JPH07194887A - Needle bar raising device of sewing machine - Google Patents

Abstract

PURPOSE:To provide a needle bar raising device of sewing machine which can separate a needle bar from a main spindle and raise it upward over a throat plate when a sewing machine is started. CONSTITUTION:In a sewing machine for vertically moving a needle bar 16 by the rotation of a main spindle to a throat plate to sew a cloth on the throat plate, a separating means 12 for separating the needle bar 16 from the main spindle and raising it upward over the throat needle when a power source is ON is provided, so that the needle bar 16 can be separated from the main spindle by the separating means 12, only by turning ON the power source, raised, and stopped in the upper position, even when the needle bar 16 is stopped in any position over the throat plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a needle bar raising device for a sewing machine, which raises the needle bar above a needle plate when starting the sewing machine.

[0002]

2. Description of the Related Art As is well known, a sewing machine performs sewing by vertically moving a needle and feeding cloth horizontally. However, at the start of sewing, a needle bar for holding the needle is set to an upper position. The needle bar is raised, and then the needle bar is moved up and down to perform sewing. In order to raise the needle bar to the upper position, conventionally, the main shaft is manually rotated to raise the needle bar, or a switch or the like is operated to rotate the main shaft to raise the needle bar.

[0003]

However, when the needle bar is above the needle plate on which the cloth to be sewn is placed, whether the needle bar is in the ascending position or in the descending position. Since it is unclear whether or not it exists, if the main shaft is rotated to raise the needle bar, it will either rise as it is, or once descend below the needle plate and then rise. Therefore, if there is an obstacle at the needle drop position at the start of sewing,
When the needle bar descends due to the rotation of the main shaft, there is a problem that the obstacle is damaged and the needle itself is damaged such as broken needle.

The present invention has been made in view of the above circumstances, and can solve the above problems by raising the needle bar above the needle plate at the start of sewing, that is, at the time of starting the sewing machine. It is an object to provide a needle bar raising device.

[0005]

In order to achieve the above object, a needle bar lifting device for a sewing machine according to a first aspect of the present invention comprises a needle plate which is moved up and down with respect to a needle plate by rotation of a main shaft. In the sewing machine for sewing the upper cloth, when the power is turned on, the needle bar is detached from the main shaft and is provided with a detaching means for raising the needle bar above the needle plate.

According to a second aspect of the present invention, there is provided a needle bar lifting device for a sewing machine, wherein a needle bar is moved up and down with respect to a needle plate by rotation of a main shaft to sew a cloth on the needle plate. Detecting means for detecting the vertical position of the rod, determining means for determining whether or not the needle bar is above the needle plate, and cutting for raising the needle bar by cutting it off from the main shaft based on the determination of the upper position. It is provided with a removing means.

[0007]

In the needle bar lifting device for a sewing machine according to claim 1 of the present invention, no matter which position the needle bar is stopped above the needle plate, when the power is turned on, the needle bar is removed. By being cut off from the main shaft by the machine and rising and stopping at the upper position, damage to the obstacle itself at the needle drop position or damage to the needle itself such as needle breakage at the start of sewing is prevented.

In the needle bar lifting device for a sewing machine according to a second aspect, even if the needle bar is stopped above the needle plate, its position is automatically detected, and the disconnecting means is determined by the determination means. When the needle bar is actuated and cut off from the main shaft and rises and stops at the upper position, damage to the obstacle at the needle drop position and damage to the needle itself such as needle breakage at the start of sewing are prevented.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a needle bar lifting device for a sewing machine according to the present invention will be described below with reference to the drawings. The needle bar raising device of the sewing machine of the first embodiment is provided with a cutting-off means 12 for cutting off the needle bar from the main shaft and raising it above the needle plate when the power is turned on. First, the structure of the cutting-off means 12 will be described with reference to FIGS. In these drawings, reference numeral 15 indicates a needle bar rocking base. The needle bar swing base 15 swings the needle bar 16 in the horizontal direction, and is rotatably supported by a shaft 17 fixed to the sewing machine frame. A shaft 18 is fixed to a lower portion of the needle bar rocking base 15, and a middle part of a needle bar rocking rod arm 19 is rotatably supported on the shaft 18. This needle bar swing rod arm 19
An eccentric shaft 20 is fixed to the lower end of the needle bar, and the left end of a needle bar rocking rod 21 is rotatably connected to the eccentric shaft 20. Further, the needle bar rocking base 15 and the needle bar rocking rod arm 19 are respectively engaged with the ends of the needle bar rocking base springs 15b.

