WO2006119486A2

WO2006119486A2 - Locking mechanism and method

Info

Publication number: WO2006119486A2
Application number: PCT/US2006/017347
Authority: WO
Inventors: Alan Uyeda
Original assignee: Adams Rite Manufacturing Co.
Priority date: 2005-05-03
Filing date: 2006-05-03
Publication date: 2006-11-09
Also published as: WO2006119486A3

Abstract

A lock mechanism includes a casing having a spring latch assembly, a dead latch assembly, an auxiliary bolt, a hold back member to engage the spring latch assembly, an adjustable casing, and a wedge shaped adjustment element between a front plate and a cover plate.

Description

LOCKING MECHANISM AND METHOD

The present application broadly discloses aspects regarding locking mechanisms that operate to selectably lock a door or similar structure in a secured state. More particularly, the embodiments shown in this specification are depicted as locking mechanisms especially useful as mortise locks that are adapted to mount in a frame portion or nose stile of a door in order to lockably secure the door relative to a doorframe. A variety of improved features are employed in these embodiments which features may be used separately or in differing combinations in mortise locks or other locking devices.

BACKGROUND OF THE INVENTION

The ability to lockably secure two structures together to permit or prevent relative movement therebetween has been a goal of many locking systems. A plethora of different locking mechanisms have been developed over the course of history in order to achieve this goal. These include key actuated locks, combination locks, code activated locks, to name a few.

Among the many types of locks available today is the mortise lock which is widely used in commercial applications. A mortise lock typically mounts in the lock stile or of a door which typically may be a nose stile or doorjamb portion of the door. The mortise lock then includes a latch that engages a latch opening in the doorframe that surrounds the door. The latch may move from an extended position wherein it is received in the latch opening to secure to the door to a retracted position to allow the door to open by pivoting along a door edge that is opposite the lock stile.

Mortise locks are known to have one or more types of latches. One such latch is a spring latch wherein a spring latch bolt is resiliently biased into an extended position. Operation of the lock mechanism withdraws the spring latch from the extended position against the restorative force of a spring latch spring. In some instances, a locking mechanism is provided to prevent operation of a spring latch without a key. Mortise locks may also include an auxiliary bolt that may either pivot or slide into place under a key or manual actuator. Where a mortise lock is provided with a spring latch, it is also known to increase the security by providing a dead latch assembly that may move between an enable and disable state. When in an enable state, the spring latch bolt may move from the extended position to the retracted position. However, when the spring latch bolt is in the extended position and the dead latch assembly is in a disable state, the spring latch bolt is prevented from moving from the extended position to the retracted position unless the locking mechanism is actuated. This structure helps prevent the insertion of a thin strip between the door frame and the door jamb to manually force the spring latch bolt from the extended position to the retracted position thereby compromising the locking structure. It is also known to provide mortise locks with a hold back assembly which enables a user to retain both the spring latch assembly in the retracted state thereby allowing a door to swing freely between the open and closed position without interaction of the latch mechanism.

Although mortise locks have been well developed and function for example, in commercial establishments, one problem exists in that doors have a different "handedness". Since the ramp face of the spring bolt engage the strike plate, it is necessary that the spring bolt be installed correspondingly to the handedness of the door. Therefore, either two oppositely handed lock mechanisms must be provided or the orientation of the bolt be reversible. Reversing the direction that the bolt faces, however, has not been easy accomplished in the past.

In addition, different types of doors have different backsets for the lock cylinder. Therefore, manufacturers have found it necessary to produce locking mechanisms of several different backsets for different doors. While some mortise locks do have the ability for minor adjustments, mortise locks have heretofore not been adapted to a wide variety of different door types and styles. A more universally adapted locking mechanism would therefore be advantageous.

Despite the development of locks in general and mortise locks, specifically, there remains a need for improved locking structures which can be readily installed in doors of different sizes. There is a further need for locking structures that have simplified mechanisms that are easy to install and use. There is a further need for mortise locks of great versatility in application. The present invention is directed to meeting these needs.

SUMMARY OF THE EXEMPLARY EMBODIMENTS

According to the exemplary embodiments, a lock mechanism is provided that has several advantageous features which may be taken alone or in any combination. According to one aspect of the invention, the lock mechanism includes a casing having a front portion and an interior. A spring latch assembly is disposed in the interior of the casing. Here, the spring latch assembly includes a spring latch bolt operative to move between an extended position wherein the spring latch bolt protrudes through the front portion of the casing in a retracted position. The spring latch assembly also includes a spring latch spring that is operative to bias the spring latch bolt toward the extended position with a restoring force. A dead latch assembly is also disposed in the interior of the casing. The dead latch assembly is operative to move between an enabled state permitting movement of the spring latch bolt between the extended and retracted positions and a disabled state prohibiting movement of the spring latch bolt from the extended position to the retracted position. The dead latch assembly includes an auxiliary bolt having a rod-shaped free end portion protruding through the front portion of the casing when the dead latch assembly is in the enabled state. The dead latch assembly also includes a dead latch spring operative to bias the dead latch assembly toward the enabled position. Here, if desired, the auxiliary bolt may terminate in a rounded nose that extends from a cylindrically shaped shank.

The spring latch assembly may include a latch control toggle associated therewith with the latch control toggle moveable between first and second positions. When the spring latch bolt is in the extended position and the latch control toggle is in the first position, the latch control toggle prohibits the spring latch bolt from moving from the extended position to the retracted position. On the other hand, when the latch control toggle is in the second position, the latch control toggle permits the spring latch bolt to move from the extended position to the retracted position. Here, a latch control toggle may be biased toward the first position. Moreover, the dead latch assembly is operative, in an enable state, to move the latch control toggle into the second position and is operative in the disabled state to allow the latch control toggle to move to the first position.

