Improvements in or appertaining to Bicycles and like Vehicles.
Year: 1895

page_text: Date of Application, 21st Dec., 1895-Accepted, 22nd Feb., 1896
Improvements in or appertaining to Bicycles and like Vehicles.
A communication by CHARLES L. TRAVIS. of Minneapolis, in the County of
Hennepin and State of Minnesota, United States of America.
I, WILLIAM PHILLIPS THOMPSON F.C.S., M.I.M.E. of The Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool, and 6, Bank Street,
Manchester both in the County of Lancaster, 118 New Street, Birmingham in
the County of Warwick and 31 High Holborn in the County of Middlesex,
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 pertains to bicycles and like vehicles, and particularly to such
as are jointed and provided with a spring member to take up the jar and concussion
occasioned by obstructions and irregularities in the roadway or surface over which
the vehicles move.
The invention consists in a novel construction hereinafter pointed out in detail,
whereby a peculiarly simple, strong, and neat frame is produced, in which the
feature of yielding to obstructions is availed of to great advantage, and the frame
is freed from the vibration and strains incident to the ordinary rigid frame
construction.
In the accompanying drawings-
Figure 1 is a side elevation of a bicycle embodying the improvements;
Figure 2 a somewhat larger elevation of the rear portion of the frame ;
Figure 3 a sectional view of the same ;
Figure 4 a rear elevation of the contractible brace in its preferred form ;
Figures 5 and 6 similar views of slightly modified forms of said brace;
Figures 7 and 8, diagrammatic views illustrating the action of the device;
Figure 9 a modification; and
Fi
Figures 10, 11, and 12, views of different forms of spring.
It is of course well understood that if a vehicle frame be made rigid and
unyielding, it must move bodily upward and downward to the extent of the
elevation or depression of each and every portion of the roadway traversed; and
in consequence of the momentum acquired, the upward movement will ordinarily
be more or less in excess of the actual elevation. Such sudden movement of the
vehicle and the load upon it brings upon the frame a great and severe strain, and
subjects the rider to a jolting and pounding that is exceedingly unpleasant, and
oftentimes quite harmful.
To obviate this difficulty, spring supported saddles have been proposed, with a
view to permitting the machine to rise and fall without transmitting an equal
movement to the rider. So too, springs have been introduced into the frame at
various points and in different forms, with a view to enabling one portion or
another of the frame to yield without necessitating bodily movement of the entire
machine.
These contrivances, as heretofore embodied, have so far failed to meet the
difficulty that pneumatic tires have come into almost universal use, the yielding
frames being quite generally discarded when such tires are adopted.
By careful study of the subject it has been ascertained that it is practicable so

page_text: to construct the frame and to apply the spring or springs that without noticeably
increasing its weight or appreciably modifying its appearance, the frame shall be
relieved of all severe shock, concussion or vibration, and the rider shall be free
from the jolting and pounding heretofore experienced.
In practice it is preferable to employ pneumatic tires, though this is not essential,
and an extremely easy riding vehicle may be produced without them.
While primarily designed for bicycles, the invention may be embodied in tricycles
and similar vehicles, and the details may be somewhat varied, though certain
features hereinafter described should be retained.
C
"
Referring now to the drawings, A indicates the front section of a "diamond
frame, such as is quite generally adopted by leading manufacturers at the present
time. This section comprises a head a, an upper bar b, a lower bar
and a
saddle post standard d, at the lower end of which latter is located the barrel or
shell e in which the pedal shaft B is carried. Flexibly connected with the
barrel e of the frame section A is a rear-wheel fork C, comprising two rods or
tubes, which may be connected at their forward ends, or separate, as preferred.
The manner of jointing or connecting the fork C with the barrel e may be
varied, or the connection may be made to some other portion of frame section A,
provided it be close to the barrel e. In practice it is advisable that the joint be
made so that the flexure shall occur close to, and preferably, just in rear of the
pedal shaft, in order that there shall be no appreciable variation in distance
between the axis of the pedal shaft and that of the rear wheel carried by the
fork, within any movement of the fork that can actually occur in the use of the
machine.
A simple and quite satisfactory connection is the hinge joint represented in
Figure 3, which permits a limited vertical play of the rear fork, but which, by
engagement of the locking faces and g, precludes the falling of the fork below a
certain level relatively to other parts of the frame.
D indicates the rear wheel, the axle of which is carried in the rear end of
fork C, as usual. Said wheel will be provided with a sprocket wheel and driven
by a chain E from a sprocket wheel on the pedal shaft, or in any other usual
way.
At the upper end of the saddle post standard d there is pivotally or flexibly
secured the closed upper end of a tubular shell h, constituting one member of a
telescopic or two-part brace F, the other member of which comprises a fork i to
straddle the rear wheel, and a tubular extension j, closely fitting and telescoping
with the shell h. The lower end of tubular extension ; is closed, as shown in
Figure 3, and within it is placed the lower end of a strong spiral spring G, the
upper end of which extends into shell and bears against the closed upper end
thereof.
With the ordinary diamond frame as now in use, the shell and the extension j
may each be conveniently made in the neighbourhood of six inches in length, and
normally telescoped to the extent of about three inches, leaving room for further
telescoping of about three inches more; but these proportions may be varied to
any extent desired. They are mentioned merely to show the abundant space
afforded for a spring, which would thus be normally about six inches in length,
allowing approximately three inches for compression.
The spring G will be made sufficiently stiff and strong to support the weight of
the rider, with due allowance or excess for momentum, this being a matter of
calculation, and to some extent of individual preference.
The lower ends of the arms of fork i are hinged, jointed, or flexibly connected to
the rear ends of the side bars of fork C, as shown in Figures 1, 2 and 3, the
precise construction of the joint being immaterial, and provision for slight play or
flexure being all that is required at either end of the brace F.
These joints or connections, as also that between the front frame section A and
the rear-wheel fork C may be made by the introduction of a flexible plate k of
steel or othef suitable material between them, as in Figure 9. The mode of

