Anti-barricading thumb turn assembly for a door lockset

An anti-barricading thumb turn assembly is configured for use with a lockset including a bolt movable to lock and unlock a door. The anti-barricading thumb turn assembly includes a spindle connected to a thumb turn with a biasing member on one side of the lockset. The lockset is also operable by a key from the other side of the door to lock and unlock the door. Under normal operation, the spindle and thumb turn rotate as the bolt is locked and unlocked. In a barricading situation in which the thumb turn is held in an attempt to prevent the spindle from rotating, the biasing member allows the spindle to rotate relative to the thumb turn upon application of sufficient force through rotation of the key to overcome the biasing force and unlock the bolt even if the thumb turn is held stationary.

TECHNICAL FIELD

The present disclosure generally relates to a lockset for a door, and more particularly but not exclusively relates to a thumb turn assembly for the lockset that is configured to prevent barricading.

BACKGROUND

Locksets can be provided that have a lock with a bolt that is operated by a key from one side of the door and a thumb turn on the other side of the door. Key operation of the lock can be blocked by someone holding the thumb turn to barricade the door to prevent the lock cylinder from being fully rotated by the key to retract the bolt. This can be problematic in certain situations, such as in schools, hospitals, behavioral health facilities, prisons, and public spaces where access to a space secured by the lock by proper authorities needs to be provided at all times.

Prior attempts to prevent barricading of a door by using the lock require a clutching mechanism that needs to be re-set if disengaged while overcoming a barricading situation. These devices may not be able to be re-set properly, requiring disassembly of the lock and potentially causing other issues. Therefore, a need remains for further improvements in this technological field.

SUMMARY

An exemplary anti-barricading thumb turn assembly is configured for use with a lockset including a bolt operable to move in a locking or extending direction and an unlocking or retracting direction to lock and unlock a door. The thumb turn assembly rotates by operation of a key on one side of the lockset or a thumb turn on the other side of the lockset to lock and unlock the bolt by rotation of the thumb turn assembly. The thumb turn assembly includes a spindle that is connected to the thumb turn with a biasing member. Under normal operation, the spindles rotate to lock and unlock the bolt by using either the key or the thumb turn. In a barricading situation in which the thumb turn is held to prevent the spindle from rotating, the biasing member allows the spindle to rotate while the thumb turn is held stationary upon application of sufficient force through rotation of the key to overcome the biasing force of the biasing member. The spindle can be rotated sufficiently to unlock the bolt even if the thumb turn is held to keep the spindle from rotating. Further embodiments, forms, features, and aspects of the present application shall become apparent from the description and figures provided herewith.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

References in the specification to “one embodiment,” “an embodiment,” “an illustrative embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may or may not necessarily include that particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. It should further be appreciated that although reference to a “preferred” component or feature may indicate the desirability of a particular component or feature with respect to an embodiment, the disclosure is not so limiting with respect to other embodiments, which may omit such a component or feature. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to implement such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

Additionally, it should be appreciated that items included in a list in the form of “at least one of A, B, and C” can mean (A); (B); (C); (A and B); (B and C); (A and C); or (A, B, and C). Similarly, items listed in the form of “at least one of A, B, or C” can mean (A); (B); (C); (A and B); (B and C); (A and C); or (A, B, and C). Further, with respect to the claims, the use of words and phrases such as “a,” “an,” “at least one,” and/or “at least one portion” should not be interpreted so as to be limiting to only one such element unless specifically stated to the contrary, and the use of phrases such as “at least a portion” and/or “a portion” should be interpreted as encompassing both embodiments including only a portion of such element and embodiments including the entirety of such element unless specifically stated to the contrary.

As used herein, the terms “lateral,” “longitudinal,” and “transverse” are used to denote motion or spacing along three mutually perpendicular axes, wherein each of the axes defines two opposite directions. In the coordinate system illustrated inFIG. 1, the X-axis defines first (+) and second (−) lateral directions, the Y-axis defines first and second longitudinal directions, and the Z-axis defines first and second transverse directions. The longitudinal directions defined by the Y-axis may alternatively be referred to herein as the upward direction (Z−) and the downward (Y−) direction, and the transverse directions defined by the Z-axis may alternatively be referred to herein as the forward direction (Z+) and the rearward direction (Z−). In the orientation illustrated inFIG. 1, the lateral axis (X) and transverse axis (Z) are horizontal axes, and the longitudinal axis (Y) is a vertical axis. However, it is to be appreciated that these terms are used for ease and convenience of description, and are without regard to the orientation of the system with respect to the environment. For example, descriptions that reference a longitudinal direction may be equally applicable to a vertical direction, a horizontal direction, or an off-axis orientation with respect to the environment.

