WO2020234717A1

WO2020234717A1 - A control system for controlling the operation of an apparatus equipped with electronically controlled and adjusted motor means

Info

Publication number: WO2020234717A1
Application number: PCT/IB2020/054616
Authority: WO
Inventors: Andrea Traunero
Original assignee: Astra S.R.L.
Priority date: 2019-05-17
Filing date: 2020-05-15
Publication date: 2020-11-26
Also published as: IT201900006980A1

Abstract

An elevator installation comprises a control circuit arranged adjacent to and synchronized with the safety device chain and a switch device (24) which is adapted to exchange the safety device chain with the control device chain in the event of a fault detected in said safety device chain.

Description

“A control system for controlling the operation of an apparatus equipped with electronically controlled and adjusted motor means”

DESCRIPTION

Field of the invention

The present invention relates to a system for controlling the operation of an apparatus equipped with electrically controlled and adjusted motor means as defined in the preamble of claim 1, in particular a system for controlling the operation of an elevator installation.

As used herein, the phrase“ electrically controlled and adjusted motor means” is generally used to distinguish any type of motor (e.g. electric motor, pneumatic motor, fluid-dynamic motor, oil-hydraulic motor, hydraulic motor, combustion engine) whose operation is electrically controlled via an electric and/or electronic card or via an electrical switchboard, e.g. to stop or regulate the power supply to an electric motor, to control the fuel supply in a combustion engine or to control and operate solenoid valves of pneumatic, fluid dynamic, oil-hydraulic or hydraulic motors.

For simplicity, the present disclosure is made by way of example and without limitation with particular reference to an elevator installation operated by electric motors and its operating panel.

Background of the invention

In the field of elevator installations, the elevator cabin is known to be driven between the various floors by acting on the floor buttons or on the cabin buttons.

Elevator installations are equipped with various safety device chains which together define a general safety chain, in particular: a chain of cabin door security devices, a chain of floor door security devices, a chain of overrun safety devices and a chain of maximum elevator cabin speed safety devices. Each safety chain generally comprises respective safety contacts which require the insertion of a removable bridge, an actuation key or another element to ensure electrical continuity in the chain. Thus, by simple forcibly pulling out a bridge or a key of a single sensor of a safety device will inhibit or stop the movement of the elevator cabin.

Figure 1 shows a diagram of a system of floor door security devices in an elevator installation, illustrating: three removable bridge P safety contacts C, the middle one having the bridge in the pulled-out position, arranged in electrical series with each other in an electric line of the safety devices L which is wired to a controller of a switchboard

M.

This certainly ensures the safety of the elevator assembly, but requires the elevator assembly to be shut down in the event of a malfunction of one or more components of the safety device chain, for example of one of the safety contacts.

In this respect, possible causes of failure to a safety contact, e.g. a removable bridge safety contact, may include: breakage or loss of elasticity of the leaf springs, contact burn-off due to overvoltage or, more simply, dust or dirt build-up on the contacts.

In all of these cases, the shutdown of the elevator installation does not apparently depend on installation safety issues, such as the case of a floor door that remains locked in the open position, whereby the elevator assembly can still be safely ensured, at least to bring the elevator cabin to the nearest floor doors, to free any passengers trapped in the elevator cabin even before the arrival of a maintenance operator.

In view of the above, the need is apparently strongly felt of ensuring proper operation of an elevator installation, or another apparatus having electrically controlled and adjusted motor means, if the chain of safety devices is opened not due to an actual problem of the apparatus but to a failure caused to malfunction of the chain of safety devices and its components.

Summary of the invention

Therefore, the present invention is based on the problem of providing a system for controlling the operation of an apparatus having electrically controlled and adjusted motor means, in particular a system for controlling the operation of an elevator assembly that can meet the aforementioned need and obviate the problems as mentioned above with reference to apparatuses with electrically controlled and adjusted motor means which require their operation to be enabled by one or more safety circuits.

The above problem is solved by a system for controlling the operation of an apparatus equipped with electronically controlled and adjusted motor means as defined in claim 1.

In a further aspect, the above problem is solved by a method as defined in claim 16 for controlling the operation of an apparatus provided having electrically controlled and adjusted motor means.

