116 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[Apuil, 



Description of the Eugravinijs. 



Fijr. 1 shows a longitudinal elevation of the 

 machine entii'ely set up, and ready to cut up a 

 large piece of wood. Fig. 2 is a longitudinal 

 section taken tlirough the axis, according to the 

 lines 1, 2, of the plan. Fig. 3 is a transverse 

 section taken perpendicularly to the preceding, 

 according to the line 3, t. Fig. ■!• is a general 

 plan of the madiine. 



By examining the several views and details of 

 the apparatus, it will be seen that the log or 

 piece of wood. A, to be cut, is not set on mere 

 conical points, as on a lathe, but on two square 

 points of the iron axis IJB', between which it is 

 held sufficiently fast to avoid its having any play, 

 but so that it may fall in steadily with the simul- 

 taneous rotary motion of these two axes. At its 

 ends are adjusted the iron cross-bars C, which 

 serve to maintain it on their points in a steady 

 manner, and to keep it always perfectly in the 

 centre from the beginning to the end of the ope- 

 ration. The forms of these cross-bars are simi- 

 lar to those shown in figs. 5 and 6 ; the largest 

 of these are applied to the largest logs of wood, 

 and the smallest replace the former when the 

 logs are reduced to a small diameter. These 

 cross-bars being at their centre pierced with 

 square holes, having the exact form of the points, 

 it is easily understood that when these points are 

 inserted in the lioles, the piece of wood is con- 

 nected with the axis B, and B', in a continuous 

 and solid manner, and must necessarily turn with 

 them when they are put in motion. 



As the logs of wood are not always of the same 

 length, it is absolutely necessary to be able to 

 cause the points, and consequently the axes, to 

 advance and recede when requisite. F'or that 

 purpose I have adapted to the end of one of 

 these axes (that marked B) a screw D, fig. 4 and 

 fig. 2, which can be turned by the hand, without 

 giving to the axis the same rotai-y motion. That 

 screw D, passing through a permanent nut E, is 

 obliged to move when turning, and consequently 

 causes the axis to advance or recede; and as that 

 axis is held by two strong supporters FF', be- 

 tween which are placed the cog-wheel G, and the 

 pulley H, set on the said axis, those two pieces 

 G and H cannot move with it, as they are kept 

 between two supports. Thus the screw D, and 

 its axis B, only move and change their position. 



The second axis B', is by itself a screw ; it is 

 wormed over all its length, and is provided, as 

 the first axis B, with a cog-wheel G', having ex- 

 actly the same diameter as the first-mentioned 

 wheel G, and which also must rest in the same 

 place, whatever may be the position given to the 

 axis. For that purpose, this wheel G is kept on 

 one side by the large supporter F", by means of 

 a nut o, which presses against it, and on the 

 other side by a nut o, which rests on the nave of 

 the wheel G'. When that axis B is to be made 

 to advance or recede, tliose nuts are loosened, 

 and then, by means of the screw U, placed above, 

 the moveable bearer I, is made to proceed. That 

 bearer I, serves at its lower extremities as a sup- 

 porter to the wormed axis B'. 



That second screw 1)', produces exactly the 

 same efi'ect as the former one D; its nut E being 

 also permanent, is oliliged to move according to 

 its length, when it is nuide to turn lengthwise on 

 tlie right or left side. 



When the position of the two axes BB', has 

 been so regulated, that their square points are 

 inserted, and kejit into the ctoss-bars which are 

 adjusted to the extremities of the log of wood, 

 as shown by figs. 2 and 4; the i)Osition of the 

 blade-bearer carriage must be adjusted so that 

 the more forward knife should advance, and rest 

 on the exteriuil surface of the log. 



Fig. 1. 



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fe ,./ 



F.g. ;j. 



V ■;- 'Z'' 



