JP2006042836A - Presser device of sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the presser device of a sewing machine capable of preventing a presser foot from obstructing cloth feed. <P>SOLUTION: A horizontal shaft 28 is turnably pivoted to the crank arm 26 of a swing shaft 11, a collar 29 is fixed to the projected end part of the horizontal shaft 28 and also a presser base 34 is connected. Also, a part 37 to be locked and an attaching part 38 positioned on both sides are projectingly provided on the crank arm 26 holding a locking part 39 projected to the side from the collar 29 between them. The horizontal shaft 28 is turned within the range until the locking part 39 is abutted on the part 37 to be locked or the attaching part 38 or is integrated with the crank arm 26 by pressing and fixing the locking part 39 to the part 37 to be locked with a screw 41 screwed to the attaching part 38. Consequently, the pressing base 34 can be turned around the swing shaft 11 or the horizontal shaft 28. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a presser device for a sewing machine, particularly an overlock sewing machine.

  A presser device for an overlock sewing machine is normally supported by a swinging shaft rotatably supported by a sewing machine frame and a crank arm at one end of the swinging shaft, and moves forward on the sewing machine bed toward the cloth feed direction. A presser base that is extended and has a presser foot attached thereto; a presser spring device that presses down the presser base; an arm that is pivotally supported by the other end of the pivot shaft and that is rotated by a pedal depression operation; When the pedal is depressed, the arm rotates with the swinging shaft against the action of the spring, so that the presser foot resists the action of the presser spring device. The presser foot can be lifted onto the needle plate.

As for this kind of presser device, in Patent Document 1 below, a collar having a locked portion protruding in a side parallel to the swing shaft is fixed to the other end of the swing shaft, and the arm is attached to the bell crank. When the bell crank lever is rotated by depressing the pedal, one end of the lever pushes and moves the locking portion of the collar and rotates the swing shaft together with the collar. It has become. Even when the presser foot vibrates in the vertical direction following the feeding teeth appearing and retracting on the throat plate during cloth feeding, the locking part swings in a state of being separated from one end of the bell crank-shaped lever. There has been disclosed a configuration in which the vibration of the moving shaft is prevented from being transmitted to the bell crank lever, and the increase of the presser foot vibration caused by the vibration inertia force of the bell crank lever, that is, the jumping phenomenon can be suppressed.
Reality 6-16604

  In the conventional sewing machine presser device, as shown in FIG. 1, the presser foot 1 swings around the shaft fulcrum A with the crank arm by the vertical movement of the feed dog at the time of cloth feeding in the cloth feeding direction F. The presser foot at the tip of the pedestal also swings up and down on the needle plate, but this movement is a diagonally upward movement as shown in the figure, so that the cloth feed by the feed dog is obstructed by the presser foot and between the upper and lower fabrics It is easy to cause a shift in the front-rear direction.

  The present invention provides a bell-crank-like lever that rotates even when the presser foot swings up and down following the feed dogs appearing and retracting on the needle plate during cloth feeding. In the presser device of the sewing machine that prevents the presser jumping phenomenon from being transmitted, the presser foot can be prevented from obstructing the cloth feed.

  According to a first aspect of the present invention, there is provided a swinging shaft rotatably supported by a sewing machine frame, a crank arm having one end fixed to the swinging shaft, and a connecting means connected to the crank arm by a sewing bed. A presser base that extends upward in the cloth feed direction and has a presser foot attached to the tip, a presser spring device that presses down the presser base, and is pivotally supported at the appropriate position of the swing shaft. It consists of a lever that rotates the shaft, and when the pedal is stepped on, the crank arm rotates about the swinging shaft, so that the presser foot turns upward against the action of the presser spring device, and the presser foot In the presser device of the sewing machine that can lift the needle plate on the needle plate, the connecting means has a horizontal axis provided parallel to the swing shaft at the free end of the crank arm, and a rotation center of the presser base. The swing shaft or A clutch means capable of switching to a flat shaft; and a spring means for urging the swinging shaft to rotate in a direction opposite to the direction in which the swinging shaft is rotated by a stepping operation of the pedal; It has a blocking means for stopping the rotation of the swing shaft to be moved at a fixed position.

