Improvements in Divers' Air Pumps.
Year: 1894

page_text: Date of Application, 22nd June, 1894
Complete Specification Left, 22nd Mar., 1895-Accepted. 27th Apr., 1895
Improvements in Divers' Air Pumps.
We, WILLIAM ROBERT FOSTER and ROBERT Fox trading as C. E. Heinke
and Company of 79 Great Portland Street, London W. Manufacturers of "Diving
Apparatus, do hereby declare the nature of this invention to be as follows:-
Our invention relates to improvements in pumps for supplying air to divers, and
it has for its object to provide an improved set of pumps whereby air may be
supplied to either one or two divers working at moderate depths or to one diver
only working at a great depth.
It also has for its object to provide improved means of keeping the pump
plungers lubricated and means of arresting the passage of oil from the cylinders
into the air pipes.
Such pumps as heretofore constructed have been double acting, each pump
barrel being fitted with a double acting piston comprising two cup leathers set
back to back. These have been liable to leak, difficult to repair and are otherwise
open to objection. Our improved air pump is provided with two pairs of single
acting pumps whose plungers are operated from a four throw crank shaft, the air
delivered being controlled by a valve so that the air delivered by each pair of
pumps may be separately supplied to two divers or the whole of the air delivered
by the two pairs of pumps may when required be supplied to one diver working in
very deep water.
Each plunger is formed of a cup leather, provided with means
of adjustment to compensate for wear as hereafter described, whereby it may be
kept tight, and each cylinder is provided with a raised cone at bottom, surrounding
the air discharge orifice and serving as a means of preventing the surplus oil
escaping into the air passage and retaining it in proximity to the sides of the
pump barrel so that the cup leather plungers will dip into the oil and be thereby
lubricated at each stroke. The cup leather plungers of these air pumps when
working at high pressures are liable to be rendered hard and horny by the heat
developed in the compression of the air so that they are no longer properly self
expanding and are liable to leak. To obviate this and provide an effectual means
of adjustment the plunger rod terminates in a coned head between which and the
end of the cup leather are confined a series of apertured discs of leather which fit
on the central stem of the plunger and are radially slit alternately from their
outside and inside edges, so as to be expansible circumferentially, a number of
these discs being superposed so that their slots "break joint
"and all fitting
accurately the interior of the cup leather, when tightened up against the coned
head of the plunger rod, have the effect of expanding the cup leather so as to keep
it tight against the sides of the barrel.
In order to prevent any oil which may be carried along with the air, in a liquid
atomised or vaporised condition from entering the flexible air pipe and destroying
the rubber of which it is made, we apply to the delivery pipes from the pumps
interceptors or filters formed of a porous mass preferably of the vegetable fibre
known as "loofah" contained within a closed chamber preferably made in halves
screwed together, the mass of porous material being clamped between a disc and the
opposite half of the chamber, the disc acting as a baffle against which the air
coming from the pump strikes so that suspended oil is deposited thereon and the air
escaping only by traversing the porous mass in the direction from its circumference

page_text: to the centre where the mass is traversed by a perforated outlet tube to which the
air pipe to the diver is coupled.
When working at high pressure means may be provided for cooling the air and
condensing the vaporised oil before reaching the filter.
Dated this 22nd day of June 1894.
Improvements in Divers' Air Pumps.
We, WILLIAM ROBERT FOSTER and ROBERT Fox, trading as C. E. Heinke
and Company, of 79, Great Portland Street, London, W. Manufacturers of
Diving Apparatus, 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:―
Our invention relates to improvements in pumps for supplying air to divers,
and it has for its object to provide an improved set of pumps whereby air may be
supplied to either one or two divers, working at moderate depths, or to one diver
only, working at a great depth. It also has for its object to provide improved
means of keeping the pump plungers lubricated, and means of arresting the
passage of oil from the cylinders into the air pipes. Such pumps, as heretofore
constructed, have been double acting, each pump barrel being fitted with a double
acting piston comprising two cup-leathers set back to back. These have been
liable to leak, difficult to repair, and are otherwise open to objection.
Our improved air-pump is illustrated in the accompanying drawings, forming
part of this Specification wherein
Figure 1 is a front elevation, and Figure 2 a plan, of the set of pumps.
Figure 3 is a vertical section of the lower part of one of the pump barrels and
its plunger, drawn full size.
Figure 4 is a plan of one of the leather packing dises of the plunger.
Figure 5 is a vertical section shewing the valve controlling the distribution of
the air.
Figure 6 is a longitudinal section, and Figure 7 a cross-section (on line 7-7,
Figure 6) of the air-filter and oil-arrester.
The same letters of reference indicate the same parts in all the figures.
The apparatus comprises two pairs A, A, and B, B, of single acting pumps
whose plungers are operated from a four-throw crank shaft C, the air delivered
being controlled by a valve D so that the air delivered by each pair of pumps
may be separately supplied to two divers, through hose pipes coupled to the two
union sockets E, F, or the whole of the air delivered by the two pairs of pumps A, A,
and B, B, may, when required, be supplied to one diver only, working in very deep
water. For this purpose, the valve D controls the communication of the delivery
passages G, H, (corresponding respectively with the two pairs A, A, and B, B, of
pumps) with the delivery hose coupled to E, F, in such manner that by placing
the valve in the full line position, shewn in Figure 5, the air from G must pass to E
aud that from H to F, or by placing the valve in the dotted position the air from
both G and H must pass to F.
Each plunger is formed of a cup-leather I, provided with means of adjustment
to compensate for wear, as hereafter described, whereby it may be kept tight, and
each pump barrel is provided with a raised cone J at bottom, covering the orifice
of the passage K in the bottom of the barrel leading to the inlet and delivery

