JPH0123428Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application] The present invention relates to a pattern cam selection mechanism built into a sewing machine.

[Prior art]

In a cam selection device for a stitch pattern forming mechanism in which a single follower is selectively engaged with one of a number of pattern cams, a cam selection device in which selection is made using a single selection dial is as follows: One cycle consists of the so-called release in which the follower is disengaged from the pattern cam by operating the dial, the subsequent movement of the follower in the cam axis direction, and the release release in which the follower is engaged with the pattern cam again. , a series of operations are performed within one step operation of the selection dial.

〔problem〕

However, when releasing and moving the follower,
An operating force that resists the spring force applied to these is required, and there are limits to how much this spring force can be weakened, and there are also restrictions on the shape of each operating cam, so when considering operability, A relatively large dial rotation angle is required, and the amount of built-in sewing patterns is limited.

[Solution] The present invention uses a clutch configuration between the selection dial and a rotation transmission mechanism consisting of a small gear for transmitting its rotation to the selection cam, and rotates the selection dial to follow the release cam. When the release arm is in a rotational position to release the follower of the pattern cam, the clutch is engaged, and the selection cam is then rotated to move the follower, and as the clutch is engaged, the retaining member is held in its engagement and the released state of the release arm by locking in a direction independent of the direction of rotation of the selection dial, thus maintaining the released state throughout the movement of the follower. This eliminates the need for force and allows these locks to be released when the operation dial is moved in the axial direction, such as by pushing in, at the rotational position where pattern selection is completed.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the drawings. In FIGS. 1 to 8, a cam block 2 built into a sewing machine main body 1 is made up of a plurality of pattern cams, which is fixed to a cam shaft 3, and has a worm 4,
It rotates synchronously with the main shaft 6 of the sewing machine via a worm wheel 5.

The followers 7, 7' are pivotally connected to the pawl shaft 8, and the pawl plates 9,
9' is pivotally connected to the claw shaft 8 and has a square hole 10 and a square hole (not shown), and the square hole 10 etc. are connected to the follower 7,
The foot portion 10 of 7′ and the foot portion (not shown) are fitted,
While being movable in the left-right direction in FIG. 1, the swinging motion of the followers 7, 7' is transmitted to the swinging width rod 12 and the feed adjustment rod 14 via the connecting portions 12, 12'. Since the mechanisms related to the followers 7 and 7' have the same structure, the mechanisms related to the followers 7 will be explained below.

The release cam 15 is attached to a dial shaft 16 and is configured to rotate integrally with the selection dial 17. The release arm 18 is biased counterclockwise by a spring 19, and when the pattern selection is completed and sewing is possible, as shown in FIG. In the section 21, the follower 7 is driven by the cam block 2, but when selecting a pattern, the peak section 2 is moved as shown in Fig. 5.
At this time, the adjusting screw 23 rotates the pawl plate 9 clockwise so that the follower 7 engaged therewith is released from the cam block 2.
The selection cam 24 is fixed to a selection shaft 25, and a selection gear 26 integrated with the selection shaft meshes with a dial gear 27.As will be described later, the dial gear 27
When the follower 7 is in the released state, it is rotated together with the selection dial 17, and the following patterns are selected depending on the amount and position of rotation. The moving plate 28 is pivotally connected to the dial shaft 16, is biased toward the left in FIG.
0 engages with the selection cam 24, and the arm portion 31 engages with the follower 7.
The follower 7 is engaged with a groove 32 provided in a boss portion of the dial 16 so that the follower 7 is moved in the axial direction of the dial shaft 16 as the selection dial 17 rotates. The split spring 33 is in contact with the selection gear 26 and provides a click for each pattern selection.

The dial shaft 16 is biased to the left in FIG. 1 by the return spring 34, while the release cam 15 is rotated together with the dial shaft 16 by the key 35 and moves the dial shaft 16 in the axial direction. By making it possible and locking it at a predetermined position, the positional relationship with the sewing machine main body 1 is maintained as shown in FIG. 3 at the end of pattern selection. Positioning plate 36 and retaining plate 3
7 is for determining and holding the axial movement position of the dial gear 27, and both are connected to the shaft portion 3.
8, is movable by a guide pin 39 in a direction parallel to the dial shaft 16, and is biased toward the left in FIG. 1 by a retaining spring 40.
The positioning plate 36 is located between the flange portion 41 of the dial shaft 27 and the selection dial 17, and the dial gear 27 is biased toward the left in FIG. 1 by the dial gear spring 42. It is in constant contact with the plate 36. When the pattern selection is completed, the holding plate 37 is locked behind the release arm 18 (see also FIG. 8) as shown in FIG. 4, and is prevented from moving to the left in FIG. Thus, the dial gear 27 is positioned at a rightward movement position as shown in FIG. When the selection dial 17 is rotated to select a pattern and the claw 20 of the release arm 18 reaches the peak 22 of the release cam 15 as shown in FIG. 6, the dial gear 27 moves to the left and comes into contact with the selection dial 17. The selection dial 17 and the dial gear 27 are formed with clutch portions 43 and 44 at opposing positions, thereby providing mutual rotational coupling. When the holding plate 37 is moved to the left as shown in FIG.
As shown in the figure, the release arm 18 is locked at its tip 45, so that the release of the follower 7 is maintained irrespective of the rotation of the release cam 15 thereafter. In FIGS. 1 and 2, the adjustment dial 46 is fixed to the adjustment dial shaft 47 and is used to adjust the width and feed amount of the stitch, but since it is not directly related to the present invention, its explanation will be omitted. is omitted.