Brief description of the drawings

Further features and advantages of system for controlling the operation of an apparatus having electrically controlled and adjusted motor means according to the present invention, will result more clearly from the following description of a few preferred embodiments thereof, which is given by way of illustration and without limitation with reference to the accompanying figures, in which:

Figure 1 is a diagrammatic view of a circuit for the safety of three floor doors and of the operating panel of an elevator installation according to the prior art;

Figure 2 is a diagrammatic view of a system for controlling the operation of an apparatus equipped with electrically controlled and adjusted motor means according to the invention in a first operating configuration;

- Figure 3 shows a diagrammatic view of the control system of Figure 2 switched to a second operating configuration;

- Figure 4 shows a perspective view of a removable double-bridge double safety contact;

- Figures 5 and 6 are respective perspective views of the removable double-bridge double safety contact of Figure 4 in partial sections as taken along horizontal sectional planes at different heights;

- Figures 7 and 8 are respective diagrammatic views of a control system of the invention according to a variant embodiment in two respective different operating configurations - Figures 9 and 10 are respective diagrammatic views of a control system of the invention according to a further variant embodiment in two respective and different operating configurations.

Detailed description of the invention

Referring to the above Figures 2 to 6, numeral 1 generally designates a system of the invention for controlling the operation of an apparatus equipped with electrically controlled and adjusted motor means (not shown).

The system 1 of the present invention comprises:

- a microprocessor 3c or another functionally equivalent controller;

- a first electric or electronic board 3 for controlling and/or adjusting said apparatus and said motor means to receive a control signal of said motor means of said apparatus from electric driving means;

- one or more first electric terminals 3 a of said first board 3 for receiving an enabling signal enabling the operation of said motor means from one or more safety contacts;

- one or more first safety contacts 2 (in the illustrated example three safety contacts), adapted to detect an enabling state or an inoperable state of said motor means and to generate a corresponding signal; and

- at least one primary electric line 6 (in the illustrated example a single primary line) to wire in series said one or more first safety contacts 2 to said first electric terminals 3a of said first board 3 and provide the microprocessor 3c of said first board 3 with an enabling signal, enabling the operation of said motor means when an operation-enabling state is detected by all of said one or more first safety contacts 2.

Preferably, the control system 1 further comprises:

- electric driving means for driving and/or adjusting the operation of said motor means of said apparatus and

- one or more electric driving lines for wiring said electric driving means to the microprocessor 3c of said first electric or electronic board 3, otherwise a non- wired connection may be provided, i.e. a wireless or another type of connection, between the aforementioned electric control means and the first electric or electronic board 3.

The actuation of said motor means is driven, for example, by said electric driving means, subject to receipt of an operation-enabling signal by said first electric terminals 3a of said first board 3.

Advantageously, the control system 1 comprises:

- a second electric or electronic control and driving board 20, having a microprocessor 20c or another functionally equivalent controller on board;

- one or more first electric control terminals 20a of said second board 20 for receiving a control signal enabling the operation of said motor means from one or more safety contacts;

- for each respective first safety contact 2 at least one second control contact 21 (in the illustrated example three second control contacts) placed near, coupled to or associated with the respective first safety contact 2 to detect an operation-enabling state or an inoperable state of said motor means and to generate a corresponding control signal;

- at least one electric control line 22 (in the illustrated example a single electric control line) to wire said one or more second control contacts 21 to said first electric control terminals 20a of said second board 20 and provide the microprocessor 20c of said second board 20 with an enabling signal, enabling the operation of said motor means when an operation-enabling state is detected by all of said one or more second control contacts 21;

- one or more auxiliary wiring lines 23 for providing second electric control terminals 20b of the microprocessor 20c of said second board 20 with an enabling signal, enabling the operation of said motor means, which is equal to or corresponding to the signal received by said first electric terminals 3a of said first board 3 via said at least one primary electric line 6 and

- a switching device 24 situated in such a position as to intercept said at least one primary electric line 6 and said at least one electric control line 22.

As a result, said switching device 24 divides:

- said at least one primary electric line 6 into an upstream section 6a between said switching device 24 and said one or more first safety contacts 2 and a downstream section 6b between said switching device 24 and said first board 3 and

- said at least one electric control line 22 into an upstream section 22a between said switching device 24 and said one or more second control contacts 21 and a downstream section between said switching device 24 and said second board 20.

Said switching device 24 is susceptible of switching between:

• a first operating state in which it establishes electrical continuity between said upstream section 6a and said downstream section 6b of said at least one primary electric line 6 and

• a second operating state in which it establishes electrical continuity between said upstream section 22a of said at least one electric control line 22 and said downstream section 6b of said at least one primary electric line 6, thereby causing said first electric terminals 3a of said first board 3 to receive either an operation-enabling signal or an inoperable state signal for said motor means generated by said one or more second control contacts 21.

