CA2029845A1 - Structure of bicycle chain transmission - Google Patents

Structure of bicycle chain transmission

Info

Publication number
CA2029845A1
CA2029845A1 CA 2029845 CA2029845A CA2029845A1 CA 2029845 A1 CA2029845 A1 CA 2029845A1 CA 2029845 CA2029845 CA 2029845 CA 2029845 A CA2029845 A CA 2029845A CA 2029845 A1 CA2029845 A1 CA 2029845A1
Authority
CA
Canada
Prior art keywords
pedal link
bearing block
link
pedal
bicycle
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
CA 2029845
Other languages
French (fr)
Inventor
Ching-Jung Wu
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
WU CHING JUNG
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to CA 2029845 priority Critical patent/CA2029845A1/en
Publication of CA2029845A1 publication Critical patent/CA2029845A1/en
Abandoned legal-status Critical Current

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Abstract

STRUCTURE OF BICYCLE CHAIN TRANSMISSION

ABSTRACT:
A bicycle chain transmission, comprising a pedal link adjustably fastened in a holder plate mounted on the outer side of a chain wheel and connected with a side projection of a bearing block which is mounted on an eccentric sleeve at the bottom of a bottom bracket bearing axle of a bicycle. The eccentric motion of the eccentric sleeve forces the bearing block to rotate eccentrically so as to squeeze the pedal link to adjust the length of its arm of force according to its angle position relative to the chain wheel, so that reduced labor consumption in pedaling can be achieved.

Description

2~2~

STRUCTURE OF BICYCLE CH~IN TRANSMISSION

BACKGROUND OF THE INVEUTIO?I_ The present invention relates to bicycle chain transmissions, and more Particularly relates to a bicYcle chain transmission of which the arm of force of the pedal crank is so automatically changed that labor consumption in pedaling can be minimiæed.

In a regular bicycle chain transmission, a crank is generally fastened in a chain wheal at the center.
During pedaling, the arm of force of a crank does not make any change. As it is known that longer arm of force of a crank can minimize energy consumption in forward pedaling.
Therefore, there is a kind of chain structure designed in nval shape so t~at the arm of force of a crank can be automatically changed during its rotation. This tyPe of design can effectively minimize energy consumption in pedaling. However, a chain may be easily disengaged from an oval shape of chain wheel during rotation.

-SUMMARY OF THE INVENTION:
The present invention has been accomplished under the circumstances in view. It is one object of the present invention to provide a bicycle chain transmission which can drive a bicycle to run 5with less labor consumption and without causing a chain to disengage.

According to the present invention, a bicycle chain transmission is generally comprised of a bottom bracket bearing device mounted on an eccentric sleeve at the bottom of the bottom bracket bearing axle of a bicycle. The eccentric rotation of the eccentric sleeve forces the 10bearing block of the bottom bracket bearing device to rotate eccentrically so as to further force the pedal link to automatically adjust the length of its arm of force accordin~ to its angle position relative to the chain wheel. Therefore, less labor consumption can be achieved during pedaling.

15More particularly, the invention provides a bicycle chain transmission, comprising: a bottom bracket bearing device comprising a bearing block having a hole at the center and a side projection at . , , one end, a spiral member having three lugs at one end, a plurali~r of bearings each having a bolt sleeve respectively secured to one of said 20lugs and received in the center hole of said bearing block, said spiral member having an outer thread screwed into a bolt hole in a bottom bracket bearing axle of a bicycle, said bottom bracket bearing a~de having an eccentric sleeve at the bottom, said eccentric sleeve having B :~ ~

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two bearings fastened at opposite ends thereoE and a round rod inserted therethrough, said round rod having two outer thread portions at said opposite ends; a chain wheel assembly compnsing two sprocket S wheels of dif~erent size connected together side by side, having a holder plate a$ one side, said holder plate having a bolt hole ~or fastening said outer thread portions of said round rod; and a pedal link movably inserted in a bore in said holder plate, said link having a fixed plate at the middle thereof connected to the side projection of said 10 bearing block, and a pedal attached to one end of said link for pedaling, said pedal link comprising two parts longitudinally aligned with each other and movably connected together by a cylindrical connector, said cylindrical connector comprising an inner wall having three grooves vertically made thereon and spaced from one another at equal intervals with a plurality of rows o~ tapered grooves transversely made therebetween for alternatively fastening a plurality of projecting strips on the connecting end of the two aligned parts of said pedal link;
wherein rotation of said eccentric sleeve forces said bearing block to rotate eccentrically, so as to move said pedal link to automatically 20 adjust its moment arm according to the angular position of said pedal link relative to said chain wheel assembly.

