Improvements in Cycle Frames.
Year: 1894

page_text: Date of Application, 23rd July, 1894
Complete Specification Left, 22nd Oct., 1894-Accepted, 24th Nov., 1894
PROVISIONAL
SPECIFICATION.
Improvements in Cycle Frames.
I, CHARLES WILLIAM BROWN, of 2 Oak Villas, Friern Park, North Finchley,
in the County of Middlesex, Journalist, do hereby declare the nature of this
invention to be as follows:-
This invention relates to cycle frames particularly those adapted to the use
of ladies, whose skirts render frames of the common type with horizontal cross
bars near the top unsuitable. The improved frame may be used with single
or tandem bicycles and with tricycles; I will describe it first as applied to a tandem
bicycle and it may be carried out in the following manner :-
The back portion of the frame may be of usual construction say for example a
horizontal tube extending from the back wheel hub to near the centre of the front
diagonal the frame generally consisting of a series of three triangles, two of them
with their apices at the top and the centre one with its apex at the bottom, the
apices of the two triangles being joined by a horizontal bar which in a frame for
the riding of a man is usually conducted to the top of the steering head, but for a
dropped frame to accommodate a skirt is stopped off at the apex of the second
triangle. With the ordinary frame the steering head and fork are carried by two
diagonals brazed on to the previously described bottom horizontal bar so as to
leave an open space for the accommodation of the front rider. In my improved
frame I take any ordinary construction of, what is known as, diamond frame such
for example as that described above and I continue down the diagonal leg of the
front triangle below the horizontal tube and connect that by a tube or stay with the
frame at or about the point where it carries the hub of the back wheel or it may be
fixed at or about the point where the crank bracket for the back rider is carried
say at the apex of the middle triangle upon the horizontal bar. Or this stay may
be connected at any point between, or otherwise to the said horizontal bar though
I prefer to connect it as far back as I conveniently can. To further stiffen and
support the frame I prefer to carry down the forward leg of the back triangle and
connect that with the previously described stay and also to carry down to the front
end of the stay a forward diagonal connected with the previously mentioned
horizontal bottom tube and the bottom of the steering head. I may also use from
the top of the steering head to the horizontal tube either at its connection with the
front diagonal or in front thereof another diagonal tube which may also be carried
down to the previously described bottom stay if required. The diagonal of the
front triangle and the diagonal from the bottom of the steering head are carried
down and meet the bottom stay forming a small triangle below the bottom
horizontal tube and the diagonal from the top of the steering head may be connected
at any point in that triangle if desired.
Where it is not necessary to provide for the accommodation of a skirt the top of
the steering head and the apex of the front triangle may be connected by a
horizontal bar in addition to what has previously been described.
Dated him 09-11
1004
W. P. THOMPSON & BOULT,
Agents for the Applicant.

