[0001] The present invention refers to a device for mechanically folding and making a hem
along two opposite edges on a piece of cloth detachable from a fabric, and comprising
a first and second conveyor tracks, endless, spaced apart and parallel, holding and
arresting devices cooperating therewith and extending over the entire width of the
fabric for squeezing portions of the fabric against the conveyor tracks.
Background of the Invention
[0002] Hemming machines of the above mentioned kind are known through e.g. FR-A-2 354 076,
US-A-2 738 746, FR-A-2 238 005, DE-A-2 130 885 and GB-A-1 249 902 and with which it
is possible to make one hem wider than the other. However, it is not possible with
these previously known machines to vary the width of one hem in a simple manner.
The Purpose and Most Essential Features of the Invention
[0003] The purpose of the present invention is to provide a device for folding and making
a hem on opposite end edges of pieces of cloth such as sheets, whereby the width of
one hem can be given a desired width. This has been obtained by the fact that the
machine further comprises a transfer carriage provided between the two conveyor tracks
and equipped with a horizontal coiler plate which is rotatable about a horizontal
axle substantially 180 degrees and having a fabric gripper means displaceably supported
thereupon, which gripper means is arranged when positioned in a first position adjacent
the first conveyor track to grip the forward end of the fabric and which gripper means
is displaceable on the coiler plate a distance from the end edge corresponding to
the width of the hem, whereby when said coiler plate and supported gripper means is
rotated to a position on the opposite side of said horizontal axle said gripped forward
end of the fabric is conveyed to a second position, wherein it is located on the second
conveyor track, whereby said fabric while still engaged by said holding and arresting
devices is arranged to be conveyed by said conveyor tracks to sewing means comprising
a sewing machine intended for each hemmed end edge.
[0004] Description of the Drawings
Figure 1 shows very schematically a section through a part of the hemming machine
and more exactly its pulling carriage and one or two holding and arresting devices,
Figure 2 shows a section through the forward end of the pulling carriage and a transfer
carriage with a gripper cooperating therewith,
Figure 3 is a section analogous with figure 2 but the transfer carriage and the gripper
are shown in a position displaced laterally,
Figure 4 shows a section through the transfer carriage in a position turned 180 degrees
relative to figures 2 and 3, the carriage thereby cooperating with a first conveyor
track,
Figure 5 shows a section analogous with figure 4 but the transfer carriage and the
gripper are shown in a position displaced laterally and with the first holding and
arresting device activated.
Description of Embodiments
[0005] The hemming machine according to the invention has a length corresponding to the
largest occurring width of the fabric e.g. a single or double sheet. The fabric 11,
which is wound on a not further shown roller, is via guide and drawing rollers (not
shown) fed to a pulling carriage 12, on which is arranged at one hand a feed roller
13 and on the other hand a squeezing device 14. The pulling carriage 12 is displaceable
in the horizontal plane along guides 15, whereby the tongue 16 of the squeezing device
can be moved past a first endless conveyor track 17. This is intended to convey the
rear end of a piece of cloth detached from the fabric to a sewing machine for hemming.
[0006] An arresting device 18 is arranged just in front of the conveyor track 17 and it
is displaceable to and from this. At the stand 19 of the arresting device 18 there
is supported a pressing device 20, which is moveable vertically relative to the stand
and which has a plurality of rubber blocks 21, which can be brought to press the fabric
11 to engagement against the conveyor track 17. The rubber blocks 21 pass through
openings in a presser base 22, which is connected to the stand 19 and which, when
a holding is desired, can be brought to engagement against the conveyor track, and
which gives less friction than the rubber blocks. In the space between the first conveyor
track 17 and the tongue 16 of the squeezing device it is possible to introduce a cutting
device 23 by means of which it is possible to detach a piece of cloth or a strip of
cloth, e.g. if the edge of the cloth shall be cut clean from the fabric 11. During
the cutting the fabric is squeezed at one hand by an arresting device 18 against the
immobile conveyor track 17 and on the other hand by the squeezing device 14.
[0007] The cutting device 23 is located thus in relation to the tongue 16 that the foward
end edge of the fabric after being cut will hang over the tongue 16 of the squeezing
device so much that a suitable folded-in part 37 is formed.
