Improvements in Winding Drums for Cable Railways.
Year: 1892

page_text: Date of Application, 23rd Feb., 1892-Accepted, 26th Mar., 1892
COMPLETE SPECIFICATION.
Improvements in Winding Drums for Cable Railways.
I, JOHN WALKER, of Lake Avenue, in the City of Cleveland, State of Ohio,
United States of America, Manufacturer, do hereby declare the nature of my
invention for "IMPROVEMENTS IN WINDING DRUMS FOR CABLE RAILWAYS
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 certain improvements in Letters Patent No. 11073:
granted to me and dated 31st day of July, 1888, for certain improvements in.
drums for cable railways, to which reference should be had.
In the said Letters Patent, the nature and object of the said invention is set
forth in substantially the following words:
"To fully understand the nature of my said invention, it must be known that in
the winding operation, the greatest wear of the drum takes place at the bottom of
the first groove, or the groove which receives the incoming cable.
I find that the
difference in circumference of the various grooves of the drums, caused by
inequality of wear, is the chief cause of the breakage of cables, as for instance,-
if by constant wear, the depth of the first groove is increased one quarter of an
inch, the circumference of the said groove is decreased a little more than one and
a half inches. With this condition of the first groove, the cable in passing from
the first to the second groove, provided the second groove is not worn to any
appreciable extent, has to stretch one and a half inches, or else slide forward that
much in the first groove of the drum.
I obviate this defect by forming all the grooves, except the first one, in peripheral
rings, adapted to turn independently of each other and of the drum. By this
means, any difference in the circumference of the grooves is compensated for by
the independent circumferential movement of the rings, and no strain is placed on.
the cable over and above that to which it is subjected in drawing the cars."
But with drums constructed as above described, the loose rings while they
obviate all difficulties arising from different diameters of grooves, do not at once-
equalize the tension of the cable throughout the various wraps or coils of the
same, when the strain is suddenly increased or reduced by adding to or taking from
the number of cars connected to the cable.
To effect this distribution, I make all the cable grooves in rings adapted to turn
independently of the drum, and dispense with the frictional contact of the rings
with each other and with the flanges of the drum.
To illustrate the advantage of having all the cable grooves in loosely turning.
rings, we will suppose that the normal strain on the cable is 10,000 pounds and
by attaching or detaching the cars, the strain is suddenly raised to 13,000 pounds,
or lowered to 7,000 pounds, the grooved rings adjust themselves circumferentially
on the drums independently of each other until every part of the cable in the
wraps is subjected to the increased or diminished strain. The first grooved ring
will, of course, receive the greatest movement, the others moving until the
increased or diminished strain is distributed.
In other words, if the strain on the cable is increased or diminished, the first.
grooved ring will immediately respond to the change in the tension of the cable by
moving forward or backward on the drum, and the other rings will move
independently of each other so as to distribute the difference in tension throughout
the wraps.
It will be understood that as all the grooved rings are loose, the movement of
the driving drum is communicated to them, and through them to the cable, entirely

page_text: by friction which is at all times automatically applied in proportion to the amount
of work to be done.
In the further description of the said invention, which follows, reference is made
to the accompanying drawing forming a part hereof, and in which,―
Figure 1 is a side elevation of the two winding drums and a portion of the cable,
the latter being reeved according to what is termed, the loop system.
Fig. 2 is a view similar to the preceding one except that the cable is reeved so
as to form what is known as a figure 8.
Fig. 3 is an enlarged cross section of a portion of one of the drums made in
accordance with my invention.
Similar letters of reference indicate similar parts in all the figures.
In the said drawing, A represents the rim, B the hub, and D the arms of the
drums. EE are circumferentially grooved rings placed side by side on the Emooth
periphery of the drums, and all adapted to move independently of each other and
of the drum.
As in Letters Patent No. 11073, the grooved rings are preferably made of
wrought iron or steel which will resist abrasion better than cast iron. The cable
is denoted by F.
G represents the fixed flange and H the loose one secured to the drum proper by
means of bolts, a.
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
claim is :-
1. A driving drum for a cable railway having all its cable grooves in peripheral
rings which are adapted to turn independently of the said drum, combined with a
similar drum, and a cable reeved around the said rings of the two drums
substantially as, and for the purpose specified.
2. A driving drum for a cable railway having all its cable grooves in peripheral
rings which are adapted to turn independently of the said drum, substantially as
and for the purpose specified.
Dated the 21st day of December 1991
JOHN WALKER.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.