JP2019054902A - sewing machine - Google Patents

Abstract

To make condensed stitch using an existing sewing machine.SOLUTION: A sewing machine 10 comprises a feed adjustment body 62 provided inside a sewing machine frame 20 and changing a feed pitch according to a rotational angle and a reverse feed lever 72 provided outside the sewing machine frame and connected to the feed adjustment body. The sewing machine further comprises an actuator 81 for rotating the feed adjustment body via the reverse feed lever 72 so as to have a feed pitch for condensed stitch and transmission bodies 82 and 83 for transmitting output of the actuator to the reverse feed lever. The actuator and the transmission bodies are installed outside the sewing machine frame. Thus, condensed stitch can be made only by attaching the actuator and the transmission bodies outside the sewing machine frame.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a sewing machine that adjusts a feed amount of a sewing product with a feed adjuster.

A conventional sewing machine includes a vertical feed mechanism that transmits a reciprocating motion in a vertical direction from a sewing machine motor to a feed dog, and a horizontal feed mechanism that transmits a reciprocating motion in a horizontal direction. And a feed adjusting body capable of changing the stroke of the reciprocating operation in the horizontal direction.
The feed adjustment body includes a feed adjustment dial that adjusts the feed pitch of the sewing product by changing the rotation angle of the feed adjustment body by manual rotation operation, and the rotation angle of the feed adjustment body by manual operation. A reverse feed lever or the like for changing the feed direction of the workpiece to be reversed is connected (for example, see Patent Document 1).

2008-194134

By the way, recent sewing machines are required to make the remaining end of the thread remaining on the cloth after the thread trimming performed at the sewing end position as short as possible, and improvements such as arranging the thread trimming knife closer to the needle hole are performed. Has been.
On the other hand, if the remaining end of the thread remaining on the fabric after thread trimming becomes shorter, the thread tends to come loose from the final knot, and to prevent this, the feed pitch is set to the minimum width at the sewing end position. Condensation stitching that performs multi-needle stitching has been studied.
However, in order to perform condensation sewing with an existing sewing machine, it is necessary to equip the sewing machine with a switching mechanism for switching the feed pitch to the minimum width at an arbitrary timing, but the switching mechanism is newly installed inside the sewing machine frame. It is difficult to secure the arrangement space for the arrangement, and in order to install the arrangement externally, an opening is formed outside the sewing machine frame through which the member that transmits the rotation operation to the feed adjusting body in the sewing machine frame is passed. There was a problem that there was a need for remodeling and there was a risk of lubricating oil leaking from the opening.

  An object of the present invention is to easily form a sewing machine that can perform condensation sewing from an existing sewing machine.

The invention according to claim 1 is a sewing machine,
A feed adjuster that is provided inside the sewing machine frame and changes the feed pitch according to the rotation angle;
In a sewing machine comprising a reverse feed lever provided outside the sewing machine frame and connected to the feed adjusting body,
An actuator for rotating the feed adjusting body through the reverse feed lever so as to have a feed pitch for condensation sewing;
A transmission body for transmitting the output of the actuator to the reverse feed lever;
The actuator and the transmission body are arranged outside the sewing machine frame.

The invention according to claim 2 is the sewing machine according to claim 1,
The transmission body is connected to the reverse feed lever through a long hole.

The invention according to claim 3 is the sewing machine according to claim 2,
The transmission body includes a first transmission body coupled to the reverse feed lever, and a second transmission body that transmits an output of the actuator to the first transmission body.

The invention according to claim 4 is the sewing machine according to claim 3,
The second transmission body is rotatably supported by an eccentric shaft,
The amount of operation transmitted from the actuator to the reverse feed lever can be adjusted by rotating the eccentric shaft.

The invention according to claim 5 is the sewing machine according to claim 4,
The reverse feed lever is provided with a protruding pin,
The pin is connected in a loosely fitted state to the elongated hole formed in one end of the first transmission body,
The other end of the first transmitter is connected to one end of the second transmitter,
The other end of the second transmission body is connected to the actuator,
The eccentric shaft is rotatably supported at a central portion of the second transmission body.

The invention according to claim 6 is the sewing machine according to any one of claims 1 to 3,
An adjustment structure for adjusting an operation amount transmitted from the actuator to the reverse feed lever is provided.

  According to the present invention, it is possible to easily form a sewing machine that can perform condensation sewing from an existing sewing machine.

It is a front view of the sewing machine which is an embodiment of the present invention. It is the block diagram which illustrated in plan view only the principal part structure in a sewing machine bed part. It is a perspective view of a feed adjustment mechanism. FIG. 3 is a right side view of the sewing machine with a motor cover removed. It is a perspective view of the right end part of the sewing machine which removed the motor cover. It is explanatory drawing which shows the adjustment operation | movement of the operation amount transmitted to the reverse feed lever from the condensation sewing solenoid by an eccentric shaft. FIG. 7A to FIG. 7C are explanatory views showing, in order, a method for adjusting the feed pitch for condensation stitching. 8 (A) to 8 (C) are explanatory views sequentially showing a method for adjusting the feed pitch of condensed stitching from the continuation of FIG. 7 (C).

