Land vehicles: wheels and axles – Wheel – Hub
Reexamination Certificate
2000-08-08
2001-11-27
Stormer, Russell D. (Department: 3617)
Land vehicles: wheels and axles
Wheel
Hub
C192S064000, C384S484000, C277S529000
Reexamination Certificate
active
06322155
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a bicycle transmission mechanism, more particularly to a bicycle hub transmission mechanism with a seal member.
2. Description of the Related Art
Referring to
FIG. 1
, a conventional free-wheel hub transmission mechanism is shown to include an axle
2
and a spoke-mounting barrel
1
mounted rotatably around the axle
2
in such a manner that a right axle portion
2
R of the axle
2
projects outwardly from a right end portion
100
of the spoke-mounting barrel
1
. A sprocket mounting member
3
is sleeved around the right axle portion
2
R of the axle
2
adjacent to the right end portion
100
of the spoke-mounting barrel
1
. The sprocket-mounting member
3
includes an outer shell
31
, a bearing unit
4
, a ratchet mechanism
7
, a bearing retention member
5
, a seal member
6
, and a locking ring
302
.
The outer shell
31
has a proximate end portion which is coupled with the right end portion
100
of the spoke-mounting barrel
1
and upon which a sprocket wheel
301
is mounted (only one is shown), and a distal threaded portion
303
. The bearing unit
4
is disposed within the outer shell
31
around the right axle portion
2
R of the axle
2
inboard to the distal threaded portion
303
of the outer shell
31
. The ratchet mechanism
7
is disposed within the outer shell
31
inboard to the bearing unit
4
, and is operably coupled with the outer shell
31
so as to permit synchronous rotation of the outer shell
31
with the spoke-mounting barrel
1
only in a forward direction. The bearing retention member
5
is sleeved fittingly around the right axle portion
2
R of the axle
2
outboard to the bearing unit
4
, and has a cross section smaller than that of the outer shell
31
, thereby defining annular space (X) therebetween. The bearing retention member
5
further has a constricted left portion
505
that abuts against the bearing unit
4
, and an enlarged right portion
506
which defines an inner shoulder
500
in cooperation with the constricted left portion
505
. The locking ring
302
is sleeved around the bearing retention member
5
, and is fastened threadedly to the distal threaded portion
303
of the outer shell
31
. A rear fork member (not shown) abuts against a right end surface of the bearing retention member
5
to prevent removal of the bearing retention member
5
from the axle
2
. The seal member
6
is disposed within the outer shell
31
between the bearing unit
4
and the inner shoulder
500
of the bearing retention member
5
, and includes an L-shaped cross-sectioned metal ring
601
which is in tight engagement with the constricted left portion
505
of the bearing retention member
5
, and a rubber ring
602
provided on the metal ring
601
in such a manner that the outer periphery of the rubber ring
602
contacts an inner wall surface of the distal threaded portion
303
of the outer shell
31
such that the seal member
6
isolates hermetically the annular space (X) with respect to the bearing unit
4
.
When the outer shell
31
rotates with respect to the axle
2
, a small clearance may be present between the outer periphery of the rubber ring
602
and the inner wall surface of the outer shell
31
in the event that the outer periphery of the rubber ring
602
does not contact any crest of the thread, and rather extends into a root of the thread. Under this condition, dust, oil and water may enter the interior of the outer shell
31
via the clearance.
In order to avoid the aforesaid disadvantage, a larger rubber ring has been proposed such that the outer periphery of the rubber ring
602
will tightly contact the inner wall surface of the outer shell
31
of the sprocket-mounting member
3
. However, a considerable friction force is incurred between the outer shell
31
and the rubber ring
602
during rotation of the outer shell
31
, thereby hindering smooth rotation of the sprocket-mounting member
3
relative to the axle
2
.
SUMMARY OF THE INVENTION
Therefore, the object of this invention is to provide a bicycle hub transmission mechanism which includes a flexible seal member of a specific configuration so as to avoid the aforesaid disadvantages that result from the use of the conventional bicycle hub transmission mechanism.
Accordingly, a bicycle hub transmission mechanism of the present invention includes an axle with left and right axle portions, a tubular spoke-mounting barrel, and a sprocket-mounting member. The spoke-mounting barrel defines an axially extending through-hole therethrough and has left and right end portions. The axle extends co-axially through the through-hole of the barrel with the right axle portion projecting outwardly from the right end portion of the barrel. The sprocket-mounting member is sleeved around the right axle portion of the axle adjacent to the right end portion of the barrel, and includes an outer shell coupled with the right end portion of the barrel for synchronous rotation therewith. The outer shell has a distal end portion upon which a sprocket wheel is adapted to be mounted. A bearing unit is disposed within the outer shell around the right axle inboard to the distal end portion of the outer shell. A ratchet mechanism is disposed within the outer shell inboard to the bearing unit, and is operably coupled with the outer shell so as to permit synchronous rotation of the outer shell with the barrel only in a forward direction. A bearing retention member is sleeved and positioned around the right axle portion outboard to the bearing unit. The bearing retention member has a cross section smaller than that of the outer shell to define an annular space between the bearing retention member and the outer shell. The bearing retention member further has a left portion abutting against the bearing unit, a right portion opposite to the left portion, and an annular outward flange formed between the left and right portions of the bearing retention member. The outward flange extends radially and outwardly into the annular space, and defines an inner shoulder in cooperation with the left portion of the bearing retention member. A tubular flexible seal member is disposed within the outer shell between the bearing unit and the outward flange of the bearing retention member. The flexible seal member includes an L-shaped cross-sectioned outer ring which is in tight engagement with the outer shell and which has a thick left portion and a thin right portion that is thinner than the thick left portion and that has an inner diameter larger than that of the thick left portion, and a truncated conical inner ring which projects integrally, inclinedly, and inwardly from a right end surface of the thick left portion of the outer ring and which has a smallest inner diameter right end that is sleeved slidably over the left portion of the bearing retention member adjacent to the inner shoulder such that the flexible seal member isolates hermetically the annular space with respect to the bearing unit.
Preferably, the right end of the inner ring of the flexible seal member has an inner diameter, when removed from the bearing retention member, that is slightly smaller than an outer diameter of a section of the left portion of the bearing retention member, on which the right end of the inner ring is sleeved.
REFERENCES:
patent: 4567973 (1986-02-01), Butz
patent: 5370404 (1994-12-01), Klein et al.
patent: 5632364 (1997-05-01), Mercat
patent: 5642796 (1997-07-01), Tabe
patent: 6062734 (2000-05-01), Bundgart
patent: 6202813 (2001-03-01), Yahata et al.
Kun Teng Industry Co., Ltd.
Ohlandt Greeley Ruggiero & Perle L.L.P.
Stormer Russell D.
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