AN IMPROVED EXHAUSTING OR BLOWING APPARATUS CHIEFLY DESIGNED TO SERVE AS A GAS-EXHAUSTER
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by Edwin Dunn and John Francis Sleat
at the Office of the Commissioners of Patents on the 8th December 1881.
EDWIN DUNN of Reedworth Street and JOHN FRANCIS SLEAT, of Albert
Street, both in the County of Surrey. "AN IMPROVED EXHAUSTING OR BLOWING
APPARATUS CHIEFLY DESIGNED TO SERVE AS A GAS-EXHAUSTER."
Our Invention relates to an improved apparatus chiefly designed to servo as an
exhauster in gas-works but which may also be used for exhausting or blowing air
or other fluids.
The said apparatus will be more efficient in its operation and moro durable
without being any more costly to manufacture, than the exhausters heretofore
constructed and will work at a very high speed with very little vibration.
The said apparatus has a cylinder closed at each end by a cover secured thereon
with air-tight joints. Within this cylinder is an annular piece or ring whose axis is
parallel with that of the said cylinder. Tho said ring has a diameter
considerably less than that of the cylinder but is arranged excentrically therein so
that its exterior periphery works against one part of the interior periphery of the
cylinder. A shaft extends centrally through the said cylinder and carries, mounted
loosely thereon, three radial vanes. The aforesaid annular piece or ring has three
long apertures or slots parallel with its axis, through which the said vanes work
while being carried round on the driving shaft by the said piece or ring. Each
vane is formed of two plates or leave swith springs placed between them. The said
springs tend always to press the two plates against the edges of the apertures in
the ring, and thereby make tight joints at theso parts. The said vanes have bosses
whereby they are mounted upon the said shaft, each leaf or plate having two
separate bosses the said bosses, being fitted together and acting like bingo joints.
These bosses, at their junction with the vanes, are so shaped that they work against
the inside of the annular piece or ring with a constant air-tight contact. The ends
of the vanes are fitted with packing strips to ensure tight joints between the same
and the cylinder covers, and the outer edges of the said vanes are also preferably
fitted with packing strips to work in contact with the inner periphery of the
cylinder. Each cover has on its inner side a groove sunk to admit the end of the
annular ring and allow for its circular motion.

page_text: One novel and peculiar feature of our Invention is a driving cam or driver which
is keyed, or otherwise fixed, on the central shaft and engages with the aforesaid
annular piece or ring. For this purpose the cover at one end of the cylinder is so
formed as to allow part of the annular ring to project through it, and this
projecting part is utilized for engaging with, and receiving motion from, the said
driver. The said cam has two wings which enter recesses in the projecting end of
the annular picco and are so formed as to work against the shoulders of the said
recesses and thereby impart the required motion to the said annular piece or ring.
The outside edge or periphery of the said cam has a continuous or uninterrupted
curvature, the outer portions of the wings being of about the same width as the
boss or central portion and the intermediate parts being smaller and consisting of
hollow curves. This peculiarly formed cam, working in combination with the
shoulders on the end of the annular piece causes the latter to impart to the vanes &
uniform, or nearly uniform, motion instead of giving them a rapid motion as they
pass through the upper portion of the cylinder and a slow motion through the
lower portion of the same, and this uniformity of motion allows the said apparatus
to run at a very quick speed without vibration. The cover at the other end of the
cylinder is provided with a stuffing box and bearing for the shaft which extends
through the same and is provided with a belt pulley whereby it is driven from any
convenient motor.
This cover also has on its outer sido two chambers which are connected by
apertures in the cover with the spaco inside the said. annular piece or ring and
connect the same with the suction and delivery passages of the apparatus. This
arrangement which is another important feature of our Invention enables us to
utilize the parts of the vanes inside the annular piece to increase the useful effect
of the said apparatus, the action of the vanes in the interior of the annular piece or
ring being similar to that of the outer portions of the said vanes, that is to say, tho
space inside, and that outside, of the said rings are independent of each other, the
contents of both of theso spaces being discharged three times during one revolution
of the said ring, or during one and a half revolutions of the cam or driver.