[Overall Configuration of Embodiment of Invention]
Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. FIG. 1 is a front view of a sewing machine 10 according to an embodiment of the present invention, FIG. 2 is a configuration diagram illustrating the cloth feed mechanism 40 and the feed adjustment mechanism 60 in the sewing machine frame 20 in plan view, and FIG. It is a perspective view.
The sewing machine 10 includes a needle up-and-down moving mechanism (not shown) that moves the sewing needle up and down, a sewing machine motor (not shown) that is a driving source thereof, and a hook mechanism 30 that entangles a lower thread with a sewing thread that is inserted into the sewing thread by the full rotary hook 31 , A cloth feed mechanism 40 that feeds the cloth to be sewn on the needle plate in accordance with the vertical movement of the sewing needle, a feed adjustment mechanism 60 that adjusts the feed amount of the cloth feed mechanism 40, and a sewing machine frame that supports each of the above components 20.

[Sewing frame]
The sewing machine frame 20 includes a sewing machine bed portion 21 positioned at the lower portion of the sewing machine 10, a standing body portion 22 erected upward at one end portion (right side to be described later) of the sewing bed portion 21, and a standing body A sewing machine arm portion 23 (not shown) extending in the same direction as the sewing machine bed portion 21 from the upper end portion of the portion 22 is provided.
In addition, a motor cover 221 that covers the sewing machine motor is detachably mounted on one side of the standing body part 22 (on the opposite side of the sewing machine arm part 23). On the front side of the motor cover 221 is provided an operation panel 222 for inputting various settings related to the sewing operation of the sewing machine 10.

  The longitudinal direction of the sewing machine bed 21 is horizontal with the sewing machine 10 installed on the upper surface of the horizontal table T. In the following description, the longitudinal direction of the sewing machine bed portion 21 is the Y-axis direction, the horizontal direction orthogonal to the Y-axis direction is the X-axis direction, and the direction orthogonal to the X-axis and Y-axis directions is the Z-axis direction. To do. Also, in one direction in the Z-axis direction, the upper side is “upper”, the lower side is “lower”, and the direction in which the operator is positioned with respect to the sewing machine in one direction in the X-axis direction is “front side” (or cloth feed direction) The upstream side), the opposite side to the “back side” (or the downstream side in the cloth feed direction), the left side as viewed from the operator side in one direction in the Y-axis direction is referred to as “left”, and the right side is referred to as “right”.

The sewing machine 10 is installed on a table T having an opening T1 for storing the sewing machine bed 21. The opening T1 of the table T is substantially equal to the planar view shape of the sewing machine bed portion 21, and the upper surface of the table T and the upper surface of the sewing machine bed portion 21 are substantially the same horizontal plane in a state where the sewing machine bed portion 21 is stored in the opening T1. It will be in the state lined up.
A bottom cover 211 of the sewing machine and a mechanism cover 212 of a condensation sewing switching mechanism 80 described later are fixedly installed on the lower surface side of the table T and below the opening T1. In the sewing machine 10, the lower part of the sewing machine bed 21 is covered with the bottom cover 211 in a state where the sewing machine bed 21 is stored in the opening T 1 of the table T, and the condensed sewing switching mechanism 80 is stored in the mechanism cover 212.
The sewing machine 10 can be tilted back on the table T around the Y axis. In this case, the bottom of the sewing machine bed portion 21 is exposed from the opening T1 of the table T, and the condensed stitch switching mechanism 80 The whole is exposed from the mechanism cover 212, and is in a state facing the operator side, and maintenance work can be performed on these.

[Needle up / down mechanism and sewing motor]
The needle up-and-down movement mechanism is disposed inside the sewing machine arm portion 23, is rotationally driven by the sewing machine motor and is disposed along the Y-axis direction, and a needle bar that holds the sewing needle at the lower end portion. A crank mechanism that converts the rotational driving force of the upper shaft into a reciprocating driving force that moves up and down and transmits it to the needle bar. Since these are well-known structures, illustration is abbreviate | omitted.
The upper shaft is fixedly equipped with a bevel gear near the right end, and the vertical feed shaft 43 of the cloth feed mechanism 40 is also fixedly equipped with a bevel gear 56. A vertical axis (not shown) along the Z-axis direction is provided in the vertical body portion 22, and the power of the upper shaft is raised and lowered by bevel gears provided at the upper end portion and the lower end portion of the vertical axis. This is transmitted to the feed shaft 43.
In addition, since the bevel gears provided on the upper shaft, the vertical axis, and the vertical feed shaft 43 are arranged in the vertical body portion 22, in order to satisfactorily transmit these operations, Is supplied with lubricating oil.
Further, the method for transmitting the power of the upper shaft to the vertical feed shaft 43 may use not only the bevel gear mechanism but also a timing belt.

