Year: 1897

page_text: [Communicated from abroad by ANDREW JACKSON VANDERGRIFT, of No.-2315, South
11th Street, St. Louis, in the State of Missouri, and United States of North
America, Mechanical Engineer.]
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for Foreign Patent
Solicitors, 322, High Holborn, in the County of Middlesex, 6, Lord Street, Liverpool,
and 6, Bauk Street, Manchester, both in the County of Lancaster, and Lower Temple
Street, Birmingham, in the County of Warwick, Civil Engineer, do hereby declare the
nature of this invention to be as follows:-
My invention relates chiefly to wheels having rigid rims, flexible tires and springs
interposed between their rims and tires; and the main objects of my improvements
are first, to provide an improved flexible tire; second, to provide an improved rim;
third, to provide an improved spring for cushioning the tire; fourth, to provide an im-
proved spring-truss, composed of said improved springs and means for yoking them
together; fifth, to arrange said springs and the trusses into which they enter, in the
most advantageous way; and sixth to secure the springs used, to the tire and rim
respectively, in a firm and durable manner.
The rim of my improved wheel, may be of any usual form, but is preferably made
flat on its outer face, so as to provide a good bearing for the bases of the
springs hereinafter described, and where it is made of metal it, is preferably made
in the form of a T, in cross section, with the central leg, thereof, projecting
inwards.
The tire is preferably made in the form of an endless band, which, may either be
flat on the inside and convex outside or flat on both sides. In the case of guide
wheels for vehicles, such for instance as bicycles, the outer face of the tire may
advantageously be inade convex in cross section, though it is preferably, but not
necessarily, inade substantially flat on the inner side.
The tires may be made of any flexible material adapted for the purpose, but I pre-
fer to use a composite tire formed of an inner and an outer layer of leather with a
band of spring metal, preferably steel, between them. This band I usually make
narrower than the tire and arrange it centrally so that the leather. projects beyond it
on each side, and I preferably secure it in place by cementing the projecting portions
of the two layers of leather together and also by fastening them together by means
of tacks, pegs stitches or rivets:
The metal band introduced into the tire, should be very flexible so as to avoid
making the tire stiff.
Between the tire and the rim of the wheel, I interpose a series of return bend
springs, arranged transversely, side by side, and fastened both to the rim and tire.
037

page_text: There are several forms of return bend springs which are available for this purpose.
The form of spring preferred is shaped somewhat like the letter Z and is preferably
bent into a spiral of one or more turns, at each turning point between the hooks
hereinafter inentioned.
Each spring preferably terminates at each end in a hook. The top hook extends
upward and the lower one downward.
The spiral bends not only give the spring increased elasticity and strength but act
as stops limiting the compression of the springs and thus protect the spring from
injury. They also tend to throw the arms of the spring out of line so as to enable
then to pass each other when the spring is compressed.
I prefer, however, to give the spring a zigzag form between bearing points whether
the spiral turns are used or not though the zigzag arrangement of the arms of the
springs is not essential in the former case. I do not confine myself to the use of the
preferred form of spring mentioned. The number of its arms may be increased so as
to give it approximately the shape of the letter M set on edge or if desired still
more arms may be added. 'In such cases the spring may be bent into a spiral at
each return bend between its books or the spiral form of bend inay be used at only
one or two points and shaped bends, or bends of other suitable form, may be
employed elsewhere. Where M shaped springs are used good results may be secured
either by using a spiral at the central return bend, and shaped bends elsewhere,
or using a spiral at both the central bend and the lower return bend. Good
though inferior results may also be secured by using plain U shaped bends at all
points.
The tire is preferably notched on its upper face along the edges to receive the
upper hooks of the springs and the rim is preferably notched in like manner aloug
the edges of its inner face to receive the lower, or inner hooks.
The upper hook of each spring is hooked into or over the tire and the lower hook is
secured to to the rim. As will be obvious these hooks, though very desirable, may
be dispensed with and this is especially true of the lower ones, where the rim is formed
of metal. In that case I preferably solder the springs to the rim and the 'hooks are
consequently less necessary, though still useful.
