JP2004160209A - Presser device of sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a presser device of sewing machine which facilitates sewing of different kinds of and thickness of cloths by a sewing machine. <P>SOLUTION: This presser device of sewing machine is equipped with a push-up lever rotatably supported on the backside of a sewing machine frame and energized in a direction by a spring, a linking rod connected to the push-up lever, a swinging shaft which is rotatably supported by a bush and a part of which is engaged with the linking rod, a presser base which is connected to the end part of the swinging shaft via a pin and has a presser foot fixed on the tip end, and a pressing bar equipped with a forked rod with a guide face for the pressing base and an elastic member engaged with the forked rod. The presser device has a mechanism in which the tip end of the presser base is energized downward around the swinging shaft by the presser bar to press cloth against the loading face of the sewing machine head. A recessed part is set in a pocket in the forked rod and a pin is fit in the recessed part with play and a groove for engagement is formed in the presser base so that the lower end of the pin fit with play in the dent part of the forked rod can be engaged with an engaging groove in the presser base. <P>COPYRIGHT: (C)2004,JPO

Description

  The present invention relates to a presser device for a sewing machine that engages a fabric from above and presses the fabric against a loading surface.

  In a conventional presser device of a sewing machine, a swing shaft connected to a presser stand is supported by a bush fixed to a sewing machine frame (for example, see Patent Document 1). The presser foot fixed to the front end of the presser table is pressed downward by a presser spring device (presser bar), that is, toward the workpiece support member (the loading surface of the sewing machine bed). Generally, the presser spring device includes a forked rod and an elastic member, and the presser moves in an arc around the swing axis by the projection and retraction of the feed dog when the sewing machine is driven.

Japanese Utility Model Publication No. 6-16604 (left column of page 2, Fig. 5)

  However, in a conventional presser device of a sewing machine, when sewing fabrics of different types and thicknesses, the presser foot sometimes hinders fabric transport. As a result, there has been a problem that the sewing cannot be properly performed by the sewing machine.

  The present invention provides a push-up lever rotatably supported on a back surface of a sewing machine frame including a sewing machine arm and a sewing machine bed and urged in one direction by a spring, a connecting rod connected to the push-up lever, and a bush. A swinging shaft that is rotatably supported and partially engages with the connecting rod, a holding table that is connected to the end of the swinging shaft via a pin, and that has a presser foot fixed at the tip, and a guide surface for the holding table. A presser bar having a forked rod having a forked rod and an elastic member engaged with the forked rod, and forcing the tip of the presser table downward around the pivot axis by the presser rod to thereby sew the fabric with the presser foot. In the presser device of the sewing machine that presses the loading surface of the fork, a recess is provided in the recess of the forked rod, a pin is loosely fitted in the recess, and a pin engaging groove is formed in the holding table, and the recess is loosely fitted in the recess of the forked rod. The lower end of the pin Characterized in that so as to.

  According to the present invention, a concave portion is provided in the concave portion of the forked rod, and the pin is loosely fitted in the concave portion, and the holding table is provided with a groove for pin engagement. The lower end can be engaged with the pin engaging groove of the holding table.

  According to the present invention, since the lower end of the pin loosely fitted in the recess of the forked rod is engaged with the pin engaging groove of the presser table, the lower end of the pin does not slide back and forth on the presser table when the sewing machine is driven. Fluctuation of the pressing force by the rod can be minimized. Further, by preventing the lower end of the pin from sliding back and forth on the holding table, wear of the lower end of the pin can be reduced. If the base end of the crank piece does not protrude leftward from the left side surface of the sewing machine arm, a space for a power saving device on the loading surface of the sewing machine bed can be secured.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The presser device of the sewing machine includes a lifting lever 1, a connecting rod 2, a swing shaft 3, a holding table 4, and a holding rod 5.
The push-up lever 1 has a hole 1a for attaching a connecting rod, and the base end of the lever 1 is rotatably supported on the back surface of the machine frame M by a stepped screw 6. The spring 7 is provided on the stepped screw 6 together with the push-up lever 1. One end of the spring 7 is locked to the sewing machine frame M, and the other end is locked to a lower portion of the push-up lever 1. The connecting rod 2 includes a hook 8 and an arm 9, and the hook 8 is attached to a hole 1 a of the lifting lever 1. The arm 9 is formed with a claw 9a and a hole 9b.

  The swing shaft 3 is rotatably interposed in the hole 9 b of the arm 9. The swing shaft 3 is rotatably supported by a bush 10, and the bush 10 is fixed to a bracket 11. The bracket 11 is attached to the back of the machine frame M with screws 12. That is, the bracket 11 is detachable from the sewing machine frame M, and can be replaced with another bracket 28 (see FIG. 5) formed by shifting the fixing position of the bush 10. A crank piece 3 a is fixed to one end of the swing shaft 3, and a collar 13 is attached to the other end by a screw 14. A spring 15 is interposed in the bush 10. One end of the spring 15 is locked to the sewing machine frame M, and the other end is locked to the lower part of the arm 9. By the action of the springs 7 and 15, the push-up lever 1 is urged in one direction, and a restoring force is applied to the push-up lever 1 rotated by a foot pedal or the like. When the push-up lever 1 is rotated by a foot pedal or the like, the claw portion 9a of the arm 9 is engaged with the locking portion 13a of the collar 13 fixed to the swing shaft 3, that is, a part of the swing shaft 3. At the same time, the swing shaft 3 rotates around the axis.

