JPS6031514B2 - Sewing machine pattern selection control circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control circuit for a sewing machine that incorporates a plurality of pattern generating cams and selects patterns using electrical means.

When selecting a pattern on a sewing machine that uses a pattern generation cam, a considerable amount of operating force is required to change the engagement between the pattern generation cam and the follower, so manual operation such as dial operation is recommended. , it is desirable to select automatically using electrical power.

The selection operation should be simple, the selection operation should be reliable, and if the user wants to continue the work after interrupting the work and turning off the power, the previous selection state will be reliably retained. preferable. In the present invention, by simply lightly operating one of the pattern selection switches corresponding to the type of sewing, the sewing machine motor is used as the driving source to automatically complete the pattern selection, and once the pattern is selected, the control circuit Even if the power is turned off, the original pattern selection remains valid unless a new pattern is selected after that, and the circuit configuration uses semiconductors so that it can be easily stored in the narrow space inside the sewing machine. The purpose is to provide a control circuit for a sewing machine.

Embodiments of the present invention will be described below with reference to figures.
FIG. 4 is a schematic diagram of the main parts of the sewing machine mechanism controlled by the control circuit according to the present invention, in which 1 is an upper shaft, 2 is a flywheel, 3 is a bush fixed to the main shaft, and a notch locking portion 4 is shown.
A belt pulley 5 is rotatably mounted on the pusher 3. A clutch pawl 7 is pivotally connected to a support shaft 6 provided as a shield on the belt pulley 5, and is biased counterclockwise in FIG. 4, the driving force of the belt pulley 5, which is driven by the belt 9 in the direction of the arrow in the figure by a sewing machine motor (not shown), is transmitted to the upper shaft 1 via the clutch pawl 7. ing. Numeral 10 is a stop cam body which is iron-mounted on the bush 3, and the stop cam body 10 and the bush 3 are relatively rotated by a considerable angle via a buffer spring 11 installed between the pusher and the stop cam body. As shown in FIG. 3, when the solenoid 16 is energized, the stopper pawl 13 pivotably attached to the shaft 12 attached to the sewing machine body engages the locking portion 14 provided with the stop cam body 101 as shown in FIG. to stop the stop cam body 10 by coming into contact with
The bush 3, which is rotating in the direction of the arrow in the figure, is forcibly stopped via a buffer spring 11, and at this time, the sewing machine needle bar is stopped in its normal position.

The stop cam body 10 further includes an engagement/disengagement cam portion 15 having a track that engages with the clutch pawl 7. Reference numeral 16 denotes a clutch solenoid, which, when excited, rotates an operating arm 18 fixed to an engagement/disengagement drive shaft 17 fixed to the sewing machine body in a counterclockwise direction against a tension spring 19 as shown in Fig. 3. the stopper claw 13 as shown in the figure.
When the stop cam body comes into contact with the small recess 14' by the compression spring 20 and stops at the predetermined position, the clutch pawl 7 moves the notch locking part 4 to the large recess 15' of the locking/disengaging cam 15. The clutch pawl 7 is released from the notch locking portion 4, and the belt pulley 5 is allowed to idle.

The return cam 11' is installed between the flywheel 2 and the stop cam body 10, and when the solenoid 16 is de-energized, it rotates the stop cam 10 in the direction of the arrow in the figure to close the bush 3. This is to return the relative position between the locking part 4 and the large flap part 15' of the stop cam body 10 to the position shown in FIG. At this time, a return force is also exerted by the buffer spring 11, but since the buffer spring 11 has a small stroke due to its function and cannot return completely, this is compensated for by the return 'imitation 11'. It is. The operating arm 18 is adapted to operate a motor changeover switch 21, which will be described later. A swing cam 22 is connected to the belt wheel 5 through a gear 5' provided on the belt wheel 5, and a swing cam follower 23 engages with the cam portion 22' provided on the circumference.

FIG. 4 is a drawing seen from the direction of arrow W in FIG. 1A in order to explain the engagement and disengagement mechanism of the follower. In FIG. 4, the solenoid 16 is not energized unlike in FIGS. At this time, the engaging/disengaging drive shaft 17 rotates the lever 24 fixed thereto counterclockwise against the compression spring 25, and causes the swing shaft 26 pivotally attached to the sewing machine body to rotate. A swing cam follower 23 which is movable in a direction is attached to a swing cam 22.
It is held in a position where it does not engage.

