JPH04347194A - Lever device for lifting holder in sewing machine - Google Patents

Abstract

PURPOSE:To enable a holder to be smoothly vertically moved even by either left or right pedal. CONSTITUTION:A lifting mechanism to drive a lifting arm 4 for vertically moving a holder 1 is composed of a pivotable lever 61 having the pivotal end connected through a chain to a foot pedal, a hook 5 having an end engaged with the lifting arm and the other end removably engaged with the pivotable lever 61, a lever link 9 having one end journalling the proximal end of the pivotable lever and rotatable about the other end, a spring body for urging the pivotable lever 61 always in a predetermined direction and a stopper 8 for regulating the rotational range of the pivotable lever 61, so that the pivotable lever 61 can rotate by a half rotation together with the lever ink 9. Since the journalling point of the pivotable lever 61 thus rotates by 180 deg., the pivotable end of the pivotable lever 61, i.e., the point engaged with the chain connected to the pedal can easily be reversed left or right. Thus, the pivotable end of the pivotable lever 61 is opposed to the desired side pedal of left and right pedals to transmit a pedalling force on the pedal smoothly to the lifting arm.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] This invention relates to a presser foot lifting device for sewing machines, particularly overlock sewing machines, and more specifically to a presser foot lifting device for raising and lowering the presser foot using a foot pedal, which operates smoothly when either the right or left foot is pressed. This invention relates to a presser foot lifting device.

0002

2. Description of the Related Art Conventionally, there is a device shown in FIGS. 6 and 7 as this type of device. In FIG. 6, M is an overlock sewing machine equipped with a presser foot lifting mechanism operated by a foot pedal, and S is a presser foot lifting mechanism that rotates a presser foot lifting arm 4, which includes a hook 5, a presser foot lifting lever 6, etc. It is growing. 7 is a chain connecting the presser foot lifting mechanism S and a foot pedal (for the right foot) RP, and LP is a foot pedal (for the left foot) for controlling the operation of the sewing machine drive motor via the rod ML.

[0003] The operator operates the presser foot lifting mechanism S by depressing the pedal RP as necessary, and controls the drive of the sewing machine motor by operating the pedal LP to perform a predetermined sewing operation. . Details of the related structure of the presser foot lifting mechanism S are shown in FIG. 7(a). In the figure, reference numeral 1 denotes a presser foot that moves up and down relative to the workpiece, 2 a presser arm that swings with the presser foot at its tip, and 3 a presser shaft that reciprocates at a predetermined angle to swing the presser arm 2. , 4 is a presser foot lifting arm fixed to the end of the presser foot shaft 3, 6 is a presser foot lifting lever, and 5 is a presser foot lifting arm 4 and a presser foot lifting lever 6.
This is a hook that connects the presser foot lifting lever 6 and transmits the reciprocating rotation of the presser foot lifting lever 6 to the presser foot lifting arm. The presser foot lifting lever 6 is normally biased clockwise by a biasing spring 6a, and rotates counterclockwise via the chain 7 when the aforementioned foot pedal is depressed, thereby lifting the presser foot 1. Release from position.

0004

[Problems to be Solved by the Invention] By the way, the sewing work in the above-mentioned prior art is performed by pressing the right pedal R as shown in FIG.
It is customary to operate the presser foot lifting mechanism S with P and control the drive motor with the left pedal LP. However, in some cases, it may be necessary to reverse the shared operations of the left and right pedals. For example, in rural areas such as Osaka, it is common for the right foot to control the sewing machine motor and the left foot to lift the presser foot. 7
and the rod ML, that is, the end of the chain 7 is changed from the right pedal RP to the left pedal LP, while
Currently, the rod ML is also used by changing the left and right sides.

However, when the chain 7 is connected diagonally in this way, unless the pedal force is large, it is not smoothly transmitted to the presser foot lifting arm 4, and it is not only impossible to perform a smooth presser foot lifting operation when necessary, but also as shown in FIG. Edge T of table T shown in 6
The chain 7 may get caught in the presser foot 1, resulting in a malfunction in which the presser foot 1 does not rise, resulting in a significant loss of productivity in sewing work.

[0006]

[Means for Solving the Problems] The present invention provides a presser foot lifting device for a sewing machine, which includes a presser foot, a presser arm whose one end holds the presser foot and the other end is fixed to a rotating shaft, and one end of which is fixed to the rotating shaft. The presser foot lifting arm is fixed to the presser foot lifting arm, and the presser foot lifting mechanism rotates the presser foot lifting arm. - and a hook whose one end is locked to the presser foot lifting arm and whose other end is removably locked to the rotating lever, and one end pivots on the base end of the rotating lever and rotates around the other end. The above-mentioned conventional problems are solved by providing a flexible lever link, a spring body that always biases the rotating lever in a predetermined direction, and a stopper that restricts the rotating range of the rotating lever. This is what I am trying to do.

Further, the proximal end of the rotating lever is formed in a semicircular shape, the spring body and the stopper are brought into contact with the circumferential edge of the semicircular part, and the hook is attached to the rotating lever. The conventional problem can be solved more effectively by engaging with either one of the slits formed at both ends of the semicircular part.

