Minimum complexity vibration damper

A minimum complexity vibration damper that integrates the function of structural components and reduced lag in a vibration damping system. This assembly utilizes pressure plate formations for spring seats and the configuration of the pressure plate for spring retention. The reactor plate or hub is designed to concentrate spring unit loading on the hub and away from other components of the assembly, thereby decreasing lag. A spring retainer plate may be utilized in conjunction with the hub and pressure plates.

BACKGROUND OF THE INVENTION 
Vibration damper constructions for vehicle friction clutches are well known 
in the art for reducing drive line vibrations emanating from the vehicle 
engine which would otherwise cause undesirable characteristics, e.g., 
impact loads, pulsations, noises, etc. in the transmission and driveline 
during operation of the vehicle. 
Conventional dampers are generally embodied in a clutch driven member 
assembly interposed between a driving member or vehicle engine and the 
vehicle transmission. Such an assembly usually includes a clutch driven 
plate and a spring retainer plate secured together in spaced relation to 
sandwich therebetween the radial flange of a hub connected to the 
transmission input shaft; the plates and hub flange having axially aligned 
sets of windows receiving damper springs. The clutch driven plate normally 
carries friction facings on its periphery that are adapted to be 
positioned between an engine flywheel and a clutch pressure plate. 
Where the vibration damper is utilized in a lock-up clutch, the damper is 
interposed between a piston plate actuated by fluid pressure from 
operation of the torque converter and a hub operatively connected to the 
turbine hub and/or to the transmission input shaft. As shown in U.S. Pat. 
No. 4,188,805, the damper assembly includes a hub with at least two radial 
arms, drive input means connected to the piston plate and axially aligned 
with the hub arms, floating equalizers journalled on the hub and having 
oppositely disposed arms, and damper springs positioned between the hub 
arms and equalizer arms; the drive input means being located in the path 
of the damper springs. 
The present invention provides a simplified vibration damper assembly 
adapted for use in either a vehicle friction clutch or a torque converter 
lock-up clutch. 
SUMMARY OF THE INVENTION 
The present invention comprehends the provision of a novel minimum 
complexity vibration damper for use in a vehicle clutch or other torsional 
coupling wherein the functions of the structural components are integrated 
so as to eliminate the need for one or both spring retainers. This 
assembly utilizes pressure or clutch plate formations for spring seats for 
the damper springs. Also, this configuration uses the form of the pressure 
or clutch plate for spring retention, thus eliminating the need for one 
spring retainer. This assembly requires a clutch or pressure plate, a hub 
plate, a retainer plate and the damper springs. 
The present invention also comprehends the provision of a novel simplified 
vibration damper utilizing an integral hub and retainer plate along with a 
pressure or clutch plate. The configuration of these two parts provides 
the spring seats for the damper springs. 
The present invention further comprehends the provision of a novel 
simplified vibration damper having a hub plate with a configuration to 
concentrate spring unit loading on the hub and away from the other 
components, thereby decreasing lag in the assembly. 
Further objects are to provide a construction of maximum simplicity, 
efficiency, economy and ease of assembly and operation, and such other 
objects, advantages and capabilities as will later more fully appear and 
are inherently possessed thereby.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring more particularly to the disclosure in the drawings wherein are 
shown illustrative embodiments of the present invention, FIGS. 1 through 5 
disclose a vibration damping assembly 10 utilized in a lock-up clutch 11 
for a torque converter 12, which assembly provides a smaller damper 
profile providing an advantage when dealing with space limitations. The 
assembly includes a generally circular piston plate 13 having an inner 
axial flange 14 defining an opening receiving the end 15 of a transmission 
input shaft, an intermediate portion 16 having a pair of inwardly offset 
arcuate channels 17, an offset securing portion 18 with circularly 
arranged openings 19, an outer annular flat friction portion 21 having a 
friction facing 22 suitably secured thereto and terminating in an axial 
peripheral flange 23. The arcuate channels 17 are provided with a pair of 
diametrically oppositely disposed outwardly offset curved spring retainers 
or pockets 24 for a pair of damper springs 25,25. 
