Improvements in or relating to Blowing Engines, Air Compressors, and the like.
Year: 1896

page_text: Date of Application, 14th Jan., 1896--Accepted, 15th Feb., 1896
COMPLETE SPECIFICATION.
Improvements in or relating to Blowing Engines, Air Compressors,
and the like.
A communication by EDWIN REYNOLDS, of Milwaukee, in the County of
Milwaukee and State of Wisconsin, United States of America, Engineer.
I, WILLIAM PHILLIPS THOMPSON F.C.S., M.I.M.E., of The Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool, and 6 Bank Street,
Manchester both in the County of Lancaster, 118 New Street, Birmingham in
the County of Warwick and 31 High Holborn in the County of Middlesex,
Civil Engineer, do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement :-
This invention relates to blowing engines, air compressors, and the like, and has
reference more particularly to a novel construction of the delivery valves and the
means for operating the same.
The object of the invention is to provide means by which the delivery valves
are left entirely free to open as soon as the pressure inside the cylinder is equal to
or exceeds the pressure in the delivery pipe; also to return the valves to their
seats, when the main piston is at or near the end of its stroke; and, finally, to
prevent the valves from opening too quick or coming into direct metallic contact
at the outward limit of their lift or movement..
In the drawings-
Figure 1 is a face view of a portion of a blowing engine (driven by a compound
steam engine) and having the improvements applied thereto;
Figure 2 is a face view, on a larger scale, of the connections for operating the
delivery valves;
Figure 3, a side view of the same;
Figures 4 and 5, sectional views of the upper and lower delivery valves
respectively; and
Figure 6 a view illustrating the application of the invention to a blowing engine
operated by a single acting steam engine.
In a blowing engine such as represented in Figure 1, the piston of the air
cylinder and the piston of the steam cylinder at each side are connected by
suitable rods to a cross-head, each of which is in turn connected by a suitable link a
to a pin b fixed at each end of a beam A, as shown.
Beam A is supported at its centre by a suitable shaft c, and is designed to be
rocked on said shaft, by means of the pitman B connected at its lower end to a
crank pin d turning with the shaft that carries the fly wheel.
From this it will be seen that the circular motion of the crank pin gives a
definite vibration to the beam, which in turn gives a positive stroke to all four
pistons.
Secured rigidly to the shaft c is an arm e, which necessarily partakes of the
motion of the beam or of the pistons, and which arm is connected by means of a
link or rod with a rocking or oscillating part or member C.
It is to be distinctly understood that the mechanism hereinbefore described for
imparting motion to the part or member C will be varied according to the
character, style, or type of engine to which the invention. is applied, and hence
the invention is not to be restricted to the precise means shown for giving motion
to the said nort C

page_text: The part or member C is an arm or lever adapted to rock or oscillate upon a
pin, stud, or short shaft g, secured to the engine frame; and it is connected by
means of a link or rod h to an arm i secured to the end of a rockshaft j, shown
in Figures 1, 2, 3 and 5, journaled on the bottom or lower head of the air
cylinder.
The said lever C, link & and arm i are so set and arranged with reference to
each other, that the centre of the lever and the centre of the link form a straight
line when the piston is at the middle of its stroke, in which position the arm on
the rockshaft is thrown back into its farthest point and the valve-piston is at its
greatest distance away from the valve.
Another link connection is arranged between the arm and a similar arm l
affixed to a second rockshaft m journaled on the top head of the air-cylinder,
thereby giving to the arm / the same motion as is given to the arm i.
On the two rockshafts j and m are also fixed the radial arms n and o which
latter move in guides p, and are connected by rods g to the pistons D moving
freely inside the delivery valves hereinafter fully described.
From this it will be seen that these last-mentioned pistons D have a motion
imparted to them by the motion of the main piston or pistons, and that the said
motion is of such a nature that these pistons D have one up and down stroke for
each stroke of the main piston or pistons. In other words, when the main piston
is at one dead centre, the valve pistons D are nearest the valve seats, but when the
main piston is at the middle of its stroke, the valve pistons D are farthest away
from the valve seats, and will gradually return towards the same as the main piston
advances toward the other dead centre. These motions occur in precisely the
same manner for each stroke of the main piston, and possess the desired features
for operating the delivery valves now to be described.
These two valves are similar in construction and a description of one will suffice
for both, such differences as are due to the different positions of the valves, being,
however, particularly pointed out.
The valve proper E, is made preferably of solid drawn steel, cylindrical in form,
with a convex or semi-spherical bottom, as shown in Figures 4 and 5.
This valve is fitted loosely inside a guide » while the piston D above referred
to is fitted loosely inside the valve. The valve is provided with a series of holes a,
a few inches from its seat, to serve as an air passage, while the piston D also has
a series of holes forming an air passage; the arrangement of the valve boles a
being such that they may be closed by the valve passing inside its guide, and may
also be closed by the piston D.
The operation of the valves, in relation to the air pressures, and to the mechanism
before described, is as follows:-
Suppose that the working pressure in the air-delivery pipe is one atmosphere
above atmospheric pressure. This will open the delivery valves when the main
piston is about at the middle of its stroke. In that position the valve piston D
will be farthest away from the valve E, and the valve being carried from its seat
by the pressure inside the cylinder, will fly toward the piston D, but the air which
is interposed between the valve and its piston, forming a cushion, is allowed to
gradually escape in diminishing quantities first through the holes in the valve and
piston, and later through the apertures in the piston. By this means the metallic
contact between the valve and its piston will not occur before the whole energy
of the valve has been absorbed by the air cushion, and after it has occurred, the
piston D will gradually carry the valve back to its seat against the current of air
yet being delivered by the main piston. When the main piston is at the end of its
stroke, the valve piston D will have brought the valve nearest to its seat.
The valve closes gradually, that is, in proportion to the air delivered from the
cylinder, the air thus delivered decreasing in quantity as the main piston reaches
the end of its stroke.
A moment later the pressure inside the cylinder will be less than that in the
delivery pipe, and the air finding its way through the apertures in the valve piston,

