JPH1015268A - Sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent entangling of needle thread or looper thread with a hand wheel, with the operation of the hand wheel enabled kept intact and without remodeling the sewing machine itself. SOLUTION: A top cover 1, which covers a machine arm A and a stand part C, is extended toward the side of the stand C to form a wheel cover 7a which covers from the top a hand wheel 3 attached to the side of the stand C. Thus, a dangling needle thread 4a or a looper thread 4b are prevented from touching the hand wheel 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine in which a handwheel operated to move a movable portion including a needle is attached to an end of an upper shaft for transmitting a needle incorporated in a sewing machine arm. About.

[0002]

2. Description of the Related Art Flat stitch sewing machines and double chain stitch sewing machines are
A needle is provided at the tip of a sewing machine arm supported on the sewing machine bed, and a looper is provided inside the sewing machine bed corresponding to the needle drop position of the needle. With the above operation, sewing is performed with the needle thread held by the needle and the looper thread held by the looper.

The needle moves up and down by a predetermined stroke which reaches the inside of the sewing machine bed at the time of downward movement, and the looper includes a needle drop position halfway in a direction crossing the feed of the sewing material on the sewing machine bed. A predetermined stroke advance / retreat operation (leftward and rightward retraction) is performed, and the sewing captures a loop of the needle thread remaining at the tip of the needle at the time of switching from downward movement to upward movement by the leftward movement of the looper. Further, in the transition from leftward to rightward retreat, the order in which the loop of the looper thread remaining at the tip of the looper is captured by the downward movement of the needle is repeated.

FIG. 3 is a perspective view showing the appearance of the flat stitch sewing machine. As shown in this figure, the flat stitch sewing machine has its base end supported by a leg C erected on a sewing machine bed B, and is located at an appropriate distance from the upper surface of the sewing machine bed B.
The sewing machine includes a sewing machine arm A extending substantially in parallel.

[0005] A needle bar 10 and a presser bar 20 are hung down at the end of the sewing machine arm A.
The presser foot 2 is attached to the lower end of the presser bar 20, and the needles 1, 1... Move up and down according to the rotation of the upper shaft built in the sewing machine arm A. At the tip of the sewing machine bed B, a looper and a feed mechanism (not shown) are provided at a lower position (needle drop position) of the needles 1, 1,..., And these are lower shafts built in the sewing machine bed B. It operates according to the rotation of.

The insides of the sewing machine arm A, the sewing machine bed B and the leg C are hollow, and the upper shaft and the lower shaft extend inside the sewing machine arm A and the sewing machine bed B along the respective longitudinal directions. , Inside the legs C, are connected by a transmission means such as a timing belt. The ends of the lower shaft and the upper shaft protrude appropriately from the side surface of the leg C. The former is connected to an output end of a sewing machine motor (not shown), and the latter is provided with a handwheel 3.

[0007] The lower shaft and the upper shaft are rotated by transmission from the sewing machine motor, and the stylus corresponding to the rotation of the upper shaft.
The vertical movement of 10, 10,... And the operation of the looper and the feed mechanism in accordance with the rotation of the lower shaft occur in synchronism with each other.
The sewing material clamped between the upper surface of the
Are sewn by the needle thread 4a set at 0, 10... And the looper thread 4b set at the looper, respectively.

The needle thread 4a, 4a... And the looper thread 4b are tensioned by a thread tensioner 4 arranged on the front surface of a leg C supporting the base end of the sewing machine arm A. The thread tensioner 4 includes a plurality of needle thread adjusting knobs 40, 40 ... corresponding to the needles 1, 1 ... and one looper thread adjusting knob, respectively, on a long board fixed to the front surface of the leg C. 41, and has a well-known structure for adjusting the elastic contact pressure between each pair of thread clamp plates provided on the respective base portions by these rotation operations.