When the solenoid 16 is energized, the swing cam 22 is engaged at a specific rotational position. Reference numeral 27 is a swing link fixed to the swing shaft 26, and the pin portion 27a allows the swing cam follower 23 to move in the direction of the shaft 26 and is connected to the swing cam follower, and the tension spring 28 moves clockwise. A release cam drive pawl 29 is pivoted to the pivot link and is biased toward the release cam.
At the same time, the oscillating motion is transmitted to the oscillating shaft 26 at different positions in all directions, and the selectable link 27', 27'' is fixed to the oscillating shaft 26, respectively, as shown in FIGS. Drive claw 2
9', transmits the swinging motion to the automatic-manual switching drive claw 29''.

30 is a stopper at the position where the swing link 27 is not engaged.

Reference numerals 31, 32, and 33 denote solenoids, and these solenoids are respectively fixed to respective shafts 34, 35, and 36 that are pivotally connected to the sewing machine body. Each drive pawl 29, 29' corresponds to the individual excitation of each solenoid with respect to the switching ratchet wheel 43.
, 29'' are enabled for selective ratchet feeding.

A release cam (not shown) is coaxially attached to the ratchet wheel 41, and a pattern selection cam (not shown), which is a selection device, is similarly attached to the ratchet wheel 42. A pattern cam (not shown) serving as a pattern generation carrier is released from the pattern selection cam to mechanically enable pattern selection. Similarly, an automatic/manual switching cam (not shown) is attached to the automatic/manual switching ratchet wheel 43, and the sewing conditions can be automatically set or manually adjusted for each pattern. Reference numeral 37 denotes a cloth feed switching link that mechanically operates the cloth feed mechanism (not shown) of the sewing machine to forward feed when the release solenoid 31 is not energized and to reverse feed when it is energized.

Reference numerals 38 and 39 indicate normally closed switches that are opened when the solenoids 32 and 33 are respectively excited.

FIG. 5 is a control circuit diagram showing an embodiment of the present invention, in which V is an AC power supply, SM is a power switch provided on the outside of the sewing machine, M is a sewing machine motor, CONT is a controller, and 21 is a motor switching switch. When the clutch solenoid 16 is not energized, the contact piece 21' is on the controller CONT side, and when it is energized, such as when selecting a cam to be described later, it is on the power source side.

SR is a full wave rectifier circuit with solenoids 16 and 31 on the (10) side.
, 32, 33. These solenoids are required to be pressed when selecting a pattern.
The connected and selected patterns A to each circuit group C^ to CH surrounded by chain lines, which have the same configuration and are arranged in parallel every day.
(1) The cathodes of each of the thyristors SCR^ to SCRH, and the cathodes of a plurality of diodes D, to D, connected in series in order to enable these solenoids independently of the thyristors upon completion of pattern selection, etc. connected to the side. The forward voltage drop of the diodes D, ~○, is larger than that of each thyristor SCR^~SCRH, and these thyristors conduct and form the main circuit of each solenoid 16''31, 32, and 33. When this happens, the current flows through the thyristor through the pond diodes D,~D,'. This is a varistor that absorbs energy during the operation and improves responsiveness to de-energization.Each switch S, , S,
′,S,″ is a switch S, whose bush piece Ct is connected to the solenoid 3 through the other solenoid 16 and the diode D3.
1 is connected to the other end through switches 38, 39 and diode D4, and each hair piece C of switch S, ′, S, ″
t,′,Ct. '' are connected to the other ends of the solenoids 32, 33, respectively, and the switch cams 51, 51',
51'' is in the position shown in the figure, and each piece has contact points a,,a
,′,a,″.And the tangent Ct,
