[0001] The present invention relates to a unit for automatically loading stockings.
[0002] The present invention is advantageously used in the field of hosiery knitting machines
and particularly in the field of stocking fixing machines, to which the following
description refers explicitly without thereby being limited thereto.
[0003] In general, in stocking production lines, once the stockings have been produced it
is necessary to subject them to particular fixing treatments suitable to give them
their final shape and appearance. These treatments are performed with fixing machines
which include a platform which rotates in steps and multiple pairs of fixing profiles
which are arranged side by side so as to face each other along a peripheral region
of the platform and are suitable to be jogged forward through a loading station, in
order to receive corresponding stockings, and through multiple process stations at
which the stockings undergo respective fixing treatments. In general, the fixing profiles
are formed starting from a tubular part which is bent into a U-shaped configuration
or from a plate member, and include an elongated portion, which reproduces the profile
of a leg and is connected to the platform, and an end portion, which protrudes upward
from the respective elongated portion and reproduces or not, depending on the type
of stockings to be processed, the profile of a foot.
Usually the stockings are loaded manually by an operator, who fits the stockings over
the profiles and simultaneously checks the quality of the stockings, rejecting those
which have any manufacturing defects. This kind of procedure, however, entails drawbacks,
since during loading the operator can accidentally strike the profiles, suffering
unpleasant burns due to the relatively high temperature at which the profiles usually
operate. Moreover, the operator must also perform a relatively tiring movement each
time, since the arms must be raised above the head owing to the considerable length
of the profiles.
[0004] In order to cope with the above described drawbacks, various automatic loading units
have recently been provided which are suitable to load the stockings onto the fixing
profiles in a fully automatic manner. A common factor in all these units is the fact
that they include at least one pair of loading profiles which can move among a loading
position, in which they are arranged outside the fixing machine in order to receive
corresponding stockings from an operator; an intermediate loading position, in which
they are arranged substantially at the end portion of a pair of fixing profiles; and
a final loading position, in which they are arranged substantially at the elongated
portion of the pair of fixing profiles in order to fit the corresponding stockings
on the fixing profiles.
[0005] Automatic loading units of the above described type have some drawbacks due to the
fact that they have a very complicated and bulky structure and also have relatively
high manufacturing
and maintenance costs.
[0006] The aim of the present invention is to provide a unit for automatically loading stockings
which solves the above described drawbacks in a simple and economic manner.
[0007] According to the present invention, a unit for automatically loading stockings comprises
two pairs of loading profiles which can move between a first process station so that
each one receives respective stockings, and a second process station, in which each
loading profile is arranged at a respective pair of fixing profiles which are stationary
in the second process station in order to feed the corresponding stockings to the
fixing profile; and a transfer means which is associated with the two loading profiles
in order to move them between the first process station and the second process station;
the unit being characterized in that the transfer means includes a carousel which
is arranged between the first station and the second station, supports the loading
profiles and is mounted so that it can rotate about a vertical rotation axis in order
to rotate the loading profiles about the rotation axis through a preset transfer angle.
[0008] The invention is now described with reference to the accompanying drawings, which
illustrate a nonlimitative example of embodiment thereof and wherein:
Fig. 1 is a schematic perspective view, with some parts shown in cross-section and
some parts removed for the sake of clarity, of a preferred embodiment of an automatic
loading unit according to the present invention; and
Figs. 2, 3 and 4 are views, with some parts shown in cross-section and some parts
removed for the sake of clarity, of a detail of the unit of Fig. 1 in respective operating
positions.
[0009] With reference to Fig. 1, the reference numeral 1 generally designates a machine
for treating stockings 2, such as pantyhoses, which are shown schematically in Fig.
1 and have an annular girdle 3, two tubular legs 4 which protrude from the girdle
3, and two cup-shaped feet 5 arranged so as to close the respective legs 4.
