CZ306649B6 - A hemming sewing machine - Google Patents

Abstract

The hemming sewing machine (10) comprises the hemming element (30) having the bottom plate part (31) and the raised panel part (32) which is arranged perpendicularly to the bottom plate part (31). The hemming element (30) is arranged for guiding the hemming tape (N) and for its placement under the needle. The hemming tape (N) is arranged on the base fabric, and is folded around the bottom plate part (31) and the raised plate part (32). And further, it comprises the bending device (60) having a pair of bending plates (61) located above the bottom plate part (31) on both of the sides of the hemming element (30) between which there is located the raised plate part (32). The bending device (60) is arranged for folding the hemming tape (N) by moving each of the bending plate (61) towards the raised plate part (32) by means of driving means and the reverse folding of the hemming tape (N) coming out of both the left end and the right end of the bottom plate part (31), towards the upper surface of the bottom plate part (31) by means of the upper part of each of the pair of the bending plates (61), while each of the upper parts faces the opposite one. The bending device (60) further comprises a pair of the bearing elements (63), each of which carries the bending plate (61) respectively, so that the upper part of the bending plate (61) is vertically movable, and the tilting element for pressing the upper part of the bending plate (61) downwards.

Description

The present invention relates to a hemming sewing machine for performing a hemming operation.

Prior art

A hemming sewing machine is, for example, a sewing machine that sews a hemming tape onto a base fabric of a garment and forms a predetermined cut on the base fabric and hemming tape, thereby forming a pocket (see, for example, Japanese Patent Publication JP-B-1-38517).

In particular, in the sewing operation to be performed by the hemming sewing machine, the hemming tape is placed on the base fabric on the upper surface of the stitch plate, being pressed by the hemming element from above. The edging element has a lower plate portion and a raised plate portion arranged vertically on the upper surface of the lower plate portion.

Both ends of the hemming tape are held in a folded state along each side plane of the raised plate portion from the upper surface of the lower plate portion of the hemming element, the base fabric and hemming tape being integrally fed by a feed mechanism in the direction along the lines where the hemming tape is folded.

At the same time, two seams are formed on both sides of the raised plate portion of the hemming element by means of a double needle, the hemming tape being sewn onto the base fabric in a back-bent state.

Further, the center knife moves vertically in synchronization with the vertical movement of the needle to create a straight center section between the seams. Then, a corner cut is formed at each end of the central cut by a vertical movement of the corner knife, which assumes a V-shape, each corner cut being formed substantially in the shape of a letter, which opens continuously from the end of the central cut. Such a sewing operation is performed, for example, when creating a pocket.

However, in the bending apparatus which folds the hemming tape in the hemming sewing machine described in Japanese Patent Publication JP-B-1-38517, the folding operation is interrupted.

As specifically shown in Fig. 9, the bending plate 202 is arranged to move horizontally to fold the edging tape along the upper surface of the lower plate portion 201a of the edging member 201. As a result, the installation height and direction of operation of the bending plate 202 are constant. Therefore, if the thickness of the edging tape is equal to or greater than the expected thickness, the bending plate 202 may stop at the center of the movement, as shown in Fig. 10, due to the thickness and stiffness of the fabric.

To overcome this problem, a method of folding a thick edging tape by replacing the rubber 203, which is adhered to the bottom surface of the large pressing device 200, including the bending plate 202, with rubber having a thickness corresponding to the thickness of the thick edging tape (hereinafter referred to as thick fabric) so that the lower surface of the bending plate 202 moves to a higher position than the upper surface of the thick fabric to be folded along the upper surface of the lower plate portion 201a when the bending plate 202 is in operation.

However, in an actual hemming operation, the thickness of the hemming tape often changes for each sewing operation. Therefore, if the thin edging tape is folded in a state where the rubber 203 for folding the thick edging tape is glued, a problem arises in that an excessive play is created.

Between the bending plate 202 and the edging tape, as shown in Fig. 11. In such a case, the amount of the fold is unstable due to the release of the fabric.

For the above reasons, it is necessary to select and re-adhere a rubber 203 having a suitable thickness corresponding to the thickness of the fabric, in order to adapt to changes in the thickness of the edging tape and to stabilize the size of the fold.

As a result, there is a problem of increased costs, and in addition, the operating speed of the equipment is reduced as a result of replacement operations.

The essence of the invention

It is an object of the present invention to provide a hemming sewing machine which is capable of smoothly folding the hemming tape independently of changes in the thickness of the fabric.