contacts a,' of switch S,' via diode D5
'This is connected. Referring also to FIG.
8' are located at 180 degrees relative to each other, and rotate on the same shaft 34 as the opening cam ratchet wheel 41. The engagement of the drive for its rotation is thus based on the energization of solenoids 16 and 31, as described above. FIG. 5 shows that these switch cam positions are in a state where the release cam (not shown) is not released, and the switch cam is 180 degrees from this state.
When rotated, it becomes released. The contact a is connected to the anode side of each of the diodes D, -D. For each switch Ssa~S2, each contact piece Ct^~CL is connected to the contact point a,' of the switch S,', and its structure is as shown in FIG. When the contact piece Ct2', which is connected to the contacts a and ' in Fig. 5 with both terminals closed in common and rotates together with the shaft 35, comes into contact with a specific contact among the contacts a to h (a in the figure) Among the contacts a' to h', the corresponding contact (a' in the figure) is opened to come into contact with the reinforcement pieces C and others. The set of bush pieces Ct2 and Ct2' means the contact pieces Ct^ to CtH in FIG. Then, any one of the contacts a to h on the ignition circuit side of each thyristor SCR^ to SCRH corresponding to each pattern A to day is selectively connected to the contact a.
. It is adapted to rotate on the same axis 35 as the selection ratchet wheel 42 . Therefore, as mentioned above, the opening and closing of the switch due to its rotation is caused by the engagement of the rotational drive between the solenoids 16 and 32.
Based on the excitation of And among the contacts a to h, pieces CL to C
The position of the ratchet wheel 42 when tH is open (the position corresponding to pattern A in the figure) is placed in the selected pattern cam with its follower (
(both not shown) correspond to engage. S^~
SH'ma is a normally open pattern selection switch provided on the outside of the sewing machine and operated, R, and R^, ~RH,, R^2 ~ RH2 are current limiting resistors for each thyristor SCR^ ~ SCRH firing circuit, and an LED. ^~LED day is a light emitting diode displayed corresponding to each pattern A~day, and selectively emits light as each thyristor becomes conductive. R2 and R^3
~RH3 is its protective resistance, D^, ~DH・, D^2~D
H2 is each diode, R3 and C are thyristor SC
These are the resistors and capacitors for preventing ignition of R^~SCRH. Each switch S3, S3' has its respective piece Ct3, C.
t3' is the contact a of the switch S,'' and the diode D6.
The contact a3 of the switch S3 is connected to the automatic side contact AUTO of the automatic/manual changeover switch S4 provided on the outside of the sewing machine and operated, and the switch S8' Contact a3' is hand side contact MA
N' are connected. Switch cams 53, 53' rotate on the same shaft 36 as the ratchet wheel 43 for automatic/manual switching.
Referring also to FIG. 6, the troughs 518 and 518' are located at 180 degrees relative to each other, and the contact piece Ct3 is
, C et al.' are connected to the diodes D, ~D, of the switch S4, and the contacts Ct4 are switched automatically or manually to connect these flea pieces (Ct3 in the figure) on the connected side (the AUTO side in the figure). None, the unconnected side is closed. The drive force for rotation of the switch cams 53, 53' is based on the excitation of the solenoids 16, 33. In these switch cam positions shown in FIG. 5, the automatic one-handed switching cam (not shown) is on the automatic side, and when the switch cam rotates 180 degrees, it is on the manual side. S5 is a normally open switch for reverse stitching for backstitching, etc., which is provided on the outside of the sewing machine and operated, and is connected to a solenoid 31 via switches 38 and 39 and a diode D.S5.
~D, open and close between. Therefore, as long as this button is pressed, reverse stitching will be performed. The present invention has the above configuration, and the fifth
The figure shows a state in which pattern A is selected.

