Анализ тенденций развития. Обзор патентной и научно-технической литературы

Examiner: Coe; Philip R. , Agent or Firm: Laff, Whitesel & Rockman claim:

. A digitally controlled motorless stirrer comprising means for generating cyclically recurring pulses, electronically controlled means for establishing a stepping magnetic field responsive to said recurring pulses, a container, a magnetic stir rod positioned in said container and against a surface thereof made from a non-magnetic material, and means for supporting said surface of said container within said magnetic field in a position where said magnetic stir rod follows the stepping of said magnetic field.

. The stirrer of claim 1 wherein said means for establishing a magnetic field comprises a plurality of coils positioned in a predetermined geometrical arrangement beneath said stir rod supporting surface, a plurality of pole pieces associated with each of said coils and extending in the predetermined arrangement toward said container, and means associated with each of said coils for completing a magnetic circuit between said coils.

. The stirrer of claim 2 and means for applying said recurring pulses to adjacent ones of said coils in an overlapping pulse relationship whereby magnetic flux is built by an energization of each individual one of the coils before the magnetic flux built by its immediately neighboring coil disappears.

. The stirrer of claim 2 and programmable means for controlling the generation and the application of said pulses to said coils.

. The stirrer of claim 2 wherein said stir rod has an enlarged equatorial region forming a bearing surface on which said stir rod may turn.

. The stirrer of claim 1 wherein said predetermined geometrical arrangement is a circle of pole pieces beneath said surface for creating a rotary magnetic field.

. The stirrer of claim 1 wherein said predetermined geometrical arrangement is a row of pole pieces for creating a sweeping linear magnetic field for moving said stir rod in at least a linear motion along said linear field.

. A method for controlling the stirring of a fluid or similar mixable substance comprising the steps of: . generating digitally controlled, recurring switching pulses for sequentially defining successive discrete time periods; . generating successive magnetic fields responsive to said switching pulses, for sequentially stepping a magnetic field in a predetermined motion; . positioning an integral non-magnetic container including the substance to be stirred within said stepping magnetic field; and . positioning a magnetic stir rod which is entirely separate from said container in said container and within said stepping magnetic field, whereby said rod moves with said magnetic field in order to stir said substance.

. The method of claim 8 and an added step wherein said switching pulses of step a. are generated and applied under control of a programmable means, whereby said magnetic stir rod may be programmed to follow a great variety of different patterns of movement by generating and applying said switching pulses in a different order.

. The method of claim 9 and the added step of generating and applying said switching pulses in overlapping relationships.

. The method of claim 9 wherein said switching pulses are generated at a recurrence rate relative to the inertia of said stir rod which causes the switching pulses to lead the stir rod as it moves, so that said rod moves continuously and does not come to rest at any pole piece.

. The method of claim 11 and the step of changing said recurrence rate with a ramp function whereby said pulses recur at an increasing or decreasing rate which varies as a function of the inertia of the stir rod so that it may accurately follow said magnetic field.

. The method of claim 12 and the step of changing the direction of the magnetic field stepping each time that said recurrence rate slows.

. An automatic stirrer comprising a circle of paired coils, each of said pair of coils being diametrically opposed in said circle, said coils being wound in directions to produce magnetically opposed flux fields, whereby one of said pair induces one magnetic pole when the opposite of said pair induces the opposite magnetic pole responsive to an energization of the pair of coils, digital means for sequentially generating switching pulses for energizing each of said pair of coils in a predetermined order around said circle, means for alternatively reversing the relative positions of said opposite magnetic poles when each of said pair of coils is energized, a free magnetic stir rod, means for supporting said stir rod in the magnetic fields created by said coils and means for varying the characteristics of said switching pulses to coordinate their generation with the inertia characteristics of said stir rod.