Knitting needle with reinforced hook

A machine knitting needle with an improved hook structure is disclosed. The hook includes a shank portion extending from the tapered part of the needle blade, a curved portion, and a portion overlapping the shank. At least a major longitudinal part of the overlapping portion has cross-sectional areas greater than the cross-sectional areas of the remainder of the hook.

This invention relates to machine knitting needles. More particularly this 
invention is an improved machine knitting needle hook. 
This new needle may be used in several ways, but the most common is for the 
making of pile and high pile fabrics. Such fabrics are used for clothing, 
clothing liners, footwear, upholstery, wall covering, paint rollers, 
carpeting, imitation fur, and a rapidly expanding further market. 
The production of all of these products have one feature in common. The 
knitting needles which make the basic knitted fabric are required to 
thrust into the face of a rotating wire brush, variously called a card 
wire wheel or doffer wire wheel, so that their hooks may receive the 
silver or fiber which is carried to them by the card wires and which will 
become the pile part of the fabric. The needles, after having the sliver 
transferred into the hook area, have a yarn introduced to the same hook 
area, and they knit the yarn to form a fabric. This knitted yarn then acts 
to hold, or lock in, the looser silver fibers. The knitted yarn is 
referred to as a backing yarn and often because of the amount of sliver 
surrounding it, it is not visible from the front side of the fabric. 
Many mills run the machines fast, hard, and long, demanding the utmost in 
performance of the needles and doffer wheels. Both the needles and the 
card wires rapidly wear out, but usually at different rates. As a result 
of the contact with the card wires, the hook section of the needle is 
quickly worn away, so quickly that needle life is measured in days. 
Sometimes the life is under ten days, usually under twenty. Almost always 
the life is under thirty days. Generally speaking, the life of a wheels 
but less than the life of two sets. The doffer or card wires wear out as a 
result of their contact with the needle hooks. When the card wiresor 
complete doffer wheels are to be changed, and it is determined that the 
partially worn needles will not last through the lifetime of a new set of 
doffer wheels, it is customary to change both the needles and the doffer 
wheels at the same time. Even though a set of needles is very expensive, 
it is still not as costly to the mill as is machine down-time. The 
operation of changing needles and doffer wheels is of considerable 
difficulty and requires partial disassembly of the machine, resulting in 
considerable financial loss due to maintenance labor cost and to the loss 
of production output on this high speed machine. Thus, a needle maker must 
make a needle which has a life which is at least as long as the life of 
one set of card wires, or else the wear-out and replacement condition will 
be reversed: The needles will wear out first, and the card wires will 
still have useful life when the doffer wheels must be replaced along with 
the needles because they will not last for the life cycle of the new 
needles. 
Most currently made needles of this type have a life equal to more than one 
but less than two times the life of a set of card wires or doffer wheels. 
However, a needle life of more than one but less than two times the life 
of a set of doffer wheels has no advantage over a needle life the same as 
the life of one set of doffer wheels. Therefore, a latch knitting needle 
which will last two or more lifetimes of the doffer wheels provides a huge 
advantage in reduced replacement cost of needles and/or downtime of the 
machine. Needle costs are cut in half or better, and, as mentioned above, 
needles are expensive, as is machine downtime for replacement. 
This new machine knitting needle with its improved hook will increase the 
needle life to a factor of two or more times the doffer wheel life. 
Briefly described, the new machine knitting needle has a tapered portion 
leading from the needle blade to the hook, and a new hook having a shank 
portion intergral with the tapered portion of the needle, a curved 
portion, and a portion overlapping the shank portion as it extends back 
toward the needle butt. At least a major longitudinal part of the 
overlapping portion has cross-sectional areas greater than the 
cross-sectional areas of the remainder of the hook, and especially of the 
shank portion.

