The invention relates to a method of producing a three-dimensional knit, i.e. a knit whose surface area is shaped spatially, as is the case of e.g. balaclava helmets or sock heels, shaping being achieved by accepted practice in loops being widened and/or narrowed in specific portions of the knit.
It is in the marginal portion of such widening or narrowing that inhomogeneities materialize due especially to the normal, i.e. not knitted three-dimensionally, knit being tensioned or deformed in the marginal portion of the three-dimensionally knitted area. Accordingly, these marginal portions represent a weakened zone having the tendency to open up when exposed to mechanical stress.
It is thus the object of the present invention to provide a three-dimensional knit which is relatively insensitive all over to mechanical stresses.
The invention relates more particularly to the production of industrial textiles.
In accordance with the invention widening or narrowing the loops is no longer done in a single defined portion, but at many locations preferably distributed homogeneously in the shaping area. In this way shaping is integrated homogeneously in the knit, i.e. excessively stressed margins no longer occur in the marginal portion of a closely defined shaping area which tend to break prematurely.
The art in accordance with the invention permits production of all possible shapes such as e.g. spherical or dished shapes without e.g. as in the conventional fashioning technique a line existing within which all loops are reduced, resulting in the knit being subjected to particular stresses in the region of this line. Due to the invention, widening or narrowing or inactivating needles is distributed over the complete portion to be shaped so that the deformation of the knit no longer occurs along a line, it instead being homogeneously distributed over the complete knit. Furthermore, the deformation at each and every widening or narrowing location or needle inactivating/activating is no longer so pronounced since due to the plurality of locations widening/narrowing/inactivation becomes less at each location, i.e. the deformation of the knit at any widening/narrowing/inactivation location is less than in prior art in which all widening/narrowing/inactivation needed for shaping was done at only a single or a few locations.
These locations as cited above are now homogeneously distributed by the invention over the portion to be shaped, this distribution being intended to be as even, i.e. homogeneous as possible. The distribution may be achieved regularly, i.e. controlled so that all widening/narrowing/inactivation locations are spaced away from each other more or less evenly. However, these locations may also be distributed statistically over the portion to be shaped, thus avoiding the creation of all and any texture possibly consistituing a design break point.
The degree of deformation is preferably controlled via the density, i.e. the mutual spacing of the locations where widening/narrowing/inactivation occurs. Should heavy deformation be desired, then these locations are arranged in a higher density than in portions in which less deformation is wanted. In this way homogeneous textile pieces may be produced comprising portions less and more deformed as desired, thus enabling homogeneous knits to be produced in any desired shape.
A basic distinction is made between two ways of producing three-dimensional textile structures. For one, a three-dimensional shape is achieved by widening and/or narrowing the loops in several portions of the knit, whereby the number of widened/narrowed or split/unified loops per location should not be excessive, e.g. not amount to more than ten loops. Widening several loops within the knit at several locations produces a bulge in the knit at the widening locations. Narrowing the loops in the knit at a plurality of locations causes the knit to pucker in this portion, again producing a bulged portion. Widening and narrowing may be combined as desired to achieve the desired shapes.
Another way of producing three-dimensional knits consists of rendering needles inactive in specific portions of the knit whilst knitting is continued with the needles in other portions. By later activating these inactivated needles, e.g. after one or more courses a puckering of the knit in this inactivated portion is achieved which in turn may be made use of to achieve specific shapes. When, for instance, in knitting the needles are made inactive in the marginal portions of the flat knitting machine, and this inactivation repeated on a spacing of a few courses differing in width, a spherical configuration is achieved having a highly homogeneous structure. In this case too, inactivating the needles should be done only over a few courses to avoid excessively deforming the knit at any one location. Furthermore, the width (needle number) of inactivating may be alternatingly varied so that also by these means a distribution of the deformed locations may be achieved in the shaping portion, these locations being positioned at points at which an inactivated portion adjoins a fully knitted portion.
Both of the principles as cited above for producing geometric knits may be put to use with the method in accordance with the invention in that widening/narrowing the loops, on the one hand, or inactivating needles, on the other, is distributed to many locations in the shaping portion. In any case, a more homogeneous structure of the three-dimensional knit is achieved, on the one hand, which in turn has enhanced mechanical properties.
A distributed widening/narrowing of the loops within the knit may be achieved to advantage by using twin needles. For example, an alternating knit may be done with the A and B needles of the twin needles, resulting in a loop count corresponding to twice the number of active twin needles or conventional needles. When a reduction in the loop count is desired, knitting is continued only with one of the A or B needles of the twin needle. This results in the loop count being reduced to half for the same width of the active portion of the needle bed. This reduction may also be achieved in other steps when the reduction to one of the two needles of the twin needle is not implemented for every twin needle but e.g. only to ever second such needle. Likewise, an increase in the loop count may be achieved by changing from knitting with one of the two needles of the twin needle to knitting with both needles, the two needles of the twin needle then being activated successively.
The invention will now be described by way of an example as illustrated schematically in the drawing in which:
Referring now to
In the construction as shown in
Whilst
To get round this disadvantage the widening in accordance with the invention is not done in a portion 30, as shown in
It will readily be appreciated from comparing the prior art knit method to the new knit method that shaping the knit is substantially more homogeneous than in prior art and that such a knit is very much more resistant to mechanical stresses and premature material fatigue. In addition to this, the geometry of the three-dimensionally shaped portion may be better controlled by the invention, i.e. via the spacing of the locations 50, 52, 54, 56, 58 and via the widening/narrowing length at each single location 50, 52, 54, 56, 58. In the present example, the longest widening is undertaken in the middle portion, i.e. the portion most bulged, whereas in the adjoining locations 52, 56 the widening is not so long and in the marginal locations 50, 58 the widening is only relatively short, here, for instance, the widening/splitting extending over one to ten courses.
The present invention is thus suitable for producing all possible geometric shapes such as spheres, cones and all kinds of regularly and irregularly shaped bulges. Both widening/narrowing the loops and partially inactivating the needles in a course may be done in an unequal spacing and to a differing extent. It may furthermore be done controlled or statistically to achieve as high a homogenity as possible. Care is to be taken, however, in the distribution of these locations and in the distribution of the extent of widening/narrowing/inactivation so that, in all, a more or less consistent shaping of the knit is achieved over the full area.
The two basic techniques of widening/narrowing, on the one hand, and fashioning, on the other, may, of course be optionally combined with each other.
Number | Date | Country | Kind |
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196 16 005 | Apr 1996 | DE | national |
This application is a division of application Ser. No. 09/171,370, filed Oct. 16, 1998, now U.S. Pat. No. 6,122,937 which is a 371 of PCT/DE97/00792 filed Apr. 18, 1997.
Number | Name | Date | Kind |
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6116057 | Roell | Sep 2000 | A |
6122937 | Roell | Sep 2000 | A |
6233976 | Roell | May 2001 | B1 |
6308536 | Roell | Oct 2001 | B1 |
Number | Date | Country | |
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Parent | 09171370 | US | |
Child | 09619842 | US |