Remotely Controlled Latch System For Fire Doors And The Like

Abstract

A remotely controlled latch system for releasably retaining a fire door or the like in a position in readiness for automatic closing to close a passage or opening. The latch system comprises latch apparatus including a dead bolt which is operable to a retracted and a projected position in which it unlatches or unlocks the door and locks it respectively. A bolt-release mechanism, operated remotely, has a latched operator or actuator that is released from a retracted position to assume a projected position in which it engages the dead bolt and causes it to assume its retracted or unlatched position. The remote control signal is applied by a sensor that senses physical conditions indicative of the presence or existence of a fire. The position of the actuator is continuously sensed and when it assumes its projected position an electrical signal is generated by a sensing switch. This signal is employed for de-energizing a solenoid that controls the unlatching or release of the actuator and may be used to indicate the operative unlatched condition of the latch system and thereby indicate that the fire door associated with the system is closed.

Parent Case Text

BACKGROUND OF THE INVENTION

This is a continuation-in-part application of my copending Ser. No. 272,346 entitled "Lock Control System" and filed July 17, 1972, now abandoned.

Description

This invention relates generally to emergency and fire door locks and more particularly to a remotely controlled latch system for such doors.

Remotely controlled lock systems for emergency exits and fire doors are known. These locks may be actuated selectively as desired but are generally controlled by command signals generated automatically by sensors which detect the presence of smoke or heat indicating the presence of a fire. These locks are generally complex and bulky.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a simply constructed emergency lock or latch system for emergency exits and fire doors that is highly reliable.

Another object is to provide remotely controlled emergency lock or latch system which is compactly constructed so that the part thereof not mounted on the door can be readily mounted in the door frame or jamb.

The remotely controlled door latch system according to the invention comprises a dead bolt operable to a retracted position and biased to a projected position corresponding to a position in which a door is latched thereby. A bolt release mechanism is mounted in the door frame or jamb and has a bolt-release member operable to a retracted position and biased to a projected position in which it engages the dead bolt and moves it to its retracted position. An actuator mechanism in the bolt-release mechanism has a solenoid receptive of an electrical signal commanding the unlatching of the latch system and the bolt-release member or actuator is released so that it retracts the dead bolt to unlock or unlatch the system.

A sensor senses the presence of a fire or smoke to generate the command electrical signal applied to the solenoid. A switch automatically controls the de-energization of the solenoid and initiates the generation of an indicating signal indicating that the system is an unlocked or unlatched state.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a fire door provided with a latch system according to the invention;

FIG. 2 is a fragmentary cross-section view taken along section line 2--2 of FIG. 1;

FIG. 3 is a fragmentary section view taken along section line 3--3 in FIG. 2;

FIG. 4 is a fragmentary cross-section view of another embodiment of the apparatus shown in FIG. 3;

FIG. 5 is a fragmentary cross-section view taken along section line 5--5 in FIG. 1; and

FIG. 6 is a perspective view of an element of the apparatus shown in FIG. 3 .

Other objects and advantages will appear from the following description of an example of the invention, and the novel features will be particularly pointed out in the appended claims.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The latch system embodying the invention will be described hereinafter as applied to a fire door. However, it will be understood that it is applicable to emergency exit doors, devices or "doors" for closing passages, ducts and the like.

As seen in the drawings, a fire door 1 is mounted on a wall 2 by automatic closing devices such as spring loaded hinges 3, 4. The fire door is retained, as later described, in a rest position in a recess 5 in the wall 2 and is framed by a door frame 6. The fire door has a door knob 7 having a manually actuated push-button 8 as part of a lock or latch system, later described, for latching the fire door.

The latch or lock system comprises a dead bolt mechanism 9 mounted in the door and a bolt-release mechanism 10 mounted in the door frame 6. The door frame 6 has a vertical member 11 on which is secured a plate 13 and top and bottom plates 14, defining a space 15 embedded in the wall 2.

The dead bolt mechanism 9 comprises a dead bolt 16 biased by a spring 17 to a projected position in which it extends out of the door through an opening in a removable inspection plate 18 mounted by mounting clips or lugs 20, 22 in an opening in the frame part 11. A casing 12 for the bolt-release mechanism is secured by screws 26, 27 to the removable inspection plate 18. Threaded screws 29, 30 removably mount the inspection plate 18 on the door frame lugs. By removing these screws the casing or box 12 containing the bolt-release mechanism can be readily removed from the space 15 and restored thereto. Thus, the entire bolt-release mechanism can be readily placed in the space 15, or removed therefrom for inspection and work thereon.

Within the casing or box 12, has within it two partitions 32, 33 that divide the interior of the box 12, as shown, into three compartments. Within a center compartment is disposed a bolt-release member or actuator 34 that is operable to a retracted position shown in FIG. 3 and has an extension 35 that forms a shoulder 36 in conjunction with the main body of the actuator 34. The actuator is held in its retracted position, as later described and is biased constantly by a spring 37 to a projected position in which its extension 35 engages the dead bolt 16 and displaces the dead bolt to a retracted position in which the latch system is unlatched or opened. The shoulder 36 on the actuator limits its travel, to the left in the drawing, by abutting against the plate 18. The extension 35 is dimensioned to move the dead bolt out of the door frame and will itself not extend outwardly of the frame to a position where it might impede the unlatching. In the unlatched condition, the fire door 1 is actuated by the spring-loaded hinges 3, 4 to a position closing an opening or passage 38.

