GB1565370A - Supply line apparatus for supplying mobile devices - Google Patents

Description

(54) SUPPLY LINE APPARATUS FOR SUPPLYING MOBILE DEVICES (71) We, SIEMENS AKTIEN GESELLSCHAFT, a German Company, of Berlin and Munich, Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The invention relates to supply line apparatus, for supplying mobile devices.

For the supply of electrical energy, for example, and possibly for the transmission of signals from and to a mobile device, for example a mobile hoisting device, it has been proposed to use a supply line which is suspended in festoon-form from a plurality of line carriages, each of which has a separate electromotive drive and which are collectively connected in an open-loop or closed-loop control system.

In such an arrangement, because the line carriages can be driven individually, the tensile and bending stresses on the line can be maintained at a low level and the mechanical system can thereby be subjected to less wear than might otherwise be the case. The drive for the line carriages can be provided either by rotating motors, for example having a friction-wheel drive, or by means of linear motors.

Now, in accordance with its position in the line festoons, each line carriage runs at a different speed and undergoes corresponding acceleration and/or deceleration during movement of the mobile device.

If the line carriages are driven by linear motors, the thrusts of the linear motors can readily be controlled by way of voltage applied thereto, and the necessary acceleration and deceleration forces, as well as the forces necessary for overcoming resistances to travel of the carriages, can readily be produced. However, this in itself may not be sufficient to ensure completely satisfactory running character.

According to the present invention, there is provided supply line apparatus for use in supplying energy to a mobile device, the apparatus comprising a supply line, connected at one end thereof to an input of the mobile device, and a series of line carriages from which the supply line is suspended at respective points therealong, so as to be festooned from one line carriage to the next, the line carriages being individually driven, to follow movements of the mobile device, under the control of respective operating signals supplied thereto by control circuitry of the apparatus, the control circuitry being adapted to provide as the said operating signals signals which are dependent upon measures of the actual velocity and of changes in the actual velocity of the mobile device that are applied to the control circuitry, when the apparatus is in use, and which are further dependent on values representing the forces exerted on the line carriages by the loops of line therebetween, which values are derived from the said measures of the actual velocity and changes in the actual velocity of the mobile device.

According to the present invention, there is also provided an arrangement for the supply of energy and for the transmission of signals from and to mobile apparatus, more particularly hoisting devices, through lines which are provided in festoon-form on line carriages each having a separate electromotive drive having open-loop or closed ioop control, characterised in that there is applied to the open-loop or closed-loop control arrangement of the line carriage drives a signal derived from the speed and the acceleration of the apparatus by means of a logic circuit, taking into consideration the direction of travel, in order to take into consideration the force component which is set up between the line carriages as a result of the movement of the festoon-form line.

An embodiment of the present invention can be constructed which provides supply apparatus for a mobile device having more nearly optimum running characteristics than previously proposed arrangements.

An embodiment of the present invention can be provided in which control signals are derived taking into account differing force components which are set up on movement of the festoons and which depend upon the positions of the line carriages in realtion to one another.

For a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a schematic synoptic view of apparatus with which an embodiment of the present invention can be employed, Figure 2 is a more detailed view of part of the apparatus of Figure 1, and Figure 3 is a graph.

There is illustrated in Figure 1 a crab 1 of a hoisting device, a bridge crane, which crab is adapted to run on a rail 2. A traction motor 3 of the crab 1 is connected to a current supply system through a movable supply line 5, one end of which is fixedly secured in position, for example to a bridge, while the other end thereof is secured to the crab 1. The line 5 is suspended at regular intervals therealong, for example at locations having a spacing a when the line 5 is extended, as shown in Figure 1, thereby to form a festoon, from line carriages 11 to 14, which are guided, for-example, on a rail 4 which is parallel with the rail 2. Each line carriage is provided with a drive, 16 to 19 respectively, preferably in the form of a linear motor.

The festoon may also comprise, in addition to the supply line for the crab 1, extra wiring or cables for supplying the various line carriages with electricity.