The casing can include at least one detent slot having a detent notch therein. The latch control toggle may then include a detent bar slideably received in the detent slot and operative to engage the detent notch when the spring latch bolt is in the extended position and the latch control toggle is in the first position. The detent bar still disengages from the detent notch when the spring latch bolt is in the extended position and the latch control toggle is in the second position.

Another optional aspect of the lock mechanism is the provision of a hold back member supported by the casing and moveable, for example linearly, between an engaged position and a disengaged position. The hold back member is operative in the engaged position to engage the spring latch assembly in the retracted position thereby to retain the spring latch bolt in the retracted position against the restoring force of the spring latch spring. When in the disengage position, the hold back member is operative to permit the spring latch bolt to move from the retracted position to the forward position. An optional disabling element may be supported by the casing with the disabling element moveable between a first state whereby movement of the hold back member between the engaged position and the disengage position is permitted and a second state whereby the disabling element prohibits the hold back member from moving from the disengaged position to the engaged position. Here, the disabling element may be operative to mechanically interfere with movement of the holdback member when in the second state.

According to another aspect of the invention, the spring latch assembly can include a spring bolt carrier slideably disposed in the casing and a separate spring latch bolt that is removeably supported by the spring bolt carrier. Thus, the spring latch bolt may be mounted to and demounted from the spring bolt carrier. The casing may be configured such that the spring latch bolt may be mounted to and demounted from the spring bolt carrier while the spring bolt carrier is disposed in the casing. Here, also, the spring bolt carrier and the spring latch bolt may be configured such that the spring latch bolt may be reversibly mounted to the spring bolt carrier thereby to reverse the operation of the spring latch bolt to accommodate different handedness of a door to which the lock mechanism is to be used. If desired, the dead latch assembly may also include an auxiliary bolt carrier that is sizably disposed in the casing and a separate auxiliary bolt that is removeably supported by the auxiliary bolt carrier. Thus, the auxiliary bolt may be mounted to and demounted from the auxiliary bolt carrier.

With the lock mechanism includes a lock cylinder disposed in the casing and a cover plate adapted to be mounted to the casing to define the front therefore. The lock cylinder has a center line located at a selected setback distance from the cover plate. Here, different spring latch bolts respectively having differing lengths may be provided whereby a selected one of the spring latch bolts may be mounted to the spring bolt carrier thereby to accommodate different setback distances. Also, different auxiliary bolts respectively having different lengths may be removeably mounted to the auxiliary bolt carrier again to accommodate different setback differences. The lock casing may include a pair of substantially flat side plates and a front plate extending therebetween such that the side plates each has a rear edge portion that defines the rear portion of the casing. The hold back member may be slideably mounted between the slide plates proximate to the rear edge portion thereof. Here, the slide plates each include at least one hold back guide slot that are opposed to one another. The hold back member includes at least a pair of pins received in the hold back slots.

The hold back member may have a cam surface formed thereon. Here, the actuator assembly includes a cam member oriented to engage the cam surface thereby to advance the hold back member from the disengaged position to the engaged position. The actuator assembly may include a cylinder and a key actuated core rotatably disposed therein. The cam member is then disposed on the core for rotation therewith between a retain position and a release position through an intermediate position. The cam member is operative to move the hold back member into the engaged position where the cam member advances into the retain position. The cam member is operative to move the hold back member into the disengaged position when the cam member advances to the release position. The cam member is further adapted to move the spring latch bolt from the extended position to the retracted position when the cam member advances from the intermediate position to the release position.

According to another aspect of the exemplary embodiment is the inclusion of an upper positional adjustor located at the top of the casing and a lower positional adjustor located at the bottom of the casing. Each of these upper and lower positional adjustors may include a threaded plug threadably received therein. Thus, a rear portion of each of the threaded plugs may protrude rearwardly of the rear edges of the side plates or the rear portion of the casing for an effective length that is selectively adjustable.

According to another aspect of the casing according to the exemplary embodiment is the inclusion of a generally planar front plate disposed proximately to the front portion of the casing and a generally planar cover plate secured in spaced relation relative to the front plate. Here, at least one bevel adjustment element may be interposed between the front plate and the cover plate. The bevel adjustor is moveable so as to selectively position the cover plate either generally parallel to the front plate or at a small acute angle on either side of a generally parallel orientation. The bevel adjustment element, for example, can be a wedge shaped element that is rotatably secured to the front plate.

The present invention also contemplates a method of managing spring latch assemblies and dead latch assemblies in the casing of a lock mechanism. Here, the method may include any of the processing steps recently or inherent in the mechanical structures disclosed herein.

These and other aspects of the exemplary embodiments of the present invention will become more readily appreciated and understood from a consideration of the following detailed description when taken together with the accompanying drawings, in which: BRIEF DESCRIPTION OF THE DRAWINGS

Figures 1(a) and 1(b) show the locking mechanism of one embodiment of the present invention mounted in the locking (nose) stiles of representative doors that have different depths;

Figure 2(a), 2(b) and 2(c) show the locking mechanism of a first embodiment depicted as a mortise lock wherein the spring latch bolt in an extended position (Figures 2(a) and 2(b)) and in a retracted position (Figure 2(c)) and with the auxiliary latch bolt in the enable state (Figure 1(a)) and in a disable state (Figure 2(b));

Figure 3 is an exploded perspective view showing the lock mechanism according to the first exemplary embodiment of the present invention depicted as a mortise lock;

Figure 4 is a perspective view of the lock casing used with the lock mechanism of Figure 3;

Figure 5 is a side view in elevation of a side plate which forms part of the lock casing of Figure 4;

Figure 6 is a front plan view of the front mounting plate of the lock casing of Figure 4;

Figure 7 is a perspective view of a spacer plate used with the lock casing of Figure 4;

