WO1988005092A1

WO1988005092A1 - Control device for a sewing machine having a variable speed motor making it usable by a handicapped operator

Info

Publication number: WO1988005092A1
Application number: PCT/FR1988/000011
Authority: WO
Inventors: Philippe Camus
Original assignee: Philippe Camus
Priority date: 1987-01-08
Filing date: 1988-01-07
Publication date: 1988-07-14
Also published as: AU1109888A; FR2609564A1; KR890700709A

Abstract

Sewing machine (1) with a variable speed motor, made usable by a handicapped operator. The control device comprises variation means (9) for varying the motor speed under the control of a displacement detector (7) mounted on a flexible adjustable support (8) to make the detector sensitive to a frontal displacement of the operator so that the operator has his hands free. An electronic box (5) contains processing means (9) for processing information from the detector translating the frontal displacements of the operator in order to produce a motor speed variation control signal and has an operation switch (80) which alternatingly determines the intervention of said processing means (9) or the usual control of the motor from a pedal (4).

Description

DEVICE FOR CONTROLLING A SEWING MACHINE WITH A VARIABLE SPEED MOTOR, MAKING IT USABLE BY A HANDICAPPED OPERATOR

The invention relates to the control of an electric motor machine such as a sewing machine, involves a device for progressive control of the speed of the electric motor. It aims to make the machine used by a disabled person.

It is known to vary the cost speed of an electric sewing machine by means of a variable-stroke pedal that the operator operates with u of his feet to vary the speed of the electric motor. For certain operators, in particular disabled persons deprived of the use of the legs, the operation of this foot control is impossible.

The object of the present invention is therefore to provide control of the variable speed electric motor of a sewing machine, by a device which is sensitive to the position of the operator relative to the machine, so that the latter This keeps your hands free so that you can, for example, move the fabric through the needle of a sewing machine.

The technical world has often been concerned with developing clean motor control devices for use by people with physical disabilities. These are most often very complex devices which allow the user, for example, to control the movement of a wheelchair, including in the direction

The control of a sewing machine poses specific problems which have not been satisfactorily resolved. In practice, little thought has been given to replacing the usual pedal, controlled by the foot, with a member of the same type, but accessible on the table of the sewing machine to be operated by pressure by hand or by the elbow, or by the bust. Such devices have no other use than to vary the speed of the motor driving the needle of the sewing machine. But they remain ill-suited, in particular in that they do not provide the necessary precision and in that they interfere with the disabled user in the overall operation of the operations, since he should keep the full use of his hands to move the fabric during sewing.

The present invention provides a better solution than the previous devices, especially suitable for controlling the motor of a sewing machine in speed, it being understood however that it can also be applied to any similar machine. It allows the operator not only to keep his hands free, but also to ensure the control of a variable speed motor by the forehead, hard organ and plane of the human body precise in its movements. In addition, the disabled operator very easily acquires the reflex of pushing forward forwards to increase the sewing speed and vice versa.

The subject of the invention is therefore a device for controlling a sewing machine with a variable speed motor, making it usable by a disabled operator, characterized in that it includes means for varying the speed of the motor under the control of a displacement detector mounted on a flexible suppo adjustable in position to make the detector sensitive to a displacement of the operator's forehead, said means comprising an electronic box containing means for processing information from the detector translating the frontal movements of the operator to produce a control signal for the variation of the motor speed.

The above case is advantageously designed to be able to be mounted on the base supporting a conventional sewing machine, at the same time as the flexib support carrying the detector, fixed on the same base or on the housing itself.

Preferably, means are also provided for adjusting said processing means to adjust the sensitivity of the detector to the movements of the operator at a nominal speed of the motor.

According to another characteristic of the invention, a device for controlling a machine for the disabled, such as a sewing machine, comprises means for transmitting information from the detector to said processing means, which are ducts wrapped in said support. flexible. The latter is advantageously in the form of a conduit formed by a succession of washers hinged together, so that it can be deformed manually over its entire length.

