This planing machine may be put in motion by means of a crank turned by a mill to give it a reciprocating mo tion ; or, on a smaller scale, it may be worked by hand in the usual manner, but as all the adjustments are made by the machinery, none of the skill of the joiner is requisite in the process.
Planing Machine in the Royal Arsenal, Notwithstanding the machine above described possessed several advantages in comparison with the manual opera tion of planing, yet it was far from being so perfect or so powerful an engine, as seemed requisite where large and heavy works were going forward. Accordingly, in the year 1302, the late ingenious Mr. Bramah invented a planing engine upon a principle altogether different from the former, and in which the operation was performed by the rotation of a vertical spindle, and a horizontal wheel furnished with cutters and planes. The first machine of this kind was erected on Mr. Brainah's own premises at Pimlico, where it is still in action ; and a second, which differs in many important points from the former, was set up in the Royal Arsenal, Woolwich, and which has been since considerably improved by various ingenious addi tions and alterations by General Millar, the snperinten dant of the carriage department in that establishment. Our drawing of it exhibits the machine in its present im proved form, Fig. 1. and Fig. 2. Plate CCCCLXI II. show ing the elevation and plan ; and the rest of the figures, sections, and delineations of such parts as require parti cular illustration.
In Fig. 1. a a is a solid bed of brick and stone work, intended to form a foundation for the machine, and rising one foot above the ground-floor ; b b are iron slides fixed firmly to the foundation stones, as shown in Fig. 2. and inclining half an inch from the horizontal line in the whole length (forty feet) towards B ; c c, d d, are the moveable carriages, on which the wood e e, intended to be planed, is supported; ff is the cylinder of an hydraulic press, having two entrance pipes, g and h, one at each extremi ty. The piston rod of this press is furnished with a rack ;, which works a pinion j, under and attached to the wheel w. Round this wheel and the three smaller wheels, NV, W,W, passes an endless chain, which may be stretch ed at pleasure, so as to keep it to its work by means of a screw attached to the moveable slider carrying the centre wheel. The cylinder containing the condensed or com pressed water is in an adjacent room, and therefore not shown in the drawing ; the water is, however, conveyed by pipes to the cocks at k, which are so contrived as to admit of the compressed fluid being directed through the pipes g or h, and such that, when the pipe g, for exam ple, is opened to the compression, the pipe h is made to communicate with the waste ; hence, when the water en ters at g, the piston is urged forwards, and the rack, working on the pinion, under the wheel w, gives motion to the chain and to the carriages attached to it, by a con trivance which will be explained below. This motion
serves to bring the carriage c c, from the extremity A towards B; and, at the same time, the carriage dd to wards A ; at least when this latter is also attached to the chain, but generally only one carriage is attached at a time ; the contrivance for attaching and detaching the chain and carriages will be explained in a subsequent pa ragraph. The carriage c c having been advanced as far as requisite towards B, the cock at k is turned, the pipe g is opened to the waste water, and the pipe h to the com pression ; the carriage then returns towards A, the pipe h is then opened to the waste, and the pipe g to compres sion, when the carriage again returns.
Having thus explained, in general terms, the means employed to give motion to the carriages, it remains, in like manner, to illustrate the operation of the planing wheel. In the elevation, Fig. 1. CC is a strong vertical iron spindle, carrying the horizontal iron wheel HH, which in its circumference, or rim, is pierced with thirty holes, furnished with twenty-eight gouges, or cutters, and two planes. This wheel, which is preserved hori zontally by twelve braces, in 1, m 1, is made to revolve by means of the wheelwork shown in the figure, at the rate of about ninety revolutions per minute, FF being the principal shaft, or axle, connected with a steam-engine in an adjacent apartment. DD, Fig. 1. are the sections of two principal beams across the workshop ; EE, EE, two uprights, or pillars, which, with the wood-work shown above in the figure, and two other pillars shown in the transverse section, Fig. 6. serve to give stability to the machine, and to support the stout wire guard n n n n, in tended to protect bystanders from accident, to which they might be otherwise exposed.