JPS5934386B2 - Selection drive device for balance in multi-needle sewing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention selects one of a plurality of needle bars attached to a movable frame by sliding the movable frame with respect to a fixed frame constituting one head. This invention relates to a lever selection drive device for a multi-needle sewing machine that performs embroidery and the like.

As is well known, this type of multi-needle sewing machine is usually equipped with a plurality of needle bars and a corresponding number of thread take-up levers.

As a means of driving these thread take-up levers, in particular those that convert the rotation of a cam into reciprocating rotation and utilize this action, although only one selected needle bar is driven. All of the balances are constantly driven.

This unnecessary drive of the balance causes vibration and noise, which has become a serious problem as work speeds have increased in recent years.

An object of the present invention is to provide a balance selection drive device that can solve the above-mentioned problems.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described in detail below according to embodiments shown in the drawings.

First, in one head of the multi-head sewing machine shown in FIG. 1, a camshaft 3 having a cam 2 is rotatably supported on a fixed frame 1 by a bearing 4.

Similarly, a base end portion of an arm 5 is rotatably supported by a shaft 7 on a part of the fixed frame 1.
A cam follower 6 that fits into the cam groove 2' of the cam 2 is attached to the tip of the arm 5.

Furthermore, a drive gear 8 is integrally attached to the shaft 7 of the arm 5.

In other words, as the cam 2 rotates, the drive gear 8 reciprocates in the direction of the arrow in FIG. 1 through the arm 5 and around the shaft 7 as a rotation fulcrum.

Further, a guide rod 9 is disposed in front of the cam 2 (to the left in FIG. 1), and the upper and lower ends of this guide rod 9 are integrally supported by the fixed frame 1. .

A needle bar holder 10 is attached to the guide bar 9 so as to be slidable in the vertical direction.

This needle bar holder 10 is connected to the cam 2 through a connecting arm 11.
It is designed to receive drive from the

That is, the needle bar holder 10 reciprocates in the vertical direction along the guide bar 9 by the rotation of the cam 2.

On the front side (left side in Figure 1) of the above fixed frame 1,
A movable frame 15 is provided so as to be able to slide along a rail 14 on the fixed frame 1 side.

As shown in FIG. 4, a plurality of needle bars 16 (six in the drawing) are arranged in a row on the movable frame 15.

Each of these needle bars 16 is slidably supported by the movable frame 15.

Of these needle bars 16, the needle bar 16a located most upwardly in the state shown in FIG. 4 has its retaining pin 17a engaged with the aforementioned needle bar holder 10 as shown in FIG. are doing.

The other engaging pins 17 of the needle bars 16 are engaged with the guide grooves 13 on the fixed frame 1 side, as shown in FIG.

That is, this guide groove 13 is formed in advance on the fixed frame 1 side over the maximum range of the movement stroke of the needle bar 16 accompanying the sliding operation of the movable frame 15, and only in the area where the needle bar holder 10 is located. It is cut out.

Further, on the upper surface of the movable frame 15, as shown in FIG. 4, a number of thread take-up levers 19 corresponding to the number of needle bars 16 described above are arranged in parallel.

Each of these balances 19 is rotatably supported by a pin 20 with respect to a supporting bracket 18, as shown in FIG.

Furthermore, a driven gear 21 is integrally attached to each balance 19.

Among these driven gears 21, as shown in FIG.
meshes with the drive gear 8 mentioned above.

The driven gears 21 of the other balances 19 are engaged with the positioning member 12 provided on the upper surface of the fixed frame 1, as shown in FIG.

This positioning member 12 is provided in advance over the maximum range of the movement stroke of the driven gear 21 accompanying the sliding operation of the movable frame 15, and is cut out only in the portion where the driving gear 8 is located, so that the positioning member 12 is a driven gear that meshes with the driving gear 8. The engagement of the gear 21a is released.

Further, this positioning member 12 engages with one unified tooth for each of the remaining driven gears 21 except for the driven gear 21a that meshes with the driving gear 8, and uniformly determines the standby posture of these balances 19. ing.

Next, selective driving of the needle bar 16 and the thread take-up 19 in one head of the multi-head sewing machine configured as described above will be explained.

It is now assumed that the movable frame 15 has been slid relative to the fixed frame 1, for example, to the position shown in FIG.

In this case, as described above, the engagement pin 17 of the needle bar 16a located at the uppermost position in FIG. 4 among the needle bars 16
a is engaged with the needle bar holder 10, and this needle bar 16a
The driven gear 21a of the balance 19a corresponding to 1 drive gear 8
(See Figure 1).

Therefore, when the cam 2 rotates, the arm 5
Through this, the drive gear 8 reciprocates in the direction of the arrow in FIG.

