JPS5917388A - Electromotive sewing machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric sewing machine, and in particular, to an electric sewing machine, the sewing mode can be switched between straight stitch and zigzag stitch, and the sewing machine can switch between straight stitch and jig stitch.
1' to improve the electric sewing machine where the knife plate and jig 1f needle plate can be replaced! ljiru.

Conventionally, some electric sewing machines capable of performing straight stitches and zig-zig stitches had lead plates replaced depending on the sewing mode.

FIG. 1 is a perspective view showing one plate for straight sewing.

As shown in the figure, a round hole H1 is formed in the straight sewing lead plate NPI to the extent that the tip ε1 of the sewing button NDL can pass therethrough. This round hole H1 is straight! When fA sewing lead plate NY] 1 is attached to the electric sewing machine body (not shown), the sewing ωt
Located at the bottom of NDL, it guides and covers the vertical movement of sewing sword NDL. This prevents the seams from shifting.

FIG. 2 is a perspective view showing a jig rig sword plate.

As shown in the figure, the throat plate NP2 for zigzag sewing has long holes 1-
12 is formed. The width of the long hole 1-12 in the longitudinal direction is the swing width (
5-7I11111). Long hole 1-
12 is located at the bottom of the sewing needles ND and L when the zigzag lead plate NP2 is attached to the electric sewing machine body (not shown in the figure).
ε1 so as not to interfere with the jigging movement ahead &1l
Guides the vertical movement of ilNDL.

However, in conventional electric sewing machines, the set plate N for straight 5sta
P 1 iI! ! If you perform zigzag sewing with the sewing needle attached, the tip of the sewing needle Nl)L cannot pass through the round hole 111 because the round hole 111 is small. Therefore, I sword N D
The L needle tip tentatively hit the nail, causing the ε1 tip to bend or break, which was very dangerous.

Therefore, the main object of the present invention is to eliminate the above-mentioned drawbacks and provide a safe Wi electric sewing machine lfi.

In summary, this invention is configured such that a straight stitch mode and a needle plate for zigzag stitches can be switched, and a lead plate for straight stitches and a needle plate for zigzag stitches are switchable. In an electric sewing machine where the plate is replaceable, it is possible to detect which mode is selected, straight Ii1gI mode or zigzag stitch mode, and whether a straight stitch needle plate or zigzag stitch sub plate is attached. is detected, and based on the detection result, in the case of the jig sewing mode, the speed control means of the sharpener motor to which the straight needle plate is attached is disabled.

Object J3 of this invention, as well as other objects and features, will become more apparent from the following detailed description with reference to the drawings.

Figure 3 shows the straight sewing lead plate N1) 10 used in this invention.
It is a sectional view showing an example. As in FIG. 1, a round hole 1-11 is formed in the self-line sewing ρ1 plate N P 10. Furthermore, four parts 2 are formed on the lower surface 1 of the straight sewing lead plate NPIO. On the other hand, the main body of the electric sewing machine (not shown) is provided with a switch SW1, which is an example of a copper plate detection means. As this switch SW1, a so-called limiter 1 switch or the like is used. The switch SW1 has a push button 3 for switching internal contacts (not shown). When the direct ml lead plate N P 10 is installed in the main body of the electric sewing machine, the push button 2 fits into the recess 2 and the push button 2 is not pressed.

Figure 4 shows the needle plate N P for zigzag sewing used in this invention.
20 is a cross-sectional view showing an example of 20. FIG. This zigzag sewing needle plate NP20 may be similar to the conventional zigzag sewing throat plate NP2 as shown in FIG. 2, and its lower surface 4 has four parts as shown in FIG. There is no blow C. Therefore, when the zigzag sewing needle plate NP2O is attached to the electric sewing machine main body, the F surface 4 presses the push button 3 of the SWIP-SWI, and the internal contact of the switch SW1 is switched.

Note that a photoelectric switch or the like may be installed in place of switch SW1.
No is fine. In addition, a permanent magnet C1 is attached to either one of the straight sewing assembly plate N P 10 and the zigzag sewing assembly plate N 1) 20, and a magnetically sensitive element (Hall element, etc.) is installed on the electric sewing machine body at a position facing the permanent magnet. ) may be provided to magnetically detect the type of assembled board mounted.