Accordingly, in accordance with a first aspect of the present invention, there is provided a hemming sewing machine comprising:

a hemming element having a lower plate portion and a raised plate portion arranged perpendicular to the lower plate portion, the hemming element being arranged to guide the hemming tape and to place it under the needle, the hemming tape being arranged on the base fabric and being folded around the lower plate parts and raised plate portions, and a bending device having a pair of bending plates located above the lower plate portion on both sides of the edging member, between which the raised plate portion is, the bending device being arranged to fold the edging strip by moving each bending plate toward the raised of the plate portion by driving means and back folding of the edging tape extending from both the left end and the right end of the lower plate portion toward the upper surface side of the lower plate portion by the upper portion of each pair of bending plates, each of the upper portions facing the second, wherein the bending device further comprises:

a pair of support members, each of which carries the bending plate, respectively, so that the upper part of the bending plate is vertically movable, and a tilting member for pressing the upper part of the bending plate downwards.

In accordance with a second aspect of the invention, related to the first aspect of the invention, the bending device further preferably comprises:

a stepped portion to ensure that the height of the upper portion of the bending plate from the upper surface of the base fabric is equal to or greater than the total thickness of the hemming tape in a folded state lying between the lower plate portion in the vertical direction when the upper portion of the bending plate is located outside the left end or the right end of the bottom plate portion.

In accordance with a third aspect of the invention, related to the first or second aspect of the invention, the upper part of the bending plate is preferably arranged to approach obliquely downwards towards the upper surface of the lower plate part when moving the pair of bending plates by drive means for folding the edging tape .

In accordance with a fourth aspect of the present invention, related to any of the preceding aspects of the present invention, the support member is preferably rotatably arranged to ensure that each upper portion of the bending plate is vertically movable.

-2EN 306649 B6

In accordance with a first aspect of the present invention, a pair of bending plates arranged on both sides of the edging member, between which a raised plate portion is located, is supported by a support member such that the upper portion of the bending plate is vertically movable.

In addition, the upper part of each bending plate is always tilted downwards by means of a tilting member. Therefore, even if the thick edging tape is folded, the upper part of the bending plate moves and moves forward along the upper surface of the edging tape and adapts to the thickness of the fabric, so that the folding operation is performed.

If the thin edging tape is also folded, the upper part of the bending plate, inclined downwards, abuts the upper surface and slides along the upper surface of the edging tape, so that the folding operation is performed.

As a result, it is possible to perform a smooth folding operation, regardless of the thickness of the edging tape to be folded. As the upper part of the bending plate is inclined downwards, the edging strip can be folded with stretching along the upper surface of the edging element. It is thus possible to stabilize the size of the fold without creating a release of the folded edging tape.

In addition, it is possible to reduce costs as well as increase the operating speed of the hemming sewing machine without having to replace the components each time the thickness of the fabric changes.

In accordance with the second aspect of the present invention, the same advantages as in the first aspect of the present invention are achieved.

In addition, the bending device is provided with a stepped part. As a result, the upper portion of the bending plate is guided to a position above the edge of the lower plate portion, so that it is ensured that the upper portion of the bending plate is positioned above the total thickness of the edging tape in a backward folded condition.

If the upper part of the bending plate rests on the edging tape during operation of the bending plate, it is possible to perform a smooth folding operation in the case of a thick edging tape without having to stop the forward movement of the edging tape.

The height provided by the stepped portion is adjusted to be equal to the total thickness of the edging tape in the rearwardly folded state lying between the lower plate portion in the vertical direction. However, it is advantageous to assume that the hemming tape is the strongest of all commonly used hemming tapes for this sewing operation.

In accordance with the third aspect of the present invention, the same advantages as in the first or second aspect of the present invention are achieved.

In addition, the upper part of the bending plate moves obliquely from above towards the upper surface of the lower plate part and abuts obliquely downwards on the upper surface of the edging tape to be folded back. As a result, the entire lower surface of the bending plate does not abut the upper surface of the folded edging strip flat, since only the upper part abuts linearly.

As a result, it is possible to guide the upper surface of the backward-folded edging strip so that it extends towards the side of the raised plate portion. It is therefore possible to fold the edging strip back along the upper surface of the edging element without releasing it. As a result, the size of the fold can be stabilized very effectively.

In addition, the bending plate approaches obliquely downwards. As a result, it is possible to adjust the thickness of the fabric to a range in which the height of the upper part of the bending plate changes by moving this upper part.

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In accordance with the fourth aspect of the present invention, the same advantages as in the first to third aspects of the present invention are obtained.

In addition, the bending plate rotates around the side of its lower end. It is therefore possible to ensure the vertical movement of the upper part of the bending plate using a very simple construction.