page_text: Improvements in Cycle Frames.
I, CHARLES WILLIAM BROWN, of 2 Oak Villas, Friern Park, North Finchley,
in the County of Middlesex, Journalist, 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 cycle frames particularly those which are commonly
known as open-fronted adapted to the use of ladies whose skirts render frames of
the common diamond type with horizontal cross bars near the top unsuitable. The
improved frame may be used with single or tandem bicycles and with tricycles but
I will describe it as applied to a tandem and a single "safety" bicycle. The object
of the invention is to increase the rigidity of the frame.
The invention will be best understood by reference to the accompanying
drawings, in which
Figure 1 is a side elevation of a tandem bicycle constructed according to one form
of this invention, and
Figure 2 is a perspective view of a portion of the frame.
Figure 3 is a side elevation of a tandem bicycle in which a slight modification of
the frame is introduced, and
Figure 4 is a perspective view of a portion of this frame.
Figure 5 is a side elevation of a single bicycle, and
Figure 6 is a perspective view of a portion of this frame.
Like letters represent like parts throughout the drawings.
Dealing first with Figures 1 and 2 it will be seen that this tandem bicycle frame,
so far as the upper portion is concerned, is very similar to forms now commonly in
use, the present invention relating to the lower portion of the frame. The
triangles A B and C are of substantially usual construction but the back fork D
terminating as a fork at the crank axle bearing O of the back rider is carried
forward as a single tube E E³ right up to the front diagonal F which connects the
bottom of the steering head G with this tube E3 by means of the angle socket E¹.
(In this and other cases where angle sockets or the like are described, I may use
other forms of connections, say for example lap joints.) The second diagonal H
which extends from the top of the steering head G is also connected to this tube E³
by the angle socket E³. A second back fork I extends from the axle bearing of
the back road wheel at D¹ to a little below the back crank axle O where by the
angle socket I¹ it is connected with an extension of the back diagonal B₁. This
fork also is carried forward as a single tube J to the front of the machine where it
joins an angle socket J¹ which also receives an extension F2 of the front diagonal F
as a short tube K which connects by the angle socket K' with the tube E. The
tube K is intended as an extension of the diagonal A¹ but is shown detached from
it here to allow of the steering rods which connect the steering fork L of the front
wheel with the second rider's steering handle or tube M being connected at the
bottom M¹; this being an ordinary way of making that connection and not forming
part of this invention is not further described here. (In Figure 3 the tube K is
shown as an extension of the diagonal A' and in this view it is actually a part of
the same tube a different arrangement of the steering mechanism not forming part
of this invention and therefore not shown being adopted to allow of this.) Where
it is possible I prefer to make the tubes K and A' in a single piece.
By this arrangement of the tubes exceptional rigidity of the frame is obtained
particularly of that part which is exposed to the shocks of the passage of the front
wheel over obstacles. The triangle formed by the tubes K E³ and the lower
part F2 of the diagonal F greatly increases the rigidity of this portion of the frame

page_text: while the lower fork or tie rods J I further assist in this result. The short
tube B serves to tie the forks D and I together at their forward ends and generally
assists in promoting the rigidity of the whole frame-work.
In Figures 1 and 2 the crank axle bearing Q of the front rider is shown pivotted
to the tube Es while in Figure 3 it is shown carried in an eccentric bracket; these
arrangements however do not form part of the present invention, and I do not bind
myself to use any particular arrangement of bearing.
Turning now to Figures 3 and 4, it will be seen that substantially the same con-
struction as that of Figure 1 is adopted, the slight modifications employed being the
following:
:-
1. The tube K instead of being an independent tube as in Figure 1 is actually a
portion of the tube A¹.
2. The tube H instead of stopping at the tube E³ as in Figure 1 is carried down
to the crank axle bearing bracket N which is provided with the necessary branch
to receive it, the tube A K also passing through this bearing bracket.
3. The fork D instead of terminating at the back crank axle O and being con-
tinued as a single tube E is a fork or double tube throughout its whole length the
two limbs of this fork passing one on each side of the tubes F H and A' with all
of which they are connected by any suitable connections say for example
the brackets E' E² and A². With the hack axle bearing O on the line of the
tubes D and E as in these figures they must be divided at this point; but if
the bearing be placed either higher or lower the tubes can be continuous throughout.
4. The fork I instead of being continued as a single tube J as in Figures 1 and 2
is, like the fork D, carried forward as a fork or double tube right up to the socket J¹
where it joins the tubes F2 and K, the latter as already explained being a cou-
tinuation of the tube A¹. The fork I J is thus composed of two nearly straight
tubes extending from the bracket D' which carries the axle of the back road wheel
to the socket Ji. This fork as in the former case is preferably tied to the upper
fork D by the short tube B2 which could be a portion of the diagonal B' unless the
crank axle should pass through it at the point O indicated in the drawings. To
allow of the tube being continuous the axle may be placed a little to one side so as
not to interrupt this tube. The perspective view, Figure 4, clearly shows how the
tubes DE and IJ are carried.
The ladies' safety bicycle shown in Figures 5 and 6 is substantially the same as
the front portion of the tandem bicycle shown in Figure 3 but as this is a single
machine the bracket D' is brought further forward, the portion of framing and
accommodation for the second rider being dispensed with. The front crank axle
bearing placed in Figure 3 so as to allow the tube A' to be continued down to
the bracket J' without interruption may in this case be altered and placed in the
axial line of the tube A¹ the reason for this being that while in the tandem it is
necessary to make the front crank axle bearing adjustable so as to tighten the chain
which runs from that axle to the back crank axle, in the single machine no such
adjustment is necessary as only one chain is used and this can be tightened by the
ordinary back slot adjustment which may also be used for tightening the back chain
of the tandem.
It will be observed that one of the special functions of the front portion E³ of the
tube E as above explained is to prevent movement at the joints of the tubes HGF,
and it will be noted that this might be effected by placing the tube E³ in some other
position or at some other level than that indicated. This would not be so satis-
factory as there would then not be the continuity of the tubes between E¹ and D¹
which there is in the forms above described and furthermore moving this portion
of the tube E higher up would place an additional strain upon the lower portions
of the diagonals F and H. While therefore much preferring to put it as above
described I have shown in dotted lines in Figure 3 a short tube P which may be
carried from the socket F¹ to the tube H and may be used instead of or in
addition to the tube Es at the lower end of those tubes; or it may be placed at
any intermediate position.

