An Improved Method of Cycle Frame Construction for Tandem Bicycles and Tricycles.
Year: 1894

page_text: Date of Application, 6th Apr., 1894
Complete Specification Left, 5th Jan., 1895-Accepted, 9th Feb., 1895
An Improved Method of Cycle Frame Construction for Tandem
Bicycles and Tricycles.
JOHN MARSHALL STARLEY and WILLIAM STARLEY Cycle Manufacturers
Saint John's Works Coventry, do hereby declare the nature of this invention to he
as follows:-
In constructing tandem bicycles & tricycles we arrange a horizontal tube running
centrally between two circular ring bearing cases, the bearing cases (front & rear)
are of such a diameter as to admit completely the chain wheels of the front driving
chain. To allow for the passage of the chain from one crank axle bearing case to
the other we cut two apertures in both bearing cases. We construct the ball
bearing cups (for the two cases) with an extended disc the largest diameter of this disc
is shrouded, the shrouded part of disc we machine to fit tightly either the inner or
the outer diameter of the crank axle bearing cases, or we may cut a thread on the
internal or external diameter of the shrouded part of the disc & cut corresponding
threads on the outer or inner diameter of the crank axle bearing cases thus forming
(with the exception of slits to admit of the passage of chain) complete bosses to
encase the two wheels of the front driving chain.
To envelop the front chain completely & to protect it from dust & dirt we
construct two straight strips of steel or any other kind of metal or material suitable
for the purpose (the section of which is preferably a segment of a circle) one of
these strips we fit or rest on the top of the two crank axle bearing cases the other
strip we fix on the lower sides of the crank axle bearing cases, a strip of leather,
American cloth or other similar material is passed round each of the two strips &
fixed at the two edges in any suitable manner.
Dated 4th day of April 1894.
JOHN MARSHALL STARLEY.
WILLIAM STARLEY.
An Improved Method of Cycle Frame Construction for Tandem
Bicycles and Tricycles.
We, JOHN MARSHALL STARLEY and WILLIAM STARLEY, both of St. John's
Works, Coventry, in the County of Warwick, Cycle Manufacturers, 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 the manner in which we construct a cycle frame for
tandem bicycles and tricycles, whereby we are enabled to adapt a more direct and
compact arrangement of the driving gear than can be obtained with the machines
of the ordinary construction.
Referring to the two accompanying sheets of explanatory drawings,
Figure 1 is a front elevation and Figure 2 a plan representing a tandem bicycle
constructed in accordance with our invention.

page_text: Figures 3 and 4 represent one convenient method of adjusting the front chain.
Figure 5 illustrates the front chain guard, and
Figures 6 and 7 are enlarged views of one type of our crank axle bearing cups.
The same reference letters in the different views indicate the same parts.
In constructing a tandem bicycle such as shown at Figures 1 and 2, we arrange
a horizontal tube A to form a direct connection between the two crank axle bearing
cases B B¹. These cases B B¹ are of such a diameter as to completely enclose the
chain wheels of the front driving chain C, suitable apertures being provided in the
cases to permit of the free passage of the chain when in motion. We tighten or
adjust the chain C in one convenient manner by dividing the tube A and the lower
tube A' at some suitable position, and connecting the adjacent ends together by
means of the adjustable socket pieces D D¹ (Figures 1, 3 and 4). The end A² of
the tube (Figures 3 and 4) has a slot a cut through it to enable it to be clipped
tightly on to the socket piece D by means of a clamping socket such as E. The
socket picce D is brazed or otherwise secured to the end A³ of the tube, and the
adjusting screw or stud F is screwed through a tapped hole formed in the lug or
projection G also secured to the end A³. On releasing the clamping socket E and
screwing the point or end of the stud F against the socket, the ends A2 and A³ of
the connecting tubes are forced away from each other and thus the distance between
On
the bearing cases B B' is increased, and the chain C tightened as required.
again tightening the clamping socket E the end A2 is securely connected to the
socket piece D thus preventing the tension of the chain from producing any sliding
of the joint.
To completely enclose and protect the front driving chain C, we employ two
strips of steel or other metal or material, preferably of a segmental circular section,
one of which we fit or support upon the top of the cases B B₁ while the other we
fix on the lower sides of the cases. We then pass a strip of leather, canvas or
other flexible material round each of the two strips and secure the edges in any
well known and convenient manner. We thus completely enclose and protect the
front driving chain as illustrated at Figure 5.
We construct the ball bearing cups for the cases B B with an extended disc or
flange H (Figures 6 and 7) having the shrouded or projecting portion H¹ machined
to fit tightly either the inner or the outer diameter of the cases. We sometimes
cut a screw thread on the internal or external diameters of the shrouded or projecting
portion to screw on to corresponding threads which we cut on the external or
internal diameters of the cases. The cases B B' with the enlarged ball bearing
cups thus form complete boxes to encase the two wheels of the front driving chain
arranged centrally within them.
We do not limit the application of our invention to any particular cycle, but
adapt it for varying types of machines making such modifications in the construction
and arrangement of the parts as may be required.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. In tandem bicycles and tricycles the method of gearing the crank axles by
means of a chain and chain wheels arranged centrally with the cycle frame
substantially as hereinbefore described and as illustrated in the accompanying
drawings.
2. In tandem bicycles and tricycles the use of crank axle bearing boxes or cases
for supporting and encasing the chain driving wheels fixed centrally within them
substantially as bereinbefore described and as illustrated in the accompanying
drawings.
3. The construction of ball bearing cups having an extended disc or flange with
a shrouded or projecting portion for fitting within or upon the crank axle bearing
cases, substantially as and for the purposes hereinbefore described and as illustrated
in the accompanying drawings.

page_text: 4. The construction of a chain guard case from strips of steel or other material
carried or supported by the crank axle bearing cases, and a strip of leather, canvas
or other flexible material substantially as herein before described.
Deted thie 3rd day of January 1895.
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents for the Applicants.