Foldable device for connecting a front fork to a handlebar of a bicycle

A foldable device is adapted to connect a front fork to a handlebar of a bicycle, and includes a linking member hingedly connected to lower and upper hingeable flanges about first and second hinge axes, respectively. The first and second hinge axes are transverse to each other. The upper and lower hingeable flanges are respectively coupled with the handlebar and the front fork. The handlebar is turned relative to the front fork about the first and second hinge axes to permit a handlebar line of the handlebar to be parallel to a longitudinal direction in which the bicycle extends so as to fold the bicycle and to minimize the entire width of the folded bicycle.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority of Taiwanese patent Application No. 098104671, filed on Feb. 13, 2009, the disclosure of which is herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a foldable bicycle, more particularly to a foldable device for connecting a front fork to a handlebar of a foldable bicycle.

2. Description of the Related Art

Referring toFIGS. 1 and 2, a conventional foldable bicycle7disclosed in Taiwanese Utility Model No. 265310 is shown to include a bicycle frame71, a front fork72which has a steering tube721extending in a head tube of the bicycle frame71, a front wheel73, a stem74which is coupled to the steering tube721via a folding device6, and a handlebar75connected to an upper end of the stem74. The folding device6includes an extension61and a connecting unit62. When a locking block621is released to permit disengagement between upper and lower portions622,623, the stem74can be turned toward the left side of the bicycle frame71about a pivot624to permit the elongated line of the handlebar75to extend in an upright direction, and can then be turned toward the bicycle frame71to be locked by a C-shaped clamp711, whereby the bicycle7is held in a folded state.

Since the front wheel73is brought to turn with the stem74during folding of the bicycle7, the entire width of the folded bicycle7is relatively large, and a wheel with a large diameter is therefore not suitable for use in the bicycle7.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a foldable device which is used to connect a front fork to a handlebar of a foldable bicycle, and which permits wheel axes of two bicycle wheels to be in line with each other when the bicycle frame is in a folded state so as to minimize the entire width of the folded bicycle.

According to this invention, the foldable device includes a lower hingeable flange, a linking member, an upper stem, an upper hingeable flange, and a clamping unit.

The lower hingeable flange is adapted to be coupled with a top end of a front fork of the bicycle, and has a bottom major surface, and lower hingeable and clampable segments.

The linking member includes a central region which defines a centerline that is parallel to a steering axis of the top end when a handlebar of a bicycle is in a position of use, a first engaging region which is hingedly connected to the lower hingeable segment about a first hinge axis to permit the linking member to move between a first closed position, where the central region is close to the bottom major surface, and a first open position, where the central region is remote from the bottom major surface, and a second engaging region which is angularly displaced from the first engaging region about the centerline.

The upper stem defines a lengthwise line that is parallel to the steering axis when the handlebar is in the position of use, and is adapted to be coupled with the handlebar.

The upper hingeable flange is connected to and extends from the upper stem, and has an overlying major surface which faces toward the bottom major surface when the handlebar is in the position of use, an upper hingeable segment which is hingedly connected to the second engaging region about a second hinge axis that is transverse to the first hinge axis to permit the upper hingeable flange to move between a second closed position, where the overlying major surface is close to the central region, and a second open position, where the overlying major surface is remote from the central region, and an upper clampable segment that is angularly displaced from the upper hingeable segment about the lengthwise line.

The clamping unit is disposed to hold the upper and lower clampable segments tightly once the linking member and the upper hingeable flange are in the first and second closed positions, respectively.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Before the present invention is described in greater detail, it should be noted that same reference numerals have been used to denote like elements throughout the specification.

Referring toFIGS. 3 to 6, the first preferred embodiment of a foldable device according to the present invention is adapted to connect a front fork13of a bicycle to a handlebar11of a bicycle frame1. The bicycle frame1extends in a longitudinal direction, and has a head tube12such that the front fork13is received in the head tube12and extends along a steering axis (X1) in an upright direction to terminate at a top end131. The handlebar11has a central portion110, and two handlebar ends111at opposite sides of the central portion110and along a handlebar line (X2).

The foldable device is shown to comprise a fork-side unit2, a linking member3, a handlebar-side unit4, and a clamping unit5.

The fork-side unit2includes a connecting member22and a lower hingeable flange21which is integrally formed with the connecting member22.

The connecting member22includes a hoop220which is fitted around the top end131of the front fork13about the steering axis (X1) and which has two opposing ends that are spaced apart from each other by a gap221, two lugs222which extend respectively and radially from the ends of the hoop220, and two screw fasteners224which are disposed to tighten the lugs222toward each other, thereby retaining the connecting member22tightly on the top end131of the front fork13.

The lower hingeable flange21extends upwardly and radially from the connecting member22relative to the steering axis (X1), and has a bottom major surface212that faces upwardly. The lower hingeable flange21includes lower hingeable and clampable segments214,211that are angularly displaced from each other about the steering axis (X1). In this embodiment, the hingeable segment214is a cavity formed in the bottom major surface212, and the clampable segment211is a cutaway surface adjacent to the bottom major surface212. Additionally, a plurality of cavities213are formed in the bottom major surface212.

The linking member3defines a centerline (X3) that is parallel to the steering axis (X1) when the handlebar11is in a position of use (as shown inFIG. 4), and includes a central region30normal to the centerline (X3), a first engaging region31which is opposite to the central region30radially relative to the centerline (X3), and which is hingedly connected to the lower hingeable segment214about a first hinge axis (H1) that is transverse to the longitudinal and upright directions to permit the linking member3to move between a first closed position, where the central region30is close to the bottom major surface212, and a first open position (seeFIG. 3), where the central region30is remote from the bottom major surface212, and second and third engaging regions32,33which are angularly displaced from the first engaging region31about the centerline (X3).

