GB191303409A - Improvements in Sand Blast Apparatus. - Google Patents

Abstract

3409. Marks, E. C. R , [Badische Maschinenfabrik & Eisengiesserei vorm. G. Sebold und Sebold & Neff]. May 23. Sand - blast. - In a sand-blast wherein the sand is supplied into an intermediate chamber 8 which is alternately put into communication with the atmosphere and with a pressure chamber 10 and the blast pressure pipe, the supply of sand into the intermediate chamber being shut off while the sand already in that chamber passes into the pressure chamber, the sand is fed into the apparatus in such manner that its weight is used for effecting the alterations in the connexions. The sand, delivered through a sieve 2 into a hopper 1, passes through a tap or cock 3 with outlets 4 into a tipping tray or pan 5 which is adapted to turn about an horizontal axis under the action of the weight of the sand in one or the other half of the pan. The tilting of the pan is used to operate the regulating-parts, and for this purpose the pivot of the pan may be fitted with a crank 15, Fig. 2, to engage the neck of a piston 17, so that when the crank presses the piston to its lowest position, the intermediate chamber is put into communication with the pressure chamber through the pipes 20, 22. The valve 7 then closes and the valve 9 opens under the weight of the sand in the intermediate chamber. The tilting of the pan to the other side causes the crank to raise the piston clear of the opening 19 and into the opening 20<1>, and the chamber 8 is then cut off from the pressure chamber and opened to the atmosphere so that the valve 9 shuts and the valve 7 opens. The compressed air is supplied through a pipe 21, and runs through the branch 22 of the pipe 20 into the chamber 10. The pressure in this chamber drives the sand through the opening 11 into the tubes 12, 13 and mouthpiece 14, from which the blast is allowed to play on to the object to be cleaned. A trap 23 serves to free the compressed air from water.