612 



BLOCK MACHINERY. 



Boring ma- 

 chine 



Plat* 

 LVR 



Fig. 4. 



Block \U- p U t into rapid motion by the machinery, when, ha- 

 ' ving a considerable strain on the pivots from its 

 work, it required a constant supply of oil, which was 

 very quickly consumed, as the centrifugal force tended 

 to draw the oil up the largest part of the cone, and 

 juently take it from the points of contact. If 

 the machine continued to work without oil, the great 

 velocity and pressure would cause such a friction, as 

 to warm one or other of the steel joints. This would 

 at once expand and soften it, so as to increase the fric- 

 tion in a two fold degree ; and if this evil continued, 

 the point would suddenly become red, or even white 

 hot, and being too soft to resist the power of the 

 saw, would then be twisted off. The broken point 

 when cold, would then be found so jambed, or ra- 

 ther welded, into the hole in the end of the spin- 

 dle, that it would be impossible to get it out except by 

 drilling. The improved spindles, as constructed 

 by Mr Maudslay, have double conical sockets, so dis- 

 posed as to' attract the oil into the fitting, instead of 

 throwing it out. For small saws, where the strain is 

 but slight, the old method is as good as can be de- 

 vised. The blocks applied to the ripping saw are 

 first split or lipped, in the direction of the grain, into 

 the proper breadth in one direction, and then in the 

 other, so as to reduce them tothe proper scantling 

 for the various sizes of blocks. 



Boring machine. The blocks, prepared by the 

 foregoing saws, are placed in the machine represented 

 in Plate LVII. Fig. 4. This machine has an iron 

 frame, AA, with three legs, beneath which the block 

 isintroduced,and the screw B being forced down upon 

 it, confines it precisely in the proper spot to receive the 

 borers 1) and E. This spot is determined by a piece 

 of metal fixed perpendicularly just beneath the point 

 of the borer E, shewn separately on the ground at X : 

 this piece of metal adjusts the position for the borer 

 D, and its height is regulated by resting on the head 

 of the screw x, which fastens the piece X down to the 

 frame. The sides of the block are kept in a parallel 

 position, by being applied against the heads of three 

 screws tapped into the double leg of the frame A. 

 These screws are represented by dotted lines in the 

 Figure. The borer D is adapted to bore the hole for 

 the centre pin in a directiou exactly perpendicular to 

 the surface resting against the three screws ; the 

 other, at E, perforates the holes for the commence- 

 ment of the sheave holes. Both borers are construct- 

 ed in nearly the same manner ; they are screwed up- 

 on the ends of small mandrels, mounted in frames si- 

 milar to a lathe. These frames, G and H, are fitted, 

 with sliders upon the angular edges of the flat 

 broad bars, I and K. The former of these is screw- 

 ed fast to the frame; the latter is fixed upon a frame 

 of its own, moving on the centre screws, at L L, be- 

 neath the principal frame of the machine. By this 

 means, the borer E can be moved within certain li- 

 o a6 to bore holes in different positions. These 

 limits are determined by two screws, one of which is 

 seen at n, the other being on the opposite side. They 

 are tapped through fixed pieces projecting up from 

 the frame. A pi | aee of metal, from the un- 



der side of tl orer E, stops against 



the ends of these screws, to limit the excursion of the 

 T!ie fi Limes for both borers are brought up to- 



wards the block by means of levers M and N. These 

 are centered on a pin, at the opposite sides of the 

 frame of the machine, andhaveoblonggroovesthrough 

 them which receive screw pins, fixed into the frames G 

 and H beneath the pulleys P, P, which give motion 

 to the spindles. 



In using this machine, the workman draws back 

 both borers, which always continue turning: He then 

 takes the block and applies one of its sides against 

 the heads of the three screws, resting it on the head 

 of the screw x above mentioned, and thrusts it against 

 the stop X. This ascertains the true position ; and 

 the screw B being screwed down upon it, holds it 

 perfectly fast. The point of this screw has a steel 

 ring, or washer, fitted upon it, the lower side of 

 which is a sharp edge. 'When the screw is twirled 

 round, the balls at the ends of its cross handle cause 

 it to act as a fly-press, to stamp the impression upon 

 the end of the block. The workman now takes the 

 handles M, N, and forces them towards the block. 

 This brings the borers against it ; and, as they are in 

 rapid motion, they will bore as fast as they can be 

 followed up to the work. This is the process of bo- 

 ring a single sheave block, when the screw-stops at a 

 are screwed so far as to confine the frame K in a ver- 

 tical position, and then its borer makes a hole through 

 the centre of the block. For a double block, the 

 screws are withdrawn so far, that when the frame is 

 held against one screw, its borer will be in the proper 

 place for one hole ; and, when inclined to the other 

 screw, will be in the proper place for the other hole ; 

 and it is evident, that these limits, or the distance be- 

 tween the holes, may be increased or diminished at 

 pleasure, to suit thick or thin blocks. The borers, 

 which are made in the same form as a carpenter's 

 centre bit, can be unscrewed, near the ends of their 

 respective spindles, at b, to put on one of a larger or 

 smaller size. The points of the screw-centers at L, 

 upon which the frame of the borer E vibrates, can be 

 put into different holes in the frame, so as to alter the 

 difference of the level between the two borers, in order 

 to suit blocks of different dimensions ; and the screw x 

 is changed for one with a thicker head, or, what is the 

 same, a washer is put under its head. Tlie stop X 

 can be altered in its position, by sliding it farther 

 from or nearer to the frame, and can be fastened by 

 the screw x. Threefold blocks are bored at one opera- 

 tion, by the machine set in the same manner as for 

 single blocks : They are then put in the machine 

 when set for double blocks, and the two external 

 holes bored. 



The mortising machine, is exhibited in Plate LVI 1 1. 

 Fig. 4. which is a perspective view of this beautiful 

 piece of mechanism. It is put in motion by an endless 

 strap passing round a drum at A, screwed to a fly- 

 wheel B,that regulates the movement. This drum turns 

 an axis D, on the extreme end of which is a crank. 

 This has a long rod extending from it up to a joint at 

 a, which connects it with a frame EE, fitted between 

 sliders b, d, and guided by a cylindrical rod F, sliding 

 through a fixed collar supported by the framing. By 

 this means the frame is moved up and down when 

 the axis D revolves. To this frame the chisels arc 

 fastened, and operate upon the block fixed at G, in a 

 carriage H, sliding horizontally in the frame of the 



Block Mi. 

 chioary. 



Method of 

 usinj; the 

 boiing ma- 

 chine. 



Mortising 



machine. 

 t .\ i I 

 LVI II. 

 I'ig. 4. . 



