A method for making a bow-shaped spring sofa and a bow-shaped spring sofa

Abstract

The present invention provides a method for making a bow-shaped spring sofa and a bow-shaped spring sofa, the bow-shaped spring sofa including a sofa seat cushion and a backrest, the sofa seat cushion internally including bow-shaped springs, a base frame or / and a seat cushion bottom board, the backrest internally including bow-shaped springs, a backrest frame or / and a backrest bottom board, characterized in that: the method for making the sofa seat cushion includes the following steps: forming a bow-shaped spring assembly on the base frame or the seat cushion bottom board, sequentially covering a lower covering layer, a filling material pad, and an upper covering layer over the bow-shaped spring assembly, and securing them with needles and thread or connectors. Straw bundles are filled between the edges of the filling material pad and the upper covering layer, and sewn onto the bow-shaped spring assembly using needles and thread. An edge-tucking curved needle and a straw gathering needle are used in combination to shape the edges of the sofa seat cushion; a custom sofa seat cushion cover is made based on the edge-shaped sofa seat cushion. The lining materials and sewing techniques are reasonable, making the seat cushion of the bow-shaped spring sofa flat, aesthetically pleasing, and ensuring stable, reliable, and durable manufacturing quality.

Description

TECHNICAL FIELD

[0001] The present invention belongs to the technical field of sofa manufacturing, specifically relates to a method for making a bow-shaped spring sofa and a bow-shaped spring sofa.BACKGROUND TECHNOLOGY

[0002] In the early days of sofa manufacturing, cylindrical springs were used to make back cushions. These cylindrical springs offered several benefits such as good elasticity, resistance to deformation, good breathability, eco-friendliness, and longevity. However, the shape of sofas or seats with these cylindrical springs needs to be fixed by hemp rope that was prone to breaking. The manufacturing process was labor-intensive, time-consuming, and required skilled craftsmen. Additionally, the varied shapes of back cushions necessitated multiple sizes and shapes of cylindrical springs, which were not suitable for making sofa armrests. Due to these complexities, high costs, and the fragility of cylindrical spring sofas, they were gradually phased out in favor of foam sofas. Form sofas, with their ease of production and lower cost, took over the market, marking the second development period of the sofa industry.

[0003] As people grew more acquainted with foam sofas, their drawbacks became apparent. The elasticity of foam sofas relied solely on the form, which had poor elasticity, breathability, and gave off strange odors. It was also prone to deformation, quick aging, and was not beneficial to human health. The filling material, polyurethane plastic foam, is toxic and harmful substance that is difficult to degrade naturally. Thus, foam sofas are products that compromise both environmental and human health, which is an issue that needs urgent addressing. Currently, about 90% of soft furniture worldwide still uses polyurethane plastic foam. In China alone, approximately 70 million foam sofas are discarded annually, causing significant environmental harm.

[0004] To address the issue posed by both cylindrical spring and foam sofas, a Chinese patent application (No. ZL 20061004505.4) introduced a method for making a bow-shaped spring sofa back cushion and armrest. Although this patent aligned with green and environmental protection concepts, it has not been widely adopted or applied. Through extensive practice, research, and analysis, it was found that the patent had several shortcomings in product structure and manufacturing processes that needed improvement. One key issue was the lack of specific sewing processes for sofa manufacturing. The multiple layers and irregular shapes of the lining material in bow-shaped spring sofas often resulted in uneven edges in the backrest, seat cushion, and armrests when conventional processing and sewing methods were used. This not only looked unsightly but also failed to highlight the unique structural features of bow-shaped spring sofas. To emphasize the distinctive and attractive shape of bow-shaped spring sofas, a suitable manufacturing method is needed. By selecting appropriate lining material and using reasonable sewing processes, the surface of the seat cushion and backrest can be made flat and achieve beautiful curved shapes. This can be better highlighting the features of the bow-shaped spring and ensure stable and reliable processing quality, which is the primary goal of the current innovation.SUMMARY OF THE INVENTION

[0005] To address the problems and shortcomings of the prior art, the present invention provides a method for making a bow-shaped spring sofa and a bow-shaped spring sofa that uses suitable lining materials and reasonable sewing processes. This method ensures that the surface of the seat cushion and backrest of the resulting bow-shaped spring sofa is flat and can achieve beautiful, curved shapes, better highlighting the features of the bow-shaped springs, with stable, reliable, and durable processing quality.

[0006] The present invention is achieved through the following technical solutions:

[0007] A method for making a bow-shaped spring sofa, the bow-shaped spring sofa including a sofa seat cushion and a backrest, the sofa seat cushion internally including bow-shaped springs, a base frame or / and a seat cushion bottom board, the backrest internally including bow-shaped springs, a backrest frame or / and a backrest bottom board, the bow-shaped springs having a middle portion that is a raised arc and two ends that are respectively bent downwards to form bent surfaces. The method for making the bow-shaped spring sofa comprises methods for making the sofa seat cushion and the backrest, the method for making the sofa seat cushion comprising the following steps:

[0008] Step 1: Fabricating the base frame and / or the seat cushion bottom board.

[0009] Step 2: Placing the bow-shaped springs longitudinally across the base frame or the seat cushion bottom board, securing the two ends of the bow-shaped springs to the base frame or the seat cushion bottom board, using a quadrangular steel wire frame to connect the bow-shaped springs with peripheral edges in one piece, and using a straight steel wire transversely placed in the middle to connect with each of the bow-shaped springs and the quadrangular steel wire frame to form a bow-shaped spring assembly.