The right end of the needle bar swing rod 21 is rotatably connected to a shaft 22. The shaft 22 is formed on an arm 23a formed on a fan-shaped gear 23, and the gear 23 is rotatably supported by a shaft 24 fixed at a portion spaced downward from the shaft 22 by a predetermined distance. ing. A needle swing motor 25 is fixedly provided on the sewing machine frame on the right side of the gear 23, and the gear 23 of the needle swing motor 25 is meshed with the gear 26. The needle bar rocking base 15 is driven by the needle swinging motor 25 to rotate the gear 26 in the forward and reverse directions.
The needle bar swing rod 21 reciprocates laterally to move the needle bar swing rod arm 19
Reciprocally move in the same direction, and thereby swing about the shaft 17 as a fulcrum. In addition, this needle bar swing base 1
The rocking of No. 5 is usually rocking to the right of the lower end of the needle bar rocking base 15 within a range where it does not abut the stopper 27 fixed to the sewing machine frame.

Further, the needle bar rocking base 15 is formed with supporting portions 15a, 15a at the upper and lower ends thereof, and the needle bar 16 is vertically slidably inserted into these supporting portions 15a, 15a. ing. A needle 28 is inserted into and fixed to the needle bar 16, and a lower end portion of the needle 28 is projected from a lower end of the needle bar 16. Further, as shown in FIG. 2, a needle bar fixing base 30 is fixed to a substantially central portion in the axial direction of the needle bar 16 by a fixing screw 31, and the needle bar fixing base 30 and an upper end portion of the swinging base 15 are fixed. The upper and lower ends of the needle bar holding spring 32 are respectively locked to and, and the needle bar 16 is biased upward by the needle bar holding spring 32 via the needle bar fixing base 30.

Further, the needle bar 16 has a needle bar fixing base 30.
At the lower position, the needle bar holder 33 is vertically slidably inserted into the needle bar holder 33, and the needle bar holder 33 has an engagement recess 34 formed therein. On the other hand, one end portion (upper end portion) of a substantially L-shaped latch 35 is rotatably supported by a shaft 37 on the needle bar fixing base 30, and a latch pawl 35 at the lower end portion of the latch 35.
The needle bar holder 33 is fixed to the needle bar 16 by engaging a with the engaging recess 34.

A drive shaft (main shaft) 38 is provided to the right of the needle bar holder 33 so as to be rotatable about its axis by a drive motor (not shown). A flange portion 38a is formed at the tip of the drive shaft 38.
A shaft 39 is fixed to the outer peripheral part of the device by screws 40. One end of a crank rod 41 is rotatably supported on the shaft 39, and a connecting shaft 42 is rotatably inserted around and fixed to the other end of the crank rod 41. The needle bar holder 33 is attached to the tip of the connecting shaft 42.
The needle bar holder 33 is configured to move up and down via the crank rod 41 and the connecting shaft 42 by rotating the drive shaft 38. Therefore, when the latch pawl 35a is engaged with the engagement concave portion 34, the needle bar 16 moves up and down as the needle bar holder 33 moves up and down.

