Foldable bicycle frame

• US 5,222,751 A
• Filed: 01/22/1991
• Issued: 06/29/1993
• Est. Priority Date: 01/22/1991
• Status: Expired due to Fees

• Current Assignee: Robert W.P. Chen
• Original Assignee: Robert W.P. Chen
• Inventors: Chen, Robert W. P.
• Primary Examiner(s): Focarino, Margaret A.
• Assistant Examiner(s): BOEHLER, ANNE MARIE M
• Application Number:
  US07/643,512
• Time in Patent Office: 889 Days
• Field of Search: 280/287, 280/278, 280/281.1, 280/288.3, 280/279, 280/280, 403/104, 403/110, 403/374, 403/377, 74/493
• US Class Current: 280/278
• CPC Class Codes: B62K 15/006 the frame being foldable
• CPC Class Codes: Y10T 403/32532 Clamped members

Abstract

A foldable bicycle frame comprises a front triangular portion and a rear triangular portion. The former includes a top tube, a down tube, a head tube and a seat tube while the latter contains a bottom bracket tube, a seat stay, a chain stay and a seat tube. Both front and rear triangular portions are hinged by means of upper and lower coupling pieces so that they can pivot to be folded. Upon being unfolded, both front and rear triangular portions are held securely by virtue of a seat stay which extends beyond the seat tube to be fastened securely to the top tube. Front and rear triangular portions can be also held so securely in another manner that a seat post is inserted into connection tube and seat tube which are coaxially arranged.

Claims

1. A foldable bicycle frame comprising:

a front triangular portion having a top tube, a down tube and a head tube;

a rear triangle portion having a bottom bracket tube, a seat tube, a seat stay and a chain stay;

an axial tube attached to said top tube having an axial line about perpendicular to a line formed between centers of front and rear wheels of a bicycle;

an upper coupling piece surrounding the axial tube;

a lower coupling piece fastened to rear end of said down tube, and arranged coaxially with the upper coupling piece; and

a connection tube located at upper portion of said seat tube and fastened to said top tube;

wherein said front triangular portion and said rear triangular portion are pivotally arranged so as to fold about an axial center of said upper coupling piece and said lower coupling piece and are joined together by means of a seat post fitted through said connection tube and said seat tube.

2. A foldable bicycle frame comprising:

a front triangle portion having a top tube, a down tube, and a head tube;

a rear triangle portion including a bottom bracket tube, a seat tube, a seat stay, and chain stay;

a connection tube fastened at rear end of the top tube oriented coaxially with and above the upper end of said seat tube;

an axial tube fastened at the rear end of the top tube near where said top tube is fastened to said connection tube, said axial tube having a center line substantially perpendicular to a line formed between centers of front and rear wheels of a bicycle;

an upper coupling piece surrounding said axial tube, a front end of said seat stay being disposed forward of said seat tube and being fastened to said upper coupling piece; and

a lower coupling piece oriented coaxially with said upper coupling piece and fastened to rear end of the down tube;

wherein said front triangular portion and said rear triangular portion are pivotally arranged so as to fold about an axial line of said upper coupling piece and said lower coupling piece.

3. A foldable bicycle frame of claim 2 wherein the lower portion of the seat tube is substantially perpendicular to a line formed between centers of front and rear wheels of a bicycle and is surrounded by said lower coupling piece oriented coaxially with said upper coupling piece.