JPH0624682U - Touchback device - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the free vibration noise of the adjustment link spring that occurs when the contact part of the feed adjustment base collides with the tip of the feed adjustment screw when the cloth feed direction is changed. [Structure] An antivibration material P is lightly contacted with an adjusting link spring 8 for urging the feed adjusting link 1 which is largely rotated when changing the cloth feeding direction in one direction, to the extent that its function is not impaired.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a touch back device for changing the feed direction in a cloth feed adjusting device of a sewing machine.

[0002]

[Prior art]

 A sewing machine having the cloth feed adjusting device shown in FIG. 1 has been widely known. That is, the cloth feed adjusting device is rotatably supported by the adjusting link fulcrum shaft 5, and the feed adjusting link 1 urged in one direction by the adjusting link spring 8 and the lower end of the feed adjusting link 1 are rotatable. A cam surface having two contact portions 3a and 3b is rotatably supported by a supported feed adjusting rod 2 and a central rotating shaft 3 ', and a rear end portion thereof has an upper end of the adjusting rod 2. It comprises a feed adjusting base 3 which is rotatably supported by the section, and a feed adjusting screw 4 whose tip is in contact with the cam surface thereof and which is movably supported by the sewing machine frame.

[0003]

[Problems to be solved by the device]

 When the touchback switch is turned on or off in the cloth feed adjusting device of the sewing machine, the base portion of the feed adjusting link 1 pivots upward or downward, and the feed adjusting rod 2 also moves upward or downward. The rear end portion of the feed adjusting base 3 is rotated upward or downward so that the contact portion 3a or the contact portion 3b collides with the tip portion 4a of the feed adjusting screw 4, and the feed dog is fed via a link mechanism inside the machine. The feed direction of is reversed. The swinging motion of the feed adjusting link 1 that occurs when the touch back switch is operated simultaneously causes the adjusting link spring 8 to expand and contract, and the contact portion 3a or the contact portion 3b of the feed adjusting base 3 collides with the feed adjusting screw tip 4a. The shock stress wave generated at that time is transmitted to the adjustment link spring 8 and excites the free vibration of the spring, causing the spring to resonate. Then, when the stress wave reciprocates between the upper and lower ends of the adjusting link spring 8, a vibration sound is generated, which gives the sewing manufacturer an unpleasant feeling.

The present invention provides a touchback device capable of reducing the free vibration noise of the adjustment link spring generated when the contact portion of the feed adjustment base collides with the tip end of the feed adjustment screw when changing the cloth feeding direction. Is intended.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the touchback device of the present invention is provided with a vibration-proof material to the extent that the function of the adjustment link spring for urging the feed adjustment link that pivots greatly in changing the cloth feed direction in one direction is not impaired. Is a light contact.

[0006]

[Work]

 In the touchback device configured as described above, when the cloth feed direction is changed, the shock stress wave generated by the contact portion of the feed adjustment base colliding with the tip of the adjustment screw is transmitted to the adjustment link spring, Vibration is suppressed by the vibration isolator, and the vibration noise generated from the adjustment link spring is reduced.

[0007]

【Example】

 1 to 5, a touch back device of the present invention and a cloth feed adjusting device of a sewing machine in which the touch back device is adopted will be described.

This cloth feed adjusting device is generally composed of a feed adjusting link 1, a feed adjusting rod 2, a feed adjusting base 3, and a feed adjusting screw 4.

The feed adjustment link 1 is U-shaped and is rotatably supported by the adjustment link fulcrum shaft 5. An adjusting link spring hook 6 is fixed to the base end portion of the feed adjusting link 1 by a round flat screw 7, and an upper end portion of the adjusting link spring hook 6 is connected to a feed spring hook 9 fixed to the sewing machine frame. The adjustment link spring 8 is hung between the two.

The lower end of the feed adjusting rod 2 is rotatably supported near the base end of the side of the feed adjusting link 1, and the upper end of the feed adjusting rod 2 is supported by the feed adjusting base pin 10 at the rear of the feed adjusting base 3. It is rotatably supported at the end.

A rotary shaft 3 ′ is projectingly provided at the center of the side surface of the feed adjusting base 3, and the rotary shaft 3 ′ is inserted into the feed adjusting base metal 11 supported by the sewing machine frame, and a round flat screw 12 It is rotatably attached by. The front end of the feed adjusting base 3 is a cam surface having two contact portions 3a and 3b whose center is recessed in a V shape.

