An Improved Method of Manufacturing Lead Encased Block Tin Piping.
Year: 1894

page_text: Date of Application. 15th. Dec., 1894
Complete Specification Left, 11th Oct., 1895-Accepted, 16th Nov., 1895
PROVISIONAL SPECIFICATION.
An Improved Method of Manufacturing Lead Encased Block Tin
Piping.
ALBERT BARRACLOUGH Plumber Walkley Lane Heckmondwike Yorkshire
do hereby declare the nature of this invention to be as follows:-
The block tin piping and the outer lead casing are first made separately the
latter being of larger bore than the external diameter of the block tin piping, the
latter is then inserted into the outer lead casing, and the whole is then passed
through a draw plate which reduces the diameter of the outer lead casing and
effects a close joint between it and the inner block tin pipe.
An alternative method is to expand the inner block tin piping either by fluid
pressure or passing it over a mandrel.
The object attained is to entirely obviate the danger of lead poisoning through
the inner block tin lining becoming alloyed with lead as in the ordinary method of
manufacture.
Dated this 13th day of December 1894.
An Improved Method of Manufacturing Lead Encased Block Tin
Piping.
I, ALBERT BARRACLOUGH, of Walkley Lane, Heckmondwike, in the County
of York, Plumber, 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:-
The object of my improved method of manufacturing lead encased block tin
piping is to obviate the danger of lead poisoning by reason of the block tin lining
becoming alloyed with the lead casing as it very frequently does in the ordinary
method of manufacture in cousequence of the high temperature at which the metals
are drawn together to form the tin lined lead piping.
In carrying out my invention, I make the lead casing and the block tin piping
separately, the bore or internal diameter of the former being larger than the
external diameter of the tin piping. The latter is then inserted into the lead
casing, and external pressure applied on all sides in order to squeeze or compress
the lead casing to a reduced diameter so as to fit tightly around and make a close
joint with the block tin piping which is thus firmly secured within the casing
throughout the whole length of same. Instead of external pressure or compression
being applied to the lead casing, I may expand the block tin piping to the interral
diameter of the lead casing by steam or gases admitted to said piping at a high
pressure.
The means employed for compressing or reducing the diameter of the lead casing
may consist of any suitable form of draw plate through which the casing after the
block tin piping has been inserted is passed, or a pair of rollers having half

page_text: circular grooves cut opposite each other on their peripheries so as to form a circular
opening between the rollers may be employed and the lead casing with block tin
piping inside passed through said opening to reduce its diameter or compress it
onto the tin piping, the said grooved rollers being similar to those employed for
making metal tubes.
In the accompanying drawings:
Figs. 1 and 2 are respectively cross section and longitudinal elevation of the lead
casing A and block tin piping B, arranged in readiness for passing through the
draw plate or between the grooved rollers.
Figs. 3 and 4 are corresponding views shewing the piping after pressure has
been applied to reduce the diameter of the lead casing or contract it on to the
block tin lining. When the joint between the two pipes is made by the expansion
of the tin piping the steam water or like fluids or gases are admitted to the tin
piping at high pressure from any suitable source.
By the methods of manufacture as above described lead encased block tin piping
can be inade in long lengths without any liability of the lead being exposed to the
water thoroughfare or of the block tin lining becoming fused or alloyed with the
lead casing, and the block tin lining is made quite as secure and as closely jointed
as in the present method of manufacture.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what
I claim is :-
Firstly. The manufacture of lead encased block tin piping by external pressure
applied to the outer lead casing by passing same through a draw plate or between
grooved rollers to reduce the diameter of the said casing and to contract it on to
the block tin lining or piping.
Secondly. The manufacture of lead encased block tin piping by expansion of the
inner tin piping against the internal walls of the lead casing by steam or like fluids
or gases at a high pressure.
Dated this 10th day of October 1895.
ALBERT BARRACLOUGH.