The common practice in turning buttons, &e., is to employ a machine having two spindles mounted in line with each other, and revolving at a high speed, the cutting tools being fixed in the spindles, and the inaterial to be operated upon being held between them by means of a "steady " and " grip," together forming a pair of tongs. The grip and cutting tools are worked by the operator by means of handles, and require a considerable amount of manual labour and skill in their manipulation. An improvement upon this plan consists in actuating the grip and tools by means of cams in connection with levers and rods in a self-acting manner, so as to open and close the grip, and push one or both tools backwards or forwards as required, enabling a girl to do a large amount of work without great labour or skill. Figs. 445, 446, show a side elevation and plan of the machine suitable fur turning buttons of wood, vegetable ivory, and similar substances : a is the framing of the lathe ; 1), b' are spindles revolving in bearings on the framing; at their ends they carry the tools for turning the front and back of the button respectively ; they are driven by straps taking on the pulleys e, ei; d is the " grip " ; e, the " steady ;" k is a cam mounted on a spindle, revolving in bearings, and caused to turn by means of a pinion m, the teeth of which gear with teeth formed on the circumference of the crank ; the pinion m is mounted on a spindle, which is caused to rotate in its bearings by a strap taking on the pulley n. The crank is formed on the outside with a groove, in which works a roller /, mounted on a bar or connecting-rod g, which is guided at one end in the bracket q, and at the other end is attached to a spring f by means of a screw r and nuts, as shown, whereby the tension of the spring can be regulated. The spring f is, by preference, jointed below, and servos to push the grip d against the piece of material. The groove in the front side of the cam k is shaped so as to make the grip self-acting, allowing the piece of material operated upon to drop in the moment the operation is finished, when the operator places another pieoe in the grip. The baek of the crank h is also formed with a groove, in whieh works a roller /' mounted ou a stud in the bracket i', which, by means of a set screw, is fixed on a square bar h that is guided in the framing a, but by preference works through stuffing-boxes. The bar has a similar bracket i at the other end.
'Through the brackets e, are passed the screws/0', which abut against the ends of the spindles b,b' connected hy the staples s,s', so that the spindles are made to partake of the movement of the bar, which is self-acting, and so timed and arranged by the shape of the back of the eam k that the tool on the end of the spindle b first cuts the face of the button, and then that on the end of the spindle b' cuts the back of the button. There upon the grip is opened, and the button falls out, pieee of now material is put in, and the opera tion continues. Fig. 447 shows a part of a self feeding appliance which is suitable for small articles that are turned very quickly ; t is a ring, which is made to revolve on four rollers placed equidistantly within it (not shown), formed with ratchet teeth all round, and actuated by a pawl. Motion is communicated by a lever and rod from a roller working iu the outer groove of the eam k. The ring t is forrned with holes in it; at each hole is a spring u for holding the picee of material ; a is the stoady. The pieces aro fed in at leisure, aud without tho hand of the workman eemiog near the tools or grip.
The next machine (Figs. 448 to 452) to be considered is an American invention, enabling all the opemtions of manufacturing covered metal buttons to be performed automatically. On a standard A,
is a horizontal table, consisting of an under solid plate B, and turning in emit tet with it a plate C, baying near its outer edge a series of holes e slightly larger than the button to be made. Above this second plate is a ring D, of the same size as tho two circular plates, beld stationary, but perforated with holes corresponding with those in the second plate. The bases of the holes in the plate C, being closed by the lower stationary plate, form a series of depressions in which the buttons are to be formed. The plate C is caused to revolve with an alternate motion by a suitable cam or ratchet wheel. At one side of the table and above it, in the line where the holes e re volve, is plaeed a vertical tube E, terminating above in a hopper F, where are plaeed the fillings for the buttons, stamped of the proper size. A brush is made to vibrate among the filliogs over the mouth of the tube, the effect of whieh is to keep the tube full when once it has been filled, and to lay the fillings flat in position, so that they may fall down one after another. The base of the tube is closed, but a slot is arranged in one side, just large enough to allow of the exit of oue filling at a time, and a reciprocatiug bar G, entering at the opposite side of the tube, pushes the fillings out iu succession, so that they fall through the holes in the upper ring D into the holes e as the revolving plate C turns round. A little beyond the tube of fillings is a hopper H for the metal faces. These aro placed in the hopper 1I, whose bottom is inclined towards the centre from each end. In the centre, is a slot-shaped depression h' , running across the hopper in a direction towards the revolving plate which turns beside it. It is but little larger than the metal faces, and just deep enough to allow them to catch and rest in it. The hopper tilts backwards and forwazds, making the faces slide over the depression h' . The machinery for causing the tilting is a cam-wheel P, operating in opposition to a spring (not shown), against a roller p on the end of a connection, with an arm fastened to the hopper, and projecting below the point at which it is pivoted, so as to tilt. In Fig. 451, one of the metal faces is seen in section, resting in the depression. In the hopper is a vibrating brush or pad I, swung by the arm i, pivoted at 0, a pin passing through an elongated slot in The lower surface of the brush sweeps away any faces not lying in proper posi tion. On the side of the depression h' towards the revolving plate, there is a slot in the side of the hopper H, through which the faces pass. After each tilting motion, the hopper pauses in a level position, owing to the shape of the cam wheel P which operates it, and the vibrating brush I being then also immediately over the depression, and the metal faces being lightly held in their position, they are pressed out of it by a reciprocating bar K through the slot on the surface of the re volving plate, where they all lie with their turned edges downward. While the hopper is tilting, the slot in the side may be kept closed by a spring (not shown), which may also be axranged to open the slot when the hopper comes to a level position. The reciprocating bar K is shown actuated by a lever M pivoted at m, motion being given in one direction by the cam wheel P Laving projecting cams at proper points on its face, which bear upon a roller 0, in the end of a connection with the lever M. Motion in the opposite direction is given to the lever by a spring N.