Waistband taping machine

Abstract

The invention belongs to the technical field of sewing machines, and particularly relates to a waistband stitcher for sewing a waistband with a folded edge onto a pant piece, the folded edge of the waistband comprising a fixed sewing side and a movable folding side, and comprising: a presser foot assembly comprising a fixed presser foot and a floating presser foot arranged side by side in a direction perpendicular to the fabric feeding direction, the front end of the floating presser foot being further provided with a tuck edge member, the tuck edge member contacting the movable folding side of the waistband folded edge from below during the sewing process and tucking it upwards to form a needle passage between the movable folding side and the fabric below; a needle, the sewing position of the needle corresponding to the tuck edge member, the needle passing through the needle passage and fixing the waistband onto the pant piece; and the sewing thread being hidden below the movable folding side after the sewing is completed. The waistband stitcher provided by the invention realizes the technical effect of sewing thread hiding by using a partitioned presser foot in cooperation with a tuck edge member.

Description

Technical Field

[0001] This invention belongs to the technical field of sewing machines, specifically relating to a sewing machine for concealed stitching on trouser waistbands. Background Technology

[0002] In the garment manufacturing industry, the sewing of the waistband is a crucial process. The waistband consists of two parts: the waistband itself and the trouser panels. The waistband is pre-hemmed to create a structure with a certain degree of stiffness and shape. When sewing the waistband onto the trouser panels, the stitching usually takes place at the junction of the waistband and the trouser panels.

[0003] Traditional waistband sewing methods typically employ visible stitching, meaning the seams are directly exposed on the surface of the waistband. While this method is simple to operate and highly efficient, it has a significant drawback: the visible stitches detract from the overall aesthetic appeal of the garment.

[0004] Several solutions for blind stitch sewing devices already exist in the prior art. For example, Chinese invention patent application CN104975441A (publication date: October 14, 2015) discloses a blind stitch sewing device for thick materials, including a composite needle plate, a feed dog disposed below the composite needle plate, a fabric turning clamp on the composite needle plate, and a composite presser foot above the composite needle plate that has both fabric turning and feeding functions. During fabric turning, the composite presser foot applies force to the fabric, causing the fabric edge to curl up, and the fabric turning clamp separates the curled fabric. This sewing device requires an additional fabric turning clamp, making its structure complex. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a concealed waistband stitching machine that uses a zoned presser foot in conjunction with a raised edge component to achieve the technical effect of hiding the stitching.

[0006] To solve the above-mentioned technical problems, the objective of this invention is achieved through the following technical solution: A concealed stitching machine for sewing a waistband with a folded edge onto a trouser piece, wherein the folded edge of the waistband includes a fixed sewing side and a movable folding side, comprising: A presser foot assembly includes a fixed presser foot and a floating presser foot arranged side by side along a direction perpendicular to the fabric feed direction. The fixed presser foot is used to press the area where the seam is fixed at the waistband fold, and the floating presser foot is used to press the non-fold fabric area adjacent to the seam seam fixed side. The front end of the floating presser foot is also provided with a lifting edge component. During the sewing process, the lifting edge component contacts the movable folding side of the waistband folding edge from below and lifts it upward, so that a needle channel is formed between the movable folding side and the fabric below. A sewing needle is used, the sewing position of which corresponds to the raised edge component. The sewing needle passes through the needle channel and fixes the waistband to the trouser piece. After sewing, the seam is hidden below the movable folding side.

[0007] As a further improvement of the present invention, the fixed presser foot holding area is a region with a larger fabric thickness; the floating presser foot holding area is a region with a smaller fabric thickness.

[0008] As a further improvement of the present invention, the floating presser foot is mounted on the presser foot base via a floating connection mechanism. The floating connection mechanism includes two elastic elements respectively disposed at the front end and rear end of the floating presser foot along the feed direction, so that the floating presser foot can float independently in the vertical direction relative to the presser foot base to adaptively press the thinner non-folded fabric area. The design of the two elastic elements at the front and rear can well cope with the uneven thickness of the fabric along the feed direction, thereby more precisely adapting to the local thickness changes of the fabric in the feed direction.

[0009] As a further improvement of the present invention, the edge-curling member is disposed on the side of the floating presser foot close to the fixed presser foot. The edge-curling member is a thin sheet-like member, the surface of which is perpendicular to the fabric surface and extends forward along the fabric feeding direction.

