JP2006075221A - Sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vertically cylindrical sewing machine allowing an adjustment operation of a differential feed mechanism disposed inside a base part of a cylindrical bed from the outside of the sewing machine and quickly and surely providing an appropriate differential feed state. <P>SOLUTION: This vertically cylindrical sewing machine is provided with a sewing arm 3 and the cylindrical bed 2 projecting vertically to the sewing machine body 1, the differential feed mechanism 5 varying a front/rear operation distance of a front feed dog 4a disposed at the tip of the cylindrical bed 2 to the front/rear operation distance of a back feed dog 4b is connected to a swinging arm 6 disposed inside the sewing arm 3 via the inside of the sewing machine 1 by a connecting link 61, while the operation of a differential adjustment means 7 from the outside of the sewing machine body 1 is transmitted to the swinging arm 6, and the differential feed mechanism 5 is operated by the swinging of the swinging arm 6 to change the front/rear moving distance of the front feed dog 4a. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is provided with a main feed dog and a differential feed dog at the tip of a cylindrical bed protruding from one side of the sewing machine body, and by these operations, feed in the axial length direction of the cylindrical bed is applied to the fabric. This is related to a vertical cylindrical sewing machine.

  Cylindrical portions such as sleeves and torso portions of various clothing items are sewn by making the fabric into a cylindrical shape and sewing the edges overlapped appropriately in width. For such sewing, conventionally, a sewing machine arm and a cylindrical bed are provided on the upper and lower sides of the sewing machine main body incorporating the sewing machine main shaft so as to project substantially in parallel with each other. A vertical cylindrical sewing machine configured to sew by passing a feed toward the proximal end in the axial length direction of the cylindrical bed through the distal end of the bed is used.

  Sewing with this vertical cylindrical sewing machine is performed by holding the fabric between the needle plate installed at the tip of the cylindrical bed and the presser foot suspended from the tip of the sewing machine arm and placing it inside the cylindrical bed. The above-mentioned feed is added by the operation of the feed dog. The movement of the feed dog is an oval motion generated by a combination of vertical movement and forward / backward movement, and the feed to the dough is applied by a feed dog that protrudes and moves backward on the needle plate at the upper position. In addition, the tubular sewn product obtained by being pushed into the base end portion of the cylindrical bed by this sewing raises the presser foot and withdraws it to the distal end side of the tubular bed and is collected.

The elliptical movement of the feed dog, like a general sewing machine, takes out the rotation of the sewing machine main shaft through separate eccentric rings and converts it into swings of the upper and lower and front and rear feed arms. This is realized by transmitting to the feed dog via the feed link. However, in the case of a vertical cylindrical sewing machine, the feed dog at the tip of the cylindrical bed is located away from the main spindle inside the machine body, so a feed base with the feed dog fixed to the tip is placed inside the cylindrical bed. A feed mechanism that extends in the axial direction and includes the exen ring and the feed arm is configured between the base end of the feed base and the main spindle of the sewing machine (see, for example, Patent Document 1).
Republic of China Patent No. 467155

  The flat stitch sewing machine and the double chain stitch sewing machine are equipped with feed dogs (differential feed dog and main feed dog) before and after the needle drop position, and feed arms for both longitudinal movements (differential feed arm and main feed). Arms) are provided separately, and by collectively changing the swinging amount of these feed arms, feed adjustment is performed to change the feed amount of the fabric by changing the back and forth stroke of both feed dogs, while swinging the differential feed arm By changing the amount of movement alone, the differential feed dog can be adjusted to increase or decrease the longitudinal stroke of the differential feed dog and change the longitudinal feed amount of the differential feed dog to be larger or smaller than the longitudinal feed amount of the main feed dog. There is something to do.

  This differential adjustment, for example, when sewing a fabric having a high elasticity, increases the feed amount of the differential feed dog, makes the feed amount on the front side of the needle drop position larger than the feed amount on the rear side, When the fabric is sewed with a desired feed (so-called shrink-sewing) and the fabric without elasticity is sewn, the feed amount of the differential feed dog is reduced and the front side of the needle drop position is reversed. The feed amount at the rear side is made smaller than the feed amount at the rear side, and the fabric is kept under tension and sewn (so-called. It is useful to get.

