CA1268270A - Device for limiting the overloading of hoisting machines - Google Patents
Device for limiting the overloading of hoisting machinesInfo
- Publication number
- CA1268270A CA1268270A CA000537115A CA537115A CA1268270A CA 1268270 A CA1268270 A CA 1268270A CA 000537115 A CA000537115 A CA 000537115A CA 537115 A CA537115 A CA 537115A CA 1268270 A CA1268270 A CA 1268270A
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- transistor
- flip
- flop
- comparator
- relay
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Abstract
DEVICE FOR LIMITING THE OVERLOADING OF HOISTING MACHINES
ABSTRACT OF THE DISCLOSURE:
The device comprises a tensoresistor bridge, the one diagonal of which is connected to a supply voltage, while the other diagonal is connected to an amplifier, a flip-flop and a relay, the one end of which is connected to the positive pole of a supply source and its other end - to the collector of a transistor. In parallel to the relay there is connected an opposite diode. The output of the amplifier is connected via three comparators to flip-flops, constant voltage sources, transistors and an optron.
ABSTRACT OF THE DISCLOSURE:
The device comprises a tensoresistor bridge, the one diagonal of which is connected to a supply voltage, while the other diagonal is connected to an amplifier, a flip-flop and a relay, the one end of which is connected to the positive pole of a supply source and its other end - to the collector of a transistor. In parallel to the relay there is connected an opposite diode. The output of the amplifier is connected via three comparators to flip-flops, constant voltage sources, transistors and an optron.
Description
~Z~i82~
The invention relates to a device for limiting the overloading of hoisting machines which can be used in electric monorail hoists, more particularly.
A known device for limiting the overloading of hoisting machines comprises a tensoresistor bridge, the one diagonal of which is connected to a supply voltage, while the other diagonal is connected to an amplifier, a flip-flop and relay, the one end of which is connected to a supply source and the other end to a transistor. In parallel to the relay there is connected an opposite diode. The flip-flop is connected via an integrator, a resistor and a secondopposite diode to the base of the transistor. The base is connected via a third opposite diode and a Zener diode to the amplifier.
The drawbacks of the known device lie in the low accuracy in limiting the overloading and the increased time for switching-off the limited load.
It is, therefore, a general object of this invention to limit the overloading of hoisting machines, which is featured by an increased speed of response at a high accuracy of limiting the overloading.
In the present application, the term "flip-flop"
should be understood as meaning a --monostable multivibrator--.
According to the present invention, there is provided a device for limiting the overloading in hoisting machines comprising a tensoresistor bridge having two diagonals, one of said diagonals being connected to a supply voltage, and another of said diagonals being connected to an amplifier, a first flip-flop and a first relay, one end of said first relay being connected to a positive pole of a supply source and another end of said first relay being connected to a collector of a first transistor, and in parallel to said first relay there being connected a first 9 ~ . ~
~Z6E~Z7V
opposite diode, device which further comprises:
- a first, a second and a third comparator, each comparator having an input and an output, said three -1268Z~3 comparators being connected to an output of said amplifier, - said output of said first comparator is connected to said first flip-flop and to said second flip-flop, said second flip-flop being connected by means of a regulating resistor to said input of said third comparator, while said first flip-flop is connected to said output of said second comparator, the input of said second comparator being connected to a first source of constant voltage, - said first flip-flop is connected to said second flip-flOp, - said input of said first compa.rator is connected to a second source of constant voltage, - said output of said second comparator is connected to bases of second and third transistors, said second and third transistors having emitters which are connected to the negative pole of a supply voltage, said negative pole being also connected to an emitter of a fourth transistor, said fourth transistor having a base connected to an optron, - said fourth transistor has a collector connected to a second relay, in parallel to which there is connected a second opposite diode, said second relay and said second opposite diode having cathodes connected to the positive pole of a supply source, - said first opposite diode has an anode which is connected by means of a switch to a collector of said third transistor to which there is connected a capacitor having an end connected to the minus of a supply voltage, and - said first transistor has an emitter which is connected to a collector of said second transistor.
