CA2035339A1 - Chain - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A chain comprises a plurality of pairs of outer and inner chain plates linked by rollers and pins, each chain plate being configured as a rectangle which has a protuberant arched portion on each transverse end thereof, and each chain plate having blade portions along longitudinal upper and lower edges thereof. Each inner chain plate has inward cylindrical flanges on an inner face thereof around a periphery of the countersunk through holes thereof. Each outer chain plate has a frustum-like projection surrounding the countersunk through holes on an inner face thereof, and an outward blade portion along an edge of each arched portion thereof.

Description

3 ~ 9 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 - : ~ :
outer chain~ p~latet a tooth o~ the larger diameter : sprocket ~ay urge a lateral end o f the outer chain ~ ~ , 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 , ~
~ ~ 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.
:, : 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 : : , 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 ' : . : ~ ~;, :

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 : :
;~: 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, .
~ 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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Claims (3)

1. A chain comprising a plurality of pairs of outer and inner chain plates linked by rollers and pins, wherein the improvement comprises:
each said outer and inner chain plates being formed as a rectangle having a protuberant lateral arched portion on each transverse end thereof and having first and second countersunk through holes, respectively, on each lateral arched portion thereof to receive a chain pin; each said inner chain plate having inward cylindrical flanges on an inner face thereof around a periphery of said second through holes for supporting said roller; each said outer chain plate having frustum-like projections on an inner face thereof around a periphery of said first through holes being fittable to said second through holes on said inner chain plates; each said lateral arched portion of said outer chain plate having a blade portion along an edge on an outer face thereof, thereby allowing said outer chain plate to reduce a twisting angle formed between an adjacent sprocket and said chain.

2. A chain as claimed in claim 1. wherein said outer and inner chain plates have an inward blade portion along each longitudinal upper and lower edge thereof.

3. A chain as claimed in claim 1. wherein said outer and inner chain plates have two holes between said through holes.