Patent GB-388536-A (GB)
Title: Improvements in or relating to weighing scales
IPC: G01G23/18
Filed: 1932-01-06
Abstract: 388,536. Weighing-apparatus. DAYTON SCALE CO., 468, Huffman Avenue, Dayton, Ohio, U.S.A.-(Assignees of Bryce, J. W. ; 160, Willard Avenue, Bloomfield, New York, U.S.A.) Jan. 6, 1932, No. 422. Convention date, Jan. 10, 1931. [Class 143.] A weighing-scale is provided with printing or other auxiliary mechanism operable separately from the weighing mechanism and having parts which are to be displaced proportionately to the weighing mechanism, and is also provided with controlling mechanism for the printing mechanism operable by modification of the action of a non-mechanical medium free from touching parts (for example, light rays) for sensing the displacements of the weighing and printing mechanisms and for controlling the action of parts (for example, the impression mechanism) of the printing mechanism. Assuming that the indicating pointer 14, Fig. 1, has been displaced by a load on the platform, the operator inserts a record slip into a slot 81 and rotates a setting handle 41 connected to printing wheels 43, 47. The spindle 39 of the handle, operating through a flexible shaft 45 and a bevel gear 34, Fig. 2, rotates a mirror 30 and a finder arm 23 carrying a mirror 29. The operator, observing the finder arm through a transparent part of the dial, slows down the movement as the finder arm approaches coincidence with the pointer 14. When the two coincide, a beam of light from a lamp 25 is reflected by an inclined mirror 21 on the pointer spindle and by the mirrors 29, 30 so as to pass through a slot in a member 31 and thence through the window of a photo-electric cell 32 or other light sensitive medium. The flow of current produced through the cell is suitably amplified and by means of a relay closes the circuit through an indicator lamp 86, Fig. 3, and thereby indicates to the operator that the precise point of coincidence has been reached. An electromagnet 73 in circuit with the lamp 86 at the same time withdraws a catch 70 from the mechanism of the printing handle 52 and permits the operator to depress the handle and, by means of spring-pressed trip mechanism 62, swing the printing hammer 61 upwards to produce a weight record from the printing wheels 43, 47 which, as described above, are set by the rotation of the handle 41. A toothed lever 75 aligns the type wheel 43. In a modification, where the mirror is dispensed with, the finder arm 23 is of forked formation and carries at its extremities both the lamp 25 and the photo-electric cell 32. When the finder arm coincides with the indicating pointer the beam from the lamp is reflected by the mirror 21 intothe photo-electric cell and unlocks the printing mechanism as described above. In a further modification, Figs. 8 and 9, a lever 100 is connected at one end by a link 99 to the usual intermediate lever 96 arranged between the platform levers and the pendulum system. The other end of the lever 100 is pivoted on a sliding rack 101 actuated by gearing when the setting handle 41, Fig. 1, is rotated. Pins 104 limit the movement of the rack. After the levers 96, 100 have been displaced by a load, the setting handle is rotated until the rack 101 restores the lever 100 to horizontal position, whereupon a beam of light from a lamp 25b passing through a condenser 26b is deflected by an inclined mirror 21b through a second condenser 26c and into the cell 32b with the result that the indicator lamp is illuminated and the printing mechanism is unlocked. In a further modification, the electromagnet 73, Fig. 3, for unlocking the printing mechanism, is controlled by a system of electric contacts on the lever 100, Fig. 9, co-operating with two relays whereby either a green or a white lamp is illuminated to indicate to the operator in which direction the setting handle 41 must be rotated, these two lamps being however cut out and the indicator lamp being illuminated when the correct setting of the type wheels is arrived at. The indicator lamp may in this modification be dispensed with.