Improvements in Variable Throw Cranks.
Year: 1897

page_text: Date of Application, 15th Nov., 1897
Complete Specification Left, 3rd Aug,, 1898-Accepted, 3rd Sept., 1898
PROVISIONAL SPECIFICATION.
Improvements in Variable Throw Cranks.
We, ARTHUR GEORGE MUMFORD, of the Culver Street Iron Works, Colchester,
in the County of Essex, Engineer, and ALFRED ANTHONY, of Beaconsfield Avenue,
in the Town and County aforesaid, Draughtsman, do hereby declare the nature of
this invention to be as follows:-
This invention relates to an improved variable throw crank which is charac-
terised by the fact that the mechanism is applicable to the ordinary cranks at
present in use on velocipedes, and is therefore more easy of application.
According to this invention a spring controlled extension adapted to carry
the pedal is employed which is capable of being attached to an ordinary crank.
The extension consists essentially of a disc adapted to be fixed to the end of the
crank by the means employed for fixing the pin of the pedal thereto. On this disc
is mounted by means of a suitably arranged ball bearing another disc carrying an
arm adapted to receive the pedal. To this disc is pivotted a rod carrying an
adjustable collar adapted to slide in a tubular arm pivotted to the larger end of a
cottar pin adapted to replace the usual cottar pin by which the crank is fixed to
the axle. This tubular arm carries a compression spring arranged to control
the movement of the disc carrying the pedal. This disc also carries an adjustable
stop adapted to engage with the crank and limit the recoil of the disc carrying the
pedal after its extension movement.
As a modification the tubular arm may be pivotted to a small bracket adapted
to be screwed on to the end of the ordinary cottar pin or to be clamped or otherwise
fixed to the crank.
ROBERT E. PHILLIPS,
Assoc. M. Inst. C.E., M.I. Mech. E.,
Consulting Engineer and Patent Agent,
70. Chancery Lane, London, W.C.,
Agent for the Applicants.
ROBERT E. PHILLIPS,
Assoc. M. Inst. C.E., M.I. Mech. E.,
Consulting Engineer and Patent Agent,
70. Chancery Lane, London, W.C.,
Agent for the Applicants.
Improvements in Variable Throw Cranks.
We, ARTHUR GEORGE MUMFORD, of the Culver Street Iron Works, Colchester,
in the County of Essex, Engineer, and ALFRED ANTHONY, of Beaconsfield Avenue,
in the Town and County aforesaid, Draughtsman, 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 an improved variable throw crank which is charac-
terised by the fact that the mechanism is applicable to the ordinary cranks at
present in use on velocipedes, and is therefore more easy of application.
Price R71

page_text: In the accompanying drawing which illustrates the invention;-
Figure 1 is a view in side elevation-partly in section.
Figure 2 is a view in transverse section on line xx Figure 1.
Figure 3 is a view in plan, and
Figure 4 is a broken view in side elevation showing a modification.
Throughout the views similar parts are marked with like letters of reference.
According to this invention a spring controlled extension adapted to carry
the pedal is employed which is capable of being attached to an ordinary crank.
The extension consists essentially of a disc A having a boss a preferably eccentric-
ally arranged which is adapted to be fixed to the end of the crank B by the means
employed for fixing the pin c of the pedal C thereto. That shown in the accom-
panying drawing being one now in common use and employed here by way of
illustration only. On the periphery of the disc A is mounted-preferably by
means of a ball bearing-another disc D carrying an arm d adapted to receive the
pin c of the pedal C the means of attachment employed being the same as was
used for fixing the pin to the crank. To the disc 1) is pivotted a rod E carrying
an adjustable collar e adapted to slide in a tubular arm F pivotted to the other
end of the crank. This is conveniently effected by pivotting it to a cottar pin G
adapted to replace the usual cottar pin by which the crank B is fixed to its axle
as shown by Figure 1, or to a bracket f adapted to be fixed to the crank or cottar
pin as shown by Figure 4.
The tubular arm F carries a compression spring H against which the collar e
on the rod E engages and so controls the movement of the disc D carrying the
pedal C. The disc D also carries an adjustable stop d' adapted to engage with the
crank B for the purpose of limiting the recoil of the said disc after its rotation on
the disc A giving the extension movement to the crank.
By this invention any ordinary crank can be converted into a variable throw
one, it being only essential that the means employed for attaching the disc A to
the crank shall be the same as that employed for attaching the pedal pins to the
cranks.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
(1) In a velocipede, the combination with an ordinary crank, of the combination
of parts herein before described and illustrated by the accompanying drawing
forming an improved automatic variable throw crank.
(2) An automatic variable throw crank for velocipedes, consisting essentially
of an ordinary crank B, of a disc A having a boss a adapted to be fixed to the
crank B by the same means employed for fixing the pedal pin thereto, of a disc D
mounted to rotate on the periphery of the disc A and having an arm d adapted
to receive the pin c of the pedal C and a stop d' adapted to engage with the
crank B, of a rod E pivotted to the disc D and carrying an adjustable collar e, of
a tubular arm F. of a spring H located in the tubular arm F and acted upon by
the collar e carried by the rod E, and of means for pivotally attaching the tubular
arm to the crank B, as and for the purpose set forth.
Dated thin and day of A 1000
ROBERT E. PHILLIPS,
Assoc. M. Inst. C.E., M.I. Mech. E.,
Chartered Patent Agent, 70, Chancery Lane, London, W.C.,
Agent for the Applicants.