Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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This invention relates to a clutch in which a hub carries a flange,
and a clutch plate and a retaining plate are mounted on opposite sides of said
flange, said flange and each of sai~ plates having aligned rectangular open~
ings therein to accommodate springs, which have their axes disposed tangen-
tially with respect to a circle concentric with said hub.
It is an object of the invention to provide for increased contact
between the plates and the springs.
According to the invention, there is provided in a clutch in which
a hub carries a flange, and a clutch plate and a retaining plate are mounted
on opposite sides of said flange, said flange and each of said plates having
aligned rectangular openings therein to accommodate torsion coil springs,
which have their axes disposed tangentîally with respect to a circle con-
centric with said hub, the improvement wherein each of the openings in each
of said plates is surrounded on the outer face by flanges on all four sides
. integral with the plate, the flanges on the two sides which are spaced apart
radially of said hub extending obliquely to the plane of the plates to lie
adjacent the spring periphery while the other two flanges extend at right
angles to the respective plate to lie adjacent the ends of the springs and
abut the spring ends to act as spring seats, said retaining plate having a
central portion which is spaced axially further from said flange on said hub
than an outer portion of said retaining plate and wherein said other two
flanges of the openings in said retaining plate are of dog-leg shape, with
a radially inner part thereof extending radially outward and axially toward
the hub flange and a radially outer part extending parallel to the hub
flange.
An embodiment of the invention will now be described, by way of
example, with reference to the accompanying drawings, in which:
: Figure 1 is a vertical sectional view of part of a clutch embody-
ing this invention,
Figure 2 is a sectional view taken on II - II of Figure 1,
Figure 3 is a vertical sectional view of a retaining plate, and
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Figure 4 is a partial sectional view taken on IV - IV of Figure 2.
Splined hub 1 of Figure 1 fits on a clutch output shaft and has an
integral outwardly extending flange 2. Flange 2 i5 pro~ided with six holes
3. Each hole 3 is a rectangular hole spaced radially from the hub 1, and
a torsion spring 4 is housed therein (~Figure 2~. A clutch plate 6, which - '
is arranged on the left hand side of the flange 2, with a friction washer 5
therebetween, has a friction facing 8 attached to its outer periphery by
a cushioning plate 7, secured by rivets 9 and holes 10 in plate 6 corres-
pond with holes 3 in flange 2. On the right hand side of the flange 2, a
retaining plate 14 is arranged with a friction washer 11, a friction plate -'~
12 and a friction spring 13 therebetween. The clutch plate 6 and the
retaining plate 14 are connected by ri~ets 15, thus applying a prescribed ~ :
force to the friction
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washers5and 11. Each rivet 15 passes through a hole 16 in the flange 2.
The inner diameter of the hole 16 is larger than the outer diameter of the
rivet 15, so that the rivet 15 and both plates 6 and 14 can rotate relative to
the flange 2 over a limited angular range. A stop pin 17 secures outer pheri- -
pheral portions of plates 6 and 14 together and defines the above-mentioned
angular range of relative rotation in combination with a notch 18 provided in
the outer peripheral part of the flange 2. Holes 19 are provided in the plate
14 in alignment with the holes 3 in plate 6. Various elements described above -~
are already known in the clutch art but the holes 10 and 19 provided in the -
plates 6 and 14 have special constructions in accordance with the teachings of
the present invention and these will now be described in detail.
The holes 19 in the retaining plate 14 have flanges on all four ~
sides thereof. Flanges 14aiand 14b, which are provided at the inside and out- -
. i
side edges of the hole, when viewed in radial direction, are formed obliquely
so as to extend from the body of the plate 14 along the cylindrical right hand
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side face of the torsion spring 4, thus lying adjacent the spring periphery.
