Lock assembly having fire resistant spindle linkage

A lock assembly includes an exterior operator assembly, an interior operator assembly, and a latch assembly. An outer spindle is operatively coupled to a latch assembly, is drivably coupled to the interior operator assembly, and has a longitudinal bore. A coupling mechanism is coupled to the outer spindle. A locking spindle assembly is rotatably received in the longitudinal bore, and is configured to selectively operate the coupling mechanism to couple the exterior operator assembly to the outer spindle upon actuation of a drive assembly. The locking spindle assembly has a fire compliant component made of a first material that melts during a fire to prevent operation of the latch assembly with the exterior operator assembly, and has a fire resistant component made of a second material and configured to block the longitudinal bore of the outer spindle to aid in preventing the spread of the fire through the door.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to door locks, and, more particularly, to a lock assembly having a fire resistant spindle linkage.

2. Description of the Related Art

Some doors and associated lock assemblies, such as those used in commercial buildings, are designed to aid in protecting against the spread of fire by preventing the passage of fire from one room to another. In order to do so, a lock assembly may be designed to ensure that the associated door is maintained in a closed and latched state in the event of fire. In some such lock assemblies, pivot joints in the latch actuation linkage may be designed with internal fusible links which may be melted at fire temperatures to render the latch actuation linkage nonfunctional, and thus the door remains latched. In some situations, however, one or more passageways through the lock mechanism may be open, or become opened as a result of the fire, which potentially may not adequately inhibit the spread of fire.

What is needed in the art is a lock assembly having a fire resistant spindle linkage. The present invention provides such a solution.

SUMMARY OF THE INVENTION

The present invention provides a lock assembly having a fire resistant spindle linkage.

The invention, in one form thereof, is directed to a lock assembly for a door. The lock assembly includes an exterior operator assembly having an exterior operator handle, an interior operator assembly having an interior operator handle, and a latch assembly having a bolt actuator mechanism and a bolt. An outer spindle is operatively coupled to the latch assembly and is drivably coupled to the interior operator assembly. The outer spindle has a longitudinal bore. A coupling mechanism is drivably coupled to the outer spindle. A drive assembly is configured to provide a driving rotation. A locking spindle assembly is rotatably received in the longitudinal bore, is drivably engaged with the drive assembly, and is configured to selectively operate the coupling mechanism to drivably couple the exterior operator assembly to the outer spindle upon actuation of the drive assembly. The locking spindle assembly has a fire compliant component made of a first material that melts during a fire to prevent operation of the latch assembly with the exterior operator assembly, and has a fire resistant component made of a second material having a higher melting temperature from that of the first material and configured to block the longitudinal bore of the outer spindle to aid in preventing the spread of the fire through the door via the longitudinal bore.

The invention, in another form thereof, is directed to a spindle assembly for use in a lock assembly. The spindle assembly includes an outer spindle having a longitudinal bore. A locking spindle assembly is rotatably received in the longitudinal bore of the outer spindle. The locking spindle assembly has a fire compliant component and a fire resistant component. The fire compliant component is made of a first material that melts in the event of a fire. The fire resistant component is made from a second material having a higher melting temperature than that of the first material and is configured to block the longitudinal bore of the outer spindle after the melting of the fire compliant component to aid in preventing the spread of the fire through the longitudinal bore.

The invention, in another form thereof, is directed to a lock assembly for use with a door. The lock assembly includes an exterior operator assembly having an exterior operator handle, an interior operator assembly having an interior operator handle, and an electronics assembly including a credential reader and a motor drive assembly electrically coupled to the credential reader. The credential reader is configured to selectively actuate the motor drive assembly. A latch assembly has a bolt actuator mechanism and a bolt. An outer spindle is operatively coupled to the bolt actuator mechanism of the latch assembly, and is drivably coupled to the interior operator assembly. The outer spindle has a longitudinal bore. A coupling mechanism is drivably coupled to the outer spindle, and is configured to selectively couple the exterior operator assembly to the outer spindle. A locking spindle assembly is rotatably received in the longitudinal bore of the outer spindle. The locking spindle includes a locking spindle tail member, a locking actuator spindle, and a locking spindle link. The locking spindle tail member has a first portion configured to be received in the longitudinal bore of the outer spindle. The locking spindle tail member is drivably coupled to the motor drive assembly. The locking actuator spindle has a second portion configured to be received in the longitudinal bore of the outer spindle. The locking actuator spindle is configured to selectively operate the coupling mechanism to drivably couple the exterior operator assembly to the outer spindle upon actuation of the motor drive assembly. The locking spindle link has a first coupling portion configured to connect to the first portion of the locking spindle tail member and has a second coupling portion configured to connect to the second portion of the locking actuator spindle. The locking spindle link is positioned within the longitudinal bore of the outer spindle. Each of the locking spindle tail member and the locking actuator spindle is made of a first material configured to melt in the event of a fire. The locking spindle link is made of a second material having a higher melting temperature than the first material and is configured to block the longitudinal bore of the outer spindle to aid in preventing the spread of the fire through the door via the longitudinal bore of the outer spindle.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate an embodiment of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings and particularly toFIGS. 1-3, there is shown a lock assembly10in accordance with the present invention for mounting on a door12, and which includes an exterior lockset14, interior lockset16, a latch assembly18, and a strike20.