These transmission means can in particular be constituted by electric wires transmitting a sign emitted by a detector of the optical or ultrasonic type which is applied to the processing means to supply the signal for controlling the speed variation of the motor. Such a detector has the advantage of being able to operate without contact, by reflection of radiation on the flat and rigid surface of the operator's forehead.

An optical type detector advantageously comprises a photocoupler or similar means, comprises an infrared radiation emitter and a receiver sensitive to reflected radiation, the opti path of which is variable in length according to the movements of the operator. The photocoupler can be associated with a push button comprising a reflective surface movable under the pressure of the operator, against a spring designed to have a resistance significantly lower than that of the flexible support. But preferably - - the photocouple works without contact, depending on the intensity of the infrared radiation directly reflected by the operator's forehead. The output signal of the photocoupler has an amplitude all the greater as the reflective surface is close to the photocouple. Especially in the case where the reflective surface is not constituted by a movable material member of the devices but directly by the operator, it is advantageous to provide electronic means for filtering frequencies, or wavelengths, to avoid disturbances by parasitic radiation.

The same characteristics apply to the case where the photodetector is replaced by an ultrasonic detector except that in this case, as it is known per se, the distance information (used to control the speed) is deducted from the time elapsing between a pulse produced on transmission and an echo pulse received after reflection.

The signal processing means can be embodied in different forms by means of conventional electronic circuits incorporated in the electrical box. In general, these circuits mainly comprise a power supply circuit, an amplifier of the detector output signal, a comparator between the amplified signal and a synchronization signal at the frequency of the power supply signal of the electric motor. power receiving the comparator output signal and providing a motor control signal. They may further comprise a circuit encoding the frequency of the emitter of the photocoupler and a decoder-discriminator circuit of the frequency of the signal of so of the photocoupler and supplying a signal which is applied to the amplifier.

Other characteristics and advantages of the present invention will appear on reading the following description of several particular examples realization in relation to the attached drawings in which:

- Figure 1 is an overall schematic view of a sewing machine according to the invention with a functional diagram of the associated electronic circuits;

- Figure 2 is a sectional view of a mechanical type detector which can be used in the electric motor control of such a machine;

- Figure 3 is an electrical diagram function of an electronic circuit which is associated with the detector of Figure 2;

- The figure is a sectional view of a mechanical / electronic type of detector which can be used in a more sophisticated control of the machine's electric motor;

- Figure 5 is an electrical diagram function of the electronic processing circuits associated with the detector of Figure M;

- Figure 6 is a sectional view of an electronic type detector which can be used as a variant of that of Figure M;

- Figure 7 is an electrical diagram function of the processing circuits associated with the detector of Figure 6;

- Figure 8 is a diagram to replace that of Figure 7 in the case where an ultrasonic detector is used rather than a photocoupler.

A conventional type sewing machine has been shown diagrammatically at 1 in FIG. 1. In this machine is integrated an electric motor with variable speed (not shown) which is supplied electrically by a connection cable 2 and whose variation in speed is controlled by an electrical signal reaching the machine by a cable 3- - 6 -

To vary the speed of the sewing machine by a non-disabled operator, a pedal is usually used - the stroke of which, controlled by the operator's foot, is a measure of the speed that the operator wants to communicate to his machine , i.e. the speed of the sewing machine will be all the more greasy when the pedal is depressed. Some handica operators cannot operate such a pedal. This is particularly the case for paraplegics. Also, according to the present invention, it is planned to replace this pedal at will with a position detector of another part of the operator's body, here the head, associated with circuits contained in an electronic unit.

We thus see in Figure 1, the diagram of this electronic unit 5, supplied with electrical energy and interposed between the pedal and the engine of the machi

(cable 3) “The detector is schematically represented 7. It is mounted at the end of a flexible support arm which envelops the mechanical or electrical cables transmitting the information emitted by the detector 7 to the electronic unit 5.

