US1969281A - Contractible spool - Google Patents

Description

Aug. 7, 1934. $TE|N 1,969,281

CONTRAGTIBLE sPooL Filed Dec. 27, 1933" Patented Aug. 7, 1934 UNITED STATES CONTBACTIBLE SPOOL Alfred Ernst Stein, Saflle, Sweden Application December 27, 1933, Serial No. 704,205 In Germany September 21, 1932 2 Claims. (Cl. 242--110) This invention relates to contractible spools, that is, to spools which are capable of yielding to a radially directed pressure to allow for shrinkage of the thread wound.thereon as occurs in the after treatment, more particularly the drying, of

artificial silk.

Contractible spools are already known whose casings are provided with radially movable members, which are pressed inwards by the shrinkage of the winding. These spools however, are costly to manufacture and allow only a comparatively small decrease of the circumference.

Contractible spools are also known in which the casing consists of a slotted, springy sheet which rolls up during the shrinking of the thread wound thereon. Athough these spools are in themselves simple and cheap their manipulation is made diflicult in that special means, such as bands or the'like, must be usedto hold the spool in position when it is empty and prevent it being flung away from the quickly rotating spool holder. Moreover, a uniform tension cannot be obtained with these spools, particularly when used for winding strongly shrinking artificial silk, as considerable force is required to overcome the springiness and friction of the spool casing when it is rolled up or contracted.

Further, contractible spools are known in which the casing comprises four quadrants whose edges overlap so that they can slide upon one another to reduce the circumference as necessary. These spools, however, are difiicult to put on the spool holder and in addition, are unsatisfactory in that when removed the quadrants collapse and so no longer hold the winding under tension.

According to the present invention the spool casing consists of an endless wire which is formed into a series of loops lying parallel to the spool axis.

One embodiment of the invention is illustrated diagrammatically in the accompanying drawing in which:

Figure 1 is a view of the complete spool and Figures 2 and 3 are developed views of the spool casing when not under tension and when under tension respectively.

As will be seen from Figures 2 and 3 a contraction of the circumference of the spool of above 50% is possible.

With this construction very little effort is required to contract the spool as the pressure applied by the winding during shrinking occurs on the arms of the loops a forming the spool casing so that a leverage is obtained when the loops are drawn together. There is also verylittle friction to be overcome as the decrease in the circumference is distributed over the entire circumference of the spool. .The compensation of tension attained is as complete as possible, if the winding is to be kept under tension throughout the whole of the shrinking processes.

In order to avoid injury to the innermost layer of thread the spool a may be enclosed within an elastic sleeve b, and this sleeve may be provided with perforations c or otherwise made pervious to fluids at the part to be covered by the thread, the ends of the sleeve which are left uncovered being made impervious to fluids.

The ends of the loops 0. can either lie in the extension of the spool casing or they may be partly flanged on the outside so as to form flange-like projections as rigid spools are usually provided with.

The diameter of these contractible spools is determined by the diameter of the spool holders with which they are to. be used. These spool holders can be more easily made and manipulated than those for the rigid spools at present used as no springs, r'ubber blocks or other means are required for holding the spool fast to the spool holder.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is' to be performed, I declare that what I claim is:- 35

1. A contractible spool having a casing consisting of an endless wire which is formed into a series of loops lying parallel to the spool axis.

2. A contractible spool having a casing consisting of an endless wire which is formed into a series of loops lying parallel to the spool axis, and an elastic sleeve enclosing the casing and pervious to fluids at the part to. be covered by the thread, the ends of the sleeve which are left uncovered being impervious to fluids.

' ALFRED ERNST STEIN.

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