Patent GB-814013-A (GB)
Title: Automatic apparatus for introducing liquid into an open-necked vessel
IPC: H01J9/22
Filed: 1956-06-27
Abstract: 814,013. Coating cathode ray tubes internally. SYLVANIA ELECTRIC PRODUCTS Inc. June 27, 1956 [June 30, 1955], No. 19948/56. Class 39(2) Apparatus for introducing liquid into an open-necked vessel, such as the inverted envelope 15 of a cathode ray tube, includes a conduit 49 mounted for reciprocating motion in the direction of its own length and also for limited movement in all directions perpendicular to its length, means for imparting the reciprocating motion to the conduit to move one end thereof into and out of the vessel, a centring device 53 carried on the conduit for guiding the end of the conduit into the vessel, means sensitive to the placing of the vessel in position for the introduction of liquid into it for initiating the operation of the apparatus, and means for the introduction of liquid into the vessel through the conduit when the end of the conduit is inside the vessel. Automatic apparatus for introducing a predetermined quantity of liquid into the envelope 15 of a cathode ray tube having an open neck, in order to treat the internal surface of the envelope, e.g. for dispensing phosphor materials, comprises a conveyer 11 provided with carriers 13 which receive the envelopes, neck upwardly, and carry them from left to right through the work stations of the machine, limit switches or sensing devices 21 being provided to start the operation when abutted by an envelope arriving beneath a fluid conduit 49 which is reciprocated vertically between an upper rest position and a lower work position wherein the conduit extends into the envelope, the conduit being aligned with the envelope neck opening by means comprising a movable supporting plate for the conduit and a centring device carried by the conduit. The dispensing and aligning assembly shown comprises two adjacent work stations and comprises a trolley 31 which is guided upon fixed vertical guide rods 34 from the upper position shown to a lower, work position. The vertical reciprocation is effected by a double-acting compressed air cylinder 39 with a valve 40 mounted on a fixed top bracket 57, the piston rod being connected to the trolley 31. The trolley 31 is connected by sleeves 33 to a bracket 42 which thereby reciprocates with the trolley 31 and has a movable plate 43 flexibly mounted upon each end, the connection between the bracket 42 and plates 43 being such that the plates have a limited movement in all directions relative to the bracket 42, e.g. by means such as ballbearings between the plates and bracket, together with a spring which tends to maintain the plates normally at a central position. Each plate 43 has mounted on it a dispensing-funnel 45 provided with an internal contamination screen 47, and the bottom of each funnel carries an integral downwardly extending dispensing tube or conduit 49 which can thus have both a lateral and a longitudinal movement. The lower ends of the tubes 49 are formed with external flanges providing limit stops for inverted conical or cup-shaped centring or aligning devices 53 which are slidable upon the tubes. The dispensing fluid is fed into the funnels 45 by way of flexible hoses 61 leading from bowls 59 which are mounted on supports on the top bracket 57. Each work station shown is provided with a neck pan 63 provided with a split membrane 75 with a central aperture to receive the neck 17 of an envelope, the object of the neck pans being to shield the envelopes by collecting drippings from the conduits 49 as the latter are approaching the envelope necks, thereby preventing marking of the exterior of the envelopes by the dispensing fluid. The neck pans 63 are carried by a bracket 67 extending between the two work stations and arranged for vertical reciprocation upon guide rods 65 by an air pressure system including a double-acting cylinder 73. A neck-pan switch block 70, mounted on the bracket 67 co-operates with a switch arm 71 when the bracket is in its "up" position. The apparatus is also provided with a drip pan 79 at each station to collect fluid drippings that would otherwise fall from the conduits 49 on to the envelopes while the apparatus is at its rest position and while envelopes 15 on the conveyer 11 are moving into their work stations. Each drip pan 79 is mounted on a bracket 81 extending laterally from a sleeve 87 mounted on a horizontal guide rod 89, the two sleeves being connected by a transverse brace 85 on the end of the piston rod of a double acting cylinder 83. The drip pans are moved into the vertical path of the conduits 49 when the latter are in the "up" position, and move forward horizontally and clear of the conduits before the neck pans 63 begin to lower. One sleeve 87 carries a contacting block 92 which, in the forward position of the pans 79 bears upon a switch arm 90 mounted on the supporting frame of the sleeve guides 89. With the dispensing apparatus in the inoperative position shown, an envelope moving from left to right contacts the sensing arm 21 which energizes the cylinder 83 to start the dispensing apparatus, so that the drip pans 79 are moved forwardly from under the conduits 49, and at the end of their travel the switch block 92 operates the switch arm 90. This actuates the air pressure cylinder 73 so that the neck pan carrier 27 is moved downwardly until the membranes 75 of the neck pans 63 embrace the necks of the envelopes. The movement of the neck pan assembly from its upper position actuates the switch arm 71, so that the pressure cylinder 39 is energized and its rod 41 lowers the trolley 31, thereby lowering the ends of the conduits 49 into the envelopes. The internal surfaces of the conical aligning devices 53 contact the edge of the envelope neck, thereby forcing the devices 53, conduits 49, and tube neck openings to become axially aligned through the flexible mounting of the movable plates 43. The downward movement of the trolley 31 actuates the arm of switch 55 which starts the flow of treating liquid from the bowls 59 and through the tubes 61 and conduits 49 into the envelopes 15. After a predetermined amount of liquid has been dispensed, a production line timing mechanism, not shown, causes the air cylinder 39 to raise the trolley 31 and hence the conduits 49. The block 37 contacts the switch 55 causing the cylinder 73 to raise the neck pans 63. The simultaneous upward movement of the switch block 70 contacts the switch arm 71. This causes the cylinder 83 to move the drip pans 79 horizontally back under the conduits 49. The apparatus is then back in the starting position.