JP3582232B2 - Sewing machine clutch mechanism - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a clutch device for engaging and disengaging an upper shaft and a handwheel in a sewing machine.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there is a clutch device of a sewing machine as disclosed in Japanese Utility Model Publication No. 59-10417. This will be described with reference to FIGS. 7 and 8 show a device for engaging and disengaging the upper shaft of the sewing machine and the pulley, and FIG. 7 shows a device in which the upper shaft and the pulley are engaged, and FIG. 8 shows a device in which the upper shaft and the pulley are disengaged. It is. In the engaged state shown in FIG. 7, the concave portion 25a of the pulley 25 and the projection 21a of the hand wheel 21 are engaged, and the rotation of the pulley 25 is transmitted to the upper shaft 22. Here, when the handwheel 21 is pulled out against the holding plate 23 against the coil spring 24, the shaft pin 26 comes off the groove 29 a of the elastic body 29. When the handwheel 21 is slightly rotated, the shaft pin 26 hits a rib portion of the handwheel 21, and the projection 21 a of the handwheel 21 is disengaged from the concave portion 25 a of the pulley 25 in a state where the shaft pin 26 is pressed by the spring 24. The state shown in FIG. In this state, the rotation of the pulley 25 is not transmitted to the upper shaft 22.
[0003]
Such a clutch device of a sewing machine is used, for example, when performing bobbin winding work using the rotation of a drive motor, for example, in order to prevent the needle connected to the upper shaft from moving up and down with the rotation of the drive motor. And disconnects the connection between the drive motor and the upper shaft.
[0004]
[Problems to be solved by the invention]
In a conventional clutch device, when engaging and disengaging a drive motor and an upper shaft in order to perform bobbin thread winding and the like, a user pulls a hand wheel once and then rotates the hand wheel. Therefore, when the user performs bobbin thread winding or the like, two operations are required, and workability is poor.
[0005]
Therefore, the present invention has been made in view of the above-described circumstances, and has as its technical object to perform engagement and disengagement between a drive motor and an upper shaft in one operation.
[0006]
[Means for Solving the Problems]
In order to solve the above technical problem, the technical measures taken in claim 1 of the present invention include an upper shaft of a sewing machine,
A pulley that is coaxially loosely fitted to the upper shaft and rotates on the upper shaft by a drive motor;
A handwheel disposed facing the pulley and rotatable coaxially with the upper shaft;
Connecting means for connecting the pulley and the handwheel,
A handwheel-side recess formed on the side of the handwheel facing the pulley,
A bottomed groove formed on the side of the handwheel side recess facing the pulley,
An upper shaft side protrusion formed on the upper shaft and insertable into the bottomed groove,
First urging means for urging the handwheel toward the pulley;
A lower thread winding mechanism disposed on a side of the pulley opposite to a side on which the handwheel is disposed;
With
The lower bobbin winding mechanism has a second urging means capable of urging the lower bobbin winding mechanism toward the pulley with a stronger force than the urging force of the first urging means,
When the lower thread winding mechanism is not urged toward the pulley by the second urging means in the first state, the upper shaft side convex portion is inserted into the bottomed groove, and the upper shaft and the upper shaft are connected to each other. The handwheel engages,
In a second state in which the lower thread winding mechanism is urged toward the pulley by the second urging means, the upper shaft-side protrusion projects from the bottomed groove and the upper shaft is connected to the handwheel. From the clutch mechanism of the sewing machine.
[0007]
The operation of the above technical means is as follows. That is, when the urging force of the second urging means is not applied to the lower thread winding mechanism by the urging start means (first state), the upper shaft-side convex portion is located in the bottomed groove formed in the handwheel. Has been inserted. For this reason, when the drive motor is driven, the pulley rotates on the upper shaft, the handwheel connected to the pulley by the connecting means also rotates, the bottomed groove formed in the handwheel rotates, and the rotation of the bottomed groove As a result, the upper shaft-side protrusion inserted into the bottomed groove and further the upper shaft rotate. On the other hand, when the user intends to perform the bobbin winding operation, the urging force by the second urging unit is applied to the bobbin winding mechanism by the urging start unit (second state). Then, the upper shaft side convex portion protrudes from the bottomed groove. Therefore, when the drive motor is rotated, the rotational force is transmitted to the pulley and the hand wheel, but the upper shaft does not rotate because the bottomed groove and the upper shaft side protrusion are not engaged.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0009]
FIG. 1 is a diagram illustrating a clutch mechanism of a sewing machine according to the embodiment. In FIG. 1, an output shaft 1a of a drive motor 1 is coaxially connected to a motor-side pulley 2. The motor side pulley 2 is connected to an intermediate gear side pulley 4 via a belt 3. The intermediate gear side pulley 4 is fitted coaxially rotatable with the intermediate gear 5, and the intermediate gear 5 is further fitted to the pulley 6. Accordingly, when the drive motor 1 is driven, its rotational driving force is transmitted to the pulley 6 via the output shaft 1a, the motor-side pulley 2, the belt 3, the intermediate gear-side pulley 4, and the intermediate gear 5, so that the pulley 6 rotates. Be composed.
