Patent Application
20120097085
This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2010-237387 filed on Oct. 22, 2010, the entire contents of which are incorporated herein by reference.
1. Technical Field
The present disclosure relates to a sewing machine presser attaching mechanism which detachably attaches to a presser bar a presser foot pressing a workpiece cloth or a presser holder supporting the presser foot, and a sewing machine provided with the presser attaching mechanism.
2. Related Art
Household sewing machines have conventionally been provided with a presser bar located in the rear of a needle bar provided on a head, for example. The presser bar has a lower end to which a presser foot is detachably attached directly or indirectly via a presser holder to press a workpiece cloth. A plurality of types of presser feet is prepared according to sewing modes, for example, those for zigzag stitches, button holing and overcast stitches. The presser feet are changed from one to another as occasion demands. A conventional presser device includes a presser holder which is mounted to a lower end of a presser bar to be fixed in position. A presser foot is attached to and detached from the presser holder with just a single touch operation.
The above-described conventional presser device allows a user to easily change presser feet to be attached to and detached from the presser holder. However, for example, some types of presser feet can be mounted directly on the presser bar without use of a presser holder depending upon types of the presser feet, for example, presser feet for embroidery sewing. In this case, the user detaches a presser holder from the presser bar by loosening mounting screws with a tool such as a screwdriver.
Subsequently, a presser foot for embroidery sewing is fixed to the presser bar by tightening attaching screws while retaining the presser foot at a mounting position with respect to the presser bar. Thus, change of the presser holder or the presser foot to be attached to the presser bar requires tightening and loosening the attaching screws depending upon the types of presser feet.
Therefore, an object of the disclosure is to provide a presser attaching mechanism for a sewing machine, which can detachably attach the presser foot or the presser holder to the presser bar with ease and a sewing machine provided with the presser attaching mechanism.
The present disclosure provides a presser attaching mechanism for a sewing machine, which detachably attaches to a presser bar a presser foot pressing a workpiece cloth or a presser holder supporting the presser foot, the presser attaching mechanism comprising a locking mechanism which is provided on a lower end of the presser bar so as to be switchable between a locking position where the presser foot or the presser holder is fixed to the presser bar and an unlocking position where the presser foot or the presser holder is released from the fixed state to the presser bar.
The disclosure also provides a sewing machine comprising a sewing machine body, a presser bar provided on the sewing machine body so that a presser foot pressing a workpiece cloth or a presser holder supporting the presser foot is detachably attached to the presser bar, and, a presser attaching mechanism comprising a locking mechanism which is provided on a lower end of the presser bar so as to be switchable between a locking position where the presser foot or the presser holder is fixed to the presser bar and an unlocking position where the presser foot or the presser holder is released from the fixed state to the presser bar.
An embodiment will be described with reference to
The sewing machine 1 includes a bed 2 extending in the right-left direction, a pillar 3 extending upward from a right end of the bed 2 and an arm 4 extending leftward from an upper end of the pillar 3. The arm 4 has a distal end serving as a head 5. On the front of the arm 4 are provided various operation switches including a start/stop switch 6 instructing start and stop of embroidery sewing and a liquid crystal display 7 having a touch panel. A needle bar 8 is mounted on the head 5 so as to be movable upward and downward. The needle bar 8 has a lower end to which a needle 9 is attached. A needle bar mechanism (not shown) is provided in the head 5 for moving the needle bar 8 upward and downward. A presser bar 10 is mounted on the rear of the needle bar 8. A presser foot lifting mechanism (not shown) is provided which has a presser-up lever (not shown) for lifting the presser bar 10 between an up-position and a down-position. A presser foot (not shown) or a presser holder (not shown) is mounted on a distal or lower end of the presser bar 10. The presser foot presses a workpiece cloth (not shown), and the presser holder supports the presser foot. The presser bar 10, the presser foot and the presser holder will be described in detail later.
A needle plate 11 is mounted on an upper surface of the sewing machine bed 2, so as to correspond to the needle bar 8. In the bed 2 are provided a hook mechanism and a feed mechanism although neither is shown. The hook mechanism is located below the needle plate 11 and accommodates a bobbin to form stitches on the workpiece cloth in cooperation with the needle 9. The feed mechanism includes feed dogs provided for feeding the workpiece cloth in the front-back direction. The feed mechanism drives the feed dogs in the front-back direction and in the up-down direction in synchronization with up-down movement of the needle bar 8. Furthermore, the sewing machine 1 includes a sewing machine motor (not shown) to drive the needle bar mechanism, the hook mechanism and the feed mechanism.
