GB263507A - Means for manufacturing metallic bellows - Google Patents

Abstract

263,507. Moore, H. R. G., and Rigby, T. P. July 25, 1925. Bellows. - In making cylindrical metallic bellows, particularly for measuring fluid pressures or for operating mechanism through the agency of fluid pressure, after forming and preliminarily corrugating the shell, the corrugations are deepened to final form by spinning in an apparatus having two eccentrically mounted and rela.- tively adjustable narrow internal rolls. The shell may be formed by cupping a blank and then drawing through a series of dies of diminishing bore or may be formed by spinning in a series of operations, annealing being effected after each operation. A disc of phosphor bronze &c. may be first spun into the form shown in Fig. 2 on a steel mandrel, being deepened in the next operation and then spun into cylindrical form. In the next operation, Fig. 5, a conical end is spun on a brass cone fitted into the mandrel and a hole then cut in the end to facilitate gripping during annealing operations and subsequent operation in the lathe. The shell is then completed to the desired length in three operations by an inclined roller 1, Fig. 9, having its corners ground in the form of a quarter ellipse so that the work hugs the mandrel closely. The mouth of the shell is trimmed off square and formed with a shallow stiffening flange. The shell is then corrugated in four operations. In the first operations corrugations of the form shown in Fig. 15 are spun in the shell which is placed on a collapsable mandrel consisting of box wood sections 2, Fig. 14, with equi-distant collars, mounted on a core, preferably tapered. Annealing is then again effected. For the subsequent operations which deepen the corrugations and contract the shell axiallv the shell is secured to a chuck 14, Fig. 15, on a lathe nose adapter 13 and is corrugated by a spinning roller engaged between internal rollers 3, 4 loosely mounted on a shaft 5 which is eccentrically mounted in a tube 6 secured to a tool post 12 having a hand rest 9. A pointer 10 on the tool post indicates the position of the roller 3. The shaft 8 is adjusted in the tube by a handle 7 so as to set the rollers to the required depth and to withdraw them for removal purposes and for moving them from one corrugation to the next. The roller 3 has a long boss on which the roller 4 is slid during operation by a non-rotatable barrel 8 of similar eccentricity to the shaft 5. The barrel is grooved to engage a collar on the roller 4 and slidably supports a hard wood ring 15 for supporting the open end of a long shell. Spinning tools and rollers of successively reduced thickness are used in the three final operations so that the rollers may be wide enough in the earlier operations to support the shell against the pressure of the tool and in the last operation narrow enough to strain harder the outer curves of the corrugations. The flanged end of the shell is spun over in the second operation to form a head and the final annealing effected after the first of these three operations.