Joining structure for frames used in bicycles and similar vehicles

• US 4,896,991 A
• Filed: 03/03/1989
• Issued: 01/30/1990
• Est. Priority Date: 04/01/1987
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Fukurotani Seisakusho
• Original Assignee: Kabushiki Kaisha Fukurotani Seisakusho
• Inventors: Yashuhara, Masanori
• Primary Examiner(s): Arola, Dave W.
• Application Number:
  US07/319,815
• Time in Patent Office: 333 Days
• Field of Search: 403/290, 285/396, 285/402, 285/915, 285/174, 285/360, 285/361, 285/376, 285/401, 285/173, 285/174, 285/422
• US Class Current: 403/290
• CPC Class Codes: B62K 19/22 Adhesive joints
• CPC Class Codes: F16B 11/008 of tubular elements or rods in coaxial engagement
• CPC Class Codes: F16B 7/20 using bayonet connections
• CPC Class Codes: Y10S 285/915 Mastic
• CPC Class Codes: Y10T 403/535 with separate force-applying means

Abstract

A joining structure for coupling and pipes in frames used in bicycles and similar vehicles including engaging projections formed on either connecting projections of the coupling or the pipe ends, and insertion cut-outs formed in the mating connecting extensions or pipe ends. After insertion, the mated parts are rotated until they are machanically locked in place by locking slots. Bonding agents may be used to increase the strength of the joints and/or intermediate parts can be used to securely join the connecting extensions and pipes by the use of locking slots and the application of bonding agents. The design provides overlapping in the joints between the intermediate parts and the pipes to increase the bonding surface area and thus the mechanical strength.

Claims

1. A joining structure for the lightweight frames of bicycles and similar vehicles formed by joining chemically and mechanically pipes and couplings, said joining structure comprising:

pipes and couplings and connecting extensions formed on at least one of said couplings made from a lightweight material selected from the group consisting of aluminum, magnesium, titanium, alloys or ceramic compositions of aluminum, magnesium or titanium, carbon fibers and composites thereof;

pipe ends formed at the extremities of said pipes made from a lightweight material selected from the group consisting of aluminum, magnesium, titanium, alloys or ceramic compositions of aluminum, magnesium or titanium, carbon fibers and composites thereof;

engaging projections formed on the external circumferential surfaces of at least one of said connection extensions or said pipe ends;

insertion cut-outs formed in at least one of the circumferential walls or internal cirumferential surfaces of the mating connecting extensions or pipe ends into which said engaging projections are inserted, the insertion cut-outs guiding said engaging projections;

locking slots oriented in the circumferential direction formed as continuations of said insertion cut-outs, with said connection extensions and pipe ends securely joined to each other by inserting the engaging projection on each of one of said connecting extensions or pipe ends into the insertion cut-out formed in each of the other mating connecting extensions or pipe ends after coating bonding agents at the contact surface between said connecting extensions and pipe ends, and then rotating the mating connecting extension and pipe end relative to each other in the circumferential direction, so that the engaging projections are locked in place by the locking slots and slippage between said couplings and said pipes is prevented after bonding.

2. A joining structure for frames, according to claim 1, further comprising:

said engaging projections formed on the external circumferential surfaces of said connecting extensions of said couplings;

insertion cut-outs formed in the axial direction in the pipe ends; and

locking slots formed in the circumferential direction in the pipe ends.

3. A joining structure according to claim 1, further comprising:

said engaging projections formed on the external circumferential surfaces of said pipe ends;

ring-form projections formed on the internal circumferential surfaces of said connecting extensions of said coupling, rims of said ring-form projections acting as locking slots; and

an insertion cut-out formed in an axial direction in each of said ring-form projections.

5. A joining structure for lightweight frames according to claim 1, wherein said bonding agent is selected from the group consisting of thermal setting adhesives, thermoplastic adhesives and synthetic gums.

4. A joining structure for lightweight frames of bicycles and similar vehicles formed by joining chemically and mechanically pipes and couplings, comprising:

pipes and couplings and intermediate parts interposed between said pipes and couplings where these members are made from a lightweight material selected from the group consisting of aluminum, magnesium, titanium, alloys or ceramic compositions of aluminum, magnesium or titanium, carbon fibers and composites thereof;

connecting extensions which connect to the intermediate parts formed on at least one of said couplings;

engaging projections formed on the external circumferential surfaces of at least one of said connecting extensions or the ends of said intermediate parts;

insertion cut-outs formed in at least one of said circumferential walls or internal circumferential surfaces of said other mating insertion cut-outs;

connecting extensions or intermediate parts into which the engaging projections are inserted, the insertion cutouts guiding the engaging projections; and

locking slots which are oriented in the circumferential direction formed as continuations of the insertion cut-outs, with said connecting extensions and intermediate parts securely joined to each other by inserting the engaging projection on each of one of said connecting extensions or intermediate parts into said insertion cut-out formed in each of the other mating connecting extensions or intermediate parts, after coating bonding agents at the contact surface between said connecting extensions and intermediate parts, and then rotating the mating connecting extension relative to each other in the circumferential direction, so that the engaging projections are locked in place by the locking slots, resulting in the joining of said couplings and said pipes by connecting the pipes to the intermediate parts by the bonding agents and the prevention of slippage between said couplings and said pipes after bonding.