[0008] After the cutting by means of the cutting device 23 the arresting device 18 is displaced
vertically upwards so much that a transfer carriage 24 located by the side thereof
can come into action. The transfer carriage 24 consists of a coiler plate 25, which
extends over the entire machine length and at which plate there is arranged on one
side a gripper 26 and on the other side a drive device 27, which under influence of
guide member 28 can give the gripper 26 a displacement movement in the plane of the
coiler plate. The coiler plate 25 is rotatable 180 degrees about the axis 29 by means
of a not further shown driving device. The transfer carriage 4 is displaceable along
guides 30 in the horizontal plane by means of an appropriate driving device, e.g.
a pneumatic piston cylinder of which has been only intimated the piston stem 31 in
figure 2.
[0009] The guiding member 28 is on one hand carried by the transfer carriage 24 and will
therefore make the same horizontal movements as this and on the other hand it is displaceable
relative to the transfer carriage by means of a separate driving device (not shown),
the motion path of which can be manually adjusted by means of a handle 32.
[0010] The gripper 26 consists of an upper and a lower gripper plate 33, 34, which by means
of pneumatically inflatable rubber hoses 35 and 36 can grip around an object along
its entire length. In figure 2 is shown how the gripper is beginning to squeeze the
forward edge of the fabric which is hanging freely over the tongue 16 between its
gripper plates 33, 34 in such manner that a folded-in part 3 is formed. In order to
allow the gripper to be able to grip the forward end edge of the fabric the pulling
carriage 12 has been displaced along the guides 15 so far that the tongue 16 of the
squeezing device 14 extends over the conveyor track 17.
[0011] When the forward end edge of the fabric and the folded-in part 37 have been squeezed
in the gripper 26 it is possible to displace the transfer carriage 24 in a direction
away from the conveyor track 17 at the same time as the guiding member 28 is displaced
on the coiler plate 25 so far as allowed by the position of the handle 32. From this
position shown in figure 3 it is possible for the transfer carriage to rotate the
coiler plate 25 through 180 degrees, whereby its forward end portion will be located
on a second endless conveyor track 38, which is shown in figure 4.
[0012] The side displacement of the gripper 26 from the collection position to the position
shown in figure 3 corresponds to the length of the hem and it is manually adjustable
with said handle 32. Also the displacement of the transfer carriage 24 along the guides
30 is adapted so that the coiler plate 25 in its delivery position according to figure
4 extends so far over the conveyor track 38 that an essential part of the hem to be,
except the outer end edge with the folded-in part, is located over the conveyor track
38.
[0013] Adjacent the conveyor track 38 is arranged a holding device 39, which in the same
manner as the arresting device 18 is provided with two squeezing devices, which are
independent of each other, and which more correctly are a first pressure plate 30
and a second pressure plate 32 provided with rubber blocks 31 and arranged at some
distance from and above the first pressure plate 30. In this plate is made openings
33 for the passage of the rubber blocks 31 and depending on if it is desired a retention
without friction it is possible to activate one or the other of the pressure plates.
The means for the rotation of the holding device and thereby the plate 30 against
the conveyor track about the axis 34 and also for the movement of the pressure plate
32 are not further shown on the drawing but they consist of appropriate driving devices,
e.g. pneumatical piston engines.
Description of the Function
[0014] The forward end edge of the fabric 11 is advanced so far that it will be located
over the first conveyor track 17 against which the end of the fabric will be pressed
by means of an arresting device 18 - figure 1. As a safe retention is desired the
pressing deivce 20 with the rubber block 21 will be activated. At the same time the
squeezing device 14 will come into function, whereby the forward portion of the fabric
will be firmly retained two retention members.
[0015] The pulling carriage 12 is displaced somewhat in a direction away from the conveyor
track 17, whereby the fabric is stretched. A cutting device 23 is moved over the stretched
fabric and will detach the forward end portion thereof, i.e. the fabrtic will be cut
clean. Thereby is formed an end edge, which will hang freely over the tongue 16 and
the length thereof will correspond to the folded-in part 37 of the hem to be.
[0016] After the detachment the cutting device is displaced to its inactive position and
the arresting device 18 is raised so much that it will not hamper the subsequent operations.
[0017] The squeezing device 14 will maintain its pressure against the fabric, whereas the
pulling carriage 12 will be displaced along the guides 15 so much that the tongue
16 extends over the conveyor track 17 such as shown in figure 2. The transfer carriage
24 is displaced in a direction against the conveyor track 17 at the same time as the
gripper 26 is moved on the coiler plate 25 to its collecting position in which the
two gripper plates 33 and 34 of the gripper will grip the folded forward end edge
of the fabric.