As has been stated, the springs are arranged transversely and they are preferably
arranged so as to cause the ends of each to be on the side opposite the corresponding
ends of the springs next it. They are also preferably arranged in what may be termed
a zigzag manner, that is, so as to incline laterally to the right and left alternately, and'
away from radial lines extending out from the hub of the wheel. They are also
preferably arranged side by side in pairs whose members slant away from each other
from their inner to their. outer ends. The inner arms of each pair are preferably
secured together by.a sheet metal sheath to which they are soldered, and the outer
arms of each pair are preferably secured together by a yoke which I have in practice
made of sheet metal and whose ends, I have bent around the upper arms of the
united springs.and soldered to them. In this way I combine the springs into a series
of spring trusses upon whose yokes the tire rests and is supported. The trusses may
be advantageously spaced apart so that their sides are about five-eighths of an inch
apart more or less at their outer ends. The use of a metal band in the tire is of
advantage in enabling the trusses to be spaced somewhat farther apart than they
otherwise could be; in preventing the tire from stretching and in causing the
pressure to come upon a larger number of spring trusses when the tire is com-
pressed than would otherwise receive it.

page_text: I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for Foreign
Patent Solicitors, 322, High Holborn, in the County of Middlesex, 6, Lord Street,
Liverpool, and 6, Bank Street, Manchester, both in the County of Lancaster, and
Lower Temple Street, Birmingham, in the County of Warwick, Civil 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:
This invention relates to wheels having rigid rims, flexible tires, and springs
interposed between their respective tires and rims, and the main objects of my
improvements are first, to provide an improved flexible tire; second to provide an
improved rim; third to provide an improved spring for cushioning the tyre; fourth,
to provide an improved spring truss, composed of said improved springs and means
for yoking them together; fifth, to arrange said springs and the trusses into which
they enter, in the most advantageous way; and sixth, to secure the springs used, to
the tire, and rim, respectively, in a firm and durable manner.
I attain these objects by the mechanism illustrated in the accompanying drawing
in which,
Figure is a side elevation on a reduced scale of a wheel embodying my
improvements in their preferred forms;
Fig. 2 is a detailed view in side elevation, on a larger scale of a section of said
wheel;
Fig. 3 is a transverse section on line 3-3 Fig. 2;
Fig. 4 is a transverse section on line 4-4 Fig. 2;
Fig. 5 is a detailed inverted plan view of the preferred form of spring truss;
Fig. 6' is a side elevation of a single detached return bend spring of the form which
I prefer to use.;,
Fig. 7 is a plan view of a section of the preferred form of tire ;
Fig. 8 is a plan view of the form of rim shown in Figs. 1, 2, 3, and 4;
Fig. 9 is a view similar to Fig. 3 except that the springs shown are compressed;
Fig. 10 is a detailed view in side elevation of a section of the rim and tire with a
compressed spring truss of the preferred form between them;
Fig. 11 is a cross section of one form of my improved tire ;
Fig. 12 is a side elevation of a modified form of my return bend spring;
Fig. 13 is an inverted plan view of the same spring;
Fig. 14 is a side elevation of another form of said spring;
Fig. 15 is a plan view of the form of spring represented in the last figure;
Fig. 16 is a side elevation of a return bend spring whose bends are all U shaped';
Fig. 17 is an end elevation of a spring truss having springs of the shape represented
in Fig. 16;
Fig. 18 is a view in perspective of an inverted truss of the same kind, furnished
with a hook at each corner of the part upon which the tire is designed to rest;
Fig. 20 is a cross section of an arm of one of my springs ;
Fig. 21 is a detailed view showing the parts of a spring truss of the form shown in
Figs. 17, 18, and 19, assembled in a former, ready to be soldered together; and
Fig. 22 is a transverse section of a metallic rim with the hooks of springs shown
broken away, soldered thereto;
Similar letters refer to similar parts throughout the several views.