[0010] As a further improvement of the present invention, the height of the edge-curling component is the same as the height of the front edge of the floating presser foot, and an arc-shaped transition surface is provided at the front corner of the edge-curling component; this structure makes the contour of the edge-curling component and the front edge of the floating presser foot match in the vertical direction, ensuring that the fabric transitions smoothly and continuously from the front edge of the floating presser foot to the edge-curling component, without any steps or gaps that would cause the fabric to get stuck; the arc-shaped transition surface avoids sharp edges from piercing or scratching the fabric during the curling process, and also allows the movable folding side to slide upward and curl up more smoothly along the arc-shaped surface.

[0011] As a further improvement of the present invention, the floating presser foot has a notch on the side near the fixed presser foot. The notch is positioned opposite to the sewing needle and forms a needle hole for the needle to pass through as it descends. The notch is positioned directly opposite the curling edge component to meet the presser foot avoidance requirements when the needle is sewing.

[0012] As a further improvement of the present invention, a pressure foot mounting groove is provided below the pressure foot base, the fixed pressure foot is fixedly assembled in the pressure foot mounting groove, and the floating pressure foot is buoyantly mounted in the pressure foot mounting groove by means of an elastic element. The front and rear ends of the fixed pressure foot and the floating pressure foot are flush, and the width of the fixed pressure foot is greater than the width of the floating pressure foot.

[0013] As a further improvement of the present invention, the elastic element is a compression spring, and the two ends of the compression spring are fixedly connected to the top of the presser foot mounting groove and the top of the floating presser foot, respectively. When the fabric thickness changes, the compression of the spring changes accordingly, and the position of the floating presser foot is adaptively adjusted, thereby realizing the floating of the floating presser foot relative to the presser foot seat through the expansion and contraction of the spring.

[0014] As a further improvement of the present invention, a spring positioning post is provided at the top of the pressure foot mounting groove and the top of the floating pressure foot, and the end of the spring is fitted onto the spring positioning post and fixed thereto; the spring positioning post only provides a base for the installation and fixing of the spring, and does not serve as a guide structure when the spring floats up and down.

[0015] As a further improvement of the present invention, when the presser foot assembly is not pressing the fabric, the bottom of the floating presser foot is lower than the bottom of the fixed presser foot; when the floating presser foot is at the limit position of the upward stroke, the bottom of the floating presser foot is flush with the bottom of the fixed presser foot.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention provides a concealed stitching machine for trouser waistbands. It employs a design where a fixed presser foot holds the fixed side of the folded edge for sewing, and a floating presser foot holds the adjacent non-folded edge area in a partitioned design. Combined with a lifting component at the front of the floating presser foot, the movable folded edge is lifted upwards to form a needle channel, allowing the needle to pass through and complete the sewing. After sewing, the movable folded edge is folded down, and the stitching is covered under the folded edge, making any sewing marks invisible from the surface of the garment, significantly improving the aesthetics of the waistband.

[0017] 2. The floating presser foot floats independently through elastic elements at both ends, automatically adjusting its holding height according to local thickness variations of the fabric along the feed direction, maintaining stable pressure on thinner areas of the fabric. Simultaneously, the fixed presser foot provides stable support for thicker areas. Together, these two elements ensure fabric flatness and smooth feeding during sewing, preventing problems such as skipped stitches, thread breaks, or fabric shifting caused by unstable pressure.

[0018] 3. This invention integrates the edge-curling function into the front end of the floating presser foot, eliminating the need for a separate fabric-flipping clamp or additional fabric-flipping mechanism, resulting in a simpler and more compact structure. While the floating presser foot holds the thin fabric area, the edge-curling component simultaneously lifts the movable folding side. The pressing and edge-curling functions are integrated and coordinated, ensuring reliable and efficient operation. Attached Figure Description

[0019] Figure 1 This is a perspective view of the present invention; Figure 2 yes Figure 1 A magnified view of a portion of the image; Figure 3 This is a 3D view of the presser foot assembly; Reference numerals: 1. Fixed presser foot; 2. Floating presser foot; 3. Edge-curving component; 4. Sewing needle; 5. Presser foot seat; 6. Elastic element; 7. Arc-shaped transition surface; 8. Notch; 9. Presser foot mounting groove. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. See also: Figure 1-3 : This embodiment provides a concealed stitching machine for sewing waistbands with folded edges onto trouser pieces. The folded edge of the waistband includes a fixed sewing side and a movable folding side. The fixed sewing side refers to the portion of the folded edge that is fixed to the main body of the waistband by sewing; this area has multiple layers of fabric and is relatively thick. The movable folding side refers to the portion of the folded edge that is not fixed and can be folded freely.