As shown in FIG. 4, a latch pin 35b is formed at the upper end of the latch 35, while a push rod capable of pressing the latch pin 35b is provided at the upper end of the swing rod arm 19. 43 is formed. Then, in the latch 35, when the swing rod arm 19 rotates counterclockwise about the shaft 18 as a fulcrum, the pressing rod 43 presses the latch pin 35b, and the latch pin 35b rotates clockwise about the shaft 37 as a fulcrum. , The latch pawl 35a is disengaged from the engaging recess 34, whereby the drive shaft 38 and the needle bar 16 are released.
It is designed to cut out and. The needle bar 16 has a drive shaft 3
When the connection with 8 is cut off, the needle bar holding spring 32 pulls it upward.

Further, the needle bar lifting device of the sewing machine of this embodiment is equipped with various devices as shown in FIG. That is, the control device 45 includes a microcomputer, ROM, RAM, I
It consists of an / O port, etc. Signals from an input device (key matrix) 46 and a spindle sensor 47 are input to the control device 45, and a display device 48, an embroidery machine 49 detachably attached to the sewing machine, a sewing machine spindle (the drive shaft 38) are provided. A signal is output to the rotating main motor 50 and the needle swing motor 25.

The input device 46, which can be operated by an operator, is an input device for operating the sewing machine, such as a selection key for selecting a pattern of embroidery using a memory card, a start switch, and the like. The main shaft sensor 47 detects the rotational phase of the main shaft 38 that is interlocked with the main motor 50, and detects the height of the needle 28 attached to the needle bar 16, and is usually composed of a sensor such as a photo interrupter. Cage, spindle 3
The needle bar position is detected by closing and opening the light emitting part and the light receiving part by a blocking plate attached to 8 at an intentional angle. There are three types of positions of the needle bar 16 with respect to the needle plate: an upper position, a lower position, and an intermediate position. In the embodiment, the needle bar upper position has a needle bar top dead center of 0 °,
Between 287 ° and 25 °, the needle bar lower position is also 85 ° to
During 287 °, the needle bar intermediate position indicates between 25 ° and 85 °, and the spindle sensor 47 detects these three types of positions. In addition to the above, a rotary encoder or the like may be used as the detection means 10.

The embroidery machine 49 has two stepping motors for driving the embroidery frame to move in the X and Y directions in a horizontal plane. While moving the hoop by these stepping motors, the needle 28 (needle bar 1
A predetermined embroidery pattern is applied to the cloth by moving 6) up and down, and the embroidery pattern is displayed on the display device 48. The needle swinging motor 25 constitutes a part of the disconnecting means 12 having the above-mentioned configuration, and by driving the needle swinging motor 25, the disconnecting means 1
2 is operated so that the needle bar 16 is cut off.

Next, the operation of the needle bar lifting device of the sewing machine having the above structure will be described with reference to FIG. First, when the power is turned on, the needle swinging motor 25 is driven in step S1 to disconnect the needle bar 16 from the main shaft 38 as follows. That is, since it is unknown at which angle the needle swing motor 25 is positioned when the power is turned on, the latch 35 drives the latch 35 sufficiently at any position to disengage the latch pawl 35a from the engaging recess 34. That is, in FIG. 1, the needle swing motor 25 is fully rotated counterclockwise. Then, the gear 23 rotates clockwise around the shaft 24 as a fulcrum, and the needle bar swing rod 21 moves to the right. As a result, the needle bar rocking rod arm 19 moves to the right, and accordingly, the needle bar rocking base 15 rotates counterclockwise about the shaft 17 as a fulcrum, and the lower end portion of the needle bar rocking base 15 moves. The tip of the supporting portion 15a of the above contacts the stopper 27.

When the needle bar rocking rod 21 further moves to the right, the needle bar rocking rod arm 19 rotates counterclockwise against the needle bar rocking base spring 15b with the shaft 18 as a fulcrum. Then, the pressing rod 43 of the vibration swing rod 19 presses the latch pin 35b of the latch 35 (see FIG. 4), and the latch pin 35
When b rotates clockwise about the shaft 37 as a fulcrum, the latch pawl 35a is disengaged from the engaging recess 34, and the drive shaft 38 and the needle bar 16 are disengaged.