page_text: securing the plate to the parts connected by it is unimportant,-brazing, rivetting
and welding being all available.
Instead of employing the shell and extension j, these parts may be made as
one integral member, and the arms of fork i made telescopic, as in Figures 5 and 6,
the principle and action remaining the same.
Referring now to Figures 7 and 8, the action of the frame and spring will be
explained. When the rider is seated upon the saddle, the front end of frame
section A is supported upon the axle of the front wheel, and the rear end of fork C
is supported upon the axle of the rear wheel D. If the weight of the rider is
greater than the resistance of the spring at its normal length, the spring will be
compressed proportionately, though it is contemplated that there shall be n
material compression when the machine is stationary, or when travelling over a
level surface.
If now, the front wheel encounter an obstruction or elevation, it will rise as
indicated by dotted lines in Figure 7, moving about the axis of the pedal shaft as
a centre and causing the rider's seat to recede slightly, with no appreciable change
in elevation. Owing to the distance between the bearing point of the front wheel
and the pedal shaft, and to the location of the rider's seat over or slightly in rear
of said shaft, the front wheel can rise with relatively little resistance, the
As soon
spring G being compressed and permitting such movement.
as the
obstruction or elevation is passed, the spring restores the parts to their normal
positions.
If the rear wheel encounter an obstruction or elevation, it will rise, the fork C
swinging upward from the point of connection with front frame section A, while
the rider's inertia causes him to maintain a practically fixed position as to height,
the action being as indicated by dotted lines in Figure 8.
It is desirable to provide for a limited yielding of the frame when slight
irregularities of surface are encountered, and for additional play when greater
irregularities are met with, and also to adapt the same machine, without change, to
light and heavy riders. This is attained by employing a spring or springs having
different portions of unequal strength or stiffness, varying the arrangement as
circumstances require or convenience suggests.
In Figure 10 is shown a spring of one continuous wire having its coils of different
diameter in different portions of its length, and consequently capable of yielding
more readily in the portion of larger diameter than in the smaller portion.
In Figure 11 is shown a spring of gradually increasing diameter, produced by
coiling about a taper mandrel.
In Figure 12 are shown two sections of spring of unequal stiffness arranged end
to end.
Under each of these plans, the weaker portion will yield until its coils are in
contact, and then the heavier part will begin to yield, and thus both the above
recited objects will be attained without any attention or action on the part of the
rider. This is an extremely important provision, and one which goes far to remove
one of the most serious objections heretofore obtaining against jointed bicycle
frames with take-up springs.
It is particularly to be observed that the spring is entirely concealed; that it is
compressed in the direction of its axis and consequently has no tendency to buckle
laterally or to exert a side strain upon the brace; that if the spring should break
or set, the machine would still be entirely serviceable; that the double thickness
produced by the shell and extension j gives great strength to resist lateral strains
to which the rear fork is subjected; and that all parts of the telescopic brace are
kept at all times below the upper member of the front frame, hence they cannot in
any manner interfere with the saddle post or with the rider.
It will also be noted that the rear fork and the brace may, under this construction,
be made of usual lightness, since there is no lateral strain applied to the brace and
transmitted through the rear fork to the front frame, as is the case where the rear

