Patent GB-1415182-A (GB)
Title: Apparatus for treating a specimen at a succession of positions
IPC: G01N1/31
Filed: 1972-11-01
Abstract: 1415182 Reciprocating conveyers GOEDECKE AG 1 Nov 1973 [1 Nov 1972] 50405/72 Heading B8A [Also in Divisions G2-G3] A specimen carrier [supporting one, or a batch of, slide(s), or organic tissue to be prepared prior to micro-sectioning] is moved under programme control in a programmed sequence between a number of liquid containers [reagent baths]. The reagent baths (2), Fig. 1 (not shown) are arranged in a two dimensional [5 x 4] array, the program taking the form of sets (10) of columns (11-14), of a plugboard, a stage [immersion of the cage in one reagent bath for a given time] of the preparation being defined by coded plugs (15) in a row, plugs in columns (11, 12) defining x and y co-ordinates of the required bath, those in columns (13, 14) defining the number of minutes, and tens of seconds for which immersion is required. If, for any stage, no plugs are present in columns (13, 14) immersion in the chosen bath is for a predetermined minimum time. Preparation is complete when either all rows have been read, or a row entirely without plugs is reached. Movement may take place in x and y components simultaneously. The plugs (15) are coded according to possible bath co-ordinate components, and immersion durations according to binary coding, using diodes, see Fig. 5B (not shown), or contain resistors whose values correspond to derived directions and times, and influence output signals accordingly. Control circuit arrangement.-Process counter 91, counted by the output 6 of sequence counter 80 at the end of each immersion stage, via decoder 92, determines the row, corresponding to the succeeding stage, of the plugboard to be read, and y components of the succeeding bath position being passed to and y comparators 94 95, the corresponding immersion time passing to time 93. Actual and y co-ordinates of cage position are optically encoded by motor driven discs 42, 62, containing, along five, respectively four radii apertures read by a row of photo transistors, the apertures along each radius representing a component of a possible bath position in binary code, such actual position signals also passing to the comparators 94, 95, the latter energizing, via controls 100, 101 driving motors 31, 51 for x and y directions, and via solenoids 32A, 52A clutches in the motor transmissions, to move the cage until equality of actual and desired cage positions are equal. A Z motor 104 is then enabled to lower the cage into the bath, while clock 105 counts timer 93 to zero, whence the cage is raised limit switches 98, 99 ensuring that x, y motors can only operate with the cage up. Outputs (1-6) of the decoder (83), Fig. 5A (not shown) in the sequence counter 80 control the sequencing of each stage according to the flow diagram of Fig. 4 (not shown). The reset process (5) takes place at the end of a preparation, enabling a new preparation to be instigated after a predetermined delay. Mechanical arrangement.-The reagent baths (2, Fig. 1) are on pull-out trays (3), the removal of any one tray locking the others in position. Carriage (22) is movable in the x direction by means of a chain drive, see Fig. 2 (not shown), and supports a jib (23) along which a slide (25) is driven in the y direction by a further chain drive, the whole being mounted over the baths. The jib (23) can be lowered relatively to the carriage (22) by an endless belt passing over pulleys (73), (77), the former being mounted eccentrically on shaft (71), 180 degrees of rotation of the latter causing cage (21) to be lowered into the reagent. In the lowered position, continuously rotating cam (78) engages wheel (79) thus oscillating jib (23) to circulate the reagent among the slides.