A base on which the various elements of the machine according to the invention are fixed (except for a peda 4), has not been shown in the figure, because its shape and design will depend on the achievements chosen by manufacturers of sewing machines or on the choice of users. However, it is considered that this base carries the housing 5 and that the flexible support 8 is fixed thereto by an end opposite to that which carries the detector. The length of the support 8 and the amplitude of its possible deformations are such that the end carrying the detect can be brought manually in the immediate vicinity of the forehead of an operator using the machine. In practice, support 8 is made of a tube known per se, consisting of a series of rings hinged on each other so that it can be deformed by curvature in all points of its length.

In the electronic unit 5, a processing circuit 9 is schematically represented to which the information coming from the detector 7 is applied. This circuit provides a signal for controlling the variation of the motor which is transmitted by the cable 3 via the 'A reversing device 10 controlled by a switch manually accessible from outside the housing. This makes it possible to determine at will either the intervention of the circuit 9 and of the control by the detector 7, or the direct control by the pedal 4, also connected to the reversing device 10. However, in the commercial implementation of the device of the invention , such a reversing switch is not necessary, and two commands are connected in parallel to the rheostat which determines the speed of the motor.

A sensitivity adjustment device 81 e also incorporated in the housing 5. It acts on the production of the control signal by the processing circuit 9 as a function of an adjustment button 82 manually actuated from outside the housing. This setting allows the sensitivity of the detector 7 to the operator's frontal movements to be adjusted to a nominal speed of the motor.

The circuits for processing the information supplied by the detector will be described below in different embodiments in conjunction with variant designs of the detector 7.

In FIG. 2, the detector used according to the invention is of the mechanical type and comprises a cable which can slide in a sheath 12, the cable-sheath assembly being housed in a flexible support 13. Each end of the flexible support 13 is fitted in a tip 14 or 15. The tip 14 constitutes the body of a push button which consists of a push button 16 and d return spring 17. The pusher 16 has a cylindrical outer part 18 which slides by sliding around the body 14 and an axial part 19 which is fitted by sliding in an axial hole 20 of the body 14, the axi hole being extended by an axial hole 21 which receives one end of the flexible support 13 - The axial part 19 is fixed to the end of the cable 11 so that the displacement of the pusher 16 causes that of the cable in its sheath 12, sheath which is integral with the flexible support 13. The return spring 17, which works in compression, has one end in contact with the front face 22 of the pusher and one end in contact with a shoulder 23 of the body 14.

At the other end of the flexible support 13, the end piece 15 is fixed in a known manner to the wall 24 of an electronic unit 33 containing an electronic circuit, the functional electrical diagram of which will be described in relation to FIG. 3. wall 24 of this housing is associated with a cable clamp 25 provided with a locking screw 26 which keeps it fixed on the cable 11. Coming into abutment on the wall 24, this cable clamp limits the movement of the cable 11 under the spring loading 17.

The end 27 of the cable 11 is connected to a mechanical control of a potentiometer 28 (Figure 3) which is part of the electronic unit. This potentiometer 28 is connected to a device 29 for controlling the phase angle and conduction of an electric motor 30 which is that of the sewing machine. A power amplifier 31 is connected between the device 29 and the motor 30, while a potentiometer 32 is connected to the device to adjust the nominal speed of use.

The operation of the assembly of the motor speed control device 30 is as follows. By pressing the pusher 16 from the front, the operator moves the cable 11 in translation in the sheath 12 of the flexible support 13, which varies the position of the potentiometer 28 which then provides an electrical signal d proximity position which is used to control the control device 29- After amplification in the amplifier 31, the output signal from the device 29 controls the power supply to the motor 30 so as to vary the speed of rotation.

In FIG. 4, the detector 40 according to the invention is of the mechanical type in that it implements a pousso 41 with a return spring 42, at the same time as it is of the electronic type in that it puts in uses a photocoupl 43 which provides an electrical signal.