Figure 8 is an exploded perspective view showing the bevel adjuster according to the first embodiment;

Figure 9 is a front perspective view of the spring bolt carrier used with the lock mechanism of Figure 3;

Figure 10 is a rear perspective view of the spring bolt carrier of Figure 9;

Figure 11 is a rear perspective view of a spring latch bolt used with the lock mechanism of Figure 3;

Figure 12 is a perspective view of the latch control toggle of the lock mechanism of Figure 3; Figure 13 is a side view in elevation, partially broken away in cross- section, showing the spring latch assembly with the latch control toggle mounted thereon;

Figure 14 is an exploded perspective view of the dead latch assembly used with the lock mechanism of Figure 3;

Figure 15 is a rear view in elevation of the auxiliary bolt carrier of the dead latch assembly of Figure 14;

Figure 16 is a front perspective view of the hold back member of the lock mechanism of Figure 3;

Figure 17 is a rear perspective view of the hold back member of Figure 16;

Figure 18(a) and 18(b) are rear views in elevation showing the hold back member of Figures 16 and 17 slidably mounted in the lock casing and, respectively, shown in a disengaged position and in an engaged position;

Figure 19 is a side view in cross-section showing the optional disablement of the hold back member;

Figure 20(a) and Figure 20(b) shown the interaction of the dead latch assembly with the spring latch assembly according to the present invention;

Figure 21 is a side view in partial cross-section showing the actuator interacting with the spring latch assembly and dead latch assembly;

Figure 22 is a perspective view of a positional adjuster used with the casing and lock mechanism in the first exemplary embodiment;

Figure 23 is an exploded perspective view illustrating the mounting of the positional adjuster of Figure 22 onto the upper portion of the casing;

Figure 24 is a perspective view of a case assembly according to another exemplary embodiment of the present invention;

Figure 25 is a perspective view of a spacer plate used with the casing of Figure 24;

Figure 26 is a rear perspective view of a spring latch bolt used with the casing of Figure 24;

Figure 27 is a perspective view of the dead latch assembly used with the casing of Figure 24; Figure 28 is a perspective view of the casing according to another exemplary embodiment of the present invention;

Figure 29 is a perspective view of a spacer plate used with the casing of Figure 28;

Figure 30 is a rear perspective view of a spring latch bolt used with the casing of Figure 28; and

Figure 31 is a perspective view of the dead latch assembly used with the casing of Figure 28.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

A lock mechanism is provided herein, with the embodiments disclosed to be particularly adapted for use as mortise locks. However, it should be understood that the scope of the present invention is in no way limited to any particular application of this locking mechanism. Moreover, the embodiments disclosed herein provide a number of different features which, alone or in combination, provide improvements over the prior art. Therefore, it should be understood at the outset that these embodiments are for illustrative purposes only so that the claims set forth below are to be construed in the broadest possible light and not limited to any particular combination of features disclosed in the exemplary embodiments.

With that in mind, a first exemplary embodiment of this locking mechanism 10 is depicted as a mortise lock is introduced in Figures 1 (a) and 1(b). Here, locking mechanism 10 is shown positioned in nose stiles 11 and 11' of two different doors where nose stiles 11 and 11' have different depths. The difference in depths is accommodated by a tube-like positional adjuster 146, discussed below. To this end, the tube adjuster may be advanced against the inner plate 12, 12' of nose stiles 11 ,11' so that the front of lock mechanism 10 is generally coextensive with outer plate 13,13' of the respective nose stile 11,11'. This, then, accommodates differing depths of the nose stile as measured between plates 12 and 13 of nose stile 11 or between plates 12' and 13' of nose stile 11'. In any event, locking mechanism 10 in Figures 1(a) and 1(b) includes a cylinder lock 14 positioned for interaction therewith. Cylinder lock 14 includes a lock cylinder 15 having a lock core 16 with a keyway 17, as is well known in the art. When a key is inserted into keyway 17, lock core 16 may be rotated relative to lock cylinder 15. However, when the key is not in the keyway, the lock core is locked against such rotation. As is shown in Figures 2(a)-2(c), an actuator 18 is affixed to lock core 16 for common rotation therewith when a key inserted into keyway 17 is used to rotate lock core 16.

It is helpful to understand that locking mechanisms, such as those used with mortise locks, often operate in several different positions or states. For example, as is shown in Figure 2(a), lock mechanism 10 is illustrated with a spring latch bolt 54 shown in an extended position and with an auxiliary bolt 94 advanced outwardly in an enable state. Figure 2(b) illustrates this same lock mechanism 10 wherein the same spring latch bolt 54 is in the extended position while auxiliary bolt 94 is withdrawn in a disable state. As is also known in the art, when the auxiliary bolt 94 is withdrawn into the disable position with spring latch bolt 54 being in the extended position, the spring latch bolt 54 is secured against movement from the extended position to a retracted position. This feature resists tampering with the lock mechanism by a thin strip of material, such as a credit card, screwdriver or the like. Finally, Figure 1 (c) illustrates lock mechanism 10 wherein the spring latch bolt 54 is retracted and the auxiliary latch bolt 94 is withdrawn. As is also well known, it is often desirable that a user may selectively retain the spring latch bolt 54 and the auxiliary bolt 94 in the relative positions as shown in Figure 1 (c) so that the locking mechanism is disengaged allowing the door associated therewith to be opened and closed without interaction of the locking mechanism

With reference now to Figures 2(a)-2(c) and 3, various structures used with the exemplary lock mechanism 10 and the assembly of lock mechanism 10 may be more fully understood. As is illustrated in these figures, locking mechanism 10 includes a casing 20 having front, rear, top, bottom and side portions so that casing 20 has an interior 21 to receive the various operative components of the locking mechanism. These include a spring latch assembly 50, a dead latch assembly 90, a latch control toggle 80, a hold back element 120, and return springs 112 and 113.

