US008406112B2
(12) United States Patent
(16) Patent N6;
Merrill et al.
(45) Date of Patent:
(54)
TURNTABLE
(76)
Inventors: George Earnest Merrill, Bartlett, TN
(56)
( * ) Notice:
.
.
.
References Cited
3,218,081 A *
3,309,094 A *
.
11/1965 Gentilini ..................... .. 369/267
3/1967 Stanton ....................... .. 369/269
3,786,288 A
l/l974 Joannou
4,106,776
8/1978
A
Subject‘ to any disclaimer, the term of this
4,202,551 A
Patent 15 extended Or adJuSIed under 35
4,365,326 A *
U.S.C. 154(b) by 0 days.
4,368,530 A
(21)
(22)
Filed:
(65)
12/1982 Ohsawa et a1. ............. .. 369/268
l/l983 Zopf
10/1984 Cooper et a1.
7/1985 Asano ...................... .. 369/4101
FOREIGN PATENT DOCUMENTS
Prior Publication Data
US 2012/0008488 A1
'
1/1983 Darnall, Jr.
4,475,184 A
4,528,653 A *
Jan. 4, 2011
G'll
5/l980 Diu?zl?lae‘lr‘
4,369,950 A
.
Appl' NO" 12/984506
Mar. 26, 2013
US PATENT DOCUMENTS
(US); Robert Edwin Williams,
Memphis, TN (Us)
.
US 8,406,112 B2
Jan. 12, 2012
EP
0017004 Bl
7/1983
JP
55038666 A *
3/1980
* cited by examiner
Primary Examiner * Thang Tran
(51)
Related US. Application Data
Provisional application NO 61/292,029’ ?led on Jan
4 2010'
’
Int CL
(52)
us. Cl. ..................................................... .. 369/264
and armboard only Come into Contact With the elastomeric
(58)
Field of Classi?cation Search ..... .. 369/2644271 .1,
layer’ which dampens energy’ allowing the turntable Produce
the audio on the record Without excessive noise.
(60)
G11B 3/64
(200601)
(57)
ABSTRACT
An improved turntable is described With inherent properties
for reducing noise generated by external sources or by the
parts of the turntable. The plinth of the turntable is comprised
of an elastomeric layer and at least one stiffening layer that
adds rigidity to the plinth. The support feet, spindle bearing,
369/2741, 248
See application ?le for complete search history.
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FIG. 7
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1
2
TURNTABLE
FIG. 5 is a cross sectional vieW of the tonearm mount as
vieWed along line 5-5 of FIG. 2.
FIG. 6 is an exploded vieW of the turntable plinth.
CROSS-REFERENCES TO RELATED
APPLICATIONS
FIG. 7 is an exploded vieW of the turntable as a Whole.
DETAILED DESCRIPTION
This application claims the bene?t of US. Provisional
Application No. 61/292,029 ?led Jan. 4, 2010 and incorpo
rated herein by reference in entirety.
The folloWing detailed description is presented to enable
any person skilled in the art to make and use the invention. For
purposes of explanation, speci?c details are set forth to pro
FIELD OF THE INVENTION
vide a thorough understanding of the present invention. HoW
ever, it Will be apparent to one skilled in the art that these
The present invention is generally directed toWard a neW
speci?c details are not required to practice the invention.
turntable With improved noise reduction properties.
Descriptions of speci?c applications are provided only as
representative examples. Various modi?cations to the pre
BACKGROUND OF THE INVENTION
ferred embodiments Will be readily apparent to one skilled in
the art, and the general principles de?ned herein may be
applied to other embodiments and applications Without
departing from the scope of the invention. The present inven
Turntables, also knoWn as record players, Work through the
transduction of mechanical vibrations of the needle into an
electrical signal Which can then be ampli?ed. Turntables are
susceptible to various sources of noise and vibration Which
20
are ampli?ed along With the recorded sound, and Which can
interfere With the enjoyment of the recording. The noise and
vibration are “energy intrusions” that degrade the quality of
signal produced by the turntable.
tion is not intended to be limited to the embodiments shoWn,
but is to be accorded the Widest possible scope consistent With
the principles and features disclosed herein.
Referring to the draWings, FIG. 1 illustrates an exemplary
embodiment of the improved turntable. The turntable 1 con
25
sists of a rotating platter 2 that supports a phonograph record,
There are three general sources of energy intrusion that
a drive source 3 for this platter (such as a motor, pulley, and
affect a turntable: airborne, mechanical, and internal noise
belt), a plate (also knoWn as the plinth 7, base, or chassis) to
mount the bearing 4 for the rotating platter 2, motor mount
ing, andpickup arm mounting. Support feet 8 are used to raise
generated by the turntable itself. Airborne energy contained
Within the environment includes sounds that cause the tum
table to vibrate. These vibrations are picked up by the tum
30
and support the plinth 7 While further reducing intruding
table and ampli?ed. Mechanical noise includes vibrations
from the environment that travel through the support feet of
energy.
the record player. For example, nearby tra?ic, subWays, con
material. In a preferred embodiment it is made of a compound
struction, or even footsteps Will cause the turntable to vibrate.
