IMPROVEMENTS IN ROTARY BLOWING ENGINES
Year: 1869

page_text: LETTERS PATENT to William Robert Lake, of the "International
Patent Office," Southampton Buildings, London, Consulting En-
gineer, for the Invention of "IMPROVEMENTS IN ROTARY BLOWING
ENGINES." A communication from abroad by Philander Higley
Roots and Francis Marion Roots, both of Connersville, Indiana,
United States of America.
Scaled the 14th April 1870, and dated the 21st October 1869.
PROVISIONAL SPECIFICATION left by the said William Robert Lake
at the Office of the Commissioners of Patents, with his Petition,
on the 21st October 1869.
I, WILLIAM ROBERT LAKE, of the "International Patent Office,"
Southampton Buildings, London, Consulting Engineer, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN ROTARY BLOWING
ENGINES," a communication, to be as follows:-
This Invention relates to that class of rotary blowing engines in which
two co-acting rotary abutments or pistons are employed within a case,
and it relates more particularly to improved methods of constructing

page_text: both the external enclosing case and the abutments, and also to a
method of operating the said abutments to cause them to rotate properly
together.
The objects of the said Invention are to secure great accuracy in the
operative parts, and at the same time to greatly reduce the cost of 5
construction as compared with other blowing engines, and also to
furnish the means whereby the use of toothed wheels for connecting the
abutments together may be dispensed with.
The said Invention consists, first, in making the concave portions or
arcs of the enclosing case of such dimensions, and so placing them 1
on one side of the plane of the axis of the shafts, and so proportioning
the end or head plates of the case as to allow the abutments to be
introduced or taken out by simply removing the binding caps of the
journals, so that the case may be cast in one entire piece.
It also consists in rendering the interior working surfaces of the case 1
true (both on the concave portions or arcs and the ends of the case), so
that they fit accurately the rotating abutments, by means of plaster of
Paris, bydraulic cement, or other suitable plastic material, such as asphalt
or compounds of india-rubber. These materials, which may be applied
in a liquid or molten state, will afterwards set or harden in any shape 2
which may be given to them by a mould or otherwise.
The said Invention consists further in constructing the central
cylindrical part or boss of the abutments of plaster of Paris or like
material, such as is used for lining the case, and which is applied in a
similar manner. A coating also of the same materials may in certain 2
constructions be applied to the peripheries of the pistons or abutments,
and they may be made true in the same manner, or may be turned in a
lathe when the coating has set. When it is desirable to use a wood
covering for the said pistons in small and medium sized blowers a con-
tinuous iron. support projecting from the central cylinder or boss is
made to extend the entire length of the pistons, with flanged projections,
upon which the wood is fastened by means of screws.
Finally, the said Invention consists in producing a simultaneous
rotary motion (in opposite directions) of the abutments or pistons of the
blower when desirable by means of cranks and connecting rods, thereby a
dispensing with the toothed wheels ordinarily employed for similar
purposes. The cranks are coupled together so that the abutments or
pistons will turn simultaneously but in opposite directions through the

page_text: medium of a guide which slides vertically between them, the cranks
being connected to the said guide by suitable rods or links; and at right
angles to the said cranks are other cranks similarly connected, and
caused to work together by means of a guide. These cranks and rods
5 may be arranged at one or both ends of the abutments.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Robert Lake in the Great Seal Patent
Office on the 20th April 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROBERT LAKE, of the "International Patent Office," Southampton
Buildings, London, Consulting Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first 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 me, the said William Robert Lake, IIer special
licence that I, the said William Robert Lake, my executors, adminis-
trators, and assigns, or such others as I, the said William Robert Lake,
my 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,
usc, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention of
"IMPROVEMENTS IN ROTARY BLOWING ENGINES," a communication to me from
abroad by Philander Higley Roots and Francis Marion Roots, both of
Connersville, Indiana, United States of America, upon the condition
(amongst others) that I, the said William Robert Lake, my executors or
administrators, by an instrument in writing under my, or their, or one-
of their hands and seals, should particularly 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 I, the said William Robert Lake, do hereby
declare the nature of the said Invention, and in what manner the same

page_text: is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the accompanying
Drawing forming a part of this Specification:-
This Invention relates to that class of rotary blowing engines in which
two co-acting rotary abutments or pistons are employed within a case,
and it relates more particularly to improved methods of constructing
both the external enclosing case and the abutments, and also to a
method of operating the said abutments to cause them to rotate properly
together.
The objects of the said Invention are to secure great accuracy in the 1
operative parts, and at the same time to greatly reduce the cost of
construction as compared with other blowing engines, and also to
furnish the means whereby the use of toothed wheels for connecting the
abutments together may be dispensed with.
The said Invention consists, first, in making the concave portions or 1
arcs of the enclosing case of such dimensions, and so placing them
on one side of the plane of the axis of the shafts, and so proportioning
the end or head plates of the case as to allow the abutments to be
introduced or taken out by simply removing the binding caps of the
journals, so that the case may be cast in one entire picce.
It also consists in rendering the interior working surfaces of the case
true both on the concave portions or arcs and the ends of the case, so
that they fit accurately the rotating abutments, by means of plaster of
Paris, hydraulic cement, or other suitable plastic material, such as asphalt
or compounds of india-rubber. These materials, which may be applied 2
in a liquid or molten state, will afterwards set or harden in any shape
which may be given to them by a mould or otherwise.
The said Invention consists further in constructing the central
cylindrical part or boss of the abutments of plaster of Paris or like
material, such as is used for lining the case, and which is applied in a 3
similar manner. A coating also of the same materials may in certain
constructions be applied to the peripheries of the pistons or abutments,
and they may be made true in the same manner, or may be turned in a
lathe when the coating has set. When it is desirable to use a wood
covering for the said pistons in small and medium sized blowers a con- 3
tinuous iron support projecting from the central cylinder or boss is
made to extend the entire length of the pistons, with flanged projections,
upon which the wood is fastened by means of screws.

