Feed arm type sewing machine

Abstract

The present invention provides a feed arm type sewing machine which reduces the number of components and the number of connecting components, thereby making miniaturization and reduction of looseness possible. The feed arm type sewing machine of the present invention has: a needle which performs reciprocating motion in linkage with the rotation of a sewing machine main shaft; a hook which captures a needle thread loop in synchronization with the needle to form a stitch; a feed table having a feed dog at the front end; a needle guard table which is provided in parallel with the feed table and has a needle guard at the front end; a needle guard table lever which is connected to the needle guard table at the front side and has an eccentric hole at the rear side, and is connected to the sewing machine main shaft through an eccentric; long holes are formed in the feed table and the needle guard table, and a fixing pin is fixed to the frame of the sewing machine by passing through the long holes and an angle block provided in the long holes; the rear end of the needle guard table and the rear end of the feed table are connected to each other in linkage through a pin and an angle block; characterized in that the eccentric makes the needle guard table perform elliptical motion, and the feed table performs up-and-down motion through the pin and the angle block of the rear end of the needle guard table and the rear end of the feed table.

Description

Technical Field

[0001] This invention relates to sewing machines, and more particularly, to a feed arm type sewing machine. Background Technology

[0002] As is known in the prior art, various feed table and needle guard drive mechanisms exist in feed arm type sewing machines. For example, in the sewing machine of Patent Document 1, the feed table and needle guard are arranged side by side. A needle guard is installed on the needle guard, and a feed dog is installed on the feed table.

[0003] The up-and-down movement of the fabric feeding table and the needle guarding table is achieved through the first eccentric wheel and the linkage mechanism, and the back-and-forth movement of the needle guarding table is achieved through the second eccentric wheel and the linkage mechanism.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2005-58700. Summary of the Invention

[0007] The technical problem to be solved by the present invention

[0008] In the technical solution of Patent Document 1, the up-and-down movement of the feed table and the needle guard table is achieved through a first eccentric wheel, while the back-and-forth movement of the needle guard table is achieved through a second eccentric wheel. In other words, the elliptical motion (up-and-down, back-and-forth) of the needle guard (needle guard table) requires two eccentric wheels. Therefore, in the solution of Patent Document 1, the large number of components results in a relatively large sewing machine, making miniaturization difficult.

[0009] Furthermore, Patent Document 1 contains a large number of components, resulting in a large number of connecting parts. For example, multiple pins and screws are used to connect the various components. This can easily lead to loosening. Loosening can affect the needle guard, potentially causing problems such as skipped stitches, broken threads, poor sewing, and decreased sewing quality.

[0010] Therefore, the present invention was made in view of the above-mentioned technical problems, and its object is to provide a feed arm type sewing machine having a reduced number of parts and connecting parts, thereby making miniaturization and loosening problems possible.

[0011] Problem-solving methods

[0012] To achieve the above objectives, the feed arm type sewing machine of the first aspect (first invention) of this application comprises:

[0013] A needle that reciprocates in conjunction with the rotation of the sewing machine spindle, the sewing machine spindle being perpendicular to the sewing direction;

[0014] The loop of needle thread is captured by the curved needle to form a stitch in sync with the reciprocating motion of the needle;

[0015] A feed table, with feed teeth installed at its front end;

[0016] A needle guarding table is arranged side by side with the fabric feeding table, and a needle guarding table is installed at the front end of the needle guarding table to protect the needle.

[0017] A needle guard rod, the front side of which is connected to the needle guard platform, and the rear side of which is provided with an eccentric wheel hole, through which an eccentric wheel is provided in the eccentric wheel hole and connected to the sewing machine spindle;

[0018] The fabric feeding table and the needle guard table have elongated holes, and the fixing pin passes through the elongated holes and the corner block provided in the elongated holes to fix it to the frame of the sewing machine;

[0019] The rear end of the needle guard and the rear end of the fabric feeding table are connected to each other and linked by pins and corner blocks;

[0020] The eccentric wheel causes the needle guard to move in an elliptical motion, and the feed table moves up and down via pins and corner blocks located at the rear end of the needle guard and the rear end of the feed table.

