Patent ID: 6255116
Filing Date: 2001-07-03
Classification: B01J,G01N,Y10T

Abstract:
An apparatus for arraying beads which comprises:a vessel containing a mixture comprising beads in a liquid, the vessel having an interior defined by a top opening, side walls and a bottom;a paddle within the vessel and immersed in the liquid therein;means for effecting reciprocating movement of the paddle within the liquid along a path having a vertical component;an array of hollow elements, each having an internal passage and an opening at an end of the internal passage, the opening being circular in shape so that it can be substantially closed off by a spherical bead, the array being insertable into the vessel so that all of the openings of the elements are immersed in the liquid within the vessel;means for drawing liquid from the vessel into the internal passages of the hollow elements through their openings, for establishing a pressure differential across each opening such that the external pressure exerted on a bead closing off the opening of each hollow element is greater than the pressure within the passage of the same hollow element, thereby holding the bead in engagement with the opening; andmeans for withdrawing the array of hollow elements from the vessel with beads in engagement with the openings thereof and for moving the array to a remote location for deposition of the bead;in which the vessel has horizontal cross-sections, and the paddle has a top and a bottom, and a horizontal projection the area of which is sufficient in comparison to the horizontal cross-sections of the vessel that movement of the paddle within the liquid along said path induces a substantial vertical movement of the liquid, whereby the beads are maintained in suspension in the liquid by the substantial vertical movement of the liquid induced by the paddle as the paddle reciprocates, and in which the paddle comprises at least two adjacent slots allowing flow of liquid through the paddle, each said slot having a relatively narrow opening at the bottom of the paddle, a relatively wide opening at the top of the paddle and sloping side walls, a side wall of one of said two adjacent slots meeting a side wall of the other of said two adjacent slots along a narrow ridge at the top of the paddle.