An auxiliary table 12 is detachably attached to the bed 2 as shown in
Next, a presser attaching mechanism 13 will be described with reference to
The general-purpose presser foot 15 is formed into the shape of a rectangular plate slightly longer in the front-back direction and has a through hole 15a which is formed in a part thereof near the front so as to be elongate in the right-left direction. The needle 9 is adapted to pass through the elongate hole 15a. The general-purpose presser foot 15 also has two protrusions 15b which are formed integrally therewith and extend forward from right and left sides thereof respectively. The protrusions 15b are slightly bent upward for the purpose of guiding a workpiece cloth. The general-purpose presser foot 15 further has a pair of right and left supports 15c formed substantially in a middle part thereof in the front-back direction and a mounting shaft 19 which extends in the right-left direction so as to connect between the supports 15c.
The pearl-attaching presser foot 16 has a generally elongate hole 16a through which the needle 9 passes as shown in
The presser holder 14 includes a generally L-shaped block-like holder body 14a as viewed from the left side surface thereof, as shown in
A known quilter mount 22 is provided on a rear upper part of the holder body 14a. A quilting ruler bar (not shown) is detachably attached to the quilter mount 22. An attaching/detaching mechanism 23 is provided on a lower part of the holder body 14a or a part of the holder body 14a located between the lower front end and the rear, as shown in
The fitting groove 26 into which the mounting shaft 19 or 20 is fitted is formed in the front end underside of the holder body 14a so as to extend in the right-left direction and so as to be open downward. The underside of the holder body 14a has a recessed groove 14b which extends rearward from the fitting groove 26 and is upwardly inclined, as shown in
The lever member 25 includes a lever 25a protruding rearward from the recess 14c, a spring 25b extending forward from the lever 25a and then folded rearwardly upward and a wire rod mount 25c located below the lever 25a, as shown in
As a result, the distal end of the wire rod 24 is located under the fitting groove 26 thereby to close the fitting groove 26 under a normal condition or when the lever 25a has not been operated by the user, as shown in
When the presser foot 15 or 16 is to be detached from the presser holder 14, the user operates the presser-up lever (not shown) to switch the presser bar 10 and the presser holder 14 to respective up-positions. When the user operates the lever 25a upward or in the direction of arrow A in
When the presser foot 15 or 16 is to be attached to the presser holder 14, the user operates the presser-up lever to switch the presser bar 10 and the presser holder 14 to the respective down-positions. In this case, when the mounting shaft 19 or 20 abuts on the distal end of the wire rod 24, the distal end of the wire rod 24 is retreated rearward from the fitting groove 26 against the spring force, whereupon the mounting shaft 19 or 20 is allowed to be moved until the mounting shaft 19 or 20 abuts on the upper surface of the fitting groove 26. When the mounting shaft 19 or 20 abuts on the upper surface of the fitting groove 26, the distal end of the wire rod 24 is located under the fitting groove 26 by the elastic force of the spring 25b thereby to substantially close the fitting groove 26, namely, the mounting shaft 19 or 20 is locked so as to be prevented from dropping out of the fitting groove 26. Thus, the presser foot 15 or 16 is attached to the presser holder 14.
On the other hand, the configuration of the presser foot 17 for embroidery sewing will be described as follows with reference to
The mounting plate 28 is located on a left end of the base plate 17a. The mounting plate 28 is mounted on the presser bar 10 in a manner as will be described later. The mounting plate 28 extends vertically and is formed into a bent shape with a right opening, as shown in
The base plate 17a has a right end formed with a pair of supports 17b which are bent at right angles from upper and lower sides thereof and extend horizontally rearward, respectively. Only the upper support 17b is shown in
An auxiliary plate 30 is provided so as to overlap the front surface of the base plate 17a. The auxiliary plate 30 has a right side plate 30a which is located on the right of the base plate 17a and is bent at right angles rearward from a right side of the auxiliary plate 30, extending vertically. The auxiliary plate 30 also has a pair of supports 30b which are formed integrally therewith so as to be bent at right angles from the upper and lower sides thereof and to extend horizontally leftward, respectively. In this case, the upper support 30b is located above the upper support 17b of the base plate 17a, whereas the lower support 30b is located above the lower support 17b of the base plate 17a. The support shaft 29 extends through the supports 30b, too.
