in the manner explained earlier and then retracts the slide frame and latch bolt.

What is claimed as new in support of Letters Patent is' a housing,

a latch bolt having a beveled outer end and movable longitudinally in said housing between an extended position wherein said outer bolt end projects beyond one end of said housing for latching engagement with a keeper plate on the door jamb to latch the door closed and a retracted position wherein said outer bolt end is disposed to clear the keeper plate and release the door for opening,

spring means urging said bolt to extended position,

a rotatable handle shaft extending transversely of said housing,

means connecting said shaft and bolt for retraction of the bolt by shaft rotation, and

means for selectively releasably locking said bolt in extended position against retraction by a force applied to the outer bolt end comprising a locking member on the outer end of said bolt movable between a retracted position wherein said bolt is freely movable into and from latching engagement with the keeper plate and an extended position wherein the member projects from the bolt for locking engagement behind the keeper plate, and actuating means for effecting selective extension and retraction of said locking member independently of extension and retraction of said bolt in a manner which permits extension and retraction of said bolt while said locking member remains in retracted position and extension and retraction of said locking member while said bolt is in extended position.

2. A door lock according to claim 1, wherein:

said locking member comprises a lock pin slidable in the bolt to and from an extended position wherein one end of the pin projects beyond one side of the bolt for locking engagement behind the keeper plate.

3. A door lock according to claim 1 wherein:

said actuating means comprises means operable by 65 l. A lock for a hinged door comprising: 25

said actuating means comprises an actuator at one side of said door for moving said locking member to locking position independently of handle shaft rotation, and means operable by handle shaft rotation for effecting retraction of said lockin m from locking position.

5. A door lock according to claim 3 wherein:

said locking means includes a catch for releasably latching said locking member in said locking position, and

said retracting means operable by handle shaft rotation comprises means for releasing said catch upon shaft rotation, and a spring for retracting said locking member upon release of said catch.

6. A lock for a hinged door comprising:

a housing,

spring means urging said bolt to extended position,

a rotatable handle shaft extending transversely of said housing,

means for releasably locking said bolt in extended position against retraction by a force applied to the outer bolt end comprising a locking pin slidable in the outer end of said bolt for movement laterally of the bolt between an extended position wherein one end of the pin projects beyond one side of the bolt for locking engagement behind the keeper plate and a retracted position flush with the bolt, a telescoping arm extending longitudinally through the housing and a slot in said bolt and including an outer member fixed to said bolt and an inner member slidably engaging the outer member, whereby said latch bolt and outer arm member are movable in unison relative to said inner arm member in the direction of extension and retraction of the bolt, and said arm and pin are movable in unison in the direction of extension and retraction of the pin relative to the bolt, means supporting said inner arm member in said housing for movement in the latter direction, and means operable on said inner arm member for moving said inner member in the latter direction to position said pin in extended and retracted positions.

7. A door lock according to claim 6 wherein:

said means operable on said arm comprises a spring for urging said arm in a direction to retract said pin, an actuator for moving said arm in a direction to extend said pin against the pressure of the latter spring, a catch for latching said arm in a position wherein said pin is extended, and means for releasing said catch.

8. A door lock according to claim 7 wherein:

said catch releasing means is operable by handle shaft rotation.

9. A door lock according to claim 8 wherein:

said means connecting said handle shaft and bolt comprises a slide frame in and movable longitudinally of said housing, means connecting said latch bolt and frame for retraction of said bolt relative to said frame by an inward force on the outer end of said bolt and retraction of said bolt with said frame by an inward force on said frame, and means on said handle shaft engageable with said frame for retracting said frame and bolt by shaft rotation.

said catch is engageable with said frame to latch said lock pin in extended position, and

said catch releasing means comprises means for effecting relative longitudinal movement of said arm and frame by handle rotation to release said catch from said frame.

10. In combination:

a door hinged within a door opening for swinging to and from a closed position wherein the outer door edge is disposed in close confronting relation to a door jamb,

a keeper plate mounted on said jamb,

a door lock mounted on said door along said door edge including a latch bolt having a beveled outer end and movable longitudinally between an extended position wherein said outer bolt end projects beyond said door edge for latching engagement with said keeper plate when said door is closed and a retracted position wherein said outer bolt end clears said keeper plate to permit opening the door, spring means for urging said bolt to extended position, means including rotatable door handles for retracting said bolt against spring pressure by handle rotation, and means for selectively releasably locking said bolt in extended position comprising a locking member on the outer end of said bolt movable between a retracted position wherein said bolt is freely movable into and from latching engagement with the keeper plate and an extended position wherein the member projects from the bolt for locking engagement behind the keeper plate, and actuating means for effecting selective extension and retraction of said locking member independently of extension and retraction of said bolt in a manner which permits extension and retraction of said bolt while said locking member remains in retracted position and extension while said bolt is in extended position.

11. The combination according to claim 10 wherein:

said actuating means comprises an actuator at one side of said door for moving said locking member to locking position independently of door handle rotation, and means operable by door handle rotation for effecting retraction of said locking member from locking position.

