IMPROVE- MENTS IN DRIVING MECHANISM FOR VELOCIPEDES AND OTHER PURPOSES
Year: 1885

page_text: I, WILLIAM HENRY PUGH of 44 Neate street, Camberwell, in the county of
Surrey, Engineer do hereby declare the nature of my invention for "IMPROVE-
MENTS IN DRIVING MECHANISM FOR VELOCIPEDES AND OTHER PURPOSES" to be
as follows
-
My invention relates to improvements in Mechanism for transmitting motion
and power from one revolving shaft to another, and 18 specially applicable as a
driving Mechanism for velocipedes and as a simple and efficient substitute for
chain-gears, cog-wheels and other well-known means of communicating motion
between parallel shafts.
To the driving shaft-which in a velocipede would be that carrying the pedals-
I attach two or more eccentrics. By preference, though not necessarily, I make
these eccentrics similar and arrange one more or less in advance of the others.
When I use a pair of eccentrics I prefer to mount them so that one shall be 90°
(ninety degrees) in advance of the other, and when I use three eccentrics-which
is the largest number I find it desirable to employ-I dispose them symmetrically
at equi-angular distances of 120°
The sheaves of the above mentioned eccentrics carry connecting rods, the remote
ends of which engage cranks suitably placed on the driven shaft. This in a
velocipede would be the shaft which carries the driving wheels of the machine.
Thus arranged and connected, if the driving shaft with its eccentrics be caused to
revolve its motion and power are transmitted by the connecting rods to the cranks
of the driven shaft with great mechanical advantage and an absence of dead
points.
When applied specially as a driving mechanism for velocipedes I prefer to place
the pedal cranks in a position intermediate between the eccentrics, so as to better
distribute the weight, and equalise the strains, by placing the pedals where they
have the greatest mechanical advantage when the cranks and eccentrics are least
favourably situated.
To minimise friction I apply balls or rollers between the moving parts of the
eccentrics.

page_text: Improvements in Driving Mechanism for Velocipedes and other
Purposes
I, WIILIAM HENRY PUGH, of 44, Neate St, Camberwell, in the County of
Surrey, Engineer, do hereby declare the nature of my said invention for "IMPROVE-
MENTS IN DRIVING MECHANISM FOR VEI OCIPEDES AND OTHER PURPOSES," and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement
My invention relates to improvements in Mechanism for transmitting motion
and power from one revolving shaft to another, and is specially applicable as a
driving mechanism for velocipedes, and as a simple and efficient substitute for
chain gears, cog-wheels and other well-known means of communicating motion
between parallel shafts.
For the purposes of my invention I construct my driving mechanism as herein
described with reference to the accompanying sheet of drawings
Fig 2 is a front elevation of my mechanism and Fig 1 a sectional elevation on
the line xx
Similar parts in both figures are denoted by the same letters of reference
To the driving shaft a-which in a velocipede would be that carrying the pedals,
shown in broken lines at g g¹-I attach two or more eccentrics co¹ By preference,
though not necessarily, I make these eccentrics similar and arrange one of them
more or less in advance of the others When I use only a pair of these eccentrics,
as shown in the accompanying drawings, I prefer to mount them so that one shall
be 90° (ninety degrees) in advance of the other, and when I use three eccentrics--
which is the largest number I in general find it desirable to employ-I dispose
them symmetrically at equi-angular distances of 120° The sheaves of the above-
described eccentrics carry connecting rods e e¹ the remote ends of which engage
cranks d d, dd, suitably placed on the driven shaft b This shaft in a velocipede
would be that which carries the driving wheels of the machine Both the driving
shaft a and the driven shaft b run in bearings in the ordinary way
drawings I have shown these bearings in connection with brackets fff and
fff, but it will be understood that the position and arrangement of these
bearings will depend upon, and necessarily vary with, the particular purposes to
which my mechanism is applied To facilitate adjustment, I construct my con-
necting rods, e el, with right and left-handed threads, and screw one end of each
into the lugs,, on the sheaves of the eccentrics and the other end into the
lugs, h¹, of the head pieces of the connecting rods that engage the crank pins of
the shaft b
In the
Having thus described the nature, arrangement and connection of my driving
mechanism, I now describe the manner in which the said mechanism acts in the
transmission of motive power
If the diving shaft, a, with its eccentrics, c c¹, be caused to revolve, its rotary
motion and power will be transmitted by the connecting rods, e e¹, to the cranks dd,
dd', of the diven shaft, b, with great mechanical advantage and an absence of

page_text: dead points, such as usually accompany the employment of crank and connecting
rod gearing
When my invention is applied specially as a driving mechanism for velocipedes
I prefer to place the pedal cranks in a position-shown in dotted lines, g g¹, in
Fig 1-intermediate between the eccentrics, so as to better distribute the weight,
and equalise the strains, by placing the pedals where they have the greatest
mechanical advantage when the cranks and eccentrics are least favourably situated.
To minimise friction, I prefer to apply balls or rollers between the moving parts
of the eccentrics
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 18
The construction and arrangement of Driving Mechanism for Velocipedes and
other purposes, consisting of a driving shaft with two or more eccentrics thereon,
from which motion and power are transmitted, by means of connecting rods, to a
suitably cranked driven shaft, substantially as and for the purposes hereinabove
described with reference to the accompanying sheet of drawings