GB2038920A

GB2038920A - Interlocking Container Doors

Info

Publication number: GB2038920A
Application number: GB7937838A
Authority: GB
Original assignee: UK Atomic Energy Authority
Current assignee: UK Atomic Energy Authority
Priority date: 1978-11-06
Filing date: 1979-11-01
Publication date: 1980-07-30
Also published as: GB2038920B

Abstract

A container 11 is releasably held against a transfer port of an enclosure 2 by a slidable locking member 10 engaging behind lug 11. A pin 17 passing through the wall of the enclosure prevents movement of the locking member 10 when the port cover 8 has been removed and prevents removal of the port cover 8 when the locking member 10 is not in its container-locking position. Cover 8 is released by rotation and bears a co- rotatable disc 16 having recess 18. In the port fastening position pin 17 prevents rotation being held in recess 18 by wing 24 on locking fork 10. When the fork 10 is in the container holding position a recess 31 can accept pin 17 which is carried into it by turning cover 8. Pin 17 then holds fork 10 in its fastening position. On closing cover 8, the reverse occurs and fork 10 may be moved to release container 1. <IMAGE>

Description

SPECIFICATION Transferring Toxic or Radioactive Materials This invention relates to the transfer of toxic or radioactive materials between an enclosure and a container in which such materials are transported.

When transferring toxic or radioactive materials it is important that there is no dispersal of the toxic or radioactive materials to the environment and, preferably, the apparatus used should be such that misuse, either accidental or deliberate, is impossible.

It is intended that the container to which the present invention is applicable will be one which has a flange adjacent an open end thereof which can co-operate with a sliding locking member on the exterior of the enclosure to retain the container in position on the wall of the enclosure with its open end aligned with a port in the enclosure wall. The container is provided with a lid which is receivable in the open end of the container and which is engageable with the container by rotation through a part of one revolution.The container lid also has means on its outer surface which cooperate with corresponding means on a port cover to interengage the container lid and port cover in such a way that those surfaces of the lid and cover which are exposed when the container with its lid fitted is removed from the port with its cover in place are protected from contamination by the atmosphere within the enclosure. Such a container is hereinafter referred to as "a container of the kind described hereinbefore".

The present invention provides a port assembly for use with a container of the kind described hereinbefore comprising a container locking member slidable from a first position in which the container is held against the exterior wall of an enclosure around a port passing through said wall and a second position in which the container may be removed, a cover for then port which is rotatably movable between first a position in which it is locked into the port and a second position in which it may be removed from the port, a locking plate which interengages with the port cover and which is rotatable therewith, a movable pin passing through the wall of the enclosure, recesses in the surfaces of the container-locking member and locking plate, said recesses being aligned with the pin only when the container-locking member is in its first position and the locking plate is in the position where the port cover is in its first position, the length of said pin being such that when one of the containerlocking member of the port cover is not in its first position the pin is urged into the recess in the other to prevent movement thereof.

The present invention also includes the combination of a port assembly as described above and a container of the kind described hereinbefore.

The invention will be illustrated by the following description of apparatus for and a method of transferring toxic or radioactive materials between a container and an enclosure.

The description is given by way of example only and has reference to the accompanying drawings in which: Figure 1 is a side view, partially in section, of a container connected to a port in a wall of an enclosure, Figure 2 is a view taken in the direction of the arrow ill in Figure 1, Figure 3 is a view taken along the line Ill-Ill of Figure 1, Figure 4 is a view taken along the line lV-lV of Figure 1, Figure 5 is a view taken in the direction of the arrow V of Figure 1, Figure 6 is a sectional view taken on the line VI--VI of Figure 3, and Figure 7 is a view similar to Figure 4 of part of a modified form of the apparatus illustrated in Figure 4.

Referring to Figure 1 there is shown a doublewalled container 1 in which toxic or radioactive materials are transported. The container 1 has a lid 2 which is releasably connected to the container by a bayonet fitting. A seal 3 is provided to prevent egress of material between the container and the lid and also to seat against the wall 4 of an enclosure around a port 5 which has a port cover 6. The port cover has a seal 7 which prevents the passage of material between the port cover 6 and the wall 4 when the port cover is in the port and also contacts the seal 3 when the container 1 is fitted around the port 5. The port cover and container lid may be interengaged by means of a bayonet connection comprising a male portion 8 on the port cover 6 and a female portion 9 on the container lid 2.The container 1 is retained in position around the port 5 by a slidable locking fork 10 which contacts a flange 11 around the Container.

The locking mechanism by means of which the port cover 6 is retained in the port 5 will be described with particular reference to Figures 2 and 3 which are views taken from inside the enclosure. In the position shown in Figure 2 the port cover is retained in the port by a bar 12 on the port cover which is held behind two arcuate plates 13. When the cover is rotated clockwise from the position shown in Figure 2 to bring the bar 12 into alignment with a gap 14 between the arcuate plates 13, the port cover 6 may be removed from the port. The bar 12 extends into cut-away portions 1 5 of a generally annular locking plate 1 6 (as can be seen most clearly from Figure 3) so that as the port cover 6 is rotated the bar 12 contacts the yocking plate 1 6 and causes it to rotate.The locking plate 1 6 can only rotate when a locking pin 17 which extends through the wall 4 of the enclosure is in its retracted position with respect to the locking plate 1 6. When the locking pin extends from the wall 4 towards the locking plate one end of the pin 17 is received in a recess 18 in the face of the locking plate 16 which is adjacent the wall 4. (See Figure 6). The other end of the pin 1 7 contacts the locking fork 10. When the pin 17 is prevented from moving to the above mentioned retracted position by the locking fork 10, as will be described hereinafter rotation of the locking plate 1 6 is prevented.

