US3872696A

US3872696A - Combination lock and fail-safe latch for exit doors

Info

Publication number: US3872696A
Application number: US406570A
Authority: US
Inventors: Arthur V Geringer
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-10-15
Filing date: 1973-10-15
Publication date: 1975-03-25
Anticipated expiration: 1992-03-25

Abstract

Combination lock and fail-safe latch for exit doors in which a locking bolt of a lock mechanism on a door frame is spring urged to an unlocked position with respect to a closed door, and is operable to a locked position by electrically energized actuator means, the locking bolt being movable from a locked position to an unlocked position by means of a bolt ejector of a locking mechanism on the door, the bolt ejector comprising a component of a door lock assembly or an attachment thereto, and being supported for movements to a retracted position and an advanced position, means normally urging the bolt ejector to the retracted position and manual actuator means being operable from the inside of the door to move the bolt ejector to an advanced position for ejecting and moving the locking bolt from locked position to unlocked position. A fail-safe feature is accomplished by providing the locking bolt and bolt ejector respectively with magnet members arranged with their adjacent pole ends in a repulsion mode to produce a magnetic force for moving the locking bolt to unlocked position upon deenergization of the electric actuator means in the event of failure of the spring urging means.

Description

United States Patent n91 Geringer 1 Mar. 25, 1975 1 1 COMBINATION LOCK AND FAIL-SAFE LATCH FOR EXIT DOORS [76] Inventor: Arthur V. Geringer, 5424 Geyser Ave., Tarzana, Calif. 91356 [22] Filed: Oct. 15, 1973 [21] Appl. No.: 406,570

[52] US. Cl 70/145, 70/281, 70/432,

292/33, 292/34, 292/37, 292/254 {51] Int. Cl... E05b 63/14, E05b 59/00, E05b 47/02 {58] Field of Search 70/101, 141, 145; 292/144,

[56] References Cited UNITED STATES PATENTS 1,044,099 1 H1912 Spring ZOO/61.67 2,219,186 10/1940 Hornfeck 292/144 2,304,941 12/1942 Mantz 292/254 3,166,144 1/1965 Price 180/82 3,596,021 7/1971 Saul 200/6193 3,751,086 8/1973 Geringer 292/144 FOREIGN PATENTS OR APPLICATIONS 23.347 1913 United Kingdom 292/144 Prt'nmry E.\'aminerA1bert G. Craig, Jr. Attorney, Agent, or Firm-Whann & McManigal [57] ABSTRACT Combination lock and fail-safe latch for exit doors in which a locking bolt of a lock mechanism on a door frame is spring urged to an unlocked position with respect to a closed door, and is operable to a locked position by electrically energized actuator means, the locking bolt being movable from a locked position to an unlocked position by means of a bolt ejector of a locking mechanism on the door, the bolt ejector comprising a component of a door lock assembly or an attachment thereto, and being supported for movements to a retracted position and an advanced position, means normally urging the bolt ejector to the retracted position and manual actuator means being operable from the inside of the door to move the bolt ejector to an advanced position for ejecting and moving the locking bolt from locked position to unlocked position. A fail-safe feature is accomplished by providing the locking bolt and bolt ejector respectively with magnet members arranged with their adjacent pole ends in a repulsion modeto produce a magnetic force for moving the locking bolt to unlocked position upon deenergization of the electric actuator means in the event of failure of the spring urging means.

17 Claims, 5 Drawing Figures COMBINATION LOCK AND FAIL-SAFE LATCH FOR EXIT DOORS BACKGROUND OF THE INVENTION The present invention relates generally to the field of 5 door locks.

The present uniform building code calls for a means of electrically unlocking all the stairway exit doors in the case of buildings having a height above a perscribed number of stories.