Preferably, in said second operating state, said switching device 24 also establishes electrical continuity between said upstream section 6a of said at least one primary electric line 6 and said downstream section 22b of said at least one electric control line 22, thereby causing said first electric control terminals 20a of said microprocessor 20c of said second board 20 to receive either an operation-enabling signal or an inoperable state signal for said motor means generated by said one or more first safety contacts 2.

Preferably the aforementioned one or more auxiliary wiring lines 23:

- ensure electrical continuity between said second electric control terminals 20b of said microprocessor 20c of said second board 20 and second electric terminals 3b of said first board 3 which receive a signal corresponding or equal to the signal received by said first electric terminals 3 a of said first board 3 (according to the embodiment of Figures 2 and 3) or

- ensure electrical continuity between said first electric terminals 3a of said first board 3 and said second electric control terminals 20b of said microprocessor 20c of said second card 20 (in accordance with an embodiment that is not shown).

Preferably, said switching device 24 comprises a manual selector 25 for switching between said first operating state and said second operating state and vice versa.

Preferably, said second electric or electronic control and driving board 20 comprises a microprocessor for driving the actuation of said switching device 24 from said first operating state to said second operating state, and vice versa.

Preferably, when said switching device 24 is in said first operating state and a condition occurs in which:

- said second electric terminals 20b of said microprocessor 20c of said second board 20 receive a signal that is equal or corresponding to an inoperable state signal for said motor means generated by said one or more first safety contacts 2 and

- said first electric control terminals 20a of said microprocessor 20c of said second board 20 receive an operation-enabling signal for said motor means generated by said one or more second control contacts 21,

then said microprocessor 20c of said second board 20 determines the automatic actuation of said switching device 24 from said first operating state to said second operating state and/or generates an error signal in the line of said one or more first safety contacts 2.

Preferably, the control system 1 comprises means for remote connection to a control center to:

- indicate any detected abnormal operation concerning said one or more first safety contacts 2 or said one or more second control contacts 21 and/or

- remotely receive a signal actuating said switching device 24.

Preferably, the operating voltage as measured at the ends of said first electric control terminals 20a of said microprocessor 20c of said second board 20 when said one or more second control contacts 21 generate an operation-enabling signal for said motor means is lower than the voltage that can be measured at the ends of said first electric terminals 3a of said first board 3, when said one or more first safety contacts 2 generate an operation-enabling signal for said motor means.

This will preserve the life of said one or more second control contacts 21 which operate at a lower voltage than said one or more first safety contacts 2.

Preferably, said one or more first safety contacts 2 and/or said control contacts 21 are forced-break contacts, preferably forced-break contacts having: - a removable bridge,

- an actuation key,

- forced-break push buttons or

- a magnetic contact with an electronic controller having safety relays.

According to the illustrated embodiment, the aforementioned one or more first safety contacts 2 and/or the aforementioned one or more control contacts 21 are double forced-break contacts, namely double-removable bridge forced-break contacts, in which one contact acts as a safety contact 2 and the other contact acts as a control contact 21.

This arrangement ensures instantaneous equal and synchronized engagement/disengagement of both contacts of each double contact.

Preferably, all or at least some of said safety contacts 2:

- comprise electric contacts that are normally closed when no abnormal condition is detected and

- are arranged with their respective electric contacts in series connection on a single electrical line 6a of safety devices to form a safety device chain, whereby an abnormal condition detected by one of said safety devices 2 will cause the respective electrical contact to open and the electrical continuity in said safety device chain to be broken.

Preferably, all or at least some of said one or more control contacts 21:

- are arranged with respective control contacts 21 in series connection on a single electric line 22a to form a control device chain,

whereby an abnormal condition of said one or more second control contacts 21 will cause the respective electrical contact to open and the electrical continuity in said control device chain to be broken.

The control system of the invention is adapted to manage the operation of an apparatus equipped with electrically controlled and adjusted motor means of various types, namely an apparatus in which the operation of an electrically controlled motor is to be subject to an enabling signal enabling the operation of multiple safety devices. For example, this apparatus can be a machine tool, a press or else.

