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21. For an Improvement in Copying Presses; A. A. Wilder, Detroit, Michigan, March 11.

"The nature of my invention consists in the use of two flat pressing plates, one of which being vertical, works on a slide, and has an adjusting screw for regulating the degree of pressure or width between the plates, according to the thickness or the nature of the material being pressed, and the second plate being fitted so in the table or bed plate, that it may have a movement so as to open like a hinge; and it possesses, also, an adjusting screw or box, through which the screw pin passes, and which is attached by link rods to the handle or lever, having its fulcrum on the opposite plate; the loose or hinge hung plate, being opened and shut by the motion up or down of the lever handle, which produces the pressure."

Claim. "What I claim as my invention, is the use of a lever handle I, having its fulcrum on the pressing plate B, attached to the opposite plate F by links H H, as shown, working in the manner described, in combination with the adjusting arrangements CE G g, for the purposes expressed, and operating together as shown, or in any other substantially similar manner.'

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22. For an Improvement in the Teeth of Saws; George F. Woolston, Orangeburg, South Carolina, March 11.

Claim. "I claim as my invention, the invention of teeth in circular saw blades, of the form and for the purpose above set forth."

DISCLAIMER.

1. For an Improvement in Machines for Making Wire Heddles; Abijah J. Williams, Utica, New York; patented September 11, 1849, date of disclaimer February 24, 1851. "The subscriber further represents, that he is the sole and exclusive owner of the said letters patent, and of the right, interest and property therein and thereby secured; and although he did not intend, in or by the specifications and drawings upon and in reference to which said letters patent were issued, (and of which copies are annexed to, and form a part of said letters patent,) to represent or claim that he was the original or first inventor of the wheel, collar, or flanch, with a sliding tooth and pulley, and treddle, or other device, hereinafter particularly mentioned, or of any part thereof; and he insists that said specifications and drawings do not, when rightly understood, represent or claim that he was such inventor; and he also insists, that said letters patent do not, when rightly understood, assume to confer on him any right, as the supposed assumed or alleged inventor thereof, or of any part thereof; yet, in order to guard against any mistake or misconstruction, in these respects, the subscriber states,

1. "That he did not mean to assert, claim or represent, in and by said specifications or drawings, that he was the original or first inventor of the wheel mentioned as wheel, fig. 8, in said specifications and drawings.

2. "Nor did he mean to assert, claim or represent, in and by said specifications or drawings, that he was the inventor of the collar or flanch, with a sliding tooth, which are partially represented on the drawing, figure 1, near letter Q, and also partially represented on the drawing figure 2, at that end of the cylinder where the receiving and discharging hook rod shows the hook, and near letter B.

3. "Nor did he mean to assert, claim or represent, in and by said specifications or drawings, that he was the inventor of the cord pulley or heddle, partially represented on the drawing, figure 1, which cord, as there shown, extends from said pulley, near letter C, to said heddle.

4. "Nor did he design or intend by said specifications or drawings to claim, assert, or represent, that his invention would make a heddle, with a slack twist in the half, or part thereof, which is towards the end where the wire is doubled.

"And the subscriber says, that if said specifications and drawings import or mean that any or either of the aforesaid things was or were invented by him, or that his invention, as claimed by him; would make a heddle with any such slack twist, as aforesaid, the same was and were, by and through inadvertence, accident and mistake, not being so designed or intended by him, and he hereby fully disclaims the several matters and things aforesaid, numbered above 1, 2, 3, 4, and each and every part thereof, under and pursuant to the seventh section of the Act of Congress, entitled "an Act in addition to the Act to promote the progress of science and useful arts," approved March 3d, 1837, and under and pursuant

to the law in such cases made and provided; insisting, however, as he does, that the same are not, nor is any part thereof, claimed in and by said specifications and drawings, or either of them, or embraced in said letters patent; this disclaimer being made for greater caution, and to guard against misconstruction and mistake in regard to said matters."

MECHANICS, PHYSICS, AND CHEMISTRY.