  Here, as the spring means for biasing the swinging shaft so as to rotate in the direction opposite to the direction in which the swinging shaft is rotated by depressing the pedal, for example, it directly engages the swinging shaft or A spring that engages with an integral member, for example, a crank arm and urges the swinging shaft to rotate in the reverse direction can be used.

  The clutch means includes, for example, a set screw screwed into the crank arm and fixed to the horizontal shaft, a locking portion formed on the collar fixed to the horizontal shaft, and a locked portion formed on the crank arm. The locked part and the mounting part protrude from the clamp, screw or crank arm to be connected, and the locking part formed on the collar fixed to the horizontal shaft is between the locked part and the mounting part. And those made of screws screwed into the mounting portion. The set screw that is screwed into the former crank arm and fastened to the horizontal shaft can be rotated by loosening, and when the set screw is screwed in, the horizontal shaft is fixed to the crank arm.

  The clamps and screws that connect the locking part and the locked part can be connected together, or the connection between them can be released. When the connection is released, the presser base is centered on the horizontal axis. It can be turned. Further, with respect to the screw to be screwed into the latter mounting portion, the locking portion is pushed in at the protruding end of the screw by screwing, and is pressed and fixed to the locked portion. On the other hand, when the screw is rotated in the loosening direction and retracted, the locking portion can be rotated between the locked portion and the screw tip or the mounting portion (when the screw is retracted into the mounting portion).

  According to a second aspect of the present invention, the clutch means according to the first aspect of the present invention is provided with a locked portion and a mounting portion that are provided to project by the crank arm and a collar fixed to the horizontal shaft. A locking portion interposed between the locking portion and the mounting portion, and a screw that is screwed into the mounting portion and presses the locking portion against the locked portion. A fixing screw is fastened to prevent loosening.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the blocking means is fixed to the swinging shaft fixed to the stopper means for stopping the lever from turning upward at the upper limit position, and can be engaged with and disengaged from the lever. It has the collar provided with the latching | locking part latched on.

  The invention according to claim 4 is the invention according to claim 3, wherein the lever extends laterally along the back surface of the sewing machine frame, and is connected to a push-up lever rotatably supported by the sewing machine frame. The stopper means is fixed to the sewing machine frame and has a protruding piece that engages with the push-up lever from above.

  According to the first aspect of the present invention, the horizontal shaft is attached to the crank arm fixed to the swing shaft, and the pivot center of the presser base is switched to the swing shaft or the horizontal shaft by the connecting means. Therefore, for example, as shown in FIG. 2, when the swing shaft 3 and the horizontal shaft 4 are arranged up and down and the center of rotation of the presser base 1 is switched to the horizontal shaft 4, the presser foot is the same as that shown in FIG. When the cloth is fed, the feed dog moves up and down diagonally, but when the center of rotation of the presser foot is switched to the swing shaft, the presser foot at the tip of the presser foot is a needle plate as shown in FIG. Since the cloth moves substantially vertically and does not obstruct the cloth feed by the feed dog, there is no deviation in the front-rear direction between the upper and lower fabrics. Also, when the center of rotation of the presser base is switched to the horizontal axis, the horizontal axis only rotates together with the presser base when the cloth is fed, and the swinging shaft is fixed at a fixed position by the spring means and the blocking means. Since the rotation of the horizontal axis is not transmitted to the swing shaft or lever, an increase in swing due to the swing inertia force, that is, a jumping phenomenon can be suppressed. Further, the generation of noise due to the swinging shaft becoming free when the sewing machine is driven is prevented. When the foot pedal is depressed to lift the presser foot onto the needle plate, the presser foot is lifted against the action of the spring means and the presser spring device.