[0010] The machine 1 includes a plurality of pairs of fixing profiles 6 (only one of which
is shown); a platform 7, which supports the profiles 6 along its peripheral region
8 and is suitable to rotate about a vertical axis (not shown) in order to produce
the stepwise advancement of the profiles 6 through a loading station 9; and an automatic
loading unit 10, which is arranged substantially at the station 9 in front of the
platform 7 and is suitable to automatically load the stockings 2 onto each pair of
profiles 6.
[0011] The profiles 6 of each pair are arranged along the peripheral region 8 in a fixed
position with respect to each other and in a loading position in which the profiles
6 are mutually parallel and face each other. In particular, the profiles 6 cantilever
out vertically upward from the platform 7 and each profile includes an elongated portion
11, which is rigidly connected at a lower end to the platform 7, and an end portion
12, which protrudes freely from the respective elongated portion 11.
[0012] In the example of embodiment shown in Figure 1, the profiles 6 are formed by a contoured
plate 13. Otherwise, in an embodiment which is not shown, the profiles 6 can be provided
by a tubular part bent into a U-shaped configuration. In both cases, anyway, each
profile 6 lies on a respective vertical plane K which is parallel to the rotation
axis and to the plane K of the other profile 6, and has a portion 11 which is substantially
shaped like the profile of a leg 4 and a portion 12 which is substantially shaped
like the profile of a foot 5.
[0013] The unit 10 includes two pairs of loading profiles 14, which are suitable to receive
from an operator (not shown) stockings 2 at a receiving station 15 arranged outside
the machine 1 so as to be substantially aligned with the station 9 along a radial
direction of the machine 1 and are suitable to fit the stockings 2 over the fixing
profiles 6 at the station 9. The unit also includes, for each pair of profiles 14,
a reversible lifting device 16 which supports the corresponding pair of profiles 14
and is suitable to move the profiles 14 in a translatory or insertion direction D1
which is parallel to the vertical axis in order to form, as described in greater detail
hereinafter, the foot of the stockings 2 on the fixing profiles 6.
[0014] The unit 10 also includes a transfer device 17 which supports the two lifting devices
16 on opposite sides with respect to a vertical rotation axis 17a which is parallel
to the direction D1 and is suitable to rotate the lifting devices 16 about the axis
17a through 180° in two opposite directions of rotation so as to alternatively arrange
one lifting device 16 between the axis 17a and the platform 7 and simultaneously arrange
the other lifting device 16 at the station 15.
[0015] The loading profiles 14 are shaped substantially like the fixing profiles 6 but are
shorter, and are provided by respective tubular parts 18 which are bent in a U-shaped
configuration on a respective vertical plane H which is parallel to the rotation axis.
Profiles 14 furthermore have a respective spacer plate 19 which is connected to the
corresponding part 18 and is arranged transversely to the respective plane H so as
to make the leg 4 of stockings 2 fitted over the profiles 14 assume a substantially
tubular shape so as to allow the gradual insertion of the corresponding fixing profile
6 inside the leg 4.
[0016] The tubular parts 18 of the profiles 14 are fixed, at their ends, to respective horizontal
supporting arms 20 which are connected to a bracket 21 of the corresponding lifting
device 16 and are hinged, at one of their ends, to a common end hinge 22 of the bracket
21 which has a rotation axis A which is parallel to the direction D1. In particular,
the arms 20 of each pair of profiles 14 are suitable to rotate about the corresponding
axis A under the action of an orientating device 23 which is part of the unit 10 and
includes, for each profile 14 of each pair of profiles 14, a linear actuator 24 which
is pivoted at one of its ends to the arm 20 of the corresponding profile 14 and to
the bracket 21 at the opposite end, and is suitable to rotate the corresponding arm
20 between an open position (shown in Figs. 1 and 3), which corresponds to a mutually
spaced position of the corresponding loading profiles 14 in which the two arms 20
are mutually aligned, and a closed position (shown in Figs. 1, 2 and 3), which corresponds
to a mutually adjacent position of the profiles 14 and in which the two arms 20 are
folded shut against each other and form an opening 25 between them.
