JPH07278U - Inner pot of sewing machine - Google Patents

Abstract

(57) [Summary] [Purpose] A sewing machine that does not cause stains on sewing products, does not cause sewing shrinkage, thread breakage, or uneven thread tightening, and is not damaged by sewing needles. Provide a kettle. [Structure] The sewing machine is provided at a position where a sewing operation is performed, and has a needle receiving port 13 through which a needle 8 with an upper thread penetrates, and is provided in a concave portion of a rotating outer hook 1. An inner hook 2 slidably held with an inner peripheral surface of the recess with the needle receiving opening exposed to the outside of the recess, wherein the inner hook is formed of a member having a low friction coefficient, The needle receiving portion forming the outer hook side edge portion of the needle receiving opening is provided with a needle abutting portion having a metal inclined surface that descends toward the needle receiving opening side.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an inner hook of a sewing machine, which is a component of the sewing machine and is provided at a position where a sewing operation is performed.

[0002]

[Prior art]

 Conventionally, the inner pot of a sewing machine is made of steel from the standpoint of durability in industrial sewing machines, except for some household sewing machines, and undergoes processes such as shaving, quenching, grinding, polishing, and hard chrome plating. It was produced after that. The outer hook and inner hook provided in the sewing machine will be described with reference to the drawings. 8 shows an assembly plan view of the outer hook 1, the inner hook 2, and the inner hook rotation preventing member 3, and FIG. 9 shows a vertical section taken along line A-A 'shown in FIG. In each figure, the same components are designated by the same reference numerals. The outer hook 1 is fixed to a shaft 4 mounted on a machine frame (not shown) by a set screw 15, and when the shaft 4 rotates in the direction of arrow B, it rotates in the direction of arrow B together with the shaft 4. On the other hand, as shown in FIG. 9, the inner hook 2 fitted into the recess 16 formed in the outer hook 1 projects into the groove 5 formed on the inner peripheral surface of the recess 16 on the outer peripheral surface of the inner hook 2. The inner hook 2 is held in the recess 16 of the outer hook 1 by the inner hook pressing member 12 which is engaged with the sliding portion 6 provided and is further screwed to the outer peripheral surface of the outer hook 1. The inner hook 2 is slidably held on the inner peripheral surface of the recess 16 with the needle receiving opening 13 exposed to the outside of the recess 16.

As described above, since the inner hook 2 is held by the outer hook 1, the inner hook 2 tries to rotate in the same direction as the outer hook 1 rotates, but as shown in FIG. The protrusion 3a of the inner hook stopper member 3 provided separately from the outer hook 1 and the inner hook 2 engages with the recess 7 formed in a part of the upper portion of the outer hook of the hook 2, and Since the stopper member 3 is fixed to the machine frame, even if the inner hook 2 tries to rotate in the same direction as the outer hook 1, the wall surface 7a of the recess 7 and the protruding portion 3a come into contact with each other and the inner hook 2 becomes the outer hook. It is prevented from rotating following the rotation of 1. Therefore, the sliding portion 6 of the inner hook 2 which is prevented from rotating and the groove 5 of the outer hook 1 slide and the outer hook 1 rotates together with the shaft 4. The upper thread passes through the gap formed in the engaging portion between the concave portion 7 and the inner hook detent member 3.

[0004]

[Problems to be solved by the device]

