Improvements in Steering Velocipedes, Road Carriages, and other Wheeled Vehicles.
Year: 1896

page_text: Date of Application, 1st June, 1895
Complete Specification Left, 1st Mar., 1897-Accepted, 15th May, 1897
PROVISIONAL SPECIFICATION.
Improvements in Steering Velocipedes, Road Carriages, and other
Wheeled Vehicles.
1 HENRY TADWELL DAVIS, of 97 Algernon Road, Lewisham, in the County
of London, Engineer, do hereby declare the nature of this invention to be as
follows:-
To ensure the proper working of wheeled carriages it is necessary that the axes
of rotation of all the wheels should be parallel to one another when the carriage is
moving on a straight course, and that they should converge to a common axis
perpendicular to the supporting plane when the carriage is moving on a curved
course.
This has hitherto been effected in vehicles having four wheels by pivotting the
axle of the front pair of wheels, but such an arrangement, without pole or shafts
to restrain its irregularities of position when obstructions are encountered by one or
other of the wheels, needs very cumbrous controlling gear.
By arranging the steering wheels to turn separately, for guiding purposes, a
greater control is possible; but as hitherto constructed their position for correct
action has only been approximate when angled for turning the carriage on a
curved course, and the error of position for sharp curves is very serious, causing
more or less side skidding accompanied by severe lateral stresses on the wheels
and tires.
This invention has for its object to so construct steering apparatus for
velocipedes, road carriages and other wheeled vehicles that the various wheels
shall at all times occupy such relative positions that their axes shall converge to
and intersect a common instantaneous axis perpendicular to the supporting plane.
In the accompanying sheet of drawings:-Fig. 1 is a diagramatic plan of a
four wheeled vehicle having two front steering wheels the hind axle being fixed.
Fig. 2 is a similar view of a modified arrangement, and Fig. 3 is also a similar
view to Fig. 1 of an arrangement in which all the wheels are employed for steering
purposes.
Referring to diagram Fig. 1, A represents the plans of two front wheels
mounted in suitable steering heads, whose line of centres B is parallel to the
axis C, and to which heads levers D are secured and connected together by means
of sleeves, or slots and pin or any suitable connecting device which permits of their
readily sliding free of each other in such manner that the projections of their axes
always intersect at a point on a line E parallel to the line B and at a distance from
it equal to that of the axis C. Ou moving the point of intersection F along the
line E the wheels A are turned into such positions that their axes always converge
to a corresponding point situated in the axis C which point forms the projection of
a common or instantaneous axis perpendicular to the supporting plane.
The device for connecting the levers D may consist of a guide block sliding on
a fixed bar or any other equivalent which will guide the point of intersection in a
right line in the required direction, the required movement being effected by hand
or other power through any suitable mechanism.
In the arrangement indicated by diagram Fig. 2 the long levers D, Fig. 1 are
replaced by short levers G operated by a sliding rod H or its equivalent aud
connected to the wheels by linkwork or other suitable connections, the action being
similar to that produced by the arrangement described with reference to Fig. 1 as
will be readily understood.

page_text: When all the wheels are used for steering purposes as indicated in diagram
Fig. 3 their axes converge to a common point or axis lying in a plane I whose
distance from the line of centres L or M is equal to that between the said lines of
centres and the lines N or O.
Dated this 1st day of June 1896.
WHEATLEY & MACKENZIE,
Agents.
Improvements in Steering Velocipedes, Road Carriages, and other
Wheeled Vehicles.
I, HENRY TADWELL DAVIS, of 115 Lewisham Road, in the County of
London, Engineer, late of 97 Algernon Road, Lewisham, 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 ensure the proper working of wheeled carriages it is necessary that the axes
of rotation of all the wheels should be parallel to one another when the carriage is
moving on a straight course, and that they should converge to a cominon axis
perpendicular to the supporting plane when the carriage is moving on a curved
course. This has hitherto been effected in vehicles having four wheels by pivoting
the axle of the front pair of wheels, but such an arrangement without pole or shafts
to restrain its irregularities of position, when obstructions are encountered by oue
or other of the wheels, needs very cumbrous controlling gear.
