JPS646787Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] The present invention relates to a needle bar conversion safety device for a sewing machine.

[Prior art]

Conventionally, in sewing operations that require thread replacement, in order to save the effort of replacing different threads, a needle bar arm with multiple needle bars is moved and only the desired needle bar is selected as the sewing position. A multi-needle sewing machine was used. Generally, this type of sewing machine is
One needle bar crank rod end was selectively engaged with respective engaging portions provided on a number of needle bars.

[Problems with conventional technology and their technical analysis]

In the conventional structure, the positions of the engaging portions of each needle bar that move laterally with respect to the rod end must all coincide with each other horizontally, and the fitting positions between the two must also coincide with each other. This leads to the stop position of the sewing machine, and when the needle bar conversion operation is performed, each needle bar is at the same predetermined height position (approximately the upper shaft rotation angle).
60°). Even if the needle bar pull-down plate for adjusting the height pulls down the needle bar in the non-sewing state by a predetermined amount of movement, the height of the needle bar may not completely match the height of the needle bar in the sewing state. In other words, the convex portion of the rod end for vertical movement of the needle bar does not coincide with the concave portion of the needle bar in the non-sewing state. If you move the needle bar arm with the needle bar fitted in this condition, you will not only cause structural problems such as damage to the rod end and deflection of the needle bar, but also
If the sewing machine is rotated in this state, the needle will break, the throat plate will be damaged, etc., making it impossible to sew, and this is extremely dangerous for the operator.

Additionally, if a worker accidentally presses the fixed dial member on the needle bar switching shaft while operating the sewing machine, the protrusion of the switching fork and the long groove of the stopper will engage.
A needle bar conversion operation occurs. Therefore, the sewing machine suddenly stops,
Other problems similar to those mentioned above occurred.

[Technical issues]

In this invention, a single needle bar arm in which multiple needle bars are fitted in a line is moved in a direction perpendicular to the seam line (fabric feeding direction), and any needle bar is moved to the sewing state. In this sewing machine, the means for pulling up and stopping all the needle bars in the non-sewing state position is configured by axial movement perpendicular to the upper shaft and rotational movement. In order to prevent malfunctions (occurring due to operation when the bar push-down heights are uneven), the dial, which is the operating member of the orthogonal shaft, is made immovable in the axial direction while the sewing machine is in operation. It is.

[Technical means]

That is, an upper shaft to which a stopper having a long groove is fixed, and a shaft orthogonal to the upper shaft are provided so as to be rotatable and slidable in the axial direction. The forked member has a protrusion that cooperates with the long groove of the stopper and operates the needle bar arm shaft in conjunction with the shaft, and a positioning member that is fixed to the dial member at one end and the arm at the other end. The switching arm that cooperates with the robot is fixed.

Further, the shaft of a solenoid, whose operation is electrically connected to starting and stopping the sewing machine, is connected to and disengaged from the small diameter stepped portion of the orthogonal shaft.

The needle bar push-down means is configured to operate via the operating switch only when the protrusion of the forked member engages with the long groove of the stopper by operating the dial member. With this, the other needle bars are pushed down to the same height as the needle bar in the sewing state position, and the needle bar arm is moved to place the desired one among the other needle bars in the sewing state position. All the needle bars in the non-sewing position were pulled upward and stopped. In addition, the limit of movement of the needle bar arm to the left or right can be finely adjusted, respectively, so that a predetermined needle position can be adjusted.

[Effect of technical means]

In sewing machines equipped with a needle bar stop positioning device that has been adopted in recent years, when the rotation of the sewing machine is stopped, the needle bar crank rod 5, that is, the rod end 1
0 is positioned at a height near the position in FIG. 1 (near the top dead center of the take-up spindle) by the electrically operated needle bar stop positioning device (not shown).

The first and second illustrated states are when the left needle bar 12 is selected, and the other needle bars 12', 12'' have their ring grooves 12b', 12b'' on the stepped shafts of the needle bar holder 22, as shown in the figure. 24', 24'' and is located above. In this position, the pin 38 attached to the switching arm 36 engages with the locking hole 35a of the switching plate 35, and the pin 38'
is inserted into the circular arc hole 35b'. (Right side in FIG. 7) In order to convert another desired needle bar, for example 12' in the center, to the sewing position under this condition, the following operation is performed.