According to the present invention, there is also provided a device for limiting an overload in hoisting machines wherein a tensoresistor bridge having two diagonals is provided, one of the diagonals being connected to a ~268270 supply voltage, and another of the diagonals being connected to an amplifier, an output of the amplifier being connected to a first input of three comparators, and an output of a first of the three comparators being connected to a first flip-flop and to a second flip-flop, the second flip-flop being connected via a regulating resistor to a second input of a third of the three comparators, the first flip-flop being connected to an output of a second of the three comparators, a second input of the second comparator being connected to a first source of constant voltage, the first flip-flop being connected to a second input of the second flip-flop, a second input of the first comparator being connected to a second source of constant voltage, the output of the second comparator being connected to bases of a second and third transistor, emitters of which being connected to a negative pole of a supply source, the negative pole being also connected to an emitter of a fourth transistor, a base of which is connected to an optron, which is a photon-coupled pair, a collector of the fourth transistor being connected to a second relay, in parallel to which there is connected a second opposite diode, a cathode of the second opposite diode and the second relay being connected to a positive pole of the supply source, an anode of a first diode being connected via a switch to a collector of the third transistor, to which there is connected a capacitor, a second end of which being connected to the negative pole, an emitter of a first transistor being connected to a collector of the second transistor, an output of the third comparator being connected to a base of the first transistor, a collector of the first transistor being connected to both the anode of the first diode and to a first relay, and an opposite end of the first relay being connected to the positive pole of the supply source.
The advantages of the device for limiting the . "~;.
~ - 3 1~682~
overloading of hoisting machines, according to the invention, lie in its higher speed of response and the higher accuracy of switching-off.
A preferred embodiment will now be described, as example without limitative manner, with reference to the attached drawings, wherein the single figure shows a block diagram of an embodiment of the invention.
The device for limiting the overloading comprises a tensoresistor bridge 1, the one diagonal of which is connected to a supply voltage, while its other diagonal is connected to a differential arnplifier 2. The device contains two flip-flops 3 and 4, and a relay 5 the one end of which is connected to the positive pole of a supply source and its other end to the collector of a transistor 6, while in parallel to relay 5 there is connected an opposite diode 7. The output of the amplifier 2 is connected to the first inputs of three comparators 8, 9 and 10. The second flip-flop 4 is connected via a regulating resistor 11 to the second input of the third comparator 10. The second input of the second comparator 9 is connected to a source of constant voltage 12. The second input of the first comparator 8 is connected to a second source of constant voltage 13. The output of the second comparator 9 is connected to the bases of a second 14 and a third 15 transistors, the emitters of which are connected to the negative pole of the supply voltage. This negative pole is also connected to the emitters of a fourth transistor 16, the base of which is connected to the optron (photon-coupled pair) 17, and its collector to a second relay 18, in parallel to which there is connected a second opposite diode 19. The anode of the first opposite diode 7 is connected via a switch 20 to the collector of the third transistor 15.
In parallel to transistor 15 there is connected a capacitor 21.
~' - 4 -~L~6~270 The device according to the invention operates as follows:
The signal of the disbalanced tensoresistor bridge 1 of the force transducer enters, after being amplified by the differential amplifier 2, the first non-inverting inputs of the comparators 8, 9 and 10. When the amplified measuring voltage is increased, in the moment of its coincidence with the reference voltage of the source 13, the comparator 8 produces a signal of positive polarity which is fed to the inputs R of the flip-flops 3 and 4 which, at that, receive permission for operation. The further increase of the amplified measuring voltage causes its coincidence with the reference voltage of source 12 and, at that, the comparator 9 produces a signal of positive polarity which is fed to the input X 2 of the flip-flop 3, which is actuated by the positive front of the signal and produces a positive pulse in its output Q with a duration which depends on the magnitudes of the capacity of the capacitor and the resistance of the resistor.
The negative front of the pulse from output Q of the flip-flop 3 is fed to the input X 1 of flip-flop 4, which produces a negative pulse by its output Q, the duration of which depends too on the magnitudes of the capacity of the capacitor and the resistance of the resistor. The negative pulse causes an approximately zero voltage of the inverting input of comparator 10 and, at the same time, the amplified measuring voltage must have a positive value. In this case, the comparator 10 produces a positive pulse with a duration equal to that fed to it by the pulse of its inverting input.
If the measuring voltage is increased quickly, i.e. for a time shorter than the delay caused by the pulse of the flip-flop 3 and is equalized with that of the slider of the regulating resistor (trimmer) 11, the comparator 10 ,. ~
9~6~32~
produces a positive voltage before the flip-flop 4 has produced a control pulse.
The voltage from the output of comparator 10 is fed to the base of transistor 6 which is rendered conductive and switches on the relay 5, since the voltage from the output of comparator 9, fed to th~e bases of transistors 14 and 15, causes a reduction of the resistance of their transition emitter-collector. The contact 20 is closed and current flows from the coil of relay 5 via the transition emitter-collector of transistor 15, a self-closing of relay 5 occurs which remains closed after the elapse of the pulse from the output of comparator 10 only if comparator 9 continues to supply a positive voltage to the base of transistor 15.
