KR101454028B1 - Sewing machine and hook system for a sewing machine - Google Patents

Abstract

The present invention discloses a hooking device for a sewing machine and a sewing machine.

A hook device of a sewing machine according to the present invention includes a hook 12 provided with a bobbin case 21 including a lifter cam 31 and a retaining rib 22. Further, a case lifter 33 is provided. The case lifter 33 includes a lifter lever 32 that can be supported by the lifter cam 31. In addition, the case lifter 33 includes a sensor 37 that contacts the control surface 39 that can be connected to the hook 12 in a non-rotating state. The control curved surface 39 has a transition region 46 with a maximum distance 42 from the minimum portion 43 and a distance 13 from the axis 13 of the hook 12 located therebetween. With this configuration, collision between the retention rib 22 and the stop cam 23 is prevented, and as a result, generation of noise is prevented.

Sewing machine, hook, control curve, noise

Description

Technical Field [0001] The present invention relates to a sewing machine and a hook system for a sewing machine,

The present invention relates to a sewing machine, and more particularly, to a sewing machine including a needle supported by the arm for guiding an arm, a base plate, and a needle thread, a needle that can be driven to move up and down, A lifter cam which is rotatably driven about an axis and is mounted on the hook so as to be freely rotatable relative to the hook, the lifter cam being provided with a lower portion facing the hook drive shaft, A bobbin case including a retaining rib that engages with a cam that is relatively stationary relative to the base plate to prevent rotation in a rotational direction, a lifter lever that can be supported by the lifter cam, and a sensor that is powered by a spring A case lifter which can be supported by the sensor As relates to a sewing machine including a control surface that can rotate about the drive axis.

The present invention also relates to a hook device of a sewing machine, and more particularly to a hook device of a sewing machine, which can be rotationally driven in a rotating direction about an axis by a hook drive shaft and includes a lower portion facing the hook drive shaft, A case lifter including a bobbin case mounted on the hook so as to be freely rotatable relative to the bobbin case and including a lifter cam and a retaining rib, a lifter lever capable of being supported by the lifter cam, The present invention relates to a hook device of a sewing machine including a control surface capable of being rotatably driven about an axis thereof with which a sensor can be supported.

In a conventional type of sewing machine known from European Patent EP 1 576 224 B1 (U.S. Patent No. 6,923,130 B2), the control curve is connected to the non-rotating transmission shaft, whereby the rotation speed of the hook is reduced by 1 / 2 < / RTI > The control curved surface is formed on the axial cam disk and acts as the cam surface of the front end portion where the sensor is pressed.

In this embodiment, as with all other known actuators, the level of noise generated by the collision of the retaining ribs of the bobbin case against the fixed cam is extremely high.

It is an object of the present invention to provide a sewing machine and a hook device for a sewing machine which can significantly reduce noise generation.

In the above-mentioned general-purpose sewing machine, the object of the present invention is to provide a sewing machine in which the control curved surface can be rotationally driven at the rotating speed of the hook, and the shape of the control curved surface is formed into a shape Of the present invention. In addition, in the above-described hook device of the general type, the object of the present invention is that the control curve is connected to the hook in the non-rotating state, and the control curve has a substantially constant distance to the maximum area, the minimum area, This is achieved by the present invention having a transition region. The gist of the present invention is substantially that the holding rib of the bobbin case is stopped just before colliding with the fixed cam and the lifting of the bobbin case in the rotating direction is stopped by the lifter lever performing the corresponding pivoting motion . Thus, the retention rib reaches the cam at a greatly reduced speed, resulting in a significant reduction in the occurrence of noise.

The features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings. Prior to that, terms and words used in the present specification and claims should not be construed in a conventional and dictionary sense, and the inventor may properly define the concept of the term in order to best explain its invention It should be construed as meaning and concept consistent with the technical idea of the present invention.

The sewing machine and the hook device for a sewing machine according to the present invention are advantageous in that generation of noise is greatly reduced by soft contact with the friction element.

The double lock stitch sewing machine shown in Fig. 1 typically includes an upper arm 1, a vertical stand 2 and a base plate 3 in the form of a lower housing. The arm shaft 4 is mounted on the arm 1. The needle bar 5 including the needle 6 is driven by the arm shaft 4 so as to be vertically movable. Further, the thread lever 7 is also driven by the arm shaft 4. The yarn tensioning device 9 is provided in front of the yarn lever 7 in the path of the needle yarn 8 extending from the yarn feeder (not shown) to the needle 6 via the yarn lever 7 have.

