JPS5855907Y2 - Sewing machine presser foot device - Google Patents

Description

[Detailed explanation of the idea] This invention relates to a presser foot device for a sewing machine.

Conventionally, the presser foot device of a sewing machine is attached to the lower end of the presser bar, and is configured to press the work cloth against the upper surface of the feed dog by the elastic force of a spring wrapped around the presser bar. During operation, the presser foot moves up and down following the up and down movement of the feed dog due to the elastic force of the spring.

However, since the presser foot of this type of sewing machine is attached to a single presser bar that passes through the sewing machine head vertically, the weight of the presser bar is heavy and its penetrating force is also large. When sewing, the presser foot cannot follow the feed dog, making it impossible to obtain an accurate feed pitch.

This invention was developed by focusing on these drawbacks, and its purpose is to reduce the weight of the presser bar that is applied to the presser foot, thereby reducing the pressing force of the presser foot on the fabric to be processed. To provide a presser foot device for a sewing machine that can obtain appropriate feed pitch and feed force.

An embodiment of this invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes an adjusting body in which an outer circumferential screw 3a is screwed into the upper part of the jaw portion 2 of the sewing machine body, and an inner circumferential screw 3b is provided at the center of the adjusting body.

Reference numeral 4 denotes a guide rod that is loosely fitted in a bearing 5 facing the adjustment body 1 and fixed below the jaw portion 2 so as to be movable up and down; 6 is a locking body provided on the outer periphery of the upper end of the guide rod 4; abutting the upper edge;
A presser bar guide rod 4 is suspended.

Note that a nut or the like may be used instead of this fastening link 6.

Reference numeral 7 denotes a coil spring as a first elastic body interposed between the adjusting body 1 and the locking body 6. Due to this elastic force, the fastening ring 6 always presses the bearing 5 and the guide rod 4.
is constantly being pushed downward.

Reference numeral 8 denotes a first presser bar, and this first presser bar 8 is screwed into the female threaded portion 3 of the presser spring adjuster 1 and is connected to a coil spring 7.
is inserted into the upper part of the guide rod 4.

Reference numeral 9 denotes a second presser bar made of a light metal member whose upper end fits into the lower part of the guide rod 4 and has a presser foot 10 provided at the lower end via a support rod 10a; This is a coil spring as a second elastic body interposed between the two presser bars 9.

Reference numeral 12 designates a guide pin that is suspended and guided from the second presser bar guide rod so as to be able to move up and down. It has a flange portion 14 and a flat surface 15.15 on the peripheral surface.

The guide pin 12 of the second presser bar 9 is fitted into a guide hole 9a provided in the intermediate portion of the second presser bar 9, and the second presser bar 9 is normally suspended and locked by a flange portion 14.

In FIG. 2, reference numeral 17 indicates a presser foot lifter lever having a cam body 17a for moving the presser foot 10 upward by abutting against the locking body 6, and 18 a four-motion feeder. The teeth and W are processed cloth.

Next, the operation of this invention will be explained.

First, the adjusting body 1 is rotated to adjust the elastic force of the coil spring 7, thereby adjusting the operating force of the presser foot lifting lever 17.

After that, when the presser foot lifting lever 17 is raised, the locking body 6 that is locked thereon rises against the coil spring 7.
Along with this, the guide rod 4, the support piece 13, and the guide pin 12
will also rise.

As the guide pin 12 rises, the second presser bar 9 and the presser foot 10 also rise, creating a gap between them and the feed dog 18.

When the work cloth W is inserted into this gap and the presser foot lifting lever 17 is lowered, the restoring force of the coil spring 7 causes the guide rod 4 to
is lowered, whereby the guide pin 12 and the second presser bar 9
, the presser foot 10 is lowered.

Then, the presser foot 10 comes into contact with the work cloth W, and the spring 11
The work cloth W is pressed by the elastic force of , and the locking body 6 locks with the bearing 5 to stop the guide rod 4 from descending.

Thereafter, the first presser bar 8 is rotated to adjust the elastic force of the spring 11 and the pressing force of the presser foot 10.

If the work cloth W is thick, it is possible to insert it between the feed dog 18 and the presser foot 10 by moving the support piece 13 upward and raising the guide pin 12 to widen the distance between the feed dog 18 and the presser foot 10. becomes.

After that, when the sewing machine is operated, especially during high-speed operation, even if the pressure applied to the workpiece cloth W is low, the inertial force acting on the presser foot 10 is only the inertial force corresponding to the mass of the second presser bar 9. Therefore, the inertial force of the first presser bar 8 does not act, and since the first presser bar 8 is made of light metal, the inertial force is further reduced, and the presser foot 10 is sufficient for the violent upward and downward movement of the feed dog 18. It is possible to accurately feed the workpiece cloth W by following the pitch.

As described above, according to this invention, the presser foot sufficiently follows the feed dog even when pressing the work cloth with low pressure when the sewing machine is operating at high speed, and the presser foot always moves the work cloth downward. This has the effect that the feed dog and the workpiece cloth are securely held together while being pressed against each other, and the workpiece cloth can be fed at an accurate pitch.

In addition, the guide pin is installed on the guide rod so that its mounting position can be adjusted up or down, so the distance between the feed foot and the feed dog when the presser foot lifter lever is raised can be changed, making it possible to handle thick workpieces. However, it can be sewn, and even a long feed leg of the support rod can be attached.

Furthermore, since the elastic forces of the first elastic body and the second elastic body can be adjusted separately, it is possible to finely adjust the pressing force of the presser foot against the workpiece cloth, and the workpiece cloth can be fed with an appropriate feeding force. can be transferred.

Furthermore, since the guide pin is provided apart from the guide rod, it is possible to prevent the second presser rod from swinging during upward and downward movement.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an embodiment of this invention, and FIG. 2 is a perspective view of essential parts of the embodiment of this invention. 1... Adjustment body, 4... Guide rod, 6...
...Locking body, 7... Coil spring (first elastic body) 8... First presser body, 9...
Second presser bar, 11... Coil spring (second
elastic body), 12...Guide pin.

Claims (1)

[Scope of utility model registration request] The adjustment body has an inner circumference screw in the center and an outer circumference screw screwed vertically above the jaw of the sewing machine body, and a bearing that faces the adjustment body and is fixed at the front under the jaw is fitted loosely so as to be movable up and down, and the upper end a guide rod having a locking body protruding horizontally from the bottom; a first elastic body interposed between the adjusting body and the locking body and having an elastic force to push the locking body downward; and a first elastic body having an elastic force that pushes the locking body downward; A first presser bar that is screwed and loosely fitted into the first elastic body and the center portion of the guide rod, a guide pin that hangs below the guide rod and is spaced apart horizontally so that the upper and lower mounting positions can be varied, and the upper end. a second presser bar that is loosely fitted into the lower end of the guide rod so as to be movable up and down, and a presser foot is fixed to the lower end, and has a guide hole that is loosely fit into the guide pin so as to be movable up and down, and the first presser bar. A presser foot device for a sewing machine comprising a second elastic body interposed between a second presser bar and having an elastic force that presses the second presser bar downward.