Improvements in Bicycle Frames.
Year: 1898

page_text: Date of Application, 26th Aug., 1898-Accepted, 26th Aug.,
1899
COMPLETE SPECIFICATION.
Improvements in Bicycle Frames.
I, HENRY THOMAS BRAGG, Manufacturer, of 253, Broadway, New York City, in
the County and State of New York, United States of America, 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 invention relates to that class of bicycle frames designed to form a casing
or housing for the driving and connecting gear of what is known as chainless
bicycles.
The object of the invention is to provide such a casing or housing, to form a
part of the bicycle frame, and embodying little weight, but rigidity and strength
corresponding to the other parts of the bicycle frame. A further object is to so
organize or construct such a housing as to permit of the removal of the connect-
ing gears.
With these and minor objects in view, the invention consists in the matters to
be hereinafter described in detail, and then briefly set forth in the claims at the
close of this specification.
In the accompanying drawings, Figure 1 is a side elevation, partly in section,
of a gear casing or housing embodying my improvement.
Figure 2 is a top plan view partly in section, of so much of a bicycle frame as
to illustrate my improvements in connection therewith.
Figures 3 and 4 are views in perspective of the two parts of the rear casing.
Figures 5 and 6 are detail views of the parts of the forward casing.
For the purposes of illustration I have shown my improved gear casing in con-
nection with a special form of driving gear, but it will be understood that its
use is not limited to the particular form of gear shown, as it may be used with
advantage with other known forms of gear.
In the form shown, the bicycle frame is provided with the usual rear fork-
sides, 1 and 2, extending from the shaft hanger to the rear wheel, and the usual
brace-rods, 3, extending from said rear wheel to the upper horizontal frame
member.
The shaft hanger is formed of two parts, A and B, comprising a central
cylindric box or housing A' for a driving gear C, which gear is keyed or other-
wise rigidly secured to the usual crank shaft C¹. Extending laterally from each
side of the central box or housing, A and B, and arranged concentric therewith
are tubular stubs or boxes a and b, within the outer ends of which are arranged
the usual anti-friction bearings for the crank shaft.
The section or part A of the crank hanger is provided with a boss a, prefer-
ably hollow, carrying a stub a³, upon which is brazed the forward end of the fork-
side 1 of the frame, the rear end of said fork-side being brazed to the usual
fork-end, thus connecting the crank hanger A and B rigidly on one side of
the machine with the rear frame thereof, and stubs a and a project from the
central enlarged part or housing A¹, of the hanger, upon which are brazed the
rear and lower ends, respectively, of the lower reach tube and the saddle post
tube or strut of the bicycle frame, thus establishing rigid connection between
the hanger and the upper and forward parts of the bicycle frame.
The part B of the hanger is provided with a hollow boss B', of such shape and

page_text: This
size as to contain a pinion designed to mesh with the gear C, secured to the
crank shaft C, and be driven thereby. At rear this hollow boss, as shown in
Figure 1, is provided with a threaded stub b, to engage an internally threaded
collar, forming part of the rear fork-side 2 of the bicycle frame.
threaded collar is shown in said figure as swiveled upon a stub 63, to which the
fork-side 2 is brazed, and as containing a cupped ball race, forming part of an
anti-friction bearing for the forward end of shaft 4, connecting the driving
gear C with the driven gear D secured to the rear hub.
The fork-side 2 is brazed at its rear end to a stub e projecting from the outer
member E of a two-part housing or casing E-E¹. Said housing, as stated, is
composed of two members E and E, the outer one being shaped at its forward
end to receive the connecting shaft 4, and at a central point to contain the anti-
friction bearings, shown in Figure 1, at the rear end of this shaft. At the rear,
the outer member of this housing is provided with an enlargement arranged
at right angles to the forward part of the member, said enlargement being
designed to contain a pinion which meshes with a gear D secured to the hub of
the rear wheel of the bicycle. The inner member E of this housing is of cup-
shaped formation, being provided centrally with a circular opening e designed to
receive and fit snugly upon, without friction, the end of the rear hub, as shown.
This inner part or section E¹ of the housing E E is designed and shaped to
contain the driven gear D attached to the hub of the rear wheel, and is provided
at an appropriate point with a stub e, upon which the brace-rod member 3 at
this side of the machine frame is brazed.
The two parts of the housing E-E at the rear end of the fork-side 2 are
rigidly connected by appropriate screw bolts F, and to relieve said bolts from
lateral strain the outer member E of the two-part housing is provided with
lugs cª, fitting snugly within the circular wall or flange of the inner member E
of the casing. In the instance shown the connecting bolts F engage threaded
lugs projecting inwardly from the circular wall or flange of the inner part E,
but I do not limit myself to this construction.
The two parts A-B of the forward housing or casing, which constitutes the
crank hanger, are also connected by bolts G, as clearly shown, the construction
described permitting of the detachment and removal of the outer parts B and F
of the casings A-B and E-E¹, so that the gears contained within said housings
may be readily removed for inspection, repair, or adjustment without the aid or
services of a. skilled mechanic, it being evident that the fork-side 2 will be
carried with said removable parts of the casings in the event of a removal, thus
permitting access, through the detached parts of the housings, to the pinions and
bearings of the connecting shaft 4.
As so far described the detachment and removal of the outer part of
the housings A-B and E-E necessitates the removal of one crank-arm, which is
sometimes objectionable, and to avoid such necessity, and permit of the removal
of the fork-side 2, with its shaft 4 and pinions, I have provided the threaded
sleeve, the construction being such that upon the detachment of the two
parts E and E of the housing of the rearward gear, the sleeve 62 may be
unscrewed from the stub 6', thus permitting of the removal of the parts in rear
of the forward housing A-B without detachment of the parts of said housing or
the removal of the crank arm, and without lateral strain on the fork-side 2, or
the parts carried thereby.
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 f..

page_text: 2. The combination with a bicycle frame, of laterally separable gear housings
forming part of said frame and a frame member secured to the separable parts of
Baid housings and removable with them, substantially as described.
3. The combination with a bicycle frame and driving gear of separable
housings containing the gears; one part, of said housing being rigidly attached to
the frame members and adapted to receive the crank-shaft and rear axle, the other
parts thereof being removable laterally without disturbing the relations of the
shafts or bearings, substantially as described.
4. The combination with a bicycle frame, of laterally separable gear housings
to contain the driving and driven gears, the rear one of said housings being
removable laterally, a fork-side rigidly secured to the detachable part of the rear
housing, and removably to the detachable part of the forward housing, substan-
tially as described.
5. The combination with a bicycle frame, of gear housings consisting of two-
part casings for containing the gears, and a fork-side connecting and removable
with laterally removable parts of said housings, substantially as described.
6. The combination with a bicycle frame and driving gear, of a two-part
housing for the rear wheel gear comprising an inner part rigidly secured to a
brace-rod of the frame, and an outer part rigidly secured to a rear fork-side,
substantially as described.
7. The combination with a bicycle frame and driving gears, of a two part
housing for the rear gear comprising an inner part rigidly secured to a brace
rod, and an outer part rigidly secured to a fork-side; the forward end of said
fork-side being detachably secured to a forward housing, substantially as
described.
8. The combination with a bicycle frame and driving gears, of two separable
housings, the inner parts of which are rigidly secured to the bicycle frame, the
outer removable parts being connected by a fork-side which is detachable from
the removable part of the forward housing, substantially as described.
Dated this 26th day of August 1898.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.