Improvements in Cycle and other Chain Driving Gear.
Year: 1895

page_text: Date of Application, 12th Feb., 1895
Complete Specification Left, 12th Nov., 1895-Accepted, 14th Dec., 1895
Improvements in Cycle and other Chain Driving Gear.
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 relates to improvements in cycle and other chain driving gear, my
object being to construct a durable chain of few and simple parts in such a manner
that it may be safely driven, in conjunction with suitably shaped chain wheels,
at a higher speed and with less friction than the chains at present in
ordinary use.
In carrying my invention into effect I produce the links of my improved chain
from steel or other metal, forming them preferably of a circular configuration with
a projecting central flange to engage the corresponding grooves or depressions in
the chain wheel. One end of each link has a concave recess or seating whilst its
opposite end has a convex or projecting face, and the links are so rivetted or
connected together that the convex face of each link projects within the concave
recess on the end of the adjacent link. I drill or form a hole through each link
and tap or screw the same for the reception of the connecting piece, the head of
which fits within the jaw cut or formed in the adjacent link, every link having a
connecting piece at one end and a jaw or recess at the opposite end. The
connecting piece is pivotted within the adjacent jaw by means of a pivot or pin
rivetted or screwed to the cheeks, and the links are thus attached to each other
by pivot connections permitting the free movement of the links relatively to each
other.
I form my improved chain wheels from steel or other metal with a periphery
preferably of a semi-circular configuration, and with grooves or depressions for the
reception of the flanges formed on the links as herein before described. On the
revolution of the chain driving wheel by the contact of the link projecting flanges
with the teeth formed on the periphery of the wheel between the grooves or
depressions, and the links being connected up to form one complete endless
chain, the transmission is continuously maintained during the revolution of the
wheel.
On the elongation of the pitch of the links or the extension of the distance
between the circular projecting flanges by reason of the wearing of the rubbing
surfaces, the original pitch is restored by giving each link a half or complete turn
thus bringing another portion of the flanges into contact with the wheel teeth.
With my improved form of links and chain wheels and by my method of
connection to form the endless or continuous chain, I am enabled to drive at a
higher speed without risk of displacement of the chain from the wheels, and
with greater smoothness and regularity than by the employment of ordinary
driving gear.
Dated this 11th day of February 1895.
MARKS & CLERK,
18 Southampton Buildings, London, W.C., and
13 Temple Street, Birmingham, Agents for the Applicant.

page_text: Improvements in Cycle and other Chain Driving Gear.
I, HAVELOCK HARFORD, of 3 Albion Terrace, South Shields, in the County of
Durham, Engiueer, 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 cycle and other chain driving gear,
my object being to construct a durable chain of few and simple parts, in such a
manner that it may be safely driven, in conjunction with suitable shaped chain
wheels, at a higher speed, and with less friction than the chains at present in
ordinary use.
In the accompanying sheet of explanatory drawings to be hereinafter
referred to:
Figure 1 is an elevation, with part in section, and Figure 2 a plan representing
two links of my improved chain.
Figure 3 is a part side elevation, and Figure 4 a part sectional end elevation of
one of the chain wheels.
The same reference letters in the different views indicate the same parts.
In carrying my invention into effect, I produce the links of my improved chain
from steel or other metal, forming them preferably of a circular configuration, with
a projecting central flange such as A, to set within the corresponding grooves or
depressions A' in the chain wheel. One end of each link has a concave recess or
seating B, whilst its opposite end has a convex or projecting face C, and the links
are so riveted or connected together that the convex face of each link projects
within the concave recess on the end of the adjacent link, as illustrated at Figures 1
and 2. I drill or form a bole either partially or entirely through each link, and
tap or screw the same for the reception of the connecting piece D, the head of
which fits within the jaw cut or formed in the adjacent link, every link having a
connecting piece at one end, and a jaw or recess at the opposite end. The con-
necting piece is pivoted within the adjacent jaw by means of a pivot or pin E,
riveted or screwed to the cheeks, and the links are thus attached to each other
by pivot connections permitting the free movement of the links relatively to each
other.
I form my improved chain wheels from steel or other metal with teeth or
projecting lugs such as F, of a semi-circular configuration, as shown at Figure 4,
and with grooves or depressions A' for the reception of the flanges A formed on
the links, as herein before described.
On the revolution of the chain driving wheel attached to the crank axle, the
motion is transmitted, by the contact of the chain link projecting flanges A with
the teeth or lugs F, to the chain wheel attached to the driving wheel of the cycle,
which is thus caused to revolve, the relative revolutions of the driving and driven
chain wheels being of the same ratio as their relative diameters.
On the elongation of the pitch of the links or the extension of the distance
between the circular projecting flanges A by reason of the wearing of the rubbing
surfaces the original pitch is restored by screwing the links further on to the
stems of the connecting pieces, thus bringing a fresh portion of the flanges
into contact with the wheel teeth, and adjusting the worn chain to run without
back lash.
With my improved form of links and chain wheels, and by my method of
connection to form the endless or continuous chain, I am enabled to drive at a
higher speed without risk of displacement of the chain from the wheels and with
greater smoothness and regularity than by the employment of the ordinary chain
driving gear.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is ;-
1. The construction of a cycle or other driving chain from a number of similar
links pivoted together, substantially as hereinbefore described and as illustrated in
the accompanying drawings.
2. In cycle and other driving chains, the method of adjusting the pitch of the
links by means of a screwed connecting piece, substantially as herein described.
3. The construction of links for a cycle or other driving chain having a projecting
flange suitable for engagement by the teeth or projecting surfaces of a chain wheel,
substantially as herein described.
4. In cycle and other driving chains, the combination of links having convex and
concave ends with screwed connecting pieces substantially as hereinbefore described
and as illustrated in the accompanying drawings.
5. The construction of chain wheels having teeth or lugs and grooves or
depressions suitable for engagement with a chain made of links with projecting
flanges and connected or pivoted together substantially as hereinbefore described.
6. The combination of a chain made up of similar adjustable links, with a chain
wheel substantially as and for the purposes herein described.
Dated this 11th day of November 1895.
MARKS & CLERK,
18 Southampton Buildings, London, W.C., and
13 Temple Street, Birmingham, Agents for the Applicant.