The mortising machine is used in the following I manner : The block brought from the boring ma- t chine has the print formed by the screw thereof ', applied to the end of one of the screws at ee. If one double or threefold sheave block is to be mortised, as shewn in the Figure, the centre screw alone-is used to hold it in ; but if two single sheaves are to be fixed: in, then only the outside screws are used, the centre one being left loose. By screwing it tight, the block is fixed between the double circle prints, before men tioned, on the bar Y ; and stops are situated on the same bar. To guide the block to its proper position, which is, that the hole bored for the commencement of the sheave hole shall be vertical, suppose the block fixed, the handle r is turned till the hole is brought be neath the sliding frame. The chisels are now adjusted. I These arehong square bars of steel TT, and arc fas tened to the frame by a clamp, seen 'separately at X, This goes behind the cress bar of the frame, and has two square holes through its ends, to receive the chisel T, and two screws to bite it fast in the square holes ; at the same time that this keeps the chisels from slipping up and down, it fixes them fast to the frame EE, by drawing the chisels forcibly against the cross bars, by means of the clamps behind them.. The two screws of each clamp being slackened, the chisels are put exactly over the holes which are to become sheave holes, and screwed fast. The machine is now. put. in motion by depressing the handle P. This is at the end of a lever, the fulcrum of which is a pin fixed in the column of the frame at s ; and a short ,rm gives action to the end of the lever L, be fore described, so as to put the machine in motion., At the first descent of the chisels, they cut through the whole depth of the holes previously bored, so as to give them a flat side when they rise up. The eccentric circle I, moving the bent lever and rod in, turns the ratchet wheel round on both, and advances the block a very minute quantity towards . the fly wheel; so that the chisels in descending cut a fresh space, and in ascending the block advances. In this manner it proceeds, with a most rapidity, through the whole length of the intended sheave hole. At this time, the loaded end of the lever o drops off the piece p, previously adjusted, and . raises the.rod nt, so that the farther advance of the..
• block•is prevented. When the boy who attends the -machine observes this, lie raises the handle P. This stops the machine, as before stated ; and the boy care to -stop • it when the chisels are at the :highest point, which lie effects by a very dextrous :movement. The finished block is now removed, and a fresh one put in ; the handle r is screwed back, to 'bring the block to the proper point, and the machine :starts, and proceeds as before.
The backs of the chisels have a small piece of • steel t fixed to them, which thrusts out the chips which they cut, otherwise these would accumulate and 'wedge up the hole, so as to obstruct the chisel most materially, by filling up the space behind it. It has •also two small cutters, called scribers, at vt, fixed .perpendicular to its edge, so as to project rather be fore it, being fitted in dovetail notches, formed in the sides of the chisels. These small scribers, in the des cent of the chisel, cut or scribe two small clefts, which include the width of the chip which -will be cut out by the chisel in the succeeding stroke. By this ingenious device, the mortice cut in this machine has its sides as smooth as if they were made by a plane. The back of the chisel is rounded, to con .form to the hole bored in the boring machine.
To adapt the mortising machine for different sized •blocks, the cross bar Y, in the back of the carriage, against which the blocks are pressed, can be fixed by notches cut in the frame, at one inch asunder, so as to hold all blocks of different lengths, having an inch difference in each. The stops, above mentioned, to ascertain the position of the block, can be fixed upon the cross bar at any point, either as to height or po- • sition sideivise, in the following manner.: The piece of iron w, .(see the separate view,) with a groove through it, carries two vertical pieces xx, at the up per and lower end of which is a knob ; these will place the sides of the blocks applied against them truly vertical. Two small pillars. an are fixed to the cross bar of the carriage ; they have a piece sliding upon them, which can be fixed at any height by screws, to adapt it for different sized blocks. The two pieces xx, are fixed at the same distance asunder as the screws in the front of the carriage ; so that when one is set in the position for a block, to be held by one screw, the other will be at the proper 'place for the other screw : by these means the car riage can be adapted to receive a block of any dimen dons, and can guide it to its proper position against the prints in the cross bar. The frame E may have any number of chisels fixed to it, corresponding to the number of mortises intended to be cut.
The corner saw (see Fig. 5. of Plate LVI I.) con sists of a mandrel mounted in a frame A, and carry ing a circular saw L, upon the extreme end of it. This mandrel and its frame being exactly similar to those at G and H, Fig. 4. Plate LV11. does not require a separate view, although it is hid behind the saw, except the end of the screw marked A.