The capacitor 21 and the resistor in the transition emitter-collector of transistor 6 form a time-delay circuit which does not permit the release of the relay by accidental interference pulses. When the relay 5 is switched-on there is an interdiction of load lift motion.
The current via optron 17 makes conductive transistor 16.
The relay 18 is switched-on, its contact is closed and there is given permission for load lift motion.
If the mains voltage or one of the supply voltages are not fed to the device, no current passes through relay 18 and its contact is opened. If the consumed current is reduced because of interruption of the tensoresistor, lack of voltage +V2 or for other reasons, no voltage is fed to the base of transistor 16 and relay 18 is not actuated and there is no permission for load lift motion.
~ - 6 -
The invention relates to a device for limiting the overloading of hoisting machines which can be used in electric monorail hoists, more particularly.
A known device for limiting the overloading of hoisting machines comprises a tensoresistor bridge, the one diagonal of which is connected to a supply voltage, while the other diagonal is connected to an amplifier, a flip-flop and relay, the one end of which is connected to a supply source and the other end to a transistor. In parallel to the relay there is connected an opposite diode. The flip-flop is connected via an integrator, a resistor and a secondopposite diode to the base of the transistor. The base is connected via a third opposite diode and a Zener diode to the amplifier.
The drawbacks of the known device lie in the low accuracy in limiting the overloading and the increased time for switching-off the limited load.
It is, therefore, a general object of this invention to limit the overloading of hoisting machines, which is featured by an increased speed of response at a high accuracy of limiting the overloading.
In the present application, the term "flip-flop"
should be understood as meaning a --monostable multivibrator--.
According to the present invention, there is provided a device for limiting the overloading in hoisting machines comprising a tensoresistor bridge having two diagonals, one of said diagonals being connected to a supply voltage, and another of said diagonals being connected to an amplifier, a first flip-flop and a first relay, one end of said first relay being connected to a positive pole of a supply source and another end of said first relay being connected to a collector of a first transistor, and in parallel to said first relay there being connected a first 9 ~ . ~
~Z6E~Z7V
opposite diode, device which further comprises:
- a first, a second and a third comparator, each comparator having an input and an output, said three -1268Z~3 comparators being connected to an output of said amplifier, - said output of said first comparator is connected to said first flip-flop and to said second flip-flop, said second flip-flop being connected by means of a regulating resistor to said input of said third comparator, while said first flip-flop is connected to said output of said second comparator, the input of said second comparator being connected to a first source of constant voltage, - said first flip-flop is connected to said second flip-flOp, - said input of said first compa.rator is connected to a second source of constant voltage, - said output of said second comparator is connected to bases of second and third transistors, said second and third transistors having emitters which are connected to the negative pole of a supply voltage, said negative pole being also connected to an emitter of a fourth transistor, said fourth transistor having a base connected to an optron, - said fourth transistor has a collector connected to a second relay, in parallel to which there is connected a second opposite diode, said second relay and said second opposite diode having cathodes connected to the positive pole of a supply source, - said first opposite diode has an anode which is connected by means of a switch to a collector of said third transistor to which there is connected a capacitor having an end connected to the minus of a supply voltage, and - said first transistor has an emitter which is connected to a collector of said second transistor.
According to the present invention, there is also provided a device for limiting an overload in hoisting machines wherein a tensoresistor bridge having two diagonals is provided, one of the diagonals being connected to a ~268270 supply voltage, and another of the diagonals being connected to an amplifier, an output of the amplifier being connected to a first input of three comparators, and an output of a first of the three comparators being connected to a first flip-flop and to a second flip-flop, the second flip-flop being connected via a regulating resistor to a second input of a third of the three comparators, the first flip-flop being connected to an output of a second of the three comparators, a second input of the second comparator being connected to a first source of constant voltage, the first flip-flop being connected to a second input of the second flip-flop, a second input of the first comparator being connected to a second source of constant voltage, the output of the second comparator being connected to bases of a second and third transistor, emitters of which being connected to a negative pole of a supply source, the negative pole being also connected to an emitter of a fourth transistor, a base of which is connected to an optron, which is a photon-coupled pair, a collector of the fourth transistor being connected to a second relay, in parallel to which there is connected a second opposite diode, a cathode of the second opposite diode and the second relay being connected to a positive pole of the supply source, an anode of a first diode being connected via a switch to a collector of the third transistor, to which there is connected a capacitor, a second end of which being connected to the negative pole, an emitter of a first transistor being connected to a collector of the second transistor, an output of the third comparator being connected to a base of the first transistor, a collector of the first transistor being connected to both the anode of the first diode and to a first relay, and an opposite end of the first relay being connected to the positive pole of the supply source.
