Improved Driving Gear for Hand-operated Centrifugal Machines.
Year: 1895

page_text: Date of Application, 24th Sept., 1895-Accepted, 23rd Nov., 1895
Improved Driving Gear for Hand-operated Centrifugal Machines.
I, FRANZ HUGERSHOFF of 28 Albertstrasse, Leipzig, Germany, Manufacturer,
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:-
This invention relates to driving gear for that class of centrifugal machines
operated by hand and which is particularly adapted for the examination of milk
and for promoting and determining the deposit of sediment in sputum, urine, and
the like.
The gear consists essentially of a grooved driving pulley or disc, upon which a
pull cord, belt, or band, can be wound, mounted movably on the vertical shaft of
the centrifugal machine and which is capable of being thrown automatically out of
engagement with a fixed clutch on the driving shaft by means of an elastic medium
such as a spring or the like.
The accompanying drawing shows one method of carrying out my invention.
In this drawing it will be seen that the shaft w of the machine has a grooved
pulley a mounted loosely on it and a clutch c pinned to it. A spiral spring b fitted
on a bolt e inserted in the frame of the apparatus presses a movable sleeve e¹ on the
top of the bolt e against the pulley a and also at the same time presses the latter
against the bracket d. The bottom of the pulley a is provided with a clutch
surface having a projecting tooth a' capable of locking with the tooth c¹ of the
clutch c.
is the ordinary receptacle of the machine and ¹ the cover shown taken off.
In working with the apparatus the cord, belt, or band, is wound, top like, around
the pulley a and is then pulled so as to rotate the apparatus. When the cord is
pulled a downward pressure, sufficient to overcome the resistance of the spring b, is
exerted on the pulley a with the result that it engages with the clutch c, and, as a
consequence, the shaft w is rotated. As soon as the pull on the cord or belt is
relaxed the spring 6 forces the pulley upwards and throws it out of gear. The
connection is subsequently restored in a similar but reverse manner so that the
centrifugal machine can be readily and conveniently operated.
The automatic disconnecting gear can be modified in various ways such as for
instance by having an india rubber pad secured to the shaft w between the pulley a
and the clutch c; or a flat spring acting on the pulley a, instead of the spiral
spring b.
The pulley a can be surrounded with leather or equivalent to prevent the cord or
belt slipping off..
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
consider novel and desire to claim is :-
Driving gear for centrifugal machines operated by hand, consisting of a driving
pulley loosely mounted on the driving shaft and rotated by means of a pull-cord
or belt and which is provided with a clutch at its lower end, a clutch fixed to the
driving shaft, and an elastic medium such as a spring or the like for automatically

page_text: disconnecting t! pulley and clutch whenever the pull on the driving cord or belt
is relaxed, substantially as herein before set forth..
Dated this 23rd day of September 1895.
H. D. FITZPATRICK,
70 Wellington Street, Glasgow,, Agent.