IMPROVEMENTS IN THE CONSTRUCTION OF ROTARY ENGINES AND PUMPS
Year: 1875

page_text: LETTERS PATENT to John Cooke, of Langley Old Hall, in the County
of Durham, Mining Engineer, for the Invention of "IMPROVEMENTS
IN THE CONSTRUCTION OF ROTARY ENGINES AND PUMPS."
Sealed the 7th September 1875, and dated the 15th March 1875.
PROVISIONAL SPECIFICATION left by the said John Cooke at the
Office of the Commissioners of Patents, with his Petition, on the
15th March 1875.
I, JOHN COокE, of Langley Old Hall, in the County of Durham,
Mining Engincer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE CONSTRUCTION OF ROTARY ENGINES AND PUMPS," to
be as follows:-
This Invention relates to such rotary pumps and engines as are
described in the Specification of an Invention for which Letters Patent
were granted to me, bearing date the 20th day of April 1868, and
numbered 1279, and in the Provisional Specification of an Invention for

page_text: which I have applied for Letters Patent on the 6th day of March 1875,
and numbered 839, and is adapted to such machines, constructed
according to the said Inventions, in which reduced dimensions, weight,
and strain of the parts and increased stiffness, especially of the "shutter,"
are desirable.
According to this Invention the shutter shaft may be actuated either
within or without the shutter box by a lever or levers of any suitable
length more or less than one-third to one-half that from the shutter
shaft to the centre line, to which approximately the lever has hitherto
been made. A secondary rocking shaft is introduced in a line with and
by preference exactly between the shutter shaft, and the centre line of
the casing or cylinder wherein the drum or piston revolves, being when
so placed between in distance from the latter about three-fourths of the
whole distance more or less.
The crank, connecting rod, and secondary lever are each made of such
proportions to their lengths specified in the herein-before mentioned
Specifications as has been selected for the distance aforesaid. The
shutter shaft and rocking shaft are then connected by a parallel motion
to the lever or levers aforesaid, either within or without the shutter box,
and the shutter works through precisely the same angles as before for a 2
given movement of the drum.
When drums 180 degrees apart are used so as to balance each other,
one crank sufficing to move the required number of shutters by means
of a reversing lever and parallel motion, the shutter shafts are placed 43+
degrees apart, more or less, according to the proportions of the shutter,
and the secondary shafts referred to are so placed respectively as just to
be clear of the shutter or shutters of the other drum or drums when as
far out of the casing as possible when in work. The fluid passes through
the casing in the same direction but enters at the other end of the
shutter for the other drums, and the equable flow of the fluid is preserved a
as far as is practically required. The centre upon which the reversing
lever works must be in the same line with the shutter shaft and drum
shaft.
E

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent
filed by the said John Cooke in the Great Seal Patent Office on
the 15th September 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
COOKE, of Langley Old Hall, in the County of Durham, Mining
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifteenth day of March, in the year of
our Lord One thousand eight hundred and seventy-five, in the thirty-
cighth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Cooko, Her special licence
that I, tho said John Cooke, my executors, administrators, and
assigns, or such others as I, the said John Cooke, 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, 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
THE CONSTRUCTION OF ROTARY ENGINES AND Pumps," upon the condition
(amongst others) that I, the said John Cooke, my executors or adminis-
trators, by an instrument in writing under my, or their, or one of their
hands and scals, should particularly describe and ascertain the nature
of the said Invention, and in what manner the same was to be per-
formed, 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 John Cooke, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement, reference being had to the Drawings hereunto
annexed, and to the letters and figures marked thereon, that is to
say :-
This Invention relates to such rotary engines and pumps as are
described in the Specification of an Invention for which Letters Patent
were granted to me, bearing date the 20th day of April 1868, and
numbered 1279, and in the Specification of an Invention for which

page_text: Letters Patent were granted to me, bearing date the 6th day of Marcl
1875, and numbered 839, and is adapted to machines constructed
according to these Inventions, in which reduced dimensions, weight, and
strain of the parts and increased stiffness, especially of the "shutter,"
are desirable.
According to this Invention the shutter shaft may be actuated either
within or without the shutter box by a lever or levers of any suitable
length forming part of the shutter or otherwise, as may be desired. A
secondary rocking shaft or gudgeon is introduced in a line with and by
preference, although not necessarily, exactly between the shutter shaft
and the centre line of the casing or cylinder wherein the drum or piston
revolves, being, when so placed, exactly between in distance from the
latter about five-eighths of the whole distance, more or less.
The crank, connecting rod, and secondary lever working on the
secondary rocking shaft or gudgeon are each made of such proportion
to the lengths specified in the herein-before mentioned Specifications
as has been selected for the distances aforesaid. The shutter shaft and
rocking shaft or gudgeon are then connected by a "parallel movement "
to the lever or levers aforesaid, either within or without tho shutter box,
and the shutter works through precisely the same angles as before for a
given movement of the drum.
When drums 180 degrees apart are used, as described in the Specifi-
cation of the Patent herein-before referred to, No. 839, 1875, one crank
can be made to move the two shutter shafts by means of a reversing lever
whose centre must be in the same line with the drum shaft and the g
corresponding shutter shaft when that of the other secondary lever is so
placed) and advantage may be taken of this to carry at hrough bar right
across the machine attached to the parallel movement so as to support
the shutter wherever required, and driven by a drum crank at each end
of the machine. The crank pins here are in the same centre line, and 3
the cranks coincide with the line from one drum centre to its shaft.
The axis of that portion of the parallel movement which is placed
behind the shutter is in a line drawn from the shutter shaft parallel to a
chord of the arc described when in work by the levers first before
mentioned, or by such part of the shutter as is chosen for attachment; 3
or the secondary rocking shaft or gudgeon may be so placed, or such

page_text: secondary rocking shaft may be varied from the line between the druin
shaft and shutter shaft if desired.
When the secondary rocking shaft is so placed or so varied the drum
crank is shifted round in the same direction and through the same angle
as that made by the secondary shaft with the line joining the shutter
shaft and drum shaft, and when at the same time a reversing lever is
used its centre must be similarly shifted through the same angle.
In some cases where the through bar is used it will be found necessary
or advisable to place the axis of the secondary lever in the line parallel
to the chord before described, and to increase the crank secondary lover
and connecting rod in the required proportion which is about 1, more
or less.
The through bar may be dispensed with by placing the axis of the
secondary lever in the line before described, and reducing the crank,
secondary lever, and connecting rod in the required proportion which is
about more or less.
I will now proceed to refer to the accompanying Drawings from
which the nature of my said Invention will be more clearly understood..
Sheet 1 shews the arrangement of a rotary engine or pump, con-
structed according to this Invention, with the drums 180 degrees apart,
and applied for ventilating mines in which a through bar is employed,
and the axis of the secondary rocking shaft placed exactly between the
shutter shaft and drum shaft.
".
Figure 1 is an end view; and Figure 2, a sectional clevation through
the line A, B, Figuro 1, the. same letters of reference indicating like
parts in the two Figures.
A is the secondary rocking shaft or gudgeon; B, the secondary lever
working thereon; C, the drum shaft; and D, the shutter shaft in tho
same line with A and C; E is the axis of that portion of the parallel
movement bebind the shutter, which axis is placed in a line parallel to
the chord of the arc described when in work by the point of attachment
F to the shutter G; H is a lever outside of the shutter box kept equal
and parallel to the secondary lever B by a connecting rod I, which rod
is, of course equal and parallel to the straight line between A. and E. A
slot:J is left in the casing at each end to allow the through bar. K to
pass right across the machine. Inside, the casing and opposite the