This frame is screwed down upon the frame BB of the machine, which is supported upon four columns, CC, DD is an inclined bench, or a kind of trough, in which a block is laid, as at E, being supported on its -edge by the CC of this bench, and its end kept 44/5' to its position by the other part of the bench DD.
By sliding the block along this bench, it is applied to the saw, which cuts off its angles, as is evident from the Figure, and prepares it for the shaping engine. All the four angles are cut off in succession, by ?tp plying its different sides to the trough or bench. In •the figure, two of them arc drawn as being cut, and the third is just marked by the saw. This machine is' readily adapted to different sizes of blocks, by the simple expedient of laying pieces of wood of different thickness against the plane DD, so as to fill it up, and keep the block nearer to or farther from the saw ; for all the blocks are required to be cut at the same angle, though, of course, a larger piece is to be cut from large than from small blocks. The block,re duced to the state of E is now taken to The shaping machine, represented in Plate LIX. as it is seen from one side. —A great deal of the ap parent complication of this figure arises from the iron cage which is provided to defend the workman, lest the blocks, which are revolving in the circles, or chuck, with an immense velocity, should be loosen ed by the action of the tool, and fly out by their centrifugal force: Without this provision, the•con sequences of such an accident would be dreadful, as the blocks would be projected in all directions with an inconceivable force. l'he principal part of this machine is its chuck, which holds the blocks. This consists of two equal wheels AA and BB, placed upon the same axis, the former of which is firmly fixed to the axis, while the latter slides upon it, in order to render the space between them greater •or less, as is required, to contain blocks of different lengths. This•s effected by five bolts, fixed into the -rim of one wheel, and passing through the rim of the other. Each bolt has a nut upon it, on the outside of the wheel B. By means of these nuts the wheel B is held fast at any required distance from the other; The head of some of these bolts are marked x. Both wheels of the chuck are divided into ten equal parts. At each of these joints, on the wheel A, a short axis, or mandrel, is fitted through a projecting part of the rim of the wheel. On the outside of the wheel, each of these mandrels has a small wheel a upon its end. On the ends, in the inside of the wheel, the mandrels have each a short cross bar fixed, just sufficiently long to contain two steel rings ;%which are exactly the same size and distance apart as those in the mortising machine, which support the block. The wheel B has, at each point opposite the man drels a, a screw centre similar to the back centre of a lathe, but furnished at its point with a steel ring, of the same dimensions as that at the end of the screw of the boring machine. The ring is fitted upon the point of the screw, to turn freely upon the end of it. The blocks are held in between the wheels, by putting the double print at one end of each block against the double rings at the end of one of the mandrels, and then screwing the screw in the other wheel tight tip, the block is confined be tween them. In this manner, the chuck heing filled with ten blocks, if they are turned round rapidly, and a chisel or gouge fixed for them to cut against, each will be formed to a segment of the circle in which they move. This gouge is supported in a frame, moving on a fixed rest D, which is curved to a•circle, whose centre is in the centre of the chuck. It is confined to move on this arch by a curved radial bar E, fitted to c 'titre on the floor beneath the ma chine at one end ; and having the utherattaclied to the frame FF, which supports the tool. This frame con tains a slider f, moving in a groove, and at the end carrying the tool g in a holder, where it is fixed by a screw. The slider has an axis or spindle, fitted per pendicularly in it at /z. On the lower end of this is. a roller, which applies itself against a curved piece of metal i, called a shape. It is fixed fast upon the framing of the machine by a_ pillar at each end. The roller is kept in contact with the shape by a. lever, centered at k on the frame F, and connected by a short coupling iron with the sliderf ; so that, when its handle 1 is pressed towards the machine, the roller. is .kept up to the shape. G is a handle jointed to the frame F ; and, by means of this, the frame F, carry ing the tool and all its apparatus, can be moved the rest D, being guided by the radial bar. E in its motion. It is evident, that if the other handle 1 is at the same time pushed forward, the roller applies itself to the shape, and, consequently, the gouge de scribes the same curvature that the shape has. This curvature can readily be altered by the following means : There is a second shape m fixed below the former, and,_by a simple movement, the roller can be depressed, by slipping its axis downwards in its socket, so as to roll along the lower shape, and give the curvature of it to the tool, instead of the upper. one.