Concrete mixer truck
First Claim
1. A concrete mixer truck comprising:
- a mixer drum adapted to be rotatably driven by means of a hydraulic system;
a water container;
a water conduit leading from said container to said drum;
a water pump;
a measuring device for sensing the drive torque of said mixer drum, said measuring device comprising a pressure sensor for sensing the pressure prevailing in the hydraulic system for determining the drive torque; and
a valve included in said water conduit an adapted to be controlled in response to said measuring defice so as to close said water conduit when said drive torque lies above a selectively adjustable rated value at least above the drive torque for the empty mixer drum.
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Accused Products
Abstract
The invention relates to a concrete mixer truck having a mixer drum adapted to be rotatably driven, a water container, a water conduit leading from the container to the drum, and a water pump. An object of the invention is to prevent the quality of a properly composed mixture contained in the drum from being deteriorated by unintentional addition thereto of water from the water container. This is accomplished by the use of a measuring device determining the drive torque for the mixer drum and a valve disposed in the water conduit and controlled by said measuring device in such a manner that the water conduit is closed when the drive torque exceeds a selectively adjustable rated value corresponding at least to the drive torque required for the empty drum.
For special conditions of for instance climatic nature requiring the addition of a limited amount of water prior to use, a further development of the invention provides the employ of a water supply opening switch adapted to be opened once during each valve-closure phase for admitting a limited and preselected amount of water.
55 Citations
11 Claims
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1. A concrete mixer truck comprising:
- a mixer drum adapted to be rotatably driven by means of a hydraulic system;
a water container;
a water conduit leading from said container to said drum;
a water pump;
a measuring device for sensing the drive torque of said mixer drum, said measuring device comprising a pressure sensor for sensing the pressure prevailing in the hydraulic system for determining the drive torque; and
a valve included in said water conduit an adapted to be controlled in response to said measuring defice so as to close said water conduit when said drive torque lies above a selectively adjustable rated value at least above the drive torque for the empty mixer drum. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
- a mixer drum adapted to be rotatably driven by means of a hydraulic system;
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9. A concrete mixer truck comprising:
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a mixer drum adapted for receiving a concrete and water mixture a hydraulic drive system operable for rotating the mixer drum, said hydraulic system being operable at or below a certain hydraulic pressure to apply a certain drive torque for rotating a substantially empty mixer drum and operable at a hydraulic pressure greater than said certain pressure to apply a drive torque for rotating a mixer drum containing a concrete and water mixture; a water container; a water conduit leading from said container to said drum; a valve operable for stopping flow of water through the conduit; and a measuring device having a sensor operatively coupled to said hydraulic system, said device being operably coupled to said valve for normally preventing water flow through the conduit when said hydraulic system is operating to apply a drive torque greater than said certain drive torque. - View Dependent Claims (10, 11)
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Specification