JPH0321735Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Purpose of the Invention] (Field of Industrial Application) The present invention relates to a needle bar conversion device for a sewing machine.

(Prior Art) A conventional sewing machine needle bar conversion device moves a needle bar arm supporting a plurality of needle bars across a terminal line and engages with the needle bar crank rod end. It is.

(Problem that the invention aims to solve) However, before the movement of the needle bar arm is completed, there is a problem that occurs due to some reason, such as the needle hitting the needle hole when the treadle pedal is operated by mistake, or some other malfunction. evoked.

Therefore, the technical problem of the present invention is to prevent the sewing machine from being driven unless the needle bar conversion is completed.

[Structure of the invention] (Means for solving the problem) In order to solve the above technical problem, the technical means taken in this invention is to move the needle bar arm supporting a plurality of needle bars across the terminal line. A needle bar converting device for a sewing machine in which one of the needle bars is cut and moved so that one of the needle bars is engaged with a needle bar crank lock end includes a detection means corresponding to each of the needle bars, and a detecting means to ensure that the movement is performed correctly. A safety device is provided, comprising a control means that allows the sewing machine to be driven in response to a signal from the detection means when the sewing machine is detected.

(Function) Therefore, the signal from the detection means is not applied to the control means unless the needle bar conversion is completed.
During the needle bar change, the sewing machine will not be driven and the above-mentioned problem will not occur.

(Example) An embodiment of the present invention will be described below.

Needle bars 2 and 2' are supported on the needle bar arm 1, and a shaft portion 1a of the needle bar arm 1 is supported by an arm 3. The needle bar guide shaft 4 is connected to the needle bar crank rod end 5.
, and the needle bar crank rod end 5 moves up and down by a mechanism not shown. This vertical movement is transmitted to the sewing needle bar by engagement between a convex portion 5a of the needle bar crank rod end 5 and a recess 2a provided at an intermediate portion of the needle bars 2, 2'.

The upper end of the needle bar is provided with recesses 2b and 2b' that engage with a protrusion 8a of a needle bar pusher 8, which is fixed to the needle bar pusher arm 6 with screws 7 and 7'. In the recess 8b of the needle bar pusher 8, a needle bar pusher 9 is fixed to the needle bar pusher 8 by screws 10, 10'.

A plunger 11a of a solenoid 11 for pushing down the needle bar is connected to a pin 12 in the middle of the arm 6 for pushing down the needle bar.
The solenoid 11 is connected to the plate 1 by
3 with a nut 14. Further, the solenoid plate 13 is fixed to the arm 3 by screws 14, 14'. A shaft portion 6a of the needle bar push-down arm 6 is supported by the arm 3, and a switching arm 15 is fixed to the end of the shaft portion 6a. Further, this switching 15 has a recess 15a.
A collar 16 is fixed to the other side of the shaft portion 6a with a screw 17 to restrict movement of the needle bar push-down arm 6 in the axial direction. A counterclockwise rotational force is applied to the needle bar push-down arm 6 by a spring 18 that locks one end of each spring to the collar 16 and the arm 3.

The switching fork 19 shown in FIG. 1 is fixed to a switching shaft 20 with a screw 21, and the lower end 19a of the switching fork 19 has a circular shape. A washer 22,
22' and elastic bodies 23, 23' are respectively attached by screws 25, 25' via collars 24, 24' as positioning members for the circular portion. Further, a rod 26 is rotatably attached to the intermediate portion of the switching fork 19 with a cutting screw 27, and the other end of the rod 26 is connected to a common plunger 28a of the needle bar selection solenoids 28, 28' by a pin 29. connected. The needle bar selection solenoid 28 is fixed to a solenoid plate 30, and this solenoid plate 30 is fixed to the arm 3 by screws 31, 31'. To select the needle bar, press the push-button switch 45 connected to the control circuit 44 once to drive the left needle bar 2', and press twice to drive the right needle bar 2. 1 is starting to move.

Further, a bracket 42 is attached to the arm 3 with screws 43, 43, and the bracket further holds a needle bar movement completion switch or a micro switch 38 and a needle bar arm 1 therebetween. 39 are fixed with screws 40 and 41, respectively. However, micro switch 38,
The levers 38a, 39a of 39 are pressed to close the micro switches 38, 39 when the needle bars 2', 2 are surely at the selected position. Micro switch 38 and 3
Unless one of the needle bar push-down solenoids 9 is closed, the control circuit 44 does not allow the needle bar push-down solenoid 11 to be energized or operated thereafter. In other words, during needle bar conversion, the control circuit 44:
It does not allow the sewing machine to be driven.

The sewing machine is driven and stopped by controlling power supply to a motor (not shown) via a control circuit 44 by operating a pedal (not shown).

The operation of this embodiment will be explained below.

When the micro switch 38 is closed near the upper shaft stop position (upper shaft angle 60 degrees), if the switch 45 is pressed twice, the control circuit 44 will allow the needle bar push-down solenoid 11 to be energized. The needle bar push-down solenoid 11 rotates the needle bar push-down arm 6 clockwise against the spring 18. Then, the needle bar waiting above is pushed down by the needle bar push-down bar 9 to the needle bar position corresponding to sewing, so that the two needle bars shown are at the same height. At this time, the switching arm 15 fixed to the shaft portion 6a of the needle bar push-down arm 6 similarly rotates, and the engagement between the recess 15a of the switching arm 15 and the pin 33 of the switching pin arm 32 is disengaged. Then, the needle bar arm 1 can be moved. When the needle bar has been pressed down after a predetermined period of time has elapsed, the control circuit 44 then energizes the needle bar selection solenoid 28' and rotates the switching prong 19 counterclockwise. At this time, the switching pin arm 32 fixed to the switching shaft 20 also rotates in the same manner.

