Improvements in the Manufacture of Pneumatic Cushions suitable for Use as Springs, and for other purposes.
Year: 1898

page_text: Date of Application, 23rd May, 1898
Complete Specification Left, 23rd Feb., 1899-Accepted, 22nd Apr., 1899
Improvements in the Manufacture of Pneumatic Cushions suitable
for Use as Springs, and for other purposes.
I, RICHARD THOMSON GLASCODINE, of 77, Cannon Street, London, E.C., Engineer,
do hereby declare the nature of this invention to be as follows:-
My invention relates to the manufacture of pneumatic cushions or springs such
as may be used on railway or tramway carriages motor vehicles or other vehicles for
rail or road also for other purposes.
A cushion according to my invention comprises two moulded ends of approxi-
mately U section to which are attached the ends of a tubular portion so as to form
an air tight receptacle. The ends may for the purpose of preventing longitudinal
expansion of the device be connected by chains or the like. A suitable cover is
provided except at the ends where no cover is necessary.
One arrangement for use as a spring designed to carry a heavy load for instance
1 to 2 tous at low pressure for instance 10 to 15 lbs. per square inch and has
accordingly an extensive bearing surface when loaded is as follows.
I make it of the shape that it will occupy when in position inflated and loaded
so as to reduce the strains on the material when in its working position.
The cushion is made rectangular in plan with ends rounded so as to allow more
freedom in flexure.
The outer cover is a length of india rubber hose, i.e. india rubber and canvas
manufactured on a mandril which may be of cylindrical or oval section the interior
surface of the ends being cut or moulded for a short distance in a conical (or
equivalent) form the cone opening towards the interior of the pipe.
*The inflation or air tube I make as follows:-I mould two india rubber cups or
cuplike pieces of shape such as the ends of the cushion will take when in working
position of approximately U section the flanges running down to a thin edge.
Each cup has imbedded in the material along its longest centre line a metal plate
of suitable dimensions to which are screwed rivetted or otherwise attached two
eyebolts the bolt standing in the concave side of the cup.
I place the cups at the distance apart they are designed to be and connect the
opposite eyebolts by chains or cords of suitable material.
I then pass over one end a length of india rubber tube such as inflation tubes
are ordinarily made of and fix it by india rubber solution or cement to the inner
surface of the flanges of the cups thus forming an airtight receptacle.
I then draw this inflation tube within the india rubber hose and inflate it, by
means of a suitable valve placed in and suitably connected to one of the cuplike
ends, when the air pressure will expand the flanges of the ends into the conical
recess referred to above.
The metal plate will prevent the outward movement of the central portion of
the ends and the flanges being pressed against the cover will be retained by
friction.
I make the cup like ends of india rubber or india rubber and canvas suitable

page_text: arranged with reference to the air pressure the cushion is designed to
withstand.
In some cases I may arrange the canvas not so as to strengthen the cushion
against outward normal expansion. but to prevent the flanges of the ends
dragging.
For this purpose the canvas might be wound round loosely with folds or corru-
gated or might have cuts longitudinally in the direction of the axis of the
cushion.
The ends are or may be provided with bosses moulded on the convex or concave
side (preferably the latter), which surround the valve or valves and the shanks
of the eyeboit or eyebolts and may be bound round with wire to prevent any
escape of air.
The number and arrangement of plates and eyebolts depends on the shape of the
cushion to be made..
In some cases the valve may act as one of the eyebolts.
The india-rubber tube may in some cases be solutioned to the outer surface of the
moulded ends..
In some cases I attach to the chains a block of india rubber designed to be used
as a safety stop in case of failure of the pneumatic cushion when used for instance
as-a spring on a vehicle.
The conical recess in the cover may be omitted.
In some cases the plates may be dispensed with; also the chains may not be
necessary.
The chains may be wired directly to the bosses mentioned above.
Pneumatic cushions or springs according to my invention may be made in various
shapes according to the purpose for which they are designed.
The inflation tube may be solutioned to the cover.
Doted this 21st day of Mar 1908
Improvements in the Manufacture of Pneumatic Cushions suitable
for Use as Springs, and for other purposes.
I, RICHARD THOMSON GLASCODINE, of 77, Cannon Street; London, E.C., Engineer
do hereby declare the nature of this invention in what manner the same is to be
performed; to be particularly described and ascertained in and by the following
statement:-
My invention relates to the manufacture in a simple and convenient manner of
pneumatic cushions or springs such as can be used on railway or tramway carriages,
motor vehicles, or other vehicles for rail or road, or for other purposes.
A pneumatic, cushion, according to this invention comprises two, moulded.end
pieces of approximately U section, to which are attached the ends of an intermediate
tubular portion so as to form therewith an air tight receptacle. which is provided
with a suitable outer cover, except at, the ends where no cover necessary. The
two moulded end pieces may, for the purpose of preventing longitudinal expansion.
of the cushion, be connected by one or more chains or the like.
Figs. 1, 2 and 3 shown respectively in longitudinal section, horizontal, section, and
end view, one construction of pneumatic cushion constructed according to this
invention and designed to carry a heavy load, say for example one or two tons, at a
low internal pressure of air, say ten to fifteen pounds to the square inch, for which
purpose it is made with an extensive bearing surface.

