US3571974A

US3571974A - Cell door locking and driving system

Info

Publication number: US3571974A
Application number: US854047A
Authority: US
Inventors: James E Browning; David Hull Youngblood
Original assignee: Southern Steel Co
Current assignee: PHELPS Inc D/B/A SOUTHERN STEEL AN UNICORPORATED DIVISION OF PHELPS Inc A DE CORP; PHELPS-TOINTON Inc A DE CORP
Priority date: 1969-08-29
Filing date: 1969-08-29
Publication date: 1971-03-23
Anticipated expiration: 1988-03-23
Also published as: DE2040790C3; DE2040790A1; DE2040790B2; GB1278715A

Abstract

A housing enclosed cell door supporting carriage driven by an electric motor driven drive pinion engaging a rack on a reciprocable slide bar on the carriage with camming means on each end of the slide bar. The slide bar being movable through an overtravel increment at each end of travel of the carriage to bias a pivotable cell door lock bar operator carried by the carriage in a direction to move the lock bar into locking engagement with the door upon arrival of the door at either a fully open or fully closed position with the camming means also serving to move the lock bar to an unlocked position upon subsequent reapplication of driving force to the rack so that the door can again be moved.

Description

United States Patent [72] Inventors James E. Browning;

David Hull Youngblood, San Antonio, Tex. [21 Appl. No. 854,047 [22] Filed Aug. 29, 1969 [45] Patented Mar. 23, 1971 [73] Assignee Southern Steel Company Santonio, Tex.

[54] CELL DOOR LOCKING AND DRIVING SYSTEM 11 Claims, 16 Drawing Figs.

52 U.S. c1 49/18 [51] Int. Cl E05b 53/00 [50] Field of Search 49/ 1 5-20 [5 6] References Cited UNITED STATES PATENTS 1,030,699 6/1912 Youngblood 49/17 Primary Examiner-Dennis L. Taylor Attorney--Mason, Fenwick & Lawrence ABSTRACT: A housing enclosed cell door supporting carriage driven by an electric motor driven drive pinion engaging a rack on a reciprocable slide bar on the carriage with camming means on each end of the slide bar. The slide bar being movable through an overtravel increment at each end of travel of the carriage to bias a pivotable cell door lock bar operator carried by the carriagein a direction to move the lock bar into locking engagement with the door upon arrival of the door at either a fully open or fully closed position with the camming means also serving to move the lock bar to an unlocked position upon subsequent reapplication of driving force to the rack so that the door can again be moved.

"' I fl 5| 1 l PATENTED MR23 |97I SHEET 8 OF 7 r m ow INVI'IN'I'UHS JAM E-Baawmua QF Demo H-YouNaaLooo CELL noon LOCKING AND muvmc SYSTEM BACKGROUND OF THE INVENTION This invention is in the field of power driven door closure members operable by reversible electric motor means and is specifically directed to a power driven cell door operating means for moving a cell door between open and closed positions and for automatically locking the cell door upon arrival at either of such positions.

Motor driven cell door opening and closing systems have long been known and have assumed a wide variety of forms.

Moreover, while some of the prior known cell door operating systems have required plural operation of all of the cell .doors of the system, others have permitted individual operation of the cell door to enable egress from and entry into an individual cell. It has also been recognized that cell door locking means should be automatically actuated to lock a cell door in either its open or closed position in response to arrival of the cell door at either of said positions.

Additionally, it goes without saying that cell door constructions should be foolproof in operation and should be tamperproof with respectto the occupants of the cell with which the door is associated.

Unfortunately, the prior art devices have not provided economical and reliable systems which have fulfilled the foregoing needs of the penal system.

SUMMARY OF THE INVENTION It is the primary object of this invention to provide a new and improved cell door operating system that is economical to manufacture and maintain and is also reliable and foolproof in operation and completely resistant to tampering.

Obtainment of the object of this invention is enabled through the provision of a cell door hangingly attached to a cell door carriage mounted on a track above the door in a closed housing for movement between an open and closed position. A vertically movable lock bar is positioned adjacent the cell door and is movable downwardly into a locking position for locking the door in either the open or theclosed position. However, the lock bar cannot move downwardly to a locking position when the door is in any intermediate position.