Explanation of drawings

The invention will be explained in more detail below with reference to examples of its embodiments, the description of which will be given with reference to the accompanying drawings, in which:

Fig. 1 is a perspective view showing a schematic construction of an entire hemming sewing machine to which the present invention is applied;

Fig. 2 is a front elevational view showing a state before the folding operation when viewed in the direction D-D of Fig. 1;

Fig. 3 is an enlarged view showing the main component of Fig. 2;

Fig. 4 is a front elevational view showing the operation of folding a thin fabric by a hemming sewing machine according to the embodiment;

Fig. 5 is an enlarged view showing the main component of Fig. 4;

Fig. 6 is a front elevational view showing the operation of folding a thick fabric by a hemming sewing machine according to the embodiment;

Fig. 7 is an enlarged view showing the main component of Fig. 6;

Fig. 8A is an explanatory view showing an example of the shape of the upper part of the bending plate that can be applied to the embodiment;

Fig. 8B is an explanatory view showing another exemplary embodiment of the shape of the upper part of the bending plate that can be applied to the given embodiment;

Fig. 9 is an explanatory view showing a folding operation performed by a conventional hemming sewing machine;

Fig. 10 is an explanatory view showing a folding operation performed by a conventional hemming sewing machine; and Fig. 11 is an explanatory view showing a folding operation performed by a conventional hemming sewing machine.

Examples of embodiments of the invention

The entire structure according to an exemplary embodiment of the present invention

The hemming sewing machine 10 according to one embodiment of the present invention will be further described with reference to Figs. 1 to 7.

Giant. 1 is a perspective view schematically showing the construction of the entire hemming sewing machine 10.

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In the present embodiment, it is assumed that the respective directions are defined based on the X Y Z axes shown in each of the figures. The direction of the Z axis is the same as the direction of vertical movement of the center knife 51, which will be described below, the working plane for performing sewing work being perpendicular to the direction of the Z axis.

The direction that is parallel to the working plane and in which the fabric is fed is referred to as the X-axis direction, and the direction that is parallel to the working plane and is perpendicular to the X-axis direction is referred to as the Y-axis direction.

The hemming sewing machine 10 sews the hemming tape N (see Fig. 3) onto the base fabric M, forming a linear center section in the feed direction of these fabrics, and a V-shaped corner section at each end of the center section.

The hemming sewing machine 10 includes a sewing machine plate 11 which is a sewing work plate, a sewing machine frame 12 located on the sewing machine plate 11, a feeding mechanism 20 of a large pressing device 21 which is a fabric feeding mechanism, including base fabric M and edging tape N, edging element 30 for depositing edging tape N on top of the base fabric M from above, a mechanism for providing vertical movement of the needle to ensure placement of the needle on both sides of the raised plate portion 32 (which will be described later) 30 near the underside in the fabric feeding direction F of the edging member 30, a knife movement mechanism which is a center knife mechanism mounted on the frame 12 of the sewing machine 10 to move the center knife 51 up and down in the center from each needle 41. on the underside in the direction F of feeding the needle fabric 41, as a result of which a central section is formed on each of the fabrics M and N, and me a corner knife mechanism for moving the corner knife 91 up and down to form a substantially V-shaped corner cut at the position of each end of the center cut.

Each part will be described in the following.

Sewing machine board and sewing machine frame

The plate 11 of the sewing machine 10 has an upper surface arranged parallel to the X-Y plane, and is used in a horizontal state. The upper surface of the plate 11 of the sewing machine 10 is formed as a longitudinal rectangle in the fabric feeding direction F, that is, in the X-axis direction.

The feeding mechanism 20 of the large pressing device 21 and the edging member 30, which will be described below, are located on the plate 11 of the sewing machine JO, and the corner knife mechanism is located under the plate 11 of the sewing machine JO.

In addition, the stitch plate 13 is arranged on the plate 11 of the sewing machine 10, and two needles 44 and 41 are arranged on top of the arm portion 12c, which will be described below, to secure the needle in two needle holes formed in the stitch plate 13, respectively.

Horizontal hooks (not shown) are respectively arranged under the needle holes, the thread inserted into each of the needles 41 and 41 being caught by a corresponding horizontal hook under the needle holes.

-5 CZ 306649 B6 13, where it is braided with a bobbin thread unwound from each of the horizontal hooks, as a result of which sewing is performed.

In addition, a slit is formed in which the central knife 51 engages, a fixed knife (not shown) for cutting the fabric by cooperating with the central knife 51 being located on the underside in the fabric feeding direction F substantially in the center of the two needle holes in the stitch plate 13. .