[0017] In their mutually spaced position, the loading profiles 14 are side by side and their
respective planes H are mutually co-planar, whilst in their mutually adjacent position
the loading profiles 14 face each other so that their respective planes H are mutually
parallel and so that the plate 19 of one of the profiles 14 is arranged substantially
in contact with the plate 19 of the other profile 14. During use, when the loading
profiles 14 are folded shut against each other in their mutually adjacent position,
the stockings 2 previously fitted on the loading profiles 14 are also folded shut
so that the respective girdle 3 is folded over in a U-like shape, whilst the respective
legs 4 and the feet 5 are substantially mutually superimposed.
[0018] The transfer device 17 comprises: a footing 26, which is arranged in a fixed position
laterally to the platform 7 and a post 27, which lies along the axis 17a of the footing
26. Transfer device 17 also comprises a carousel 28, which is mounted transversely
to the axis 17a of the post 27 in order to support the two lifting devices 16; and
a motor 29, which is connected to the carousel 28 by a connecting transmission 30
in order to turn the carousel 28 alternatively about the axis 17a.
[0019] In particular, the carousel 28 includes a fixed circular portion 31, which is rigidly
connected to the post 27, and a movable circular portion 32, which is rotatably coupled
to the portion 31 in order to rotate about the axis 17a and is connected to an output
pinion 33 of the motor 29 by virtue of a toothed belt 34 which is part, together with
the pinion 33, of the transmission 30 and is wound in a loop around the portion 32
and the pinion 33.
[0020] The transfer device 17 also includes a retaining and positioning device 35, which
is adapted to mechanically position the carousel 28 at each rotation through 180°
of the carousel 28 about the axis 17a in order to stop the lifting devices 16 and
in particular the corresponding loading profiles 14 exactly at the loading station
9 and at the receiving station 15. In particular, the device 35 includes two stop
members 36 which are fitted on opposite sides of the axis 17a along a peripheral region
of the fixed circular portion 31 at 180° to each other and includes, for each stop
member 36, a respective movable abutment 37 which is fitted along a peripheral region
of the movable portion 32 of the carousel 28 at 180° with respect to the other abutment
37 and is suitable to stop against a stop member 36, exactly determining the angular
position of the carousel 28.
[0021] Each lifting device 16 comprises a guiding column 38, which rises vertically from
the movable circular portion and is parallel to the axis 17a and to the post 27, and
a carriage 39, which is fitted so that it can slide along the corresponding column
38 and is formed by a plate 40 for supporting a corresponding bracket 21 and by three
wheels 41 which are rigidly coupled to the plate 40, are fitted on the opposite side
of the plate 40 with respect to the bracket 21, and are coupled so that they can rotate
along two tracks 42 formed laterally with respect to the corresponding column 38 for
guiding the carriage 39 in the direction D1.
[0022] Each lifting device 16 also comprises a motor 43 which is supported by a plate 44
for connection between the two columns 38 which is arranged at the upper ends of the
columns 38, is rotatably mounted on the post 27, and is connected to a belt drive
45 for moving the corresponding carriage 39 along the corresponding column 38 between
a lowered operating position, in which the corresponding profiles 14 are arranged
substantially at a lower end of the corresponding tracks 42, and a raised operating
position, in which the corresponding profiles 14 are arranged substantially at an
upper end of the corresponding tracks 42. In particular, each belt drive 45 includes
two guiding pulleys 46, which are rigidly mounted at the opposite ends of the corresponding
column 38 in order to rotate about respective horizontal rotation axes, and a belt
47, which is wound in a loop around the pulleys 46 and is rigidly coupled to the plate
40 along one of the two respective transmission portions in order to move the corresponding
carriage 39 along the tracks 42 parallel to the direction D1.