[0010]
The pulley 6 is loosely fitted coaxially to the upper shaft 7 of the sewing machine. Therefore, when the drive motor 1 is driven, the pulley 6 rotates around the upper shaft 7.
[0011]
On the right side of the pulley 6 in the figure, a handwheel 8 is disposed so as to face the pulley 6, and an upper shaft 7 is inserted into a central portion of the handwheel 8.
[0012]
The pulley 6 is provided with a pulley-side connecting projection 6 c at a position facing the handwheel 8 and including the upper shaft 7. On the other hand, the handwheel 8 is also provided with a handwheel-side connecting projection 8c at a position facing the pulley 6 and including the upper shaft 7. In the present embodiment, the outer diameter of the pulley-side connection protrusion 6c and the outer diameter of the handwheel-side connection protrusion 8c are both the same, and are configured concentrically with the upper shaft 7. The two connecting projections 6c and 8c are configured to be abutted. A first concave portion 8f is formed in the handwheel-side connecting convex portion 8c so as to open on a surface facing the pulley 6. A pin 9 is press-fitted into the upper shaft 7, and both ends of the pin 9 project from the upper shaft 7. On the other hand, the handwheel 8 has a bottomed groove 8a formed at the bottom of the first concave portion 8f, and the projection of the pin 9 is normally inserted into the bottomed groove 8a. When the handwheel 8 is turned in such a state, the rotation driving force is transmitted from the bottomed groove 8a to the pin 9 and from the pin 9 to the upper shaft 7, so that the handwheel 8 and the upper shaft 7 rotate integrally. Is configured.
[0013]
A helical leaf spring 10 is wound around the outer periphery of the pulley-side connection protrusion 6c and the handwheel-side connection protrusion 8c. The leaf spring 10 is made of stainless steel in the present embodiment, and the spiral diameter in the natural state is set smaller than the outer diameters of the pulley-side connecting protrusion 6c and the handwheel-side connecting protrusion 8c. For this reason, in a state where the leaf spring 10 is wound around both the connection protrusions 6c and 8c, the both connection protrusions 6c and 8c are fastened to the leaf spring 10. The direction in which the leaf spring 10 is wound is the same as the direction in which the pulley 6 rotates when the drive motor 1 is driven to rotate forward. This is because, as can be seen from FIG. 2 conceptually showing the pulley 6, the connecting protrusion 6c, and the leaf spring, the leaf spring 10 moves as shown in FIG. That is, it is wound in the same direction as the arrow A direction. When the pulley 6 is rotated in the direction A in the drawing, the leaf spring 10 tries to further wind around the connecting protrusion 6c, and as a result, the tightening force of the leaf spring 10 increases. On the other hand, when the pulley 6 is rotated in the direction opposite to the direction A in the drawing, the leaf spring 10 tries to unwind the connection protrusion 6c, and as a result, the tightening force of the leaf spring 10 becomes weak.
[0014]
When the winding direction of the leaf spring 10 shown in FIG. 2 is viewed from the handwheel side, the winding direction is as shown in FIG. In this case, when the sewing machine wheel 8 is rotated in the same direction as the direction A in the pulley 6 (the direction B in the drawing), the leaf spring 10 tries to unwind the connection convex portion 8c. The power becomes weak. When the sewing machine wheel is rotated in the opposite direction, the leaf spring 10 tries to further wind around the connecting projection 8c, and as a result, the tightening force of the leaf spring 10 increases. Therefore, when the pulley 6 is rotated in the direction of arrow A in FIG. 2, the tightening force of the leaf spring 10 is increased, and the rotational force is transmitted to the sewing machine wheel 8 (engaged state). When rotated in the direction of arrow B, the tightening force of the leaf spring 10 is weakened, and the rotation of the sewing machine wheel 8 is not transmitted to the pulley 6.
