Improved Differential Speed Gearing.
Year: 1891

page_text: Date of Application, 2nd Apr., 1891
Complete Specification Left, 1st Jan., 1892-Accepted, 2nd Apr., 1892
PROVISIONAL SPECIFICATION.
Improved Differential Speed Gearing.
We JOHN JAMES MANN and JAMES HOYLE SMITH, Fustian Cutters and
HENRY GEORGE READ Engineer all of Ordsall Lane Mills Salford in the
County of Lancaster, do hereby declare the nature of this invention to be as
follows:-
Our invention relates to mechanism employed for, obtaining different rates of
speed for the driving of machines or parts of machinery where it is desired to
employ at alternate intervals or at will either a slow or quick speed; and our
improved gearing is so arranged that either speed is instantaneously available with
no stoppage of the machinery to which it may be applied and no shock to any of
its parts, either speed being also entirely independent of the other.
Our apparatus is preferably arranged as a set of fast and loose pulleys all
revolving upon a fixed stud or bar the driving belt running on the loose pulley
when the machinery to which the gearing is applied is to remain at rest.
To the wheel which drives the said machinery (and which may be a toothed
wheel or pulley or other equivalent) is attached or cast one of the fast pulleys
which may either be actuated directly by the driving strap before named or by
internal gearing actuated by an adjacent pulley which thus acts as a second fast
pulley when the driving strap is moved on to it, this second fast pulley being
preferably intermediate between the loose pulley and that to which the driving
wheel is attached.
The internal gearing above mentioned may be modified in a variety of ways, but
we prefer to adopt the following arrangement which we have invented for the
purpose.
Upon the fixed stud or bar on which the fast and loose pulley's run, is keyed or
otherwise secured or cast, a plate or yoke of suitable form (preferably a disc)
enclosed between the two fast pulleys.
On that side of the said plate or yoke on which the first above named fast pulley
is placed is an annular or internally toothed wheel free to revolve upon the fixed
stud or a boss thereon.
The outside periphery of this wheel is formed with wedge shaped recesses in
cach of which is placed a small roller which wedges between the internally toothed
wheel and the interior of the first named fast pulley and consequently the latter
will be driven by the said internal wheel.
Gearing into this internally toothed wheel we mount a carrier wheel or wheels
driving a pinion or pinions on a short shaft or shafts carried by the fixed plate or
yoke, on the other side of which is another pinion, on the same short shaft
gearing with a toothed wheel cast or attached to the boss of the second named fast
pulley.
The carrier wheels will give to the internal wheel the same direction of motion
as that of the second fast pulley when the driving strap is moved on to the latter
and the intermediate gearing may be proportioned to give any required reduction
of speed to the said internal wheel and through it to the first fast pulley and
through the driving wheel or pulley attached to the latter to the machinery, to
which the differential gear is applied.
When however the strap is moved upon the first named fast pulley the wedging
rollers above named will run into the deeper part of the recesses in the periphery
of the internally toothed wheel which will then remain stationary and the driving
wheel or pulley is actuated directly by the driving strap,
The inside rim of the first named fast pulley is preferably turned to fit part of the

page_text: periphery of the internally toothed wheel which is also flanged and turned to fit
upon the fixed plate or yoke.
The contiguous edges of the two fast,pulleys are fitted together with internal
and external facings.
Thus the weight of the two pulleys and the internally toothed wheel is carried
by the fixed plate or yoke as well as by their several bosses on the fixed stud or
bar and any lubricant supplied to the interior of the mechanism will be retained
and will not rapidly leak away.
In some instances where very high speeds necessitate that the mechanism be run
in liquid lubricant such as soap and water or thin oil, we may insert hide, leather
or other washers between the pulley rins, such lubricant is preferably supplied to
the interior of the mechanism by making the fixed shaft hollow with retaining
vessels for the lubricant fixed at the end or ends thereof.
If preferred the wedge shaped recesses may be made in the rim of the pulley
instead of in the periphery of the internally toothed wheel. Also two differentially
driving pulleys may be combined with one first driving pulley, thus obtaining three
different speeds instead of two. The pulleys may also be placed differently with
regard to each other if preffered.
It will be seen from the foregoing description that the driving belt can be
instantaneously shifted (by any known means) from the loose pulley to either of
the fast pulleys without shock or noise and the belt may remain partly on one of
tlic latter and partly on the other with no detriment to itself or to the mechanism
composing our differential speed gearing, as in such case the machinery would be
driven by the fast pulley over which the driving belt had most control.
Dated this 1st day of April 1891
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicants.
COMPLETE SPECIFICATION.
Improved Differential Speed Gearing.
We JOHN JAMES MANN and JAMES HOYLE SMITH Fustian Cutters, and
HENRY GEORGE READ Engineer all of Ordsall Lane Mills Salford in the
County of Lancaster 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 :—
Our invention relates to mechanisın employed for obtaining different rates of
speed for the driving of machines, or parts of machinery where it is desired to
employ at alternate intervals, or at will, either a slow or quick speed, and our
improved gearing is so arranged that either speed is instantaneously available with
no stopping of the machinery to which it may be applied, and no shock to any of
its parts, either speed being also entirely independent of the other.
The nature of our said invention and the manner in which the same is to be
performed or carried into practical effect will be readily understood on reference
to the two sheets of drawings hereunto annexed and the following explanation
thereof.
Fig. 1 on the drawing is a longitudinal section and Fig. 2 an internal face view.
of our invention arranged as a set of fast and loose pulleys mounted on a fixed stud
or bar and Fig. 3 is a half face view of a slight modification thereof.
The driving belt runs on the loose pulley when the machinery to which the
gearing is applied is to remain at rest.
To the wheel which drives the said machinery (and which may be a toothed
wheel, or pulley, or other equivalent) is attached or cast one of the "fast" pulleys,
which may be either actuated directly, or by the driving strap before named, or by
internal gearing actuated by an adjacent pulley which thus acts as a second fast
pulley when the driving strap is moved onto it, this second "fast" pulley being

