The R2P2 ‘cluster tool’ is a development of the linear rack and pinion transporter, where a single ended rack and pinion can be rotated within a circular vessel until it is aligned in a preset position at a radial port on the housing chamber by a rotary drive. Once locked in position, the same rotary drive moves the rack out through the chamber port.
R2P2's are normally mounted at the centre of a series of chambers and form a central hub from which all of the transfer takes place; they can be also used to join one or more systems together. The R2P2 chamber is normally connected by isolation valves to each of the connecting chambers allowing it to be sealed off as required. Careful design can allow storage carousels to be placed inside the chamber to allow sample storage as well as transfer from one vessel.
A port mounted at the base of the R2P2 allows a pump to maintain the chamber at a pressure lower than 10-10 mbar if required.
There are two sizes of R2P2: the first uses a 635 mm O.D. (25") chamber to give a rack insertion of 305 mm; the other uses a 762 mm O.D. (30") chamber also giving a rack insertion of 305 mm.