One proposed approach to the problem of meeting the code provisions is to utilize a lock assembly on the door which incorporates a bolt that can be operated to an unlocked position by means of a small solenoid. Such approach, however, poses a number of problems:

a. It is difficult to provide a dependable supply of electric current from the stationary door frame to the lock of the movable door. A power transfer hinge has been developed for this purpose, but this does not eliminate all the difficulties, and still leaves the problem of conducting the electric current from the hinge along or through the door to the lock mechanism. I

b. Two types of solenoids are presently used, one of these being arranged for momentary duty and the other for continuous duty. Both types of solenoids must have a continuously available power supply, and require expensive inspection and maintenance routines to assure dependability. The continuous duty solenoid is mounted in the lock and is arranged to keep the outside knob in locked position, the inside knob being free. The continuous duty solenoid also presents a hazard due to the relatively greater power required. Because of this larger power requirement, heat is generated and conducted to the outside knob as well as the inside knob of the lock. A problem is thus presented in that people are reluctant to grasp the heated knob and open the door. This condition thus presents a psychological hazard which is in opposition to the primary concept of the safety concept provided by the exit door.

In order to overcome the above enumerated problems, the present invention provides in effect two lock mechanisms. One of these lock mechanisms is mounted on the stationary door frame, and embodies a locking bolt that is spring urged to an unlocked position, and which may be electrically actuated to a locked position. The other lock mechanism embodies a bolt ejector which is manually operable from inside the door to eject and move the locking bolt from a locked to unlocked position. The electrically actuated lock being on the door frame is easily supplied with electric current and therefore requires relatively low maintenance. Moreover, any heat that is generated in the electrically actuated lock will not be conducted to the manual actuated means of the lock mechanism on the door.

As a further feature, a fail-safe arrangement is provided which operates according to the basic principles disclosed in my U.S. Pat. No. 3,751,086, dated Aug. 7, 1973. In the present invention, bar magnets are provided in the locking bolt and bolt ejector, these magnets having their adjacent ends in a repulsion mode, and being operative to set up a magnetic force which will move the locking bolt to an unlocked position, when its actuating solenoid is deenergized, and even though the associated spring for accomplishing such purpose has been damaged or rendered ineffectual.

SUMMARY OF THE INVENTION The present invention relates generally to improved locking mechanisms for exit doors, and which embodies a fail-safe operating feature.

Having in mind the inherent disadvantages and problems encountered with the conventionally available locking mechanisms for exit doors, the present invention has for one object the provision of an improved fail-safe locking mechanism of the electrically manually operable type for emergency exit doors, which is more dependable, and yet is economical as to the main tenance and inspection requirements to maintain its dependability.

A further object is to provide a locking mechanism which can be mounted on a door frame, and which embodies an electrically actuated locking bolt that will remain locked so long as it is energized, but will be unlocked automatically when deenergized.

A further object is to provide a locking mechanism according to the foregoing-object in which another associated locking mechanism is mounted on the door and provided with a bolt ejector which can be manually actuated from inside the door to eject the locking bolt of the locking mechanism on the door frame to permit opening of the door.

Another object-is to provide improved locking means for emergency exit doors, in which an electrically actuated lockingbolt on the door frame and a manually operable bolt ejector on the door are provided with failsafc means in which magnets in the locking bolt and bolt ejector generate a magnetic force which will function to move the locking bolt to an unlocked position, when the locking bolt is electrically deenergized.

Still another object is to provide improved locking means for exit doors in which an electrically actuated locking bolt mounted on the door frame can be moved to an unlocked position by means of a manually actuated bolt ejector which may be embodied in a plurality of different lock organizations such as a mortise lock, cylindrical lock, unit lock, panic bar actuator, and the like, or may be provided as an attachment to an existing lock, for example, a cylindrical lock.

Further objects of the invention will be brought out in the following part of the specification, wherein detailed description is for the purpose of fully disclosing the invention without placing limitations thereon.

BRIEF DESCRIPTION OF THE DRAWINGS Referring to the accompanying drawings, which are for illustrative purposes only:

FIG. I is a perspective view illustrating the cooperative association of an electrically actuated locking mechanism mounted on a door frame, and a manually operable locking mechanism mounted on the door, according to the present invention;

FIG. 2 is a fragmentary sectional view showing details of the solenoid actuated locking bolt, taken substantially on line 2-2 of FIG. 1;

FIG. 3 is a fragmentary sectional view showing details of the bolt ejector, taken substantially on line 33 of FIG. 1;

FIG. 4 is a sectional view illustrating an alternate arrangement in which the bolt ejector is incorporated as an attachment for the door mounted locking mechanism; and

FIG. 5 is a schematic view showing the control circuitry.