The photocoupler 43, which comprises in an known manner an infrared emitter 44 (FIG. 5) and a receptacle 45, is housed inside a hollow end piece 46 whose cylindrical outer surface cooperates by sliding with the pusher 41. The spring of reminder 42, which works in compression, tends to move the pusher 41 away from the photocoupler 43 and there is a circlip 47 mounted in an inner groove of the pusher 41 and abutting on the rear of the end piece 46 to maintain the pusher 41 aut of the end piece 46 despite the effect of the spring 42. The front part 48 of the pusher 41 has an internal surface 49 which reflects the infrared radiation emitted by the emitter The photocoupler 43 is connected to an electronic box or circuit 50 (FIG. 5 ) by a flexible support 51 which contains the connecting electrical wires 52 transmitting the information from the detector.

It will be noted that the spring 42 (as indeed the spring 17 of the previous embodiment) has a resistance much lower than that which could cause untimely deformation of the flexib support itself.

As shown in FIG. 5, which is a functional diagram of a device for controlling the speed of an electric motor implementing the posit detector 40 described in relation to FIG. 4, the housing or electronic circuit 50 includes a power supply circuit 53 which supplies the photocoupler 43, an amplifier 54 a comparator 55. A power interface 56, controlled by comparator 55, is connected to the motor 30 of the sewing machine. A potentiometer 57, connected to the amplifier 54, allows manual adjustment of the nominal speed of use of the motor 30 as a function of the sensitivity of the frontal displacement desirable for the detector 40.

In Figure 5, there is also shown in schematic form, in a frame 58, the position detector of Figure 4 with its reflective surface 49 the arrows 59 indicating the direction of infrared radiation.

The operation of the control device of an electric motor described in relation to Figures 4 e

5 is as follows. The electrical signal supplied by the photocoupler 43 has an amplitude the greater the greater the reflective surface 49 is closer to the photocoupler 43. This electrical signal is applied to the interface 54 whose output signal is applied to the comparator 5 which also receives a synchronization signal at the sector frequency of the power supply circuit 53. This is the output signal from the comparator 55 which controls the motor 30 via the power amplifier 56

In FIG. 6, the detector 60 according to the invention is of the entirely electronic type and does not comprise any moving part. It includes, as for the position detector of FIG. 4, a photocoupler 61 which is housed in a body 62 having the external shape of a cylinder whose front part, on the photocoupler side 61, is closed by an infrared filter 63, and the rear part of which serves as a tip for a flexible support 64 enveloping electrical wires 65 which conduct the displacement information emitted by the detector.

The box or electronic circuit 70 of the figu 7 is similar to that of FIG. 5 in that it comprises a power supply circuit 66, an amplifier 67, a comparator 68, a power interface 69 and an adjustment tiometer bud 72. But it differs from it in which it further comprises a frequency coder 71 which controls the infrared transmitter 44 and a frequency decoder-discriminator 73 which decodes the signal detected by the infrared receiver 45.

The operation of the electric motor control device described in relation to Figures 6

7 is partly the same as that of FIGS. 4 and 5. control signal for the variation of the motor is produced as a function of the intensity of the infrared radiation received by the receiver 45.

The distance which determines this intensity is that which separates the photocoupler from the front of the operator placed in front of the filter 63. In connection with this particularity, the frequency coding and decoding make it possible to avoid measurement disturbances which could cause parasitic radiation. emitted by the operator environment.

Naturally, the transmitter and the receiver of infrared radiation which have been described integrated together in a photocoupler could as well be constituted by two separate members mounted in the detector.