The needle threads 4a, 4a,...
After passing between the thread clamp plates 0, 40..., It is guided to the upper end of the needle bar 10 through a thread path set along the front surface of the sewing machine arm A, and further along the front side of the needle bar 10. The needles are guided downward and set in a state where they pass through the thread holes at the tips of the needles 1, 1,.
After passing the looper thread 4b between the thread clamp plates of the looper thread adjusting knob 41, the looper thread 4b is guided to the inside of the sewing machine bed B and set on the looper at the end of the sewing machine bed B. This set state is schematically indicated by a dashed line in the figure.

The needle threads 4a, 4a,.
When the needles 1, 1,... Are moved downward, the needle thread adjusting knobs 40, 40,.
Is pulled out by the operation of the looper against the clamping force of the looper thread adjusting knob 41 between the thread catching plates, and at this time, a tension according to the degree of elastic contact of each thread catching plate is applied, The seams formed on the sewn fabric are tightened.

The handwheel 3 attached to the projecting end of the upper shaft is provided so that the upper shaft and the lower shaft can be manually rotated by gripping and rotating the handwheel. This operation is convenient for repairing various inconveniences such as breakage of the needle thread 4a, 4a... Or looper thread 4b, breakage of the needles 1, 1,. , A movable part such as a looper is moved to a good position. In some sewing machines, the rotation operation of the hand wheel 3 is used for other purposes, such as changing the pitch of a stitch formed on the sewing material.

[0012]

In the flat stitch sewing machine constructed as described above, the needle thread 4a, 4a... And the looper thread 4b are pulled out from a spool (not shown) and passed through the thread tensioner 4 as described above. These spools do not interfere with the operation of the thread tensioner 4 for adjusting the tension and the operation of the hand wheel 3 for manually rotating the upper and lower shafts. In order not to hinder sewing on the bed B, it is generally installed at the upper rear side of a leg C that supports the base end of the sewing machine arm A, and needle threads 4a, 4a,. The looper thread 4b is set on the thread tensioner 4 so as to cross over the leg C.

However, since no tension is applied to the needle thread 4a, 4a... And the looper thread 4b from the thread winding to the thread tensioner 4, they hang down during the sewing operation performed as described above. Leg C and sewing machine arm A located at
May come into contact with the upper surface of the
There is a danger that the handwheel 3 may get into a small gap between the side surface of the handwheel 3 and the handwheel 3 protruding from the side surface and be wound around the upper shaft to which the handwheel 3 is attached and cut.

In this state, the entangled needle thread
.. Or the looper thread 4b, and the work of resetting the needle thread 4a, 4a... And the looper thread 4b newly drawn from the thread winding becomes necessary, which causes a problem of lowering the working efficiency. Further, the needle thread 4a wound around the upper shaft,
4a ... or the looper thread 4b may remain without being completely removed. In this case, the remaining thread enters the bearing that supports the upper shaft, and the rotation of the upper shaft is hindered, forcing disassembly and repair. There was even fear.

In order to prevent such entanglement, conventionally, as shown in FIG. 4, a circular recess 5a surrounding the protruding portion of the upper shaft 5 is formed on the side surface of the leg C, and the recess 5a is formed in the recess 5a. An attachment structure of the handwheel 3 in which the base is fitted is adopted. Reference numeral 7 in the figure denotes an upper cover that covers the legs C and the upper portions of the sewing machine arm A, and is removably attached over substantially the entire length of the sewing machine arm A as shown in FIG.

According to this configuration, the gap between the recess 5a and the handwheel 3 is bent in a U-shape as shown in the figure, so that the needle thread 4a, 4a. The entry of the looper thread 4b can be prevented, and the above-described problem can be reduced. However, in this configuration, the leg C
Requires a sewing machine body having a recess 5a formed on the side surface of the sewing machine, which requires extra man-hours for machining the recess 5a, and is difficult to apply to a sewing machine already in use.

