Patent GB-550225-A (GB)
Title: Improvements in or relating to apparatus for viewing films
Filed: 1941-06-26
Abstract: 550,225. Optical-projection apparatus. BRITISH TABULATING MACHINE CO., Ltd. June 26, 1941, No. 8015. Convention date, June 27, 1940.. [Class 97 (i)]. [Also in Group XI] A film viewing mach; ine for viewing a film, Fig. 10, bearing lines of characters denoting data belonging to different groups and transversely disposed-code marks 130 denoting the numbers of the groups comprises photo - electric cells adapted to be controlled. by the codemarks to stop the film at a desired group and to show at least one line of the group on the viewing screen. Additional marks 131, 132 may be provided in line respectively with the "total" line-of each group orwith the code marks 130 to-cause the film to stop at the "total" line or at the first line of the group. The machine may also be set for control by the mark 131 or 132 irrespective of the group code marks 130. General arrangement. -The machine parts are arranged on a base 20. Fig. 2, within side frames 21, Fig. 3. The front has an upper viewing screen 95, Fig. 1, and a lower panel, on which are provided a plug board 153, a number of control knobs 147 ... 151, and a Hand-set group selector 141. On one side there is a hand wheel 65 for manual drive of film forward or backward, and on the other side a door 93 to allow access to the mechanism and insertion and removal of film reels. Film drive device.-The film comes from a supply reel 29, Fig. 2, passes over roller 36, under idler sprocket 37, over driving sprocket 38, through gate 39 with usual slack loop,. under driving sprocket 40, over idler sprocket 41, and under roller 42, and is taken up by a reel 32. Each reel is detachably secured by a spring' ball catch on the square end of its spindle. These spindles and the spindles of the driving sprockets 38, 40 are driven through gearing by a motor 44; when a one-revolution clutch is engaged under the control of an electromagnet. The drive is transmitted through concentric shafts 60, 61, Fig. 9, fast with flanges 62, 67 which are normally connected by means of hand-wheel 65 and keying pins 63. 66. This connection may be broken by pushing the hand-wheel inwards against springs 69, thereby freeing the hand-wheel from the pin 63. The film may then be driven in either direction by the hand-wheel. A switch controlled by a lever bearing on the film causes the machine to stop when no film' is present under the lever. Optical-projection devices.-The film in the gate 39, Fig. 2, is illuminated by means of a lamp 98 and a condensing lens system 99, and an image is projected-by a lens system 100. While the film is running, the projected image is thrown on a number of photo-electric cells 135, 135a, 135b, on some, directly and on others, through mirrors 133, 134, Figs. 2 and 3; but when the. desired data cause the circuits of the photoelectric devices to operate; the drive is stopped and a mirror 97 is swung up to the dotted line position and, in conjunction. with another mirror 96, throws the image on a viewing screen 95. The particular fine of the film to which attention is desired is indicated'by a pointer 156, Fig. 1, controlled by an electromagnet 159. In one position, Fig. 1, the pointer uncovers a legend "list"; in the other position, Fig. 1a, it uncovers the legend " total." The mechanism for moving the mirror 97, Figs. 2 and 3, comprises an arm on the spindle 102 of the mirror connected by a link 104 to an eccentric 105 driven by the motor 44 through gearing including a Geneva gear 109 and a one-revolution controlled by an electromagnet. Each revolution of the clutch causes half a revolution of the eccentric, so that successive operations of the clutch bring the mirror up and down alternately. Photo-electric devices.-There are 32 photoelectric cells, one for each of the ten digits of the units, tens, and hundreds of the code columns for the marks 130, Fig. 10, and one for each of the side marks 131, 132. For compactness of arrangement, the photo-electric cells are disposed in three rows 135, 135a, 135b, Figs. 2 and 3, the cells in the row 135 being exposed directly in the light beam from the projector 100 and the cells in the rows 135a, 135b being exposed to beams reflected by rows of mirrors 133, 134. These mirrors and the cells are arranged in staggered formation so that the first cell 135 corresponds to the first column of the code marks, the second column corresponds to a cell in row 135b, the third column to a cell in row 135a, and the fourth column to a cell in row 135 again, and so on for all the cells and columns. The machine can be set by the knob 147, Fig. 1, to operate in four different ways. When the knob 147 is set at the point SL the first line of a desired group of data is projected ; at the point L1 the beginning of every group is projected ; and at the point TO the total of every group is projected. In addition to setting the knob 147, certain connections have to be made between the sockets of the plug board 153. Assuming for example that the first line of groups numbered 256 are desired, the group selector 141 is set to the number 256 the knob 147 to the point SL the desired connections made on the plug-board 153, and the mains switch is closed whereupon the projection lamp 98 is lighted, the driving motor 44 starts the electromagnet 159 depresses the pointer 156 against spring 158 to uncover the legend "list" and to point to the first line of a group. The filament switch 151 is closed and also the start switch 148. The film is thereby set in motion until the code marks 130 corresponding to the group number 256 reaches the optical projection gate. When this happens, all the cells corresponding to these marks and to the mark 132 in line therewith are obscured, relays in amplifiers connected to these cells all operate, and this combination being in accordance with sets of contacts adjusted by the group selector 141, control electromagnets are switched off and to stop the film and to move the mirror 97 up to project the first line of the group on the viewing screen 95. When this line has been viewed and it is desired to pass on to the next group of the same number, the start switch 148 is again depressed and a similar operation is repeated. If it is desired to project the total of the group, the knob 147 is turned to the point SLT, the electromagnet 159 is not energized, the pointer 156 uncovers the legend " total," the relay of the cell corresponding to the mark 131 is connected up and causes the drive of the film to continue after the code marks 130 have operated their relays until the mark 131 also operates in relay when the film stops and the " total " line is projected on the viewing screen opposite the pointer 156. If the knob is turned to the point L1, the code marks 130 are inoperative, and the mark 132 causes the film to stop at the first line of every group. If the knob is turned to the point TO, the code marks 130 are again inoperative and the mark 131 causes the film to stop at the "total" line of every group.