Page:Popular Science Monthly Volume 92.djvu/51

 Weighing Goods Automatically

��A machine that insures the merchant against loss

��IN putting up package goods such as sugar, coffee and rice there are two sources of loss. One is undue waste of time in weighing the contents by hand filling, and the other is due to giving over- weight.

Consider firs t — t h e weighing by hand. A good clerk can weigh only five or six packages a minute, and experiments show- that each of the packages con- tains a "pres- ent" for the purchaser, of half an ounce or less of the commodity.

Some mer- chants have tried the plan of setting the scales to weigh

short, trusting to correct the overweight in this manner, but this is by no means ac- curate. This was proved by a test in a large grocery where that system was tried. Out of two thousand pack- ages reweighed, it was found that over ninety percent ran overweight. Less than five percent showed underweight, although the scales had been set two ounces short.

An electrically-operated weigher has been produced to overcome this defect. It handles from fifteen to twenty-five weighings per minute. Its features are an even balance scale, agate mounted, a mechanical cut-off, tripped by elec- tricity, which cuts off the flow of the commodity in full stream and a control

���When the desired amount has been weighed out, an automatic cut-off is operated which prevents waste

���box which allows for the amount in sus- pension; that is, the amount in the air at the moment the cut-olT is operated.

The weight plate of the scales rests upon the lever, which is thereby depressed, and

the electrical contact is broken. When the goods ap- proach the weight re- quired, the tension of the spring causes the weight plate to be raised a bit prematurely and contact is made by which the electric cir- cuit is com- pleted and the cut-off tripped.

All of the parts are made of the highest qual- ity of metal, to prevent in- accuracy due to wear. The tension screw is adjustable, so that it can be regulated to allow for all conditions, even for weather, which might cause a variation in the flow of the commodity. A test weight is used and then the standard of accuracy is divided into three parts, high, low^ and exact balance. The machines are self-test- ing, so that the need of adjustment is quickly made evident, and their regula- tion is easily accomplished even by an unskilled operator. Thus extrenie ac- curacy as well as high speed in w-eighing package goods is secured. On the other hand, automatic weighers of many designs allow for practically no inaccuracy.

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��Contact baK Binding post How the weigher works automatically

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