page_text: wheel is attached.
De between the 100SC purrey and that to which the driving
We would here remark that the term "fast" pulley is (in this Specification) used
to denote pulleys actuating the machine, as distinguished from the "loose" pulley
upon which the belt runs when the machine is at rest.
The internal gearing above mentioned may be modified in a variety of ways
but we prefer to adopt the arrangement shewn on the drawings, which we have.
invented for the purpose.
a is a fixed stud or bar upon which run loosely two tubular bosses & and c. To
the boss bis cast or otherwise fixed the first fast pulley band to the tube c is fixed
the boss of the second fast pulley e'; is the loose pulley.
Upon the fixed stud or bar a on which the fast pulleys and run, is keyed or
otherwise secured, or cast, a plate or yoke d of suitable form (preferably a disc
enclosed between the two fast pulleys band c¹).
g
On that side of the said plated on which the fast pulley 61 is placed is an
annular or internally toothed wheel e free to revolve upon the fixed stud a or a boss
thereon. The outside periphery of this wheel e is formed with wedge shaped
recesses (see Fig. 3) in each of which is placed a small roller
which wedges
between the internally toothed wheel e and the interior of the first named fast
pulley or instead of these rollers we modify the form of the recesses f (as
shown at Figs. 1 and 2 and employ catches g which have pins or studs cast there-
with, one of these pins fits in a hole made in the rim of the wheel e and the other
runs in a groove turned in the inside of the pulley and consequently the latter
will be driven by the internal wheel in one direction only.
Gearing into the internally toothed wheel e we mount a carrier wheel or wheels i
(see Fig. 2) driven from a pinion or pinions on a short shaft or shafts / carried
by the fixed plate or yoke on the other side of which is another pinion m on the
same short shaft gearing with a toothed wheel attached to the boss of the
second fast pulley .
The carrier wheels will give to the internal wheel e the same direction of
motion as that of the second fast pulley e' when the driving strap is moved onto the
latter and the intermediate gearing may be so proportioned as to give any required
reduction of speed to the said internally toothed wheel e and through it and its
wedging rollers or catches g' to the first fast pulley and through the driving
wheel (or pulley o¹) attached to the latter, to the machinery to which the
differential gear is applied.
When however the strap is moved upon the first fast pulley the wedging
rollers g or catches will fall back into the deeper part of the recesses in the
periphery of the internally toothed wheel e which will then remain stationary and
the driving wheel or pulley is actuated directly by the driving strap.
The inside rim of the first fast pulley is preferably turned at 3 to fit part of
the periphery of the internally toothed wheel e which is also flanged and turned at e¹
to fit upon the fixed plate or yoke d.
The contiguous edges of the two fast pulleys and care fitted together with
internal and external facings and thus the weight of the two pulleys and c¹ and
the internally toothed wheel e is carried by the fixed plate or yoke d as well as by
their several bosses on the fixed stud or bar a and any lubricant supplied to the
interior of the mechanism will be retained and will not rapidly leak away.
In some instances where very high speeds necessitate that the mechanism be run
in a liquid lubricant such as soap and water or thin oil, we may insert hide, leather
or other washers between the pulley rims. Such lubricant is preferably supplied to
the interior of the mechanism by making the fixed shaft a hollow, with retaining
vessels for the lubricant, fixed at the end or ends thereof.
If preferred the wedge shaped recesses may be made in the rim of the
pulley & instead of in the periphery of the internally toothed wheel e. Also two
differentially driving pulleys may be combined with one first driving pulley, thus
obtaining three different speeds instead of two, or two differentially driving pulleys.

page_text: may be combined with two first driving pulleys thereby obtaining further variation
in the speeds.
The pulleys may also be placed differently with regard to each other if
preferred.
It will be seen from the foregoing description that the driving belt can be
instantaneously shifted (by any known means) from the loose pulley to either of
the fast pulleys without shock or noise and the belt may remain partly on one
of the latter, and partly on the other with no detriment to itself or to the
mechanism composing our differential speed gearing, as in such case the machinery
would be driven by the fast pulley over which the driving belt had most control.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is
1. The combination of a fixed stud or bar carrying a loose pulley or pulleys
and two or more driving or "fast" pulleys, the driving wheel or pulley which
communicates motion to the machine or apparatus to which the gear is to be
applied being driven directly by one or more of the above named "fast" pulleys
which in its turn can be driven by suitable intermediate gear by the other "fast
pulley or pulleys substantially as and for the purpose hereinbefore described.
2. The improved differential gear constructed substantially in the manner
hereinbefore described and illustrated by the drawings annexed.
Dated this 31st day of December 1891.
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicants.