JP2903625B2 - Sewing machine presser foot device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cloth presser device of a sewing machine having a plurality of cloth pressers and capable of replacing a presser used in accordance with a sewing operation.

[Prior Art] Conventionally, a plurality of presser feet are attached to a peripheral portion of a disc-shaped presser foot support, and the center of the presser foot support is attached to a mounting member fixed to the tip of a presser bar. 2. Description of the Related Art There is known a cloth presser device in which a presser foot support used in a sewing operation can be replaced by rotating a presser foot support by being rotatably mounted on a shaft. In recent years, automation of the sewing machine has been required. In a sewing machine equipped with such a cloth presser device, it is considered that the presser foot can be automatically replaced by rotating a presser foot support using a motor. (JP-A-62-204789).

[Problems to be Solved by the Invention] In this type of presser foot, if the presser foot support rotates during sewing, the presser foot cannot be satisfactorily performed. When the presser foot is disposed at the presser foot position, the rotation of the presser foot support is suppressed by using an urging member such as a leaf spring.

Therefore, when the presser foot is exchanged by rotating the presser foot, the rotation torque required at the start of the rotation and the necessary presser foot at the presser foot position after the start of the rotation are necessary. When the presser foot support is rotationally driven by a motor as described above, a high-performance motor and drive circuit that have a large rotational torque and that can precisely control the rotation must be used. There was a problem that must be. In addition, the sewing machine is required to be miniaturized as well as being automated, but in order to rotate the presser foot support by a motor,
In order to obtain high torque, the motor must be large, and there is a problem that it is not possible to meet such demands.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to simplify and reduce the size of a driving device for a presser foot support in a cloth presser device capable of replacing a presser foot by rotating and driving the presser foot support as described above. It was made as.

Means for Solving the Problems In order to achieve the above object, the present invention provides a presser foot support rotatably attached to a presser bar of a sewing machine and having a plurality of presser feet around a rotation axis. And a presser foot changing member for changing the presser foot disposed at the presser foot position by rotating the presser foot support, wherein the presser foot changing member is capable of reciprocating. A drive source for reciprocating the rod by fluid pressure or electromagnetic force, a cam mechanism for converting the reciprocating movement of the rod into a rotational movement of a predetermined angle, and a rotational mechanism obtained by the cam mechanism. And a power transmission mechanism for transmitting to the presser foot support.

[Function] In the presser foot device of the sewing machine of the present invention configured as described above, the presser foot changing member converts the reciprocating motion of the rod of the drive source into a rotational motion at a predetermined angle via the cam mechanism, and the rotation is performed. By transmitting the motion to the presser foot support via the power transmission mechanism, the presser foot support is rotationally driven.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. In the following description, the appearance of the sewing machine shown in FIG.
FIG. 2B is a front view of the sewing machine, FIG. 2B is a left side view thereof, FIG. 2 is an enlarged sectional view showing an attachment state of the presser foot support to the presser bar, and FIG. FIG.

As shown in FIG. 1, the arm 2 of the sewing machine 1 is provided with a presser bar 4 to which a cloth presser 3 is attached, and a needle bar 6 on which a sewing needle 5 is mounted so as to be able to move up and down. .
The presser bar 4 is supported in the arm 2 via a presser bar storage case 7 fixed in the arm 2 as shown in FIG. 2 so that the presser bar 4 can be moved up and down. , The presser foot 8 provided on the cloth presser 3 is urged downward so as to press the work cloth disposed on the bed 9 of the sewing machine 1 with a predetermined pressure.

As shown in FIG. 2, the presser foot 3 is formed in a circular umbrella shape and has a plurality of presser foot support members 12 each having a plurality of projections 11 for mounting the presser foot on the outer wall. A mounting member 13 for movably supporting the work clamp 3 and detachably fixing the work clamp 3 to the presser bar 4 is constituted as a main part.

The attachment member 13 is formed in an umbrella shape similarly to the presser foot support 12, and a hole 14 for fixing the presser foot support 12 is formed at the center thereof. A hole 15 having a diameter larger than that of the hole 14 is formed in the center of the presser foot support 12, and the presser foot support 12 and the mounting member 13 are overlapped with each other.
By inserting a step screw 16 through 15 and tightening the step screw 16 with a nut 17, the presser foot support 12 can be attached to the mounting member 13.

On the other hand, a plurality of protrusions 11 for attaching the presser foot are respectively located on the extension line of the axis of the presser bar 4 by the rotation of the presser foot support 12 on the mounting member 13, and the presser foot 8 attached to the protrusion 11 is A ball 19 is provided that fits into a recess 18 formed in the presser foot support 12 when it is disposed at the presser position. The ball 19 is urged toward the presser foot support 12 by two leaf springs 20 and 21 fixed between the nut 17 and the mounting member 13, and the urging force causes the ball 19 to move. It bites into the recess 18 and the presser foot support 12 is firmly fixed.