By arranging the steering wheels to turn separately for guiding purposes a
greater control is possible; but as hitherto constructed their position for correct
action has only been approximate when angled for turning the carriage on a
curved course, and the error of position for sharp curves is very serious, causing
more or less side skidding accompanied by severe lateral stresses on the wheels and
tires.
This invention has for its object to so construct steering apparatus for
velocipedes, road carriages and other wheeled vehicles that the various wheels
shall at all times tend to rell on their peripheries free from side slip or skidding
action, or in other words that they shall occupy such relative positions that their
axes converge to and intersect a common instantaneous axis perpendicular to the
supporting plane. This is effected by means of the peculiar construction of the
steering gear whose action is governed by a special triangular arrangement of parts
hereinafter more fully explained.
In the accompanying four sheets of drawings:
Fig. 1 is a diagramatic plan of a four wheeled vehicle having two front steering
wheels the hind axle being fixed.
Fig. 2 is a similar view of a modified arrangement and
Fig. 3 is also a similar view to Fig. 1 of an arrangement in which all the wheels
are employed for steering purposes.
Figs. 4, 5 and 6 are side elevation, part end elevation and plan respectively of
one arrangement of steering apparatus applied to the under frame of a vehicle.
Figs. 7, 8 and 9 are corresponding views of a modified arrangement of steering
apparatus.
Figs. 10 and 11 show diagramatic plans of further modified arrangements in
which the steering gear is constructed separately and connected to the steering
heads by suitable linkwork, and
Figs. 12, 13 and 14 are full plan, plan of interior and vertical section of the
ercased steering gear.

page_text: Referring to diagram Fig. 1, A represents the plans of two front wheels mounted
in suitable steering heads, whose line of centres B B' is parallel to the axis C C¹,
and to which heads levers D are secured and connected together by means of
sleeves, or slots and pin or any suitable connecting device which permits of their
readily sliding free of each other in such manner that the projections of their axes
always intersect at a point on a line E E', parallel to the line B B' and at a
distance from it equal to that of the axis C C. On moving the point of inter-
section F along the line E E¹ the wheels A are turned into such positions that
their axes always converge to a corresponding point P situated in the axis C C¹
which point forms the projection of a common or instantaneous axis perpendicular
to the supporting plane.
The device for connecting the levers D may consist of a guide block sliding on a
fixed bar or any other equivalent which will guide the point of intersection in a
right line in the required direction, the required movement being effected by hand
or other power through any suitable mechanism.
In the arrangement indicated by diagram Fig. 2 the long levers D Fig. 1 are
replaced by short levers G operated by a sliding rod H, or its equivalent, and
connected to the wheels by linkwork or other suitable connections, the action
being similar to that produced by the arrangement described with reference to
Fig. 1 as will be readily understood.
When all the wheels are used for steering purposes as indicated in diagram
Fig. 3 their axes converge to a common axis lying in a plane 1 I' whose distance
from the line of centres L L or M M is equal to that between the said lines of
centres and the lines N N' or O O¹.
Referring to Figs. 4, 5 and 6 which illustrate the undercarriage and steering
apparatus of a road vehicle, a spur wheel a mounted on a spindle b working in
bearings in a supporting bracket c secured to the front axle d gears with a rack e
secured between bars secured together and held at a suitable distance apart by
bolts and sliding in guide brackets h, also secured to the axle d, the spur
spindle being coupled by the socket i to the steering spindle 7 working in a guide
Each end of the
bracket m and carrying a steering wheel n all as clearly shown.
axle d is connected to the central part by a vertical joint o and carries a tiller
lever p free to slide in a block q pivoted by trunnions r to the bars f between
which it is free to turn to adjust itself to any position taken up by the lever p. It
will thus be seen that as the bars fare slidden in their guides the levers p and
wheels A are caused to rotate about the axis of the joints o. By constructing and
adjusting the relative parts so that the centre lines FB, F B1, B B 1, through the
levers p and joints o, form a triangle whose apex F is in a line E E' parallel and
equidistant with the axis C C1 from axis B B1 the said apex traverses the line in
all positions of the levers p and the wheels A and also, the axes of the wheels A',
in all positions, intersect in a point P in the axis C C which point is the projection
of an instantaneous axis, perpendicular to the supporting plane of the vehicle, about
which all the wheels roll without any tendency to side slip at any instant. It will
be obvious that by turning the steering wheei n the wheels A may be caused to
take up any desired position.
