Improvements in Grippers for Vehicles Propelled by Rope Traction.
Year: 1893

page_text: Date of Application, 17th Mar., 1893
Complete Specification Left, 15th Dec., 1893-Accepted, 10th Feb., 1894
PROVISIONAL SPECIFICATION.
[Communicated from abroad by GEORGE SEXTON EVANS, of Sunny Lodge, North
Rond, Elstenwick, Melbourne, Victoria, Australia, Engineer.]
Improvements in Grippers for Vehicles Propelled by Rope Traction.
I, OLIVER IMRAY, of No. 28, Southampton Buildings, Chancery Lane, in the
County of London, Chartered Patent Agent, do hereby declare the nature of this
invention to be as follows:-
In propelling vehicles by rope traction by means of grippers fixed to the vehicles
which seize the travelling rope, it has heretofore been necessary to make the
traction rope much larger and heavier than is actually required for affording the
necessary strength for haulage, on account of the considerable wear to which the rope is
subjected by the different forms of grippers at present employed, these being so
constructed that in order to start the vehicle without detrimental jerk or strain on
the rope it is necessary to allow the travelling rope to slide with considerable and
gradually increasing friction between the rough surfaces of the gradually closing
jaws of the gripper, until the vehicle has attained the same speed as the rope, or
nearly so.
The damage thus done to the rope also leads to many other serious evils, such as
the bunching of the strands, choking of the grippers &c. resulting in stoppage of
the traffic and accidents of various kinds.
According to my present invention I obviate these several defects by a con
struction of gripper which will permit of the vehicle being brought gradually from
a state of rest to a speed equal to that of the rope, practically without causing any
friction between the gripper and the rope.
For this purpose the fixed framing of the gripper carries two grooved rollers
whose horizontal axes are situated in one and the same plane in such a position that
the traction rope passes along over the top of the grooves of both rollers.
Between these rollers is a third grooved roller mounted on a bar sliding in
vertical guides on the gripper frame and provided with suitable gearing within the
vehicle, such as a rack and toothed quadrant, screw gear, and the like, whereby the
bar with the third roller can either be raised up above the two fixed rollers or be
forced down between them. Thus when the middle roller is in the raised position,
the traction rope passes free through the gripper, leaving this and the vehicle
stationary; when the vehicle has to be started, the middle roller is gradually forced
down on to the rope so as to bend it down between the two fixed rollers, so that the
rope in thus meeting a gradually increasing resistance to its passage through the
rollers, will commence to drag the gripper and vehicle along with it at a slow initial
speed, while at the same time the rope, in passing between the rollers at a greater
speed, will cause these to rotate on their axes, so that only rolling friction will
occur between them.
As the middle roller is forced farther down so as to increase the bend of the
rope, the resistance to its passage through the gripper will increase in proportion,
until such resistance equals the force required for hauling the vehicle along at the
same speed as the rope.
When it is desired to stop the vehicle, the middle roller is raised again so as to
free the rope from the hold of the gripper, whereupon the vehicle is stopped by the
brakes in the usual manner.
The above described rollers are mounted on pins projecting from one side of the
gripper frame and sliding bar, and the latter carries, at a certain distance below its