In this embodiment, as shown in FIG.
Is divided into three equal parts around the hole 15 (rotation angle
At 120 °), three projections 11 are formed at predetermined positions, and different presser feet 8 are attached to the respective projections 11 via mounting screws 11a, and the presser foot support 12 is rotated by 120 ° at a time. The presser foot 8 used for the sewing operation can be sequentially changed.

Next, of the two leaf springs 20 and 21, the outer leaf spring 20 is used.
Is formed larger than the inner leaf spring 21 so as to protrude upward from the pressing position of the ball 19. On the other hand, when the presser bar 4 is disposed at the ascending position on the arm 2 side, it engages with the leaf spring 20 protruding above this to displace the leaf spring 20 in the direction of arrow A shown in the figure. The projection 22 is fixed.
Therefore, when the presser bar 4 is at the raised position, that is, when the presser foot 8 is disengaged from the cloth presser position and sewing is not performed, the urging force for urging the ball 19 toward the presser foot support 12 decreases. The force of biting into the concave portion 18 of the ball 19 is reduced, and the presser foot support 12 can be rotated with a small force.

Next, on the periphery of the presser foot support 12,
The teeth 12 are formed so that the gears themselves rotate around the step screw 16.
When the presser bar 4 is disposed at the raised position, the teeth 12a mesh with a gear 23 as a power transmission mechanism fixed to the arm 2 side, and the presser foot support 12 can be turned. The gear 23 has the same diameter and number of teeth as the diameter and number of teeth of the periphery of the presser foot support 12.

Hereinafter, a drive device 25 as a presser foot changing member for changing the presser foot used in the sewing operation by rotating the presser foot support 12 by the gear 23 will be described with reference to FIGS. 4 and 5. FIG.

First, FIG. 4 shows the internal structure of the drive device 25, and FIGS. 4A and 4B show the drive device 25 as viewed from the left side and the rear side of the sewing machine 1, respectively.

As shown in FIG. 4, the driving device 25 includes the gear 23, an air cylinder 27 as a driving source for reciprocating a rod 26 by air pressure input from the outside, and a reciprocating motion of the rod 26 by a cam plate 28. A cam mechanism 29 for converting into rotary motion,
A fixed plate 30 for attaching these components to the arm 2 is constituted, and the rotation of the cam plate 28 is transmitted to the presser foot support 12 via the gear 23 to thereby rotate the presser foot support 12. .

The cam mechanism 29 includes six camshafts 31 protruding from the cam plate 28.
And a lever 33 attached to the distal end of the rod 26 via an attachment member 32. Each camshaft 31 is disposed at a predetermined position on the cam plate 28, which divides one rotation of the cam plate 28 into six equal parts around the rotation shaft 28a.
Are formed with two projections 33a and 33b which can be simultaneously engaged with the two camshafts.

The lever 33 is protruded when the rod 26 moves downward in the figure.
When the tips of 33a and 33b hit the camshaft 31, they are pivotally supported by the mounting member 32 so as to rotate in the direction of arrow B shown in the figure. A regulating member 34 for regulating movement of the 28 in the direction of the rotating shaft 28a, and a coil spring for urging the tip of the lever 33 toward the regulating member 34
35 are provided.

In addition, three notches 35 are formed on the periphery of the cam plate 28 at positions where one rotation of the cam plate 28 is equally divided, and a leaf spring 36 that engages with the notch 35 is formed on the fixed plate 30. Thus, when the driving device 25 is not operating, the leaf spring 36 is engaged with the notch 35 of the cam plate 28 to suppress the rotation of the cam plate 28.

Next, the operation of the driving device 25 thus configured will be described with reference to FIG.

First, when the rod 26 of the air cylinder 27 starts to extend, the lever 33 starts to move downward from the reference position shown in FIG. With this movement, when the tips of the projections 33a and 33b hit the camshaft 31, as shown in FIGS.
Turns downward in the direction of arrow B while avoiding the camshaft, and at the most extended position of the rod 26, a projection 33b on the rod 26 side is disposed at the right end of the cam plate 28 as shown in FIG. The lower camshaft 31-2 of the two camshafts 31-1 and 31-2 is engaged.

