IMPROVEMENTS IN METALLIC PISTONS FOR STEAM ENGINES AND IN THE MANUFACTURE THEREOF
Year: 1869

page_text: LETTERS PATENT to Eustace Wigzell and Joseph Pollit, of the Firm
of Timothy Bates and Company, of Sowerby Bridge, near Halifax,
in the County of York, Engineers and Millwrights, for the
Invention of "IMPROVEMENTS IN METALLIC PISTONS FOR STEAM ENGINES
AND IN THE MANUFACTURE THEREOF."
Sealed the 5th April 1870, and dated the 6th October 1869.
PROVISIONAL SPECIFICATION left by the said Eustace Wigzell and
Joseph Pollit at the Office of the Commissioners of Patents, with their
Petition, on the 6th October 1869.
We, EUSTACE WIGZELL and JOSEPH POLLIT, of the Firm of Timothy
Bates and Company, of Sowerby Bridge, near Halifax, in the County of
York, Engineers and Millwrights, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN METALLIC PISTONS FOR STEAM ENGINES
AND IN THE MANUFACTURE THEREOF," to be as follows:-
This Invention relates to the metallic pistons commonly called or
known as "Mather and Platt's pistons" wherein helical or spiral metal

page_text: springs are used. Heretofore these rings have been manufactured by first
casting a cylinder of metal and then turning, cutting, or chasing it in a
lathe to the helical or spiral form required. Now our improvements
consist in casting the said helical or spiral springs to the proper form
and size ready for use (without having to turn, cut, or chase them after-
wards to the form required), thereby retaining or keeping the crust of
the cast metal thereon, which will make the spring or ring more durable
and elastic and not so liable to corrosion or eating away by the condensed
steam and water. Also the cost of manufacture will be considerably less,
besides effecting a saving of time in accomplishing the result.
The means or apparatus we employ for the manufacture or casting of
these springs is as follows:-We prepare a cylinder or an outer shell and
a core of the size required by ordinary loom moulding apparatus, and
when dry we take the core (by preference) and fix it upon a table or
face plate or upon a mandrill to which rotary motion is given, and by
means of a tool having a slide motion given to it at a suitable relative
speed to the table, face plate, or mandrill we cut out of the loom a spiral
groove of the size and form required, or we may place the outer shell
upon the table or face plate and cut the groove therein instead of in the
core, if desirable, we then put the parts of the mould together and cast
in the usual manner.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Eustace Wigzell and Joseph Pollit in the Great
Seal Patent Office on the 5th April 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, EUSTACE
WIGZELL and JOSEPH POLLIT, of the Firm of Timothy Bates and
Company, of Sowerby Bridge, near Halifax, in the County of York,
Engineers and Millwrights, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixth day of October, in the year
of our Lord One thousand eight hundred and sixty-nine, in the thirty-
third year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said Eustace Wigzell and Joseph Pollit,
Her special licence that we, the said Eustace Wigzell and Joseph Pollit,

page_text: our executors, administrators, and assigns, or such others as we, the said
Eustace Wigzell and Joseph Pollit, our executors, administrators, and
assigns, should at any time agree with, and no others, from time to time
and at all times thereafter during the term therein expressed, should
and lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle
of Man, an Invention for "IMPROVEMENTS IN METALLIC PISTONS FOR STEAM
ENGINES AND IN THE MANUFACTURE THEREOF," upon the condition (amongst
others) that we, the said Eustace Wigzell and Joseph Pollit, our
executors or administrators, by an instrument in writing under our,
or their, or one of their hands and seals, should particulary describe and
ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that we, the said Eustace Wigzell and Joseph Pollit
do hereby declare the nature of our said Invention, and in what manner
the same is to be performed, to be particularly described and ascer-
tained in and by the following statement, and accompanying Sheet of
Drawings (that is to say) :-
This Invention relates to the metallic pistons commonly called or
known as "Mather and Platt's pistons" wherein helical or spiral metal
springs are used. Heretofore these rings have been manufactured by
first casting a cylinder of metal and then turning, cutting, or chasing
it in a lathe to the helical or spiral form required. Now our improve-
ments consist in casting the said helical or spiral springs to the proper
form and size ready for use (without having to turn, cut, or chase them
afterwards to the form required) thereby retaining or keeping the crust
of the cast metal thereon, which will make the spring or ring more durable
and elastic and not so liable to corrosion or eating away by the condensed
water and steam. Also the cost of manufacture will be considerably
loss, besides effecting a saving of time in accomplishing the result.
The means or apparatus we employ for the manufacture or casting
of these springs is as follows:-We prepare a cylinder or an outer
shell and a core of the size required by ordinary loam moulding
apparatus, and when dry we take the core (by preference) and fix it
upon a table or face plate or upon a mandrill to which rotary motion is.

page_text: given, and by means of a tool having a slide motion given to it at a,
suitable relative speed to the table, face plate, or mandrill we cut out of
the loam a spiral groove of the size and form required, or we may place
the outer shell upon the table or face plate and cut the groove therein
instead of the core if desirable. We then put the parts of the mould t
together and cast in the usual manner.
The manner in which this Invention is performed or carried into
practice will be readily understood by reference to the accompanying
Drawings of apparatus constructed for the purpose.
Fig. 1 is an elevation with a core of "loam" cut to. the form required 1
for mould, and Fig. 2 is a plan of the same.
A is a table or horizontal face plate mounted upon a shaft B, which is
supported in suitable framework C, and by means of the bevel gearing D,
shaft E, and handle F rotary motion can be given to it. The periphery
of the table forms a spur wheel gearing with a pinion G fixed on a short 1
shaft on which is also a spur wheel H in gear with another spur wheel I
fixed on the end of a screw J placed centraly within an upright pillar K,
on which pillar is fitted a slidable tool head M, which by means of a nut
fixed thereto passing through a slot in the pillar, the screw gives slide
motion to at such relative speed to the rotation of the table as may be 2
required, and which speeds may be varied or altered according to cir-
cumstances by changing the wheels H and I for others of different
relative sizes, as will be well understood. The tool N is slidable in the
head by means of a screw and handle P, and is thereby adjustable for
thus cutting a spiral groove in the loam core Q in a similar manner to 2
ordinary screw cutting tools for iron or other metal. It will now be
easily seen that by this means and apparatus any form and size of
spiral groove may be cut in a core of loam, and the same used in
conjunction with an outer shell mould for moulding or casting the
metal helical or spiral springs used in metallic pistons. And it will 3
also be evident that the groove may (if desirable) be cut in the outer
shell by having the table mounted on the pillar which carries the tool
head, but we prefer to cut the core.
Having thus described the nature of our said Invention, and shewn
by Drawings how the same is or may be performed or carried into 3
practical operation, we would have it understood that what we claim

page_text: as of our Invention is, the method of casting helical or spiral springs
for metallic pistons, as shewn and described.
In witness whereof, I, the said Joseph Pollit, for and on behalf of
myself and the said Eustace Wigzell, have hereunto set my hand
and seal, this Fourth day of April, in the year of our Lord One
thousand eight hundred and seventy.
JOSEPH POLLIT. (L.S.)
Signed, sealed, and delivered by
the within-named Joseph Pollit,
in the presence of
JOSEPH STEAD,
Clerk to W. Tasker,
Patent Agent,
Halifax & Bradford.