Improvements in Variable-speed and Reversing Mechanism for Gas, or Vapor, or other Motors.
Year: 1893

page_text: Date of Application, 12th Apr., 1893
Complete Specification Left, 10th Feb., 1893-Accepted, 17th Mar., 1893
PROVISIONAL SPECIFICATION.
Improvements in Variable-speed and Reversing Mechanism for Gas,
or Vapor, or other Motors.
I, PETER BURT, of Mountblue Engineering Works, Camlachie, Glasgow, in
the County of Lanark, North Britain, Engineer, do hereby declare the nature of
this invention to be as follows, that is to say :-
My said invention has for its object to provide in connection with a gas or other
motor improved mechanism by means, of which the motion transmitted from the
motor may be easily, quickly, and conveniently, changed in speed or in direction.
An important application of my invention is for railway or tramway or common-
road locomotives or carriages driven by means of gas or vapor motors; it may
however be advantageously applied for various other purposes.
In carrying out my invention according to one modification I arrange the motor
to drive a crank shaft or first-motion shaft, which is horizontal and, in the case of
a tramway car or locomotive is disposed longitudinally thereon.
The shaft is
between two disks which are on short transverse shafts held in suitable bearings;
and these disks are made on the sides facing each other each with two bevilled
annular surfaces at different distances from the centre, there being annular concave
parts between the two bevilled surfaces. The said bevilled surfaces are designed
to be acted frictionally upon by conical driving pulleys on the crank shaft, there
being four of such pulleys, two on each side of the centres of the disks. The
pulleys are fitted on the shaft with tubular bosses or sleeves and with grooves and
feathers or keys, so as whilst turning with the shaft to be adjustable along it; and
means are provided for putting any one of the four pulleys into driving contact
with the disks. Each pulley is adjusted by means of a groove formed around the
tubular boss, there engaging in the groove a ring or part ring formed or fixed on a
boss which is internally screwed and is upon a screwed part of a horizontal shaft
parallel to the crank shaft. There are two such horizontal shafts, one for adjusting
the two pulleys at one side of the disks and the other for adjusting the two pulleys
at the other side of the disks; and these two horizontal adjusting shafts can be
turned by handwheels operating through bevil gearing, or in any other convenient
way. The two screwed parts of each adjusting shaft are right-handed for one
pulley and left-handed for the other, so that the turning of the shaft moves the
two pulleys in opposite directions. In the middle positions of either pair of pulleys
neither pulley of a pair is in contact with the disks; and on turning an adjusting
shaft in one direction the outer pulley is moved into contact with the outer bevilled
surfaces of the disks and drives the disks at a slow speed; but if the adjusting
shaft is turned in the opposite direction the outer pulley is moved out of contact,
and the inner pulley is moved into contact with the inner bevilled surfaces of the
disks and drives the disks at a quicker speed. The disks rotate oppositely to each
other, but the directions of their rotations are reversed by adjusting a driving
pulley at one side of their centres to act on them, instead of a driving pulley at the
other side. The resistance of the disks to the necessary driving pressure of the
pulleys is provided for in the bearings of the shafts of the disks, friction being
reduced either by ball bearings or by antifriction rollers applied to the outer sides
of the disks opposite the part at which the driving pulleys act on them.
In the case of a tramway locomotive or car, motion is transmitted to the wheel
axles from the shafts of the disks by means of sprocket wheels and pitch chains,
the motion of one disk shaft being communicated through a pair of pinions so as to
act in the same direction as that of the other disk shaft.