The frame 12 of the sewing machine 10 includes a base portion 12a located on the side from the center position in the longitudinal direction of the plate 11 of the sewing machine 10, a vertical drum portion 12b extending from the base portion 12a, and an arm portion 12c extending in the Y-axis direction from the upper vertical end. drum parts 12b, the main structures of the mechanism for ensuring the vertical movement of the needle and the mechanism for ensuring the movement of the knife being housed in the arm part 12c, which will be described in more detail below.

In addition, two needles 41 and 41 and a central knife 51 are arranged at the lower end of the upper side of the arm portion 12c.

Mechanism for ensuring vertical movement of the needle

The mechanism for ensuring the vertical movement of the needle comprises two needles 41 and 41, representing a double needle, and two needle bars 42 and 42 for holding the needles 41 and 41 at the lower ends.

In addition, the mechanism for providing the vertical movement of the needle includes a support frame for slidably supporting the needle bars 42 and 42 in the longitudinal direction, a needle bar holder for accommodating two needle bars 42 simultaneously, a main shaft motor of the sewing machine, which is a source of drive for vertical needle movement. a sewing machine shaft for performing a rotary and driving operation by a main sewing machine motor, a rotating weight attached and connected to one of the ends of the main sewing machine shaft and serving to perform a rotary movement, a crank rod whose one end is connected to an eccentric position from the center rotating a rotating weight, the other end of which is connected to the needle bar carrier, and a rotating shaft, one end of which is connected to the support frame and to which a rotational and driving force acts by a source of rotation and drive (not shown) not shown in this embodiment.

When the rotational and driving force at full rotation is applied to the main shaft of the sewing machine by the motor driving operation of the main shaft of the sewing machine, the motion component in the Z-axis direction is transmitted to each of the needle bars 42 and 42 via a rotating weight and a crank rod. each of the needles 41 and 41 performs a rectilinear reciprocating vertical movement.

Furthermore, if the rotational force is applied from the rotary shaft within a predetermined angular range, the needles 41 and 41 located at the lower ends of the needle bars 42 and 42 move uniformly in the sewing direction, so that a so-called stitching sewing operation can be performed, i.e. that the stitch is formed at a shorter stroke in the opposite direction to the feed direction F of the fabric.

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Mechanism for securing the movement of the knife

The knife movement mechanism includes a center knife 51 for forming a center section, a knife bar (not shown) provided with a center knife 51 at the lower end and slidably mounted in the Z-axis direction in the arm portion 12c, a knife motor (not shown) which is a stepping motor. serving as a drive source for providing vertical movement of the center knife 51, and an air cylinder (not shown) which is a drive source for the switching operation to enable the cut and the cut control state of the center knife 51.

The knife movement mechanism switches the forward movement position and the backward movement position of the air cylinder, as a result of which the knife control state in which the rotational and driving force from the knife motor is not transmitted to the center knife and the cut enable state change. in which the rotational and driving force of the knife motor is converted into a vertical rectilinear reciprocating movement of the central knife 51, which performs a central cut having the desired length.

Corner knife mechanism

As shown in Fig. 1 and Fig. 2, the corner knife mechanism is located in the passage of the large pressing devices 21 and 21 (see Fig. 2) of the feed mechanism 20 and under the plate 11 of the sewing machine 10. The corner knife 91 is inserted from below into the edging tape N and the base fabric M fed by the feeding mechanism 20, as a result of which a corner section having a substantially V-shape is formed at a position at each end of the center section.

The corner knife mechanism includes two corner knives 91 and 91 spaced in the fabric feeding direction F, a cover member (not shown) for covering each of the corner knives 91 from its upper side, and a motor for providing vertical movement (not shown) for providing vertical movement. each of the corner knives 91 and the cover member by a respective predetermined transmission mechanism.

Edging element

The edging element 30 will now be described.

The edging member 30 is located on the rear side of the needles 41 and 41 in the X-axis direction, and includes a lower plate portion 31 formed by a long plate and a raised plate portion 32 extending perpendicular to the upper surface of the lower plate portion 31 in the longitudinal direction of the lower plate. plate portion as shown in Fig. 1.

The edging member 30 is mounted on a support mechanism (not shown) comprising an air cylinder, being spaced from the position below both needles 41 and 41, as shown in Fig. 1, when not in use.

In use, the hemming element is lowered by the driving operation of the air cylinder, as a result of which it is set in the position of the stitch plate.