Then, the needle bar holder 33 with which the latch 35 is engaged is not fixed to the needle bar 16, so that the needle bar 16 is held.
Becomes free, is pulled upward by the needle bar holding spring 32, and stops at the upper position, as shown in FIG. At this time, the drive of the main motor for rotating the main shaft 16 is stopped in step S2 until the needle bar 16 is raised.

After the needle bar 16 reaches the upper position,
In step S3, the main motor 50 is rotated to rotate the main shaft (driving shaft) 38, and the main shaft sensor 47 attached to the main shaft 38 detects the main shaft angle to detect the needle bar 16
Is detected to be in the upper position, the main motor 50
To stop. After that, in step 4, the needle swing motor 25 is rotated in the reverse direction to move the needle bar swing rod 21 to the left to engage the latch pawl 35a of the latch 35 with the engaging recess 34,
The ascending operation ends.

Therefore, according to the needle bar raising device for the sewing machine of the above-described embodiment, no matter which position the needle bar 16 is above the needle plate, the needle bar 16 can be pushed by pressing the needle bar raising switch.
Since the cutting-off means 12 raises and stops at the upper position, even if there is an obstacle at the needle drop position, the needle bar or the needle does not collide with the obstacle, so that damage to the obstacle or the needle is prevented. It is possible to prevent breakage of the needle itself.

Next, the needle bar raising device of the sewing machine of the second embodiment will be explained. In the present embodiment, the detection means 1 for detecting the vertical position of the needle bar 16 when the sewing machine power is turned on.
0, a determination means 11 for determining whether or not the needle bar 16 is located above the needle plate, and a cutting-off means 12 for cutting out the needle bar from the main shaft and raising it according to the determination of the upper position. ing.

That is, the spindle sensor 4 of the first embodiment.
7 constitutes the detection means 10. The spindle sensor 47 (detection means 10) detects the vertical position of the needle bar 16 by detecting the spindle angle, and sends this detection signal to the control device 45, and the control device 45 causes the position of the needle bar 16 to be detected. To judge. Therefore, the control device 45 constitutes the judging means 11 for judging whether or not the needle bar 16 is located above the needle plate, and when the needle bar 16 is above the needle plate, this judgment signal is sent to the needle. It is supplied to the swing motor 25 to operate the disconnecting means 12 to raise the needle bar 16 to the upper position in the same manner as in the first embodiment. When the needle bar 16 is below the needle plate, it does not collide with an obstacle, so the main shaft 38 is driven to raise the needle bar 16 to the upper position.

In the needle bar lifting device of the sewing machine of this embodiment, the damage of the needle itself such as the damage of the obstacle and the broken needle can be prevented as in the first embodiment, and the sewing machine power is turned on.
Only by doing so, there is an advantage that the position of the needle bar 16 can be automatically detected and the needle bar 16 can be cut off and raised.

7 and 8 show a third embodiment of the needle bar lifting device for a sewing machine according to the present invention. The needle bar lifting device for a sewing machine shown in these figures is different from that of the second embodiment. Since the points are a part of the configuration of the cut-off means 12, only this point will be described, the other common components will be denoted by the same reference numerals, and description thereof will be omitted. That is, in this embodiment, the solenoid 55 is used in place of the needle swing motor 25 as means for rotating the latch 35.

This solenoid 55 is the needle bar swing base 15
Of the solenoid shaft 55a is rotatably connected to the needle bar swinging rod arm 19 by a pin 56. Therefore, in this embodiment, as shown in FIG. 8, in the block diagram for controlling the operation of the sewing machine, the solenoid 55 is connected to the control device (determination means) 45, and the needle bar 16 is positioned above the needle plate. When it is in the position, the solenoid 55 is actuated, that is, the solenoid shaft 55a is pulled in, so that the needle bar swing rod arm 1
9 is pulled and rotates counterclockwise about the shaft 18 as a fulcrum, and the latch 35 is disengaged from the engaging recess 34 and the needle bar 16 is lifted and stopped at the upper position in the same manner as in the first embodiment. It is supposed to do.

