Patent GB-1174182-A (GB)
Title: Apparatus for inserting a Predetermined Volume of Liquid into a Receptacle
IPC: G01F11/10
Filed: 1967-02-13
Abstract: 1,174,182. Dispensing measured quantities of liquids. TEXAS INSTRUMENTS Inc. 13 Feb., 1967 [16 Feb., 1966], No. 6695/67. Heading B8N. Apparatus for inserting a predetermined quantity of liquid into a receptacle includes a supply station 64 having means for containing a liquid, an insertion station 66 having means for supporting a receptacle, a pair of fingers 54 suitable for forming a capillary cavity therebetween and means for holding the fingers in predetermined relationship, for at least partially immersing the fingers in the liquid contained in the liquid supply means, for transporting the fingers to a receptacle supported by the support means and for spreading the fingers to deposit the liquid carried thereby. As illustrated the apparatus is for inserting a predetermined quantity of glass slurry into a receptacle 10 formed by a ring frame 12 and a baseplate 14 of a semi-conductor flat pack to insulate leads 16 from the receptacle and comprises four pairs of fingers 54 positioned respectively at the supply station 64, the insertion station 66, a washing station 68 and a drying station 70, the fingers in each pair being carried by a rigid arm 72 and a movable arm 76 and being separated by an adjustable stop 84 to form a capillary cavity 56. The arms are mounted on a shaft 74 which is rotatable through 90 degrees via a Geneva mechanism (Figs. 9a-9c, not shown) by a timer shaft 126 continuously rotated by an electric motor (not shown) to move each pair of fingers to the next successive station. Prior to and after rotation the shaft 74 is raised and lowered by action of a cam 138 on the shaft 126 and follower 140. The supply station 64 includes a tank for the slurry and a helical screw 220 which, when the tank is rotated by a motor, transfers the slurry into an annular chamber 194 into which a pair of fingers extend when the shaft 74 is lowered. A fibrous wick 226 in a tank 228 surrounding the chamber is wetted by water and reduces the evaporation of the slurry. Upon raising and rotating, the shaft 74 advances the pair of fingers to the insertion station and upon lowering of the shaft a locating pin 88 on arm 72 engages a female socket 277 and the tips of the fingers enter into the receptacle. The slurry is dispensed by intermittent movement of the arm 76 by a lever 281 engaging a cam block 86. The lever 281 is rocked via a linkage by a cam 292 and follower 290. A carrier assembly (11) (Figs. 1 and 2, not shown) supports a plurality of receptacles 10 accurately positioned relative to a lead frame plate (18) and includes cam ways 46 which are engaged by rollers 250 carried by a member 252 rotatable to advance the assembly when the shaft 74 is rotated. The pair of fingers are next indexed to the washing station where the fingers are opened by a stationary cam 360 engaging the cam block 86, and are brushed by brushes 310 to which water is applied via a pipe 318. The water is contained in a tank 300 which is vibrated by an ultrasonic transducer 308. At the drying station the fingers are lowered into a chamber (400) (Fig. 13, not shown) and are opened by a cam 434 engaging the block 86. Air is introduced into the chamber either continuously or only when the shaft 74 is in its lowered position. Any glass particles on the fingers drop into a tray (412) and the air stream passes through a filter (424) to atmosphere.