 By the way, when the outer pot 1 and the inner pot 2 are made of a steel material as described above, the sliding friction between the groove 5 of the outer pot 1 and the sliding portion 6 of the inner pot 2 is large, and this friction is reduced. Therefore, it is necessary to lubricate the sliding portion between the groove 5 and the sliding portion 6, which causes a problem that the sewn product becomes dirty. In addition, the friction increases the rotational torque of the inner hook 2 in the direction of the arrow C shown in FIG. 8, which is in the same direction as the outer hook 1 as the rotation speed of the outer hook 1 increases. At 2, a pressing force is generated which is pressed against the protrusion 3a of the inner hook detent member 3. As described above, the upper thread passes through the gap formed in the engaging portion between the recess 7 and the inner hook stopper member 3, but the increased pressing force means that the upper thread is in the inner hook 2 and the inner hook. This will prevent it from passing through between the whirl-stop member 3 and the upper thread must pass while spreading the inner hook 2 pressed against the inner-hook lock member 3. Therefore, the upper thread needs a tension to resist the pressing force, and the large friction causes the pressing force to be strong, resulting in shrinkage, thread breakage, and thread tightening unevenness during sewing. There is also. In order to improve such a state, it is known that the inner pot 2 is made of a plastic material having a smaller friction coefficient than a metal material so as to reduce the friction. However, as shown in FIG. 9, the needle 8 may bend as shown by the dotted line depending on the sewing condition. When such bending occurs in the needle 8, a situation occurs in which the needle tip comes into contact with the needle receiving portion 9 forming the outer hook side edge of the needle receiving port 13. In such a case, when the inner pot 2 is made of a plastic material, the hardness of the plastic material is lower than that of the metal that is the material of the needle 8, so that the needle tip moves the needle 8 into and out of the inner pot 2. There is a problem that the needle receiving portion 9 of the needle receiving port 13 is pierced and the needle receiving portion 9 of the inner pot 2 is damaged thereby. The present invention has been made in order to solve such a problem, and does not cause stains on a sewn product and does not cause shrinkage, thread breakage, or thread tightening unevenness, and a sewing needle. The purpose of the present invention is to provide an inner hook of a sewing machine that is not damaged.

[0005]

[Means for solving the problem]

 The present invention, which is a component of a sewing machine and is provided at a place where a sewing operation is performed, has a needle receiving port through which a sewing needle, through which an upper thread penetrates, and which is provided in a recess of a rotating outer hook. An inner pot, which is slidably held on the inner peripheral surface of the recess with the needle receiving opening exposed to the outside of the recess, wherein the inner pot is made of a material having a smaller dynamic friction coefficient than a metal material. The needle receiving portion forming the outer hook side edge portion of the needle receiving opening is provided with a needle abutting portion having an inclined surface made of metal and descending toward the needle receiving opening side.

[0006]

[Action]

 With this structure, sliding friction between the inner hook and the outer hook is reduced. Therefore, it is not necessary to apply oil to the sliding portion between the inner hook and the outer hook, and it works to prevent the oil from adhering to the sewn product. In addition, reducing the friction reduces the force of pinching the upper thread between the inner hook and the inner hook stopping member, and therefore acts to eliminate the occurrence of sewing shrinkage, thread breakage, and uneven thread tightening. Further, the needle contact plate provided in the needle receiving portion of the inner hook causes the needle tip to come into contact with the metal inclined surface of the needle contact plate even if the sewing needle is bent, and Since the inclined surface is inclined toward the needle receiving port side, it functions to guide the needle tip contacting the inclined surface to the needle receiving port.

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. It should be noted that, of the components shown in FIGS. 1 to 6, the same components as those shown in FIGS. 8 and 9 are designated by the same reference numerals, and the description thereof will be omitted.

The inner kettle 20 is substantially the same in shape, configuration, and operation as the inner kettle 2 described above, but the material for molding the inner kettle 20 is a synthetic polymer compound such as a plastic material. Specifically, it is a polyimide resin. A plastic material having a dynamic friction coefficient in the range of 0.07 to 0.2 is preferable. An example of such a plastic material is Mitsui Toatsu Chemical Co., Ltd., product number JRF4025, and dynamic friction coefficient 0.16. By molding the inner pot 20 with the plastic material as described above, the inner pot 20 is molded with a metal material, for example, a steel material, which is equal to or higher than the S15C material defined by JIS, for example, chrome molybdenum steel. The coefficient of friction between the groove 5 of the outer pot 1 and the sliding portion 6 of the inner pot 20 engaging with the groove 5 is reduced as compared with the case of metal-to-metal. Therefore, it is not necessary to lubricate the engaging portion between the groove 5 and the sliding portion 6, so that oil does not adhere to the sewn product. Further, since the friction is reduced, the pressing force with which the inner hook 2 is pressed against the protrusion 3a of the inner hook stopper member 3 is reduced even if the rotation speed of the outer hook 1 is increased. Therefore, it becomes easier for the upper thread to pass through between the inner hook 2 and the inner hook detent member 3, and no excessive tension is generated in the upper thread. No uneven tightening occurs.

