Adjustable handlebar for bicycle

Claim 2

An adjustable handlebar for a bicycle, comprising two handlebar members whose adjacent ends are pivotally supported by two studs extending from an upper portion of a handlebar stem, gear teeth formed on said adjacent ends of the handlebar members and in mesh with each other such that when one of said handlebar members is pivotally moved about said stud, the other handlebar member is also pivotally moved about the other stud, anchoring means provided between engagment surfaces of said upper portion of said handlebar stem and of said adjacent ends of said handlebar members for anchoring said handlebar members, and a cam and cam follower assembly having a lever for engaging and disengaging said anchoring means.

Claim 3

An adjustable handlebar as set forth in claim 1, wherein said anchoring means are two sets of thrust serrations in opposition to each other and respectively formed on said engagement surfaces of said handlebar stem and said handlebar members, and said serrations have radial crests, isosceles triangle-shaped in section and positioned concentrically to said studs, thereby urging said adjacent ends away from the upper portion of said handlebar stem by a wedge action of said serrations.

Claim 4

An adjustable handlebar as set forth in claim 1, wherein said cam and cam follower assembly comprises a retainer plate formed with two holes for passing therethrough said studs and a cam fitting groove, an elongated cam having a semicircular cross-section to be received in said cam fitting groove such that said cam is rotated about its longitudinal axis so as to assume positions enabling said anchoring means to engage and disengage.

Claim 5

An adjustable handlebar as set forth in claim 1, wherein said upper portion of the handlebar stem is formed by a rear part and a front part pivotally movable relative to said rear part about a substantially horizontal axis in a transverse direction of the bicycle and clamped to said rear part by clamping means and said two studs extend from said front part, thereby, enabling inclined angles of grips of the handlebar to be changed.

Claim 6

An adjustable handlebar as set forth in claim 4, wherein said rear part of said upper portion of the handlebar stem is a bracket extending in a front direction of the bicycle and having a horizontal hole in the transverse direction, and said front part of said upper portion of the handlebar stem is an ellipse-shaped disc provided on its rear surface with two brackets embracing said first mentioned bracket and having apertures in alignment with said horizontal hole of said first mentioned bracket to form an integral handlebar support member, and wherein said clamping means comprises at least one sleeve joint longitudinally divided into semicircular sleeve members and inserted in the alinged horizontal hole and apertures of the first mentioned bracket and said two brackets, said sleeve member formed with apertures inwardly tapered from both ends of said joint, an outer tapered cotter to be fitted in one of the tapered apertures of said sleeve joint and centrally formed with a bolt passing-through aperture, an inner tapered cotter to be fitted in the other tapered aperture of said sleeve joint and centrally formed with a screw-threaded aperture, and a bolt extending through said bolt passing-through aperture of said outer tapered cotter to be threadedly engaged in said screw-threaded aperture of said inner tapered cotter, thereby enabling said handlebar support member to be movable or clamped relative to said handlebar stem by reducing or enlarging an outer diameter of the sleeve joint by loosening or tightening said bolt.

Claim 7

An adjustable handlebar as set forth in claim 1, wherein said studs extend in parallel with each other.

Claim 8

An adjustable handlebar as set forth in claim 1, wherein said studs are arranged so that extensions of axes of said studs are crossing in front of the bicycle.

Claim 9

An adjustable handlebar as set forth in claim 5, wherein instead of said two studs, there are provided two bolts which are screwed from the front side of the bicycle in screw-threaded apertures formed in said handlebar support member so that extensions of axes of said bolts are crossing in front of the bicycle.

Claim 10

An adjustable handlebar as set forth in claim 8, wherein nuts as lock nuts are threadedly engaged on screw-threaded ends of said bolts extending through said handlebar support member in a rear direction of the bicycle.

Claim 11

An adjustable handlebar as set forth in claim 1, wherein said adjacent ends of said two handlebar members are formed with spaces about said studs extending therethrough, in which space are provided coil springs about said studs to urge said adjacent ends of the handlebar members away from said upper portion of said handlebar stem, whereby positively disengaging said anchoring means when said studs are loosened.

Claim 12

An adjustable handlebar as set forth in claim 1, wherein said cam and cam follower assembly comprises a cam holder adjacent to and in front of said adjacent ends of said handlebar members, a retainer plate adjacent to and in front of said cam holder to form in their adjacent portions a cam fitting cylindrical space, said studs passing through said cam holder and said retainer plate so as to permit said holder and plate to slide thereon when the bolts are loosened, and a cam lever formed at one end with ellipsoid-shaped cams extending in lateral directions and received in said cam fitting cylindrical space to move said cam holder away from said retainer plate when said ellipsoid-shaped cams are rotated in said cylindrical space by moving said cam lever.