Finally, a turntable has its oWn internal sources of energy
The rotating platter 2 can be manufactured from any solid
containing Bakelite, cellulose and resin. This compound has
35
Which Will be ampli?ed and negatively affect the sound.
These include energy generated from the motor, drive system,
s1on.
Preferably a rubber cork compound mat is used to place the
platter support bearings, and tone arm release energy as Well
as energy generated by stylus to groove contact during track
ing of the record.
The presently disclosed turntable solves the problem of
unWanted noise by isolating the intruding energy. The reduc
a high density, a loW resonance top, and dimension stability.
These characteristics make it ideal for reducing energy intru
record upon the rotating platter 2, thus aiding to quell vibra
40
tions Within the vinyl as the stylus 26 is tracking the grooves
of the record. HoWever, a felt mat or rubber mat may also be
employed.
The rotating platter 2 design and material consideration
tion in energy intrusions results in a cleaner signal.
along With the mat control the internal energy that is gener
SUMMARY OF THE INVENTION
45
ated by the stylus 26 making contact With the grooves of the
record during tracking.
In one embodiment, the platter shaft 9 is manufactured
from precision ground stainless steel With a hardened thrust
ball placed at the end. The platter is supported by a bearing 4
An improved turntable With vibration isolating properties
is disclosed. This improved turntable reduces vibration
through a unique plinth material, internal bracing, and vibra
tion absorbing feet. As a result, the turntable reproduces the
recorded audio more faithfully and Without unWanted noise.
50
face is provided at the bottom of this bearing 4 to alloW the
shaft thrust ball to ride With virtually no friction, thus pre
The claimed device comprises a turntable With a plinth
made of composite material With both ?rm and elastomeric
layers, a noise reducing platter, internal bracing, and noise
reducing feet.
manufactured from graphite impregnated nylon or preferably
molybdenum disul?de impregnated nylon. A hardened sur
55
venting additional noise.
The plinth 7 also greatly reduces energy intrusion. The
plinth 7 is the heart of the turntable that supports all three
energy generating parts: the motor, bearing/ spindle, and tone
BRIEF DESCRIPTION OF THE DRAWINGS
arm.
Further advantages of the invention Will become apparent
by reference to the detailed description of preferred embodi
ments When considered in conjunction With the draWings:
FIG. 1 depicts a perspective vieW of the turntable.
The plinth 7 has a novel construction that signi?cantly
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other elastomer sandWiched betWeen stiffening layers 10.
FIG. 2 is a top plan vieW of the turntable.
FIG. 3 is a cross sectional vieW of the feet as vieWed along
line 3-3 of FIG. 2.
FIG. 4 is a cross sectional vieW of the turntable as vieWed
along line 4-4 of FIG. 2.
reduces energy intrusion. As can be seen in FIG. 6, the plinth
7 is constructed from a laminate of an elastomeric layer 11 or
65
The elastomeric layer is preferably a dense rubber With a
durometer of 80, but any elastomeric material may be used.
This stiffening layers 10 are preferably made of a hard mate
rial. such as carbon ?ber, aluminum, or plyWood. The elasto
meric layer 11 absorbs vibration and energy, While the stiff
US 8,406,112 B2
3
4
ening layer 10 provides structure and support. The operating
The ?at of the hemisphere is placed in a support base 17 to
alloW retention of its shape and for uniform input of energy
into the foot. The feet are designed such that only elastomeric
portions of the feet come into contact With the elastomeric
parts of the turntable that produce energy, such as the motor,
spindle, and tonearm do not come into contact With the stiff
ening layer 10. Instead, the stiffening material is cut aWay
from the laminate, and these operating parts are attached
directly to the elastomeric layer 11. The space betWeen the
operating parts and the sideWalls of the stiffening material is
5
cantly dampened.
Airborne energy is dampened by the overall energy absorb
ing capability of the laminate 7, feet 8, and rotating platter 2.
knoWn as energy isolation valleys 12. These gaps in the stiff
As a result, the Whole turntable is virtually impervious to
airborne energy encountered in a normal listening environ
ening layer 10 of the laminate material prevent the operating
parts from transmitting energy directly to the stiffening layers
10. Vibrational energy travels easily through hard material
Without signi?cant dampening. HoWever, vibrational energy
ment
It should be understood that features of any of these
embodiments may be used With another in a Way that Will noW
does not travel Well through elastomeric materials because
the elastomeric materials absorb much of the energy. The
unique composite laminate material of the plinth 7 absorbs
vibrational energy While providing rigidity to support the
platter. The advantage of this system is that energy developed
by each of these operating parts is only transmitted through
the elastomeric layer 1 1, and is absorbed and dissipated by the
elastomeric layer 11 before it can intrude and affect the other
parts. For example the motor energy is dissipated before it can
affect the energy release from the pickup arm.
