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A Selection of Equipment of Use in the Production and Maintenance of Aircraft and Components Gears (straight spur, helical or double helical), from Automatic Gear Brushing Machine approximately 4 in. outside diameter up to 24 in. It is common practice in the engineering industry to outside diameter, can be accommodated on the ma deburr newly cut gears by the lengthy process of chine, the number of teeth being calculated at 24 teeth hand filing. Recently the Elgro Machine Tool Co., a per brushing head maximum, i.e. with four brushing subsidiary of Gem Brushes (Luson) Ltd., London, heads a gear having 96 teeth would be the maximum N.W.10, has produced a machine which greatly re that could be brushed using the standard control gear. duces the time taken to deburr a gear. Special control gear can be supplied to order. The machine consists basically of a central oscil lating spindle incorporating a self-clamping mandrel Surface Roughness Scales on to which the gears are placed. Surrounding this Rubert and Co. Ltd., Levenshulme, Manchester, spindle are four rotary wire brushes, each complete motors continuously rated at 1·5 b.h.p. One grinder, have recently begun to manufacture sets of roughness with its own power unit. In the base of the machine is with a 7 in. diameter disk, runs at 8,000 r.p.m., the surface scales for use where touch and sight methods the main drive motor, which supplies the motive power other, with a 9 in. diameter disk, runs at 6,000 r.p.m. of testing are preferred. One set contains ten specimens for the oscillating spindle, a motor-driven pump and The disks are depressed centre reinforced grinding of stainless steels, with finishes ranging from 1-500 associated hydraulic equipment, and the variable disks, which can be supplied from 3/ to ⅜ in. thick. micro-inches C.L.A. Each specimen indicates the Grinding is carried out with the edge of the disk. method by which it is produced (lapping, grinding, The machine can be used also with cut-off wheels milling, shaping or turning). The second set is similar for cutting ferrous and non-ferrous metals and stone, but larger: it contains thirty rectangular stainless steel and with sanding disks. specimens and ten round carbon steel specimens, and the range of finishes is from 1-1,000 micro-inches C.L.A. This set is also produced in a special case Automatic Piston Grinder with a glass cover, for wall mounting. A new 5 in. x 8 in. type H precision grinder auto matically loads, grinds and discharges pistons. It has Drill Holder and Setting Gauge been developed by the Landis Tool Company of the The B.S.A. drill holder and setting gauge has U.S.A. to meet the increasing needs of automation in been designed to enable the accurate drilling of com high production operations. Burton Griffiths are sole ponents to pre-set depths. The holder can accommo selling agents in this country. date any size of drill, reamer, counterbore, or tool The aluminium alloy pistons can be delivered to the possessing a standard morse taper shank. Its com machine by conveyor and transfer mechanism. An ponent parts are a main body, a knurled locking ring, automatic timed loader places the piston in the grind combined bush and stop-nut. ing position. Rotation begins as the grinding wheel To assemble, the drill is inserted into the holder, advances rapidly to the grinding position. Slow grind followed by the bush and stop-nut which is threaded ing feed then proceeds to a positive, predetermined up the body sufficiently far to give the required depth size. After a timed sparkout period, the grinding of drilling, i.e. the distance between the drill point wheel retracts rapidly to a back position and the and the lower face of the bush. The locking ring is piston is ejected to another conveyor. Simultaneously tightened against the bush when the required depth is another piston is loaded and the cycle is repeated. determined. The complete unit is then inserted in the The pistons are ground by the infeed method, using machine spindle. An adjustable setting gauge is sup a wide wheel which reciprocates laterally during the plied with the unit in order that the required depth of grinding cycle. The elliptical shape of the pistons is speed unit controlling the output speed of the main drilling can be checked, particularly after point produced by using a master cam and rocking work drive motor. The control panel is a separate unit, but grinding the drill. cradle. can be integral. The holder, bush and stop nut, and locking ring Wheel dressing is automatic after a predetermined The machine operates as follows: cam-gear oscil are normally threaded left-hand. This is a precau number of pistons are ground. The wheel head auto lates the gear to be deburred in a manner and path tionary measure against the inadvertent failure, on the matically advances the same amount as the size of the similar to the actual shape of the teeth of the gear. part of the operator, to lock the bush in place. In such wheel is decreased by dressing. This eliminates com In this way the teeth are moved about the wire a circumstance, where a normal right-hand rotation pensation by hand to return the wheelhead to the brushes. During one oscillation a tooth is presented machine is employed, the bush would tend to work correct position for proper size. to each brush and the gear indexed forward one space. down the holder, thus decreasing the drilling depth The 5 in. type H piston grinder has microsphere In this manner, using four wire brushing heads, the to avoid drilling to too great a depth. bearings for both the work head spindle and the gear is completely brushed in only one quarter of a grinding wheel spindle. These bearings are of one revolution. A larger number of brushing heads can Angle Grinders piece steel construction with babbitt-metal lining be incorporated, up to a maximum of eight. To set faces. The spherical shape permits perfect alignment Wolf Electric Tools Ltd., Hanger Lane, London, the required cycle of oscillations, the number of to the spindle and adjustable running clearance. W.5, have recently produced two high speed heavy- teeth on the gear should be roughly divided by the Lubrication to the bearings is automatic. duty angle grinders, driven by specially designed number of brushing heads and the control set to the resulting figure. Automatic self-compensation is incorporated to allow for wear of the brushes, and this is controlled by the hydraulic circuit. The speed control unit attached to the main drive motor will enable the speeding up or slowing down of the cycle to be easily ■ controllable according to the amount of burr to be removed from the gear. A separate cam-gear will be required for each different size or type of gear. The type of rotary brush used will depend on the material to be brushed and the extent of the burrs to be removed. June 1955
Aircraft Engineering and Aerospace Technology – Emerald Publishing
Published: Jun 1, 1955
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