US3681873A

US3681873A - Automatic door operating mechanism for radiation proof enclosures

Info

Publication number: US3681873A
Application number: US888091A
Authority: US
Inventors: Carl Arthur Hansen
Original assignee: RAY PROOF CORP
Current assignee: SHIELDING SYSTEMS Corp A DE CORP; RAY PROOF CORP
Priority date: 1969-12-24
Filing date: 1969-12-24
Publication date: 1972-08-08
Anticipated expiration: 1989-08-08
Also published as: CA939688A; GB1313894A

Abstract

Motor operated and, connected thereto a manually operated mechanism, for the initial opening and final closing operations of a door for such enclosures which because of the construction of the radiation barrier joints between the door and its frame require considerable pressure for the final closing operation and the initial opening operation. A second independent manually operated release mechanism enables the door to be unlocked should the motor operated and connected manually operated mechanism become inoperable.

Description

United States Patent Hansen AUTOMATIC DOOR OPERATING MECHANISM FOR RADIATION PROOF ENCLOSURES [72] Inventor: Carl Arthur Hansen, Bethel, Conn.

[73] Assignee: Ray Proof Corporation, Norwalk,

Conn.

[22] Filed: Dec. 24, 1969 [21] Appl. No.: 888,091

[52] US. Cl. ..49/l39, 49/280 [51] Int. Cl. .1505! 15/12 [58] field of Search........................49/276-28l, 300, 49/302, 139; 109/ l, 74, 75; 250/108;

[56] References Cited UNITED STATES PATENTS 2,833,536 5/1958 Joachim et al ..49/280 X [151 3,681,873 51 Aug. 8, 1972 Gibbs et al ..49/276 Moorman et a]. ..49/276 Primary Examiner-J. Karl Bell Attorney-Pennie, Edmonds, Morton, Taylor & Adams [57] ABSTRACT Motor operated and, connected thereto a manually operated mechanism, for the initial opening and final closing operatiom of a door for such enclosures which because of the construction of the radiation barrier joints between the door and its frame require considerable pressure for the final closing operation and the initial opening operation. A second independent manually operated release mechanism enables the door to be unlocked should the motor operated and connected manually operated mechanism become inoperable.

16 Claims, 13 DrawingFigures PATENTEDAUG 8 I972 3.681. 873 sum 1 or e INVENTOR, CARL ARTHUR HANSEN ATTORNDS PATENTEUA B 3 SHEET 2 BF 6 3 mm w INVENTOR. CARL ARTHUR HANSEN BY M daml L mx H/5 ATTORNEYS PATENTEDAUG a ma SHEET 3 BF 6 CARL ARTHUR HANSEN BY EMMA-Q} I ll-a ATTORNLYS PATENTEDAus 8 I972 SHEET u CF 6 JNYENTOR. CARL ARTHUR HANSEN '7 5 BY [W 4 H/S ATTORNEYS PATENTEDAUB 8 m2 SHEET 5 OF 6 FIG.

FIG. 9

1x \EMQR. CARL ARTHUR HANSEN M' 5 BY /4 6/ M 2,?

05 ATTORNEYS AUTOMATIC DOOR OPERATING MECHANISM FOR RADIATION PROOF ENCIDSURFS BACKGROUND OF THE INVENTION Field of the Invention SUMMARY OF THE INVENTION Radiation proof or radiation shielded enclosures have inner and outer wall surfaces each surface having a grounded metallic sheet, such as copper, secured thereto. They also have radiation barriers between the edges of the doors and their frames. These barriers are in the form of cooperating metal parts mounted one around the edges of the door and the other around the door frame. One of these parts has flexible resilient fingers which provide electrical and mechanical contact between the two parts when the door is closed. The part mounted on the door frame is electrically connected with the grounded metallic wall surface sheets. The present invention provides mechanism for moving the door on its hinges sufficiently to cause the metal parts to engage one another during the movement of the door just prior to its reaching closed position, about 2 inches, and also to move the door in the reverse or opening direction until the parts are disengaged or in other words until the edge of the door opposite its hinges has moved about 2 inches from the frame. When the cooperating metal parts mounted respectively on the door and the door frame are disengaged the door may be opened farther by hand, or a conventional door-operating mechanism may be used. Also such mechanism may close the door to the point where the mechanism of the present invention becomes operatrve.

