IMPROVEMENTS IN FLEXIBLE TUBULAR AND FLEXIBLE DIAPHRAGM' PISTONS AND PLUNGERS
Year: 1884

page_text: We, JAMES NAYLOR, of Bakewell, in the county of Derby, Engineer, and THOMAS
GARDINER GELL, of Cheadle, in the county of Chester, Calenderer and Finisher do
hereby declare the nature of our said invention for "IMPROVEMENTS IN FLEXIBLE
TUBULAR AND FLEXIBLE DIAPHRAGM' PISTONS AND PLUNGERS to be as follows:-
This invention is closely allied to the well known principle of the flexible
diaphragm, but differs from the usual adaptation of that principle in having
generally a more tubular shape, a feature which is especially manifested as the
movement in the reciprocating mechanism becomes longer than the dimension
across the line of movement. By the adoption of this feature in the flexible
material used, we are enabled to overcome the difficulties that have hitherto
prevented (except to a very limited extent) the use of diaphragm engines, pumps,
or similar mechanism, and we shall henceforward, for convenience of reference,
indicate this feature of the flexible material used in this invention by the words
the "flexible tube" or other words of equivalent meaning.
The difficulties in the use of a flexible diaphragm in lieu of a piston or of a
diaphragm piston are first and foremost, the difficulty of making a diaphragm that
will withstand the full pressure of the steam or water, and second, that will be
light and thin enough to enable it to double back repeatedly on itself in opposite
directions without being too pervious or fragile.
Now our invention takes the strain off a large part of the material of the flexible
tube used, and in the case of heavy pressures divides it between several flexible
tubes, while at the same time the flexible tube being usually more or less conical it
can double into itself with greater ease than a cylindrical sleeve could.
We form our apparatus of a cylinder or its equivalent and a piston or its
equivalent connected together in fluid-tight manner by one or more flexible tubes
or sleeves; either the cylinder or the piston has a reciprocating motion, we prefer
the piston to have it.
The flexible tube is of india-rubber hose or other suitable flexible impervious
material.
For ordinary steam engine purposes we form the equivalent of a cylinder of two
parts, preferably of truncated conical shape with the wider ends of the truncated
cones abutting against each other but holding the flange of the flexible tube firmly

page_text: between them. The flexible tube is preferably in the form of a cone fitting loosely
inside the cylinder or the cones of the equivalent, and has an exterior flange firmly
held between the two halves of the cylinder or its equivalent hereafter grouped
under the common designation cylinder, and a central head on the smaller end of
the cone firmly held between the piston and its cover, or a flange firmly attached
to or embedded in the piston.
Where powerful pressure is applied as in hydraulic cylinders, two, three or more
flexible tubes are used joined together, or if (but we do not recommend them) true
cylinders be used, then three single ones are employed, the central one being larger
than the two exterior ones, or two cones can be employed with one or more cylinders
between them. Between the two flexible tubes is a double conical piston attached
to both or all the flexible tubes, and having a piston and rod firmly secured to it
on the opposite side of the one flexible tube and a cap on the opposite side of the
other, the whole forming a single compound piston. Or a single large piston with
H cross section can have an internal flange of the flexible tube or sleeve firmly
fixed into each end, or the various flexible tubes can be flanged into or onto the
cylindrical piston, or into or onto the cylinder in any convenient manner.
The arrangement of having several flexible tubes on one piston and one long
cylinder can be modified' in numerous ways. In order to make more than one
flexible tube serviceable, each must take a part of the pressure, or in other words
there must be differential pressures between the various flexible tubes. We manage
this in the following manner: opening out of the end actuating compartment (of a
single acting engine pump or hydraulic ram for instance) and out of each inter-
mediate compartment, we place a series of cylinders with pistons or cylinders or
diaphragm pistons receiving their actuating fluid from one common closed reservoir;
these cylinders are arranged with equal areas exposed to the interior of the com-
partment of the main cylinder, but unequal areas exposed to the fluid in the closed
reservoir inversely in the proportion 1, 2, 3 ... N, N being the area of exposure
in the piston acting against the pressure in the actuating end, and each succeeding
compartment having less pressure bearing against it. By this or equivalent means,
such for instance as having the intermediate compartments open to certain constant
heads of water, only a part of the pressure bears on each flexible tube, the
remainder being counterbalanced by the head of water or other fluid behind it.