A first coil spring 31 is provided around the support shaft 29 so as to be located between the upper support 17b of the base plate 17a and the lower support 30b of the auxiliary plate 30 as shown in
A limit pin 33 is provided on a lower part of the support shaft 29 so as to protrude forward. The limit pin 33 extends through a vertically long slit (not shown) formed in the base plate 17a and a vertically long slit 30c formed in the auxiliary plate 30. As a result, rotational directions and vertical relative movement of the support shaft 29, the base plate 17a and the auxiliary plate 30 are limited by the limit pin 33. A pivot lever 34 is mounted on an upper part of the auxiliary plate 30 to move the presser foot 18 upward relative to the base plate 17a.
A presser attaching mechanism 13 according to the embodiment is constructed as follows. Firstly, the presser bar 10 is generally formed into the shape of a round bar and has a lower end provided with a mount 35 which is formed into the shape of a flat plate that is thin in the right-left direction, as shown in
An operating member 36 constituting a locking mechanism is inserted through the insertion hole 35a thereby to be mounted. The operating member 36 is formed into the shape of a bar and is elongated in the right-left direction or in the direction of a rotational axis O in
The mounting wall 21 of the presser holder 14 and the mounting plate 28 of the embroidery sewing presser foot 17 have respective mounting holes which are each formed into the shape of a horizontally long ellipse and through which the head 37 is insertable. The first shaft 36a located on the right of the head 37 is formed into the shape of a column having a diameter corresponding to a short axis (an up-down dimension). The second shaft 36b has a slightly smaller diameter than the first shaft 36a and is formed into the shape of a column having such an outer diameter that the first shaft 36a is rotatably inserted into the insertion hole 35a of the mount 35. The mount 36c is formed into a horizontally long elliptic shape and has a slightly smaller diameter than the second shaft 36b.
The first shaft 36a has two surfaces which are continuous to a periphery thereof and are located in front and on the back thereof. The surfaces serve as engaging portions which are to engage engaged portions of the mounting wall 21 and the mounting plate 28 respectively, as will be described later. These engaging portions are located so as to be symmetric about an imaginary plane passing the rotational axis O (a vertical plane passing the rotational axis O, in the embodiment). The engaging portions are formed with respective cam surfaces 38. The front cam 38 is inclined so as to come closer to the first shaft 36a side as the front cam 38 goes upward, as shown in
The operating member 36 thus configured is mounted in the insertion hole 35a of the mount 35 of the presser bar 10 as shown in
Consequently, the operating member 36 is rotatable about the rotational axis O relative to the mount 35 of the presser bar 55. The operating member 36 is rotatable (switchable) between a first position (an unlocking position) where the head 37 is situated transverse or horizontally long as shown in
On the other hand, the mounting wall 21 of the presser holder 14 has a circular recess 21b which is open at the left side thereof and has a depth that is substantially one-half of a thickness thereof, as shown in
As the result of the above-described configuration, when situated transverse or horizontally long as shown in
The operating member 36 is then rotated substantially 90° in the direction of arrow B (see
The mounting plate 28 of the embroidery sewing presser foot 17 is also formed with a mounting hole 28a which has a horizontally long shape corresponding to the shape of the head 37 and through which the head 37 is passed. The mounting hole 28a has an opening located in the rear of the mounting plate 28. As a result, the head 37 can be inserted into the mounting hole 28a when the operating member 36 occupies the unlocking position and the mounting plate 28 or the embroidery sewing presser foot 17 can be fixed to the presser bar 10 when the operating member 36 occupies the locking position, in the same manner as the presser holder 14.