Marble Sawing and Polishing Machinery, Worked by Steam Power. By CHARLES HOLTZAPFFEL.*

Marble has of late years been extensively worked by machinery driven by steam power; the processes are closely analogous in principle to those pursued by hand, but with various modifications of the apparatus, and it is now proposed to explain briefly some of the peculiarities of the machine

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In the simplest application of machinery to sawing marble, as for making one or two cuts in a large block, the construction of the ordinary stone saw is closely followed, but the frame is made much stronger, of squared · From the London Artizan, for January, 1851.

timber firmly bolted together, and stayed with chains; to constitute three sides of a rectangular frame; the place of the pole and tightening chain of the saw, is occupied by two fixed beams, and the saw is held and stretched by means of two clamps, with screws passing through the ends of the frame, and tightened by nuts on the outside. The saw frame works between vertical guide posts to keep it upright, and it is reciprocated horizontally by a connecting rod fixed to a crank driven by the engine. The connecting rod is attached to the frame by a loop, which can be placed at various heights so as always to keep the stroke of the connecting rod nearly horizontal, notwithstanding the gradual descent of the saw in the

cut.

These saw frames are sometimes made as large as 16 feet long, and 10 feet high, for cutting huge blocks of marble; and to prevent the great weight of these frames from pressing on the cut, they are suspended at each end by chains or slings which vibrate with the saw, and are connected with a counterpoise weight, that is adjusted to allow of the necessary pressure for the cutting, which is effected with sand and water supplied in the same manner as for the stone saw used by hand, but the introduction of the guide principle, renders the chasing of the stone for the entry of the saw unnecessary. In some cases smaller saws of similar construction are used for cutting thick slabs into narrow slips, and sometimes several cuts are made at once by an equal number of saw blades, arranged in a rectangular frame, that is suspended horizontally by vibrating slings, and works between vertical guide posts.

In the horizontal sawing machine for marble patented by Mr. James Tulloch in 1824, the entire arrangements are combined in a very effective manner, for cutting a block of marble into a number of parallel slabs, of any thickness, at the one operation. The iron framework of the machine, shown in fig. 1, consists of 4 vertical posts strongly connected together at the top and bottom, to form a stationary frame from 10 to 14 feet long, 4 to 5 feet wide, and 8 to 12 feet high, within which the block of marble to be sawn is placed. The two upright posts at each end of the stationary frame have, on their insides opposite to each other, perpendicular grooves, within each pair of which slides up and down a square vertical frame; to the lower end of each of these slides is affixed a spindle carrying two guide pulleys, or riggers, upon which the horizontal saw frame rests, and is reciprocated backwards and forwards. The saw frame is thus traversed within the fixed framing, and supported upon the four guide pulleys of the vertical slides, which latter are themselves suspended by chains coiled upon two small drums placed overhead. On the same spindle with the drums is a large wheel, to which a counterpoise weight is suspended by a chain. The weight of the counterpoise is so adjusted as to allow the saw frame to descend when left to itself, and which thus supplies the necessary pressure for causing the penetration of the saws.

The saw frame is made rectangular, and from 2 to 3 feet longer than the distance between the vertical slides, in order to permit of the hori zontal traverse of the saws, which is from 18 to 20 inches. To allow of the blades being fixed in the frame with the power of separate adjustment, every blade is secured by rivets in a clamp or buckle at each end; the one extremity of the buckle embraces the saw, the other is made as a hook, the

buckle at one end of the saw is hooked upon a horizontal bar fixed across the end of the saw frame, and the opposite end of the frame has a groove extending its entire width, through which a separate hook, provided with a vertical tightening wedge, is inserted for every saw, which thus admits of being replaced without deranging the position of the neighboring blades. The distances between the saws, and their parallelism with the sides of the frame, are adjusted by means of iron blocks made of the exact thickness required in the slabs of marble; the blocks and blades are placed alternately, and every blade is separately strained by its tightening wedge until it is sufficiently tense; the blocks are sustained between two transverse bars, called gage bars, and are allowed to remain between the blades. to give them additional firmness.

'The traverse of the saw frame is given by a jointed connecting rod, attached by an adjustable loop to a long vibrating pendulum, that is put in motion by a pair of connecting rods, placed one over the other, and leading from two cranks driven by the engine. All three connecting rods admit of vertical adjustment on the pendulum. The connecting rod of the saw frame is placed intermediately between the other two, but its exact position is regulated by the height at whtch the saws are working, as it is suspended by a chain and counterpoise weight, which allow it to descend gradually downwards on the pendulum, with the progress of the cut, so as always to keep the connecting rod nearly horizontal.