The embodiment shown in Figs. 1 and 2 is a so-called post sewing machine.

This means a sewing machine on which a vertical support called a post 10 is mounted on a base plate 3. The post serves as a hook bearing case and a hook bearing 11 is disposed at an upper end thereof. A vertical hook 12, that is, a double lock stitch hook 12, is mounted on this hook bearing 11 so as to be rotatable about a vertical axis line 13. The hook drive shaft 14 drives the hook 12 and is drivable around the vertical axis 13. The hook drive shaft 14 is additionally mounted in an angular gear 15, which is comprised of a generally bevel gear mounted on a base plate 3. The hook drive shaft 14 is provided with a reduction gear 15, a transmission shaft 16 for driving the reduction gear 15, an arm shaft 16 for driving the transmission shaft 16 through a synchronous belt drive 17 4). The synchronous belt drive 17 has a transmission ratio of 1: 1. The mesh gear 15 has a speed ratio of 1: 2. This means that the hook 12 rotates twice during one rotation of the arm shaft 4 or the transmission shaft 16, respectively.

The needle plate 18 having the stitch hole 19 is mounted on the post 10 on the upper side of the hook 12. The cup-shaped hook 12 includes a beak 20 which directly passes the needle 6 to hold the needle chamber 8. A bobbin case 21 is disposed within the hook 12 and is capable of freely rotating around the vertical axis 13 with respect to the rotation of the hook 12. The bobbin case 21, which is opened upward, includes a retaining rib 22. The retaining rib 22 protrudes radially outward of the axis 13 and protrudes upward with respect to the needle plate 18. [ The retaining ribs 22 are held between two retaining cams 23, 24 formed on the lower surface of the needle plate 18 so as to be rotatable only at a certain degree of rotation angle. This will be described in detail later.

4 to 7, the first transverse space 25 is disposed between the first holding cam 23 and the holding rib 22, and the upper space 26 is disposed between the holding ribs 22, And a second permanent lateral air gap 27 is disposed between the retaining rib 22 and the second cam 24. The second retaining rib 22 and the second retaining rib 22 are disposed between the retaining rib 22 and the needle plate 18, At the central position of the retaining ribs 22, the spaces 25, 26, 27 form a continuous duct. A bobbin 29 held in the bobbin case 21 is disposed in the bobbin case 21 by a latch 30 which houses the bobbin chamber 28 and is capable of being locked and released.

The bobbin case 21 includes a lifter cam 31 at its upper end. The lifter cam projects radially outwardly of the axis 9 and engages with a lifter lever 32. The lifter lever 32 constitutes an arm of the case lifter 33. The case lifter 33 serves as a support for the lifter lever 32 and is designed as a double arm lever which is substantially vertical, that is, parallel to the axis 13. The case lifter (33) includes a lifter shaft (34). The lifter shaft 34 is formed by a bolt and is mounted in the post 10 about an axis 35 perpendicular to the axis 13 and is under the force of a return spring 36.

At the lower side of the lifter shaft 34, the sensor 37 formed by the lever is attached to the case lifter 33. Mounted on the hook drive shaft 14 is a control disc 38 which includes a control curved surface 39 on its periphery and which sensor 37 has a returning force And is supported on the control curved surface 39 by using the same. The control curved surface 39 extends in the form of a closed curved surface over the entire outer periphery of the control disc 38 and has various radial distances from the axis 13. [ Thus, the lifter lever 32 performs reciprocating and pivoting movements of the hook drive shaft 14 and the hook 12 during rotation. The control disk 38 includes a retaining ring 38a that is secured to the hook drive shaft 14 by a clamping screw 38b.

The hook 12 including the hook drive shaft 14, the control disc 38 including the control curved surface 39, the bobbin case 21 and the case lifter 33 form a hook device.

The basic operating mode is the same as that generally known for the case lifter 33. When the lifter lever 32 does not contact the lifter cam 31 the bobbin case 21 is accompanied by the hook 12 in the rotational direction 40 so that the retention rib 22 of the bobbin case 21 1 held by the holding cam 23. In this case, the second transverse space 27 is expanded and the first transverse space is closed. Due to the corresponding shape of the control curve 39, the lifter lever 32 is pivoted such that a space having a width of 1 to 1.5 mm is formed between the lifter cam 31 and the lifter lever 32. At the engagement position of the hook 12 and the bobbin case 21, a thread loop formed by the needle chamber 8 is captured by the beak 20. The bobbin chamber 28 is guided to a stitch hole 19 through a latch 30. As the hook 12 rotates, the control curved surface 39 also rotates in the rotational direction 40 at a speed corresponding to the speed of the hook 12.