It is a characteristic of linear motors that vehicles driven thereby start gently. In the present case, therefore, because of the weight of the festoons which have to be pulled open or apart, the line carriages may not, in some circumstances, be able to follow up the moving device, e.g. the crab of a bridge crane, with sufficient rapidity, with the result that the festoons are not pulled apart or open uniformly. In other words, the operation in this case is basically a static one. To adapt line carriage speed to crab speed, in control of the line carriage drives a force component is taken into account which is derived from the rpm of the crab drive, the acceleration derived therefrom and from the direction of travel thereof, and which makes allowance for the lifting work required of the line carriages by increasing the voltage applied to the linear motors thereof accordingly. That is to say, when the festoons are extended, the line sections present between successive line carriages in the respective festoons are lifted. In this action, therefore, lifting work is performed, which work is terminated when the ends of the festoon-form line move back towards one another. The lifting work is taken into consideration by an additional force component in the control of the drives.

If the crab drive is open-loop controlled and not closed-loop controlled, this force component is derived from the actual rpm of the crab drive by means of a tachomachine and a logical circuit arrangement. If the crab drive has provision for speed variation, the component can be derived, on the basis of values instructed by a start transmitter of the apparatus, from the rpm set value, the acceleration and the direction of travel.

When a line carriage is deflected from the central position in relation to the two adjacent line carriages, for example as illustrated with reference to the line carriage 12 in Figure 2, there is set up as a result of the difference between the festoons in the line to respective sides of carriage 12 a restoring force F which tends to pull back the line carriage 12 into the central position between adjacent carriages 11 and 13, i.e.

has a stablising action. The forces exerted by the cable on the line carriage 12 in the directions along the running track 4 are denoted by F 12.11 and F 12.13 in Figure 2.

The resultant of these two forces, i.e. the restoring force, is equal to zero when carriage 12 is in the central position between carriages 11 and 13, as indicated by broken lines in the Figure. The rise of the restoring force in dependence upon the magnitude of the deflection of carriage 12 from the central position is greater when the line is as a whole widely extended than when it is less widely extended. These conditions are illustrated in Figure 3, in which the deflection s of carriage 12 from a central position between adjacent carriages is plotted along the abscissae and the restoring force F along the ordinates. The broken line indicates the restoring force when the line is run together and the solid line represents the restoring force when the line is extended. The system thus shows a dynamic behaviour which differs in accordance with the amount by which the festoon is extended. This dynamic behaviour is taken into consideration by a further force component in the control of the linear motors.

Thus, this further force component deals with the dynamic behaviour of the festoons, whose line carriage drives are usually openloop controlled and not close-loop controlled. From the above description, it is apparent that, ideally, the distances between the various line carriages, and therefore the individual festoons, are equal.

In normal operation, however, the distances between the line carriages vary, so that the festoons apply different forces to the discrete line carriages as shown in Figures 2 and 3. Taking into account this further force component, a value for which is also derived from crab rpm, acceleration and direction of movement, ensures that different forces are not applied to any two adjacent line carriages. Thereby a preselected relative spacing relationship can be maintained between the line carriages during movements of the festoons, for example when the length of line between each pair of adjacent carriages is equal as in the illustrated example, the spacings between the line carriages are maintained equal to each point in time during movement of the festoons.

Thus, for taking account of the two aforesaid force components, the speed of the mobile device and its acceleration, both in magnitude and in direction, must be ascertained. In an embodiment of the present invention, these quantities are associated with one another by means of a logic circuit, so that there is set up at the output of the logic circuit a control signal of a value corresponding to the required force component. The values for the speed and the acceleration may be derived, for example, from an actual value of the speed of travel of the device by way of a tachogenerator, and in the case of drives having closed-loop control also from a desired value for the speed of travel of the device.

WHAT WE CLAIM IS: 1. Supply line apparatus for use in supplying energy to a mobile device, the apparatus comprising a supply line, connected at one end thereof to an input of the mobile device, and a series of line carriages from which the supply line is suspended at respective points therealong, so as to be festooned from one line carriage to the next, the line carriages being individually driven, to follow movements of the mobile device, under the control of respective operating signals supplied thereto by control circuitry of the apparatus, the control circuitry being adapted to provide as the said operating signals signals which are dependent upon measures of the actual velocity and of changes in the actual velocity of the mobile device that are applied to the control circuitry, when the apparatus is in use, and which are further dependent on values representing the forces exerted on the line carriages by the loops of line therebetween, which values are derived from the said measures of the actual velocity and changes in the actual velocity of the mobile device.