[Hook mechanism]
The shuttle mechanism 30 is provided inside the left end of the sewing machine bed portion 21, holds the full rotary shuttle 31 described above and the full rotary shuttle 31 at one end portion thereof, and extends in the Y-axis direction within the sewing machine bed portion 21. The hook shaft 32 is rotatably supported in the state where it is rotated, and a speed increasing gear 33 provided at the other end of the hook shaft 32 is provided.
The speed increasing gear 33 provided on the hook shaft 32 meshes with a main driving gear 48 provided on a vertical feed shaft 43 of a cloth feed mechanism 40 described later, and the double speed rotation from the vertical feed shaft 43 to the hook shaft 32 is achieved. Is to be granted.

  The shuttle mechanism is not limited to a full rotary hook, and may be a sewing machine equipped with a half rotary hook or a horizontal hook.

[Cloth feed mechanism]
The cloth feed mechanism 40 is arranged along the vertical direction (Z-axis direction) of the feed dog 41 that feeds the cloth in a predetermined direction by appearing and dropping from the opening of the needle plate, the feed base 42 that holds the feed tooth 41, and the feed base 42. Rotation of the vertical feed shaft 43, the vertical feed shaft 43 that rotates to reciprocate in the direction, the horizontal feed shaft 46 that reciprocates to reciprocate the feed base 42 along the feed direction (X-axis direction), and the vertical feed shaft 43. An eccentric rod 50 serving as an operation converting rod that converts the driving force into a driving force for reciprocating rotation by an eccentric cam 49 and applied to the horizontal feed shaft 46, and a reciprocating rotational operation of the horizontal feed shaft 46 are transmitted to the feed base 42. A horizontal feed arm 47 and a transmission rod 45 for converting the rotational driving force of the vertical feed shaft 43 into a reciprocating vertical movement by an eccentric cam 44 and transmitting it to the feed base 42 are provided.

  The vertical feed shaft 43 is supported so as to be rotatable along the Y-axis direction in the sewing machine bed portion 21, and is arranged on the upstream side (front side) of the cloth feed direction with respect to the shuttle shaft 32 described above. As described above, full rotation torque is input to the vertical feed shaft 43 from the upper shaft by the bevel gear 56.

  Further, the left end portion of the vertical feed shaft 43 extends below the needle plate, and an eccentric cam 44 is fixedly mounted on the left end portion. The lower end of the transmission rod 45 is connected to the vertical feed shaft 43 via the eccentric cam 44. The transmission rod 45 rotatably holds a circular eccentric cam 44 at its lower end, and the upper end is rotatably connected to one end of the feed base 42. Since the transmission rod 45 has a connecting end with the feed base 42 located substantially above the connecting end with the vertical feed shaft 43, the eccentric cam 44 reduces the amount of eccentricity when the vertical feed shaft 43 rotates. A driving force for reciprocating movement along the vertical direction is applied to one end of the feed base 42 with a double stroke.

Further, an eccentric cam 49 is also fixedly provided near the right end portion of the vertical feed shaft 43, and the eccentric rod 50 is connected via the eccentric cam 49. The eccentric rod 50 has a circular eccentric cam 49 rotatably held at one end thereof, and the other end extends substantially in the horizontal direction. For this reason, when the vertical feed shaft 43 rotates, the other end portion performs a reciprocating operation along the horizontal direction with a stroke twice the eccentric amount by the eccentric cam 49.
On the other hand, a horizontal feed shaft 46 arranged in parallel with the vertical feed shaft 43 is fixedly equipped with a rotating arm 51 extending to the vertical feed shaft 43 side. The other end portion of the eccentric rod 50 and the rotation end portion of the rotation arm 51 are connected by a link of the feed adjustment body 62 of the feed adjustment mechanism 60. Thereby, a reciprocating rotation operation is applied from the vertical feed shaft 43 to the horizontal feed shaft 46, and the width of the applied reciprocating rotation angle can be adjusted by the feed adjusting body 62. The feed adjusting body 62 will be described later.

The horizontal feed shaft 46 transmits a reciprocating driving force along the X-axis direction from the left end portion to the feed base 42 via the horizontal feed arm 47.
The horizontal feed arm 47 is fixedly connected to the left end portion of the horizontal feed shaft 46 at the base end thereof, and is connected to the feed base 42 in a state where the swing end portion is directed substantially upward.
The feed base 42 is disposed below the needle plate, the front end is connected to the vertical feed shaft 43 via the transmission rod 45, and the back end is connected to the horizontal feed shaft 46 via the horizontal feed arm 47. It is connected to. Further, a feed dog 41 is fixedly mounted on the upper part of the intermediate position of the feed base 42 in the X-axis direction.

