Improvements in or Applicable to Pumps.
Year: 1888

page_text: COMPLETE SPECIFICATION.
Improvements in or Applicable to Pumps.
I EMIL HEINRICH CONRAD OEHLMANN of 70 Dresdener Str. Berlin in the German
Empire Engineer do hereby declare the nature of my said invention and in what
manner the saine is to be performed to be particularly described and ascertained in
and by the following statement :—
32
In pumps driven by toothed gearing it has not hitherto been possible to obviate
the beating or jarring of the toothed wheels which, particularly after continued
working of the pump, becomes unpleasantly noticeable in consquence of the "racing
of the gear-wheel, mounted on the crankshaft, when the dead centres are being
passed. It has been sought to remedy this by using gearing so made as to give the
least possible play between the teeth engaging with one another but without permanent
success.
Apart from the troublesome noise there was considerable wear of bearings and
journals and in fact of the entire pump, caused by the constant jars and shocks so that
frequent repairs were requisite.
The object of this invention is to remedy these defects and the jarring is prevented
by causing a brake to act continuously upon the toothed wheel on the crankshaft, upon
a disc specially provided for that purpose on the crank shaft, or upon the crankshaft.
directly. By reason of the application of the brake "racing" of the parts can not
take place and the toothed wheels must remain in correct engagement with one
another.
In the accompanying drawings a brake is, by way of example, shown applied directly
upon that gearwheel which is mounted on the crank shaft. This will generally be the
simplest manner of applying this invention as it calls for no alteration of the pumps
itself.
In the accompanying drawings
Fig. 1 shows a pump embodying this invention in front elevation.
Fig. 2 shows a side elevation thereof with the brake-arrangement in section.

page_text: In the example illustrated by the figures the brake device consists in a flat curved
spring fixed on the arm a and provided with lugs c and d for receiving the brake-
block e.
The screw serves for pushing the brake-block e home whilst at the same
time putting tension upon the spring b.
g
It will be readily seen that by the action of the brake upon the wheel / keyed on
the crank shaft 66
racing" of the same is prevented and the teeth must always gear
as shown in fig. 3 that is to say the teeth of the driving wheel i must constantly and
firmly bear with their sides against those of the driven wheel h.
Fig. 4 shows the space formed between the teeth of the wheel and those of wheel i
when the former is "racing." It is apparent that by the
"
racing considerable
shocks must be produced in the gearing. The brake is applied with little force, only
as much as will just prevent "racing."
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that I claim :-
The application of a brake to pumps driven by toothed gearing for the purpose of
preventing the "racing" of the gearwheels, substantially as specified.
Dated this 22nd day of Santambar 1888
BERNHARD DUKES,
226, High Holborn, London, W.C.,
Agent for the Applicant.