FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1915
1915 - 0814.PDF
A PROPELLER-SHAPING MACHINE. SOME little while back we described and illustrated an ingenious lathe designed by Messrs. Wadkin and Co., of North Evington, Leicester, by means of which exact facsimiles of an aeroplane strut are automatically produced. The firm have just recently turned out another useful machine for accurately shaping propellers from any given model. From the accompanying illustrations it will be seen that this machine is by no means complicated. It will take propellers up to 12 ft. diameter, and will produce an exact facsimile of the " original" placed into the machine. This " original" consists of one blade only together with hub, which is mounted on a mandrel in a horizontal plane opposite to a carriage, which is longitudinally slidable on a bedplate. This carriage is adapted to support two pivoted arms, the lower one of which carries the original roller, and the top one the cutterblock, mounted on a reciprocating headstock. At their opposite ends the two pivoted arms are connected together by a link, which is adjustable, to enable the size of re-production to be varied if desired. The headstock driving by open and crossed belts pulleys mounted upon a shaft, and thence by reduction gearing, to operate the forward displacement of the carriage. When this has reached the end of the blade the propeller is turned round upon its mandrel to bring the next blade into position, and cutting now takes place on the reverse traverse. The support for the "original" and the work, as pre viously stated, consists of mounting them on a mandrel. The mandrels are each mounted on a pivoted flange plate having arms linked together, and provision is made for adjusting the inclination of the mandrels relatively to the headstock whilst the machine is running, to enable the work to be so regulated as to provide the minimum vertical displacement of the cutter arm during its traverse across the blade. The mandrels are, of course, locked securely in any position of adjustment. As previously stated, the "original" consists of one blade and the hub portion, and is made preferably of cast iron, and corresponds identically in shape to the blade to be formed, thus enabling existing gauges and The Wadkin propeller-shaping; machine. supporting these two arms is reciprocated transversely of the bed by means of a crank motion, so that the cutters will traverse across the work. As each end of the stroke is reached the carriage is moved longitudinally | in., so that cutting takes place both on the forward and the backward stroke across the work, thus saving considerable time. The cutterblock is fitted with 12 cutters, six on the front and six on the back. The spindle is mounted on ball bearings running in dust proof housings, and the end thrust is taken by a special double ball thrust washer. The drive is by means of a flat endless belt running over a two-step pulley, which is also mounted on ball bearings, and carried by a bracket fixed to the sliding headstock. A second flat endless belt now runs vertically downwards over guide pulleys, on to the driving pulley, which is fixed, and traverses with the carriage along a splined shaft. This shaft carries at one end a pair of fast and loose driving pulleys. The loose pulley runs on phosphor-bronze bush, and is fitted with a stauffer lubricator. This shaft also carries a pulley templates to be used to ensure the accuracy of the " original." It is, of course, essential that the shape of the blade should be accurately kept along its longitudinal edges ; means must therefore be provided to prevent the original roller falling abruptly. A few holes are there fore drilled and tapped along the edges of the " original " for securing to same a wooden guide which is shaped to enable the roller to run down a slight incline. When one face of the blade has been cut it is only necessary to reverse the work and also the original in its support. Means are provided for securely holding both the original and the work whilst it is being cut. A feature of the machine which is particularly important is that an old or broken propeller may be used as the " original" and an exact duplicate made from same. The machine combines the best materials and work manship throughout. It is built for hard continuous wear, and is provided with ample means for lubricating the various parts.
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