Furthermore, motion or spacing along a direction defined by one of the axes need not preclude motion or spacing along a direction defined by another of the axes. For example, elements which are described as being “laterally offset” from one another may also be offset in the lateral, longitudinal and/or transverse directions, or may be aligned in the lateral, longitudinal and/or transverse directions. The terms are therefore not to be construed as limiting the scope of the subject matter described herein.

With reference toFIG. 1, illustrated therein is a closure assembly10and a lockset30, according to certain embodiments. The closure assembly10includes a door12, and may further be considered to include the lockset30. The door12includes a free edge14and a door cutout16that extends from the free edge14, and in which at least a portion of the lockset30is seated. The door12is pivotally mounted to a frame (not shown) for swinging movement between an open position in which the free edge14is offset from a side jamb (not shown), and a fully-closed position in which the free edge14is aligned with the side jamb.

In the illustrated embodiment, the lockset30is provided in the form of a mortise lockset, and includes a trim assembly32mounted to the face of the door12, and a mortise chassis40seated in the door cutout16. The lockset30also includes a faceplate34that is secured to the free edge14of the door12, thereby retaining the chassis40within the door cutout16. The trim assembly32includes a first manual actuator and a second manual actuator, which in the illustrated embodiment are provided in the form of a handle36and a thumb turn38, respectively. One example of a suitable mortise lockset is disclosed in U.S. Pat. No. 8,997,534 which is incorporated herein by reference, although other types of locksets and mortise locksets are also contemplated herein.

The chassis40includes a latchbolt42, a deadbolt44, and a mortise case41in which the bolts42,44are movably mounted. The chassis40may further include a trigger46, which in the illustrated form is movably mounted between the latchbolt42and the deadbolt44. Each of the latchbolt42and the deadbolt44is movable between an extended position in which the bolt42/44projects beyond the faceplate34and is operable to engage the strike box (not shown), and a retracted position in which the bolt42/44is positioned at least primarily within the case41. Similarly, the trigger46is movable between a projected position in which the trigger46projects beyond the faceplate34, and a depressed position in which the trigger46is positioned at least primarily within the case41. The latchbolt42is biased toward its extended position, and the trigger46is biased toward its projected position. The latchbolt42includes a latchbolt head43, and may further include a tongue48movably mounted to the latchbolt head43. The tongue48may facilitate movement of the latchbolt42between its extended and retracted positions, for example by reducing or counteracting resistive forces resulting from frictional engagement with the faceplate34, the case41and/or the strike box.

The chassis40further includes a transmission assembly49that is operatively connected with the trim assembly32, the latchbolt42, and the deadbolt44. More specifically, the transmission assembly49drivingly connects the handle36with the latchbolt42, and drivingly connects the thumb turn38with the deadbolt44. As a result, the handle36is manually operable to drive the latchbolt42from its extended position to its retracted position, and the thumb turn38is manually operable to drive the deadbolt44between its extended and retracted positions. In one embodiment, the transmission assembly49is also operatively connected with the trigger46.

In certain embodiments, the transmission assembly49may connect the deadbolt44with one or more other components of the lockset30to provide for automatic movement of the deadbolt44in response to one or more actions. For example, the transmission assembly49may be configured to retract the deadbolt44in response to actuation of the handle36, thereby providing for automatic unlocking when the lockset30is operated from the secured side of the door12. As another example, the transmission assembly49may interconnect the latchbolt42, the deadbolt44, and the trigger46to provide for automatic extension of the deadbolt44when the door12is driven to its closed position. In such forms, the transmission assembly49may be configured to drive the deadbolt44toward its extended position in response to extension of the latchbolt42when the trigger46is in its depressed position, thereby providing for automatic locking when the door12is closed. The transmission assembly49may also include a thumb turn assembly50connected to one or both of bolts42/44that is operable to extend or retract bolts42/44by manual operation of thumb turn38on one side of door12and/or a key54inserted in a keyway52of a lock cylinder51on the other side of the door12. The transmission assembly49may be provided in any of a number of forms known within the art, and the manner in which transmission assembly49performs the above-described functions need not be described in further detail herein.