FIG. 5 is a circuit diagram showing one embodiment of the present invention. 43 in the configuration, the plug PL is, for example, a commercial electric plug PL.
A full-wave rectifier die is installed at both ends of the output of 4-1:D'
A series circuit with 4 and D5 and a series circuit with diodes D6 and D7 are connected in parallel. Furthermore, a series circuit of 5CR (relay resistor) 1 and 5CR2 is connected to both ends of the output of the plug PL.

This S CR1 and SC [The two series circuits are
[ ] 4 O J, and Dia j -1' D In cooperation with 5, a full-wave rectifier circuit is constructed, and its conduction phase is controlled to control the amount of power supplied to the electric IIJ machine M, and II-d Ru. 5C
A voltage is connected between the connection point of the cathodes of R1 and SCR2 and the connection point of the anodes of the diodes 1)4 and D5. The electric motor M is, for example, a series motor, and both ends 1 and 2 of the field coil FC are connected to freewheel dies A and D3.

On the other hand, the output of the full-wave rectifier circuit composed of diodes D4 to D7 is applied to both ends of a constant voltage diode ZD via a voltage drop resistor R5.

Therefore, a constant trapezoidal wave voltage is generated across the constant voltage diode ZD. This constant voltage diode ZD
The 13th sword is connected to P via the resistor R8, the 1st collector J3 of the l-transistor 1R, and the variable resistor V11.
It is connected to the anode of UT' (one programmable two-junction transistor). The transistor 4'R has a switch S W 1 a3 which will be described later.
J: is controlled by switching of SW2 and SW2. Then, the power supply J to the frost-block M and the cutoff of the power supply are controlled by the transistor TR.

The variable resistor VR is connected to the so-called foot 1 to controller pedals for controlling the speed of the electric sewing machine, and its resistance value is controlled in series depending on how long the pedals are pressed. be done. Furthermore, the anode of PUT is connected via a capacitor C (constant voltage diode f
Connected to the anode of D. This capacitor C, variable resistor vR, resistor 1 to transistor 11, and resistor R8 constitute a so-called CR time constant circuit. The cathode of the PUT and the anode of the constant voltage diode ZD are connected to both ends of the primary winding of the pulse transformer P1. A constant bias voltage divided by
An oscillation circuit is constructed with a variable resistor vR, a transistor 1R, and a resistor R8, and the oscillation period is determined by the time constant of the CR time constant circuit (e) above.
Apply pulse voltage to the next winding. Therefore, Palst U]
/S 1) A pulse voltage is applied to the secondary winding of 1.

One end of the secondary winding of pulse 1 to lance 1)-1 is connected to the respective anodes of diodes D1 and D2.
LZ>. '/-(-A-doD 163J: and D2's 1! are respectively connected to the gates of SCR163 and SOR2 via anti-[<1 and 2) !; Also, a resistor R3 is inserted between the gate 1- and the cathode of SC, R1.
A resistor R4 is inserted between the gate of the circuit and the circuit board.

The switch SW1 as shown in FIG. 3 J3 and FIG. 4 has an internal contact and an L common contact a1. Includes cutting contacts b1 and C1. The common contact a'l is connected to the anode of a constant voltage □voltage diode door 1]. t, the switching contact b1 is connected to the base of the transistor 1'R through resistors R10 and R9.This resistor R10 is connected to the base of the transistor T when the zigzag sewing nail plate N P 20 is attached. One base current light path of 11 is inserted to reduce the conductivity of transistor TR.The maximum speed of J: C1 is set low.Switching terminal c11.LI-ED( A light emitting diode (light emitting diode) and a resistor (11 and n) are connected to the cathode of a constant voltage diode (ZD).

Here, the contact switching operation 1γ of the switch SW'I will be briefly explained. As shown in Fig. 3, when the straight sewing assembly plate N P 10 is attached, the switch SW
The pushbutton 3 of No. 1 is pressed. At this time, the common contact a1 is connected to the switching contact C1.

Conversely, when the zigzag assembly plate NP2O is mounted and the push button 3 is pressed as shown in FIG. 4, the common contact a1 is connected to the switching contact b1.

The mode changeover switch SW3 is a switch for switching the mode 1 of the electric sewing machine between a straight stitch mode and a zigzag stitch mode. A switch SW2 is installed in conjunction with this mode changeover switch. This switch SW
2 includes a common contact a2 and switching contacts b2, J: and C2, similar to the switch SW1. The common contact a2 is connected to the anode of the constant voltage diode ZD. The switching contact b2 is connected to the base of the 1-transistor TR via the aforementioned resistor R9. The switching contact C2 is in the flow 1~state.

