Patent GB-858788-A (GB)
Title: Apparatus for carrying out time, work and motion studies
Inventor: LORENZ FRIEDRICH
Filed: 1958-10-16
Abstract: 858,788. Controlling magnetic tape machines. LORENZ, F. Oct. 16, 1958 [Oct. 19, 1957], No. 33013/58. Class 40 (2). [Also in Group XIX]  Apparatus for assisting time, work and motion studies comprises three magnetic recording and reproducing heads 1636, 1739, 1843 for recording on magnetic tape 12, in tracks 19, 20, 21 respectively, a text spoken into a microphone 26, time signals from a clock 28, stop signals marking phases of an operation being studied, and for picking up signals from the tracks 19, 20, 21 respectively, to render the text audible at a loud-speaker 38, to count the time signals on counters 41, 42 and to use each stop signal in turn simultaneously to break frictional contact between the tape 12 and a drive roller 1348 and to stop the tape 12 by a friction brake 56, 57. Recording. With a double-throw switch 60 in the position shown in full lines, the apparatus is set for recording. The operator holds a unit 93 in his hand, closes switch 23 to start motor 1549 driving the tape 12 at normal speed, closes a switch 29 to record each phase of a machine operation and makes a spoken commentary into the microphone 26. If the commentary is to be brief, relative to the length of the phase, he closes a switch 24 instead of switch 23 to apply reduced voltage to the motor and thus reduce the speed of the tape. A lamp 34 in the unit 93 flashes so long as a head 32 picks up signals from the tape and thus indicates that the apparatus is working. Evaluating. After recording a complete study, the tape 12 is fed through the apparatus again with the switch 60 thrown to the position shown in dotted lines. As soon as the head 1843 picks up the first marking signal, a control relay 45 energizes a solenoid 46 and lifts a plunger 53 against the pull of a spring 54 and so raises an arm 52 which carries a pressure roller 1450 and brake shoe 57. Thus, frictional contact is broken between the drive roller 1348 and the tape 12 and made between the brake shoe 56 and the tape 12, thus bringing the tape instantaneously to rest. The operator then sets the counters 41, 42 to zero and closes switch 51 to de-energize the solenoid 46, releasing the brake and applying driving pressure. The tape moves, the text picked up from track 19 is reproduced audibly and the counters 41, 42 count the signals picked up from track 20 until the next mark in track 21 stops the tape again. One counter may be reset for each phase, while the other may count elapsed time for the whole study. General arrangement and modifications. To facilitate connecting and disconnecting the various parts of the apparatus, coupling arrangements 66, 66<SP>1</SP>, 74 and 79 are provided. If desired, printing mechanism may be provided for recording the readings of the counters 41, 42, operation of the printing handle being used to actuate the restart switch 51. Magnetic tape which will take pen or pencil marks may be used for the tape 12 and a further solenoid operated by a switch 31 (not shown) supplementing switch 29 may be provided to actuate a pen arm or to take a print from a supplementary time counter.