Patent GB-151819-A (GB)
Title: Improvements in or relating to grading and supplying systems for abrasives
IPC: B24B57/00
Filed: 1919-09-25
Abstract: 151,819. Kann, W. L., and Kann, R. G. Sept. 25, 1919. Supplying abrading-materials and fluids.-A system of grading and supplying abrading-material, such as sand, .for plate glass grinding-machines &c. comprises means whereby used sand mixed with water after leaving the grinding-machine is graded in a series of boxes and means whereby any grade may be separately led from a box and returned to the machine for further use therein. The invention is shown as applied to a plate glass grinding-machine 1 on which is provided a ditch 4 into which the sand and water discharge from the machine, new coarse sand being supplied as required from a well 5. At one side of the machine, and at a lower level than the table thereof, is a pit 7 having therein two reversely inclined gutters 7<a>, 7<b>, the gutter 7<a> leading to a sewer 8 and the gutter 7b leading into a well or sump 24. At one end of the pit 7, a used-sand receptacle 9 is provided which receives the used sand and water from the ditch 4, and has an outlet at one end controlled by an adjustable weir 12 leading to a sluice way 13 which conducts sand and water to grading-boxes 14 - - 17, the overflow from one box passing into the next box over adjustable partitions 18. The boxes have inclined bottom and side walls, bottom outlets 22 with valves 23 adapted to discharge into the gutter 7<b>, valved side outlets 27 discharging into the gutter 7<a>, and discharge openings with controlling gates leading to the gutter 7b. The used sand receptacle has a bottom valve 25 leading to the gutter 7<b> and an adjustable overflow 26 leading to the gutter 7<a>. The last grading-box 17 has an adjustable overflow 31 to a box 32 which is adapted to discharge to the sewer through an adjustable gate 33. Water is supplied to the boxes by pipes 30; an overflow 29 leads from the upper end of the sump 24 to the gutter 7<a> to maintain a constant head of water in the sump. In operation, new coarse sand is supplied to the machine, and after use passes to the receptacle 9. When this is full, the water and sand pass over the weir 12 to the grading- boxes in each of which sand is deposited according to its grade, the flow of water and sand being regulated by the weir 12 and the overflow 26; slime and sand too fine for further use pass over the overflow 31 to the box 32 and thence to the sewer. When sufficient sand has been supplied for coarse grinding, the supply is shut off and sand from the receptacle 9 is discharged through the valve 25 to the sump 24, and is returned therefrom to the machine through a pipe 34 by means of a pump 28. This operation is repeated until all the sand coarse enough to deposit in the receptacle 9 is used up, the clear water that then passes from the receptacle being used to wash out the machine, the valves of discharges 27 being opened to let out surplus water. After washing out, the valve 23 at the bottom of box 14 is opened and sand from this box is discharged to the sump and returned to the machine. After the box 14 has been emptied, the discharge valve of box 15 is opened, and so with the remaining boxes until all the finer grades have been used up. In order to stop the flow of any grade of sand before all of this is used up, the pipe 34 is provided with a valved branch 35 with a flexible portion 36; by closing the valve 37 in the pipe 34 the sand may be delivered, by means of the flexible pipe, either into the used sand receptacle 9 or returned to its proper grading box. The apparatus may also be. used to make grades from new sand or from used sand without operating the grinding machine. For this purpose, the gate 33 is closed and a grate 33<a> at the opposite side of the box 32 leading to the gutter 7b is opened and the receptacle 9 is supplied with new or used sand and water, and by means of the pipe 36 the sand is removed. Liquid other than water may be employed. In a modification, one of the side walls of each of the grading boxes may be made adjustable towards or from the opposite wall to vary the capacity of the box.