[0010] Step 3: Encasing the bow-shaped spring assembly by lining materials in a layered manner; wherein the lining materials include, from innermost to outermost, a lower covering layer, a filling material pad, an upper covering layer, and fiber filling, first sequentially covering the lower covering layer, the filling material pad, and the upper covering layer above the bow-shaped spring assembly, using needles and thread or connectors to partially connect and secure the lining materials to the bow-shaped spring assembly, thereby forming an initially shape-formed sofa seat cushion.

[0011] Step 4: Lifting the edges of the upper covering layer, inserting straw bundles as shaping materials between the filling material pad and the upper covering layer in the regions corresponding to the front edge and the left and right sides of the upper part of the sofa seat cushion, then folding the upper covering layer downwards to enclose the straw bundles, and inserting a fixing needle through the lower covering layer, the filling material pad, the straw bundles, and the upper covering layer to fix the straw bundles initially.

[0012] Step 5: Using a straw gathering needle to initially nudge and gather the straw bundles towards the front edge and the left and right edges of the upper part of the sofa seat cushion, then using a sewing needle and thread to stitch diagonally at a certain distance from the front edge and the left and right edges of the upper part of the sofa seat cushion, tying knots to sew the upper covering layer, the straw bundles, the filling material pad, and the lower covering layer together onto the bow-shaped spring assembly, forming a basic edge-tucking shape of the sofa seat cushion.

[0013] Step 6: Using an edge-tucking curved needle in conjunction with the straw gathering needle to shape the edges of the sofa seat cushion, using the edge-tucking curved needle and thread to stitch and tie knots along the front, left, and right edges of the upper part of the sofa seat cushion; using the straw gathering needle for nudging the straw bundles into a column shape, and enclosing and securing the straw bundles within the upper covering layer, completing an edge shaping of the sofa seat cushion.

[0014] Step 7: Building upon the edge shaping of the sofa seat cushion completed in Step 6, fabricating a custom cover of the sofa seat cushion; the cover of the sofa seat cushion including a top face and three adjoining side faces, the inner side of a seam where the top face and the three side faces meet having a remaining edge, forming a piping on the outer side of the seam where the top face and the three side faces of the sofa seat cushion cover meet.

[0015] An improvement to the above technical solution further includes Step 8: Laying the fiber filling on the upper covering layer of the sofa seat cushion produced in Step 6, making the top face of the sofa seat cushion cover flat and forming an appropriate thickness and shape, then folding up the edges of the custom-made sofa seat cushion cover from Step 7 and laying them flat on the sofa seat cushion, aligning the top face of the sofa seat cushion cover with the four corners of the top face of the sofa seat cushion and securing it with a fixing needle, then using the edge-tucking curved needle and thread to stitch and tie knots along the remaining edge on the inner side of the sofa seat cushion cover corresponding to the front edge and the left and right edges of the upper part of the sofa seat cushion, integrating the piping of the sofa seat cushion cover with the sofa seat cushion, and finally folding the edges of the sofa seat cushion cover down to complete the making of the sofa seat cushion.

[0016] Another improvement to the above technical solution is that in Step 3, a method for securing the lining materials by the connectors includes: wrapping the lower covering layer around the bow-shaped spring assembly, using C-clips from a C-clip gun to connect and fix the lower covering layer to the quadrangular steel wire frame of the bow-shaped spring assembly, using clamp strips from a clamp strip gun to fix the edges of the lower covering layer to the base frame or the seat cushion bottom board, then covering the filling material pad on the lower covering layer, using C-clips from a C-clip gun to connect and fix the filling material pad to the quadrangular steel wire frame of the bow-shaped spring assembly, using clamp strips from a clamp strip gun to fix the edges of the filling material pad to the base frame or the seat cushion bottom board, and finally, covering the upper covering layer and using the fixing needle to temporarily secure the middle portion of the upper covering layer.

[0017] Another improvement to the above technical solution is that in Step 3, a method for securing the lining materials using needles and thread is: sequentially covering the bow-shaped spring assembly with the lower covering layer, the filling material pad, and the upper covering layer, then folding the edges of the upper covering layer downwards, inserting the fixing needle through the edges of the lower covering layer, the filling material pad, and the upper covering layer, and then using a long sewing needle with pointed ends at both sides and a needle eye at one end, along with a thread, to stitch and tie knots along the middle portion of the upper covering layer, stitching the upper covering layer, the filling material pad, and the lower covering layer together vertically, and securing them onto the bow-shaped spring assembly.

[0018] A further improvement to the above technical solution is that in Step 2, a specific method for securing the bow-shaped springs longitudinally on the base frame or the seat cushion bottom board includes: the base frame or the seat cushion bottom board is made of wood or plastic wood, and U-shaped grooves are set at the positions on the base frame or the seat cushion bottom board where the bow-shaped springs are installed, placing the two ends of the bow-shaped springs into the corresponding U-shaped grooves, the two ends of the bow-shaped springs are U-shaped, using a bow-shaped spring securing piece to fix both ends of the bow-shaped springs into the corresponding U-shaped grooves, the plate-like body of the bow-shaped spring securing piece has at least one securing hole in the middle, with four securing wings extending from the middle, at least three of the securing wings having claws at the ends that bend towards the same side, the overall shape of the bow-shaped spring securing piece is cross-shaped.

[0019] A further improvement to the above technical solution is that the filling material pad is a palm fiber pad, coconut fiber pad, grapefruit fiber pad, or bamboo fiber pad wrapped in hemp cloth, the lower covering layer and the upper covering layer are both made of hemp cloth or synthetic fiber cloth, and the fiber filling is made of materials such as cotton, pearl cotton, silk cotton, or synthetic fibers.

[0020] A further improvement to the above technical solution is that the seat cushion bottom board, with the bow-shaped spring assembly installed and fixed and covered with the lining materials, is fixed to the base frame.