The invention includes mechanism for latching and unlatching the door with respect to a catch on the door frame and to pull or push the door towards or away from the frame. This mechanism is operated by a power device such as an electric motor but should there be a power failure manually operated mechanism for tuming the motor shaft is provided. In addition the catch on the door frame is provided with releasing mechanism by which it can be freed from the latch on the door.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a portion of a door and its adjacent jamb or frame at the edge of the door opposite its hinges which are not shown. On the door is mounted a casing for the mechanism of the invention.

FIG. 2 is a view in elevation of a smaller casing mounted on the inside of the door and cooperating with the outer casing.

FIG. 3 is a view partly in elevation and partly in vertical section, the front portion of the outside casing being broken away.

FIG. 4 is an elevation of a detail shown in FIG. 3 but drawn to a larger scale.

FIG. 5 is a horizontal section taken on line 5-5 of FIG. 3.

FIG. 6 is a detailed horizontal section taken on line 6-6 of FIG. 1 and drawn to a larger scale.

FIG. 7 is a detailed view partly in vertical transverse section and partly in elevation taken on line 7-7 of FIG. 5.

FIG. 8 is a vertical transverse section taken on broken line 8-8 of FIG. 5.

FIG. 9 is a view similar to FIG. 8 with parts shown in different positions.

FIG. 10 is a transverse vertical section taken on line 10-10 of FIG. 5.

FIG. 11 is a longitudinal vertical section taken on line 1l-11 of FIG. 5 showing a detail.

FIG. 12 is a vertical transverse section taken on broken line 12-12 of FIG. 5 showing another detail, and

FIG. 13 is a fragmentary vertical section taken on line 13-13 of FIG. 5 illustrating still another detail.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 a portion of a door is shown at 20, and at 21 is a portion of a door jamb or frame with which the front edge of the door, that is, the edge opposite the hinges (not shown) engages. The mechanism of the invention is mounted within a casing 22 on the front of door 20 and a smaller inner casing 23 shown in FIGS. 2 and 5.

The frame or wall of the enclosure, a portion of which is shown at 21 is constructed usually of laminated wood as indicated in section in FIGS. 5, 6, 8 and 9. Door 20 is of similar construction but considerably thicker than the wall of the enclosure as indicated in FIG. 5. The inner surface of frame 21 has secured thereto a metallic sheet 24 which covers the entire inner surface of the radiation-proof room or enclosure. Another metallic sheet 25 covers the entire outer surface of the frame 21 of the enclosure. Similarly door 20 has an inner metallic sheet 26 covering its entire inner surface, and a somewhat thicker metallic sheet 27 on its outer surface. Both of these sheets are grounded.

The construction of the radiation-proof joint between door 20 and frame 21 is shown in FIGS. 5 and 6. Referring especially to FIG. 6 a metallic member 28 having spaced inner and outer flanges 29 which fit the inner and outer surface of frame 21 extends along all of the edges of the opening in the enclosure for door 20, that is to say, along the vertical side edges of this opening and along the horizontal upper and lower edges of the opening. The members on the several edges are constructed so as to be continuous at the comers. Each member 28 has a slot 30 closed at its inner end and open at its outer end, and on the opposite parallel walls of this slot are mounted metallic comb members 31 which are firmly secured in position in any convenient manner. Comb members 31 have flexible resilient integral fingers 32. These fingers are spaced close to one another throughout the entire length of slot 30.

For cooperating with the structure just described each of the edges of the door 20 is provided with a metallic member 33 having parallel side flanges 34 on its inner and outer sides which are fitted to the opposite side surfaces of the door. As shown in FIG. 6 member 33 cooperates with member 28 on the door frame, and for this purpose a flange 35 which is a continuation of flange 34 extends outwardly from the outer surface of member 33 and supports a blade-like member 36 which is tapered at its inner end so as to enter between the opposing resilient fingers 33 and spread them apart slightly as the door is closed. FIG. 6 and FIG. 5 show the condition when the door is completely closed. It will be understood that the members 33 are united at the corners of the door so as to surround the door with a continuous structure including the blade-like members 36 as described. The outer thick sheet or plate 27 of door 20 is provided with an extension 37 beyond the end of flange 35 so as to render the joint between the door and the door frame completely radiation-proof. It will be understood that extensions 37 project from each of the four edges of sheet 27.