[0021] In the sewing machine of the first aspect, only a single eccentric wheel is used to make the needle guard table move elliptically and to move the feed table up and down. This reduces the number of parts and connecting components, enabling miniaturization of the equipment. Furthermore, the fewer connecting components reduce the occurrence of loosening, allowing the device to operate accurately for extended periods without malfunction.

[0022] In the second aspect (second invention) of this application, in the feed arm sewing machine of the first aspect, the parameters of the feed arm sewing machine are set such that when the needle is at the top dead center, the feed dog is at the top dead center, and when the looper ends its needle thread catch, the guard is at the back dead center.

[0023] In a third aspect (third invention) of the present application, in the feed arm type sewing machine of the second aspect, the parameters include at least one of the following: the eccentricity of the eccentric wheel, the position of the fixing pin, the position of the sewing machine spindle, the mounting position of the needle guard rod on the needle guard platform, the mounting position of the feed dog on the feed platform, and the mounting position of the needle guard on the needle guard platform.

[0024] Through the second and third aspects mentioned above, the movements of the needle, feed dog, curved needle, and needle guard can be coordinated to form an ideal motion.

[0025] In the fourth aspect (fourth invention) of this application, in the feed arm type sewing machine of the first to third aspects, when the feed arm type sewing machine is in operation, the sewing machine spindle is located directly below the needle guard and the fabric feed table at least for a portion of the time.

[0026] The fourth aspect of sewing machines can further reduce the size of the equipment in the front-to-back direction, which is conducive to further miniaturization of the equipment.

[0027] In the fifth aspect (fifth invention) of this application, in the feed arm type sewing machine of the first to third aspects, the needle guard rod is integrally formed with the needle guard.

[0028] In the fifth aspect of the sewing machine, since the needle guard rod and the needle guard table are integrated, the fasteners between the needle guard rod and the needle guard table are no longer needed, which further reduces the number of parts and connecting parts.

[0029] In the sixth aspect (sixth invention) of this application, in the feed arm type sewing machine of the first to third aspects, the front end of the feed table is shorter than the front end of the needle guard table, and the feed dog is connected to the front surface of the front end of the feed table by a fastening member.

[0030] In the sixth aspect of the sewing machine, the feed dog can be appropriately located at the front end of the feed table and appropriately positioned across the feed table and the needle guard.

[0031] In the seventh aspect (seventh invention) of this application, in the feed arm type sewing machine of the first to third aspects, the feed table is one or more.

[0032] This application can be applied to sewing machines with a single feed table or sewing machines with differential feed.

[0033] Invention Effects

[0034] According to the present invention, the elliptical motion (up-down and back-and-forth motion) of the needle can be achieved by using only a single eccentric wheel, and the up-down motion of the feed table can be achieved by the same eccentric wheel.

[0035] Furthermore, by setting the parameters of the sewing machine, ideal motion coordination between the needle, feed dog, needle guard, and looper can be achieved.

[0036] In addition, the number of parts and connecting parts is reduced, thus miniaturizing the device and reducing the probability of parts becoming loose. Attached Figure Description

[0037] Figure 1 This is a perspective view of a delivery arm sewing machine according to an embodiment of this application.

[0038] Figure 2This is a schematic diagram of the front end of the feed table and the needle guard table.

[0039] Figure 3 This is a diagram of a needle and a curved needle.

[0040] Figure 4 This is a three-dimensional view of the fabric feeding and needle guard assembly.

[0041] Figure 5 This is an exploded view of the fabric feeding and needle guard assembly. Detailed Implementation

[0042] Figure 1 This is a perspective view of a feed arm type sewing machine 1 according to an embodiment of this application. The sewing machine 1 includes a frame 11, a support arm 12, and a feed and needle guard assembly 13. The feed and needle guard assembly 13 is housed in the frame 11.

[0043] As shown in the figure, the three-dimensional directions in space are represented by X, Y, and Z. In this embodiment, the X direction is called the front-back direction, the Z direction is called the up-down direction, and the Y direction is called the left-right direction. The +X direction is referred to as front, and the -X direction as back. Of course, this is merely an example and not a limitation.

