Patent GB-190622636-A (GB)
Title: Improvements in Turbines.
Filed: 1906-10-12
Granted: 1907-10-03
Abstract: 22,636. Belliss & Morcom, Morcom, R. K., and Jude, A. Oct. 12. Elastic-fluid turbines.-Relates to the fixing of turbine blades, and consists in developments of the principle set out in Specifications Nos. 20,394 and 23,400, A.D. 1905, in which the blade roots or filling-pieces, or both, are expanded into undercut grooves. The blade roots a<1>, Fig. 2, are made with holes a<2> through which a wide stringer c<0> may be threaded. The groove into which the shanks are forced is made with side notches b<1>. On force being applied to the blade, the shank is crushed so that the stringer is tightly gripped and the root is expanded so as to fill the notches b<1>. In a modification, the end of the shank is bent round, as shown in Fig. 4, and filling-pieces d, d<0>, made similar to the shank shown in Fig. 2, are expanded in the groove. In another modification, the centre part of each blade root is bent to form a foot, two outer fangs being left which are expanded into undercut grooves. Filling-pieces with expanding fangs are used between the blades. In another modification, shown in Fig. 13, the shanks or roots are made with holes through which passes a stringer c. Fanged blocks d<1> are driven in between the blades and are expanded by the stringer, which is itself distorted by the downward thrust of the block d<1>. In another modification, the blades are formed with feet upon which rests the stringer, the distortion of the latter thereby being prevented. In another modification the blades are formed with feet a<3>, Fig. 21, and are held in position by centre blocks e, notched similarly to the groove, on each side of which is an expanded perforated block d. Fanged blocks, expanded by wires at the bottom of the groove, may be used instead of the blocks d, Fig. 21, or only one expanding block may be used, the other side of the block e being held by a wire half imbedded in the block and half imbedded in the side of the groove. In another modification, an angle piece h<0>, Fig. 26, is expanded between the foot of the blade and a filling-piece i. A piece of tube may be substituted for the anglepiece, or both may be dispensed with, the foot of the blade being bent and expanded into the undercut grooves. In the modification shown in Fig. 39, the sides of the vanes are notched to accommodate stringers j which are pressed into side grooves b<3> by an expanding filling-piece k<0> of H-section. In another modification, a notched stringer is passed through holes in the blade roots and rests in the bottom of the groove. Fanged filling-pieces are expanded by the stringer which is itself distorted. In another modification, a number of fanged filling-pieces are combined in one strip and are notched to accommodate fangs forming a kind of double-blade root. The strip and blade fangs are together expanded into undercut grooves. In the modification shown in Fig. 52, the blades are formed with feet a<3> and are fitted in holes formed in a channelled strip p the edges of which are expanded into undercut grooves b<4>. Instead of having feet, the blades may be perforated, perforated filling-blocks of rectangular section occupying part of the channelled strip, a wire stringer holding the blades, blocks, and strip together. The strip is secured to the rotor as shown in Fig. 52. In other modifications, each shank has two perforations side by side, through each of which passes a wire stringer. The stringers between the blades are expanded into undercut grooves by a wedge-shaped tool and expanding filling-blocks are inserted. In another modification, the blade may have a cylindrical shank, the bottom of which has a conical indentation and is slit diametrically, the shank being expanded by a ball or other piece of metal in the bottom of the slot. In a further modification, fanged blades are expanded into fanged spacing-blocks which are then themselves expanded into undercut grooves in the rotor. Blades may be expanded into longitudinal instead of circumferential grooves in the drum, or they may be fitted into helical grooves. In a modification, both longitudinal and circumferential grooves are used, the blades being placed at the places where they cross and held by stringers. Expanding filling-blocks are then crushed into the vacant spaces.