The lower plate portion 31 is formed to have a rectangular shape, and is mounted so that its longitudinal direction is parallel to the X-axis direction, and its lower surface is arranged against the upper surface of the plate 11 of the sewing machine 10.

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The raised plate portion 32 is formed by a rectangular plate and is arranged perpendicularly in the center position in the transverse direction (X-axis direction) of the lower plate portion 31 above the upper surface of the lower plate portion 31, the longitudinal direction being aligned with the lower plate portion 31.

The edging member 30 is formed integrally so that the lower plate portion 31 and the raised plate portion 32 assume an inverted T-shape when viewed in the longitudinal direction.

When the edging tape N is placed and positioned on the upper side of the base fabric M, pressed against the stitch plate 13 by means of large pressing devices 21 and 21, the edging element 30 is placed on the edging tape N from above, both ends in the transverse direction Y in Fig. 1) of the edging strip N extending from both the left and right ends of the lower plate portion 31 are folded back and are erected from both ends in the transverse direction of the lower plate portion 31, and both ends in the transverse direction of the edging strip. N are held along the side surfaces on both sides of the raised plate portion 32 by means of bending plates 61 and 61, respectively, which will be described in more detail later (see Fig. 3).

The edging tape N is held from one of the side surfaces of the raised plate portion 32 to the other side surface by the lower plate portion 31. The edging tape N and the base fabric M are thus fed in a state in which the edging tape is arranged to be wound around the edging member 30. at the same time a sewing operation is performed by means of two needles 41 and 41 on both sides of the raised plate portion 32. At this time, a center cut is performed by a vertical movement of the center knife 51.

Feeding mechanism of the large pressing device

The feeding mechanism 20 of the large pressing device 21 will now be described.

As shown in Fig. 1 and Fig. 2, the feeding mechanism 20 of the large pressing device 21 includes a pair of left and right large pressing devices 21 and 21 for feeding the hemming tape N and the base fabric M, which are inserted into the hemming element 30, a support member 22 for accommodating these large pressing devices 21 and 21, an air cylinder (not shown) for providing vertical movement of the large pressing devices 21 and 21 by the support member 22, a motor for pressing devices (not shown) for moving the edging tape N and the base fabric M, pressed by the large pressing devices 21 and 21 in the fabric feeding direction F by the support member 22, and the bending device 60 for folding the edging tape N back toward the upper side of the lower plate portion 31 of the edging member 30.

Each of the large pressing devices 21 and 21 assumes a rectangular shape when viewed from above and is mounted on the support member 22 in a longitudinal direction corresponding to the X-axis direction.

In addition, each of the large pressing devices 21 and 22 has a bottom surface parallel to the XY plane, and has an upper surface in which the peripheral side portions, opposite each other, are formed so as to lie lower, having a wedge-shaped shape as seen in the direction of the X axis (see Fig. 2 or Fig. 7).

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The bending plates 61 of the bending device 60, which will be described in more detail below, are arranged on the upper surface of the respective large pressing devices 21 and 22, being slidable toward the side of the edging member 30 along the inclined upper surfaces of the large pressing devices 21 and 21.

In addition, the large pressing device 21 can be switched to two positions, upper and lower, by an air cylinder drive operation, being separated from the upper surface of the sewing machine plate 11 in the upper position while lying at the upper surface of the sewing machine plate 11. 10 in the lower position.

In addition, the large pressing devices 21 and 21 are housed in a separate state so that at least the raised plate portion 32 of the edging member 30 can be inserted between them.

The support member 22 is driven by the motor of the pressing device (not shown) by means of a ball screw mechanism (not shown), and is movably mounted in the X-axis direction above the plate 11 of the sewing machine 10.

The large pressing devices 21 and 21 are connected to the support member 22 by means of an arm 23 of the large pressing device 21 provided with a forked end. These large pressing devices 21 and 22 are arranged to pass through both sides of the vertical path of movement of the two needles 41 and 41.

A bending device 60 arranged on a hemming sewing machine 10 according to one embodiment of the present invention will now be described in more detail.

The bending device 60 comprises a pair of bending plates 61 and 61 located on both the left and right sides, between which is a raised plate part 32 of the edging element 30 above the lower plate part 31, bending rollers 62 and 62 representing drive means for providing movement of the bending plates 61 and 61 to move them apart and approach the raised plate portion 32, as a result of which the edging tape N is bent along the upper surface of the lower plate portion 31, a pair of support members 63 and 63 for accommodating the bending plates 61 and 61 by the bending rollers 62 and 62 such that their upper portions are vertically pivotable, and coil springs 64 and 64 forming tilting members to ensure that the upper portions of the bending plates 61 and 61 are pressed downward.