First, when the sewing machine is stopped, the dial member 31 is pressed from the solid line position shown in FIG. 4 to the dotted line position, that is, to the front. (At this time, the small diameter stepped portion 30a of the switching shaft 30
As shown, the solenoid shaft 60a is in a disengaged state, but when the sewing machine is started, the two move to an engaged state. ) As a result, the switching fork 42 and the switching arm 42a fixed to the switching shaft 30 are moved to the stopper 45.
The pins 38 and 38', which enter the long groove 45a and are fixed to the switching arm 36, are inserted into the locking hole 35 of the switching plate 35.
a, it comes off from the circular arc hole 35b' and is pushed out to the outer surface of the switching plate.

At this time, the operating terminal 55a of the switch 55 is pushed in by the flange of the dial member 31, and the switch is turned on.

Therefore, the air cylinder 27 is activated, and the lowering plate 23 is rotated clockwise about the support point 23a.

With this, the needle bar holder 22 that engages with the shaft portion 23b of the pull-down plate is pushed down from the two-dot chain line to the solid line position shown in FIG. to lock.

Next, when the dial member 31 is turned clockwise while facing the front, the fork portion 42b (circular portion) of the switching fork 42 moves the shaft portion 11a of the needle bar arm 11 to the left as seen in FIG. .And the V groove 1 of the shaft part
1b and a steel ball 47 placed on the positioning holder 46
(See Figure 6). At this time, the position of the switching arm 36 is as shown in FIG.
enters the circular arc holes 35b, 35b' of the switching plate 35. Since the switching shaft 30 is constantly pressed outward (in the direction of the dial) by the spring 32, the switching shaft 30 is
1b and the steel ball 47 are engaged and the switching arm 36 is in the state shown in FIG. Return to

Then, each needle bar has the same height as shown in FIG.
2a'' is located horizontally in a line.Here, needle bar arm 1
1 moves, the protrusion 10a of the rod end 10 disengages from the recess 12a of the needle bar 12, and the needle bar 1 moves.
2' is engaged with the recess 12a'.

Furthermore, when the operating terminal 55a of the switch 55 separates from the flange of the dial member 31, the switch is turned off. Therefore, air cylinder 2
7 is the original position, that is, the pull-down plate 23 and the needle bar holder 22 are pushed up to the original position. At this time, the needle bars 12 and 12'' are connected to the needle bar holder 22 by the engagement of the stepped shafts 24 and 24'' and the ring grooves 12b and 12b''.
It is pushed up in the same way.

At this time, since the concave portion 12a' of the needle bar 12' is engaged with the protrusion 10a of the rod end 10, the engagement between the stepped shaft 24' and the ring groove 12b' is disengaged.

The needle is switched by the series of operations explained above. When switching to needle bar 12'',
The only difference is that the pin 38' attached to the switching arm 36 engages with the locking hole 35a' side of the switching plate 35, and the ring groove 11b and the steel ball 47 disengage.Other operations are the same. be.

As can be seen from the above description, the needle position conversion in the device of the present invention involves changing the engagement position between the steel ball 47 of the positioning holder 46 and the V groove 11b on the needle bar arm shaft 11a to the central position. The sewing position of the needle bar 12' was used as the selection criterion. And dial member 3 as desired.
Even if another needle bar is selected by operation 1, the dial member 31 is prevented from moving in the axial direction during operation of the sewing machine.

[Special effects produced by the present application]

Not only can the needle bar position be changed accurately, quickly and easily, but also because the dial member, which is the needle bar switching operation member, is prevented from moving in the axial direction while the sewing machine is rotating, the needle bar switching operation can be performed easily. Therefore, there is no handling error by the operator, and the above-mentioned inconvenience can be prevented.

In addition, the means for engaging and disengaging the switching shaft and the solenoid shaft is
It has a simple structure and is advantageous in terms of manufacturing and cost, and the solenoid itself can be placed at the back of the machine frame, so it does not interfere with sewing work.