When the power switch SM is turned on, only the thyristors SCR^ to SCRH constitute the ignition circuit, but the main circuit is the link, and each solenoid 16
, 31, 32, and 33 do not constitute a main circuit via the thyristors or diodes D, ~D, and each switch maintains the state shown in the figure. Pattern A is selected and the switch 21 is in the control state. . -ra CONT is enabled to enable sewing. and light emitting diode LED
is lit by a full-wave rectified current through the thyristor SCR^ to display pattern A. Next, when you press the pattern selection switch SB once to select pattern B, the thyristor S
CR8 is ignited and the light emitting diode LEDB lights up,
Solenoids 16 and 31 are energized.

Even after the pattern selection switch SB is turned on, the conduction of the thyristor SCR8 is maintained by the holding current caused by its inductance. As the thyristor SCR8 becomes conductive, the gate current of the thyristor SCR^ becomes 0, and the thyristor SCR receiving the AC voltage
＾ is extinguished and the light emitting diode LED ＾ goes out. Clutch solenoid 16 operates switch 21 to drive motor M independently of controller CONT. Then, the stopper claw 13 shown in FIGS. 1 to 3 disconnects the upper shaft 1 from the drive of the belt pulley 5 at the first specific phase, disables the sewing drive of the sewing machine, stops the sewing machine, and drives the motor. The force causes the clutch pawl 7 to move the notch locking part 4 to the large bulge part 15' of the engagement/disengaging cam 15, thereby releasing the clutch pawl 7 and making the rotation of the belt pulley 5 independent of the upper shaft 1. The solenoid 16 rotates the lever 24 shown in FIG. 4 clockwise to engage the swing cam follower 23 in the first specific phase of the swing cam 22, thereby driving each drive pawl 29, 2.
The release solenoid 31 drives the ratchet wheel 41 to swing each switch cam 61, 51', 51.
'' rotates 180 degrees, the release cam (not shown) moves to the release position to allow pattern selection, and at the same time, the bush piece Ct of switch Si
i contacts contact ai to energize the selection solenoid 32,
Therefore, the switch 38 is opened and the release solenoid 31 is opened.
is de-energized and the ratchet wheel 41 is stopped. The solenoid 32 drives the ratchet wheel 42, and the contact piece Ct^ of the switch S2^ closes the contact a'. Then, the contact piece CtB of the switch S28 is changed from the contact b' side to the contact b side, the solenoid 32 is de-energized, and the movement of these rear pieces is stopped. At the same time, when the saddle point is switched, the thyristor SCR8 continues to enable the ignition circuit to turn on the light emitting diode. Keep LED8 lit. At this time, the pattern selection cam (not shown) is moved to face the pattern cam (not shown) for pattern B. De-energization of solenoid 32 causes switch 38 to close again and solenoid 31 to close again.
is excited via switch S, diodes D, ~D, and each switch cam 61, 51', 51'' is further energized by 180
o rotates to the position shown in Fig. 5, switch S is opened, and the solenoids 16 and 31 are de-energized and the switch cam 5 is turned.
1, 51', and 51'', the release cam (not shown) enables the pattern cam (not shown) for sewing, and the switch 21 connects the controller CONT to finish pattern selection. - Contact piece Ct4 of manual changeover switch S4
When the switch is switched from the state shown in Fig. 5 to the contact MAN side, the solenoids 16 and 31 are energized and the switch cams 51 and 51'
, 51'' rotates 180 degrees and switches S,,S,',S
,'' are both closed, and the solenoid 33 switches to switch S,''
, S3', S4, and diodes D, ~○, the switch 39 de-energizes the solenoid 31, and rotates the switch cams 53, 53' by 180° to turn the solenoid 33 on via the switch S3'. The solenoid 31 is de-energized and the solenoid 31 is energized again in the same manner as described above, and the switch cams 51, 51'51'' are placed in the position shown in FIG. 5 to complete the selection process in which the sewing condition is set to manual reversal. A circuit that electrically controls the selection of the sewing machine's pattern cam is used, and the pattern selection switch is interposed between a thyristor and an ignition circuit, making it more compact. After the star is ignited, the sewing machine motor is selected as the driving source and the selection is automatically ensured, and the main circuit of the thyristor corresponding to the selected pattern is activated by the mechanism. Since the circuit is opened by a switch, even if the power to the control circuit is turned off, the originally selected pattern remains valid unless a new pattern is selected after that, and it is necessary to select it again as in general electrical control. This is a very useful invention from an industrial and practical point of view, as there is no need to worry about the troublesome nerves even when sewing work is interrupted and restarted.

[Brief explanation of drawings]

1 to 4 are schematic diagrams of the main parts of the sewing machine mechanism controlled by the control circuit according to the present invention, and the cross section in FIG. 1A is the 1-1 cross section in FIG. 3, and the cross section in FIG. Fig. 4 is a view taken along arrow N in Fig. 1 A, Fig. 5 is a control circuit diagram showing an embodiment of the present invention, and Fig. 6 is a switch for release cam and automatic/manual switching. and detailed diagrams of related switches, No. 7
FIG. 7a is a detailed view of the selection cam switch cam and its related switches, and FIG. 7b is a skin-to-skin sectional view of FIG. 7a. In the figure, 29' is a driving pawl that is the main element of the driving device, selection solenoid 32 is a solenoid device that engages and disengages the driving pawl, ratchet wheel 42 is the main element of the selection device, M is a sewing machine motor, and thyristors SCRA to SCRH is the main element of the switching circuit, S^~SH is the pattern selection switch, S2A
~S2 is a switch device that operates in synchronization with the selection cam. Figure 1 Figure 1 Figure 2 Figure 3 Figure 4 Figure 6 Figure 7 Mountain boat

Claims (1)

[Claims] 1. A plurality of sewing pattern generation signal carriers, a follower for extracting the signals, and enabling a specific carrier among the plurality of sewing pattern generation signal carriers in accordance with the selected pattern. In a sewing machine equipped with a selection device,
A switching circuit including a driving device for driving the selection device, a solenoid device for engaging and disengaging the driving device from the sewing machine motor power, and a thyristor provided for each of the plurality of sewing pattern generation signal carriers, any of which a switching circuit for activating the solenoid device to engage the drive device with the sewing machine motor power based on conduction; and for selecting one of the plurality of sewing pattern generation signal carriers. A switch for selecting a pattern, which is provided corresponding to each carrier and manually operated, supplies an ignition voltage to the gate of a specific thyristor through the switch for selecting a pattern in response to the operation. A pattern selection switch and a switch device operating in synchronization with the selection device to open the main circuit of the specific thyristor corresponding to the operation of the pattern selection switch and to close the main circuits of other thyristors. 1. A pattern selection control circuit for a sewing machine, comprising a switch device for establishing an effective positional relationship between the sewing pattern generating signal carrier and the follower, which are paired with the specific thyristor.