Improvements in Bicycles.
Year: 1896

page_text: Date of Application, 5th Dec., 1896
PROVISIONAL SPECIFICATION.
Improvements in Bicycles.
I, EDWARD DAVIS THOMPSON, of No. 914 Kentucky Street, Lawrence, County
of Douglas, State of Kansas, United States of America, Civil Engineer, do
hereby declare the nature of this invention to be as follows:
The purpose of my invention is to utilize the elastic pressure of compressed air
as a spring that will yield when the wheels encounter an obstacle, and thereby
save the rider from shock. This is accomplished by a piston working in one of
the framing tubes of the bicycle against the force of compressed air. In order to
do this successfully, the leakage of air past the piston is prevented by the inter-
position of a liquid seal, which acts as a prolongation of the piston to the portion
of the chamber wherein the compressed air is contained. It is immaterial
whether the compressed air is in the same tube with the piston or in a com-
municating tube.
In the form illustrated, the chamber which is under pressure consists of the
main tube and a forward inclined tube, the interiors of which are in com-
munication at or near their lower ends, and contain a liquid, which in the main
tube supports the piston, the weight upon which is balanced by the air pressure
upon the liquid column in the inclined tube. The inclined tube is, in the
diamond-frame machine, the lower forward tube of the frame, and in the drop-
frame machine, is either of the forward inclined tubes. It will thus be seen that
my invention is capable of being varied in detail without departing from its
essential features, and two forms thereof will now be described.
In the accompanying drawings, which form a part of this specification,
Figure 1 is a side elevation, partly in section, of a bicycle having my invention,
in which the tubes are connected near their lower ends.
Fig. 2 is an enlarged sectional view in which the tubes are connected at their
lower ends.
Fig. is a top view of the cap on the main tube.
Fig. 4 is an enlarged sectional view of a modified form having the air-chamber
in the seat-post.
Fig. 5 is a top view of the cap in the main tube of the preceding figure.
The main tube A receives in its upper end, the seat-supporting post C which
fits therein as a piston, the lower end of the post being packed at 1) to form a
liquid-tight joint, and close the tube. The post should be kept from turning
within the tube in order to prevent the seat, which is carried by it, from turning
around. This is accomplished by making the post of hexagonal or other 'form
suitable to prevent rotation, and providing a cap G at the top of the main tube
with a hole of similar outline through which the post is guided. A collar J is
adjustably attached to the post below the cap to determine the upward limit of
movement of the post and height of the seat. As shown, this adjustment is
effected by cutting screw threads on the corners of the post, and threading the
interior of the collar so that it can be screwed up and down to lower and raise the
seat, as is needed to fit the bicycle to the rider,"

page_text: The interior of the main tube A and the inclined tube H communicate at or
near their lower ends, either through a connecting tube K, as shown in
Fig. 1, or through a trough within the crank-shaft bracket B, as shown in Fig. 2.
The chamber thus formed in the two tubes is entirely closed, but has in it near
the upper part of the inclined tube H a valve E through which air may be
pumped in.
A suitable liquid entirely fills the main tube A from the bottom of the piston
downward and the lower part of the inclined tube H and the connection between
the tubes, and forms a liquid extension of the piston. The quantity of this liquid
must be sufficient to reach past the connection between the tubes and into the
tube H in all positions of the piston when in use. In a bicycle provided with this
invention, the expansive force with which the seat is held up may be adjusted for
any weight of rider by varying the air pressure within the air chamber.
In applying my invention the collar J is first adjusted up or down as is needed
so as to limit the upper position of the seat to the proper reach of the rider. Air
is then forced through the valve E into the inclined tube H until the pressure is
sufficient to sustain the rider on the seat. With this adjustment there will be no
upward movement of the seat when riding over an even surface, but it will yield
downwardly whenever the bicycle rides over any obstacle, and shock to the rider
is thus prevented.
In the form shown in Figs. 4 and 5 the air-chamber, instead of being within
the inclined tube H, is within the seat-supporting post C, and has the valve E¹
at the upper end of this post. A cap G¹ is clamped at the mouth of the main
tube A and a collar J¹ adjustably attached to the post, by threading or otherwise,
determines the upward limit of movement of the post and height of the seat.
This collar may contact with the cap, but it is preferable to interpose a sleeve,
so that the threaded portion of the post on which the collar is adjusted can be
lower down, and not exposed above the cap. At the lower end of the post is a
guiding collar I. A suitable packing D¹ is provided between the post and the
main tube to prevent the escape of the liquid. As shown, I have attached it
about mid-way to the post, but it is immaterial whether the packing is attached
to the post, and travels up and down with it, or is a stuffing box at the end of the
main tube. In the form here shown, the post is kept from turning by being
flattened on one side and passing through a hole or similar outline in the cap G¹.
I have also devised many other forms in which the air-chamber and piston are
variously placed and the liquid seal interposed, but it is thought that the fore-
going will sufficiently indicate the scope of my invention.
Dated this 24th day of November 1896
EDWARD DAVIS THOMPSON,
By Day, Davies & Hunt,
Chartered Patent Agents, 321 High Holborn, London,
Agents for the Applicant.
I, EDWARD DAVIS THOMPSON, of No. 914 Kentucky Street, Lawrence, County
of Douglas, State of Kansas, United States of America, 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:-
The purpose of my invention is to utilize the elastic pressure of compressed air