[0044] In the support arm 12 of the sewing machine 1 of this application, the needle 14 reciprocates up and down (in the Z direction) in a rotational linkage with the sewing machine spindle. The feed dog transports the fabric along the +X direction, which is the sewing direction. The sewing machine spindle is configured to extend along the Y direction, that is, perpendicular to the sewing direction. The feed table and needle guard move in the X and Z directions to realize the movement of the feed dog and needle guard. The specific structure will be described in detail later.

[0045] Figure 2 This is a schematic diagram of the front end of the feed table 21 and the needle guard table 22. (See diagram below.) Figure 2 As shown, the feed table 21 and the needle guard table 22 are arranged side by side. A feed dog 23 is installed at the front end of the feed table 21. The front end of the feed dog 23 in the +X direction is formed to protrude further towards the +X direction than the front end of the needle guard table 22 in the +X direction.

[0046] The width of the feed dog 23 in the Y direction is approximately the sum of the widths of the feed table 21 and the needle guard table 22 in the Y direction. Viewed along the +Y direction, the feed dog 23 is bridge-shaped, forming a space below. A needle guard 24 is installed at the front end of the needle guard table 22. The needle guard 24 protrudes from the needle guard table 22 toward the +Z direction and is located in the space below the feed dog 23.

[0047] Figure 3 This is a schematic diagram of needle 14 and looper 25. (See diagram below.) Figure 3As shown, there can be multiple needles 14, such as three. Of course, this is just an example, and there can be other numbers of needles 14. A looper 25 is mounted on a looper drive shaft 26. The looper drive shaft 26 is arranged parallel to the needle guard 22 and is linked to the rotation of the sewing machine spindle. Thus, the reciprocating motion of the looper 25 and the needles 14 synchronously captures the thread loop to form a stitch.

[0048] Figure 4 This is a perspective view of the fabric feeding and needle guard assembly 13. (See diagram below.) Figure 4 As shown, the feed table 21 and the needle guard table 22 are arranged side by side. Elongated holes 21a and 22a are formed in the middle portions of the feed table 21 and the needle guard table 22, respectively. Fixing pins and corner blocks are disposed in the elongated holes 21a and 22a. The front side of the needle guard table rod 3 is connected to the needle guard table.

[0049] In this figure, the needle guard rod 3 is connected to the needle guard platform by fasteners such as bolts. Alternatively, the needle guard rod 3 can be integrally formed with the needle guard platform. This further reduces the number of connecting parts, thus further decreasing the possibility of loosening.

[0050] As shown in Figure A, an eccentric wheel hole 31 is formed on the rear side of the needle guard rod 3. As shown in Figure B, an eccentric wheel 32 is provided in the eccentric wheel hole 31. The eccentricity of the eccentric wheel 32 is e. Through this eccentric wheel 32, the needle guard rod 3 is connected to the sewing machine spindle 4. As shown in the figure, the sewing machine spindle 4 is perpendicular to the sewing direction +X. When the sewing machine spindle 4 rotates, the needle guard rod 3 transmits its up-and-down and back-and-forth motion to the needle guard table 22 through the eccentric wheel 32.

[0051] Figure 5 This is an exploded view of the fabric feeding and needle guard assembly 13. (See diagram below.) Figure 5 As shown, the front end of the feed table 21 is shorter than the front end of the needle guard table 22. The feed teeth 23 are fastened to the front surface of the feed table 21 by fasteners such as bolts. The needle guard 24 is mounted to the needle guard table 22 by fasteners such as bolts.

[0052] The retaining pin 27 and corner blocks 28a and 28b pass through the elongated holes 22a and 21a. The retaining pin 27 is fixed to the frame 11 of the sewing machine 1. With this structure, the retaining pin 27 becomes the fulcrum for the up-and-down movement of the needle guard 22. A double-forked portion 21b with a rear end opening is formed at the rear end of the feed table 21, and a pin hole portion 22b is formed at the rear end of the needle guard 22.

