Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 4, 1802).djvu/239

211&#93; THR THR [in Description of Air. James Ward- KOP's Thrashing Machine, with Elastic Flails. A, the floor, over which the flails are fixed. B, represents that part of the floor, on which the sheaves are laid : it is made of wicker-work, through which the grain falls, and is conveyed to the fan or screen below; the pivot of the fan is de- lineated at P, and is turned by a band from the wheel or wallower, D. C, C, C, is a thin board raised round the floor, to prevent the •wheat from being scattered; and which is made shelving outwards, that the straw may be raked off iTKire easily. D, the wheel orwallower. E, crank-handle for turning the tvheel. F, F, F, are the flails. G, G, G, levers or arms, to which fiails are attached by mearfs of ropes. H, H, H, are teeth or catches for raising tlie arms. I, the post, OB which the wal- lower D, is fixed. K, K, the beam on which the levers rest; being fixed by an iron rod passing through them, and in- iserted into this beam. Lj L, a check-beam, to prevent the end of the arms from rising. M, a beam, into which the ends of the flails are mortised. N, N, N, are fly-ends, weighted with lead, but which are not ne- inotion by horses. To render the operation of the inachinery somewhat more evident, ■we have annexed another, though only 4)artial, view of it, together ivitb a few additional explanation». -y^.2 Lfc^'_ . fc- ., .,^,^. IXI This figure represents the arms G, G, G, working in the keeps, O, O, O, and also the manner ia which those parts are connected. The model from which these de- lineations have been made, was de- signed to be worked by two men : it was constmfted on the scale of' a twelve-foot flail, having a spring that required a power of 20 lbs. ta raise it three feet high at the point. The teeth or catches are mortised into the shaft of the wallow-er, and placed round its circumference ; soi as to form an angle of 30 degrees. These teeth catch the arms G, G, G, that raise the flails, alternately: thus, the whole power, namely, 20lbs., a6ls upon three of the flails, when they are about to strike^ three others are two-thirds raised; tlinree more are elevated one- third; and the remaining three flails are at rest; so that thfe whole weight to be overcome^ amounts to 120lbs.' Mr. Wardrop direfts the arma to be arranged in such manner, that a Kne drawn perpendicularly frorai tlieir lifting extremity, would ex- tend to the middle of the flail: the ropes must be fixed soniewhat nearer towards the end, that a pro- per tangent may be obtained. Far- ther, the extremities of the lift- ers, and the teeth in the wallowef, P2 )»l}oaId
 * essary in a machine that is set in