Casing 20 according to the first exemplary embodiment is shown best in Figure 4. Here, it may be seen that casing 20 includes a pair of side plates 22 which, in this exemplary embodiment, are identical with one another. Side plates 22 are positioned in opposed relation to one another and are held apart in substantially parallel relation by a plurality of spacer plates 23. A front mounting plate 24 extends along the front of casing 20 between side plates 22.

A representative side plate 22 is illustrated in Figure 5. Here, it may be seen that side plate 22 has a large threaded opening 25 adapted to threadably receive the cylinder lock 16. Side plate 22 also has slideways defined by spring latch slot 26, a dead latch slot 27 and a detent slot 28 that are in generally spaced parallel to one another. An array of mounting holes 29 is provided to mount spacer plates 23. A pair of "guide" or retainer slots 30 and a detent hole 31 are provided for hold back member 120, and an access opening 32 is provided, all as discussed below. A pair of posts 33 are provided to mount a return spring retainer 114, also as discussed below.

Front plate 24 is best illustrated in Figure 6. Front plate 24 has a rectangular spring bolt opening 34 and a circular auxiliary bolt opening 35 formed therein. An array of mounting holes 36 is provided to mount spacer plates 23. In addition, as is shown in the figure and in Figure 8, front plate 24 has a pair of bevel adjustment elements 76 rotatably secured on its front surface by means of a rivet 77 extending through hole 45 and mated with hole 47. With reference to Figure 8, it may be seen that each bevel adjustment element 76 is formed as a truncated wedge. Rotation of the adjustment elements 76 about rivet 77 allows a cover plate 46 (Figures 19a) and 1(b)) to be oriented generally parallel to the front face of front plate 24 or at a small acute angle or "bevel" on either side of the parallel orientation.

A representative spacer plate 23 is illustrated in Figure 7. Here, it may be seen that each spacer plate 23 has a plurality of side prongs 37 and a plurality of front prongs 38 projecting outwardly therefrom. Spacer plate 23 also has a threaded opening 39 located on a central portion 40 thereof.

With reference again to Figure 4, the connection of side plates 22 and front plate 24 together by spacer plates 23 to form casing 20 may now be appreciated with better understanding. It should be appreciated that there are three spacer plates 23 used in this embodiment, one at the top of casing 20, one at the bottom of casing 20 and one intermediate thereof. More particularly, side prongs 37 of each spacer plate 23 extend through respective ones of mounting holes 29 and are crimped to secure side plates 22 in generally parallel spaced relation. Front prongs 38 of each spacer plate 23 extend through respective ones of mounting holes 36 and are crimped to secure front plate 24 to side plates 22. Thus, casing 20 has an interior 21 adapted to receive the various components of the lock mechanism.

As noted above, spring latch assembly 50 is one such component mounted in casing 20, and, as is illustrated in Figure 3, includes the spring bolt carrier 52 and the spring latch bolt 54. Spring bolt carrier 52 is illustrated in greater detail in Figures 9 and 10 with spring latch bolt 54 being illustrated in greater detail in Figure 11. With reference to these figures, it may be seen that spring bolt carrier 52 includes a central body portion 55 and a forwardly extending rib 56 that terminates in a nose ridge 57. Upper and lower plate portions 58 and 59 define a cavity 60 on each side of rib 56, and a pair of spaced apart trunnion mounts 61 are in opposed relationship to one another at an upper portion of central body 55. Spring bolt carrier 52 also includes a first bay 62 sized and adapted to receive a leg and foot portion of latch control toggle 80 and a second bay 63 sized to receive an actuator portion of auxiliary bolt carrier 92, as described below. In addition, central body 55 of spring bolt carrier 52 includes a cylindrical cavity 64 formed to receive a portion of spring latch return spring 112, also as described below. A hole 65 extends through rib 56, and seats 66 are formed on each side of central body portion 55 opposite to one another. An upper bore 67 is provided to receive a small spring 68 and a hollow pin 69 that mateably receives a portion of spring 68. With reference to Figure 11 , it may be seen that spring latch bolt 54 includes a nose portion 70 and a pair of spaced apart flanges 71 extending rearwardly thereof. A stepped channel 72 extends vertically of spring latch bolt 54 with channel 72 sized and adapted to receive rib 56 and nose ridge 57 of spring bolt carrier 52. Thus, it should be understood that spring latch bolt 54 is adapted to mate with spring bolt carrier 52 with flanges 71 nested in cavities 60 between upper and lower plate portions 58 and 59. Spring latch bolt 54 is removeably secured to spring bolt carrier 52 by means of a suitable screw 73 (Figures 3 and 13) extending through hole 74, through hole 65 in rib 56 and into threaded opening 75. Hardened pins 49 are provided, as is known in the art, to rotate in spring bolt 54 to resist an attempt to saw through the spring bolt.

Spring bolt carrier 52 pivotally mounts the latch control toggle 80 by means of a latch pivot pin 82, as shown in Figure 3. However, the structure of latch control toggle 80 is best illustrated in Figure 12 where it may be seen that latch control toggle 80 includes a cylindrical pivot portion 83 provided with a bore 84 to receive the shank of latch pivot pin 82. A leg 85 extends downwardly from cylindrical portion 83 to terminate in a foot 86. A head 87 extends upwardly from cylindrical portion 83 opposite leg 85. A detent bar 88 projects rearwardly of latch control toggle 80 when mounted to spring latch assembly 50 and a catch portion 89 also extends rearwardly when in the mounted position. Catch portion 89 has an upwardly projecting lip that, as described below, interacts with hold back element 120.