The advantages of the device for limiting the . "~;.
~ - 3 1~682~
overloading of hoisting machines, according to the invention, lie in its higher speed of response and the higher accuracy of switching-off.
A preferred embodiment will now be described, as example without limitative manner, with reference to the attached drawings, wherein the single figure shows a block diagram of an embodiment of the invention.
The device for limiting the overloading comprises a tensoresistor bridge 1, the one diagonal of which is connected to a supply voltage, while its other diagonal is connected to a differential arnplifier 2. The device contains two flip-flops 3 and 4, and a relay 5 the one end of which is connected to the positive pole of a supply source and its other end to the collector of a transistor 6, while in parallel to relay 5 there is connected an opposite diode 7. The output of the amplifier 2 is connected to the first inputs of three comparators 8, 9 and 10. The second flip-flop 4 is connected via a regulating resistor 11 to the second input of the third comparator 10. The second input of the second comparator 9 is connected to a source of constant voltage 12. The second input of the first comparator 8 is connected to a second source of constant voltage 13. The output of the second comparator 9 is connected to the bases of a second 14 and a third 15 transistors, the emitters of which are connected to the negative pole of the supply voltage. This negative pole is also connected to the emitters of a fourth transistor 16, the base of which is connected to the optron (photon-coupled pair) 17, and its collector to a second relay 18, in parallel to which there is connected a second opposite diode 19. The anode of the first opposite diode 7 is connected via a switch 20 to the collector of the third transistor 15.
In parallel to transistor 15 there is connected a capacitor 21.
~' - 4 -~L~6~270 The device according to the invention operates as follows:
The signal of the disbalanced tensoresistor bridge 1 of the force transducer enters, after being amplified by the differential amplifier 2, the first non-inverting inputs of the comparators 8, 9 and 10. When the amplified measuring voltage is increased, in the moment of its coincidence with the reference voltage of the source 13, the comparator 8 produces a signal of positive polarity which is fed to the inputs R of the flip-flops 3 and 4 which, at that, receive permission for operation. The further increase of the amplified measuring voltage causes its coincidence with the reference voltage of source 12 and, at that, the comparator 9 produces a signal of positive polarity which is fed to the input X 2 of the flip-flop 3, which is actuated by the positive front of the signal and produces a positive pulse in its output Q with a duration which depends on the magnitudes of the capacity of the capacitor and the resistance of the resistor.
The negative front of the pulse from output Q of the flip-flop 3 is fed to the input X 1 of flip-flop 4, which produces a negative pulse by its output Q, the duration of which depends too on the magnitudes of the capacity of the capacitor and the resistance of the resistor. The negative pulse causes an approximately zero voltage of the inverting input of comparator 10 and, at the same time, the amplified measuring voltage must have a positive value. In this case, the comparator 10 produces a positive pulse with a duration equal to that fed to it by the pulse of its inverting input.
If the measuring voltage is increased quickly, i.e. for a time shorter than the delay caused by the pulse of the flip-flop 3 and is equalized with that of the slider of the regulating resistor (trimmer) 11, the comparator 10 ,. ~
9~6~32~
produces a positive voltage before the flip-flop 4 has produced a control pulse.
The voltage from the output of comparator 10 is fed to the base of transistor 6 which is rendered conductive and switches on the relay 5, since the voltage from the output of comparator 9, fed to th~e bases of transistors 14 and 15, causes a reduction of the resistance of their transition emitter-collector. The contact 20 is closed and current flows from the coil of relay 5 via the transition emitter-collector of transistor 15, a self-closing of relay 5 occurs which remains closed after the elapse of the pulse from the output of comparator 10 only if comparator 9 continues to supply a positive voltage to the base of transistor 15.
The capacitor 21 and the resistor in the transition emitter-collector of transistor 6 form a time-delay circuit which does not permit the release of the relay by accidental interference pulses. When the relay 5 is switched-on there is an interdiction of load lift motion.
The current via optron 17 makes conductive transistor 16.
The relay 18 is switched-on, its contact is closed and there is given permission for load lift motion.
If the mains voltage or one of the supply voltages are not fed to the device, no current passes through relay 18 and its contact is opened. If the consumed current is reduced because of interruption of the tensoresistor, lack of voltage +V2 or for other reasons, no voltage is fed to the base of transistor 16 and relay 18 is not actuated and there is no permission for load lift motion.