The wheel shown in drawings (Fig. 1) has a body composed of a hub A, a rim B,
and spokes C and is of the suspension type. My improvements are applicable,
however, to wheels of other types. No partibular form of rim is essential and it may
:

page_text: be made of either of the materials heretofore used but its outer face .b
(Figs. 1, 2, 3, 4, 9, 10 and 22) is preferably flat and along each edge it preferably
contains a series of indentations or recesses b¹ as shown in Figs. 3 and 8. Where a
metal rim is used it is preferably given the form of a T, in cross section, with the
leg of the T extending inwards as shown in Fig. 22. That form gives it great
strength in proportion to its weight.
The spokes C may be secured to the rim in suitable manner. In Figs. 2 and 4
they are shown secured to the rim by means of nuts c passing through openings in
the rim and having heads c¹ of common form.
The rim B is surrounded by a flexible tire D (Figs. 1, 2, 3, 7, 9, 10, 11) preferably
formed of two or more layers d of leather or other suitable flexible material and a
band. d of spring metal, preferably spring steel. The inner face of the
tire is preferably flat. The tread may be either at or convex. In guide
wheels the tread of the tire may advantageously be made convex in cross
section to enable it to be turned with ease. This convexity may be secured
by interposing a flexible filling piece d² (Fig. 11) convex on the outer side, between
the inner and outer layers d'of the tire. The metal band d is preferably narrower
than the layers d of leather and is interposed between the inner and outer layer and
preferably next the inner one. It should be thin so as to be both flexible and light.
It is preferably arranged at equal distances from the two edges of the tire and is
preferably secured in place by cementing the projecting portions of the layers d
together, and also by means of pegs, pins, stitches or rivets d³ (Figs. 3, 7, 9, 11)
through said layers d. The outer face of the rim is preferably provided with a series
of recesses or indentatious d¹ for the reception of the ends of hooks attached to the
springs hereinafter described. The form of return bend spring which I prefer to use
is shown detached in Fig. 6, in a detached spring truss E in Fig. 5, and in spring
trusses in place, in Figs. 1, 2, 3, 9, and 10, and is lettered e. In this form of spring
there are two return bends not including the hooks hereinafter described, at each of
which the wire of which the spring is formed is shown bent into a spiral 2. The
object in using the spiral bend e2 is in part to increase the strength and elasticity of
the spring and in part to furnish stops adapted to limit compression, and thus avoid
injury from over compression. The preferred form of spring is shaped somewhat
like the letter Z and has but three arms e³, but additional arms may be added if
desired.
The return bend spring e illustrated in. Figs. 12 and 13 is shaped somewhat like
the letter M set on edge and is bent into spirals e² at the two lower 'bends only, the
other return. bende being shaped like the letter U. This form of spring possesses
substantially the same advantages as to safety from injury by overcompression,
possessed by the spring e but is heavier and unnecessarily long for practical
purposes.
The spring e represented in Figs. 14 and 15 is like the one illustrated in Figs. 13
and 14 except that it has two U shaped bends e and only one spiral bend e2 which is
located at the central bend. It answers my purpose well but is inferior to the forms
described above.
In Figs. 16, 17, 18, 19 and 21 a form of return bend.spring is illustrated in which
all of the return bends are U shaped. It is inferior to the other forms because.
heavier in proportion to its strength and elasticity and because it possesses no stops
adapted to avoid over compression. Each spring, whatever its form may be in other
respects, is preferably provided with a hook e' at its inner end, and a book es at its
outer end, the former designed to embrace one.edge of the rim and enter a recess.b¹
therein and the latter to embrace one edge of the tire and enter a recess d¹,
in it.