  As a result, the feed base 42 is given a reciprocating drive force in the vertical direction from one end thereof, and a reciprocating drive force in the feed direction is given from the other end in the same cycle. Then, by combining these reciprocating driving forces, an ellipse motion is performed along the XZ plane. The feed dog 41 also performs an elliptical movement with the feed base 42, and the tip of the feed dog 41 protrudes upward from the opening of the needle plate when passing through the upper region of the elliptical movement trajectory to feed the cloth. Making it possible.

[Feed adjustment mechanism]
FIG. 2 is a perspective view of the feed adjustment mechanism 60. As shown in FIGS. 1 and 2, the feed adjusting mechanism 60 includes a feed adjusting body 62, a rotation support shaft 63 fixedly connected to the feed adjusting body 62 and disposed along the Y-axis direction, and a feed amount. A feed dial 64 for performing the adjustment operation, a feed adjustment screw 65 as a feed adjustment member for moving forward and backward by the feed dial 64, and a feed as a cam member that rotates when the feed adjustment screw 65 abuts to produce an angle change. An adjustment base 66, a connecting rod 67 whose upper end is connected to the rotating end of the feed adjusting base 66, and a first that is fixedly connected to the rotating support shaft 63 and connected to the lower end of the connecting rod 67. The fixed input arm 68, the back tack solenoid 69 that rotates the feed adjusting body 62 to switch to the reverse feed state, and the switching lever that is fixedly connected to the support shaft 71a and connected to the plunger of the back tack solenoid 69. And over 71, a reverse feed lever 72 provided on the right end portion of the rotation support shafts 63, and a condensed stitch changeover mechanism 80 for executing a condensed stitch.

The other end of the eccentric rod 50 and the rotating end of the rotating arm 51 are connected via a link, and the eccentric rod 50, the rotating arm 51, and a link connecting them together constitute a four-bar link mechanism. doing.
The feed adjusting body 62 regulates the moving direction of the connecting point between the other end of the eccentric rod 50 and the link, which is one of the four nodes of the four-link mechanism. The feed adjusting body 62 rotates about the rotation support shaft 63, so that the moving direction of the connecting point between the other end of the eccentric rod 50 and the link can be changed about the Y axis. And if the moving direction of the said connection point changes, the angle range of the reciprocating rotation of the horizontal feed shaft 46 will change, and the feed pitch by the feed dog 41 can be changed.
Further, when the feed adjusting body 62 is rotated in one rotation direction across an axis angle (making it a neutral point) that makes the feed pitch 0, the feed pitch can be changed by forward feed, and the neutral point is sandwiched. When it is turned in the other turning direction, the feed pitch can be changed by reverse feed.

The connecting rod 67 has an upper end connected to the feed adjusting base 66 and a lower end connected to the rotating end of the first fixed input arm 68. The connecting rod 67 can rotate the feed adjusting body 62 through the rotation support shaft 63 by vertical movement.
The feed adjustment stand 66 includes cam portions 66b having a forward feed cam surface and a reverse feed cam surface on both sides of the feed adjustment screw 65, and either cam surface is in contact with the tip of the feed adjustment screw 65. Even in this case, the direction around the support shaft 66a along the Y-axis direction is determined according to the contact position. When the feed adjusting screw 65 moves along the X-axis direction by rotating the feed dial 64, the contact position with the cam surface changes, and the direction of the feed adjusting table 66 around the support shaft 66a changes.
Since the rotation end portion of the feed adjusting base 66 is connected to the upper end portion of the connecting rod 67, the connecting rod 67 moves up and down by rotating the feed dial 64, and the rotation adjusting portion of the feed adjusting body 62 is supported. The angle around the axis can be adjusted, whereby the feed pitch of the feed dog 41 can be changed.

Further, when one of the two cam surfaces of the feed adjusting base 66 abuts on the tip of the feed adjusting screw 65, the feed pitch in the forward direction of the feed dog can be changed, and the other of the two cam surfaces can be fed. When contacting the tip of the adjusting screw 65, the feed pitch in the reverse direction of the feed dog can be changed.
Normally, one cam surface (a cam surface that changes the forward feed pitch) is maintained in contact with the tip of the feed adjusting screw 65 by a spring (not shown), and the other is driven by the back tack solenoid 69. Can be switched to a state in which the cam surface is in contact with the tip of the feed adjusting screw 65.

The back tack solenoid 69 is mounted on the outside of the rear surface of the vertical trunk portion 22, and the tip end of the plunger 691 is connected to the switching lever 71. The switching lever 71 is rotated around the support shaft 71a along the Y-axis direction. Can be rotated.
The switching lever 71 is a bell crank provided with two arms 711 and 712 that rotate about a support shaft 71a. One arm 711 extends upward and has a rotating end at a back tack solenoid 69. The plunger 691 is connected.
The other arm 712 extends rearward and is provided with a pin 713 along the Y-axis direction at the rotating end. The pin 713 is in contact with a notch formed in the connecting rod 67 from below.
For this reason, when the plunger 691 of the back tack solenoid 69 moves forward, the switching lever 71 rotates clockwise as viewed from the left, and the pin 713 pushes up the connecting rod 67. As a result, it is possible to switch from the state in which one cam surface of the feed adjustment stand 66 abuts on the tip of the feed adjustment screw 65 to the state in which the other cam surface abuts on the tip of the feed adjustment screw 65.
That is, when the plunger 691 of the back tack solenoid 69 is advanced to the front side, the cloth feed direction can be switched from the normal feed to the reverse feed. Back tack sewing can be performed by advancing the plunger 691 of the back tack solenoid 69 forward at the start or end of sewing.

