Background of the Invention
This invention relates to lock mechanisms and more particularly to mechanisms which are electrically actuated.
In high security areas such as banks, computer rooms, museums, etc., electrically actuated door locks of either the fail-secure or fail-open type are employed. For such applications, it is often preferable that the lock mechanism be mounted in a conventional narrow door stile or frame member and, therefore, it is necessary that the lock mechanism be relatively narrow, shallow, and compact.
In a fail-secure electric door lock of this type, it is desirable to provide automatic deadlatching on electrical failure and a manual mechanical release. In a fail-open electric door lock, it is similarly desirable to provide normal electrical deadlatching, automatic unlatching on electrical failure and manual mechanical override to deadlatch the door.
A fail-secure electric door lock mechanism is disclosed herein providing automatic deadlocking of the bolt upon de-energization of the lock mechanism and manual mechanical withdrawal of the bolt from the locked condition in the event of power failure. Also disclosed is a fail-open electric door lock mechanism providing manual mechanical and electrically actuated deadlatching.
It is a principal object of this invention to provide a new and improved electrically operated door lock mechanism.
It is a further object of the invention to provide a fail-secure electric door lock having a manual mechanical release.
A further object of the invention is to provide an automatic deadbolt assembly that can be employed with a fail-secure electric door lock.
A still further object of the invention is to provide a fail-open electric door lock having an electrically operated deadlatch and a mechanical override.
Yet another object of the invention is to provide an electric door lock mechanism that is economical to manufacture, durable in use, and reliable in operation.
Other objects will be in part obvious and in part pointed out in more detail hereinafter.
The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth and the scope of the application of which will be indicated in the appended claims.
Brief Description of the Drawings
FIG. 1 is a side sectional view of a fail-secure electric door lock mechanism incorporating an embodiment of this invention showing the lock mechanism in a locked condition.
FIG. 2 is view similar to FIG. 1 showing the door lock mechanism in an unlocked condition.
FIG. 3 is an enlarged view, partly broken away, of the door lock mechanism showing automatic deadlatch assembly thereof with its bolt slightly retracted from its position shown in FIG. 1.
FIG. 4 is a partial rear view, partly broken away, of the lower end of the lock mechanism of FIG. 1 and showing a manually operated rotary lock subassembly thereof.
FIG. 5 is a side sectional view of a fail-open electric door lock mechanism incorporating a second embodiment of this invention, and showing the lock mechanism in an unlocked condition.
FIG. 6 is a view similar to FIG. 5, showing the door lock mechanism in a locked condition.
FIG. 7 is an enlarged partial rear view, partly broken away, of the lower end of the lock mechanism of FIG. 5.
FIG. 8 is a partial side sectional view taken generally along line 8--8 of FIG. 7, showing the electric deadlatch assembly in a de-energized position.
FIG. 9 is a view similar to FIG. 8, showing the deadlatch assembly in an energized position.
Description of the Preferred Embodiment
Referring to the drawings wherein like numerals are used thoughout to designate the same or like parts, a "fail-secure" electric door lock mechanism of this invention is shown in FIG. 1 and generally designated by the numeral 10.
The door lock 10 includes an elongated housing assembly 12 having an upper support housing 14, a lower support housing 16, and a lockfront or plate 18. The housing assembly 12 is dimensioned and configured for mounting in a conventional narrow door stile or frame member wherein the depth limitation is significant.
A bolt 20 is slideably mounted in the upper housing 14 for movement between a projected locking position as shown in FIG. 1 and a retracted non-locking position as shown in FIG. 2. In the projected locking position, the outer end 22 of the bolt 20 extends through an aperture 24 in the strike plate 26 mounted on door (not shown) adjacent lockfront 18. Strike plate 26 and lockfront 18 contain a number of screw apertures for securement to the door and frame member.
The bolt 20 has a generally tubular body or shank portion 30 extending between the outer end 22 and a flanged inner end 32. The flanged end 32 rides within a cylindrical recess 33 in the upper housing 14 and a compression spring 34 mounted within the recess 33 engages the upper housing 14 and the flanged end 32 to normally urge the bolt 20 toward the projected locking position as shown in FIGS. 1 and 3.
The bolt 20 is moved inwardly by the pivotal movement of a bellcrank lever 36. The lever 36 is pivotally mounted at its lower end to the upper housing 14 by a pivot pin 38. The upper end 40 of the lever 36 has a rounded edge 48 and extends through a longitudinally extending slot 42 in the wall 44 of bolt 20. Being of tubular configuration, wall 44 forms an interior chamber 46 and the upper end 40 extends through slot 42 into chamber 46 to rest against the interior surface of the flanged end 32 of the bolt 20. A flat spring 50 is mounted to the lever 36 and has a curved end portion 51 disposed between the rounded edge 48 and the flanged end 32.
The lever 36 is pivotable about the pivot pin 38 between a rest position as shown in FIG. 1 to an operating position as shown in FIG. 2. Upon pivotable movement of lever 36 from the rest position to the operating position, the rounded edge 48 pushes on the flanged end 32 against the tension of spring 34 to slide the bolt 20 to the retracted non-locking position. Thus, the pivotal movement of the lever 36 from the first position to the second position operates to retract the bolt 20.
