GB698402A - Improvements in and relating to recording apparatus - Google Patents

Abstract

698,402. Driving sound film, tape or wire. NIBLETT, E. H. Dec. 30, 1949 [Dec. 31, 1948], No. 33615/48. Class 40 (ii) [Also in Group XVI] In a recording apparatus in which the record is carried by a tape, web or ribbon drawn onto a rotating storage reel, a pair of members are adapted to engage the tape so that any interruption in at least that part of the tape so engaged will cause at least one of the members to move, and a pair of electrical contacts not in engagement with the tape are actuated by the movement of the tape-engaging member (or members), whereby, on interruption of the tape, the rotation of the storage reel is stopped. In one embodiment, Fig. 4, the tape 10 is guided over a fixed guide pulley 11 which has a recess 21 into which a pressure member 12 on an arm 13, pivoted at 14, is constrained to enter by a spring 15, but is prevented by the tape. When there is a break in the tape the arm 13 moves and thereby moves a contact arm 23 which meets a fixed contact, thereby completing an electrical circuit to short- or open-circuit, a solenoid associated with the recording apparatus to which the invention is applied (as described in Specification 698,401), and thus to stop the rotation of the reel on which the tape is being wound. The contacts may be inside a recess in the pulley 11 and operated by the member 12 when it enters the recess. A break in the tape may be purposely provided by a slot in the centre of its width. Instead of there being a separate contact area, the arm 13 may itself carry the moving contact. In another embodiment, Fig. 6, the tape 10 passes between pads 25 on fingers 24, which are secured to a bracket 28 and urged together by a spring. The bracket 28 is pivoted on an axle 33 and carries an arm 29 with a moving contact 30, a spring 32 tending to hold the parts so that the contact 30 presses on a fixed contact 31. When the tape 10 moves in the direction of the arrow the friction between it and the pads 25 pivots the finger 24 about the axle 23 and opens the contacts, and when there is a break in the tape the spring 32 closes the contacts. This arrangement can be combined with means, operated by the recording apparatus, for deflecting the spring fingers to allow the tape to be removed without breaking the solenoid circuit. Regarding this second embodiment, the Provisional Specification states that, owing to the comparatively large movement, the contacts 30, 31 may be dispensed with and the lever 29 may act as a mechanical trip. The Provisional Specification also discloses an arrangement in which the moving contact is also the pressure member, the fixed contact being the guide pulley. In this arrangement a tape may be used which ends in a length of metallic foil, by which means electrical contact is made and the tape stopped before it leaves its reel.