Means for both opening and closing the door and for operating the lock bar are incorporated in the housing in which the cell door carriage travels and a single unitary means is employed for both locking the door and moving the door. This means comprises a pivotable lock bar actuator comprising a channel member attached to the carriage and pivoted intermediate its ends with a roller on the top of the latch bar riding within the trough of the channel member. Normally, the channel member is oriented in a horizontal position at such a level as to retain the lock bar in its upper unlocked condition. Rollers on each end of the pivotable channel member normally engage one of apair of axially aligned control rails separated by a control slot for maintaining the pivotable member in its horizontal position. The control slot is adjacent the lock bar and when the door is either in the open or closed position, one of the rollers is then positioned above the control slot so that it is free to move downwardly to cause pivotable downward movement of that end of the operator member so that the lock bar is moved to its locked position. A slide bar on the carriage has a rack attached to its upper surface to which drive to the carriage is applied by means of a drive pinion with the slide bar being capable of an overtravel movement after the carriage is stopped at either the door closed or door open position. Cam plates on each end of the slide bar engage the pivotable operator member to depress the particular roller into the control slot during the overtravel movement so that the lock bar is forcefully moved to the locked position in response to arrival of the door at either the closed or open positions. However, upon reapplication of power to the drive rack, the camming means engages the pivotable operator member to return it to its horizontal position which consequently raises the lock bar to permit subsequent travel of the door. However, when the door reaches the limit of movement in the opposite direction, the cycle is again repeated so that the lock bar is automatically moved to its locked position by one of the cams to retainthe door in this position until drive force is again applied to the rack. The lock bar is then deadlocked and cannot be pushed up from the locked position until the drive motor is again activated by the proper authorities. For this reason, the system is not subject to tampering or unauthorized operation by the persons within the cell with which the particular door is associated.

Additionally, the structure of this invention is uniquely simple and efficient in that a single linear movement effects both cell door movement and cell door locking The inventive system is uniquely simple and rugged and requires a minimum of initial adjustment and no adjustments are necessary following installation. Therefore, maintenance is kept to a minimum.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevational view of the preferred embodiment of this invention illustrating the parts in a position in which the cell door is open;

FIG. 2 is a sectional view taken along lines 2-2 of FIG. 1;

FIG. 3 is a front elevational view similar to FIG. 1 but illustrating the parts in an intermediate position in which the cell door is being moved between an open and closed position;

FIG. .4 is a sectional view taken along lines 3-3 of FIG. 3;

FIG. 5 is a front elevational view similar to FIG. 1 but illustrating the cell door in a fully closed position;

FIG. 6 is a sectional view taken along lines 6-6 of FIG. 5;

FIG. 7 is an exploded perspective view of the main components of the preferred embodiment;

FIG. 8 is a top plan view of a cell door carriage drive and control means of the preferred embodiment in which portions of the covering casing are removed for clarity and illustrating the parts in an intermediate position of travel analogous to the positions of FIGS. 3 and 4;

FIG. 9 is a sectional view taken along lines 9-) of FIG. 8; FIG. 10 is a sectional view taken along lines 10-10 of FIG.

FIG. 11 is a sectional view taken along lines 11-11 of FIG. 10;

FIG. 12 is a sectional view taken along the same lines as FIG. 11 but illustrating the parts in a door closed position analogous to the position of FIGS. 5 and 6;

FIG. 13 is a sectional view taken along the same lines as FIG. 9 but illustrating the parts in a cell door closed position analogous to FIGS. 5 and 6;

FIG. 14 is a sectional view taken along lines 14-14 of FIG. 13;

FIG. 15 is a sectional view taken along lines 15-15 of FIG. 13; and

FIG. 16 is a sectional view taken along lines 16-16 of FIG. 15.

DESCRIPTION OF THE PREFERRED EMBODIMENT Attention is initially invited to FIG. 1 of the drawings which illustrates the preferred embodiment in a cell door open position. A cell door carriage 22 is supportingly mounted in a housing in the form of a metal casing 20 connected by conventional means in the building in which it is located. Casing 26) also provides a protected enclosure for the cell door carriage mounted within its interior. Carriage 22 includes a main carriage frame member 32 in the form of a solid plate which has a cell door hanger 24 (FIG. 7) connected to its midportion and extending downwardly through a slot opening 26 formed in a bottom housing plate 28 of the housing 20. A peripheral rim 30 extends about slot opening 26 to protect the interior of the casing from unauthorized tampering from the exterior of the casing. The lower end of the cell door hanger 24 is welded to the top of a cell door 25 and the upper end of the cell door hanger is welded to the main carriage frame member 32.

