Patent GB-763249-A (GB)
Title: Improvements in or relating to electro-mechanical recording systems
Inventor: FELDHUSEN IGOR VLADIMIR
IPC: G01R13/04
Filed: 1953-11-04
Abstract: 763,249. Recording-apparatus. STANDARD TELEPHONES & CABLES, Ltd. Oct. 29, 1954 [Nov. 4, 1953], No. 30510/53. Class 106 (4). An electro-mechanical system for recording the time variation of transmission equivalent in a telecommunication transmission channel within a given overall period of time comprises a plurality of detector devices connected to the channel, each adapted to respond to a particular value or range of values of transmission equivalent for the duration or durations of time such value or range of values persists, wherein for each value or range of values a recording pen H is provided co-operating with a common recording medium R and driving equipment for each pen is individually controlled by a corresponding one of the detector devices, all the driving equipments being controlled by an overall timing equipment, whereby the time records made by the individual pens summate to the overall period of time. For' making periodic records of the duration and intensity of fading of a propagation constant, readings of the level thereof are classified into six ranges and six associated recorders mark parallel traces across the record sheet R. A synchronous motor D, Fig. 2, may be provided for each recorder to drive permanently magnetized rollers E1, E2, E3 and E4, each at a tenth of the speed of its predecessor so that the pen H attached to a magnetized carriage G records time on a semi-logarithmic scale, being driven by the rollers in succession, tilting into engagement with each roller in turn as it drives off its predecessor. Each motor is energized only while its associated range is being defected and each carriage is returned to zero position at the end of the period, e.g. every 10,000 secs. or 3,600 secs. Alternatively a single synchronous motor may drive all the recorders, the magnetic clutches being replaced by electromagnetic clutches which are selectively energized according to the range detected. In another embodiment comprising a single synchronous motor 1, Fig. 8, each recorder has a pen 20 carried by a sector 19 driven successively by gear wheels 11, 12, 13, 14 driven through free-wheel devices 15, 16, 17, 18 from rollers 6, 8, 9, 10 rotating at speeds in descending decade ratio, the devices 12, 13, 14 freewheeling so long as the sector 19 is driven by the fastest gear 11 and so on. A sector 19 on a common shaft 21 is provided for each range, the recorder being driven at any time being selected by the associated detector, causing an idler gear 4 to put a gear-wheel 5 into engagement with a gear-wheel 3 driven by the common motor 1. Records on an approxi. mately logarithmic scale may be produced by attaching the pen H, Fig. 4, to a lever Q pivoted on a subsidiary carriage J connected to the main carriage G by a rod K and guided by rollers M on a fixed rack L which meshes with a gear-wheel N carrying two diametricallylocated pins P against one of which the lever Q is urged. By a suitable choice of dimensions linear movement of the carriage G is converted to approximate logarithmic movement of the pen H. The detecting devices may cause one pen to move at a time according to the range or all to move at once each stopping when a corresponding value is reached. The record sheet may be stationary or may move at a speed of the order of that of the slowest roller. The records may be continuous traces made by pen, pencil or stylus-on-wax or, if the record sheet is stationary, a short line or dot may be marked immediately before the end of a period in which case spark and other electrical recording means would also be suitable. Specification 688,599 is referred to.