Here, regarding the relationship between the mode switching operation of the mode selection switch SW3 and the contact switching operation of the switch SW2, -C1
1! 7 without explaining to the person in question. Mo1=' + sword change switch S
Straight line Gi by W3! -E- mode, the common contact 82 is connected to the switching contact 1)2.

Conversely, when the zigzag sewing mode is switched by the seven-way changeover switch SW3, the common contact a2 is switched to the changeover contact C.
Connected to 2.

Operation smell - C1 maf mode changeover switch S ~ ■ 3 to J
:Explanation when straight stitch mode is selected J
Ru. In this case, the common contact 82 of the switch SW2 is connected to the switching contact b2 as described in 1-1.

Therefore, 1 to base J of transistor TR, 1
The current from the full-wave rectifier circuit (consisting of diodes D4 to D7) is delivered through the resistor [<9].

Then, the transistor TR is turned on, and the transistor ``[1 (d, resistor R8, variable resistor VR, etc.]
The output of the time constant circuit consisting of capacitor C etc.]j is P
tJ given to T. P LJ T oscillates at a period determined by the time constant of the time constant circuit. This oscillation output is connected to the diode D1i13J via the pulse 1-run transistor P1.
:Bi1]2 is given. In response, diodes D1 and D2 turn on, causing 5CRI and S'CR, respectively.
Apply a trigger current to 2. Therefore, S CRI J
5 and 5CR2 alternately pass through every half cycle of the AC power supply to give the motor M an f4 current. Here, when the resistance value of the variable resistor VR is changed by pressing the roll pedal to buttons 1 to 1 (not shown), the time constant of the above-mentioned time constant circuit changes, and the oscillation period of PUT changes. . Correspondingly, the conduction phase of 5CR1 and SCR2 changes during each half cycle of the AC power supply. by this,
The amount of power supplied to the electric motor M changes, and the rotational speed of the electric motor M changes. In other words, the resistance of variable resistor VR
: By changing the filling, the rotation speed of the electric KIM can be changed.

Here, it is assumed that the electric sewing machine main body is equipped with the straight sewing assembly plate NP10. In this case, switch SW
1 common contact 81 is connected to switching contact C1. Therefore, the energizing current increases in the LED.

The LED lights up. When the LED lights up, the user can confirm that the straight sewing ε1 plate NPIO is attached:
be able to recognize that

Next, use the mode changeover switch SW3 to select Jig 1 or Wa.

1-], l)"; RIR8n□8.3., 工 yo m'
j'A. □□ In this case, the common contact a2 of the switch SW2 is connected to the switching contact C2. - Nowadays, I installed a nail plate NP2O for zigzag sewing on the main body of my electric sewing machine.
When the switch SW1 is installed, the □common contact a1 of the switch SW1 is connected to the switching contact b i. However, from the base of transistor TR, resistors R9 and R
The current from the full-wave rectifier circuit is supplied via 10. In response, transistors i to TR become conductive. Thereafter, the sewing machine performs the sewing in the same way as in the straight stitch mode, and the electric IJIM is energized. Note that, unlike when the straight sewing nail plate NP10 is attached, there is a resistor R in the base current path from 1 to the transistor TR.
9 as well as a resistor R10 are inserted. Therefore, the current supplied from the base of transistor TR becomes smaller, and the degree of conduction of i-transistor TR also becomes smaller. Therefore, the maximum rotational speed of the electric 1% iM is lower in the zigzag stitch mode than in the straight stitch mode.Generally, zigzag stitches are sewn at a lower speed than straight stitches. It is preferable that the fifth
In the circuit shown, stitch 4! Automatically emit electricity depending on the type of poison.
The speed of the lI machine M has been roughly set, making it extremely practical. is high.

Here, a case will be described in which the zigzag sewing mode is selected even though the straight copper plate NP10 is attached. In this case, the common contact a of switch SW1
It is connected to the switching contact C1.

Therefore, the base current path of the 1-ran transistor TR is separated from the full-wave rectifier circuit, and no current is applied to the base of the 1-ran transistor TR. For Lee’s sake!・Ran resistor T
R becomes A-f, and PUT does not oscillate. Therefore-(,
sc-+ti and 5CR2 are turned on, electric);(
Power is not supplied to M. In other words, straight sewing nail plate N
l) If Jig 1 is attached and Jig 1
When f-g stitch mode is selected 1. Lr! ia force IE
Rotation of JM is prohibited. As a result, the conventional J, Unaω1. This prevents dangers such as bending.

