Improvements in Pitch Chains for Cycles, Motor Cars and other Vehicles.
Year: 1897

page_text: .
PROVISIONAL SPECIFICATION.
Improvements in Pitch Chains for Cycles, Motor Cars and other
Vehicles.
I, FREDERICK WOODCOCK, Commercial Traveller, Inventor, of 5, Marshfield Place,
West Bowling, Bradford, in the County of York, do hereby declare the nature of
this invention to be as follows:-
:-
This invention consists of an improvement in pitch chains by introducing into
the said chains, steel springs in the following manner. Steel springs are to be
made of steel wire or flat ribbon steel cut into appropriate lengths. The ends are
then bent round in the same direction, with the points opposite each other so as to
form an ellipse with one side taken out, leaving them like a pair of wide open
calipers, or they may be spiral springs with hook ends as aforesaid.
The long side of the spring can be serpentine, horizontally, in a wire spring but
vertically in a flat or ribbon spring. The middle links of the chain are dealt with
in this arrangement.
The middle links of an ordinary cycle chain are made of mild steel, each having
two eyeholes for connection in the usual manner. The bottom part is slightly
I concave to fit the smaller toothed wheel. The top part is sunk down between the
ends as much as possible having regard to the strength of the links, thus shaping
the ends like two parallel cylinders connected at the bottom by a bar.
I will now shew the use of the springs and how they are to be applied.
An ordinary chain for cycles consists of about 108 centres and centre pins, and
the necessary play for freedom although almost infinitesimal in each separate centre,
yet amounts to of an inch in the length of the chain.
The springs I have described will take up this of an inch and deal with it
in a beneficial manner.
In ordinary chains the bearing on the pins and eyes being always in the same
direction, the chain elongates and gives a jerk. This besides causing annoyance to
the rider, often causes the chain to break.
Again the amount of friction in 108 centres is enormous; the sudden impact in
pushing against a rigid chain is injurious to the constitution, destructive to the
machine, whether pedal or motor, and is also a great source of vibration.
APPLICATION OF SPRINGS.
The middle links of the chain are all coupled together by the springs in the
following manner.
Holes are to be made in these middle links and in the necks where the cylinders
join the bottom parts.
The hooked ends of the springs take hold in these holes, or the said springs may
be connected with the outer links by cross pieces for the hooks to catch hold of.
Thus each spring couples two links, and these in pulling against each other
reverse the bearings so that when a chain is used in going down hill or has
[Price 8d.1

page_text: comparatively no work on, the bearings are in the opposite direction to what they
are when ascending a hill.
This arrangement greatly reduces the friction, secures smoothness in running,
and increases the durability of the chain.
I do not confine myself to any particular kind of springs, manner of connecting
with the links, or the part of links to which they may be applied.
Dated this 6th day of October 1807
Improvements in Pitch Chains for Cycles, Motor Cars and other
Vehicles.
I, FREDERICK WOODCOCK, of 5, Marshfield Place, West Bowling, Bradford, in
the County of York, 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 :-
This invention relates to improvements in pitch or driving chains for cycles,
motor cars and other vehicles, and it consists in the application of springs arranged
to take up the "back lash" of the chains or play between the links and thus
impart a certain amount of elasticity to the chain.
To fully describe my invention reference is made to the accompanying sheet of
drawings forming a part of this specification, in which similar letters of reference
indicate corresponding parts in each of the figures.
Figure 1, represents a side view partly in section of a pitch chain with my
improvements applied to it.
Figure 2, is a cross section of one of the middle links.
The middle links A are made with recesses B against the ends B² of which the
inwardly projecting points or ends C of the wire springs C2 bear. This draws
the links A towards each other to the extent allowed by the play between the
holes A² in the links and the pins D connecting them to the outer or side links E.
Figure 3, is a plan view of Figure 1 but the spring O2 is of waved or serpentine
form to increase its elasticity.
Figures 4 and 5 are similar views to Figures 1 and 2 and show the application of
a spring of flat cross section instead of a round wire one. Figure 6, is a separate
view of the underside of the spring. Figure 7, is an elevation of part of a sprocket
wheel with a portion of the form of chain and spring shown in Figure 4 in
position.
Figure 8, is a side view of a portion of a chain fitted with a spring adapted to
pull the side links E towards each other. In this case the links have parts E
pressed outwards and slots E³ formed through them and the hooked ends C of the
spring C² are hooked into the slots. Figure 9, is a cross section of one of the
links E and Figure 10, is a separate view of one of the springs which is shown
made with two single coils C³ to increase its elasticity.
Figure 11, illustrates a method of taking up the back lash by drawing the
pins D towards each other. In this arrangement the pins D project sufficiently to
receive the eyes C4 on the ends of the springs and are made with heads D² to keep
the springs on. The head of one of the pins is cut off to show the section of the
pin at the point where the eyes C4 bear.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I would have it

page_text: understood that I do not confine myself to any particular form of springs nor to
any particular mode of applying them but what I claim is :-
The combination with a pitch chain of springs adapted to take up the back lash
or play between the links and make the chain elastic to the extent of such back
lash, substantially as herein shown and described.
Dated this 6th dow of Tule 1000
DRACUP & NOWELL,
Patent Agents, Bradford.