DESCRIPTION OF THE SEVERAL EMBODIMENTS OF THE INVENTION For illustrative purposes, there is shown in FIG. 1 a door locking arrangement for emergency exit doors in which an electrically operable locking mechanism, as generally indicated at 10, is mounted on the door frame 11 for operative association with a manually operable locking mechanism, as generally indicated at 12, mounted on a door 13.

The locking mechanism is contained within a tubular housing 14 which is secured at its open end to a strike plate 15 so as to extend rearwardly therefrom. Within the housing is a solenoid actuator for a locking bolt 16 which is connected in axial alignment with a solenoid plunger 17 having operative association with a solenoid coil 18. The locking bolt is axially reciprocable with the solenoid plunger and is normally retained in a retracted position by means of a compression coiled spring 19 which surrounds the locking bolt, one end of this spring being engaged with an annular flange secured to the inner end of the bolt, and the other end of the spring being engaged with the inner surface of the strike plate 15. The spring 19 normally urges the locking bolt to a retracted position, when the solenoid coil 18 is deenergized. Upon energization of the solenoid coil, the plunger will be moved towards the right as seen in FIG, 2 and the locking bolt moved from its unlocked retracted position into a locked position in which it extends through an opening 21 in the strike plate 15 as shown in phantom lines. The strike plate is secured to the edge face of the door frame by retaining

screws

22, 22, and at one edge is provided with a laterally projecting curved caming flange 23.

As further shown in FIGS. 1 and 3, the locking mechanism 12 is shown as comprising a conventional mortise type lock which has been modified for operation with the locking bolt 16 of the locking mechanism 10. The locking mechanism is housed within a casing 24 which is connected to and extends from a laterally tapered base plate 25 which is secured with its outer surface flush with the edge surface of the door 13 by means of retaining screws 25, 25'.

It is to be understood that the components of the locking mechanism may vary as to their configuration and operative association. For purposes of illustration, the locking mechanism has been shown in this case as comprising a conventional split hub arrangement in which an inner hub 26 and a similar outer hub (not shown) are supported in coaxial rotatable relation. The hubs are respectively coupled with knob spindles, the inner hub knob spindle being indicated at 27. This spindle and a similar outer knob spindle (not shown) are connectable to appropriate knob or other means for independent manual operation of the lock mechanism from the inside or the outside of the door. The inner and outer hub members respectively carry semicircular cam members 28 and 29 which have their opposite ends diametrically disposed on opposite sides of the associated hub. The cam members 28 and 29 are respectively operatively associated with an inside hub lever 30 and outside hub lever 31. Each of these levers is pivoted for swinging movement on a fixed pivot at its lowermost end. The free end of each hub lever is formed to extend around the associated hub and provide diametrically disposed arms as indicated at 33 and 34 for abutting engagement by the opposite ends of the associated hub cam member when rotated in opposite directions. Thus, upon rotation of the hub in either direction, the associated hub lever will be swung about its pivot in a clockwise direction as seen in FIG. 1. A spring 35 continuously urges each hub lever in a counter-clockwise direction, one end ofthis spring being anchored in the fixed pivot 32 and the opposite end being connected with the hub lever.

The hub levers 30 and 31 are operatively connected with a latch bolt 36 which extends through an opening 37 in the face plate 25 and is adapted to enter an opening 38 in the strike plate 15 when the door is in closed position. The latch bolt is supported for reciprocative movement by means of a shaft 39 which extends be tween spaced guide pins 40 and 41 and is provided at its innermost end with a head portion 42. The bolt is normally urged into an extended latching position by means of a compression spring 43 having one end engaged with the latch bolt 36 and its other end engaged against a collar 44 interposed between the spring end and the guide pins 40, 41, this collar being slidably mounted on the shaft 39. The latch bolt is movable to a retracted unlatched position by manual actuation of either of the hub levers 30, 31, by virtue ofthe engagement of the lever arm 34 in each case, behind the head portion 42. As thus arranged, the latch bolt 36 can be moved to unlatched position by means of the inside or outside knobs.

The conventional mortise lock has been modified according to the features ofthe present invention by providing a bolt ejector 45 which is positioned above the latch bolt 36 and supported for reciprocative movement within a tubular support 46 havingan open end in registration with an opening 47 in the face plate 25, this opening being so positioned that it will be axially aligned with the opening 21 of the strike plate 15, when the door is in closed position, and thereby permit the reception of the outermost end of the locking bolt 16 when it is moved to a locking position.