  According to the second aspect of the present invention, the locking portion is pressed against the locked portion by rotating the screw, and the rotation center of the presser base is switched to the swing shaft by integrating the collar and the crank arm. Also, by retracting the screw, the locking part can be separated from the locked part by a certain amount, so that the horizontal axis rotates by a certain amount until the locking part hits the locked part. It becomes possible, and the center of rotation of the presser foot can be switched to the horizontal axis.

  In the invention according to claim 3, when the rotation center of the presser base is switched to the swing shaft by the clutch means, the lever is held at the upper limit position by the stopper means even if the swing shaft swings during cloth feeding. The jumping phenomenon can be suppressed since the movement of the swing shaft is not transmitted to the lever.

  According to the fourth aspect of the present invention, the upward rotation restriction of the lever is performed right next to the sewing machine frame, and the protruding amount of the lever and the stopper means from the sewing machine frame can be suppressed.

  FIG. 3 is a left side view of an overlock sewing machine equipped with a presser device according to the present invention, FIG. 4 is an exploded perspective view of a mechanism for rotating the swing shaft 11 by pedal operation in the presser device, and FIG. The rear view of the principal part of a presser apparatus, FIG. 6 is the top view, FIG. 7 shows a side view.

  As shown in FIG. 4, the swing shaft 11 is rotatably inserted into a bush 13 that is inserted into a machine frame of a sewing machine and fixed by a set screw 12, and a collar 14 is attached to a screw 15 at one end thereof. The collar 14 is formed with a locking portion 14a projecting laterally.

  The collar 14 is adjacent to a bell crank-shaped lever 17 that is pivotally supported by the bush 13. The lever 17 is connected to a push-up lever 19 through a linkage 21, and the push-up lever 19 is connected to the sewing machine frame. It extends sideways along the back of the. The base end of the push-up lever 19 is pivotally attached to the sewing machine frame so as to be rotatable by a stepped screw 18. The helical spring 16 wound around the bush 13 urges the lever 17 around the swinging shaft 11 in one rotation direction, and the action of the spring 16 urges the push-up lever 19 in the always lifting direction. Yes.

  The push-up lever 19 is connected to a foot pedal or the like (not shown) by a chain or the like. When the push-up lever 19 is pushed down by stepping on the foot pedal or the like, the lever 17 acts on the winding spring 16 via the linkage 21. On the way, the claw portion 17a at one end of the lever is engaged with the locking portion 14a of the collar 14, and the collar 14 is rotated together with the swing shaft 11 integral with the collar 14. It has become. The push-up lever 19 is formed with a plurality of locking holes 19a, and one of the locking holes 19a is locked, and the position of the locking hole 19a where the connecting rod 21 locks is determined. By changing, the amount of rotation of the lever 17 can be changed.

  In the figure, reference numeral 22 denotes a stopper means which is fixed to the sewing machine frame with a screw 23 and restricts the range of rotation of the push-up lever 19. As shown in FIG. 8, the upper limit position of the push-up lever 19 is set by the protruding piece 22a. The lower limit position can be regulated by the screw 24, and the push-up lever 19 is linked by a helical spring 16 that urges the lever 17 to rotate upward unless the stepping pedal is depressed. It is urged | biased so that it may similarly rotate upwards via 21, and it comes to engage with the protrusion 22a, and comes to be stopped at an upper limit position. The stopper means constitutes a blocking means for stopping the rotation of the swing shaft 11 at a fixed position together with the collar 14 provided with the locking portion 14a.

  A crank arm 26 is also fixed to the swing shaft 11 at the other end. As shown in FIG. 9, the crank arm 26 has one end locked to the sewing machine frame and the other end locked to the crank arm 26. The wire spring 27, which is the spring means, is urged to rotate about the swing shaft 11 in the clockwise direction in FIG. 9 (counterclockwise in FIG. 7). This wire spring may be engaged with the collar 14 in place of the crank arm 26 and urge the swing shaft 11 to rotate in the clockwise direction of FIG.