  Note that the two cam surfaces of the feed adjusting base 66 are rotated by the connecting rod 67 so that the leading end of the feed adjusting screw 65 moves from one forward feed cam face to the other reverse feed cam face. The shape of each cam surface is set so that the feed pitch of the forward feed and the reverse feed have the same width when the abutment position is switched. That is, even when the reverse feed is switched, the feed pitch set by the rotation operation of the feed dial 64 is maintained.

The above-described right end portion of the rotation support shaft 63 is disposed so as to protrude outward from the right side surface of the standing body portion 22 of the sewing machine frame 20, and is opposite to the protrusion end portion of the rotation support shaft 63. A feed lever 72 is provided.
The reverse feed lever 72 includes a reverse feed plate 721 that is fixedly mounted on the right end portion of the rotation support shaft 63 and an operation member 722 that is rotatably supported with respect to the rotation support shaft 63.

  The reverse feed plate 721 extends from the rotation support shaft 63 toward the front side, and an input projection 721a that abuts on the lower portion of the operation member 722 protrudes leftward from the extended end portion. The reverse feed plate 721 has a short extension to the near side, and the entire reverse feed plate 721 is stored inside the motor cover 221.

The operation member 722 extends from the rotation support shaft 63 toward the front side to the outside of the motor cover 221 and is further bent and extended toward the left.
The portion of the operation member 722 that extends to the left can be swung up and down on the front side of the front surface of the upright body portion 22, and can be rotated downward to operate the cloth feed mechanism 40. The feed direction can be switched to reverse feed.
As described above, the operation member 722 is rotatable with respect to the rotation support shaft 63, and the rotation support shaft 63 cannot be directly rotated even if the operation member 722 is rotated downward. However, when the operation member 722 is rotated downward, the input projection 721a of the reverse feed plate 721 is contacted from above, and the rotary support shaft 63 can be rotated via the reverse feed plate 721.

  When the operation member 722 is rotated downward until it stops, the first fixed input arm 68 pushes up the connecting rod 67 from the rotation support shaft 63 and rotates the feed adjusting table 66 to rotate the feed adjusting screw 65. The abutment position of the front end portion is switched from the forward feed cam surface to the reverse feed cam surface, and the cloth feed mechanism 40 can be switched to the reverse feed state. In this case also, the forward feed pitch and the reverse feed pitch are equal in magnitude.

  The operation member 722 rotates the rotation support shaft 63 via the reverse feed plate 721. This is because the operation member 722 is switched to reverse feed by the operation of the back tack solenoid 69 described above. This is to prevent a sudden lowering operation in conjunction with it.

[Condensation sewing switching mechanism]
4 is a right side view of the sewing machine 10 with the motor cover 221 removed, and FIG. 5 is a perspective view of the right end of the sewing machine 10 in the same state.
As shown in the figure, a condensation sewing switching mechanism 80 is disposed outside the right end portion of the sewing machine bed portion 21 of the sewing machine frame 20.
The condensation sewing switching mechanism 80 includes a condensation sewing solenoid 81 as an actuator for rotating the feed adjusting body 62 so as to have a condensation sewing feed pitch, and a transmission body for transmitting the output of the condensation sewing solenoid 81 to the reverse feed lever 72. The first transmission body 82 and the second transmission body 83, the bracket 84 for supporting the condensation sewing solenoid 81, and the eccentric shaft as an adjustment body for adjusting the operation amount transmitted from the condensation sewing solenoid 81 to the reverse feed lever 72. 85.

The bracket 84 is attached below the upper surface of the sewing machine bed portion 21 at the right end portion of the sewing machine bed portion 21, and supports the condensation sewing solenoid 81 depending on the two arms extending rightward. Yes.
The bracket 84 is screwed to a screw hole (not shown) formed on the outer surface of the right end portion of the sewing machine bed portion 21. The screw hole has a bottom and is formed so as not to penetrate the inside of the sewing machine bed portion 21, thereby preventing lubricating oil leakage from the screw hole.

