Improvements in and relating to Cable Tramways.
Year: 1890

page_text: Date of Application, 30th July, 1830-Accepted, 30th Aug.,
1890
COMPLETE SPECIFICATION.
Improvements in and relating to Cable Tramways.
I, GEORGE SMITH DUNCAN, of Melbourne Chambers Little Collins Street Melbourne
in the Colony of Victoria Civil Engineer de 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 cable tramways, that is, to those in which the propelling
power is communicated from the engine to the vehicle by means of a cable running in
à tunnel or subway.
Its object is to reduce the constructing and working expenses of such tramways,
first, by lessening the depth of the tunnels or, subways in which the cable travels;
secondly, by allowing the cable to be carried a very short distance above the cable-
supporting or "line pulleys" when the car is being propelled; thirdly, by entirely
freeing the cable from the gripper whilst the car is at rest instead of, as at present,
allowing it to run over sheaves on the lower end of said gripper; fourthly, by
dispensing with the use of elevating sheaves or deviations in the slot beams and track
rails at crossings; fifthly, by enabling the gripping dies or jaws of the gripper to be
adjusted whilst the car is travelling; and sixthly, by dispensing with the labour
involved in chipping and planing the gripping dies and thereby saving considerably
in the maintenance of the grips.
I accomplish these objects-First, by providing such subways or tunnels with
depressible cable-carrying sheaves or pulleys, and Secondly, by a novel construction
of gripper.
The peculiarity of the cable-carrying sheaves or pulleys is, that whilst they are
sufficiently rigid to support the travelling cable they are susceptible of a downward
pressure so as to be pressed below the normal line of said cable and at the same time
are so constructed as that when released from this downward, pressure they will return
to their normal position and will support the cable.
I am enabled to lessen the height to which it is now necessary to raise the cable by
the grippers in order that they may pass freely over the supporting sheaves, partly by
making such sheaves depressible, and partly by a novel construction of gripper which
provides for the impartation of this depressing influence whenever its gripping die is
lowered sufficiently to come into contact with said sheaves.
I am also enabled to dispense-Firstly, with the appliances which are at present
in use for throwing the cable out from between the jaws or gripping dies of the
grippers, and Secondly, with the sheaves or pulleys which are usually mounted upon
the lower end of the gripper to support said cable after it has been so discharged from
between the gripping dies.
According to my invention, I support the haulage rope or cable upon sheaves or
pulleys, which are capable of being depressed by the passage of the gripper over them
in the event of the gripping die of said gripper being lowered sufficiently to contact
with said sheaves, whilst at the same time these latter are normally held in their raised
positions so that they will support the cable either by being counterbalanced or else
by being mounted in vertically sliding bearings supported by spiral or other springs
of sufficient tension to carry the weight of the cable.
In carrying my invention into practice I arrange the lower die of the gripper so
that it can be adjusted to and from the upper fixed die preferably by an arrangement
of levers and links hereinafter described, whereby 1 provide for imparting sufficient
movement with one lever for either lowering the cable onto its supporting sheaves or
for picking it up and gripping it with sufficient force to propel the car along a fairly
level road, whilst with the other I am enabled to grip such cable with considerable
pressure. The construction and arrangement of my improved gripper and cable-

page_text: supporting pulleys will be readily understood from the following description, reference
being had to my drawings, wherein
Figure 1 is a front elevation of my improved gripper for cable tramways, illus-
trating same with its movable gripping die or jaw in its lowest or cable-releasing
position.
Figure 2 is a similar view, but illustrating said gripper as having picked up the
cable, and
Figures 3 and 4 are respectively an end elevation and a plan of said gripper with
its parts in the positions illustrated in Figure 2.
Figure 5 is a side elevation of said gripper, illustrating the parts as they would be
when the cable is tightly gripped, that is, when the main gripping lever has been
operated.
Figure 6 is a side elevation of the lower part of my improved gripper, illustrating
the application of a certain "rubbing and depressing bar" thereto for the purpose of
depressing the cable-supporting pulleys when the movable gripping die is lowered into
its lowest position.
Figure 7 is a vertical transverse section on line 7-7, Figure 6.
