PIPE-CUTTING AND THREADING MACHINES. Forbes' Die Stock.—Figs. ] and 2 illustrate the front and back views of the Nos. 1 and 11 Forbes' die stocks, made by Curtis & Curtis, of Bridgeport, Conn. One set of (lies is supplied with the machines for each of the standard threads cut, so that only six sets of dies are necessary for thread tiug the sixteen different sizes of pipe in cluded in the range of the No. 1 machine, and three sets for the nine sizes of the No. .1?,, machine. The dies are set by turning the face-plate to the proper graduation, and any variation in the fittings may be allowed for, and the pipe cut either over or under standard size, by making the proper allowance at the graduation. When the dies are set to the proper size, the pipe is inserted through the self-centring vise at the back, with the end to be threaded against the hack of the dies, and is clamped and brou4ht central with the dies by turning the hand wheel shown on top of the machine. The crank is then put on to the square end of the pinion, shown in front of the ma chine, and through it the power is transmitted to the die-carrying gear; as the die is thus revolved a very slight pressure on the lever. shown on top of the machine, causes the gear to recede into the shell and the dies are fed on to the pipe. When the thread is cut to the required length. the machine is run back wards for about one turn, so as to take off any burr that the dies may leave; the dies arc then drawn back and the pipe is removed from the machine. The depth of the shell allows a thread to be cut about twice the standard length, and if a still longer thread is desired, it eau be cut to any length by loosening the vise and pulling the gear, with the pipe still in the dies, forward, so as to give it anew start as many times as is required. Fig. :; shows a heavy power pipe-cutting and threading machine on the same principle. The vise for holding the pipe is self-centring, and the dies are opening and adjustable to any vari ations of the fittings.
Pipe-threading Attachment for 4 shows an attachment. which can be at tached to any lathe, within certain limit of size, and with which a lathe can be turned into a power pipe-threading machine in a few min utes, and pipe of any length threaded very rapidly and correctly. This attachment con sists of a (lie-carrying head, attached to the spindle like a chuck; an adjustable, self-cen tring vise attached tothe carriage, and an adjust able pipe rest, attached to the bed of the lathe, to support long lengths of pipe, as shown by the heavy engraving in the accompanying i I 1 ust ra tion. The pipe is held
securely by the vise on he carriage and fed to the revolving dies by moving the carriage. This can be done automatically by setting the lead screws of the lathe to cut the number of threads corresponding to standard of pipe to be cut. When the thread is cut to the length required the dies can be opened by turning the face plate, and the pipe taken out without running back. All the dies are made adjustable to any variation of the fittings, and they adjust from one size of pipe to another, so that each set of dies threads sev eral sizes of pipe without changing.
Saunders' Pipe-cutting and Threading Hachine.—Fig. 5 shows a pipe-cutting and threading machine made by D. Saunders' Sons, Yonkers, N. Y. It may be run either by hand or by belt. It is arranged so that pipe can be threaded and afterwards cut off, without removing any part of the machine. It is capable of cutting off and threading pipe up to 4 in. diameter, admitting the use of either solid or adjustable expanding dies. The cutting off arrangement is fastened to the face of the large driving gear. between the gear and the die, in such a manner that either may be used without one interfering with the other. On the face of the large gear are ways for slides which hold V-shaped jaws of steel which are closed on the pipe by a right and left screw, which adjusts the pipe to the centre of die; also stead ies it when being cut off. The cutting-off arrange ment is provided with a ratchet and pawl, and a short lever which pro jects through an opening in the gear, and twice in each revolution comes in contact with a trip, which causes it to feed the cutting-off tool, thus securing an automatic feed. There is provided a universal gripping chuck on back end of the machine for holding pipe, to which is at tached a threaded sleeve which engages with a ring having threaded sections in it, these sections being movable by a lever, so as to be engaged with the threaded sleeve or not, as desired. Thus large pipes are forced into the dies at the proper rate.