Further, in order to prevent the above-mentioned entanglement, a separate cover for covering the entire handwheel 3 serving as a rotating portion can be attached. Such a cover is a sewing machine in which the rotational force of the sewing machine motor is directly transmitted to the upper shaft via a belt, and for the purpose of preventing fingers from being caught in the belt, Japanese Utility Model Publication No. 54-38463. JP-A-55-25039, JP-A-63-46083, JP-A-2-29671, JP-A-6-23187, and JP-A-6-36588.

However, in the case of the interlock stitch sewing machine, as described above, the transmission from the sewing machine motor is controlled by the sewing machine bed B.
The internal shaft is transmitted to the lower shaft, and the transmission to the upper shaft is performed via a transmission means such as a timing belt wound around the lower shaft inside the leg portion C. Of the sewing machine motor and the belt wound around the projecting end of the lower shaft will be attached to the handwheel 3 attached to the handwheel 3 attached to the projecting end of the upper shaft. 4a ... or looper thread 4b cannot be prevented from being involved. When a similar cover is attached so as to cover the handwheel 3, the handwheel 3 for manual rotation of the upper and lower shafts or adjustment of the stitch pitch is used.
May be disturbed.

The present invention has been made in view of such circumstances, and it is possible to wind a needle thread or a looper thread into a hand wheel without changing the sewing machine main body while enabling the operation of the hand wheel. An object of the present invention is to provide a sewing machine having a configuration capable of preventing the sewing machine.

[0020]

A sewing machine according to the present invention comprises:
A thread tensioner is provided at the front of a leg supporting the base end of a sewing machine arm having a built-in upper shaft for transmission to a needle on a sewing machine bed, and a handwheel is provided at a protruding end of the upper shaft on a side surface of the leg. A sewing machine having a hand wheel for manually operating a movable portion including the needle, and for adjusting a tension of a needle thread and a looper thread by operating the thread tensioner, wherein the leg of the hand wheel is provided. A wheel cover that covers a side close to the side surface of the section from above and prevents a needle thread or a looper thread supplied to the thread tensioner from contacting the hand wheel.

In the present invention, the side (base end side) near the side surface of the leg of the hand wheel is covered by the wheel cover from above, and the needle thread or looper thread hanging down from above comes into contact with the wheel cover, Since the needle thread or the looper thread does not come into direct contact with the base end of the wheel, there is a risk that these needle threads or looper threads may be caught by the upper shaft projecting from the side face of the leg through the gap between the side face and the hand wheel. Without
The occurrence of yarn breakage due to the winding is prevented beforehand. Further, the wheel cover does not hinder the operation of the hand wheel performed by gripping the tip side (the side away from the side surface of the leg) of the hand wheel.

Further, the wheel cover is characterized in that an upper cover for covering the legs and the upper portion of the sewing machine arm is extended toward the hand wheel.

In the present invention, the wheel cover is formed by extending the upper cover which is originally required to cover the upper side of the sewing machine arm and the leg. The upper cover can be used as a common part for a sewing machine having a sewing machine arm and a leg part having different shapes according to specifications, and can configure a wheel cover without forcing a remodeling of a main body. Application is possible only by replacing the upper cover.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing the embodiments. FIG. 1 is a perspective view showing an appearance of a main part of a sewing machine according to the present invention, and FIG. 2 is a longitudinal sectional view of the same.

In the illustrated sewing machine, a plurality of needles 1 are attached to a lower end of a needle bar 10 which is hung on a distal end of a sewing machine arm A whose base end is supported by a leg C provided on a sewing machine bed B.
Are attached, and a presser foot 2 is attached to the lower end of the presser bar 20, and a looper and a feed mechanism (not shown) are arranged inside the front end side of the sewing machine bed B facing below the needles 1, 1. This is a flat-stitch sewing machine. FIG.
And FIG. 2 shows a leg C supporting the base end of the sewing machine arm A.
Are shown, and the needle bar 10, the needles 1, 1,..., The presser bar 20, and the presser foot 2 are not shown.
This is similar to the conventional flat stitch sewing machine shown in FIG.

