IMPROVEMENTS IN FORMING BENDS AND OTHER FORMS OR PARTS OF NON- METALLIC PIPES, AND IN MACHINERY OR APPARATUS EMPLOYED FOR SUCH PURPOSES, PART OF WHICH IMPROVEMENTS ARE APPLICABLE ALSO TO THE FORMATION OF BENDS OR CURVES IN SOME KINDS OF METALLIC PIPES
Year: 1861

page_text: PROVISIONAL SPECIFICATION left by George Bish and James Dredge at
the Office of the Commissioners of Patents, with their Petition, on the
3rd August 1861.
We, GEORGE BISH, of High Street, Stratford, in the County of Essex,
Engineer, and JAMES DREDGE, of 11, Adam Street, Adelphi, in the County of
Middlesex, Civil Engineer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN FORMING BENDS AND OTHER FORMS OR PARTS OF NON-
METALLIC PIPES, AND IN MACHINERY OR APPARATUS EMPLOYED FOR SUCH PURPOSES,
PART OF WHICH IMPROVEMENTS ARE APPLICABLE ALSO TO THE FORMATION OF BENDS
OR CURVES IN SOME KINDS OF METALLIC PIPES," to be as follows:-
It consists, firstly, in the application of heat (either dry or moist) to pipes
and tubes, such as are manufactured from paper, canvass, linen, felt, and other
non-metallic substances, for the purpose of rendering them sufficiently pliable
to bend freely, and to be bent or moulded into any required form. The nature
of the heating medium employed, and the mode of application may be varied
to suit the nature of the material operated upon.
Secondly, in a method of bending or curving such pipes or tubes by means
of a series of rings, the width of each of which (in a line parallel with its axis)
is greater at one side of the diameter thereof than at the other, so that when
placed closely in contact, they assume the form of the curve or bend required.
A series of these rings is placed either at the outside or within the pipe or tube
required to be bent, in such mnnner that the wider portions of the rings are in
contact with each other. The whole is then submitted to the action of heat

page_text: until the pipe operated upon loses its rigidity and becomes soft and flexible.
The two ends of the pipe are then drawn towards each other by screws or
other suitable means, until the narrower sides of the rings are brought to
touch, and the pipe or tube has consequently been made to assume the curve
or bend required. Otherwise rings, as described, may be employed both
externally of and within the pipe. When the rings are used externally, a
coiled spring covered with wire gauze or other contrivance easily withdrawable
when the pipe is set and rigid in its new form, may be employed to prevent
collapse during the operation of bending.
Thirdly, in the application of rings as described to the bending of pipes
formed of malleable metal.
Fourthly, in a method of making cast bends. for pipes in non-metallic sub-
stances, by moulding them on collapsible mandrils capable of being easily
withdrawn when the casting is set.
Fifthly, in a method of making up bends by wrapping strips of paper, linen,
or other non-metallic substance, around collapsible mandrils, layer upon layer,
until a sufficient thickness and strength is attained.
Sixthly, in a method of manufacturing branch-and-service-pipes_of_any
description, such as T-pieces, and so forth, as follows:-An extra thickness
or extra thicknesses of paper, linen, or other suitable material, is or
are wrapped around the pipe where the joint is to be made, in order to
give additional strength; a hole is then cut to admit the other pipe, which
being inserted, a water-tight cement is placed around the junction, and the
whole is softened until the different parts are sufficiently adapted to and in-
corporated with each other, when the joint is allowed to harden and all
internal projections are removed.
.
Seventhly, in a method of manufacturing socket joints by stamping out the
socket in the softened pipe, or otherwise, by working up the joint with extra
thicknesses of paper, linen, or other suitable material.
Eighthly, in constructing tubes intended to be bent or curved with a thick-
ness of material gradually increasing from the side intended to form the inner
or smaller curve of the bend to that intended for the outer or larger curve
thereof, or in other words, making the bore of the pipe eccentric to its outer
diameter, in such proportion as that, when bent, the pipe shall be of equal
strength throughout.