The operation of the above configuration will be explained below. 3 and 4 show a state in which pattern selection has already been completed and sewing is possible, and the dial gear 27 is detached from the selection dial 17.

Select dial 17 to select a new pattern
Rotate the claw 20 of the release arm 18 as shown in Figure 5.
When the release cam 15 reaches the peak 22, the follower 7 is moved to the cam block 2 via the adjusting screw 23 and the pawl plate 9.
The holding plate 37, which had been locked by the release arm 18, is released and is moved to the left by the holding spring 40, together with the positioning plate 36, as shown in FIG. but,
Similarly moved by the dial gear spring 42,
Selection dial 1 by clutch mechanisms 43 and 44
Combined with 7. The release arm 18 will be referred to as the holding plate 3 from now on.
7 and can be held in the state shown in FIG. When the selection dial 17 is further rotated,
The selection cam 24 rotates, and the follower 7 moves in the axial direction of the pawl shaft 8. At the movement position where the selection of each pattern is completed, the claw 20 of the release arm 18 faces the peak 22 of the release cam 15, as shown by the chain line in FIG. When dial 17 is pushed in, dial gear 27
is pushed in against the dial gear spring 42, and at the same time, the positioning plate 36 and the retaining plate 37 are also pushed in against the retaining spring 40.
pushed against the The release arm 18 is attached to the holding plate 37
The trough 22 of the release cam 15 is released.
When the selection dial 17 is released, the return spring 34 returns it to its original position as shown in FIG. Since it is then locked, it is removed from the selection dial 17 without moving and the pattern selection is completed.

〔effect〕

As described above, according to the present invention, when selecting a pattern,
Once the selection dial is rotated to release the follower from the pattern cam, no force is applied to the selection dial to maintain the released state during subsequent pattern selection movements of the follower, so the operating force is reduced. Since it is possible to reduce the division angle of the selection dial for each pattern, it is possible to incorporate a large number of pattern cams, and the structure is simple. It has effects such as those that can be achieved by a simple operation using the operating section.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention, and is a sectional view of the main parts of the sewing machine seen from the direction shown in FIG. 2, FIG. 2 is a cross-sectional view along the side of FIG. 4, 5, and 7 are explanatory diagrams of the operation, and are all -, -, - sectional views of FIG. 1, and FIGS. 6 and 8 are similarly explanatory diagrams of the operation, 5 and 7, respectively. In the figure, 2 is a cam block, 7 is a follower, 8 is a pawl shaft, 15 is a release cam, dial shaft 16 is an operating shaft,
17 is a selection dial, 18 is a release arm, 24 is a selection cam, dial gear 27 is a rotation transmission mechanism, positioning plate 36 and holding plate 37 are holding members, dial gear spring 42 is a spring, and 43 and 44 are clutch mechanisms.

Claims (1)

[Scope of utility model registration request] A cam block consisting of a plurality of pattern cams that rotates in synchronization with the main shaft of the sewing machine, and a pawl shaft provided parallel to the rotation center axis of the cam block, which is movable in the axial direction of the pawl shaft, and is attached to one of the pattern cams. A follower that is selectively engaged and swings; a selection dial that is manually rotated to bring about the selective engagement; and a rotating cam body that rotates integrally with the operating shaft of the selection dial. a release cam which operates a release arm engaged with a cam surface of the rotary cam body at every predetermined rotation angle to release the engagement of the follower; and a release cam that operates in conjunction with the operation of the selection dial. a selection cam for effecting axial movement of the released follower, the cam being pivotally connected to the actuation shaft of the selection dial and loaded by a spring for movement in a proximal direction with the selection dial; a rotation transmission mechanism that is connected via mutual clutch mechanisms and transmits the operation of the selection operation to the selection cam when the rotation transmission mechanism moves in the proximity direction; a member for enabling or inhibiting movement to engage and disengage the connection by the clutch mechanism and for retaining operation of the release arm, the member being configured to prevent movement in the proximal direction by a non-released position of the release arm; The release arm is locked to prevent movement in the approaching direction, and the lock is released to enable movement in the proximal direction while maintaining the release position of the release arm and axially moving the selection dial. a holding member that interlocks with the holding member to release the holding member and return the rotation transmission mechanism, which has been returned against the spring along with the axial movement operation, to prevent movement in the proximal direction. Cam selection mechanism.