Method and apparatus for mixing concrete in a concrete mixing device to a specified slump

• US 5,713,663 A
• Filed: 05/15/1996
• Issued: 02/03/1998
• Est. Priority Date: 05/15/1995
• Status: Expired due to Term

• Current Assignee: Boral Resources Pty Limited (Heidelberg Materials AG)
• Original Assignee: Boral Resources Pty Limited (Heidelberg Materials AG)
• Inventors: Zandberg, Henry, Briedis, Hussein
• Primary Examiner(s): Cooley, Charles E.
• Application Number:
  US08/647,834
• Time in Patent Office: 629 Days
• Field of Search: 366/1, 366/2, 366/6, 366/43, 366/44, 366/8, 366/53-61, 366/142, 366/175.3, 366/187, 366/220-231, 366/601, 366/17
• US Class Current: 366/8
• CPC Class Codes: B01F 35/212 of the driving system data, e.g. torque, speed or power data
• CPC Class Codes: B28C 5/421 Drives in general B28C5/0831
• CPC Class Codes: B28C 7/026 by measuring data of the driving system, e.g. rotational speed, torque, consumed power
• CPC Class Codes: B28C 7/0454 Volumetric measuring devices, e.g. for consecutively delivering predetermined volumes of ingredients
• CPC Class Codes: G01N 2203/0676 Force, weight, load, energy, speed or acceleration

Abstract

A method and apparatus for mixing concrete in a concrete delivery mixing truck is provided which can yield a mix with an approximate required slump. This is achieved by monitoring the torque loading on hydraulic drive which rotates a mixing barrel and noting an anticipated minimum torque loading which, in turn, approximates to a required slump value. Liquid component is added to a mix until this minimum torque loading is noted. A CPU (17) is used to process information derived from a hydraulic pressure sensor (15) connected in the hydraulic drive motor used to rotate the mixing barrel. A volume/mass input sensor (21) can be used for meaning the amount of particulate ingredients, and a water volume sensor (25) can be used to measure the volume of liquid component added to the mix. When a known maximum volume of liquid component is added a computer can operate to prevent further liquid being added, unless it is purposely overridden. The computer can be used to print a delivery docket via a printer with all the specified concrete data and all the measured parameters, and can also be used to transfer information to a main computer at a concrete depot, so the information can be used as a record of the concrete delivered and also as data for account processing.

Claims

1. A method of mixing concrete comprising:

charging a specified amount of particulate ingredients into a mixing barrel;

rotating the mixing barrel by driving means to mix the ingredients;

monitoring torque loading on said driving means used to rotate the mixing barrel;

adding a liquid component into the mixing barrel to wet the ingredients and continuing mixing to produce a mix;

adding said liquid component in sufficient volume to approach a specified slump for the mix to attempt to approach a predetermined minimum torque loading on said driving means for the amount of the particulate material in the mixing barrel related to the specified slump; and

discharging the mix from the mixing barrel.

2. A method as claimed in claim 1 comprising monitoring the volume of said liquid component added.

3. A method as claimed in claim 2 comprising storing results of said monitoring of the volume of said liquid component in a store means so as to be retrievable from said store means.

4. A method as claimed in claim 1 wherein processing means is used to monitor the volume of said liquid component added and to calculate a slump value from a monitored value of torque loading following addition of said liquid component.

5. A method as claimed in claim 4 wherein said processing means operates control means to prevent addition of said liquid component in excess of that needed to achieve said specified slump.

6. Concrete mixing apparatus having a mixing barrel and driving means for rotating said mixing barrel, said driving means having a torque loading sensing means which monitors the torque loading on said driving means required to rotate said barrel, said torque loading sensing means being connected with a processing means programmed to enable a concrete mix in said mixing barrel to be optimized to approximate a required slump by calculating a predetermined minimum torque loading on said driving means for the required slump for an amount of particulate material in said mixing barrel, so that an operator can monitor the torque loading sensed by said torque loading sensing means as liquid component is added to said concrete mix during mixing, and cease adding liquid component when the monitored torque loading sensed by said torque loading sensing means approaches said predetermined minimum torque loading.

7. Apparatus as claimed in claim 6 including means for monitoring the volume of said liquid component added to the barrel and wherein the monitored results are stored in a store means and wherein said results are retrievable from said store means to provide a report concerning the mixing.

8. Apparatus as claimed in claim 7 wherein said processing means is programmed to determine a required volume of liquid component to be added to said barrel to reach said predetermined minimum torque loading for the amount of particulate material in said barrel.

9. Apparatus as claimed in claim 8 wherein said store means stores information relating to the concrete mix provided from said processing means, said information comprising at least:

1. said required slump;

2. said amount of particulate material in said concrete mix, and wherein said store means is accessible to retrieve all of said information to provide a report for a particular mix of concrete.

10. Apparatus as claimed in claim 9 wherein said processing means has a printer and wherein said stored results and said stored information are retrievable as a printed report from said printer.

11. Apparatus as claimed in claim 9 wherein said store means also stores information as to:

3. customer details;

4. mix type;

5. date;

6. time of delivery;

7. water content of said particulate ingredients; and

wherein said information is also retrievable from said store means to provide said report.

12. Apparatus as claimed in claim 9 wherein said processing means has an area of memory means configured as a look-up table comparator and wherein information concerning a range of possible mixes is stored in said look-up table comparator and wherein said processing means processes the monitored torque loading and the monitored volume of liquid component added and compares said monitored torque loading and said monitored volume of liquid component against said look-up table information.

13. Apparatus as claimed in claim 8 including a liquid component reservoir from which said liquid component can be discharged.

14. Apparatus as claimed in claim 13 including liquid component control means connected with said processing means to prevent addition of said liquid component above a predetermined volume for the required slump.

15. Apparatus as claimed in claim 7 including a depot with a further processing means and wherein information stored in said store means can be retrieved by said further processing means for processing at said depot.