Claims

1. A lock for a hinged door comprising: a housing, a latch bolt having a beveled outer end and movable longitudinally in said housing between an extended position wherein said outer bolt end projects beyond one end of said housing for latching engagement with a keeper plate on the door jamb to latch the door closed and a retracted position wherein said outer bolt end is disposed to clear the keeper plate and release the door for opening, spring means urging said bolt to extended position, a rotatable handle shaft extending transversely of said housing, means connecting said shaft and bolt for retraction oF the bolt by shaft rotation, and means for selectively releasably locking said bolt in extended position against retraction by a force applied to the outer bolt end comprising a locking member on the outer end of said bolt movable between a retracted position wherein said bolt is freely movable into and from latching engagement with the keeper plate and an extended position wherein the member projects from the bolt for locking engagement behind the keeper plate, and actuating means for effecting selective extension and retraction of said locking member independently of extension and retraction of said bolt in a manner which permits extension and retraction of said bolt while said locking member remains in retracted position and extension and retraction of said locking member while said bolt is in extended position.

2. A door lock according to claim 1, wherein: said locking member comprises a lock pin slidable in the bolt to and from an extended position wherein one end of the pin projects beyond one side of the bolt for locking engagement behind the keeper plate.

3. A door lock according to claim 1 wherein: said actuating means comprises means operable by rotation of said handle shaft for retracting said member from locking position.

4. A door lock according to claim 1 wherein: said actuating means comprises an actuator at one side of said door for moving said locking member to locking position independently of handle shaft rotation, and means operable by handle shaft rotation for effecting retraction of said locking member from locking position.

5. A door lock according to claim 3 wherein: said locking means includes a catch for releasably latching said locking member in said locking position, and said retracting means operable by handle shaft rotation comprises means for releasing said catch upon shaft rotation, and a spring for retracting said locking member upon release of said catch.

6. A lock for a hinged door comprising: a housing, a latch bolt having a beveled outer end and movable longitudinally in said housing between an extended position wherein said outer bolt end projects beyond one end of said housing for latching engagement with a keeper plate on the door jamb to latch the door closed and a retracted position wherein said outer bolt end is disposed to clear the keeper plate and release the door for opening, spring means urging said bolt to extended position, a rotatable handle shaft extending transversely of said housing, means connecting said shaft and bolt for retraction of the bolt by shaft rotation, and means for releasably locking said bolt in extended position against retraction by a force applied to the outer bolt end comprising a locking pin slidable in the outer end of said bolt for movement laterally of the bolt between an extended position wherein one end of the pin projects beyond one side of the bolt for locking engagement behind the keeper plate and a retracted position flush with the bolt, a telescoping arm extending longitudinally through the housing and a slot in said bolt and including an outer member fixed to said bolt and an inner member slidably engaging the outer member, whereby said latch bolt and outer arm member are movable in unison relative to said inner arm member in the direction of extension and retraction of the bolt, and said arm and pin are movable in unison in the direction of extension and retraction of the pin relative to the bolt, means supporting said inner arm member in said housing for movement in the latter direction, and means operable on said inner arm member for moving said inner member in the latter direction to position said pin in extended and retracted positions.

7. A door lock according to claim 6 wherein: said means operable on said arm comprises a spring for urging said arm in a direction to retract said pin, an actuator for moving said arm in a direction to extend said pin against the pressure of the latter Spring, a catch for latching said arm in a position wherein said pin is extended, and means for releasing said catch.

8. A door lock according to claim 7 wherein: said catch releasing means is operable by handle shaft rotation.

9. A door lock according to claim 8 wherein: said means connecting said handle shaft and bolt comprises a slide frame in and movable longitudinally of said housing, means connecting said latch bolt and frame for retraction of said bolt relative to said frame by an inward force on the outer end of said bolt and retraction of said bolt with said frame by an inward force on said frame, and means on said handle shaft engageable with said frame for retracting said frame and bolt by shaft rotation. said catch is engageable with said frame to latch said lock pin in extended position, and said catch releasing means comprises means for effecting relative longitudinal movement of said arm and frame by handle rotation to release said catch from said frame.

10. In combination: a door hinged within a door opening for swinging to and from a closed position wherein the outer door edge is disposed in close confronting relation to a door jamb, a keeper plate mounted on said jamb, a door lock mounted on said door along said door edge including a latch bolt having a beveled outer end and movable longitudinally between an extended position wherein said outer bolt end projects beyond said door edge for latching engagement with said keeper plate when said door is closed and a retracted position wherein said outer bolt end clears said keeper plate to permit opening the door, spring means for urging said bolt to extended position, means including rotatable door handles for retracting said bolt against spring pressure by handle rotation, and means for selectively releasably locking said bolt in extended position comprising a locking member on the outer end of said bolt movable between a retracted position wherein said bolt is freely movable into and from latching engagement with the keeper plate and an extended position wherein the member projects from the bolt for locking engagement behind the keeper plate, and actuating means for effecting selective extension and retraction of said locking member independently of extension and retraction of said bolt in a manner which permits extension and retraction of said bolt while said locking member remains in retracted position and extension while said bolt is in extended position.

11. The combination according to claim 10 wherein: said actuating means comprises an actuator at one side of said door for moving said locking member to locking position independently of door handle rotation, and means operable by door handle rotation for effecting retraction of said locking member from locking position.