[0021] A further improvement to the above technical solution is that the method and steps for making the backrest and the materials used are the same as those for making the sofa seat cushion.

[0022] The present invention also provides a bow-shaped spring sofa, including a sofa seat cushion and a backrest, wherein the sofa seat cushion and the backrest are made using the method for making the bow-shaped spring sofa described above.

[0023] The present invention has many advantages and positive effects compared to the prior art:

[0024] 1. The present invention combines the advantages of foam sofas, which are easy to make and low in price, and cylindrical spring sofas, which have good elasticity, do not deform, have good breathability, are environmentally friendly, comfortable to use, and have a long service life. The bow-shaped springs used in the present invention are made of steel wire, and the lining materials and straw used for shaping is natural materials. Therefore, there is no pollution, and most of the raw materials can be recycled or reused after disposal, which is in line with China's development goals of independent innovation, green environmental protection, and circular economy.

[0025] 2. The present invention, through the selection of suitable lining materials, shaping materials, and reasonable sewing processes, ensures that the surface of the seat cushion and backrest of the bow-shaped spring sofa is flat and can achieve beautiful curved shapes, better highlighting the features of the bow-shaped springs, with stable, reliable, and durable processing quality.

[0026] 3. The present invention has a convenient processing method, the resulting product has a simple structure, the cost of raw materials is relatively low, and it is easy to promote and apply.BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 is a top view of the seat cushion bottom board in Embodiment 2 of a bow-shaped spring sofa according to the present invention;

[0028] FIG. 2 is a top view of the seat cushion bottom board shown in FIG. 1 after the bow-shaped springs have been fixed using the bow-shaped spring securing pieces;

[0029] FIG. 3 is a top view of the base frame in Embodiment 1 of a bow-shaped spring sofa according to the present invention;

[0030] FIG. 4 is a perspective view of the bow-shaped spring assembly formed by installing the bow-shaped springs and securing components on the base frame shown in FIG. 3;

[0031] FIG. 5 is an internal structural schematic diagram after covering the bow-shaped spring assembly shown in FIG. 4 with the lower covering layer, the filling material pad, the straw bundles, and the upper covering layer;

[0032] FIG. 6 is a schematic diagram after securing the lining materials with a fixing needle on the basis of the sofa seat cushion shown in FIG. 5;

[0033] FIG. 7 is a schematic diagram after connecting the middle portion of the sofa seat cushion with a long sewing needle and thread on the basis of the sofa seat cushion shown in FIG. 6;

[0034] FIG. 8 is a schematic diagram after stitching and tying knots with a sewing needle and thread at a certain distance from the front edge and the left and right edges of the upper part of the sofa seat cushion on the basis of the sofa seat cushion shown in FIG. 7;

[0035] FIG. 9 is a schematic diagram after gathering the straw bundles towards the front edge and the left and right edges of the upper part of the sofa seat cushion using a straw gathering needle on the basis of the sofa seat cushion shown in FIG. 8;

[0036] FIG. 10 is a schematic diagram after collaboratively using an edge-tucking curved needle and thread with the straw gathering needle to stitch and tie knots for edge tucking at the front edge and the left and right edges of the upper part of the sofa seat cushion on the basis of the sofa seat cushion shown in FIG. 9;

[0037] FIG. 11 is a schematic diagram after stitching and tying knots with an edge-tucking curved needle and thread along the front edge and the left and right edges of the upper part of the sofa seat cushion to sew the piping on the top face edge of the sofa seat cushion cover onto the sofa seat cushion on the basis of the sofa seat cushion shown in FIG. 10;

[0038] FIG. 12 is a perspective view of the overall structure of a bow-shaped spring sofa in Embodiment 1 or Embodiment 2 according to the present invention;

[0039] FIG. 13 is a schematic diagram of the stitching and knot-tying process using a long sewing needle and thread for the sofa seat cushion shown in FIG. 7;

[0040] FIG. 14 is a schematic diagram of the stitching and knot-tying process using a sewing needle and thread for the sofa seat cushion shown in FIG. 8;

[0041] FIG. 15 is a schematic diagram of the stitching and knot-tying process using an edge-tucking curved needle and thread for the sofa seat cushion shown in FIG. 10 or FIG. 11.REFERENCE NUMBERS1: Seat cushion bottom board;

[0043] 2: U-shaped groove

[0044] 3: Bow-shaped spring securing piece

[0045] 4: Securing screw

[0046] 5: Bow-shaped spring

[0047] 6: Base frame

[0048] 7: C-clip

[0049] 8: Quadrangular steel wire frame

[0050] 9: Straight steel wire

[0051] 10: Clip

[0052] 11: Lower covering layer

[0053] 12: Filling material pad

[0054] 13: Upper covering layer

[0055] 14: Straw bundle

[0056] 15: Securing needle

[0057] 16: Long sewing needle

[0058] 17: Sewing needle

[0059] 18: Straw gathering needle

[0060] 19: Edge-tucking curved needle

[0061] 20: Sofa seat cushion cover

[0062] 21: Sofa seat cushion

[0063] 22: Armrest

[0064] 23: BackrestDETAILED DESCRIPTION OF THE EMBODIMENTS

[0065] Referring to FIG. 3 to FIG. 12, the present invention provides a method for making a bow-shaped spring sofa (Embodiment 1). The bow-shaped spring sofa includes a sofa seat cushion 21 and a backrest 23. The sofa seat cushion 21 internally includes a base frame 6 and bow-shaped springs 5. The middle portion of the bow-shaped springs 5 is a raised arc, with both ends bent downwards to form bent surfaces. The method for making a bow-shaped spring sofa includes a method for making the sofa seat cushion 21 and a method for making the backrest 23. The seat cushion 21 is produced through the following steps:

[0066] Step 1: Fabricating the base frame 6. The base frame 6 includes a quadrangular edge frame and a fixed transverse beam set in the middle. Preferably, the base frame 6 can be made of wood or plastic wood in the shape of the Chinese character “” (as shown in FIG. 3), the Chinese character “”, a square frame, and the like.

