Improvements in Driving Chains and Wheels.
Year: 1895

page_text: Date of Application, 19th Dec., 1895-Accepted, 25th Jan.. 1896
COMT LUI IUIFICATION.
Improvements in Driving Chains and Wheels.
I, HANS RENOLD, of Green Lane, Brook Street, Manchester, in the County of
Lancaster, Chain Manufacturer, 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 driving chains and wheels used for the
transmission of rotary power.
It is a well known fact that the tension exerted upon new driving chains when
put to work, causes the links to bed down, and produces a difference in pitch. As
the joints of the chain wear, the said difference increases continuously and causes
only one of the chain studs, rollers or blocks to be in working contact with its
tooth, the others touching more or less up the incline of the tooth and acting
as wedges prevent the chain stud, roller or block from getting into its proper
seating.
These defects have been overcome to a certain extent by making the pitch of the
driver wheel larger than that of a new chain and the space between the teeth wider
than the bare accommodation of the stud, roller or block would require, which
allows the latter to sit into the tooth space without the slightest hinderance and
for which method of constructing chains and wheels I have obtained Letters
Patent, No. 4496, dated March, 13th, 1891.
I am also aware that attempts have been made to provide a chain and wheels
wherein the chain was supposed to adjust itself in relation to the axis of the wheel
and thereby compensate for the aforesaid constant increase in the pitch of the
chain, such arrangement however has been found not to answer being only suitable
for transmitting very small power and impractical to make as to be of commercial
value when attempted in large sizes.
The object of this invention is to construct a driving chain which will allow of
making the driver and the driven wheel in pitch alike and whereby any difference
in the pitch of chain and wheels, may it be caused by the stretch of the chain
or the wear of both chain and wheels, will be compensated for by the chain
itself.
Another important feature of my invention is that my improved chain will work
practically silent, which renders the same applicable in cases wherein heretofore
chain gear could not be used.
My invention also facilitates the manufacture of chains in a very quick, simple,
inexpensive and accurate manner and allows the chains being made of any strength
without increasing its pitch and as about half the number of teeth of each wheel
will come into working contact with the chain in lieu of only one, two or three as
heretofore, the strain upon the ingoing and outgoing tooth will be greatly reduced
and thus the chain and wheels caused to work with less friction.
And in order that my invention may be more fully understood I have caused to
be appended hereunto two sheets of drawings marked with letters of reference
indicating like parts in the various figures.
Fig. 1, Sheet I, is a sectional side view of a wheel and chain,
Fion plan of the chain mantle in cration

page_text: ig. › a side view of a chain link detached constructed in accordance with my
invention.
Figs. 4, 5 & 6 are sectional side views of chains and wheels of larger pitch than
that shown in Figs. 1 & 2, Fig. 5 showing the position of the chain on the wheel
before and Fig. 6 after it has stretched and thus increased in pitch.
Fig. 7, Sheet II, is a side view and Fig. 8 a sectional plan of the chain wheel
separately.
A chain constructed in accordance with my present invention is non-reversible and
forms practically an endless internally, toothed flexible rack a, into which the chain
wheel 6 gears, the teeth 61 of the latter extending without break across the wholo
width of the wheel and being adapted to enter between the chain teeth a' only and
not between the narrow spaces a² of alternate links, see Fig. 2.
My improved chain consists of links a stamped out uniform in shape and
connected together by means of joint pins c as hereinafter fully described, each link
end having a tooth a which projects into the tooth space 62 of the wheel, the outer
sides of the chain teeth a' serving as the actual contact or working surfaces whilst
the inner sides have no work to perform and are clear of the adjacent wheel tooth.
These outer sides are formed straight at an angle which coincides with that of the
sides of the wheel teeth and varies in degree according to the number of the teeth
the wheel has, say "below" and "above" twenty teeth.
The part of the links a between the joint pins c I form curved so as to clear the
top of the wheel tooth 6', whilst the bottom of the tooth space 62 and the top of
the tooth b¹, particularly in wheels with large pitch. I may form round, as shown
in Fig. 4.
The teeth of the chain wheels b I form by means of a double cutter which
shapes simultaneously the opposite sides or halves of two teeth in alternate
fashion.
It will be readily seen from Fig. 1, that according to my invention the strain
received and delivered by each wheel tooth is less than when received by one or
two teeth only as hitherto and that the chain teeth contact with the sides of the
wheel teeth parallel which causes a practically silent approach and run of the chain
and wheels, whereas heretofore the chain links snapped into the wheel and caused
objectionable noise.
As will be seen from Fig. 6 the chaiu when increasing in pitch will adjust itself
radially upon the chain wheel in such a manner that always one half of the
number of wheel teeth 6' will remain in working contact with the chain teeth a',
the clearance shown between the links and pins and dotted lines indicating the
way in which the wear takes place.
In order to give all the outer links a, a', the same free play around their joint
pins c as the inner links have and thus distribute the wear thereon uniformly
form each end of the pin e with a shoulder d nearly level with the outside of the
links a, al, see Fig. 2, adapted to receive a washer e, against which the end of the
pin c is rivetted, the chain links a, a', by preference being arranged to alternate or
interlock.
In order that the rivet heads may not be worn away by wheel flanges a protective
form may be given to the washer or the heads countersunk in coned holes.
As previously described in this invention the wheel teeth do not enter and thus
do not hold the chain laterally in position on the wheel which renders a provision
necessary whereby the chain is prevented from slipping off the wheel. For this
purpose I secure to each side of the wheel a ring h, as shown in Figs. 7 & 8,
Sheet II, preferably by means of rivets i lodged in slots cut into a number of
the wheel teeth b. The said rings I may let into the side of the teeth b so as to
become level therewith and in some instances particularly in the case of cycles,
I form the same of such a width as to expose the bottom of the tooth space and
thus allow any dirt that may accumulate between the teeth of falling out.
the latter purpose I also narrow the rim f of the wheel so as to leave openings f
For
at each side thereof communicating with the tooth space &³, Fig. 8.

page_text: Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim, is;-
"In driving chains and wheels."
1st. A driving chain having links formed with inwardly projecting teeth adapted
to gear with and engage between the teeth of chain wheels, substantially as and
for the purpose set forth.
2nd. In a driving chain forming the joint pins with a shoulder and rivetting
thereto a washer, all substantially as and for the purpose set forth.
3rd. In combination with the construction of chain, specified in the preceding
claim, furnishing each side of the chain wheel with a rim partly exposing the
wheel teeth and forming the tooth spaces with openings through the rim, all
substantially as and for the purpose set forth.
Dated this 18th day of December 1895.
F. BOSSHARDT & Co.,
4, Corporation Street, Manchester, Agents to Applicant.