[0015]
As shown in FIG. 4, the leaf spring 10 has one end 10 a bent and inserted into a leaf spring recess 8 d formed in the handwheel 8, and the one end 10 a is integrated with the handwheel 8. It is designed to rotate. By fixing one end of the leaf spring 10 in this manner, the pulley 6 and the handwheel 8 can be more reliably engaged and disengaged.
[0016]
As shown in FIG. 1, the pulley 6 is formed with several grooves 6a, and a claw 8d formed on the handwheel is caught in the groove 6a. It prevents movement in the direction.
[0017]
In the handwheel 8, a second concave portion 8e is formed on a side opposite to a portion where the handwheel side connecting convex portion 8c is formed. The upper shaft 7 extends through the handwheel 8 to the second concave portion 8e. The end of the upper shaft 7 is fastened to the stop ring 11 by fastening means such as caulking. The stop ring 11 is in contact with a washer 12, and a spring 13 is provided between the washer 12 and the handwheel 8. For this reason, the washer 12 is always urged in the direction of the stop ring 11 by the spring 13 and the handwheel 8 is urged leftward in the drawing, and the pin 10 is securely inserted into the bottomed groove 8a by this urging force. It will be in the inserted state.
[0018]
In FIG. 1, a lower thread winding mechanism 14 is disposed on the left side of the pulley 6. The lower thread winding mechanism 14 is connected to a fulcrum 13a, a lower thread winding arm 13b and a lower thread winding arm 13b extending from the fulcrum 13a, as can be seen from FIG. The lower bobbin winding bar 13c, a ring-shaped rubber member 13d connected to the lower periphery of the lower bobbin winding bar 13c, and a coil spring 13e connected to one end of the bobbin winding arm 13b. One end of the coil spring 13e is connected to one end of the lower thread winding arm 13b, and the other end is connected and fixed to a sewing machine arm (not shown).
[0019]
The operation of the clutch mechanism of the sewing machine having the above configuration will be described below.
[0020]
(When driving motor)
First, when the driving motor 1 is driven, its rotational driving force is transmitted from the output shaft 1a to the pulley 6 via the motor side pulley 2, the belt 3, the intermediate gear side pulley 4, and the intermediate gear 5, and Rotates. At this time, the pulley-side connection protrusion 6c formed on the pulley 6 also rotates, but the pulley-side connection protrusion 6c is integrated with the handwheel-side connection protrusion 8c by the leaf spring 10 disposed on the outer periphery thereof. , And a tightening force is applied to both connecting projections by the leaf spring 9. Therefore, when the pulley 6 rotates, the leaf spring 10 also tries to rotate so as to be followed by the rotation of the pulley 6. When the leaf spring 10 tries to rotate further, the tightening force of the leaf spring 10 on both the connecting portions becomes stronger. Therefore, the connection between the pulley 6 and the handwheel 8 is strengthened, and the rotation of the pulley 6 is transmitted to the handwheel 8, so that the handwheel 8 rotates with the rotation of the pulley 6. When the handwheel 8 rotates, the pin 9 inserted in the bottomed groove 8c also receives a rotational force, and the pin 9 and the upper shaft 7 into which the pin 9 is pressed are rotated. Thus, the torque of the drive motor 1 is transmitted to the upper shaft.
[0021]
(During manual operation)
Next, when the operator operates the upper shaft 7 manually, the drive motor 1 is stopped. Then, the operator only needs to turn the handwheel 8 in the same direction as the pulley 6 rotates when the drive motor 1 rotates forward. Then, the leaf spring 10 wound around the two connecting projections receives a rotational force in a direction opposite to that in driving the motor. Therefore, the tightening force of the two connecting members by the leaf spring 10 is weakened, and the rotational force of the handwheel 8 is not transmitted to the pulley 6. Therefore, the drive motor 1 connected to the pulley 6 does not move, and the operator can turn only the handwheel 8 and the upper shaft 7. Therefore, the driving torque when the handwheel 8 is manually operated is reduced.
[0022]
(At the time of bobbin winding)
Next, an operation at the time of bobbin thread winding will be described.
[0023]
At the time of bobbin thread winding, first, the drive motor 1 is stopped. In this state, the lower thread winding mechanism 14 is in a state shown by a solid line in FIG. 6 (first state). Then, the bobbin is inserted into the bobbin winding rod 14c, and the bobbin winding arm 14b is swung toward the pulley with the fulcrum portion 14a as a fulcrum. At this time, at the initial stage of the swinging of the bobbin winding arm 14b, the distance between the ends of the coil spring 4e is reduced (from the distance A to the distance B in FIG. 6), and the repulsive force due to this is reduced by the swing direction of the bobbin winding arm 14b Although a slight swing driving force is required to work in the opposite direction, when swinging halfway, the distance between the ends of the coil spring 14e is increased thereafter (from the distance B in FIG. 6 to the distance C), Since this extension force acts in substantially the same direction as the swinging direction of the bobbin winding arm 14b, the bobbin winding arm 14e automatically swings. Then, it stops when the rubber member 14d collides with the pulley 6. In this stopped state, the lower thread winding mechanism 14 is urged toward the pulley 6 by the extension force of the coil spring 14e. This state is the state shown by the dotted line in FIG. 6 (second state).