Carriage supporting rollers 34 are journaled on each end of the main carriage frame member 32 and ride upon a carriage supporting rail 36 fixed to the bottom housing plate 28 as best illustrated in FIG. 7. Consequently, carriage 22 is reciprocable along the length of track 36 to move the attached cell door 25 between the open position illustrated in FIG. 1 and the closed position illustrated in FIG. 5.

The open door position is determined by an open door stop best illustrated in FIG. 16 and comprising a vertical outer plate 38 of the right cell door jam which is generally designated 39 and which also includes an inside plate 40 separated along one edge from plate 38 by a separator plate 41. A keeper plate 42 is welded to the other edges of

plates

38 and 40 for preventing outward swinging movement of the lower end of the door. It should be noted that the space between

plates

38, 40, 41 and 42 define an elongated rectangular opening in which a cell door lock bar 44 is mounted for axial reciprocation between an upper or door unlocking position in which the cell door is free to move and a lower or door locking position in which the cell door is locked in place. The manner in which the lock bar 44 locks the cell door will be discussed in detail hereinafter.

Cell door 25 includes a pair of T-shaped vertical frame members 46 and 48 (FIG. 7) having

head flanges

47 and 49 respectively and comprising the left and right edges of the cell door.

Frame members

46 and 48 are connected adjacent their top ends by means of an angle member 50 which has an upper horizontal plate 51 constituting the top of the door. Plate 51 is provided on its left end with a door open locking slot 52 which is engageable by a portion of lock bar 44 in a manner discussed in detail hereinafter to enable the locking of the door in its open position. Similarly, a door closed locking slot 54 is provided adjacent the right end of the angle 50 for enabling lock bar 44 to lock the door in its closed position. Additionally, the lower end of the

members

46 and 48 are connected by means of a T-frame bottom plate 56 (FIG. which has a running flange 58 located inwardly of the lower edge of keeper plate 42. A lower door open locking slot 60 (FIG. 3) which is in alignment with the upper door open locking slot 52 is formed in the upper edge of flange 58 on the left end thereof. Additionally, a lower door closed locking slot 62 is formed in the upper edge of the right end of flange 58 in vertical alignment with the upper slot 54 of plate 51 for enabling the locking ofthe cell door in its closed position.

It should be noted that the open door position is determined by engagement of the left-hand edge of flange 47 with plate 38 which, as was noted previously, constitutes an open door stop for positioning the door while the door is stopped in its open position by engagement of the inner edge of the head flange 47 with plate 38. Similarly, engagement of the inner edge of the right head flange 49 with plate which constitutes a door closed stop serves to position the door in the closed position.

Lock bar 44 has an actuator roller (FIG. 7) on its upper end and includes a travel permitting slot 64 which is in horizontal alignment with the horizontal plate 51 when the lock bar is in its upper or unlocked position as shown in FIG. 10. Consequently, the cell door is then free to move when the lock bar is in its upper position. However, when the cell door is in its closed position, lowering of lock bar 44 causes a lock lug 66 formed in the upper end of the lock bar adjacent slot 64 to move to a position in alignment with horizontal plate 51 to enter the slot 54 of plate 51 as shown in FIG. 15. A lock lug 68 on the lower end of lock bar 44 is provided to simultaneously enter the lower door closed locking slot 62 of flange 58. Consequently, both the upper and lower ends of the door are then forcefully locked.

On the other hand, when door 25 is in its open position, downward movement of the lock bar 44 to the locking position causes lock lug 66 to enter the slot 52 while lock lug 68 simultaneously enters slot 60. Force necessary to create vertical movement of the lock bar 44 is provided through the roller 45 on the upper end of the lock bar in a manner to be discussed in detail hereinafter.

The lock bar actuator means for moving the lock bar from locked to unlocked position and vice versa includes a pivotable lock bar operator 70 in the form of a channel member which is connected to a pivot shaft 72 at its midpoint as shown in FIG. 7 with the pivot shaft being received in a bearing block 74 bolted to the lower side of a rearwardly extending guide and support plate 76 which is boltingly connected to the middle of the main carriage frame 32. Lock bar operator 70 provides a linear trough 71 into which roller 45 is received so that the trough moves with respect to roller 45 when the carriage frame 32 carrying operator 70 is moved along tracks 36.

