Improvements in Mechanical Joints for Vehicle-frames.
Year: 1897

page_text: Date of Application, 30th Sept., 1897-Accepted, 8th Jan., 1898
COMPLETE SPECIFICATION.
Improvements in Mechanical Joints for Vehicle-frames.
I, ALBERT AUGUSTUS POPE, of Cohasset, County of Norfolk, State of Massa-
chusetts, United States of America, Manufacturer, 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 ;-
The object of my invention is to provide a vehicle frame, and more particularly
the frame for a velocipede or bicycle, so constructed as to the joints and means
for securing the several parts of the frame together, as to enable the parts to be
firmly united and afterwards readily separated without requiring the parts to be
heated or subjecting them to unequal and uncertain strains.
To this end my invention consists in a vehicle frame comprised of separable
members with a joint so constructed as to involve mechanical means of union
only, as hereinafter described and more particularly pointed out in the claims.
Referring to the drawings:-
Figure 1 is a view in central section through. a bracket member and the end of
a tubular member of the frame, showing details of the joint.
Figure 2 is a like view in central section through the bracket member and the
end of a tubular member showing a modified form of joint construction.
Figure 3 is a detail view in central lengthwise section through a part of a
bracket member and the end of a tubular member showing another modified forin
of the construction of joint.
Figure 4 is a detail view in side elevation of the filling ring shown in Fig. 1.
Figure 5 is a detail view in side elevation of the filling ring shown in Fig. 2.
Figure 6 is a view in cross section through the joint of the form shown in
Fig. 2.
In the accompanying drawings the letter a denotes a bracket member of the
frame having a tang b with a reduced screw-threaded portion c leaving a shoulder d
at the inner end of the reduced portion.
The end of the tubular member e of the frame has an interior screw-thread
which fits and engages a screw-thread on the tang so that the two parts are united
by screwing them together. The extreme end of the tube is provided with a
tapered surface which co-operates with a tapered surface on the filling ring and
by forcible contact therewith serves to bind the parts more firmly together.
In the form of filling ring shown in Fig. 1 of the drawings the ring g is pro-
vided on both sides of its inner surface with a bevel g¹ g, the beveled surface g¹
being adapted to make contact with the end of the tube and the other to encounter
a shoulder on the tang.
In frames for bicycles and velocipedes, to which my improvement is particularly
adapted, the tube is of very thin metal and in most instances requires a reinforce,
as h, which is secured to the tube, although the required thickening may be formed
in the tube when it is drawn. In any event the end of the tube is made of
sufficient thickness to enable a thread to be cut therein without any dangerous weaken-
ing of the parts.
In a frame constructed in accordance with my invention the tubular members

page_text: are cut to the required length as closely as may be and are connected to the bracket
members by screwing the parts together, the ring having first been placed upon
the tang. The final adjustment of the parts for the proper alignment of the frame
is made by forcing the tube end against the ring, the parts yielding to a sufficient
degree to enable, small final adjustments to be provided.
In the form of the invention shown in Figs. 2 and 3 of the drawings the filling
ring is of considerable breadth counterbored to form a recess in the end of
the ring adjacent to the shoulder on the tang, and counterbored to form a tapered
surface on the side adapted to receive the end of the tubular member of the
frame. This form of ring is also threaded to fit upon the threaded portion of the
tang so that close lateral contact between the ring and the shoulder on the tang
is not essential as is. the case with the form shown in Fig. 1 of the drawings.
The end of the tube is tapered slightly to fit within the recess in the ring, and
in the final adjustment of the connecting means the end of the tube is clamped
forcibly upon the tang so that the parts are held not only against lengthwise
movement upon each other, as by means of the thread, but also against rotation
with reference to each other, as by means of the clamping action of the ring.
The overhanging edges of the ring which overlic on the one side the tang and
effect upon the thin steel tube by the heating to which it is subjected in the brazing
and keeping them from springing up..
In the form of the joint shown in Figs. 2 and 3 of the drawings the ring being
threaded upon the tang enables it to have a limited lateral adjustment so that the frame
can be trued up to the exact gage required and the parts clamped in this final
position.
The main object of my invention is to provide a frame in which there need be
no brazing of the main component parts, which is the method commonly employed
in the prior art and is a source of expense, of loss, and of unknown danger owing
to the fact that the factor of safety in a frame in which the bracket members and
tubular members are united by brazing is always a matter of uncertainty. The exact
effect upon the thin steel tube by the heating to which it is subjected in the brazing
operation and the subsequent unequal cooling of the parts is not known, except
that the tube is apt to be distorted and in forcing it to place unequal strains are
set up so that a slight blow is apt to cause a breakage of the parts. The surplus
metal used in brazing is removed by filing with the attendant danger of cutting
through or into the thin wall of the tube to such an extent as to cause it to break
under a slight shock or strain in use, and this weakness due to filing is covered
up by the enameling or finishing of the tube and frame in such manner that the
defect is not discovered in time to prevent an accident of greater or less gravity
in the use of the bicycle of which the frame forms a part.
My improved mechanical joint, so-called to distinguish it from any brazing
operation. or like method of uniting the parts, has been proved effective by actual
tests in bicycle frames used in bicycles which have been ridden for several thousand
miles under severe conditions of use, and proved to be a simple, compact and
secure device for uniting the parts without weakening thereof by continued wear
in the vibrating strains which are set up in the use of the wheel on the road.
It is evident that my improvements are also applicable in cases where the
longer frame-members are made solid instead of tubular. For example such
longer frame-members are made with hollow, recessed or cupped ends, expanded
flared or otherwise shaped and adapted to receive the screw-threaded portion c of
the projection or tang 6 of the bracket member a or its equivalent.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1. In combination, in a vehicle-frame composed of bracket members and separable
tubular or longer members, a bracket. member provided with a screw-threaded
tang, a tubular or longer member having a screw-threaded end fitting upon the

page_text: screw-threaded tang, and a filling ring located between the end of the said tubular
or longer member and a shoulder on the tang, with a tapered surface overhanging
the end of the said tubular or longer member while the ring is held against lateral
movement lengthwise of this member, all substantially as described.
2. In a vehicle-frame, in combination with a bracket member having a screw-
threaded tang, a tubular or longer member having a screw-thread fitting the
screw-thread upon the tang, a filling ring screw-threaded to fit upon the tang with
its edges overhanging the adjacent surfaces on the tang and on the said tubular
or longer member, the inner surface of the ring adjacent to the end of the said
tubular or longer member being tapered, all substantially as described.
Hastfowl Conn TISA September 7th 1897.
ALBERT AUGUSTUS POPE.
D. Young & Co.,
11 and 12 Southampton Buildings, London, W.C.,
Agents for the Applicant.