US1942952A - Construction of spools - Google Patents

Description

Jan. 9, 1934. T. G. BAXENDEN El AL CONSTRUCTION OF SPOOLS Filed Aug. 21, 1931 s w T N m W M y R Patented Jan. 9, 1934 UNITE ICE CONSTRUCTION OF SPOOLS Thomas George Baxendcn, Watford, and John Robert Collyear, Bushey, England 1 Claim.

This invention relates to the construction of spools which are formed wholly of metal and relates more particularly to metallic spools which are used for carrying the photographic film in 5 roll-film cameras or in cinematographic cameras or projectors and the invention has for its object to provide a construction or" spool which shall be cheap and easy for manufactin'e and yet be of considerable mechanical strength and rigidity.

In a known construction of photographic film spool in which the spool is constructed from a rolled-up sheet metal blank and end discs secured thereon, it has been proposed to secure the end discs in position by forming the tubular barrel with end portions of reduced diameter and forming the end discs with sleeves or collars adapted to fit over the ends of the barrel, the end discs being secured in position by forcing bushes into the hollow ends of the tubular barrel to exert an expanding or wedging action thereon.

In this known construction, however, the sleeves or collars on the end discs form an integral part of the latter, being formed up from the material of which the end disc is made, and, moreover, the end discs require to be secured in position by means of wedges or plugs which have to be forced into the open ends of the tubular barrel; both of these features present difiiculties in practical manufacture and the necessity for the provision of the wedges or plugs prohibits the use of this construction for spools having solid barrels.

According to the present invention a metallic spool, constructed from a cylindrical barrel portion and end discs secured thereon, has each of the end discs secured in position on the barrel by means of a thimble or ferrule welded to the inner face of the end disc, this thimble or ferrule being forced on to the swaged down end of the barrel, the arrangement being such that the ferrule, and end disc welded thereto, are securely held in position without any additional securing means. With this arrangement the construction is applicable either to spools having tubular barrels or to spools having a solid spindle or barrel.

In such construction when applied to photographic filrn spools the usual form or" key slot and key stop would be fitted as required.

The construction of the device according to the invention, as applied to photographic film spools, is illustrated by way of example in the accompanying drawing, wherein Fig. 1 is a sectional view of one end of a spool showing the parts before being fitted together; Figs. 2 and 3 are a sectional view and plan, respectively, of one end of a completed spool.

Like characters of reference indicate corresponding parts in the different views.

Referring to the drawing; the spool comprises a tubular barrel or body 1 and end discs 2, only one end of the barrel and one end disc being shown. The end disc 2 has welded to its inner face 3 a cylindrical thimble or ferrule 4, the closed end 5 of the thimble 4 abutting against, and being welded to the inner face of the end disc as shown in Fig. 2. The end disc shown is that provided with the usual key slot 6, by which the spool is rotated and the sides '7 of this key slot are turned inwardly and register with the turned in edges 8 of a similarly shaped slot in the thimble i in order to ensure that the two slots are correctly aligned when the disc and thimble are secured together.

The thimble l with the end disc welded thereto is then forced on to the end of the barrel 1, the end 9 of which is swaged down to receive the thimble or ferrule 4 so that the completed spool has a body of uniform diameter throughout its length as shown in Fig. 2 which shows one end of a completed spool. The external diameter of the swaged end 9 of the barrel and the internal diameter of the ferrule 4 are so proportioned that when the ferrule is forced on to the end of the barrel it is retained firmly in position without any other additional securing means. The end disc at the other end of the barrel to that shown is similarly secured in position, and this end disc is provided with a plain circular hole to form a bearing for the spindle as is usual in the construction of spools for photographic film cameras. Although in Figs. 1 and 2 the barrel is shown as of tubular form, it could obviously be made solid if desired.

What we claim as our invention and desire to secure by Letters Patent is:-

A spool constructed wholly of metal and comprising a cylindrical barrel reduced in diameter or swaged down for a portion of its length at each end, end discs for said barrel, a thimble or ferrule welded to each disc, a, key slot in one of said end discs, the edges of said key slot being turned inwardly, a corresponding but larger, key slot in the ferrule welded to this disc, the key slot in said ferrule having turned-in edges cooperating with the turned-in edges of the key slot in said disc, whereby said slots are aligned, said thimble or ferrule being forced over the end of said swaged down portion of said barrel to secure the end disc firmly in position.

THOMAS GEORGE BAXENDEN. JOHN ROBERT COLLYEAR.

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