JPS6232546Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a presser foot lifting device for separating the presser foot above the throat plate in a sewing machine equipped with an upper feed dog for pinching and feeding cloth in cooperation with a lower feed dog. It is related to.

Conventionally, in this type of sewing machine, as shown in FIG. 1A, in order to raise the upper feed dog 4 from above the throat plate 3 as the presser foot 2 rises, the presser foot 2 is provided with a convex portion 2a that projects upward. is provided so that when the presser foot 2 is raised, the convex portion 2a comes into contact with the support portion 5 of the upper feed dog 4 and is raised (FIG. 1B).

However, in the above configuration, when the presser foot 2 is raised, the lower surface of the upper feed dog 4 protrudes downward from the lower surface of the presser foot 2, so when the cloth W is inserted, the upper feed dog 4 becomes an obstacle. It had the disadvantage of becoming.

This invention was developed in view of the above-mentioned drawbacks, and provides a presser foot lifting device for a sewing machine that is configured to raise the lower surface of the upper feed dog above the lower surface of the presser foot when the presser foot is raised. The purpose is to

Hereinafter, an embodiment of this invention will be described based on the drawings. Reference numeral 8 denotes a support shaft rotatably supported on the machine frame around an axis horizontally orthogonal to the cloth feeding direction; 9, a support shaft 8;
The operating arm 10 is integrally formed with an operating arm 10 that projects in a direction crossing the axial direction of the support shaft 8 (forward in the cloth feeding direction). Reference numeral 11 denotes a cloth presser arm, whose base end is rotatably supported by the connecting arm 9 about a vertical axis, and a presser foot 12 is fixed below the free end in front of the cloth feed direction. The adjustment screw 13 is threadably supported on the machine frame, the pressing body 14 has its upper end supported loosely in a vertical hole 13a formed through the center thereof, and its lower end is in contact with the presser arm 11, and the space between them. The presser arm 11 is normally subjected to a downward elastic force by a pressing means consisting of a coil spring 15 which is compressed. 17 is a support rod supported on the machine frame in the vertical movement direction, and 16 is an engaging body fixed to the lower end of the support rod 17 and having its tip engaged with a notch 14b provided on the side surface of the pressing body 14. As shown, via the protrusion 18 that protrudes horizontally from the support rod 17,
A lifting operation is enabled by an operating lever 20 supported on the machine frame so as to be swingable about a fulcrum 19.

22 is an upper feed shaft that swings around a fixed axis in conjunction with the main shaft, and 21 is a horizontal drive body whose base end is fixed to the upper feed shaft 22 and whose lower end rotatably supports a square piece 23. be.

25 is an operating shaft that is linked to the main shaft and oscillates within a certain rotation angle range in synchronization with the horizontal drive body 21;
is an actuating body fixed to the actuating shaft 25.

Reference numeral 26 denotes an upper feed swinging arm which is arranged parallel to the presser foot arm 11 and has a notch 26a in the middle thereof that opens downward and into which the square piece 23 is slidably inserted in the vertical direction. The tip in the cloth feed direction is slidably fitted into the groove 8a provided at the end of the support shaft 8, and the tip in the cloth feed direction (left side in FIG. 2) is inverted L.
The support portion 26b is formed by bending it into a letter shape. Reference numeral 29 denotes an upper feed movement rod to which the upper feed dog 28 facing the lower feed dog 27 is fixed in the front, and the rear part thereof is rotatably supported on the support part 26b by a vertical shaft 30, and the upper feed arm 26 and the upper feed movement rod 29 are interlocked to move horizontally. Further, the upper feed arm 26 is always elastically acted in the clockwise direction in FIG. 2 about the support shaft 8 by a pressing means consisting of an adjusting screw 31, a pressing body 32, and a coil spring 33 at the front in the cloth feeding direction. Empower.

34 is a movable body connected to the pressing body 14 via a connecting rod 35, and moves up and down in conjunction with the pressing body 14 along a groove 36 formed in the machine frame. Reference numeral 37 denotes an actuating body whose one end is connected to a shaft 39 eccentrically fixed to the vertical drive body 24 via a link 38, and whose intermediate portion is rotatably supported by a shaft 40 relative to the lower end of the movable body 34; The provided pin 41 is brought into contact with the front lower surface of the upper feed swing arm 26 (the fourth
(See Figures A and 4B).

