A NEW OR IMPROVED METHOD OF PREVENTING BACKWARD MOTION OF TOOTHED WHEELS USED IN PULLEY-BLOCKS AND IN OTHER CONTRIVANCES FOR LIFTING LOADS, ALSO OF REDUCING THE FRICTION OF SUCH WHEELS WHEN IN USE
Year: 1879

page_text: LETTERS PATENT to Carl Kesseler, of 63, Mohrenstrasse, Berlin, W., in the
Empire of Germany, Civil Engineer and Patent Solicitor, for the Invention
of "A NEW OR IMPROVED METHOD OF PREVENTING BACKWARD MOTION OF
TOOTHED WHEELS USED IN PULLEY-BLOCKS AND IN OTHER CONTRIVANCES FOR
LIFTING LOADS, ALSO OF REDUCING THE FRICTION OF SUCH WHEELS WHEN IN
USE." A communication from Ernst Brauer, of Berlin, Prussia, German
Empire
Sealed the 9th April 1880, and dated the 22nd October 1879.
PROVISIONAL SPECIFICATION left by the said Carl Kesseler at the Office
of the Commissioners of Patents on the 22nd October 1879.
CARL KESSELER, of 63, Mohrenstrasse, Berlin, W., in the Empire of Germany,
Civil Engineer and Patent Solicitor. "A NEW OR IMPROVED METHOD OF
PREVENTING BACKWARD MOTION OF TOOTHED WHEELS USED IN PULLEY-BLOCKS
AND IN OTHER CONTRIVANCES FOR LIFTING LOADS, ALSO OF REDUCING THE FRICTION
OF SUCH WHEELS WHEN IN USE." [A communication from Ernst Brauer, of Berlin,
Prussia, German Empire.]
The object of this Invention is to check or stay the retrograde motion of toothed
wheels used in appliances for lifting loads, and to reduce the friction thereof when
in operation.
To effect this object two toothed wheels are mounted, say, one, the smallest or
operating wheel is provided with 5 teeth, and the other or operated wheel is made
with 20 teeth; the teeth of the small wheel are set a little further apart than
those of the larger or operated wheel. This arrangement of the teeth causes the
relative circular motion of the two wheels to vary or be interrupted, because, while
the small operating wheel turns uniformly, the large operated wheel has periodically
a momentary stoppage.
When in action only one tooth of the small wheel comes between and acts upon
the teeth of the larger wheel; when the flat face of this small-wheel tooth comes in
contact with the shoulder of the large-wheel tooth, which it has been forcing round,
it acts simply as a stay or stop to the large wheel and preventing any backward
movement thereof; during the time occupied by the said flat face of the small-
wheel tooth moving past or over the said shoulder of the large-wheel tooth the
next following tooth of the small wheel reaches and comes in contact with the
next following tooth of the large wheel, which latter is thereby forced round, and
the operation previously described is repeated, and so on of all the teeth con-
tinuously. It will be seen that by the said relative arrangement of the teeth of
the two wheels the area of contact of such teeth on each other is limited to one
tooth on each wheel at the same time or thereabouts, by which arrangement much
friction, "wear and tear," and labour are saved.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent nieu
by the said Carl Kesseler in the Great Seal Patent Office on the 19th April
1880.
CARL KESSELER, of 63, Mohrenstrasse, Berlin, W., in the Empire of Germany,
Civil Engineer and Patent Solicitor. "A NEW OR IMPROVED METHOD OF
PREVENTING BACKWARD MOTION OF TOOTHED WHEELS USED IN PULLEY-BLOCKS
AND IN OTHER CONTRIVANCES FOR LIFTING LOADS, ALSO OF REDUCING THE FRICTION
OF SUCH WHEELS WHEN IN USE." A communication from Ernst Brauer, of Berlin,
Prussia, German Empire.
The object of this Invention is to check or stay retrograde motion of toothed
wheels used in appliances or machinery for lifting loads, and to reduce the friction
thereof when in operation.
In order that the said Invention may be more fully understood and be more
readily performed, I will explain the same with the aid of the accompanying
Drawing which forms part of this Specification, reference being made thereto by
the numerals and letters marked thereon; the same index letters refer to the same
parts in each Figure of the said Drawing.
Figs. 1 and 2 each represent a larger wheel of 20 teeth geared with a smaller
one of 5 teeth.
In Fig. 1 the tooth a of the smaller or operating wheel acts on or against the
tooth b of the larger or operated wheel in the same manner as with ordinary
toothed wheels, whereas in Fig. 2 a relative position of the said teeth is attained
which cannot occur with ordinary wheels. In this position the flank of the tooth b
comes in contact with the outer end or face of the tooth a, and as a perpendicular
line drawn from the centre of such face passes through the centre A of the said
smaller wheel, the normal pressure between the two teeth cannot produce rotary
motion in either wheel. The tooth a has therefore assumed the nature of a catch
or stop, and the larger wheel has become a stopping wheel, similarly to that of a
wheel and ratchet. Immediately after this position is established the tooth al of
the operating wheel, the motion of which continues, reaches the tooth b¹ (which has
been stationary during the period of stoppage,) moves it onward, and then the
position, shown in Fig. 1, repeats itself, and so on.
This process is mainly brought about by making the divisions of the operating
wheel somewhat larger than those of the operated wheel; as a consequence of this
arrangement the relative velocity of the two wheels somewhat differs, because,
while the operating wheel is turning uniformly, the operated wheel first takes the
same circular velocity and then is momentarily stationary,
In cases of slow motion, such as is usual for lifting-gear moved by hand, the
want of strict uniformity in the motion of the said wheel is without perceptible
disadvantage,, and when great speed is attained the irregularity is scarcely
apparent.
This improved apparatus can be applied to all kinds of lifting gear and stopping
contrivances, especially to pulley-blocks, whether the motive power used acts
vertically, horizontally, or obliquely.
Having thus fully described and ascertained the nature of the said Invention,
and the method of performing the same, I wish it to be understood that I do not
restrict myself to the precise details and forms now described, as they admit of
variation without departing from the main characteristics of the Invention; for
instance, the said wheels may either be cylindrical, conical, or hyperbolical in form,

page_text: or as rack and pinion; but I claim as novel, and desire to secure by the before-
mentioned in part recited Letters Patent,―
The method of preventing or stopping the backward motion of the main or
operated toothed wheel in hoisting or hauling machinery or apparatus, substantially
as herein described.
In witness whereof, I, the said Carl Kesseler, have hereunto set my hand
and seal, this Sixteenth day of April, in the year of our Lord One thousand
eight hundred and eighty.