Improvements in the Construction and Manufacture of Cycle Frames.
Year: 1894

page_text: This Print is in accлdance with the Original Specification as it stands after
Amendment (under Section 18 of the latents, &c. Act, 1883), as allowed
by the decision of the Comptroller General of the 20th day of April 1896.
Improvements in the Construction and Manufacture of Cycle Frames.
WILLIAM HOPKINSON 165 New Kent Road S.E. in the County of London
Mechanical Engineer do hereby declare the nature of this invention to be as
follows -
This invention which relates to the manufacture of cycle frames consists of
certain novel arrangements whereby all brazing of joints are dispenced with in
their construction.
My process consists of placing the tubes in any desired position in a frame or
cradle. The tube then being placed into a mould or chill, and my alloy of metals
which consist of copper 1000, tin 60-500 autimony 18.3 zine 200, or thereabout,
or any other inetal cast on to the tube when placed into the moulds on chills as
described.
COMPLETE SPECIFICATION (AMENDED,
Improvements in the Construction and Manufacture of Cycle Frames.
I, WILLIAM HOPKINSON, of 165 New Kent Road, in the County of London,
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 invention relates to cycle frames and has for its objects to provide improved
frames and also to provide for the manufacture of such frames in a very simple and
easy manner.
It has heretofore been the custom to first cast the parts or connections which
join the several tubes of the frame and then after cleaning and machining the same
to fit and braze the ends of the tubes therein. This is a long and costly process and
moreover very often weakens the tubes by reason of the heat which is employed in the
brazing operation.
According to my invention I make provision for uniting the several tubes which
Price Rd 1

page_text: form the flame, by means of parts cast on the tubes in suitable chills or moulds after
the said tubes have been placed in position. I thereby cast the parts and unite them
to the frame in one operation.
In order that my invention may be more clearly understood I will now proceed
to describe one method of carrying out the same with reference to the accompanying
drawing in which
Figure 1 shows the several tubes for forming a "diamond" frame with the chille
partly placed in position around the joints.
Figure 2 is a similar view shewing one of the back forks which is provided with
a step.
Figure 3 is a view of the two lowermost parts of the chili of the bottom bracket,
shewing the interior of said parts.
Like figures denote corresponding parts throughout the drawings.
In Figures 1 and 2 portions of the chills are turned back to shew the interiors of
the same.
Referring now to Figure 1, A is a framing or cradle of wood or other material adapted
to enclose the tubes and chills when placed in position; B, B¹, B², B³, B4, B5, B6, B7
are the several tubes of the cycle frame, C, D, E, F, G, II are the chills which
may be in two or more parts for convenience in placing the same in position and
emoving the same after the metal has been cast therein. In the case of a
"diamond" frame as shewn, the chills C, D for the upper and lower parts of the
front tube B and the chill E for that back fork which is not provided with a step
are conveniently made in two parts, the chill F for the upper part of the diagonal
tube B and the chill G for the second back fork which is provided with a step
shewn in Figure 2 in three parts, and the chill H for the bottom bracket in four
parts.
As an example of a chill made in two parts I will briefly describe the chill C for
the upper part of the front tube. C is the lower half of the chill and is the
upper half.
In Figure 1 the upper half is turned back to shew the interior of the
chill. When the two parts are placed in contact the two sides that are connected
by dotted lines in the figure are brought together, projections C³, C on the upper
part engaging with corresponding recesses C, C in the lower part. Any suitable
guides may be provided to ensure that the moulds shall accurately register when
they are brought together. C is the pouring hole and C the vent, both these
orifices being made in the upper part of the chill. The casting which connects the
tube B with the tube B has a suitable groove, shewn in the chill as a fillet C",
which ultimately serves as a ball race for the upper row of balls in the steering
head. If desirable the ball races may be formed by steel cups inserted m the
casting.
In all the joints of the frame the tubes which are connected abut against each other
as shewn, for instance the tube B₁ is placed so as to abut against the tube B, the
tube B also abutting against the tube B as shewn.
In a similar manner the tubes B, B³ and B, B7 touch each other at their ends and
the tube B abuts against the diagonal tube B. The tubes B², B, B', B which are
connected by the bottom bracket do not however touch each other, being separated by
a core as hereinafter explained.
The other chills D, E which are in two parts are constructed in a similar manner
to the chill C hereinabove described the pouring holes being placed as shewn at D¹, E¹
and the vent holes being at D, E in the upper part of the chills.
A core D is provided in the chil! D so that the bottom part of the casting is
formed with a groove for the lower ball race of the head as shewn.
The chill F is constructed in three parts F1, F2, F two of which F1, F2, when the
sides connected by dotted lines are placed together, embrace the diagonal tube 134,
the third part F³ is placed against the other two, and the whole bound together by
the straps F, F' as shewn. The diagonal tube B' extends through the mould to the
outside of the part F. In the particular frame illustrated the back stays B5, B7