  To change the swing amount of the differential feed arm for differential adjustment, a slider that can slide along the differential feed arm is attached to the differential feed arm, and the slider and the differential feed dog are connected. This is realized by a differential feed mechanism configured to change the sliding position of the slider on the differential feed arm and increase or decrease the effective arm length of the differential feed arm. The same configuration can be realized in a vertical cylindrical sewing machine, and the vertical cylindrical sewing machine disclosed in Patent Document 1 includes a differential feed dog and a main feed dog before and after the needle drop position, These are connected to different feed arms via sliders, and differential adjustment is performed by relatively changing the feed amount of the main feed dog and the feed amount of the differential feed dog by adjusting the position of each slider. A differential feed mechanism is provided.

  However, in a vertical cylindrical sewing machine, a feed arm (differential feed arm and main feed arm) connected to the machine main shaft via an eccentric ring is arranged inside the base of a cylindrical bed protruding from the machine body. In addition, there is a problem that it is difficult to provide operation means for changing the position of the slider mounted on the feed arm because there is not enough space around the arrangement position. Also in Patent Document 1, the existence of an operation means for changing the sliding position of the slider is not disclosed. For example, a part of the cylindrical bed is opened in the vicinity of the position where the feed arm is disposed. It is necessary to change the position of the slider via the opening, and it takes time to perform the differential adjustment operation by this change operation, and it is possible to quickly realize an appropriate differential feed state according to the type of fabric. It is difficult and unusable.

  The present invention has been made in view of such circumstances, and the adjustment operation of the differential feeding mechanism disposed on the inner side of the base portion of the cylindrical bed can be performed from the outside of the sewing machine main body, depending on the type of fabric. An object of the present invention is to provide a vertical cylindrical sewing machine that can realize a proper differential feed state promptly and reliably and is easy to use.

  A sewing machine according to a first aspect of the present invention includes a sewing machine arm and a cylindrical bed, which are respectively provided above and below a sewing machine main body incorporating a sewing machine main shaft and projecting in a direction substantially orthogonal to the sewing machine main shaft. Main feed dogs and differential feed dogs arranged side by side in the axial length direction at the front end are individually fed by transmission from the sewing machine main shaft, and are fed to the cloth supplied to the needle drop position at the front end of the cylindrical bed. In a vertical cylindrical sewing machine configured to add a feed in the long direction, the longitudinal feed amount of the differential feed dog is set on the inner side of the base of the cylindrical bed in the vicinity of the main spindle of the sewing machine. A differential feed mechanism that is variable with respect to the longitudinal movement amount, a swing arm that is disposed inside the sewing machine arm and has a tip that swings up and down substantially directly above the differential feed mechanism; The tip of the swing arm and the differential feeder Characterized in that it comprises a connecting link for connecting through the interior of the sewing machine body, and the differential adjusting means for oscillating the oscillating arm by operating outside of the sewing machine body and.

  In the present invention, the differential feed mechanism arranged on the inner side of the cylindrical bed projecting on the one side lower part of the sewing machine main body is arranged on the inner side of the sewing machine arm projecting on the one upper side of the sewing machine main body. It is connected to the moving arm via a connecting link that passes through the inside of the sewing machine body, the swinging arm is swung by an operation from the outside of the sewing machine body, and this swinging is connected to the differential feed mechanism connected by the connecting link. Communicate and change the feed amount by the differential feed dog.

  A sewing machine according to a second invention of the present invention is such that the differential feed mechanism according to the first invention swings about an axis substantially parallel to the sewing machine main shaft by transmission from the sewing machine main shaft, A slider that slides along the differential feed arm, a feed base that extends in the axial length direction of the cylindrical bed and includes the differential feed dog at the tip, a base end of the feed base, and the slider And a differential feed link for connecting the slider and the slider, wherein the link is connected to the slider.

  In this invention, the differential feed mechanism inside the cylindrical bed is connected to a slider that slides on a differential feed arm that is oscillated by transmission from the sewing machine spindle to a feed base of a differential feed dog. The slider is connected to the swing arm via a connecting link, and the slide position of the slider on the differential feed arm is changed by the swing of the swing arm, so that the differential feed dog is realized. Increase or decrease the feed amount.