[0053] The corner block 29 is disposed within the double-fork portion 21b by means of a pin 30 inserted into the pin hole portion 22b. Therefore, the corner block 29 is not fixed relative to the feed table 21, and the corner block 29 can move back and forth within the double-fork portion 21b. With this structure, the up-and-down movement of the needle guard 22 is transmitted to the feed table 21, but the back-and-forth movement of the needle guard 22 is not transmitted to the feed table 21.

[0054] like Figure 5 As shown, the needle holder rod 3 is connected to the sewing machine main shaft 4 via the eccentric wheel 32 located in the eccentric wheel hole 31. The rod 6 is connected to the sewing machine main shaft 4 via the eccentric wheel. The other end of the rod 6 is connected to the swing member 62 via a pin 61. The swing shaft 5 passes through the center hole of the swing member 62. Furthermore, the swing shaft 5 passes through the center hole of the swing member 63. Figure 4 As shown, the swing components 62 and 63 are spaced apart. The front end of the rod 7 is connected to the feed table 21 by fasteners. The rear end of the rod 7 is connected to the swing component 63 by fasteners.

[0055] With the above structure, when the sewing machine spindle 4 rotates, the needle guard 22 moves back and forth and up and down via the eccentric wheel 32. Simultaneously, the up and down movement of the needle guard 22 is also transmitted to the feed table 21 via the pin 30 and corner block 29, thus causing the feed table 21 to move up and down. Furthermore, the rotational motion of the sewing machine spindle 4 is transmitted to the feed table 21 sequentially via the rod 6, swing component 62, swing shaft 5, swing component 63, and rod 7, causing the feed table 21 to move back and forth.

[0056] Therefore, the forward and backward up and down movement (i.e., elliptical motion) of the needle guard 22 and the up and down movement of the feed table 21 are achieved through a single needle guard rod 3 and eccentric wheel 32. In the sewing machine 1 of the present application embodiment, the amount and timing of the elliptical motion of the needle guard 24, and the amount and timing of the up and down movement of the feed dog 23 are affected by multiple factors.

[0057] For example, factors affecting the amount and timing of the elliptical motion of the needle guard 24 may include the installation position of the needle guard 24 on the needle guard table 22, the installation position of the fixing pin 27, the installation position of the needle guard table rod 3 on the needle guard table 22, the eccentricity of the eccentric wheel 32, and the position of the sewing machine spindle 4.

[0058] For example, factors affecting the amount and timing of the feed dog 23's up-and-down movement may include the installation position of the feed dog 23 on the feed table 21, the installation position of the fixing pin 27, the installation position of the needle guard rod 3 on the needle guard table 22, the eccentricity of the eccentric wheel 32, and the position of the sewing machine spindle 4. When the needle 14 is at the top dead center, the feed dog is at the top dead center, and when the looper finishes capturing the thread loop, the needle guard is at the back dead center, the sewing machine 1 can perform ideal movement.

[0059] Therefore, the parameters that affect the elliptical motion of the needle guard 24 and the up-and-down movement of the feed dog 23 need to be calculated during the manufacturing stage or adjusted during use so that when the needle 14 is at the top dead point, the feed dog is at the top dead point, and when the curved needle finishes capturing the needle thread loop, the needle guard is at the back dead point.

[0060] Given the installation positions of the feed dog 23 on the feed table 21, the fixing pin 27, the needle guard rod 3 on the needle guard table 22, and the sewing machine spindle 4, the eccentricity e1 of the eccentric wheel 32 is calculated to ensure that the feed dog is at the top dead center when the needle 14 is at the top dead center. Furthermore, given the installation positions of the needle guard 24 on the needle guard table 22, the fixing pin 27, the needle guard rod 3 on the needle guard table 22, and the sewing machine spindle 4, the eccentricity e2 of the eccentric wheel 32 is calculated to ensure that the needle guard is at the back dead center when the looper catches the thread loop.

[0061] If e1 and e2 are equal, then theoretically a single eccentric wheel can be used to simultaneously achieve the elliptical motion of the needle guard and the up-and-down motion of the feed table. Of course, other parameters can also be changed during the manufacturing or usage stage, as long as it ensures that when needle 14 is at the top dead center, the feed dog is at the top dead center, and when the curved needle finishes capturing the thread loop, the needle guard is at the back dead center.

