GB465938A - Improvements in or relating to electric follow-up devices for measuring instruments - Google Patents

Abstract

465,938. Electric follow-up devices. SOC. FRANCAISE DE METROGRAPHIE. Aug. 12, 1935, No. 2417/37. Convention date, Aug. 2, 1935. Divided out of 462,663 under which a Specification was laid open to inspection under Sect. 91 of the Acts, Feb. 14, 1936. [Class 40 (i)] In a follow-up device, more particularly for positioning numeral wheels of weighing apparatus, a searching member, which normally occupies a zero position, hunts for the position of an index pointer to operate the numeral wheels and when engagement with the pointer is established, the member is unclutched and restored to the zero position. Fig. 1 shows two numeral wheels 61, 65 driven from a motor 79 through gearing 80, 81, 85, 87 the wheels being geared through gearing 72, 73. A searching arm 99 loosely mounted on the shaft 66 of the wheel 65 is adapted to be clutched to the shaft when a pivoted lever 146 is forced into engagement with an abutment 145 by a rod 102 which is moved longitudinally in the shaft 66 when a magnet 108, Fig. 6, is operated at the commencement of a measuring operation. When the searching arm 99 overtakes the index 26, Fig. 6, magnet 118 is operated and a relay 113 previously operated by press button 109 is released and the motor 79 is stopped. Simultaneously magnet 108 is de-energized and the arm 99 is unclutched and restored to normal by a spring 143. Magnet 91 also is operated to cause a pawl 89 to align the numeral wheel 61. If the wheel 61 is outside the region of zero, contacts 120, 121, Fig. 2, are closed by a cam 93 to operate magnet 124 and a pawl 125, Fig. 5, moves the wheel 65 backwards into its proper position. If the wheel 61 is however within the region of zero contacts 120, 122 are closed and magnet 126 operates an auxiliary pawl 127 which is displaced slightly relatively to the relative position of the pawl 125 and the aligning teeth of the wheel 65. The pawl 127 enters the correct tooth space, the wheel 65 is moved backwardly and pawl 125 operated by magnet 124, which is also energized upon energization of magnet 126, correctly aligns the wheel. The magnet 124 also operates the printing relay 134 which pulls up relay 136 to effect release of the pawl actuating magnets. Contact 138 is operated when the driving lever 146 is off-normal and consequently upon operation of relay 136, the motor 79 is operated to drive the numeral wheels to normal. Specifications 418,987 and 456,850, [both in Group XVIII], are referred to.