[0024]
The direction of the urging force applied to the pulley 6 by the swinging operation of the bobbin winding arm 14b is opposite to the direction of the urging force applied to the sewing machine wheel 8 and the pulley 6 by the spring 13. Therefore, if the extension force of the coil spring 14e is set to be larger than the urging force of the spring 13, the pulley 6 and the handwheel 8 move rightward in FIG. When the pulley 6 and the handwheel 8 move rightward in the figure, the pin 9 pressed into the upper shaft 7 moves from the bottomed groove 8a of the handwheel 8 and is located in the concave portion 8f. Thereby, the engagement between the upper shaft 7 and the handwheel 8 is released. If the drive motor 1 is rotated in this state, the pulley 6 and the hand wheel 8 rotate, but the upper shaft 7 does not rotate, and the rotation of the pulley 6 is transmitted to the rubber member 14d, and the lower thread winding rod 14c is rotated. Then, the bobbin winding operation is performed.
[0025]
【The invention's effect】
The invention of claim 1 has the following effects.
[0026]
When lower bobbin winding or the like is performed, the user simply applies an urging force to the lower bobbin winding mechanism with the second urging means, and the engagement between the upper shaft and the handwheel is released. The upper shaft and the handwheel can be detached by the operation.
[Brief description of the drawings]
FIG. 1 is a partial sectional view illustrating a clutch mechanism of a sewing machine according to an embodiment of the present invention.
FIG. 2 is a schematic diagram showing a relationship between a rotation direction of a pulley and a winding direction of a leaf spring in an embodiment of the present invention.
FIG. 3 is a schematic diagram showing a relationship between a rotation direction of a handwheel and a winding direction of a leaf spring in an embodiment of the present invention.
FIG. 4 is a sectional view taken along line BB in FIG. 1;
FIG. 5 is a side view of the lower thread winding mechanism in the embodiment of the present invention.
FIG. 6 is a top view of the lower thread winding mechanism in the embodiment of the present invention.
FIG. 7 is a diagram illustrating a clutch mechanism of a sewing machine according to the related art, and is a diagram illustrating a state where an upper shaft and a pulley are engaged.
FIG. 8 is a diagram illustrating a clutch mechanism of a sewing machine according to the related art, and is a diagram illustrating a state where an upper shaft and a pulley are disengaged.
[Explanation of symbols]
Reference Signs List 1 drive motor 6 pulley 7 upper shaft 8 handwheel, 8a groove with bottom, 8f first recess (recess on handwheel side)
9 pin (upper part on upper shaft side)
10 leaf spring (connection means)
13 Spring (first biasing means)
14 lower bobbin winding mechanism, 14e coil spring (second biasing means)

Claims (1)

The upper shaft of the sewing machine,
A pulley that is coaxially loosely fitted to the upper shaft and rotates on the upper shaft by a drive motor;
A handwheel disposed facing the pulley and rotatable coaxially with the upper shaft;
Connecting means for connecting the pulley and the handwheel,
A handwheel-side recess formed on the side of the handwheel facing the pulley,
A bottomed groove formed on the side of the handwheel side recess facing the pulley,
An upper shaft side protrusion formed on the upper shaft and insertable into the bottomed groove,
First urging means for urging the handwheel toward the pulley;
A lower thread winding mechanism disposed on a side of the pulley opposite to a side on which the handwheel is disposed;
With
The lower bobbin winding mechanism has a second urging means capable of urging the lower bobbin winding mechanism toward the pulley with a stronger force than the urging force of the first urging means,
When the lower thread winding mechanism is not urged toward the pulley by the second urging means in the first state, the upper shaft side convex portion is inserted into the bottomed groove, and the upper shaft and the upper shaft are connected to each other. The handwheel engages,
In a second state in which the lower thread winding mechanism is urged toward the pulley by the second urging means, the upper shaft-side protrusion projects from the bottomed groove and the upper shaft is connected to the handwheel. A clutch mechanism for a sewing machine, which is disengaged from the clutch.

Images