Folding bicycle structure

Claim 2

An improved folding bicycle structure comprising: a retractable front tube set including an outer tube having an inner tube therein, an action rod having a top and a bottom being provided in said inner tube; a first handle being provided on a first side of said top of said action rod, and a second handle being provided at a second opposing side of said top of said action rod; an eccentric rotation device being pivotally coupled and releasably engagable with said top of said action rod; a coned piece being coupled adjacent at said bottom of said action rod, said action rod displaces said coned piece into said inner tube to expand said inner tube in said outer tube for fixing a position thereof responsive to rotation of said eccentric rotation device; a seat tube having a distal end pivotally connected to said front tube set, said seat tube being provided with a saddle at a top end of said seat tube; a rear tube having a top end pivotally connected to said seat tube; a fastening device being provided between said rear tube and said seat tube, said fastening device fixing said seat tube when said rear tube pivotally rotates with respect to said seat tube to unfold; and a joint link connected between said front tube set, said seat tube and said rear tube for displaceably interconnecting said front tube set, said seat tube and said rear tube to unfold and fold with respect to one another.

Claim 3

The improved folding bicycle structure as claimed in claim 1 further comprising a rear rack, which is pivotally provided at a tail portion of said rear tube, said rear rack being pivotally turned to become horizontal for carrying articles thereon, said rear rack being pivotally turned to become vertical for folding and letting said bicycle be erect on the ground.

Claim 4

The improved folding bicycle structure as claimed in claim 1 , wherein said eccentric rotation device is further firmly connected with said first handle, said eccentric rotation device being released from engagement with said action rod to release said first handle to rotate to said second side of said action rod adjacent said second handle, said eccentric rotation device being engaged with said action rod to secure said first handle at said first side of said action rod opposite of said second handle.

Claim 5

The improved folding bicycle structure as claimed in claim 1 , wherein said seat tube is a retractable seat tube.

Claim 6

The improved folding bicycle structure as claimed in claim 1 , wherein a fixing member is displaceably coupled to said joint link to releaseably fix said joint link when said front tube, said seat tube and said rear tube are in an unfolded position.

Claim 7

An improved folding bicycle structure comprising: a retractable front tube set including an outer tube having an inner tube therein, an action rod having a top and a bottom being provided in said inner tube; a first handle being provided on a first side of said top of said action rod, and a second handle being provided at a second opposing side of said top of said action rod; an eccentric rotation device being pivotally coupled and releasably engagable with said top of said action rod, said action rod being releaseably engaged with said inner tube to expand said inner tube in said outer tube for fixing a position thereof responsive to rotation of said eccentric rotation device; a seat tube having a distal end pivotally connected to said front tube set, said seat tube being provided with a saddle at a top end of said seat tube; a rear tube having a top end pivotally connected to said seat tube; a fastening device being provided between said rear tube and said seat tube, said fastening device fixing said seat tube when said rear tube pivotally rotates with respect to said seat tube to unfold, wherein said fastening device including: a support arc piece connected with said rear tube; a U-shaped piece connected with said support arc piece, two projective points being provided at inner sides of two clamping arms of said U-shaped piece; and a U-shaped clamping body whose opening opposes an opening of said U-shaped piece and is pivotally connected therewith, two clamping arms of said U-shaped clamping body being inside said two clamping arms of said U-shaped piece, said U-shaped clamping body being clamped outside said seat tube, said rear tube being used to drive said U-shaped piece to pivotally turn and let said support arc piece support said seat tube and said two projective points compress said U-shaped clamping body so as to drive said two clamping arms of said U-shaped clamping body to contract inwards and clamp said seat tube when said rear tube pivotally turns with respect to said seat tube, thereby fixing said seat tube; and a joint link connected between said front tube set, said seat tube and said rear tube for displaceably interconnecting said front tube set, said seat tube and said rear tube to unfold and fold with respect to one another.

Claim 8

An improved folding bicycle structure comprising: a retractable front tube set including an outer tube having an inner tube therein, an action rod having a top and a bottom being provided in said inner tube; a first handle being provided on a first side of said top of said action rod, and a second handle being provided at a second opposing side of said top of said action rod; an eccentric rotation device being pivotally coupled and releasably engagable with said top of said action rod, said action rod being releaseably engaged with said inner tube to expand said inner tube in said outer tube for fixing a position thereof responsive to rotation of said eccentric rotation device; a seat tube having a distal end pivotally connected to said front tube set, said seat tube being provided with a saddle at a top end of said seat tube; a rear tube having a top end pivotally connected to said seat tube; a fastening device being provided between said rear tube and said seat tube, said fastening device fixing said seat tube when said rear tube pivotally rotates with respect to said seat tube to unfold, wherein said fastening device including: a support arc piece connected with said rear tube; a U-shaped piece connected with said support arc piece, two projective points being provided at inner sides of two clamping arms of said U-shaped piece; and a U-shaped clamping body whose opening opposes an opening of said U-shaped piece and is pivotally connected therewith, two clamping arms of said U-shaped clamping body being inside said two clamping arms of said U-shaped piece, said U-shaped clamping body being clamped outside said seat tube, said rear tube being used to drive said U-shaped piece to pivotally turn and let said support arc piece support said seat tube and said two projective points compress said U-shaped clamping body so as to drive said two clamping arms of said U-shaped clamping body to contract inwards and clamp said seat tube when said rear tube pivotally turns with respect to said seat tube, thereby fixing said seat tube; and a joint link connected between said front tube set, said seat tube and said rear tube for displaceably interconnecting said front tube set, said seat tube and said rear tube to unfold and fold with respect to one another.

Claim 9

The improved folding bicycle structure as claimed in claim 6 , wherein a shock absorber is further provided between said support arc piece and said rear tube.