[0067] Step 2: Positioning the bow-shaped springs 5 longitudinally across the base frame 6 and securing both ends of the bow-shaped springs 5 to the base frame; using a quadrangular steel wire frame 8 to connect the bow-shaped springs with peripheral edges in one piece; using a straight steel wire 9 transversely placed in the middle to connect with each of the bow-shaped springs 5 and the quadrangular steel wire frame 8, forming a bow-shaped spring assembly. Preferably, the quadrangular steel wire frame 8 can be attached and secured to the bow-shaped springs 5 using C-clips 7 from a C-clip gun. The straight steel wire 9 can be connected and fixed to each of the bow-shaped springs 5 and the quadrangular steel wire frame 8 using clamp strips 10 from a clamp strip gun, as shown in FIG. 4.

[0068] Step 3: Encasing the bow-shaped spring assembly in a layered manner using lining materials. The lining materials, from the innermost to the outermost, include a lower covering layer 11, a filling material pad 12, an upper covering layer 13, and fiber filling. Initially, sequentially covering the bow-shaped spring assembly sequentially with the lower covering layer 11, the filling material pad 12, and the upper covering layer 13; using needles and thread or connectors to partially secure and fix the lining materials to the bow-shaped spring assembly, thereby forming an initially shape-formed sofa seat cushion, as shown in FIG. 5.

[0069] The specific methods for laying and connecting the lining materials are as follows:

[0070] The first method employs connectors for fixation. In Step 3, the procedures for securing the lining materials using connectors are as follows: initially, wrapping the lower covering layer 11 around the exterior of the bow-shaped spring assembly; using C-clips from a C-clip gun to connect and fix the lower covering layer 11 to the quadrangular steel wire frame 8 of the bow-shaped spring assembly, and using clamp strips from a clamp strip gun to secure the edges of the lower covering layer 11 to the base frame 6; next, positioning the filling material pad 12 atop the lower covering layer 11; using C-clips from a C-clip gun again to connect and fix the filling material pad 12 to the quadrangular steel wire frame 8 of the bow-shaped spring assembly, and using clamp strips from a clamp strip gun to secure the edges of the filling material pad 12 to the base frame 6; finally, covering the upper covering layer 13 and using a securing needle 15 to temporarily secure the middle portion of the upper covering layer 13.

[0071] The second method utilizes needles and thread for fixation. In Step 3, the procedure for securing the lining materials using needles and thread is as follows: initially, sequentially covering the bow-shaped spring assembly with the lower covering layer 11, the filling material pad 12, and the upper covering layer 13; then, folding the edges of the upper covering layer 12 downwards; next, inserting a securing needle 15 through the edges of the lower covering layer 11, the filling material pad 12, and the upper covering layer 13; using a long sewing needle 16, equipped with pointed ends and a needle eye at one end, along with a thread, stitch and tie knots along the middle portion of the upper covering layer 13. This process vertically secures the upper covering layer 13, the filling material pad 12, and the lower covering layer 11 together, securing them onto the bow-shaped spring assembly. For detailed steps, refer to FIGS. 6, 7, and 13, inserting the fixing needle 15 from the front and back sides of the upper part of the sofa seat cushion in an upward diagonal direction, penetrating the edges of the upper covering layer 13, the filling material pad 12, and the lower covering layer 11. The insertion points of the fixing needle 15 are sequentially A1, A2, A3, . . . , and the needle exit points are sequentially B1, B2, B3, B4, B5, B6. After initially securing the edges of the sofa seat cushion, using the long sewing needle 16 to stitch and tie knots as illustrated in FIG. 13, the process begins by inserting the lower pointed end of the long sewing needle 16 at point C, with the upper pointed end with the needle eye exiting at point D, then following the arrow direction in FIG. 7 to stitch the middle portion of the sofa seat cushion until the upper pointed end of the needle exits at point E, at which point the sewing process is complete. This ensures that the surface of the upper covering layer 11 of the sofa seat cushion is flat and well-positioned, preventing any shifting. As depicted in FIG. 7, the long sewing needle 16 features pointed ends on both sides, with one end having a needle eye. The length of the long sewing needle 16 is essentially consistent with the thickness of the sofa base, facilitating easy insertion and stitching.

[0072] Step 4: Lifting the edges of the upper covering layer 13; inserting straw bundles 14 as shaping materials between the filling material pad 12 and the upper covering layer 13 in the regions corresponding to the front edge and the left and right sides of the upper part of the sofa seat cushion; subsequently, folding the upper covering layer 13 downwards to enclose the straw bundles 14; next, inserting the fixing needle 15 through the lower covering layer 11, the filling material pad 12, the straw bundles 14, and the upper covering layer 13 to initially secure the straw bundles 14 in place. One end of the fixing needle 15 features a pointed tip, while the other end is equipped with a handle. The handle of the fixing needle 15, as illustrated in FIG. 6, is circular; however, it may also be of other shapes suitable for gripping.

