IMPROVEMENTS IN DRUMS FOR CABLE RAILWAYS
Year: 1888

page_text: I, JOHN WALKER, of the City of Cleveland, in the County of Cayahoga, and State
of Ohio, United States of America, Manufacturer, do hereby declare the nature of
my invention for "IMPROVEMENTS IN 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 the construction of the driving
drums around which the cable is wound, as will hereinafter fully appear.
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. 1 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 that much on 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 inde-
pendent 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.
In the further description of the said invention which follows, reference is made to.
the accompanying drawings 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 preceeding one, except that the cable is reeved so as to form what
is known as a Figure 8.

page_text: -
Figure 3 is an enlarged cross section of a portion of a drum, as nsually constructed,
that is to say, with the grooves formed in the rim of the drum. Figs. 4 and 5,
are sectional views of the druin made in accordance with my invention, as will herein-
after appear.
Similar letters of reference indicate similar parts in all the Figures.
In the said drawing, A, represents the rin, B, the hub, and D the arms of the
drum. The grooves are denoted by a, and by reference to Fig. 3, which as before
stated, shows a drum of ordinary construction, it will be seen that the grooves are
formed in the rim which is a fixed part of the drum. In Fig. 4, the grooves, a, are
formed in rings, c, which are placed side by side on the smooth periphery of the drum.
The ring containing the first groove, is attached to the flange, d, by means of bolts,
one of which is shown and denoted by, e, while the other rings are loose and thereby
adapted to inove independently of the first ring, and of each other. To allow of the
loose rings being placed in position on the periphery of the drum, the other flange, g,
is made loose and secured to the rim by means of bolts, h, and in order to make the
contact sides of the-rings frictional surfaces, and to compensate for wear of the said
surfaces, I leave a space between the flange, g, and the adjoining face of the rim, as
shown in Figs. 4 and 5.
The said rings, are by preference, made of wrought iron or steel which will resist
abrasion better than cast iron.
In Fig. 5, the first groove is cast in the rim of the druni, but the other grooves are
formed in independent rings, as shown in Fig. 4. The construction shown in Fig. 5,
saves the expense of making the first ring, and securing it in place but the objection
to a cast iron surface still exists.
Supposing that in course of time, a drum made in accordance with my invention
should wear so that the first groove be deepened, say, one quartor, the second, one
eighth, and the third, one sixteenth of an inch; in the winding operation, the first
loose ring will move circumferentially of the drum, three quarters, and the second,
three eighths of an inch, and no additional strain will be placed on the cable.
It is evident that both drums should bo provided-with-loose-rings as-described...
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. A grooved driving drum for a cable railway, having the first of the series of
grooves formed in a stationary or fixed part of the drum, and the remaining ones in
rings adapted to turn on, and independently of, the said drum, combined with a
second grooved drum, all the grooves of the two drums being of a practically common
diameter, and a cable reeved around so as to connect the said drums, substantially
as, and for the purpose specified.
2. A driving drum having a series of grooved peripheral rings in contact with each
other, 'and adapted to turn on the surface of the drum, and a removably secured flange,
substantially as, and for the purpose specified.
Dated this 2nd day of Tule 1000