RIVETING MACHINES. Elastic Rotary-blow Riveting Machine.—The use of the ma chine shown in Fig. 1—made by John Adt & Son, New Haven, Conn.—extends to almost every branch of manufacturing where articles are held together by rivets. Its most important feature is in the combina tion and working of the cylinder and hammer-rod. The hammer-rod, suspended by springs and confined air within the cylinder, partakes of its reciprocating motion, and produces a sharp, quick blow,which.with its rotating action, enables the machine to perform the work almost instantly. The blow is rendered elastic by the springs in connection with the air cushions, and its force can be regulated at the will of the operator by more or less pressure applied to the treadle at the right of the machine ; the yoke to which the treadle is attached is self-acting, and the moment the pressure is removed the blows cease, and the work can be withdrawn.
The hammer always strikes on the rivet, heading it equally, and as it is rotated while the blows are being struck, the bead eonforms to the shape of the peen of the hammer, and any style of head can be formed.
Riveting .Machine, Hydraulic.—The riveting machine shown in Fig. 2 was designed and built by William Sellers & Co., of Philadelphia. It lies a gap of LOS in. measured from the
center of the riveting dies to the base of the throat, and the distance. between the frames or stakes is 4 ft. 6 in. The rani is operated by hydraulic pressure, and is capable of exerting variable pressures of 25, 50, or 75 tons upon the rivet, at the will of the operator, from a fixed accumulator pressure of 9,000 lbs. per sq. in. These variations are obtained directly at the machine itself by a valve of special construction, and by the simple movement of a single lever conveniently located. The stakes are of cast-steel, and the requisite spread is obtained by means of the massive cast-iron box at the base, the whole being securely tied together by the large through bolts shown. The cylinder is also of east-steel, and has cast with it the bearing fur the riveting ram, which bearing is necessarily prolonged by the large overreach. The machine. instead of being placed in a pit, as is frequently the case, so as to make the floor line form the working platform, is set with the bottom of the throat level with the shop floor, and a platform (not shown) is attached to the main stake about 3 ft. below the center of the rain, so as to bring the operators at the most convenient distance to the