IMPROVEMENTS IN "BLOWING ENGINES
Year: 1885

page_text: I WILLIAM KENT, residing at 26 Highland Avenue Jersey City, in the County
of Hudson and State of New Jersey in the United States of America, gentleman,
do hereby declare the nature of my invention for IMPROVEMENTS IN "BLOWING
ENGINES" and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:—
My invention relates to certain novel and useful improvements in blowing and
air compressing engines, for blast furnaces, Bessemer convertors, and the like and
has for its object to obviate the disadvantages now existing in this class of engines
i.e. high first cost, lack of economy of steam and liability to "break-downs" through
excessive strains and with these ends in view my invention consists in certain
details of construction and combination of elements hereinafter fully explained and
then specifically designated by the claims.
In order that those skilled in the art to which my invention appertains may
fully understand its construction and operation, I will proceed to describe the
same in detail referring by letter to the accompanying drawing, forming a part of
this specification in which-Fig. 1 is a front elevation of my improvement, showing
the relative position of the steam and air cylinders one of the former being broken
away and sectioned to show the piston and rod and Fig. 2, is a side view showing
the relative angles of the cranks.
Similar letters denote like parts in both the figs. of the drawings.
A, is the frame work of my improved engine, which may be of any convenient
or desired shape, B, are steam cylinders three in number, supported by the two
housings M, which transmit the strains directly to the pillow blocks L, C, are three
air cylinders, arranged above the steam cylinders, and separated by braces D, adapted
to receive and sustain the strain on said cylinders. E are piston rods which pass
through the steam cylinders up into the air cylinders and have on their upper
ends the pistons F.
The lower ends of these piston rods form heads 'G, to which are connected tho
pitinans H, their lower ends in turn being connected to the crank-pins I, secured
in the cranks J, K, is a shaft journaled within the pillow blocks L; on this shaft
are arranged the three cranks J, at 120° to each other as shown in Fig. 2.
The disadvantages above referred to result chiefly from the fact that in the
present construction of blowing engines, the strains in the air and steam cylinders
do not balance each other but on the contrary when the pressure on the steam
piston is greatest, the resistance to the air piston is the least, and when the pressure
on the steam piston has decreased by the expansion of steam, the resistance to the
air piston has increased by the.compression of air.

page_text: These differences of pressure and resistance thus produced are balanced by very
heavy fly-wheels, to and from which the straius are transmitted through heavy
cross heads and connecting rods.
These cross-heads and connecting roda are subjected to severe transverse strains,
frequently repeated in reverse directions which are often the cause of dangerous
"break downs."
In my improved construction the work done is divided into three portions
within three air-cylinders and the difference of pressure and resistance between
the air and steam cylinders are not only divided by three, but are perfectly balanced
by means of the crank shaft, with its three cranks at 120° to each other. Thus
the heavy cross heads for transmitting strains from the pistons to the fly wheels
are dispensed with and I am also enabled to dispense with fly-wheels and at the
same time use the steam expansively and obtain steadiness of motion although
I may employ one or more small fly wheels to increase this steadiness as shown in
the drawings.
The utmost economy of steam may be secured by arranging the three steam
cylinders as a compound engine.
The arrangement that I prefer is that the middle be the high pressure cylinder
and that the two side cylinders receive an equal portion of the exhaust steam from
this high pressure cylinder, and these cylinders exhaust their steam into the
condenser, (not shown).
The arrangement of one high pressure cylinder and two equal size low pressure
cylinders with three cranks at 120° has been found of great value in marine
engines in diminishing and equalizing strains on cranks and crank pins and in
securing economy of steam, and I do not claim any such arrangement broadly.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
1. In a blowing engine, three air cylinders, each having a steam cylinder arranged
opposite it with the same piston rod, and coupled together by means of a crank-
shaft, the cranks of which are set at an angle of 120° to each other, whereby all
strains proceeding from the. weight of parts or from the pressure of steam or air
are balanced substantially as set forth.
2. A blowing engine having three air cylinders of equal size each with a steam
cylinder opposite it and having the same piston-rod and coupled together by means
of a crank-shaft, the cranks of which are set at angles of 120° to each other, the
steain cylinders being proportioned so that each does an equal amount of work
substantially as shown and described.
3. A blowing engine containing three air cylinders each with a steam cylinder
opposite it and upon the same piston rod, the cylinders of which are arranged as a
compound engine, with one high pressure and two low pressure cylinders and
coupled together by means of a crank-shaft, the cranks of which are set at an angle
of 120° to each other,