IMPROVEMENTS IN MOTIVE-POWER ENGINES, AND IN FITTINGS FOR BOILERS EMPLOYED THEREWITH, PARTS OF WHICH IMPROVEMENTS ARE APPLICABLE TO OTHER SIMILAR PURPOSES
Year: 1876

page_text: LETTERS PATENT to John Gillott, of Barnsley, in the County of York,
Engineer, for the Invention of IMPROVEMENTS IN MOTIVE-POWER ENGINES,
AND IN FITTINGS FOR BOILERS EMPLOYED THEREWITH, PARTS OF WHICH
IMPROVEMENTS ARE APPLICABLE TO OTHER SIMILAR PURPOSES."
Sealed the 8th May 1877, and dated the 11th November 1876.
PROVISIONAL SPECIFICATION left by the said John Gillott at the Office of
the Commissioners of Patents on the 11th November 1876.
"IMPROVEMENTS
JOHN GILLOTT, of Barnsley, in the County of York, Engineer.
IN MOTIVE-POWER ENGINES, AND IN THE FITTINGS FOR BOILERS EMPLOYED THERE-
WITH, PARTS OF WHICH IMPROVEMENTS ARE APPLICABLE TO OTHER SIMILAR
PURPOSES."
My Invention relates more particularly to the construction and arrangement of the
pistons, slide valves and air pumps of steam or other motive-power engines, and to the
safety valves of steam boilers, but is also partly applicable to other purposes for
which like apparatus are employed.
The first part of my Invention has reference to pistons, and consists in the
application to a piston of devices or contrivances by means of which one or more
spiral springs enlosed in the piston are compressed in the direction of its circumfer-
ence in such a manner as to adjust the pressure of the packing rings against the
cylinder, so as to maintain a steam tight fit, whilst at the same time reducing the
piston to a minimum. These devices or contrivances may consist of levers, a cain,
or wedge, or a combination of them, but I employ by preference a worm wheel made
hollow and formed on its interior with a right and left handed screw thread, with
which engages a corresponding male screw, such worm wheel being actuated by a
worm, so that when the latter is by means of a key passing through this piston
cover the screws are forced out against lugs cast on the inside of an internal V ring,
thereby pressing the latter against the springs, and forcing the packing rings into
contact with the cylinders: The-piston cover is also threaded for the reception of a
nut for setting the worin fast when the piston is properly adjusted. The adjust-
ment (which is best accomplished with the pressure of steam or other motive fluid
against the piston) may be readily obtained if desired without removing the

page_text: cylinder cover by providing an opening for the introduction of a key opposite the
aperture in the piston cover. This part of my Invention is also applicable to the
pistons or plungers of pumps and to other like purposes.
My Invention relates secondly to a side valve, and consists according to one
modification in providing in the interior of the valve a table formed or attached
across the opening of the exhaust port, the upper surface of which table is planed
parallel with the face of the cylinder for the reception of an upper valve face, which
is also truly planed so as to work over it. The valve is made open at the back,
whereby it is relieved of the pressure of the steam or other motive fluid which is
received and sustained by the table.
According to another modification a plate is fitted to bear against the upper
valve face which is formed on a ring resting upon an elastic packing contained in
the body of the valve. This plate is maintained in contact with the upper valve
face by means of springs placed between it and the steam sheet cover, but which
admits of its rising in case of the engine priming; set screws or wedges are provided
for the purpose of adjusting the plate to the ring as required.
My Invention relates thirdly to safety valves for steam boilers, and consists
according to one modification in constructing the valve with a double annular face
fitting corresponding annular seats, with which the valve may be maintained
in contact by means of the ordinary lever arrangement, or as is preferred by means
of a weight or weights attached to or suspended from the underside of the valve in
any suitable manner. The weight or weights is or are enclosed in a dome or cover
in order to prevent them from being tampered with when the boiler is empty.
According to another modification the safety valve is made in two parts forming
a duplex valve, the two valves of which are of different areas. The small valve lias
its sent in the large one, and is maintained in contact therewith by means of a
weight connected to or suspended from its under side, whilst the larger valve is
kept to its seat by means of a weighted lever in the ordinary manner.
The top
of the large valve is made to cover the small valve, and is provided with openings
for the exit of the steam which passes the small valve when it is opened by the
excess of pressure in the boiler, thereby relieving the large valve of a portion of its
load.
My Invention relates 4thly to air pumps, and consists, as applied to vertical
engines, in placing the pump barrel below the level of the foot and delivery valves,
so that the water and air and uncondensed steam can flow freely out of the condenser.
This arrangement admits of the employment of a piston in substitution for the
costly bucket ordinarily used, and also of the pump and valves being made of
much smaller dimensions than are usually required. The principle is also applicable
to horizontal engines, the pump in that case being made double acting.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Gillott in the Great Seal Patent Office on the 11th May 1877.
JOHN GILLOTT, of Barnsley, in the County of York, Engineer. "IMPROVEMENTS
IN MOTIVE-POWER ENGINES, AND IN FITTINGS FOR BOILERS EMPLOYED THERE-
WITH, PARTS OF WHICH IMPROVEMENTS ARE APPLICABLE TO OTHER SIMILAR
PURPOSES."
My said Invention relates more particularly to the construction and arrangement
of the pistons, and air pumps of steam or other motive-power engines, and to the
safety valves of steam boilers, but is also partly applicable to other purposes for
which like apparatus are employed.
The first part of my said Invention has reference to pistons, and consists in the
application to a piston fitted with a packing ring or rings of one or more spiral springs
enclosed in the piston in combination with devices or contrivances by means of which