[0023] The loading unit 10 also comprises a suction device 48 adapted to make it easier
to fit the stockings 2 on the loading profiles 14, and a lighting device 49 which
is mounted in a fixed position at the station 15 and is suitable to light the stockings
2 as they are loaded onto the profiles 14 in order to allow the operator to check
the quality of the stockings 2.
[0024] The device 48 comprises a suction impeller 50, which is arranged above a plate 51
mounted at an upper end of the post 27, and a suction duct 52, which runs parallel
to the post 27 in a downward direction and toward the receiving station 15 and is
connected in output to the impeller 50 and in input to a hood 53 which is part of
the device and is arranged directly above the station 15 at a preset distance from
a pair of profiles 14 which are waiting for corresponding stockings 2. The device
48 is adapted to draw the legs 4 of each pair of stockings 2 into the hood 53 and
along part of the duct 52, so as to allow the operator to better fit the stockings
2 on the profiles 14.
[0025] The lighting device 49 is interposed between the post 27 and the station 15 to light
a pair of profiles 14, which are arranged in the station 15 and are waiting for a
corresponding pair of stockings 2, and includes a light-box 54, which is supported
by a beam having a quadrangular cross-section which protrudes downward from the plate
51. The light-box is formed by a semitransparent plate 56 made of translucent material
and by a box 57 which supports the plate 56 and contains two lamps (not shown). The
plate 56, in addition to forming a lateral wall of the box 57, is furthermore parallel
to a pair of profiles 14 arranged in their mutually spaced position and allows the
bracket 21 to pass under it during the positioning of a pair of profiles 14 in the
station 15 during use.
[0026] The operation of the unit 10 is now described with reference to only one of the two
pairs of loading profiles 14, with reference to Figs. 2, 3 and 4, and starting from
the time when a pair of fixing profiles 6 is placed by the platform 7 so that it is
stationary at the loading station 9 and the loading profiles 14 are arranged at the
receiving station 15 in their mutually spaced position in front of the plate 56 and
in their lowered position below the hood 53.
[0027] At this time the operator, by gripping the stockings by the corresponding girdle
3, throws the legs 4 upward. The legs are partially sucked up by the suction device
48 inside the hood 53, and the operator arranges the stockings 2 on the loading profiles
14 whilst the girdle is stretched and arranged substantially on a plane which is co-planar
to the planes H and so that the legs 4 and the feet 5 are arranged around the profiles
14 and the spacing plates 19. During the loading operation, the operator, by virtue
of the light diffused by the light-box 55 and of the fact that the loading profiles
14 are hollow profiles, checks the stockings 2 against the light so as to detect any
manufacturing defects.
[0028] After the pair of stockings has been fitted over the loading profiles 14, the carousel
28 rotates through a transfer angle of 180°, turning the reversible lifting device
16 related to the pair of profiles 14 about the axis 17a and arranging the lifting
device 16 substantially in front of the fixing profiles 6 that are stationary in the
station 9. The rotation of the carousel 28 is limited by the retention and positioning
device 35, and during this rotation the carriage 39 is moved upward in the direction
D1 along the corresponding tracks 42 and the profiles 14 are arranged in their mutually
adjacent position. In this manner, when the profiles 14 arrive at the station 9, the
profiles 14 are arranged vertically above a pair of fixing profiles 6.
[0029] Whilst the loading profiles 14 fold shut against each other, the girdle 3 is folded
over in a U-shaped configuration, whilst the legs 4 and the feet 5 are arranged so
as to face each other.
[0030] At this time the carriage 39 is lowered along the column 38, moving the loading profiles
14 with respect to the fixing profiles 6 so as to gradually fit the stockings 2 over
the fixing profiles 6. In particular, the lowering of the profiles 14 causes the profiles
6 to gradually engage the opening 25 and to arrange themselves so that the plate 13
of each one is substantially adjacent to the tubular parts 18 and in an intermediate
position between the respective spacing plates 19. In this manner, the profiles 6
gradually enter the girdle 3 and then the legs 4 until the respective end portions
12 make contact with the feet 5.