page_text: pulley a projection or stud which, when the bar is sufficiently raised for the purpose,
will lift the rope out of the grooves of the fixed pullies so as to throw it off the
gripper, where required at crossing- &c.
With the above described construction the additional advantages are gained that
as the gripper occupies very little space in the rope tunnel "as compared with
ordinary grippers, very sharp curves can be employed, and the rope tunnel can be
made comparatively sinall, so that it can be readily constructed as a box girder of
limited dimensions. A guard is provided on the sliding bar for preventing the
rope from running of the rollers at curves.
Dated this 17th day of March 189R
ABEL & IMRAY.
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Grippers for Vehicles Propelled by Rope Traction.
1, OLIVER IMRAY, of No. 28, Southampton Buildings, Chancery Lane, in the
County of London, Chartered Patent Agent, 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:-
to which
In propelling vehicles by rope traction by means of grippers fixed to the vehicles
which seize the travelling rope, it has heretofore been necessary to make the
traction rope much larger and heavier than is netually required for affording the
necessary strength for haulage, on account of the considerable wear
the rope is subjected by the different forms of grippers at present employed, these
being su constructed that, in order to start the vehiële without detrimental jerk or
strain on the rope, it is necessary to allow the travelling rope to slide with
considerable and gradually increasing friction between the rough surfaces of the
gradually closing jaws of the gripper, until the vehicle has attained the same speel
as the rope, or nearly so.
The damage thus done to the rope also leads to many other serious evils, such as
the bunching of the strands, choking of the grippers &c. resulting in stoppage of
the traffic and accidents of various kinds.
According to my present invention I obviate these several defects by a
construction of gripper which will permit of the vehicle being brought gradually
from a state of rest to a speed equal to that of the rope, practically without causing
any friction between the gripper and the rope.
For this purpose, as shown in front view Fig. 1 and side views Figs. 2 and 3 of
the accompanying drawings, the fixed framing D, F of the gripper carries two
grooved rollers A, C, whose horizontal axes are situated in one and the same plane,
in such a position that the traction rope passes along over the top of the grooves of
both rollers.
Between these rollers is a third grooved roller B mounted on a bar E sliding in
vertical guides on the gripper frame and provided with suitable gearing within the
vehicle, such as a rack G and toothel quadrant II or it might be screw gear, or the
like, whereby the bar E with the roller B can either be raised up above the two
lixed rollers A Cor forced down more or less between them as shewn in side view
Fig. 2. Thus, when the middle roller B is in the raised position, as shewn in side
view Fig. 3, the traction rope passes free through the gripper, leaving this and the
vehicle stationary; when the vehicle has to be started, the middle roller B is
gradually forced down on to the rope so as to bend it down between the two fixed
rollers A, C, so that the rope, in thus meeting a gradually increasing resistance to
its passage through the rollers, will commence to drag the gripper and vehicle
along with it at a slow initial speed, while at the same time the rope in pussing

page_text: between the rollers at a greater speed, will cause these to rotate on their axes, so
that only rolling friction will occur between them.
As the middle roller is forced farther down so ns to increase the bend of the
rope, the resistance to its passage through the gripper will increase in proportion,
until such resistance equals the force required for hauling the vehicle along at the
same speed as the rope.
When it is desired to stop the vehicle, the middle roller is raised again so as to
free the rope from the hold of the gripper, whereupon the vehicle is stopped by the
brakes in the usual manner.
The above described rollers are mounted on pins projecting from one side of the
gripper frame and sliding bar E, and the latter carries, at a certain distance below
its pulley a projection or inclined stud N which, when the bar is sufficiently raised
for the purpose, will lift the rope out of the grooves of the fixed pullies, so as to
throw it off the gripper where required at crossings &c.
With the above described construction, the additional advantages are gained that,
as the gripper occupies very little spaec in the rope tunnel as compared with
ordinary grippers, very sharp curves can be employed, and the rope tunnel can be
made comparatively small, so that it can be readily constructed as a box girder of
limited dimensions.
To prevent the roller B from being pushed too far down by a careless operator,
shields T T' above and S S' below the rope may be provided as shewn in Figs. 2
and 4.
Having now particularly described and ascertained the nature of this inven-
tion and in what mauner the same is to be performed, 1 declare that what I
claim is :-
:-
A rope gripper for a vehicle propelled by rope traction, consisting of two grooved
rollers mounted under the rope and an intermediate grooved roller above the rope,
which can be more or less depressed to bend the rope, substantially as and for the
purpose set forth.
Dated this 15th day of December 1893.
ABEL & IMRAY,
Agents for the Applicant.