Abstract: A tube machining apparatus is described which comprises a support frame (2), an intermediate body (6) arranged to carry tools (7), a clamp (8) for locking at least one tube (4) at a predetermined processing or machining station (9), and at least one gripper (16) for acting by grasping on each tube. Gripper (16) and tools (7) are carried by the intermediate body (6) and movement means (17) is provided which is interposed between the intermediate body (6) and the support frame (2) and is capable of simultaneously moving both the gripper and the different tools between respective rest and work positions.

Abstract: A composite pipe comprising a corrugated external pipe and a smooth internal pipe possesses a socket which, at its bottom, adjoins the internal pipe and the external pipe by an expanded section. Subsequent to the expanded section, the socket comprises a smooth-walled and substantially single-walled section which is again followed by a composite pipe section having an internal pipe section and an external pipe section with at least two annular corrugation crests.

Abstract: A motor whose stator is equipped with a main winding (DP) and with an auxiliary winding which consists of two half-windings (B1, B2) that are wound in opposite directions and is supplied through a full-wave rectifier (GR) and by means of two commutating switches (T1, T2) controlled by a control circuit (COM) which alternately closes the switches at a frequency equal to the frequency of the supply voltage. The motor comprises, in parallel with the half-windings, at least one device (DAP) which limits the voltage across the terminals of the switches when they are opened, to a value higher than the supply voltage.

Abstract: A combination compressor unloader which has a horizontal cylinder and a double acting piston forming two compression chambers. Each chamber communicates by a passageway with a supplementary chamber with each passageway associated with a reversible actuator having an attached unloader plug capable of sealing the passageway from a remote control. A second means is provided to form a reversible by pass that can deactivate at least one cylinder end of said double ended piston.

Abstract: The present invention provides a removable attachment for a partial denture with a sliding locking assembly. The locking assembly is provided with a relatively wide slot and narrower sliding slot or recess which has a major axis which is horizontal and at a right angle to the row of teeth, a locking member including a lock pin and a protruding member suitable for being retained in a recess of the denture and has a hole which may be engaged by the lock pin. The lock member is retained in position by a spring loaded pin and detent to receive the pin. The attachment may be easily operated by a fingertip without injury to the finger and no sudden separation of the partial denture is experienced. It may be used in cases where only the canine teeth of both sides exist as well as in cases where bilateral and/or unilateral teeth are missing. General dental instruments can be adapted for use with this attachment and no special instruments are necessary.