In addition to plate 76, first and second rearwardly extending

bearing support plates

78 and 80 respectively are connected to the left and right ends of the main frame member 32 and respectively support

grooved slide bearings

82 and 84 on their rearmost ends.

Grooved slide bearings

82 and 84 provide support for an elongated rack 88 which is mounted for reciprocation on the slide bearings. A slide bar 90 is connected to and beneath rack 88 by means of first and second outer spacer blocks and 102 and inwardly positioned spacer stop blocks 104 and 106, all of which serve to position the upper surface of slide bar 90 immediately below the lower surfaces of

plates

76, 78 and 80 as shown in FIG. 9. A retainer plate 108 is bolted to the stop blocks 106 and is located adjacent the bottom surface of the slide bar 90 for providing a rigid connection between the rack 88 and the slide bar 90. Movement of the rack is limited by the stop blocks 106 and 104 which alternately engage the edges of the plate 76 in the manner that block 104 is engaging plate 76 in FIG. 12. Therefore, it will be seen that the slide bar 90 and rack 88 are mounted for reciprocation between fixed limits as a unit on the

carriage elements

32, 76, 78, 80 etc.

First and second triangular shaped

cam plates

110 and 114 are attached to the lower side of slide bar 90 for a purpose to be described hereinafter.

Drive to the rack 88 is provided by means of an output pinion 116 of a drive motor 118 supported on a drive motor support bracket 120 extending from the inner wall of the easing 20 as best shown in FIG. 10. Microswitches I19 and 121 for controlling motor 118 through circuitry forming no part of this invention are attached to motor 118 for respective engagement by

actuator arms

132 and 134 on the respective ends of rack 88.

Additionally, it should be noted that an angle member having a horizontal plate 86 which serves as a cover plate for the slot 26 is attached to the main frame member 32 for movement therewith. Cover plate 86 prevents unauthorized tampering with the interior of the casing or housing 20.

A stub shaft 122 extends forwardly from the left end of pivot lock bar operator 70 as viewed in FIG. 7 and has a positioning roller 124 on its outer end separated from the body of the operator bar 70 by a cam follower roller 126. Similarly, the right end of the pivotable lock bar operator 70 is provided with a stub shaft 128 which has a positioning roller 130 mounted adjacent its outer end and separated from member 70 by a cam follower roller 132. Cam follower roller 126 is engageable with the inwardly facing surface of cam 110 while cam follower 132 is engageable with the inwardly facing surface of cam 114. The first positioning roller 124 is positioned over a first lock bar operator track 134 for rolling movement along the top surface of track 134 while the second positioning roller 130 is positioned in alignment with a second lock bar operator track 136 for rolling movement along the top surface of track 136.

Tracks

134 and 136 are connected to bottom plate 28 of casing 20 and are in axial alignment with each other but are separated by an open control space 138 which is aligned with a slot 140 through which lock bar 44 extends.

Control space 138 is of slightly greater width than the diameter of

rollers

124 and 130 so thatthese rollers can enter the control space when positioned in alignment with the control space. However, such positioning only occurs when the cell door is in its fully closed or fully opened positions.

The manner in which the invention operates will now be discussed in detail with initial reference being made to FIGS. 1, 2 and 12 which illustrate the cell door 25 in its locked open position. In this position, the lock bar operator member 70 is inclined so that the end of the trough 71 in which the roller 45 is positioned is tilted downwardly as best illustrated in FIG. 12. Additionally, it should be noted that the positioning roller 1 24 is positioned in the control space 138. Bar 70 would not be able to assume the inclined position illustrated in FIG. 12 if roller 124 were not positioned in control space 138. The lower position of roller 45 consequently results in lock bar 44 being in its lower or locking position in which the. upper locking lug 66 is within the confines of slot 52 and the lower locking lug 68 is in slot 60, Consequently, the door is locked in the open position and cannot be moved until lock bar 44 is raised to its unlocking position. It should also be noted that rack 88 is in its extreme limit position of leftward movement as viewed in FIG. 5 with stop 104 abutting against plate 76 with this position constituting a door open overtravel position resultant from movement in the door opening direction overand above the movement of the carriage.