A male screw is formed on the outer periphery of the feed adjusting screw 4 and is screwed with a female screw formed in a through hole of the sewing machine frame. A feed adjusting dial 13 is fixed to the base end of the feed adjusting screw 4 by a flat screw 14.

The cloth feed adjusting device has been outlined above, but the feed adjusting link 1 is urged by the force of the adjusting link spring 8 in the direction of arrow A, which faces downward in FIG. The adjusting rod 2 is also urged downward, and the feed adjusting base 3 is urged in a downward arrow C direction in FIG. 1, and normally the contact portion 3b is in pressure contact with the feed adjusting screw tip portion 4a. When the touchback switch is turned on, an electromagnet or the like works to cause the feed adjusting link 1 to rotate in the direction of arrow B pointing upward in FIG. 1 against the force of the adjusting link spring 8, and the feed adjusting rod 2 also moves upward. The feed adjusting base 3 rotates in the direction of the arrow D pointing upward in FIG. 1, the contact portion 3a collides with the feed adjusting screw tip portion 4a, and the feed direction of the feed dog reverses via the link mechanism inside the sewing machine. . Further, when the touchback switch is turned off, the feed adjusting base 3 reversely rotates in the direction of arrow C, the contact portion 3b collides with the tip end portion 4a of the feed adjusting screw, and the feed direction of the feed dog is reversed.

By the way, as shown in FIGS. 2 and 3, a vibration isolator P made of a viscoelastic material such as a rubber plate is always in light contact with the adjustment link spring 8. The vibration isolator P may be attached to any member as long as it does not impair the function of the adjustment link spring 8 and can reduce its free vibration noise. Will accidentally utilize a wire cable patch 15 for a conventional wire cable 16 as shown in FIG. That is, the vibration isolator mounting plate 17 is fixed to the wire cable pad 15, and the vibration isolator P is attached thereto. By doing so, the fixing angle of the wire cable contact 15 to the sewing machine frame can be adjusted, and the pressing force on the adjustment link spring 8 can be adjusted.

In this way, if the vibration isolator P is kept in light contact with the adjustment link spring 8 at all times without impairing its function, when the touchback switch is turned on or off, the feed adjustment base 3 comes into contact with it. An impact stress wave generated when the portion 3a or the contact portion 3b collides with the tip portion 4a of the adjusting screw 4 is transmitted to the adjusting link spring 8, but its free vibration is caused by the vibration isolator P lightly touching the adjusting link spring 8. The vibration noise generated from the adjustment link spring 8 is suppressed and reduced.

FIG. 5 shows the impact noise level generated when the touchback switch is turned on or off. This is the case where the vibration isolator P is not provided, and the vertical axis and the horizontal axis respectively represent impact noise level (dBAI) and time. In this figure, a and b are collision sounds of the feed adjustment base 3 and the feed adjustment screw 4 when the touchback switch is on and off, respectively, and c and d are free vibration sounds of the adjustment link spring 8. Is. If the vibration-proof material P is kept in light contact with the adjustment link spring 8, the free vibration noise C and D can be suppressed.

[0017]

[Effect of device]

 Since the present invention is configured as described above, it has the following effects.

That is, it is possible to reduce the free vibration noise of the adjustment link spring that is generated when the contact portion of the feed adjusting base collides with the tip end of the feed adjusting screw when changing the cloth feeding direction. Can be reduced.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a cloth feed adjusting device.

2A and 2B are diagrams of the vicinity of an adjustment link spring when a touchback switch is turned on, where FIG. 2A is a front view and FIG. 2B is a right side view.

3A and 3B are views of the vicinity of an adjustment link spring when the touchback switch is off, where FIG. 3A is a front view and FIG. 2B is a right side view.

FIG. 4 is a perspective view of a vibration isolator mounting portion.

FIG. 5 is a graph of impact noise level generated when a touchback switch is operated.

[Explanation of symbols]

 1 Feed adjusting link 2 Feed adjusting rod 3 Feed adjusting base 4 Feed adjusting screw 6 Feed spring hook 8 Adjustment link spring P Vibration isolator

Claims (1)

[Scope of utility model registration request] 1. A touchback device in which an antivibration material is brought into light contact with an adjustment link spring that biases a feed adjustment link that rotates greatly when changing the cloth feed direction in one direction, to the extent that its function is not impaired.