MULTIPLE FORCE-MEASURING DEVICE, FORCE-MEASURING MODULE, AND METHOD FOR MONITORING A CONDITION OF THE MULTIPLE FORCE-MEASURING DEVICE

• US 20100084199A1
• Filed: 12/07/2009
• Published: 04/08/2010
• Est. Priority Date: 06/07/2007
• Status: Active Grant

• Current Assignee: Mettler Toledo GmbH
• Original Assignee: Mettler-Toledo AG (Mettler-Toledo International Inc.)
• Inventors: Bucher, Cyrill, Bliss, Douglas, Uster, Markus, Skidmore, Aaron
• Granted Patent: US 8,648,266 B2
• Time in Patent Office: Days
• US Class Current: 177/25.130
• CPC Class Codes: G01G 23/01 Testing or calibrating of weighing apparatus
• CPC Class Codes: G01G 23/3707 using a microprocessor

Abstract

A multiple force-measuring device, especially a multiple weighing device has at least two force-measuring modules. Each force-measuring module includes a force-measuring cell and a power delivery means. The power delivery means of at least one of the force-measuring modules in this arrangement is connected, directly or through a junction element, to a control cable that is connected to a power supply unit. The force-measuring modules are connected directly to each other through a module-connection cable that transfers electrical power therebetween.

Claims

1. A multiple force-measuring device, particularly a multiple weighing device, comprising:

at least two force-measuring modules, each comprising a force-measuring cell and a power delivery means;

a power supply unit for supplying electrical power;

a control cable that connects the power delivery means of at least one of the force-measuring modules to the power supply unit, directly or through a junction element; and

a module connection cable that connects each force-measuring module to another force-measuring module and transfers electrical power therebetween.

2. The multiple force-measuring device of claim 1, wherein:

the at least two force-measuring modules are at least three force-measuring modules, connected in a chain-like manner by the module-connection cables, such that the first and the last of the force-measuring modules in the chain-like connection are each connected to the control cable, directly or through the junction element.

3. The multiple force-measuring device of claim 1, wherein:

only one force-measuring module is connected to the control cable.

4. The multiple force-measuring device of claim 1, wherein:

all of the force-measuring modules are connected to each other in a chain-like manner.

5. The multiple force-measuring device of claim 1, further comprising:

a means for communications, associated with each of the force-measuring modules, the communication means connected to the module-connection cable to transmit communication signals therethrough by means of a bus system.

6. The multiple force-measuring device of claim 1, further comprising:

a device for determining and/or monitoring the voltage of the power delivery means of each force-measuring module relative to a common potential.

7. The multiple force-measuring device of claim 1, wherein:

the module-connection cables have substantially identical conductor resistances.

8. The multiple force-measuring device of claim 1, further comprising:

a device for interrupting the continuing power supply path, associated with one of the force-measuring modules or the module-connection cables.

15. A method for determining and monitoring the condition of a multiple force-measuring device, comprising the steps of:

providing a force-measuring device of claim 1, having at least two force-measuring modules, and

monitoring the power supply of the force-measuring modules.

16. The method of claim 15, wherein:

the monitoring step comprises the substeps of;

monitoring the voltages of the force-measuring modules for compatibility with threshold values; and

in the case of a malfunction or if the threshold value of a force-measuring module is exceeded, triggering an action, comprising at least one of;

transmitting a message;

recalibrating the force-measuring module; and

switching off the force-measuring module.

17. The method of claim 16, further comprising the step of:

determining threshold values through at least one of;

a reference measurement; and

theoretical calculations that account at least for;

the characteristic quantities of the module-connection cables, such as conductor length and conductor cross-section; and

the internal resistance values of the force-measuring module.

18. The method of claim 15, further comprising the step of:

measuring the voltage of the power delivery means in reference to a common potential.

19. The method of claim 15, further comprising the step of:

monitoring a communications means that interconnects the force-measuring modules with each other; and

terminating the connection provided by the communications means, if applicable.

20. The method of claim 15, further comprising the step of:

recognizing a chain-like connection of between two to four force-measuring modules, in at least one of;

a terminal, a junction element and one of the force-measuring modules; and

cutting off the transfer of electrical power to further force-measuring modules, if applicable.

21. The multiple force-measuring device of claim 5, wherein:

the bus system is a CAN bus system.

24. The method of claim 15, wherein:

the voltage of the power supply is monitored.

9. A force-measuring module for a multiple force-measuring device, particularly a multiple weighing device, comprising:

a force-measuring cell;

a power delivery means;

an adaptation for connecting the force-measuring module through a control cable that in turn connects to a power supply, directly or through a junction element, and

an adaptation for connecting the force-measuring module through a module-connection cable to at least one further force-measuring module of the same, transferring electrical power between the respective force-measuring modules.

10. The force-measuring module of claim 9, further comprising:

a means for communications, acting through the module-connection cable to transmit communication signals between the force-measuring module and the at least one further force-measuring module.

11. The force-measuring module of claim 10, further comprising:

a device for monitoring and/or terminating the connection of the communication means with the at least one further force-measuring module.

12. The force-measuring module of claim 9, further comprising:

a device for determining and for monitoring the power supply.

13. The force-measuring module of claim 9, comprising:

at least one plug connector for connection of each of the module-connection cable and the control cable.

14. The force-measuring module of claim 13, wherein:

each of the at least one plug connectors is at least one of;

encapsulated and/or sealed against influences of the ambient environment, in particular against dirt, liquids or gases, and

provided with at least one electrical contact surface with a corrosion-resistant design.

22. The force-measuring module of claim 10, wherein:

the bus system is a CAN bus system.

23. The force-measuring module of claim 12, wherein:

the device determines and monitors the voltage of the power supply.