Patent GB-1055825-A (GB)
Title: Improvements in sheet feeding apparatus
Inventor: LYMAN BROOKS
IPC: F15C1/00
Filed: 1964-08-04
Abstract: 1,055,825. Feeding and delivering sheets. PITNEY-BOWES Inc. Aug. 4, 1964, No. 31529/64. Headings B6B and B6H. In a pneumatic sheet feeding system, sheets are driven along a predetermined path formed by a guide surface, by a number of air jets arranged along the path, and the jets are controlled from a sensing means comprising one or more devices which direct a jet of air across the sheet path to sense the presence of a sheet passing the device. The system is described, Figs. 1 to 28 of the drawings (not shown), as applied to apparatus for separating documents 77 from a stack 73, and feeding them around a curved path 32a, along the left side of a gate 33, past a sensing head 35, and back to the gate 33 where they then pass to the right to a stacker device 34. The inclined short strokes (Fig. 1) represent the propelling air jets, and the ones designated by references, such as A1, are subject to the control means. The guide track consists of a narrow plate 40, Fig. 2, secured upright on a horizontal support plate 30. Each propelling jet comprises a hole 44 in the guide 40, with its axis inclined at an angle P to the guide surface 41 of the guide, and on the opposite side is secured a nozzle 46 connected to a pipe line 48. The issuing air jet 45 holds a document against the surface 41 and propels it along that surface by reason of the differential air pressure existing on opposite sides of the document. The longitudinal spacing between successive air jets is less than the length of the shortest document. Sensing and control means arranged along the track are shown at A, B, C, D, E, and F, and each comprises a hole 61, Fig. 8, in the guide 40 connected to a nozzle 62 which directs an air jet normal to the guide; a document crossing such a jet causes an increase in pressure in the air line of the jet, and this pressure increase is detected by a control device which includes a bi-stable fluid amplifier 110, Fig. 22, to control the operation of certain air jets 45. Each amplifier 110 comprises two flat plates secured together, the inner face of the bottom plate having a main groove 113, a nozzle-like groove 114, and two branch grooves 115, 116. Coaxial control grooves 117, 119 are also formed in the bottom plate to join the junction between the groove 114 and the grooves 115, 116. Air lines 120-124 are coupled to the grooves 113, 115, 116, 117, and 118. The line 120 is connected to the main air supply, the lines 121, 122 are connected to a pair of sensing air jets, such as A and B, C and D, or E and F, one branch line 123 is connected to a set of propelling air jets, such as A1-A4, and the other line 124 is connected to another set of air jets, such as B1-B4. The control device also includes adjustable plugs 130, Fig. 25, which can close one or more vents to atmosphere, whereby the static pressure in certain air lines can be regulated. When air pressure impulses are imported into one of the control lines 121, 122, only one of the branches 123. 124 will conduct air jets from the main line 120, whereby the propelling jets for the documents are controlled, and this control is exercised automatically by the passage of a document across the sensing devices A-F. Sheet separation.-Documents stacked at 77, Figs. 1 and 12, in a magazine 73 are urged resiliently towards the document guide track, and are extracted sequentially and fed by the air jets B1-B4, each constructed as shown in Fig. 2. A single separated document will follow the curved track, but other documents separated will abut a stop plate 83, Figs. 12 and 13, and be held there until the top document has been separated completely. Sheet feeding and stacking operation.-A document separated from the magazine 73 is fed by the air jets B1-B4, and D1-D4 up to a stop 72, Figs. 1 and 12. As it passes sensing means A, the jets A1-A4 become operative and jets B1-B4 become inoperative, and as it passes sensing means C, the jets C1-C4 become operative and the jets D1-D4 become inoperative; thus the document will be propelled away from the stop 72 and around the track past the sensing means D to enter the circular track 32a. The sensing means D will render the jets C1-C4 inoperative and the jets D1-D4 operative. The document is fed to the gate 33 where the jets F1-F4 are operative to feed it past the sensing device E which renders the jets E1-E4 operative and the jets F1-F4 inoperative, whereupon when the document again reaches the gate 33 it is fed past sensing devices F and B to a stacker 34. The device F renders the jets F1-F4 operative and the jets E1-E4 inoperative, the device B renders the jets B1-B4 operative and the jets A1-A4 inoperative. An air jet assists the stacking of the sheets in the stacker 34.