Exterior lockset14includes an exterior operator assembly22, a credential reader24, and an exterior escutcheon26. Exterior operator assembly22includes an exterior operator handle28.

Interior lockset16includes an interior operator assembly30, a control electronics module32, an interior escutcheon34and a battery cover36. Interior operator assembly30includes an interior operator handle38. Control electronics module32is electrically connected to credential reader24.

Referring also toFIG. 4, interior operator assembly30includes a handle sleeve assembly40. An exterior of handle sleeve assembly40is configured to mount interior operator handle38. Referring also toFIG. 5, an exterior of handle sleeve assembly40is drivably coupled to an inside square drive spindle coupler42. Within handle sleeve assembly40there is a chamber for mounting a motor drive assembly44. Motor drive assembly44is electrically connected to control electronics module32via wire conductors45.

Also shown inFIG. 5is a spindle assembly46that includes an outer square spindle48within which there is rotatably received a locking spindle assembly50. A coupling mechanism52is provided to selectively drivably couple exterior operator assembly22to outer square spindle48. Locking spindle assembly50has a first end50-1that is mechanically coupled to a rotatable shaft of motor drive assembly44. Locking spindle assembly50is operably coupled to coupling mechanism52to selectively couple and decouple exterior operator assembly22to outer square spindle48, with the normal, or rest, state being a decoupled state.

Referring also toFIG. 6, latch assembly18is configured with a bolt actuator mechanism54and a retractable bolt56, as is customary in the art. Bolt actuator mechanism54is operable by a rotation of outer square spindle48of spindle assembly46to retract bolt56. As is illustrated inFIG. 6, exterior operator handle28, interior operator handle38, and spindle assembly46are longitudinally aligned along an axis58.

Interior lockset16is configured such that during normal operation interior operator handle38is always operatively coupled to spindle assembly46, and in particular, to outer square spindle48via inside square drive spindle coupler42, and in turn to latch assembly18. As such, in normal operation a rotation of interior operator handle38always will result in a retraction of bolt56. Also, in normal operation motor drive assembly44is always operatively coupled to locking spindle assembly50.

Referring toFIGS. 2 and 6, exterior lockset14is configured such that exterior operator handle28is selectively coupled to latch assembly18. In a locked condition, exterior operator handle28is decoupled from spindle assembly46, and thus a rotation of exterior operator handle28does not result in a retraction of bolt56. In an unlocked condition, exterior operator handle28is coupled to spindle assembly46via coupling mechanism52to operate latch assembly18, and thus a rotation of exterior operator handle28will result in a retraction of bolt56.

The unlocked condition may be achieved by providing a valid credential, e.g., an RFID card, to be read by credential reader24, which in turn sends a signal to control electronics module32. Control electronics module32then compares the read credential to a database of stored authorized credentials, and if a match is found, responds by operating motor drive assembly44to rotate the inner portion, i.e., locking spindle assembly50, of spindle assembly46to activate coupling mechanism52to couple exterior operator handle28to latch assembly18via coupling mechanism52and outer square spindle48(see alsoFIG. 5).

Additionally, exterior lockset14is provided with a mechanical override in the form of a key operated interchangeable keyed lock core60that is operatively coupled to coupling mechanism52, such that a valid operator key may be used to effect a coupling of exterior operator handle28to latch assembly18.

In accordance with an aspect of the present invention, locking spindle assembly50is provided with fire compliant and fire resistant components to both render lock assembly10inoperable by exterior lockset14in the event of a fire, and also to block a potential through hole through spindle assembly46to aid in preventing the spread of fire.

Referring now also toFIG. 7, spindle assembly46includes the outer square spindle48. Square spindle48has a first end48-1, a second end48-2, and a longitudinal bore48-3that extends between first end48-1, a second end48-2. Longitudinal bore48-3of square spindle48is sized to rotatably receive locking spindle assembly50. Second end48-2of square spindle48is configured to drivably connect to a body52-1of coupling mechanism52.

