IMPROVEMENTS €6 IN THE MANUFACTURE OF METAL CYLINDERS HAVING A SMOOTH INTERNAL OR EXTERNAL SURFACE
Year: 1884

page_text: I, EDMUND EDWARDS, of the firm of Edwards and Co:-Patent Agents and
Engineers, of 35 Southampton Buildings, Chancery Lane, in the County of
Middlesex do hereby declare the nature of the invention for IMPROVEMENTS
€6
IN THE MANUFACTURE OF METAL CYLINDERS HAVING A SMOOTH INTERNAL OR
EXTERNAL SURFACE" to be as follows:-
This invention relates to cylinders which it is desired should be smooth and
polished on either their exterior or interior surface, as for instance the bored
cylinders used for pumps or Engines of different kinds, water or other meters and
for other purposes where the cylinder is fitted with a moveable piston working in
it; or to turned and polished cylinders such as the plungers of pumps or motive
power engines.
The invention has for its object a novel method of making such cylinders, so that
the expensive method of turning and boring them as hitherto ordinarily used is
avoided.
For this purpose tubes of brass or other suitable metal are used, of the required
size, and drawn with or without a longitudinal seam, their internal or external.
surface being rendered perfectly true and smooth in the process of drawing.
Where it is required that the cylinder should be true internally, in order to
obtain the necessary resisting strength at little expense, a tube or cylinder of the
kind described of little thickness and consequently cheap, is placed in an external
cylinder of cast or wrought iron 'unbored, a space being left between the two
cylinders all round. Into this space is then inserted a suitable incompressible
material, and in this way a compound cylinder is obtained the bore of which is
true, and the inner cylinder of which though thin has sufficient resisting strength
on account of the incompressible material surrounding it which is itself supported
by the rough external cylinder: The incompressible material may be wood,
cement, concrete, plaster, resinous matter, cast lead or tin, sand well packed, or &
mixture of one or more of such materials or of others of a suitable kind. Or, by

page_text: making a joint between the ends of the external and internal cylinders, an
incompressible fluid such as water may be used, by which any pressure upon the
inner cylinder is transferred to the outer one.
The cylinders described are applicable to air or vacuum brakes on railways, to
hydraulic brakes, or to any purpose in which the cylinder. is required to be true,
strong, and inexpensive.
Where the invention is to be applied to cylinders polished outside instead of
inside, similar thin tubes true outside are used but filled with the incompressible
materials already described, or with water. Where great strength is required a
mass of cast or wrought iron, or wood, may be inserted in the tube, a space being
left between into which the incompressible material is inserted.
Where the tube is used as the plunger of a pump, its ends are closed perfectly
tightly and strongly in order to prevent the escape of the material. For very high
pressure an opening may be formed at the bottom of the inner rough iron cylinder
into which the material such as resinous matter, or lead, is introduced between the
inner cylinder and the outer tube. This hole is then stopped up, and an end plate
may be added to keep the outer tube in its place.
For plungers of great length, an interior cylinder of turned wood may be inserted
into the external tube whilst the latter is heated, and on cooling it contracts and
holds the wood tightly.
The upper and lower ends are provided with tight joints to prevent the wood
from moving and the latter may be made in separate lengths screwed together at
their ends by metal sockets fitting into the tube india rubber washers being
inserted where necessary, whilst if desired a central bolt may traverse the plunger
from end to end.
Dated thia 92nd day of Februano 1901

