Improvements relating to Chain Driving Gear for Cycles, Motor Cars, I and for other Services.
Year: 1897

page_text: Date of Application, 23rd Mar., 1897
Complete Specification Left, 23rd Dec., 1897-Accepted, 29th Jan., 1898
Improvements relating to Chain Driving Gear for Cycles, Motor Cars,
I and for other Services.
I, HAVELOCK HARFORD, of 3, Albion Terrace, South Shields, in the County of
Durham, Engineer, do hereby declare the nature of this invention to be as
follows:-
This Invention consists of improvements in chain driving gear for cycles, motor
cars, and for other services, and relates chiefly to gearing chains of a circular
configuration such as described in my Specification No. 3025 of 1895 on which
Letters Patent have been granted to me.
The objects of my present invention are to simplify and improve the construc-
tion of such chains, and to provide simple and effective means for adjusting the
pitch diameter of chain wheels employed either with my circular chain or with
other and ordinary types of chain employed for gearing purposes.
In constructing my circular chain in one manner in accordance with this
invention, I make the entire chain from the required number of exactly similar
links, formed from one piece of metal and secured together by knuckle joint
connections. Each link is provided with a central flange to engage the corre-
sponding grooves or seatings in the chain wheel, and has a jaw at one end and a
corresponding boss or head at the opposite end. The jaw of one link embraces
the head of the adjacent link, the two parts being connected by a pin or rivet,
thus forming the complete joint.
Instead of forming each link from one piece of metal as herein before described,
I sometimes form them in two pieces, in such a manner that the parts can be
readily secured by the pin or rivet used for jointing the links together.
In another modification I make the parts or half-links of a hollow form, and
before connecting them together I insert a ball between the parts, at the head
end of the link to give an efficient working surface upon the pin.
In constructing a chain with means for adjusting the pitch of the links or the
distance between the central flanges, I employ a screwed connecting piece at one
end of each link, but to prevent any accidental turning movement of such pieces
when in service I secure each of them to their links by a suitable locking spring
or catch.
The
In the provision of means for the adjustment of the pitch diameter of the
chain wheels, I employ independent teeth or lugs and secure them to the rim of
the wheels by screwed stems and nuts or in any other convenient manner.
pitch diameter of such a chain wheel can be increased when required on the chain
becoming worn, by removing the teeth or lugs and placing a metallic or other
strip or band around the wheel rim. On replacing the teeth or lugs the strip

page_text: will be effectually secured to the wheel and the pitch radius will be increased by
an amount equal to the thickness of the strip.
Dated this 22nd day of March 1897.
MARKS & CLERK.
18, Southampton Buildings, London, W.C., and
3. Temple Street, Birmingham, Agents for the Applicant.
Improvements relating to Chain Driving Gear for Cycles, Motor Cars,
"and for other Services.
I, HAVELOCK HARFORD, of 3, Albion Terrace, South Shields, in the County of
Durham, Engineer, 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:-
att 2
This Invention consists of improvements in chain driving gear for cycles, motor
cars, and for other services, and relates chiefly to gearing chain of a circular.con-
figuration, such as described in my British Specification No. 3025 of 1895 on
which Letters Patent have been granted to me.
The objects of my present invention are to simplify and improve the construc-
tion of such chains, and to provide simple and effective means for adjusting the
pitch diameter of the chain wheels.
...
In the two accompanying' sheets of explanatory drawings to be hereinafter
referred to,
Figure 1 is a side elevation and Figure 2 à plan, representing two links of my
improved chain, each of such links being formed from one piece of metal.
Figure 3 is a side elevation, Figure 4 a plan, and Figure 5 a section, repre-
senting two links of my improved chain, each link being formed from two pieces
of metal.
Figure 6 is a sectional view representing a portion of two links of my improved
chain, the links in this case being of a hollow form.
Figure 7 is a side elevation with part in section, and Figure 8 a plan repre-
senting two of my improved chain links provided with means for adjustment of
their pitch length.
Figure 9 is an elevation of a short length of my improved chain passing over a
chain wheel...
Figure 10 is a side view and Figure 10 an end view to a larger scale than
Figure 9, representing the true form of one of the chain wheel teeth.
Figure 11 is an end view of an annular packing strip for adjustment of the
pitch diameter of the chain wheel.
The same reference letters in the different views indicate the same parts.
Referring to Figures 1 and 2, I make the entire chain from the required number
of exactly similar links, formed from one piece of metal and directly secured
together by knuckle joint connections. Each link is provided with a central
flange A to engage the corresponding grooves or seatings in the chain wheel, and
has a jaw as B at one end and a corresponding head or eye boss C at the opposite
end of the adjacent link. The jaw of one link embraces the head of the adjacent
link, the two parts being connected by a pin or rivet D, thus forming the complete
joint.
Instead of forming each link from one piece of metal as in Figures 1 and 2,
I sometimes form them in two pieces, in such a manner that the parts can be

page_text: readily secured by the pin or rivet used for jointing the links together. Such
segmental or two part links are illustrated at Figures 3, 4 and 5.
In another modification I make the parts or half-links of a hollow form, as
illustrated at Figure 6 Sheet 2, and before connecting them together I insert a
ball or bearing piece E between the parts, at the head end of the link, to give an
efficient working surface upon the pin.
In constructing a chain with means for adjusting the pitch of the links or the
distance between the central flanges A, I employ a screwed connecting piece F
(Figures 7 and 8) at one end of each link, but to prevent any accidental turning
movement of such pieces when in service I employ a locking device consisting
of a spring or catch such as G having one end secured in any convenient manner
to the connecting piece, whilst the opposite or free end engages with a groove in
the central flange A.
In the provision of means for the adjustment of the pitch diameter of the chain
wheels, I employ independent teeth or lugs, and secure them to the rim of the
wheels by screwed stems and with lock nuts as illustrated at Figure 9 or in any
other convenient manner. The correct form of the teeth or lugs is shown by the
separate views of one of them, to a larger scale, at Figures 10 and 10. The pitch
diameter of such a chain wheel can be increased when required on the chain
becoming worn, by removing the teeth or lugs and placing an annular packing
strip such as H around the wheel rim. A separate view of the packing strip H
is represented at Figure 11. On replacing the teeth or lugs the strip H will be
effectually secured to the wheel, and the pitch radius will be increased by an
amount equal to the thickness of the strip.
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
1. A driving or gearing chain composed of a number of similar links each
having a projecting flange for engaging with the chain wheels, the links being
connected directly to each other, substantially as described, and as illustrated.
2. A driving or gearing chain of a circular configuration having two part or
segmental links, the parts or segments being secured by the jointing pins, substan-
tially as described and as illustrated.
3. A driving or gearing chain of a circular configuration having hollow
segmental links each fitted with an internal ball or bearing piece, substantially
as described and as illustrated.
4. A driving or gearing chain of a circular configuration having adjustable
connecting pieces between the links and a lock or catch piece in combination with
each of such connecting pieces, substantially as described and as illustrated.
5. The combination with a chain wheel for circular driving or gearing chains
of detachable teeth and a packing strip, substantially as described and as
illustrated.
This Dond J. of Donamba 1907
MARKS & CLERK,
18, Southampton Buildings, London, W.C.,
13, Temple Street, Birmingham, Agents for Applicant.