Patent GB-1000645-A (GB)
Title: Vacuum transfer mechanism for feeding articles such as sheets
Inventor: COOK RONALD JOHN
IPC: B65H5/10
Filed: 1963-04-16
Abstract: 1,000,645. Feeding and delivering sheets; screen-printing apparatus. GAYLER & HALL Ltd. April 16, 1964 [April 16, 19631, No. 14821/63. Headings B6B, B6C and B6H. Sheet feeding apparatus comprises a fixed and a reciprocable carrier member, the latter being movable between first and second extreme positions, each carrier member has at least one suction station thereon and the suction stations are adjacent when the reciprocable carrier member is at its first extreme position, means are provided to apply suction alternately to the fixed and reciprocable carrier members, whereby a sheet placed on the suction station of the reciprocable carrier member when it is in its second extreme position is held thereon and carried by the reciprocable carrier member to its first extreme position, suction is then applied to the fixed carrier member and the sheet held thereon while the reciprocable carrier member returns to its second extreme position, means are provided to move the sheet from the suction station of the fixed carrier member while the reciprocable member is moving from its second to its first extreme position. Pile tables and supports; separators.-Mica sheets are retained in a hopper 23 by lips 25. They are separated one at a time from the bottom of the hopper by a reciprocating suction tube 19 fast with a head 26. The latter is reciprocated by a piston and cylinder 29, 30, and guided by vertical rods 27, 28, attached to the head and passing through bores in a block 18. Single-sheet feeds; sheet carriers and forwarders; delivering sheets.-The sheets are supported on a stationary bar 12 having suction stations 13-15 and carrying the block 18 at the feeding-in side of the apparatus. A movable carrier member 32 is associated with the bar 12 and comprises two spaced bars 32a positioned on either side of the bar 12. The member 32 is attached to a cross-head 35 slidable along two rails 36 and reciprocated by pneumatic means 33. The member 32 is provided with three suction stations 39, 62 and 63 (not shown). The suction stations of the bar 12 and member 32 are actuated alternately whereby a sheet is fed step-by-step along the bar as the member 32 reciprocates. The sheets are finally fed from the apparatus by an endless belt 67. The upper run of the belt is above the level of the bars 32a which pass either side of the belt. The sheets are guided on to the belt by a pair of spaced inclined ramps 75. Screen-printing.-A screen-printing head is pivoted at 44 above the suction station 15 and acts to deposit a suspension of finely divided silver in a viscous medium on a predetermined area of each mica sheet. Said sheets are used in the manufacture of electrical capacitors. The squeegee 49 is mounted on a support 50, pivoted at 51 on a slide 47. The latter is carried by a pair of slide rails 46 and is provided with limiters 53, 54 to limit pivotal movement of the squeegee towards and away from the silk screen 48. The squeegee is reciprocated by a piston and cylinder arrangement 57, 58. Stopping etc.; controlling sheet-feeding &c.- If the vacuum in the interior of the sheet separator 19 falls during operation, due to the supply of sheets having become exhausted, a vacuum-operated relay acts to prevent reciprocation of the slide which operates the squeegee.