〔Example〕

1 is an arm of the sewing machine, 2 is an upper shaft, and 3 is a needle bar crankshaft, which is fixed to the needle bar crank 3, into which one end of a needle bar crank rod 5 is loosely fitted.

Reference numeral 6 denotes a guide rod of a needle bar crank rod end (hereinafter referred to as rod end), which will be described later, and is fixed to the arm 1, and a sliding member 8 is loosely fitted onto the guide rod 6. The sliding member 8 has a shaft portion 8a, and the shaft portion 8
The lower part of the needle bar crank rod 5 is loosely fitted into the needle bar crank rod 5, and a square piece 9 is loosely fitted on the shaft end of the needle bar, and the square piece 9 engages with a vertical groove of an arm (not shown) so as to be able to move up and down. There is. Reference numeral 10 denotes a rod end, which has a protrusion 10a and is fixed to the sliding member 8.

Therefore, as the upper shaft 2 rotates, the rod end 10 moves up and down on the guide rod 6 together with the sliding member 8 via the needle bar crank 3 and the needle bar crank rod 5.

Reference numeral 11 denotes a needle bar arm, which includes a plurality of needle bars 12, 12', 1
2″ is in line with the guide member and the screw 14 is attached to the arm 1,
14', one end of which is bent at 13a.
be done. Thus, the lower part of the needle bar arm 11 is one side 1a of the concave portion of the arm and the bend 13a of the guide member 13.
It is located between the inner surfaces of the
be prevented. A stopper plate 15 is fixed to the arm 1 with screws 16, 16', and a stopper 17 is screwed into the arm 1 with a nut 18 so that the set position can be adjusted.

Thus, the left travel limit of the movement of the needle bar arm 11 in the direction perpendicular to the cloth feeding direction is adjusted and regulated by the stopper 17, and similarly, the right travel limit is adjusted and regulated by the adjustment screw 19 screwed into the arm. Ru.

The plurality of needle bars 12, 12', 12'' have recesses 12a, 12'' that fit with the projections 10a of the rod ends.
2a', 12a'', and the upper end has ring grooves 12b,
12b', 12b'', and on the opposite side of the recess are vertically long surfaces 12c, 12c', 1 for regulating rotation of the needle bar.
2c'' is provided.

20, 20', 20'' are needle bar rotation control plates,
One end is locked to the vertically long surface 12c, 12c', 12c'' of the needle bar, respectively, and fixed to the upper surface of the needle bar arm 11 by screws 21, 21', 21''.

22 is a needle bar holder, which holds the needle bars 12, 12',
It has holes 22b, 22b', 22b'' for holding 12'', and a recess 22a into which a shaft 23b of a pull-down plate 23 rotatably supported on the arm is inserted. In addition, the ring grooves 12b, 12b', 1 of the needle bar
2b'', a spring 25 that presses the flute shaft toward the needle bar, and rings 26, 26', 26" that limit the stroke are provided, respectively. .

An upper end 23c of a needle bar push-down means 27 (an air cylinder in this illustration) operated by a switch member to be described later is loosely attached to an intermediate portion of the pull-down plate 23, and a lower end thereof is attached to an arm by a screw 29. It is fixed.

Reference numeral 30 denotes a switching shaft, which is disposed on the arm 1 so as to be orthogonally rotatable and axially slidable above the upper shaft 2, and a small diameter stepped portion 30a is formed on the side thereof (left side in the figure).

Reference numeral 31 denotes a dial member, and a spring 32 is interposed at one end of the switching shaft 30 (on the right side in the figure), and the screw 3
3, and a switching arm 36 is fixed to the other end of the shaft 30 with a screw 37 in sliding contact with the outside of a switching plate 35 that is fixed to the arm 1 with a screw 34.

Therefore, an appropriate gap l is normally maintained between the inner surface of the flange of the dial member 31 and the outer wall of the arm,
The dial member 31 is assembled so as to be biased in the direction of the arrow by a spring 32.

A solenoid 60 is attached to the back of the machine frame by a plate 62, and has a solenoid shaft 60a electrically connected to start and stop the sewing machine. That is, the shaft 60a moves forward while the sewing machine is rotating and engages with the small-diameter stepped portion 30a of the switching shaft, and separates when the rotation stops, thereby preventing or allowing axial movement of the switching shaft 30.