At this time, the height at which the pin 41 provided on the operating body 37 comes into contact with the lower front surface of the upper feed swing arm 26 is adjusted as follows. That is, by pressing down the tip of the operating arm 10 by depressing a pedal (not shown) connected via the chain 42, the connecting arm 9 rotates counterclockwise around the support shaft 8. , the presser foot 12 fixed to the lower end of the presser foot arm 11 via the presser foot arm 11 rises from the upper surface of the needle plate 3. Along with this, the presser foot arm 11
The pressing body 14 that constantly presses the coil spring 15
The connecting rod 3 rises against the pressing force of
5, pin 41, upper feed swing arm 26, inverted L-shaped part 2
6a, the groove 8 of the support shaft 8 of the upper feed swing arm 26
A counterclockwise rocking force is applied to the upper feed movement rod 29 centering on the portion supported by a, and the upper feed dog 28 fixed to the tip of the upper feed movement rod 29 rises from the throat plate. Therefore, the operating body 24, the operating body 3
7. As shown in FIG. 5B, when the link 38, shaft 40, and pin 41 are raised by the above operation to raise the presser foot 12, the lower surface of the upper feed dog 28 is at least above the lower surface of the presser foot 12. Adjust accordingly.

Note that the upward movement of the pressing body 14 is controlled by the upward swinging arm 26.
As shown in FIG. 6, the mechanism for transmitting the signal to the
It may also be something that is just fixed. However, in this case, the movement of the vertical drive body 24 is controlled by the upward swinging arm 26.
It is necessary to separately provide a connecting member for transmitting the signal to the

Next, the operation of the above configuration will be explained.

First, when the presser foot 12 and the upper feed dog 28 are in the state shown in FIG. Connecting arm 9
rotates counterclockwise (FIG. 2) about the support shaft 8. As a result, the presser foot arm 11 whose base is supported by the connecting arm 9 also rotates counterclockwise around the support shaft 8, so that the presser foot 12 fixed to the tip of the presser foot arm 11 moves away from the throat plate 3. As the presser foot moves upward, the pressing body 14, which is constantly pressing the upper surface of the presser arm 11, is pushed upward against the pressing force of the coil spring 15. As the pressing body 14 rises, the movable body 34 is pulled up via the connecting rod 35. Then, the actuating body 37, which is supported by the movable body 34 by the shaft 40 and is connected to the vertical drive body 24 via the link 38, can move up and down since the shaft 39 is rotatable. 4A to the state shown in FIG. 4B along with the body 34, and the upper feed swing arm 2 is moved up via the pin 41.
The right end (rear end in the cloth feeding direction) of 6 is lifted upward. However, since the upper feed swing arm 26 is slidably supported at the left end (front end in the cloth feeding direction) by the groove 8a on the support shaft 8, this groove 8a
It swings counterclockwise (FIG. 2) using the support shaft 8 as a fulcrum through the supported portion. This counterclockwise rocking motion is transmitted to the upper feed movement rod 29 via the inverted L-shaped support portion 26b, that is, the upper feed movement rod 29
eventually moves in a counterclockwise direction (second direction) around the support shaft 8
), the upper feed dog 28 fixed to the tip of the upper feed movement rod 29 rises from the throat plate 3.
At this time, by setting the position of the pin 41 that contacts the upper feed swinging rod 26 appropriately in advance,
As shown in FIG. 5B, the lower end of the upper feed dog 28 is located above the lower end of the presser foot 12.

In this way, when the cloth is inserted between the throat plate 3 and the presser foot 12 and the pedal (not shown) is released, the counterclockwise direction (second Since the rotational force shown in FIG.
(Fig.), and the presser foot 12 fixed to the tip of the presser foot arm 11 comes to press the cloth. Along with this, the pressing body 14 descends, so the connecting rod 3
5, the movable body 34 is pushed down, and as a result, the actuating body 37 supported at the lower end of the movable body 34
The state shown in FIG. 4A is restored from FIG. . That is, the upper feed swing arm 26 swings clockwise around the support shaft 8,
This oscillation is caused by the upper feed motion rod 2 via the support portion 26b.
9, the upper feed dog 28 fixed to the tip of the upper feed movement rod 29 descends to a position where it can come into contact with the cloth (FIG. 5A). Note that the presser foot 12 is attached to the throat plate 3.
When the operating lever 20 is pushed down during the upward movement, the support rod 17 rises, the operating means 16 engages with the notch 14b of the pressing body 14, and pushes up the pressing body 14 against the elastic force of the coil spring 15. . Then, as described above, the connecting rod 35, the moving body 34,
The upper feed movement rod 29 swings counterclockwise (FIG. 2) via the operating body 37 and the upper feed swing arm 26, and the fifth
As shown in Fig. C, the presser foot 12 does not rise, and only the upper feed dog 28 rises. Next, when the operating lever 20 is released, the pressing body 14 is lowered by the pressing force of the coil spring 15, so that the upper feed dog 28 is lowered to the state shown in FIG. 5A.

