Abstract: In a pneumatically actuated screwdriving machine having a tubular screw receiving nose which surrounds the rotatable screwdriver head and which may slide axially towards the body of the machine by being carried and guided by longitudinal rods secured to the said nose and slidably supported by the said body, one of these rods has a peripheral groove and acts as a movable slide valve member in cooperation with annular chambers provided within the body. When the nose has been pushed towards the body, the air under pressure admitted through the valve which controls the pneumatic motor of the machine is also supplied through a flexible air conduit to the selector of a screw feeding apparatus which takes a screw from the screw container of the apparatus, while when the nose is returned to its advanced position, the air conduit is depressurized and the screw is transferred towards the nose through a flexible screw conveying conduit.

Abstract: An automatic coupling for the joining of two pipes has a male element and a female element with an internal bore to receive the male element. The female element incorporates a locking member arranged to engage behind an annular shoulder on the male element, and retain the male element in the female. The locking member is slideable transversely to the bore in the female element, and has a keyhole shaped opening through it. The shoulder passes through the wider part of the keyhole opening after which a return spring engages the narrower part of the keyhole opening behind the shoulder.To provide an automatic coupling action the narrower part of the keyhole opening has two doubly oblique surfaces. When the male element is inserted, a frusto conical leading surface to the shoulder bears on these doubly oblique surfaces and displaces the locking member against the return spring to allow the shoulder to pass through the wider part of the keyhole opening.