  The sewing machine according to a third aspect of the present invention is the sewing machine according to the first or second aspect, wherein the differential adjustment means has a differential adjustment shaft that penetrates the side surface of the sewing machine body inward and outward, and an outer side of the sewing machine body of the differential adjustment shaft. A differential adjusting lever fixed to the extending end of the differential adjusting shaft, a differential adjusting arm fixed to the extending end of the differential adjusting shaft to the inside of the sewing machine body, a tip of the differential adjusting arm, and the And a differential adjustment link connecting the tip of the swing arm.

  In this invention, the differential adjustment lever is arranged on the side surface of the sewing machine body which can be easily operated by the sewing manufacturer, and the operation of this differential adjustment lever is controlled by the differential adjustment shaft penetrating the side surface of the sewing machine body. In addition, the signal is transmitted to the swing arm inside the sewing machine arm via the differential adjustment arm and the differential adjustment link, and the differential feed is adjusted according to the swing of the swing arm.

  In the sewing machine according to the first aspect of the present invention, the swing of the swing arm arranged inside the sewing machine arm is transmitted to the differential feed mechanism arranged inside the cylindrical bed by a connecting link passing through the inside of the machine body. Therefore, it is possible to configure the differential feed adjusting means while avoiding the inside of the cylindrical bed, which has a large space limitation, and the connecting end of the swing arm is differentially fed. Since it is arranged almost directly above the mechanism, the influence of this connection on the differential feed mechanism can be suppressed to a small extent, and a stable feed operation with the adjusted feed amount can be performed.

  In the sewing machine according to the second aspect of the invention, a general differential feed mechanism that changes the sliding position of the slider on the differential feed arm is adopted to enable differential adjustment operation from the outside of the sewing machine body. Therefore, good usability can be obtained with a simple configuration.

  Further, in the sewing machine according to the third aspect of the invention, the sewing manufacturer can perform the differential adjustment by operating the differential adjustment lever provided on the outer side surface of the sewing machine body, and performs the sewing while facing the tip of the cylindrical bed. The present invention has excellent effects, such as improved usability for the user.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof. FIG. 1 is a perspective view schematically showing the external appearance of a sewing machine according to the present invention, in which a small cylindrical bed 2 protrudes from a lower part of one side of a sewing machine body 1 erected on a base 10. It is configured as a vertical cylindrical sewing machine having a sewing machine arm 3 projecting from the upper part on the same side so as to be substantially parallel to the cylindrical bed 2.

  A sewing machine main shaft 11 is installed on the inner lower portion of the sewing machine body 1 so that the protruding direction of the cylindrical bed 2 and the sewing machine arm 3 and the axial length direction are substantially orthogonal to each other. One end of the sewing machine main shaft 11 penetrates the side wall of the sewing machine main body 1 and protrudes to the outside. A driving pulley 12 is fitted and fixed to the protruding portion, and is fixed to the lower position of the base 10 (not shown). The sewing machine main shaft 11 is coupled to the output end of the sewing machine motor via a driving belt 13 so that the sewing machine main shaft 11 is driven to rotate around the shaft by the rotation of the sewing machine motor transmitted through the driving belt 13 and the driving pulley 12. There is.

  A needle plate 20 is installed on the top surface of the distal end portion of the cylindrical bed 2, and a feed dog hole 21 whose longitudinal direction is the axial length direction of the cylindrical bed 2 is formed in the needle plate 20. On the other hand, a needle bar 30 and a presser bar 31 are suspended and supported on the lower surface of the tip of the sewing machine arm 3. Needles 32 and 32 are attached to the lower end of the needle bar 30, and a presser foot is attached to the lower end of the presser bar 31. 33 is installed.

  In the sewing by the sewing machine according to the present invention configured as described above, the cloth supplied onto the needle plate 20 from the tip of the cylindrical bed 2 is held between the presser foot 33 that is lowered by the downward movement of the presser bar 31. The feed dog projecting on the needle plate 20 through the feed dog hole 21 feeds the feed toward the proximal end of the cylindrical bed 2 as will be described later, and the needles 32 and 32 are moved together with the needle bar 30 in synchronization with this feed. This is done by moving up and down and operating a looper (not shown) under the needle plate 20 at the tip of the cylindrical bed 2.

