A NEW STEAM ENGINE FOR SMALL POWER
Year: 1876

page_text: LETTERS PATENT to Gustaf Hagelin, of Stockholm, in the Kingdom of Sweden,
Civil Engineer, for the Invention of "A NEW STEAM ENGINE FOR SMALL
POWER."
Sealed the 15th June 1877, and dated the 16th December 1876.
PROVISIONAL SPECIFICATION left by the said Gustaf Hagelin at the Office
of the Commissioners of Patents on the 16th December 1876.
GUSTAF HAGELIN, of Stockholın, in the Kingdom of Sweden, Civil Engineer.
"A NEW STEAM ENGINE FOR SMALL POWER."
The object of this Invention is by the improved construction of some parts to
produce an improved engine which is more particularly suitable for small power.
By these improvements the friction is considerably reduced, leakage of steam is
prevented even in small engines, the bearings need not be adjusted, and hence
require no repair till quite worn out; the engine requires no attention except a little
lubrication; no packing rings are required for small powers; the engines can
advantageously be made as small as one man's power; the most advantageous
expansion may be applied without special contrivances therefor; the engine can
safely be run at much more than a thousand revolutions per minute, as proved by a
year's trial of a half horse-power engine, and the speed can thus be varied as much
as required, so that an engine yielding at one time, say, '/, horse power may with
the same economy yield one horse power or more.
According to this Invention a peculiar slide valve exposed to pressure in one
direction only is employed, and a peculiar arrangement of valve gear is used, also
cylinders having pistons exposed to pressure on the upper side only. The expansion
and consequent economy is produced partly by the peculiar slide valve gear, and
partly also by the use of one or more expansion cylinders. Packing rings
become less necessary by the use of long well fitting (ground in) pistons, which
however, may be formed with spiral grooves as is well known; the cylinders are
open below, and the condensed water in the grooves assists in keeping the pistons
tight.
There is an inlet valve or cock to the slide jacket in which fits a cylindrical slide
valve which works steam-tight with exception of a smaller central portion. The
slide rod is actuated by a double-armed lever turning on a fulcrum, and at the other
end jointed to a link, the other end of which is jointed to the crank pin at the

page_text: engine shaft; the arrangement and inclination of these parts is such that the slide
valve during its in-and-out stroke receives different speed. The connecting rod is
by ball-and-socket joint connected to the piston, and its other end is jointed to a
one-armed lever which at a point, still further from the fulcrum, by a link is con-
nected to the crank pin. When the latter passes over the dead centre a port is
opened quickly and the steam enters the cylinder. When the crank has passed
nearly one-fourth round, the port is closed again. During this time the slide rises till
the crank pin has come nearly to the bottom; the upper steam-tight part of the slide
now begins to open the port again, so that the steam exhausts from the cylinder to
the space round the middle part of the piston slide valve, and thence by the exhaust
pipe into the steam jacket, and then into the atmosphere, or the steam jacket may
be dispensed with. The piston is now nearly at its lowest position; freed from the
steam, the fly wheel turns the shaft further round; the piston rises again, and the
slide valve does not hinder this movement, but rather furthers it. The crank pin
having come a little beyond the upper point the upper part of the slide valve begins
to shut off the steam port, whereby the steain above the piston is compressed,
although only during a small portion of the stroke still remaining; a new revolution
then cominences as before.
According to a modified arrangement I use two cylinders, one of which works
with expansion. The steam is let in by means of a special admission slide with
stem and handle. When the handle is in the middle position the steam is only let
into an upper port, and thence direct into the smaller cylinder when the admission
slide is fully open; another port is also opened, admitting steam, the consequence
being that the steam always goes directly into the aforesaid small cylinder, and for
every other stroke also into the large cylinder, all according as the distributing
slide valve is in any intermediate position. This peculiar steam admission into
both cylinders causes the motion of the engine, whereby the steam only exhausts
into the air from the large cylinder, but flows from the small into the large cylinder.
The work is thus always done with full pressure; as the piston of the small
cylinder moves down the work is dependant upon the direct pressure thereon, but
during the down stroke of the large piston it depends upon the difference between
the full pressure against the up going small piston, and that on the large one which
is double the area.
It is more advantageous to charge the small cylinder only, and later on to expand
it in the large cylinder. The steam then goes only through the lower port into the
small cylinder, drives down the piston and also the crank from the highest point.
The slide valve meanwhile assumes an intermediate position between the positions
wherein the steam in the large cylinder can exhaust into the atmosphere. When
piston and crank pin of small cylinder have come to their lowest position (the piston
and crank for large cylinder, hence in the highest position), the slide valve assumes
a higher position, and the steam from the small cylinder has expanded a little.
The next moment the slide valve opens for the steam to the large cylinder; the
piston therein is then driven down by the expanding steam from the small cylinder;
this movement continues until the slide valve quite cuts off. As long as this goes
oll,
that is, so long as the terminal position has not been passed the steam in the
small cylinder will be compressed, but this is obviously only a very small part of
the stroke. But as soon as the upper edge of the valve has passed the upper edge
of the upper port, the engine will commence a new revolution as before.
The transmission of notion of the pistons to the cranks is direct by connecting rods,
but may be done in a manner similar to that described with reference to the first
described arrangement. The slide motion is derived from a crank pin at end of
the engine shaft and connecting rod, which latter is formed with two open bearings
on opposite sides and in opposite direction. When the engine goes in one direction
the pin on a lever is placed in one bearing, the slide valve is then pressed from
above, and the bottom joint of a connecting rod taking on a pin on a lever fixed on
the same weigh shaft as the just-named lever, retained in the said open bearing;
the slide valve thus obtains its up-and-down motion. If the engine is to go in