page_text: are connected to the casting on the diagonal stay B' and the top stay B₁ by a bolt
and the said casting is split so that the saddle pillar can be very tightly gripped
therein by tightening the said bolt. I therefor insert a core F³ through the mould
so as to leave a hole for the bolt in the casting.
The back stays B³, B7 are as hereinabove mentioned not cast onto the diagonal
stay B and top stay B¹. It will be obvious therefore that the back forks cannot
be cast at the same time as the parts connecting the said diagonal and top stays
but must be cast after the said connecting part has been cast and the mould F
removed.
In some frames the back stays B5, B7 are connected to the top stay B¹ and diagonal
stay B in which case the core is dispensed with and the metal may be cast in
moulds C, D, E and F at the same time.
The parts forming the chill G are shewn clearly in Figure 2; G1 is the lower
part of the mould; the parts G2, G3 are supposed to be first of all turned back as
shewn on each side of, and connected by dotted lines to, the part G¹, the said parts
being also shewn further turned over again so as to exhibit those faces of each
which are applied to the part G. It will be obvious that the metal must be
first cast in the chill E and the chill G then put together the bottom part G
of the chili ( being held up by a block or other suitable support. If however
the frame be tilted before the back forks are cast these may be cast at the same
time.
The construction of the chill H. for the bottom bracket is shewn in Figures 1
and 3. The chill is in four parts H¹, H, H³, H', maintained in position by the
strap 15.
Figure 3 shews the parts H¹, H' separated and in Figure i the
parts H³, H are turned down to shew the interior. I provide a core H* extending
completely through the chill as shewn.
The chills are preferably so shaped on the outside as to fit the angles of the
frame or cradle A which serves as a receptacle for the chills and determines the
proper relative position of said chills. The said chills can be very readily placed
in position in the frame and the tubes of the frame placed in the chills. Suitable
pouring holes and vents are provided in the chills in a manner understood by every
practical moulder.
I prefer to place the chills C, D, F with the tubes B, B1, B2, B4 in position first
and cast the parts in said chills, then the tubes B³, B' are put in place and the
connecting part is cast in the chill E. Lastly the tubes B, B are put in place and
the bottom bracket and the other back fork cast in the chills H, G.
Before the tubes are placed in position in the chills I plug the ends of said tubes
with a small metal disc, or with loam or other material to prevent the metal flowing
into the same.
The alloy I prefer to use for connecting the parts is a mixture of tin 00-5 parts,
copper 10 parts, antimony 18-3 parts, and zinc 21 parts, which melts at a com-
paratively low temperature and is very suitable for this purpose. The copper is
melted in a crucible and the other metals are then added to it. The said connecting
parts when made of this alloy are susceptible of a high degree of polish and I thus
avoid the necessity for nickeling said parts moreover the alloy wears well and is
the same colour thoughout. Other alloys or metals may be used if desired.
Before placing the tubes into the chills, the ends of the tubes are cleaned by being
dipped into acid and are then coated with the alloy or metal by being dipped in a
molten mass of the same. When the alloy is cast round the ends of the tubes it
unites with the coating and as it cools contracts, and firmly grips the tubes, making
a very strong joint or connection.
The chills are preferably made of gun-metal and are divided in any manner suited
to the description of joint which varies with the type of frame to be made.
"
Although I have particularly described how a "diamond frame may be made
I wish it understood that I can use my improved method of joining the tubes to
form any description of cycle frame.

page_text: 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
A "diamond" or other cycle frame constructed substantially as herein before
described.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.