A spring retainer plate 26 has a central opening 27 and a generally flat 
rectangular portion 28 defined by parallel edges 29,29, the ends of the 
plate terminating in axial flanges or offset portions 31,31 and radial 
mounting flanges 32,32 having openings 33 axially aligned with openings 19 
for rivets or other suitable securing means 34 to secure the plates 13 and 
26 together. The plate is provided with a pair of arcuate, outwardly 
offset spring retainers or pockets 35,35 aligned with the retainers or 
pockets 24 to encompass the damper springs 25. 
A substantially rectangular hub or reactor plate 36 has a central opening 
with internal splines 37 receiving the outer splined surface 39 of a 
generally cylindrical barrel 38 having an internally splined passage 41 
receiving the splined end 15 of the transmission input shaft. The hub 
plate has parallel side edges 42,42 and arcuate end edges 43,43 fitting 
within the arcuate offset portions 31 of the retainer plate 26. Each end 
of the hub plate contains a generally arcuate spring window 44 axially 
aligned with the spring retainers or pockets 24 and 35 of the piston plate 
and retainer plate, respectively. Each spring window has a pair of 
outwardly diverging flat ends or edges 45,45, an inner arcuate edge 46 and 
an outer edge consisting of outer inclined flat edge portions 47,47 
connected by a central arcuate portion 48; the end edges of the pockets 24 
and 35 being outwardly diverging and generally aligned with the edges 
45,45. 
The angles of the inclined portions 47,47 are greater than the angles of 
the arcuate outer edges of the spring retainers 24 and 35 so that as 
torque is applied to the piston plate 13 in either direction of rotation, 
the piston plate and retainer plate pockets contact one end 49 of each 
damper spring to compress the spring. As the spring is compressed by the 
pockets of the plates and the opposite end edge 45 of the hub plate as 
shown in dotted lines, the outer corner of the spring does not ride on the 
inclined edge portion 47 reducing friction lag in the damper operation. 
This action will continue until the outer corner of the spring engages the 
arcuate central portion 48 of the outer edge. As seen in FIG. 3, thrust 
buttons 51 having central raised portions 52 received within the end coils 
of the springs 25 are optionally used within the spring pockets of the 
plates. 
FIGS. 6 and 7 disclose an alternate embodiment of low complexity vibration 
damper 55 eliminating the need for separate spring retainers. This 
embodiment utilizes a piston or pressure plate 56 having a central axial 
flange 57 defining a central opening for the transmission input shaft, a 
generally flat portion 58, an outer annular portion carrying a friction 
facing and an outer peripheral flange substantially identical to the 
showing in FIGS. 1 and 2. The flat portion 58 includes a pair of 
diametrically oppositely disposed inwardly offset and substantially 
triangular spring abutments 59 having outwardly diverging contact surfaces 
61. 
A generally circular hub or reactor plate 62 has a central splined opening 
63 receiving exterior splines 65 on a generally cylindrical hub barrel 64 
also having a central splined passage 66, and an annular channel 67 acting 
as a damper spring housing and terminating in a radial lip 68. The channel 
is interrupted by a pair of diametrically opposite inwardly offset straps 
69 having outwardly diverging edges 71. 
The channel 67 conformably receives the spring abutments 59, as seen in 
FIG. 7, with each abutment having a central opening 72 to receive one end 
of a guide or shoulder rivet 73 which also extends through an elongated 
arcuate slot 74 in the channel to limit relative rotation between the 
members. The rivets are headed at both ends to secure the members in their 
operative position. Two pairs of damper springs 75,75 and 76,76 are 
positioned within said channel between the spring abutments 59 and the 
offset straps 69. Only one pair of springs will be active in the drive 
direction while the opposite pair of springs will be active in the coast 
direction. 
Although both of the above described assemblies are shown for use in a 
torque converter lock-up clutch having a piston or pressure plate 13 or 
56, the assemblies are equally adaptable for use in a friction clutch of a 
vehicle manual transmission or in a torsional coupling between two axially 
aligned shafts. Obviously, the pressure plate would either be altered to 
provide a plate carrying friction facings at its periphery adapted to be 
positioned between a flywheel and pressure plate of a vehicle clutch 
assembly or provided with mounting means to be secured to a rotating 
flange of a drive shaft in a torsional coupling arrangement.