IMPROVEMENTS IN DRIVING WHEELS APPLICABLE TO TRACTION ENGINES
Year: 1870

page_text: LETTERS PATENT to Benjamin Walker, of Leeds, Engineer, and John
Frederick Augustus Pflaum, also of Leeds, Engineer, for the In-
vention of "IMPROVEMENTS IN DRIVING WHEELS APPLICABLE TO TRACTION
ENGINES."
Sealed the 21st February 1871, and dated the 22nd September 1870.
PROVISIONAL SPECIFICATION left by the said Benjamin Walker and
John Frederick Augustus Pflaum at the Office of the Commissioners
of Patents, with their Petition, on the 22nd September 1870.
We, BENJAMIN WALKER, of Leeds, Engineer, and JOHN FREDERICK
AUGUSTUS PFLAUM, also of Leeds, Engineer, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN DRIVING WHEELS APPLICABLE TO
TRACTION ENGINES," to be as follows:-
This Invention has for its object improvements in driving wheels
applicable to traction engines.
When traction engines are upon hard uneven ground the driving
wheels are very liable to slip in consequence of the imperfect bearing
taken by their broad surfaces.

page_text: According to our Invention we form such wheels with a groove or
recess around the periphery or bearing surface; this groove or recess
receives a loose but rigid ring or tyre of somewhat larger diameter
than the ordinary tyre or bearing surface of the wheel, and springs are
interposed all around between the loose ring or tyre and the wheel.
When the wheel is in use the weight upon it compresses the lower
springs until the ordinary or fixed tyre or tyres of the wheel also come
in contact with the road or surface, and so a double bearing is obtained.
A further increase of bearing surface may be obtained by employing two
or more such loose rigid tyres supported on springs.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Benjamin Walker and John Frederick Augustus
Pflaum in the Great Seal Patent Office on the 22nd March 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, BENJAMIN
WALKER, of Leeds, Engineer, and JOHN FREDERICK AUGUSTUS PFLAUM,
also of Leeds, Engineer, send greeting.
WHEREAS Her most .Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-second day of September, in the
year of our Lord One thousand eight hundred and seventy, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto us, the said Benjamin Walker, and John Frederick
Augustus Pflaum, Her special license that we, the said Benjamin
Walker and John Frederick Augustus Pflaum, our executors, admini-
strators and assigns, or such others as we, the said Benjamin Walker
and John Frederick Augustus Pflaum, our executors, administrators,
and assigns, should at any time agree with, and no others, from time
to time and at all times thereafter during the term therein expressed,.
should and lawfully might make, use, exercise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN DRIVING WHEELS
APPLICABLE TO TRACTION ENGINES," upon the condition (amongst others) that
we, the said Benjamin Walker and John Frederick Augustus Pflaum,
our executors or administrators, by an instrument in writing under our
or their hands and seals, or under the hand and seal of one of us
or them, should particularly describe and ascertain the nature of the

page_text: said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Seal Patent Office within
six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that we, the said Benjamin Walker and John
Frederick Augustus Pflaum, do hereby declare the nature of the said
Invention, and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement
thereof, that is to say :-
This Invention has for its object improvements in driving wheels
applicable to traction engines.
When traction engines are upon hard uneven ground the driving
wheels are very liable to slip in consequence of the imperfect bearing
taken by their broad surfaces.
According to our Invention we form such wheels with a groove or
recess around the periphery or bearing surface; this groove or recess
receives a loose but rigid ring or tyre of somewhat larger diameter than
the ordinary tyre or bearing surface of the wheel, and springs are
interposed all around between the loose ring or tyre and the wheel.
When the wheel is in use the weight upon it compresses the lower
springs until the ordinary or fixed tyre or tyres of the wheel also come
in contact with the road or surface, and so a double bearing is obtained.
A further increase of bearing surface may be obtained by employing two
or more such loose rigid tyres supported on springs.
In order that our said Invention may be most fully understood and
readily carried into effect, we will proceed to describe the Drawings
hereunto annexed.
Figure 1 is a longitudinal section and Figure 2 a transverse section
of a driving wheel constructed according to our Invention, and in the
way which we prefer.
a, a, is the axle; b is the boss or nave of the wheel capable of rotating
thereon; c, c, are side plates or discs fixed to the boss and having
rivetted to them at their peripheries the rings d, these rings which are
rectangular in section form the tyre or ordinary bearing surface of
the wheel. The side plates or discs c are connected by the hoop e, and

page_text: also by cross ties which stiffen the construction. f and f¹ are loose
rings or tyres of somewhat larger diameter than the ordinary bearing
surface d. 9, 9, g', g', are springs like ordinary carriage springs, they
are attached by screw clips to the hoop e, and the longest plate of each
spring is also attached by a rivet at each end to the loose spring or
tyre for f¹, as the case may be. The holes in the ends of the springs
are elongated and the rivets do not bind the springs tightly, so that the
freedom of their play may not be destroyed. The strength of the springs
is proportioned to the weight which the wheel has to bear, it is not
sufficient to prevent the surfaces d from taking a bearing on the road
or land and sustaining their share of the weight upon the wheel.
Having thus described the nature of our said Invention, and the
manner of performing the same, we would have it understood that we
do not confine ourselves to the exact details which we have described;
but what we claim as our improvements in driving wheels applicable
to traction engines is, the construction of such wheels with a loose but
rigid ring or tyre of somewhat larger diameter than the orginary tyre
or bearing surface of the wheel and supported by springs, substantially
as described.
In witness whereof, we, the said Benjamin Walker and John
Frederick Augustus Pflaum, have hereunto set our bands and
seals, this Twentieth day of March, in the year of our Lord One
thousand eight hundred and seventy-one.