JPS6020369Y2 - sewing machine - Google Patents

Description

[Detailed description of the invention] This invention relates to a sewing machine that is equipped with a wood stitching mechanism and an edge stitching mechanism, and is capable of performing two types of sewing, lock stitching and edge stitching, with one sewing machine.

This type of sewing machine is already known from Japanese Patent Laid-Open No. 53-67551, but this sewing machine has the following drawbacks.

In other words, 1. A belt is passed between the motor pulley and the pulley that moves to the left or right on the upper spindle to switch between lockstitch and hem stitch, so when switching the pulley is If the belt is moved, the belt will tilt accordingly, resulting in insufficient power transmission and the belt becoming prone to wear and tear.

2 Switching between lock stitching and edge S-stitching is done by moving the pulley to the left or right, then rotating it slowly until the fixing pin and the small hole are aligned, then the two are fitted together. , this operation is relatively troublesome.

3. There is a risk that the pulley may move due to careless contact and the stitching may be switched.

Therefore, the present applicant previously proposed a fixed pulley that is fixed in the axial direction of the upper die shaft and a movable pulley that is movable in the axial direction for switching operation in Utility Application No. 55-2150@. By splitting the belt and hooking the fixed pulley to the motor pulley, the belt does not tilt when switching, and the movable pulley engages the double-stitch mechanism in addition to lockstitching and hem S-stitching. We proposed a sewing machine that can be switched to a neutral position where the machine is not in use.

This invention aims to further improve the above-mentioned sewing machine and provide a sewing machine which has a simpler structure and can be easily switched.

To explain this using drawings, in Figures 2 and 3,
1 is the upper main shaft of the lockstitch mechanism for driving the needle 2 and thread take-up 3 in FIG. A clutch mechanism for switching and driving the upper main shaft 1 or the lock upper shaft 4 is provided on the upper die shaft.

This clutch mechanism will be explained below.

A flange tubular clutch body 7 is loosely fitted to the upper main shaft 1, and the clutch body 7 has a pulley 8 in its tube portion 71.
A pair of stepped pins 10 and 10 each having a spring 9 built into the flange 72 are fitted in symmetrical positions with the center in between so that the small diameter portions of the ends thereof are oriented in opposite directions.

A donut plate 12 having a larger diameter than the flange is fixed to both sides of the flange 72 to form a brim shape (see Fig. 3.4), and the spring 9 is in elastic contact with the donut plate 12. The stepped pin 10 is biased in one direction, causing the stepped portion at the tip to protrude from the small hole 13 formed in the donut plate.

The pulley 8 attached to the tube portion 71 is slidably coupled to the tube portion and the key 15 only in the axial direction, and a timing belt 17 is installed between the pulley 8 and the motor pulley 16.

Thus, the clutch body 7 is always rotating on the upper main shaft 1 via the motor pulley 16, timing belt 17, and pulley 8 while the motor is driving.

A gear 20 is loosely fitted into the boss portion 19 of the pulley 8 and meshes with a gear 21 fixed to the lock upper shaft 4. Furthermore, the gear is secured with a set screw to a clutch plate 23 which has a pin hole 24 in its side surface into which the small diameter portion of the tip of the stepped pin can fit. I'm wearing it.

Here, the pulley 8 has a structure in which the gear 20 is sandwiched between the clutch plate 23 and the latch plate 23 and the gear 2.
0, the movement in the axial direction is held in a restricted state.

The clutch plate 23 is also fixed to the upper main shaft 1 and is attached to a pulley 25 on the side surface of the pulley 25, which is attached to a belt (not shown) by a belt. It is set wider than the interval between the tip tubes of the double stepped pins 10 that protrude in opposite directions from both sides of the pin 72,
This makes it possible to position the clutch body 7 in a neutral position and prevent the tips of each pin from engaging with any of the clutch plates 23.

28 has a central part pivoted to the sewing machine frame, and a lower end to which a roller 29 which fits between the flanges formed by the pair of donut plates 12 and 12 is pivoted; When the lever 28 is rotated by the handle, the clutch body 7 moves to the left or right, and the clutch plate 2
It is designed to be disconnected from 3.