To understand the new development, it is necessary to examine the nature of 
the hook of a conventional machine knitting needle. One common version is 
called a pressed hook, shown on the pivoting-latch needle in FIG. 1 . The 
needle is pressed or flattened in the hook areas. It includes a pair of 
cheeks 12 and 14 (See FIG. 3) forming a slot 16 in the needle blade. The 
slot 16 is adapted to receive a pivotable latch 17 (partially shown in 
FIG. 1) which pivots about latch pivot 19 to alternately open the needle 
hook as shown in FIG. 1 and to close the hook by pivoting over so that the 
free end of the latch lies against the overlapping portion 26 of the hook. 
The needle has a tapered portion 18 which interconnects the hook 20 and the 
blade. The hook has a shank portion 22 extending in the same general 
direction as the longitudinal axis of the needle, a curved portion 24, and 
an overlapping (not shown) portion 26 which extends back in the direction 
of the needle butt which overlaps the shank portion 22. For purposes of 
this description and the appended claims, the term "hook" is intended to 
mean the shank portion 22 which is overlapped by the overlapping portion 
26, the curved portion 24, and the overlapping portion 26. 
The cross-sectional areas of the entire hook may be equal, or the 
cross-sectional areas of the curved portion 24 may be slightly greater 
than the cross-sectional areas of the overlapping portion 26, and the 
cross-sectional areas of the shank portion 22 may be further slightly 
greater. The width of the overlapping portion 26 may be the same as the 
widths of the curved portion 24 and of the shank portion 22, or the width 
may increase from the overlapping portion 26 through curved portion 24 and 
shank portion 22. 
In other types of prior art machine knitting needles the cross-section of 
the shank, curved portion, and overlapping portion of the hook are round 
and in general of the same cross-sectional areas. Other needles are round 
in those cross-sections but the cross-sectional areas increase as you 
progress from the free end of the hook back around the curved portion into 
the shank portion and on into the needle blade. 
It is the nature of all known latch needles that the cross-sectional areas 
of the overlapping portions of the hook are equal to or smaller than the 
cross-sectional areas at the shank portion of the hook. 
Our new needle is constructed to resist the severe wear caused by the card 
wires of the doffer wheels brushing against the needles in the manufacture 
of pile fabrics. The problem is solved by putting an extraordinary amount 
of metal in the overlapping area of the hook where the card wires or 
doffer wires generally cause most of the wear which results in the failure 
of these needles, thus incresing that hook wear life without making the 
rest of the needle unduly heavy or bulky. The sections of the hook which 
are beat against by the card wires may be harder then the rest of the 
needle only on particular areas of the surface or on the total surface 
area of those sections. 
Referring to FIG. 4, the pivoting-latch version of our new machine knitting 
needle includes the usual pair of cheeks 12 and 14 (See FIG. 8) which form 
the slot 16 for receiving the pivotable latch. The tapered portion 18 
interconnects the new hook structure, indicated generally by the numeral 
40, and the cheeks. The hook 40 has a shank portion 42 extending in the 
same general direction as the longitudinal axis of the blade, a curved 
portion 44, and an overlapping portion 46 which extends back toward the 
butt and overlaps the shank portion 42. 
At least a major longitudinal part of the overlapping portion 46 of the 
hook has cross-sectional areas greater than the cross-sectional areas of 
the remainder of the hook, and especially of the shank portion. In the 
embodiment shown in FIG. 4, the entire overlapping portion 46 has 
cross-sectional areas greater than the cross-sectional areas on the 
remainder of the hook. Thus the overlapping portion 46 has a greater 
height 48 (See FIG. 5) than the height 50 (See FIG. 7) of the shank 
portion 42. The height of the curved portion 44 increased from the shank 
portion 42 to the overlapping portion 46. The median height 52 of the 
curved portion 44 is indicated in FIG. 6. The overlapping area 46 is much 
larger in cross-sectional areas than the rest of the hook, thus providing 
a great deal of hook material to be worn through by the card wires, before 
hook failures without effecting the remaining needle structure. In the 
preferred embodiment the height 48 is at least 1.20 times the median 
height 50 of the shank portion 42 often it will be at least 1.50 times 
that height. 
The width 54 may be constant throughout the entire hook, and may be as 
great as the width of the needle across the cheeks. The width of the 
overlapping portion 46 may even be greater than the width of curved 
portion 44 and/or shank portion 42, and may even be greater than the width 
across the cheeks of the needle. It can be understood particularly by 
reference to FIG. 5 that in the embodiment shown, a tangent to the 
outermost part 56 of outer surface 58 of the overlapping portion 46 would 
be substantially parallel to a tangent to the innermost part 60 of the 
inner surface 62, and each would be generally parallel to the surfaces of 
the shank portion 42. However, if desired, the outer and inner tangents 
need not be parallel, and the hook might be of the "closed in" type where 
the surfaces point inwardly at acute angles toward the tapered portion or 
of the "turned out" type where the surfaces of the overlapping portion 
point angularly outwardly away from the shank portion. Also, the 
overlapping portion 46 need not be uniform in cross-sectional area, nor 
need the cross-sectional dimensions from one cross-section be equal to the 
comparable dimensions of another cross-section. There may be tapers or 
multiple tapers, curves or compound curves. However, the cross-sectional 
areas of the major portion of the overlapping portion will be manufactured 
larger than cross-sectional area of the shank portion and possibly also of 
the curved portion of the hook. The extreme free end of the hook wire may 
be cut off flat-ended as shown, or its edges may be rounded or bevelled. 
If desired, the cross-sections of the hook can be any other shape than that 
shown in FIGS. 4 through 7, including round. In addition, the 
cross-sections of any one hook do not all have to be the same shape. For 
example, the cross-sections of the overlapping portion could be 
substantially rectangular and the cross-sections of the shank and curved 
portion could be round. Each hook section could even be varying in shape 
and in cross-sections. As long as the volume of metal of the overlapping 
portion exceeds that volume normally in the overlapping portion because 
that portion has previously, in prior art, been no larger in 
cross-sectional area than the curved portion and the shank. 
FIG. 9 illustrates our new hook on a slide-latch machine knitting needle, 
showing the increased volume of needle material built into the overlapping 
portion to be worn away by the card wires of the doffer wheel. In this 
case, the hook section 70 is comparable to the hook section 40 of the 
pivoting-latch needle of FIG. 4. However, instead of having a pivoting 
latch to close and open the hook, there is a sliding latch 74 which is 
attached to an element of the knitting machine in such fashion that it can 
be reciprocated independently from the remainder of the needle which 
includes the hook. 
Knitting machines utilizing the slide-latch knitting needles generally can 
be operated at higher speeds than can machines with pivoting-latch 
needles. Thus the need for longer needle life is even greater for these 
faster-operating machines where needles and doffer wheels wear out faster 
and down-time for replacement comes around more often, and lost production 
is greater for each period of non-productivity.