Patent Application
20070167295
1. Field of the Invention
This invention relates to a resistance generating device for a training bicycle, more particularly to a resistance generating device which imparts an increased resistance force to a wheel of a training bicycle in response to a higher rotation speed of the wheel.
2. Description of the Related Art
In U.S. Pat. No. 6,736,761 B2, entitled “Stationary Bicycle Resistance Generator,” a support unit is disposed to suspend a bicycle wheel of a stationary bicycle exerciser from a ground surface so as to permit rotation of the bicycle wheel. A resistance unit includes a friction wheel which is rotatably mounted on a rotating shaft and which frictionally engages the bicycle wheel to be rotated therewith, a magnetically attractive member which is mounted on the rotating shaft and which is disposed at a side of the friction wheel, and a plurality of magnets which surround the magnetically attractive member and which are angularly displaced from one another such that, when the bicycle wheel is rotated by means of a pedaling action to rotate the friction wheel, a magnetically induced resistance force is generated by the magnets and is imparted to the bicycle wheel for training purposes.
Although the resistance force can be varied by adjusting the distance between the magnetically attractive member and the magnets, during pedaling of the bicycle at a higher speed, an inertia and a centrifugal force resulting from the rotation of the bicycle wheel will counteract a part of the resistance force so that the resistance effect is reduced.
The object of the present invention is to provide a resistance generating device for a training bicycle which can impart an increased resistance force to a wheel of the training bicycle in response to a higher rotation speed of the wheel.
According to this invention, the resistance generating device includes a seat which is adapted to be mounted on a support stand that suspends a bicycle wheel of a training bicycle from a ground surface, a rotatable shaft which is mounted on and which is rotatable relative to the seat about a rotating axis, a friction wheel which is mounted on and which is rotatable with the rotatable shaft about the rotating axis, and which is adapted to frictionally engage the bicycle wheel so as to be rotated therewith, a first magnetically attractive member which is disposed to surround the rotating axis, a second magnetically attractive member which is mounted to be rotatable with the rotatable shaft at a higher or lower speed, and which is disposed to be spaced apart from the first magnetically attractive member along the rotating axis, a biasing member which is disposed to bias the first and second magnetically attractive members away from each other, and an actuating mechanism. The first and second magnetically attractive members are configured to be shiftable towards or away from each other along the rotating axis in response to the higher or lower speed of the second magnetically attractive member so as to increase or decrease a magnetically induced resistance force generated therebetween to be imparted to the bicycle wheel. The actuating mechanism is disposed on one of the first and second magnetically attractive members to effect the relative shifting movement of the first and second magnetically attractive members in response to the higher speed of the rotatable shaft to force the first and second magnetically attractive members towards each other against the biasing force of the biasing member, thereby increasing the resistance force.
Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments of the invention, with reference to the accompanying drawings, in which:
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 to
The resistance unit 4 includes a seat 41 which is adapted to be mounted on the support stand 3 adjacent to the bicycle wheel 7, a rotatable shaft 43 which is mounted on and which is rotatable relative to the seat 41 about a rotating axis (X) parallel to the wheel axis, and which has an extension segment 431 extending outwardly of the seat 41, and a friction wheel 42 which is mounted on and which is rotatable with the rotatable shaft 43 about the rotating axis (X). The friction wheel 42 is adapted to frictionally engage the bicycle wheel 7 so as to be rotated therewith.
The magnetically inductive unit 5 includes a casing 51 which is fixed to one side of the seat 41 to surround the extension segment 431, a first magnetically attractive member 52 which is fixed to the casing 51 to be spaced apart from the seat 41 and which surrounds the rotating axis (X), a second magnetically attractive member 53 which is mounted on the extension segment 431 to be rotatable with the rotatable shaft 43 at a higher or lower speed, and which is disposed to be spaced apart from the first magnetically attractive member 52 along the rotating axis (X) by a distance (D), and a biasing member 54 which surrounds the extension segment 431 and which abuts against an end of the rotatable shaft 43 and the second magnetically attractive member 53 so as to bias the second magnetically attractive member 53 away from the first magnetically attractive member 52. The first magnetically attractive member 52 is a permanent magnet, or is provided with a permanent magnet thereon. The second magnetically attractive member 53 is made from a metal material with a magnetically attractive property. The second magnetically attractive member 53 is disposed to be displaceable towards or away from the first magnetically attractive member 52 along the rotating axis (X) in response to a higher or lower speed of the second magnetically attractive member 53 so as to increase or decrease a magnetically induced resistance force generated therebetween to be imparted to the bicycle wheel 7.
The actuating mechanism 6 includes amount 61 which is mounted on the extension segment 431 to be rotated therewith and which is disposed between the seat 41 and the second magnetically attractive member 53, a pair of restricting members 62, and two thrusting members 63.
The mount 61 has an axial passage 611 which extends along the rotating axis (X) such that the extension segment 431 of the rotatable shaft 43 passes through the axial passage 611 and an extension 531 of the second magnetically attractive member 53 that extends into the axial passage 611, and two radial holes 613 which extend radially relative to the rotating axis (X) to be communicated with the axial passage 611. The mount 61 further has a pair of tubular blocks 616, each of which defines a passageway 614 extending parallel to the rotating axis (X), and each of which has confronting and abutted ends 6161, 6162 that are proximate to and distal from the second magnetically attractive member 53, respectively.
With reference to FIGS. 5and 6, each of the thrusting members 63 is received in the respective radial hole 613 to be rotated with the rotatable shaft 43, and has a fulcrum which is pivoted to the mount 61 about a pivoting axis, and a flung end 632 and a pressing end 631 at two opposite sides of the fulcrum such that the flung end 632 is flung more outwardly by an increased centrifugal force during the rotation of the rotatable shaft 43 at the higher speed from a normal position (as shown in
Moreover, the mount 61 includes a tubular barrier 612 which is disposed to surround the extension segment 431 and which confronts the extension 531 along the rotating axis (X) so as to restrict the shifting movement of the second magnetically attractive member 53 away from the first magnetically attractive member 52.
Referring again to
As illustrated, when the bicycle wheel 7 is initially rotated by a pedaling action, the friction wheel 42 and the rotatable shaft 43 are rotated therewith such that a magnetically induced resistance force is generated between the first and second magnetically attractive members 52, 53 and imparted to the bicycle wheel 7. Thereafter, as the rotation speed of the bicycle wheel 7 increases, the thrusting members 63 are displaced to the thrusting position by virtue of an increased centrifugal force to press the second magnetically attractive member 53 to be closer to the first magnetically attractive member 52, thereby increasing the resistance force imparted to the bicycle wheel 7. The higher the rotation speed, the larger will be the resistance force. Hence, a good training effect of the training bicycle can be achieved.
It is noted that the second magnetically attractive member 53 also may be a permanent magnet and the first magnetically attractive member 52 may be made from a metal material with a magnetically attractive property.
Referring to
Referring to
Each of the thrusting members 63 is in form of a roller 64 which is movably received in the respective recess 615, such that the roller 64 is moved by virtue of the increased centrifugal force from the proximate region 6171 to the distal region 6172 so as to place the second magnetically attractive member 53 in the thrusting position.
Referring to
While the present invention has been described in connection with what is considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretations and equivalent arrangements.