Power is applied to the reversible motor 118 to cause drive pinion 116 to rotate in a counterclockwise direction asviewed in FIG. 12 as the first step in closing the door toinitiate movement of rack 88 and plate 90 to the right from their FIG. 12 position. The initial movement of rack 88 is not conveyed to the carriage since the rack merely slides-on slide ,

bearings

84 and 82 since there is no driving connection between either rack 88 or any of the elements of slide bar 90 and the carriage at this stage of operation. However, it should be kept in mind that the rack 88, slide bar 90 and cams ,110 and ll4 move as a unit and the initial movement causes cam 114 to engage the cam follower roller 132 as shown in FIG. 12 .to consequently depress cam follower roller 132 and initiate rotation of the lock bar operator channel 70 in a counterclockwise direction as viewed in FIG. 12. This initial rotation of the lock bar operator obviously results in upward movement of the right end of the lock bar operator 70 and roller 45 and consequently raises the lock bar from its locking position to its unlocked position in which the cell door is then free to begin movement to the right toward a closed position.

The initial movement of rack 88, slide bar 90 and

cams

110 and 114 results in the movement of operator 70 from the position shown in FIG. 12 to a horizontal position. Rotation of the lock bar is stopped by engagement of roller 130 with track 136 at which time lock bar 44 reaches its upper position. It should be noted that the positioning of the lock bar 70 in the horizontal position occurs simultaneously with engagement of the positioning roller 130 with the upper surface of track 136. Engagement prevents any further. counterclockwise pivotable movement of member 70 so that continued movement of cam 114 to the right as shown in FIG. 12 initiates movement of the main carriage frame 32 etc. and cell door 25 to the right toward a closed position. The parts are then in an intermediate position in which the operator member 70 is perfectly horizontal, the lock bar is in its upper position and the rack 88, slide bar 90 and the main carriage 32 etc. move as a unit to carry the door toward its closed position. Roller 45 merely rolls across the lower flange of operator 70 as the door 25 moves toward the closed position. This intermediate position of the parts is best illustrated in FIG. 11 in which the door has moved half the distance from open to closed position; this intermediate position is also illustrated in FIGS. 3, 4, 8, 9 and 10.

l The

operative parts

88, 90 etc. continue to remain in the intermediate position with respect to the carriage illustrated in FIGS. 11 etc. until the cell door is stopped by the closed door stop means. Stopping of movement of the cell door in the closed position obviously also stops movement of the main carriage frame 32 and the operator member 70 attached thereto while motor 118 continues to drive rack 88 and bar etc. to begin an overtravel movement of these elements beyond the stopped position of the carriage. As the cell door reaches its closed position, the positioning roller I30 moves from the lock bar operator track 134 into the open control space 138. The continued overtravel movement of rack 88 and bar 90 then causes cam 114 to move follower 132 downwardly into space 138 to consequently pivot the operator 70 from the horizontal position to the inclined position illustrated in FIGS. 5, 13 and 15 with the locking lug 66 being moved into slot 54 and the locking lug 68 being received in slot 62 to consequently lock the cell door in its closed position. Upon arrival of the parts to the FIG. 13 position, the stop 106 engages the right'edge'of plate 76 as viewed in FIG. 13

and switch 121 is engaged by the switch actuator 144 to deactivate motor 118 by conventional means and the rack 88 and associated slide bar 90 etc. are in their door closed overtravel position. The lock bar is deadlocked in its lower locking position and cannot be moved upwardly until motor 118 is reac tivated to initiate movement of the rack 88 toward the right as viewed in FIG. 13. r

Subsequent actuation of motor 118 to move rack 88, slide bar 90 and cam etc. to the right initially causes downward movement of follower 126 and a consequent counterclockwise pivotal movement of member 70 as viewed in FIG. 13. Upon member 70 assuming a horizontal position, the lock bar is in its upper locked position so that the continued movement of cam 110 begins movement of the carriage and the attached cell door toward the open position. The rack 88 and slide bar 90 etc. are then in an intermediate position with respect to the carriage frame 32 etc. as shown in FIG. 11 and continue in this position until the cell door is stopped in its open position. Stopping of the cell door in the open position initiates the overtravel movement of rack 88 from the intermediate position shown in FIG. 9 to the overtravel open door position shown in FIG. 12 which is determined by engagement of stop 104 with the right edge of plate 76 as viewed in FIG. 12. This overtravel movement from the intermediate position to the FIG. 12 position causes cam 110 to depress roller 126 into opening 138 and operator 70 to consequently lower the lock bar 44 to its locking position. The parts are then in the door open locked position in which the description of the cycle of operation began.

