Mutually linkable bicycles

Abstract

A clutch means includes an immobile tube (60) disposed between a top tube (2) and a head tube (6) of a bicycle frame, with a bearing portion (20) mounted to one of the facing end portions and axially supporting the end portions, whereby the top tube (2) and the immobile tube (60) are disposed so as to be capable of relative rotation. In the outer periphery of the bearing portion (20) and the immobile tube (60) axially supported therein, pin holes (22, 62) are respectively opened. The pin holes (22, 62) are bored at positions that are centrally aligned when a front fork (4) of the bicycle is are linearly positioned.

Claims

1. A mutually linkable bicycle which includes an immobile tube interposed between a top tube and a head tube of a frame to divide the frame into two and a bearing portion mounted at an end portion of the top tube or the immobile tube to axially support the opposed end portions so that the top tube and the immobile tube are disposed so as to be capable of relative rotation, the mutually linkable bicycle comprising: pin holes which are respectively formed in the outer periphery of the bearing portion and in the outer periphery of the end portion axially supported therein in such a way as to coincide with each other when a front fork of the bicycle is put in a line; clutch means which is formed when a fixing pin is inserted into the two coinciding pin holes in such a way as to be freely inserted or drawn out and which is mounted between the top tube and the immobile tube; a screw portion which is mounted at the end of the fixing pin; and a synchronizer having a nut which is attached to the inner face of the front fork and to which the screw portion is spirally inserted, so as to control relative rotation of the top tube according to rotation of the head tube.

2. A mutually linkable bicycle according to claim 1, which includes an immobile tube interposed between a top tube and a head tube of a frame to divide the frame into two and a bearing portion mounted at an end portion of the top tube or the immobile tube to axially support the opposed end portions so that the top tube and the immobile tube are disposed so as to be capable of relative rotation, the mutually linkable bicycle comprising: pin holes which are respectively formed in the outer periphery of the bearing portion and in the outer periphery of the end portion axially supported therein in such a way as to coincide with each other when a front fork of the bicycle is put in a line; clutch means which is formed when a fixing pin is inserted into the two coinciding pin holes in such a way as to be freely inserted or drawn out and which is mounted between the top tube and the immobile tube; a hand-grip which is formed integrally to the fixing pin to be bent at almost 90 degrees and has a fixing protrusion formed at the end of the outer periphery thereof; and a synchronizer having a clamp which is attached to the inner face of the outer periphery of the front fork to tighten the hand-grip of the fixing pin, so as to control relative rotation of the top tube according to rotation of the head tube.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a partially perspective view of a bicycle according to a preferred embodiment of the present invention.

(2) FIG. 2 is a side sectional view of FIG. 1.

(3) FIG. 3 is a partially perspective view of a bicycle according to another preferred embodiment of the present invention.

(4) FIG. 4 is a partially perspective view of a bicycle for women to which the present invention is applied.

(5) TABLE-US-00001 <Explanation of essential reference numerals in drawings> 2: top tube 20: bearing portion 22: pin hole 24: guide ring 4: front fork 40: synchronizer 42: nut 44: clamp 46: clamp lever 6: head tube 60: immobile tube 62: pin hole 64: reinforcing shaft 66: stopper 68: stop ring 8: fixing pin 80: hand-grip 82: screw portion 84: ball plunger 820: fixing protrusion

DETAILED DESCRIPTION OF THE INVENTION

(6) Reference will be now made in detail to the preferred embodiment of the present invention with reference to the attached drawings.

Embodiment 1

(7) FIG. 1 illustrates an assembled state of a top tube 2, a front fork 4 and a head tube 6 of a frame which are essential parts of a mutually linkable bicycle according to the present invention.

(8) As shown in FIG. 1, a bearing portion 20 which is larger in diameter than an immobile tube 60 of the head tube 6 facing the bearing portion 20 is formed at the front end of the top tube 2 to axially support the end portions of the immobile tube 60. Pin holes 22 and 62 are respectively formed on the outer peripheries of the bearing portion 20 and the immobile tube 60. The pin holes 22 and 62 are bored at positions that the pin holes 22 and 62 coincide with each other when the front fork 4 of the bicycle is put in a straight line.

(9) Moreover, the bearing portion 20 is formed integrally with the end of the immobile tube 60 of the head tube 6, and the front end of the top tube facing is axially supported by the bearing portion 20.

