A connection device between two plates, one being a fixed plate and the other being a movable plate, each of the two plates supporting at least one hydraulic, pneumatic and/or electrical type circuit connection element (5, 11) intended to pair with a connection element (5, 11) of the same type on the other plate, the connection device being disposed on one of the two plates and comprising: - a cylinder body extending along a central axis and comprising a main cavity, - a shaft movable in translation within the cylinder body along the central axis of the cylinder body, - a piston, integral with the shaft, movable within the main cavity of the cylinder body and dividing the main cavity between a front chamber and a rear chamber, the connection device comprising further: - a sleeve extending around the shaft, this sleeve being movable along the central axis with respect to the cylinder body between a rear position and a front position, - locking members housed in the sleeve, each locking member being movable relative to the sleeve between a locking configuration where each locking member is spaced from the central axis and a release configuration where each locking member is closer to the central axis than in the locking configuration, the shaft being movable along the central axis between: - a disconnected position in which the shaft does not oppose the movement of the locking members in their release configuration, and the sleeve is in the forward position, - and a connected position, in which the shaft opposes the movement of the locking members in their release configuration, and the sleeve is in a rear position, - through an intermediate position between the release position and the connected position, in which the shaft resists movement of the locking members into their release configuration, and the sleeve is in the forward position. - a cylinder body extending along a central axis and comprising a main cavity, - a shaft movable in translation within the cylinder body along the central axis of the cylinder body, - a piston, integral with the shaft, movable within the main cavity of the cylinder body and dividing the main cavity between a front chamber and a rear chamber, - a sleeve extending around the shaft, this sleeve being movable along the central axis with respect to the cylinder body between a rear position and a front position, - locking members housed in the sleeve, each locking member being movable relative to the sleeve between a locking configuration where each locking member is spaced from the central axis and a release configuration where each locking member is closer to the central axis than in the locking configuration, - a disconnected position in which the shaft does not oppose the movement of the locking members in their release configuration, and the sleeve is in the forward position, - and a connected position, in which the shaft opposes the movement of the locking members in their release configuration, and the sleeve is in a rear position, - through an intermediate position between the release position and the connected position, in which the shaft resists movement of the locking members into their release configuration, and the sleeve is in the forward position.