Abstract:
A needle for use in creating fabric from yam having an elongate, substantially parallel-sided shaft and a tip, the tip having a transition part whose diameter and cross-section substantially matches shaft&#39;s diameter and cross section, and a tapered part which tapers from the diameter of the transition part to a point, the Up and shaft being releasably engageable with each other.

Description:
BACKGROUND TO THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to the creation of fabric from yarn or thread using needles to pull loops of yam or thread through each other. Examples include knitting and crochet. 
         [0003]    Both knitting and crochet are performed, at least when undertaken manually, using a pair of needles around which the yarn (colloquially referred to in the UK as ‘wool’ within this context, regardless of the actual composition of the yam or thread) is looped. The ends or tips of the needles are then manipulated in order to interloop the yarn in the correct manner to create a body of fabric. Because the yarn is looped around the needles, needle diameter will determine the size of the loops which, in turn, since the resultant fabric is made of many such loops, determines the ‘gauge’ of the overall fabric. It follows that, in order to alter the gauge of the fabric, one must use a different needle diameter which is, therefore, the single most important characteristic of a needle and needles are carefully selected for use on the basis of their diameter. 
         [0004]    2. Description of Related Art 
         [0005]    One type of existing knitting needle is monolithic, in that it consists of a single rod of material. Other designs of needle are known from U.S. Pat. No. 2,633,720, U.S. Pat. No. 3,280,595 and U.S. Pat. No. 4,007,610. 
       SUMMARY OF THE INVENTION 
       [0006]    A first embodiment of the present invention provides a needle for use in creating fabric from a yarn by interloping the yam having a longitudinal shaft and a tapered tip, the tip being releasably connected to the shaft. 
         [0007]    A further aspect of the present invention provides a needle kit having at least one shaft and a plurality of tapered tips, releasably connectable to the shaft, at least two of the tips differing in respect of at least one of a plurality of characteristics selected from the group consisting of tip taper angle, tip taper length and point radius. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0008]    Embodiments of the present invention will now be described, by way of example, and with reference to the accompanying drawings in which: 
           [0009]      FIG. 1  is a plan view of a needle according to an embodiment of the present invention: 
           [0010]      FIGS. 2 to 4  show details of  FIG. 1 ; 
           [0011]      FIG. 5  is a plan view of a further embodiment of the present invention including a kit of a plurality of needle tips and shaft; and 
           [0012]      FIGS. 6A-C  are plan views of further embodiments of needles according to the present invention. 
       
