Gas administration apparatus

Claim 2

A gas flow unit adapted to be mounted on a gas-administration apparatus in a removable plug-in fashion, the unit comprising means for controlling the admission to the unit of gas from a supply provided by the appratus, a locking mechanism for cooperation with the apparatus to lock the unit in place when mounted on the apparatus, and an interlock system in which the manipulation of the control means into an operating position which provides for the admission of gas from the apparatus to the unit is prevented unless the locking mechanism has been moved into a position in which it is adapted to lock the unit in the apparatus.

Claim 3

A gas-flow unit as claimed in claim 1, in which the control means controls the admission to the unit of gas from a supply provided through one or more cooperating ports on the apparatus, the or each port having a valve member normally urged into a position in which it acts to close the respective port, and the unit including actuating means forming part of the interlock system such that when the unit is mounted on the apparatus, the actuating means is effective to move the respective valve member of the or each cooperating port away from the port closing position only when the control means has been manipulated to its operating position.

Claim 4

A gas flow unit as claimed in claim 1 or 2, in which the interlock system includes at least one pin extendible outwardly from the unit on manipulation of the control means to its operating position to prevent the control means of a similar adjacent unit mounted on the apparatus from being manipulated to its operating position.

Claim 5

A gas-flow unit as claimed in claim 1 or 2, in which the interlock system inciudes two springloaded pins each adapted to extend from opposite sides of the unit against the bias of its spring on manipulation of the control means to its operating position to prevent the control means of a similar adjacent unit mounted on the apparatus from being manipulated to its operating position, the pins each being movable towards their extended position bya further pin depending from a spring-loaded platform for reciprocal movement of the platform against its spring bias caused by the rotation of a crank, an end portion of which bears upon the platform, the crank being rotatable by a cam itself rotatable on rotation of a dial forming part of the control means.

Claim 6

A gas-flow unit as claimed in any one of claims 4, in which the locking mechanism includes a shaft on the unit rotatable between a clocked and an unlocked position, the shaft having a profiled groove which engages a latching member in a recess of the apparatus adapted to receive the shaft.

Claim 7

A gas flow unit as claimed in claim Sin which the interlock system includes a plate having at least one upstanding pin which, on rotation of the shaft to its unlocked position, prevents the control means being manipulated to its operating position.

Claim 8

A gas flow unit as claimed in claim 6, in which the pin, in the unlocked position of the shaft, engages the platform to prevent movement of the platform against its spring bias.

Claim 9

A gas-flow unit adapted to be mounted on a gas administration apparatus in a movable plug-in fashion, constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the figures of the accompanying drawings.

Claim 10

A gas-flow unit adapted to be mounted on a gas administration apparatus in a movable plug-in fashion, constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the figures of the accompanying drawings.