According to a preferred embodiment, the system for controlling the operation of an apparatus equipped with electrically controlled and adjusted motor means of the invention is designed to control the operation of an elevator installation of a building, in which:

- said electric driving means are the floor buttons, the cabin buttons and/or the maintenance driving buttons located on the roof of the cabin of said elevator installation;

- said one or more safety contacts 2 comprise cabin door safety devices, floor door safety devices, maximum lift cabin speed safety devices and lift cabin overrun safety devices;

- said control and/or adjustment board 3 comprises the operating panel of said lift system.

Preferably, a plurality of safety devices arranged in series connection along one same electric line 6a identifies a safety device chain and said elevator installation comprises, according to an illustrative, non-limiting list:

- a chain of cabin door security devices,

- a chain of floor door security devices,

- a chain of lift cabin overrun safety devices and

- a chain of maximum lift cabin speed safety devices,

wherein:

- the interruption of only one of said safety device chains prevents said board 3 from receiving an operation-enabling signal for said electrically controlled and adjusted motor means from said safety device chains.

Preferably, multiple second control contacts 21 connected in series along the same electric line 22 identify a safety device control chain of said lift system.

Therefore, the interruption of only one of said safety device chains prevents the board 3 of the switchboard from receiving the operation of the electrically controlled and adjusted motor means.

If the control system of the invention is used to control an electric apparatus other than an elevator installation, safety devices 2 may be provided, which comprise active sensors capable of generating an electrical signal, so that the aforementioned operation enabling signal received by the board 3 from the safety devices 2 may also correspond to either receipt or non-receipt of said electric signal by the safety devices 2.

According to the invention, the method of controlling the operation of an apparatus equipped with electrically controlled and adjusted motor means includes providing a control system as described above and, from an initial operating state in which said switching device 24 is in said first operating state in which it establishes electrical continuity between said upstream section 6a and said downstream section 6b of said at least one primary electric line 6 includes the steps of:

- checking whether, using said second board 20, namely said microprocessor 20c, the operation-enabling control signal or the inoperable state signal for said motor means generated by said one or more safety contacts 2 matches the enabling control signal or the control inoperable state signal for said motor means generated by said one or more second control contacts 21 and

- in case of mismatch between the signal generated by said one or more safety contacts 2 and the control signal generated by said one or more second control contacts 21, checking whether the signal generated by said one or more first safety contacts 2 is an inoperable state signal for said motor means and, in the affirmative case, actuating said switching device 24 to set it to said second operating state and/or to generate an error signal in the line of said one or more first safety contacts 2.

Preferably, in case of mismatch between the signal generated by said one or more safety contacts 2 and the control signal generated by said one or more second control contacts 21, the method includes the step of checking whether the control signal generated by said one or more first safety contacts 2 in operable state signal for said motor means and, in the affirmative case, generating an error signal in the line of said one or more second control contacts 21.

In view of the structural and functional characteristics of the control system as described above, particularly with reference to use in the field of elevators, it will be appreciated that this device advantageously allows the safety device chain to be restored (remotely by authorized personnel, automatically or manually by acting on the manual selector 25 according to the operating mode to be used to comply with the legal provisions in force in each country) and, at the same time, the function of the safety contacts to be monitored so as to predict the occurrence of a problem.

In particular, the control contacts and the electric control lines define a control circuit which is adjacent to and synchronized in operation with the corresponding safety circuit, while the aforementioned switching device, for example a bistable switching relay, is interposed between the safety device chain and the operating panel of the elevator. Under normal conditions of use, i.e. when no abnormal condition is found in the safety device chain, the aforementioned switching device does not interfere with either the safety device chain or the operating panel, and does not change the operation of the apparatus equipped with electrically controlled and adjusted motor means in any manner.

At the same time, the control circuit allows the second board of the control system of the invention to receive additional information resulting from the check of the open or closed state of the safety device chain. This is particularly evident when double contacts are designed to be used, one operating as a first safety contact and the other as a second control contact.

As needed, i.e. when an abnormal condition is detected in the safety device chain, the switching device is adapted to be driven to exchange the safety device chain with the control circuit to ensure proper operation of the apparatus in case the abnormal condition detected by the safety device chain does not result from an actual danger condition (for example, a floor door locked in the open position) but from a fault in the safety device chain components, for example a first safety contact.

This is ensured in that the controller (or microprocessor) of the second electric or electronic control and driving board receives:

- the open/closed state signal of the control contacts at the first terminals, and

- the open/closed state, or a corresponding state, of the first safety contacts, at the second terminals.

