LAURENT & COLLOT'S AUTOMATIC INJECTION PUMP.


As well known, in every well-constructed injection pump, there is a
system of gearing which acts upon the suction valve and stops the
operation of the pump as soon as the requisite pressure is reached;
but the piston, for all that, continues its motion, and, besides the
resistant work of the pump has passed through different degrees of
intensity, seeing that at every moment of its operation the piston
has preserved the same stroke and velocity. We are speaking, be it
understood, of pumps that are controlled mechanically. In the one that
we are about to describe, things take place far otherwise. In measure as
the pressure increases, the stroke of the piston diminishes, and when it
has reached its maximum, the motion of the piston ceases entirely. If,
during the operation progression undergoes more or less variation,
that is, for example, if it diminishes at a given moment to afterwards
increase, the stroke of the piston undergoes all the influences of it.

The pump of which we speak is shown in Figs. 16 to 21, and is the
invention of Messrs. Laurent Bros. & Collot. It may be described briefly
as follows:

The apparatus, as a whole, has for base a cast-iron reservoir; A, to the
top of which is fixed the pump properly so-called, B, as well as the
clack box, A, and safety valve. The pump is placed opposite an upright,
D, whose top serves as a guide to the prolongation, E, of the piston
rod. This latter is traversed by a pivot, a (Fig 19), on which is
mounted a lever, F, whose outer extremity is articulated with a
connecting rod, G, which is itself connected with the cranked shaft,