The bolt ejector 45 has its outer end inwardly positioned with respect to the opening 47, and at its other end is connected with one end of a shaft 48 which extends through an opening 49 in the bottom of the tubular support, this shaft at its outer end being provided with a head portion 50. The bolt ejector 45 is normally urged to a retracted position in which it engages the ad jacent surface of the bottom of the support, by means of a compression coiled spring 51 which surrounds the shaft and has one end bearing against the bottom of the support 46 and its other end bearing against the head portion 50.

Provision is made for moving the bolt ejector to an advanced position in which the outer end of the bolt will be moved into the opening 47 to a position in which its end surface will be flush with the outer surface of the face plate 25 in response to actuation of the inside hub lever 30 by means of the inside knob. With the movement of the bolt ejector to its advanced position as just described, it will function to move the locking bolt from its locked position in the opening 47 to an unlocked position which will permit the door to be opened, since the actuation of the inside knob also retracts the latching bolt 36 at the same time. To accomplish this operation, a rocking lever 52 is pivotally supported between its ends for swinging movement on a fixed pivot 53. The rocking lever hasan upwardly extending arm 54 which extends over and bears against the head portion 50. A downwardly extending arm 55 carries an end pin 56 which is in the path of movement of the inside hub lever 30. The rocking lever 52 is normally urged in a clockwise direction as seen in FIG. 1 by means of a spring 57, one end of this spring being anchored in the fixed pivot 53, and the other end being secured to the rocking lever. Thus, the pin 56 will be urged at all times into engagement with the inside hub lever 30. Swinging movement of the hub lever in a clockwise direction will operate to swing the rocking lever 52 in a counter-clockwise direction and move the bolt ejector from its retracted position to its advanced position for ejecting the locking bolt 16 when the door is in locked position.

While the locking bolt and bolt ejector concept of the present invention has been described above with respect to a mortise type of lock mounted on the door, the invention is not so limited and may be practiced with respect to other types of locking mechanisms, such as a cylindrical lock, unit lock or with respect to panic bar actuators, wherein the bolt ejector may be embodied in an attachment for the existing lock structure. The attachment may be arranged for different types of manual operating media, for example, knob actuator, lever actuator, panic bar actuator, or other suitable forms. As illustrative of the attachment concept, there is shown in FIG. 4, a conventional type of cylindrical lock which embodies conventional locking components and includes conventional split hub arrangement (not shown) contained within a housing 58, an outside hub 59 being connected by a spindle 60 with an outside knob 61 mounted thereon. In a similar manner, an inside hub 62 connects with a modified replacement spindle 63 which is longer than the normally supplied spindle in order to provide for the ejector bolt attachment. The outer end ofthe spindle 63 is connected with the inside knob 64.

The hubs 59 and 62 are conventionally connected through components (not shown) for operating a latch bolt 36 which is adapted in the closed position of the door to enter the opening 38 of the strike plate 15.

The attachment assembly, as generally indicated by the numeral 65 comprises a hollow housing 66 having spaced wall members 67 and 68 containing axially aligned

openings

69 and 70 for receiving the knob spindle 63 therethrough. The housing 66 is secured to the back surface of the door 13 by appropriate means such as screws. A bolt ejector 45 of cylindrical configuration is supported for reciprocative movement within an open ended bore 71 formed in a support member 72 within the housing. The bolt ejector at its innermost end is in this case connected to an axially aligned shaft 73 having a terminus head portion 74 which is adapted to bear against a diametrically extending camming face 75 formed at the bottom of a recess 76 provided in the spindle 63. The bolt ejector 45 is urged to a retracted position by means of a compression coiled spring 77 which surrounds the shaft 73, one end of this spring being in engagement with the head portion 74, and the other end of the spring being in engagement with a washer 78 interposed between the spring end and the adjacent end of the supporting member 72. As thus arranged, the outermost end of the bolt ejector 45 is inwardly spaced from theouter open end of the bore 71.

In this embodiment, the locking mechanism 10 is illustrated as being associated with a hollow metal door frame which is extruded or otherwise formed to provide side wings, one of which is indicated by the numeral 79, these side wings being arranged for anchoring in conventional known manner in a plaster side wall as indicated at 80.