The condensation sewing solenoid 81 is screwed to the bracket 84 with the plunger 811 facing upward. The plunger 811 of the condensation sewing solenoid 81 is in a state of being retracted downward during normal sewing, and projects upward to switch the feed pitch during condensation sewing.
A pin 812 that protrudes to the right is fixedly mounted on the upper end portion of the plunger 811, and the pin 812 is formed in a slot-like notch 831 formed at an end portion of the second transmission body 83 described later. The second transmission body 83 is imparted with a turning motion when the plunger 811 protrudes.
Note that the plunger 811 of the condensation sewing solenoid 81 passes vertically through the main body portion in which the coil is stored, and the lower end portion of the plunger 811 protrudes downward from the lower end portion of the main body portion.

  The first transmission body 82 is a link member, and an elongated hole 821 is formed at one end, and a pin 721b protruding rightward from the reverse feed plate 721 of the reverse feed lever 72 is connected in a loosely inserted state. The other end of the first transmission body 82 is connected to one end of the second transmission body 83 so as to be rotatable about the Y axis.

As described above, the second transmission body 83 has one end connected to the first transmission body 82 and the other end connected to the plunger 811 of the condensation sewing solenoid 81. And the center part of the 2nd transmission body 83 is supported by the eccentric shaft 85 so that rotation around the Y-axis is possible.
Therefore, when the plunger 811 of the condensation sewing solenoid 81 protrudes upward, the other end portion of the second transmission body 83 rotates upward, and the first transmission connected to one end portion of the second transmission body 83. The body 82 is pulled down, and the reverse feed plate 721 of the reverse feed lever 72 rotates downward. As a result, the feed adjusting body 62 is rotated through the rotation support shaft 63, and is adjusted so that the feed pitch of condensation sewing is smaller than the original feed pitch.

FIG. 6 is an explanatory diagram showing the adjustment operation of the operation amount transmitted from the condensation sewing solenoid 81 to the reverse feed lever 72 by the eccentric shaft 85.
The eccentric shaft 85 has a shaft main body 851 inserted into the second transmission body 83 and a support shaft portion 852 that is eccentric with respect to the shaft main body 851 (see FIG. 8B). 852 is inserted into a support hole (not shown) of the bracket 84.
The support shaft portion 852 of the eccentric shaft 85 is fastened and fixed by a fixing screw 86 (see FIG. 7C) provided on the bracket 84 so as not to rotate.

The eccentric shaft 85 can rotate the second transmission body 83 according to the amount of eccentricity of the support shaft portion 852 by loosening the fixing screw 86 and performing a rotation operation, thereby the first transmission body. 82 can be moved up and down.
For example, as shown by a two-dot chain line in FIG. 6, when the first transmission body 82 is moved and adjusted upward by rotating the eccentric shaft 85, the upper end portion of the long hole 821 in contact with the pin 721b is In contrast, a gap having a width d is generated.
As a result, the downward movement amount given to the first transmission body 82 by the plunger 811 of the condensation sewing solenoid 81 projecting is shortened by the width d from the state before the adjustment, and the amount corresponding to this is reduced. The rotation angle applied to the reverse feed plate 721 of the reverse feed lever 72 is also reduced.
That is, by rotating the eccentric shaft 85, the feed pitch of the condensation stitch set by the condensation stitching solenoid 81 can be increased or decreased.

[How to adjust the feed pitch for condensation sewing]
FIG. 7A to FIG. 8C are explanatory views sequentially showing a method for adjusting the feed pitch of condensation stitching. Based on these, this adjustment method will be described.

First, the sewing machine frame 20 of the sewing machine 10 installed on the table T is tilted back (FIG. 7A).
As a result, the lower part of the sewing machine bed portion 21 stored in the opening T1 of the table T is exposed, and the condensed sewing switching mechanism 80 is pulled out from the mechanism cover 212 and exposed on the table T.

Next, the feed dial 64 is rotated and adjusted so as to have a feed pitch when performing condensation sewing. It is desirable that the feed pitch for condensation sewing be greater than 0 and as small as possible. Here, as an example, a case of 0.5 [mm] is illustrated (FIG. 7B).
As a result, the feed adjusting body 62 is rotated to a position at which the condensation sewing target feed pitch is obtained, and the reverse feed plate 721 of the reverse feed lever 72 is rotated to the sewing machine bed portion 21 side in conjunction with it. As a result, the width d (see FIG. 6) of the gap between the end of the elongated hole 821 of the first transmission body 82 (the upper end when the sewing machine frame 20 is not tilted) and the pin 721b of the reverse feed plate 721 is increased. .

Here, the fixing screw 86 of the condensed stitching switching mechanism 80 is loosened, and the eccentric shaft 85 can be rotated (FIG. 7C).
Then, the plunger 811 of the condensation sewing solenoid 81 is manually pushed out from the lower end portion in the protruding direction (FIG. 8A). As a result, the second transmission body 83 rotates counterclockwise and the first transmission body 82 moves to the sewing machine bed 21 side, and the end of the elongated hole 821 of the first transmission body 82 (the sewing machine frame 20 is tilted down). The width d of the gap between the upper end portion in the state of not being connected) and the pin 721b of the reverse feed plate 721 decreases.