In applying the flexible tube to the slide valve of a steam engine, in order to
secure the advantages attained by the use of an equilibrium slide valve, we use two
flexible tubes suitably connected near to the end of the slide valve and to some
convenient part of the steam chest, by this means preventing the steam from the
boiler from operating upon the top of the valve and avoiding the friction incident
to an equilibrium valve that attains the same end by the use of packing.
Arrangements of flexible tubes altered to suit can be applied to vibrating pumps
and engines and water and other meters, whether reciprocating or vibratory, but
we do not describe them as any engineer with a description of the foregoing arrange-
ments could supply similar mechanism for almost any variety of vibratory or
reciprocating mechanism of this description, "and their name is legion." One
point to be observed in all cases is that no sharp angles should be allowed to bear
against the flexible tube, but should be rounded in all cases to at least a ¼ of an
inch radius.

page_text: We JAMES NAYLOR of Bakewell in the county of Derby Engineer and THOMAS
GARDINER GELL of Cheadle in the county of Chester Calenderer and Finisher
do hereby declare the nature of our said invention for IMPROVEMENTS IN
FLEXIBLE TUBULAR AND FLEXIBLE DIAPHRAGM PISTONS AND PLUNGERS and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
This invention is closely allied to the well known principle of the flexible
diaphragm, but differs from the usual adaptation of that principle in having
generally a more tubular shape, a feature which is specially manifested as the
movement in the reciprocating mechanism becomes longer than the dimension across
the line of movement. By the adoption of this feature in the flexible material used,
we are enabled to overcome the difficulties that have hitherto prevented (except to
a very limited extent) the use of diaphragm engines, pumps, or similar mechanism,
and to apply thereto flexible tubular pistons or plungers.
The difficulties in the use of a flexible diaphragm in lieu of a piston or of a
diaphragm piston are first and foremost, the difficulty of making a diaphragm that
will withstand the full pressure of the steam or water, and second that will be light
and thin enough to enable it to double back repeatedly on itself in opposite directions
without being too pervious or fragile.
Now our invention takes the strain off a large part of the material of the flexible
tube used, and in the case of heavy pressures, divides it between several flexible
tubes, while at the same time the flexible tube being usually more or less conical
it can double into itself with greater ease than a cylindrical sleeve could.
It is best described by aid of the accompanying drawings in which:
Figure 1 is sectional elevation of cylinder of a steam or other fluid engine,
shewing single flexible tube applied to the piston, and to a stuffing box.
Figure 2 sectional elevation of cylinder of steam or other fluid engine, with
double flexible tubes and pistons.
Figure 3 sectional elevation shewing the invention applied to pump plunger.
Figure 4 sectional elevation shewing it applied to bucket or lift pump.
Figure 5 sectional elevation of hydraulic ram apparatus in which very heavy
pressure is used.
Figure 6 sectional elevation shewing the invention in its simplest form, the
flexible tube being without internal support as applied to a pneumatic lift.
In carrying out our invention the flexible tube A may be made of india rubber,
hose or other suitable flexible impervious material, but we prefer to have it
composed of a combination of impervious and textile materials such as india rubber
and cloth, thereby adding to the impervious material the strength of the textile
without materially affecting or interfering with its flexibility. The india rubber is
cut out of a sheet of that material and formed into two preferably conical tubes of
the size required, a sound joint being obtained by placing a strip of the same, or
some textile material over the junction of the edges, and held in position by suitable
rubber solution or cement. One of these tubes so formed, is then placed onto a
conical block as large as the cylinder, less, double the thickness of the tube when
completed. Over this is then placed a similar tube of textile material, which by
india rubber solution or cement may be made to adhere to the india rubber tubes
and over this is then placed the second impervious tube or the three tubes may be
allowed to remain separate and distinct except at the flanges which we now
describe. The material for these tubes is cut of sufficient length beyond. the length

page_text: required for the tube to allow of flanges being formed one at each end. An internal
flange at the narrower end and an external flange at the broader end of the tube.
The internal flange may be formed by turning the lower edges of the tube inwards
and cementing same to a rigid substance, a ring or flat disc on its inner side which
afterwards serves as an attachment by means of which it is firmly united to the
piston or plunger. The material may be cut or serrated at the edge to prevent its
puckering or wrinkling when doubled inwards. The external flange at the broad
end may be formed by stretching the elastic material into position and cutting the
textile material to allow it to spread out and then cementing the whole together.