[0073] Step 5: Initially, using a straw gathering needle 18 to preliminarily nudge and gather the straw bundles 14 towards the front edge and the left and right edges of the upper part of the sofa seat cushion; subsequently, using a sewing needle 17 and thread, stitch diagonally at a certain distance from the front edge and the left and right edges of the upper part of the sofa seat cushion, and tying knots to secure the upper covering layer 13, the straw bundles 14, the filling material pad 12, and the lower covering layer 11 together onto the bow-shaped spring assembly, forming a basic edge-tucking shape of the sofa set cushion. For detailed steps, refer to FIG. 8 and FIG. 14, initially, using the straw gathering needle 18 to preliminarily nudge and gather the straw bundles 14 towards the front edge and the left and right edges of the upper part of the sofa seat cushion; then using the sewing needle 17 and thread, stitch diagonally and tie knots at a certain distance from the front edge and the left and right edges of the upper part of the sofa seat cushion; initiating stitching by inserting the sewing needle 17 at point G in FIG. 8, proceeding downwards and then upwards to exit at point F; continuing stitching according to the method depicted in FIG. 14, following the arrow directions along both sides to the rear edge, terminating at points H1 and H2. As shown in FIG. 8, one end of the sewing needle 17 features a pointed tip, while the other end is equipped with a needle eye. In comparison to an ordinary sewing needle, it is longer, thicker, and possesses a larger needle eye. However, the sewing needle 17 is shorter than the previously mentioned long sewing needle 16.

[0074] Step 6: Using an edge-tucking curved needle 19 in conjunction with the straw gathering needle 18 to shape the edges of the sofa seat cushion. Beginning by using the edge-tucking curved needle 19 and thread for stitching and tying knots along the front, left and right edges of the upper part of the sofa seat cushion; using the straw gathering needle 18 for nudging the straw bundles 14 into a columnar shape, and enclosing and securing the straw bundles 14 within the upper covering layer 13 to complete an edge shaping of the sofa seat cushion, as illustrated in FIG. 5. Referring to FIGS. 9, 10 and 14, the detailed steps include: inserting the straw gathering needle 18 from points J and K, as shown in FIG. 9, for gathering the straw bundles 14 towards the front end, and then gradually moving towards the two side edges for continuing to gather the straw bundles, concluding at points L1 and L2. Simultaneously, using the edge-tucking curved needle 19 and thread for stitching and tying knots along both sides of the front edge and the left and right edges of the upper part of the sofa seat cushion. Beginning by inserting the edge-tucking curved needle 19 from point M in FIG. 10 and moving upwards, after penetrating the lining materials and the straw bundles 14, exiting from point N. Following the stitching method depicted in FIG. 14, stitching along both sides, terminating at points P1 and P2, thereby completing the edge shaping of the sofa seat cushion. As shown in FIG. 9, the straw gathering needle 18 features a pointed tip at one end and lacks a needle eye at the other end. A handle can be optionally fixed at the end without the pointed tip as needed. As illustrated in FIG. 10, the edge-tucking curved needle 19 is crescent-shaped, with one end being a pointed tip and the other end equipped with a needle eye.

[0075] Step 7: Building upon the edge shaping of the sofa seat cushion completed in Step 6, fabricating a custom cover of sofa seat cushion 20. The cover of sofa seat cushion 20 comprises a top face and three adjoining side faces. The inner side of a seam, where the top face and the three side faces converge, includes a remaining edge, forming a piping on the outer side of the seam where the top face and the three side faces of the cover of sofa seat cushion 20 meet.

[0076] Further, the method comprises Step 8, including beginning by laying fiber filling on the sofa seat cushion completed in Step 7, covering the stitched areas and any uneven parts to ensure the top face of the sofa seat cushion is flat and achieves the appropriate thickness and shape. Next, folding up the edges of the custom-made cover of sofa seat cushion 20 from Step 7 and laying it flat on the sofa seat cushion. Aligning the top face of the cover of sofa seat cushion 20 with the four corners of the top face of the sofa seat cushion and securing it with the fixing needles 15. Following this, using the edge-tucking curved needle 19 and thread for stitching along the remaining edge on the inner side of the cover of sofa seat cushion 20 corresponding to the front edge and the left and right edges of the upper part of the sofa seat cushion. This process integrates the piping of the cover of sofa seat cushion 20 with the sofa seat cushion; finally, folding the edges of the cover of sofa seat cushion 20 downwards to complete the fabrication of the sofa seat cushion. For specific stitching steps, refer to FIG. 11 and FIG. 15. Folding the edges of the custom-made cover of sofa seat cushion 20 from Step 8 and laying them flat on the sofa seat cushion. Aligning the top face of the cover of sofa seat cushion 20 with the four corners of the top face of the sofa seat cushion and securing it with four fixing needle 15 at points S1, S2, S3, and S4 to establish the basis for the stitching distance during the stitching process with the edge-tucking curved needle 19. Then, inserting the edge-tucking curved needle 19 and thread from point Q and exiting from point R, penetrating the lining materials and the straw bundles 14; pulling the thread back from point R to point Q and tying a knot; repeating this process along both sides of the sofa seat cushion as shown in FIG. 15 until reaching points S3 and S4, stitching the piping on the top face of the cover of sofa seat cushion 20 together with the sofa seat cushion into a unified structure, completing the piping stitching process; finally, folding the edges of the cover of sofa seat cushion 20 downwards to complete the fabrication of the sofa seat cushion.

[0077] Additionally, the specific method for securing the bow-shaped springs 5 longitudinally across the base frame 6 in Step 2 is described further. The base frame 6 is constructed from wood or wood-plastic composite, and U-shaped grooves 2 are positioned at the locations on the base frame 6 where the bow-shaped springs 5 are installed. The method includes: placing the two ends of the bow-shaped springs 5, which are U-shaped, into the corresponding U-shaped grooves 2; using a bow-shaped spring securing piece 3, which has a plate-like body featuring a securing hole in the center, to secure both ends of the bow-shaped springs 5 into the corresponding U-shaped grooves; Using a securing screw 4 through the securing hole to fix the bow-shaped spring securing piece 3 to the base frame 6. The bow-shaped spring securing piece 3 includes four securing wings extending from the center, with at least three of the securing wings featuring claws at the ends that bend towards the same side. These claws secure the two U-shaped ends of the bow-shaped springs 5. The overall configuration of the bow-shaped spring securing piece 3 is cross-shaped.