Further, rather than going through the steps of shaving, quenching, grinding, polishing, and hard chrome plating as in the case of manufacturing a metal inner pot, by molding the inner pot of a complicated shape with the above plastic. The number of manufacturing steps can be reduced and the productivity of the inner pot can be improved.

Further, as shown in FIG. 2 or 3, the inner hook 20 covers the needle receiving portion 9 formed in the inner hook 20, and the square needle contact plate 10 as shown in FIG. The longitudinal direction is made to coincide with the circumferential direction of the inner pot 20, and the inner pot 20 is fixed by an appropriate method such as an adhesive fixing method. The needle abutting plate 10 is bent or substantially bent along an arc forming the outer peripheral surface of the inner hook 20, or is made of a metal, for example, a steel material, which is equivalent to the S15C material defined by JIS. It is a thin plate made of the above-mentioned material, for example, chromium molybdenum steel, and is hardened by a method such as quenching. Furthermore, a part of the needle contact plate 10 extending along the extending direction of the elongated hole-shaped needle receiving port 13 is bent so as to form an inclined surface 10a that is inclined toward the needle receiving port 13 side. . As shown in FIG. 3, the needle contact plate 10 may be embedded in the inner hook 20 so that the surface 10b of the needle contact plate 10 is flush with the surface 20a of the inner hook 20. Alternatively, it may be placed on the surface 20a of the inner pot 20.

With this configuration, as shown in FIG. 1, even when the needle 8 is bent as shown by the dotted line due to the sewing state, the needle tip is made of the above plastic material. The needle contact plate 10 that covers the needle receiving portion 9 that contacts the inclined surface 10a. As described above, since the needle contact plate 10 is made of metal, the needle tip does not pierce the needle contact plate 10, and the needle tip is guided by the inclination of the inclined surface 10a so that the needle reception port 13 Be led to. Therefore, even if the inner hook 20 is molded of the above plastic material, the needle 8 does not damage the needle receiving portion 9 of the inner hook 2 by providing the needle contact plate 10 on the inner hook 20.

The needle contact plate is not limited to the shape described above, but may be the needle contact plate 11 having the shape shown in FIG. 7, for example. As shown in the attached state in FIGS. 5 and 6, the needle contact plate 11 is made of a metal material, for example, the entire needle receiving portion 9 that forms the needle receiving port 13 of the inner pot 20 molded of the plastic material. The needle contact plate 11 is a member that replaces the steel material, and the needle contact plate 11 is a part corresponding to the needle receiver 9 and is formed integrally with the metal needle receiver 11b and the metal needle receiver 11b. It is composed of a plate-shaped fixing portion 11c for attaching and fixing 11 to the inner pot 20. The needle contact plate 11 is hardened, for example, by quenching, and the fixed portion 11c is fixed to the fixed portion 11c in order to prevent the needle contact plate 11 from falling out of the inner pot after molding. A through hole 11f is formed to allow the above plastic material to wrap around 11c.

As shown in FIG. 5, the metal needle receiving portion 11 b has a width substantially equal to the longitudinal length of the needle receiving opening 13 having a long hole, and the side wall of the needle receiving opening 13 on the outer hook side. Is formed, and preferably an upper surface 11d forming an arc which is the same curved surface as the outer peripheral surface of the inner hook 20 is formed, and further from the upper surface 11d to the end surface 11e toward the needle receiving port 13 side. A descending inclined surface 11a is formed. Further, as shown in FIG. 6, the thickness of the metal needle receiving portion 11b is substantially equal to the wall thickness of the inner pot 20. In the metal needle receiving portion 11b molded in this manner, the end surface 11e constitutes a side wall of the needle receiving port 13 on the outer hook side, and the upper surface 11d is flush with the outer peripheral surface of the inner hook 20. As described above, the fixing portion 11c is disposed in the needle receiving portion 9 of the inner hook 20 and is embedded in the inner hook 20 so that the inner hook 20 is molded and fixed at a predetermined position at the same time.