As noted above and as illustrated in Figure 13, spring latch assembly 50 carries with it latch control toggle 80 which is pivotally mounted between trunnion mounts 61 by means of latch pivot pin 82 received in the openings of trunnions 61. Here, first bay 62 receives leg 85 and foot portion 86 of latch control toggle 80. As is illustrated in Figure 13, spring 68 and a pin 69 bias latch control toggle 80 into a first position. It may also be seen that spring latch bolt 54 is retained on spring bolt carrier 52 by means of screw 73.

With reference now to Figures 3, 14 and 15, it may be seen that dead latch assembly 90 includes auxiliary bolt carrier 92 which carries auxiliary bolt 94. Auxiliary bolt carrier 92 includes a central body 95 having a threaded bore 96 formed therein. Auxiliary latch bolt 94 is in the form of a cylindrical prong having a forwardly extending cylindrical shank 97 and a rearwardly extending threaded mount 98 sized and adapted to threadably mate and threadable bore 96. Shank 97 and terminates in a rounded nose 99. Hex portion 100 is provided to allow tightening of auxiliary bolt 94 to central body 95.

As is known, the width of the auxiliary bolt can impact operation of the locking mechanism. By forming the auxiliary bolt 94 as a cylindrical prong, the spring bolt 54 is more assured of initial contact with the striker plate on the door jamb. This helps eliminate the likelihood that the auxiliary bolt will be inadvertently depressed before contact of the spring bolt which, if it occurs, will cause the spring latch assembly to be latched against retraction. Should such latching occur, as is known, the spring latch bolt prevents the door from closing because it bounces off of the door jamb.

With continued reference to Figures 14 and 15, an arm 102 extends upwardly from central portion 95 and includes a profile 103 configured to mate with bay 63 in spring bolt carrier 52. When assembled, profile 103 will interact with leg 85 and foot 86 as described below. Central body 95 also includes a bore 104 sized to receive a portion of dead latch spring 113. A seat 105 is formed in the side of central body 95.

Spring latch assembly 50 and dead latch assembly 90 are mounted in the interior of casing 20 for reciprocal sliding motion. To this end, spring latch assembly 50 is first positioned in casing 20. Rollers 106 are then seated in seats 66 and secured by screws 107 such that each roller 106 are located in a respective spring latch slot 26. Likewise, auxiliary bolt assembly 90 is first positioned in casing 20. Additional rollers 108 are then seated in seats 105 and secured by screws 109 such that each roller 108 is located in a respective dead latch slot 27. As best seen in Figure 3, each roller 106, 108 is constructed by a cup 111 nested in a cup 110.

When spring latch assembly 50 is mounted in casing 20, detent bar 88 of latch control toggle 80 is positioned in detent slot 28, as shown in Figures 2(a)- 2(c). With reference to these figures and to Figures 3, 10 and 15, a first return spring or spring latch spring 112 has an end portion mated in cavity 64, and a second return spring or dead latch spring 113 has an end portion mated in bore 104. Springs 112 and 113 are provided to bias, respectively, spring latch assembly 50 and dead latch assembly 90 into the extended position and disable state. Springs 112 and 113 are retained in position by means of return spring retainer 114. Return spring retainer 114 is shown in Figure 3 as a clip-like element having side wings 115 and 116 provided with holes 117 that engage posts 33 on side plates 22 of casing 20.

A hold back element 120 is also provided to selectably secure the spring latch assembly 50 so that spring latch bolt 54 is in a retracted position and thus the auxiliary bolt 94 withdrawn as in the disable state so that lock mechanism 10 will be retained in the configuration shown in Figure 2(c). Hold back element 120 is illustrated in Figures 16, 17, 18(a) and 18(b). Here, it may be seen that hold back element 120 includes a wedge-shaped head portion 121 terminating in a ridge 122. Ridge 122 is provided to interact with actuator 18 of cylinder lock 14, as described below.

Head portion 121 extends between two side portions 123 which each have a pair of threaded bores 124 formed therein. Hold back element 120 is slideably mounted between side plates 22. To this end, slots 30 are formed in each slide plate 22. Pins in the form of set screws 125 extend through slots 30 and engage threaded bores 124 in hold back element 120 so that hold back element 120 can slide between two positions relative to side plates 22. A pair of ball detents 126 are provided and include a spring 127 and a ball 128 received in each bore 129 formed in side portions 123. Ball detents 125 selective engage detent holes 31 in each side plate 32 to facilitate the retention of hold back element 120. The ball detents are offset from one another. Thus, as is illustrated in Figures 18(a) and 18(b) hold back element 120 can slide between two positions relative to side plates 22. By having the offset relation, one ball detent engages a detent hole when in each of the two positions of the hold back member. The hold back feature can be overridden or "disabled" as is illustrated in Figure 19. Here, a screw 78 is threaded into a hole 79 in side plate 22 to move between first and second states thereby to physically interfere with and prevent movement of the hold back element from the disengage position to the engage position.

Turning now to Figures 20(a) and 20(b), the interaction between spring bolt carrier 54 and auxiliary bolt carrier 94 along with latch control toggle 80 may be appreciated with greater understanding. In Figure 20(a), it may be seen that, when arm 102 and profile 103 are not engaged with spring bolt carrier 52, spring biased pin attacks a lower portion of detent bar 88 so as to move latch control toggle 80 in a counter clockwise direction. However, as is illustrated in Figure 20(b), when latch bolt carrier 92 engages spring bolt carrier 52, profile 103 contacts foot 86 thereby rotating latch control toggle 80 to a second position against the restorative force of spring biased pin 69.

