Improvements in Chain Adjusting Devices for Cycles and like Vehicles.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Chain Adjusting Devices for Cycles and like
Vehicles.
I, WILLIAM FRASER, of "Dovedale," School Road, Moseley, in the City of
Birmingham, Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to the adjustment of the back spindle of a bicycle. for
the purpose of tightening or adjusting the chain. My object is to provide
an adjustment which secures that the spindle shall always remain at right angles
to the plane of the cycle in any position.
My invention consists in applying toothed racks to the forks of the chain stays
and in attaching to or forming on the back hub spindle toothed wheels which
gear into the racks. The wheels so gear that when the spindle nuts are screwed
home a toothed wheel at each end of the spindle remains firmly in gear with
the racks. When the nuts are slack back the fork may be sprung out and the
teeth then gear each wheel in one rack only. On turning the spindle by
means of a spanner the teeth then travel in the rack and the spindle moves
backwards or forwards, always preserving a position at right angles to the
plane of the machine.
In carrying my invention into effect according to one modification I provide
the forks at the end of the chain stays with a double metallic rack which is
slipped between the forks and is fastened to the forks by suitable projections
passing through the metal of the forks at one end and passing over check down
parts at the outer end, each piece has two racks, one rack above, one below.
One of the racks (either that above or below) is made of about half the width
of the other rack, though of the same length and with the same number of teeth.
A toothed wheel or pinion is formed or attached one at each end of the back
hub spindle. This toothed wheel at each end gears into the top and bottom
rack when the forks are screwed home. When, however, the outside nuts are
slackened to enable the spindle to be adjusted the forks spring out and one of
the racks on each side withdraws from engagement with the teeth in the wheels,
each wheel thus finds itself then in engagement with one rack at each end only,
both racks, of course, being either above or below. On turning the spindle by
means of a suitable spanner the teeth move in the rack and the spindle is caused
to either move backwards or forwards as desired. However moved, by means of
the teeth engaging in a rack at each end, the spindle always maintains its
position at right angles to the plane of the machine. When the adjustment is
completed the outside nuts are screwed home and the teeth in the wheels then
gear in both racks top and bottom, the narrow rack as well as the wide one,
and thus the back spindle is held immovable and it does not depend on friction
for its position. The chain is thus kept in a constant state of tension.

page_text: The forks are so made that when the outside nuts are screwed out the spring
of the forks causes them to move out so as to provide that the narrow racks
move clear of the toothed wheels automatically, leaving the wheels in gear with
the broad racks only.
It is to be understood that the racks may be applied to the forks or chain
stays in any convenient manner. They may be constructed as I have described
either in brass or other metal separately from the fork ends and fastened to the
forks in any convenient way. They thus may be made top and bottom racks in
one piece slipped into the slot at the ends of the forks or chain stays and attached
thereto, or the ends of the chain stays may be forged in one piece with provision
of metal for forming the rack teeth in themselves. The teeth, for instance,
may be stamped or they may be machined. In fact, the constructive 'part of
my invention may be considerably modified without departing from the inven-
tion itself.
.
i
Instead of arranging a top and bottom rack one rack half the width of the
other I may arrange one rack only on each side and I may lock the spindle in
any desired position by means of serrations or corrugations on the outsides or
insides of the fork or chain stay surfaces, the corrugations may thus be upright
and a serrated washer may be arranged in the screw down nuts, which washer
engages with the corrugations when the nuts are screwed home and is disengaged
when the nuts are loosened.
MARKS & CLERK,
18, Southampton Buildings, London, W.C.,
13, Temple Street, Birmingham, and
25, Cross Street, Manchester,
Agents.
COMPLETE SPECIFICATION.
Improvements in Chain Adjusting Devices for Cycles and like
Vehicles.
I, WILLIAM FRASER, of "Dovedale," School Road, Moseley, in the City of
Birmingham, Engineer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
My invention relates to the adjustment of the back spindle of a bicycle for
the purpose of tightening or adjusting the chain. My object is to provide
a simple, convenient, and effective. adjustment of the type which secures that
the spindle shall always remain at right angles to the plane of the cycle in
any position.
My invention consists in applying double toothed racks to the forks of the
chain stays and in attaching to or forming on the back hub spindle toothed
wheels which gear into the racks. The wheels so gear that when the spindle
nuts are screwed home a toothed wheel at each end of the spindle remains
firmly in gear with the double racks. When the nuts are slack back the forks
spring out and the wheel teeth then each gear only with a single rack at each
side, so that on turning the spindle by the application of a spanner thereto, or
by applying a slight turning movement by hand to the road wheel rim, the

