Patent GB-190629319-A (GB)
Title: Improvements in Scraping Machines for Sand Filters.
Inventor: BLAISDELL HIRAM WHEELER
Filed: 1906-12-22
Granted: 1907-11-28
Abstract: 29,319. Blaisdell, H. W. Dec. 22. Excavating.-Travellingapparatus for scraping sand from the surface of filter-beds and removing it for washing is shown in plan in Fig. 1 and in vertical section in Fig. 4 in connexion with a covered filter, the roof 1 of which is supported by piers 2. Wheels 8, mounted in the frame of the'apparatus, travel on tracks 4, which rest on brackets 3 attached to the piers and are supported intermediately by hangers 6 from the roof. Helical conveyers 54 scrape the sand from the bed and pass it to the centre of the front of the machine. Thence it is raised by a bucket elevator 55, which discharges it down a shoot 76 to a receiver 34 connected with an hydraulic sand ejector 35. Fluid is supplied through a flexible hose 28 which is wound on a reel 26 but has one end fixed to a supply source. The other end is attached to a hollow shaft 24 round which the reel turns and from which the fluid is passed by a flexible connexion 33 to the receiver 34 or ejector 35. From the ejector the mixed sand and fluid are discharged through a pipe 36 to a hose 27 arranged in a similar manner to the hose 28. The conveyers 54 and elevator 55 are carried by an auxiliary frame 44 balanced over pulleys 48, 49 by counterweights 50, which regulate the pressure of the frame on the surface of the bed. A box 51 having a shoe 52 adapted to slide on the bed is attached to the frame. This frame also carries conveyers 72 which push in sand from the spaces between the pier and are mounted in sliding bearings attached to the piston - rods of hydraulic cylinders, so that they can be drawn in when passing the piers 2. An electric motor 57 drives the upper pulley of the elevator 55 by means of belt and spur gearing. The conveyers 54 are on the shaft of the lower elevator pulley, and the conveyers 72 are driven by belt gearing from the shaft of the upper elevator pulley. The apparatus is moved to and fro by a motor 9 connected to the shaft of the forward supporting- wheels 8 by worm, spur, and chain gearing arranged to allow of a quick return movement. The hose is wound upon the reels during the return journey by communicating the motion of the rear supporting-wheels to the reels by means of belts 41 having tightening-devices 43 and by pinions gearing with large spur-wheels on the reels. In modified apparatus shown in plan and vertical section respectively in Figs. 5 and 7, the reels are supported on a separate carriage, and the operative parts are balanced on horizontal bearings and can move transversely over the bed. For this purpose, they are supported in a frame moving on rails 108 on the frame 7. An electric motor 99 drives the shaft 95 by spur gearing, and a sleeve on the shaftcan be moved by levers from the handle 103, so that spur-wheels of various sizes can be put into gear with'others on a shaft 85. From this shaft motion is communicated to the travelling wheels 8 by bevel and worm gearing. For the transverse movement, the rotation of the shaft 95 is transmitted by friction bevel-gearing and spur gearing to a rope 192, which passes over pulleys 193 and has its ends attached to the auxiliary frame. The operative parts are suspended from the latter by screws 119 passing through lugs in a plate 116 which has other lugs from which depend screws 114 supporting castings with bearings 112. The tubular frame 111 of the operative parts is roughly balanced about these bearings, but at the front a shoe 123, having a shield 124 attached, rests upon the bed. The shoe has tubular extensions 122 which can be adjusted vertically from the handle 131 by bevel and screw gearing. The frame 111 can be further tilted about the bearings 112 by means of a rope 198 passing around a pulley 197. The apparatus removes the sand in the same way as that described above. The delivery of the sand from the elevator to the ejector is aided by a stream of water from a pipe opening within the hood of the elevator. Figs. 9 and 13 show a form of fourway valve used in connexion with the hydraulic cylinders by means of which the sliding bearings of the side conveyers are moved. The casing 171 of the valve has four passageways, two of which are connected respectively with one of the cylinders at opposite sides of the piston, while the other two are respectively connected to the water inlet of the sand ejector and to exhaust. 'Communication is made between pairs of the passages by means of passages 174 in the plug, which is partly rotated whenever one of the rollers 179 is brought into contact with brackets 180 fixed on the rails 4.