In the circuit shown in Figure 5, the jig sewing button plate NP2
When the zigzag Vl-Th-mode is selected when O is 81, a resistor [≧10] is inserted in the base current path of the transistor TR, and the maximum rotational speed of the motor M is the same as the zigzag Vl-Th-mode. The settings are set to those suitable for the sewing mode.

According to the above-described J: sea urchin, according to the embodiment shown in FIG.
Next J: Various effects are produced.

First, bending and breaking of the sewing needle due to the installation of the needle plate and the switching of the tI mode (3FU), which occurred at the end of the sewing machine, is prevented, making the electric sewing machine extremely safe.

Also, check whether the needle plate of the chair is installed.
, it is possible to reduce the number of incorrect installations of copper plates.

Furthermore, depending on the installation of the nail plate and the switching of the mode, 1~
The conductivity of transistor TR can be changed! Therefore, it is possible to automatically set the electric motor N4 to an unusual speed J11, which is of great practical value.

In addition, the rotation of 'tri 1IIa M is prohibited to prevent danger, and the speed setting and J: bypass circuit (14), which is performed by Jl 1-transistor TR, are created, making the circuit configuration extremely simple and inexpensive. can spell.

As mentioned above, in this invention, in the zigzag sewing mode, the speed control means of the electric motor is disabled only when the straight plate 11 is attached, so there are two steps.
Even if a nail board is installed at a later date, the conventional sea urchin set is prevented from bending, breaking, or hanging. Therefore, a very safe electric sewing machine can be obtained.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a nail plate for straight sewing. FIG. 2 is a perspective view showing a nail plate for sewing a jig leg. FIG. 3 is a sectional view showing an example of the nail plate NPIO for straight sewing used in the present invention. FIG. 4 is a sectional view showing an example of the ωl plate NP2O for zigzag sewing used in the present invention. FIG. 5 is a circuit diagram showing an embodiment of the present invention.

Claims (5)

[Claims] (1) Control the power supply (PL), the electric current (M) that is turned on by the power supply (PL>), and the current given to the electric motor IN (M) from the power supply (1) L). 1011 speed steps (SC) for controlling the rotational speed of the electric motor (M).
R1, 5CR2, VR), the IH is configured so that the straight line and the jig & IE can be switched,
In an electric sewing machine in which the nail plate for straight stitching and the sword plate for jig stitching are interchangeable, in response to the switching of the mode,
mode detecting means (SW2) for detecting which of the zig-zig sewing mode and the zig-zig sewing mode is selected for each straight stitch mode 1; Detection by the nail plate detection means (SWl), +15 and the mode detection means (SW'2) for detecting whether the nail plate for zigzag sewing is attached or not, and the SI nail plate detection means SW
In the case of the zig-zig stitching mode, a disabling means (T) disables the speed control means (SCR1, 5CR2, VR) only when the straight nail plate is attached. An electric iFJ+ sewing machine characterized by having R>. (2) means (R10) for switching the speed control 11 range by the speed control means (SCR1, 5OR2, VR) based on the detection by the mode detection means (Sψ2) and the detection by the nail plate detection means (SWI'); )including,
An electric sewing machine according to claim 111. (3) 111th speed 11JI11-1 (SCR1,5
CR2, VR) is applied to the switching element with control electrode (SCR1, 5CR2) inserted in the main power supply path of the electric motor (M) and the control t911 electrode of the switching element with control electrode (SCRI. 5CR2). Means (1) for generating a voltage to conduct the switching elements with control electrodes (SCR1, SC'R2>) 6.D7.P and 1-"
) and, by its operation, the voltage generating means (1) 6°D7. P
means (VR) for controlling the appropriate phase υII =J of the above-mentioned 1'l till electric current (4; TR) is responsive to the detection by the mode detection means (SW2') and the detection by the nail plate detection means (SWl), and conduction or non-conduction of the child is controlled, and the voltage generation means (D6. 3. The electric sewing machine according to claim 1 or 2, comprising a one-herald resistor ("R") for inactivating and inactivating D7.PUT). (4) The speed control tan range switching means (RIO) responds to the detection by the copper plate detection means by switching the resistors (RIO) connected to the base inputs of the transistors ('l-R).
O) The electric sewing machine according to claim 3, comprising: O). (5) The electric sewing machine according to any one of claims 1 to 4, including means (LED) for displaying the detection result of the copper plate detection means (SWI).