As shown in FIG. 2, the inside of the sewing machine arm A, the sewing machine bed B and the leg C are hollow, and the upper shaft 5 is inside the sewing machine arm A, and the inside of the sewing machine bed B is inside. The lower shafts 6 are supported so as to be rotatable around respective longitudinal axes. The lower shaft 6 protrudes from one side of the sewing machine bed B to the outside, and a pulley 60 fitted to the protruding end.
Is connected to an output end of a sewing machine motor (not shown) via a transmission belt V wound around the shaft C. The upper shaft 5 and the lower shaft 6 are fitted to respective corresponding positions inside the leg C. Are connected to each other by a timing belt V ₁ wound between the belt pulleys 51 and 61.

The upper shaft 5 and the lower shaft 6 rotate synchronously around the respective shafts by the transmission from the sewing machine motor, and the needles 1, 1,... The needle bar 10 moves up and down a predetermined stroke in accordance with the vertical movement of the needle bar 10 in accordance with the rotation of the upper shaft 5, and the looper and the feed mechanism inside the sewing machine bed B rotate the needles 1, 1 in accordance with the rotation of the lower shaft 6.
Perform a predetermined operation synchronized with the vertical movement of.

The vertical movement strokes of the hands 1, 1,... Are set so as to reach the inside of the sewing machine bed B when the hands are moved down, and the operation of the looper is performed by moving the hands 1, 1,. (Retreat position) in the longitudinal direction of the sewing machine bed B including the middle position (falling position)
It is.

A sewing cloth (not shown) is sandwiched between the upper surface of the sewing machine bed B and the presser foot 2, and
By the operation of the internal feed mechanism, a predetermined feed is given in a direction substantially perpendicular to the operation direction of the hands 1, 1... And the looper, respectively. Are sewn by the needle threads 4a, 4a set on the needles 1, 1,... And the looper thread 4b set on the looper.

Upper shaft 5 supported inside sewing machine arm A
Is protruded from one side surface of the leg C supporting the base end of the sewing machine arm A to the same side as the lower shaft 6 beyond the supporting portion by the bearing 50. Is attached. The handwheel 3, which rotated the upper shaft 5 by rotation operation by gripping a needle 1,1 ... with vertically moves the front end side of the sewing machine arm A, the upper shaft 5 and the timing belt V ₁ The lower shaft 6 is connected to the sewing machine B to rotate the lower shaft 6 and operate the looper and the feed mechanism on the leading end side of the sewing machine bed B. This operation is performed by, for example, the needle thread 4a, 4a.
When various inconveniences occur during sewing work, such as thread breakage of the needles, breakage of the needles 1, 1,..., Malfunction of the looper, etc., move the movable parts such as the needles 1, 1,. It is done to move.

Further, the handwheel 3 of the sewing machine shown in FIG.
Are mechanically connected to the transmission system to the upper shaft 5 inside the leg C, and the stitches formed on the sewn fabric as described above by an operation different from manual operation of the needles 1, 1,. You can also change the pitch. As shown in FIG. 1, a plurality of graduation lines 3a, 3a,
3a are formed, and a pointer 30 is attached to the upper side of the leg portion C so as to be able to be viewed from the front with the graduation lines 3a, 3a, and the stitch pitch is changed by operating the hand wheel 3. Can be easily performed from the front side by setting desired scale lines 3a, 3a.

The upper sides of the sewing machine arm A and the leg C are provided over substantially the entire surface for inspection and adjustment of a connecting portion between the upper shaft 5 supported inside and the movable portions such as the lower shaft 6 and the needle bar 10. The opening is provided with a flat upper cover 7. The edge of the upper cover 7 on the side of the leg C is extended so as to project to the same side as shown in FIGS. 1 and 2 to form a wheel cover 7a which covers the base end side of the hand wheel 3 from above. ing.