Figure 8 is a horizontal section on line 8-8, Figure 6, and
Figure 9 is a horizontal section on line 9-9, Figure 6.
Figures 10 and 11 are respectively a side elevation and an edge view of the shoe
into which the lower end of the main operating lever is fitted, and
Figure 12 is a vertical central section on line 12-12, Figure 10, whilst
Figures 13, 14, and 15 are respectively a side elevation, plan and end elevation of
one of my improved cable-supporting or "line" pulleys, and
Figure 16 is a cross-section of the permanent way of a cable tramway system fitted
with my rocking cable-supporting pulleys and constructed for use with one of my
improved cable grippers.
Similar letters of reference indicate the same parts in all the Figures.
The
A represents the lower gripping die or jaw which is, according to my invention,
either secured to or else is made integral with a central plate a adapted to slide up
and down within the fixed framing B of the gripper in the ordinary manner.
upper part of this central vertically sliding plate a is connected by a pair of links c-c
with a block C which is capable of sliding freely up and down within a groove c¹
formed in the shoe d into which the lower end of the main operating lever D.is fixed
in any convenient manner.
The lower end of the shoed is pivoted at ' to some convenient part of the framing B
of the gripper, whilst the main operating lever D is provided near its upper end with
a small spring-retaining catch d2 adapted to engage in teeth or serrations d³ formed in
the upper surface of a quadrant d secured to the upper part of the fixed framing of
the gripper, somewhat in the ordinary manner.
E represents the cable lowering and picking up lever hereinbefore mentioned,
which said lever is pivoted at e to some convenient part of the framing B preferably
adjacent to the pivoted end of the shoe d. Said lever E is moreover provided at
its lower end with a pair of crank arms.e', which may be formed integral with or may
be secured directly to said lever, or else may be keyed or otherwise secured to the
pin or spindle e upon which said lever turns.
The outer ends of these crank arms e¹ are connected by links e-³ with the
sliding block to which, as above mentioned, the adjustable die carrying plate a is
also connected. The upper end of the cable lowering and picking up lever E is
provided with a small spring-retaining pawl or catch e adapted to engage with the
teeth or serrations et formed in the upper surface of the quadrant e which may if
desired be provided with adjustable stops to limit the movement. of the lever E.
The lower side of the lower gripping die A is by preference rounded off, as
illustrated at a (see Figures 3 and 7) in order to facilitate the picking-up of the
cable. thus sobviating the necessity for forming kinks in the latter wherever it is
desired to lead the cable into or out of the jaws of the gripper, as will be well
:understood.

page_text: Either to the lower end of the vertically sliding plate a, as shown, or else to the
front of the lower gripping die A is secured a pulley depressing or rubbing bar F
which projects from said plate sufficiently far to contact with the upper surface of an
inclined guide G (Vide Figures 13, 14, 15, and 16) secured alongside the cable
supporting pulloys H. These latter are, according to my invention, mounted in suit-
able bearings near one end of a rocking beam I, whose other end is made sufficiently
heavy to keep the pulley-and therefore the cable thereon up to its normal level,
whilst leaving said pulley free to be depressed when required by the passage of the
gripper over it, as hereinafter described. The rocking beam I is mounted in suitable
bearings carried by a frame or casting i, which can readily be secured and supported
within the cable tunnel, as clearly illustrated in Figure 16, according to the height at
which it is required to carry the cable.
The usual manner of employing my invention is as follows:
Assuming the parts to be in the position illustrated in Figure 1, that is, with the
lower die A in its lowest or depressed position and the cable to be running freely
between the two dies and on the cable supporting pulleys, then if it is required to
propel the car it is necessary to operate the cable picking-up lever E, that is, to shift
it into about the position indicated in Figure 2, whereby the die A will raise the
cable into position ready to be gripped by the gripping lever D, as clearly illustrated
in said Figure. With the mechanical advantage obtainable with this lever E, as
hereinbefore mentioned, sufficient grip of the cable may be obtained (provided the
main gripping lever D has been previously placed in about the position indicated in
Figure 5) to propel the car along a fairly level road or even up a slight incline. A
tighter grip of the cable may be obtained with the main gripping lever D if required,
owing to the increased mechanical advantage obtainable."