With this configuration, as in the case of the needle contact plate 10 described above, even when the needle 8 is bent due to the sewing state as shown by the dotted line, the needle tip is The needle tip does not pierce the needle contact plate 11 by contacting the inclined surface 11a of the metal needle contact plate 11 forming the receiving portion 9, and the needle 8 is guided by the inclination of the inclined surface 11a. And is guided toward the needle receiving port 13. Therefore, by providing the needle contact plate 11, even if the inner pot 20 is molded of the plastic material, the needle 8 does not damage the needle receiving portion 9 of the inner pot 2.

[0015]

[Effect of device]

 As described in detail above, according to the present invention, by molding the inner pot made of a material having a smaller dynamic friction coefficient than the metal material, the friction between the outer pot and the inner pot is reduced, and the sliding There is no need to lubricate moving parts, and oil will not adhere to sewn products. Also, since the above-mentioned friction is reduced, the force with which the inner hook is pressed against the protrusion of the inner hook stopper member is reduced even if the rotation speed of the outer hook increases, so the inner hook and inner hook stopper The upper thread can easily pass through between the member and the member, excessive tension is not generated in the upper thread, and sewing shrinkage, thread breakage, and uneven thread tightening do not occur. Furthermore, by providing the needle contact plate on the inner pot made of a material having a smaller dynamic friction coefficient than the metal material, even if the needle is bent due to the sewing condition, the needle tip is made of the metal of the needle contact plate. Since the needle abuts on the inclined surface, it is possible to prevent the needle from sticking into the needle receiving portion of the inner hook, and it is possible to prevent damage to the inner hook due to the needle sticking.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of an inner pot of the present invention with a needle contact plate attached.

FIG. 2 is a plan view showing a state where an example of a needle contact plate is attached to the inner pot of the present invention.

3 is a cross-sectional view taken along line BB ′ shown in FIG.

4 is a perspective view showing a needle contact plate shown in FIGS. 1 to 3. FIG.

FIG. 5 is a plan view showing a state in which another example of the needle contact plate is attached to the inner pot of the present invention.

6 is a cross-sectional view taken along the line CC ′ shown in FIG.

7 is a perspective view showing a needle contact plate shown in FIGS. 5 and 6. FIG.

FIG. 8 is a plan view showing a state in which a conventional inner pot is attached to an outer pot.

9 is a vertical cross-sectional view taken along the line DD ′ shown in FIG.

[Explanation of symbols]

1 ... Outer pot, 2 ... Inner pot, 3 ... Inner pot detent member, 4 ... Shaft,
5 ... Groove, 6 ... Sliding part, 8 ... Needle, 9 ... Needle receiving part, 10 ... Needle contact plate, 10a ... Inclined surface, 11 ... Needle contact plate, 11a ... Inclined surface, 20 ... Inner pot.

Claims (3)

[Scope of utility model registration request] 1. A sewing machine having a needle receiving opening (13) into and out of which a sewing needle (8) through which a needle thread penetrates, which is provided at a position where a sewing operation is carried out An inner hook (2) which is slidably held in the recess of the hook (1) with the needle receiving opening exposed to the outside of the recess, and which is slidable with the inner peripheral surface of the recess. The needle contact part, which is made of a material having a smaller dynamic friction coefficient than the metal material, and forms the outer hook side edge of the needle receiving port, has a needle contact with a slanting surface made of metal that descends toward the needle receiving port side. Inner hook of the sewing machine, which is equipped with a section. 2. The inner hook of the sewing machine according to claim 1, wherein the needle contact portion is a needle contact plate that covers the needle receiving portion and is fixed to the inner hook. 3. The inner hook of the sewing machine according to claim 1, wherein the needle contact portion is the entire needle receiving portion and is integrally formed with the inner hook.