Mixing apparatus
First Claim
1. In a mixing apparatus for producing a liquid having a plurality of components mixed in a selected ratio which comprises flow means for receiving the respective components, and a plurality of metering pumps for the respective components connected to said flow means and operable to cause delivery thereto of the components, each pump having a respective stepping motor as a drive motor and comprising a piston burette, the piston of which is driven by said stepping motor to sweep a predetermined increment of volume in response to each step of the stepping motor,the improvement comprising an automatic control means connected to the pump motors to control same and being operable to supply individual control signals thereto as respective trains of pulses, said control means having input means for receiving input data determining the selected mixing ratio and including computer means (a) being responsive to such input data to compute and establish the pulse interval for each pulse train such that the pumps cause quantities of the respective components to be delivered to said flow means in the same period of time in accord with said selected ratio and at a respective uniform rate during said period and (b) being arranged to compute initial piston positions for the burettes in accord with the quantities of the respective components to be delivered to the flow means in accord with said selected ratio;
- and said automatic control means further including an interface device connected to each stepping motor and responsive to commands generated by the computer means to supply pulses to the associated stepping motor to establish the initial position of the associated burette piston and to subsequently control the supply of the train of pulses to the stepping motor to cause delivery of the associated component to said flow means.
1 Assignment
0 Petitions
Accused Products
Abstract
A mixing apparatus utilizes piston burettes driven by stepping motors as metering pumps to deliver component liquids to be mixed into a liquid stream in a selectable constant mixing ratio. A computer-based automatic control system is used to control the regulated take up of the respective components by the burettes and the delivery of them to a mixing device. The computer calculates the rates of stepping of the respective motors so that each component is delivered over the same period of time and at a respective uniform rate. The computer also controls associated switching valves via an interface device and may be a desk top machine with keyboard or pre-programmed data input.
44 Citations
11 Claims
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1. In a mixing apparatus for producing a liquid having a plurality of components mixed in a selected ratio which comprises flow means for receiving the respective components, and a plurality of metering pumps for the respective components connected to said flow means and operable to cause delivery thereto of the components, each pump having a respective stepping motor as a drive motor and comprising a piston burette, the piston of which is driven by said stepping motor to sweep a predetermined increment of volume in response to each step of the stepping motor,
the improvement comprising an automatic control means connected to the pump motors to control same and being operable to supply individual control signals thereto as respective trains of pulses, said control means having input means for receiving input data determining the selected mixing ratio and including computer means (a) being responsive to such input data to compute and establish the pulse interval for each pulse train such that the pumps cause quantities of the respective components to be delivered to said flow means in the same period of time in accord with said selected ratio and at a respective uniform rate during said period and (b) being arranged to compute initial piston positions for the burettes in accord with the quantities of the respective components to be delivered to the flow means in accord with said selected ratio; - and said automatic control means further including an interface device connected to each stepping motor and responsive to commands generated by the computer means to supply pulses to the associated stepping motor to establish the initial position of the associated burette piston and to subsequently control the supply of the train of pulses to the stepping motor to cause delivery of the associated component to said flow means.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
Specification