Patent GB-697162-A (GB)
Title: Automatic immersion apparatus for subjecting articles or material to the action of various liquids
IPC: G01N1/31
Filed: 1949-05-17
Abstract: An apparatus for use in the preparation of specimens which are to be subjected to microscopic examination comprises a frame on which is mounted a horizontal support, arranged to carry several receptacles for containing liquids and a conveyer for moving a specimen holder vertically and laterally to bring the specimen holder into and out of said receptacles in succession, and is characterized in that the frame has provision for mounting a second horizontal receptacle support above the first support and the conveyer is provided with means for moving a second specimen holder into and out of the receptacles on the second support when it is in use.  The apparatus shown comprises annular supports 46, 48, Fig. 1, held in spaced relation by several rods 42, each secured to one of several brackets 40 on a base 38 supported by a cabinet 32.  Between the supports is mounted a circular plate 64 carrying upwardly and downwardly projecting arms 66, 68 to each of which is attached a bracket 80. Each bracket may carry two covers 62, one for each of two liquid containing receptacles 54 accommodated in shallow pans 50 on the supports 46, 48; or one cover 62 and a cover 62a.  The covers 62 are each suspended from a bracket 80 by a pin which engages a slot in the bracket and is retained therein by an enlarged head 98.  Each cover 62a is also suspended from a bracket 80 by a pin, this pin being slidable axially in a fitting, which is clamped in an open ended slot in the bracket and houses a rotatable gear, having internal teeth meshing with teeth formed on the upper end of the pin and being carried by a shaft, rotatable by bevel gears under the control of a flexible shaft in a cable 168 and connected with a gear casing 172 supported on the plate 64, Figs. 1 and 5.  The lower end of the pin carries a member for supporting therebelow a specimen holder.  Gear casing 172 includes a bevel gear 334, Fig. 5, carried by the upper end of a shaft 358, which is rotatably mounted in a shaft 174 and is normally clutched at 354 to a member 360 coupled to a shaft 390, which is continuously rotatable by an electric motor and a linkage such that the shaft 358 and thus each specimen holder coupled thereto, is rotated alternately in opposite directions during each revolution of shaft 390.  The shaft 174 has clamped thereto a collar 214 carrying rods 212, which pass through apertures in a Geneva gear member 242, secured to a member 202 that is rotatably mounted in an apertured plate 194 carried by a fixed part of the apparatus and is supported on said plate by a member 204.  An annular shoulder on the shaft 174 supports a plate <PICT:0697162/III/1> <PICT:0697162/III/2> <PICT:0697162/III/3> <PICT:0697162/III/4> 224 to which is clamped the plate 64 and the gear casing 172.  The Geneva gear member 242 is driven by a member 244 including a driving pin 248 and a dwell portion 246, the member 244 being carried by a shaft 252 which is geared at 272 and 274 to a shaft 268 driven by an electric motor 288, Fig. 4.  The underside 320 of the collar 214 is engaged by a roller 316, Fig. 6, carried by a lever 298, which is pivoted at 300 to a fixed part of the apparatus and carries a roller 312 that constantly engages a cam 290.  This cam is attached to a gear 276, Figs. 4 and 6, on the shaft 268.  The cam is so shaped and the Geneva gear mechanism is so arranged that rotation of the shaft 268, when motor 288 is energized, causes the cam 290 to lift the shaft 174 and thereby move the plate 64 upwards and withdraw the specimen holders from the receptacles 54, the Geneva gear to rotate the shaft 174 and thereby rotate plate 64 to position each specimen holder above the receptacle next to that from which it has been withdrawn and finally causes the cam 290 to lower the shaft 174 whereby the plate 64 descends and the specimen holders are immersed in the liquids contained in said next receptacles.  When shaft 174 is lowered, the clutch member 360 engages the lower end of shaft 358 so that each specimen holder is caused to oscillate in the liquid in which it is immersed.  This cycle of operations is repeated after a time interval determined by either of two electrical timing devices 34, 36 housed in the cabinet 32, Fig. 1.  Each timer includes an electric motor driving a notched disc which is engaged by a lever for actuating a micro-switch, which may be connected in the same circuit as a micro-switch 468 or 470, Fig. 4, that is operable under the control of a cam 480 or 482 carried by the shaft 268.  In use, the apparatus is connected to a power supply so that the motor driving the shaft 390 is energized and the specimen holders are rotated in their respective liquids.  A double throw switch 456 on the cabinet 32, Fig. 1, is rotated to energize the electric motor in the timing device 34 or 36 which it is desired to use.  This motor drives the notched disc which, after a known time, connects the micro-switch in the timer in circuit with the micro-switch 468 or 470 and energizes the motor 288.  This motor rotates the shaft 268 which, during one revolution thereof, causes the withdrawal of the specimen holders, the rotation of the plate 64 and then the immersion of said holders in the next receptacles.  When shaft 268 has completed one revolution, the came 480 or 482 thereon operates the micro-switch controlled thereby and thus de-energizes the motor 288.  The specimen holders now oscillate in the liquids until the notched disc in the operative timer starts a fresh cycle of operations.  Specifications 570,430, 670,168, [both in Group XX], 697,214 and 697,215 and U.S.A. Specifications 2,157,875, 2,157,876, 2,324,122, 2,341,197 and 2,341,198 are referred to.