Claim 13

An adjustable handlebar as set forth in claim 11, wherein said cam lever further comprises a lever lock slidably movable on a main body of said cam lever and always springly urged in the front direction and provided at its front end with at least one pawl engageable with a projection of said cam holder, thereby preventing the cam lever from being moved until said lever lock is retracted against the springly urged action.

Claim 14

An adjustable handlebar as set forth in claim 12, wherein said cam lever is further formed on the other end with a grip and a clearance between a front portion of said grip and said main body of said cam lever, said lever lock is formed in a U-shaped cross-section so as to be fitted on said main body of said cam lever such that a rear part of said lever lock is inserted in said clearance and legs of said U-shaped lever lock embrace said main body of said cam lever, and said cam lever further comprises a coil spring received in a slot formed in said main body of said cam lever and a pin slidably received in said slot formed in said main body and retained with its ends in apertures formed in said legs of said U-shaped lever lock so as to urge said U-shaped lever lock in the front direction by said coil spring.

Claim 15

An adjustable handlebar as set forth in claim 13, wherein said lever lock is further formed with a latch with which a cyclist retracts said lever lock by fingers.

Claim 16

An adjustable handlebar as set forth in claim 14, wherein said latch is formed like stairs inclined as a whole.

Claim 17

An adjustable handlebar as set forth in claim 13, wherein said pawl is formed on its underside with an inclined surface which engages said projection of said cam holder so as to permit said pawl to move beyond said projection of said cam holder during moving said cam lever, thereby enabling said cam lever to be in a locked position without manually retracting said lever lock.

Claim 18

An adjustable handlebar for a bicycle, comprising two handlebar members whose adjacent ends are pivotally supported by two bolts threadedly engaged in screw-threaded apertures formed in an upper portion of a handlebar stem, extensions of axes of said bolts being crossing in front of the bicycle, gear teeth formed on said adjacent ends of the handlebar members and in mesh with each other such that when one of said handlebar members is pivotally moved about said bolt, the other handlebar member is also pivotally moved about the other stud, two sets of thrust serrations in opposition to each other and respectively formed on said engagement surfaces of said handlebar stem and said handlebar members, said serrations having radial crests, isosceles triangle-shaped in section and positioned concentrically to said studs, coil spring arranged about said bolts and received in spaces formed in said adjacent ends of said handlebar members along said bolts to urge said adjacent ends of the handlebar members away from said upper portion of said handlebar stem, thereby positively disengaging said serrations when said bolts are loosened, a cam holder adjacent to and in front of said adjacent ends of said handlebar members, a retainer plate adjacent to and in front of said cam holder to form in their adjacent portions a cam fitting cylindrical space, said bolts passing through said cam holder and said retainer plate so as to permit said cam holder and said retainer plate to slide thereon when the bolts are loosened, and a cam lever formed at one end with ellipsoid-shaped cams extending in lateral directions and received in said cam fitting cylindrical space to move said cam holder away from said retainer plate when said ellipsoid-shaped cams are rotated in said cylindrical space by moving said cam lever, and said cam lever further comprising a lever lock slidably movable on a main body of said cam lever and always springly urged in the front direction and provided at its front end with at least one pawl engageable with a projection of said cam holder, thereby preventing the cam lever from being moved until said lever lock is retracted against the springly urged action.

Claim 19

An adjustable handlebar for a bicycle, comprising two handlebar members whose adjacent ends are pivotally supported by two bolts threadedly engaged in screw-threaded apertures formed in an upper portion of a handlebar stem, extensions of axes of said bolts being crossing in front of the bicycle, gear teeth formed on said adjacent ends of the handlebar members and in mesh with each other such that when one of said handlebar members is pivotally moved about said bolt, the other handlebar member is also pivotally moved about the other stud, two sets of thrust serrations in opposition to each other and respectively formed on said engagement surfaces of said handlebar stem and said handlebar members, said serrations having radial crests, isosceles triangle-shaped in section and positioned concentrically to said studs, coil spring arranged about said bolts and received in spaces formed in said adjacent ends of said handlebar members along said bolts to urge said adjacent ends of the handlebar members away from said upper portion of said handlebar stem, thereby positively disengaging said serrations when said bolts are loosened, a cam holder adjacent to and in front of said adjacent ends of said handlebar members, a retainer plate adjacent to and in front of said cam holder to form in their adjacent portions a cam fitting cylindrical space, said bolts passing through said cam holder and said retainer plate so as to permit said cam holder and said retainer plate to slide thereon when the bolts are loosened, and a cam lever formed at one end with ellipsoid-shaped cams extending in lateral directions and received in said cam fitting cylindrical space to move said cam holder away from said retainer plate when said ellipsoid-shaped cams are rotated in said cylindrical space by moving said cam lever, and said cam lever further comprising a lever lock slidably movable on a main body of said cam lever and always springly urged in the front direction and provided at its front end with at least one pawl engageable with a projection of said cam holder, thereby preventing the cam lever from being moved until said lever lock is retracted against the springly urged action.