BRIEF DESCRIPrION OF THE DRAWINGS:
Fig. 1 is a plan view of a bicycle chain wheel according to the prior art;

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2~2~4~3 Fig, 2 is a perspective fragmentary view of the preferred emhodiment of bicycle chain transmission according to the present invention;
Fig. 3 is a top view of ~he cylindrical connector;
Fig. 4 is a perspective and partly sectional view of the cylindrical connector;
Fig. 5 is a sectional elevational view of the cylindrical connector;
Fig. 6 is a sectional assembly view of the preferred embodiment according to the present inventicn;
Figs. 7 through 9 illustrate various Positioning conditions of the two aligned parts of the pedal link in the cylindrical connector;
Fig. 10 illustrates the relative position of the eccentric sle0ve, the spiral member and its connected ..
bearings in the bearing block;
Fig. 11 is a sectional elevation taken on Fig. 10;
Figs. 12 through 14 illustrate the uperation of the present invention.
.
~: 20 DETAILED DESCRIPTION OF THE iREFERRED EH80DIMENT.
Referring to Figs. 2 and 6, a bicycle chain ' ' :

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transmission in accordance with the pr0sent invention is generally comprised of bottom bracket bearing device 2, chain wheel 3 and pedal link 4. The bottom bracket bearing device 2 is comprised of a spiral mamber 20 which has three lugs 201, 202 and 203 at the front, a plurality of~ bearings 21, 22 and 23 which have each a bolt sleeve 2000, 2200 or 2300 fastened therein1 and a bearing block 24 which has a center hole 240 for holding bearings. There are provided three screws 210, 220 and 230 respectively inserted through the round holes 2010, 2020 and 2030 on the lugs 201, 202 and 203, and screNed in the bolt sleeves 2100, 2200 and 2300 which are resPectively fastened in the bearings 21, 22 and 23 and received inside the center hole 240 of the bearing block 24. The spiral member 20 has an outer thread 200 scre~ed up with the bolt hole 2040 of the bottom bracket bearing axle 204 of a bicycle. The bottom bracket bearing axle 204 has an eccentric sleeve 2040 (see Fig. 11) at the bottom. Tuo bearings 2041 and 2042 which have each a round hole through its central axis are resPectively fastened inside the ; 20 eccentric sleeve 2040 at two opposite ends. There is a round rod 205 which has two outer thread portions 2050 and 2051 at two opposite ends inserted in the eccentric sleeve 2 ~
s 2040. Rfter assembly, the outer thread portion 2050 or 2051 is fastened in the bolt hole 31 of the bottom bracket bearing device holder 30 which is mounted on the outer side of the chain wheel 3. Further, the bearing block 24 has a unitary side proiection 241 at one end, which is inserted through the chain wheel 3 and secured to a fixed plate 40 on the crank 4 by a lock pin 400. The pedal link 4 is fastened in the device holder 30 and disposed in a vertical position against the bottom bracket bearing device 2. T~o bearings 41 are mounted on the pedal link 4 and resPectively disposed at two opposite sid0s of the device holder 30.
The pedal link 4 is comprised of two parts longitudinally aligned with each other and adjustably connected together bY
a cylindrical connector 42 The cylindrical connactor 42 comprises three grooves vertically made on the inner wall surface thereof and spaced from one another at an interval of 120angle, with a plurality of rows of tapered grooves 4200, 4210 and 4220 respectively transversely made therebetNeen (see Figs. 3,4 and 5) for fastening the projecting strips 423, 424, 425, and 426, 427, 428, of the two aligned parts of the pedal link 4. Therefore, the total length of the pedal link 4 can adjusted (see Figs. 7 through 9) as desired.

