USRE36806E - Internally damped rotatable storage article - Google Patents

Internally damped rotatable storage article Download PDF

Info

Publication number
USRE36806E
USRE36806E US09313336 US31333699A USRE36806E US RE36806 E USRE36806 E US RE36806E US 09313336 US09313336 US 09313336 US 31333699 A US31333699 A US 31333699A US RE36806 E USRE36806 E US RE36806E
Authority
US
Grant status
Grant
Patent type
Prior art keywords
material
damping
article
storage
rotatable
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
US09313336
Inventor
Donald T. Landin
Jeffrey W. McCutcheon
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
3M Innovative Properties Co
Original Assignee
3M Innovative Properties Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Grant date

Links

Images

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16FSPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F3/00Spring units consisting of several springs, e.g. for obtaining a desired spring characteristic
    • F16F3/08Spring units consisting of several springs, e.g. for obtaining a desired spring characteristic with springs made of a material having high internal friction, e.g. rubber
    • F16F3/087Units comprising several springs made of plastics or the like material
    • F16F3/093Units comprising several springs made of plastics or the like material the springs being of different materials, e.g. having different types of rubber
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16FSPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F1/00Springs
    • F16F1/36Springs made of rubber or other material having high internal friction, e.g. thermoplastic elastomers
    • F16F1/3605Springs made of rubber or other material having high internal friction, e.g. thermoplastic elastomers characterised by their material
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16FSPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F15/00Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion
    • F16F15/02Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems
    • F16F15/04Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems using elastic means
    • F16F15/08Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems using elastic means with rubber springs ; with springs made of rubber and metal
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16FSPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F9/00Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
    • F16F9/30Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium with solid or semi-solid material, e.g. pasty masses, as damping medium
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16FSPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F9/00Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
    • F16F9/30Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium with solid or semi-solid material, e.g. pasty masses, as damping medium
    • F16F9/306Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium with solid or semi-solid material, e.g. pasty masses, as damping medium of the constrained layer type, i.e. comprising one or more constrained viscoelastic layers
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/2403Layers; Shape, structure or physical properties thereof
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16FSPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F2224/00Materials; Material properties
    • F16F2224/04Fluids
    • F16F2224/048High viscosity, semi-solid pastiness
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16FSPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F2228/00Functional characteristics, e.g. variability, frequency-dependence
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S428/00Stock material or miscellaneous articles
    • Y10S428/913Material designed to be responsive to temperature, light, moisture
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S430/00Radiation imagery chemistry: process, composition, or product thereof
    • Y10S430/146Laser beam
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/21Circular sheet or circular blank
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/25Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/25Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
    • Y10T428/252Glass or ceramic [i.e., fired or glazed clay, cement, etc.] [porcelain, quartz, etc.]
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/25Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
    • Y10T428/254Polymeric or resinous material
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/25Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
    • Y10T428/256Heavy metal or aluminum or compound thereof
    • Y10T428/257Iron oxide or aluminum oxide
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/31504Composite [nonstructural laminate]
    • Y10T428/31511Of epoxy ether
    • Y10T428/31515As intermediate layer
    • Y10T428/31522Next to metal

Abstract

The present invention provides a method for internally damping a rotatable storage article which is subject to resonant vibrations. More specifically, the present invention provides a method of improving the damping properties of a rotatable storage article by introducing a viscoelastic material as an inner layer(s) of the rotatable storage article. The invention also provides the damped rotatable storage articles themselves.

Description

FIELD OF THE INVENTION

The present invention relates to a method for internally damping a rotatable storage article which is subject to resonant vibrations. More specifically, the present invention relates to a method of improving the damping properties of a rotatable storage article by introducing a viscoelastic material as an inner layer(s) of the rotatable storage article. The invention also relates to the damped rotatable storage articles themselves.

BACKGROUND OF THE INVENTION

Periodic or random vibrations or shocks can excite the resonant frequencies in a rotatable storage article which can be problematic due to the resultant formation of undesirable stresses, displacements, fatigue, and even sound radiation. Such undesirable vibrations or shocks are typically induced by external forces and can be experienced by a wide variety of articles and under a variety of conditions. For example, resonant vibrations can cause excessive vertical displacement of art optical disk's surface during operation which may lead to poor laser focus. Proper laser focus is a key to optimum write/read characteristics, signal quality, and tracking ability.

Various techniques have been used to reduce vibrational and shock effects (stresses, displacements, etc.) on storage articles. Three basic techniques to reduce vibration and shock effect include

1) adding stiffness or mass to the rotatable storage article so that the resonant frequencies of the rotatable storage article are not excited by a given excitation source,

2) isolating the rotatable storage article from the excitation so the vibrational or shock energy does not excite the rotatable storage article's resonant frequencies, and

3) damping the rotatable storage article so that given excitations do no result in excessive negative effects at the resonant frequencies of the rotatable storage article.

An isolation technique for limiting vibration transmission is described in U.S. Pat. No. 4,870,429 issued Sep. 26, 1989. A single-sided or double-sided optical disk structure is described which includes two sheets of substrate bonded to each other with a foam spacer interposed between the two substrates to restrict or isolate the vibrations caused by external forces. The spacer is made from an elastomeric foam material and is positioned between the two substrates to restrict the transmission of such forces (e.g. vibrations or shocks). The thickness of the spacer is stated to be preferably not less than 0.2 mm, more preferably not less than 0.4 mm, because when the thickness is too small the effect of the spacer to restrict or isolate forces is not exhibited sufficiently. Such a system adds to the overall size of the rotatable storage article and may be impractical where close positioning of the article to other structures is desired.