The apparatus is shown in its normal straight-forward direction, the dotted lines
showing the direction of the wheels changed for a curved course and the governing
triangles F B B1, P B B1 having their apices in their proper positions as will be
readily understood.
In the modified arrangement shown in Figs. 7, 8 and 9 a spur wheel a gears with
a rack e on a sliding bar to the ends of which are jointed levers p sliding in
heads s secured to the forks t in which the wheels A are mounted. It will be
obvious that the steering gear may he placed on either side of the axle d provided
proper attention be given to the arrangement of the parts so as to effect the
requisite distribution of the governing triangles. The action is in all respects
similar to that shown in Figs. 4, 5 and 6.
In the modified arrangement shown in Figs. 10 to 14 iuclusive the distribution of

page_text: the governing triangles is indicated, the distance between the parallels E E',
B B, C C' being equal as in the hereinbefore described arrangements shown in
Figs. 4 to 9.
In this arrangement the sliding bars f previously described are dispensed with,
the steering head levers on the wheel forks being connected to the steering gear
by links as shown.
The gear proper is contained in a split casing secured together by bolts w.
A spur pinion a mounted on the steering spindle 6 gears with a rack e forming part
with a block sliding in a guide channel y in one side of the casing, while a similar
block slides in a corresponding guide channel in the other side of the said casing.
Connected to the said blocks az by pins a' are two open links b' in which slide
blocks c' secured to spindles d' on which crank levers el are mounted so that when
the spur pinion a is rotated by the steering wheel the blocks slide in their guide
channels causing the links b¹ to turn the spindles d' and levers e'. These levers e¹
are connected by links to the levers on the steering heads of the wheel forks, each
pair of levers so connected being equal and parallel to each other as will be
readily understood on reference to Figs. 10 and 11 of the drawings.
It will be obvious that by mounting a third pair of wheels on axis II (Fig. 3)
and suitably connecting the governing triangles of the leading and trailing steering
wheels my invention can be applied to vehicles having six wheels.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I would have it
understood that I do not claim broadly causing the axes of all the wheels of a
vehicle to converge to an axis perpendicular to the supporting plane as this is done
in all three wheeled vehicles having two wheels mounted on a fixed straight axle
and one steering wheel free to turn about a vertical axis and in four wheeled
vehicles where the guiding wheels are mounted on a common axle also free to turn
about a vertical axis, but I declare that what I do claim is :-
1. In vehicles in which the steering wheels are arranged transversely in pairs
and rotate about independent axes, causing all the axes of the supporting wheels
to converge to one common axis substantially in the manner described and for the
purpose set forth.
2. In vehicles in which the steering wheels are arranged transversely in pairs
and rotate about independent axes, causing all the axes of the supporting wheels
to converge to one common axis substantially as described with reference to
Figs. 1, 2 or 3 of the drawings.
3. In vehicles in which the steering wheels are arranged transversely in pairs
and rotate about independent axes, the arrangement, construction and combination
of parts substantially as described with reference to Figs. 4, 5 and 6 of the
drawings.
4. In vehicles in which the steering wheels are arranged transversely in pairs
and rotate about independent axes, the arrangement, construction and combination
of parts substantially as described with reference to Figs. 7, 8 and 9 of the
drawings.
5. In vehicles in which the steering wheels are arranged transversely in pairs
and rotate about independent axes, the arrangement, construction and combination
of parts substantially as described with reference to Figs. 10 to 14 inclusive of the
drawings.
Dated this 1st day of March 1807
WHEATLEY & MACKENZIE,
40 Chancery Lane, London, W.C., Agents.