The operation logic of such controller (or microprocessor) may be very simple. For example, if proper operation requires both the safety device chain and the control device chain to provide a closed state signal (i.e. the state occurring using normally open NO safety contacts and control contacts) the operation logic may be as follows:

I) If the safety device chain is open and the control device chain is open, the elevator will operate normally, probably the open state of both chains being probably caused, for example, by an open floor door and in this state, the operation of the electric motors for driving the elevator cabin is inhibited;

II) If the safety device chain is closed and the control device chain is closed, the elevator will operate normally, and in this state the operation of the motor means is permitted;

III) If the safety device chain is closed and the control device chain is open, there is a fault in the elevator, probably simply caused by a failure in the control device chain, the actuation of the electric motors for driving the elevator cabin will be in any case permitted but an error signal may be generated in the line of said one or more second control contacts, to warn the maintenance operator of the elevator installation, and

IV) If the safety device chain is open and the control device chain is closed, there is a fault in the elevator installation, probably simply caused by a failure in the safety device chain, the actuation of the electric motors for driving the elevator cabin may be permitted (for example by an operator providing remote assistance) by operating the switching device to exchange the safety device chain with control device chain. The state described under IP) above results and the operation of the elevator cabin is again permitted, possibly only to cause the elevator cabin to reach the floor. Conversely, if after the switching operation between the safety device chain and the control device chain performed by said switching device at the first terminals of the first board an abnormal condition still exists in the new safety device chain, the operation of the electric motors of the elevator cabin remains inhibited.

It shall be noted that, if forced-break safety and control contacts are located/connected to be joined together and synchronized during engagement/disengagement, in case of mismatching signals between the safety device chain line and the control device chain, the chain that is found in the“open” state is certainly the one with a fault, e.g. in one of the electric contacts.

Referring to the state PI) above, it shall be noted that if the control device chain is damaged this might predict an impending fault also in the safety device chain, whereby the elevator is still in working condition but requires action from an operator to restore the control circuit.

Concerning the remote service, the operator may elect to send a signal to the control system to reverse the safety device chain with the control device chain by the action of the switching device, thereby restoring the elevator function, in view of restoring the damaged circuit as soon as possible.

It shall be further noted that, if the control circuit is faulty, the elevator may still operate properly, the control system detecting the abnormal mismatch between the safety device chain and the control device chain and generating an alarm signal for the maintenance operator, who can schedule maintenance in due time, assuming that the safety device chain will also fail shortly.

It will be appreciated from the above that the system for controlling the operation of an apparatus equipped with electrically controlled and adjusted motor means of the invention will fulfill the above discussed need and also obviate the prior art drawbacks as set out in the introduction of this disclosure.

Those skilled in the art will obviously appreciate that a number of changes and variants may be made to the system for controlling the operation of an apparatus equipped with electrically controlled and adjusted motor means of the invention to meet specific needs, without departure from the scope of the invention, as defined in the following claims.

Thus, for example, a conveniently integrated first control board 3 is provided instead of a second control board 20, to provide the electric terminals for connection of the control device chain, and is designed to operate according to the previously described operation logic. In short, the second control board as discussed above may be incorporated in the first control board, which has been conveniently modified and integrated with respect to a control board that can manage a safety device chain only.

This is the state that occurs with the control system of the invention as shown in Figures 7 and 8 and explained below.

First of all, it shall be noted that the parts of the system as shown in Figures 7 and 8, functionally or structurally corresponding to the parts of the control system 1 as shown in Figures 2 and 3, are designated by the same reference numerals as already used and will not be further described.

As compared with the control system 1 of Figures 2 and 3, the control system 1 of the invention as shown in Figures 7 and 8 only substantially differs in that it only has the first electric or electronic board 3 for controlling and/or adjusting said apparatus, with the microprocessor 3c, or any other functionally equivalent controller on board.

In this embodiment, the first board 3 is formed with the aforementioned one or more first electric control terminals 20a which are associated with the microprocessor 3c and receive a control signal enabling the operation of said motor means from one or more safety contacts via the electric control line 22b.

Namely, said one or more first electric control terminals 20a of the microprocessor 3c of the first board 3 as modified in Figures 7 and 8 are wired with said downstream portion 22b of the electric control line 22, that is, the section 22b that extends from the switching device 24 to the second electric terminals 20a of the microprocessor 3c of the first board 3 as modified in Figures 7 and 8.

Here, the microprocessor 3c of the first electric or electronic board 3 also performs the task as discussed above with reference to the microprocessor 20c of the second electric or electronic board 20 of the control system as shown in Figures 2 and 3.

This embodiment of the control system of the invention (in shown in Figures 7 and 8) advantageously allows incorporation of all the control and actuation logic functions in a single control board. The embodiment is suitable in case of a new installation or replacement of the electric board or the operating panel of an existing installation.

Conversely, the first embodiment of the control system of the invention (as shown in Figures 2 and 3) can also advantageously implement the control system in existing systems without requiring replacement of the entire operating panel, but only the addition of the second control board 20 comprising the microprocessor 20c, the switching device 24 and the selector 25, and the required wiring.

Figures 9 and 10 show a further variant embodiment of the control system of the invention. First of all, it shall be noted that the parts of the system as shown in Figures 9 and 10, structurally and/or functionally corresponding to the parts of the control system 1 as shown in Figures 2 and 3, are designated by the same reference numerals as already used and will not be further described.

As compared with the control system 1 of Figures 2 and 3, the control system 1 of the invention as shown in Figures 9 and 10 differs substantially in that it comprises sensor means 26 for detecting current flowing in said primary electric line 6.

These sensor means 26 are wired via one or more auxiliary wiring lines 23 to provide the second electric control terminals 20b of the microprocessor 20c of the second board 20 with a signal enabling or inhibiting the operation of motor means, in response to detection or non-detection of current by the sensor means 26 respectively, considering that, also in this embodiment, the first electric control terminals 20a are electrical terminals of the second electric or electronic control and driving board 20.

Preferably, the above discussed sensor means comprise a Hall-effect sensor. According to the embodiment as shown in Figures 9 and 10, the section 6b of the primary electric line is connected in series with the solenoid of the sensor while the one or more auxiliary wiring lines 23 extend in the solenoid of the aforementioned Hall-effect sensor.

Alternatively, non-Hall-effect sensor means 26 may be provided for detecting current flowing in said primary electric line 6, possibly also of optoelectronic type.

Preferably, these sensor means 26 for detecting current flowing in said primary electric line 6 are arranged in such positions as to be able to detect the flow of current in the downstream section 6b of said primary electric line 6 which is located between the switching device 24 and the first board 3. Advantageously, this allows the same sensor means 26 to be used for detection of current flowing in said secondary electric line 22, namely in the upstream section 22a between said switching device 24 and said one or more second control contacts 21, once the switching device 24 has been switched to the second operating condition as shown in Fig. 10.

It will be also appreciated that a plurality of sensor means 26 may be used to detect current flowing in said primary electric line 6 and in said secondary electric line 22 although this is detrimental to the structural simplicity of the system for controlling the operation of an apparatus of the invention.

Concerning the switch 24, in the embodiments as shown in Figures 2, 3, 7, 8, 9 and 10, such switch is illustrated as a single body, although there may be a switch comprising two or more physically separated parts, each adapted to act on two branches or a respective branch of a control circuit.

It shall be noted that the aforementioned signal for enabling or inhibiting the operation of the motor means may be an analog signal (for example a voltage and current signal), a digital signal or an optoelectronic signal.

Claims

1. A control system for controlling the operation of an apparatus equipped with electronically controlled and adjusted motor means, said system comprising:

- a first electric or electronic board (3) for controlling and/or adjusting said apparatus and said motor means which is designed to receive a driving signal for driving said motor means of said apparatus from electrical driving means;

- one or more first electric terminals (3 a) of said first board (3) for receiving an enabling signal enabling the operation of said motor means from one or more safety contacts;

- one or more first safety contacts (2), adapted to detect a consent state or an inoperable state of said motor means and to generate a corresponding signal;

- at least one primary electric line (6) to wire said one or more first safety contacts

(2) to said first electric terminals (3 a) of said first board (3) and provide said first board

(3) with an enabling signal enabling the operation of said motor means when an operation-enabling consent state is detected by all of said one or more first safety contacts (2);

wherein the actuation of said motor means is driven by said first board (3) subject to receipt an operation-enabling signal by all said first electric terminals (3 a) of said first board (3),

characterized in that it comprises:

- for each respective first safety contact (2) at least one second control contact (21) placed near, coupled to or associated with the respective first safety contact (2) to detect an operation-enabling consent state or an inoperable state of said motor means and to generate a corresponding control signal;

- one or more first electric control terminals (20a) for receiving a consent control signal enabling the operation of said motor means from one or more control contacts (21);

- at least one electric control line (22) to wire said one or more second control contacts (21) to said first electric control terminals (20a) and provide said first electric control terminals (20a) with a consent control signal enabling the operation of said motor means when an operation-enabling consent state is detected by all of said one or more second control contacts (21);

- a switching device (24) situated in such a position as to intercept said at least one primary electric line (6) and said at least one electric control line (22),

and in which said switching device (24):

- divides said at least one primary electric line (6) into an upstream section (6a) between said switching device (24) and said one or more first safety contacts (2) and a downstream section (6b) between said switching device (24) and said first board (3);

- divides said at least one electric control line (22) into an upstream section (22a) between said switching device (24) and said one or more second control contacts (21) and a downstream section (22b) between said switching device (24) and said first electric control terminals (20a);

- is susceptible to switch between:

• a first operating state in which it establishes electrical continuity between said upstream section (6a) and said downstream section (6b) of said at least one primary electric line (6) and

• a second operating state in which it establishes electrical continuity between said upstream section (22a) of said at least one electric control line (22) and said downstream section (6b) of said at least one primary electric line (6), thereby causing said first electric terminals (3a) of said first board (3) to receive either an operation-enabling signal or an inoperable state signal for said motor means generated by said one or more second control contacts (21),

wherein:

I) said first electric control terminals (20a) are electric terminals of a second electric or electronic control and driving board (20) and said control system (1) comprises one or more auxiliary wiring lines (23) to provide said second electric control terminals (20b) of said second board (20) with an enabling signal to operation or an operation inhibiting signal for said motor means, which is equal or corresponding to the signal received by said first electric terminals (3a) of said first board (3) through said downstream section (6b) of said at least one primary electric line (6), or II) said first electric control terminals (20a) are electric terminals of said first board (3) for providing said electric control terminals (20a) of said first board (3) with an enabling signal to operation or an operation-inhibiting signal for said motor means by said one or more second control contacts (21) through said downstream section (22b) of said at least one electric control line (22), or

III) said first electric control terminals (20a) are electric terminals of a second electric or electronic control and driving board (20) and said control system (1) comprises:

• sensor means (26) to detect the passage of current in said primary power line (6) and

• one or more auxiliary wiring lines (23) to provide said second electric control terminals (20b) of said second board (20) with an enabling signal to operation or an operation inhibiting signal for said motor means correlated respectively to the detection or non-detection of current passage by said sensor means (26).

2. A control system according to claim 1, wherein said sensor means (26) to detect the passage of current in said primary power line (6) are positioned to detect the passage of current in said downstream section (6b) of said at least one primary electric line (6) between said switching device (24) and said first board (3).

3. A control system according to claim 1 or 2, wherein sensor means (26) comprise an Hall-effect sensor.

4. A control system according to any claim 1 to 3, wherein, in said second operating state, said switching device (24) also establishes electrical continuity between said upstream section (6a) of said at least one primary electric line (6) and said downstream section (22b) of said at least one electric control line (22), thereby causing said first electric control terminals (20a) to receive either an enabling signal to operation or an inoperable state signal for said motor means generated by said one or more first safety contacts (2).

5. A control system according to any claim 1 to 4, wherein said one or more auxiliary wiring lines (23):

- ensure electrical continuity between said second electric control terminals (20b) and second electric terminals (3b) of said first board (3) which receive a signal corresponding or equal to the signal received by said first electric terminals (3 a) of said first board (3) or

- ensure electrical continuity between said first electric terminals (3a) of said first board (3) and said second electric control terminals (20b).

6. A control system according to any claim 1 to 5, wherein said switching device (24) comprises a manual selector (25) for switching between said first operating state and said second operating condition and vice versa.

7. A control system according to any claim 1 to 6, wherein said second control board (20) or said first driving board (3) comprise a microprocessor (3c, 20c) to drive the actuation of said switching device (24) from said first operating state to said second operating state and vice versa.

8. A control system according to claim 7, wherein, when said switching device (24) is in said first operating state, said microprocessor (3c, 20c) causes automatic actuation of said switching device (24) from said first operating state to said second operating state subject to the occurrence of a condition in which:

- said first electric terminals (3a) receive an inoperable state signal for said motor means generated by said one or more first safety contacts (2) and

- said first electric control terminals (20a) receive an operation-enabling signal enabling the operation of said motor means generated by said one or more second control contacts (21).

