Improvements in Tension Mechanism for Chains of Safety Bicycles, Tricycles, and other Mechanism Run upon Chain Gearing.
Year: 1890

page_text: Date of Application, 8th Oct., 1890
Complete Specification Left, 7th July, 1891-Accepted, 5th Sept., 1891
PROVISIONAL SPECIFICATION.
Improvements in Tension Mechanism for Chains of Safety Bicycles,
Tricycles, and other Mechanism Run upon Chain Gearing.
A communication from abroad by Philippe ArISTIDE LARIPPE, 26, Avenue
de la Grande Armée, Paris, France, Dealer in Velocipedes.
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, and 323, High Holborn, in the County of
Middlesex, Civil Engineer, do hereby declare the nature of this invention to be as
follows:
The invention has for its object a simple and convenient mechanism permitting
the exact regulation of the tension of the chain of safety bicycles, tricycles and
other vehicles worked by means of pedals enabling one to take off and replace at
will this chain without it being necessary to make use of any special tool but simply
by acting with the hand upon a button or nut, or a hand gear arranged for this
purpose.
This improved mechanism is best set forth by a description of the experimental
apparatus in this a wheel fixed upon the pedal shaft commands the chain, said shaft
being maintained in a sleeve in which it can freely turn and which is itself
suspended by means of arms or cars to a fixed axis held in the base of the rigid
body of the safety bicycle or tricycle, and it works ordinarily upon the sleeve by
means of a filleted rod provided with a screw which operating with more or less
difficulty causes the chain to be slackened or tightened.
The articulated mechanism forming the subject of the present application is
composed of a screw maintained in position between two pieces in which it can turn
freely, and which are carried rigidly by any convenient means upon the body or
frame of the vehicle. Upon this screw is mounted a nut bound by means of two
links to an car or crank of sufficient length and fixed on the sleeve above described
or made solid with this sleeve. Lastly the upper part of the screw is provided with
a winged collar or button or mechanical equivalent which permits of being easily
turned by hand. It will be understood that any movement of rotation conveyed
to the screw by means of the winged collar will oblige the movable nut to displace
itself in one direction or another carrying with it the links, the car or crank and
consequently the sleeve of the pedal shaft of which the axis of suspension is in the
fixed axis aforesaid as has already been explained above.
In this case, for example, after the screw is made to turn in such fashion as to
cause the nut to descend, the shaft will be displaced in a backward direction. This.
action will determine the amount of loosening of the chain. If on the contrary the
screw be made to turn in the other direction, the nut is elevated and causes any.
degree of tension of the chain that may be desired. Furthermore, the travel of
the nut being great enough permits of the chain being sufficiently released for one
to be able to take it off and replace it at will. Further this simple and solid
mechanism is easily accessible to the hand and can be formed in such fashion as to
tend to the ornamentation of the safety bicycle upon which it is mounted.
Dated this 7th day of October 1890.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in Tension Mechanism for Chains of Safety Bicycles,
Tricycles, and other Mechanism Run upon Chain Gearing.
A communication from abroad by PHILIPPE ARISTIDE LARIPPE, of 26, Avenue
de la Grande Arinée, Paris, in the Republic of France, Dealer in Velocipedes.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.L.M.E., of the Agency for
Foreign Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street,
Manchester, both in the County of Lancaster, and 323, 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 :-
The invention has for its object a simple and convenient mechanism permitting
the exact regulation of the tension of the chain of safety bicycles, tricycles and other
vehicles worked by means of pedals enabling one to take off and replace at will
this chain without it being necessary to make use of any special tool, but simply
by acting with the hand upon a button or nut, or a hand gear arranged for this
purpose.
These important advantages render this system very suitable for use in certain
special cases, for instance, when travelling over uneven ground, the degree of speed
transmitted by the gearing to the driving wheel of safety bicycles, tricycles, etcetera,
may be rapidly changed.
The invention will best be understood by reference to the accompanying sheet of
drawings, in which :-
:-
Figure 1 is a side elevation of the mechanism.
Figure 2 is a front view of the tension portion of same.