Flanges 14c~-which are provided at the two other edges of the hole, extend at
right angles to the plate 14 to support end faces 4a (Figure 2) of the spring
4. An area by which a flange 14c supports an end face of a spring 4 is shown
by means of hatched lines in Figure 1. Between the plate 14 and the flange 2
there are the friction washer 11, the friction plate 12, and the friction -~
spring 13, so that a central portion of the retaining plate 14 is spaced from
the flange 2 by a comparatively large distance Ql However, the body of the
retaining plate 14 inclines from the vicinity of the outer periphery of the
friction spring 13 toward the flange 2 over a radial distance ~2 and extends
outwardly along the flange 2 thereafter. Therefore, the flange 14c at either
end of the spring is dog-legged or bent in its course as shown in Figure 1 and
Figure 3. For this reason the contact area between the flange 14c and the end
face of the torsion spring is as large as possible although the central por- j !
tion of the retaining plate 14 is spaced a considerable distance from the
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flange 2.
The clutch plate 6 also has perpendicular flanges 6c at both ends
of the holes 10 and oblique flanges 6a and 6b at the inside and outside edges
thereof. An area over which a flange 6c contacts an end face of a torsion
spring is shown by means of hatched lines in the same manner as for flange 14c.
Generally, the holes in the clutch plate 6 and the retaining plate
14 have hitherto been provided only with flanges 6a9 6b, 14a, and 14b for pre-
venting the torsion spring 4 from falling out. The end edges of the holes in
the plates 6 and 14 have had widths corresponding only to the thicknesses of
the plates 6 and 14. Accordingly, the areas of contact with the end faces of ~ -
the torsion spring 4 have been very small, any increase in contact pressure
causing an increase in wear at the contact area, thus shortening the service
life of the plate and the torsion spring. In order to increase the contact
area, part-cylindrical covers which surround the torsion spring 4 on both
sides could be formed integrally with the plates so as to completely cover the
holes in the clutch plate and the retaining plate from the outside. In this
case, however, the cylindrical side face of the torsion spring would be apt
to rub against the inner faces of the said covers and the hysterisis charac-
teristic of the clutch disc would be apt to be affected adversely.
Moreover, a cover which completely covers the side faces of the
torsion spring would increase the weights of both plates, lower the clutch
performance due to an increase in inertia moment, and at the same time impair
the radiation effect thereof.
In accordance with this invention, on the other hand, the holes 10
and 19 are provided with flanges over their entire periphery, radially spaced
flanges 6a, 6b, 14a, and 14b being provided with sufficient width to prevent
falling out of the torsion spring 4, while tangentially spaced flanges 6c and
14c stand up perpendicularly from the plate body to the same height as the
said flanges 6a, 6b, 14a, and 14b. Therefore, the contact area at both ends
of the torsion spring 4 can be enlarged as shown by means of hatched lines in
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Figure 1, the rigidity of both plates 6 and 14 can be increased, and wear at -
the contact areas can be decreased owing to a decrease in contact pressure,
thus prolonging the service life of the torsion spring. Even when the rota-
tional tirections of the plates 6 and 14 ant the flange 2 are reversed due to
torque fluctuation to cause collision of the end faces of the torsion spring 4
with the flanges 6c and 14c, the collision force can be alleviated owing to an
increase in the contact area, and thus the aboveconstruction is effective in
improving durability of the disc.
Further, the disc is so designed that the greater part of the cy-
lindrical side face of torsion spring 4 projects from the holes 10 and 19, so
j that there is little possibility of the torsion spring 4 rubbing against the -~
plates 6 and 14. Thus, there is minimized disturbance of the hysterisis cha-
racteristic and the radiation performance is improved even when the torsion
spring 4 expands radially outward under the influence of centrifugal force.
1~ The additional flanges 6c and 14c increase the rigidity of the plates 6 and
t~ I4 to make a decrease in plate thickness possible, and can form comparatively
j~ large sized holes 10 and 19 to lighten the whole weight of the clutch, thus
i proving the clutch performance owing to a decrease in the inertia moment
thereof.
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Moreover, the decrease in the plate thickness lowérs the cost there-
of.
When the flange 14c is dog-legged as illustrated in Figure 1, the ~
3~ contact area of the torsion spring end face with the flange 14c is made as ~ -
large as possible although the central portion of the retaining plate is
spaced frot the flange 2 in order to acco~nodate the friction ~ashcr 11, etc.
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