The bending plate 61 is formed as a plate member of almost rectangular shape, its longitudinal direction being located in the X-axis direction, being arranged against each of the upper surfaces of the large pressing devices 21 and 21 in the standby state (see Fig. 2 and Fig. 3). .

Each of the bending plates 61 and 61 is connected to the movable portion P of each of the bending rollers 62 and 62 by a connecting member in the center of the longitudinal direction.

The bending rollers 62 and 62 are formed by single-acting type air rollers and are located with their mutually moving portions P on the side of the edging member 30, the upper portions being turned downwardly, as shown in Fig. 2.

The bending roller 62 is mounted and mounted on the support member 63 in a state in which the movable portion P can be freely driven. In addition, the bending roller 62 holds the bending plate 61 so that its direction of forward and backward movement is parallel to the transverse direction of the bending plate 61 (this is a direction that is perpendicular to the longitudinal direction).

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The support member 63 carries the bending roller 62 almost in the Y-axis direction at its upper portion, and is further connected to the arm 23 of the large pressing device 21 rotatably about an axis along the X-axis direction at the rotation support location 63a.

In other words, the support member 63 has the function of supporting the bending roller 62 pivotable in the direction of the arrow A or arrow B shown in Fig. 2 around the rotation support point 63a, as a result of which the upper portion of the bending plate 61 connected to the movable portion P of the bending roller 62 so as to be vertically movable in the direction of the arrow A or the arrow B shown in Fig. 2.

In addition, the coil spring 64 is arranged in the bending device 60 according to one embodiment of the present invention.

The coil spring 64 has one end connected almost to the center in the longitudinal direction of the bending roller 62, the other end of which is connected to the upper end of the large pressing device 21 (see Fig. 2).

The coil spring 64 is a tension spring which tilts the end of the bending roller 62 against the movable part P upwards, i.e. in the direction of the arrow A in Fig. 2. Specifically, if a tilting force acts on the bending roller 62 mounted integrally with the support member 63 by means of a coil spring 64, so the bending roller 62 is tilted in the direction of the arrow A in Fig. 2 around the support point 63a for rotation on the support member 63.

As a result, the upper portion of the bending plate 61 connected to the upper portion of the movable portion P of the bending roller 62 is always tilted toward the lower side, that is, in the direction of the arrow A in Fig. 2.

Thus, in the bending device 60, each of the bending plates 61 and 61 is driven by the bending air cylinder 62, as a result of which it moves and approaches the upper surface of the lower plate portion 31 obliquely downward, and approaches the raised plate portion 32, the upper portion of each from the bending plates 61 and 61 abuts both ends of the edging strip N, extending from both the left and the right side of the lower surface of the lower plate portion 31, so that the edging strip N is folded back towards the upper side of the lower plate portion 31.

In accordance with one embodiment of the present invention, a rubber plate 24 is adhered to each of the lower surfaces of the large pressing devices 21 and 21 as a stepped portion for securing the bending plate 61 from the upper surface of the base fabric in the outer positions of both the left and right ends of the lower plate. part 3J, so that the height of the bending plate 61 from the upper surface of the base fabric is equal to or greater than the total thickness d of the hemming tape N in the rearwardly folded state, lying between the lower plate part 31 in the vertical direction.

The rubber plate 24 can be peeled off and glued to the bottom surface of each of the large pressing devices 21 and 21 in their longitudinal direction.

In the present embodiment, the initial height at which the upper portion of the bending plate 61 abuts the edging tape N, i.e., the height G provided by the rubber plate 24 (stepped portions), is equal to or greater than the total thickness d of the edging tape N in the backward folded state between the lower plate portion 31 in the vertical direction.

This means that G> d holds (see Fig. 5).

For example, the height can be adapted to the thickness of the thick fabric in the case where the total thickness d of the thick fabric in the backward bend is approximately 3.2 mm.

In addition, the upper surface of each large pressing device 21 and 21 is inclined so that the extension (see dashed line S shown in Fig. 3) in the direction of movement of the upper portion is set on the lower plate portion 31 from the range between the lower plate portion 31 and raised plate

Part 32 in the edging element 31, when each of the bending plates 61 and 61, slidably arranged on the upper surface of each of the large pressing devices 21 and 21, which will be described in more detail below, bends the thin edging strip N.

Reference numerals 25 and 25 denote a flap base for a flap arrangement, which is not shown in Fig. 3, Fig. 5 and Fig. 7 for the sake of simplicity.

