Machine element or mechanism – Gearing – Interchangeably locked
Reexamination Certificate
2002-03-27
2004-04-13
Bonck, Rodney H. (Department: 3681)
Machine element or mechanism
Gearing
Interchangeably locked
C475S015000
Reexamination Certificate
active
06718840
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sun and planet gear mechanism.
2. Description Related to the Prior Art
A sun and planet gear mechanisms is widely used as a clutch mechanism which selectively transmits the drive of a motor to a gear train in accordance with a direction of the rotation of the sun and planet gear mechanism caused by the motor. The sun and planet gear mechanism is constructed of a fixed shaft, a sun gear rotatable around the fixed shaft, a planet lever and a planet gear supported by the planet lever. The planet lever swings in the same rotational direction of the sun gear. Accordingly, the planet gear revolves around the fixed shaft to mesh with one of the two gear trains. For changing the gear train with which the planet gear meshes, the swing of the planet gear is necessary. The Japanese Patent Laid-open Publication No. H11-52461 supposes an improvement of the sun and planet gear mechanism for easy swing of the planet lever.
As shown in
FIG. 7 and 8
, the sun and planet gear mechanism disclosed in the above Publication is constructed a sun gear
2
, two planet gears
3
,
4
, a planet lever
5
and a fixed shaft
6
. The planet lever
5
is V-shaped and has two arms. On a crossed position of two arms is formed a shaft cylinder
5
a,
and in ends of the respective arms are formed gear shafts
5
b,
5
c.
The shaft cylinder
5
a
fits in a hole
2
a
formed in the sun gear
2
. The gear shafts
5
b,
5
c
is inserted in shaft holes
3
a,
4
a
formed the planet gears
3
,
4
so as to rotatably support them. The shaft cylinder
5
has a hole
5
d
in which the fixed shaft
6
is inserted.
In the sun gear
2
, a ring-shape groove
2
b
is formed around a rotational axis
7
. Into the groove
2
b
are inserted elastic protrusions
5
e,
5
f
formed so as to protrude from the planet lever
5
upwards with inclination. When the sun and planet gear mechanism is assembled, the fixed shaft
6
is inserted in the hole
5
d
of the planet lever
5
, and then the shaft cylinder
5
a
of the planet lever
5
is inserted into the shaft hole
2
a
of the sun gear
2
. Thereby the two elastic protrusions
5
e,
5
f
enter in the groove
2
b
of the sun gear
2
and presses an outer wall
2
c
of the groove
2
b.
When the sun gear
2
rotates, there is a friction between the outer wall
2
c
and the elastic protrusions
5
e,
5
f.
According to the friction, the planet gear
5
swings by following the rotation of the sun gear
2
. Therefore, the planet gears
3
,
4
revolve.
However, as the planet lever
5
contacts the fixed shaft
6
, there is a contact resistance between the hole
5
d
and the fixed shaft
6
. Therefore, a force of the rotation of the sun gear
2
is not enough transmitted to the planet lever
5
. Therefore the sun gear often does not rotate smoothly. In this case, the planet gears hardly revolve.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a sun and planet gear mechanism in which a planet gear revolve smoothly.
Another object of the present invention is to provide a sun and planet gear mechanism in which a contact resistance is small.
In order to achieve the object and the other object, in a sun and planet gear mechanism of the present invention, a sun gear is rotatably fitted on a fixed shaft. A part of the sun gear contacts to a planet lever to generate a frictional force. Accordingly, when the sun gear rotates, the frictional force causes to swing the planet lever. In the sun gear is formed a cylindrical portion in which the fixed shaft is fitted, and in the planet lever is formed a shaft cylinder in which the cylindrical portion is fitted. The shaft cylinder can move on a periphery of the cylindrical portion of the sun gear smoothly.
Further, the planet lever has a contact portion for fitting to a groove which is formed around the cylindrical portion of the sun gear. As there is an adequate friction between the contact portion and the periphery, the rotation of the sun gear is transmitted to the planet lever.
According to the sun and planet gear mechanism of the present invention, the sun gear is fitted on the rotary shaft, a contact resistance may be decreased while the rotation of the sun gear is transmitted to the planet lever. Therefore, the planet lever is smoothly swung.
REFERENCES:
patent: 829068 (1906-08-01), Fox
patent: 2344434 (1944-03-01), Wigglesworth
patent: 2535194 (1950-12-01), Carpenter
patent: 2754697 (1956-07-01), Luebking
patent: 4516648 (1985-05-01), Berger et al.
patent: 5018401 (1991-05-01), Ida et al.
patent: 5365301 (1994-11-01), Sugita et al.
patent: 5456419 (1995-10-01), Ezawa
patent: 5729779 (1998-03-01), Oshima
patent: 5823454 (1998-10-01), Erck
patent: 5835805 (1998-11-01), Izaki et al.
patent: 6086503 (2000-07-01), Konishi et al.
patent: 6343880 (2002-02-01), Kamoda et al.
patent: 11-052461 (1999-02-01), None
Bonck Rodney H.
Fuji Photo Optical Co., Ltd.
Le David D.
Young & Thompson
LandOfFree
Sun and planet gear mechanism does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sun and planet gear mechanism, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sun and planet gear mechanism will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3211567