As shown in the drawing, the wheel cover 7a is formed so as to cover a region where the front end side of the hand wheel 3 (the side distant from the side surface of the leg C) is appropriately extended over substantially the entire width. Thus, the base end of the handwheel 3 and the leg C
The upper part of the gap formed with a width δ (see FIG. 2) between itself and the side surface of the handwheel 3 is completely covered, and the needle 1, 1,. Also, there is no hindrance to the manual operation of the looper and the operation of changing the stitch pitch.

The needle thread 4a, 4a... And the looper thread 4b are tensioned by a thread tensioner 4 disposed on the front surface of the leg C. The thread tensioner 4 is provided with a plurality of needle thread adjusting knobs 40, 40,... Corresponding to the needles 1, 1,. With knob 41, by these rotation operation,
It has a well-known configuration for adjusting the elastic contact pressure between each pair of thread clamp plates provided at each base.

The needle thread 4a, 4a... And the looper thread 4b are respectively pulled out from a thread spool (not shown) arranged on the rear side of the leg C,
After being guided to the thread tensioner 4 across the upper part of the sewing machine arm A, the needle thread 4a, 4a... Is passed between the thread clamp plates of the respective needle thread adjusting knobs 40, 40. 3 and is guided to the upper end of the needle bar 10 through a thread path set along the sewing machine arm A, and further downward along the front side of the needle bar 10 as shown in FIG. Each of the needles 1, 1... Is set in a state of being passed through a thread hole at the tip. The looper thread 4b is
After passing between the thread clamp plates of the looper thread adjusting knob 41, the thread is guided to the inside of the sewing machine bed B through the thread hooking portion 42 fixed to the lower front surface of the leg C, and is passed through the looper at the tip of the sewing machine bed B. Set.

The needle threads 4a, 4a,.
When the needles 1, 1,... Are moved downward, the needle thread adjusting knobs 40, 40,.
Is pulled out by the operation of the looper against the clamping force of the looper thread adjusting knob 41 between the thread catching plates, and at this time, a tension according to the degree of elastic contact of each thread catching plate is applied, The seams formed on the sewn fabric are tightened.

A needle thread 4a, 4a... And a looper thread 4b
Is provided on the rear upper portion of the leg C that supports the base end of the sewing machine arm A, as described above.
a, 4a... and the looper thread 4b are connected to the sewing machine arm A and the leg C.
Are set on the thread tensioner 4 across the upper part of the sewing machine. However, since no tension is applied to the upstream side of the thread tensioner 4, these are suspended on the upper surfaces of the sewing machine arm A and the leg C. Due to the action of the external force (wind force or the like) in the state, it may flow toward the handwheel 3 arranged on one side surface of the leg C.

The sewing machine according to the present invention is provided with a wheel cover 7a formed by extending the upper cover 7 of the sewing machine arm A and the leg C as described above, and the wheel cover 7a extends from the base end of the hand wheel 3 from above. Covering. Therefore, even when the needle thread 4a, 4a... Or the looper thread 4b hanging on the upper surfaces of the sewing machine arm A and the leg C flows to the hand wheel 3 as described above, at least the base end side of the hand wheel 3 is required. And there is almost no possibility of entering the gap between the base end of the hand wheel 3 and the side surface of the leg C, and the needle thread 4a, 4a... Or the looper thread 4b is wound around the upper shaft 5. Can be prevented beforehand.

Since the wheel cover 7a covers the upper portion of the hand wheel 3 except for the front end side, the above-described operation performed by gripping the front end side of the hand wheel 3 does not interfere. . Further, the wheel cover 7a
Is formed by extending the upper cover 7 that covers the upper openings of the sewing machine arm A and the leg portion C.
By changing the shape of the above, it can be realized without adding parts.