The lever 36 is pivotally displaced by the vertical movement of the plunger 52 of the solenoid 54. The plunger 52 has a push rod 56 at its upper end engaging a recess 57 in the lower surface of the lever 36. The plunger 52 is electrically actuated from a normal retracted position within the solenoid 54 as shown in FIG. 1 to an extended position as shown in FIG. 2. The plunger 52 is slidably mounted within the solenoid 54 to allow mechanically actuated movement of the plunger 52 from the retracted position to the extended position. Therefore, the plunger 52 may also be mechanically extended to attain a manual retraction of bolt 20.
Referring to FIG. 3, the end portion 40 of the lever 36 is configured to form an automatic deadlatch means generally designated by the numeral 58 and comprising a first retaining surface 60 facing the outwardly disposed lateral edge 62 of the slot 42 and a second retaining surface 64 below the bolt 20. The retaining surfaces 60 and 64 are generally orthogonal and form a notch in the upper end 40 of the lever 36.
In the projected locking position of FIG. 1, the lateral edge 62 of the slot 42 is adjacent and slightly spaced apart from the first retaining surface 60. Turning to FIG. 3, an external driving force "F" is shown acting upon bolt 20 toward its retractive non-locking position. Such an external force, as would occur if there is an attempt to force open the lock, will move the bolt 20 inwardly so that edge 62 engages the first retaining surface 60. The spring 50 is connected by a threaded fastener 66 to lever 36 and engages the inner end 32 of the bolt 20 to bias or urge the upper end 40 of the lever 36 towards the lateral edge 62. The spring 50 provides sufficient biasing force to insure that the retaining surface 60 remains in position to engage the lateral edge 62 an does not pivot upwardly through the slot 42 as a result of the external driving force.
The contact of the lateral edge 62 with the first retaining surface 60 will cause upward pivotal movement of the lever 36 about the pivot pin 38. This pivotal movement will cause the second retaining surface 64 to engage the outer surface of wall 44 thereby preventing further upward pivotal movement of lever 36. Since the engagement of the second retaining surface 64 with the wall 44 prevents further pivotal movement of the lever 36, the first retaining surface 60 is thus rigidly fixed in position to stop any further inward movement of the bolt 20 towards the retracted non-locking position. Accordingly, the interaction of the retaining surfaces 60 and 64 with the bolt 20 deadlatches the bolt 20 against any external driving force.
The deadlatching operation of the deadlatch assembly 58 is automatic. During the normal retraction of the bolt 20 by pivotal movement of the lever 36, the second retaining surface 64 pivots upwardly through the slot 42 and avoids contacting the wall 44 and the lateral edge 62 because there is sufficient clearance between the lateral edge 62 and the first retaining surface 60. During an abnormal external force acting upon the bolt 20, the first retaining surface 60 is held in position by the spring 50 to abut the lateral edge 62 and initiate the deadlatching action.
The automatic deadlatching feature of the crank lever 36 is not restricted to an electric lock but may be benefically utilized in various mechanical locks as it provides a compact, reliable, and economical mechanism for retracting and automatic deadlatching a bolt. Thus, the crank lever 36 provides a dual function, namely to retract the bolt upon pivotal movement and to deadlatch the bolt against forced retraction.
Returning to FIG. 1, a manually operative rotative assembly for mechanically moving the plunger 52 to its extended position is generally designated by the numeral 68 and is shown mounted to the lower housing 16. The assembly 68 functions to mechanically retract the bolt 20 from the locked position in the event of power failure or electrical failure of the solenoid 54 and includes a lever arm or movable plate 70 which pivots about a pivot pin 72 and is limited in downward movement by a stop pin 74. A manually rotative key cylinder 76 and a manually rotative thumb turn 78 with attached cams 80 are mounted to the housing 16 below the plate 70. The cam 80 has a radially extending cam arm 82 whereby manual rotation of the key 77 or the thumb turn 78 will rotate the cam arm 82 into engagement with the lower surface of the plate 70 to pivot the plate 70 upwardly. As shown in FIG. 2, the pivoted plate 70 engages the lower end 84 of the plunger element 52 to displace the plunger 52 upwardly. The plunger 52 in turn pivots the lever 36 to retract the bolt 20.
The lower surface of the plate 70 has a "V" shaped cutout or notch 86 to interlockingly engage the outer end 88 of the cam arm 82. The notch 86 acts as a limit on the rotation of the cam 80 and latches the cam 80 in the upright position (shown in FIG. 2) due to the force applied by the compression spring 34 through the lever 36, the push rod 56 and the plunger 52. In this latched condition, the bolt 20 is held in the fully retracted unlocked position. With the lock in this latched position, rotation of either the thumb turn 78 or the key 77 in the reverse direction will disengage the cam arm 82 from the notch 86 and all the components will assume the locked position of FIG. 1 through the force of the compression spring 34.