Here, the coupling between the clutch body 7 and the clutch plate 23 is achieved by fitting the tip of the stepped pin into the pin hole 24 as described above, but when the clutch body moves during switching, the tip of the stepped pin When the stepped pin 10 is not aligned with the bottle hole 24, the stepped pin 10 is pressed against the clutch plate 23 and temporarily retreats into the donut plate 12 against the action of the spring 9.

Thereafter, when the tip of the stepped pin reaches the bottle hole 24 as the pulley 18 is rotated, it is fitted into the bottle hole 24 by the action of the spring 9, and the handle portion 31 is set to the right position in FIG. Then, the clutch body 7 engages with the left clutch plate 23 and lockstitching is performed.If the clutch body 7 is set to the left position, S-edge stitching is performed in the same way, and if it is further set to the center position, the clutch body 7 is sewn. 7 is idle on the upper die shaft, and by bringing the roller (not shown) of the winding device into contact with the donut plate 23, the winding device can be driven.

In order to position the handle portion in the right, center, and left positions, the operating lever 28 has three recesses 38 that fit into projections (not shown) provided on the frame.

Instead of forming a recess in the operating lever, a convex portion may be provided and the convex portion may be fitted into a recess formed in the frame, but all of these means are well known and the details thereof will be omitted. do.

As described above, in this invention, since the pulley 8 is fixed in the axial direction, the timing belt 17, which is passed between the pulley and the motor pulley, will not tilt regardless of whether the pulley is switched or not.

In addition, this device can switch to a state where the unwinding device can be operated when sewing is stopped, in addition to lockstitching and edge S-stitching, and this switching operation is performed with a lever, so it is possible to As previously proposed by the applicant in U.S. Pat.

In addition, the clutch mechanism has an extremely simple structure because it consists of a clutch body that is moved in the axial direction by a lever and a pair of clutch plates that are disposed on both sides of the clutch body and that are removably engaged with the clutch body as the clutch body moves. It is.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a sewing machine according to the present invention, FIG. 2 is a sectional view of essential parts of the sewing machine, FIG. 3 is an exploded perspective view of the device shown in FIG. 2, and FIG. 4 is an explanatory diagram of operation. 1...Upper spindle, 4...Tatsuku upper axis, 7.
...Clutch body, 8...Pulley, 9.
...Spring, 10...Stepped pin, 12...
...Donut board, 13...Small hole, 15...
...Key, 16 ...Motor pulley, 1
7...Timing belt, 23...Clutch plate, 24...In hole, 2.8...
Operation lever.

Claims (1)

[Scope of utility model registration request] A clutch body 7 in the form of a flange tubular, which has a lockstitch mechanism and a hem mechanism, is integrally connected in the rotational direction with a pulley 8 that rotates in conjunction with a motor, and is slidably connected in the axial direction; The flange portion 72 of the clutch body is disposed on one side of the flange portion 72 on the same axis as the clutch body 7 so as to be rotatable while being restricted from axial movement, and is removably engaged with one side of the flange portion. Upper die shaft 1 in the lockstitch mechanism
a first clutch plate 23 for driving the flange, and a first clutch plate 23 which is rotatably arranged on the same axis as the clutch body on the same axis as the clutch body, and is rotatably arranged on the other side of the flange. a second clutch plate 2 for driving the lock upper shaft 4 in the overlocking mechanism which is removably engaged with the overlocking mechanism;
3, and an operating lever 28 that engages with the clutch body 7 and slides the clutch body in the axial direction by being driven by the operation of a handle member 31 provided protruding outside the sewing machine frame, By operating the handle member, the clutch body can be switched to three positions: a position where it engages with the first clutch plate, a position where it engages with the second clutch plate, and a neutral position where it does not engage with any clutch plate. A sewing machine that can perform two types of sewing, lockstitch and overedge stitch, with a single machine.