IMPROVEMENTS IN DRIVING BY ROPES
Year: 1878

page_text: LETTERS PATENT to James Barbour and Abram Combe, of Belfast, Ireland, for
the Invention of "IMPROVEMENTS IN DRIVING BY ROPES."
PROVISIONAL SPECIFICATION left by the said James Barbour and Abram
Combe at the Office of the Commissioners of Patents on the 18th December
1878.
JAMES BARBOUR and ABRAM COMBE, of Belfast, Ireland.
DRIVING. BY ROPES."
"IMPROVEMENTS IN
The ordinary method of communicating rotary motion by ropes over grooved
pullies consists in placing a number of endless ropes alongside each other in corre-
sponding grooves in pullies, and under certain conditions this arrangement
communicates power satisfactorily; but where the pullies to be connected are
perpendicular or nearly so to each other, or where the centres of the pullies are too
near each other the usual arrangement of a series of separate ropes cannot be used
with satisfaction.
The arrangement constituting this Invention overcomes these difficulties, and
enables the driving by ropes in grooved pullies to be applied in circumstances where
it has hitherto been deemed impracticable or disadvantageous. Moreover, the
crossing of the ropes can be effected without friction of contact between their
running surfaces taking place.
Instead of transmitting the motion from the driving grooved pulley to be driven
grooved pulley by several ropes I use one endless rope, laying the same in two,
three, or more laps around the two grooved pullies which are to be connected
together, and then leading the rope to a tension pulley, which has a single groove
and delivers the rope back to the pulley from which it received it. To facilitate
this guiding of the rope it is convenient to cant the tension pulley, which position
will insure a near approximation to parallelism in the advancing and returning
portions of the rope. When desired, the laps of rope over the many grooved
pulleys may be crossed, thus reversing the direction of motion of the pulley to be
driven.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Barbour and Abram Combe in the Great Seal Patent Office on
the 18th June 1879.
JAMES BARBOUR and ABRAM COMBE, of Belfast, Ireland.
DRIVING BY ROPES."
"IMPROVEMENTS IN
This Invention relates to the use of an endless rope lapped around grooved
pulleys in conjunction with a tension or guide pulley. The method of carrying out
this Invention will be understood from the following description in connection with
the accompanying Drawing, wherein the same letters of reference always apply to
the same or like parts.
Figures 1, 2, and 3 shew an arrangement for driving a pulley mounted above and
adjacent to its driver; Figures 4 and 5 shew an arrangement in which the driven
pulley is mounted above its driver at such distance as to admit of the tension or
guide pulley between them; and Figures 6 and 7 are an example of driving an
adjacent pulley by "crossed" ropes.
To transmit motion from a driving grooved pulley a to the driven grooved
pulley b we use one endless rope c, laying the same in two, three, or more laps
around the two grooved pulleys a and b which are to be connected together, and
then leading the rope c to a tension pulley d, which has a single groove and delivers
the rope c back to the pulley b from which it received it.
To guide the rope c from one groove to the other in the driven pulley b it is
necessary to "cant" the tension pulley d to such a position as will insure a near
approximation to parallelism in the advancing and returning portions of the rope c
in the different positions the tension or guide pulley may assume, according to the
When desired the laps of the rope c over the many grooved pulleys a and b may
be crossed, as in Figures 6 and 7, thus reversing the direction of motion of the
pulley b to be driven.
length of the rope c.
Having now set forth the nature of this Invention of "Improvements in Driving
by Ropes," and explained the manner of carrying the same into effect, we wish it
to be understood that under the above in part recited Letters Patent, we claim,-
The use of an endless rope lapped round a pair of many grooved pullies in
conjunction with a tension or guide pulley, as and for the purpose above explained.
In witness whereof, we, the said James Barbour and Abram Combe, have
hereunto set our hands and seals, the Sixteenth day of June, in the year of
our Lord One thousand eight hundred and seventy nine.
JAMES BARBOUR. (L.S.)
ABRAM COMBE.
(L.S.)