We claim:

1. In a motor driven cell door operating system of the type having a fixed support means supporting a cell door carriage drivingly connected to fixed reversible motor means and including a main carriage frame supporting a cell door for reciprocable movement between a door open position and a door closed position defined by fixed door stops for said door open and door closed positions,'the improvement comprising a movable lock bar mounted adjacent said door and axially positionable in a locked position engaging said door to prevent movement of said door and an unlocked position in which said door is free to move between its open position and its closed position, lock bar operating means carried by said carriage for moving said lock bar to its locked position in response to the arrival of said cell door at either said open position or said closed position and for moving said lock bar to its unlocked position when driving force in a door closing direction is applied to said carriage when said door is locked in its open position or when driving force in a door opening direction is applied to said carriage when said door is locked in its closed position, said lock bar operating means including a pivotable lock bar operator engageable with a connector member on the top of said lock bar, pivot means connecting said pivotable operator to said carriage and carnming means comprising first and second cam plates respectively attached adjacenteach end of an elongated slide bar mounted for reciprocation on said main carriage frame between first and second positions of movement and being positionable inan intermediate position for pivoting said pivotable operator bar to consequently cause movement of said lock bar.

3. The invention of claim 1 wherein said lock bar operator is pivotally attached to the main carriage frame and comprises a U-shaped channel member defining a hollow trough axially extending along its length and wherein said connector member on the top of said lock bar comprises a roller member received within said trough so that reciprocation of said carriage causes relative movement between said trough and said roller member.

3. The invention of claim 2 wherein said lock bar operating means additionally include first and second positioning rollers respectively attached to each end of said lock bar operator and respectively engageable with first and second aligned lock bar operator tracks for positioning said lock bar operator in a horizontal position with said operator tracks being separated by an open control space larger than the diameter of said first and second positioning rollers.

4. The invention of claim 3 additionally including cam followers on each end of said lock bar operator respectively adjacent one of said cam plates during movement of said cell door between open and closed positions whereby the positioning roller on the trailing end of said lock bar operator opposite the direction of movement of said lock bar operator will be moved by the adjacent cam plate into said open space as said door is physically stopped by arrival at either of said open or closed positions to pivot said U-shaped channel member into a horizontally inclined position to cause said lock bar to move to its locked position while driving force continues to be applied to said carriage by said electric motor means so that said slide bar moves from its intermediate position to one of its end limit positions and the adjacent trailing cam plate on the end of said slide plate opposite the direction in which the door has been moving will move over its associated cam follower to retain said lock bar operator and said lock bar in their locked position.

5. A cell door operating means for opening, closing and locking a cell door comprising, a cell door carriage mounted for horizontal movement along a horizontal supporting track in either a door opening direction or a door closing direction, a cell door fixedly connected to and hanging beneath said cell door carriage for reciprocable movement with said carriage between an open position and a closed position, an open position stop for stopping said cell door in its open position and a closed position stop for stopping said cell door in its closed position, lock bar means vertically movable between a locked position for locking said door in either an open or closed position and an unlocked position in which said cell door is free to move, slide bar means mounted on said carriage for limited reciprocation parallel to the direction of movement of said carriage between two fixed positions so that said slide bar is movable with said carriage when in an intermediate position with respect to said carriage for the full extent of carriage movement and is additionally movable from said intennediate position through an overtravel increment in a door opening direction to a door open overtravel position and is also movable from said intermediate position an overtravel increment in a door closing direction to a door closed overtravel position, a carriage drive rack attached to said slide bar and oriented parallel to the direction of carriage movement, a drive pinion engageable with said rack for driving said rack to effect movement of said cell door between its open and closed position, and lock bar operating means carried by said carriage for moving said latch bar to its locked position in response to overtravel movement of said slide bar in either said door opening direction or said door closing direction from said intermediate position and for moving said lock bar to its unlocked position upon subsequent movement of said slide bar from either of its overtravel positions to said intermediate position.

6. The invention of claim 5 wherein said lock bar operating means includes a pivotable lock bar operator engageable with a connector member on the top of said lock bar, pivot means connecting said pivotable operator to said carriage and first and secon cam plates on each end of said slide bar WhlCh are engageable with cam followers on each end of said lock bar operator.