page_text: the opposite direction the other open boaring is connected to the pin on the lever,
and the steam pressure retains it therein similarly; this is one of the peculiarities
of the engine.
There is one common slide jacket whereinto the steam is let by the admission slide
or stop-cock; it has four steam ports also a piston slide valve having three close
fitting piston parts (instead of two as above described), and two intermediate
smaller parts. The extreme positions are the same as with the just described
engine. One cylinder has a piston and is formed in one with a larger cylinder
wherein a piston works; also in one with the piston of the smaller cylinder. In a
similar manner there are another and small and large cylinder with pistons. For
larger sizes piston rings may be applied.
The movement of pistons and slide valves are as in the just described engine, with
the exception that the steam does not exhaust into the atinosphere from the sinaller
of the last-named two cylinders, but flows into the corresponding larger cylinder,
and that the smaller cylinder of the first-named couple simultaneously becomes
charged; from the corresponding larger cylinder the steam flows into the larger
cylinder of the second couple, while the steam simultaneously flows into the smaller
of the second couple, and at last from the corresponding larger cylinder into the
atmosphere, or by preference into a condenser, especially when as here contemplated
the expansion is, say, eleven fold the diameter of the first couple of cylinders, being
respectively in the proportion of about 13 and 28, and the diameters of the second
couple about 18 and 39.
The one cylinder engines herein described may be combined in any required
number.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Gustaf Hagelin in the Great Seal Patent Office on the 16th June
1877.
GUSTAF HAGELIN, of Stockholm, in the Kingdom of Sweden, Civil Engineer.
"A NEW STEAM ENGINE FOR SMALL POWER."
The object of this Invention is by the improved construction of some parts to
produce an improved engine especially suitable for small power and which I call
the "colibri."
By these improvements the friction is considerably reduced, leakage of steam is
prevented even in small engines, the bearings need not be frequently adjusted, and
hence require no repair till quite worn out; the engine requires no attention except
a little lubrication ; no packing rings are required nor even desirable for small powers;
the engines can advantageously be made as small as one man's power or even less;
the most advantageous expansion may be applied without special contrivances
applied to the slide valve; the engine can safely be run at much more than a
thousand revolutions per minute, as proved by more than a year's trial of a half
horse-power engine, and the speed can thus be varied as much as required, so that
an engine yielding at one time, say, '/, horse power, may with the same economy
yield one horse power or more.
According to this Invention a peculiarly constructed cylindrical slide valve
exposed to pressure in one direction only is employed and a peculiar arrangement
of valve gear is used, also cylinders having pistons exposed to pressure on the upper
side only. The expansion and consequent economy is produced partly by the
peculiar slide valve gear and partly also by the use of one or more expansion
cylinders. Packing rings become less necessary by the use of long well fitting
(ground in) pistons, which however may be formed with grooves, as is well known;
the cylinders are open below, and the condensed water in the grooves assists in keep-
ing the pistons tight.