A ring of some rigid or other material may be used to support or strengthen the
flange.
'
Instead of the whole textile tube before mentioned, narrow strips or ribbons of
textile material may be substituted partially overlapping at their adjoining edges.
The joints also of the rubber or textile tubes may be secured by using two
thicknesses of material the whole part of one thickness crossing the joint of
the other.
The object of using the elastic rubber is to prevent the tube forming creases or
puckers and the textile material is used to prevent stretching longitudinally. In
use the tube contracts or expands in its diameter at each stroke of the mechanism.
The piston B or plunger B¹ working in conjunction with the flexible tube, is
attached to it by the internal flange a at its smaller end and is made of a size to
allow the double thickness of the tube to freely pass between it and the walls of
the cylinder, and thus allow sufficient room for the tube to double back upon itself
at each stroke. In the case of rams or of pistons or plungers propelling the fluid,
We make the tube longer than the block of said ram piston or plunger over which
it has to turn. It accordingly doubles freely at this point. In the case of pistons
propelled by the fluid, we make the tube rather smaller in diameter than the block
and stretch it over. In this case the tube doubles back on itself first at the
junction with the cylinder, and not as in the case of rams at its junction with
the piston.
Parallel cylinders may be used, but we prefer them conical because less
expansions and contractions are needed in the tube when in use.
Referring more particularly to the drawings. In Figure 1.. A is the flexible
tube. B is the piston working in conjunction with it. C the cylinder of a steam
or other fluid engine or the equivalent of a cylinder formed of two parts preferably
of truncated conical shape with the wider ends of the truncated cone abutting
against each other and flanged at their junction, hereinafter designated a cylinder.
c the ports. D the piston rod passing through each end of the cylinder. E stuffing
box of ordinary construction at one end of the cylinder. El stuffing box at the
other end constructed with flexible tubular diaphragm.
The cylinder C is formed of two parts bolted together by means of flanges C¹,
between these flanges the external flange a¹ of the flexible tube is placed and a
firm and tight joint is made by any of the ordinary methods well known to
engineers for the purpose, and the whole rigidly bolted together. The piston B is
preferably made of the form shewn with projecting sides or flanges 6 tapering to
correspond with the taper of the tube and slightly greater in diameter so that the
tube may closely fit over them-as it doubles over first to one side and then to the
'other....
· The flexible tube A is by means of its internal flange fixed between the two
parts of piston B by bolts through the whole, a steam or waterproof joint being
made in the usual way. The main object of making the tubes conical is that the
whole extent of the motion desired in the piston or bucket can be attained without
their having rubbing friction upon the cylinder or barrel, or the tube having
rubbing friction upon either the piston or bucket or cylinder or barrel or itself,
while at the same time the fluids upon the opposite sides of the piston or bucket
are kept from contact or communication with each other and from escaping through
the space that but for the tube- would otherwise -exist-between the piston and

page_text: cylinder or bucket and barrel, and assuming the tube is of suitable material not to
be prejudiciously affected by either the pressure or heat of the steam it will be seen
that as the piston moves in the return stroke the tube will begin to change its
form, that part next to where it is secured to the cylinder owing to the pressure of
the fluid upon it, moving in the same direction as the piston and its interior
surface at the same time turning in the direction of the cylinder. At the end of
the stroke it has again assumed the form possessed at the commencement, only at
the opposite end of the cylinder. If now another return stroke be conceived as
having been made, similar changes in the form of the tube will take place but in a
contrary direction.
The use of the tapering sides b to the piston is not absolutely essential, but
where there is considerable pressure on the piston they support the tube, and
relieve it of some of the strain. The stuffing box E¹ works in similar manner to
the piston just described, the flexib'e tube A is held in position by the ring e bolted
to the inner walls of the cylinder cover c¹, and the conical pieces e¹ affixed to the
piston rod D, support the tube alternately as it is turned one way or the other.
By the use of the flexible tube instead of a stuffing box of ordinary construction,
the friction consequent upon the passage of the rod to and fro is obviated.