Body52-1of coupling mechanism52includes a slot52-2and a longitudinal opening52-3. Longitudinal opening52-3is co-axial with longitudinal bore48-3along axis58. Slot52-2is arranged to perpendicularly intersect longitudinal opening52-3. A slide member52-4is received in slot52-2in a sliding arrangement, such that slide member52-4is selectively extendable from body52-1. Slide member52-4has a cam opening52-5and a coupling tab52-6. Coupling tab52-6is configured to selectively engage a coupling portion of exterior operator assembly22, such that when so engaged, exterior operator handle28is rotatably coupled to square spindle48to operate latch assembly18.

Locking spindle assembly50is a three piece elongate sub-assembly, generally round in cross-section, which transfers a torque function that is required to lock and unlock lock assembly10via the lifting and lowering of slide member52-4of coupling mechanism52. More particularly, locking spindle assembly50includes a locking spindle tail62, a locking actuator spindle64, and a locking spindle link66. Each of locking spindle tail62, locking actuator spindle64, and locking spindle link66has a cylindrical exterior portion that is received in a snug rotating fit within the longitudinal bore48-3of square spindle48.

Locking spindle tail62has a coupling end62-1having a pair of diametrically opposed surface recesses62-2. Likewise, locking actuator spindle64has a coupling end64-1having a pair of diametrically opposed surface recesses64-2. In addition, locking actuator spindle64includes a cam protrusion64-3that is configured to be received in cam opening52-5of body52-1of coupling mechanism52, so as to raise or lower slide member52-4based on a rotational position of cam protrusion64-3. A head portion64-4of locking actuator spindle64is located opposite coupling end64-1, with cam protrusion64-3interposed between head portion64-4and coupling end64-1, and with cam protrusion64-3adjacent head portion64-4.

Locking spindle link66is configured as an H-shaped structure having a pair of axially opposed U-shaped clip ends66-1and66-2that are separated by an interposed solid core66-3. U-shaped clip end66-1includes a pair of diametrically opposed inwardly facing protrusions66-4sized and configured to engage the corresponding pair of diametrically opposed surface recesses62-2of locking spindle tail62in an interlocking relationship and/or a snap fit, so as to connect locking spindle link66to locking spindle tail62. U-shaped clip end66-2includes a pair of diametrically opposed inwardly facing protrusions66-5sized and configured to engage the corresponding pair of diametrically opposed surface recesses64-2of locking actuator spindle64in an interlocking relationship and/or a snap fit, so as to connect locking spindle link66to locking actuator spindle64.

Referring particularly toFIG. 7, to assemble spindle assembly46, coupling end64-1of locking actuator spindle64is inserted through longitudinal opening52-3of body52-1of coupling mechanism52, and through cam opening52-5of slide member52-4. Head portion64-4serves as a stop to engage coupling mechanism52to position cam protrusion64-3in cam opening52-5of slide member52-4. Coupling end64-1of locking actuator spindle64is then connected to U-shaped clip end66-2of locking spindle link66. Coupling end62-1of locking spindle tail62is then connected to U-shaped clip end66-1of locking spindle link66.

Locking spindle assembly50is then inserted, first end50-1first, through longitudinal bore48-3of square spindle48, such that second end48-2of square spindle48drivably engages body52-1of coupling mechanism52. A snap ring68is inserted into a snap ring groove62-3of locking spindle tail62. The resulting assembled arrangement of spindle assembly46is illustrated inFIG. 5.

Each of the outer square spindle48of spindle assembly46and the inner locking spindle link66of locking spindle assembly50that is received in longitudinal bore48-3of square spindle48is made of a material having a relatively high melting temperature, such as steel or similar alloy. However, each of locking spindle tail62and locking actuator spindle64is made of a non-steel material, such as zinc, aluminum, polymer, or non-ferrous suitable alloy, having a relatively lower melting temperature.

Thus, in case of a fire, locking spindle tail62and locking actuator spindle64will melt away, rendering lock assembly10inoperable using exterior operator handle28, i.e., a rotation of exterior operator handle28cannot retract bolt56of latch assembly18. However, advantageously, the fire-resistant locking spindle link66of locking spindle assembly50remains in longitudinal bore48-3of square spindle48, thus completely obstructing the passage through longitudinal bore48-3of square spindle48. Since locking spindle link66does not melt away, locking spindle link66will remain in the middle of otherwise hollow square spindle48to aid in blocking the transfer of fire and/or heat through square spindle48, and thus aiding in blocking the transfer of fire and/or heat through door12.

Thus, with locking spindle assembly50, the locking spindle link66, e.g., made of steel, is configured to inhibit the spreading of fire and/or heat through door12during a fire condition, while locking spindle tail62and locking actuator spindle64, e.g., made of non-steel material having a lower melting temperature than that of locking spindle link66, are configured to deliver the required functional torque to lock and unlock lock assembly10by motor drive assembly44during normal operation.