Because of the construction of the joint between the edges of door 20 and the edges of frame 21 it will be understood that some little pressure is required to overcome the friction force produced by the engagement of blade-like members 36 as they enter between the resilient fingers 32 during the final closing movement of the door, or in other words during approximately the last 2 inches of movement of the outer edge of the door shown in FIGS. and 6. A similar friction force has to be overcome during approximately the first 2 inches of movement of the opening of the door. The mechanism of the invention provides for applying an adequate force both in the closing direction and the opening direction so that these movements can be obtained merely by pushing a button controlling an electric circuit. However if the electric power should fail this mechanism is operable by hand and with little effort. Should there be both a failure of the electric power and a jamming of the manual operating mechanism a third way of opening the door from the outside, or by an occupant on the inside, is available. This is a manually operated release mechanism which unlocks the door, but the pressure to open it must be applied by the occupant throwing his weight against the inside of the door.

The initial opening movement of the door (about 2 inches) is accomplished by means of a door actuator arm 38 shown in FIGS. 5, 8 and 9 which has a latch roller 39 mounted on a short shaft 40 which projects laterally near the inner end of the actuator arm (FIG. 5). When actuator arm 38 is moved inwardly with respect to the compartment or enclosure by the operation of an electric motor 41 and interconnecting mechanism to be described, roller 39 engages a plate member 42 (FIG. 8) mounted on the inner surface of frame 21 and pushes the door to open position where the blade-like member 36 has become disengaged from the friction fingers 32.

In the position of actuator arm 38 and roller 39 shown in FIGS. 5 and 8 the roller is serving as a latch member engaged with a catch member 43 mounted on frame 21. This catch member and its supporting and releasing mechanism will be described later on.

The operating or interconnecting mechanism between actuator arm 38 and electric motor 41 is shown in FIGS. 5 and 8-10. Motor 41 has at its left end an integral flange 44 by which it is supported. Adjacent this flange is a mounting bracket 45 which is a part of the mechanism-supporting structure within casing 22. Four short bolts 44a (FIG. 5) secure flange 44 to bracket 45 but only two of these bolts are visible. Spaced to the left of bracket 45 there is a rectangular plate 46 and spaced farther to the left is a second rectangular plate 47.

Plates

46 and 47 are supported by bracket 45 in the positions indicated in FIG. 5 by means of four rods 48 which pass through aligned apertures in bracket 45 and plate 46, and are threaded into apertures in rectangular plate 47. Rods 48 are shown in FIGS. 8, 9 and 10 but only one is visible in FIG. 5. Spacing collars 49 on these cap screws maintain plate 46 properly spaced from mounting 45, and somewhat similar collars 50 maintain rectangular plate 47 in spaced relation to plate 46.

The output shaft of motor 41 is shown at 51 and is driven from the main motor shaft through reduction gearing arranged within a housing 52 at the left end of the motor. Shaft 51 therefore rotates at a comparatively low speed when motor 41 is energized. Mounted on output shaft 51 of the motor there is a drive wheel 53 and the periphery of this drive wheel is supported in ball bearings 54 in order to take the thrust due to the opening and closing operations of door 20 as will be apparent presently. The outer bearing ring 55 of this ball bearing is supported in a circular aperture in rectangular plate 46.

The door actuator arm 38 slides horizontally in contact with the outer surface of rectangular plate 47, and sliding on the inner side of this plate there is a driving block 56 of considerable thickness. Actuator arm 38 and driving block 56 are supported in slidable relation with the opposite sides of rectangular plate 47 by means of two spaced rollers 57 and 58 which rotate on two collars 59 supported on two cap screws 60. These cap screws are fitted in openings in actuator arm 38 and their inner ends are threaded into apertures in driving block 56 as shown. Rollers 57 and 58 both operate in a single, horizontal slot 61 in rectangular plate 47 (FIGS. 8 and 9).

Driving block 56 is actuated by means of a roller 62 mounted on the outer end of a bolt 63 which is in turn mounted eccentrically on drive wheel 53. Roller 62 operates in a vertical groove 64 in driving block 56.

Horizontal slot 61 in rectangular plate 47 has at its outer end a lobe 65 which projects laterally upwardly as shown in FIGS. 8 and 9, and at its uppermost portion lobe 65 has a Vlier detent 66 which projects from the inner end of a screw 67 threaded in an aperture extending downwardly from the top edge of rectangular plate 47. Detent 66 is slidably mounted in an axial hole in screw 67 and is provided with a compression spring (not shown) which urges the detent downwardly.