[0008]

[Operation] In this invention, the presser foot lifting mechanism that rotates the presser foot lifting arm includes a rotating lever whose rotating end is connected to the foot pedal via a chain, and one end of which is latched to the presser foot lifting arm. A hook that is removably attached to the rotating lever at the other end, a lever link that supports the proximal end of the rotating lever at one end and is rotatable about the other end, and a lever link that supports the rotating lever at the other end. Since it is composed of a spring body that is always biased in a predetermined direction and a stopper that restricts the rotation range of the rotary lever, the rotary lever can be rotated half a turn together with the lever link, and as a result, the rotary lever Since the pivot point of the lever also rotates 180 degrees, the pivoting end of the pivoting lever, that is, the locking point with the chain connected to the pedal, can also be easily reversed.

[0009] Therefore, since the rotating end of the rotating lever can be opposed to a desired pedal of the left and right foot pedals, the pedal force applied to the pedal is smoothly transmitted to the presser foot lifting arm.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be explained based on the drawings. Note that the same parts as in the conventional example are given the same reference numerals, and redundant explanation will be omitted. 1 to 5 are part 1 of this invention.
It is a figure showing an example. FIG. 1 is a partially cutaway perspective view showing how the presser foot lifting mechanism S is installed on the back of the sewing machine M;
FIG. 2 is an exploded perspective view of the presser foot lifting mechanism S. In the figure, reference numeral 61 is a rotary lever, and its tip, that is, the rotary end is connected to foot pedals RP and LP (not shown) via a chain 7.
connected to either. And this rotating lever
The base end 61a, which is also the pivot end of the hook 61, is formed in a semicircular shape, and slits 61b, 61b for locking the tip of the hook 5 are bored at both ends thereof. 61e
A rotary lever 61 is attached to a protrusion 9a1 of a lever link 9, which will be described later.
The hole 61c for pivotally supporting the lever link 9 is also an opening for operating a fixing screw 9c of the lever link 9, which will be described later. Further, a stepped portion 61f is formed approximately in the center of the rotating lever 61 in order to prevent the front half of the rotating end side from coming into contact with a stopper 8, which will be described later, when the rotating lever 61 rotates. ing. 61d is a screw that passes through the hole 61e and screws into a projection 9a1 of the lever link 9, which will be described later, to pivotally support the rotary lever 61.

Reference numeral 8 denotes a rotary screw as a stopper, which is supported at a predetermined position on the back side of the frame of the sewing machine M by a metal fitting 8a. The tip of this rotary screw 8 is adapted to abut against the periphery of the semicircular base end 61a of the rotary lever 61.
For example, in FIG. 1, the rotating lever 61 is prevented from excessively rotating clockwise about the screw 61d. 9 is a lever link that rotates together with the rotation lever 61 when necessary, and a pin 9a is fixed at one end (right side in the figure).
A projection 9a1 that fits into the hole 61e of the rotating lever 61 is formed on the head of the lever 61, and a projection 9a1 is formed on the other end for fixing the lever link 9 to a predetermined position on the back of the sewing machine M with a fixing screw 9c. A hole 9b is bored. The fixing screw 9c is tightened and released through the opening 61c of the rotary lever 61 as described above.
This is done using a screwdriver or the like.

Reference numeral 10 denotes a biasing spring supported at a position facing the stopper 8 by a metal fitting 10a fixed to the back surface of the sewing machine M, the end of which is connected to the semicircular base end of the rotating lever 61. 61a and rotate the rotary lever 61 with the screw 6.
In the case of FIGS. 1 and 2, the force is always applied clockwise around 1d. The above-mentioned stopper 8 acts to appropriately restrict the rotational bias of the rotary lever 61 in the clockwise direction and maintain the rotary lever 61 in the horizontal direction as shown in the figure. In addition, in FIG. 2, 5a connects the end of the hook 5 to the slit 6.
This is a split pin for fixing to 1b.

Based on the above configuration, the operation of this embodiment will be explained with reference to FIGS. 3 to 5. First, in the state shown in FIG. 1, the turning end of the turning lever 61 protrudes in the left horizontal direction.
The presser foot lifting mechanism is connected to the pedal RP shown in , and the presser foot lifting mechanism is operated with the right foot. To do this with the left foot, perform the operation shown in FIGS. 3 and 4 to reverse the rotation lever 61. This operation will be explained below.

First, remove the chain 7 from the rotating end of the rotating lever 61, remove the end of the hook 5 from the slit 61b of the rotating lever 61 as shown in FIG. 3, and insert the driver from the opening 61c. Insert D and tighten the fixing screw 9c of the lever link 9.
loosen. Next, the rotating screw 8 serving as a stopper is moved back to release its tip from the circumferential edge of the semicircular base end 61a of the rotating lever 61, and the rotating screw 8 is rotated as shown in FIG. 4(a). Rotate the movable lever 61 and lever link 9 clockwise around the fixing screw 9c.