  A pin 16 is fixed to a crank piece 3 a of the swing shaft 3 with a screw 17. The holding table 4 is rotatably connected to the crank piece 3 a of the swing shaft 3 via a pin 16. The base end of the crank piece 3a does not protrude leftward from the left side surface ML of the sewing machine arm A. This secures a space for the power saving device on the loading surface BS of the sewing machine bed B. A presser foot 4a is fixed to the tip of the presser stand 4 with a screw 4c. The presser foot 4a can change the fixed position with respect to the presser base 4 when the screw 4c is loosened. The presser bar 5 is arranged in the middle of the presser table 4. The presser bar 5 is provided on a cylinder 18 penetrated by the sewing machine arm A, and has a coil spring (elastic member) 19 and a forked rod 20. The coil spring 19 is inserted in the cylinder 18. The forked rod 20 is hollow, and the lower end of the rod 20 has a recess 20a. The bifurcated rod recess 20 a has a guide surface for guiding the left and right surfaces of the presser table 4.

  An engagement piece 21 for the coil spring 19 is fixed to a hollow portion of the forked rod 20 by a locking tool 22. The lower end of the engagement piece 21 is positioned deeper than the recess 20a of the forked rod, and this space forms the recess 20aa of the forked rod 20. A pin 23 is loosely fitted in the recess 20aa of the forked rod 20. The upper surface of the holding table 4 is provided with a groove 4 b, and the lower end of the pin 23 is engaged with the groove 4 b of the holding table 4. As a result, the pressure from the pin 23 does not come off the groove 4b of the holding table 4. The manual lever 25 is attached to the sewing machine arm A via a stepped screw 26. By the rotation operation of the manual lever 25, the claw portion 25a of the manual lever 25 is engaged with the locking member 22 of the forked rod 20, and the pressing of the holding table 4 by the forked rod 20 is released.

  Further, the left and right surfaces of the tip of the pin 23 are chamfered, and the chamfered portion 23a is engaged with the guide surface of the recess 20a formed at the lower end of the forked rod. That is, in the bifurcated rod 20, the interval between the guide surfaces in the recess 20a is made smaller than the inner diameter of the recess 20a. By doing so, the pin 23 does not come off the forked rod 20 when the manual lever 25 releases the presser table 4. The pressing force of the coil spring 19 on the forked rod 20 is adjusted by turning the adjusting screw 27. The presser bar 5 normally urges the tip of the presser table 4 downward around the swing axis. Thus, the presser foot 4a fixed to the end of the presser table 4 presses the fabric against the loading surface BS of the sewing machine bed B.

  In the present embodiment, the circular locus of the presser foot near the loading surface of the sewing machine bed is changed by replacing the fixing position of the bush with another bracket formed by shifting the position, but the present invention is not limited to this. . For example, as shown in FIG. 6, the bracket 29 having the elongated hole 29 a may be fixed to the machine frame M with a screw 30. By doing so, when the tightening by the screw 30 is loosened, the fixing position of the bracket can be moved within the elongated hole 29a, and the arc locus of the presser near the loading surface of the sewing machine bed can be changed. Also, when the bracket 28 is replaced, as shown in FIG. 7, when the swing shaft corresponding to the bracket 28, that is, the swing shaft 32 in which the crank piece 32a is changed is also replaced, the loose shaft is loosely fitted in the recess of the forked rod 20. The lower end of the pin 23 can be engaged with the pin engaging groove 4b of the holding table 4.

1 is an exploded perspective view of a presser device of a sewing machine according to the present invention. It is a rear view of the sewing machine provided with the same device. It is a left view of the sewing machine provided with the same device. It is sectional drawing which shows the principal part of the presser bar of the same apparatus. FIG. 11 is a perspective view of another bracket formed by shifting a fixing position of a bush. It is a perspective view which shows another form of a bracket. FIG. 6 is a perspective view showing the bracket of FIG. 5 and a corresponding swing shaft.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Push-up lever 3 Oscillating shaft 3a Crank piece 4 Presser base 4a Presser foot 4b Groove 5 Presser bar 7 Spring 8 Hook (Linked rod)
9 arms (joint rod)
DESCRIPTION OF SYMBOLS 10 Bush 11 Bracket 15 Spring 16 Pin 20 Bifurcated rod 20a Depression 20aa Depression 28, 29 Bracket 32 Swing axis A Sewing arm B Sewing bed BS Loading surface M Sewing machine frame

Claims (2)

A push-up lever rotatably supported on the back of a sewing machine frame consisting of a sewing machine arm and a sewing machine bed and biased in one direction by a spring, a connecting rod connected to the push-up lever, and rotatably supported by a bush. A swinging shaft partially engaged with the connecting rod, a presser stand connected to the end of the swinging shaft via a pin and fixing a presser foot at the tip, and a forked rod having a guide surface for the presser stand. A presser bar having an elastic member engaged with the bifurcated rod.The presser bar urges the tip of the presser table downward around the swing axis, and presses the cloth onto the loading surface of the sewing machine bed by the presser foot. In a presser device of a sewing machine for pressing, a concave portion is provided in a concave portion of a forked rod, a pin is loosely fitted in the concave portion, and a pin engaging groove is formed in a holding table. Make the lower end engage the pin engaging groove of the holding table. Presser device of a sewing machine, characterized in that the. 2. The presser according to claim 1, wherein the end of the swing shaft is a crank piece, and the base end of the crank piece does not protrude leftward from the left side surface of the sewing machine arm, and the connection with the holding table is performed at the tip of the crank piece. apparatus.

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