With reference to the figures and especially Figures 2(a)-2(c), the ordinarily artisan in this field should now realize that, when spring latch bolt 54 is in the extended position under the restorative force of spring 112, auxiliary bolt 94 may also be advanced outwardly of the casing 20. In this state, the spring latch assembly is enabled because profile 103 contacts foot 86 under the force of spring 113. This rotates latch control toggle 80 to the position shown in Figure 18(b). Detent bar 88 is in detent slot 28, but detent bar 88 does not engage detent notch 42 of slot 28. The spring latch assembly and the dead latch assembly may accordingly be moved from the position shown in Figure 2(a) to the position shown in Figure 2(c).

However, if auxiliary bolt 94 is moved to the position shown in Figure 2(b) without depressing spring latch bolt 52 to the retracted state, profile 103 disengages from foot 86. The force of spring 68 acting through pin 69 causes rotation of latch control toggle 80to the orientation of Figure 20(a). Thus, detent bar 88 is moved to the orientation shown in Figure 2(b). Here, detent bar 88 engages detent notch 42 thereby preventing subsequent movement of the spring latch bar from the extended to the retracted position. This, then, resists tampering with the locked mechanism.

Another aspect of this embodiment provided by the hold back member 120 can be explained in reference to Figure 21. When the spring latch assembly is retracted, rotation of actuator 18 in the direction of arrow "A" causes lobe 19 to move hold back member 120 from the position shown in Figure 18(a) to the position shown in Figure 18(b). Ridge 129 therefore engages the lip of catch 89 on latch control toggle 80. This engagement retains spring latch assembly 50 in the retracted position against the forces of return springs 112 and 113. Therefore spring latch bolt 54 is in the retracted position and auxiliary bolt 94 is withdrawn thereby leaving the associated door in an unlocked state. However, when actuator 18 is rotated in a direction opposite arrow "A", lobe 19 attacks ridge 122 to move hold back member 120 from the position shown in Figure 18(b) to the position shown in Figure 18(a). Finally, as is shown in phantom in Figure 21, when spring latch assembly 50 is in the extended position (regardless of the state of the dead latch assembly), rotation of actuator 18 in a direction opposite arrow "A" will cause lobe 19 to attack head 87 of latch control toggle 80 thereby driving the spring latch assembly from the extended position to the retracted position. Thus, it should be appreciated that actuator 18 rotates between a retain position (placing the hold back member in the engage state) and a release position (to disengage the hold back member) through an intermediate position. When moving from the intermediate position to the release position, actuator 18 moves the spring latch bolt from the extended position to the retracted position.

As noted above, another aspect of this exemplary embodiment is its ability to adjust to different depths of nose stiles. This accomplished by a positional adjuster 140 on opposite ends of casing 20. A representative positional adjuster 140 is depicted in Figures 22 and 23. Here it may be seen that positional adjuster includes an L-shaped mounting plate 141 and a U-shaped bracket 142 that may be mounted to spacer plate 23 by means of a screw 143 extending through holes 144 and 145 to threadably engage threaded opening 39 in spacer plate 23. A threaded plug 146 may be mated with threaded opening 147 in bracket 142. As is shown in Figure 22, plug 146 has a hex bore 148. Opening 149 in bracket 141 allows the installer to adjust the effective length "I" of plug 146. Therefore, with reference again to Figures 1(a) and 1(b) the locking mechanism may accommodate differently dimensioned lock stiles.

Furthermore, yet another aspect of this embodiment is the ability to interchange spring latch bolts for different handedness of a door. Since spring latch bolt 54 is releasably mounted on spring bolt carrier 52, it is a simple matter to change out one spring latch bolt for another. To this end, access opening 32 is located so that the installer can slightly depress the spring latch bolt thereby registering the head of screw 73 with access opening 32. The installer can then remove screw 73 to detach the spring latch bolt 54 and reverse its attach direction.

A second exemplary embodiment of the casing is depicted in Figure 24. Here, casing 220 is provided to accommodate a deeper set back for a lock cylinder. Casing 220 has side plate 22 and a front plate 24 that are the same as described above. However, spacer plate 223, as is shown in Figure 25, is of a greater length to hold front plate 24 forwardly of side plates 22 and, correspondingly place the centerline of the lock cylinder a farther distance back of the nose of the door. Since the components of the locking mechanism assume the same mounting orientation relative to side plates 22, it is necessary in this embodiment to provide a longer dimension to spring latch bolt 254 with hardened pins 249, as is illustrated in Figure 26. Due to the ease of interchangeability of the spring latch bolt on the spring bolt carrier, the replacement of a standard spring latch bolt with a longer spring latch bolt is a simple matter. Likewise, it is necessary to provide a longer dimension to the dead latch assembly 290, and particularly auxiliary bolt 294, as is shown in Figure 27. Here, again, such replacement is a simple matter since the longer auxiliary bolt 294 can simply thread onto the standard dead bolt carrier 92.

Finally, with reference to Figures 28-31, a still deeper set back may be accomplished by using casing 320 along with longer dimensioned components, as illustrated. Here, casing 320 again includes side plates 22 However, additional side extension plates 321 are located forwardly of side plates 22. A plurality of longer dimensioned spacer plates 323 are the used to secure side plates 22, side extension plates 321 and front plate 24 together. A still longer spring latch bolt 354 with hardened pins 349 and a longer auxiliary bolt 394 are used to match the depth added by the side extension plates 321 in order to accomplish the deeper set back.

Accordingly, various aspects of the exemplary embodiments should now be more fully appreciated. Naturally, modifications or changes may be made to the exemplary embodiments, and the scope of the invention should not be limited to any specific aspect of combination of aspects of these exemplary embodiments. In addition, it should be understood that the present invention also contemplates a method of managing spring latch assemblies and dead latch assemblies located in the casing of a lock mechanism. As should be appreciated, the method may include any of the processing steps recently or inherent in the mechanical structures disclosed herein as would be apparent to the ordinarily skilled artisan in this field.