[0021] The waistband stitching machine includes a presser foot assembly, which includes a presser foot base 5 and a presser foot mounting groove 9 below the presser foot base 5. A fixed presser foot 1 and a floating presser foot 2 are arranged side-by-side in the presser foot mounting groove 9, perpendicular to the fabric feeding direction.

[0022] The fixed presser foot 1 is fixedly assembled in the presser foot mounting groove 9, and its position in the vertical direction remains unchanged. The fixed presser foot 1 is used to press down the area where the seam is fixed at the waistband fold, which is a thicker area of ​​fabric. The fixed presser foot 1 provides a stable support base for the entire sewing process.

[0023] The floating pressure foot 2 is mounted in the pressure foot mounting groove 9 of the pressure foot base 5 via a floating connection mechanism. The floating connection mechanism includes two elastic elements 6—a front compression spring and a rear compression spring—which are respectively disposed at the front end and rear end of the floating pressure foot 2 along the feed direction. The upper ends of the front compression spring and the rear compression spring are respectively connected to the top of the pressure foot mounting groove 9, and the lower ends are respectively fixedly connected to the top of the floating pressure foot 2.

[0024] The floating presser foot 2 is used to hold the non-folded fabric area adjacent to the fixed side of the folded seam. This non-folded fabric area is the part of the waistband that has not been folded and overlapped, with fewer fabric layers and a thinner fabric thickness. The floating presser foot 2 can float independently in the vertical direction relative to the presser foot base 5 through a front compression spring and a rear compression spring, so as to adaptively hold the thinner non-folded fabric area. Since the front compression spring and the rear compression spring are respectively set at the front and rear ends of the floating presser foot 2, the front and rear ends of the floating presser foot 2 each have independent floating strokes, which can adapt to local thickness changes of the fabric along the feed direction.

[0025] The floating presser foot 2 is also provided with a curling edge component 3 at its front end. The curling edge component 3 is located on the side of the floating presser foot 2 near the fixed presser foot 1. It is a thin sheet-like component with its surface perpendicular to the fabric surface and extending forward along the fabric feeding direction. The height of the curling edge component 3 is the same as the height of the front side of the floating presser foot 2 when curled up. The front corner of the curling edge component 3 is provided with an arc-shaped transition surface 7 to avoid damaging the fabric during the curling process.

[0026] Preferably, the floating presser foot 2 has a notch 8 on the side near the fixed presser foot 1. The notch 8 is positioned opposite to the sewing needle 4 and forms a needle hole for the sewing needle 4 to pass through as it descends.

[0027] Preferably, the front and rear ends of the fixed presser foot 1 and the floating presser foot 2 are flush, and the width of the fixed presser foot 1 is greater than the width of the floating presser foot 2.

[0028] Preferably, when the presser foot assembly is not pressing the fabric, the bottom of the floating presser foot 2 is lower than the bottom of the fixed presser foot 1; when the floating presser foot 2 is at the limit position of the upward stroke, the bottom of the floating presser foot 2 is flush with the bottom of the fixed presser foot 1.

[0029] The complete workflow of this concealed waistband stitching machine is as follows: Step 1: Fabric Placement. The operator neatly folds the pre-hemmed waistband and trouser pieces according to the process requirements, and then places the folded fabric under the presser foot assembly. When placing the fabric, the seam fixing side of the waistband fold should be aligned with the side where the fixed presser foot 1 is located in the width direction, and the non-folded fabric area adjacent to the seam fixing side should be aligned with the side where the floating presser foot 2 is located.

[0030] Step 2: Press down the presser foot assembly. During the pressing process, manually lift the movable folding side, causing it to be lifted by the lifting member 3. Finally, the fixed presser foot 1 stably holds the fixed sewing side of the folded edge, while the floating presser foot 2, under spring compression, adaptively holds the non-folded fabric area. The movable folding side is then lifted upwards by the lifting member 3, forming a needle channel 4 between it and the fabric below. During this process, the compression springs at the front and rear ends of the floating presser foot 2 independently adjust their compression according to the local thickness differences of the fabric along the feed direction, maintaining a constant holding force.