page_text: as a spring that will yield when the wheels encounter an obstacle, and thereby
save the rider from shock. This is accomplished by a piston working in one of
the framing tubes of the bicycle against the force of compressed air. In order to
do this successfully, the leakage of air past the piston is prevented by the inter-
position of a liquid seal, which acts as a prolongation of the piston to the portion
of the chamber wherein the compressed air és contained. It is immaterial
whether the compressed air is in the same tube with the piston or in a com-
municating tube.
In the first form illustrated, the chamber which is under pressure consists of
the main tube and a forward inclined tube, the interiors of which are in com-
munication at or near their lower ends, and contain a liquid, which in the main
tube supports the piston, the weight upon which is balanced by the air pressure
upon the liquid column in the inclined tube. The inclined tube is, in the
diamond-frame machine, the lower forward tube of the frame, and in the drop-
frame, is either of the forward inclined tubes. In the second form illustrated,
the chamber which is under compression consists of the main tube and the seat-
supporting post, the lower end of which communicates with the main tube. It
will thus be seen that my invention is capable of being varied in detail without
departing from its essential features.
In the drawings filed with the Provisional Specification, which are hereby made
a part of this specification,
Figure 1 is a side elevation, partly in section, of a bicycle having my invention,
in which the tubes are connected near their lower ends.
Fig. 2 is an enlarged' sectional view in which the tubes are connected at their
lower ends.
Fig. 3 is a top view of the cap on the main tube.
Fig. 4 is an enlarged sectional view of a modified form having the air-chamber
in the seat-post.
Fig. 5 is a top view of the cap in the main tube of the preceding figure.
The main tube A received in its upper end, the seat-supporting post C which
fits therein as a piston, the lower end of the post being packed at D to form a
liquid-tight joint, and close the tube. The post should be kept from turning
within the tube in order to prevent the seat, which is carried by it, from turning
around. This is accomplished by making the post of hexagonal or other form
suitable to prevent rotation, and providing a cap G at the top of the main tube
with a hole of similar outline through which the post is guided. A collar J is
adjustably attached to the post below the cap to determine the upward limit of
movement of the post and height of the seat. As shown, this adjustment is
effected by cutting screw threads on the corners of the post, and threading the
interior of the collar so that it can be screwed up and down to lower and raise
the seat, as is needed to fit the bicycle to the rider.
The interiors of the main tube A and the inclination tube H communicate at
or near their lower ends, either through a connecting tube K, as shown in Fig. 1
or through a trough within the crank-shaft bracket B, as shown in Fig. 2. The
chamber thus formed in the two tubes is entirely closed, but has in it near the
upper part of the inclined tube H a valve E through which air may be pumped.
A suitable liquid entirely fills the main tube A from the bottom of the piston
downward and the lower part of the inclined tube H and the connection between
the tubes, and forms a liquid extension of the piston. The quantity of this liquid
must be sufficient to reach past the connection between the tubes and into the
tube H in all positions of the piston when in use. In a bicycle provided with
this invention, the expansive force with which the seat is held up may be adjusted
for any weight of rider by varying the air pressure within the air-chamber.
Air
In applying my invention the collar J is first adjusted up or down as is needed
so as to limit the upper position of the seat to the proper reach of the rider.
is then forced through the valve E into the inclined tube H until the pressure is
sufficient to sustain the rider on the seat. With this adjustment there will be no