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0013]    Referring now to  FIG. 1 , a knitting needle comprises a longitudinal shaft  10 , which in the present embodiment is a substantially constant width along its length and, in the present example, has a substantially cylindrical cross-section of diameter D. The needle has a tapered tip  20  at one end and, at the other, a wider stop-element  30 , in this embodiment provided by a flange  30  (the circular surface of which will typically be imprinted with characters identifying the needle diameter). In use, the stop element  30  prevents loops of yarn or the shaft  10  from falling off the beck of the needle. 
         [0014]    The present embodiment of tip  20  includes a transition part,  22  having the same diameter and cross section as the shaft  10 , and a frusto-conical taper  24  from the transition part  20 A which terminates in a substantially spheroidal point  26 , in the present embodiment provided by grinding the tip to a very small hemisphere. Thus, the term point in this context is really referring to a curved end of relatively small diameter. The taper  24  of the tip  20  is, in the present illustrated embodiment, frusto-conical in geometry. It is equally possible, however, for the taper to be of a curved or arcuate nature such that, for example, the taper is defined by a circular arc of a particular radius, a parabolic curve or other curvilinear geometries. 
         [0015]    The tip  20  is releasably connected to the shaft  10 , in this embodiment by means of a screw threaded spigot  40  on the tip engaging with a screw-threaded bore  42  on the shaft  10  (though the spigot  40  and bore  42  may be swapped onto the shaft  10  and tip  20  respectively). Other releasable connections are equally possible, such as by means of a spring-loaded detent mechanism (for example provided by a compression spring and ball bearing) of the kind frequently employed with interchangeable socket spanners. This configuration enables interchange of needle tips while retaining the same diameter needle. This is useful in order to enable the user to optimise the configuration of the needle tip to suit as closely as possible the nature of the knitting they are undertaking. 
         [0016]    The diameter of the needle determines the size of the loops of yarn that are created using the needle and, consequently, the density of stitches in the resultant material which is created, known as the ‘gauge’. The choice of needle diameter will, therefore, be selected based upon the characteristics of the fabric to be created. Referring now to  FIGS. 2 to 4 , further important characteristics of a needle are the taper angle α of the tip, the length y of the taper and the radius r of the needle point, each of which is illustrated in  FIGS. 2 to 4  respectively. These three parameters are, to a degree interdependent to the extent that a given combination of values of any two determines the value of the third. Thus, for a given radius r and taper length y, there can only be a single value for the taper angle α. The same applies to any combination of taper angle α and radius r, or taper length y and taper angle α. 
         [0017]    When knitting with a lighter yarn, that is to say a yam with a smaller diameter, the yam has, as result of its smaller diameter, a lower longitudinal elasticity which is experienced by the knitter as the yam having less ‘give’. Accordingly, when knitting with lighter weight yarn, for any given needle diameter, it is easier to use needles with a shallower taper angle since these will require lower forces to insert the needle into an aperture between needle and yarn. Thus, where fabric is to be constructed of multiple, different yarn weights, but using needles of the same diameter (because the gauge of the resultant fabric is to remain the same regardless of yam weight), the present embodiment of the invention makes it possible simply to change the tip of the needle to use a shallower or steeper taper angle dependent upon the yarn weight. 
         [0018]    To ensure easier and speedier knitting, it is desirable to have as short a taper length as possible for any particular, specified taper angle. It follows that, for a given taper angle, the shorter the taper length, the greater will be the size of the needle point, i.e. the greater the radius of the circle at the tip of the needle; the needle point must be sufficiently small that it can easily be inserted into apertures to knit quickly, smoothly and accurately. This means that, for a specified taper angle, the minimum taper length with be determined by the size of the aperture through which the needle point is to be inserted which, in turn, is a function of the gauge of the fabric created and, ultimately therefore, the diameter of the needle. 
         [0019]    The table set out below sets out various characteristics of the needle tip, showing combinations and reference to yarn weights and gauge size Consistent with the Craft Yarn Council yarn guide. 

 
         [0020]    Referring to  FIG. 5 , in accordance with a further embodiment, there is provided a kit which includes at least one shaft  100  to which a plurality of tips  200  (illustrated to a larger scale to demonstrate their different configurations and geometries) are connectable. Thus, tip  202  is similar to that of the tip connected to the shaft  100 , having a frusto-conical taper  222  but of longer length. Tip  204  has a taper  244  having an arcuate geometry. Tip  206  has a similar geometrylo that of tip  204  but a longer taper  264 . Typically, a kit will include a plurality of tips, at least two or more of which have a differing taper angles, and/or taper lengths and/or point radii to enable different knitting operations with different weights of yam and gauges of fabric to take place. In the present example, the tips are interchangeably connected to the shaft by means of a screw thread; but alternative methods of connection may equally be employed, including but not limited to biased detent mechanisms providing translational ‘snap’ fitting, fittings providing a combination of translation and rotational relative motion to ensure engagement for example by means of a cam (such as those used in BNC-type video/audio connectors), magnetic connection whether linear or rotational disconnectable either by the application of greater force manually, by some other suitable manner of releasable connection. 
         [0021]    In an alternative embodiment, the or each needle (i.e. whether individual or as part of a kit) is ‘circular’. That is to say that two substantially rigid shafts are interconnected by a flexible shaft and a tip is provided at each end (a releasably-engageable tip may be provided at both ends of the circular needle or, alternatively, at only one end, as desired). Such circular needles are known per se. 
         [0022]    FIGS.  6 A- c  show further embodiments of needles according to the present invention.  FIG. 6A  shows various relative dimensions of needles for a mid-range point size on the needle tip.  FIG. 6B  shows various dimensions of needles for a sharp, or stiletto point size on the needle tip.  FIG. 6C  shows various relative dimensions of for a ‘blunt’ (i.e. relatively rounded and therefore large) point size on the needle tip. 
         [0023]    The various modifications disclosed are not limited to use with the embodiments in connection with which they were first described; all modifications or alternatives may be equally applicable in conjunction with each of the disclosed embodiments.