In operation, electrical actuation of the solenoid 54 by a switch (not shown) will extend the plunger arm 52 upwardly to pivot the crank lever 36 to retract the bolt 20 to the unlocked position of FIG. 2. The lock 10 is "fail-secure" in that the lock will return to the locked position upon a de-energizing of the solenoid 54 because of a loss of electrial power. In the event of an interruption of electricity to the solenoid 54, the compression spring 34 moves the bolt 20 to the locking position and returns all the other components to the "rest" position of FIG. 1.
In the projected locking position, the bolt 20 is automatically deadlatched by the interaction of the deadlatch assembly 58 of the lever 36 with the bolt 20. A manual mechanical release of the bolt 20 is also provided that allows the bolt to be retracted and maintained in the unlocked position of FIG. 2 irrespective of de-energization of the solenoid.
Turning to FIG. 5, a "fail-open" electric door lock mechanism of this invention is generally designated by the numeral 11. In this configuration, the compression spring 34 is mounted about the bolt 20 between the front plate 18 and the flanged inner end 32 to urge the bolt 20 toward the retracted non-locking position. A bellcrank lever 36 is pivotally mounted at its lower end to the upper housing 14 by a pivot pin 38. The upper end 40 of the lever 36 has a rounded pusher edge 48 which engages the outer surface of the flanged end 32 of the bolt 20. Upon pivotal movement of the lever 36 from the rest position of FIG. 5 to the operating position of FIG. 6, the rounded edge 48 pushes upon the flanged end 32 to slide the bolt 20 against the tension of the spring 34 to the locked position of FIG. 6.
The upward extension of the plunger 52 of the solenoid 54 pivots the lever 36 to project the bolt 20 into the locked position of FIG. 6 wherein the bolt 20 extends into the aperture 24 of the strike plate 26.
Similar to the embodiment of FIG. 1, the plunger 52 is electrically actuated from a normally retracted position within the solenoid 54 as shown in FIG. 5 to an extended position as shown in FIG. 6 by the energizing of the solenoid 54. The plunger 52 may also be mechanically extended by the manually operative rotative assembly 68 to attain a manual projection of the bolt 20.
Upon manual projection of the bolt 20, the bolt 20 is also automatically deadlatched in a locked position. That is, rotation of the cam arm 82 is latched by the notch 86 interlockingly engaging the outer end 88 of the cam arm 82 as shown in FIG. 6. Because of the direct contact between the bolt 20, the lever 36, the push rod 56, and the plunger 52, any inward movement of the bolt 20 is prevented by the locked condition of the plunger 52 due to the plate 70 and the cam 80. The bolt 20 is thereby deadlatched to resist any external driving of the bolt towards the retracted unlocked position.
Deadlatching can also be selectively attained by the manual rotation of the cam 80 after projection of the bolt 20 by electrical actuation of solenoid 54.
Additionally, deadlatching can be selectively attained by an electrically actuated deadlatch assembly generally designated by the numeral 92 and comprising a rotary solenoid 94 having an angularly rotative armature 96 as shown in FIGS. 8 and 9. A cam 98 is mounted to the armature 96 by threaded fasteners 99 and has a cam arm 100 with an outer end 104. The outer end 104 interlockingly engages the notch 86 to provide deadlatch of bolt 20 and resist any external driving force on the bolt 20 toward the retracted position. As with the mechanical deadlatching feature, the bolt 20, the lever 36, the push rod 56, the plunger 52, the plate 70, and the cam arm 104 are in direct contact to thereby deadlatch the bolt 20 against external driving. Thus, electrically actuated deadlatching is provided in addition to manual deadlatching.
Prior to energizing the solenoid 94, it is necessary that the bolt 20 be electrically or mechanically projected into the locked position to avoid the cam arm 100 striking the plate 70. Indicator lights (not shown) provide a visual indication that the bolt 20 is in the projected position. To release the electric deadlatching feature, the solenoid 94 is de-energized and a coil spring (not shown) returns the cam 98 to its rest position as shown in FIG. 8.
In operation, the energizing of the solenoid 54 moves the bolt 20 from the retracted unlocked position to the projected locked position. After electric projection of the bolt 20, it may be deadlatched either mechanically by rotation of the cam arm 82 into interlocking engagement with the notch 86 or electrically by actuating the solenoid 94 to rotate the cam arm 104 into interlocking engagement with the notch 86. Both deadlatching features operate individually (or concurrently) to resist any external driving of the bolt 20 toward the retracted position and also operate to maintain the door lock 11 in the "locked" mode should electrical power to the solenoid 54 be interrupted or should the solenoid 54 fail.
Alternately, the bolt 20 can be projected into the locked position by manual rotation of the rotative assembly 68 either by a key 77 or a thumb turn. This provides a mechanical override of the solenoid 54 as well as mechanical deadlatching.
Accordingly, a fail-open electric door lock mechanism is provided having mechanical override, mechanical manual deadlatching and electrically actuable deadlatching. In another embodiment, a fail-secure electric door lock mechanism is provided having manual mechanical release and automatic deadlatching.
As will be apparent to persons skilled in the art, various modifications and adaptations of the structures above described will become readily apparent without departure from the spirit and scope of the invention, the scope of which is defined in the appended claims.