[0078] The bow-shaped spring securing piece 3 can be the one detailed in the Chinese patent titled “A Bow-shaped Spring securing Piece and a Bow-shaped Spring Sofa” (Patent No.: CN201920330710.9), Using the same or similar installation and fixation method. Alternatively, it can be fixed as illustrated in FIG. 2, and thus, a detailed description is omitted here. The aforementioned bow-shaped springs 5 can be those described in the Chinese patent titled “A Method for Making the Backrest, Seat Cushion, and Armrest of a Sofa Using Bow-shaped Springs” (Patent No.: CN200610045054.5), utilizing the same or similar installation and fixation method, and therefore, a detailed description is omitted here.

[0079] To facilitate the securing of the lining materials and to enhance the aesthetic appeal of the sofa seat cushion, a long wooden strip 6.1 is positioned on each of the left and right sides of the base frame 6, forming a stepped shape that is lower on the outside and higher on the inside. Using nails from a nail gun to fix the edges of the lower covering layer 11, the filling material pad 12, and the upper covering layer 13 to the outer side of the long wooden strip. Finally, after covering with fiber filling, the two side faces of the entire lining material are substantially aligned with the left and right sides of the base frame 6. Preferably, the length of the aforementioned wooden strip 6.1 is less than the distance between the two U-shaped ends of the bow-shaped springs 5.

[0080] Furthermore, the aforementioned filling material pad 12 comprises a palm fiber pad, coconut fiber pad, grapefruit fiber pad, or bamboo fiber pad wrapped in hemp cloth. The aforementioned lower covering layer 11 and upper covering layer 13 are both fabricated from hemp cloth or synthetic fiber cloth. The aforementioned fiber filling is composed of materials such as cotton, pearl cotton, silk cotton, or synthetic fibers.

[0081] Additionally, the method for fabricating the backrest is substantially similar to the method for fabricating the sofa seat cushion and employs the same materials, and thus, a detailed description is omitted here. If the bow-shaped spring sofa also includes sofa armrests 22, the method for fabricating the armrests 22 and the materials employed can be the same as the method for fabricating the backrest described above or can refer to the method for fabricating armrests detailed in the Chinese patent (Patent No.: CN200610045054.5). Finally, the fabricated sofa seat cushion 21, backrest 23, and armrests 22 are assembled together to complete the entire bow-shaped spring sofa.

[0082] As illustrated in FIG. 12, Embodiment 1 of a bow-shaped spring sofa according to the present invention comprises a sofa seat cushion 21, a backrest 23, and armrests 22. The aforementioned sofa seat cushion 21, backrest 23, and armrests 22 are fabricated using Embodiment 1 of the method for making a bow-shaped spring sofa described above. Embodiment 1 of a bow-shaped spring sofa according to the present invention can also be a bow-shaped spring sofa without armrests22 (not illustrated).

[0083] Referring to FIGS. 1 and 2, Embodiment 2 of a method for making a bow-shaped spring sofa according to the present invention includes a sofa seat cushion and a backrest. The sofa seat cushion comprises a base frame, a seat cushion bottom board 1, and bow-shaped springs 5. The backrest comprises a backrest frame, a backrest bottom board, and bow-shaped springs 5. The middle portion of the bow-shaped springs 5 is a raised arc, with both ends bent downwards to form bent surfaces and being U-shaped. The method for making the bow-shaped spring sofa includes methods for making the sofa seat cushion and the backrest. Embodiment 2 is substantially similar to Embodiment 1 in terms of the method and steps for making the sofa seat cushion, with the distinction being that in Embodiment 2, U-shaped grooves 2 are positioned on the seat cushion bottom board 1 instead of on the base frame, and the two U-shaped ends of the bow-shaped springs 5 are fixed and installed in the U-shaped grooves 2 on the seat cushion bottom board 1. The bow-shaped spring assembly is assembled on the seat cushion bottom board 1, after which the lining materials are used to cover the bow-shaped spring assembly and fix its shape. Finally, the seat cushion bottom board 1, with the bow-shaped spring assembly installed and fixed and covered with the lining materials, is fixed to the base frame. The method for securing the two ends of the bow-shaped springs 5 is illustrated in FIG. 2. The bow-shaped spring securing piece 3 is utilized for fixation, specifically referring to the fixation method detailed in the Chinese patent (Patent No.: CN201920330710.9), or the fixation method related to bow-shaped springs detailed in the Chinese patent (Patent No.: CN200610045054.5), and thus, a detailed description is omitted here.

[0084] Embodiment 2 is substantially similar to Embodiment 1 in terms of the method and steps for making the sofa seat cushion, and thus, a detailed description is omitted here. Similarly, in Embodiment 2, the method and steps for making the backrest and the materials employed are substantially similar to those for making the backrest in the method for making the sofa seat cushion in Embodiment 1, and thus, a detailed description is omitted here.

[0085] The seat cushion bottom board 1 can be a wooden bottom board, a plastic-wood bottom board, or a steel board bottom board fabricated by stamping a steel plate. Barbs (replacing the spring securing piece 3) can be positioned on the steel board bottom board to fix the U-shaped ends of the bow-shaped springs 5, providing a simple and relatively secure fixation method.

[0086] When the seat cushion bottom board 1 is fabricated from a relatively thick wooden board in the shape of a frame, the Chinese character “”, or the Chinese character “”, in Embodiment 2, the seat cushion bottom board 1, with the bow-shaped spring assembly installed and fixed and covered with the lining materials, does not need to be fixed to the base frame. Instead, the seat cushion bottom board 1 is directly employed as the base frame to assemble the bow-shaped spring sofa.

