IMPROVEMENTS IN COMPOUND PUMPS FOR AIR in
Year: 1882

page_text: LETTERS PATENT to Hermann Egells, Councilor of Commerce, and Wilhelm
Adolph Kux, Engineer both of Berlin Prussia Managing Directors of the
"Internationaler Vacuum-Eis-Maschinen-Verein," Berlin Prussia German
Empire for an invention of "IMPROVEMENTS IN COMPOUND PUMPS FOR AIR
in vi
PROVISIONAL SPECIFICATION left by the said Hermann Egells and
Wilhelm Adolph Kux at the Office of the Commissioners of Patents on the
22nd May 1882.
HERMANN EGELLS councilor of commerce, and WILHELM ADOLPH KUX,
Engineer, both of Berlin, Prussia, managing directors of the "Internationaler
Vacuum-Eis-Maschinen-Verein," Berlin, Prussia, German Empire, "IMPROVEMENTS
IN COMPOUND PUMPS FOR AIR AND VAPOUR"
Our invention relates to the compound pump for air and vapour described in
the Specification of the English patent A.D. 1880 No 1801, and which comprises
two cooperating pumps of different capacity; and the improvement consists in so
constructing the operating mechanism of these pumps that either of them may be
operated independently of the other one.
In the said compound pump as hitherto executed, the pistons of the two pumps
are connected to a common working beam in such a manner that both pumps
always operate together. In some cases it may, however, be desired to use at times
but one pump, and for this purpose we at present construct the compound pump in
such a manner, that each single pump may with facility be stopped, while the
other one continues to work.
Each pump may, for instance, be driven by a separate motor; or motion is
conveyed from a line of shafting to each of thein by means of pulleys and a strap
arranged to be shifted from a fixed pulley to a loose one; or they are each operated
separately by the medium of disengaging-couplings, friction-wheels, or other known

page_text: disengaging-gear. When both pumps are driven by the same working-beam, the
parts inserted between the beam and either piston, may be so constructed as to
slide in or upon each other when a cotter is withdrawn, while the connection is
established when the cotter is put in its place. The latter arrangement may
also be used in combination with other means of transmission of motion to the
pumps.
When a condenser is to be combined with the pumps, the same may be arranged
to surround the small pump as formerly; but in some cases it will be preferable to
place a condenser of any suitable kind between the two pumps.
The pumps, instead of having different capacity, may be of the same size; but
in this case one of them must work faster than the other.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Hermann Egells and Wilhelm Adolph Kux in the Great Seal Patent
Office on the 14th November 1882.
"
HERMANN EGELLS, Councillor of Commerce, and WILHELM ADOLPH KUX,
Internationaler
Engineer, both of Berlin, Prussia, managing directors of the
"IMPROVEMENTS
Vacuum-Eismaschinen-Verein," Berlin Prussia, German Empire
IN COMPOUND PUMPS FOR AIR AND VAPOUR
"
Our invention relates to the compound pump for air and vapour described in the
specification of the English patent A.D. 1880 No 1801, and which comprises two
cooperating pumps of different capacity; and the improvement consists in so
constructing the driving mechanism of these pumps that either of them may be
operated independently of the other one.
In the said compound pump as hitherto executed, the pistons of the two pumps
are connected to a common working beam so that both pumps always operate
together. In some cases it may, however, be desired to use, at times, but one
pump, and for this purpose we construct the compound pump in such a manner
that each single pump may be stopped while the other one continues to work.
Motion may for instance be conveyed to either pump from a common driving
shaft by means of pulleys and straps, the latter being arranged to be shifted from a
fixed pulley to a loose one. This system is represented in Figs. 1 and 2 of the
annexed sheet of drawings, where the large pump A is operated by the pulleys k
and c and the strap a, the small pump B by the pulleys and d and the strap b,
the pulleys and 7 being keyed on the same shaft S, while loose pulleys together
with means for shifting the straps are combined with the pulleys c and d in the
well known manner. Instead of this arrangement the disengaging device may,
however, also consist in a cotter f, shown in connection with the large pump, and
by which the crosshead,e is secured to the piston-rod. This cotter being withdrawn,
the crosshead will slide on the piston-rod, the pump consequently remaining at
rest. Moreover, a disengaging coupling of any kind may be employed to connect
either of the two driving pulleys of one or of both pumps with the respective shafts.
Also friction wheels with disengaging arrangement might be made use of. We do
not, however, limit ourselves to the devices mentioned, as there may be other
known connecting and disconnecting means suitable for the purpose in question.
Fig. 3 shows an arrangement in which both pumps are driven by the same
working beam. The piston-rod of the pump A is, in this case, coupled to the
crosshead e by means of a removable cotter f, as in Figs. 1 and 2. In the pump B
the disengaging arrangement differs, from the latter only in so far as the rod con-
veying motion from the beam D to the piston, consists of a tubular part i and a
solid part h inserted into i and adapted to slide therein, the connection of the two
O parts being again made by a cotter, f¹.
5
0
The two pumps may also be driven by separate motors. This mode of working
not only allows either pump to be stopped or started independently of the other
one, but under certain conditions it also affords facilities in varying the speed of
either one of them.
According to Fig. 1 a condenser C is combined with the pump B in the manner
described in the specification of the aforesaid English Patent. The condenser might,
however, also be placed at any point between the two pumps, as is shown in Fig. 2,
where the condenser is marked by the letter C¹. When the pumps are driven at
different speeds, the condenser also acts as receiver.
If at the beginning of every evacuating operation, and until the deep vacuum is

page_text: required, the large pump is kept stopped, the return or relief-valve described in
the said specification is not required.
In order to attain a difference in the total working capacity of the two pumps A
and B, it is not necessary that their capacity be equal for every stroke. They may
indeed be alike in this respect; but, in such case, the working speed of A must be
greater than the speed of B, as the total capacity of A, i.e. the capacity for any
given amount of time, will thereby also be rendered superior to that of B.
Having thus described the nature and object of this invention, and the manner,
in which it is to be carried out in practice, we hereby claim:
The combination with a receptacle in which a vacuum is to be created, of a
pump A drawing air and vapour from the said receptacle, and of a pump B of
smaller total capacity than A, and arranged to receive air and vapour from A, in
order to discharge them into the surrounding air, the pumps being so connected
with the driving machinery that one of them may work while the other is stopping,
substantially as and for the purpose described.
In Witness whereof we, the said Hermann Egells and Wilhelm Adolph
Kux, have hereunto set our hands and seals this ninth day of November
in the year of Our Lord One thousand eight hundred and eighty two.