[0031] Step 3: Sewing. The operator starts the sewing machine, and the feeding mechanism moves the fabric along the feed direction, while the needle 4 begins to move up and down reciprocally. Since the sewing position of the needle 4 corresponds to the lifting edge component 3, and the floating presser foot 2 has a notch 8 on the side near the fixed presser foot 1 that corresponds to the needle 4, the needle 4 descends from the position corresponding to the notch 8 and passes through the needle 4 channel formed by the lifting edge component 3. As the needle 4 passes through the needle 4 channel, it secures the movable fold side of the waistband to the lower trouser piece. Throughout the sewing process, the lifting edge component 3 continuously keeps the movable fold side in a raised state, and the needle 4 reciprocates through the needle 4 channel to complete continuous sewing.

[0032] Step 4: Complete the sewing and conceal the seams. After sewing is complete, the operator lifts the presser foot assembly using the presser foot lifting mechanism and removes the sewn trouser piece. At this point, the external force causing the movable fold side to lift disappears, and the movable fold side automatically folds down. Since the seam is sewn underneath the movable fold side, after the movable fold side folds down, the seam is covered and hidden under the fold, achieving a concealed stitching effect on the waistband.

[0033] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A waistband concealed stitching machine for sewing a waistband with a folded edge onto a trouser piece, wherein the folded edge of the waistband includes a fixed sewing side and a movable folding side, characterized in that, include: A presser foot assembly includes a fixed presser foot (1) and a floating presser foot (2) arranged side by side along a direction perpendicular to the fabric feed direction. The fixed presser foot (1) is used to press the area where the seam is fixed at the waistband fold, and the floating presser foot (2) is used to press the non-fold fabric area adjacent to the seam seam fixed side. The front end of the floating presser foot (2) is also provided with a lifting edge component (3). During the sewing process, the lifting edge component (3) contacts the movable folding side of the waistband folding edge from below and lifts it upward, so that a needle channel is formed between the movable folding side and the fabric below. A sewing needle (4) is used, the sewing position of which corresponds to the edge-curling member (3). The sewing needle (4) passes through the sewing needle channel and fixes the waistband to the trouser piece. After sewing, its seam is hidden below the movable folding side.

2. The concealed stitching machine for trouser waistbands according to claim 1, characterized in that, The fixed presser foot (1) presses on the area where the fabric is thicker; the floating presser foot (2) presses on the area where the fabric is thinner.

3. The concealed stitching machine for trouser waistbands according to claim 2, characterized in that, The floating presser foot (2) is mounted on the presser foot base (5) via a floating connection mechanism. The floating connection mechanism includes two elastic elements (6) respectively disposed at the front end and rear end of the floating presser foot (2) along the feeding direction, so that the floating presser foot (2) can float independently in the vertical direction relative to the presser foot base (5) to adaptively press the non-folded fabric area with a smaller thickness.

4. The concealed stitching machine for trouser waistbands according to claim 1, characterized in that, The edge-curling component (3) is located on the side of the floating presser foot (2) near the fixed presser foot (1). The edge-curling component (3) is a thin sheet component with its plate surface perpendicular to the fabric surface and extending forward along the fabric feeding direction.

5. A trouser waistband concealed stitching machine according to claim 4, characterized in that, The height of the raised edge component (3) is the same as the height of the front raised edge of the floating presser foot (2), and an arc-shaped transition surface (7) is provided at the front corner of the raised edge component (3).

6. The concealed stitching machine for trouser waistbands according to claim 1, characterized in that, The floating presser foot (2) has a notch (8) on the side near the fixed presser foot. The notch (8) is positioned opposite to the sewing needle (4) and forms a needle hole for the sewing needle (4) to pass down.

7. A trouser waistband concealed stitching machine according to claim 3, characterized in that, The presser foot base (5) is provided with a presser foot mounting groove (9) below it. The fixed presser foot (1) is fixedly assembled in the presser foot mounting groove (9). The floating presser foot (2) is buoyantly installed in the presser foot mounting groove (9) through an elastic element (6). The front and rear ends of the fixed presser foot (1) and the floating presser foot (2) are flush. The width of the fixed presser foot (1) is greater than the width of the floating presser foot (2).

8. A trouser waistband concealed stitching machine according to claim 7, characterized in that, The elastic element (6) is a compression spring, and the two ends of the compression spring are fixedly connected to the top of the pressure foot mounting groove (9) and the top of the floating pressure foot (2), respectively.

9. A trouser waistband concealed stitching machine according to claim 8, characterized in that, When the presser foot assembly is not pressing the fabric, the bottom of the floating presser foot (2) is lower than the bottom of the fixed presser foot (1); when the floating presser foot (2) is at the limit position of the upward stroke, the bottom of the floating presser foot (2) is flush with the bottom of the fixed presser foot (1).

Images