Process for manufacturing a semi-finished item for the production of briefs with a circular knitting machine

The process has: a first step of formation of an elastic border, a second step of formation of a tubular body of knitting starting from the elastic border for a preset number of complete rows, a third step in which a first group of needles and a second group of needles of the machine, which operate on mutually angularly spaced portions of the tubular body, are excluded from working to define a pair of missing portions which constitute the leg apertures of the briefs; the needles excluded from working gradually increase in number for a widening of the missing portions. In the second step, during the knitting of the last complete rows of the tubular body, a preset number of needles, which operate in the mutually angularly spaced regions, and, in the third step, a preset number of needles proximate to the first group and to the second group of needles, are fed with yarn and with elastic thread for the formation of an elastic border around the leg apertures.

BACKGROUND OF THE INVENTION 
The present invention relates to a process for manufacturing a 
semi-finished item for the production of briefs with a circular knitting 
machine for knitwear, stockings and the like. 
As is known, men's or women's briefs are currently generally manufactured 
with portions of knitting cut to size which are sewn together at the hips 
and possibly at the crotch region. Briefs are also subject to a finishing 
operation which consists of the application, by sewing, of an elastic 
border at the leg apertures and in the upper part intended to girdle the 
hips of the user. 
Processes are furthermore known for the execution of semi-finished items 
which are manufactured with circular knitting machines for knitwear and 
stockings and are subsequently subject to finishing operations for the 
obtainment of briefs. 
One of these processes, described in the U.S. Pat. No. 4,010,627, 
substantially consists of the execution of an elastic border intended to 
girdle the user proximate to the hips and, subsequently, all of the 
needles of the machine are carried to a working position in the knitting 
process to execute a tubular body with complete rows of knitting. At the 
end of the second step, two groups of needles which operate on two 
mutually angularly spaced portions of the tubular body are excluded from 
working and the number of needles in the two groups gradually increases so 
as to define, on the lateral surface of the tubular body, a pair of 
missing portions which gradually widen and constitute the leg apertures of 
the briefs to be manufactured. Once the knitting is terminated, the 
needles are disengaged from the last loops of knitting which they have 
formed and an elastic border is applied to the semi-finished item at the 
leg apertures. Subsequently, the briefs are completed by superimposing and 
mutually sewing the two flaps of the tubular body which are opposite to 
the elastic border formed by the machine. 
This process, though it allows to obtain briefs without lateral sewings and 
avoids the application of the elastic border intended to girdle the hips 
of the user, requires in any case sewing operations for the application of 
the elastic border at the leg apertures. Such sewing operations must be 
executed with particular machines and increase the production time of the 
finished article, severely affecting its production cost. 
SUMMARY OF THE INVENTION 
The aim of the present invention is to obviate this disadvantage by 
providing a process which allows the manufacture of a semi-finished item 
for the production of briefs with a circular knitting machine for knitwear 
and stockings, which requires no further sewing operations for the 
application of elastic borders at the leg apertures. 
Within this aim, an object of the invention is to provide a process which 
can be simply executed on known circular knitting machines for knitwear or 
stockings. 
This aim, as well as this and other objects which will become apparent 
hereinafter, are achieved by a process for manufacturing a semi-finished 
item for the production of briefs with a circular knitting machine for 
knitwear, stockings or the like, comprising: a first step of formation of 
an elastic border intended to girdle the user proximate to the hips, a 
second step of formation of a tubular body of knitting starting from said 
elastic border for a preset number of complete rows, a third step in which 
a first group of needles and a second group of needles of the machine, 
operating on mutually angularly spaced portions of said tubular body, are 
excluded from working to define, on the lateral surface of said tubular 
body, a pair of missing portions constituting the leg apertures of the 
briefs, said first group of needles and said second group of needles 
excluded from working gradually increasing in number for a widening of 
said missing portions, and a fourth step of disengagement of the needles 
from the loops of said tubular body, characterized in that, in said second 
step, in the knitting of the last complete rows of said tubular body, a 
preset number of needles, operating in said mutually angularly spaced 
regions, is fed with yarn and with elastic thread and in that, in said 
third step, a preset number of needles, proximate to said first group and 
to said second group of needles, is fed with yarn and with elastic thread 
for the formation of an elastic border around said leg apertures.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
With particular reference to FIGS. 3 and 4, the process according to the 
invention substantially consists of a first step in which an elastic 
border 1 intended to girdle the hips of the user is executed, of a second 
step in which a tubular body 2 of knitting is executed starting from the 
elastic border 1 for a preset number of complete rows, of a third step in 
which a first group of needles and a second group of needles of the 
machine, which operate on mutually angularly spaced portions of the 
tubular body, are excluded from working so as to define on the lateral 
surface of the tubular body 2 a pair of missing portions 3a and 3b which 
constitute the leg apertures of the briefs. The number of needles of the 
first and of the second group gradually increases so as to obtain a 
gradual widening of the leg apertures in an opposite direction to the 
elastic border 1. 