Then, the eccentric shaft 85 is manually rotated to adjust the positions of the first transmission body 82 and the second transmission body 83 (FIG. 8B), and the end (sewing machine) of the elongated hole 821 of the first transmission body 82 is adjusted. The upper end of the frame 20 in the state where the frame 20 is not tilted) and the pin 721b of the reverse feed plate 721 are adjusted to a position where the width d is zero.
Further, the fixing screw 86 is fastened (FIG. 8C), and the eccentric shaft 85 is fixed.

Thereafter, the pushing state of the plunger 811 of the condensation sewing solenoid 81 is returned to the original retracted state, the sewing machine frame 20 is rotated forward, and the original standing state is restored.
Further, the feed dial 64 is returned to the normal sewing feed pitch (for example, 3 [mm]).

Thereafter, when performing a sewing operation, for example, when a front pedal of an operation pedal connected to the sewing machine 10 is depressed, the sewing machine motor is activated and sewing is started at a normal sewing feed pitch.
When the thread trimming operation is input by reversely depressing the operation pedal at the sewing end position, the back tack solenoid 69 is activated, the plunger 691 is projected, and one cam surface of the feed adjusting table 66 is adjusted in feed. By switching from the state of contact with the tip of the screw 65 to the state of contact of the other cam surface with the tip of the feed adjustment screw 65, the cloth feed direction is switched from normal feed to reverse feed, and the set number of stitches is backed. Tuck stitching is performed.
Then, after the back tack sewing is completed and the back tack solenoid 69 is turned OFF, the condensation sewing solenoid 81 is actuated, the plunger 811 is projected to rotate the second transmission body 83 counterclockwise, and the first One transmission body 82 descends. At this time, since the width of the gap between the elongated hole 821 of the first transmission body 82 and the pin 721b of the reverse feed plate 721 is adjusted to be the feed pitch of the condensation sewing, the reverse feed plate 721 is a normal sewing machine. Rotation is applied from the position of the feed pitch (3 [mm]) to the position of the feed pitch (0.5 [mm]) for condensation stitching, and the feed adjuster 62 is rotated to an appropriate position.
Then, after the condensation sewing is performed for the specified number of stitches at the feed pitch of the condensation sewing, the sewing machine motor stops and the thread trimming operation is performed, and the sewing is completed.

[Explanation of effect of embodiment]
The sewing machine 10 is arranged outside the sewing machine frame 20 and at the outside of the sewing machine frame 20 while the entire configuration of the condensation sewing switching mechanism 80 having the condensation sewing solenoid 81 and the first and second transmission bodies 82 and 83 is arranged. The operation of switching to the feed pitch for condensation sewing is performed via the reverse feed lever 72.
For this reason, it is possible to add the function of condensation sewing to an existing sewing machine that does not originally have the function of performing condensation sewing only by externally attaching the condensation sewing switching mechanism 80.
Further, since the condensation stitch switching mechanism 80 performs the switching operation to the feed pitch of the condensation stitch through the reverse feed lever 72, it is not necessary to form an opening or the like for accessing the inside of the sewing machine frame 20, and the sewing frame 20 Even when lubricating oil is used inside, leakage to the outside can be suppressed. In addition, when the condensation sewing switching mechanism 80 is attached, it is possible to eliminate the need for a sealing process for preventing leakage of lubricating oil.

  Further, since the first transmission body 82 of the condensed stitch switching mechanism 80 of the sewing machine 10 is connected to the reverse feed plate 721 of the reverse feed lever 72 through the long hole 821, the pin 721b is within the range of the long hole 821. By adjusting the position, it is possible to arbitrarily adjust the feed pitch of condensation stitching.

Further, the transmission body of the condensation sewing switching mechanism 80 has a first transmission body 82 connected to the reverse feed lever 72 and a second transmission body 83 that transmits the output of the condensation sewing solenoid 81 to the first transmission body 82. Therefore, the degree of freedom of arrangement of the condensation sewing solenoid 81 in the X-axis direction can be increased as compared with the configuration in which the condensation sewing solenoid 81 operates the reverse feed lever 72 with a single transmission body.
For this reason, in the case of the sewing machine 10 in which the sewing machine frame 20 is rotatable with respect to the table T, the condensed sewing solenoid 81 is brought as close as possible to the fulcrum side when the sewing machine frame 20 is rotated with respect to the table T. Can be arranged.
Thus, when the condensation sewing solenoid 81 approaches the fulcrum side of the sewing machine frame 20, when the sewing machine frame 20 is tilted, the radius of rotation of the condensation sewing solenoid 81 is reduced, so that an opening T1 formed in the table T is formed. It is possible to reduce the width of the opening for the condensed stitch switching mechanism 80 in FIG.
Accordingly, the opening T1 of the table T can be reduced to prevent a decrease in strength, and the work space on the upper surface of the table T can be increased.
Furthermore, when the opening T1 becomes large, it cannot be hidden by the motor cover 221 alone, and a separate lid for hiding the opening for the condensation sewing switching mechanism 80 in the opening T1 is necessary. By reducing T1, such a lid is unnecessary, and it is possible to reduce the number of components and the complexity of opening and closing the lid.