Claims

We claim:

1. A lock mechanism, comprising:

(A) a casing having a front portion;

(B) a spring latch assembly disposed in the interior of said casing, said spring latch assembly including

(1) a spring latch bolt operative to move between an extended position wherein said spring latch bolt protrudes through said front portion and a retracted position, and

(2) a spring latch spring operative to bias said spring latch bolt toward the extended position with a restoring force; and

(C) a dead latch assembly disposed in the interior of said casing, said dead latch assembly operative to move between an enable state permitting movement of said spring latch bolt between the extended and retracted positions and a disable state prohibiting movement of said spring latch bolt from the extended position to the retracted position including, said dead latch assembly including:

(1) an auxiliary bolt having a rod-shaped free end portion protruding through said front portion when said dead latch assembly is in the enable state and

(2) a dead latch spring operative to bias said dead latch assembly toward the enable position.

2. A lock mechanism according to claim 1 wherein said auxiliary bolt terminates in a rounded nose.

3. A lock mechanism according to claim 2 wherein said auxiliary bolt has a cylindrically-shaped shank.

4. A lock mechanism according to claim 1 wherein said spring latch assembly includes a latch control toggle associated therewith, said latch control toggle movable between first and second positions such that:

(A) when said spring latch bolt is in the extended position and said latch control toggle is in the first position, said latch control toggle prohibits said spring latch bolt from moving from the extended position to the retracted position, and

(B) when said latch control toggle is in the second position, said latch control toggle permits said spring latch bolt to move from the extended position to the retracted position.

5. A lock mechanism according to claim 4 wherein said latch control toggle is biased towards the first position.

6. A lock mechanism according to claim 5 wherein said dead latch assembly is operative in the enable state to move said latch control toggle into the second position and is operative in the disable state to allow the latch control toggle to move into the first position.

7. A lock mechanism according to claim 4 wherein said casing includes at least one detent slot having a detent notch therein, said latch control toggle including a detent bar slideably received in the detent slot and operative to engage the detent notch when said spring latch bolt is in the extended position and said latch control toggle is in the first position, said detent bar being disengaged from the detent notch when said spring latch bolt is in the extended position and said latch control toggle is in the second position.

8. A lock mechanism according to claim 4 including a hold back member supported by said casing and movable between an engage state and a disengage state, said hold back member operative:

(A) when in the engage state to engage said spring latch assembly in the retracted position thereby to retain said spring latch bolt in the retracted position against the restoring force of said spring latch spring; and

(B) when in the disengage state to permit said spring latch bolt to move from the retracted position to the extended position.

9. A lock mechanism, comprising:

(A) a casing having an interior;

(B) a spring latch assembly disposed in the interior of said casing, said spring latch assembly including (1) a spring latch bolt operative to move between an extended position and a retracted position, and

(2) a spring latch spring operative to bias said spring latch bolt toward the extended position with a restoring force;

(C) a hold back member slideably disposed on said casing and movable between an engage position and a disengage position, said hold back member operative

(1) when in the engage position to engage said spring latch assembly when the spring latch bolt is in the retracted position thereby to retain said spring latch bolt in the retracted position against the restoring force of said spring latch spring, and

(2) when in the disengage position to permit said spring latch bolt to move from the retracted position to the extended position; and

(D) an actuator assembly including a actuator member movable between a retain position and a release position through an intermediate position, said actuator assembly operative

(1) to move said hold back member into the engage position when said actuator member advances into the retain position, and

(2) to move said hold back member into the disengage position when said actuator member advances into the release position.

10. A lock mechanism according to claim 9 wherein said spring latch assembly includes a latch arm associated therewith, said latch arm movable between first and second positions such that

(A) when said spring latch bolt is in the extended position and said latch arm is in the first position, said latch arm prohibits said spring latch bolt from moving from the extended position to the retracted position, and

(B) when said latch arm is in the second position, said latch arm permits said spring latch bolt to move from the extended position to the retracted position.

11. A lock mechanism according to claim 10 wherein said latch arm is biased towards the first position.

12. A lock mechanism according to claim 10 including a dead latch assembly disposed in the interior of said casing, said dead latch assembly including

(A) an auxiliary bolt operative to move between an enable state wherein said spring latch bolt may move between the extended and retracted positions and a disable state which prohibits said spring latch bolt from moving from the extended position to the retracted position, and

(B) a dead latch spring operative to bias said auxiliary bolt toward the enable position.

13. A lock mechanism according to claim 12 wherein said auxiliary bolt is operative in the enable state to move said latch arm into the second position and is operative in the disable state to allow the latch arm to move into the first position.

14. A lock mechanism according to claim 13 wherein said casing includes at least one slideway having a detent notch therein, said latch arm including a detent portion slideably received in the slideway and operative to engage the detent notch when said spring latch bolt is in the extended position and said latch arm is in the first position, said detent portion being disengaged from the detent notch when said spring latch bolt is in the extended position and said latch arm is in the second position.

15. A lock mechanism according to claim 10 wherein said hold back member engages said latch arm when said spring latch assembly is in the retracted position and said hold back member is in the engage state.

16. A lock mechanism according to claim 15 wherein said latch arm includes a lip, said hold back member including a ridge sized and adapted to engage said lip when said spring latch assembly is in the retracted position and said hold back member is in the engage state.

17. A lock mechanism according to claim 9 wherein said hold back member includes a spring-biased ball detent operative to releasably retain said hold back member in the engage position.

18. A lock mechanism according to claim 9 wherein said spring latch bolt moves in a linear direction between the extended position and the retracted position, said hold back member oriented to slide in a generally planar manner in a plane substantially perpendicular to the linear direction as said hold back member moves between the engage position and the disengage position.

19. A lock mechanism according to claim 9 wherein said casing includes a pair of substantially parallel side plates and a front plate extending therebetween, said side plates each having a rear edge portion with said hold back member slideably mounted between said side plates proximately to the rear edge portions thereof.