page_text: The pneumatic cushion is made of the shape that it will assume when inflated and
loaded in position, so as to minimize, when in use, the strains on the material of
which the cushion is composed and is made of approximately rectangular shape in
plan with its ends rounded so as to allow freedom in flexure.
The puematic cushion shown comprises two connected cupped shaped end pieces, 1
of india rubber, an inner indation or air tube 2, and an outer cover 3. The end
pieces 1 are moulded of india rubber to the shape the ends of the cushion will take
when in use and of approximately U-shape in longitudinal section, their sides or
flanges being of gradually, decreasing thickness as shown. Each of these cupped end
pieces 1 has imbedded therein along its longest centre line, a metal plate 4 of suitable:
dimensions to which are screwed, riveted or otherwise securely attached two
eyebolts 5, the bolts extending into the concave side of the end piece. The said end
pieces are placed at the distance apart they are to finally occupy and the opposite
eyebolts 5 are connected together by suitable connectors 6, such as chains, cords or
wires, wire connectors are shown, of suitable material. A length of india rubber
tube 2 of good quality, such for example as the inflation tubes of pneumatic tyres
are ordinarily made of, is then drawn over one of the end pieces 1 and its ends are
fixed by india rubber solution or cement to the inner surface of the sides or flanges
of the cupped end pieces 1, so as to form therewith an air-tight receptacle. This
receptacle, which may be regarded as an inflation tube, is then drawn within the
outer cover 3 which consists of a length of hose pipe composed, as usual, of india
rubber and canvas, and made upon a mandrel which may be of circular or oval
section. The interior of the outer cover, for a short distance from each end, may be
cut or moulded in such a way as to form a taper passage the cross sectional area of
which increases towards the central portion of the cover as shown. The cushion
thus constructed is inflated with air under pressure which is forced by a suitable
pump through an air valve 7 which may be of any suitable kind, such as is commonly
used with pneumatic tyres, and which is firmly secured in one of the cupped end
pieces 1. When thus inflated, the longitudinally connected end plates 4 serve to
effectually prevent outward movement of the central portions of the cupped end
pieces 1, the internal air pressure at the same time acting to force the side or flange
portions of the said end pieces against the outer cover which.. serves to limit the
outward expansion of such end pieces and also of the inner tube 2. In practice
it is found advantageous to permanently secure the cover 3 to the cupped end
pieces 1 and also, it may be, to the portion of the tube 2 between such end
pieces, by india-rubber solution or cement. The outer cover 3 instead of having
its end portions formed internally as described, may be made of uniform cross
section throughout, especially when it is permanently secured to the end pieces 1
and inner tube 2, by india rubber solution or cement.
The cupped end pieces 1 instead of being made of india rubber alone, may in some
cases be made of india rubber and canvas these being suitably arranged in relation
to one another with reference to the air pressure which the pneumatic cushion is
designed to withstand. In some cases the end portions of the canvas, that is to
say those portions in the side or flanges of the end pieces 1, may be so arranged as
not to strengthen the cushion against outward normal expansion, i.e., in a direction
at right angles to the length of the cushion, but only so as to prevent the sides or
flanges of the said end pieces lengthening. For this purpose the canvas may
be arranged loosely, that is to say, with longitudinal folds or corrugations within
the sides or flanges of the end pieces, or it may be slit at several places in a longi-
tudinal direction, i.e., in the direction of the length of the cushion.
The end pieces 1 are or may be provided with bosses 1* moulded on their convex,
or, as shown, on their concave side, preferably the latter, these bosses being arranged
to surround the valve 7, (or valves) and the shanks of the eyebolts 5. These bosses
may be bound round with wire to prevent any escape of air along the exterior of
the valve (or valves) or eyebolts. The number and arrangement of plates 4 and
eyebolts 5 will depend on the size and shape of the cushion to be made. If desired
the air valve may be constructed to serve also as one of the eyebolts.

page_text: In some cases there may be attached to the wire or other connectors 6, a block 8
of india rubber designed to serve as a safety stop to limit the closing movement of
the pneumatic cushion in the event of failure thereof, as for example when the
cushion is used as a spring on a vehicle.
Pneumatic cushions or springs according to my invention can be made in various
shapes according to the purpose for which they are designed to be used and the
details of their construction can be variously modified without departing from the
essential feature thereof. Thus in some cases the plates 4 and the wires 6 or other
means for connecting them together longitudinally, may be dispensed with. Also
the wires 6, or their equivalent, when used, may be connected directly to the
bosses 1 of the end pieces 1.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what I
claim is:-
1. A pneumatic cushion comprising cupped end pieces, an inner inflation tube,
and an outer cover, these parts being constructed and combined, substantially as
herein before described.
2. A pneumatic cushion of the kind referred to in the preceding claim wherein
the cupped end pieces are strengthened by plates embedded therein and are con-
nected together by chains, wires or the like extending longitudinally through the
cushion, substantially as described.
3. A pneumatic cushion constructed, arranged and operating, substantially as
herein before described with reference to the drawings annexed.
February 1
For the Applicant,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.