[0018] In the next phase the transfer carriage 24 is displaced in a direction away from
the conveyor track 17 and the gripper 26 is also by means of the guiding member 28
displaced a predetermined distance along the coiler plate 25 corresponding to the
length of the hem and the squeezing device 14 is furthermore opened to allow the feed
roller 13 to feed a length of the fabric corresponding to the length of the piece
of cloth, i.e. the future sheet such as shown in figure 3.
[0019] The coiler plate 25 of the transfer carriage 24 is thereupon rotated 180 degrees
round the axis 29, whereby the forward end portion of the plate will be located in
engagement with the second conveyor track 38, such as shown in figure 4. The holding
device 39 will now come into function and it is revolved to engagement with the coiler
plate 25, whereby the future hem of the fabric 11 is pressed against the conveyor
track 38. At this squeezing the pressure plate 32 with the rubber blocks 31 is active
and presses under good friction the fabric against the conveyor track 38. The forward
portion of the coiler plate 25 has a surface of low friction and it might therefore
be pulled out of the hem although the squeezing device exerts a pressure on the fabric.
[0020] Prior to the transfer carriage 24 being moved in the direction away from the conveyor
track 38 the gripper 26 will be opened to let free the folded in part 37. This position
is shown in figure 5. During the transfer of the fabric 11 to the conveyor track 38
the pulling carriage 12 has returned to its initial position shown in figure 1, whereby,
when the coiler plate has been pulled out of the hem (fig. 5), the arresting device
18 can be put in action, whereby an inner portion of the fabric 11 is pressed to contact
against the conveyor track 17. The same procedure as that is now repeated, i.e. the
squeezing device 14 holds the fabric against the tongue 16, the pulling carriage 12
stretches the fabric and the cutting device 23 separates a piece of cloth from the
fabric. Two end edges of the piece of cloth are pressed against the conveyor tracks
17, 38 by the presser base 22 of the presser device 20 and by the presser plate 30
of the holding device 39, whereupon both conveyor tracks is rotated synchronously,
whereby the piece of cloth is conveyed in a direction against two sewing machines
(not shown). On its way to those machines the rear end edge of the piece of cloth
will pass a folding device of a known design, which makes the hem which has a non-variable
width.
[0021] With the method and the device according to the invention it is thus provided a completely
mechanized hemming of e.g. sheet fabric, where the width of one of the hems can be
varied.
1. A device for mechanically folding and making a hem along two opposite edges of
a piece of cloth detachable from a fabric, and comprising a first (17) and a second
(38) conveyor tracks, endless, spaced apart and parallel, holding (39) and arresting
(18) devices cooperating therewith and extending over the entire width of the fabric
for squeezing portions of the fabric against the conveyor tracks, characterized in,
that it further comprises a transfer carriage (24) provided between the two conveyor
tracks (17, 38) and equipped with a horizontal coiler plate (25) which is rotatable
about a horizontal axle (29) substantially 180 degrees and having a fabric gripper
means (26) displaceably supported thereupon, which gripper means (26) is arranged
when positioned in a first position adjacent the first conveyor track (17) to grip
the forward end of the fabric and which gripper means (26) is displaceable on the
coiler plate a distance from the end edge corresponding to the width of the hem, whereby
when said coiler plate (25) and supported gripper means (26) is rotated to a position
on the opposite side of said horizontal axle (29) said gripped forward end of the
fabric is conveyed to a second position, wherein it is located on the second conveyor
track (38), whereby said fabric while still engaged by said holding (39) and arresting
(18) devices is arranged to be conveyed by said conveyor tracks (17, 38) to sewing
means comprising a sewing machine intended for each hemmed end edge.
2. A device according to claim 1, characterized in, that the holding (39) and arresting
(18) devices are each provided with two sets of clamping members (21) one set of which
has low friction and the other set has high friction relative to the fabric.
3. A device according to claim 2, characterized in, that the gripper means (26) is
adpated in one end position to cooperate with a delivery edge (16), which forms part
of a pulling carriage (12) provided with a squeezing device (14) for squeezing the
fabric.