Further, a horizontal shaft 28 that is parallel to the swing shaft 11 is rotatably supported at the free end of the crank arm 26.
As shown in FIG. 3, the base of the presser base 34 is connected to the guide piece 32 fixed to the end of the horizontal shaft 28 protruding from the crank arm 26 with a pin 35, and the presser base 34 is connected to the pin 35. And a presser foot 33 is fixed to the tip of the presser base 34.

  The clutch means constituting the connecting means of the crank arm 26 and the presser base 34 together with the horizontal shaft 28 and the guide piece 32 is fixed to the horizontal shaft 28 by being fastened to the screw 31, and the protruding piece-like locking portion 39 protrudes to the side. A protruding piece-like engagement located on both sides of a locking portion 39 that protrudes from the collar 29 and protrudes to the side of the collar 29 and that protrudes from the free end of the crank arm 26 with a certain interval. The stop portion 37 and the attachment portion 38, and a screw 41 screwed into the attachment portion 38 are included. This clutch means integrates the horizontal shaft 28 and the crank arm 26 to which the collar 29 is fixed by pressing the locking portion 39 against the locked portion 37 by screwing the screw 41, and also loosens the screw 41. Then, the crank arm 26 and the horizontal shaft 28 are released from being integrated, and the locking portion 39 is moved to the crank arm 26 within a range in which the locking portion 39 can move between the locked portion 37 and the screw tip or the mounting portion 38. On the other hand, the horizontal shaft 28 can be rotated.

  In the figure, reference numeral 42 denotes a set screw for fixing the screw 41. 3 indicates a presser spring device that presses down the presser base 34.

  This device is configured as described above, loosening the set screw 42, swinging the screw 41, pressing the locking portion 39 against the locked portion 37, and fixing the screw 41 with the set screw 42. FIG. In the state shown in FIG. 2, the crank arm 26, the horizontal shaft 28, and the collar 29 are integrated, so that the presser base 34 can swing around the swing shaft 11. Accordingly, the presser foot 33 at the tip of the presser foot moves substantially vertically on the needle plate due to the vertical movement of the feed dog at the time of cloth feeding, similar to the one that swings around the swing shaft 3 in FIG. There is no hindrance to cloth feeding. In this case, even if the presser base 34 is swung by the vertical movement of the feed dog at the time of cloth feeding, the locking portion 14a of the collar 14 fixed to the rocking shaft 11 is reciprocated away from the claw portion 17a of the lever 17. In other words, since the swing of the swing shaft 11 is not transmitted to the lever 17, the jumper phenomenon of the presser foot can be suppressed.

  Next, in the state shown in FIG. 10 in which the set screw 42 is loosened and the screw 41 is retracted into the mounting portion 38, the horizontal shaft 28 is a range from the locking portion 39 to the locked portion 37 and the mounting portion 38. The presser foot 33 at the tip of the presser base swings around the horizontal shaft 28 within this range. In this case, even if the presser base 34 swings due to the vertical movement of the feed dog during cloth feeding, the locking portion 39 swings between the locked portion 37 and the mounting portion 38 as shown in FIG. Thus, the crank arm 26 is not swung, and therefore the rocking shaft 11 and the lever 17 are not swung, so that the presser jumping phenomenon can be suppressed. At this time, the presser base 34 is urged in a direction to be pressed down only by the presser spring device X, and the locking portion 14 a of the collar 14 fixed to the swing shaft 11 acts as a linear spring 27 that locks to the crank arm 26. To engage the claw portion 17a at one end of the lever 17.