~ - 6 -
Claims (3)
1. Device for limiting the overloading in hoisting machines comprising a tensoresistor bridge having two diagonals, one of said diagonals being connected to a supply voltage, and another of said diagonals being connected to an amplifier, a first flip-flop and a first relay, one end of said first relay being connected to a positive pole of a supply source and another end of said first relay being connected to a collector of a first transistor, and in parallel to said first relay there being connected a first opposite diode, device which further comprises:
- a first, a second and a third comparator, each comparator having an input and an output, said three comparators being connected to an output of said amplifier, - said output of said first comparator is connected to said first flip-flop and to said second flip-flop, said second flip-flop being connected by means of a regulating resistor to said input of said third comparator, while said first flip-flop is connected to said output of said second comparator, the input of said second comparator being connected to a first source of constant voltage, - said first flip-flop is connected to said second flip-flop, - said input of said first comparator is connected to a second source of constant voltage, - said output of said second comparator is connected to bases of second and third transistors, said second and third transistors having emitters which are connected to the negative pole of a supply voltage, said negative pole being also connected to an emitter of a fourth transistor, said fourth transistor having a base connected to an optron, - said fourth transistor has a collector connected to a second relay, in parallel to which there is connected a second opposite diode, said second relay and said second opposite diode having cathodes connected to the positive pole of a supply source, - said first opposite diode has an anode which is connected by means of a switch to a collector of said third transistor to which there is connected a capacitor having an end connected to the minus of a supply voltage, and - said first transistor has an emitter which is connected to a collector of said second transistor.
- a first, a second and a third comparator, each comparator having an input and an output, said three comparators being connected to an output of said amplifier, - said output of said first comparator is connected to said first flip-flop and to said second flip-flop, said second flip-flop being connected by means of a regulating resistor to said input of said third comparator, while said first flip-flop is connected to said output of said second comparator, the input of said second comparator being connected to a first source of constant voltage, - said first flip-flop is connected to said second flip-flop, - said input of said first comparator is connected to a second source of constant voltage, - said output of said second comparator is connected to bases of second and third transistors, said second and third transistors having emitters which are connected to the negative pole of a supply voltage, said negative pole being also connected to an emitter of a fourth transistor, said fourth transistor having a base connected to an optron, - said fourth transistor has a collector connected to a second relay, in parallel to which there is connected a second opposite diode, said second relay and said second opposite diode having cathodes connected to the positive pole of a supply source, - said first opposite diode has an anode which is connected by means of a switch to a collector of said third transistor to which there is connected a capacitor having an end connected to the minus of a supply voltage, and - said first transistor has an emitter which is connected to a collector of said second transistor.
2. Device according to claim 1, wherein said optron is a photon-coupled pair.
3. Device for limiting an overload in hoisting machines wherein a tensoresistor bridge having two diagonals is provided, one of said diagonals being connected to a supply voltage, and another of said diagonals being connected to an amplifier, an output of said amplifier being connected to a first input of three comparators, and an output of a first of said three comparators being connected to a first flip-flop and to a second flip-flop, said second flip-flop being connected via a regulating resistor to a second input of a third of said three comparators, said first flip-flop being connected to an output of a second of said three comparators, a second input of said second comparator being connected to a first source of constant voltage, said first flip-flop being connected to a second input of said second flip-flop, a second input of said first comparator being connected to a second source of constant voltage, the output of said second comparator being connected to bases of a second and third transistor, emitters of which being connected to a negative pole of a supply source, said negative pole being also connected to an emitter of a fourth transistor, a base of which is connected to an optron, which is photon-coupled pair, a collector of said fourth transistor being connected to a second relay, in parallel to which there is connected a second opposite diode, a cathode of said second opposite diode and said second relay being connected to a positive pole of said supply source, an anode of a first diode being connected via a switch to a collector of said third transistor, to which there is connected a capacitor, a second end of which being connected to said negative pole, an emitter of a first transistor being connected to a collector of said second transistor, an output of said third comparator being connected to a base of said first transistor, a collector of said first transistor being connected to both said anode of said first diode and to a first relay, and an opposite end of said first relay being connected to said positive pole.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000537115A CA1268270A (en) | 1987-05-12 | 1987-05-12 | Device for limiting the overloading of hoisting machines |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000537115A CA1268270A (en) | 1987-05-12 | 1987-05-12 | Device for limiting the overloading of hoisting machines |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1268270A true CA1268270A (en) | 1990-04-24 |
Family
ID=4135661
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000537115A Expired - Fee Related CA1268270A (en) | 1987-05-12 | 1987-05-12 | Device for limiting the overloading of hoisting machines |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1268270A (en) |
-
1987
- 1987-05-12 CA CA000537115A patent/CA1268270A/en not_active Expired - Fee Related
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| MKLA | Lapsed |