In the London Marble Works four of these sawing machines of different sizes are grouped together, with the driving shaft and pendulums in the middle, and so arranged that each pair of saw frames reciprocate in opposite directions at the same time, in order to balance the weight, and reduce the vibration.

Another mode of traversing the saw frame sometimes adopted, is by means of a vertical frame that is reciprocated horizontally on slides, and the connecting rod, instead of being jointed, is fixed rigidly to the saw frame, and slides upon a vertical rod. Various other unimportant modifications in the construction of the machines are also adopted.

One of the most difficult points in the application of these machines, was found to be the supplying of the sand and water mechanically to the whole of the cuts at the same time. This is now successfully effected by the following arrangement. Above the block of marble to be sawn is fixed a water cistern, or trough, extending across the whole width of the frame, and measuring about 1 foot wide and 1 foot deep; about 20 small cocks are arranged along each side of the cistern, and a small but constant stream from each of the cocks is received beneath in a little box; a sloping channel leads from every box across the bottom of a trough filled with sand, which mingles with the water, and flows out in separate streams, that are conducted to each of the saw cuts. In the first construction of this apparatus for the feed, the sloping channels were led straight across the bottom of the sand trough, but it was then found that the water excavated little tunnels in the sand, through which it flowed without carrying the sand down. This difficulty was overcome by leading the channels across the bottom of the trough in a curved line, when viewed in plan. The form of the channels is shown in fig. 2, which represents four channels cut across the middle of their length, to show their section, from which it will

be seen that the channels are made as a series of Gothic shaped tunnels, supported only on one side, and open on the other for the admission of the sand; the water flows through these tunnels, and continually washing against the convex side of the channel, undermines the sand, which falls into the water and is carried down: to assist this action the attendant occasionally stirs up the sand to loosen it. There is a sand trough and set of channels on each side of the water cistern, so that every saw cut receives two streams of sand and water in the course of its length. The saws having been adjusted to the proper distances for the required slabs, the saw frame is raised by means of a windlass and the suspended chains attached to the vertical frames, and the block of marble to be sawn is mounted upon a low carriage, and drawn into its position beneath the saws, and adjusted by wedges. The saws are then lowered until they rest upon the block, the counterpoise weights are adjusted, and the mixed sand and water allowed to run upon the saw blades, which are put in motion by attaching the connecting rod to the pendulum. The sawing then proceeds mechanically until the block is divided into slabs, the weight of the saw frame and connecting rod causing them gradually to descend with the progress of the cutting.

Fig. 2.

To allow the sand and water to flow readily beneath the edges of the saw blades, it is desirable that the horizontal frame should be slightly lifted at the end of each stroke. This is effected by making the lower edges of the frame, which bear upon the guide pulleys, straight for nearly the full length of the stroke, but with a short portion at each end made as an inclined plane, which on passing over the guide pulleys lifts the frame just sufficiently to allow the feed to flow beneath the saws.

For cutting slabs of marble into narrow pieces, such as shelves, and which is effected by hand with grub saws, a machine called a ripping bed is employed, in which as many cuts as may be required in the one slab are effected simultaneously, by an equal number of circular saws with smooth edges, revolving vertically, and fed, as usual, with sand and water. This machine, represented in fig. 3, consists of a bench about 12 or 14 feet long, 6 or 7 wide, and about 2 feet 6 inches high; upon the top of the bench is fixed two rails, upon which a platform, mounted on pulleys, is drawn slowly forward by a weight. The horizontal axis carrying the saws revolves about 9 inches above the platform, and to ensure the rotation of the saws, the axis is provided with a projecting rib or feather extending its whole length. The saws are made as circular plates, about 17 inches diameter when new. The saws, or cutters, are clamped between two collars about 6 inches diameter, fitted so as to slide upon the spindle, and be retained at any part of its length by side screws. The saws having been adjusted to the required distances for the widths of the slips to be cut, and fixed by the side screws, the slab of marble is embedded in sand upon the platform, and the edge of every saw is surrounded on one side with a small heap of moist sand. The saws are then set in motion, so as to cut upwards, and the platform is slowly

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