When the door12is in its closed position and the bolts42/44move toward the extended positions thereof, the bolts42/44travel in the second lateral (X−) direction. When the bolts42/44are subsequently moved toward the retracted positions thereof, the bolts42/44travel in the first lateral (X+) direction. Accordingly, the second lateral (X−) direction and the first lateral (X+) direction may alternatively be referred to as the bolt-extending (X−) direction and the bolt-retracting (X+) direction, respectively.

During operation of the closure assembly10, the door12may be driven from its open position to its closed position. When the door12approaches its fully-closed position, the latchbolt42enters the latchbolt opening of the strike box as the chassis40returns the latchbolt42to its extended position. With the trigger46retained in its depressed position, the transmission assembly49may drive the deadbolt44toward its extended position in response to extension of the latchbolt42, thereby causing the deadbolt44to enter the deadbolt opening of the strike box. Alternatively or additionally, as shown inFIG. 2, the retracted or unlocked deadbolt44may be driven to its extended or locked position44′ by transmission assembly49as shown by transmission assembly49′ via manual operation of the thumb turn38to a rotated position38′. The deadbolt44may also be driven to its extended position44′ by manual operation of key54inserted in keyway52for rotation of the thumb turn assembly50from the other side of door12. With the bolts42,44received in the openings of the strike box, the door12is secured in its closed position relative to the frame.

A person or persons may barricade his or her self in a room or area secured by door12by holding handle36and/or thumb turn38to defeat retracting bolt42/44by operation of key54. As shown inFIGS. 3-4, thumb turn assembly50is configured to defeat barricading by allowing the bolt42/44to retract via operation of the key54even if handle36and/or thumb turn38is held stationary.

Thumb turn assembly50includes an elongated spindle60that is engaged to transmission assembly49so that rotation of spindle60operates the transmission assembly49to lock and unlock bolt42/44. Spindle60includes a body62that extends between a first end64and an opposite second end66along a center axis A. In the illustrated embodiment, body62is an elongated solid shaft with a non-circular cross-section, such as a square cross-section. However, other cross-sectional shapes are also contemplated by body62. In one embodiment, in the installed position of lockset30the center axis A is aligned with or parallel to the transverse axis (Z).

First end64of body62is positioned in engagement with transmission assembly49so that rotation of thumb turn assembly50is transmitted to bolt42/44. The second end66of body62is engaged to thumb turn38via a hub70and a biasing member100. Thumb turn38is configured to rotate about center axis A to rotate spindle60and lock and unlock the door under normal (non-barricading) operation.

In the illustrated embodiment, hub70includes a center passage72that receives the body62of spindle60. Hub70also includes a cylindrical first body section74and a cylindrical second body section76that are positioned along center axis A so that second body section76is located toward thumb turn38and the first body section74is located on and projects axially from second body section76opposite of thumb turn38. The second body section76also projects radially outwardly from the first body section74. The second body section76has an outer wall78that defines a groove80extending radially inwardly therein to engage biasing member100, as discussed further below. Second body section76also includes at least one hub arm82projecting axially therefrom toward thumb turn38.

Thumb turn38includes a base member86and a handle member88projecting from base member86that can be grabbed by the user to manipulate thumb turn assembly50. Handle member88is in the form of a semi-circular plate in the illustrated embodiment, but any suitable configuration is contemplated. Base member86includes an outer cylindrical wall90that defines a cavity92for receiving hub70therein. The cavity92includes an inner wall94with a hole96therethrough. First and second legs98a,98bextend axially from inner wall94on opposite sides of hole96toward hub70so the legs98a,98binteract with biasing member100to maintain it in alignment around the hub70. In addition, the one or more hub arms82can be received in hole96to maintain hub70in rotational alignment with base member86.

Outer cylindrical wall90also includes a slot91extending therein for engagement to biasing member100. In the illustrated embodiment, biasing member100is a torsion spring with two or more coils formed by a bar102that is wound between an inner end104and an outer end106. The inner end104is bent to form a first flange112and the outer end106is bent to form a second flange110.

Biasing member is coupled between hub70and thumb turn38with first flange112engaged in groove80of hub70and second flange110engaged in slot91of base member86. The coiled body of biasing member100is positioned around hub70within the cavity92. Biasing member100is configured so that under normal conditions the rotation of thumb turn38is transferred to spindle60to extend and retract bolt42/44for locking and unlocking. However, if thumb turn38is held in position to attempt to barricade the lock, then a key54inserted into keyway52to unlock the door can be used to overcome the force of biasing member100and rotate spindle60to retract the bolt42/44to unlock the lock while thumb turn38remains stationary.

