Patent GB-1191645-A (GB)
Title: Recording Apparatus
IPC: G01D15/24
Filed: 1967-08-08
Abstract: 1,191,645. Recording apparatus. AMERICAN GAGE AND MACHINE Co. Aug. 8, 1967 [Oct. 5, 1966], No.36383/67. Heading G1J. Apparatus, Fig. 15, for recording a variable and the occurrence of an independent event on a chart 30 moved along a path adjacent a meter needle 22, comprises a stylus 64 on the needle operated periodically by a cam 78 to mark the chart and another stylus 84 moved between marking and non- marking positions by a solenoid, operable independently of the cam 78. A synchronous motor 38 drives the cam 78 and through a gear train 42, Fig. 9, sprockets for driving the chart 30 between a platen 88 and meter dial 23, over which the needle 22 of a galvanometer swings moving the stylus 64 over the chart 30, but out of contact therewith, and outside the periphery of the dial 23. As the cam 78 rotates it co-operates with a cam follower 80 carried by a pivoted yoke 66, which under the influence of a spring 76, presses the stylus against the pressure-sensitive chart 30 to record the variable influencing the galvanometer 20. Upon the occurrence of an event, a solenoid 94 is arranged upon energization to lift the stylus 84 into a gap 86 in the platen 88 so that the yoke 66 by means of a leaf spring also moves the chart 30 against the stylus 84 to mark the underside periodically for the duration of the event. The gear train 42 is provided for varying the speed of the chart 30 and includes a gear 44 which can be set by means of a knob 146 on an extension 144 of a lever 140 to select one of four gears on the shaft of the motor 38 which also carries the cam 78. Of the four gears, one 130 has teeth round its entire periphery, the next 132 has an open space among its teeth and the gears 134, 136 have successively larger spaces. When the gear 44 engages gear 130, the chart speed depends solely on the motor speed whereas when the gear 44 engages one of the others it becomes disengaged for successively larger parts of each revolution causing increasing periods of hesitation. These can be related to the profile of the cam 78 so that the stylii mark the chart during stationary periods. A control knob for interlocks and switches can be set to one of four positions (i) "record" in which the galvanometer 20 and motor 38 are switched on (ii) "read" in which the yoke 66 is held clear of the cam 78 to inhibit recording, the galvanometer is switched on and the motor 38 off. (iii) "off" (iv) "cover release". Other adjustments can be made including (i) means to adjust the movement 158 of the galvanometer 20 relative to the yoke 66 to determine the pressure it will exert on the stylus 64; (ii) a threaded connection between the yoke 66 and follower 80 enables the latter to be adjusted relative to the cam 78 and a further fine adjustment is provided for the gear plate 164 carrying the cam 78 and gear assembly 42; (iii) adjustment to the pivot for the housing cover which carries the galvanometer 20 provides for lateral adjustment to align the movement 158 with the chart 30. A one way clutch in the sprocket drive shaft 58 allows for manual unwinding when setting the chart 30 and tension control is provided for the take-up roll 34.