192 clutches and power-stop control – Clutches – Velocipede free wheel
Reexamination Certificate
2001-08-14
2003-02-25
Marmor, Charles A (Department: 3681)
192 clutches and power-stop control
Clutches
Velocipede free wheel
C192S094000, C192S054510, C301S110500
Reexamination Certificate
active
06523660
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a wheel hub device, more particularly to a wheel hub device for a bicycle, which permits smooth idle rotation of a hub shell relative to a driving barrel, and which ensures non-operation of the pedals when the cyclist drags the bicycle backwards so as to prevent possible injury to the cyclist.
2. Description of the Related Art
FIGS. 1 and 2
show a freewheeling hub device disclosed in co-pending U.S. patent application Ser. No. 09/761908 filed by the applicant on Jan. 17, 2001. As shown, the freewheeling hub device includes a hub shell
2
mounted rotatably on an axle
1
of a bicycle (not shown), a driving barrel
3
coupled to a lateral end of the hub shell
2
, a limiting element
4
disposed to limit a lateral end of the driving barrel
3
, a coupling socket
5
inserted via an opposite lateral end of the hub shell
2
and engaged threadedly with the driving barrel
3
, a coil spring
6
having one end connected to an outer wall surface of the coupling socket
5
, a connecting spring
7
connected to an inner wall surface of the coupling socket
5
, a sliding member
8
connected to the connecting spring
7
, a limiting block
9
, and a cup
401
disposed to limit a lateral end of the limiting block
9
. The hub shell
2
has an annular wall
201
with an inner wall surface
202
. A tapered inner friction wall portion
203
and a shoulder portion
204
are disposed on the inner wall surface
202
. The driving barrel
3
includes a toothed head portion
301
and an externally threaded portion
302
that extends axially from one end of the head portion
301
. The coupling socket
5
has a tapered outer friction wall portion
501
formed on the outer wall surface thereof, and an internally threaded portion
502
threadedly engageable with the externally threaded portion
302
. The coil spring
6
has a securing end
601
and an abutting end
602
, and spirals clockwise from the securing end
601
to the abutting end
602
with a gradually enlarged curvature radius. The securing end
601
is insertably retained in an insert hole
503
in the coupling socket
5
via an insert pin
601
′, whereas the abutting end
602
abuts against the shoulder portion
204
. The inner wall surface of the coupling socket
5
is in frictional contact with one end of the connecting spring
7
. The sliding member
8
is connected to an opposite end of the connecting spring
7
, and is disposed to fit into a non-circular hole in the cup
401
such that the sliding member
8
can displace only along an axial direction.
When the pedals of the bicycle are moved forwardly to rotate the driving barrel
3
corresponding to the direction of advancement of the bicycle, the coupling socket
5
is brought to displace toward the head portion
301
of the driving barrel
3
(the coil spring
6
being in a compressed state at this time), and the outer friction wall portion
501
engages the inner friction wall portion
203
of the hub shell
2
. As such, the driving barrel
3
, the coupling socket
5
and the hub shell
2
are coupled as a whole to enable the driving barrel
3
and the hub shell
2
to rotate synchronously to thereby move the bicycle forward. Conversely, when the pedals are moved backwards, the outer friction wall portion
501
will disengage from the inner friction wall portion
203
so that the hub shell
2
performs idle rotation relative to the driving barrel
3
.
When the bicycle continues to move forward due to the action of inertia resulting from previous forward pedaling, the ideal situation is that the shoulder portion
204
retains the abutting end
602
of the coil spring
6
in a direction corresponding to the direction of advancement of the bicycle (as indicated by the arrow in FIG.
1
), and that, when the abutting end
602
is being retained, due to the transmission of torque generated by the coil spring
6
, the securing end
601
forces the coupling socket
5
to rotate relative to the connecting spring
7
(the torque of the coil spring
6
must be greater than the frictional force between the coupling socket
5
and the connecting spring
7
), and the outer friction wall portion
501
quickly disengages from the inner friction wall portion
203
to allow the hub shell
2
to rotate freely in the idle state. Under the condition that the outer and inner friction wall portions
501
,
203
are not engaged, when the cyclist gets off the bicycle to drag the bicycle backwards, the pedals will not turn to strike the cyclist's legs. However, the hub device described above may suffer from the following drawbacks:
1. As the coil spring
6
does not have a uniform curvature radius, during the transmission of torque, the several coils immediately before the abutting end
602
will also be retained by the shoulder portion
204
so that the abutting end
602
is squeezed outwardly toward the inner wall surface
202
of the hub shell
2
and may come into contact therewith to obstruct smooth rotation of the hub shell
2
and transmission of torque of the coil spring
6
.
2. During the inertial forward motion of the bicycle, in order for the outer friction wall portion
501
to disengage from the inner friction wall portion
203
smoothly, the coil spring
6
must produce a torque that can resist the frictional force between the coupling socket
5
and the connecting spring
7
. However, the retaining force provided by the shoulder portion
204
against the abutting end
602
is not sufficient to enable the securing end
601
to produce a sufficient torque to force the coupling socket
5
to rotate relative to the connecting spring
7
, with the loss of torque during transmission taken into account. Thus, the outer friction wall portion
501
may not disengage from the inner friction wall portion
203
smoothly.
SUMMARY OF THE INVENTION
Therefore, the main object of the present invention is to provide a wheel hub device for a bicycle, which permits smooth idle rotation of a hub shell relative to a driving barrel, and which ensures non-operation of the pedals when the cyclist drags the bicycle backwards so as to prevent possible injury to the cyclist.
Accordingly, a wheel hub device according to the present invention is adapted for use in a bicycle which includes an axle extending in an axial direction, a sprocket wheel mounted coaxially around and rotatable relative to the axle, and a bicycle wheel which is mounted on the wheel hub device for rotation. The wheel hub device includes a hub shell, a driving barrel, a coupling socket, a sliding member, an associating spring, and a coil spring. The hub shell is adapted to be rotatably mounted on the axle, and has first and second lateral ends which are disposed opposite to each other in the axial direction, and an inner peripheral wall surface which extends in the axial direction to communicate the first and second lateral ends and which defines a through hole. The inner peripheral wall surface has a first wall portion and a second wall portion respectively proximate to the first and second lateral ends, and an intermediate wall portion which is disposed between the first and second wall portions and which defines a shoulder facing towards the second lateral end. The driving barrel is adapted to be rotatably mounted on the axle and is rotatable relative to the hub shell. The driving barrel includes a head portion which is disposed outwardly of the first lateral end and which is adapted to be rotated with the sprocket wheel, and an externally threaded portion which is disposed opposite to the head portion in the axial direction and which extends into the through hole so as to be surrounded by the intermediate wall portion. The coupling socket is disposed rotatably and movably in the through hole in the axial direction, and is adapted to be rotatably mounted around the axle. The coupling socket includes an engaging end, a coupling end, and an abutment member. The engaging end has a friction wall surface that confronts the intermediate wall portion, and an int
Ken Teng Industry Co., Ltd.
Marmor Charles A
Renner , Otto, Boisselle & Sklar, LLP
Williams Eric M.
LandOfFree
Wheel hub device for a bicycle does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Wheel hub device for a bicycle, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Wheel hub device for a bicycle will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3119670