The metal door frame is of generally U-shaped crosssection and is formed with a bridging portion 81 having an outwardly projecting stop 82 against which the edge of the door is adapted to engage in its closed position. The tubular housing for the locking bolt 16' is positioned in the stop 82 by being secured as by welding or otherwise to the rear surface of a supporting plate 83 which extends over an opening 84 in the outer surface of the stop. The supporting plate is formed with an opening 85 to receive the outermost end of the locking bolt 16 during movement between locked and unlocked positions. In the closed position of the door, the locking bolt in its locked position will extend into the adjacent end of the bore 71 so that its end is juxtaposed to the outer end of the bolt ejector 45.

In the case of emergency exit doors of public buildings, it is extremely important that the locking mechanisms embody fail-safe operating characteristics. From the foregoing description, it will be apparent that the spring 19 provides in a sense a fail-safe action which will unlock the bolt in the event that energization of the solenoid actuator is terminated for any reason. However, the crystalization or malfunction of this spring could produce a most dangerous situation. It is therefore an important feature of the present invention to augment the pseudo fail-safe characteristic of the solenoid actuator in a manner to positively open the locked door and move the locking bolt element to its unlocked position, even though the spring 35 should fail to operate.

In the present case this is accomplished by providing a pair of

permanent magnets

86 and 87. The magnet 86 is embraced within the outer end of the locking bolt 16 or 16' and will move with the bolt to its locked and unlocked positions. The other magnet 87 is embraced by the

bolt ejector

45 or 45. These magnets are mounted so that when the door is closed andthe locking bolt is at its locked position, the magnets will have like poles adjacently positioned in a repulsion mode. For example, the adjacent ends may constitute the north poles of the magnets, as shown. Upon spring failure, the magnetic forces generated by the magnets is of sufficient force to move the locking bolt to unlocked position without the aid of the spring normally utilized for this purpose.

. The magnet 87 in the bolt ejector may be utilized for eliminating the spring 77 in the arrangement shown in FIG. 4. For this purpose, the spindle 63 would be constructed of a suitable metal or the cam face covered with a suitable metal such as steel or other magnetizable material, so that the magnet, which would in this case be extended to the head portion 74, would operate to always maintain the head portion in bearing engagement with the associated camming surface.

In utilizing the locking concept of the present invention, particularly in the case of emergency exit doors, it is desirable to provide appropriate electrical control indicating components, which will now be described. Open and closed positions of the door are utilized to control a reed switch 88 which is mounted on the rear surface of the supporting plate 83. This switch has normally open contacts which will be operated to close position, when the door is in closed position, by means of a magnet 89 mounted in an appropriate position on the door structure or locking mechanism. As illustrated, the magnet 89 is supported in a confronting portion of the support member 72.

It is also desirable to know whether the locking bolt is in a locked or unlocked position. A reed switch 90 is also mounted on the supporting plate member 83. This switch has normally open contacts which are operatively controlled by the magnet 86 carried by the locking bolt. When the locking bolt is moved to an unlocked position, the magnet 86 will close the switch contacts.

A key switch 91 is provided for controlling the energizing circuit of the solenoid coil 18 of the actuator for the locking bolt. This switch is shown as being mounted on the side wing 79 of the door frame for access from the outside of the door. The switch has normally closed contacts which are arranged to be momentarily opened by actuation of the key. The key is removable only when the contacts are in closed position.