As a result, the above-mentioned balance 19a is driven by its driven gear 21a.
It performs reciprocating rotation (balancing action) around the pin 20 through the pin 20.

At the same time, as the cam 2 rotates, the needle bar holder 10 reciprocates along the guide bar 9 through the connecting arm 11 as described above.

Then, the above-mentioned needle bar 16a has its engagement pin 17a
The movable frame 15 reciprocates in the vertical direction in FIG. 1 through the movable frame 15.

In other words, the rotation of the cam 2 causes one needle bar 16a and the corresponding thread take-up 19a to perform their respective operations, thereby performing a predetermined sewing operation.

Next, by sliding the movable frame 15 along the rails 14 of the fixed frame 1, any needle bar from among the needle bars 16 is selected, and its engagement pin is engaged with the needle bar holder 10. If this is done, the corresponding driven gear of the balance will mesh with the drive gear 8 described above.

In this way, the needle bar and the corresponding thread take-up can be selectively driven.

The needle bars other than the one being driven are maintained in their standby posture by the guide grooves 13 of the fixed frame 1, as shown in FIG. 3, and the balance is maintained in its standby posture by the positioning member 12. ing.

Next, the embodiment shown in FIGS. 5 to 7 will be described.

In this embodiment, a movable frame 15 with respect to a fixed frame 1 is used.
This is an example in which the sliding operation is changed to a rotating operation centered on one point.

First, as shown in FIGS. 5 and 6, a ring-shaped guide member 14 is provided on the upper part of the fixed frame 1 in this embodiment.
A is added integrally with the fixed frame 1.

On the other hand, the upper plate 15' and lower plate 15'' of the movable frame 15 are formed in a fan shape as shown in FIGS. 6 and 7.

The upper plate 15' of the movable frame 15 is provided with a plurality (three in the drawing) of rollers 22 that rotate in contact with the outer peripheral surface of the guide member 14A.

In addition, the lower plate 15'' of the movable frame 15 is connected to the fixed frame 1.
On the other hand, it is rotatably supported by a pin 23.

The center of the guide member 14A and the axis of the pin 23 coincide, so that the movable frame 15 can be rotated around the center of the guide member 14A, that is, the axis of the pin 23. ing.

In addition, in connection with the rotation operation of the movable frame 15, the balance 19
are arranged as shown in FIG. 6, and the needle bars 16 are arranged as shown in FIG.

Furthermore, along with this, the positioning member 12 for the balance and the guide groove (not shown) for the needle bar shown in FIG. 5 are arranged in an arcuate shape.

In the embodiments shown in FIGS. 5 to 7 described above,
Components that are considered to have the same or equivalent configuration as those of the embodiment shown in FIGS. 1 to 4 described above will be designated by the same reference numerals in the drawings, and explanations of overlapping configurations and functions will be omitted.

In this way, in a type of needle take-up that uses a cam to drive the thread take-up, it is possible to select and drive only one thread take-up that corresponds to the needle bar that is being driven. Avoid vibration and noise caused by uncontrolled balance drive.
It is possible to speed up the work.

Furthermore, in the present invention, the standby posture of each balance other than when it is being driven is determined using the teeth of its driven gears, so that the standby posture can be accurately positioned, and the driven gears can also be easily engaged with and disengaged from the drive gear. It can be done smoothly.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a side sectional view of one head of a multi-head sewing machine, FIG. 2 is a sectional view of one of the thread take-up levers other than the one shown in FIG. 1, and FIG. is a sectional view showing one of the needle bars other than the one shown in FIG. 1, FIG. 4 is a top view of FIG. 1, FIG. 5 is a sectional view showing a head of a different embodiment, and FIG. The top view of the figure and FIG. 7 are sectional views taken along the line ■--■ in FIG. 1: Fixed frame, 2: Cam, 8: Drive gear, 12: Positioning member, 15: Movable frame, 16 Two-needle bar, 19:
Balance, 21: Driven gear.

Claims (1)

[Claims] 1 By sliding the movable frame with respect to the fixed frame that constitutes one head, one of the plurality of needle bars attached to the movable frame can be selected and driven, and the movable frame In a multi-needle sewing machine which is equipped with a number of thread take-up levers corresponding to each of the needle bars described above so as to be able to operate independently, the fixed frame has a mechanism that converts the rotation of the cam by a predetermined drive source into reciprocating rotation. A drive gear is provided, and this drive gear is disposed so as to mesh with a driven gear of a take-up lever corresponding to the needle bar to be selectively driven. A positioning member for the balance is provided over the maximum range of the movement stroke of each of the driven gears, and this positioning member is cut out in the portion where the drive gear is located, and is used for each of the balances other than those engaged with the drive gear. A selection drive device for a balance, characterized in that it is engaged with a driven gear.