IMPROVEMENTS IN THE CONSTRUCTION OF PRIME MOVERS
Year: 1875

page_text: LETTERS PATENT to Joseph Theodore Dann, of 43, Cowley Road,
North Brixton, in the County of Surrey, Civil Engineer, for the
Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF PRIME MOVERS.”-
A communication from abroad by Joseph Guyot, of 127, Rue de
Vaugirard, Paris, in the Republic of France, Engineer.
Sealed the 13th August 1875, and dated the 3rd June 1875.
PROVISIONAL SPECIFICATION left by the said Joseph Theodore
Dann at the Office of the Commissioners of Patents, with his .
Petition, on the 3rd June 1875.
I, Joseph THEODORE DANN, of 43, Cowley Road, North Brixton, in
the County of Surrey, Civil Engineer, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF PRIME
MOVERS," a communication to me from abroad by Joseph Guyot, of 127,
Rue de Vaugirard, Paris, in the Republic of France, Engineer, to be as
follows:-
The chiect of this Invention is to provide an unexpensive and exna

page_text: ditious motive power for prime movers intended to effect the traction of
vehicles, to actuate machinery, or to propel ships, by substituting com-
pressed atmospheric air or other compressed gases for steam in all those
cases in which steam is at present applied or applicable as a motive
power. To this end I provide in the case of railway engines a duplex
air pump, placing one cylinder thereof to the right and one to the left
of the vertical axis of each leading wheel, so that a locomotive with
two leading or driving wheels will have four such cylinders to it.
In the case of stationary engines, locomobiles, or marine engines as are
at present worked by steam, I place one or more similar air pumps in
close vicinity to the main shaft of such engines. Upon the axle of each
driving wheel of a locomotive, or upon the main shaft of other engines,
I fit an eccentric, so connected by links with the pistons of the air
pumps as to cause these pistons to move up and down alternately, that is
to say, to depress the piston of the right-hand cylinder while the one on
the left hand is being lifted, and vice versa.
Having previously fed the engine with the requisite quantity of com-
pressed air or gas, I cause the air coming from the cylinders of the air
pump through suitable pipes to enter and circulate in a tubular recipient
placed by the side of the air pump. I also provide another tube in
connection with each recipient and filled with air, by means of which a
counter pressure is exercised upon the air in the recipients.
The air having circulated within the tubular recipients passes thence
to another receptacle, from whence it forces its way through a conduit
pipe to the cylinder of the engine, within which it acts in the same
manner in which steam is used in engines constructed upon any one of
.the customary plans. By this method I am enabled not only to work
by atmospheric or compressed gas power all stationary, marine, or
locomotive engines at present actuated by steam, but also to furnish
every machine or vehicle with a simple and compact appliance for
actuating the same by means of compressed air or gas.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Joseph Theodore Dann in the Great Seal Patent
Office on the 3rd December 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
THEODORE DANN, of 43, Cowley Road, North Brixton, in the County of
Surrey, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Third day of June, in the year of
our Lord One thousand eight hundred and seventy-five, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Joseph Theodore Dann, Her special
licence that I, the said Joseph Theodore Dann, my executors, adminis-
trators, and assigns, or such others as I, the said Joseph Theodore
Dann, 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 PRIME MOVERS," a communication
to me from abroad by Joseph Guyot, of 127, Rue de Vaugirard, Paris, in
the Republic of France, Engineer, upon the condition (amongst others)
that I, the said Joseph Theodore Dann, my executors or administrators, 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 performed, 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 Joseph Theodore Dann, 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 and accompanying Sheet of Drawings:-
The object of this Invention is to provide an inexpensive and expe-
ditious motive power for prime movers intended to effect the traction of
vehicles, to actuate machinery, or to propel ships, by substituting com-
pressed atmospheric air or other compressed gases for steam in all those'