Then, as shown in FIG. 4(b), when the rotary lever 61 and the lever link 9 have rotated 180 degrees and come to a position opposite to the original position, the fixing screw 9c is tightened again. The rotating lever 61 and the lever link 9 are fixed in their positions. Note that while the rotating lever 61 rotates, the tip of the biasing spring 10 remains in contact with the periphery of the base end 61a of the rotating lever 61, but since the base end has a semicircular shape, it cannot be rotated. As the movable lever 61 rotates, it smoothly slides on its proximal periphery.

The rotating lever 61 and the lever link 9 are shown in FIG.
When the hook 5 is fixed at the position shown in (b), the hook 5 is attached to the slit 61b on the opposite side of the rotary lever 61, and then the rotary screw 8 serving as a stopper is advanced to release the biasing spring 10. The pivot lever 61, which is urged to rotate counterclockwise around the screw 61d, is regulated to a horizontal position. Then, as shown in Fig. 5, the chain 7
This connects the rotating end of the rotating lever 61 and the left pedal LP. In this way, the rotary lever 6 of the presser foot lifting mechanism
The direction of 1 can be changed almost with one touch, and the rotating lever 61
The rotating end of can be made to face either the left or right pedal. Further, in the above embodiment, the slit 61b was provided as shown in FIG. 2, but the same effect can be obtained even if a hole is provided instead of the slit 61b.

[0017]

As explained above, the present invention provides a presser foot lifting device for a sewing machine that includes a presser foot, a presser arm whose one end holds the presser foot and the other end is fixed to a rotating shaft, and one end of which is fixed to the rotating shaft. It consists of a presser foot lifting arm fixed to a moving shaft and a presser foot lifting mechanism that rotates the presser foot lifting arm, and the presser foot lifting mechanism has a rotation end connected to a foot pedal via a chain. a movable lever, a hook having one end locked to the presser foot lifting arm and the other end removably hooked to the rotary lever; one end pivotally supporting the proximal end of the rotary lever and the other end being centered; lever that can be rotated to
The rotary lever includes a link, a spring body that always biases the rotary lever in a predetermined direction, and a stopper that restricts the rotation range of the rotary lever, and the proximal end of the rotary lever has a semicircular shape. The spring body and the stopper are brought into contact with the circumferential edge of the semicircular part, while the hook is formed into a rotating lever.
Since the pivot lever is locked to either one of the slits formed at both ends of the semicircular part, the pivot lever can be rotated half a time together with the lever link, and the pivot point of the pivot lever is also 180 degrees. Because of the rotation, the rotation end of the rotation lever, that is, the locking point with the chain connected to the pedal, can also be easily reversed.

Therefore, the rotating end of the rotating lever can be opposed to the desired side of the left and right foot pedals, so that the pedal force on the pedal is smoothly transmitted to the presser foot lifting arm, making it easier to work. Employee fatigue is eliminated, there are no malfunctions, and productivity is therefore improved.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing one embodiment of a presser foot lifting mechanism according to the present invention.

FIG. 2 is an exploded perspective view of the presser foot lifting mechanism.

3 is a perspective view showing a state in which the rotary lever of the presser foot lifting mechanism shown in FIG. 1 is ready for reverse rotation; FIG.

FIG. 4 is a perspective view showing the reverse movement of the same moving lever.

FIG. 5 is a perspective view showing a reversed rotation lever and a left foot pedal connected by a chain in the overlock sewing machine.

FIG. 6 is a perspective view of an overlock sewing machine equipped with a conventional presser foot lifting mechanism.

FIG. 7 is a perspective view showing the main parts of the presser foot lifting mechanism and a state in which the mechanism and the left foot pedal are connected by crossing the chains.

[Explanation of symbols]

1 Presser foot 2 Presser arm 4 Presser foot lifting arm 5 Hook 61 Rotating lever 7 Chain 8 Stopper 9 Lever link 10 Biasing spring

Claims (3)

[Claims] 1. A presser foot, a presser arm that holds the presser foot at one end and is fixed to the presser foot shaft at the other end, a presser foot lifting arm that has one end fixed to the presser foot shaft, and a presser foot that rotates the presser foot lifting arm. a lifting mechanism, and the rotating end of the presser foot lifting mechanism is connected to a chain.
a rotary lever connected to the foot pedal via a hook; a hook having one end hooked to the presser foot lifting arm and the other end removably hooked to the rotary lever; A lever link that supports the base end of the lever and is rotatable around the other end, a spring body that always biases the rotating lever in a predetermined direction, and a stopper that restricts the rotation range of the rotating lever. A presser foot lifting lever device for a sewing machine, characterized by comprising: 2. A base end of the rotating lever is formed in a semicircular shape, and the spring body and the stopper are in contact with a circumferential edge of the semicircular portion. Presser foot lifting lever device for sewing machines. 3. The presser foot lifting lever device for a sewing machine according to claim 2, wherein the hook is configured to engage with either one of slits formed at both ends of a semicircular portion of the rotating lever. .