US 4,286,732 AGranted

Variable ratio dispensing apparatus

AssigneeAccuratio Systems, Inc.

InventorsJames R. James, Michael P. Neathery

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Abstract

Dispensing apparatus with a pain of fluid dispensing cylinders each having a piston driven through a separate differential transmission with two inputs. One of the inputs of both transmissions is driven by a first electric motor. The other inputs are connected to counterrotating output shafts of a gear box driven by a variable speed second electric motor to introduce unlike inputs into the differential transmissions so that the ratio of fluid dispensed by the cylinders is varied by operation of the second motor in different directions and at different speeds. During the return stroke of the pistons the second motor is operated at a rate higher than its rate during the dispensing stroke so that any difference in the length of the dispensing stroke of the pistons is reduced to zero before the pistons home, whereupon the second motor is de-actuated and the first motor alone homes the pistons to prevent the pistons from getting out of phase.

Claims13

Dependent claims

In an apparatus having a plurality of cylinder and piston assemblies each operable upon relative movement of its piston at a given rate to dispense a fluid from said cylinder at a predetermined rate, and means for varying the rates of said movement in the respective assemblies for varying the ratio of dispensing fluids from said cylinders, improved structure which comprises,

a differential transmission associated with each of said assemblies and having an output connected for producing said relative movement of its piston, each said differential transmission having a first input and a second input,
first motor means drivingly connected with said first input of each of said differential transmissions,
and second motor means drivingly connected with power transmitting means having a plurality of output means each connected with a separate one of said second inputs of said differential tranmissions for varying the rates at which said differential transmissions drive their respective assemblies,
each said second input being responsive to variations in the direction and rate of operation of said second means.

1 more element

Dependencies are inferred from the claim text.