Year: 1889

page_text: I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent Agents,
Southampton Buildings in the County of Middlesex, do hereby declare the nature of
this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
This invention has reference to an improved form of pump for compressing air,
or other elastic fluid which is illustrated in the accompanying drawings in which
Figure 1 is an end elevation, and
Figure 2 a side elevation of the complete pump.
Figures 3 and 4 are details of the speed regulator and
Figures 5, 6 and 7 aro details of the air admission valve.
The pump consists of an air compressing cylinder a connected to the steam
cylinder 6 by two hollow supports c, c which also serve as air chambers and water
separators as described later on.
The air compressing piston k is connected to the steam piston by two piston
rods d, d' and causes the crank-shaft to revolve by two connecting rods e, e¹ ending: in
bearing common to both on the crank pin ƒ.
a
The air compressing piston k carries a cylinder of considerably smaller area. than
the main cylinder a and acts as follows. On the downstroke, atmospheric air is drawn
through the valve g (shown in detail in Figures 5 and 6) into the main cylinder a, on
the up stroke this air is driven through the valve h into the smaller cylinder carried by
the air compressing piston k.

page_text: On the next down stroke, this cylinder, sliding over the fixed piston 1, still further
compresses the air through the valve into the first air chamber and water separator c.
The air admission valve 9 Figures 5, 6 and 7 is made as light as possible the
greatest possible strength being combined with extreme lightness by making the
valve of T cross section.
This valve is arranged to give the required area of opening with very small lift, by
being made of annular form, so as to discharge on the inside as well as on the outside
circumferences.
In compressing air it is essential to introduce continuously a small quantity of water
into the compressing cylinders, so as to fill up all clearances at the end of the stroke,
this water must however in most cases he separated from the compressed air afterwards
so that it is desirable that as little water as possible should pass over with the air at
each compression that is, the air should in each case be as nearly as possible com-
pletely discharged, before the water has a chance to escape by the discharge valves.
To accomplish this object, the air compressing piston and the smaller fixed
piston are made higher in the middle than at the edges, and the valves h, i occupy
in each case the highest position on these pistons so that the clearance filling water
remains below the surface of the valves h, i until the very end of the up and down
stroke respectively, and thus the minimum quantity of water is allowed to pass over
with the air.
This clearance filling water is taken from that employed for cooling the compressing
cylinders, and is provided by a small force pump m worked from one of the piston rods d.
The water is caused to circulate first through the annular space between the air
delivery tube n and the water tube o, thence into the interior of the fixed compression
piston and then it is forced through the spiral passage w formed in the wall of the
main compressing cylinder a finally ending in a two-way branch p.
From this branch part of the water passes at each stroke into the compressing
cylinder a through the small valve 9 the remainder, the amount of which may be
regulated by the cock », being the overflow.
The water separators c c' allow the water to separate itself from the compressed air
by gravitation, and are provided with drain cocks, a¹ in the usual manner.
These separators are arranged "in series," that is to say, the air enters first the
separator and throws down there part of the water held in suspension, and then
passes to the separator c¹ which still further deprives it of the water; thence the dry
air passes by the outlet valve s to the accumulator or reservoir.
Steam is admitted to the steam cylinder by a piston slide valve, or other balanced
slide valve of usual construction worked by an excentric t (Figures 3 and 4), which is
so constructed, by being pivoted to the crank disc y at some distance from its centre
of rotation, and by having considerable excess of weight on one side as to act as a
speed governor or regulator, tending to fly out by centrifugal force, in opposition to
the spring v, or being forced in by the spring according as the speed of rotation is
greater or less than normal, and so, by altering its excentricity, admitting less or
more steam to the cylinders.
Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed as communicated to me by my foreign
correspondents I declare that what I claim is,
First. In apparatus for compressing air or other elastic fluid, the double discharge
valve g of specially light construction, in combination with the compressing pistons k
and, both of special form, that is with their centres higher than their edges, and
with their valves h, i occupying the highest positions substantially as shown and
described and for the purposes set forth.
Second. In apparatus for compressing air or other elastic fluid the force pump m for
the circulation of cooling water, in combination with the annular space between the
air tuben and the water tube o, and with the spiral passage in the wall of the main com-
pressing cylinder a substantially as shown and described, and for the purpose set forth.

page_text: Third. In apparatus for compressing air or other elastic fluid the speed regulator
consisting of pivoted excentric t having considerable excess of weight on one side, in
combination with the spring v and acting in the manner described.
Fourth. In apparatus for compressing air or other elastic fluid the hollow
supports c, c, adapted to be used as water separators, in combination with the general
arrangement, of the different parts, substantially as shown and described.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London,
Agents for the Applicant.