IMPROVEMENTS IN EJECTORS FOR EXHAUSTING AIR
Year: 1876

page_text: LETTERS PATENT to John Y. Smith, of Pittsburgh, Pennsylvania, United States
of America, but now residing at 85, Lancaster Road, in the County of Middlesex,
Engineer, for the Invention of "IMPROVEMENTS IN EJECTORS FOR EXHAUSTING
AIR."
Sealed the 12th January 1877, and dated the 11th October 1876.
PROVISIONAL SPECIFICATION left by the said John Y. Smith at the Office
of the Commissioners of Patents on the 11th October 1876.
JOHN Y. SMITH, of Pittsburgh, Pennsylvania, United States of America, but
now residing at 85, Lancaster Road, in the County of Middlesex, Engineer.
PROVEMENTS IN EJECTORS FOR EXHAUSTING AIR."
"IM-
My Invention relates to an improved form of ejector which is chiefly designed to
facilitate the working of the continuous vacuum brake described in the Specifications
of former Letters Patent dated the 23rd January, 1873, No. 279; the 28th of August,
1874, No. 2950; the 9th day of March, 1875, No. 875; and the 6th day of
September, 1875, No. 3125.
I have from time to time in connection with the aforesaid vacuum brake
apparatus used ejectors of various forms, and in the course of my experiments
in connection with such vacuum brake apparatus I have discovered that the
most perfect vacuum is obtained by using an ejector constructed as to the body
thereof substantially in the manner shewn in the Specification of the last
mentioned former Letters Patent, but having the nozzle of the air eduction pipe
and that portion of the outer frame of the steam chamber of the ejector immediately
surrounding the nozzle and beyond the outer extremity thereof, constructed in the
proportions and with the angles herein-after mentioned, a nozzle of 2 inches internal
diameter at the outlet being taken as an example. The nozzle is constructed with
the exterior of that portion of the sides thereof which forms the nozzle proper con-
verging towards the outlet of the ejector at such an inclination that lines drawn
corresponding to the two sectional sides and continued in a straight line will' cross or
intersect at a point exactly 8 inches from the end of the nozzle. The interior sides
or walls of the steam chamber of the ejector are constructed at the portion imme-
diately opposite the nozzle in the following manner :-Taking one sectional side as

page_text: an example with which the opposite side corresponds, the side is constructed of two
portions or lengths of a different inclination which converge and form an angle of
174° at a point exactly 5/8 th of an inch from the outer end of the nozzle measured
from the extremity thereof inwards, a space of 1/16th of an inch is left between the
angle formed by the said converging portions and the opposite point of the external
side of the nozzle, which space being continued all round forms an annular orifice
for the passage of the steam. That converging portion of the sectional side which
is situate on the side of the angle towards the outlet of the ejector is continued for
a distance of 4 inches, and at its termination it joins at an angle of 170° 30',
another length, forming a line nearly parallel with a line drawn through the centre
of the nozzle, and which additional length is continued to the requisite distance to
form the outlet of the ejector.
The other converging portion of the sectional side at the part where the nozzle is
situate is continued for a distance of 5/8ths of an inch from the angle in the opposite
direction, beyond which point it may be enlarged and form any desired contour.
By this means I obtain a more perfect vacuum than has previously been attainable
by means of a steam ejector.
For the purpose of obtaining increased power when required I combine the
ejectors construsted in the form above mentioned, substantially in the manner
described in the Specification of the said former Letters Patent, No. 2950, 74,
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Y. Smith in the Great Seal Patent Office on the 11th April
1877.
JOHN Y. SMITH, of Pittsburgh, Pennsylvania, United States of America, but
now residing at 85, Lancaster Road, in the County of Middlesex, Engineer. "IM-
PROVEMENTS IN EJECTORS FOR EXHAUSTING AIR."
My Invention is designed to facilitate the working of the vacuum brake described
in the Specifications of former Letters Patent dated the 23rd January, 1873, No.
279; the 28th August, 1874, No. 2950; the 9th day of March, 1875, No. 875; and
the 6th day of September, 1875, No. 3125.
It will be found by reference to the said Specifications that an important feature
of the Inventions described therein is the employment of an ejector which exhausts
or expels the air from the collapsible vacuum chamber or cylinder of the aforesaid
vacuum brake apparatus, and my present Invention relates to the combination of a
peculiarly constructed exhauster with the said collapsible chamber or cylinder or
other similar part of a brake apparatus for exhausting air from the same.
I have from time to time used ejectors of various forms, and in the course of my
experiments in connection with such vacuum brake apparatus I have discovered that
the most perfect vacuum can be obtained by using an ejector constructed as
shewn in the accompanying Drawing, which is a longitudinal section of my said
Invention.
This ejecting apparatus has the nozzle A of the air eduction pipe B and that
portion of the outer frame C of the steam chamber C' of the ejector immediately
surrounding the nozzle and beyond the outer extremity thereof, constructed in the
proportions and with the angles herein-after mentioned a nozzle of 2 inches internal
diameter at its outlet being taken as an example. The nozzle A is constructed with
the exterior of that portion of the sides thereof which forms the nozzle proper,
namely, from a to b, converging towards the outlet D of the ejector at such an in-
clination that lines drawn corresponding to the two sectional sides and continued in
a straight line will cross or intersect at a point c about 8 3/8 inches from the end of
the nozzle. The interior sides or walls of the steam chamber C¹ of the ejector are
constructed at the portion immediately opposite the nozzle in the following

page_text: manner: Taking the upper sectional side as an example with which the opposite
side corresponds, the side is constructed of two portions or lengths of a different in-
clination which converge and form an angle of 174 degrees at a point d 5/8 of an
inch from the outer end 6 of the nozzle A measured from the extremity thereof in-
wards; a space of 1/16 of an inch is left between the angle formed by the said
converging portions and the opposite point d' of the external side of the nozzle,
which space being continued all round forms an annular orifice for the passage of
the steam. That converging portion of the sectional side which is situate on the
side at the angle d towards the outlet D of the ejector is continued for a distance of
4 inches, namely to e, and its termination at e joins at an angle of 176° 30',
another length e, f, forming a line nearly parallel with an imaginary axial line D, D',
drawn through the centre of the ejector, and which additional length is continued
to the requisite distance, as for example to f, to form the outlet of the ejector. The
other converging portion of the sectional side at the part where the nozzle A is
situate is continued for a distance of 5/8 of an inch from the angle d in the
opposite direction, namely to g, beyond which point it may be enlarged as shown
and have any desired contour. By the use of the ejecting apparatus constructed as
above described in combination with the collapsible chamber or cylinder of the brake
apparatus I obtain a more perfect vacuum than has previously been attainable for
brake purposes by means of a steam ejector.
For the purpose of obtaining increased power when required I combine two
ejectors constructed as above described, and arranged side by side with one steam
pipe common to both of them.
Having thus fully described my said Invention and the manner of performing the
same, I wish it understood that I claim,-
The ejector for exhausting air, consisting of the apparatus constructed as shown
in the accompanying Drawing and as above described, and combined with the col-
lapsible chamber or cylinder or other chamber or vessel from which air has to be
exhausted, drawn, or expelled, in the working of a vacuum brake as above set
forth.
In witness whereof, I, the said John Y. Smith, have hereunto set my hand
and seal, this Tenth day of April, in the year of our Lord One thousand
sight hundreds
JOHN Y., SMITH. (L.S.)