page_text: such spring or springs is or are compressed in the direction of the circumference of
the piston in such a manner as to adjust the pressure of the packing ring or rings
against the cylinder so as to maintain a steam-tight fit, whilst at the same time
reducing the friction to a minimum.
My said Invention has reference secondly to safety valves for steam boilers, and
consists, according to one modification, in constructing the valve with a double
annular face fitting corresponding annular seats with which the valve is maintained
normally in contact either by means of the ordinary lever arrangement or as is
preferred by means of a weight or weights attached to or suspended from the under
side of the valve in any suitable manner. The weight or weights is or are enclosed
in a dome or cover in order to prevent them from being tampered with.
According to another modification of this part of my said Invention, the safety
valve is made in two parts forming a duplex valve, the two valves of which are
of different areas.
The small valve has its seat in the large one, and is maintained
normally in contact therewith by means of a weight connected to or suspended
from its underside, whilst the large valve is kept to its seat by means of a weighted
lever in the ordinary manner. The top of the large valve is made to cover the
small valve, and is provided with openings for the exit of the steam which passes
the small valve when it is opened by the excess of pressure in the boiler, thereby
relieving the large valve of a portion of its load.
My Invention has reference thirdly to air pumps, and consists in placing the pump
barrel below the level of the foot and delivery valves, so that the water and air and
uncondensed steam can flow freely out of the condenser. This arrangement admits
of the employment of a piston in substitution for the costly bucket ordinarily used,
and also of the pump and valves being made of much smaller dimensions than are
usually required. This part of my said Invention is especially adapted for vertical
engines, but is also applicable to horizontal engines, the pump in the latter case
being made double acting.
And in order that my said Invention may be fully understood I shall now
proceed more particularly to describe the same, and for that purpose shall refer to
the several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in all the Figures.
Figure 1 of my Drawings represents a transverse section taken along the line 1,
2, 3, Figure 2; and Figure 2 is a corresponding plan of a piston constructed
according to my said Invention.
Figure 3 represents a vertical section of a safety valve constructed according to
one modification of my said Invention; and Figure 4 is a corresponding plan of
the same.
Figures 5 and 6 are similar views illustrating another modification of the safety
valve.
Figure 7 is a vertical section, and Figure 8 a plan of an air pump, and so much of
the contiguous parts of an engine as is sufficient to illustrate the third part of my
said Invention.
Referring to Figures 1 and 2, A is the body of the piston, and B, B, are split or
divided packing rings fitted in an annular groove or recess formed therein, so as to
be capable of being forced outwards into contact with the bore of the cylinder;
C, C, are spiral springs enclosed in a chamber D provided in the piston A, and each
confined between lugs a, b, formed on two segments of rings, the spring C being
confined between the two segments E, E', whilst the spring C¹ is confined between
the two segments E, E, the three segments E, E¹, E³, forming together an annular
ring surrounded by the packing rings B, B. This part of my said Invention consists
chiefly in the employment of devices or contrivances by means of which the
springs C, C, are compressed in the direction of the circumference of the piston in
such a manner as to force out the packing rings B, B, into contact with the bore of
the cylinder. These devices or contrivances may consist of levers, a cam or wedge,
or a combination of them, but I employ by preference the arrangement shewn in
the Drawing and next herein-after described; F is a worm wheel made hollow and