page_text: I have hitherto described the stay I J as extending from the bottom of the
triangle F E K at J¹ to the bracket D' which carries the axle of the back road-
wheel and this is the construction which I prefer; nevertheless I may if desired
connect it to the fork or tube DE at any point between the points A2 and D' say.
for example at the crank axle bearing O of the second rider in the tandem bicycle.
This would produce very much the same result so far as the triangle F E³ K is
concerned but does not look so well and does not give quite the support to the back
part of the frame which is obtained when the stay is carried back to D' and joined
to the diagonal B³.
From the foregoing description and an examination of the drawings it will be
seen that in both the tandem and the single machine a material portion of the frame-
work is below the level of the crank axle bearings whereas in machines of this
description hitherto made the frame practically and in most cases absolutely did
not extend below the level of the crank axle bearings.
Although not required for strength I may for the sake of appearance where the
machine is to be ridden by a man, place a tube or stay R (shown in dotted lines in
Figure 5) so as to make the machine look like one of the ordinary diamond type ;
I prefer to make this detachable so that the machine may still be ridden by a lady.
I am aware that such a detachable stay is already in use in some tandem bicycles
with open fronts, it being, with such machines of ordinary construction required to
strengthen the machine when used by two male riders.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
:-
1. In a cycle frame the combination with a triangle or triangular extension such
as K F³ and E³ of a fork or stay such as J or Jl connecting the said triangle
with the back portion of the frame substantially as described and illustrated in the
accompanying drawings.
2. In a cycle frame the combination of a fork or stay such as J or I J and the
extensions and K respectively of the diagonals F and A' with the extension E³
of the stay or fork E from the diagonal A¹ to the diagonal F substantially as
described and illustrated in the accompanying drawings.
3. In a cycle frame the combination of a fork or stay such as J or I J and the
diagonal extension F2 and separate tube K with the extension E³ of the single or
double stay or fork E from the diagonal A' to the diagonal F substantially as
described and illustrated in the accompanying drawings.
4. In a frame such as described in the above preceding claims stopping off the
diagonal A¹ at or about the point M' and completing the triangle by a separate
tube K substantially as described and illustrated in Figure 1 of the accompanying
drawings so as to allow of the connection of the second steering handle with the
front or steering fork.
5. In a cycle frame connecting the diagonals FH and A' with an extension of
the back fork D substantially as described and illustrated in the accompanying
drawings.
6. In a cycle frame the combination with the diagonals FH and A' of stay tubes
or fork such as E passing upon each side of the said diagonals and connected to
them substantially as described and illustrated in the accompanying drawings.
7. In a cycle frame the combination with the two front diagonals F and H the
extensions F2 and K and fork or stay J I of a cross support such as P or E³
substantially as described and illustrated in the accompanying drawings.
8. The combination and arrangement of parts constituting the complete cycle
frame substantially as described and illustrated in Figures 1 and 2 of the
accompanying drawings.
9. The combination and arrangement of parts constituting the complete cycle
frame substantially as described and illustrated in Figures 3 and 4 of the
accompanying drawings,

page_text: 10. The combination and arrangement of parts constituting the complete cycle
frame substantially as described and illustrated in Figures 5 and 6 of the
accompanying drawings.
C. W. BROWN.
W. P. Thompson & Boult,
Agents for the Applicant.