JPS5927911Y2 - Sewing machine cloth cutting knife drive device - Google Patents

Description

[Detailed description of the invention] This invention allows a cloth cutting knife to be operated in conjunction with the sewing machine to cut the cloth along the seam line during sewing, and also to be able to stop without interlocking with the sewing machine. This invention relates to a cloth cutting knife drive device for a sewing machine, in particular, a blocking means that prevents the cloth cutting knife from rising at a predetermined position due to inertial force when the cloth cutting knife is stopped by cutting off the interlock with the sewing machine. This prevents some links from being distorted by the strong inertia of the cloth cutting knife after the drive mechanism connected to the cloth cutting knife stops, and the joint surface with the links is subject to strong friction.
Another object of the present invention is to prevent the switching lever from becoming stuck due to the frictional force of the joint surface when operating the switching lever to drive the cloth cutting knife, and to improve operability.

An embodiment of this invention will be described below with reference to the drawings. Reference numeral 1 denotes a known sewing machine, in which a rod 4 is attached to an eccentric portion 3 of a main shaft 2 supported on a machine frame so as to rotate in one direction during operation. The lower end of this rod 4 is connected to the free end of the oscillating body 6 and the upper end of the first link 7, the base of which is supported by a step screw 5 to be able to swing around an axis parallel to the main shaft 2 relative to the machine frame. Connect with screw 8.

Reference numeral 9 denotes a bushing fixed to the machine frame, and a block 11 is provided at the lower end of an operating body 10 which is loosely fitted in the hollow of the bushing so as to be movable up and down along a fixed vertical line. is fixed with a screw 13, and a blocking means 14 is vertically screwed into the upper end of the block 11 to support it, and is provided so as to be securely fixed via a nut 15.

Further, the lower end of the second link 16 is supported at the upper end of the operating body 10 by a step screw 17, and the upper end of the second link 16 is connected to the lower end of the first link 7 by a step screw 18.

Note that the center distance between the step screws 8 and 18 is equal to the center distance between the step screws 5 and 8.

Reference numeral 19 denotes a horizontal shaft whose one end protrudes from the jaw 20 to the outside of the machine frame and is rotatably supported by the machine frame in parallel with the main shaft 2. The base of the interlocking body 21 is fixed to one end inside the machine frame. Furthermore, interlocking body 2
One end of the third link 22 is connected to the first link 7 and the second link 16 by a step screw 18, and the other end of the third link 22 is connected to the free end of the third link 22 by a step screw 23.

Further, a rotating body 24 is fixed to a protrusion of the machine frame of the horizontal shaft 19.

This rotating body 24 has a regulating surface 2 facing the tips of screws 26 and 27 screwed into and supported by a support 25 fixed to the machine frame.
Although not shown in detail, an elastic body 32 is compressed and arranged between a pin 30 fixed to the machine frame and a pin 31 fixed to the rotating body 24, and its elastic force causes the rotating body 24 to move. The position where the regulating surface 28 hits the screw 26 and the regulating surface 2
9 is provided so that it can be locked at the position where it abuts against the screw 27.

33 is a switching lever, the base of which is attached to the shaft 34 on the machine frame at the rear of the sewing machine.
The rotating body 24 is swingably supported, and its free end is placed in front of the sewing machine, and a pin 35 fixed in the middle is loosely fitted into an elongated hole 36 formed in the rotating body 24 along its longitudinal direction.

When the regulating surface 29 of the rotating body 24 is in contact with the screw 27, each axis P1 of the stepped gears 8, 17, and 18 as shown in FIG. P2. P3 is approximately on the moving direction line of the actuating body 10 -
When they are lined up in rows and the regulating surface 28 of the rotating body 24 is in contact with the screw 26, the axis of the stepped screw 18 is extremely far away from the moving direction line of the actuating body 10, as shown in FIG. The respective members are constructed in relation to each other so as to coincide with the axis of.

This invention has the above structure, and its operation will be explained next.