The above-described presser attaching mechanism 13 will work as follows. Firstly, the following describes the procedure for mounting the ordinary sewing holder 14 on the mount 35 of the presser bar 10. When attaching the presser holder 14 to the presser bar 10, the user switches the head 37 of the operating member 36 to the unlocking position as shown in
Furthermore, the embroidery sewing presser foot 17 needs to be attached to the presser bar 10 when the sewing work is switched from an ordinary sewing mode to an embroidery sewing mode. More specifically, the presser holder 14 needs to be detached from the presser bar 10 and the embroidery sewing presser foot 17 needs to be attached to the presser bar 10. In this case, the head 37 occupying the locking position is rotated substantially 90° counter-clockwise (in the direction of arrow C in
When attaching the embroidery sewing presser foot 17 to the presser bar 10, the user causes the head 37 to occupy the unlocking position as shown in
Thereafter, the head 37 is rotated substantially 90° clockwise (in the direction of arrow B) so as to be switched from the unlocking position to the locking position. As a result, the cam surface 38 of the head 37 serving as the engaging portion presses the periphery of the mounting hole 28a serving as the engaged portion or the upper and lower portions rightward or toward the mount 35, whereby the embroidery sewing presser foot 17 is fixed to the presser bar 10, as shown in
According to the above-described presser attaching mechanism 13, the mount 35 located at the lower end of the presser bar 10 is provided with the operating member 36 which is switchable between the locking position where the presser holder 14 or the embroidery sewing presser foot 17 is fixed and the unlocking position where the presser holder 14 or the embroidery sewing presser foot 17 is released from the fixed state. As a result, the presser holder 14 or the embroidery sewing presser foot 17 can easily be attached to and detached from the presser bar 10. Furthermore, the operating member 36 is rotatively movable and the presser holder 14 is formed with the mounting hole 21c or the embroidery sewing presser foot 17 is formed with the mounting hole 28a. Thus, the presser attaching mechanism 13 can be realized by a simple construction. Furthermore, since the operating member 36 is rotatively movable, the user can easily operate the operating member 36.
Particularly in the embodiment, the presser holder 14 or the embroidery sewing presser foot 17 is pressed against the presser bar 10 by the biasing force of the wave spring 39 serving as the biasing unit. As a result, the presser holder 14 or the embroidery sewing presser foot 17 can be fixed to the presser bar 10 in a closely adhering state when the operating member 36 occupies the locking position. In this case, since the presser holder 14 or the embroidery sewing presser foot 17 is pressed against the presser bar 10 by the two engaging portions or the two cam surfaces 38, the presser holder 14 or the embroidery sewing presser foot 17 can be fixed more stably. Furthermore, the operating member 36 can be prevented from being loosened by the biasing force of the wave spring 39 even during the sewing, whereupon the operating member 36 can reliably be retained at the locking position.
The biasing force of the wave spring 39 is varied by the provision of the inclined cam surfaces 38 in the operating member 36. When the user rotates the operating member 36 from the unlocking position to the locking position, an operating force to rotate the operating member 36 is gradually increased from a small force to a larger force. On the contrary, when the user rotates the operating member 36 from the locking position to the unlocking position, an operating force to rotate the operating member 36 is gradually decreased from a large force from to a smaller force. Accordingly, the user can sense the switching of the operating member 36 between the unlocking position and the locking position, based on the variation in the operating force. This can prevent erroneous operation due to carelessness.
The user switches the operating member 36 to the unlocking position in attachment of the presser holder 14 in the above-described configuration. The head 37 and the first shaft 36a are inserted through the opening 52 into the recess 21b and the mounting hole 21c. Subsequently, the user grasps the knob 51 to rotate the operating member 36 from the unlocking position to the locking position and fixes the presser holder 14. When the presser holder 14 is to be detached, the user grasps the knob 51 to rotate the operating member 36 from the locking position to the unlocking position and drops out the operating member 36 through the opening 52. Consequently, the presser holder 14 can easily be attached to and detached from the presser bar 10 without use of a tool such as a screwdriver.
The above-described embodiments should not be restrictive but may be modified or expanded as follows. For example, the presser holder 14 supporting the presser foot or the embroidery sewing presser foot 17 is detachably attached to the presser bar 10 in the foregoing embodiments. However, a device which is detachably attached to the presser bar may be various types of attachments. These attachments may include side cutters and walking feet. Additionally, various changes may be made in an overall construction of the sewing machine, the shape, structure and type of the presser foot.
The foregoing description and drawings are merely illustrative of the present disclosure and are not to be construed in a limiting sense. Various changes and modifications will become apparent to those of ordinary skill in the art. All such changes and modifications are seen to fall within the scope of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2010-237387 | Oct 2010 | JP | national |