page_text: valves of the pump. This cone serves to prevent most of the surplus oil escaping
into the air passage and to retain it in proximity to the sides of the pump barrel,
so that the cup-leather plunger I will dip into the oil and be thereby lubricated at
each stroke. This cone J is perforated with a number of fine holes leading from
the summit to an annular channel j, at the underside in communication with the
air passage K, the cone making an oil-tight joint at its edge with the bottom of
the barrel. The cup-leathers of these air-pump plungers when working at high
pressures are liable to be rendered hard and horny by the heat developed in the
compression of the air, so that they are no longer properly self-expanding and are
liable to leak. To obviate this, and provide an effectual means of adjustment, the
plunger rod terminates in a coned head L between which and the crown of the
cup-leather I are confined a series of apertured discs M of leather which are slipped
on the central stem of the plunger and are radially slit alternately from their
outside and inside edges, as shewn at m in Figure 4, so as to be expansible circum-
ferentially and capable of assuming a conical form, a number of these discs being
superposed so that their slits "break joint." The expansibility of the discs permits
of their peripheries being made to accurately fit against the interior of the cup-
leather, which has the effect of expanding the cup-leather so as to keep it tight
against the sides of the barrel. The tightening up is effected by means of nuts
and a metal washer N of coned form on its under face, which concentrates the
pressure of the nuts towards the inner edges of the discs, a leather washer n being
interposed between the coned washer and the crown of the cup-leather. The
coned head L is preferably covered with a coned washer 2 which is not slit radially
like the discs M.
In order to prevent any oil which may be carried along with the air, in a liquid,
atomized, or vaporized condition, from entering the flexible hose and destroying
the rubber of which it is made, we apply to the delivery nozzles E, F, from the
pumps, interceptors or filters, shewn in Figures 6 and 7, formed of a porous mass O,
preferably of the vegetable fibre known as "loofah," contained within a closed
chamber P preferably made in halves screwed together, the mass of porous material
being clamped between a disc Q and the opposite half of the chamber P, the disc
acting as a baffle against which the air coming from the pump strikes so that
suspended oil is deposited thereon and the air escaping only by passing around the
edge of the disc and traversing the porous mass in the direction from its circum-
ference to the centre, as shewn by the arrows, the air passing out at a central
perforated outlet tube R to which the hose pipe leading to the diver is coupled.
By means of the filter, auy impurities suspended in the air, such, for instance, as
the bodies of cockroaches or other insects, which get into the pumps in hot climates,
will be retained.
When working at high pressure, means may be provided for cooling the air and
condensing the vaporized oil before reaching the filter, for instance by means of
refrigerating worms interposed between the nozzles E, F, and the filters, the worms
being placed in a tub of water.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. The herein described combination of two pairs of pumps fitted with single
acting plungers constructed as described and capable of delivering air from each
pair separately or from the two pairs conjointly under the control of a valve,
substantially as specified.
2. Constructing the air pump plungers each of a cup leather expanded by
radially slitted washers superposed within the cup leather and pressed into conical
form between the conical head of the plunger rod and the pressure nut and
washer as described, so as to expand against the sides of the cup leather, as
specified.

page_text: 3. Providing the air passage in the bottom end of each pump barrel with a raised
cone to prevent the entry of oil into the said passage, as specified.
4. The herein described construction of air-filter and oil-interceptor, consisting
of a porous mess clamped between a baffle disc and an enclosing chamber and
traversed by a perforated exit tube so that oil suspended in the air will be knocked
out against the disc and impurities will be retained by the filter, substantially as
specified.
Dated this 22nd day of March 1895.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.