7. The invention of claim 5 wherein said lock bar operator comprises a U-shaped channel member defining a hollow trough axially extending along its length and wherein said connector member onthe top of said lock bar comprises a roller member received within said trough.

8. The invention of claim 7 wherein said lock bar operating means additionally includes first and second positioning rollers respectively attached to each end of said lock bar operator and respectively engageable with first and second aligned lock bar operator tracks for positioning said lock bar operator in a horizontal position during movement of said carriage with said operator tracks being separated by an open control space aligned with said lock bar and larger than the diameter of said first and second positioning rollers into which one of said positioning rollers is received when said door is in its closed or opened position to consequently pivot said lock bar operator and move said lock bar to its locked position.

9. The invention of claim 8 wherein said first and second cam plates have inwardly facing inclined cam surfaces which bracket the cam followers on each end of said lock bar operator.

10. The invention of claim 9 wherein said cell door is connected to said carriage by means of a cell door hanger extending downwardly through a slot in a bottom housing plate of housing means in which said carriage is mounted.

11. The invention of claim 10 additionally including a slot cover plate attached to the bottom of said carriage and through which said cell door hanger extends so that said slot in said bottom housing plate is always covered.

Claims

1. In a motor driven cell door operating system of the type having a fixed support means supporting a cell door carriage drivingly connected to fixed reversible motor means and including a main carriage frame supporting a cell door for reciprocable movement between a door open position and a door closed position defined by fixed door stops for said door open and door closed positions, the improvement comprising a movable lock bar mounted adjacent said door and axially positionable in a locked position engaging said door to prevent movement of said door and an unlocked position in which said door is free to move between its open position and its closed position, lock bar operating means carried by said carriage for moving said lock bar to its locked position in response to the arrival of said cell door at either said open position or said closed position and for moving said lock bar to its unlocked position when driving force in a door closing direction is applied to said carriage when said door is locked in its open position or when driving force in a door opening direction is applied to said carriage when said door is locked in its closed position, said lock bar operating means including a pivotable lock bar operator engageable with a connector member on the top of said lock bar, pivot means connecting said pivotable operator to said carriage and camming means comprising first and second cam plates respectively attached adjacent each end of an elongated slide bar mounted for reciprocation on said main carriage frame between first and second positions of movement and being positionable in an intermediate position for pivoting said pivotable operator bar to consequently cause movement of said lock bar.

5. A cell door operating means for opening, closing and locking a cell door comprising, a cell door carriage mounted for horizontal movement along a horizontal supporting track in either a door opening direction or a door closing direction, a cell door fixedly connected to and hanging beneath said cell door carriage for reciprocable movement with said carriage between an open position and a closed position, an open position stop for stopping said cell door in its open position and a closed position stop for stopping said cell door in its closed position, lock bar means vertically movable between a locked position for locking said door in either an open or closed position and an unlocked position in which said cell door is free to move, slide bar means mounted on said carriage for limited reciprocation parallel to the direction of movement of said carriage between two fixed positions so that said slide bar is movable with said carriage when in an intermediate position with respect to said carriage for the full extent of carriage movement and is additionally movable from said intermediate position through an overtravel increment in a door opening direction to a door open overtravel position and is also movable from said intermediate position an overtravel increment in a door closing direction to a door closed overtravel position, a carriage drive rack attached to said slide bar and oriented parallel to the direction of carriage movement, a drive pinion engageable with said rack for driving said rack to effect movement of said cell door between its open and closed position, and lock bar operating means carried by said carriage for moving said latch bar to its locked position in response to overtravel movement of said slide bar in either said door opening direction or said door closing direction from said intermediate position and for moving said lock bar to its unlocked position upon subsequent movement of said slide bar from either of its overtravel positions to said intermediate position.

6. The invention of claim 5 wherein said lock bar operating means includes a pivotable lock bar operator engageable with a connector member on the top of said lock bar, pivot means connecting said pivotable operator to said carriage and first and second cam plates on each end of said slide bar which are engageable with cam followers on each end of said lock bar operator.

7. The invention of claim 5 wherein said lock bar operator comprises a U-shaped channel member defining a hollow trough axially extending along its length and wherein said connector member on the top of said lock bar comprises a roller member received within said trough.