  In addition, since the second transmission body 83 of the condensed stitch switching mechanism 80 is rotatably supported by the eccentric shaft 85, the reverse feed plate 721 of the reverse feed lever 72 from the condensed stitch solenoid 81 is operated by rotating the eccentric shaft 85. The amount of operation transmitted to the sewing machine can be adjusted, the adjustment work of the feed pitch in the condensation sewing can be easily performed, and the workability can be improved.

[Others]
In the above embodiment, the case where the adjustment work of the feed pitch of the condensation sewing is performed by the rotation operation of the eccentric shaft 85 that supports the second transmission body 83 is exemplified, but the present invention is not limited to this.
For example, it is possible to adopt an adjustment structure in which the position of the bracket 84 can be adjusted in the vertical direction and the feed pitch of condensation sewing is adjusted according to the height of the bracket 84.
Similarly, it is also possible to adopt an adjustment structure in which the condensation sewing solenoid 81 can be adjusted in the vertical direction with respect to the bracket 84 and the feed pitch of the condensation sewing is adjusted according to the height of the condensation sewing solenoid 81. is there.
As for the height adjustment of the bracket 84 and the condensation sewing solenoid 81, these can be moved and adjusted by a long hole along the vertical direction, and may be fixed by a screw. Further, the vertical movement of the bracket 84 and the condensation sewing solenoid 81 may be performed by bringing the outer peripheral cam such as an eccentric cam into contact with the bracket 84 and the condensation sewing solenoid 81 and operating the cam.

  In the above embodiment, an example in which the condensation sewing switching mechanism 80 is mounted on the main sewing machine is shown. However, the condensation sewing switching mechanism 80 can be mounted on any sewing machine having a reverse feed lever outside the sewing machine frame 20. It is.

In the above embodiment, when a thread trimming operation is input by depressing the operation pedal, the back tack solenoid 69 is activated, and after performing the back tack sewing for the set number of stitches, the condensation sewing solenoid 81 is activated. Although the example in which the condensation sewing is performed for the specified number of stitches has been shown, the condensation sewing may be performed without performing the back tack sewing after the input of the thread trimming operation.
In that case, when the thread trimming operation is input by depressing the operation pedal in reverse, the condensation sewing solenoid 81 is actuated, and after the specified number of stitches are condensed at the feed pitch of condensation sewing, the sewing machine motor stops. The thread trimming operation is performed and sewing is completed.

DESCRIPTION OF SYMBOLS 10 Sewing machine 20 Sewing machine frame 21 Sewing machine bed part 22 Standing trunk part 23 Sewing arm part 30 Hook mechanism 40 Cloth feed mechanism 41 Feed dog 43 Vertical feed shaft 46 Horizontal feed shaft 60 Feed adjustment mechanism 62 Feed adjustment body 64 Feed dial 69 Back tack solenoid 72 Reverse feed lever 721 Reverse feed plate 80 Condensed stitch switching mechanism 81 Condensed stitch solenoid (actuator)
811 Plunger 82 First transmission body 821 Elongated hole 83 Second transmission body 84 Bracket 85 Eccentric shaft 851 Shaft body 852 Support shaft portion 86 Fixing screw 212 Mechanism cover T Table T1 Opening portion

Claims (6)

A feed adjuster that is provided inside the sewing machine frame and changes the feed pitch according to the rotation angle;
In a sewing machine comprising a reverse feed lever provided outside the sewing machine frame and connected to the feed adjusting body,
An actuator for rotating the feed adjusting body through the reverse feed lever so as to have a feed pitch for condensation sewing;
A transmission body for transmitting the output of the actuator to the reverse feed lever;
A sewing machine characterized in that the actuator and the transmission body are arranged outside the sewing machine frame.   The sewing machine according to claim 1, wherein the transmission body is connected to the reverse feed lever through a long hole.   The sewing machine according to claim 2, wherein the transmission body includes a first transmission body coupled to the reverse feed lever, and a second transmission body that transmits an output of the actuator to the first transmission body. The second transmission body is rotatably supported by an eccentric shaft,
The sewing machine according to claim 3, wherein an operation amount transmitted from the actuator to the reverse feed lever can be adjusted by a rotation operation of the eccentric shaft. The reverse feed lever is provided with a protruding pin,
The pin is connected in a loosely-fitted state to the elongated hole formed at one end of the first transmission body,
The other end of the first transmitter is connected to one end of the second transmitter,
The other end of the second transmission body is connected to the actuator,
The sewing machine according to claim 4, wherein the eccentric shaft is rotatably supported at a central portion of the second transmission body.   The sewing machine according to claim 1, further comprising an adjustment structure that adjusts an operation amount transmitted from the actuator to the reverse feed lever.

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