Therefore, the needle bar lifting device for the sewing machine of this embodiment has the advantage that the number of parts is smaller than that of the second embodiment and the cost of the device itself is low. Of course, it is possible to obtain the same effects as those of the second embodiment.

[0029]

As described above, according to the first aspect of the present invention.
According to the needle bar lifting device of the sewing machine, when the power is turned on,
The needle bar is detached from the main shaft and provided with a disconnecting means for raising it above the needle plate.Therefore, even if the needle bar is stopped at any position above the needle plate, the needle bar will be turned on when the power is turned on. Since it is cut off from the main shaft by the cutting-off means and rises and stops at the upper position, even if there is an obstacle at the needle drop position, the needle bar or the needle does not collide with it, so that It is possible to prevent damage to the needle itself such as damage or broken needle.

According to the needle bar raising device of the sewing machine of the second aspect, when the power is turned on, the detecting means for detecting the vertical position of the needle bar and whether the needle bar is above the needle plate or not. Since it is equipped with a judging means for judging whether or not the needle bar is cut off from the main shaft and lifted by judging the upper position, even if the needle bar is stopped above the needle plate, it is automatically cut. The position is detected, the disconnecting means is activated by the determination of the determining means, the needle bar is disconnected from the main shaft, rises and stops at the upper position, so even if there is an obstacle at the needle drop position,
The needle bar or needle does not collide with this, so
It is possible to prevent damage to the obstacle and damage to the needle itself such as broken needle.

[Brief description of drawings]

FIG. 1 is a side view showing a needle bar raising device for a sewing machine according to a first embodiment of the present invention.

FIG. 2 is a side view showing an engaged state of a needle bar holder and a latch in the first embodiment.

FIG. 3 is a side view showing a state where the latch and the needle bar holder are disengaged in the first embodiment.

FIG. 4 is a side view showing an engaged state of a latch and a needle bar swing rod arm in the first embodiment.

FIG. 5 is a block diagram for controlling the operation of the embroidery sewing machine in the first embodiment.

FIG. 6 is an operation flow chart for detecting the origin of the hoop according to the first embodiment.

FIG. 7 is a side view showing a needle bar avoidance device for an embroidery machine according to a third embodiment of the present invention.

FIG. 8 is a block diagram for controlling the operation of the embroidery sewing machine in the third embodiment.

[Explanation of symbols]

 10 Detecting Means 11 Judging Means 12 Cutting-off Means 15 Needle Bar Swing Base 16 Needle Bar 19 Needle Bar Swing Rod Arm 21 Needle Bar Swing Rod 25 Needle Swing Motor 32 Needle Bar Holding Spring 33 Needle Bar Holder 34 Engagement Recess 35 Latch 38 Spindle 45 Control device (determination means) 47 Spindle sensor (detection means) 55 Solenoid

Claims (2)

[Claims] 1. A sewing machine for sewing a cloth on a needle plate by moving a needle bar up and down with respect to a needle plate by rotating a main shaft, and when the power is turned on, the needle bar is cut off from the main shaft to A needle bar lifting device for a sewing machine, which is provided with a disconnecting device for lifting the plate. 2. A sewing machine for sewing a cloth on a needle plate by moving the needle bar up and down with respect to a needle plate by rotation of a main shaft to detect the vertical position of the needle bar when the power is turned on. Means, a determining means for determining whether or not the needle bar is located above the needle plate, and a disconnecting means for disconnecting and raising the needle bar from the main shaft according to the determination of the upper position. Characteristic sewing machine needle bar lifting device.