As the hook 12 rotates, the thread loops of the needle thread 8 are guided along the periphery of the substantially stationary bobbin case 21 in a known manner. The pivoting movement of the case lifter 33 in the direction opposite to the rotating direction 40 of the case lifter 33 is performed immediately before the thread looper reaches the maximum extent by the hook 12, The pivoting movement of the lifter lever 32 is triggered by a corresponding shape of the control surface 39, The retaining rib 22 moves up and out of the first retaining cam 23 and the retaining rib 22 moves in the substantially intermediate portion between the two retaining cams 23 and 24 to thereby move the first transverse space 25 ), The upper space 26 and the second transverse space 27 are in a continuously open state. The needle thread loops can be slid unhindered through ducts defined by these spaces 25, 26,

As the hook 12 continues to rotate, the lifter lever 32 pivots rearward by the continuous rotation of the control curved surface 39. The space 41 between the lifter lever 32 and the lifter cam 31 is opened again so that the thread loops slide unobstructed through the space 41 to be dropped from the bobbin case 21, And combined with the seal 28 to form a double lock stitch.

Only one stitch is formed per two turns of the hook 12, but the case lifter 33 performs a complete operating stroke during each rotation of the hook 12.

The foregoing is further illustrated by way of the following examples:

As shown in Figs. 3 and 5, the control curve 39 has a maximum portion 42 and a minimum portion 43 which are disposed at substantially opposed positions. In other words, the control curved surface 39 has a portion located at the maximum or minimum distance from the axis 13. When the sensor 37 moves via the maximum portion 42, the lifter lever 32 is not refracted. According to Fig. 8, the refraction angle of the lifter lever 32 becomes zero. This corresponds to the first position 44 of the lifter lever 32 of Figs. 4 and 5. Accordingly, the bobbin case 21 is pivoted to the maximum possible range in the opposite direction of the rotation direction 40. [ In other words, the second space 27 has a minimum width. Therefore, the first space 25 has a maximum width of about 1.5 mm, and the range of the width is 1.2? A? 1.8 mm. However, when the sensor 37 is moved via the minimum portion 43 of the control curved surface 39 in a state of being pressed by the return spring 36, the lifter lever 32 is moved to the third position 45 And is pivoted to the maximum possible range in the rotation direction 40 until the space 41 is formed by lifting the lifter lever 32 away from the lifter cam 31. [ The holding ribs 22 of the bobbin case 21 are supported by the first holding cams 23 of the needle plate 18 as shown in Fig. As the sensor 37 and the lifter lever 32 move in the opposite direction about the axis 35, the curved surface according to Fig. 8 reaches the maximum portion, And contacts the minimum portion 43.

0.1 mm이다. 이 천이영역(46)을 경유하여 이동시, 센서(37)는 더욱 극감된 속도로 회전하고, 결국 제1의 유지 캠(23)의 유지 리브(22)에 지지되어 정지한다. 이와 같은 부드러운 접촉에 의해 유지 리브(22)와 제1의 유지 캠(23) 사이의 강한 충돌이 방지되므로 소음의 발생이 방지된다. 다음, 보빈 케이스(21)의 회전은 중단되지만 센서(37)와 리프터 레버(32)는 더욱 회전된다. 리프터 레버(32)와 리프터 캠(31)의 사이의 공간(41)은 폭(c)이 1.0 mm ≤ c ≤ 1.5 mm될 때까지 개방된다.A transition region 46 is formed between the maximum portion 42 and the minimum portion 43 of the control curve 39 at the front of the rear portion and the minimum portion 43 of the maximum portion 42 with respect to the rotational direction 40 Respectively. In this region, the control curved surface 39 has a substantially constant distance from the axis 13 by taking a substantially circular shape concentric with the axis 13 of the hook shaft 14. When the sensor 37 moves via the transition area 46 of the control surface 39, the sensor 37 and the lifter lever 34 do not substantially pivot. This transition area 46 corresponds to the second position 47 in Fig. This transition area 46 is started when the holding rib 22 has a distance b from the first holding cam 23. The distance b is in the range of 0.05 mm? B? 0.15 mm, preferably b

0.1 mm. The sensor 37 rotates at a more extreme speed and is eventually supported by the holding ribs 22 of the first holding cams 23 and stops. Such soft contact prevents strong collision between the holding ribs 22 and the first holding cams 23, thereby preventing the generation of noise. Next, the rotation of the bobbin case 21 is stopped, but the sensor 37 and the lifter lever 32 are further rotated. The space 41 between the lifter lever 32 and the lifter cam 31 is opened until the width c becomes 1.0 mm? C? 1.5 mm.

