US546879A

US546879A - Ley williamson

Info

Publication number: US546879A
Authority: US
Publication date: 1895-09-24
Anticipated expiration: 1912-09-24

Description

J. DYSON & R. H. WILLIAMSON.

Patented Sept. 24, 1895.

(No Model.) 3 Sheets-Sheet 2.

J. DYSON & R. H. WILLIAMSON. MOLD FOR CASTING SCREWS. N0. 54 ,379. Patented Sept. 24, 1895.

ilsir'rao STATES LYNE, ENGLAND.

MOLD FOR CASTING SCREWS.

SPECIFICATION forming part of Letters Patent No. 546,879, dated September 24, 1895.

Application filed January 10, 1894:. Serial No. 496,421. (No model.)

To aZZ whom it may concern:

Be it known that we, JAMES DYSON, a resident of Good Hope Mill, and RICHARD HAR- LEY WILLIAMSON, a resident of 21 Victoria Street, Ashton-under-Lyne, county of Lancaster, England, subjects of the Queen of Great Britain and Ireland, have invented a Mold for Casting Screws, of which the following is a specification.

This invention relates to an improved mold or chill for casting the ribbon-shaped vanes or blades of Archimedean screws.

In the accompanying drawings, Figure 1 is a side elevation of the complete screw, the blades of which are formed by this invention. Fig. 2 is a sectional view of Fig. 1, showing an end of the screw. Fig. 3 is a front elevation of the mold. Fig. 4 is a plan with the top part removed. Fig. 5 is a perspective view of the lower section of the mold, and Figs. 6 and 7 are perspective views of the screw-sections produced by the mold.

The blade of the screw is built up of sections, which engage with each other at the ends, and also engage with one or more flats on the central shaft by means of straight edges formed on the inner edges of the sections forming the blade, as set forth in our United States Patent No. 525,194, dated August 29, 1894. For casting the said sections we employ an iron mold or chill. (Shown in Figs. 3, 4, and 5.) The mold is in two parts a and b, the adjacent contact surfaces of which are formed as a screw. Each of the parts a and b is so hollowed out in its interior that when the mold is closed by screwing the top part a, down on the lower part b the internal cavity corresponds to one of the sections of the blade of the screw. Of the said cavity, one half is formed by the upper part a and the other half by the lower part b, as indicated bydotted lines at d in Fig. 3. The central part c is left solid, so as to form a core corresponding to the central shaft.

The longitudinal surfaces 70 joining the two halves of the mold are undercut, and it is therefore necessary to give a twisting or screwing motion to the top section when putting the mold together. This undercutting insures perfect registering of the molds and to a certain extent prevents the upper section rising when the metal is poured in. The two halves of the mold are then secured by turning down the handles e, so as to engage with the tongues f.

To cast a section of the blade the mold is closed and laid on its side and the metal is poured through the casting-hole g, which is placed about the center of the length of the section to be cast, so that the metal may run toward both ends of the mold at the same time. After casting, the mold is opened by disengaging the handles 6 and screwing off the top part a, when the cast section may be removed from the lower part of the mold.

We claim as our invention- A two-part mold or chill, consisting of two parts a and I), having helical contact surfaces, undercut jointing surfaces and a central projection c for casting an entire convolution of Archimedean screw blade, substantially as set forth.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

JAMES DYSON. RICHARD HARLEY WILLIAMSON.

Witnesses:

JOSEPH BENTON, JOHN HALL.