20. A lock mechanism according to claim 19 wherein said side plates each include at least one hold back guide slot with the hold back guide slots opposed to one another, said hold back member including at least a pair of pins received in the hold back guide slots.

21. A lock mechanism according to claim 9 wherein said hold back member has a cam surface formed thereon, said actuator assembly including a cam member oriented to engage the cam surface thereby to advance said hold back member from the disengage position and into the engage position.

22. A lock mechanism according to claim 9 wherein said actuator assembly includes a cylinder and a core rotatably disposed therein, and including a cam member disposed on said core for rotation therewith between the retain position and the release position through the intermediate position, said cam member operative

(A) to move said hold back member into the engage position when said cam member advances into the retain position, and

(B) to move said hold back member into the disengage position when said cam member advances into the release position.

23. A lock mechanism according to claim 22 wherein said cam member is adapted to move said spring latch bolt from the extended position to the retracted position when said cam member advances from the intermediate position to the release position.

24. A lock mechanism according to claim 9 including a disabling element supported by said casing and movable between a first state whereby movement of said hold back member between said engage and disengage positions is permitted and a second state whereby said disabling element prohibits said hold back member from moving from the disengage position into the engage position.

25. A lock mechanism according to claim 24 wherein said disabling element is operative to mechanically interfere with movement of said hold back member when in the second state.

26. A lock mechanism, comprising:

(A) a casing having a front; and

(1) a spring bolt carrier slideably disposed in said casing,

(2) a spring latch bolt removably supported by said spring bolt carrier such that said spring latch bolt may be mounted to and demounted from said spring bolt carrier, said spring latch bolt operative when mounted to said spring bolt carrier to move between an extended position wherein said spring latch bolt protrudes from the front of said casing and a retracted position, and

(3) a spring latch spring operative to bias said spring bolt carrier so that said spring latch bolt is biased toward the extended position with a restoring force.

27. A lock mechanism according to claim 26 wherein said casing is configured such that spring latch bolt may be mounted to and demounted from said spring bolt carrier while said spring bolt carrier is disposed in said casing.

28. A lock mechanism according to claim 26 wherein said spring bolt carrier and said spring latch bolt are configured so that said spring latch bolt may be reversibly mounted to said spring bolt carrier thereby to reverse the operation of said spring latch bolt to accommodate different handedness of a door to which the lock mechanism is to be used.

29. A lock mechanism according to claim 26 including a dead latch assembly disposed in the interior of said casing, said dead latch assembly operative to move between an enable state permitting movement of said spring latch assembly between the extended and retracted positions and a disable state prohibiting movement of said spring latch assembly from the extended position to the retracted position, said dead latch assembly including:

(1 ) an auxiliary bolt carrier slideably disposed in said casing,

(2) an auxiliary bolt removably supported by said auxiliary bolt carrier such that said auxiliary bolt may be mounted to and demounted from said auxiliary bolt carrier, said auxiliary bolt having a free end portion protruding through said front plate when said dead latch assembly is in the enable state, and

(3) a dead latch spring operative to bias said dead latch assembly toward the enable position.

30. A lock mechanism according to claim 26 including a lock cylinder disposed in said casing and cover plate adapted to be mounted to said casing to define the front therefor, said lock cylinder having a centerline located at a selected set back distance from said cover plate, and including different spring latch bolts respectively having differing lengths whereby a selected one of said spring latch bolts may be mounted to said spring bolt carrier thereby to accommodate different set back distances.

31. A lock mechanism according to claim 30 including a dead latch assembly disposed in the interior of said casing, said dead latch assembly operative to move between an enable state permitting movement of said spring latch assembly between the extended and retracted positions and a disable state prohibiting movement of said spring latch assembly from the extended position to the retracted position, said dead latch assembly including:

(1 ) an auxiliary bolt carrier slideably disposed in said casing,

(2) differently auxiliary bolts respectively having different lengths and removably mountable to said auxiliary bolt carrier such that a selected auxiliary bolt may be mounted to and demounted from said auxiliary bolt carrier whereby a selected one of said auxiliary bolts may be mounted to said auxiliary bolt carrier thereby to accommodate different set back distances, and

32. A lock mechanism according to claim 26 wherein said casing includes:

(1) a pair of side plates oriented in substantially parallel spaced relation to one another and each having front and rear edges,

(2) a front plate extending between front edge portions of said side plates, and

(3) a plurality of spaced plates extending between said side plates.

33. A lock mechanism according to claim 32 including an upper positional adjuster located at a top of said casing and a lower positional adjuster located at a bottom of said casing, each of said upper and lower positional adjusters including a threaded plug threadably received therein such that a rear portion of each said threaded plugs may protrude rearwardly of the rear edges of said side plates for an effective length that is selectively adjustable.

34. In a lock casing having front and back portions and top and bottom portions, the improvement comprising an upper positional adjuster located proximately to the top portion of said casing and a lower positional adjuster located proximately to the bottom portions of said casing, each of said upper and lower positional adjusters including a threaded plug threadably received therein such that a rear portion of each said threaded plugs may protrude rearwardly of the back portion of said casing for an effective length that is selectively adjustable.

35. In a lock casing having front and back portions and top and bottom portions, the improvement comprising a generally planar front plate disposed proximately to the front portion of said casing, a generally planar cover plate secured in spaced relation relative to said front plate, and at least one bevel adjustment element interposed between said front plate and said cover plate, said bevel adjuster movable so as to selective position said cover plate either generally parallel to said front plate or at a small acute angle on either side of a generally parallel orientation.

36. The improvement according to claim 35 wherein said bevel adjustment element is wedge-shaped in configuration and is rotatably secured to said front plate.