page_text: Finally, the said Invention consists in producing a simultaneous
rotary motion in opposite directions of the abutments or pistons of the
blower when desirable by means of cranks and connecting rods, thereby
dispensing with the toothed wheels ordinarily employed for similar
purposes. The cranks are coupled together so that the abutments or
pistons will turn simultaneously but in opposite directions through the
medium of a guide which slides vertically between them, the cranks
being connected to the said guide by suitable rods or links; and at right
angles to the said cranks are other cranks similarly connected, and
caused to work together by means of a guide. These cranks and rods
may be arranged at one or both ends of the abutments.
Figure 1 is a longitudinal vertical section of the said blowing machine;
Figure 2 is a vertical transverse section on the line Y, Y, of Figure 1.
Similar letters of reference indicate corresponding parts throughout the
Drawings.
A is the case or shell with accurately described arcs B, B', which are
concentric with the peripheries of the abutment pistons, and less than
a half circlo in extent; C, C', are the revolving abutments; D, D',
represent the pistons. The pistons D on the abutments C are made of
iron, which may be turned and made true in a lathe, or may be coated
with cement or plaster of Paris. The other pistons D' are of wood
secured by screws to the flanged projections of the arm Cs of the central
cylinder E'. The cylinder E of the abutment C is formed of plaster of
Paris, while the cylinder E of the abutment C' is of wood. F, F, repre-
sent the end plates of the case, and F is a plaster of Paris facing or
lining on cach of the said end plates, and between the same and a
secondary or internal end plate Fe metal guards are provided to protect
this lining.
For small and medium sized blowers it is advantageous for many
reasons to cast the case in one piece. By making the concave arcs B, B',
a little more than a quarter of a circle in extent, and arranging them.
chiefly on one side of the plane of the axes of the abutment shafts, the
opening in the case on the opposite side of such plane is correspondingly
increased, allowing the end plates F to he reduced, so that ample room is
afforded for introducing or taking out the abutments by simply removing
or replacing the boxes which hold the shafts in place without requiring the

page_text: "
case to be taken to pieces. If the concave arcs B, B', were materially
increased in extent and arranged equally or nearly so on the two sides of
the plane of the shafts the abutments of the blower so made could not be
taken out or replaced without removing some part or parts of the case.
In making the interior of the case truc so as accurately to fit the rotating
abutments with cements, plaster of Paris, or similar plastic substances I
generally employ either a ". sweep or a mould. Both are usually mado
with journals, so that they may be placed in the journal boxes of the shafts
of the abutments. When a "sweep" is used a coating of plaster of Paris
is applied in a soft or plastic state to the inner surface of the casc, and
shaped exactly by the " Sweep " to suit the dimensions of the abut-
ments. When a mould is used I frequently apply a coating of the
plaster as above, and then press the mould to its proper position while
the plaster is soft, the said mould being removed when the plaster sets
or hardens. In other cases when a mould is used it is first placed in a
correct position, and the plaster in a liquid state is poured into the
interstice between the case and the mould. In cases where a secondary
end plate is used the said end plate is made in its general configuration
to conform to the end of the case. The secondary plate is placed in the
correct position relatively to the abutment, and a mixture of liquid
plaster is poured into the interstice between it and the end of the case,
in which position it is afterwards firmly held by screws. The central
cylinder may be very economically and accurately formed of the same
materials used for the lining of the case, as shown at E. For this
purpose I generally use hollow semi-cylindrical moulds, which are easily
brought into the correct position by wheels or rings of the size of the
central cylinder, and placed on the shafts of the abutments. Into the
mould thus formed the plaster is poured in a liquid state. Some cements
are rendered plastic by heat, and are used in a molten condition.
Having thus fully described the said Invention, as communicated to
me by my foreign correspondents, I wish it understood that I claim,-
First. A rotary blower case, the interior of which is rendered true and
accurate by means of plaster of Paris, hydraulic cement, or other cements
(which may be applied in a plastic, liquid, or molten state, and which
afterwards set or harden in the desired form), substantially as set forth.
Second A rotary blower case, the ends or head plates of which are
rendered true and accurate by the use of plaster of Paris, hydraulic or
other cements, substantially as set forth.

page_text: Third. A rotary blower case, the concave arcs of which are rendered
true and accurate by means of plaster of Paris, hydraulic or other
cements, as set forth.
Fourth. A rotary blower case, having concave arcs B, B', in com-
bination with end plates F, arranged to allow the abutments to be
introduced or removed without removing any part of the case.
Fifth. A rotary blower case, having secondary end plates supported by
plaster of Paris or other cements, substantially as set forth.
Sixth. The abutments of a rotary blower, having the central cylinder
made of plaster of Paris or other cements, substantially as set forth.
Seventh. The abutments of a rotary blower, having the external
peripheries of their pistons covered with wood secured to flange pro-
jections on arms extending from the central cylinders, substantially as
set forth.
Eighth. The abutments of a rotary blower, the external peripheries of
whose pistons are rendered true with plaster of Paris, hydraulic or other
cements, substantially as set forth.
Ninth. The employment of cranks and connecting rods in combination
with the pistons, substantially as and for the purposo set forth.
In witness whereof, I, the said William Robert Lake, have here-
unto set my hand and scal, this Twentieth day of April, in the
year of our Lord One thousand eight hundred and seventy.
WILLIAM ROBERT LAKE. (L.S.)
Witness,
J. TEARE,
Clerk to Messrs. Haseltine, Lake, & Co.,
Southampton Buildings,
London.