page_text: Torces the valve to its seat, while the said piston will be withdrawn by the
mechanical movement already described. By virtue of said movement, the valve
piston will now make one up and one down stroke within the valve without any
effect. For the purpose of having the delivery-pipe pressure in the space between
the valve and its cover, a series of holes is drilled in the guide piece for the
valve.
It will be noted from the above that the pressure is relied upon for keeping the
valves on their respective seats. While this is true after the pressure has been
gained, and holds good at all times for the top valves, in a vertical machine, it will
not do for the bottom valve of a vertical machine nor for the valves in a horizontal
machine. In the latter cases it becomes necessary to employ a spring v, Figure 5,
of sufficient strength to sustain the weight of the valve until the necessary pressure
has been accumulated to make the valves work normally.
When the invention is applied to a single-acting engine, the beam is dispensed
with, and the cross head connected with the main piston is connected by means of
pin w and link with one end of an arm or lever y, as shown in Figure 6.
The said lever y is secured to a rockshaft z which is mounted on the main frame
and which rockshaft carries the part or member C. Of course the rising and
falling of the cross head will impart a rocking or oscillating motion to the rockshaft
and its member C.
It is to be understood that any convenient connection may be made between
the delivery valve pistons and any moving part of the blowing or air-compressing
machinery, provided only that the described relation be maintained as to the times
of their respective movements. The expression "connected with the main piston
is therefore to be understood as meaning connected through any intermediate
devices or mechanism which shall preserve the stated relation and action of the
parts.
"
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is :-
1. In a blowing engine or like machine, the combination with the cup-shaped
valve, of a guide therefor, a piston fitting within said valve, and means for imparting
motion to the valve piston from a moving part of the machine, in a certain definite
relation to the stroke of the main piston.
2. In a blowing engine or like machine, the combination with a valve arranged
to be raised from its seat when the pressure in the cylinder exceeds that in the
delivery pipe, of a piston fitting within the valve and having a positive motion of a
certain definite relation to the stroke of the main piston.
3. In combination with the cup-shaped valve closed at one end, the piston fitting
within the valve and having a movement of a definite relation to the movement of the
main piston of the machine, and air passages formed in the valve and piston, whereby
the air confined between the valve piston and the end of the valve, forms a cushion
to control the opening of the valve.
4. In combination with the cup-shaped valve provided with an air passage, the
piston working within the valve and also provided with an air passage, a guide for
the valve provided with an air passage leading from the delivery pipe, and means
for moving the valve piston.
5. In a blowing engine, the combination with the delivery valve thereof, of a
piston for said valve, and connections between the valve piston and a moving part
of the engine whereby the valve piston shall carry the valve to its seat when the
main piston is at the end of its stroke.
6. In a blowing engine, the combination with the delivery valve thereof, of a
piston for said valve, and mechanical means operatively connecting the valve piston
with a moving part of the engine whereby the valve-piston shall be so moved as to
allow the valve to be raised from its seat to open fully, when the main piston is at
the middle of its stroke.

page_text: 7. In a blowing engine, the combination with the delivery valve thereof, of a
piston for said valve, and mechanical connections between the valve piston
and a moving part of the engine whereby the valve-piston shall carry the valve to
its seat when the main piston is at the end of its stroke, and whereby also the valve
piston shall be so moved as to allow the valve to be raised from its seat to open
fully, when the main piston is at the middle of its stroke.
8. In a blowing engine, the combination of the delivery valves and their pistons,
and mechanical devices receiving motion directly or indirectly from the main
piston, and connected with the valve pistons whereby the delivery valves are all
forced to their respective seats when the main piston is at dead centers, and all of
said valves are free to open automatically by the pressure created by the travel of
the main piston at any part of its stroke.
9. In a blowing engine, the combination of the delivery valves and their pistons,
a spring for supporting the valves until the pressure is gained, and mechanical
devices receiving motion directly or indirectly from the main piston and connected
with the valve pistons, whereby the delivery valves are all forced to their respective
seats when the main piston is at dead centres, and all of said valves are free to open
automatically by the pressure created by the travel of the main piston at any part
of its stroke.
10. In a blowing engine, the combination with a delivery valve free to open
automatically by the pressure due to the travel of the main piston at any part of
its stroke, of a piston for said valve, and connections between the valve piston and
a moving part of the engine for causing said valve piston to force the valve to its
seat when the main piston is at dead centres.
11. In an air compressor, blowing engine, or like machine, the combination with
the delivery valve and its piston, of the main pumping piston, a rocking lever C, a
rockshaft provided with an arm n connected with the valve piston, a second arm i
secured to said shaft j, a link or rod k connecting the lever with the arm i, and
devices for imparting to the arm C a movement having a definite relation to the
movement of the main piston, whereby when the main piston is at the middle of its
stroke, the rod h shall be in line with the lever C and the valve piston shall be at
its greatest distance from the valve seat.
Dated this 13th day of January 1896.
WM. P. THOMPSON & Co.,
Agents.