The elastic border 1 can be manufactured in a known manner similar to the 
elastic border of stocking-pants or stockings, i.e. so that it is folded 
on itself to assume a flattened tubular configuration. 
For the execution of the second step of the process, i.e. for the 
production of the tubular body 2, the machine is actuated in a known 
manner as for the execution of tubular portions of socks, stockings or 
knitwear. 
According to the invention, in the second step of the process, in the 
execution of the last complete rows of knitting of the tubular body 2 a 
preset number of needles of the machine which operate on the mutually 
angularly spaced portions of the tubular body 2, i.e. proximate to the 
upper border of the missing portions 3a and 3b, is fed with yarn 4 and 
with elastic thread 5; furthermore, in the third step of the process, a 
preset number of needles of the machine, proximate to the needles of the 
first and of the second group which are excluded from working, is also fed 
with yarn 4 and with elastic thread 5. In this manner one obtains the 
border of the missing portions 3a and 3b constituted by an elastic border 
6a and 6b. 
In the first embodiment of the process according to the invention, a 
circular knitting machine can be used which is actuated, in a known 
manner, with continuous rotary motion, i.e. with a continuous rotary 
motion of the needle cylinder relatively to one or more feeds to which the 
yarn 4 and the elastic thread 5 are fed. In this case, after the yarn 4 
and the elastic thread 5 have been fed to the needles which will 
subsequently be excluded from working, both the yarn 4 and the elastic 
thread 5 are cut at the border of the aperture and are subsequently fed to 
the needles which knit the opposite border. Once the knitting of the 
opposite border is complete, the elastic thread 5 is cut again. Obviously 
it would be possible to maintain the yarn 4 and/or the elastic thread 5 
floating between the counterposed borders of the missing portions 3a and 
3b and to provide a successive cutting operation on the semi-finished item 
7 which is obtained, indeed to define the missing portions 3a and 3b. 
In the second embodiment of the process according to the invention, a 
circular knitting machine is used which is actuated, in a known manner, 
with alternating rotary motion, i.e. with an alternating rotary motion of 
the needle cylinder relatively to the feeds to which the yarn and the 
elastic thread are fed. The semi-finished item 8 which is obtained with 
this second embodiment of the process is illustrated in particular in 
FIGS. 5 and 6 in which 9 indicates the elastic border intended to girdle 
the user proximate to the hips, 10 indicates the tubular body and 11a and 
11b indicate the pair of missing portions which constitute the leg 
apertures of the briefs. In this case it is not necessary to perform the 
cutting of the yarn and of the elastic thread at the borders of the 
missing portions 11a and 11b, since the yarn and the elastic thread, 
respectively indicated by the numerals 12 and 13, during the outward 
motion, at the needles excluded from working, are recovered by the machine 
and again fed to the needles working during the return motion of the 
needle cylinder. 
In this case it is necessary to provide two separate yarns for the 
execution of the two portions of the tubular body 10 which extend between 
the missing portions 11a and 11b and four separate elastic threads for the 
execution of the borders of said missing portions. 
To avoid accidental ladders during knitting, possible due to the tensioning 
of the semi-finished item being formed both in the first embodiment and in 
the second embodiment, the last loop formed by a needle, which in the 
formation of the successive row of knitting is excluded from the knitting, 
is retained by the same needle until the end of the formation of the 
entire semi-finished item when all the loops are cast off the related 
needle and the finished semi-finished item is extracted from the machine. 
To provide a pair of briefs 14 of the type illustrated in FIGS. 1 and 2 it 
is sufficient to execute a pair of sewn seams 20,21, superimposing on one 
another the two flaps 22,23 of the tubular body 2 or 10 which are at the 
end of the tubular body opposite with respect to the elastic border 1 or 
9. 
Using scarcely slideable yarns, such as for example cotton, and also by 
virtue of the presence of the elastic thread which makes the knitting more 
finely meshed, it is possible to exclude with sufficient certainty the 
possibility of accidental ladders at the borders of the missing portions 
3a and 3b or 11a and 11b. Furthermore, again at the border of these 
missing portions the knitting tends to fold on itself defining a small 
border which gives the briefs a more than acceptable degree of finishing. 
In practice it has been observed that the process according to the 
invention fully achieves the intended aim since, by requiring no 
operations of sewing elastic borders along the leg apertures, it allows 
the manufacture of briefs with considerably reduced costs with respect to 
known processes. 
Another advantage of the process according to the invention is that it can 
be simply executed on known types of circular knitting machines for 
knitwear or stockings. 
The process thus conceived is susceptible to numerous modifications and 
variations, all of which are within the scope of the inventive concept; 
furthermore, all the details may be replaced with other technically 
equivalent elements. Thus, for example, during the formation of the 
tubular body 2 or 10 it is possible to perform, in a known manner, 
embroidery or designs according to the various requirements. 
In practice, the materials employed, as well as the dimensions, may be any 
according to the requirements and the state of the art.