i
The extreme inner and outer arms of the springs, are preferably substantially
parallel when in position but the intermediate arm, or arms, are preferably bent so
as to give them a zigzag appearance when viewed from above substantially as shown
In Figs. 5, 13, 15 and 19. This is particularly desirable where plain Ushaped return
bends alone are used as it enables the arins to pass each other when compressed and
72

page_text: though the spirals e³, when used, enable the arms to pass each other even when they
are all parallel, I prefer to bend the arms between the outer ones, into a zig-zag form,
even where the spirals are used, as it makes interference more difficult.. In that
case the zigzag form, though desirable, is not necessary. The appearance of a
compressed truss is illustrated by Figs. 9 and 10. Whichever of the described forms
of springs is used, the springs are preferably coupled together in pairs so as to form
a series of spring trusses E (Figs. 1, 2, 3, 5, 9, 10, 17, 18, and 19). The members of
each truss are arranged oppositely side by side so as to slant away from each other
and so as to bring the bends of one on the side of the wheel opposite the corresponding
bends of the other, as shown most clearly in Figs. 1, 2, 5, 17, 18, and 21. Their
innermost arms are preferably connected by a sheathe preferably formed of sheet
metal soldered to and around them, and their outermost arms are preferably yoked
together by a yoke elo preferably of sheet metal whose end edges are preferably bent
around said arms and soldered thereto. The soldering may be done in a form F
(Fig. 21) in which the parts of the truss can be assembled, or in any other suitable
manner. The trusses E are preferably arranged between the rim B and the tire D'as
shown in Figs. 1, 2, 3, 9, and 10 so as to cause the sheathe eº of the truss to rest
upon the rim of the wheel and the tire D to rest upon and be supported by the truss
yokes elo.
The opposite outward slants given the springs of each truss,> is very
advantageous in holding the tire in position when subjected to the usual slanting
pull away from the rim, and also in bracing the tire against a push and in giving
a quick recovery; and this arrangement is therefore very important whether the
springs are arranged in trusses or the means of coupling the members of each
truss together are omitted as they may be. The arrangement of the springs so
that the bends of each will always come on the side of the wheel opposite the
one on which the corresponding bends of the other member of the truss are
located is also of great importance in giving an equal support to each edge of
the tire, and the same plan is followed out in arranging the spring trusses with
reference to each other. The trusses are arranged so that the bends of each spring
will be on the side opposite the one occupied by the corrresponding bends of the
spring next it in the adjoining truss, as shown most clearly in Fig. 2. The form
of truss represented in Figs. 1, 2, 3, 5, 9, and 10 is provided with but four
hooks two hooks e7, which einbrace the rim of the wheel on opposite sides and two
hooks, which embrace opposite edges of the tyre.
.
Under some circumstances where unusual strength is required I furnish the truss
with four hooks e as shown in Fig. 18. I do this by enclosing with each outer arms
of the truss when I attach the yoke a piece el having at the end opposite the hooked
end of the adjoining arm a hook e adapted to embrace the edge of the tire just as
the book of the arm e³ does. The spring trusses are ordinarily attached to the tire by
merely inserting the tips of their hooks in the recesses and clamping the tire
between them, and their respective yokes.e10; and the hooks e are in like manner
clamped around the edges of the rim in the recesses b'. Where a metallic rim,
such for instance as the one shown in Fig. 22 is used, the hooks e' are preferably
attached to it by means of solder.
The metallic band d¹ of the tire is not only of use in preventing the tire from
stretching but also in causing a larger number of spring trusses to be compressed
together than would otherwise be. It also contributes to the lightness of the
wheel by enabling a smaller number of springs to be used than would otherwise
be necessary.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, as communicated to me
by my foreign correspondent, I declare that what I claim is :-
1. A spring wheel, having a rigid rim and a flexible tyre connected by a series
of return bend springs arranged oppositely and transversely side by side sub-
stantially as set forth.
2. For a spring wheel a flexible tyre composed of two or more layers of leather

page_text: -
or the like enclosing a band of spring steel and with or without a filling piece so
shaped as to render the tread surface of the tyre convex.
3. The various constructions of spring wheels substantially as described with
reference to the accompanying drawings.
Dated this fith day of March 1900