Rotary shafts – gudgeons – housings – and flexible couplings for ro – Coupling accommodates drive between members having... – Torque transmitted via intermediate element
Reexamination Certificate
2002-09-11
2003-12-16
Browne, Lynne H. (Department: 3679)
Rotary shafts, gudgeons, housings, and flexible couplings for ro
Coupling accommodates drive between members having...
Torque transmitted via intermediate element
C464S137000, C464S106000
Reexamination Certificate
active
06663493
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority of Taiwanese Application No. 091210644, filed on Jul. 12, 2002.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a coupling device to be coupled to a rotary drive unit for enabling transmission of rotation from the drive unit, more particularly to a coupling device with an enhanced transmission efficiency and a longer service life.
2. Description of the Related Art
A coupling device is a device that couples a work shaft to a rotary-drive unit so as to enable the work shaft to rotate with the drive unit.
FIG. 1
illustrates a conventional coupling device which includes a bearing seat
100
, a transmission shaft
200
, a clutch wheel
30
, first and second coupling plates
50
,
40
, and a work shaft
60
. The seat
100
is stationary, and includes a tubular part, that defines an axial hole
101
. Two bearing rings
102
are mounted in the axial hole
101
. The transmission shaft
200
has a rear end extending through the axial hole
101
and the bearing rings
102
and to be coupled to a rotary drive unit (not shown), and a front end provided with a mounting block
201
which is formed with a semi-circular cavity
203
that opens upwardly and forwardly. The mounting block
201
has a pivot hole
205
formed through a lower end thereof and extending transverse to an axis of the transmission shaft
200
. The clutch wheel
30
is formed with a central hole
301
which has a shape generally corresponding to that of the mounting block
201
. The mounting block
201
extends into the central hole
301
so as to be coupled co-rotatably with the clutch wheel
30
. The clutch wheel
30
has a pivot hole
302
formed therethrough and aligned with the pivot hole
205
in the mounting block
201
. A pivot axle
303
extends through the pivot holes
302
,
205
in the clutch wheel
30
and the mounting block
201
for mounting the clutch wheel
30
pivotally on the mounting block
201
. The first coupling plate
50
is fan-shaped, and is fastened to a front side surface of the clutch wheel
30
adjacent to the central hole
301
. The second coupling plate
40
is disposed on a front side of the clutch wheel
30
, and is fastened to a front end wall of the mounting block
201
. When the clutch wheel
30
is in a first position in which the clutch wheel
30
is perpendicular to an axis of the transmission shaft
200
, as shown in
FIG. 2
, the first and second coupling plates
50
,
40
cooperatively form a circular disk, and cooperatively confine a polygonal coupling hole
401
registered with the central hole
301
in the clutch wheel
30
and the cavity
203
in the mounting block
201
. The work shaft
60
has a coupling end portion
601
with a polygonal cross-section corresponding to that of the coupling hole
401
.
In use, the clutch wheel
30
together with the first coupling plate
50
mounted thereon are moved pivotally relative to the mounting block
201
to a second position shown in
FIG. 3
, in which the clutch wheel
30
extends along another plane that is inclined relative to the axis of the transmission shaft
200
. In this position, the first coupling plate
50
is spaced apart from the second coupling plate
40
to permit access to the coupling hole
401
, and a top opening of the cavity
203
in the mounting block
201
is exposed at this time. The coupling end portion
601
of the work shaft
60
can thus be extended into the coupling hole
401
and into the cavity
203
from above. The clutch wheel
30
is then moved pivotally back to the first position shown in
FIG. 2
such that the coupling end portion
601
is received in the coupling hole
401
and is coupled co-rotatably with the first and second coupling plates
50
,
40
, the clutch wheel
30
and the mounting block
201
. The work shaft
60
is thus coupled to the transmission shaft
200
so as to permit transmission of rotation from the rotary drive unit (not shown) to the work shaft
60
.
It is noted that connection between the work shaft
60
and the transmission shaft
200
is achieved by the coupling between the polygonal coupling end portion
601
of the work shaft
60
and the polygonal coupling hole
401
confined by the first and second coupling plates
50
,
40
. High precision is thus required when forming the polygonal coupling end portion
601
of the work shaft
60
and the first and second coupling plates
50
,
40
. This unavoidably increases the manufacturing cost. Moreover, slight deviations in the precision of the size and shape of the polygonal coupling end portion
601
and the polygonal coupling hole
401
can cause the polygonal coupling end portion
601
to collide with the first and second coupling plates
50
,
40
during rotation. This results in noise and in wear and tear of these components to thereby reduce the service life of the conventional coupling device.
SUMMARY OF THE INVENTION
Therefore, the main object of the present invention is to provide a coupling device with enhanced transmission efficiency and a longer service life.
Accordingly, the coupling device of the present invention includes a transmission member and a work shaft. The transmission member includes a cylindrical rod with an axis, a rear end adapted to be coupled to a rotary drive unit so as to be rotated by the drive unit, a front end, and a circumferential outer surface extending between the front and rear ends. The transmission member further includes a curved coupling flange which has a cross-section in the form of a circular sector and which extends circumferentially and co-axially along the outer surface of the cylindrical rod. The coupling flange is fixed to the outer surface of the cylindrical rod and projects forwardly relative to the front end of the cylindrical rod. The coupling flange has a concave face confronting the axis of the cylindrical rod and formed with a plurality of engaging protrusions, and a convex face opposite to the concave face. The work shaft includes a main body which extends along the axis of the cylindrical rod of the transmission member and which has a spherical end, and a tubular sleeve sleeved on the spherical end and co-rotatable with the spherical end. The tubular sleeve cooperates with the spherical end to form a coupling end portion of the work shaft. The tubular sleeve is formed with a plurality of engaging grooves which are angularly displaced from one another with respect to the axis of the cylindrical rod of the transmission member. The coupling end portion is disposed on the concave face of the coupling flange so as to enable engagement between the engaging grooves and the engaging protrusions in order to permit transmission of rotation of the transmission member to the work shaft.
REFERENCES:
patent: 3199311 (1965-08-01), Hill
patent: 3246858 (1966-04-01), Alexeff
patent: 3729953 (1973-05-01), Wanzer
patent: 4344304 (1982-08-01), Eiche
patent: 4551117 (1985-11-01), Kunz
patent: 4681478 (1987-07-01), Kunz
patent: 4758113 (1988-07-01), Kunz
patent: 4838725 (1989-06-01), Fazis
patent: 4848934 (1989-07-01), Blakely et al.
patent: 4887926 (1989-12-01), Kunz
patent: 5295913 (1994-03-01), Pyka et al.
Browne Lynne H.
Christensen O'Connor Johnson & Kindness PLLC
Thompson Kenn
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