In Figure 2 is shewn an arrangement of engine cylinder where two flexible
tubes and pistons are used, each of these work in a manner very similar to that
already described under Figure 1 and like letters refer to like parts. This arrange-
ment may be used when the movement has to be constantly or suddenly reversed
or when working under greater pressure or when found more desirable. Between
the two flexible tubes A is a double conical piston B attached to both the flexible
tubes, and having a piston and rod firmly secured to it on the opposite side of the
one flexible tube, and a cap on the opposite side of the other, the whole forming a
single compound piston. Or a single large piston with H, cross section can have
an internal flange of the 'flexible tube or sleevo firmly fixed into each end, or the
various flexible tubes can be flanged into or onto the cylindrical piston, or into or
on to the cylinder in any convenient manner.
1
Figure 3 shews the flexible tube A attached to the plunger B¹ of a pump, the
lower end of the plunger B¹ being made conical to correspond with the shape of
the tube.
Figure 4 shews it attached to the bucket of a lifting pump.
Figure 5 shows a longitudinal section of a hydraulic ram or piston where great
pressure is employed, in which the full pressure of the water comes on the same
at X and only atmospheric pressure at Y. In order to withstand the pressure, we
make two three or more tubes A. A' A' each of which withstands an unbalanced
pressure of one third of the total pressure, consequently if there be 300 pounds
pressure at X there will be 200 at W and 100 at V.
The pressure is automatically regulated by the following arrangement.
XU is a tube conveying the full ✗ pressure to chamber T. R and S two.
pistons and rods, their rods opening into said chambers, their pistons PQ being of
one and a half and three times the area of their rods respectively. Both rods and
pistons are made watertight by cup leathers 00. M M are two ports open to the
chamber T. N N N¹ N₁ four ports open to the atmosphere. N¹ being behind the
piston rod is shown in dotted lines only. The piston P being three times the area
of rod R one third the pressure on P balances that on R, if therefore chamber T is
at 300 pounds, chamber V will be at 100, if it is less than 100 the piston sinks till
port L comes opposite port M. and water rushes in from Tand restores the pressure,
raising the piston and closing the connection, if from. leakage from W or Tor
other cause the pressure at V increases beyond the one third of that at T the
piston rises till water can escape at N and the equilibrium is restored. A similar
working takes place at the piston Q the proportions being 2 to 3 instead of 1 to 3.
Figure 6 shows the simplest form of the flexible tube A without internal support
as may be suppl ed to a pneumatic lift.

page_text: In applying the flexible tube to the slide valve of a steam engine, in order to
secure the advantages attained by the use of an equilibrium slide valve, we use
two flexible tubes suitably connected near to the end of the slide valve, and to
some convenient part of the steam chest, by this means preventing the steam
from the boiler from operating upon the top of the valve, and avoiding the friction,
thus securing the advantages of an equilibrium valve that attains the same end by
the use of packing.
Arrangements of flexible tubes altered to suit can be applied to vibrating pumps
and engines and water and other meters whether reciprocating or vibratory but we
do not describe them as any engineer with the description of the foregoing
arrangements could supply similar mechanism for almost any variety of vibratory
or reciprocating mechanism of this description "and their name is "legion." One
point to be observed in all cases is that no sharp angles should be allowed to bear
against the flexible tube, but should be rounded in all cases to at least a + of an
inch radius.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is:
1st. The manufacture of sleeve or diaphragm engines or pumps in which a piston
block or cylinder takes nearly all the pressure from the diaphragm or sleeve
leaving only a narrow space just wide enough for the tube to double on itself for
the steam, water or other fluid to exert itself upon, substantially as described.
2nd. The arrangement in sleeve or diaphragm engines or pumps of several
sleeves or diaphragms to one piston rod with differential pressures between,
whereby only an aliquot part of the unbalanced pressure falls on each diaphragm,
substantially as described.
3rd. The combination with a tube piston of an internal support approximately
parallel with the cylinder whereby the tube is still further shielded from the
pressure of the steam, substantially as described.
4th. The tube for the purposes described formed of two outside impervious
elastic tubes with an internal textile tube, or rubber textile substitutes, whereby.
the strength of the textile tube is obtained with the stiffness and elasticity of the
rubber tube, substantially as described.
5th. The combined tube, piston, plunger or ram and cylinder, substantially as
described and shown in each of the Figures 1, 2, 3, 4, 5 and 6 respectively.
AL
"
1004