Equipment for gamma radiography of closed vessels and pipelines

Claim 2

A radioactive source container comprising: a two-part radiation shield including a fixed part and a part movable with respect thereto, said movable part butting against said fixed part when in the closed position and being positioned in spaced-apart relationship thereto when in the open position; a fixed sourceholder of radiation-emitting material positioned to lie wholly within the movable part of the shield when in the closed position and to be exposed when said movable part is in the open position; continuously acting closure means tending to force said movable part of said shield towards said fixed part; opening means for moving said movable part of said shield away from said fixed part and against the action of said closure means; and a latching mechanism for holding said movable part in the open position against the action of said closure means.

Claim 3

The container as claimed in claim 1 in which the two parts of the shield are cylindrical in shape and have a common axis, the movement of said movable part being along said axis and the sourceholder being located in a central bore along said axis.

Claim 4

The container as claimed in claim 2 in which said movable part of said shield is in two sections, one section having a sectorial cross section whereby movement thereof exposes radiation from said sourceholder in a radially extending sector only, said opening means comprises a rod lying on said common axis and connected to said one section, and in which selection means is provided for selecting either said one section or the whole of said movable part for movement by said opening means, said selection means comprising a rotatable selector sleeve surrounding said rod and secured to move axially with the remainder of said movable part of said shield, and locking means between said rod and said sleeve which in one angular position of the sleeve locks the sleeve to the rod for axial movement of both thE rod and the sleeve and in another angular position allows axial movement of the rod, and with it said one section, relative to the sleeve.

Claim 5

The container as claimed in claim 2 in which the location of the sourceholder is such that it lies midway in the gap between the two parts of the shield when the shield is in the opened position and is out of the plane of the butt when the shield is in the closed position.

Claim 6

The container as claimed in claim 1 in which a cocking mechanism and two spring means are provided, one of said spring means comprising said opening means and the other of said spring means comprising said closure means and said cocking mechanism operating to energize both of said spring means, and wherein said latching mechanism also holds said movable part in the closed position against the action of said opening means, the latching means comprising two latches, each of said two latches operating to hold a respective one of said spring means in its energized state without allowing movement of said movable part of said shield, the release of one of said latches causing the release of its associated spring means to move said movable part of said shield to its opened position and the release of the other of said latches causing the release of its associated spring means to move said movable part of said shield to the closed position.

Claim 7

The container as claimed in claim 1 in which a timing means is provided for operating the latching mechanism and which determines the time during which the shield is held open.

Claim 8

The container as claimed in claim 5 in which timing means are provided for separately operating both of the latches.

Claim 9

The container as claimed in claim 1 in which the two-part shield and closure means are detachable from the remainder of the container.