[0087] As illustrated in FIG. 12, Embodiment 2 of a bow-shaped spring sofa according to the present invention comprises a sofa seat cushion 21, a backrest 23, and armrests 22. The aforementioned sofa seat cushion 21, backrest 23, and armrests 22 are fabricated using Embodiment 2 of the method for making a bow-shaped spring sofa described above. Embodiment 2 of a bow-shaped spring sofa according to the present invention can also be a bow-shaped spring sofa without armrests 22 (not illustrated).

[0088] Of course, the above description is not intended to limit the present invention. Those skilled in the art can make modifications, substitutions, additions, or simplifications within the substantive scope of the present invention.

Claims

1. A method for making a bow-shaped spring sofa, the bow-shaped spring sofa comprising a sofa seat cushion and a backrest, the sofa seat cushion internally comprising bow-shaped springs, a base frame or / and a seat cushion bottom board, the backrest internally comprising bow-shaped springs, a backrest frame or / and a backrest bottom board, the bow-shaped springs having a middle portion that is a raised arc and two ends that are respectively bent downwards to form bent surfaces, wherein the method for making the bow-shaped spring sofa comprising a method for making the sofa seat cushion and a method for making the backrest, the method for making the sofa seat cushion comprising the following steps:step 1: fabricating the base frame or / and the seat cushion bottom board;step 2: placing the bow-shaped springs longitudinally across the base frame or the seat cushion bottom board, securing the two ends of the bow-shaped springs to the base frame or the seat cushion bottom board, using a quadrangular steel wire frame to connect the bow-shaped springs with peripheral edges in one piece, and using a straight steel wire transversely placed in the middle to connect with each of the bow-shaped springs and the quadrangular steel wire frame to form a bow-shaped spring assembly;step 3: encasing the bow-shaped spring assembly by lining materials in a layered manner; wherein the lining materials include, from innermost to outermost, a lower covering layer, a filling material pad, an upper covering layer, and fiber filling, first sequentially covering the lower covering layer, the filling material pad, and the upper covering layer above the bow-shaped spring assembly, using needles and thread or connectors to partially connect and secure the lining materials to the bow-shaped spring assembly, thereby forming an initially shape-formed sofa seat cushion;step 4: lifting the edges of the upper covering layer, inserting straw bundles as shaping materials between the filling material pad and the upper covering layer in the regions corresponding to the front edge and the left and right sides of the upper part of the sofa seat cushion, then folding the upper covering layer downwards to enclose the straw bundles, and inserting a fixing needle through the lower covering layer, the filling material pad, the straw bundles, and the upper covering layer to fix the straw bundles initially;step 5: using a straw gathering needle to initially nudge and gather the straw bundles towards the front edge and the left and right edges of the upper part of the sofa seat cushion, then using a sewing needle and thread to stitch diagonally at a certain distance from the front edge and the left and right edges of the upper part of the sofa seat cushion, tying knots to sew the upper covering layer, the straw bundles, the filling material pad, and the lower covering layer together onto the bow-shaped spring assembly, forming a basic edge-tucking shape of the sofa seat cushion;step 6 : using an edge-tucking curved needle in conjunction with the straw gathering needle to shape the edges of the sofa seat cushion, using the edge-tucking curved needle and thread to stitch and tie knots along the front, left, and right edges of the upper part of the sofa seat cushion; using the straw gathering needle for nudging the straw bundles into a column shape, and enclosing and securing the straw bundles within the upper covering layer, completing an edge shaping of the sofa seat cushion;step 7: building upon the edge shaping of the sofa seat cushion completed in Step 6, fabricating a custom cover of the sofa seat cushion; the cover of the sofa seat cushion comprising a top face and three adjoining side faces, the inner side of a seam where the top face and the three side faces meet having a remaining edge, forming a piping on the outer side of the seam where the top face and the three side faces of the sofa seat cushion cover meet.

2. The method for making the bow-shaped spring sofa according to claim 1, further comprising:step 8: laying the fiber filling on the upper covering layer of the sofa seat cushion produced in the step 6, making the top face of the sofa seat cushion cover flat and forming an appropriate thickness and shape, then folding up the edges of the custom-made sofa seat cushion cover from the step 7 and laying them flat on the sofa seat cushion, aligning the top face of the sofa seat cushion cover with the four corners of the top face of the sofa seat cushion and securing it with a fixing needle, then using the edge-tucking curved needle and thread to stitch and tie knots along the remaining edge on the inner side of the sofa seat cushion cover corresponding to the front edge and the left and right edges of the upper part of the sofa seat cushion, integrating the piping of the sofa seat cushion cover with the sofa seat cushion, and finally folding the edges of the sofa seat cushion cover down to complete the making of the sofa seat cushion.

3. The method for making the bow-shaped spring sofa according to claim 1, wherein in the step 3, a method for securing the lining materials by the connectors comprises:wrapping the lower covering layer around the bow-shaped spring assembly, using C-clips from a C-clip gun to connect and fix the lower covering layer to the quadrangular steel wire frame of the bow-shaped spring assembly, using clamp strips from a clamp strip gun to fix the edges of the lower covering layer to the base frame or the seat cushion bottom board, then covering the filling material pad on the lower covering layer, using C-clips from a C-clip gun to connect and fix the filling material pad to the quadrangular steel wire frame of the bow-shaped spring assembly, using clamp strips from a clamp strip gun to fix the edges of the filling material pad to the base frame or the seat cushion bottom board, and finally, covering the upper covering layer and using the fixing needle to temporarily secure the middle portion of the upper covering layer.