page_text: upward movement of the seat when riding over an even surface, but it will yield
downwardly whenever the bicycle rides over any obstacle, and shock to the rider
is thus prevented.
In the form shown in Figs. 4 and 5 the air-chamber, instead of being within the
inclined tube H, is within the seat-supporting post C¹, and has the valve E¹ at the
upper end of this post. A cap G is clamped at the mouth of the main tube A¹
and a collar J adjustably attached to the post, by threading or otherwise,
determines the upward limit of movement of the post and the height of the seat.
This collar may contact with the cap, but it is preferable to interpose a sleeve,
so that the threaded portion of the post on which the collar is adjusted can be
lewer down, and not exposed above the cap. At the lower end of the post is a
guiding collar I. A suitable packing D¹ is provided between the post and the
main tube to prevent the escape of the liquid. As shown, I have attached it about
midway to the post, but it is immaterial whether the packing is attached to
the post, and travels up and down with it, or is a stuffing box at the
end of the main tube. In the form here shown, the post is kept from turning by
being flattened on one side and passing through a hole of similar outline in
the cap G¹.
In both of the forms illustrated it will be seen that the packing D moves up and
down with the seat post C', the two forming a piston, and that the liquid in the
tube is a liquid seal interposed between this piston and the air-chamber. The
two forms differ in the location of the air-chamber. The second form, shown in
Fig. 4, possesses the advantage that the liquid is not only forced into the air-
chamber on the descent of the seat post, but that the closed end of the air-chamber
is at the same time forced toward the liquid, thus increasing the air compression
with a given movement of the seat post.
I have also devised many other forms in which the air-chamber and piston are
variously placed and the liquid seal interposed, but it is thought that the fore-
going will sufficiently indicate the scope of my invention.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
1. In a bicycle, the combination of a main tube, a seat, a seat-supporting post
playing in the main tube, an air-chamber upon the air in which the seat is
supported, the air being compressed when the pressure on the seat is increased,
and a body of liquid for sealing the air-chamber and in contact with the seat post,
substantially as described.
2. In a bicycle, the combination of a main tube, a seat, a seat-supporting pest,
an air-chamber upon which the seat is supported, a piston for compressing the
air in the air-chamber when the seat-supporting post is moved, and a liquid seal
interposed between the piston and the air-chamber, the liquid being confined in
the main tube, substantially as described.
3. In a bicycle, the combination with a main tube, of a seat-supporting post
moving therein and forming a piston, a seat carried by the post, the main tube
enclosing an air-chamber, a liquid within the main tube sealing the lower end of
the air-chamber into which liquid the post projects, and guides for preventing
the rotation of the post in the main tube, substantially as described,
4. In a bicycle, the combination with a main tube, of a seat-supporting post
moving therein and having a cavity forming a chamber, a liquid seal in the main
tube closing the said cavity, and a packing upon and moving with the post and
resting upon the liquid seal, substantially as described.
5. In a bicycle, the combination with the main tube and inclined tube of the
frame the interiors of which are in communication near their lower ends, of a
seat-supporting post having a piston within the main tube, the inclined tube being
provided with a valve, means for preventing the outward flow of air which has
been forced in through the valve, and a liquid column interposed between the

page_text: piston and the air-chamber so as to entrap air in the inclined tube, substantially
as described.
Dated this 1st day of September, 1897.
DAY, DAVIES & HUNT,
Chartered Patent Agents, 321 High Holborn, London, W.C.,
Agents for the Applicant.