Motor 41 is reversible and its operation is started by either of two

push buttons

68 and 69. When either one of these buttons is pushed motor 41 causes drive wheel 53 to rotate through 180 only, its rotation being stopped by one or the other of two

limit switches

70 and 71 arranged l apart (FIG. 10). These switches are actuated by a tripper 72 mounted on one side of drive wheel 53. While drive wheel 53 rotates one half revolution tripper 72 turns from engagement with limit switch 71 to engagement with limit switch 70, or vice versa, and roller 62, on bolt 63, is carried l80 to the opposite side of shaft 51.

Such movement of roller 62 in groove 64 of driving block 56 causes door actuator arm 38 to be shifted from the position shown in FIG. 8 to that shown in FIG. 9. This causes the latch roller 39 to engage plate 42 on frame 21 and push door 20 some 2 inches outwardly from its closed position thus disengaging the

radiation barrier members

36 and 32 of FIGS. 5 and 6. In addi tion actuator arm 38 is rocked to the position of FIG. 9

where latch roller 39 is above catch member 43 so that when the door is moved farther open either by hand or by a conventional power mechanism, roller 39 will move in a path above catch member 43. The angular rocking movement of door actuator arm 38 is caused by the engagement of roller 58 with the lateral lobe 65 at the right end of slot 61.

When the door is to be closed it is first moved either by hand or by the conventional power mechanism to the position where the latch roller 39 is just inside of the catch member 43. This brings the radiation barrier members of FIG. 6 near to one another but not in engagement. Thus the blade-like member 36 is about ready to enter between the flexible fingers 32. Thereupon push button 68 is again actuated to activate motor 31 in the opposite direction of rotation. This causes drive wheel 53 to be rotated 180 in the opposite direction so that tripper 72 is returned into engagement with the upper limit switch 71. This also causes roller 62 to operate in groove 64 (FIG. 9) and move block 56 back to the position of FIG. 8.

At the beginning of this movement roller 58 retreats from lobe 65 thus causing actuator arm 38 to rock downwardly and place latch roller 39 in line with and behind catch 43, on wall or frame 21. The Vlier detent 66 aids in urging the rocking of actuator arm 38 downwardly. Continued left-hand movement of actuator arm 38 causes latch roller 39 to return into engagement with catch 43 and pressure against it forces door to close and door 20 is again locked in the closed position of FIGS. 8 and 5.

The manually operated mechanism for operating door 20 actuator arm 38 by hand in the event of power failure or motor failure is shown at the right of motor 41 particularly in FIG. 5 and FIGS. 4, 11, 12 and 13, as well as in FIG. 3. This mechanism has a cross shaft 73 having manual crank wheels 74 fixed to both its outer and inner ends. Radio frequency shielding is provided where shaft 73 passes through the door. This comprises a threaded sleeve 75 (FIG. 5) having a brass fitting 76 secured to its outer end. At its inner end a nut 77 clamps the part securely in place. At about the center of the door, shaft 73 has a recess 78 (FIG. 13) within which is mounted a bronze collar 79 having flexible fingers 80 which engage the interior of hollow sleeve 75.

The shaft of motor 41 is visible at its right end and is indicated by reference number 81 (FIGS. 5 and 11). A shaft 82 rotated by the manual mechanism is supported in a housing 83 in alignment with shaft 81. Shaft 82 is operatively connected with cross shaft 73 by means of beveled gearing (not shown) located within the triangular portion 84 of this housing so that when hand operated shaft 74 is turned it causes rotation of shaft 82.

In order to operate the manual mechanism, shaft 82 must be first connected with shaft 81 of the electric motor 41, and a friction brake on the motor shaft must be released. These mechanisms which will be described in detail below are shown in FIGS. 11 and 12.

A shaft 85 to control these mechanisms is arranged parallel with shaft 73. Shaft 85 is actuated by handles 86, one arranged on the outer end of the shaft and the other on the inner end. This control shaft where it passes through door 20 is provided with radio frequency interference shielding similar to that described in connection with shaft 73.

The friction brake which serves to stop motor shaft 81 instantly when its circuit is interrupted by either of the limit switches or 71 is indicated at 87 and consists of a drum 88 fixed to motor shaft 81 and a friction band 89 surrounding this drum and having its opposite ends secured to an operating lever 90 (FIG. 12). The brake is normally held in applied position by means of a tension spring 91, the lower end of which is attached to lever 90 and the upper end of which is secured to a plate 92 which is mounted on the right end of the frame of motor 41. Lever 90 is pivoted to this plate at 93. A solenoid 94 is also mounted on plate 92 and has an armature 95 the lower end of which is pivoted to the left end of lever 90.