The bolt-release mechanism has a spring latch 40 secured to the lower partition 33 with a latch extension 40a that extends through an opening in the lower partition and engages a shoulder 41 on the actuator 34 holding it releasably in its retracted position. A bracket 42 secured to the inspection plate 18 mounts a solenoid 43 that has an armature 45 connected to the latch 40. When the solenoid is energized, as later described, the armature is operated to a retracted position in which it withdraws the latch 40a from engagement with the actuator so that the biasing spring 37 projects the bolt-release member or actuator to its projected position, guided on the partitions, engaging the dead bolt 16 and overcoming the force of the biasing spring 17 so that the latch system is unlatched and the fire door is then free to move.

The latch system makes provision for remote control of the actuator for unlatching the system by use of a sensor device 47 that senses heat and smoke. This device is provided with the known type cells that senses heat or smoke for detecting the presence of a fire. When a detection takes place, a command signal is generated and a control circuit, not shown, applies the command signal to the solenoid 43 so that the latch system is unlatched as described above.

Moreover, once the fire door has been released, so that it can assume its operative position closing a passageway, it is desirable to indicate the condition. This is accomplished by a switch 50 that has a sensor 51 in the form of a follower configured as a roller mounted on a resilient support biasing the roller through an opening in the upper partition 32 into contact with an upper surface of the actuator 34. When the bolt-release member or actuator 34 is in a retracted position the sensor is deflected upwardly and it holds a contact on the underside of the switch deflected upwardly. The actuator is provided with a beveled surface 53 that assumes a position in alignment with the sensor 51 when the actuator 34 assumes its projected position. This allows the roller of the sensor to move dounwardly so that the resilient sensor is disengaged from the switch contact and an indicating signal is developed by the switch 50. The signal is transmitted, to a control circuit, not shown, through leads 54 which extend through a conduit 56 in the wall 2 and into the box 12. The indicating signal indicates that the latch system is unlatched and therefore the fire door has assumed its intended operative position. A visual indication of the condition established is effected by having the signal control the lighting of an indicating lamp connected in the control circuit, not shown. Furthermore this same signal developed by the switch 50 and its sensor 51 is applied to the control system to control the deenergization of the solenoid 43.

A second embodiment of a latch system according to the invention is illustrated in FIG. 4 in which the parts corresponding to those of the embodiment in FIG. 3 have corresponding reference numerals but which are primed in FIG. 4. Those reference numerals primed in FIG. 3 are double primed in FIG. 4 whereby the second embodiment is more easily understood and need not be described in as great detail. The second embodiment operates in about the same manner as the first embodiment.

In the second embodiment a bolt-release member 34' is hollow and has its biasing spring 37' housed therein. The latch for the actuator 34' is constructed differently instead of the latch being resilient a spring 55 biases the armature 45' mounting a latch member 56 so that a latch 57 engages the shoulder 36' of the actuator 34' and it is this shoulder that limits the projected position of the actuator 34' and cooperates with the latch 57 to releasably retain the actuator in a retracted position. When the solenoid 43' is energized, the biasing spring 55 is overcome and the bolt-release member 34' is released.

The switch sensor 51' in this embodiment is in a lowered position when the actuator 34' is in a retracted position. When the actuator 34' assumes its projected position, the sensor 51' is deflected upwardly so that the switch 50' generates a signal as before described which can be used to control indication of the condition and/or to control de-energization of the solenoid 43' as described with respect to the first embodiment.

The system according to the invention is constructed so that it will function with the corresponding electrical power either a.c. or d.c. For example, the first described embodiment may be made for use with direct current. Moreover, the apparatus can be made so that it functions with either alternating current or direct current by using a converting element 60 that converts direct current to alternating current.

In this second embodiment, the construction of the bolt-release mechanism is that of an integral unit easily removed from a door frame as a unit by easily removing an inspection plate 18' as before described. The mechanism on the door itself is different from the first embodiment. A dead bolt 16' is connected to a rod 62' slidably guided by a fixed guide 63 which also acts as a stop for an end of a biasing spring 17' disposed between the stop and the dead bolt 16'. The rod has fixed thereto a cam plate 65. A pivoted cam operated by a knob or a pin tumbler lock, not shown, is provided for contacting the cam plate and manually operating the dead bolt 16' to a retracted position. The dead bolt 16' can be locked in the retracted position by use of a key in the tumbler pin lock, not shown. However, when the dead bolt is in its projected position illustrated in FIG. 4 is is retracted by remote control by application of a command signal to the solenoid 43' energizing it and retracting the latch 57. The command signal is developed by a sensor as before described.