In FIG. 5, the solid line indicates the selected state of the switching lever 33 that stops the cloth cutting knife 12.

That is, in this state, the elastic force of the elastic body 32 pushes the rotating body 24 clockwise, and the acting force stops the rotating body 24 and the switching lever 33 at the position where the regulating surface 28 hits the screw 26. There is.

In this state, the horizontal shaft 19 is rotated to the maximum clockwise in the figure, and the interlocking body 21 is also rotated to the maximum clockwise as shown in FIG.
The axis of the step screw 5 overlaps with the axis of the stepped screw 5 in a straight line.

Therefore, even if the oscillator 6 swings via the rod 4 due to the rotation of the main shaft 2, the first link oscillates together with the oscillator 6 around the stepped screw 18, so the second link 16 has the first link 7. No motion is transmitted and the actuating body 10 is held in the position shown in FIG.

Furthermore, when the axis of the stepped screw 18 is aligned with the axis of the stepped screw 5, the upper end of the stiff blocking means (14) provided on the block 11 comes into contact with the lower surface of the sewing machine jaw 20, so that the operating body 10 receives an upward external force. However, it does not move upward.

Next, when the switching lever 33 is pressed downward from the state shown by the solid line in FIG. 5, the rotating body 24 rotates counterclockwise in the figure against the elastic force of the elastic body 32 via the pin 35 and the elongated hole 36. .

During this rotation, the elastic body 32 is held against the rotating body 24.
There is a put point for the acting force, and after that point the acting direction of the elastic force of the elastic body 32 is reversed, so that the rotating body 24 and the switching lever 3 are affected by the acting force.
3 is actively rotated clockwise in the figure, and the rotating body 24
It stops at the position indicated by the two-dot chain line in the figure, where the regulating surface 29 hits the screw 27.

By operating the switching lever 33, the interlocking body 21 is rotated counterclockwise from the position shown in FIG. 3 via the horizontal shaft 19.

As a result, the step screw 18 moves diagonally to the left via the third link 22, and at this time, since the position of the step screw 8 is fixed, the first link 6 rotates clockwise in the figure around the step screw 8. ,
As a result, the second non-stop 16 also rotates in the counterclockwise direction in the same figure around the stepped screw 17, as shown in FIG.
While pushing down the operating body 10 from the position shown in the figure, the first link 7 and the second link 16 stand up, and the axes PI, P2. P3 are lined up in approximately - row on the moving direction line of the actuating body 10.

Therefore, when the swinging body 6 swings around the step screw 5 via the rod 4 due to the rotation of the main shaft 2, the first link 7 and the second link 16 swing while the third link 22 swings around the step screw 23. The actuating body 10 moves up and down in conjunction with this movement to operate the cloth cutting knife 12.

Note that when the switching lever 33 is moved from the position indicated by the chain dotted line in Fig. 5 to the position indicated by the solid line in Fig. 5 while the sewing machine is in motion, the step screw 18 is not operated after moving from the position shown in Fig. 4 to the position shown in Fig. 3. Since the body 10 tends to move further upward due to inertial force, if the blocking means 14 is not provided, the second link 16 will move from the state shown in FIG. From the state of step screw 17, rotational force is applied clockwise around step screw 18 through step screw 17, and step screw 17.
18 and the second link 16 and the operating body 10 moves upward within the allowable limits of the fitting play and distortion between the second link 16 and the second link 16.
rotates around the stepped screw 18, which shortens the center distance between the stepped screws 17 and 18.
The second link 1 is pushed out so as to widen the center space between the step screw 18 and the step screw 18.
The inner circumferential surface of the bearing section 6 comes into pressure contact with the outer circumferential surface of the means 17 and 18, and their sliding surfaces engage and cause strong friction. The friction force causes the object to become heavy or want to move.