page_text: I, EDMUND EDWARDS, of the firm of Edwards and Co-Patent Agents and
Engineers, of 35 Southampton Buildings, Chancery Lane, in the County of
Middlesex 'do hereby declare the nature of the invention for "IMPROVEMENTS
"
IN THE. MANUFACTURE OF METAL CYLINDERS. HAVING A SMOOTH INTERNAL OR
EXTERNAL SURFACE' (a communication to me from abroad by Henri Crouan, of
Paris, in the Republic of France) and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement and
accompanying drawing:-
This invention relates to cylinders which, it is desired should be smooth and
polished on either their exterior or interior surface; as for instance (in the first
case) cylinders used for air pumps, vacuum pumps, and pumps for water or other
fluid or semi fluid substances, and for steam or other .motive power Engines, for
water or other meters, and other machines or apparatus in which cylinders fitted
with moveable pistons are used. Or, (in the case where the cylinders are required
to be smooth and polished externally) for the plungers; of pumps or motive power
Engines, water motors, or the pistons or plungers of lifts, or other purposes of the
like kind:
The methods of rendering the exterior or interior surfaces of such cylinders
smooth and polished ordinarily used are very expensive, and the present invention
has for its object novel methods of making such cylinders so that they are cheap
and at the same time effective for the purposes required.
1
For. this purpose tubes of brass or other suitable metal are used, of the required
size and drawn either with or without a longitudinal seam, the internal or external
surface being left true and smooth in the process of drawing.
'
Such tubes if used of sufficient thickness to form by themselves the cylinders
required; would be too expensive, but by the present invention cheap thin tubes of
the kind can be used.
For this. purpose, in cases where it is required that the cylinder should be
smooth and polished internally, in order to obtain the necessary resisting, strength
at small expense, a tube or cylinder of the kind required and of little thickness, of
brass or other suitable metal drawn so that its interior surface is smooth and
-polished, is placed in a rough external cylinder of cast iron or other metal unbored,
a space being left between the two cylinders, all round. Into this space is then
inserted a suitable incompressible material and in this way a compound cylinder is
obtained, the bore of which is true and polished and the inner cylinder of which
though thin has sufficient resisting strength by reason of the incompressible
material surrounding it which is itself supported by the rough external cylinder.
The incompressible material used as described may be any suitable substance,
such as wood, cement, concrete, plaster, resinous matter, cast lead or tin, sand well
packed, or a mixture of one or more of such materials or of others of a suitable
kind. Or, by making a tight joint between the ends of the internal and external
cylinders an incompressible fluid such as water may be used, by which any pressure
in the inner cylinder is transferred to the outer strong one.
Cylinders constructed in the novel manner described are applicable to air
pressure or vacuum brakes on railways, to hydraulic brakes, or to any purpose
in which the cylinder is required to be true, strong, and cheap.
Where the invention is to be applied to cylinders true and polished outside
instead of inside, similar thin tubes are used but drawn with their exterior instead
of their interior surface smooth and polished and filled with the incompressible

page_text: materials, or with water as already described and where great strength is required
a mass of cast or wrought iron, or wood may be inserted in the tube, a space being
left between them into which the incompressible material is introduced.
In the accompanying drawing which is in illustration of the invention, figure 1
shews it applied to a pump cylinder, a being the exterior rough cylinder, 6 the thin
inner cylinder, and c the material introduced between them as described, such as
resinous substances or cement if cold water only is to be used; or lead, or fine sand,
if hot water is to be used.
Figure 2 shows a cylinder similarly constructed but of great length in proportion.
to its diameter, a being the outer rough cylinder, b the thin inner one, and c the
material between them.
Figure 3 shows a plunger pump, the plunger of which consists of an exterior thin.
brass tube b, filled with a packing of wood or of water as described and shewn at c.
An end plate at each end of the plunger is shewn at d, d, soldered or tightened
hermetically against the ends of the tube b. The tube may be filled with any
suitable material as already explained.
Figure 4 shews a force pump for high pressure.
a is a thin exterior tube, and
6 the interior filling of metal, leaving the annular space c which is filled with à
suitable resisting material as described.
An opening for introducing the latter is left in the bottom of the plunger and
is afterwards closed by a plate fitting upon the end of the tube a and held by a
screw, as shewn at e.
Figure 5 shews the invention applied to the piston or plunger of a lift. a, a, are
the thin exterior brass tubes filled with wood c turned to fit tightly and introduced
into the tubes whilst the latter are warm so that they hold the wood tightly
when cold.
The top and bottom ends are fitted with ends tightened up to prevent any play
of the wood, and the different parts of the plunger are shewn connected together
by metal tubes f, f, screwed upon the wood and into each other. A bolt g is shewn
extending from end to end of the plunger to hold all its parts tightly together. An
india rubber ring at each joint prevents the possibility of water entering, and the
tubes may also have soldered joints.
The invention may be applied to all kinds of water, gas, or hot air engines,
meters, hydraulic cranes or capstans, lifts, and accumulators, and other machines in
which cylinders or plungers true internally or externally are required.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is The combination of the thin metal tube having an internal or external
polished surface, the rough supporting cylinder, and the intervening space filled
with a sufficiently incompressible material, substantially as and for the purposes
described and shewn in the Drawing.
$
TAL: 001 1
1004