(10) In the meantime, a fixing pin 8 is inserted into the pin holes 22 and 62, which coincide with each other when the front fork 5 is put in a straight line, in such a way as to be freely inserted and removed. By virtue of the effect that the fixing pin 8 is inserted into and removed from the pin holes, a state between the top tube 2 and the head tube 6 can be controlled into a clutch state that the top tube 2 cannot rotate relative to the head tube 6 or into an un-clutch state that the top tube 2 can rotate relative to the head tube 6, so that the bicycle can be transformed into a single-seat bicycle in the clutch state or into a multi-seat bicycle in the un-clutch state.

(11) As another example of the fixing pin 8, the fixing pin 8 may include a hand-grip 80 attached to the top of the fixing pin to make it easy to use and a screw portion 82 formed at a lower end of the opposite side.

(12) The fixing pin 8 is used as an assembling part for the synchronizer 40 by the screw portion 82.

(13) In other words, in this embodiment, the synchronizer 40 includes: a nut 42 attached to the inner face of the outer periphery of the front fork 4; a guide ring 24 attached to the bottom side of the outer periphery of the bearing portion 20; and the fixing pin 8 drawn out of the pin hole 22 and 62. As indicated by the dashed dotted line of FIG. 1, when the fixing pin 8 is inserted into the guide ring 24 to penetrate the guide ring 24 and the screw portion 82 of the end is spirally inserted into the nut 42, the synchronizer 40 which synchronizes and interworks by connection of the fixing pin 8 and the guide ring 24 with each other is mounted between the top tube 2 and the front fork 4, and at the same time, the state between the top tube 2 and the immobile tube 60 is converted into the un-clutch state for relative rotation, so that the bicycle can be used as the multi-seat bicycle.

(14) In a case of the multi-seat bicycle, during a curved traveling, when a rider steers a handle, because the fixing pin 8 is rotated at the same angle as the steering angle of the handle and a turning angle is controlled in line with the top tube 2 of the latter bicycle by a synchronization action for interworking the guide ring 24, a rotation angle difference between the top tube 2 and the immobile tube 60 is naturally dissipated, and then, the bicycle can show a normal curve traveling.

(15) In this embodiment, the synchronizer 40 is arranged between the top tube 2 and the front fork 4, but it is not essential. For instance, if a rider is skillful in operation of the mutually linkable bicycle according to the present invention, the rider may not feel difficulty in operation even though there is no synchronizer 40.

(16) In this embodiment, the immobile tube 60 should not be separated from the bearing portion 20 between the top tube 2 and the head tube 6. FIG. 2 shows a preferable connection structure between the top tube 2 and the head tube 6.

(17) As shown in FIG. 2, a reinforcing shaft 64 is fixed integrally with the inner center of the immobile tube 60, and a pin hole extending from the pin hole 62 penetrates through the reinforcing shaft 64. The bearing portion 20, the immobile tube 60 and the reinforcing shaft 64 are connected with one another by the fixing pin 8.

(18) Furthermore, a stopper 66 is fixed on the outer periphery of the reinforcing shaft 64 and is spaced slightly apart from the end of the immobile tube 60. A stop ring 68 is axially inserted between the end of the immobile tube 60 and the stopper 66 and is fixed by a set screw 26 inserted from the outer periphery of the bearing portion 20, so as to support the immobile tube 60 not to be separated from the bearing portion 20.

(19) Additionally, the stop ring 68 is axially inserted into the reinforcing shaft 64 to come into contact with the end of the immobile tube 60 earlier than the stopper 66. Next, the stopper 66 is fit into the reinforcing shaft 64, and then, is axially supported by the bearing portion 20 in a state where the stopper 66 is fixed integrally with the reinforcing shaft 64 by welding. After that, the set screw 26 is spirally inserted from the outer periphery to fix the stop ring 68.

(20) Then, the immobile tube 60 and the reinforcing shaft 64 are axially supported to be freely rotate inside the bearing portion 20 and the stop ring 68 axially supports the stopper 66 not to be separated, so that the top tube 2 and head tube 6 can do relative rotation.

(21) In the drawings, unexplained reference numeral 84 is a ball plunger for fixing the fixing pin 8, which is mounted in the bearing portion 20, to prevent unintentional separation of the fixing pin 8 during traveling.

(22) The mutually linkable bicycle according to the present invention is provided as a general single-seat bicycle when it is sold.

(23) That is, the present invention is a single-seat bicycle that the fixing pin 8 of FIG. 1 penetrates through the two pin holes 22 and 62 and the top tube 2 and the immobile tube 60 are connected to each other integrally.