  The feature of the sewing machine according to the present invention lies in the configuration of the feed drive system that operates the feed dog that feeds the fabric during sewing as described above. FIG. 2 is a side view showing a configuration of a main part of the feed drive system, and FIG. 3 is a perspective view schematically showing a connection relation of each part of the feed drive system shown in FIG. In FIG. 3, a connecting portion that can be relatively rotated is indicated by a white circle, and a connecting portion that is not capable of relative rotation is indicated by a black circle.

  In FIG. 2, the outlines of the sewing machine body 1, the cylindrical bed 2, and the sewing machine arm 3 are indicated by two-dot chain lines. A front feed dog 4a serving as a differential feed dog and a rear feed dog 4b serving as a main feed dog are arranged side by side at the front end of the cylindrical bed 2. The front feed dog 4a is fixed to the front end of a bar-shaped front feed base 40 extending in the longitudinal direction of the cylindrical bed 2, and the rear feed dog 4b is arranged on one side of the front feed base 40. It is fixed to the tip of the rear feed base 41 (see FIG. 3).

  The front feed base 40 is supported inside the cylindrical bed 2 together with the rear feed base by a support shaft 43 inserted through a long hole 42 provided substantially at the center in the longitudinal direction. Also, the rear feed base is connected by a pair of square pieces 44, 44 inserted and held in a slot formed in the distal end and a notch formed in the base end. With the above configuration, the front feed base 40 can swing about the support shaft 43 and move back and forth within the length range of the long hole 42. The front feed dog 4a at the tip of the feed base 40 can be moved along an oval locus indicated by an arrow in FIG.

  On the other hand, the rear feed base 41 arranged side by side with the front feed base 40 moves up and down integrally with the front feed base 40 under the restraint by the square pieces 44, 44, while following the respective long holes and notches. It is possible to move back and forth independently of the front feed base 40 by sliding the square pieces 44, 44. The rear feed dog 4b at the tip of the rear feed base 41 has an ellipse similar to the front feed dog 4a. The movement can be performed with a longitudinal movement stroke different from that of the forward feed dog 4a.

  The vertical feed and the forward / backward movement of the front feed dog 4a and the back feed dog 4b are performed using the sewing machine main shaft 11 in the sewing machine body 1 as a drive source. A feature of the sewing machine according to the present invention is that the front / rear movement of the front feed dog 4a as a differential feed dog is performed by variably adjusting the operation amount with respect to the front / rear movement of the rear feed dog 4b as a main feed dog. FIG. 2 shows only the structure of this feed transmission system.

  As shown in FIG. 2, a front / rear feed shaft 14 is laid horizontally inside the base portion of the cylindrical bed 2 so as to be parallel to the sewing machine main shaft 11. In the middle of the front / rear feed shaft 14, a base end of a short feed arm 15 is fitted and fixed, and the tip of the feed arm 15 is an outer periphery of an eccentric ring 16 attached to a corresponding portion of the sewing machine main shaft 11. It is connected to the tip of a feed rod 17 projecting from. With this configuration, when the sewing machine main shaft 11 rotates, the feed rod 17 projecting from the eccentric ring 16 undergoes a reciprocating motion with a stroke corresponding to the amount of eccentricity of the eccentric ring 16, and the tip of the feed rod 17 is The front end of the connected feed arm 15 is pushed and pulled, and the front and rear feed shaft 14 to which the base end of the feed arm 15 is fixed is repeated around the axis within the angle range according to the eccentricity. It can be rotated.

  A slider arm 50 is fitted and fixed at a position different from the feed arm 15 in the middle of the longitudinal feed shaft 14. The slider arm 50 holds a slider 51 so as to be slidable along the slider arm 50. The slider 51 is connected to a midway portion of the front feed base 40 via a differential feed link 52. With this configuration, the slider arm 50 swings in response to the above-described repeated rotation of the front / rear feed shaft 14, and the swing amount generated at the position of the slider 51 is transferred to the front feed base 40 via the differential feed link 52. Accordingly, the forward feed base 40 and the forward feed dog 4a fixed to the tip of the forward feed base 40 are moved back and forth.