[0031] Once the end portions 12 of the fixing profiles 6 have made contact with the respective
feet 5, the gradual lowering of the loading profiles 14 causes the simultaneous removal
of the stockings 2 from the profiles 14 and the full insertion of the profiles 6 inside
the stockings 2. When the stockings 2 have fully disengaged the loading profiles 14,
the device 23 opens the profiles 14, arranging them again in their mutually spaced
position, and fully disengages the profiles 14 from the profiles 6.
[0032] The above described operations, which as mentioned relate to one of the two pairs
of loading profiles 14, are performed in the same manner for the other pair of profiles
14 as well, but are
delayed by a time interval which is equal to one loading cycle.
[0033] Where technical features mentioned in any claim are followed by reference signs,
those reference signs have been included for the sole purpose of increasing the intelligibility
of the claims and accordingly, such reference signs do not have any limiting effect
on the scope of each element identified by way of example by such reference signs.
1. Unit (1) for automatically loading stockings (2), comprising two pairs of loading
profiles (14) which can move between a first process station (15) so that each one
receives respective stockings (2), and a second process station (9), in which each
loading profile (14) is arranged at a respective pair of fixing profiles (6) which
are stationary in said second process station (9) in order to feed the corresponding
stockings (2) to said fixing profile (6); and a transfer means (17) which is associated
with the two loading profiles (14) in order to move said loading profiles (14) between
the first process station (15) and the second process station (9); said unit (1) being
characterized in that said transfer means (17) comprises a carousel (28) which is
arranged between the first station (15) and the second station (9), said carousel
(28) supporting said loading profiles (14) and being mounted so that it can rotate
about a vertical rotation axis (17a) in order to rotate the loading profiles (14)
about said rotation axis (17a) through a preset transfer angle.
2. Unit according to claim 1, characterized in that the first process station (15) and
the second process station (9) are arranged on opposite sides of said rotation axis
(17a) and determine a specific breadth of said transfer angle.
3. Unit according to claim 2, characterized in that the breadth of said transfer angle
is 180°.
4. Unit according to claim 3, characterized in that said loading profiles (14) are arranged
on opposite sides of said rotation axis (17a) at a mutual distance which is equal
to said set breadth.
5. Unit according to claim 3 or 4, characterized in that it comprises an orientation
means (23) which is associated with said loading profiles (14) in order to orientate
said loading profiles (14) between a receiving position, in which said loading profiles
(14) are stationary in said first process station (15) and are mutually side by side
and co-planar, and a loading position, in which said loading profiles (14) are stationary
in said second process station (9) and are folded shut against each other.
6. Unit according to claim 3, 4 or 5, characterized in that it comprises a reversible
lifting means (16) which is associated with said loading profiles (14) in order to
move said loading profiles (14) in an insertion direction (D1) which is parallel to
said rotation axis (17a).
7. Unit according to any one of claims 3 to 6, characterized in that it comprises a retaining
and positioning means (35) which is associated with said carousel (28) in order to
stop the carousel (28) at each rotation equal to said transfer angle.
8. Unit according to claim 7, characterized in that it comprises a single motor (43)
for driving said carousel (28) in order to rotate said carousel (28) alternatively
through said transfer angle about said rotation axis (17a).
9. Unit according to any one of the preceding claims, characterized in that it comprises
a lighting means (49) which is arranged in a fixed position at said first station
(15) in order to light a pair of loading profiles (14) which are stationary in said
first station (15).
10. Unit according to claim 6, characterized in that said lifting means (16) comprises
a guiding means (38), which lies vertically and is arranged peripherally to said carousel
(28), and a carriage (39) which can move in a reciprocating manner on said guiding
means (38) under the actuation of a motor unit (43) by means of a flexible transmission
member (45) which winds around a pair of pulleys (46) which are supported, at the
opposite ends of said guiding means (38), so as to rotate about parallel horizontal
axes.