The handlebar-side unit4includes an upper stem42and an upper hingeable flange41which is integrally formed with the upper stem42.

The upper stem42defines a lengthwise line (X4) that is parallel to the steering axis (X1) when the handlebar11is in the position of use, and has an upper connected end421and an upper coupling end422that is opposite to the upper connected end421and that is adapted to be coupled with the central portion110of the handlebar11.

The upper hingeable flange41is connected to and extends from the upper connected end421radially relative to the lengthwise line (X4). The upper hingeable flange41has an overlying major surface412which faces toward the bottom major surface212when the handlebar11is in the position of use. The upper hingeable flange41includes an upper hingeable segment414hingedly connected to the second engaging region32about a second hinge axis (H2) (seeFIG. 7) that is transverse to the first hinge axis (H1) to permit the upper hingeable flange41to move between a second closed position, where the overlying major surface412is close to the central region30, and a second open position, where the overlying major surface412is remote from the central region30. The upper hingeable flange41further includes an upper clampable segment411that is angularly displaced from the upper hingeable segment414about the lengthwise line (X4). In this embodiment, the upper hingeable segment414is a cavity formed in the overlying major surface412, and the upper clampable segment411is a cutaway surface adjacent to the overlying major surface412. Additionally, a plurality of cavities413are formed in the overlying major surface412, and mate with the cavities213in the bottom major surface212to define an accommodation space therebetween, such that the overlying major surface412is partially superimposed upon the bottom major surface212, and the linking member3is received in the accommodation space when the linking member3is in the first closed position.

The clamping unit5includes a tightening bolt52which has a threaded segment engaged with the third engaging region33of the linking member3, and an enlarged head55opposite to the threaded segment, and a jaw member53which is movably sleeved on the tightening bolt52. When the linking member3and the upper hingeable flange41are respectively in the first and second closed positions, i.e., when the handlebar11is in the position of use, by manually operating the enlarged head55, the jaw member53can be brought to move toward the steering axis (X1) to tightly hold the upper and lower clampable segments411,211by virtue of engagement of the threaded segment of the tightening bolt52with the linking member3. In addition, a biasing member54is disposed between the linking member3and the jaw member53to bias the jaw member53away from the steering axis (X1).

When it is desired to fold the bicycle frame1, the enlarged head55is turned to permit disengagement of the jaw member53from the upper and lower clampable segments411,211. The user can then grip the enlarged head55and turn the linking member3and the handlebar11about the first hinge axis (H1) so as to move the linking member3to the first open position, as shown inFIG. 6. At this stage, the handlebar line (X2) is transverse to the longitudinal direction in which the bicycle frame1extends, and the second hinge axis (H2) extends in the upright direction. Subsequently, the user can turn the handlebar-side unit4and the handlebar11about the second hinge axis (H2) to move the upper hingeable flange41to the second open position, as shown inFIG. 7. At this stage, the second hinge axis (H2) extends in the upright direction, and the handlebar line (X2) is parallel to the longitudinal direction. Thus, axes of front and rear bicycle wheels (not shown) can be maintained in line with each other during folding of the bicycle frame1, thereby minimizing the entire width of the folded bicycle.

Referring toFIGS. 8 to 10, the second preferred embodiment of a foldable device according to this invention is shown to be similar to the first preferred embodiment in construction. In this embodiment, the upper and lower hingeable flanges41,21and the linking member3are in the form of blocks. The linking member3has upper and lower major surfaces34,38that are opposite to each other along the centerline (X3) and that are disposed to be sandwiched between the bottom and overlying major surfaces212,412when the handlebar (not shown) is in a position of use (as shown inFIG. 8), and a middle peripheral surface35that interconnects the upper and lower major surfaces34,38and that surrounds the centerline (X3). Additionally, the upper and lower hingeable flanges41,21respectively have upper and lower clamped major surfaces415,215that are respectively opposite to the overlying and bottom major surfaces412,212. The upper and lower hingeable flanges41,21further have upper and lower peripheral surfaces43,23, respectively, which are flush with the middle peripheral surface35when the handlebar is in the position of use.

Additionally, the lower hingeable segment214of the lower hingeable flange21is in the form of a lug which extends upwardly from the bottom major surface212. The first engaging region31of the linking member3is concaved from the middle peripheral surface35toward the centerline (X3), and is mated and hinged to the lower hingeable segment214. The second engaging region32of the linking member3is in the form of a lug which extends in a direction parallel to the centerline (X3) from the upper major surface34. The upper hingeable segment414of the upper hingeable flange41is concaved from the upper peripheral surface43toward the lengthwise line (X4), and is mated and hinged to the second engaging region32.

Additionally, the linking member3and the upper and lower hingeable flanges41,21respectively have concavities36,416,216which are concaved from the middle, upper and lower peripheral surfaces35,43,23, respectively, and which are aligned with one another when the handlebar is in the position of use. The upper and lower clampable segments411,211are concaved from the upper and lower clamped major surfaces415,215, respectively. The clamping unit5includes an insert bolt56which is insertable into the concavities36,416,216, and upper and lower abutting portions57,58which are engaged with the upper and lower clampable segments411,211, respectively. The lower abutting portion57is sleeved on the insert bolt56. The upper abutting portion58is threadedly engaged with the insert bolt56. The insert bolt56has an enlarged head59which is operable manually such that screw-in movement of the insert bolt56results in movement of the upper abutting portion58so as to press the upper clamped major surface415toward the lower clamped major surface215.