Improvements in Pumps.
Year: 1891

page_text: Date of Application, 22nd July, 1891
Complete Specification Left, 19th May, 1892-Accepted, 18th June, 1892
PROVISIONAL SPECIFICATION.
Improvements in Pumps.
I, FERDINAND STRNAD, of 1, Alexanderstrasse, Augsburg, in the Empire of
Germany, Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to pumps for liquids or gases (vacuum pumps, air pumps
for steam engines and evaporating apparatus, high pressure pumps), and comprises
more especially a distributing device for such pumps.
According to the said invention I combine a circular slide valve such as for
instance a Corliss slide valve, or a cuck with a flap or other valve, which is arranged
so as to enable it to open automatically towards the delivery chamber or delivery
pipe of the pump, if during the forcing-stroke the pressure in the cylinder reaches
or exceeds that in the delivery chamber or delivery pipe. The commencement and
termination of the period of suction, and the termination of the period of delivery
are caused by positive motion through the medium of the circular slide valve or
cock itself, and as the closing of the said flap or other valve has no effect upon the
distribution of the gas or liquid, it may be retarded at will.
Dated the Twentieth day of July 1891.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Pumps.
I, FERDINAND STRNAD, of 1, Alexanderstrasse, Augsburg, in the Empire of
Germany, Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
My invention relates to pumps for liquids or gases (vacuum pumps, air pumps
for steam engines and evaporating apparatus, high pressure pumps), and comprises
more especially a distributing device for such pumps.
According to the said invention I combine a circular slide valve such as for
instance a Corliss slide valve, or a cock with a flap or other valve, which is arranged
so as to enable it to open automatically towards the delivery chamber or delivery
pipe of the pump, if during the forcing-stroke the pressure in the cylinder reaches
or exceeds that in the delivery chamber or delivery pipe. The commencement and
termination of the period of suction, and the termination of the period of delivery
are caused by positive motion through the medium of the circular slide valve or
cock itself, and as the closing of the said flap or other valve has no effect upon the
distribution of the gas or liquid, it may be retarded at will.
In order to make this Specification more easily intelligible I refer to the
accompanying drawings in which similar letters denote similar parts throughout
the several views.
Fig. 1 shows the device as applied to a cylinder having the valves situated

page_text: by means of which the cylinder is brought into communication with the pressure
chamber D of the pump, is provided with a cover or flap or valve k, held down on
the said port by means of a spring f
The device operates in the following manner :-
At the pressure stroke of the piston, the port d of the circular slide valve R corre-
sponds with the port of the cylinder C, so that as soon as the pressure in the cylinder
exceeds that in the delivery chamber D, the flap or valve & will be opened. As
however the commencement and termination of the period of suction as also the
termination of the period of delivery, are caused by the positive motion of the
circular valve R, the flap or valve k, having no further influence on the distribution
of the gas or liquid is free to close under the influence of its spring, and may be
retarded at will, thus enabling a perfectly noiseless closure of said valve, even in
machines running at a high speed.
Fig. 4 shows a modified form of valve & in which the valve is guided vertically
and pressed down on its seat by means of a spiral spring f.
I wish it to be clearly understood that I do not confine myself to any particular
form of valve, and it is obvious that more than one valve may be employed without
departing from the spirit of my invention.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what I
claim is :
1. The combination with a circular slide valve of a cover, flap or valve, to close
the delivery port, said valve adapted to open when the pressure in the cylinder
exceeds that in the delivery chamber and to close after the delivery port has been
closed by the positive motion of the circular valve, substantially as described.
2. The combination with the delivery port of a circular slide valve of a spring
actuated cover valve or flap adapted to open when the pressure in the cylinder
exceeds that in the delivery chamber substantially as described.
Deted the 10th day of May 1892.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.