Improvements in the Manufacture of Frames for Safety and other Cycles.
Year: 1892

page_text: Date of Application, 7th Dec., 1892
Complete Specification Left, 7th Sept., 1893-Accepted, 7th Oct., 1893
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Frames for Safety and
other Cycles.
JOHN MACKENZIE of Egglescliffe, Yarm-on-Tees, and WILLIAM MINTO of
Stockton-on-Tees, Cycle Agent and Manufacturer, do hereby declare the nature of
this invention to be as follows:-
Frames for safety and other cycles have hitherto been made by jointing several
short pieces of tubes and castings or stampings together by brazing or soldering.
The object of this invention is to dispense with all the short lengths of tubes
castings and stampings and the necessity for brazing, and in place thereof, to make
a cycle frame as follows.
We take a sheet of metal long enough and wide enough to form both sides of
the frame, we then, cut the sheet to the desired shape, and stamp or emboss the
sheet in such a way as will give the desired strength; the piece is then bent,
preferably at the part forming the head of the frame, and the two sides brought
together and joined by rivets or bolts or other means, preferably at the seat pillar
and the bottom bracket, or at any other desired point, and thus form a frame from
one piece of sheet metal.
We do not confine ourselves to use one piece of sheet metal, as two or more may
be used.
"
JOHN MACKENZIE.
WILLIAM MINTO.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Frames for Safety and
.
other Cycles.
We, JOHN MACKENZIE, of Egglescliffe, Yarm-on-Tees, Engineer, and WILLIAM
MINTO, of Bishopton Lane, Stockton-on-Tees, Cycle Agent, both in the County
of Durham, 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 consists of a special way of constructing the frames of safety and
other cycles which for cheapness of manufacture are produced in large numbers
from the same pattern, but have hitherto been built up of a combination of several
separate pieces consisting of tubes, castings and stampings joined together as one
frame by brazing and soldering.
The object of this invention is to dispense with a combination of separate short
lengths of tubes, castings and stampings together with the brazing and soldering
required to form the joints and to construct the frame of sheet metal stamped,
embossed and cut down in the manner hereinafter described with reference to the
annexed sheet of drawings.
In the drawings the several figures illustrate the bare frame in the usual form
as used for an ordinary safety cycle when constructed according to our invention
which frame is to be taken as the representative of cycle frames generally so far as
this invention can be usefully applied to them it being understood that the economy
effected thereby is dependent upon a large turn out of cycles of exactly the same
pattern in respect of the frame.

page_text: Figure 1 represents a side elevation of a cycle frame constructed according to
our invention and detached from the rest of the machine.
Figure 2, is a corresponding view in plan and Figures 3, 4 and 5 are sectional
views taken on lines x, x, y y, and zz, respectively of Figure 1.
In Figure 1 the dotted lines a, a', a², a³, a' are intended to mark out the size and
figure of a sheet of metal for stamping and enibossing therefrom a side of the
frame b, b1, 62, 63, 64 the other side being similarly embossed or stamped from
another sheet precisely similar, or if a a' be taken as the centre line of a sheet of
metal exactly the double of the figure in dotted lines from this sheet the duplicate
of frame b, b, 12 63, 64 could be embossed and stamped out with one half of the
duplicate frame lying to the right of line a a' and the other half to the left, round
which line a a' the duplicate would be bent double and so form both sides of the
cycle frame out of one piece of sheet metal.
We will however describe the frame shown in the figures as made up of two
separate sheets of metal rivetted or bolted together especially about the seat pillar
tube at and along the front top stay which consists of a uniform circular
section with flanged edges as shown more especially at c in Figure 5. The head of
the frame is brought together and fastened in the same way as the front tube stay
by means of rivets or solder or by clinching. The sides of the frame are made to
diverge towards for the accomodation of the bottom bracket tube d and also
towards for the accomodation of the driving wheel fork.
It will be observed from the figures and more especially from the sectional views
in Figures 3, 4 and 5 that the several members of the frame are stamped in the
form of a half circle in sectional area, so that when opposite parts of the frame are
close together their combined form in sectional area becomes a full circle.
In this way we combine in our cycle frames the requisite lightness and rigidity
with a very simple mode of construction and fewness of parts, and we do not
confine ourselves to the particular arrangement of parts shown, nor to the use of
our invention with one class of cycles only as the hereinbefore described mode of
construction can be adapted to a variety of forms and designs of cycle frames as
well as to the particular form illustrated in the drawing.
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
The construction and use in combination with the working parts of a cycle of a
frame of sheet metal, the sheet metal being embossed, stamped, and put together
for use as a frame, substantially in the manner and for the purpose as hereinbefore
described and illustrated by way of example in the accompanying drawing
G. J. CLARKSON,
Chartered Patent Agent,
Stockton-on-Tees, Agent for the Applicants.