Improvements in and Connected with the Frames of Velocipedes.
Year: 1896

page_text: Date of Application, 4th Sept., 1896
Complete Specification Left, 4th June, 1897-Accepted, 28th Aug., 1897.
PROVISIONAL SPECIFICATION.
Improvements in and Connected with the Frames of Velocipedes.
I, PHILIP LOUIS RENOUF, of the Holford Engineering Works, Perry Barr near
Birmingham, Engineer, do hereby declare the nature of this invention to be as
follows:-
My improvements relate principally to the framework of Velocipedes made out of
Aluminium or other substance requiring similar treatment.
Where the frame has been cast in one piece and one part of the mould has been
subjected to cooling action, the result is unreliable as too large a volume of metal is
kept in a semi-solid state to allow the liquid head to follow up the shrinkage. I
therefore keep the moulds so hot that the metal remains liquid until all impurities
have escaped; where artificial shrinkage is resorted to, I combine it with a
simultaneous maintenance of heat in the upper part of the mould so that an
unbroken downward pressure of the metal is not impeded by an intermediate layer
of pasty mass. I prefer to confine the mould in an oven while the pouring takes
place, then after allowing the impurities to clear themselves (sometimes by moving
the mould too & fro) I let the mould gradually drop through the bottom of the
oven so that the lower part may be cooled while the upper part is kept hot.
In the case of the tubular steering stem of the front fork I prefer to stiffen it by
swaging it by driving into it a taper mandril while the outside is confined in a die.
Sometimes however this stem is a separate part provided with a head and locked
to the fork crown by a nut: the neatest way is to head the lowest extremity of the
stem, pass it through the crown and use the lower ball cone or disc as the locknut.
Dated this 1st day of September 1896.
PHILIP LOUIS RENOUF.
COMPLETE SPECIFICATION.
Improvements in and Connected with the frames of Velocipedes.
I, PHILIP LOUIS RENOUF, of the Holford Engineering Works, Perry Barr near
Birmingham 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 :-
My improvements relate principally to the framework of Velocipedes made out of
Aluminium or other substance requiring similar treatment. Where the frame has
been cast in one piece and one part of the mould has been subjected to cooling action,
the result is unreliable as too large a volume of metal is kept in a semi-solid state to
allow the liquid head to follow up the shrinkage. I therefore keep the moulds so hot
that the metal remains liquid until all impurities have escaped; where artificial
D....

page_text: shrinkage is resorted to, I combine it with a simultaneous maintenance of heat in the
upper part of the mould so that an unbroken downward pressure of the metal is not
impeded by an intermediate layer of pasty mass. I prefer to confine the mould in an
oven while the pouring takes place then after allowing the impurities to clear
themselves (sometimes by moving the mould to and fro) I let the mould gradually
drop through the bottom of the oven so that the lower part may be cooled while the
upper part is kept hot. With regard to the steering stem I prefer to use a separate
tube and lock it to the fork crown by a nut; the neatest way is to head the lowest
extremity of the stem, pass it through the crown and use the lower ball cone or disc
as the locknut. Referring to the drawings Fig. 2 illustrates the method of casting,
A. being a metal mould with a pourgate a. held together by a series of clams or
equivalent fastenings. This mould is suspended inside an oven or muffle B. by rods
or chains and balanced by a counterpoise C.; D, D1 are branches through which
flames of gas are blasted on to the mould so that the same is raised to an even red
heat all over. The aluminium is then poured in till the gate or gates are filled; the
mould is lowered till the lowest part is well immersed in the bath of water E.
(preferably of running water). By this means the lowest portion of the casting is
chilled and solidified but the upper portions kept liquid during sufficient time to
allow the requisite amount of metal to follow up the contraction caused by the
chilling. Sometimes the whole mould is immersed very gradually, sometimes
the lowest portion only; in the latter case the hot blast must be stopped very soon
after immersion.
Castings produced by this method are very strong owing to the great condensation
of the metal produced by shrinkage, but in the case of the front fork and steering
tube of a velocipede I prefer to cast the forks F. F. and crown G. in one piece and
join a separate steering tube H in the following manner:
His provided at its lower end with a head or shoulder h, and is screwed partly with
a left handed and partly with a right handed thread the lower portion fitting the hole
in the centre of the crown, and the upper portion the ball bearing disc I. His firmly
screwed through the crown G up to the head or shoulder h, and locked in position
by the disc I.
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) The process of lowering a mould A (Fig. ) heated in a stove or muffle as
described, into a chilling bath situated below the stove or muffle and thereby of
chilling the lower part of the casting whilst keeping the upper part liquid for the
purpose and in manner described.
(2) A closed muffle or stove as described for the purpose of heating up moulds
and provided with a series of gas jets in the manner described.
(3) The combination of an Aluminium fork crown of a Velocipede with a separate.
steering tube, the two being screwed and locked together in the manner illustrated
in Fig. 1 and described.
Dated this 4th day of June 1897.