In the above embodiment, the presser foot arm 11 and the upper feed movement rod 29 are swingably supported by the common support shaft 8, but each is supported by a separate support shaft (for example, the support shaft of the cloth presser arm 11). may be supported so that it is located in front of the support shaft of the upper feed movement rod in the cloth feed direction.

Further, the raised position of the upper feed dog 28 does not need to be adjusted by the distance from the support shaft 8 as a fulcrum to the pin 41. A mechanism may be provided to transmit this increased amount of rise to the upper feed swing arm 26.

As described above, according to this invention, a member is provided that connects the base end of the upper feed motion rod to which the upper feed dog is fixed to the tip, and the base end of the presser foot arm to which the presser foot is fixed to the tip, As shown in Figure 5B, when the presser foot is raised, the lower end of the upper feed dog is located above the lower end of the presser foot, so the presser foot is raised and the fabric is placed between the throat plate and the presser foot. When inserting the cloth between the two, the lower surface of the upper feed dog does not come into contact with the cloth and interfere with the insertion of the cloth, thereby improving work efficiency.

[Brief explanation of the drawing]

Figures 1A and 1B are diagrams showing the ascending and descending states of the presser foot and upper feed dog in the conventional configuration, Figure 2 is a perspective view of the drive mechanism for the upper feed dog and presser foot in the present invention, and Figure 3 Figures 4A and 4B are diagrams showing the positional relationship between the tip of the upper feed swing arm and the pin of the operating body, and Figures 5A, 5B, and 5C are diagrams of the lifting and lowering mechanism of the pressing body that presses the upper feed movement rod. In this invention, a diagram showing the positional relationship between the throat plate, upper feed dog, and the raised position of the presser foot,
FIG. 6 is a perspective view of another embodiment of the connection mechanism between the pressing body of the upper feed movement rod and the upper feed swing arm. 28...Upper feed dog, 29...Upper feed movement rod, 1
2... Presser foot, 11... Presser foot arm, 14, 35,
34, 37, 38, 41, 43...transmission means,
8,26...Motor expansion means.

Claims (1)

[Scope of Claim for Utility Model Registration] The base of the presser foot is supported on the machine frame so as to be rotatable about a horizontal axis, and the presser foot is placed in a lowered position where it contacts the throat plate and a raised position where it is spaced apart above the throat plate, and the presser foot is always in a downward position. The presser arm 11 receives elastic force, has an upper feed dog, is capable of reciprocating movement along the upper surface of the throat plate, and is supported at its base on the machine frame so as to be able to swing up and down about an axis horizontally orthogonal to the direction of reciprocating movement, and is always directed downward. upper feed arms 26, 29 which receive an elastic force acting on the upper feed arms; a horizontal movement element 21 which operates in conjunction with the main shaft to give horizontal movement to the upper feed arm; and a horizontal movement element 21 which operates in conjunction with the main shaft and in synchronization with the horizontal movement element In a sewing machine having a vertical movement element 24, the operating means is connected to the presser arm at a horizontal intermediate position between the center of rotation of the presser arm and the presser foot, and is operable to move the presser arm to a lowered position and a raised position. and the upper feed dog is connected to the operating means or the presser arm at a horizontal intermediate position between the center of rotation of the upper feed arm and the upper feed dog, and is configured to raise the upper feed dog in conjunction with the rise of the presser arm to the raised position. The upper feed arm is provided with transmission means 35, 36, 37, and 41 that can be engaged with the feed arm, and the upper feed arm is connected to the connecting position of the operating means and the presser arm so that the upper feed dog is above the presser foot when the presser foot is in the raised position. A presser foot lifting device for a sewing machine, characterized in that the connecting position of the operating means or the presser arm is separated from each other in the longitudinal direction of the upper feed arm.