As shown in FIG. 5, the solenoid coil 18 is energized through an energizing circuit as follows: From one terminal 92a of an electric source, the contacts of key switch 91, the bolt position switch 88, the solenoid coil 18 and thence to the other terminal 92b of the electrical sourcev With the door 13 in open position, the contacts of switch 88 will be open, and as a consequence the solenoid coil 18 will be deenergized and the locking bolt 16 will be in its unlocked position. In this position the bolt position switch 90 will close its contacts and close a monitor circuit to indicate by means of a light or other suitable signal that the locking bolt is in an unlocked position. Upon closure of the door 13, the magnet 89 will be in a position to actuate the contacts of switch 88 to closed position, whereupon the solenoid coil 18 will be energized to move the locking bolt 16' to its locked position. This locking bolt actuation will automatically occur when the door is closed, and as a result of the locking bolt movement, the magnet will be in a position which will permit the contacts of switch 90 to open the monitoring circuit. Should it be desired to open the locked door from the outside thereof this can be accomplished by means of the actuation of the key switch 91 so as to momentarily open its contacts, wherupon the locking bolt 16 will be moved to its unlocked position so that the door may be unlatched by turning the outermost knob 61 of the locking mechanism to permit swinging movement of the door. It is not necessary to deenergize the solenoid 18 in order to close an open door. Closure of the door will manually force the latch 36' and locking bolt 16 to retracted positions until the door is closed, whereupon the latch 36 and bolt 16 will assume their extended latching and locking positions. In the event it is desired to open the door from the inside, this is done simply by turning knob 65 or other actuating device, which will retract the latch 36 and simultaneously move the bolt ejector 45 to a position which will move the locking bolt 16 from a locked position to an unlocked position, whereupon the door may be swung to open position. a

From the foregoing description and drawings, it will be clearly evident that the delineated objects and features of the invention will be accomplished.

Various modifications may suggest themselves to those skilled in the art without departing from the spirit of my invention, and, hence, I do not wish to be restricted to the specific form or forms shown or uses mentioned, except to the extent indicated in the appended claims.

I claim: 1. Fail-safe locking means for a door element supported for movements to opened and closed positions with respect to an associated door frame element comprising:

a. first and second bolt means each mounted on one of said elements, each of said bolt means being operable between an extended and retracted position in relation to the other of said elements; b. manual actuating means on one of said elements for said first and second bolt means including: an accessible outside member operable to move one of said bolt means to its retracted position. and

an accessible inside member operable to move both of said bolt means to retractable positions; and

c. electrically controlled means operably associated with one of said bolt means, and upon energization retaining said elements against relative movement from a closed to opened position by said outside member, but upon deenergization permitting relative opening movement of said elements in response to the actuation of the other of said bolt means to its retracted position by said outside member.

2. Locking means according to claim I, wherein said one of said bolt means comprises a locking bolt mounted on the door frame element;

the other of said bolt means comprises a latch bolt mounted on the door element, and

said actuating means is mounted on the door element and includes:

a bolt ejector mounted for selective movements to advanced and retracted positions, said bolt ejector in the closed position of said door element being axially aligned with said locking bolt, and upon movement to said advanced position being operative to move said locking bolt to its retracted position.

3. Locking means according to claim 2, wherein said one of said bolt means includes a striker plate having an opening through which the locking bolt is extendable and retractable; the other of said bolt means comprises a mortise lock assembly with a face plate having an opening for receiving the outer end of the locking bolt when the door element is in closed position, and for receiving the outer end of the bolt ejector when moved to its advanced positionasaid face plate having a second opening through which said latch bolt is extendable and retractable, and said striker plate having a second opening for receiving the outer end of the latch bolt in the closed position of the door element.

4. Locking means according to claim 2, wherein said one of said bolt means includes a striker plate having an opening through which the locking bolt is extendable and retractable; the other of said bolt means comprises an attachment for a door element lock assembly, said attachment including a housing mountable on the rear surface of the door element, said bolt ejector being mounted in the housing for advanced and retractable whereby upon deenergization of said electrically controlled means, said urging force returns said locking bolt to its retracted position.

7. Locking means according to claim 6, wherein the means normally urging said locking bolt towards said retracted position comprises a spring; the electrically controlled means comprises a solenoid connected with said locking bolt operable upon energization to move said locking bolt from said retracted position to said extended position against the force of said spring; and including a magnet carried by said locking bolt coacting with a magnet carried by said bolt ejector to provide a magnetic force supplementary to said spring for moving said locking bolt to its retracted position upon failure of the spring to function.

8. Locking means according to claim 6, wherein the electrically controlled means comprises a solenoid hav-' ing a reciprocable plunger axially aligned with and connected to said locking bolt, and said urging means comprises a spring.

9. Locking means according to claim 6, including an energizing circuit connecting said electrically controlled means with an electrical source; switch means mounted on said door frame including a reed switch having normally open contacts in said circuit; and a magnet carried by the door element arranged to be juxtaposed to said switch and operate said contacts to circuit closing position in response to movement of said door element to closed position.