  The forward / backward movement amount of the forward feed dog 4a generated in this way, that is, the forward / backward feed amount by the forward feed dog 4a is changed by sliding the slider 51 along the slider arm 50, as shown by the solid line in FIG. It becomes smaller when the slider 51 is located on the proximal end side of the slider arm 50, and becomes larger when the slider 51 is located on the distal end side of the slider arm 50, similarly as indicated by a two-dot chain line. The slider arm 50 has an arcuate curved shape centering on the connection position of the differential feed link 52 to the forward feed base 40, and the slider 51 slides when the forward feed base 40 and the forward feed are moved. The front and rear positions of the teeth 4a can be performed without any change.

  On the other hand, as shown in FIG. 3, the rear feed base 41 is connected to the tip of a swing arm 53 fitted and fixed in the middle of the front / rear feed shaft 14 at a position different from the feed arm 15 and the slider arm 50 via a connecting link 54. Are connected. With this configuration, the back feed base 40 and the back feed teeth 4b are moved back and forth in accordance with the swing of the swing arm 53 as the back and forth feed shaft 14 is repeatedly rotated. The forward / backward feed amount by 4b corresponds to the swing amount of the tip of the swing arm 53, and differential adjustment with the forward / backward feed amount by the front feed teeth 4a that can be changed as described above becomes possible.

  Further, the front / rear feed amount by the front feed dog 4a and the rear feed dog 4b can be collectively increased / decreased by changing the eccentric amount of the eccentric ring 16. The feed adjustment mechanism for this adjustment is provided in various sewing machines in order to make it possible to change the feed amount according to the fabric to be sewn, and illustration and detailed description thereof are omitted.

  As described above, the slider arm (differential feed arm) 50 that swings around the axis of the longitudinal feed shaft 14 by transmission from the sewing machine main shaft 11, the slider 51 that slides along the slider arm 50, and the cylindrical bed 2, a forward feed base 40 having a forward feed dog (differential feed dog) 4a attached to the tip thereof, and a differential feed link 52 for connecting the forward feed base 40 and the slider 51 to each other. The differential feed mechanism 5 is constituted by the inner side of the base of the cylindrical bed 2 in the vicinity of the sewing machine main shaft 11. The base of the cylindrical bed 2 is larger than the tip as shown in FIG. 1 in order to accommodate various mechanisms including the differential feed mechanism 5.

  On the other hand, on the inner side of the upper part of the sewing machine main body 1 from which the sewing machine arm 3 is projected, a swing arm 6 is attached with its base end pivotally supported by a support shaft 60 which is substantially parallel to the sewing machine main shaft 11. The tip of the swing arm 6 is extended to the inside of the sewing machine arm 3 and slides along the upper position of the differential feed mechanism 5 disposed inside the cylindrical bed 2, more specifically, along the slider arm 50. The tip of the swing arm 6 that has reached the upper position of the slider 51 and swings up and down at this position is connected to the slider 51 by a long connecting link 61 that extends downward through the inside of the sewing machine body 1. Has been. The connecting link 61 is bent as shown in FIG. 2 so as to avoid interference with the front wall of the sewing machine body 1, and the swing arm 6 is similarly bent so that the transmission mechanism for the needle bar 30 is provided. Thus, interference with various transmission mechanisms provided inside the sewing machine arm 3 is avoided.

  Further, a differential adjustment shaft 70 penetrating one side wall inward and outward is supported in the middle of the sewing machine main body 1 so as to be rotatable about the axis, and the differential adjustment shaft protruding outside the sewing machine main body 1 is supported. A differential adjustment lever 71 is fixed to one end of 70. The tip of the differential adjustment lever 71 extends forward along the outer surface of the sewing machine main body 1, and the differential adjustment shaft 70 can be rotated by grasping the tip and swinging up and down. It is. A scale plate 72 is attached to the outer surface of the sewing machine body 1 so as to overlap the mounting area of the differential adjustment lever 71, and an arcuate guide hole 73 provided in the scale plate 72 prevents the differential adjustment lever 71 from being attached. In addition to guiding the swing, the swing angle of the differential adjustment lever 71 can be displayed by a scale (not shown) formed along the side edge of the guide hole 73. The differential adjustment lever 71 and the scale plate 72 are also shown in FIG.

  Further, the base of the differential adjustment arm 74 is fitted and fixed to the other end of the differential adjustment shaft 70 that protrudes to the inside of the sewing machine body 1, and the tip of the differential adjustment arm 74 that extends forward is differentially adjusted. It is connected to the tip of the swing arm 6 via a link 75. The differential adjustment link 75 also has a bent shape as shown in FIG. 2 and realizes connection with the swing arm 6 while avoiding interference with the front wall of the sewing machine body 1.