As shown in FIG. 1, the upper cover 7 is screwed on both sides in the width direction with a pair of set screws 7b, 7b at a plurality of locations in the longitudinal direction, and is detachably attached to the upper surface of the sewing machine arm A. It is a plate-shaped member and can be used as a common component for a plurality of types of sewing machines having different shapes of the main body housing including the sewing machine arm A and the leg C. Thus, FIG.
In addition, in the sewing machine shown in FIG. 2, by slightly changing the shape of the upper cover 7, a wheel cover 7 a that can be commonly used for many sewing machines is obtained, and the needle thread 4 a, 4 a. It is possible to prevent entanglement and the occurrence of thread breakage due to the entanglement, and the present invention can be applied to a sewing machine that is already in use only by replacing the upper cover 7.

It is desirable that the wheel cover 7a is formed by extending the upper cover 7 and integrally formed with the upper cover 7. However, a separate flat plate is fixed to the side surface of the leg C by an appropriate fixing means such as screwing. Alternatively, it may be configured to be fixed to the end face of the upper cover 7. Also in this configuration, the wheel cover 7a needs to cover the upper portion of the hand wheel 3 with an excess of the distal end side of the hand wheel 3, so that the needle thread
.. Or the looper thread 4b can be prevented from being wound around the upper shaft 5 without disturbing the operation of the hand wheel 3 for adjusting the stitch pitch.

In the above embodiment, an example of application to a flat stitch sewing machine has been described. However, in the present invention, a handwheel 3 for adjusting the transmission to the upper shaft 5 is provided at the end of the upper shaft 5. With a needle thread 4 across the top of the handwheel 3.
Needless to say, the present invention can be applied to general sewing machines configured to supply a, 4a, and / or the looper thread 4b.

[0043]

As described above in detail, in the sewing machine according to the present invention, the side near the side surface of the hand wheel leg attached to the projecting end of the upper shaft from the side surface of the leg is covered from above by the wheel cover. Therefore, the needle thread or the looper thread hanging from the upper side does not directly contact at least the base end side of the handwheel, and the occurrence of thread breakage due to the needle thread or the looper thread being wound around the upper shaft beforehand. This prevents the need for resetting the needle thread or the looper thread due to thread breakage, thereby contributing to an improvement in work efficiency, and does not hinder the operation of the handwheel.

Further, the wheel cover is constructed by extending the upper cover for covering the upper side of the sewing machine arm and the leg supporting the base end thereof to the side of the hand wheel, so that the above-mentioned wheel cover is not required to add new parts. The effect is obtained,
The present invention has an excellent effect such that a sewing machine that is already in use can be dealt with only by replacing the upper cover.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an appearance of a main part of a sewing machine according to the present invention.

FIG. 2 is a longitudinal sectional view of a main part of the sewing machine according to the present invention.

FIG. 3 is a perspective view showing an appearance of the flat stitch sewing machine.

FIG. 4 is an explanatory view of a conventional entanglement prevention measure.

[Description of Signs] 3 Hand wheel 4 Thread tensioner 4a Needle thread 4b Looper thread 5 Upper shaft 6 Lower shaft 7 Upper cover 7a Wheel cover A Sewing arm B Sewing bed C Leg

Claims (2)

[Claims] 1. A thread tensioner is provided in front of a leg supporting a base end of a sewing machine arm on a sewing machine bed, which incorporates an upper shaft for transmission to a needle, and an upper shaft is mounted on a side surface of the leg. A sewing machine provided with a hand wheel at a protruding end thereof so that manual operation of a movable portion including the needle can be performed by the hand wheel, and tension adjustment of a needle thread and a looper thread can be performed by operating the thread tensioner. A sewing machine, comprising: a wheel cover that covers a side of the hand wheel near the side surface of the leg from above, and prevents a needle thread or a looper thread supplied to the thread tensioner from contacting the hand wheel. 2. The sewing machine according to claim 1, wherein the wheel cover is configured such that an upper cover that covers the legs and an upper portion of the sewing machine arm is extended toward the hand wheel.