The coupling of manually operated shaft 82 to motor shaft 81 for manual operation is indicated at 96 (FIG. 11) and comprises a sleeve member which is axially slidable on shaft 82 and which has a pair of slots 97 at its left end for engaging a cross pin 98 fixed to motor shaft 81. Coupling 96 is shifted into and out of connection with shaft 81 by means of a yoke member 99 which is fixed on control shaft 85 by welding or otherwise. At its upper end yoke 99 is operably connected with coupling 96 through a circular groove. At its lower end yoke 99 has a leftward extension 101 (FIG. 4) to which a chain 102 is connected, the upper end of this chain being connected to the right end of lever 90.

With this construction the tension spring 91 normally maintains friction brake 87 in applied position, and also maintains coupling 96 in its uncoupled position with respect to motor shafi 81.

When it is desired to use the manual mechanism for either opening or closing door 20, handle 86 is rocked to the right in FIG. 1 which causes shaft 85 to angle in the counterclockwise direction as shown by the arrow in FIG. 11. This first causes a switch 103 (FIG. 4) to be opened by earn 104 so that all current is cut off from motor 41 and its control circuits. This prevents the possibility of injury to the operator of the manual mechanism. The movement of handle 86 also causes yoke 99 to move coupling 96 into coupling position with shaft 81 and it simultaneously draws down the right end of lever 90 through chain 102 and causes the release of friction brake 87. Thereupon either of the crank handles 74 may be turned to cause the closing or opening of door 20 as previously described. During this operation handle 86 must be held by hand in its rocked position against the tension of spring 91. Ordinary door handles 105 are mounted on the outside and inside casings respectively.

It will be understood that solenoid 94 is energized whenever motor 41 is to be activated for opening or closing the door. This will maintain the friction brake 87 in released position and coupling 96 in the uncoupled position.

Should any personnel be within the enclosure with the door closed and find that the door can not be opened either by the operation of electric motor 41 or by the manual mechanism through manipulating handle 86 and crank handle 74 a further means for unlocking the door is provided. This is the catch mechanism 106 illustrated in FIGS. 1, 5 and 7. This catch mechanism includes a mounting block 107 which may be secured on the outer surface of frame 21 in any suitable manner. As shown in FIG. 5 mounting block 107 is secured on the outer end of a screw threaded sleeve 108 having a nut 109 at its inner end.

Mounting block 107 has a shallow horizontal recess 110 in its outer surface. Fitting within this recess is a catch member 111. This member is nearly in the form of a cube and catch portion 43 extends horizontally from its right end as shown in FIG. 5. Catch portion, or catch 43 has a flat vertical surface as shown in FIG. 7 and front surfaces 112 and l 13 which are angular.

When catch portion 43 is in the horizontal position shown in FIGS. and 7 it forms the catch for latch roller 39 on actuator arm 38 as previously described. Catch member 111 is supported so that it is free to rotate under the weight of catch portion 43 when the catch member is moved out of the shallow recess 1 in mounting block 107. As illustrated catch member 111 has a horizontal opening through its center and is supported on a shaft 114. This shaft carries two operating handles 1 on its outer and inner ends respectively. A portion of shaft 114 is threaded and its threads engage threads in a cylindrical member 116 which is received in a circular aperture in catch member 111 at right angles to shaft 1 14. The fit of the threads on shaft 114 and in member 116 is loose, and member 116 is arranged to have a loose fit within its aperture. In this way no binding engagement with shift 114 can occur and catch member 111 is freely supported so that as soon as it is moved out of recess 110 by the rotation of the handle shaft 114 it turns immediately to the position where catch portion 43 is vertically below shaft 114 as shown in F IG. 7 by dotted lines.

The handles 115 are manipulated either directly by hand or by using a slender rod 117 (FIG. 3) which is inserted between the fingers of the handle and provides a considerable leverage.

I claim:

1. [n a radiation shielded enclosure having:

a. a door,

b. a frame surrounding the door,

c. frictionally engageable radiation barrier parts on the edges of the door and frame respectively, and

d. means for moving the door with respect to the frame to engage or disengage said parts and to lock or unlock the door comprising:

1 a door actuator am,

2. a latch mounted on the actuator 3. a catch member mounted on the frame and spaced outwardly therefrom near the frame,

4. an electric motor, and

5. means interconnecting said motor and said actuator arm for driving said arm in one direction to cause the latch thereon to disengage the catch member and move the actuator arm against the frame causing the door to open, said interconnecting means also being operable for driving the actuator arm in the opposite direction to cause said latch member to engage the catch member and by pressure thereon move the door to closed position against said frame.

