IMPROVEMENTS IN THE CONSTRUCTION OF AIR CYLINDERS OF BLAST ENGINES, AND IN THE VALVE ARRANGEMENTS FOR THE SAME
Year: 1867

page_text: PROVISIONAL SPECIFICATION left by Louis Rudolph Bodmer at the
Office of the Commissioners of Patents, with his Petition, on the 23rd
September 1867.-A communication from Franz Stiehler, of Vienna, in
the Empire of Austria, Civil Engineer.
I, LOUIS RUDOLPH BODMER, of 2, Landsdowne Road, Notting Hill, in the
Connty of Middlesex, Engineer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF AIR CYLINDERS OF BLAST
ENGINES, AND IN THE VALVE ARRANGEMENTS FOR THE SAME," a communication
from Franz Stiehler, of Vienna, in the Empire of Austria, Civil Engineer, to
be as follows:-
This Invention consists in the combined application of the elastic hoop,
ring, or belt valve with the flap valve, and in the peculiar construction and
arrangement of the cylinder and its parts for this purpose. The object of
the said construction and arrangement is to combine the advantages which
the elastic belt valve possesses over other valves when used as suction valve
with those possessed by the flap valve as pressure valve. The elastic belts
possess in the nature of the material of which they are made, vulcanized
india-rubber, those properties which cause the valve to perform so admirably
the functions of the suction valve, owing to their elasticity they close the
valve instantaneously at the end of the stroke, when suction ceases entirely
independent of the return stroke of the piston, and without noise or concussion
whatever be the speed of the piston. Owing to the introduction of the
elastic belt valve blast engines can be worked at greatly increased piston
speed now usual, and through which the former collassal dimensions of blast

page_text: engines have become unnecessary; applied as pressure valve however the
elasticity of the belt valve cover offers no advantage whatever, whilst other
peculiarities of the valve act most disadvantageously. The great number of
openings or holes through which the compressed air has to pass cause a large
amount of friction, and the belt subject to great and unequal pressure is bent
and strained in all directions. Another and very serious disadvantage peculiar
to those valves as pressure valves consists in the large valve surface which
has to be covered by the belt in proportion to the total area of the air passages;
the flap valves on the other hand, of every shape and size, fulfil every require-
ment as pressure valves. The improved construction and arrangement of the
air or blast cylinder, and parts in which the elastic belt suction valves are
applied in conjunction with the flap pressure valves consist in an universal
and outer cylinder cast in one piece, the inner one is the cylinder proper in
which the piston works, and it occupies an excentric position to the larger
outer cylinder, the periphery of the one uniting with that of the other; the
two cylinder covers of the outer cylinder at the same time form the covers
of the inner cylinder, and on the inner surface of such cover is formed the
perforated ring or short cylinder which forms the seating of the belt valve. In
the open space between the inner and outer cylinder opposite the part where
the two peripheries join is formed the air passage, at each end of which a flap
pressure valve is screwed to flanges uniting the inner with the outer cylinder
which communicates with its corresponding end of the air cylinder. As the belt
suction valves are much larger in diameter than the air cylinder, the number
of air holes can be considerably increased with a total sectional area iu
proportion to that of the cylinder far in excess of what has hitherto been
obtained. Another advantage of this construction is that the flap valves are
easy accessible by removing the cylinder covers.
The above described improvements are applicable to both high and low
pressure blast engines.