A plural component pumping apparatus including a piston and cylinder for
each component to be pumped. Reciprocation of the piston in the cylinder
draws the component into the cylinder during an intake stroke of the
pumping apparatus and exhausts the material from the cylinder during an
exhaust stroke of the pumping apparatus. Intake and exhaust valves are
provided into the cylinder. Each of the intake and exhaust valve includes
a housing oriented outside the cylinder to facilitate repair or
replacement of the valves. A pumping motor on each side of the cylinder is
coupled to a support and to the piston to move the support and piston
relatively toward each other during the exhaust stroke and relatively away
from each other during the intake stroke. A position indicator is coupled
to the pumping motor. The pumping motor controls sense the position of the
position indicator.
