THE

London

JOURNAL AND REPERTORY

OF

Arts, Sciences, and Manufactures.

CONJOINED SERIES.

No. LXIV.

Recent Patents.

TO JOHN M'DOWALL, of Johnstone, in the county of Renfrew, North Britain, and of Manchester, in the county of Lancaster, engineer, for his invention of certain improvements in machinery for sawing timber, and in the mode of applying power to the same.[Sealed 24th June, 1836.]

THIS invention consists, firstly, in an improved con. struction or arrangement of machinery for sawing and cutting timber into planks or boards; secondly, in a modification of the same, suited to the sawing or cutting of balks or logs of heavy timber into scantlings or boards; thirdly, in the adaptation of a steam cylinder and piston to each of the said cutting frames, for the purpose of independently driving its machinery.

By this arrangement each sawing frame is converted 2 c

VOL. X.

into a separate engine, is perfectly distinct from the adjoining sawing frames, is capable of being worked or stopped at the pleasure of the operator, without affecting any other of the said frames contiguous to it, and by this may be driven faster or slower than the others, as the qualities or natures of the various kinds of timber under operation may require.

These improved machines may be used (when not employed in cutting) as ordinary steam-engines, for driving other machinery by various modes, as placing a pulley on the main driving shaft of the engine, which, by having a strap passed round it, may either be made to drive circular saws, or for other light works.

In case of this improved arrangement of sawing machinery being constructed without the steam cylinder and piston, it may be actuated by an ordinary stationary steam-engine, there being a fast and loose pulley mounted upon the main shaft, and a strap leading from the actuating part of such station engine may be connected to the said driving pulley.

In order that these improvements may be clearly understood, have I attached to this specification drawings, exhibiting the machinery in complete elevation and sectional views; and I have marked the same with several letters of reference, which respectively point out similar parts in all the figures.

Plate X., figs. 1, 2, and 3, represent the "saw-frame," intended to be employed to saw or cut "deals" or small timber into such boards or planks as may be required. Figs. 4, 5, and 6, exhibit the “balk frame," or that which is proposed to be employed for cutting or sawing heavy balks or logs of timber into planks or thicknesses called "scantlings" or boards.

Fig. 1, represents a front elevation of the improved

machine for cutting light timber, called the "deal frame." Fig. 2, is an end elevation, or side view, taken at the left hand of fig. 1; and fig. 3, is a partial sectional elevation taken vertically at the dotted lines A, B, in fig. 1.

The standards or main upright framings of the machine are shown at a, a, bolted to the foundation, and otherwise firmly secured in their places by flanges, and they are also bolted to the main beams that support the flooring b, b, thus dividing the machinery between the upper and lower apartments; the one of which contains the engine or driving power, while the other is occupied by the machinery which more immediate operates upon the timber.

The cylinder of the steam-engine, by the agency of which the sawing machinery is to be driven, is shown at c it is supplied with steam in the usual manner through slide valves, contained in the valve box or steam chamber d, d, being fed or charged with steam from the boiler through the main steam pipe e, and the induction pipe f; and from which box or chamber the steam is discharged by the eduction pipe g, into the waste steam pipe h, h, after its elastic force has been exerted upon the piston.

The main driving shaft i, i, is mounted upon pedestals or bearings fixed upon the top of the upright castings or standards a, a: this shaft carries two fly wheels. jj; two eccentrics k 1, and k 2, and also two disc crank plates v, v, in which are fixed the crank pins m, m, connected by the links or rods p, p, to the shaft n, n, carrying the frame of saws o, o, which travel in the slides or guide pieces o*, o*, attached to the frames a, á.

It will be seen that while the eccentric k 1, is working the slide valves, which admit and discharge the