The same parts as those described above in the embodiment according to Figs. 9 to 14 are denoted by the same reference numerals as those described above. Components having the same function as those of the above-described components but slightly different in configuration are denoted by the same reference numerals as those of the above-described reference numerals.

The hook device shown in Figs. 9 to 14 is basically the same double-lock stitch hook device as shown in Fig. However, unlike FIG. 1, the entire hook device is integrated in the base plate 3. This is a common form of sewing machine. This hook device is thus for a so-called flat bet sewing machine.

The hook device includes a hook bearing case 52, and an angular reduction gear 15, which is a bevel gear, is disposed below the hook bearing case 52. The needle plate 18 is mounted on the upper side of the hook 12.

In this embodiment, the control disc 53, including the control curved surface 54, is mounted on the underside 55 of the hook 12 facing the hook drive shaft 14 '. The control disk 53 is a flat disk. The sensor 56 of the case lifter 33 'designed as a sensor lever is supported by the elastic force of the return spring 36' on the control curved surface 54 formed on the outer periphery of the control disc 53.

The control disc 53 shown in Figs. 11 and 12 can be integrally formed with the hook 12. Fig. In other words, the control disc 53 and the hook can be integrally manufactured as shown in Fig. However, the control disc 53 may be designed to be attached to the hook 12 as shown in Fig. In this case, the control disk 53 is connected to the hook 12 in a non-rotating state and is positioned at an angular position relative to the hook 12 by a driver pin 57. A plurality of bores 58 formed at mutually small intervals are provided on the underside 55 of the hook 12 and / or the control disc 53 to provide a relative angular position between the control disc 53 and the hook 12 Can be provided.

A driver pin 57 is inserted into the bore 58 to achieve an angular position relative to the hook 12 of the control disc 53 and the control curved surface 54.

The thickness d of the control disk 53 and the control curved surface 54 in the direction of the axis 13 is extremely thin as in the range of 2.0 mm? D? 5 mm. The dimension e of the extended portion of the sensor 56 designed as the sensor lever in the direction of the axis 13 is in the range of 1.5 mm? E? 4.0 mm, which is slightly smaller than the thickness d.

In this embodiment, the hook 12 includes a hook drive shaft 14 ', a control disc 53 including a control curved surface 54, a bobbin case 21, and a hooking device 33' .

The lifter lever 32 and the sensor 37 of the embodiment of Figures 2-8 are rotated in the opposite direction and the lifter lever 32'and the sensor 56 of the embodiment of Figures 9-14 are rotated in the same direction . Likewise, the control curve 54 has a maximum portion 42 ', a minimum portion 43' and a transition region 46 ', wherein the lifter lever 32' The lifter lever 32 'is maximally deflected as the result sensor 56 of the lifter lever 56 moves through the maximum portion 42'. According to Fig. 14, the lifter lever 32 'is at the maximum refracting position. This corresponds to the third position 45. Upon movement through the transition region 46 ', the lifter lever 32' reaches the second position 47. Upon movement through the minimum portion 43 ', the lifter lever 32' finally reaches the first position 44, where the refraction of the lifter lever 32 'is zero.

1 is a side view of a double lock stitch sewing machine;

Fig. 2 is an enlarged view of a hook including the hook bearing of the sewing machine of part II of Fig. 1; Fig.

3 is an enlarged plan view of the control curve;

4 is a plan view of the hook including the case lifter of arrow IV in Fig. 1 in the first position of the bobbin case;

5 is a top plan view of the hook including the bobbin case and the needle plate in the first position of Fig. 4;

Figure 6 is a plan view corresponding to the hook of Figure 4 in the second position of the bobbin case;

Figure 7 is a plan view corresponding to the hooks of Figures 4 and 6 in the third position of the bobbin case;

8 is a graph showing the movement path of the lifter lever of the case lifter;

Figure 9 is a partial cutaway plan view of a modification of the hook of Figure 2;

Figure 10 is a plan view of the hook device according to Figure 9;

Fig. 11 is a bottom view of Figs. 9 and 10 showing the hook with the control curved surface formed thereon; Fig.