4. The method for making the bow-shaped spring sofa according to claim 1, wherein in the step 3, a method for securing the lining materials using needles and thread comprises:sequentially covering the bow-shaped spring assembly with the lower covering layer, the filling material pad, and the upper covering layer, then folding the edges of the upper covering layer downwards, inserting the fixing needle through the edges of the lower covering layer, the filling material pad, and the upper covering layer, and then using a long sewing needle with pointed ends at both sides and a needle eye at one end, along with a thread, to stitch and tie knots along the middle portion of the upper covering layer, stitching the upper covering layer, the filling material pad, and the lower covering layer together vertically, and securing them onto the bow-shaped spring assembly.

5. The method for making the bow-shaped spring sofa according to claim 1, wherein in the step 2, a specific method for securing the bow-shaped springs longitudinally on the base frame or the seat cushion bottom board comprises: the base frame or the seat cushion bottom board is made of wood or plastic wood, and U-shaped grooves are set at the positions on the base frame or the seat cushion bottom board where the bow-shaped springs are installed, placing the two ends of the bow-shaped springs into the corresponding U-shaped grooves, the two ends of the bow-shaped springs are U-shaped, using a bow-shaped spring securing piece to fix both ends of the bow-shaped springs into the corresponding U-shaped grooves, the plate-like body of the bow-shaped spring securing piece has at least one securing hole in the middle, with four securing wings extending from the middle, at least three of the securing wings having claws at the ends that bend towards the same side, the overall shape of the bow-shaped spring securing piece is cross-shaped.

6. The method for making the bow-shaped spring sofa according to claim 1, wherein the filling material pad is a palm fiber pad, coconut fiber pad, grapefruit fiber pad, or bamboo fiber pad wrapped in hemp cloth, the lower covering layer and the upper covering layer are both made of hemp cloth or synthetic fiber cloth, and the fiber filling is made of materials such as cotton, pearl cotton, silk cotton, or synthetic fibers.

7. The method for making the bow-shaped spring sofa according to claim 1, wherein the seat cushion bottom board, with the bow-shaped spring assembly installed and fixed and covered with the lining materials, is fixed to the base frame.

8. The method for making the bow-shaped spring sofa according to claim 1, wherein the method and steps for making the backrest and the materials used are basically the same as those for making the sofa seat cushion.

9. The method for making the bow-shaped spring sofa according to claim 5, wherein the method and steps for making the backrest and the materials used are basically the same as those for making the sofa seat cushion.

10. A bow-shaped spring sofa, comprising a sofa seat cushion and a backrest, wherein the sofa seat cushion and the backrest are made using the method for making the bow-shaped spring sofa according to claim 1.

11. The method for making the bow-shaped spring sofa according to claim 2, wherein in the step 3, a method for securing the lining materials by the connectors comprises:wrapping the lower covering layer around the bow-shaped spring assembly, using C-clips from a C-clip gun to connect and fix the lower covering layer to the quadrangular steel wire frame of the bow-shaped spring assembly, using clamp strips from a clamp strip gun to fix the edges of the lower covering layer to the base frame or the seat cushion bottom board, then covering the filling material pad on the lower covering layer, using C-clips from a C-clip gun to connect and fix the filling material pad to the quadrangular steel wire frame of the bow-shaped spring assembly, using clamp strips from a clamp strip gun to fix the edges of the filling material pad to the base frame or the seat cushion bottom board, and finally, covering the upper covering layer and using the fixing needle to temporarily secure the middle portion of the upper covering layer.

12. The method for making the bow-shaped spring sofa according to claim 2, wherein in the step 3, a method for securing the lining materials using needles and thread comprises:sequentially covering the bow-shaped spring assembly with the lower covering layer, the filling material pad, and the upper covering layer, then folding the edges of the upper covering layer downwards, inserting the fixing needle through the edges of the lower covering layer, the filling material pad, and the upper covering layer, and then using a long sewing needle with pointed ends at both sides and a needle eye at one end, along with a thread, to stitch and tie knots along the middle portion of the upper covering layer, stitching the upper covering layer, the filling material pad, and the lower covering layer together vertically, and securing them onto the bow-shaped spring assembly.

13. The method for making the bow-shaped spring sofa according to claim 2, wherein in the step 2, a specific method for securing the bow-shaped springs longitudinally on the base frame or the seat cushion bottom board comprises: the base frame or the seat cushion bottom board is made of wood or plastic wood, and U-shaped grooves are set at the positions on the base frame or the seat cushion bottom board where the bow-shaped springs are installed, placing the two ends of the bow-shaped springs into the corresponding U-shaped grooves, the two ends of the bow-shaped springs are U-shaped, using a bow-shaped spring securing piece to fix both ends of the bow-shaped springs into the corresponding U-shaped grooves, the plate-like body of the bow-shaped spring securing piece has at least one securing hole in the middle, with four securing wings extending from the middle, at least three of the securing wings having claws at the ends that bend towards the same side, the overall shape of the bow-shaped spring securing piece is cross-shaped.

14. The method for making the bow-shaped spring sofa according to claim 2, wherein the filling material pad is a palm fiber pad, coconut fiber pad, grapefruit fiber pad, or bamboo fiber pad wrapped in hemp cloth, the lower covering layer and the upper covering layer are both made of hemp cloth or synthetic fiber cloth, and the fiber filling is made of materials such as cotton, pearl cotton, silk cotton, or synthetic fibers.

15. The method for making the bow-shaped spring sofa according to claim 2, wherein the seat cushion bottom board, with the bow-shaped spring assembly installed and fixed and covered with the lining materials, is fixed to the base frame.

16. The method for making the bow-shaped spring sofa according to claim 2, wherein the method and steps for making the backrest and the materials used are basically the same as those for making the sofa seat cushion.

Images