As stated above, the latch system mechanism mounted on the fire door 1 itself is provided with suitable elements for manually retracting the dead bolt 16' and locking it manually in its retracted position by depressing the pushbutton 8 on the door knob.

The latch system according to the invention provides for simplified latches for releasably securing "doors." The latch illustrated in FIG. 5 may be used in conjunction with the apparatus disclosed in FIGS. 3 and 4 and may be used alone in releasably retaining a "door." It will be described in conjunction with the fire door 1. The simplified latch is generally designated by the reference 70. The door 1 is provided along an upper edge with a plate 71 to which is secured a casing 73 within which is mounted a latch mechanism comprising a roller 76 corresponding to the dead bolts of the two embodiments heretofore described. The roller is carried on a rod 77 pivoted on a support 78. The rod 77 is axially guided by two fixed guides 80, 81 and is provided with a collar 77a. A biasing spring 82 is mounted between the collar and one fixed guide 81 constantly biasing the dead bolt 76, in the form of a roller, to a projected position in which it is received in a latch opening provided in a plate 83 in the underside of the door frame 11 above the fire door. The dead bolt mechanism is mounted in the fire door similarly to the dead bolts of the other apparatus before described.

The latch apparatus disclosed in FIG. 5 is provided with a bolt-release mechanism similarly to those before described except that instead of being arranged in a vertical position the elements thereof are disposed horizontally. In order to simplify the drawings, the bolt-release mechanism is illustrated fragmentally by a bolt-release member or actuator 85 that is constructed similarly to the actuator 34 of the first embodiment. The actuator is releasably latched and is operable to a retracted position shown in the drawing and is actuated by a spring, not shown, to a projected position in which it engages the periphery of the roller-type dead bolt and overcomes the force of its biasing spring 82 to move the dead bolt to a retracted position in which an unlocked or unlatched condition is established.

Those skilled in the art will understand that the actuator in this third embodiment is remotely controlled by a sensor when the presence of a fire is detected. Furthermore, the locks or latches described may be used on emergency exit doors which are always locked and opened by remote control when an emergency, such as a fire, exists. Moreover, the various apparatus may be used on smoke discharge windows, air condition duct dampers, automatic smoke shutters, for suspended partitions that drop into position to form fire screens and the like.

Furthermore, the compactness of the apparatus allows mounting in frames where easy access to is provided for inspection or removal by use of inspection plates that are removable to provide access to the apparatus.

The system of the invention can be used in conjunction with a control system of the type disclosed in my copending application Ser. No. 301,651 filed concurrently herewith. Thus, provision can be made for sequencing the unlocking of emergency exits and the closing of fire doors as described in my copending application.

Claims

What I claim is:

1. In a door latch system, a latch automatically opened by remote control comprising, a dead bolt operable to a retracted position and biased to a projected position corresponding to a latching position, a bolt-release mechanism having a bolt-release member operable to a retracted position and a projected position and mountable opposed to the dead bolt, biasing means biasing the bolt-release member to a projected position for engaging the dead bolt in its projected position and biasing it to a retracted position, electrically actuated actuator means releasably latching said bolt-release member in its retracted position, means in said actuator means for receiving an electrical command signal to effect release of said bolt-release member for actuation to its projected position under control of said biasing means, and an electrical switch having a sensor sensing the position of said bolt-release member to control de-energization of said actuator means when the bolt-release member assumes its projected position and for initiating a signal indicating the bolt-release member is in a projected state thereby indicating the lock is unlocked.

2. In a door latch system, according to claim 1, including biasing means continuously biasing the dead bolt to its projected position.

3. In a door latch system, according to claim 2, in which said means in said actuator means for receiving said electrical command signal comprises a solenoid.

4. In a door latch system, according to claim 3, in which said actuator comprises a latch actuatable by said solenoid for releasing said bolt-release member.

5. In combination, a fire door, biasing means biasing said door to a closed position, a latch system releasably retaining said door in a position of readiness for release by remote control for movement to a closed position under control of said biasing means comprising a latch means mounted on the door biased toward a projected position latching the fire door in said position of readiness, an actuator mechanism mounted in an area framing the door and having means in a retracted position operable to a projected position by remote control in response to a control command signal for engaging said latch means in its projected position and unlatching the door by activating said latch means to its retracted position, means for generating said control command signal upon detection of a physical quantity indicating the presence of burning of a substance.

6. The combination according to claim 5, in which said latch means comprises a rod in said door mounting a roller actuated to a projected position latching the door and to a retracted position unlatching the door, means constantly biasing said rod for maintaining said rod in a position retaining said roller in its projected position, said actuator means in a retracted position being disposed for engaging the periphery of said roller and actuating said rod for retracting said roller to its retracted position.

7. The combination according to claim 5, in which said latch means comprises a dead bolt biased to a projected position corresponding to a position in which said fire door is releasably latched in said position of readiness, said actuator mechanism comprising a bolt-release mechanism having a bolt-release member operable to a retracted position and a projected position corresponding to a position in which said bolt-release member engages the dead bolt in its projected position and biases it to a retracted position, said actuator means including means actuated electrically for latching and unlatching said bolt-release member.