JP3355115B2 - Embroidery machine or lower thread spool replacement device for sewing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for replacing a lower thread spool in a looper of an industrial embroidery machine or a sewing machine driven via a looper shaft.

[0002]

2. Description of the Related Art In each embroidery machine or sewing machine, as is known, a lower thread spool is removed from a looper and a new thread is used when the lower thread is exhausted and the spool is empty or when the lower thread breaks during the embroidery or sewing process. Must be replaced by a new spool. The replacement axis is performed only when the machine stops. The stoppage is generally automatic and takes place via a lower thread monitor or a lower thread detector. However, with a standard bobbin spool having a normal rotational speed of 700 RPM and a yarn length of about 100 m, the bobbin thread disappears after about 45 minutes.

The required replacement of an empty lower thread spool when the machine is stopped requires only approximately 5 to 8 seconds for a trained person. This stop time is important for industrial embroidery machines, because it usually stops 12 to 20 embroidery heads operating at the same time as soon as one of the embroidery heads finishes the bobbin thread. Because it has. In a machine with 20 heads, approximately three minutes of production time are lost per working hour due to the required periodic replacement of all lower thread spools.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to create a device for the replacement of a lower thread spool which significantly reduces the downtime of the machine and the resulting production losses.

[0005]

SUMMARY OF THE INVENTION In accordance with the present invention, an object of the present invention is to provide a carriage having at least two clutch shafts oriented parallel to a looper shaft, each of the clutch shafts being a looper. A looper is provided at the end facing the shaft, and the end facing the looper shaft is provided so that when the looper shaft stops, the carriage is perpendicular to the looper shaft and parallel to the throat plate plane. The problem is solved by being reversibly movable by the distance of the axis and being connectable to the looper.

In the replacement device proposed according to the invention, the embroidery head or the sewing head or each embroidery head is provided with at least two loopers with a lower thread spool filled at the start of production. One of each of these loopers is in a working position which supplies a bobbin thread for an embroidery machine or sewing machine as usual. Other loopers are still stopped and in the park position. When the thread storage of the lower thread spool is exhausted in the first looper or the thread breaks, the machine keeps its state. Instead of replacing the empty bobbin spool of the looper with a full bobbin spool as in the conventional case, the carriage is moved until another looper that has been waiting up to that time comes to its working position. This replacement process requires less than one second for each head. The machine can then immediately start again. In the running machine, the empty bobbin spool of the looper in the standby position is then replaced with a full bobbin spool without primary pressing. This replacement process is repeated many times when the lower thread is used up.

In a typical multi-head embroidery machine where most of the heads embroider the same pattern, the bobbin spool of one of the heads is exhausted, so that as soon as the machine stops, the bobbin thread of all the heads It is recommended that the spool be replaced at the same time. This is because, after approximately one second, restarting all the machines with the full bobbin thread spools generally requires a small amount of bobbin thread storage to be used for each individual spool in this position, and thus a number corresponding to the number of heads This is because it is more economical than accepting the downtime of the machine.

In a preferred embodiment of the changer, the looper shaft has a transverse groove which is oriented parallel to the direction of movement of the carriage when the looper shaft stops, and each of the clutch shafts can be fitted in the transverse groove. It has a driver with a wedge portion. This embodiment is in a state where the industrial embroidery machine or sewing machine and hence its looper shaft is not arbitrary but rather stops at a precisely specified position.

According to a preferred configuration of this embodiment,
The lateral grooves and / or wedge portions have an entry taper. This allows a secure connection of each clutch shaft with a looper shaft that drives even with tight tolerances between the transverse groove at the end of the looper shaft and the wedge portion of each clutch shaft. On the other hand, as described above, when the machine is stopped, the position of the looper shaft is accurately fixed, and the clutch shaft of each looper in the standby position is moved from the position required for the clutch process during the replacement of the lower thread spool, for example. It may be twisted unexpectedly. Therefore, in particular, in the preferred embodiment of the clutch device, it is reasonable that the clutch shaft is provided with an effective torsion prevention portion at the disengaged position.

As noted above, instead of the looper shaft having the transverse groove and the clutch shaft having the wedge portion, the reverse configuration is also possible. However, the preferred embodiment here has the advantage that the anti-twist for the clutch shaft can be formed at the height of the wedge as a simple sliding path parallel to the movement of the carriage. For sufficiently accurate guidance of the carriage, there are possibilities known in principle to the person skilled in the art.
Profiled rails have been demonstrated for this purpose.

Generally, the carriage has a driving device driven by an electric motor. A rotary or linear standard drive, preferably combined with an incremental process sensor, is considered, wherein the process sensor stops at a predetermined position, with the carriage by which the actuating looper's clutch axis is exactly aligned with the looper axis. To ensure that. However, studies show that simple microswitches can provide sufficiently accurate positioning.