page_text: frame is made in the form of an elbow lever, and a spring is arranged to act against
the upper arm of said lever.
The improvement may be readily and cheaply applied to machines now in use,
as has in fact been done by my correspondent with perfect success.
Having now particularly described and ascertained the nature of the 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. In a bicycle, the combination of a rigid front frame, a rear wheel fork flexibly
connected with said front frame, a telescopic tubular brace extending from the rear
of said fork upward to the rear of the front frame, and a spring encased within the
tubular brace and tending to elongate the same.
2. In combination with a rigid front frame, a rear wheel fork flexibly connected
therewith at or near the pedal bearing, a two-part brace extending from the rear
portion of said fork upward to the rear of the front frame, and having its extremities
flexibly connected with said fork and frame respectively, and a spring interposed
between the two members of the brace and tending to elongate the same.
3. In combination with a rigid front frame, a rear wheel fork flexibly connected
therewith at or near the pedal shaft bearing, a tubular shell flexibly connected at
its upper end to the upper rear portion of the front frame, a forked brace flexibly
connected to the rear portion of the rear wheel fork, and provided at its upper end
with a tube adapted to telescope with the tubular shell, and a coiled spring having
one end seated in the tubular shell and the other end seated in the tubular extension
of the forked brace, substantially as shown and described, whereby the use of a long
and elastic spring is permitted.
4. In a bicycle or like vehicle, the combination of a rigid front frame carrying
a rider's seat support and a pedal shaft bearing, a rear wheel fork flexibly connected
with said front frame at or near the pedal shaft bearing, a longitudinally contractible
brace extending from the upper rear portion of the front frame to the rear portion
of the rear wheel fork and flexibly connected at its extremities with said parts, and
a spring in axial alignment with said brace and tending normally to extend the
same.
5. In a bicycle or like vehicle, the combination of a rigid front frame provided
with a rider's seat support and a pedal shaft bearing, a rear wheel fork flexibly
connected with the front frame at or near the pedal shaft bearing, and a telescopic
tubular brace flexibly connected at its upper end to the upper rear portion of the
rigid front frame, and flexibly connected at its lower end to the rear wheel fork,
substantially as described and shown.
6. In combination with a rigid front frame, a rear wheel fork counected therewith
at or near the pedal shaft bearing by means of a lock or stop joint, and a longi-
tudinally contractible brace extending from the rear portion of the rear wheel fork
upward to the rear portion of the rigid front frame, substantially as described.
7. In combination with a bicycle frame comprising two members flexibly connected
one to the other, an interposed brace consisting of two tubular shells, one fitting
within the other and each closed at its outer end, and a spring enclosed within said
shells and bearing at its ends against the closed ends of the shells, whereby the
double thickness of the shells is utilised to give lateral strength to the brace and
the entire space between their closed ends is utilised for the reception of the spring,
thus permitting the use of a long and highly elastic spring.
8. In combination with a rigid front frame carrying a saddle post and pedal
shaft, a rear fork flexibly connected to said front frame, a two-part brace pivoted
at its lower end to the rear fork and at its upper end to the front frame at a point
below the top of the upper member of the front frame, and a spring interposed
between the two members of said brace and serving to elongate the same, whereby
said brace is kept below and is prevented from interfering with the saddle post.
9. In combination with a rigid front frame, a rear wheel fork flexibly connected

page_text: therewith, a telescopic tubular brace interposed between said frame and fork, and a
spring bearing at its ends against the respective members of said two-part brace,
substantially as and for the purpose set forth.
10. In combination with a rigid front frame carrying the saddle post and pedal
shaft, a rear fork jointed to said front frame, a two-part member pivoted at its
lower end to the rear fork, and at its upper end to the front frame, and a spring
interposed between the two parts of said member in line with its axis, substantially
as and for the purpose set forth.
11. In combination with a rigid front frame provided with a pedal shaft and with
a rider's seat or support, a rear wheel fork jointed to the front frame at or near
the pedal shaft barrel, a telescopic brace or member jointed to said rear fork near
the rear end of the latter and jointed at its upper end to the rear upper portion
of the front frame, and a spring enclosed within the telescopic member and serving
to take up the shock and vibration imparted to the frame.
12. In a bicycle or like vehicle, the combination of a rigid front frame A provided
with pedal shaft bearing e, shaft B and rider's support b, rear fork C hinged to
frame A at or near bearing e, rear brace F comprising members h, i and, the
former jointed to front frame A at its rear and upper portion and the latter jointed
to rear fork C, and spring G bearing at its ends against the members h and j
respectively and tending to hold them apart.
13. In combination with a jointed vehicle frame, an interposed brace and a spring
acting against said brace and having portions of unequal stiffness or strength adapted
to come into action successively.
14. In combination with a jointed frame substantially such as described, an
interposed spring comprising sections of unequal strength or stiffness substantially
as and for the purpose explained.
15. In combination with rigid front frame A, rear fork C flexibly connected
therewith, telescopic brace F interposed between said parts and a spring applied to
said brace and having portions adapted to come successively into action, substantially
as explained.
Dated this 20th day of December 1895.