Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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TITLE- An ImProved Chain
BACKGROUND OF ~IE INVENTION
This invention relates to a chain, especially to a
chain used on a bicycle.
05 Conventionally, a chain :is composed of a plurality
o-~ links, each link comprising a pair o-~ outer chain
plates, inner chain plate~, rollers, chain pin sleeves,
and chain pins. The chain plates are typically qhaped
as a dumbbell, with a circular portion o~ the inner
chain plate having a larger diameter than that of the
outer chain plate. and the chain pin having a longer
length than a width of a combination of the outer and
: inner chain `plates and rollers :to effectively combine
all~ elementQ mentioned above. Thus, the chain pin
; protrudes ~fro~the ou~er chain plate~ ~
When a rlder~shlfts from a higher ~ear ratio to a
lower gear ratio, l e.,~from a sprocket with a smaller
diameter to~a sprocke~ with a larger diameter, the
: chaln is tilted~and guided by a derailleur to ths
target sprocket.:Since the outcr chain plate has a
aertain thickness and. the chain pi~ protrudes ~rom the
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outer chain~ p~latet a tooth o~ the larger diameter
: sprocket ~ay urge a lateral end o f the outer chain
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plate:or the protruding chain pin to tilt the chain? so
-25 ~s to cause~a larger "t~isting an~le" of the chain
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be-tween the two sprockets. Such a condition will caus0
the Ghain to easiily be broken.
It is the purpoie of this present invention,
therefore~ to mitigate ancl/or obviate the above-
05 mentioned drawback in the ~lanner set ~orth in thedetailed description of the preferred embodiment.
SUMMARY OF THE INVENTION
The present invention provides a rectan~ular chain
plate, rather than a dumbbell ~haped chain plate, which
has a protruding arched portion on e~ch tran3~er~e end
thereof, The arched portion is provided with a
countersink, On an inner ~ace o~ the outer chain plate
there is provided ~ frustum-like projection along a
periphery of each countersink, and bLade portion~ are
15~ provided alon~ upper and lower edges thereo~. The
nner chain plate i9 :slmilar to the outer chain plate
on~an inner ~ace thereof. e~cept for the frusitu~-like
proJection bein~ ~ cylinùrical ~lange.
; Furthermore~ the outer chain pLate ha~ a blade
~0 portion along an ed~e o~ ea~h later~l arched portion
thereo~ so as to avoid a tooth o~ a sprocket urging the
; ~ chaln during the hi~ting operation.
Additionnlly, the chain plates have two holes
between the~ cou~tersink~ thereo~, thereby reducing the
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~ ~ 25 total m~s~ o~ the ahain.
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Therefore, it is a primary object of thi~
invention -to provide ~ cha.in which i5 capable of
reducing a turning angle between the sprocket and chain
in order to protect the chain from breaking during the
05 shifting operation.
It is a ~urther an object of this in~ention to
provide A chain havin~ a space defined by either the
inner chain pLates or the ou-ter chain plate~ which is
larger than that of conventional chains~
It i~ another object of this inv~ntio~ to provide
a chain which is lighter than traditional chains.
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: BRI~ D~SC~IPTION OF ~ D~AWINGS.
: Fig. 1 is a perspec~ive view of a link of a chain
: in accordance with the present inven~ion;
: ~Fig. 2 is an e~ploded:view of Fig. 1;
Fis. 3 is a cross- ectional view taken at line 3-3
of ~ Fio . 2; : : ~ ~
Fig. 4 i~ a cross-~ectional view ta~er~ at line 4-4
:of~Flg.~2
20~:: : :~:Fig. 5 is a top el~vation view partiall~ cross-
sectioned to illustrate a co~bina-tion of the: link of
the~present invention:
Fig. 6~is a top ele~ation ~iew ~howing a turning ~.
angle occurrin~ durin~ ~hi~tln~; and
5 :~ Fi~. 7 is a view simil~r to Fig. 6 according to
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prior art.