Ordinarily, I arrange the height of the cable-supporting pulleys H in the tunnels so
that the lower die A of the grippers will pass freely over them when in their raised
position, that is, when gripping the cable as illustrated in full lines in Figure 16.
In the event of the cable being released by lowering the bottom gripping die A the
latter would be liable to contact with the cable supporting pulleys H if the pulley
depressing or rubbing bar F did not contact with the inclined guides G on the sido
of said pulleys, the effect of such contact being to depress such pulley, as indicated
in dotted lines in Figures 13 and 16, thus allowing the lower die A to pass freely
over them without injury. It will be readily understood that the cable when released
by tho gripper will rest upon the line or cable pulleys II, instead of as heretofore
being supported by the lower die of the gripper or running over sheaves or small
pulleys upon the lower end of the gripper itself. By this means much wear and tear
of the cable is prevented, and it is moreover allowed to remain comparatively straight
whilst at work, instead of being caused to assume a wavy" or irregular form as
heretofore.
#
It will be readily understood by all persons skilled in the art to which my
invention relates that I am enabled with my improved gripper to adjust the dies at
any time, even whilst the car is in motion, by means of the cable lowering and
picking up lever E instead of as heretofore having to slack back or tighten up several
set screws and lock nuts. Moreover with my improved gripper I am enabled to
provide sufficient opening between the gripping dies to allow for the passage of a
"bunch" in a "stranded rope, instead of as heretofore occasionally necessitating
the stoppage of the cable in order to release the car therefrom.
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 cable tramway, the employment of a series of sheaves or pulleys (such as H)
placed at intervals within the cable tunnel and normally adapted to support such
cable, whilst free to be depressed by the passage of the gripper over them, substantially
as and for the purposes specified and as illustrated in my drawings.
2. In a cable tramway the employment of a cable-supporting pulley or sheave

page_text: (such as H) mounted in bearings in the end of a counterbalanced rocking beam
(such as I) supported in suitable bearings within the cable tunnel, substantially as
and for the purposes herein described and explained and as illustrated in my
drawings.
5. In a cable tramway the combination with a cable supporting pulley (such as H)
of an inclined guide (such as G) bolted to the side thereof and adapted to be pushed
downward by a depressing or rubbing bar (such as F) connected with the lower die
of the cable gripper, substantially as and for the purposes herein described and
explained and as illustrated in my drawings.
4. A gripper for cable tramways wherein a vertically sliding plate (such as a)
carrying a lower gripping die is connected by links or otherwise to a pair of levers
adapted the one to move such plate and die sufficiently to enable the cable to be
picked up and gripped to a certain extent, whilst the other is so arranged that
considerable pressure may be applied to such cable, the whole being employed without
any throwing-out devices whatever, the cable being simply allowed to pass freely
between the jaws of the gripper when released, substantially as and for the purposes
herein described and explained and as illustrated in my drawings.
5. In a gripper for cable tramways the combination with a lower movable gripping
die (such as A) of a pair of levers (such as D and E) the one being adapted to pick
up and slightly grip the cable, whilst the other enables a tight grip to be obtained,
substantially as and for the purposes specified and as illustrated in my drawings.
6. In a gripper for cable tramways the combination with a lower movable gripping
die or jaw (such as A) of a pair of operating levers (such as D and E) the one having
a block (such as C) arranged to slide up and down within a groove (such as c¹) in
the lower end of said lever, and connected by a pair of links (such as c) with a
vertically sliding plate carrying said lower gripping dic, whilst short crank arms
(such as e¹) on the lower end of the other lever are also connected by links (such
as e²) to said sliding block, substantially as and for the purposes herein described and
explained and as illustrated in my drawings.
7. In a gripper for cable tramways the combination with the lower movable
gripping die (such as A) of a pulley depressing or rubbing bar (such as F), whether
secured to said die or to the lower end of a vertically sliding plate (such as a)
connected therewith, said bar being adapted to ride over an inclined or other guide
(such as G, Figures 13 to 16) secured alongside the cable supporting pulleys,
substantially as and for the purposes herein described and explained and as illustrated
in my drawings.
Dated this Twentieth day of June One thousand eight hundred and ninety.