In a meaningful way, the electric motor drive of the carriage is associated with the machine control so that the drive can only be activated when the looper shaft is stopped. In a multi-head machine, the controller controls whether the stop of the machine simultaneously activates only the carriage drive attached to this head or activates all carriage drives for the detection of bobbin thread at the head. It is recommended to be configured to

It is proposed to operate the electric motor drive of the carriage via an electromechanical control in conjunction with a bobbin thread monitor associated with each embroidery head or sewing head. In the figures, a switching device according to the invention is shown schematically in a selected embodiment in a simplified manner. The invention will now be described with reference to the drawings in which advantageous embodiments are described.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The proposed changer is, for example, under a table board which is only indicated diagrammatically in a conventional embroidery machine. The device has a substrate 2 suspended via a column 3 and fixed below a table plate. This also makes it possible to retrofit existing machines with replacement devices.

The exchanging device itself comprises a carriage 4 on which two clutch shafts 6 and 7 oriented parallel to the looper shaft 5 are mounted, each of which is opposite the looper shaft 5. It has a looper 8 or 9 at the end. The carriage 4 is movable at right angles to the looper shaft 5 on a profiled guide rail 10 between two end positions. The end position is specified by two diagrammatically shown microswitches 11 and 12 with sensing levers 11a and 12a activated by the end face of the carriage 4.

For the reversible travel of the carriage 4, an electric motor drive is used, which in the exemplary embodiment is represented by an electric motor 15, which is connected to the cams 17 and 18 via a transmission. The eccentric disk 16 between them is rotated, the cam being fixed at the other end to the end of an arm 19 connected to the carriage 4. In FIG. 2, the carriage 4 is in its leftmost position, in which position the right looper 9 is in its working position, in which position the right looper 9 is in position.
Is connected to the looper shaft 5 via the clutch shaft 7.
FIG. 3 shows the carriage 4 moving on the rail 10 at an intermediate position.

To selectively connect the looper shaft 5 to the clutch shaft 6 or 7 of the looper 8 or 9 when the looper shaft 5 is stopped, the looper shaft 5 is provided with a horizontal groove 21 which is positioned horizontally at the stopped position. And a head 20 having the same. On the other hand, each of the clutch shafts 6 and 7 is provided with a follower 6a or 7a having a wedge portion 22 or 23 insertable into the lateral groove 21.
On the edge facing the The wedge portions 22, 23 have entry tapers 22a and 23a as shown. As a result, the carriage 4 reversibly moves on the guide rail 10 by the distance between the two clutch shafts 6 and 7, so that the looper shaft 5 is connected to the end of the clutch shaft 6 or 7 facing the looper shaft 5. It is possible.

A rail 30 is arranged parallel to the guide rail 10 to ensure that the wedge portions 22, 23 remain in the horizontal position required for the connection after disengagement, FIG.
The middle upper end surface 31 forms a sliding track at the height of the wedge portions 22, 23, and the sliding track reaches near the looper shaft 5 on both sides.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a part of an embroidery machine provided with an apparatus according to the present invention.

FIG. 2 is a top view taken along line II-II of FIG.

FIG. 3 is a perspective view of the exchange device seen in the direction of arrow III of FIG. 1;

[Description of sign]

 Reference Signs List 1 needle plate plane 4 carriage 5 looper shaft 6 clutch shaft 7 clutch shaft 8 looper 9 looper 21 lateral groove 22 wedge portion 23 wedge portion

Continuation of the front page (56) References JP-A-4-73094 (JP, A) JP-B-61-27075 (JP, B2) JP-A-6-504225 (JP, A) WO 98/28481 (WO, A1) British Patent 908215 (GB, B) (58) Fields investigated (Int. Cl. ⁷ , DB name) D05B 59/00-59/04

Claims (9)

(57) [Claims] An apparatus for changing a lower thread spool in an industrial embroidery machine or a looper driven via a looper shaft of a sewing machine, wherein at least two of the lower thread spools are oriented parallel to the looper shaft (5).
A carriage (4) with two clutch shafts (6, 7) is provided, the clutch shafts (6, 7) each having a looper (8, 9) at the end facing away from the looper shaft (5). The end of the clutch shaft (6, 7) facing the looper shaft (5) is connectable to the looper shaft (5), and the carriage (4) is rotated when the looper shaft (5) stops. The embroidery machine or the embroidery machine, characterized in that it is reversibly movable perpendicular to the axis (5) and parallel to the throat plane (1) by the distance between the two clutch axes (6, 7). Replacement device for lower thread spool of sewing machine. 2. The looper shaft (5) has a head (20) with a transverse groove (21) oriented parallel to the direction of movement of the carriage (4) when the looper shaft (5) stops. 2. The device according to claim 1, wherein each of the clutch shafts (6, 7) has a driver with a wedge portion (22, 23) which can enter into the transverse groove. 3. A lateral groove (21) and / or wedge portion (22, 2).
3. The device according to claim 2, wherein 3) has an entry taper (22a, 23a). 4. The device as claimed in claim 1, wherein the clutch shaft is provided with an anti-torsion effective in its disengaged position. 5. The wrinkle preventing portion includes a wedge portion.
5. The device according to claim 4, which comprises a sliding path (31) parallel to the direction of movement of the carriage (4) at a height. 6. A carriage (4) having a profiled rail (1).
0) The device according to any one of the preceding claims, running on 0). 7. The device according to claim 1, wherein the carriage (4) is movable via an electric motor drive (15-19). 8. The device according to claim 7, wherein the electric motor drive is operable only when the looper shaft is stopped. 9. The device according to claim 7, wherein the electric motor drive of the carriage is operable via a thread monitor.