page_text: ..
wheel teeth travel in the racks and the spindle moves backwards or forwards,
lways preserving a position at right angles to the plane of the machine.
In the accompanying sheet of explanatory drawings to be hereinafter
eferred to.
Figure 1 is an end elevation with part in section, and Figure 2 a side elevation
showing a portion of a cycle frame with the rear wheel axle or spindle having
ny invention applied thereto.
Figure 3 is a sectional end elevation, on the line a a¹ Figure 2, showing one
end of the axle, with its nut removed in readiness for adjustment.
Figure 4 is a plan of one of the double rack pieces.
The same reference letters in the different views indicate the same parts.
Referring to the drawings I provide the forks A A¹ at the end of the chain
stays with double metallic rack pieces B B¹, one piece for each side. Each rack
piece is slipped between the forks and is fastened thereto by suitable projections
as bb and a passing respectively through the metal of the forks at one end
and over reduced parts at the outer end. The two racks as 63 and 6 of each
piece are of unequal widths one being made of about half the width of the other,
though of the same length and with the same number of teeth. Toothed wheels
or pinions as C C₁ are formed or attached one at each end of the back hub
spindle. The toothed wheel at each end gears into the top and bottom rack of
its rack piece when the forks are screwed home as shown at Figure 1. When,
however, the outside nuts D and D' are slackened to enable the spindle E to be
adjusted in position, the forks spring out and one of the racks on each side
withdraws from engagement with the teeth in the wheels, each wheel is then
in engagement with one rack at each end only, as illustrated at Figure 3. On
turning the wheel on the spindle E as hereinbefore described the teeth of the
wheels or pinions C C¹ move in the respective racks and the spindle is caused
to move either backwards or forwards as desired, always maintaining its position
at right angles to the plane of the machine. When the adjustment is completed
the outside nuts D and D¹ are screwed home and the teeth in the wheels or
pinions C C then gear in both racks, top and bottom, of the respective rack
pieces B, B', the narrow rack as well as the wide one, and thus the back
spindle E is held immovable, and without dependence on friction.
The forks are so made that when the spindle nuts are slackened the spring of
the forks causes them to move out to the position indicated at Figure 3, so as
to provide that the narrow racks move clear of the toothed wheels automatically,
leaving the wheels in gear with the broad racks only.
It is to be understood that the racks may be applied to the forks or chain
stays in any convenient manner. They may be constructed as I have described,
either in brass or other metal, separately from the fork ends and fastened thereto
in any convenient way, or may be formed in the forks themselves sufficient
metal being provided for that purpose.
Instead of arranging a top and bottom rack one rack half the width of the
other I may arrange one rack only on each side, and I may lock the spindle in
any desired position by means of serrations or corrugations on the outsides or
insides of the fork or chain stay surfaces, the corrugations may thus be upright
and a serrated washer may be arranged with the screw nuts, which washer
engages with the corrugations when the nuts are screwed home and is dis-
engaged when the nuts are loosened.
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
1. Chain adjusting devices for cycles and like vehicles comprised in part of
toothed racks permitting of adjustment of the axle or spindle when the nuts
on the ends of the said spindle are slackened, but locking the spindle in position
when the nuts are tightened, substantially as described,

page_text: 2. In chain adjusting devices for cycle and like vehicles, the general arrange-
ment and combination of parts substantially in the manner and for the purposes
described and as illustrated.
MARKS & CLERK,
18, Southampton Buildings, London, W.C.,
13, Temple Street, Birmingham, and
25, Cross Street, Manchester,
Agents.