page_text: If desired the disks may be made with three bevilled annular surfaces for three
different speeds instead of two, the driving pulleys and their adjusting mechanism
being suitably modified.
Dated this Flavanth day of Anril 1902
EDMUND HUNT,
Applicant's Agent.
COMPLETE SPECIFICATION.
Improvements in Variable-speed and Reversing Mechanism for Gas,
or Vapor, or other Motors.
I, PETER BURT, of Mountblue Engineering Works, Camlachie, in the County
of the City of Glasgow, North Britain, Engineer, 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, that is to say :-
My said invention has for its object to provide in connection with a gas or
vapor or other motor improved mechanism by means of which the motion transmitted
from the notor may be easily, quickly, and conveniently changed in speed or in
direction. An important application of my invention is for railway, or tramway,
or common-road locomotives or carriages driven by means of gas or vapor motors;
it may however be advantageously applied for various other purposes.
In carrying out my invention according to one modification I arrange the motor
to drive a crank shaft or first-motion shaft which is horizontal, and, in the case of
a tramway car or locomotive, is disposed longitudinally thereon. The shaft is
between two disks or transverse shafts and made with two bevilled annular
surfaces at different distances from the centre, designed to be acted frictionally on
by conical driving pulleys on the crank shaft, there being four of such pulleys,
two on each side of the centres of the disks. By means of hand wheels and
gearing any one of the four driving pulleys can be put into contact with its proper
disk surface, whereupon the disks will be driven in opposite directions at a quick
or slow speed, and so as to propel the car in one direction or the opposite.
In the case of a tramway locomotive or car, motion is transmitted to the wheel
axles from the shafts of the disks by means of sprocket wheels and pitch chains,
the motion of one disk shaft being communicated through a pair of pinions so as
to act in the same direction as that of the other disk shaft.
If desired the disks may be made with three bevilled annular surfaces for three
different speeds instead of two, the driving pulleys and their adjusting mechanism
being suitably modified.
And in order that my said invention and the manner of performing the same
may be properly understood I hereunto append three sheets of explanatory
drawings to be hereinafter referred to and representing an example of my improved
variable-speed and reversing mechanism.
Figure, 1, on Sheet, 1, of the drawings is a sectional plan, Figure, 2, on
Sheet, 2, a sectional side elevation, and Figure, 3, on Sheet, 3, an end elevation.
In these drawings the same reference letters and numerals are used to mark the
same or like parts wherever they are repeated.
The mechanism is carried on a bed frame, A, which is combined with the car
frame (not shown) the longitudinal first-motion shaft, A 1, being carried in a
bearing, A 2, at one end of the bed-frame, A, and in other bearings (not shown)
and having on it a flywheel, A 3. The shaft, A 1, is between two disks, B, C,
which are on short transverse shafts, B 1, C 1, held in bearings, B 2, B 3, C2, C3,
and these disks are made, on the sides facing each other, each with two bevilled
annular surfaces, D, E, at different distances from the centre, there being
annular concave parts between the two bevilled surfaces. In Figure, 2, one of
the disks is supposed to be removed to show clearly parts between the disks.

page_text: The bevilled surfaces, D, E, are designed to be acted frictionally upon by conical
driving pulleys, F, G, H, J, on the crank shaft, A 1, there being four of such
pulleys, two on each side of the centres of the disks. The pulleys, F, G, H, J,
are fitted on the shaft, A 1, with tubular bosses or sleeves and with grooves and
feathers or keys, so as whilst turning with the shaft to be adjustable along it.
Each pulley is adjusted by means of a groove formed around the tubular boss, there
engaging in the several grooves rings, F 1, G 1, H 1, J 1, made in halves bolted
together and formed with trunnions which engage in elongated holes in double
levers, F 2, G 2, H 2, J 2, centered on the bed frame, A, and with their upper
ends engaging with internally screwed bosses, F 3, G 3, H 3, J 3. The screwed
bosses are on screwed parts of two shafts, K, L, which are in line with each other
and parallel to and above the crank shaft, A 1; and the shafts, K, L, are by bevil
wheels, K 1, I 1, at their ends geared with transverse shafts K 2 L 2, having hand
wheels, K 3, L3, on them. The two screwed parts on each shaft, K, L, are one
right-handed and the other left-handed, so that when either shaft, K, or, L, is
turned it moves the pulleys, F, G, or H, J, on which it acts in opposite directions.
In the middle positions of either pair of pulleys, F, G, or H, J, neither pulley of
a pair is in contact with the disks, B, C; and in turning either shaft, K, L, in one
direction the outer pulley, F, or, J, is moved into contact with the outer bevilled
surfaces, D, of the disks and drives the disks at a slow speed; but if the
shaft, K, or, L, is turned in the opposite direction the outer pulley, F, or, J, is
moved out of contact, and the inner pulley, G, or, H, is moved into contact with
the inner bevilled surfaces, E, of the disks and drives the disks at a quicker speed.
The disks, B, C, always rotate oppositely to each other, and the directions of their
rotations are reversed by adjusting a driving pulley at one side of their centres to
act on them instead of a driving pulley at the other side. The resistance of the
disks, B, C, to the necessary driving presssure of the pulleys is provided for in the
bearings, B 3, C 3, (or it might be in the bearings, B 2, C 2) of the shafts of
the disks, and friction may be reduced either by ball bearings or by antifriction
rollers applied to the outer sides of the disks opposite the parts at which the
driving pulleys act on them.
Motion is transmitted from the disk shafts, B 1, C 1, to the wheel axles, M, N,
by means of sprocket wheels and pitch chains. A sprocket wheel, M 1, on one
axle, is acted on by a pitch chain, M 2, (indicated by a partly dotted line) directly
from a sprocket wheel, M 3, on one disk shaft, B 1: whilst a sprocket wheel, N 1,
on the other axle is acted on by a pitch chain, N 2, from a sprocket wheel, N 3,
on a shaft, N 4, driven by means of a pair of pinions, N 5, from the other disk
shaft, C 1.
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. The combination and arrangement of parts constituting my improved variable
speed and reversing mechanism for gas or vapor or other motors substantially as
herein before described and as shown in the accompanying drawings.
2. The combination of a pair of disks each formed with two or more annular
bevilled surfaces with adjustable conical frictional driving pulleys substantially as
and for the purposes herein before described.
Dated this Ninth day of February 1804