page_text: formed on its interior with right and left-handed screw threads for the reception of
corresponding male screws G, G¹, the outer ends of which are respectively in contact
with lugs a, b, formed on the segments E, E³. With the worm wheel F
engages a worm H which is operated by means of a key inserted into the recess e
so as to turn the worm wheel F, whereby the screws G, G³, which are maintained
between guides at f in order to prevent their rotation are moved longitudinally,
thereby acting through the lugs a, b, upon the segments E, E, and thence through
the lugs a, b, upon the springs C, C, which are thus compressed and caused to act
through the segments E, EL, E², upon the packing rings B, B, and force the same
into contact with the cylinder. The piston cover I is threaded for the reception of
a nut K for setting the worm H fast when the piston is properly adjusted. The
adjustment, which is best accomplished with the pressure of steam or other motive
fluid against the piston, may be readily obtained if desired without removing the
cylinders by providing an opening for the introduction of a key opposite the
aperture at K in the piston cover I. This part of my said Invention is also
applicable to the pistons or plungers of pumps and to other like purposes.
The second part of my said Invention which relates to improvements in safety
valves for steam boilers is illustrated by two modifications in Figures 3 and 4 and
Figures 5 and 6 respectively.
According to the modification which is shewn in Figures 3 and 4, the valve L is
constructed with a double annular face g, g', fitting corresponding annular seats in
the valve casing M with which the valve is normally maintained in contact either
by means of the ordinary lever arrangement, or as preferred and shewn in the
Drawing by means of a weight or weights N suspended by a rod O from a plate P
attached by pins Q to the valve L or connected to the valve in any other suitable
manner. The weight N is enclosed in a dome or cover R so as to prevent it from
being tampered with.
According to the modification which is illustrated by Figures 5 and 6, the safety
valve is made in two parts L, L', forming a duplex valve, the two valves L, L', of
which are of different areas. The smaller valve L¹ has its seat at G in the valve L,
and is maintained in contact therewith by means of a weight suspended at P from
its spindle O, whilst the large valve L has its seat at g in the valve casing M, and
is maintained in contact therewith by a weighted lever N¹. When an excess of
pressure takes place in the boiler the valve L' rises into contact with the under side
of the valve L which covers it; the steam then escapes around the periphery of the
valve L and through openings h formed in the valve L, and if the pressure remains
in excess the valves L and L' are lifted together bodily until the pressure is reduced
to the required maximum.
My said Invention has reference thirdly to improvements in the construction of
air pumps, and is applicable both to horizontal and vertical engines, but is especially
adapted for the latter, which I have taken as an example of the application of this
part of my said Invention as illustrated by Figures 7 and 8 of my Drawings;
$ is the condenser; T, the foot valve; T', the delivery valve; and U the pump
barrel, which latter I place below the level of the valves T, T¹, so that the water
and air and uncondensed steam can flow freely out of the condenser S. This
arrangement admits of the employment of a simple piston A, as shewn in sub-
stitution for the bucket ordinarily used, and also of the dimensions of the air pump
and valves being reduced. When this part of my said Invention is applied to
horizontal engines, the air pump is made double acting, similar advantanges being
obtained.
Having now described and particularly ascertained the nature of my said Inven-
tion, and the manner in which the same is or may be used or carried into effect, I
would observe in conclusion that what I consider to be novel and original, and
therefore claim as the Invention secured to me by the herein-before in part recited
Letters Patent is,―
First. The employment in pistons fitted with a packing ring or rings of a spiral
spring or springs in combination with devices or contrivances for effecting the

page_text: compression of such spring or springs in the direction of the circumference of the
piston for the purpose of adjusting the pressure of the packing ring or rings against
the cylinder, substantially as herein before described.
Second. Constructing safety valves with a double annular face, substantially as
herein-before described.
Thirdly. The construction of duplex safety valves consisting of two valves of
different areas, the one having its seat in the other when arranged and operating.
substantially in the manner and for the purposes herein-before described and as
illustrated by my Drawings.
Fourthly. A safety valve maintained normally in contact with its seat by enclosed
suspended weights, substantially as herein-before described and illustrated by
Figures 3, 4, 5, and 6 of my Drawings.
Fifthly. Arranging the air pump barrel in steam engines below the level of the
foot and delivery valves, substantially as and for the purposes herein-before
described.
In witness whereof, I, the said John Gillott, have to this my Specification set
my hand and seal, this Ninth day of May, One thousand eight hundred and
seventy-seven.
JOHN GILLOTT. (L.S.)