1. Dispositif pour la réalisation mécanique d'un pli et d'un ourlet le long de deux
bords opposés d'une pièce de toile détachable d'une étoffe, et comprenant un premier
(17) et un second (38) chemin transporteurs sans fin, espacés et parallèles, des dispositifs
de maintien (39) et d'arrêt (18) coopérant avec ceux-ci et s'étendant sur toute la
largeur de l'étoffe pour serrer des parties de l'étoffe contre les chemins transporteurs,
caractérisé en ce qu'il comprend encore un équipage de tansfert (24) prévu entre les
deux chemins transporteurs (17, 38) et muni d'une plaque enrouleuse horizontale (25)
qui peut tourner pratiquement de 180° autour d'un axe horizontal (29) et qui porte
un moyen de préhension d'étoffe (26) supporté sur elle avec liberté de déplacement,
lequel moyen de préhension (26) est agencé pour agripper, lorsqu'il est placé dans
une première position voisine du premier chemin transorteur (17) le bord avant de
l'étoffe et lequel moyen de préhension (26) peut être déplacé sur la plaque enrouleuse
jusqu'à une distance du bord d'extrémité qui correspond à la largeur de l'ourlet,
de sorte que, quand ladite plaque bobineuse (25) et le moyen de préhension (26) qu'elle
supporte pivotent jusqu'à une position située sur le côté opposé dudit axe horizontal
(29), ladite extrémité avant de l'étoffe qui a été agrippée est transportée jusqu'en
une seconde position, dans laquelle elle est située sur le second chemin transporteur
(38), si bien que ladite étoffe, alors qu'elle subit encore l'action desdits dispositifs
de maintien (39) et d'arrêt (18), est placée pour être transportée par lesdits chemins
transporteurs (17, 38) jusqu'à un moyen de couture constitué par une machine à coudre
prévue pour chaque bord d'extrémité ourlé.
2. Dispositif selon la revendication 1, caractérisé en ce que les dispositifs de maintien
(39) et d'arrêt (18) sont pourvus chacun de deux ensembles d'organes de serrage (21)
l'un des ensembles ayant un frottement faible et l'autre un fottement fort par rapport
à l'étoffe.
3. Dispositif selon la revendication 2, caractérisé en ce que le moyen de préhension
(26) est agencé pour coopérer dans une position extrême avec un bord d'amenée (16),
qui fait partie d'un chariot de traction (12) muni d'un dispositif de serrage (14)
pour le serrage de l'étoffe.
1. Vorrichtung zum maschinellen Falten und zur Herstellung eines Saumes an zwei gegenüberliegenden
Endkanten eines von einer Gewebebahn abtrennbarem Stoffstückes, und bestehend aus
einem ersten (17) und einem zweiten (38) endlosen auf gegenseitigem Abstand und parallel
zueinander angeordneten Förderbändern, sowie mit diesen zusammenwirkenden Halterungs-
und (39) Arretiervorrichtungen (18), die sich über die ganze ßreite der Gewebebahn
zum Fesdrücken dieser gegen die Förderbahnen erstrecken, dadurch gekennzeichnet, dass
ein Überführungswagen (24) mit einer Drehplatte (25) zwischen den beiden Förderbändern
(17, 38) vorgesehen ist, die um eine horizontale Achse (29) hauptsächlich 180° drehbar
ist, und auf welcher Drehplatte ein Greifer (26) verschiebbar geführt und vorgesehen
ist in einer ersten Position neben dem ersten Förderband (17) die vordere Endkante
der Gewebebahn zu ergreifen, und welcher Greifer auf der Drehplatte eine Strecke von
der Endkante verschiebbar ist, die der Breite des Saumes entspricht, wobei, wenn die
Drehplatte (25) und der Greifer (26) in eine Stellung auf der gegenüberliegenden Seite
der horizontalen Achse (29) gedreht ist, die ergriffene vordere Endkante der Gewebebahn
in eine zweite Position geführt wird, in welcher sie auf dem zweiten Förderband (38)
zu liegen kommt, und welche Förderbänder (17, 38) unter Einfluss der erwähnten Halterungs-
und Arretiervorrichtungen (39, 18) die Gewebebahn zu Nähvorrichtungen transportieren,
die je eine Nähmaschine für je eine mit Saum zu versehene Endkante umfassen.
2. Vorrichtung nach Anspruch 1, dadurch gekennzeichnet, dass die Halterungs- und Arretiervorrichtungen
(39, 18) je mit zwei Aufstellungen Pressvorrichtungen (21) versehen sind, von denen
eine Aufstellung geringen Reibung während die andere Aufstellung hohe Reibung gegenüber
der Gewebebahn aufweisen.
3. Vorrichtung nach Anspruch 2, dadurch gekennzeichnet, dass die Greifer (26) in einer
Endposition mit einer Ablieferungskante (16) zusammenwirken, die einen Teil eines
Zugwagens (12), der mit einer Klemmenvorrichtung (14) zum Festklemmen der Gewebebahn
versehen ist, bildet.