Various aspects of the present disclosure are contemplated. For example, according to one aspect, an anti-barricading system for a door includes a lockset configured for mounting to the door. The lockset includes a lockset housing configured for mounting within the door and at least one bolt mounted for movement relative to the lockset housing between a locked position and an unlocked position. The lockset includes a thumb turn on one side of the door for moving the bolt between the locked position and the unlocked position and a keyway on the other side of the door for receiving a key for moving the bolt between the locked position and the unlocked position. The system also includes a thumb turn assembly mounted to the lockset. The thumb turn assembly includes a spindle engaged to the thumb turn and a biasing member coupled to the spindle. The biasing member is configured so that rotation of the thumb turn rotates the thumb turn assembly to move the bolt between the locked position and the unlocked position and rotation of the key rotates the thumb turn and the thumb turn assembly together to move the bolt between the locked position and the unlocked position. In response to the thumb turn being held from rotation, the biasing member is configured to allow the thumb turn assembly including the spindle to rotate in response to sufficient force being applied to overcome the biasing force of the biasing member with rotation of the key to move the bolt between the locked position and the unlocked position while the thumb turn remains stationary.

In one embodiment of the system, the thumb turn assembly includes a base member for mounting to the lockset and a hub positioned in the base member, and the spindle is coupled to the hub so that rotation of the spindle rotates the hub. In a refinement of this embodiment, the biasing member is engaged between the base member and the hub. In a further refinement, the biasing member is a torsion spring that extends around the hub within the base member. In yet a further refinement, the torsion spring includes at least two coils that extend around the hub. In still a further refinement, a first end of the torsion spring includes a first flange that is engaged in a groove formed in an outer periphery of the hub and a second end of the torsion spring includes a second flange that is engaged in a slot of the base member.

In another embodiment of the system, a hub is provided that includes a central passage for receiving the spindle to fixedly couple the spindle to the hub. In one refinement, the passage is non-circular and the spindle includes a non-circular cross-section. In another refinement, the base member includes an outer sidewall that extends around a cavity of the base member, and the hub is positioned in the cavity. In yet a further refinement, the base member includes a hole in the cavity and the hub includes a central passage for receiving the spindle with the central passage in alignment with the hole.

According to another aspect, an anti-barricading thumb turn assembly is provided for use with a lockset including a movable bolt. The thumb turn assembly includes a thumb turn positionable on a first side of the lockset for moving the bolt between a locked position and an unlocked position and a spindle that is engaged to the thumb turn. The thumb turn assembly also includes a biasing member coupled to the spindle. The biasing member is configured so that rotation of the thumb turn rotates the spindle to move the bolt between the locked position and the unlocked position. In response to the thumb turn being held from rotation, the biasing member is configured to allow the spindle to rotate in response to sufficient force being applied to overcome the biasing force of the biasing member with rotation of a key from a second side of the lockset to move the bolt between the locked position and the unlocked position while the thumb turn remains stationary.

In one embodiment of the assembly, the biasing member is coupled to the spindle with a hub that is positioned within a base member and the biasing member extends between and is engaged to the base member and to the hub.

In another embodiment of the assembly, a base member is provided for mounting with the lockset and a hub positioned in the base member, and the spindle is coupled to the hub so that rotation of the spindle rotates the hub. In a refinement of this embodiment, the biasing member is engaged between the base member and the hub. In a further refinement, the biasing member is a torsion spring that is positioned within the base member and extends around the hub. In still a further refinement, the torsion spring includes an elongated bar that forms at least two coils extending between an inner end within the at least two coils and an outer end outside of the at least two coils. In still a further refinement, the inner end of the torsion spring is engaged to the hub and the outer end of the torsion spring is engaged to the base member. In yet a further refinement, the inner end and the outer end of the torsion spring each includes a flange for engaging respective ones of the hub and the base member.

In another embodiment of the assembly, a base member of the thumb turn includes an outer sidewall that extends around a cavity of the base member, and the hub is positioned in the cavity. In a refinement of this embodiment, the base member includes a hole in the cavity and the hub includes a central passage for receiving the spindle with the central passage in alignment with the hole.