To reduce the possibility of sagging, spar bracing 18 may
also be introduced into the elastomeric layer 11 of the lami
nate to further support the Weight of a heavy platter. In an
be understood in vieW of the foregoing disclosure. Although
the present invention has been described and illustrated With
respect to at least one preferred embodiment and use therefor,
20
25
2. The turntable of claim 1 further comprising an armboard
mounted Within said energy isolation valley.
30
and bottom aluminum stiffening layers respectively, thus
increasing the rigidity of the plinth.
5. The turntable of claim 1 further comprising a spindle
bearing mounted Within said energy isolation valley.
35
meric layer 11. As can be appreciated by FIG. 4 and FIG. 5,
7. The turntable of claim 1 further comprising stiffening
material connected to said stiffening layer.
8. The turntable of claim 1 further comprising a rotating
40
9. The turntable of claim 1 further comprising a mat com
posed of a material selected from the group consisting of
rubber cork compound, felt, and rubber.
45
three directions so that the armboard 19 is parallel to the
rotating platter 2.
Mechanical energy intrusion from the surface that the tum
table 1 rests upon is managed by a system called the isolation
support foot 8 Which consists of an inverted hemisphere 14
consisting of an elastomeric material. An adjustable support
column 13 is attached to the elastomeric layer 11 of the plinth
7 and is resting upon a inverted hemisphere 14, preferably
made of highly absorbent rubber. This support column 13
utiliZes a positioning pin to hold the foot 8 in place. The
support column 13 consists of tWo parts: the height adjust
ment collar 15 and the hemisphere coupler With positioning
pin 16. A bolt is inserted through a compressing Washer and
the plinth elastomeric layer 11 into the hemispherical coupler,
draWing the adjustment collar 15 and hemispherical coupler
16 tightly together. This creates a support column 13 that is
extremely solid While still having height adjustment capabili
ties. The curved face on the hemispherical coupler 16 varies
contact With the inverted hemisphere 14 Which changes the
spring rate, further helping to subdue energy transmission.
platter composed of a compound containing Bakelite, cellu
lose, and resin.
stiffening layer 10 around it. This isolation valley 12 prevents
the armboard from coming in contact With the stiffening layer
10. Upper armboard 19 is secured to loWer armboard 24 by
fasteners that pass through elastomeric layer 11. These fas
teners alloWs for easy adjustment of the arm mounting in all
6. The turntable of claim 1 further comprising internal
bracing in said plinth.
the tone arm 28 is mounted to an upper armboard 19. The
upper armboard 19 rests directly on the elastomeric layer 11
in an area that is absent of stiffening layers 10. An isolation
valley 12 exists betWeen the upper armboard 19 and the
3. The turntable of claim 1 further comprising a drive
source mounted Within said energy isolation valley.
4. The turntable of claim 1 further comprising a support
foot mounted Within said energy isolation valley.
The tone arm mounting system accomplishes the dissipa
tion of tonearm release energy by using an energy transfer
isolation valley is an area of said plinth that is not in contact
With said stiffening layer.
truss. For example, in one embodiment a 1.25 inch aluminum
tonearm mounting platform coupled to the damping elasto
it is not to be so limited, since modi?cations and changes can
be made therein Which are Within the fully-intended scope of
the invention.
We claim:
1. A turntable comprising a plinth Which is further com
prised of an elastomeric layer and a stiffening layer, Wherein
said stiffening layer is in contact With said elastomeric layer
except in an energy isolation valley, Wherein said energy
alternative embodiment, added stiffening material may be
used to directly connect the stiffening layers 10 to form a rigid
cylinder strut is placed through a hole in the elastomeric layer
11 and the top and bottom of the cylinder are glued to the top
portion of the turntable, thus ensuring that energy is signi?
10. The turntable of claim 1 further comprising a platter
shaft composed of stainless steel.
11. The turntable of claim 2 Wherein adjustable fasteners
are used to mount said armboard Within said energy isolation
valley.
50
12. The turntable of claim 4 Wherein said support foot is
composed of an elastomeric support material.
13. The turntable of claim 12 Wherein said elastomeric
support material is in the shape of an inverted hemisphere.
14. The turntable of claim 4 Wherein said support foot
55
further comprises an adjustable height column.
15. The turntable of claim 5 Wherein said spindle bearing is
composed of molybdenum disul?de impregnated nylon.
16. The turntable of claim 5 Wherein said spindle bearing is
composed of graphite impregnated nylon.
60
17. The turntable of claim 15, Wherein the plinth further
comprising internal bracing.
18. The turntable of claim 15, Wherein the plinth further
comprising stiffening material connected to said stiffening
layer.