In the variant of FIG. 8, the photocouple is replaced by an ultrasonic emitter-detector associated with the appropriate equipment. In this figure, the motor 30 is shown, connected to the electrical network at 8 with the electronic unit 80, and on the other hand the ultrasonic detector 88, placed in front of the operator's forehead 82. In the housing 80, as in the previous case, there is a power source 86, a comparator amplifier 83 and the interface 89, as well as amplifier 84, with gain adjustable at 85 to grant the sensitivity of the device as a function of the desired nominal speed. The specific equipment for ultrasonic detection includes a clock 87, time base and pulse generator, an analog switch 9 which transmits the transmission pulse to the detector 88 and which receives the echo pulse from this detector for transmit, via an amplifier 90 and a shaping circuit 91, to a detection circuit 92. The latter provides a signal proportional to the time separating the two pulses to send it to the comparate 83 via the amplifier 84.

The invention has been described with the aid of several specific embodiments and in its application to the control of the motor speed of a sewing machine. However, the invention is not limited to these exemplary embodiments or to the illustrated application. All kinds of variants can be made to the particular embodiment which has been described by way of example and to its constituent elements without departing from the scope of the invention.

The invention thus encompasses all the means constituting technical equivalents of the means described as well as their combinations.

Claims

1. Control device for a variable speed motor sewing machine, making it usable by a disabled operator, characterized in that it comprises means (9) for varying the motor speed under the control of a displacement detector (7 mounted on a flexible support (8) adjustable in position p to make the detector sensitive to displacement of the operator's front, said means comprising an electronic unit (5) containing processing means (9) for information from the detector translating the front displacements of the operator to produce a signal for comma of the speed variation of the motor.

2. Device according to claim 1, character ized in that said flexible support (8) is deformable manually by curvature over its entire length.

3. Device according to claim 1 or 2, characterized in that said housing (5) comprises means for parallel connection or an operating switch (80) alternately determining the intervention of said processing means (9) or the command usual engine from a pedal (4).

4. Device according to claim 1, 2 or 3, characterized in that it further comprises means (81,82) for adjusting said processing means (9) to adjust the sensitivity of the detector (7) to displacements operator on a nominal motor speed.

5. Device according to claim 2, 3 or 4, characterized in that it comprises means for transmitting information from the detector to said processing means which are ducts wrapped in said flexible support

6. Device according to claim 5, character ized in that said transmission means consist of a cable (11) mechanically connecting a push button (16) of the detector actuated by the operator to a potentiometer (28) whose variation in resistance as a function of the movements of the push button provides the signal for controlling the speed variation of the motor.

AND

7- Device according to claim 5, caracté¬ ized in that the displacement detector (40) comprises u transmitter (44) and a receiver (45) of radiation, and a push button (41) having a reflective surface (49 ) mobile under the pressure of the operator, which reflects 0 towards the receiver (45) the radiation received from the transmitter (44), the output signal from the receiver (45) having an amplitude the greater the greater the area reflis¬ health (49) is close to him.

8. Device according to claim 5, characterized in that the displacement detector (60) comprises a transmitter (44) and a receiver (45) of radiation, associated with a bandpass filter (63) transparent in the infrared the output signal from the receiver (45) being characteristic of the position of the operator whose front reflects towards him the radiation from the transmitter (44).

9. Device according to claim 6, 7 or 8, characterized in that it comprises electronic circuits comprising a supply circuit (53 or 66), an amplifier (54 or 67) of the output signal from the photocoupler 5 43 or 61), a comparator (55 or 68) between the amplified signal and a synchronization signal at the frequency of the electric motor supply signal (30) and a power interface (56 or 69) receiving the output signal of the comparator (55 or 68) and supplying a signal 0 for controlling said motor (30).

10. Device according to claims 8 and 9, characterized in that the electronic circuit further comprises an encoder circuit (71) of the frequency of the transmitter (44) and a decoder-discriminator circuit (73) of the frequency of the receiver output signal (45) and providing a signal which is applied to the amplifier (67).

11. Device according to claim 5, characterized in that the displacement detector (88) is of ultrasonic t, operating by reflection of an ultrasonic pulse on the forehead of the operator.