Next, in this state, when the rod 26 starts to contract,
33 starts to move upward from the lower end position shown in (d). At this time, since the projection 33b is engaged with the camshaft 31-2, the camshaft is moved as shown in FIG.
31-2 also rises, and as a result, the cam plate 28 rotates. Then, the rod 26 further contracts, and the cam shaft 31-
2. When the camshaft 31-3 is provided, the projection 33a on the distal end side of the lever 33 is engaged with the gum shaft 31-3, as shown in (f), and the camshaft as shown in (g). Increase 31-3. Since the contraction of the rod 26 continues until the lever 33 returns to the reference position, when the lever 33 returns to the reference position, the cam shaft 31-1 is provided at the start of the extension of the rod 26 as shown in (h). The camshaft 31-3 is disposed at the position where it was set. Each cam shaft
Reference numeral 31 denotes a cam plate 2 on a cam plate 28 centered on a rotating shaft 28a.
Since the cam plate 28 is disposed at a position where one rotation (360 °) of 8 is divided into six equal parts (60 °), the cam plate 28 eventually rotates 120 ° with the reciprocating movement of the rod 26.

Therefore, when the presser bar 4 is in the raised position and the gear 23 and the presser foot support 12 are connected, if air is supplied to the air cylinder 27 to make the rod 26 reciprocate once, the cam plate 28 rotates. By the movement, the presser foot support 12 is driven to rotate by 120 ° so that the presser foot 8 used for the sewing operation can be changed.

As described above, in the present embodiment, the driving device 25 for rotationally driving the presser foot support 12, the air cylinder 27 for reciprocating the rod 26, and the cam plate 28 by the reciprocating movement of the rod 26.
Since it is composed of the cam mechanism 29 that rotates 120 ° and the gear 23 that suppresses the rotation of the cam plate 28 and transmits it to the foot support 12, there is no need for a control circuit that controls the rotational torque as in the case of using a motor. In addition, the configuration of the drive system can be simplified. In the air cylinder, since the driving torque is obtained by the gas pressure, it is not necessary to increase the size of the air cylinder itself to obtain the driving torque, and the driving system can be reduced in size.

In this embodiment, an air cylinder is used to reciprocate the rod 26. However, other than the air cylinder, for example, a hydraulic cylinder, an electromagnetic solenoid, or the like can be used.

In the above embodiment, the presser foot support 12 and the gear 23
Since the same diameter and number of teeth were used, the cam mechanism 29 was
Although the cam plate 28 is configured to rotate 120 ° by the reciprocating motion of the rod 26, if the presser foot support 12 and the gear 23 have different diameters and different numbers of teeth, the rod 26 By adjusting the rotation angle of the cam plate 28 with respect to the reciprocating movement of the rod 26, the presser foot can be changed in one reciprocation of the rod 26.

[Effects of the Invention] As described above in detail, according to the presser foot device of the sewing machine of the present invention, in order to rotationally drive the presser foot support, a configuration such as an air cylinder, a hydraulic cylinder, and an electromagnetic solenoid is simple. In addition, a driving source capable of obtaining a high driving torque is used, and furthermore, the reciprocating motion obtained from the driving source can be changed to a rotating motion of a predetermined angle required for changing the driving presser foot by the cam mechanism, so that the presser foot support A control device for controlling the rotation amount is not required. For this reason, the structure of the presser foot support drive system can be simplified and the size can be reduced.

[Brief description of the drawings]

1 (a) is a front view showing the appearance of the sewing machine, FIG. 1 (b) is a left side view of the same, FIG. 2 is an enlarged sectional view showing a state where a presser foot support is attached to a presser bar, and FIG. 3 is an explanatory view showing a presser foot mounting portion of the presser foot support, FIG. 4 (a) is a side view showing the internal structure of the driving device viewed from the left side of the sewing machine, and FIG. FIG. 5 is a rear view showing the internal structure of the driving device as viewed from the rear, and FIG. 5 is an explanatory diagram for explaining the operation of the driving device. DESCRIPTION OF SYMBOLS 1 ... Sewing machine, 2 ... Arm, 3 ... Fabric presser 4 ... Presser bar, 8 ... Presser foot, 12 ... Presser foot support 13 ... Mounting member, 23 ... Gear, 25 ... Drive device 26 ... Rod, 27 ... Air cylinder 28 ... Cam plate, 29 ... Cam mechanism 31 ... Cam shaft, 33 ... Lever

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-204789 (JP, A) Jikken-sho 43-7785 (JP, Y1) (58) Fields investigated (Int. Cl. ⁶ , DB name) D05B 29/00-31/00 D05B 39/00

Claims (1)

(57) [Claims] 1. A presser foot support rotatably mounted on a presser bar of a sewing machine and having a plurality of presser feet around a rotation axis, and a presser foot support rotated to be disposed at a cloth presser position. A presser foot changing member for changing a presser foot to be operated, wherein the presser foot changing member includes a reciprocally movable rod, and causes the rod to reciprocate by fluid pressure or electromagnetic force. A drive source, a cam mechanism for converting the reciprocating motion of the rod into a rotary motion at a predetermined angle, and a power transmission mechanism for transmitting the rotary motion obtained by the cam mechanism to the presser foot support. Sewing machine's presser foot device.