An Improved Device for Preventing the Slipping of Driving Belts on Quick Running Driving Pulleys.
Year: 1897

page_text: An Improved Device for Preventing the Slipping of Driving Belts on
Quick Running Driving Pulleys.
I, FRANZ SCHEBEN, of Hennef, on the Sieg, in the Empire of Germany, do hereby
declare the nature of this invention to be as follows:-
As is well known in the case of quick running pulleys or shafts the drawback
becomes evident that the belts or straps serving for transmitting the power begin
to slip as soon as a given speed is exceeded. The consequence of this is that
part of the power employed is lost for effective work.
In order to effectively overcome this evil I arrange bolts or tappets in the rim,
so as to project from the periphery as soon as a given speed is exceeded. By this
means the belt or band is stretched, thus preventing any slipping of the same
even at higher speed. To this end a bolt is inserted in a radial boring of the
pulley rim. Said bolt having a thickened head is retained by means of a screwed
in block or a lining in such a way that it can only project to a certain extent
from the periphery of the pulley rim when centrifugal force compels it to do so
on a given limit of speed being exceeded. The desired stretching of the driving
belt then of course takes place, which prevents the slipping of the same. Up
to this limit of speed the bolt or bolts, of which preferably several are arranged
at equal intervals, are pressed inwards by the belt in such a way that they can
exert no deleterious pressure thereon.
The bolt end may be rounded or be suitably shaped to correspond to the bear-
ing surface of the pulley rim.
The bolt may be constantly pressed outwards by means of a spring, the lining
or block being dispensed with. In this arrangement the belt up to a certain
maximum speed is in a position to press the bolt inwards overcoming the pressure
of the spring, whilst after exceeding this maximum speed, centrifugal force assists the
spring so far that the bolt is permanently projected and the belt stretched.
The bolt may also be pivotally suspended at its inner end which is bent to an
angle and be merely left to the action of centrifugal force as in the first examples.
Permanent experiments have shown with the most favourable result that the
arrangement hereinbefore described is equally effective and advantageously appli-
cable for smooth belts or straps as well as for those which are provided with
perforations.
D
DOLL
1007
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.

page_text: An Improved Device for Preventing the Slipping of Driving Belts on
Quick Running Driving Pulleys.
I, FRANZ SCHEBEN, of Hennef, on the Sieg, in the Empire of Germany, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:
1
As is well known in the case of quick running pulleys or shafts the drawback
becomes evident that the belts or straps serving for transmitting the power begin
to slip as soon as a given speed is exceeded. The consequence of this is that part
of the power employed is lost for effective work.
In order to effectively overcome this evil, I arrange bolts or tappets in the rim,
so as to project from the periphery as soon as a given speed is exceeded. By
this means the belt or band is prevented from slipping on the same, even at a
high speed as will be hereinafter explained.
The arrangement is shown in the accompanying drawings:-
Figure 1 being a side view of a belt pulley a fitted with four different arrange-
ments for obtaining this result with a perforated belt;
Figure 2 shows a piece of the perforated or slotted belt.
Figure 3 shows the action of the invention with an unperforated belt.
In the example I, a bolt c is inserted in a radial boring of the pulley rim b.
Said bolt having a thickened head is retained by means of a screwed-in block
or lining d in such a way that it can only project to a certain extent from the
periphery of the pulley rim when centrifugal force compels it to do so on a given
limit of speed being exceeded. The desired grip of the driving belt is attained
by providing the belt with perforations or slots h as shown in Figure 2, into which
slots the bolt c engages when protruded under the action of centrifugal force,
whereby any slipping of the belt is prevented. There are preferably several bolts c
arranged at equal intervals in the rim of the pulley.
As shown by the example indicated by II, the bolt end may be rounded, instead
of as in the previous example I, being suitably shaped to correspond to the bear-
ing surface of the pulley rim b.
As shown by III, the bolt c may be constantly pressed outwards by means of
a spring e, the lining or block d being dispensed with.
As shown by the example indicated by IV, the bolt c may be pivotally sus-
pended at g and bent to an angle and be merely left to the action of centrifugal
force as in the examples I and II.
Permanent experiments have shown with the most favourable result that the
arrangement hereinbefore described is equally effective and advantageously
applicable for unperforated or ordinary belts or straps f as well as for those which
are provided with perforations such as shown in Figure 2.
Figure 3 shows the use of an unperforated belt fi.e. an ordinary belt. In
this case up to a certain speed the belt will keep the bolts c within the rim so that
the pulley will act as an ordinary pulley, but when such speed is exceeded, the
bolts will be protruded or forced radially outwards from the rim to some extent
either by the centrifugal force alone (example IV) or by centrifugal force with the
assistance of a spring e (example III) thereby increasing the diameter of the
pulley so to speak, which has the effect of stretching or tightening the belt and
thus preventing any slipping of the same.

page_text: 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:
A device for preventing the slipping of driving belts or straps on quick running
pulleys or shafts, characterised by the arrangement of bolts or projections (c)
adapted on a given maximum speed being exceeded to be influenced by centri-
fugal force in such a way as to project beyond the periphery of the pulley or shaft
and bear against the belt or strap, or in the case of perforated belts engage in
the perforations thereof, such centrifugal force being capable of being assisted
by the action of a spring substantially as hereinbefore described and shown in
the accompanying drawings.
Dated the 17th
Dana 100%
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.