The bar 1 2 is provided with a shaped slot 1 9 into which a tool (not shown) is fitted to cause the port cover 6 to rotate. As the port cover is rotated the male portion 8 of the bayonet connection on the port cover rotates within the female portion 9 on the container lid to interengage the cover 6 and lid 2 and to release the container lid from the container. The interengaged port cover and container lid are then removed into the enclosure enabling material to be transferred between the enclosure and the interior of the container. When the interengaged cover and lid are inside the enclosure those surfaces which are exposed to the environment when the container with its lid in place and the port with its cover in place are separated abut and the seal 7 prevents the ingress of contamination.

The container 1 is retained in position around the port by a sliding locking fork which is located on the outside of the wall 4 by screws 20,21 which pass through slots 22, 23 in the locking fork 10. The slots enable the locking fork to slide to the left from the position shown in Figure 4, so that shoulders 24, 25 on the locking fork 10 contact the flange 11 around the container 1 and hold the container against the wall 4 of the enclosure. To prevent rotation of the container in its locked position a slot 26 in the outer surface of a cover member 27 which is connected to the locking fork 10 by screws 28 and moves with the locking fork surrounds a projection 29 on the outer end of the container 1. The projection has a cross-sectional shape which is shown in Figure 5 and which comprises the area between two parailel chords of a circle.The distance between the two chords is slightly less than the distance between the sides of the slot 26 so that when the projection is in the slot as it will be when thelocking fork has been moved to the left from the position shown in Figures 4 and 5 rotation of the container is prevented. One side of the slot is extended to provide a surface 30 which contacts the projection 29 when the container is being located around the port so that the container adopts the correct orientation relative to the port cover 6.

The pin 1 7 passing through the wall 4 of the enclosure contacts the shoulder 24 of the locking fork 10 when in the position shown in Figures 4 and 6. The pin 17 is thus prevented from moving from the position in which it extends into the recess 18 in the locking plate 1 6. Rotation of the locking plate 1 6 to release the port cover is therefore not possible when the locking fork 10 is in the position shown in Figure 4. When the locking fork has been moved to the left to retain the container 1 a recess 31 in the surface of the shoulder 24 adjacent the wall 4 is aligned with the pin 17. In this position the pin 1 7 can move into its retracted position with respect to the locking plate and so rotation of the plate is possible.This arrangement ensures so the port cover cannot be removed until the container locking fork is in the container-retaining position.

As the locking plate rotates a sloping portion 32 of the recess 1 8 in the locking plate contacts the pin 1 7 and causes it to move so that it extends from the outside of the wall 4 into the recess 31 of the locking fork. When the locking plate is fully rotated to allow the port cover 6 to be removed the end of the pin facing the interior of the enclosure contacts the surface of the locking plate 1 6 to retain the pin in the position in which the other end of the pin extends into the recess 31 of the locking fork. Thus when the locking plate 1 6 is in any position except that in which the port cover 6 is locked into position in the port, the locking fork cannot be moved from the position in which the pin 1 7 can enter the recess 31.Because it is the bar 12 on the port cover 6 which causes the locking plate 1 6 to rotate and it would be difficult to rotate the locking plate 16 in any other way, this arrangement ensures that the locking fork 10 cannot be moved to release the container until the port cover has been replaced and moved to its locked position. As the locking fork 10 is moved to the right as shown in Figure 4 from its container-retaining position a sloping portion 33 of the recess 31 pushes the pin through the wall 4 so that it enters the recess 18 to prevent rotation of the locking plate 1 6.

The above-described embodiments prevent the removal of the container when the port cover is not locked into place and the removal of the port cover when the locking fork is not in its containerretaining position. However the locking fork could be moved to the container-retaining position without a container being present and this would allow the port cover to be removed and the interior of the enclosure to be open to the environment through the port. Figure 7 shows a modified form of the apparatus described hereinbefore to prevent the locking fork 10 being moved to the container-retaining position when no container is present. The shoulder 25 is provided with a horizontal slot 34 in which is pivotted an arm 35. The arm 35 pivots around a pivot pin 36 and is spring loaded so that the enlarged end portion 37 is urged towards the wall 4. When a container is present the enlarged end portion rides over the flange 11 of the container as the locking fork is moved towards the container-retaining position and the sliding motion of the fork is not impeded. However, if no container is present the enlarged end portion 37 will be urged into the port opening and if the locking fork is then moved towards the containerretaining position the end portion will contact the wall 38 of the port opening and further movement towards the container-retaining position will be prevented.

The apparatus described above allows material to be transferred between a container and an enclosure without the risk of spreading contamination to the environment by preventing exposure of all external surfaces of the port cover and container to the atmosphere within the enclosure, by preventing accidental misuse and making deliberate abuse difficult.

Claims

1. A port assembly for use with a container of the kind hereinbefore defined comprising a container locking member slidable between a first position in which the container is held against the exterior wall of an exclosure around a port passing through the wall and a second position in which the container may be removed, a cover for the port which is rotatably movable between a first position in which it is locked into the port and a second position in which it may be removed from the port, a locking plate which interengages with the port cover and which is rotatable therewith, a movable pin passing through the wall of the enclosure, recesses in the surfaces of the container-locking member and the locking plate, the recesses being aligned with the pin only when the container-locking member is in its first position and the locking plate is in the position where the port cover is in its first position, the length of the pin being such that when one of the container-locking member or the port cover is not in its first position the pin is urged into the recess in the other to prevent movement thereof.

2. A port assembly according to claim 1 including means to prevent movement of the container-locking member to its said first position in the absence of a container, said means comprising an arm pivotally mounted on the member and urged continuously into engagement with the wall.

3. A port assembly substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.