GB126436A - Improvements in Indicators of the Type Comprising Carry-over Gear, such as is used in Counting Instruments, for use in Signalling. - Google Patents

Abstract

126,436. Barr & Stroud, and Macgill, C. D. May 3, 1918. Transfer mechanism; registering difference of positive and negative actuations.-Relates to indicating-apparatus for use in signalling, adapted to indicate angles from zero to 180 degrees port or starboard, " deflections " from zero to 49 knots right or left, or a change of range from zero to a maximum opening and closing, of the kind described in Specifications 29422/04 and 16256/06, and involving counting-apparatus provided with transfer mechanism whereby indications can be shown on either side of zero, and consists in the provision of one set of drums only, the two sets of indications being shown on each drum. A shutter-like device formed with apertures, which may also act as a numeral-bearing element, is provided to mask one set of indications and uncover the other as the zero point is passed through. An intermittingly-driven shaft B has secured thereon a drum C which acts as the lowest denomination drum, and is marked with fractional indications as shown in Fig. 8. Loosely mounted on the same shaft are drums D, E bearing two sets of indications, Fig. 9, and the reading aperture shutter F bearing numeral indications as shown in Fig. 2. Connexion between the drum C and the remaining members is effected by double teeth G on the drums and transfer pinions H, K, the arrangement being such that the first movement of the drum C from the neutral position shown in Figs. 2, 3 and 4 in either direction causes the drums D, E to move through a space equal to one graduation and as all the transfer teeth are in engagement, this movement is transmitted to the shutter, which takes up a position to show either the plus, or minus graduations through apertures L<1> or L at a slot in the casing. Subsequent movements cause the drums to move through a space occupied by two indications. In the form shown, the indications are repeated on the fraction drum C and two sets of transfer teeth G are provided, but more or less than this number may be employed. In a modification the drums are replaced by disks or endless bands may be employed.