Patent GB-790871-A (GB)
Title: Tape-reading apparatus
IPC: G06K13/30
Filed: 1955-08-31
Abstract: 790,871. Feeding webs. NATIONAL CASH REGISTER CO. Aug. 31, 1955 [Sept. 30, 3954], No. 24954¥55. Class 100(1) [Also in Group XL(b)] In a tape reading device, which may be photo-electric or magnetic, a continuously operating driving member yieldably engaging the tape moves it past the reading device which in response to stop signals recorded on the tape causes an electrically operated brake to grip and stop the tape. As shown, the tape passes from a supply spool 16, Fig. 1, to a take-up spool 48, both of which are described below, pass-. ing between the jaws of an electric-magnetically operated main brake 37 normally in light contact with the tape and through a photo-electric reading device comprising light source 76 and photo-electric cell assembly 36, and over a main capstan drive 35 with which the tape is held in contact by a spring loaded arm 38. At pre-arranged intervals along the tape are apertures indicating that the tape is to stop in those positions for a period adequate to allow the data already sensed to be tabulated. When these apertures are sensed by the photo-electrical cell assembly 36 the high speed electro-magnetic brake 37 is energized and the tape is clamped so that capstan drive 35 slips. To prevent the insertion of the supply and take-up drum from preventing the immediate stopping of the tape, loops of tape 15<SP>1</SP> and 53 are allowed to form at each end of the length of tape extending through the high speed brake, reading head, and capstan. The input loop 15<SP>1</SP> is formed by auxiliary capstan 22 which feeds tape more quickly than capstan 35. The loop 15 varies in length until it interrupts light passing from source 30 to a photo-electric cell in a housing 31 when an auxiliary brake 33 clamps the tape before capstan 22, thus preventing further feed. The output loop 53 is used similarly to interrupt a light beam from a source 51 to photo-cell 52, but here the arrangement is that an auxiliary brake 54 "downstream" of the loop is operated when the light is not interrupted then allowing the loop to increase in length. When the light is interrupted the brake is de-energized and take-up drum 48 takes the tape away at such speed that the loop again shortens. Tape supplying mechanism. (Figs. 1 and 4), comprises a tape feeding drive 134 and two auxiliary drives 135, 136 coupled together by a belt 137 located below the plate 17 and above plate 138. Three arcuate shoes 139, 140, 141 are provided and the reel of tape to be wound off is placed outside these while the leading end is brought over an angled driven roller 144 which draws the tape 16 from the inside of the reel and guides it vertically upwards. When roller 134 has drawn off the inner coil of tape, the tape becomes taut between the edges of the shoes and thus engages the auxiliary drives 135, 136. Drive 135 draws off the next coil of the tape which is then kept firmly in contact with the drives. The tape take-up mechanism (Fig. 5) consists of a supply shaft on which is mounted a driving flange 49 and the spool 48. The flange 49 receives a friction drive at its periphery from a capstan 50 and from a felt friction disc (not shown) engaging its outer surface. The spool 48 consists of a pair of discs spaced apart by studs (not shown) and these discs include notches 189 in which is clamped by a spring 201, the end of a felt strip 190. The tape and felt strip are wound in together, tape on felt and then felt on tape. By pulling outwards a tab 202, attached, to the end of the felt, tape may be removed from between the first two turns of the reel, to permit its removal from the spool. Brake. The high speed electro-magnetic brake shown in Fig. 2 comprises an upper set of laminations 93 which are able to move vertically in guides 95, and rest on the tape. When the coil 96 is energized these laminations clamp, the tape against the lower laminations 94. A modified brake for use with magnetic tape is shown in Fig. 7 in which the tape 15a is clamped between a brass member 561, attached to a pivoted magnetic armature 567, and a fixed brass' member 572.