2~2~8~

Further, there is a pedal 43 attachsd to the pedal link 4 at one end, through ~hich the chain wheel 3 is pedaled to rotate.

Referring to Figs. 7 through 9, while rotation of . -S the bottom bracket bearing device 2, the bearing block 24 is carried to rotate eccentrically. The eocentric rotation of the bcaring block 24 forces the pedal link 4 to change the length of its arm of force according to its angls position ~ ;~
relative to the chain wheel 3.

Referring to Figs. 12, 13 and 14, when the pedal link 4 is moved forward from a vertical position to a horizontal position, the eccentric sleeve 2040 on the bottom bracket bearing axle 204 forces the bearing block 24 to rotata eccentrically. During the eccentric motion of the bearing block 24, the pedal link 4 is simultaneously pushed .
by the side proiection 241 to extend outNards, so as to increase its arm of force. When the pedal link 4 is continuously rotated down~ard from a horizontal position to a vertically position, it is pulled back by the side projection 2~ 241 of the bearing block 24 to shorten its arm of force.
~' When the pedal link 4 is rotated backuards from ~ vertical position to a horizontal position, the arm of force of the pedal link 4 is in a shortest form so that the pedal link 4 can be continuously rotated forward to a vertical position S for next stroke, with less labor consumption.

i: , ; As described above, the present invention is to provide such a bicYcle chain transmission, in Yhich the arm of force of the pedal:link:is automatically adiusted during its rotation so that labor consumption in pedaling can be : 10 minimized.

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Claims

CLAIM
1. A bicycle chain transmission, comprising:
a bottom bracket bearing device comprising a bearing block having a hole at the center and a side projection at one end, a spiral member having three lugs at one end, a plurality of bearings each having a bolt sleeve respectively secured to one of said lugs and received in the center hole of said bearing block, said spiral member having an outer thread screwed into a bolt hole in a bottom bracket bearing axle of a bicycle, said bottom bracket bearing axle having an eccentric sleeve at the bottom, said eccentric sleeve having two bearings fastened at opposite ends thereof and a round rod inserted therethrough, said round rod having two outer thread portions at said opposite ends;
a chain wheel assembly comprising two sprocket wheels of different size connected together side by side, having a holder plate at one side, said holder plate having a bolt hole for fastening said outer thread portions of said round rod; and a pedal link movably inserted in a bore in said holder plate, said link having a fixed plate at the middle thereof connected to the side projection of said bearing block, and a pedal attached to one end of said link for pedaling, said pedal link comprising two parts longitudinally aligned with each other and movably connected together by a cylindrical connector, said cylindrical connector comprising an inner wall having three grooves vertically made thereon and spaced from one another at equal intervals with a plurality of rows of tapered grooves transversely made therebetween for alternatively fastening a plurality of projecting strips on the connecting end of the two aligned parts of said pedal link; wherein rotation of said eccentric sleeve forces said bearing block to rotate eccentrically, so as to move said pedal link to automatically adjust its moment arm according to the angular position of said pedal link relative to said chain wheel assembly.
CA 2029845 1990-11-13 1990-11-13 Structure of bicycle chain transmission Abandoned CA2029845A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CA 2029845 CA2029845A1 (en) 1990-11-13 1990-11-13 Structure of bicycle chain transmission

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CA 2029845 CA2029845A1 (en) 1990-11-13 1990-11-13 Structure of bicycle chain transmission

Publications (1)

Publication Number Publication Date
CA2029845A1 true CA2029845A1 (en) 1992-05-14

Family

ID=4146412

Family Applications (1)

Application Number Title Priority Date Filing Date
CA 2029845 Abandoned CA2029845A1 (en) 1990-11-13 1990-11-13 Structure of bicycle chain transmission

Country Status (1)

Country Link
CA (1) CA2029845A1 (en)

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