2. A radiation shielded enclosure according to claim 1 in which the means interconnecting said motor and said door actuator arm comprises:

a. a drive wheel,

b. means for supporting said door actuator arm for horizontal reciprocating movement, and

0. means operatively interconnecting said drive wheel and said actuator arm for imparting reciprocating movement thereto.

3. A radiation shielded enclosure according to claim 2 including in addition, means for rocking said actuator arm to raise the end thereof adjacent the door near the 5 inner end of the reciprocating movement of the actuator.

4. A radiator shielded enclosure according to claim 1 in which the means interconnecting said motor and said door actuator arm causes the path of the latch to be shifted so as to avoid the catch member to allow the door to open sufficiently for access to the enclosure.

5. A radiation shielded enclosure according to claim 1 in which the means interconnecting said motor and said door actuator comprises:

a. a drive wheel,

b. a vertical stationary plate arranged parallel with said wheel and having a horizontal slot therein,

c. said actuator arm being arranged to slide on said stationary plate and having a portion operating within said slot, and

d. means interconnecting said drive wheel and said actuator arm causing it to reciprocate with respect to said slot, said slot having an upward lobe at its inner end for rocking said actuator to raise the end thereof adjacent the door near the inner end of the reciprocating movement of the actuator arm.

6. A radiation shielded enclosure according to claim 1 in which the means interconnecting said motor and said door actuator arm comprises:

a. a drive wheel,

b. a vertical stationary plate arranged parallel with said wheel and having a horizontal slot therethrough with a lateral lobe at its inner end,

c. a driving block sliding on the side of said plate adjacent said drive wheel,

d. said block having a slot therein,

e. a driving roller mounted on the face of the drive wheel and operating in said slot,

f. said door actuator arm sliding on the opposite face of said plate, and

g. two rollers within said horizontal slot, each roller being mounted on a common support extending through said slot between said actuator arm and said block.

7. A radiation shielded enclosure according to claim 6 having an electrically operated friction brake mechanism for stopping the motor as soon as the motor current is cut ofi by the control circuit, and in which means for manually rotating the motor shaft is additionally provided, and including means for simultaneously releasing said friction brake and for interconnecting the manual mechanism with the motor operated mechanism.

8. A radiation shielded enclosure according to claim 7 including in addition means for cutting off current to the electric motor simultaneously with the interconnecting of the manual and motor operated mechanisms.

60 9. [n a radiation shielded enclosure having:

a. a door,

b. a frame,

c. securing means for holding the door closed includl. a latch on said door,

2. a catch mechanism on said frame, said catch mechanism comprising:

a. a mounting block secured to the frame having a horizontal recess in its outer surface,

b. a catch member including:

1. a body having a portion thereof received in said recess,

2. a catch portion projecting horizontally from said body when said body is within said recess,

c. means for shifting the catch member out of engagement with said recess to allow the catch member to turn to place the catch portion out of catch position.

10. A radiation shielded enclosure according to claim 9 in which the means for shifting the catch member out of an engagement with said recess is operable from the inside as well as the outside of said door.

11. A radiation shielded enclosure according to claim 9 in which the means for shifiing the catch member is a shaft extending through the door frame and having threaded engagement with the catch member.

12. A radiation shielded enclosure according to claim 11 in which the threaded shaft for shifting the catch member is provided with a handle at each end so as to enable said shaft to be rotated from the inside as well as the outside of the door.

13. [n a radiation shielded enclosure having:

a. a door,

b. a frame surrounding the door,

c. frictionally engageable radiation barrier parts on the edges of the door and frame respectively,

d. means for moving the door with respect to the frame to engage or disengage said parts and to lock or unlock the door,

e. mechanisms operated selectively by power or manually for actuating said door-moving means including,

I. an electric motor,

2. a control circuit for said motor,

3. said means for moving the door being operated by the shaft of said motor,

4. an electrically operated friction brake mechanism for stopping said motor when the motor current is cut off by said control circuit, and

5. means for manually rotating said motor shaft including means for simultaneously releasing said friction brake and interconnecting said manually and power operating mechanisms.