Figure 12 is a bottom view according to Figure 11 showing the hook with the control curved surface formed;

13 is a plan view of a control disk including a control surface;

14 is a view showing the deflection angle of the lifter lever of the case lifter with respect to the rotation angle of the control surface of the embodiment according to Figs. 9 to 13. Fig.

Claims (13)

Arm 1; A base plate 3; A needle 6 supported by the arm 1 so as to guide the needle chamber 8 and can be driven for up and down movement; And includes a lower portion 55 which can be rotationally driven about an axis 13 in the rotational direction 40 by the hook drive shafts 14 and 14 'and which faces the hook drive shafts 14 and 14' A hook (12); A bobbin case 21 mounted on the hook 12 so as to be freely rotatable relative to the hook 12; The case lifters 33 and 33 'including the lifter levers 32 and 32' and the sensors 37 and 56 which are urged by the springs 36 and 36 '; And Is rotatably driven around the axis 13 of the hook drive shaft 14 or 14 'at the rotational speed of the hook 12 and is formed on the outer periphery of the control discs 38 and 53, , 56) are supported, wherein the control surfaces (39, 54) The bobbin case 21 includes a lifter cam 31 cooperating with the lifter lever 32, 32 ' The bobbin case 21 has a retaining rib 22 cooperating with a cam 23 which is relatively stationary with respect to the base plate 3 to prevent rotation of the bobbin case 21 in the rotation direction 40. [ Lt; / RTI > The control curved surfaces 39 and 54 have a shape in which the velocity in the rotation direction 40 of the holding ribs 22 is reduced rapidly at the distance b of the front surface of the stop cams 23, The control curved surfaces 39 and 54 include transition areas 46 and 46 'having a maximum distance 42, 42', a minimum distance 43 and 43 ', and a distance therebetween to the axis 13, Wherein said transition region (46) starts when said retention rib (22) continues to have a distance (b) towards said stop cam (23), said distance (b) being 0.05 mm < 0.15 mm. ≪ / RTI > delete The sewing machine according to claim 1, wherein the distance (b) is 0.1 mm. delete delete The sewing machine according to claim 1 or 3, wherein the control curved surface (39, 54) is connected to the hook (12) in a non-rotating state. 7. A sewing machine according to claim 6, characterized in that the control curved surface (39) is mounted on the hook drive shaft (14). 7. A sewing machine according to claim 6, characterized in that the control curved surface (54) is mounted on the lower part (55) of the hook (12). A hook device of a sewing machine, And includes a lower portion 55 which can be rotationally driven about the axis 13 in the rotational direction 40 by the hook drive shafts 14 and 14 'and facing the hook drive shafts 14 and 14' A hook (12); A bobbin case 21 mounted on the hook 12 so as to be freely rotatable relative to the hook 12; The case lifters 33 and 33 'including the lifter levers 32 and 32' and the sensors 37 and 56 which are urged by the springs 36 and 36 '; And Is rotatably driven around the axis 13 of the hook drive shaft 14 or 14 'at the rotational speed of the hook 12 and is formed on the outer periphery of the control discs 38 and 53, , 56) are supported, characterized in that the control surfaces (39, 54) The bobbin case 21 includes a lifter cam 31 cooperating with the lifter lever 32, 32 ' The bobbin case 21 includes a retaining rib 22 for preventing rotation of the bobbin case 21 together with the stop cam 23 in the rotation direction 40, The control curved surfaces 39 and 54 have a shape in which the velocity in the rotation direction 40 of the holding ribs 22 is reduced in a distance b from the front surface of the stop cams 23, The control curved surfaces 39 and 54 include transition areas 46 and 46 'having a maximum distance 42, 42', a minimum distance 43 and 43 ', and a distance therebetween to the axis 13, Wherein said transition region (46) starts when said retention rib (22) continues to have a distance (b) towards said stop cam (23), said distance (b) being 0.05 mm < 0.15 mm. ≪ / RTI > delete 10. The hook device of a sewing machine according to claim 9, characterized in that the control curved surface (39, 54) is connected to the hook (12) in a non-rotating state. 12. A hook device according to claim 11, characterized in that the control curved surface (39) is mounted on the hook drive shaft (14). 12. A hook device according to claim 11, characterized in that the control curved surface (54) is mounted on the lower part (55) of the hook (12).

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