JPH0236455Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a needle bar engagement/disengagement mechanism when skip stitching is performed in a zigzag sewing machine.

[Prior Art] Conventionally, when performing pattern stitching or basting stitching on a zigzag sewing machine, it is often necessary to perform so-called "skip stitching" (basting stitching) with a large stitching pitch. In order to disengage the needle bar at this time, conventionally, a unique needle bar engagement/disengagement swing solenoid is provided, and the needle bar is disengaged via a latch means, or a linear servo motor is used to disengage the needle bar. The needle bar was engaged and disengaged by swinging the needle bar outside the needle swing range for normal sewing.

FIG. 4 shows an exploded perspective view of essential parts of an example of a conventional needle bar disconnection mechanism. This figure is published in Japanese Patent Publication No. 58-183191.
In order to avoid duplication with cited documents, detailed explanations will be omitted and only the outline will be explained. The needle bar 22 is supported to reciprocate in the vertical direction within the needle bar gate 24.
Further, the upper bearing 26 of the gate 24 engages with the upper spherical socket 27 of the bracket 30 mounted on the sewing machine head, and the lower part of the gate 24 is arranged so that the needle bar 22 is moved laterally along the slot 33. It is constructed so that it can swing back and forth in a zigzag pattern.

The skip stitch mechanism is operated by driving the fingers 58 of the bracket 57 at the top end of the needle bar gate 24 by a solenoid (not shown), etc.
A latching member 44 mounted on the needle bar carrier 34
When the wedge 46 is removed from the notch 21 in the drive stud hinge pin 20 through the wedge 46, the cam finger 49, the drive stud 18, the drive stud hinge pin 20, etc., and the needle bar 22 is separated from the drive stud 18, the tension spring is released. Reference numeral 52 is for pulling up the needle bar 22 to its uppermost position.

[Problems to be solved by the invention] However, the conventional examples described above require a unique drive source such as a solenoid, which increases the cost and is also limited by the space inside the sewing machine. It was hot.

In addition, in the case of a mechanism that uses a linear servo motor for needle swing, engagement and disengagement are performed via a disengagement clutch by the rotation of the needle bar oscillating table itself. Since the needle bar is swung to a range outside the needle hole of the needle plate or the needle hole of the presser foot, there is a risk of the operator touching the workpiece cloth, and if the needle moves incorrectly, the needle will hit the throat plate and break. There were safety issues, including the risk of

The present invention was devised in view of the problems of the prior art as described above, and aims to provide a needle bar engagement/disengagement mechanism that is low in construction cost and has excellent safety.

[Means for solving the problem] Therefore, in the present invention, a disconnection link is provided which pivots on a rocking table that swings the needle bar in a zigzag manner, and is driven by a needle swing pulse motor. By connecting the swinging rods and applying a disconnection signal to the motor, via the outer swinging rod and the disconnection link,
The above object is achieved by activating a disconnection clutch means disposed between a needle bar fixing base and a needle bar clamp loosely fitted to the needle bar.

[Function] With the above-mentioned simple configuration, the needle bar can be operated at low cost without increasing the swing range of the needle bar.
The needle bar can be safely disengaged.

[Examples] The present invention will be described below based on Examples. FIG. 1 is a schematic side view of the essential parts of an embodiment of the needle bar disconnection mechanism according to the present invention, FIG. 2 is an explanatory diagram of the needle bar engagement and disconnection operation, and FIG. A partially cutaway perspective view is shown.

(Structure) In FIG. 1, F is a frame of a zigzag sewing machine, H is a head thereof, N is a sewing needle, 7 is a needle bar, and 6 is a throat plate. Further, M is a needle swing pulse motor. An arm Ma is fixed to the needle swing pulse motor M axis. On the other hand, the rocking table 2 that supports the needle bar 7 in vertical reciprocating motion swings around the pin 2a, and the needle N is moved back and forth in the needle swing section S of the pulse motor M axis by an input signal, as will be described later. The needle hole 6 is inserted through the swinging rod 5 and the detachable link 1.
It is configured to perform a reciprocating zigzag movement in a predetermined range in the lateral direction within a.