14. A radiation shielded enclosure according to claim 13 in which said manually operated mechanism for actuating said door-moving means is operable from the inside as well as the outside of the door.

15. A radiation shielded enclosure according to claim 13 wherein said manually operated mechanism for actuating said door-moving means includes a rotary shaft extending through said door, and a handle on each end of said shaft for rotating the same.

16. A radiation shielded enclosure according to claim 13 in which the manually operated mechanism for actuating said door-moving means includes a rotary shaft extending through said door and a radio frequency shielding device surrounding said shaft.

Claims

1. In a radiation shielded enclosure having: a. a door, b. a frame surrounding the door, c. frictionally engageable radiation barrier parts on the edges of the door and frame respectively, and d. means for moving the door with respect to the frame to engage or disengage said parts and to lock or unlock the door comprising: 1. a door actuator arm, 2. a latch mounted on the actuator 3. a catch member mounted on the frame and spaced outwardly therefrom near the frame, 4. an electric motor, and 5. means interconnecting said motor and said actuator arm for driving said arm in one direction to cause the latch thereon to disengage the catch member and move the actuator arm against the frame causing the door to open, said interconnecting means also being operable for driving the actuator arm in the opposite direction to cause said latch member to engage the catch member and by pressure thereon move the door to closed position against said frame.

2. a latch mounted on the actuator

2. a catch mechanism on said frame, said catch mechanism comprising: a. a mounting block secured to the frame having a horizontal recess in its outer surface, b. a catch member including:

2. a catch portion projecting horizontally from said body when said body is within said recess, c. means for shifting the catch member out of engagement with said recess to allow the catch member to turn to place the catch portion out of catch position.

2. A radiation shielded enclosure according to claim 1 in which the means interconnecting said motor and said door actuator arm coMprises: a. a drive wheel, b. means for supporting said door actuator arm for horizontal reciprocating movement, and c. means operatively interconnecting said drive wheel and said actuator arm for imparting reciprocating movement thereto.

2. a control circuit for said motor,

3. said means for moving the door being operated by the shaft of said motor,

3. A radiation shielded enclosure according to claim 2 including in addition, means for rocking said actuator arm to raise the end thereof adjacent the door near the inner end of the reciprocating movement of the actuator.

3. a catch member mounted on the frame and spaced outwardly therefrom near the frame,

4. an electric motor, and

5. A radiation shielded enclosure according to claim 1 in which the means interconnecting said motor and said door actuator comprises: a. a drive wheel, b. a vertical stationary plate arranged parallel with said wheel and having a horizontal slot therein, c. said actuator arm being arranged to slide on said stationary plate and having a portion operating within said slot, and d. means interconnecting said drive wheel and said actuator arm causing it to reciprocate with respect to said slot, said slot having an upward lobe at its inner end for rocking said actuator to raise the end thereof adjacent the door near the inner end of the reciprocating movement of the actuator arm.

6. A radiation shielded enclosure according to claim 1 in which the means interconnecting said motor and said door actuator arm comprises: a. a drive wheel, b. a vertical stationary plate arranged parallel with said wheel and having a horizontal slot therethrough with a lateral lobe at its inner end, c. a driving block sliding on the side of said plate adjacent said drive wheel, d. said block having a slot therein, e. a driving roller mounted on the face of the drive wheel and operating in said slot, f. said door actuator arm sliding on the opposite face of said plate, and g. two rollers within said horizontal slot, each roller being mounted on a common support extending through said slot between said actuator arm and said block.

7. A radiation shielded enclosure according to claim 6 having an electrically operated friction brake mechanism for stopping the motor as soon as the motor current is cut off by the control circuit, and in which means for manually rotating the motor shaft is additionally provided, and including means for simultaneously releasing said friction brake and for interconnecting the manual mechanism with the motor operated mechanism.

9. In a radiation shielded enclosure having: a. a door, b. a frame, c. securing means for holding the door closed including:

11. A radiation shielded enclosure according to claim 9 in which the means for shifting the catch member is a shaft extending through the door frame and having threaded engagement with the catch member.

13. In a radiation shielded enclosure having: a. a door, b. a frame surrounding the door, c. frictionally engageable radiation barrier parts on the edges of the door and frame respectively, d. means for moving the door with respect to the frame to engage or disengage said parts and to lock or unlock the door, e. mechanisms operated selectively by power or manually for actuating said door-moving means including,