[0062] When the sewing machine 1 in this embodiment is working, such as Figure 4 As shown, the sewing machine spindle 4 is located directly below the needle guard and feed table at least part of the time. This structure allows for a compact design of the sewing machine 1, thus facilitating miniaturization.

[0063] Furthermore, only one feed table is shown in this embodiment. This application is not limited to this embodiment; multiple feed tables may also be used. In the case of multiple feed tables, the feed tables may move differentially. Moreover, this application only shows exemplary embodiments. Various modifications can be made by those skilled in the art based on this disclosure. The scope of this application is defined only by the claims.

[0064] Symbol Explanation

[0065] 1. Sewing machine

[0066] 3. Needle protection stand

[0067] 4. Sewing machine spindle

[0068] 5. Balance axis

[0069] 6 and 7 strokes

[0070] 11 Framework

[0071] 12 arms

[0072] 13 Fabric feeding and needle guard assembly section

[0073] 14 stitches

[0074] 21. Fabric delivery table

[0075] 21a Long hole

[0076] 21b Double-forked section

[0077] 22 Needle Protection Table

[0078] 22a Long hole

[0079] 22b Pin Hole

[0080] 23. Delivery of cloth teeth

[0081] 24 needles

[0082] 25. Curved needle

[0083] 26. Bending needle drive shaft

[0084] 27 Fixed pins

[0085] Corner pieces 28a, 28b, and 29

[0086] 30 sales

[0087] 31 Eccentric wheel hole

[0088] 32 Eccentric Wheel

[0089] 61 sales

[0090] 62, 63 Oscillating components.

Claims

1. A feed arm type sewing machine, comprising: A needle that reciprocates in conjunction with the rotation of the sewing machine spindle, the sewing machine spindle being perpendicular to the sewing direction; The loop of needle thread is captured by the curved needle to form a stitch in sync with the reciprocating motion of the needle; A feed table, with feed teeth installed at its front end; A needle guarding table is arranged side by side with the fabric feeding table, and a needle guarding table is installed at the front end of the needle guarding table to protect the needle. A needle guard rod, the front side of which is connected to the needle guard platform, and the rear side of which is provided with an eccentric wheel hole, through which an eccentric wheel is provided in the eccentric wheel hole and connected to the sewing machine spindle; The fabric feeding table and the needle guard table have elongated holes, and the fixing pin passes through the elongated holes and the corner block set in the elongated holes to fix it to the frame of the sewing machine; The rear end of the needle guard and the rear end of the fabric feeding table are connected to each other and linked by pins and corner blocks; Its features are, The eccentric wheel causes the needle guard to move in an elliptical motion, and the pin and corner block located at the rear end of the needle guard and the rear end of the feed table cause the feed table to move up and down.

2. The feed arm type sewing machine as described in claim 1, characterized in that, The parameters of the feed arm sewing machine are set such that when the needle is at the top dead center, the feed dog is at the top dead center, and when the looper finishes capturing the thread loop, the guard is at the back dead center.

3. The feed arm type sewing machine as described in claim 2, characterized in that, The parameters include at least one of the following: the eccentricity of the eccentric wheel, the position of the fixing pin, the position of the sewing machine spindle, the mounting position of the needle guard rod on the needle guard platform, the mounting position of the feed dog on the feed platform, and the mounting position of the needle guard on the needle guard platform.

4. The feed arm type sewing machine as described in any one of claims 1-3, characterized in that, When the feed arm type sewing machine is in operation, the sewing machine spindle is located directly below the needle guard and the fabric feed table at least for a portion of the time.

5. The feed arm type sewing machine as described in any one of claims 1-3, characterized in that, The needle guard rod is integrally formed with the needle guard platform.

6. The feed arm type sewing machine as described in any one of claims 1-3, characterized in that, The front end of the fabric feeding table is shorter than the front end of the needle guarding table. The feed teeth are connected to the front surface of the front end of the feed table via fastening components.

7. The feed arm type sewing machine as described in any one of claims 1-3, characterized in that, The fabric feeding table is one or more.

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