Improvements in Gears for Use in Driving Motor Cars and for other Purposes.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Gears for Use in Driving Motor Cars and for
other Purposes.
I, HERBERT AUSTIN, Works Manager to the Wolseley Sheep Shearing Machine
Company, Limited, of Sydney Works, Alma Street, in the City of Birmingham,
Manufacturers, do hereby declare the nature of this invention to be as follows:-
Differential gear in which two toothed wheels of equal diameter having a com-
mon axis, but capable of turning independently of one another, are driven through
the medium of a drum or wheel which is made to revolve around the same axis,
has been used for driving two wheels of a motor car, cycle, traction engine, or
the like, alternatively, at the same velocity or at relatively varying velocities;
and a similar arrangement of mechanism in which one of the two toothed wheels
is a driving wheel, and in which the drum or surrounding wheel may be alterna-
tively held from revolving or be rotated from the driving wheel, is described and
claimed in my Patent Specification No. 20,401 of 1895, as applicable for the pur-
pose of gearing together a driving and a driven shaft in such manner that,
alternatively, the driven shaft may remain at rest while the driving shaft is
revolving, or may be driven at the same velocity as the driving shaft, or at a
less velocity, as desired.
In gearing of the above type, whether the two equal toothed wheels are driven
through the medium of a surrounding drum or wheel, or one of such wheels is
itself used as a driving wheel, such wheels have heretofore been bevel wheels
and have been both geared with the same bevel pinion which is carried by a stud
projecting inside the drum. Bevel teeth are, however, very expensive to machine,
especially if they are to be shaped perfectly true; and the object of this invention
is to devise a toothed gear of the above type in which the teeth are ordinary spur
or parallel teeth, which may be readily and accurately shaped.
In a gear constructed according to this invention, the two equal toothed wheels
which have a common axis are formed as ordinary spur wheels with parallel teeth.
The surrounding drum or wheel carries two straight toothed spur pinions, one of
which gears with one only of the spur wheels, and the other of which gears only
with the other of the spur wheels, but which themselves gear together. If the
surrounding drum or wheel be held from turning, and the pinions then revolved,
it will be obvious that the spur wheels with which the pinions, respectively, gear
will be caused to revolve in opposite directions; and it will thus be seen that, if
the mechanism is adapted for driving two wheels of a motor car, cycle, traction
engine, or the like, which are geared together only through such mechanism,
then if the drum or surrounding wheel is revolved and the resistances against the
turning of the spur wheels are equal, as for instance when a motor car is running
straight, the two pinions will not revolve around their axes, but simply carry
round the equal spur wheels; whereas, if a greater resistance is opposed to the
turning of one of the wheels than to the other, as when a motor car is turning a

page_text: corner, the pinions will revolve and the one wheel will be driven faster than the
other. It follows, also from the explanation already given, that the mechanism
is adapted for use in gearing together two shafts in the manner referred to as
described in my aforesaid Patent. Specification.
The pinions are geared togetlier along portions of their lengths which come
opposite to the space between the two wheels which have a common axis, and the
axes of these pinions are, of course, parallel with the common axis of the two
wheels.
Two pairs of pinions may be used, if desired, in positions opposite to one another
around the wheels. .
Improvements in Gears for Use in Driving Motor Cars and for..
other Purposes.
I, HERBERT AUSTIN, Works Manager to the Wolseley Sheep Shearing Machine
Company Limited, of Sydney Works, Alma Street, in the City of Birmingham,
Manufacturers, 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;-
-
This invention has for its object to simplify and cheapen the construction of
differential or double driving gear of the type in which two toothed wheels
of equal diameter having a common axis, are capable of turning independently of
one another, and are driven through the medium of a drum or wheel which is
made to revolve around the same axis, whereby two wheels of a motor car, cycle,
traction engine, or the like, may be driven alternatively at the same velocity or
at relatively varying velocities; and to simplify and cheapen also the construction
of the modified type of such gearing which is described in my Patent Specifica-
tion No. 20401 of 1895 according to which one of two toothed wheels which
have a common axis is a driving wheel, and a drum or surrounding wheel may
be alternatively held from revolving or be rotated from the driving wheel, such
modification being applicable for the purpose of gearing together a driving and
a driven shaft in such manner, that, alternatively, the driven shaft may remain
at rest while the driving shaft is revolving or may be driven thereby.
I will describe the invention by reference to the accompanying drawings, which
illustrate the type of gear above described in which two toothed wheels having a
common axis are driven through the medium of a surrounding drum or wheel,
when its application to the modified type of such gear above described will be
obvious without need for further illustration.
Figure 1 is a section through the gear taken in a plane indicated by lineæ
of Figure 2; and Figure 2 is a transverse section through the gear taken in the
plane indicated by line y y of Figure 1.
A A¹ are the two spur wheels which are capable of turning independently of
one another, and have a common axis. These wheels are shewn as mounted on
the ends of axles B B which are, of course, carried in suitable bearings, and the
wheels are rigid with their respective axles. C is a drum which surrounds and
encloses the wheels A A¹ and is mounted to be capable of turning independently
thereof, and in the particular instance shewn is provided with sprocket teeth e for