9. A control system according to any claim 1 to 8, comprising means for the remote connection to a control center to:

- indicate any detected abnormal operation concerning said one or more first safety contacts (2) or said one or more second control contacts (21) and/or

- remotely receive a signal actuating said switching device (24).

10. A control system according to any claim 1 to 8, wherein the operating voltage as measured at the ends of said first electric control terminals (20a) when said one or more second control contacts (21) generate an enabling signal enabling the operation of said motor means is lower than the voltage as measured at the ends of said first electric terminals (3a) of said first board (3), when said one or more first safety contacts (2) generate an enabling signal enabling the operation of said motor means.

11. A control system according to any claim 1 to 10, wherein said one or more first safety contacts (2) and/or said control contacts (21) are forced-break contacts, are preferably removable bridge contacts operated by an actuation key or by magnetic contact with an electronic controller having a safety relay.

12. A control system according to any claim 1 to 11, comprising double forced-break contacts, preferably double removable bridge break contacts, with one contact acting as a safety contact (2) and the other contact acting as a control contact (21).

13. A control system according to any claim 1 to 12, wherein at least part of said safety contacts (2):

- comprise electric contacts that are normally closed when no anomaly is detected and

- are arranged with respective electric contacts in series connection on a single electric line (6a) of safety devices to form a safety device chain,

whereby an abnormal condition detected by one of said safety devices (2) causes the respective electrical contact to open and the electrical continuity in said safety device chain to be broken.

14. A control system according to any claim 1 to 13, wherein at least part of said one or more second control contacts (21):

- comprises electric contacts that are normally closed when no abnormal condition is detected and

- is arranged with respective electric contacts connected in series along a single electric line (22a) of safety devices to form a control device chain,

whereby an abnormal condition detected by one of said one or more second control contacts (21) causes the respective electrical contact to open and the electrical continuity in said control device chain to be broken.

15. A control system according to any claim 1 to 14, wherein said apparatus having electrically controlled and adjusted motor means constitutes a lift system of a building, wherein:

- the electric driving means are the floor buttons, the cabin buttons and/or the maintenance buttons of said lift system;

- said one or more safety contacts (2) comprise cabin door safety devices, floor door safety devices, maximum lift cabin speed safety devices and lift cabin overrun safety devices;

- said control and/or adjustment board (3) comprises the operating panel of said lift system.

16. A control system according to claim 15, wherein multiple safety devices connected in series along the same electric line (6a) identify a safety device chain and said lift system comprises:

- a chain of cabin door security devices,

- a chain of floor door security devices,

- a chain of lift cabin overrun safety devices and

- a chain of maximum lift cabin speed safety devices,

wherein:

- the interruption of only one of said safety device chains prevents said board (3) from receiving a consent enabling operation of said electrically controlled and adjusted motor means from said safety device chains.

17. A control system according to claim 15 or 16, wherein multiple second control contacts (21) connected in series along the same electric line (22) identify a safety device control chain of said lift system.

18. A method of controlling the operation of an apparatus having electrically controlled and adjusted motors, said control method comprising the step of:

- providing a control system as claimed in any of claims 1 to 17 and, from an initial operating state in which said switching device (24) is in said first operating state in which it establishes electrical continuity between said upstream section (6a) and said downstream section (6b) of said at least one primary electric line (6),

- checking whether the operation-enabling signal or the inoperable signal for said motor means generated by said one or more safety contacts (2) matches the control operation-enabling signal or the control inoperable signal for said motor means generated by said one or more second control contacts (21) and - in case of mismatch between the signal generated by said one or more safety contacts (2) and the control signal generated by said one or more second control contacts (21), checking whether the control signal generated by said one or more first safety contacts (2) is an inoperable state for said motor means and, in affirmative case, actuating said switching device (24) to set it to said second operating state and/or to generate an error signal in the line (6) of said one or more first safety contacts (2).

19. A method of controlling according to claim 18, wherein, in case of mismatch between the signal generated by said one or more safety contacts (2) and the control signal generated by said one or more second control contacts (21), it comprises the step of checking whether the control signal generated by said one or more first safety contacts (2) is an operation-enabling signal for said motor means and, in affirmative case, generating an error signal in the line (22) said one or more second control contacts (21).