SECOND SESSION-AFTERNOON OF TUESDAY, JUNE 4, 1940 (The Conference reassembled at 2:15 p. m., at the National Bureau of Standards, Lyman J. Briggs, President of the Conference, in the chair.) AUTOMATIC-INDICATING SCALES-PRINTED WEIGHT PAPER OF J. F. CRUIKSHANK, GENERAL SCALE SALES, FAIRBANKS, MORSE & CO. The general characteristics and fundamentals of the dial as a weight-indicating device are, we believe, quite generally understood by those interested in weighing equipment. It will therefore be necessary to mention only such features as are exclusive in the Fairbanks design, and we will confine our discussion principally to the construction and operation of the printing device, which will be referred to under its trade name "Printomatic Weigher." We have two standard types of dials, the single column, as shown in figure 1, and the cabinet shown in figure 2. The Fairbanks dial is of the double-pendulum type but differs from other designs in that the pendulums, instead of swinging away from each other when the load is applied, swing in toward each other. As with all pendulum dials, the pendulum movements are actuated by a cam and steel tapes. Our standard dials have a 20-inch diameter at the reading line and are limited to a maximum of 1,000 graduations, so the capacity that may be placed on the dial chart proper depends upon the minimum graduation required. When capacities are required in excess of what can be placed on the dial chart, it is necessary to use a capacity beam or bottle weight with the single-column dial, or if the entire weight is to be indicated on the dial chart, the cabinet-type dial is used with drop weights for the additional capacity. With the cabinet-type dial and drop weights, each drop weight has a value equivalent to the capacity of the dial chart, so when the load to be weighed exceeds the chart capacity, weights are dropped onto a carrier connected to the beam lever, by means of a mechanical device operated by a wheel on the outside of the cabinet, as shown in figure 2. This same operation rotates a back chart to indicate the additional capacity at a series of windows in the face of the dial directly adjacent to the numbers shown on the dial chart, as illustrated in figure 3, no mental calculation is required. This is an exclusive feature. The removal of the drop weights from the carrier is accomplished by a reverse movement of the wheel to which reference has been made. The Printomatic Weigher is attached to the side of the dial housing, as shown in figures 1 and 2, and is purely a mechanical operation entirely independent of the weight-indicating mechanism of the dial; in other words, the dial can be operated as a plain dial or as a dial and printer. Our standard Printomatic Weigher mechanism consists of four selector wheels mounted on the dial-indicator shaft, a horizontal selector wheel, a small motor, a clutch, cams, cam levers, type sectors and connection, ribbon feed, etc., most of which can be seen in figure 4. The selector wheels are separated by spreader bushings but securely fastened together, so they rotate with the indicator as one unit. Three of the selector wheels represent numerical digits; the first, or one nearest to the dial face, represents units; the second, tens; and the third, hundreds. The fourth is termed the "star" or "locking" wheel. Teeth or notches are cut in the peripheries of the wheels, and on each tooth of the first wheel there are 9 notches or steps; on the second wheel there is 1 notch for each 10 notches on the first wheel, and on the third wheel there is 1 notch for each 10 notches on the second wheel. The periphery of the fourth wheel is very much like a finetoothed circular saw, and has a tooth for each graduation on the dial chart. This wheel and its finger comprise the locking device for the dial indicator. The selector fingers are mounted in a guide and have the same horizontal spacing as the selector wheels, so that the point of the finger, which is cut to fit exactly the notches on the wheel, will properly engage the notches. The other end of the finger is attached to one arm of a bell crank, which may be seen in figure 4. To the other arm of this bell crank is attached the type sector by means of a vertical bar. Each selector finger is actuated by a horizontal coil spring in tension. The selector fingers are adjusted so that the fourth or locking finger which engages the "star wheel" is advanced slightly farther than the other fingers, but all fingers are held back clear of the selector wheels (until the printing operation starts) by means of a cam-actuated bar under one arm of the bell crank, as shown in figures 4 and 5. This leaves the dial indicator and selector wheels free to rotate to the proper weight indication. Figure 5 shows a side view of the type sectors, the printing platen, and the arrangement for printing records on a continuous tape. The type sectors are suspended from a shaft as shown, and are rotated thereon by the vertical movement of the connections to the bell cranks shown above the type sectors. The standard Printomatic Weigher prints the record on a ticket; however, it can be furnished for printing on an original and duplicate tape, on a ticket and tape, and also on special record forms that may be used by the industry. The weight is always printed in full digits, as shown in figure 6. The operation of the standard Printomatic Weigher is semiautomatic. The operator inserts the weigh ticket when the load is applied to the platform, and when the dial indicator comes to rest, a push button is depressed with the finger; this starts the motor and at the same time releases the clutch which starts the camshaft rotating. As the cams rotate, the bar holding the selector fingers back from the selector wheels is dropped, releasing the selector fingers to find the proper notches on their respective selector wheels. The locking finger being set ahead of the other fingers finds its position on the "star wheel" and locks the dial indicator and selector wheels against any further movement during the printing cycle; the other selector fingers, which move forward at the same time, find their respective positions on the selector wheels, at the same time setting up the type sectors to a position where the digit on the sector corre |