10. Locking means according to claim 9, in which a key-controlledswitch mounted on said door frame has i normally closed contacts connected in series with said reed switch. i

ll. Locking means according to claim 6, including means coactive between said locking bolt and said bolt ejector providing a magnetic force supplementary to said urging force for moving said locking bolt to its retracted position upon failure of said urging means.

12. Locking means according to claim 4, wherein the means providing said magnetic force comprises permanent magnets having one set of their like poles positioned in a repulsion mode.

13. Locking means according to claim 12, wherein one permanent magnet is carried by said locking bolt, and another permanent magnet is carried by said bolt ejector.

l4. Locking means according to claim 13,- wherein the like poles are in juxtaposed relation when the door element is in closed position and the locking bolt is in extended position.

15. Locking means according to claim 13, in which said actuating means includes a cam member engaged with said bolt ejector, and the magnet carried by said bolt ejector normally urges the bolt ejector against said cam member.

16. Locking means according to claim 13, including a monitor circuit; and switch means having normally open contacts in said circuit which are operable to circuit closing position by the magnet on said locking bolt in response to movement of said locking bolt to retracted position.

17. Locking means according to claim 16, wherein said switch means includes a reed switch, and a magnet carried by the locking bolt is arranged to be juxtaposed to said switch in the retracted position of said locking bolt.

Claims

1. Fail-safe locking means for a door element supported for movements to opened and closed positions with respect to an associated door frame element comprising: a. first and second bolt means each mounted on one of said elements, each of said bolt means being operable between an extended and retracted position in relation to the other of said elements; b. manual actuating means on one of said elements for said first and second bolt means including: an accessible outside member operable to move one of said bolt means to its retracted position, and an accessible inside member operable to move both of said bolt means to retractable positions; and c. electrically controlled means operably associated with one of said bolt means, and upon energization retaining said elements against relative movement from a closed to opened position by said outside member, but upon deenergization permitting relative opening movement of said elements in response to the actuation of the other of said bolt means to its retracted position by said outside member.

2. Locking means according to claim 1, wherein said one of said bolt means comprises a locking bolt mounted on the door frame element; the other of said bolt means comprises a latch bolt mounted on the door element, and said actuating means is mounted on the door element and includes: a bolt ejector mounted for selective movements to advanced and retracted positions, said bolt ejector in the closed position of said door element being axially aligned with said locking bolt, and upon movement to said advanced position being operative to move said locking bolt to its retracted position.

3. Locking means according to claim 2, wherein said one of said bolt means includes a striker plate having an opening through which the locking bolt is extendable and retractable; the other of said bolt means comprises a mortise lock assembly with a face plate having an opening foR receiving the outer end of the locking bolt when the door element is in closed position, and for receiving the outer end of the bolt ejector when moved to its advanced position; said face plate having a second opening through which said latch bolt is extendable and retractable, and said striker plate having a second opening for receiving the outer end of the latch bolt in the closed position of the door element.

4. Locking means according to claim 2, wherein said one of said bolt means includes a striker plate having an opening through which the locking bolt is extendable and retractable; the other of said bolt means comprises an attachment for a door element lock assembly, said attachment including a housing mountable on the rear surface of the door element, said bolt ejector being mounted in the housing for advanced and retractable movement through a housing opening adapted to receive the locking bolt in its extended position and when the door element is in closed position.

5. Locking means according to claim 4, wherein the lock assembly is a cylindrical lock.

6. Locking means according to claim 2, including means providing a force normally urging said locking bolt towards said retracted position; and said electrically controlled means upon energization acting to move said locking bolt from said retracted position to said extended position against said urging force, whereby upon deenergization of said electrically controlled means, said urging force returns said locking bolt to its retracted position.

8. Locking means according to claim 6, wherein the electrically controlled means comprises a solenoid having a reciprocable plunger axially aligned with and connected to said locking bolt, and said urging means comprises a spring.

10. Locking means according to claim 9, in which a key-controlled switch mounted on said door frame has normally closed contacts connected in series with said reed switch.

11. Locking means according to claim 6, including means coactive between said locking bolt and said bolt ejector providing a magnetic force supplementary to said urging force for moving said locking bolt to its retracted position upon failure of said urging means.

14. Locking means according to claim 13, wherein the like poles are in juxtaposed relation when the door element is in closed position and the locking bolt is in extended position.