page_text: cases in which steam is at present applied or applicable as a motive
power. To this effect I provide in the case of railway engines a duplex
air pump, placing one cylinder thereof to the right and one to the left
of the vertical axis of each leading wheel, so that a locomotive with two
leading or driving wheels will have four such cylinders to it.
In the case of stationary engines, locomobiles, or marine engines such
as are at present worked by steam, I place one or more similar air pumps
in close vicinity to the main shaft of such engines. Upon the axle of
each driving wheel of a locomotive, or upon the main shaft of other
engines, I fit an eccentric, so connected by links with the pistons of the
air pumps as to cause these pistons to move up and down alternately,
that is to say, to depress the piston of the right-hand cylinder while the
one on the left hand is being lifted, and vice versa.
Having previously fed the engine with the requisite quantity of com-
pressed air or gas, I cause the air coming from the cylinders of the air
pump through suitable pipes to enter and circulate in a tubular recipient
placed by the side of the air pump. I also provide another tube in
connection with each recipient and filled with air, by means of which a
counter pressure is exercised upon the air in the recipients.
The air having circulated within the tubular recipients passes thence to
another receptacle, from whence it forces its way through a conduit pipe
to the cylinder of the engine, within which it acts in the same manner
in which steam is used in engines constructed upon any one of the
customary plans. By this method I am enabled not only to work by
atmospheric or compressed gas power all stationary, marine, or loco-
motive engines at present actuated by steam, but also to furnish every
machine or vehicle with a simple and compact appliance for actuating
the same by means of compressed air or gas.
Instead of an eccentric being fixed upon the axle of a driving
wheel of a locomotive or upon the main shaft of another engine, the
pistons of the air pumps may be directly connected by means of rods or
links with the driving wheels, fly wheels, or other appliances within
which the working power of the engine is accumulated, and by this
means the number of air pumps may be reduced, and instead of pro-
ducing the alternate action herein-before alluded to by alternating the
strokes of the pistons of two air pumps, these pistons may be made to
Ε

page_text: shewn the axis in the three positions corresponding to the four extreme
positions s¹, 82, 83, 84, of the pin of the rod R and of the eccentric or its
equivalent S.
The working of my motor, as shewn in the accompanying Sheet of
Drawings, is as follows:-The vessel A being filled with compressed air
or gas, and the pistons of the engine being started upon the customary
plan, the rods R, R, are actuated by means of the connecting rods T,
and they in their turn actuate the pistons D, D, of the air pumps C, C,
by the intermediate organs, the operation of which must become
apparent by a glance at the Drawing. As the pistons move up the air
within the pumps is rarefied, the suction valves open and immediately
fill the pumps with air drawn from the outer atmosphere. As they go
down again the air in C is compressed, the valve F shuts, the side
valve H opens, and the air compressed within C is added to that accumu-
lated within the vessel A. In this manner the supply of compressed
air is constantly kept up, and provided all the joints are air tight the
continuous working of the engine by means of compressed air in lieu of
steam is fully insured.
The feeding of the air vessel A is to take place by means of a feed pipe
upon the plan usually followed in filling vessels with liquid or gaseous
substances. It is perfectly immaterial to the working of the engine
from what quarter such compressed air may be derived. For the sliding
gear M, N, O, shewn in Figure 2, any one other method of converting a
rotatory into a rectilinear motion may be substituted, such as cranks,
universal joints, and rods, or any other similar appliances, provided the
main object be thereby attained of securing a continuous working of the
air pumps pari passû with the cylinders of the engine.
Having now described the nature of my said Invention and illustrated
the same in the accompanying Sheet of Drawings, I wish it to be under-
stood that I do not claim the use of atmospheric air generally as a
motive power, such atmospheric force having been known and employed
heretofore; but what I claim is,―
First. The use or employment of compressed air or compressed gas as
a motive power, in the manner herein set forth and illustrated in the
accompanying Sheet of Drawings.-
Secondly. The construction and use or employment of air pumps
communicating with the cylinders of engines, in the manner and for

page_text: the purpose herein set forth and illustrated in the accompanying Sheet
of Drawings.
In witness whereof, I, the said Joseph Theodore Dann, have
hereunto set my hand and seal, this Third day of December,
in the year of our Lord One thousand eight hundred and seventy-
five.
JOSEPH THEODORE DANN. (L.S.)