DETAILED DESC~IPTION OE E P EFER~ED EMBODIMENT
Re~erring to Figs. 1 and 2 7 a link of a chain can
be seen. The link is combined by a pair of outer chain
05 plates 1, a pair of inner chain plates 2, a pair of
rollers 3, and a chain pisl 4. Each outer chain plate 1
is formed as a rectangle which has an arched portion 11
on each transverse end thereof. E~ch arched pnrtion 11
has a fir~t countersunk through hole 15 therein and
fir b1ade portions 12 along a periph~ral edge on an
outer face thereof. On an inner Pace of each o~ter
chain plate 1, there is provided a ~ru~tum-like
projectlon 16 around a peripher~ of each fir~t through
hole 15 and seco~d blade portions 14 along an:upper and
~:a lower edge thereof.~The $irst and second blade
portions ~re p~rticularl~ shown in Figs. 3 and 4.
The inner chain plate~ 2 have a confi~uration the
same a ;the outer chaln plate .t. but also has arched
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portions 21, second countersun~ through holes 25, and
third blade portions 24. Particularly, each inner chain
~; ~plate 2 has an inw~rd cylindrical ~lan~e Z6 around a
: ~periphery of each ~econd through hole 25 osl an inner
- ~ :i'ace thereo~
Each pt~ripheral ~lan~e 26 ~erYes as a ~upport for
: 25 a roller 3 and allows an insertion o~ the chain pin 4.
: : Thus, to co~bine the element ~bove mentioned, the
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inner chain plates 2 are pos:itioned so as to sandwich
.the rollers ~, and each outer chain plate 1 inserts one
o~ the frustum-like projections 16 thereo~ into a
conical surface of on of the second through holes 25 of
05 the inner chain plates 1. ~he chain pin 4 i~ then
inserted into the ~irst and second through holes 15 and
25 to rotatably support the inner and outer chain
plates 2 and 1 and the rollers 3, such as shown in Fig.
5.
It should be noted that the ~irst blade portions
12 provide a tapered lateral end of the outer chain
plates 1. Referring to Eig. 6, when a rider shift~ fro~
a hi~her gear ratio ta a lower ~ear ratio, the
derailleur tWistY the chain to ~it to an adjacent
:15~;~ sproc~et 5 with a larger diameter, wherein the sprocket
9 is~rotating in ~ ~direc~ion of arrow F. A sprocket
toot~ 51 beside the outer chain plate 1 attaches to a
lateral end. i.e., the ~lrst blade portion 12, o~ the
outer chain plate 1. .Since the blade portion has a
thinner thickness than that of conventionMl ch~ins, -the
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;~: turning an~le caused by the sprocket is smaller, ~o
that the probabilit~ o~ breakage is r~dused.
Furthermore, rePerrin~ back to Fig~. 1, 2 ~d 4,
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~ the outer chain plate~ 1 provide second blade portions
~ ~ 2~ 14 alon~ up]~er and lower edges thereof. Each inner
chain plate~2 ~as a blade portion 24~ which i~ ~imilar
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to the blade portions 14 of the outer chain plates 1,
such that each pair of outer and inner chain plates 1
and 2 respectively de~ine a l.arger space therebetween,
with respective to lon~ikudinal edges thereo~, thereby
05 ~acilitating the receip-t of a tooth of a sprocket.
Additionally, the inner and o~ter chain plates 2
and 1 are provided with holes 17 and 27, respectively.
Since the amount of material need to manufacture the
chain plates is reduced by the blade portion~ and the
holes, the total m~ss of the chain is reduced and le~s
than th&t of conventional chain~.
. It is to be understood, however, that even thou~h
numerous characteri~tic.~ and advanta~es of the presen-t
invention have been set forth in the foregoing
,
1~ ;descriptiont to~ether:wlth details o~ the ~tructure and
function of the invention, the d1sclosure is
: illustrative only, and changes may be made in detail,
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especially in ~atters of shape, size and arrangement of
parts w:ithin the principles of the invention to the
full extent indicated b~ thç broad ~eneral meaning of
: the terms in which the appended claims are expres~ed. .. ..
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