(24) When the present invention is used as the single-seat bicycle, it is the same as the normal bicycle. However, in order to the bicycle as a multi-seat bicycle, front wheels (not shown) are removed from all bicycles except the foremost bicycle, and the front fork 4 of each bicycle is axially supported to an axle of the rear fork of the former bicycle so that the bicycles are connected to each other integrally.

(25) Continuously, before the multi-seat bicycle travels, the fixing pins 8 of all bicycles except the foremost bicycle are removed from the bearing portion 20. As indicated by the dash dotted line of FIG. 1, when the screw portion 82 of the end is inserted into the guide ring 24 and is spirally inserted into the nut 42 of the front fork 4, the synchronizer 40 is mounted.

(26) At the time of curve traveling of the multi-seat bicycle, a difference in slope angle arises between the rear fork of the former bicycle and the front fork 4 of the latter bicycle axially supported on the axle of the rear fork. However, in the present invention, the difference in slope angle is dissipated by relative rotation between the immobile tube 60 and the top tube 2, and at the same time, the synchronizer 40 properly controls the relative rotation of the top tube 2 to the immobile tube 60, so that all of the latter bicycles can travel normally without being turned down.

(27) Furthermore, the mutually linkable bicycle according to the present invention includes means for regulating the state between the top tube 2 and the immobile tube 60 into a rotatable state or into a non-rotatable state. The means for regulating the state between the top tube 2 and the immobile tube 60 has an extremely simple structure including two pin holes 22 and 62 which coincide with each other when the front fork 4 of the bicycle is put in a straight line and a fixing pin 8 penetrating through the two pin holes 22 and 62.

Embodiment 2

(28) In this embodiment, the synchronizer 40 has a structure that the screw portion 82 of the fixing pin 8 is spirally inserted into the nut 42 of the front fork 4, but such a structure has a risk that the connected portion is easy to break when an external force is applied to the screw portion 82 during synchronization.

(29) FIG. 3 is a partially perspective view of a bicycle according to another preferred embodiment of the present invention. In this embodiment, the fixing pin 8 includes a hand-grip 80 which is bent at almost 90 degrees and a fixing protrusion 820 formed on the outer periphery of the hand-grip 80 in the axial direction.

(30) Moreover, a clamp 44 instead of the nut 42 is fixed on the inner face of the front fork 4. The clamp 44 has a clamp lever 46 for tightening or releasing the hand-grip 80 of the fixing pin 8 fit into the clamp 44 by a cam action.

(31) According to the above-mentioned structure, because the fixing protrusion 820 is connected to the clamp 44 by the clamp lever 46 in a state where the fixing protrusion 820 is matched with an empty space inside the clamp 44 when the hand-grip 80 is fit into the clamp 44, the hand-grip 80 is firmly fastened to the clamp 44 without being moved laterally.

(32) Also in another embodiment of the mutually linkable bicycle according to the present invention, like the above-mentioned embodiment, the mutually linkable bicycle provides the clutch action that the fixing pin 8 is inserted into the two pin holes 22 and 62 and the top tube 2 and the immobile tube 60 are connected to each other integrally, and provides the synchronizer 40 that is formed when the fixing pin 8 drawn out of the pin holes 22 and 62 is inserted and fit into the clamp 44 in such a manner that the end bent at almost 90 degrees penetrates through the guide ring 24.

(33) In the meantime, in the mutually linkable bicycle according to the present invention, a down tube of the frame may be omitted like the bicycle disclosed in Korean Patent No. 869602 proposed by the same inventor as the present invention, or may be connected to a middle side of the top tube 2 to make relative rotation between the top tube 2 and the immobile tube 60.

(34) Additionally, the mutually linkable bicycle according to the present invention enables a rider to easily ride on. As shown in FIG. 4, the mutually linkable bicycle according to the present invention can be applied to bicycles for women in which the top tube 2 is omitted and the down tube of a lower part is directly connected to the head tube 6.

(35) In FIG. 4, the frame structure is omitted because it does not fit for mounting the synchronizer 40. However, if the bicycle is designed in such a manner that the center of the frame is located at the lower part and relative rotation between the immobile tube 60 and the bearing portion 20 is made within a predetermined angle, the latter bicycles can always travel in a stable condition by a downward central action. In addition, even at the time of curve traveling, because a traveling trouble of the bicycle is dissipated while the immobile tube 60 rotates to the bearing portion 20 at a predetermined angle, any of the latter bicycles is not turned down during traveling.

(36) As described above, the mutually linkable bicycle according to the present invention can be used as bicycles for leisure because it can be transformed into a normal single-seat bicycle or a multi-seat bicycle that a plurality of the single-seat bicycles are connected to each other in tandem.