GB1286647A - Recording apparatus for sonar and echo sounding systems - Google Patents

Abstract

1286647 Recording apparatus SIMRAD A S 26 Nov 1969 57890/69 Heading G1J In apparatus with means for unwinding a recording strip 17 from a spool 2 and rewinding it on a spool 1 with a predetermined linear velocity, one of the spools is slipably coupled to first driving means 8 while the outermost layer of the strip 17 wound on the spool 1 is frictionally and unslipably coupled to second driving means 11, in order to adjust the linear velocity of the strip to the predetermined value while the first driving means 8 is continuously slipping. In apparatus for sonar and echo sounding systems driving torque is supplied to a shaft 5, which drives a friction wheel 8 pressed by a spring 18 against a rim of spool 1. The shaft 5 also drives two endless belts 11 frictionally engaging the roll of the strip 17 already wound on the spool 1. The belts 11 run round rollers 19, 13 and are pressed against the strip 17 by a spring acting on a frame 15 supporting the rollers 19, 13 and pivoted on the shaft 5, the friction in the pivot increasing the contact pressure. The velocity ratios are such that the wheel 8 would always drive the strip 17 faster than the belts 11, but as the wheel 8 can slip and the belts cannot the strip 17 is driven at constant speed by the belts. Alternatively the wheel 8 may engage the spool 2 at an angular velocity such as to underdrive the strip 17 which is brought to the desired velocity by the belts 11 with the wheel and slipping. The spools 1, 2 are mounted in a cartridge 3 moulded from electrically non-conductive material provided with a conductive layer on its face 3a to provide a return lead for the electrical signals to be recorded. The cartridge 3 may be inverted to reverse the functions of the spools with respect to unwinding and rewinding. The strip 17 is kept taut during recording by a brake 12, which is omitted if the friction wheel 8 is applied to the supply spool instead of to the take-up spool. In the embodiment of Fig. 4 (not shown) the shaft 5 drives through a slipping clutch, a pinion engaging a pinion on the spool 1 and the frame 15 carries a friction roller urged by the spring 16 into contact with the strip 17 on the spool 1.