In the present invention, a detachable link 1 rotatably attached around a pin 3 is disposed on the oscillating table 2, and a oscillating table spring (tension coil spring)
4, one end of the link is biased so as to always come into contact with the stopper 8. On the other hand, a "<"-shaped swinging rod 5 is pivoted between pins 5b and 5a provided at a position close to the stopper 8 of the disconnection link 1 and at the tip of the oscillating pulse motor M-axis arm Ma, respectively. It is connected. The setting force of the rocking table spring 4 is sufficiently strong, and the rocking table 2 and the rocking rod 5 are normally configured to move together. In addition, in the figure, 13 is a stopper for limiting the swing range of the swing table 2 in one direction.

Next, in FIG. 3, 9 is a needle bar fixing base, 1
0 is a needle bar holder loosely fitted to the needle bar 7, and the needle bar fixing base 9 is held in a predetermined position by a needle bar position holding spring (tension coil spring) 14, while the needle bar fixing base 9 and the needle The bar holder 10 is the needle bar fixing base 9.
A torsion coil spring 12 constantly engages a protrusion 11a on the release clutch plate 11, which is pivotally connected to the top by a pin 9a, and a groove 10a carved in the protrusion on the needle bar holder 10. By biasing them so that they can move together.

Reference numeral 11b designates a pin protruding from the disengagement clutch plate 11, which is used to disengage the engagement between the disengagement link 1 and the disengagement link 1.

(Operation) Next, the operation of engaging and disengaging the needle bar in the above configuration will be explained. In Fig. 2, pulse motor M
When receiving the disconnection signal, the normal needle swing section S
, rotates to the cutting section T and reaches the B position. At this time, the rocking table 2 comes into contact with the stopper 13 at the A position, which is one end of the needle swing section S, and
Although it does not move any further, as the pulse motor M rotates toward the disconnection section T, the disconnection link 1 rotates to the position shown by the broken line, and the rocking platform spring 4 is extended. When the disconnection link 1 rotates,
As shown in FIG. 3, the top end of the link 1 comes into contact with the pin 11b of the disengagement clutch plate 11 and rotates the clutch plate 11 around the pin 9a, resisting the torsion spring 12 and engaging the protrusion 11a. The engagement with the groove 10a is disengaged, and the integral connection between the needle bar holder 10 and the needle bar fixing base 9 by the clutch means is released. As a result, the needle bar fixing base 9 is held at a fixed position by the spring 12, while the needle bar holder 10, which is loosely fitted to the needle bar 7, moves up and down along the needle bar 7. It is no longer transmitted to the needle bar 7.

(Function) Through the series of operations described above, it is possible to perform skip stitching by disengaging the needle bar 7 within the needle swing range S (within the throat plate needle hole range 6a). The needle oscillating pulse motor M is held at the cutting/disengaging position B only during the needle bar cutting/disconnecting period, and when it is desired to move the needle bar 7 up and down again, the motor M is rotated to the needle oscillating section S through a signal, and the needle bar 7 and the needle bar holder 10 are connected to each other.

[Effect of the invention] As explained above based on the examples,
According to the present invention, it has become possible to safely disengage the needle bar without exceeding a predetermined needle swing interval by using a needle swing pulse motor and with a simple configuration at low cost.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a main part of an embodiment of the needle bar disconnection mechanism of the present invention, FIG. 2 is an explanatory diagram of the needle bar engagement/disconnection operation, and FIG. FIG. 4 is an exploded perspective view of essential parts of an example of a conventional needle bar disconnection mechanism. DESCRIPTION OF SYMBOLS 1... Cut-off link, 2... Rocking stand, 5... Rocking rod, 5a, 5b... Pin, 7... Needle bar, 9...
Needle bar fixing base, 10...needle bar holder, 10a...slot, 11...disconnection clutch plate, 11a...protrusion, M...needle swing pulse motor, Ma...arm, S...needle swing section, T... Cutout section.

Claims (1)

[Scope of Claim for Utility Model Registration] A zigzag sewing machine equipped with a rocking table for swinging a needle bar by a needle swing pulse motor, comprising: a cut-off link rotatably disposed on the rocking table; and a cut-off link. and a swinging rod having both ends pivotally connected to an arm fixed on the needle swing pulse motor shaft, a needle bar fixing base fixed to the needle bar, and one end pivotally supported on the needle bar fixing base. , a cutout clutch plate having a protrusion formed on its tip; a needle bar holder loosely fitted to the needle bar; The groove is fixedly arranged at a distance from the needle bar fixing base, and as the disconnection link rotates to a predetermined position, the disconnection link comes into contact with the disconnection clutch plate,
A needle bar disconnection mechanism for a zigzag sewing machine that releases the engagement between the protrusion and the groove.