Figure 3 is an elevation of the axle of the centre of the driving wheel..
As is commonly known, the pedal shaft a, on which the gearing, which actuates
the chain, is fixed, is usually maintained in a sleeve c where it can freely revolve,
and which is itself suspended by means of arms or cars d to a fixed axis e held in
the base of the rigid body of the safety bicycle or tricycle, and, ordinarily,
it is by working the sleeve e by means of a filleted rod, provided with a screw,
which operates with more or less difficulty, that causes the chain m to be slackened
or tightened.
C
The articulated mechanism forming the subject of the present application is
composed of a screw g maintained in position between two fixed pieces i, where it
can turn freely, and which are attached rigidly by any convenient means to the
body or frame of the vehicle. Upon this screw is mounted a nut h, bound by
means of two links to an ear or crank k of sufficient length and fixed on the
sleeve e above described or made solid with this sleeve. Lastly, the upper part of
the screw is provided with a winged collar or button or mechanical equivalent,
which permits of being easily turned by hand. It will be understood, from this,
that any movement of rotation given to the screwy by means of the winged collar j
will oblige the movable nut to move in one direction or another, carrying with it
the links, the ear or crank, and, consequently, the sleeve e of the pedal shaft,
the axis of suspension of which is at e, as has already been explained above.
C
In this case, if, for example, the screw be made to turn in such fashion as to
cause the nut h to descend, the shaft a will be moved in the direction shown on the
drawing by the arrow on the dotted are of a circle. This action will determine the
amount of loosening of the chain m. If, on the contrary, the screw g be made to
turn in the other direction, the nut will be elevated and will cause any degree of
tension of the chain that may be desired. Furthermore--the travel of the nut h,
being great enough, permits of the chain m being sufficiently released to allow of
its being taken off and replaced at will. Further, this simple and solid mechanism

page_text: is easily accessible to the hand and can be formed in such fashion as to tend to the
ornamentation of the safety bicycle upon which it is mounted.
As stated before, this arrangement permits of the power, transmitted to the
wheel of a safety bicycle, for instance, being varied even during a journey.
For this purpose it suffices to arrange, on both sides of the axle o of the driving
wheel of the safety bicycle, two pinions n and n' of different diameters, and to
arrange this axle in such a way that it may be easily and quickly removed from its
bearings.
Under these conditions, we will suppose the chain m is actuating the pinion n,
for instance, as shown in Figure 1, and it is desired to cause the chain to pass
onto the other pinion n', the operation would be performed in the following
manner :-
'
The chain is completely loosened by means of the wing nuts j so as to bring it
into the position shown in dotted lines on the drawings which allows of its being
withdrawn from the teeth of the pinion n, then the axle o is released from its
bearings and the vehicle being slightly raised by one hand the wheel is seized with
the other hand, and is caused to describe a half revolution so as to bring the axle o
at both ends into its bearings.
P
The chain m is then placed in the teeth of the pinion and when it has been
stretched to the required extent the safety bicycle is again ready to work geared to
a different speed to what it was before.
In order to facilitate the return of the driving wheel, its bearings are preferably
fitted with jointed caps p kept closed simply by means of a pin also jointed, and
having a milled nut as shown in Figure 1. In this manner by unscrewing this nut,
and raising the jointed pin, the movable part of the bearing turning freely on its
joint, sets free the axle o and the above described process may be carried out
without difficulty for changing the speeds of the gearings of the safety bicycle.
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
foreign correspondent, I declare that what I claim is :-
In safety bicycles, tricycles and other mechanism run by chain gearing, the
improved tension mechanism by which the tension of the driving chain can be easily
and considerably varied; and consisting of a screw held between two fixed pieces i i
which screw may be caused to easily turn by hand, and on which a nut moves
governing by means of links or rods a lug fitted to the sleeve which carries the
pedal or equivalent axle, all substantially as described above and illustrated on the
accompanying sheet of drawings.
Dated this 4th day of July 1891.
WM. P. THOMPSON & Co.,
Agents for the Applicant.