GB721536A - Improvements in or relating to measuring arrangements comprising counting devices - Google Patents

Abstract

721,536. Counting-apparatus ; zeroizing- mechanism. ENGLISH NUMBERING MACHINES, Ltd. Jan. 25, 1952 [May 31, 1951], No. 12874/51. Class 106 (1). [Also in Group XXII] A measuring arrangement comprises a counting device having first and second number wheels with transfer mechanism there-between, the first wheel indicating both the first and the second digits of a number counted, and a rotatable operating member coupled to the counting device and to a rectilinearly displaceable member so that the number counted indicates the displacement of the latter member in a predetermined unit of measure or a multiple or submultiple thereof. The counter 20, Fig. 1, is used to indicate the displacement of a machine tool member 30, e.g. a work-holder, table or cutting tool, by a spindle 24, the gear ratio of wheels 22, 23 being chosen in accordance with the unit of measurement, e.g. inches or cms. The first numeral wheel 32, which indicates 1/1000 and 1/100 of the unit by means of numerals 35, Fig. 4, coacting with 100 marks 41, and numerals 36 respectively, is larger than and eccentrically mounted with respect to the higher order wheels 33, 34. A friction disc 53 in the drive from spindle 24 allows the wheel 32 to be rotated to zero for any initial datum point of the member 30, the wheels 33, 34 being independently zeroized by handle 52. A counter 20<1> is operated similarly to indicate the displacement of member 30 in a perpendicular direction by spindle 24<1>. Other forms of gearing for driving the first numeral wheel are described. For example, the numeral wheel gear 322, Fig. 7, is driven by gears 323, 3231, which may be exchanged for others providing a different gear ratio. The gear ratio may be so chosen that e.g. when a lathe tool is moved along a radius of a cylinder the counter indicates the cylinder diameter or circumference. Also, means 356 may be so arranged as, e.g., to stop a machine tool when the value on the counter 320 reaches a preset number visible through windows 3371, 3381. In an alternative counter construction, Figs. 8 and 10, the numeral wheels are of equal size and coaxially mounted, and are displaced together with machine tool member 430 by rotation of shaft 424. The first numeral wheel 432 is driven through a disc 500 keyed to the shaft, a drum 494, gears 490, 484, 485, 491 and a plate 492. If, however, wing nut 497 is loosened, bolt 496 slides freely in an annular slot in the drum and the counter is not operated, thus enabling the member 430 to be set to a datum point. Transfer is effected by teeth (not shown) engaging pinions 479 which mesh with gears 471, 472 coupled to numeral wheels 433, 434 respectively by spring-urged balls 476 engaging ratchet teeth. The numerals on wheel 432 are similar to those on 32, Fig. 4, the wheel 433 has five sequences of the digits 0-9 (and therefore five transfer teeth) and the wheel 434 displays the numerals 0-49. The first numeral wheel may indicate the first three or more (in place of two) digits of a number. The counting devices may be applied also to gauges, e.g. for measuring distances or angles. Zeroizing-mechanism. The knurled numeral wheels 432-434, Figs. 8 and 10, may be separately manually reset, after the nut 497 has been loosened, the balls 476 ratcheting over the teeth on the wheels 433, 434.