Sewing operation of hemming sewing machine

The operation of bending the hemming tape in the hemming sewing machine 10 will now be described in more detail with reference to Figs. 3 to 7.

Before starting the operation of bending the edging tape N, the large pressing device 21 is placed on the base fabric M placed on the board 11 of the sewing machine, after which the edging tape N is placed on the base fabric M between the large pressing devices 21 and 21. from above above the edging tape N (see Fig. 3).

Subsequently, both ends of the edging strip N are bent upwards between the rubber plate 24 and the end of the lower plate part 31 of the edging element 30. In addition, the bending roller 62 is out of operation at this stage, the bending plate 61 being located on both the left and right sides. of each of the large pressing devices 21 and 21, i.e. in the high position of the inclined surface of each of the large pressing devices 21 and 21, the entire lower surface coming into frontal contact with the upper surface of each of the large pressing devices 21 and 21 facing each other and the upper bending side. of the plate 61 is tilted towards the underside.

In particular, the bending operation performed in the case where the thin edging tape N is bent will be described.

When each of the bending rollers 62 and 62 is put into operation, the bending operation is started so that the movable portion P of the bending roller 62 moves forward (in the direction of movement of the bending roller 62 during the driving operation). As a result, each of the bending plates 61 and 61 connected to the movable portion P of the bending roller 62 moves obliquely downwardly above the upper surface of each of the large pressing devices 21 and 21 and slides over the upper surface of each of the pressing devices 21 and 21 toward to the raised plate portion 32 (see Fig. 4).

The bending plates 61 and 61 abut the edging tape N as the respective upper portions pass over the edges of the large pressing devices 21 and 21, and bend and guide both the left and right ends of the edging tape N, extending from both the left and right ends. the lower plate portion 31 of the edging member 30 toward the upper surface side of the lower plate portion 3L

In the hemming sewing machine 10 according to this embodiment, as already described above, the thickness (or height) of the rubber pad 24 is adjusted provided that one of the thicker hemming tapes is used in a folded back condition. Therefore, when the thin edging tape N is bent, the bending plate 61 moves in the original direction of movement using the bending roller 62, i.e. in the downward direction along the upper surface of the large pressing device 21, until the edging tape N is pushed and folded back by the upper part of the bending plate 61 in contact with the upper surface of the lower plate part 31 (see Fig. 5).

When the upper part of the bending plate 61 reaches the upper surface of the thin edging strip which is folded back, the bending plate 61 slides over the upper surface of the edging strip N and moves towards the raised plate portion 32, the upper part pressing the edging strip N towards the lower side. of the plate portion 31 by means of a downward tilting force which constantly acts on the bending plate 61.

- 11 CZ 306649 B6

In other words, the bending plate 61 is always tilted downward by the coil spring 64 by means of the bending roller 62. As a result, the upper part of the bending plate 61 moves to tilt the edging tape N downward and expands the upper surface of the edging tape, which is folded back along the lower plate portion 31, as a result of which the edging tape N is guided to the lower end of the raised plate portion 32. Therefore, the edging tape N is suitably folded without releasing it around the lower plate portion 31.

Next, a description will be given of the bending operation performed when bending the thick edging tape N,

In particular, the operation of approaching the bending plate 61 to the raised plate portion 32 by the driving operation of the bending roller 62 is the same as when the thin edging tape N is bent.

In the bending device 60 of the hemming sewing machine 10 according to the embodiment described above, it is ensured that the thickness of the rubber pad 24 is strong enough to accommodate the case where the thick hemming tape N is bent (hereinafter referred to as thick fabric N). If the bending plate 61 abuts the thick fabric N, then the upper part of the bending plate 61 is forced to abut obliquely from above on the upper surface of the thick fabric N, which is folded back (see Fig. 6 and Fig. 7).

Furthermore, when the thick fabric N is bent, the upper portion of the bending plate 61 is guided to move along the upper surface of the thick fabric N. The bending plate 61 thus continuously performs the bending operation, pressing the thick fabric N downwardly on the upper portion during the bending drive operation. cylinder 62 when pressing a thick fabric N.

In other words, in the hemming sewing machine 10 according to this embodiment, the bending roller 62 is pivoted about the rotatable support place 63a of the support member 63, so that the bending plate 61 is movable in the vertical direction. Therefore, even when the thick edging tape N is bent, the upper portion of the bending plate 61 can move freely and move along the upper surface of the edging tape N adapted to the fabric thickness, and thus fold the fabric over the upper surface of the lower plate portion 31 very reliably. Also in the case where a thick fabric as well as a thin fabric is bent, the bending operation is performed without interruption.

