| 摘要 |
1,232,479. Feeding sheets. U.S.M. CORP. 20 June, 1968 [21 June, 1967], No. 29420/68. Heading B8R. A stack S, Fig. 1, of permeable sheets is supported on a table 16, and the rear of the stack is defined by the walls 20 of, for example, two laterally spaced vacuum chambers 18, each such wall having a grid comprising five vertical slots 22 aligned with the upper part of the stack, a baffle plate 28 causing greater suction at the top of the grid. The resulting suction forces produce a pressure drop which is greater through the top sheet than through the second, so that separation of the top sheet alone is facilitated, and the forces also hold the stack against the wall. For separation, vacuum is connected to a tube 34 and causes the end of the top sheet to engage forwardly-directed points 48 of a card cloth 46. Pressure fluid introduced into a cylinder 50 causes a piston-rod 52 to move the card cloth and sheet to the right to a position over a belt conveyer and on release of the suction in the tube 32 the sheet is released on to the conveyer. The fluid is then exhausted from the cylinder 50 and a spring returns the separator to the position of Fig. 1, said actions being controlled by two limit switches as 56. The table 16 is raised by a screw 14 under the control of a roller 66 engaging the top of the stack. The rear of the top of the stack is engaged by members 30 aligned with the chambers 18. Downwardly directed air pressure from a device 68 causes fluttering of the top sheet during separation. In another form, Fig. 6, sheets are separated from the bottom of the stack S1, and the grid is inverted and at the lower end of the wall 20a. In another form, Fig. 9, the grids, table raising device and fluttering device is the same as in Fig. 1, but the separator comprises a vacuum chamber 118 provided with seven radially extending legs 122 each comprising an adjustable bent tubular member ending with a foot carrying a card cloth. The assembly is movable by a double acting piston and cylinder arrangement 106 outwardly to the release position shown in chain lines, and is also rotatable about the vertical axis of a rotary motor 88 so that the sheets can be delivered to release positions arranged in various positions concentric with the axis. The legs and feet are adjustable respectively rotatably and radially so as to engage sheets of various shapes at a plurality of points. A further motor in a housing 94 can rotate the assembly 118, 122 to control the orientation of the sheets when released. The feet are also vertically adjustable to accommodate stacks which are not flat. For use with the apparatus of Fig. 1 or Fig. 9, another form of separator comprises a yoke 140, Fig. 15, supporting a rotatable tubular element 142 carrying four hollow cross members 144 having at each end a slot carrying a card cloth, the element 142 being rotated when necessary to alter the height of the leading end of the sheet and its orientation with respect to the horizontal. A further form of separator comprises an inverted T- shaped arm 152, Fig. 19, carrying eight horizontal sleeve elements 152 each carrying a telescoping foot member carrying a card cloth, and each element 152 can be set to project in either direction, which, together with the adjusting of the feet, accommodates sheets of various shape. |