  The differential adjustment shaft 70, the differential adjustment lever 71, the differential adjustment arm 74, and the differential adjustment link 75 as described above constitute the differential adjustment means 7 that can be operated outside the sewing machine body 1. By operating the differential adjustment lever 71 as the operation end, the differential adjustment arm 74 is swung with the rotation of the differential adjustment shaft 70, and this swing is transferred to the swing arm 6 via the differential adjustment link 75. The swing arm 6 can be swung up and down about the support shaft 60 as a pivot.

  In FIG. 2, the state of each part when the operation end of the differential adjustment lever 71 is in the lower position is shown by a solid line, and the case where it is also in the upper position is shown by a two-dot chain line. When the differential adjustment lever 71 is swung toward the upper position, the differential adjustment arm 74 is swung inside the sewing machine body 1 due to the rotation of the differential adjustment shaft 70 accompanying the swing. The movement is transmitted to the tip of the swing arm 6 via the differential adjustment link 75, and the swing arm 6 swings upward about the support shaft 60 as a pivot. By this swinging, the connecting link 61 connected to the tip of the swinging arm 6 together with the differential adjustment link 75 is pulled up, and a pulling force is applied to the slider 51 connected to the lower end of the connecting link 61. Then, it slides to the upper position along the slider arm 50, and the forward / backward feed amount by the forward feed dog 4a increases as described above. On the other hand, when the differential adjustment lever 71 is swung toward the lower position, the front-rear feed amount by the front feed dog 4a is reduced.

  In this way, it is possible to carry out differential adjustment that changes the front / rear feed amount by the front feed dog 4a as the differential feed dog to be larger or smaller than the front / rear feed amount by the rear feed tooth 4b as the main feed dog. However, in the sewing machine according to the present invention, this differential adjustment can be performed by swinging the differential adjustment lever 71 arranged on the outer side surface of the sewing machine body 1 according to the type of cloth. An appropriate feed state can be realized quickly and reliably.

  Further, in order to transmit the operation of the differential adjusting means 7 to the differential feeding mechanism 5 configured on the inner side of the base of the cylindrical bed 2, avoiding the inner side of the cylindrical bed 2 having a large spatial restriction, Since the swing arm 6 arranged on the inner side and the connecting link 61 arranged on the inner side of the sewing machine main body 1 are used, the degree of freedom in design increases, and a design with a margin becomes possible.

  Furthermore, since the tip of the swing arm 6 is positioned substantially directly above the differential feed mechanism 5, more specifically, approximately directly above the slider 51 that slides along the slider arm 50, the slider arm 50 is The influence on the front-back operation of the front feed base 40 that occurs in response to the swinging can be minimized. FIG. 4 is an explanatory diagram showing the influence of the tip position of the swing arm 6 on the longitudinal movement of the forward feed base 40. As shown in FIG.

  The front feed base 40 is connected to a slider 51 moving along the slider arm 50 via a differential feed link 52, and the front feed base 40 moves back and forth with a stroke corresponding to the swing amount of the slider 51. To do. On the other hand, the slider 51 is connected to the tip of the swing arm 6 via a connecting link 61. The swing of the slider 51 is centered on the tip of the swing arm 6, and the effective length of the connecting link 61 is set to a radius. It occurs along the arc A.

  4A shows a case where the tip end position of the swing arm 6 is positioned substantially directly above the slider 51, and FIG. 4B shows a case where the tip end position of the swing arm 6 is from approximately right above the slider 51. In the case of FIG. 4 (a), the vertical movement of the slider 51 that is restrained by the connecting link 61 within the range of the swing angle of the slider arm 50 is shown. In the case of FIG. 4B, they occur in the same direction, and the vertical movement amount δ of the slider 51 during the swing of the slider arm 50 is the swing arm. By disposing the tip of 6 directly above the differential feed mechanism 5, the front feed base 40 can be moved back and forth under substantially the same swing arm length.