page_text: Figure 1, Sheet 1, is an end elevation of a steam engine constructed according to
this Invention and for about double expansion; Figure 2 is a side elevation partly
in section; Figure 3 is a plan of the steamn cylinder; and Figure 4, a plan of parts
below the same.
A is the inlet valve or cock to the cylindrical slide jacket B in which fits a
cylindrical slide valve C, and which works steamtight with exception of a smaller
central portion c, c. The slide rod M is actuated by a double armed lever K turning
on a fulcrum O, and at the other end jointed at 2 to a link L, the other end of
which is jointed to the crank pin I at the engine shaft J; the arrangement and in-
clination of these parts is such that the slide valve during its in-and-out stroke
receives different speed. In the position of C, shown here, the steam cannot enter
the cylinder D through the port a; the cylinder piston E is at its highest point.
The connecting rod H is by ball-and-socket joint connected to the piston E, and its
other end is jointed to a one-armed lever G, which at a point still further from the
fulcrum by a link F is connected to the crank pin I. When the latter passes
over the dead centre the port a is opened quickly and the steam enters the
cylinder D. When the crank has passed nearly one-fourth round, the port a is
closed again.
While the piston E moves down the slide C rises till the crank
pin I has made nearly half a revolution, that is, has come nearly to the bottom;
the upper steam-tight part C of the slide now begins to open the port a again,
so that the steam exhausts from the cylinder to the space round the middle
part C of the piston slide valve, and thence by the exhaust pipe P into the
steam jacket, and then into the atmosphere; or the steam jacket may be dispensed
with as here shown. The piston E is now nearly at its lowest position; freed from
the steam the momentum of the fly wheel now turns the shaft further round, the
piston E rises again, and the slide valve does not hinder this movement but rather
furthers it. The crank pin I having come to nearly its highest point the upper part
of the slide valve begins to shut off the steam port a, whereby the steam above the
piston is compressed although only during a small portion of the stroke still remain-
ing; a new revolution then commences as before.
Figures 1 to 6, on Sheet 2, represent a modified arrangement, viz., with two
cylinders, one of which works with expansion. Figure 1 is an end elevation;
Figure 2, a side elevation partly in section; Figure 3, a vertical cross section ;
Figure 4, a plan; Figure 5, a plan section through line c, a, f, of Figure 3;
and Figure 6, a plan section below the cylinder. The steam is let in by means
of a special admission slide A with stem and handle as shown. When the handle
stands in the middle position, as shown, the steam is only let into the port a and
thence direct into the smaller cylinder D; when the admission slide is fully open,
that is, when it is moved down into its lowest position another port a', Figure 3, is
also opened admitting steam, the consequence being that the stean always goos
directly into the aforesaid small cylinder D, and at every second half stroke also
into the large cylinder D, all according as the distributing slide valve B is in any
intermediate position. This peculiar steam admission into both cylinders causes the
motion of the engine whereby the steam only exhausts into the air from the large
cylinder D, but flows from the small into the large cylinder. The work is thus
always done with full pressure; as the piston E of the small cylinder D moves down
the work is dependant upon the direct pressure thereon, but during the down stroke
of the large piston E¹ it depends upon the difference between the full pressure
against the up-going small piston E, and that on the large one E', which is double
the area.
It is nevertheless more advantageous to charge the small cylinder only, and later
on to expand it in the large cylinder D'. The steam then goes only from the slide
jacket B through the port a into the small cylinder D, drives down the piston and
also the crank from the highest point to the lowest point; the piston E¹ of the larger
cylinder D meanwhile assumes its highest position, but before the piston E has
reached its lowest point the port a' closed, whereby consequently the steam in
that cylinder is expanded a little. In the next moment the port a¹ is opened by

page_text: the slide valve and thus the steam goes from the small cylinder D through the slide
valve B, around the small part of same, through the port a¹¹, into the large cylinder
D¹, pressing the piston E¹ down; the steam then again passes through the
same port al, as well as through the port a¹, and through the pipe P into the
atmosphere.
The transmission of motion of the pistons E and E¹ to the cranks I and I' is direct,
as shown by connecting rods F and F, but may be done in a manner similar to that
described with reference to the first described arrangement. The slide motion is
derived from a crank pin R at end of the engine shaft K and connecting rod ?,
which latter is formed with two open bearings and in opposite sides and in
opposite directions. When the engine goes in one direction the pin L on a lever M
is placed in one bearing I, but if the pin L' is placed in the bearing the motion
takes place in the opposite direction. To make the engine move in the one or the
other direction it is only necessary to place the rod r so that the pin L is made to
rest in the bearing 7 or the pin L' in the bearing ; the steam pressure in the slide
jacket will then press the pin firmly against its bearing, thus making double bear-
ings superfluous; this is one of the peculiarities of the engine.
The one cylinder engines herein described may be combined in any required
number. Three expansion cylinders with similar motion and slide mechanism may
be combined. When the engines are to assume larger dimension proportions the
pistons ought to be fitted with packing rings. With three expansion cylinders, and,
say, up to elevenfold expansion, the steam is by preference let into a condenser. The
one cylinder engines may be combined in any desired number.
And having thus fully described and ascertained the nature of this Invention, I
declare that I do not limit myself to the exact configuration and arrangement of
parts here shown, but I claim,-
Firstly. The slide mechanism as shown in the Drawings, and the peculiar mode
of operation of same, as described in and reference thereto.
Secondly. Forming the slide gear operating rod with open bearings, as and for
the purposes set forth.
Thirdly. The employment of plain pistons without packing rings and worked
only from above for an engine operating substantially as herein set forth.
Fourthly. The combination of pistons and slide gear, substantially as set forth.
Fifthly. The application of open bearings to the gear from transmitting the
motion of the piston to the crank shaft similar to those employed in the slide
gear.
In witness whereof, I, the said Gustaf Hagelin, have hereunto set my hand
and seal, this Eleventh day of June, in the year of our Lord One
GUSTAF HAGELIN. (L.S.)