  In a state where the foot pedal is not depressed, the push-up lever 19 is attached so as to be also turned upward via the linkage 21 by the helical spring 16 that urges the lever 17 to turn upward. The lever 17 is fixed in a state where it stays at a fixed position because it is pressed and held against the protruding piece 22a of the stopper means 22. As described above, the rocking shaft 11 is urged by the wire spring 27 to rotate clockwise in FIGS. 4 and 7, so that the locking portion 14 a of the collar 14 is engaged with the lever 17. Even if the lever 17 is to be lifted by engaging with the stop portion 17a, the swinging shaft 11 cannot be rotated because the push-up lever 19 is engaged with and stopped by the protruding piece 22a of the stopper means 22, and in this state It becomes a fixed state. Therefore, there is no wobbling around the axis of the rocking shaft 11 during driving of the sewing machine, and vibration due to wobbling around the axis of the rocking shaft 11 is also prevented. The fixed state of the swing shaft is substantially released by depressing the pedal or driving the sewing machine.

  As described above, the center of rotation of the presser base 34 can be changed to the swing shaft 11 or the horizontal shaft 28 by screwing or holding the screw 41, thereby preventing a seam formation failure or a cloth feed failure. It becomes possible.

  When the presser foot 33 is lifted onto the needle plate by depressing the foot pedal, the locked portion 37 pushes the locking portion 39 and swings the horizontal shaft 28 in either case of FIGS. The presser foot 33 is lifted together with the presser foot base 34 by rotating counterclockwise around the moving shaft 11.

The diagram of the presser foot at the time of cloth feeding in the conventional presser device. The diagram of the presser foot at the time of cloth feeding in the presser device concerning the present invention. A side view of an overlock sewing machine. The disassembled perspective view of a part of presser apparatus. The rear view of the principal part of a presser apparatus. FIG. The side view at the time of fixing a horizontal axis. The figure which shows the stopper of the raising lever 19. FIG. The other side view of a crank arm. The side view at the time of making a horizontal axis movable.

Explanation of symbols

1, 34 .. Presser base 3, 11, swing shaft 4, 28, horizontal shaft 13, bush 14, 29, collar 16, helical spring 17, bell crank-shaped lever 19, push Raising lever 22 · Stopper 26 · Crank arm 32 · Guide piece 35 · Pin 37 · Locked portion 38 · Mounting portion 39 · · Locking portion 41 · · Screw 42 · · Set screw

Claims (4)

  A swing shaft that is rotatably supported by the machine frame, a crank arm having one end fixed to the swing shaft, and connected to the crank arm by a connecting means. A presser foot that is extended and has a presser foot attached to the tip, a presser spring device that presses down the presser foot, and a lever that is pivotally supported at an appropriate position of the swing shaft and rotates the swing shaft when the pedal is depressed. Thus, when the pedal is depressed, the crank arm rotates about the swinging shaft, whereby the presser foot rotates upward against the action of the presser spring device, and the presser foot is lifted onto the needle plate. In the sewing machine presser device, the connecting means has a horizontal shaft provided at the free end of the crank arm in parallel with the swing shaft, and the center of rotation of the presser base is the swing shaft or horizontal shaft. Can be switched A spring means for biasing the swinging shaft to rotate in a direction opposite to the direction in which the swinging shaft is rotated by depressing the pedal, and swinging to be rotated by the spring means A presser device for a sewing machine having blocking means for stopping rotation of a shaft at a fixed position.   A locked portion and a mounting portion that protrude from the crank arm so as to face the clutch means, and a locking portion that protrudes from the collar fixed to the horizontal shaft and is interposed between the locked portion and the mounting portion. 2. A presser device according to claim 1, comprising a screw that is screwed into the mounting portion and presses the locking portion against the locked portion.   The blocking means has a collar provided with stopper means for stopping upward rotation of the lever at the upper limit position, and a locking portion fixed to the swing shaft and detachably locked to the lever. A presser device for a sewing machine according to claim 1 or 2. A lever extends laterally along the back of the machine frame and is connected to a push-up lever supported rotatably on the machine frame via a linkage. A stopper means is fixed to the machine frame and is 4. The presser device for a sewing machine according to claim 3, further comprising a protrusion that engages with the raising lever from above.

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