Patent GB-168737-A (GB)
Title: Improvements in or relating to sand-blast and like machines
IPC: B24C3/22
Filed: 1920-07-09
Abstract: 168,737. Miller, W. J. July 9, 1920. Sand-blast.-A machine for treating glass or other articles by a sand-blast or like means comprises a number of rotating platforms, for supporting the articles, carried by a rotary table, each platform being located within a compartment and having associated therewith two movable jets; the jets become inoperative as each compartment in turn comes opposite to an aperture in a casing surrounding the machine. On a bed 1 is rotatably mounted, by ball bearings 5, a table 3 having near ite periphery a number, preferably eight, of vertical sleeves 7 in each of which is rotatably mounted a sleeve 9 carrying a work-supporting disc 14 of wood &c. provided with grooves to allow the escape of sand from the interior of the article. The sleeves are rotated, during rotation of the table 3, by the engagement of pinions 15 thereon with a stationary circular rack 16, the table being rotated by a pinion 18 and teeth 17 on the table. Secured to the table is a vertical hollow column 21 supporting an upper table 23, and between the tables, and associated with each platform are sets of three hollow columns 24-26. In each column 24 is a slidable rod 27 movable vertically by a cam 29 and connected at its upper end to a lever 81 adjustably pivoted to a standard 32 on the upper table. Linked to the lever is a rod 33 connected by a link at its lower end to a lever 37 pivoted at 38 and carrying at its inner end a jet; rotation of the table thus causes oscillation of the jet whereby the sand is directed over the whole of the exterior of the article. The jet comprises a box 39 having an outlet nozzle 40 and a fluid-pressure-inlet nozzle 41, sand being drawn in through a pipe 42 from a reservoir formed by the table 3 and walls 43. The inner end of the lever 31 is linked to a vertical rod 47 slidable in the column 25 and having at its lower end a bracket 48 carrying a pipe 49 slidable in the sleeve 9 and carrying a nozzle 51 for discharging sand on the interior of the article. Sand is drawn to this nozzle through a pipe 54 and fluid is supplied by a pipe 56. The main fluid supply pipe 58 is located inside the column 21, the upper end of which forms a fluid chamber 59 having a port 63 for each platform, each provided with a depending valve box 64. Inside each box is a conical seat 67 and a ball valve 68, and each box is connected by a flexible pipe 70 with the nozzle 41; the pipes 70 may be branched to supply both nozzles 41, 51 for treating the exterior and interior of an article simultaneously. The top of the pipe 59 carries an adjustable, and normally stationary, member 71 which covers in succession the ports 63 and so cuts off the sand blast as the articles arrive at a position where they are to be removed. The valves 68 are normally held raised by the tappet rods 72 resting on levers 73 connected at their outer ends to levers 76 pivoted at 77. These levers carry at their outer ends members 80 which engage the tops of the articles under treatment. When an article is removed or broken, the member 80 falls and the valve 68 drops on to its seat, cutting off the fluid supply. A stationary annular casing 81 encloses the space between the tables 3, 23, extending into the sand reservoir and engaging at its upper end a flexible guard 82 carried by the upper table. The casing has a take-out aperture, and as a platform arrives opposite this, the member 80 is raised by a cam-operated rod 84. Vertical radial partitions 89 divide the space between the tables into segmental compartments each containing a platform and its associated jets, &c. The casing 81 may have a vent hole 90 for each compartment or communicating holes may be provided in the partitions and one vent hole only provided. A water inlet pipe 91 may be provided for use when wet sand is required, and a sand inlet pipe may be provided for charging the reservoir. If the exterior only of the articles is to be treated, a short lever 38<1> may be substituted for the lever 31. In operation, the tables &c. are rotated slowly or intermittently, and stop or slow down, when an article comes opposite the take-out aperture. Each article is carried round once by the tables, rotating meanwhile with its platform and being operated upon by the jets as these are raised and lowered.