Patent GB-687653-A (GB)
Title: Improvements in or relating to multiple recording instruments
IPC: G01D9/42
Filed: 1948-12-31
Abstract: 687,653. Electric indicating systems. GENERAL ELECTRIC CO., Ltd., and ROLLIN, L. Dec. 30, 1949.[dex. 31, 1948], No. 33668/48. Class 40 (i) [Also in Group XIX] In a multiple recording instrument wherein a plurality of measuring circuits are repeatedJy and sequentially connected to a meter, an optical image of the meter pointer is projected sequentially upon a corresponding plurality of photosensitive record elements in synchronism with the connection of the corresponding measuring circuits, and the photosensitive elements are carried on a support moved to form a time base whereby each record element is successively exposed according to variations in the corresponding variable being measured. The moving coil 62, Fig. 4, of the micro-ammeter 1, Fig. 1 'is sequentially connected to twenty-four different measuring circuits by the wipers 54, 55 of a selector switch 58. stepped at two second intervals under the control of contacts 31 actuated by a cam 32 driven by a synchronous motor 4, An image of the meter pointer 8, Fig. 1, is projected by a lamp 5, optical system 6, a slot 14 in the meter support 13 and individual lenses 21. on to the corresponding photosensitive paper strips 3 held in a support 2, moved along guide rails 17, by a cam 18 driven by the motor 4. The shutter mechanism as described in Specification 687,654. [Group XX], comprises four parallel shutters 22 above corresponding rows of the lens mosaic and six parallel shutters 23 disposed at right angles to the shutters 22, below rows of the lens mosaic. Eachlongitudinal shutter 22 and each lateral shutter 23 is actuated to the open position by energization of a corresponding magnet 9, and to uncover any lens 21 both the shutters 22; 23 individual thereto must be opened. A further selector switch 10, Fig. 3, is stepped at one second intervals under the control of contacts 28 operated by a cam 30 also driven by the motor 4 and over its switch banks 43-46 the magnets 9 are energized in pairs to effect sequential uncovering of the lenses 21. The selectors 10. 58 are synchronized as in Specification 687,652 over a circuit including banks 47, 48, 56 the arrangement being that as each measuring circuit is connected to the meter 1, the wipers 59 of selector 58 are stepped to dead contacts and the meter has one second to take up its new position before selector 58 is again stepped to energize the corresponding pair of magnets 9 to expose the meter reading on the corresponding record element 3. For calibration, nine thin wires are fixed across the slit 14 in the meter support 13, their image being projected with that of the meter pointer at each exposure, and during the first cycle of the selector, a relay 15 is energized by manually operated contacts 16 to expose numerical values against the calibration lines on all record elements 3. Modifications: The record elements may be in the form of one or more photosensitive paper rolls, the lenses 21 being all arranged in a line parallel to the roll axis. The meter may be a mirror galvanometer the reflected image being applied to the record elements. The meter may be a cathode ray oscilloscope. Two meters may be used simultaneously or alternately. Two or more variables may be recorded simultaneously on one recording element.