2. Arrangement for the supply of energy and for the transmission of signals from and to mobile apparatus, more particularly hoisting devices, through lines which are provided in festoon-form on line carriages each having a separate electromotive drive having open-loop or closed-loop control, characterised in that there is applied to the open-loop or closed-loop control arrangement of the line carriage drives a signal derived from the speed and the acceleration of the apparatus by means of a logic circuit, taking into consideration the direction of travel, in order to take into consideration the force component which is set up between the line carriages as a result of the movement of the festoon-form line.

3. Arrangement according to Claim 2, characterised in that there are formed from the signal further control signals for taking account of the differing force component which is set up in the movement of the festoons and which depends upon the positions of the line carriages in relation to one another.

4. Arrangement according to Claim 3, characterised in that, in the case where the drive has open-loop control, the signal is derived from the actual value of the speed of travel of the apparatus, and in the case where the drive has closed-loop control, it is derived from the desired value and/or the actual value of the speed of travel.

5. A supply line apparatus for use in supplying energy to a mobile device, the apparatus comprising a supply line, substantially as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. and 3. Taking into account this further force component, a value for which is also derived from crab rpm, acceleration and direction of movement, ensures that different forces are not applied to any two adjacent line carriages. Thereby a preselected relative spacing relationship can be maintained between the line carriages during movements of the festoons, for example when the length of line between each pair of adjacent carriages is equal as in the illustrated example, the spacings between the line carriages are maintained equal to each point in time during movement of the festoons. Thus, for taking account of the two aforesaid force components, the speed of the mobile device and its acceleration, both in magnitude and in direction, must be ascertained. In an embodiment of the present invention, these quantities are associated with one another by means of a logic circuit, so that there is set up at the output of the logic circuit a control signal of a value corresponding to the required force component. The values for the speed and the acceleration may be derived, for example, from an actual value of the speed of travel of the device by way of a tachogenerator, and in the case of drives having closed-loop control also from a desired value for the speed of travel of the device. WHAT WE CLAIM IS:

1. Supply line apparatus for use in supplying energy to a mobile device, the apparatus comprising a supply line, connected at one end thereof to an input of the mobile device, and a series of line carriages from which the supply line is suspended at respective points therealong, so as to be festooned from one line carriage to the next, the line carriages being individually driven, to follow movements of the mobile device, under the control of respective operating signals supplied thereto by control circuitry of the apparatus, the control circuitry being adapted to provide as the said operating signals signals which are dependent upon measures of the actual velocity and of changes in the actual velocity of the mobile device that are applied to the control circuitry, when the apparatus is in use, and which are further dependent on values representing the forces exerted on the line carriages by the loops of line therebetween, which values are derived from the said measures of the actual velocity and changes in the actual velocity of the mobile device.

2. Arrangement for the supply of energy and for the transmission of signals from and to mobile apparatus, more particularly hoisting devices, through lines which are provided in festoon-form on line carriages each having a separate electromotive drive having open-loop or closed-loop control, characterised in that there is applied to the open-loop or closed-loop control arrangement of the line carriage drives a signal derived from the speed and the acceleration of the apparatus by means of a logic circuit, taking into consideration the direction of travel, in order to take into consideration the force component which is set up between the line carriages as a result of the movement of the festoon-form line.

3. Arrangement according to Claim 2, characterised in that there are formed from the signal further control signals for taking account of the differing force component which is set up in the movement of the festoons and which depends upon the positions of the line carriages in relation to one another.

4. Arrangement according to Claim 3, characterised in that, in the case where the drive has open-loop control, the signal is derived from the actual value of the speed of travel of the apparatus, and in the case where the drive has closed-loop control, it is derived from the desired value and/or the actual value of the speed of travel.

5. A supply line apparatus for use in supplying energy to a mobile device, the apparatus comprising a supply line, substantially as hereinbefore described with reference to the accompanying drawings.