page_text: shutter G and working on the shaft E are the levers L kept equal and
parallel to the line D, F, by the links M which are themselves equal
and parallel to the line D, E.
The levers L may be connected to the through bar K rigidly in any
suitable manner, but in the Drawing are shewn as attached thereto by
the straight bars N. By this arrangement the shutter G moves through
the same angles as when directly connected, as described in my former
Specifications, and consequently maintains such approximate contact as
is required. The other shutter shaft O and shutter P are moved in a
similar manner by means of the reversing lever Q, whose centre R is in
the same line with the drum shaft C and shutter shaft O. The axis S of
the parallel movement is placed in a line parallel to the chord of the arc
described by the point of attachment T to the shutter P. The shafts R
and S are connected by equal and parallel levers U and V by means of
the connecting rod W which is equal and parallel to the line R, S. The
rod W passes at about of its length from the lever V out of the mine
into the air, and the opening through which it passes may be either left
unprotected, or any suitable joint may be made. The lever V is bent
from its point of attachment to W so as to work the through bar X
carried by the stays Y from the shaft S. The through bar X is also
carried right across the machine, but is kept within the casing. The
levers Z are placed opposite the shutter and made equal and parallel to
the line O, T, by means of the links a which are themselves equal and
parallel to the line O, S. Bars of the required length are carried by the
levers Z parallel to the shutters at b, and which bars are rigidly attached
The drums are shewn at d
to the through bar X by the straight rods c.
and e, the crank at f, and the connecting rods working the two shutters
at g and h, the crank at the other end of the drums being in the same
position as that shown at f; i is the mine shaft; and, the passage for
the exit of the foul air.
In Sheets 2 and 3, Figure 3 is an end view of a machine with a
through bar in which only one drum centre is used, the shutters being
made one to swing and the other to rock about a vertical line, as
described in the Specification of my former Patent, No. 839, 1875; and
Figure is a sectional clevation of the same through the line A, B,
Figure 3, the same letters of reference indicating like parts in both
Figures. A, A, are the secondary shafts placed behind the shutters in
the line parallel to the chord of the are described when in work by the

page_text: points of attachment B, B, in the shutters; C, C, the shutter shafts;
D, D, the secondary lovers; E, the drum shaft; and F, the crank which
makes an angle with the line from E to the drum centre, equal to that
made by A, E, with O, E; G, G, are the through bars which work through
slots in the casing, and which slots are protected from leakage in any
suitable manner. Opposite the shutters and inside the casing are the
levers H, H, equal and parallel to the line C, B, and connected to B by
the links I which are themselves equal and parallel to A, C; K, K, aro
the connecting rods connecting the shutters to the crank F; L, L, are
the inlets for the foul air from the mine; and M, M, the outlets for the
same, N being the shaft of the mine.
In Sheets 4 and 5, Figure 5 is an end elevation of a machine, con-
structed according to this Invention, without a through bar, and in
which the crank, secondary lever, and connecting rod are reduced as
herein-before described; and Figure 6 is a sectional elevation through
the line A, B, Figure 5. The same letters refer to similar parts in both
Figures. A is the shutter shaft; and B, the secondary rocking shaft
placed in the line parallel to the chord of the arc described when in
work by the point of attachment C of the shutter; and D is the drum
shaft; the anglo which B, D, and A, D, makes with each other is the
same that the crank E makes with the line from D to the centre of the
drum. F, G, is the secondary lever, and H its connecting rod; and I,
the connecting rod to the reversing lever K which works the other
shutter shaft J, its shaft L being moved from the line joining the drum
shaft D, and the other shutter shaft J through an angle equal to that
the crank makes with the line joining D and the centre of the drum F,
and connected to the axis of the parallel movement M by the lever N
and connecting rod O; P is the other drum. On the shaft B and within
the shutter box are the levers Q equal and parallel to the line A, C, and
connected to C by the links R, and in the same way on the shaft M are
the levers S equal and parallel to the line J, T, and connected to the
shutter at the points T by the links U. V is the shaft from the mine;
and W, the passage for the outlet of the foul air.
Having thus described and ascertained the nature of my said Inven-
tion, and in what manner the same is to be performed, I would observe
in conclusion that what I consider novel and original, and therefore
claim as constituting the Invention secured to me by the herein-
before in part recited Letters Patent is, the combination and arrange-

page_text: ment of parts and mechanism in the construction of rotary engines and
pumps, in the manner and for the purposes herein-before set forth and
described, or any mere modifications thereof.
In witness whereof, I, the said John Cooke, have hereunto set
my hand and seal, this Eleventh day of September, in the year
of our Lord One thousand eight hundred and seventy-five.