Improved Means and Appliances for Taking up the Slack of Driving Chains of Safety and other Cycles.
Year: 1889

page_text: Date of Application, 12th Nov., 1889
Complete Specification Left, 12th Aug., 1890-Accepted, 13th Sept., 1890
PROVISIONAL SPECIFICATION.
Improved Means and Appliances for Taking up the Slack of Driving
Chains of Safety and other Cycles.
I, FREDERICK SAMUEL BUCKINGHAM of Arthur Street, Birmingham, Engineer, do
hereby declare the nature of this invention to be as follows:-
This invention relates to novel means or appliances attachable to the frame of the
driving wheel of a safety or other cycle to enable the slack of the driving chain to be
taken up more readily and easily than heretofore.
According to known methods, the chain is either tightened by an eccentric
arranged in connection with the pedal or crank axle which has the disadvantage of
increasing the distance and consequently the position of the cranks to the inconvenience
of the rider, or as in another case, the driving axle is constructed with a pin or stud
set eccentrically with and forming part of the axle, this being fastened by a nut on
the outer end of the stud and bearing against the main frame, the disadvantage of
this plan is, the chain soon slackens itself again on account of the screw nut becoming
loose from the jolting motion of the wheel while travelling.
Now by my invention, I obviate these inconveniences by making the axle of the
driving wheel, or that part (or parts) of it which has a bearing in a socket of D shape
and in fitting said part (or parts) in a corresponding hole of an eccentric block which
is shiftable in a clip of the main frame by a spanner acting upon an extension of the
axle, there being a pin or lug to limit and fix the eccentric block.
The clip may in some cases be like an open fork in or along which the axle can
slide when moved by the eccentric, the tension of the driving chain being regulated
in an easy manner and with great exactness.
COMPLETE SPECIFICATION.
Improved Means and Appliances for Taking up the Slack of Driving
Chains of Safety and other Cycles.
I FREDERICK SAMUEL BUCKINGHAM of Arthur Street, Birmingham, Engineer do
hereby declare the nature of said 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 novel means or appliances attachable to the frame of a
driving wheel of a safety or other cycle to enable the slack of the driving chain to be
taken up more readily and easily than heretofore.
According to known methods the chain is either tightened by an eccentric arranged
in connection with the pedal or crank axle, which has the disadvantage of increasing
the distance and consequently the position of the cranks to the inconvenience of
the rider, or as in another case the driving axle is constructed with a pin or stud set
eccentrically with and forming part of the axle, this being fastened by a nut on the
outer end of the stud and bearing against the main frame, the disadvantage of this
plan is the chain soon slackens itself again on account of the screw nut becoming
Joose from the jolting motion of the wheel while travelling.
Now by my invention I obviate these inconveniences by making the axle of the
driving wheel or that part (or parts) of it which has a bearing in a socket of D shape
and in fitting said part (or parts) in a corresponding hole of an eccentric block which

page_text: K. holes in eccentric studs.
I. nuts for tightening up after adjustment, both ends of the axle being alike.
Instead of the nuts L being on the axle pin I for cramping the eccentrics against
the sides of the hearing E as will be understood by the arrangement shown at
Figure 3. the eccentrics can be clamped by bolts passed through the clips of the straps
as indicated by the example shewn at Figure 5.
According to the adjustment and chain tightening devices represented by Figure 1
the driving wheel is set farther to the rear and according to the method shown by
Figure 3 the slot may be at an angle away from the pedal axle.
If the slots be at an angle in the bearings E. E the eccentrics are preferably set
downwards
I am aware that drive chains of cycles have been capable of adjustment by eccentric
devices before the date of my application for Letters Patent but these have been
effected from the pedal driver axle which has in every case necessitated an alteration
of the seats position to enable the rider to have full command over the pedals. I
therefore disclaim every method of adjusting the chain for fair gearing into the driver
chain wheels except the method or arrangement indicated by the annexed drawings,
viz. that of effecting it from the bearings of the drive wheel substantially in the manner
described.
Having now particularly described and ascertained the nature of said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1. The improved means or appliances herein before described for adjusting the
length of chain to obtain perfect gear action with the gear wheels of cycles, said
adjustment being effected from eccentrics in connection with slotted bearings of the
driver wheel as set forth.
2. Fitting eccentrics in or to the bearings of the driving wheel of a cycle, said
eccentrics being on the axle and rotatable in slots or forks for adjustment of the chain
as described.

page_text: 3. The particular arrangement of appliances shown in the annexed drawings and
the method by which the slack of the chains of safety and other cycles can be taken
up from the axle of the driving wheel as described.
Dated this 12th day of August 1890.
H. GARDNER,
Patent Agent, 166, Fleet Street, London, Agent for the said F. S. Buckingham.