  The swing arm 6 can be arranged, for example, inside the sewing machine main body 1, but the tip of the swing arm 6 when this arrangement is adopted is a cylindrical bed as shown in FIG. In order to stably perform the feed operation of the front feed base 40 and the front feed dog 4a at the tip of the front feed base 40, it is necessary to displace it from a position substantially directly above the differential feed mechanism 5 located inside the base of 2. difficult. In the sewing machine according to the present invention, the above problem is solved by arranging the swing arm 6 inside the sewing machine arm 3.

  The differential adjusting means 7 only needs to be able to swing the swing arm 6. For example, the support shaft 60 of the swing arm 6 protrudes from one side of the sewing machine arm 3, and this protrusion Although it can be realized by a configuration other than that shown in the embodiment, such as a configuration in which an operating lever is attached to the end and the swing arm 6 is swung via the support shaft 60 by operating the control lever, According to the configuration shown in the embodiment in which the differential adjustment lever 71 is attached to the differential adjustment shaft 70 penetrating the side surface of the main body 1, the arrangement of the differential adjustment lever 71 as the operation end is as shown in FIG. It is easy to operate for the sewing manufacturer who works facing the tip of the shape bed 2, and there is an effect that good usability can be obtained.

  In the above embodiments, the front feed dog 4a is a differential feed dog and the rear feed dog 4b is a main feed dog. However, the rear feed dog 4b is a differential feed dog and the front feed dog 4a is a main feed dog. It goes without saying that teeth may be used.

1 is a perspective view schematically showing an appearance of a sewing machine according to the present invention. It is a side view which shows the structure of the principal part of the feed drive system of the sewing machine which concerns on this invention. FIG. 3 is a perspective view schematically showing a connection relation of each part of the feed drive system shown in FIG. 2. It is explanatory drawing which shows the influence which the front-end | tip position of a rocking | fluctuation arm has on the front-back operation | movement of a front feed base.

Explanation of symbols

1 sewing machine body 2 cylindrical bed 3 sewing machine arm
4a Front feed dog (Differential feed dog)
4b Rear feed dog (main feed dog)
5 Differential feed mechanism 6 Oscillating arm 7 Differential adjustment means
11 Sewing machine spindle
40 Forward carriage
41 Reverse feed
50 Slider arm (differential feed arm)
51 Slider
52 Differential feed link
61 Link
70 Differential adjustment shaft
71 Differential adjustment lever
74 Differential adjustment arm
75 differential adjustment links

Claims (3)

A sewing machine arm and a cylindrical bed are provided on the upper and lower sides of the sewing machine main body containing the sewing machine main shaft, respectively, in a direction substantially orthogonal to the sewing machine main shaft, and are arranged in the axial direction at the tip of the cylindrical bed. A vertical cylinder configured to feed the dough fed to the needle drop position at the tip of the cylindrical bed in the axial direction by causing the feed dog and the differential feed dog to individually feed by transmission from the sewing machine main shaft. In the form of sewing machine,
A differential feed mechanism that is disposed on the inside of the base of the cylindrical bed in the vicinity of the sewing machine main shaft, and that makes the longitudinal movement amount of the differential feed dog variable with respect to the longitudinal movement amount of the main feed dog;
A swing arm that is disposed inside the sewing machine arm and has a tip that swings up and down substantially directly above the differential feed mechanism;
A connecting link that connects the tip of the swing arm and the differential feed mechanism through the inside of the sewing machine body;
A differential adjusting means for swinging the swing arm by an operation on the outside of the sewing machine main body.   The differential feed mechanism includes a differential feed arm that swings about an axis substantially parallel to the sewing machine main shaft by transmission from the sewing machine main shaft, a slider that slides along the differential feed arm, The connecting link includes a feed base extending in the axial length direction of the cylindrical bed and having the differential feed dog at a tip thereof, and a differential feed link for connecting the base end portion of the feed base and the slider. The sewing machine according to claim 1, wherein the sewing machine is connected to the slider.   The differential adjustment means includes a differential adjustment shaft penetrating a side surface of the sewing machine body inward and outward, a differential adjustment lever fixed to an extending end of the differential adjustment shaft to the outside of the sewing machine body, A differential adjustment arm fixed to an end of the differential adjustment shaft extending to the inside of the sewing machine main body; and a differential adjustment link connecting the tip of the differential adjustment arm and the tip of the swing arm. The sewing machine according to claim 1 or 2.

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