However, in this invention, the step screw 18 is moved from the position shown in Fig. 4 to the third position.
1.
4 is connected to the bottom surface of the sewing machine jaw 20.
By loosening 5 and adjusting the amount of protrusion of the screw 14 in advance, the inertial force of the operating body 10 is absorbed by the sewing machine frame via the screw 14, and the inertial force is not transmitted to the second link 16. Even if the operation of the cloth cutting knife 12 is stopped while the sewing machine is in operation, the second link 16 will remain loosely fitted to the tiers 17 and 18 as shown by the two-dot chain line in FIG. Next, when operating the cloth cutting knife, the switching lever 33 can be operated lightly.

As described above, according to this invention, the first link whose upper end is connected to the rocking body and the second link whose lower end is connected to the actuating body are connected to each other, and the The connecting axes of the first link and the second link are aligned with the center axis of the swinging body to make the actuator stationary, and the actuator is separated downward from the center axis of the swinging body of the swinging body to move the actuator to the first link and the second link. In a drive device for a cloth cutting knife that is linked to a swinging body through a second link, the actuating body moves upward after the connecting axis is aligned with the swinging center axis of the swinging body by the action of the blocking means. Since the structure is configured to prevent movement, even if the switching lever is operated to stop driving the cloth cutting knife while the sewing machine is running, the second link will not move between the connecting shaft with the operating body and the connecting shaft with the first link. This prevents the sewing machine from being forced to spread between the connecting shafts, causing the sliding parts to become stuck and not returning to their original state, making it easier to operate the switching lever even while the sewing machine is running. This has the effect of allowing you to easily and reliably control the drive and stop of the cloth cutting knife.

In the above embodiment, the screw 1 is used as the blocking means.
4 is screwed vertically into the upper end of the block 11 so that the amount of vertical protrusion can be adjusted. Alternatively, the block 11 is rotatably supported on the side surface of the block 11 about a horizontal axis, and the eccentric portion of the shaft is connected to the sewing machine frame by aligning the axis of the stepped screw 18 with the axis of the swinging body 6. The same effect as described above can be obtained even if the structure is configured so as to be joined to the above.

[Brief explanation of the drawing]

Figure 1 is an external perspective view of the sewing machine, Figure 2 is II of Figure 1.
Fig. 3 is a left side view of Fig. 2 seen through the main part, showing the rest state of the cloth cutting scalpel, and Fig. 4 is a longitudinal cross-sectional view of the main part taken along line II. FIG. 5, which is a left side view of the machine and shows the driving state of the cloth cutting knife, is an explanatory diagram of the operation of the switching lever, and FIG. 6 is an explanatory diagram of the conventional drawbacks. In the figure, 6 is a swinging body, 7 is a first link, 10 is an operating body, 12 is a cloth cutting knife, 14 is a screw as a blocking means,
16 is a second link, 21 is an interlocking body, 22 is a third link,
33 is a switching lever.

Claims (1)

[Scope of utility model registration request] An operating body 10 having a cloth cutting knife 12 at its lower end and supported on a machine frame so as to be movable up and down along a vertical line; A rocking body 6 that swings at a constant angle around the center, and a first cylinder 7 that has a center distance equal to the center distance between the base end and the free end of the rocking body and whose upper end is rotatably connected to the free end of the rocking body. , a second link 16 whose lower end is connected to the actuating body and whose upper end is rotatable to the lower end of the first link; Interlocking body 2 that can be rotatably locked in an active position that moves away and a non-active position that approaches
1, the connecting axis of the first link and the second link coincides with the center of oscillation of the oscillator when the interlocking body is moved to the inactive position, and the oscillation center of the oscillator when the interlocking body is moved to the active position. The third link 22 is rotatably connected to the free end of the interlocking body and the lower end of the first link so that the center of motion is removed, and the inertia of the actuating body moves the interlocking body upward after the interlocking body is moved to the inactive position. A cloth cutting knife drive device for a sewing machine, comprising a blocking means 14 for absorbing the inertial force of an operating body into a sewing machine frame so as to prevent movement.