Improvements in and relating to Rope Driving Mechanism.
Year: 1894

page_text: Date of Application, 28th Aug., 1894-Accepted, 29th Sept., 1894
COMPLETE SPECIFICATION.
Improvements in and relating to Rope Driving Mechanism.
I, JOSEPH HINSON WEBSTER HOADLEY, a citizen of the United States of
America, residing at 3641 Prairie Avenue in the City of Chicago, County of Cook,
and State of Illinois, one of the United States of America, Mechanical 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 :-
This invention relates to that class of power transmitting mechanism known as
rope-driving gearing, wherein a fibrous rope is wound about grooved drums with a
number of wraps in such a manner as to create traction for transmitting power from
one drum to another, the same as in the case of flat flexible bands, but with
multiplied wraps of a rope that can be varied in number as the amount of power,
or other conditions, may require. The object of the invention is to increase the
efficiency of apparatus of this sort and prevent loss of power. It consists essentially
in means for increasing the traction upon the smaller drum, or in preventing the
rope from slipping thereon, and also in certain details in the construction, arrange-
ment, and combination of parts, substantially as will be hereinafter described and
claimed.
In the annexed drawings illustrating my invention―
Figure 1 is a perspective view of my improved rope-driving apparatus ;
Figure 2 is a top plan view of the same."
Like letters of reference designate like parts in both figures.
In a rope-power mechanism there are commonly two drums, one being the driver
and the other the driven drum, and one being usually somewhat smaller than the
other, said drums being grooved, and having the rope or cable passed around them
with a sufficient number of wraps. In the use of an apparatus with these parts, a
practical difficulty is encountered which detracts from its efficiency. It is found
that the rope will slip more or less upon the smaller drum. This is especially the
case in a large apparatus. When the drums are running at a regular rate of speed,
the smaller druni does not do its full work by reason of the slipping of the rope
thereon, and a consequent loss of power is the result. I aim to avoid this difficulty,
which to my knowledge has never been obviated before, and I do this by increasing
the traction upon the smaller drum, that is to say, I wrap the rope around the
smaller drum a greater number of times than I do around the larger, say twice as
many times, and in order to do this I have to increase the size of the smaller drum,
not diametrically, but between its euds, making it thicker or wider, so that more
grooves may be formed thereon. By thus increasing the surface contact of the
smaller drum with the actuating rope, and consequently increasing the traction on
the smaller drum, I effectually overcome the slipping referred to, and prevent loss
of power, and I accomplish this with only a trifling extra expense in the con-
struction of the apparatus, an expense which is wholly incomparable with the
advantages gained.
A denotes the larger, and B the smaller drum of a rope-driving gearing, D an
idle pulley, and C a tension pulley which acts to take up any slack in the rope.
The rope, as shown, passes around all these pulleys, it being wound upon the two
main drums A and B with a sufficient number of wraps and one wrap being carried
around the pulleys C and D.
The smaller drum B is provided with a larger number of grooves than are formed
in the large drum A, preferably with twice as many. The drum B is therefore
made wider to accommodate the extra grooves. The rope is consequently wound

page_text: with twice as many wraps on drum B as on drum A. a denotes that part of the
rope which passes with five wraps (for instance) as shown, around drums A and B,
and 6 that part of the rope which passes with five more wraps around drum B and
an extra drum E located a short distance from drum B to permit this extra wrapping
of the rope around drum B. The part c of the rope passes around the pulleys C
and D with one wrap leading preferably from drum A to pulley C and from
pulley D to drum B and thence on to drum E, and so on. Thus the rope or cable
is arranged so as to have a much larger area of frictional contact with the surface
of drum B than it has with drum A, so far as the widths of the two drums is
concerned, and thus the slipping of the rope upon the smaller drum is effectively
avoided.
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 what I
claim is :-
1. In a rope driving apparatus, the combination of the driving and driven
drums, one of which is larger than the other, the rope wound with a larger number
of wraps upon the smaller drum, and a third drum arranged in connection with the
smaller drum to receive the extra wraps of the rope, all being arranged so that the
rope may have a larger area of frictional contact with the surface of the smaller
drum than it has with the surface of the larger drum so as to prevent the slipping
of the rope upon the smaller drum, substantially as described.
2. In a rope driving apparatus, the combination of the driving and driven drums
one of which is larger than the other, the rope wound in a larger number of wraps
upon the smaller drum, a third drum located adjacent to the smaller drum for the
purpose of receiving the extra wraps of the rope so that the rope may be thus
arranged to have a much larger area of frictional contact with the surface of the
smaller drum than it has with the surface of the larger drum so as to avoid the
slipping of the rope upon the smaller drum, the idle pulley, and the tension pulley,
likewise receiving the rope which passes around all of the drums, substantially in
the manner and for the purpose set forth.
3. The combination of the driving and driven drums the rope wound in a larger
number of wraps upon the smaller drum, a third drum for receiving the extra wraps,
the idle pulley, and the tension pulley, substantially as described.
Dated this 00th day of August 1801
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.