After suitable folding and holding of the hemming tape N before starting the sewing operation, i.e. needle placement, the bending plate 61 is kept in the forward position (in the pressing position) from the start of sewing to the end of sewing, continuously keeping the hemming tape folded.

Advantages of this design

As already described above, in the hemming sewing machine 10 according to the present embodiment, the folding operation can be prevented from stopping due to the difference in fabric thickness, and a smooth folding operation can be achieved independently of the thickness of the folded hemming tape N.

In addition, the upper part of the bending plate 61 is tilted downwards. Therefore, it is possible to stretch and fold the edging tape N around the upper surface of the edging element 30 (especially the lower plate portion 31) and stabilize the amount of the fold without causing the folded edging tape N to be released.

In addition, it is not necessary to change the components every time the thickness of the fabric changes. It is thus possible to reduce costs and increase the operating speed of the JO hemming sewing machine.

Furthermore, if the upper part of the bending plate 61 abuts the edging tape N during operation of the bending plate 61, stopping the forward movement by the edging tape N can be prevented, so that a smooth folding operation can also be performed in the case of a thick edging tape N.

- 12 CZ 306649 B6

In addition, the bending plate moves obliquely downwards. It is therefore possible to adapt to the thickness of the fabric in the range of the height of the position of the upper part, which is variable due to the movement of this upper part. In addition, the bending plate 61 rotates about the lower end side of the bending plate 61, as a result of which a vertical movement of the upper part of the bending plate 61 can be ensured by a simple construction.

Other

In the present embodiment, a construction has been used in which the bending plate 61 is supported by the bending roller 62 and the support member 63, so that the upper portion is pivotable about the lower end side. However, it is also possible, for example, to use a construction in which the bending plate 61 is mounted so as to be vertically movable in parallel by means of a spring member such as a coil spring or a resilient member such as rubber so that the upper part can move vertically.

In addition, the bending plate 61 may have an upper portion having a shape that bends upward, or may be formed so that the lower portion of the upper side is rounded. In such a construction, the upper end of the bending plate bends upwardly as the thick edging tape is folded (see Fig. 8A and Fig. 8B).

In addition, the bending roller 62 for driving the bending plate 61 may be a double-acting type roller, as well as a single-acting type roller.

In addition, the height G, which is secured by the rubber plate 24 (stepped portion), is set to be equal to or greater than the total thickness of the edging tape N in the folded back condition between the lower plate portion 31 in the vertical direction (G> d). . It is preferable that the height G be adjusted with respect to the strongest hemming tape used in the sewing operation.

Claims (4)

PATENT CLAIMS A hemming sewing machine (10), comprising: a edging element (30) having a lower plate portion (31) and a raised plate portion (32) which is arranged perpendicular to the lower plate portion (31), the edging element (30) being arranged to guide the edging strip (N) and to placing it under the needle, the edging tape (N) being arranged on the base fabric and being folded around the lower plate portion (31) and the raised plate portion (32), and a bending device (60) having a pair of bending plates (61) located above the lower plate portion (31) on both sides of the edging element (30), between which the plate portion (32) is raised, the bending device (60) being arranged to fold the edging strip (N) by moving each bending plate (61) towards to the raised plate part (32) by means of drive means and back-folding of the edging tape (N), starting from both the left end and the right end of the lower plate part (31), towards the upper surface side of the lower plate part (31) by means of the upper part each of a pair of bending plates (61), wherein ka each of the upper parts faces the other, characterized in that the bending device (60) further comprises: a pair of support members (63), each of which carries a bending plate (61) respectively such that the upper part of the bending plate (61) is vertically movable, and a tilting member for pressing the upper part of the bending plate (61) downwards. - 13 CZ 306649 B6 The hemming sewing machine according to claim 1, characterized in that the bending device (60) further comprises: a stepped portion to ensure that the height of the upper portion of the bending plate (61) from the upper surface of the base fabric is equal to or greater than the total thickness of the edging tape in the folded back state lying between the lower plate portion (31) in the vertical direction when the upper portion is the bending plate (61) is located outside the left end or the right end of the lower plate portion (31). Hemming sewing machine according to claim 1 or 2, characterized in that the upper part of the bending plate (61) is arranged to approach obliquely downwards towards the upper surface of the lower plate part (31) when moving the pair of bending plates (61) by drive means for folding the edging tape (N). Hemming sewing machine according to any one of claims 1 to 3, characterized in that the support member (63) is rotatably arranged to ensure that each upper part of the bending plate (61) is vertically movable.