When the needle bar selection solenoid 28' is energized, the needle bar arm 1 moves to the right so as to engage the concave portion 2a of the needle bar 2 with the convex portion 5a of the needle bar crank lock end 5. If the rightward movement is not performed correctly, the current state of the needle bar arm 1 will be maintained because the micro switch 39 will not be closed. When the rightward movement is performed correctly, the needle bar arm 1 closes the micro switch 39, so the control circuit 44 cuts off the power supply to the needle bar push-down solenoid 11.

When the power supply to the needle bar push down solenoid 11 is cut off, the arm 6 is rotated counterclockwise by the spring 18 while the needle bar is pushed down, and at the same time, the needle bar in the non-sewing position is moved upward and placed on standby. At the same time, the switching arm 15 also rotates in the same manner, and the recess 15
and pin 33' engage, and the needle bar arm is fixed.
When the needle bar push-down arm 6 rotates to the upper standby position, the needle bar selection solenoid 28 is de-energized and the needle bar conversion is completed.

The left and right movement of the needle bar arm 1 is restricted by stoppers 34 and 35, but the rotation of the switching fork 19 is
The elastic body 23, 2 moves slightly more than the movement of the needle bar arm 1.
Rotate until 3' is pressed. This extra rotation of the switching fork 19 absorbs the play between the recess 15a of the switching arm 15 and the switching pins 33, 33', and eliminates the play of the needle bar arm (left and right movement of the needle).

FIG. 6 shows the timing of the energization of the needle bar push-down solenoid 11 and the needle bar selection solenoid 28, the mechanical movement of the needle bar push-down arm 6, and the mechanical movement of the needle bar arm 1. energizes the needle bar selection solenoid.

In other words, the needle bar arm is moved only after the concave portion 2a provided in the intermediate portion of the needle bar is at the same height.

After the counterclockwise rotation of the needle bar push-down arm 6 is completed by the spring 18, the needle bar selection solenoid 28 is de-energized. During this time lag B, the needle bar arm 1 is moved to the normal position, the needle bar arm 1 is fixed at this position by the transfer arm 15 and the switching pin 32, and then the needle bar selection solenoid 28 is energized. This is to block the

Note that the following configurations may also be adopted.

In the specific example, the sewing machine operable region shown in FIG. 6 is a case where either the needle bar movement completion switch 38 or 39 is ON. However, for safety reasons, it is preferable to turn off the electricity to the needle bar selection solenoids 32, 32'. Operation of the sewing machine is prohibited until the power supply to 32 and 32' is cut off.

As shown in FIG. 1, the needle bar movement completion switch 38,
Although the two switches No. 39 are provided, one micro switch is provided to detect the movement of the plunger of the solenoid 11 for pushing down the needle bar.

For example, if the standby state of this switch is set to ON, when the needle bar conversion is performed, the switch will turn ON →
Changes from OFF to ON.

Therefore, if the switch does not change from ON to OFF to ON during needle bar conversion, or if the switch is not ON in the standby state, this is assumed and the sewing machine is prohibited from operating.

The opposite is true if the standby state is OFF.

In the specific example, a micro switch is used to detect the movements of the needle bar arm 1 and the needle bar push-down solenoid 11, but it is easily possible to use a photocoupler, a magnet (Hall element), or a proximity switch.

In the specific example, the needle bar selection solenoid and the needle bar push-down solenoid are used to automatically change the needle bar, but the present invention can also be used for manually changing the needle bar without these solenoids. Switches are applicable.

[Effect of idea]

As described above, in the present invention, the needle bar arm supporting a plurality of needle bars is moved across the terminal line, and one of the needle bars is engaged with the needle bar crank rod end. In the needle bar conversion device of the sewing machine, a safety device is provided which includes a detection means corresponding to each needle bar, and a control means that allows the sewing machine to be driven by a signal from the detection means when the movement is performed correctly. , the signal from the detection means is not applied to the control means until the needle bar conversion is completed.
During needle bar conversion, the sewing machine will not run and cause any problems.

[Brief explanation of the drawing]

Fig. 1 is a front view illustrating the configuration of the needle bar converting device of the present invention, Fig. 2 is a side view of Fig. 1, Fig. 3 is a diagram showing the operation of the illustrated members, and Fig. 4 is the portion of Fig. FIG. 5 is a control block circuit diagram of the device shown in FIG. 1, and FIG. 6 is a signal timing diagram. 1... Needle bar arm, 2... Needle bar, 5... Crank lock end, 38, 39... Micro switch,
44...Control circuit.

Claims (1)

[Scope of utility model registration request] In a needle bar conversion device for a sewing machine, a needle bar arm supporting a plurality of needle bars is moved across a raphe line, and one of the needle bars is engaged with a needle bar crank rod end. a detection means corresponding to the needle bar;
A needle bar conversion device for a sewing machine, comprising a safety device comprising a control means for permitting the sewing machine to be driven in response to a signal from the detection means when the movement is performed correctly.