The switching arm 36 has pins 38, 38' attached to the screws 3.
9 and 39', and the switching plate 35 has the pins 38 and 38' inserted into the locking holes 35a and 39'.
35a' and circular arc holes 35b, 35b' for escape of the pin, and stoppers 40, 40' for adjusting and regulating the rotation of the switching arm 36 are provided in the nut 4.
1,41'.

42 is a switching fork, which is connected to the switching shaft 30 by a screw 43.
It has a protrusion 42a and a forked part 42b which sandwich the shaft part 11a of the needle bar arm at an approximately intermediate position. The protrusion 42a faces a stopper 45 having a long groove 45a, which is fixed to a predetermined rotational angle position of the upper shaft 2 with a screw 44, and is configured so that it can enter into the long groove 45a by sliding in the axial direction of the switching shaft 30. It's summery.

As can be seen from FIGS. 2 and 3, the shaft portion 11a of the needle bar arm 11 is supported by the arm 1, and a positioning holder 46 is loosely fitted into the intermediate portion thereof. This positioning holder 46 is provided with the shaft portion 1 of the needle bar arm.
Steel body 4 that engages with V groove 11b provided on 1a
7 is biased by a screw 49 via a spring 48,
The needle bar arm 11 is positioned by the engagement.

The holder 46 is attached to the arm 1 through the hole (which may be a long hole) 46a so that its mounting position can be finely adjusted in the axial direction of the needle bar arm shaft portion 11a using screws 50, 50'. It is fixed. Therefore, this allows for a predetermined needle position adjustment.

Further, on the shaft portion 11a of the needle bar arm 11, a fork portion 42b (circular portion) of the switching fork is sandwiched.
Collars 53, 53' are fixed with screws 54, 54', respectively, with washers 51, 51' and elastic bodies 52, 52' interposed therebetween.

A switch 55 is fixed to a switch holder 57 with screws 56 and 56', and the switch holder is fixed to the arm 1 with a screw 58.

In addition, 55a indicates the operating terminal of the switch 55,
Push the safety pin 80 to the right and dial member 31
By pressing in the axial direction, the bifurcated member 42 moves forward via the switching shaft 30, and its protrusion 42a enters and engages the long groove 45a of the stopper 45, and the flange of the dial member 31 engages with the operating terminal. 55
Press a to turn on the switch. As a result, the needle bar pressing means 27 (air cylinder) is activated.

However, this is the case when the upper shaft 2 is stopped at a predetermined rotation angle position, and when the upper shaft 2 is stopped at a position other than the predetermined position, even if the dial member is pressed, the protrusion 42a does not stop at the stopper 4.
The dial member 31 does not move forward as it comes into contact with the outer periphery of the needle 5, so the switch 55 is not turned on and the needle bar pressing means does not operate.

[Brief explanation of the drawing]

FIG. 1 is a front view of a sewing machine equipped with the device of the present invention with the face plate removed, FIG. 2 is a right side view of FIG. 1, and FIG. 3 is a front view of the needle position converting device. FIG. 4 is a cross-sectional view taken along line A-A in FIG.
5 is a view taken along the line B-B in FIG. 2, FIG. 6 is an explanatory cross-sectional view of the member indicated by the arrow C in FIG.
The figures are explanatory diagrams of the operation of the needle position switching arm, and FIG. 9 is an explanatory diagram of the operation of the needle bar. 2... Upper shaft, 6... Guide rod, 11... Needle bar arm,
12...Needle bar, 30...Switching shaft, 31...Dial member, 42...Switching fork, 45...Stopper,
60... Solenoid, 60a... Solenoid shaft.

Claims (1)

[Scope of utility model registration request] A single needle bar arm in which multiple needle bars are fitted in a line is moved in a direction perpendicular to the cloth feeding direction, and any needle bar is moved to the sewing position, resulting in a non-sewing position. In a sewing machine configured such that the means for pulling up and stopping all of A needle bar conversion safety device for a sewing machine, which controls axial movement of the switching shaft by engaging and disengaging a solenoid that operates automatically with the solenoid shaft.