page_text: a chain, though it might in some instances be driven by a belt or by spur gear
engaging with teeth thereon. Within this drum are mounted spur pinions a a¹
having transverse axes, that is to say, axes which are parallel with the common
axis of the axles B B¹. These pinions are conveniently carried to be capable of
turning upon transverse pins 6b which pass through the sides of the drum C
and may be used in holding the removable side d of the drum securely in place
against, and partly entering within, the body of the drum. The wheels À A¹
and pinions a a¹ are formed with ordinary parallel teeth, as shewn. The teeth
of the pinion a gear directly with the teeth of the wheel A, and the teeth of the
pinion a gear directly with the teeth of the wheel A¹. The teeth of the pinion a
extend considerably beyond the inner side of the wheel A, but stop short of the
inner side of the wheel A' so that they do not gear with the teeth of such wheel;
and the teeth of the pinion at extend considerably beyond the inner side of the
wheel A', but stop short of the inner side of the wheel A so that they do not gear
with the teeth of such wheel. The portions of the teeth of the pinions which
extend, respectively, beyond the inner sides of the wheels A and A¹ gear directly
with one another.
If the drum C be held from turning, and the pinions a a¹ be then caused to
rotate, it will be obvious that the spur wheels A A¹ with which the pinions,
respectively, gear will be caused to revolve in opposite directions; and it will
thus be seen that, if the mechanism is adapted for driving two wheels of a motor
car, cycle, traction engine, or the like, which are geared together only through
such mechanism, that is to say, which are driven by the wheels A A', respectively,
then if the drum is revolved and the resistances against the turning of the spur
wheels are equal, as for instance when a motor car is running straight, the two
pinions will not revolve around their axes, but will simply carry round the equal
spur wheels A A¹; whereas, if a greater resistance is opposed to the turning of
one of the wheels than' to the other, as when motor car is turning a corner, the
pinions will revolve and the one wheel will be driven faster than the other.
Two pairs of pinions such as a a¹ may be used, if desired, in positions opposite
to one another around the wheels A A¹, and indeed such an arrangement would
be an advantage in the case of transmitting considerable power. When two pairs
of pinions a a are used, the side d of the drum will be securely held in place by
their pins; but if only one pair of such wheels is used an additional pin è is used
through the opposite side of the drum.
In adapting the invention to the type of gear described in my Patent Specifica-
tion No. 20401 of 1895, a pair of wheels with straight teeth is substituted for the
pair of bevel wheels lettered a b upon the drawings accompanying such speci-
fication, or for each such pair of bevel wheels if two sets of the gear are used as
shewn upon such drawings, and two pinions gearing, respectively, directly with
the wheels of the pair, or of each pair as the case may be, and gearing also directly
with one another, are substituted for the wheel lettered c, or each such wheel as
the case may be, such pinions being carried upon axes which are fixed in relation
to the drum or drums described in the said specification and which are parallel
with the axis of the pair of wheels, or the axes of the pairs of wheels which are
substituted for the wheels a b. In this case also two pairs of pinions a b may bo
used with a set, or each set, of gear.
Having now particularly described and ascertained the nature of my said in-
vention, and in what manner the same is to be performed, I declare that what I
clain is:-
11
1. In differential or double driving gear, two spur wheels having a common
axis and formed with straight or parallel teeth and capable of turning indepen·
dently of one another, and two pinions carried by a drum or part which is con-
centric with such wheels and is capable of being rotated, each pinion being formed
with straight or parallel teeth and having its axis parallel with the common
axis of the two wheels, the teeth of one of such pinions engaging directly with

page_text: the teeth of one only of the wheels and extending beyond the inner ends thereof;
and the teeth of the other of such pinions gearing directly with the teeth of the
other only of such wheels and extending beyond the inner ends thereof, the por-
tions of the teeth of the pinions which extend beyond the ends of the teeth of
the wheels gearing directly with one another, substantially as described.
2. In driving gear such as described in my aforesaid Specification No. 20401 of
1895, the substitution for the pair of bevel wheels having a common axis, or for
each pair of such wheels as the case may be, of spur wheels having straight or
parallel teeth, and the substitution for the bevel wheel which gears with the two
bevel wheels having a common axis, or for each bevel wheel which gears with
two bevel wheels having a common axis, as the case may be, of two pinions
formed with straight or parallel teeth and having their axes parallel with the
common axis of the wheels and fixed in relation to the corresponding drum, the
teeth of which pinions gear, respectively, directly with the teeth of the two spur
wheels and extend beyond the inner ends of the teeth of the wheels, the extended
portions of the teeth of one of such pinions gearing directly with corresponding
portions of the teeth of the other of such pinions, substantially as described.
Dated this 17th day of November 1898.
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicant.