between them; a double fence, furnished with upper and lower friction-rollers, extends a sufficient distance on either side of the central partition for guiding the deals through the saws. The upper friction-rollers are arranged so as to act as guides to the upper parts of deals of varying depths when being sawn, the other side of the deals being acted on by the smooth feedrollers; thus the inconvenience arising from any unevenness in the sides of the deals is obviated. A frame adapted to cut deals up to 11" x 3" is speeded to run at the very high rate of 400 revolutions per minute. To overcome in a measure this speed, in addition to counterbalancing the swing frames, they are made specially light of wrought iron and steel, and care is taken in the workmanship of the general details to ensure accuracy. CHAPTER VII. TIMBER AND DEAL FRAMES, ETC.-continued. SEVERAL patents have recently been taken out for improvements in reciprocating saws, amongst which may be mentioned one by Mr. Edwin Chabot, of Sonth Norwood, dated 1877, who claims as novel, on behalf of Ferrando Morel, of Barcelona, an arrangement for sawing timber in such a manner that four thick planks may be simultaneously sawn up by four sets of saws carried in one reciprocating frame. It is described as follows:- -'I arrange the machine in such manner that in place of the reciprocating frame carrying only one set of saws on either side of the travelling carriage, I arrange it to carry two sets of saws, and I provide separate guides for each plank of timber, to be held up to one plank on each side of the carriage, the one being pressed towards the travelling carriage, and the other away from it, up to their respective guides. The guides can be set towards or away from their respective sets of saws without stopping the machine. The machine, as heretofore, is provided with a main driving-shaft, having upon it a crank for giving motion to the reciprocating saw-frame, and with rollers for supporting the planks, and with a slowly moving carriage, actuated by a rack and pinion, for traversing forward the planks of timber up to the saws. Provision is also made for setting the saws situated at one side of the traversing carriage to cut up a single plank of considerable width, whilst at the same time the saws on the opposite side are set to cut up two planks. The saws, as heretofore, are set to any desired distance apart, according to the number of pieces into which it is desired to divide the planks. By the above construction of machine, four different kinds of work can be performed simultaneously, instead of two, as heretofore." Mr. Samuel Worssam also in 1876 secured a patent for improvements in equilibrium saw-frames. These chiefly consisted in using two separate rack-feeds placed side by side, intermediate of the two saw frames, and placing the feed wheels both on the same side of the machine, thereby enabling the feed of each deal or plank to be regulated independently of the other, and enabling a single attendant to attend to both feed wheels from the side of the machine, thus doing away with the expense of a second sawyer. Improvements in the general arrangements of the parts, and the mode of operating horizontal reciprocating saws for cutting boards, have recently (1879) been patented by Mr. Adam Knox, of Glasgow, by which he claims a greatly increased production with less power. His designs, although slightly complex, have considerable merit in arrangement; we therefore describe them somewhat at length. The improvements claimed are as follows: The general construction or arrangement and combination of the parts of wood-sawing machines or mechanism, of the horizontal reciprocating class with blade or band saw or saws, reciprocated on the periphery of segmental levers or on pulleys. The carrying and actuating of a horizontal reciprocating blade or band saw or saws on the periphery of reciprocated segmental levers or on pulleys, either having an edge-rocking or curvilinear motion given to them or not, as desired, for the cutting of wood in horizontal sawing machines. The carrying of the reciprocating segmental levers or pulleys with their saw or saws on fixed centres (either with or without antifriction pulleys) on vertical slides or guide frames, to give the different thicknesses of wood to be cut in horizontal sawing machines. The giving of the edge-rocking action to the segmental levers or pulleys carrying and actuating horizontal reciprocating saws (in wood-sawing machines) by radial links, cams, or angled centres. According to one modification and arrangement, in coupling the horizontal transverse reciprocating saw by its two ends direct, by buckles or other suitable couplings, to two broad, thin blades of steel or other equivalent elastic or flexible bands, so mounted on as to reciprocate over the upper periphery of two large strong but slight oscillating pulleys, or it might be duplex segmental pulleys oscillating vertically on strong studs projecting from the face of two slides mounted and worked simultaneously by screw spindles on strong vertical planed guide frames, with long bracketed sole behind on each side of the ordinary longitudinal carriage carrying the wood to be cut, and traversed on the main stationary bed frame, which may rest in front on the strong deep traverse frame, secured to the foundation below, and carried or branched up so as to be secured to the vertical slide guides or standards on each side, to stay or make the whole securely steady and rigid. |