Two types of surface or external damping treatments which can be used to reduce shock or vibration impact on rotatable articles are: (1) free layer damping treatments; and (2) constrained layer damping treatments. Both of these damping treatments, Dan provide high levels of damping to a structure, i.e., dissipation of undesirable vibrations, without sacrificing the stiffness of the structure. The use of viscoelastic materials as exterior surface damping treatments is described in EP 0507515 published Oct. 7, 1992. Examples of additional surface or external damping techniques are described, for example, in U.S. Pat. Nos. 2,819,032 (issued Jan. 7, 1953); 3,071,217 (issued Jan. 1, 1963); 3,078,969 (issued Feb. 26, 1963); 3,159,249 (issued Dec. 1, 1964); and 3,160,549 (issued Dec. 8, 1964). All of the aforementioned damping techniques can add complexity and expense to the design of the rotatable storage article, limit the amount of exterior article surface available for data storage, and can increase the overall size of the article.

Free layer damping; treatment is also referred to as "unconstrained layer" or "extensional damping" treatment. In this technique, damping occurs by applying a layer of viscoelastic damping material to one or more exterior surfaces of the article to be damped. The material can be applied to one or more exterior surfaces of the article to be damped. The mechanism by which this treatment method dissipates undesirable energy, e.g., resonant vibrations, involves deformation. That is, when the article is subjected to cyclic loading, for example, the damping material is subjected to tension-compression deformation and dissipates the energy through an extensional strain mechanism.

Constrained layer damping treatment is also referred to as "shear damping" treatment. For a given weight, this type of damping treatment is generally more efficient than the free layer damping treatment. In this technique, damping occurs by applying a damper consisting of one or more layers of viscoelastic damping material and one or more layers of a higher tensile modulus material to one or more exterior surfaces of the article to be damped. That is, this damping technique is similar to the free layer damping treatment wherein a viscoelastic material is applied to one or more exterior surfaces of a structure, the difference being that the viscoelastic material is additionally constrained by a layer having a higher modulus than the viscoelastic material, e.g., a metal layer, in the constrained layer treatment. Energy dissipates from the viscoelastic damping material via a shear strain mechanism. The shear strain results from constraints by the higher modulus constraining layer and the base structure.

Although these exterior surface damping techniques are used, the degree of damping is oftentimes limited by thickness or spacing requirements as well as application difficulties. Furthermore, the exterior damper must be applied to potential data storage surface areas, limiting information storage capability. In addition, external dampers can interfere with information retrieval from the storage article. Another disadvantage is that the external damper may be subject to degradation by the environmental conditions in which it is used. As way of example, if a rotatable storage article is desired to be a component in a size limited application, such as hard disk drives for portable computer systems, computers, or calculators, the ability to adequately damp the rotatable storage article by means of an "add-on" exterior surface damper may not be possible due to overall thickness requirements to meet a "form factor" requirement or the necessity of using the exterior surface for data/information storage. Thus, an alternative approach is needed to damp vibrational or shock energy without adversely affecting the overall size or thickness or available surface area of the rotatable storage article.

SUMMARY OF THE INVENTION

We have found such an alternative approach. The present invention provides an internally damped rotatable storage article.

The term "rotatable storage article" as used herein refers to a media that has information stored on it and/or which is capable of storing information. The article is typically capable of being rotated in some manner that allows the data stored on the article to be passed by a read or write element to allow reading of information from the article, or writing of information on the article, or both. Examples of storage articles include rigid disk drive disks, optical disks, compact disks (CDs), magneto-optical disks, records, drums, floppy disks and the like.

The present invention also provides a method of improving the vibration damping characteristics of a rotatable storage article by providing an internally damped rotatable storage article. The method typically involves incorporating one or more layers of a vibration damping material into the storage article typically by adding one layer or a plurality of layers of a damping material during the manufacture of the rotatable storage article as an inner layer. The layer(s) may be continuous or discontinuous. The discontinuous layer may be separated by space(s) and/or a non-damping material. A continuous layer may comprise the same damping material or different damping material adjacent to each other, thereby forming a continuous surface.

The vibration damping material includes a viscoelastic material or combination of different viscoelastic materials. Useful viscoelastic materials are those having a storage, modulus of at least about 1.0 psi (6.9×103 Pascals) and a loss factor of at least about 0.01, at the temperature and frequency of use. Advantageously and preferably, a layer(s) of the vibration damping material is placed in areas of high strain energy as an inner layer(s) to provide improved damping in the desired frequency and temperature range. The added damping layer(s) increases the vibrational damping, as measured by the system loss factor, of the rotatable storage article or the structural material of which it is made, by at least about 10% in at least one vibrational mode. System loss factor is a measure of the damping in a structure.

In certain preferred embodiments, the vibration damping material also includes an effective amount of a fibrous material. The vibration damping material preferably includes an amount of fibrous material effective to improve vibration damping of the article or the structural material of which the article is made by a factor of at least about two in strain energy ratio of at least one vibrational mode. Typically, this requires incorporating about 3 to 60 wt % of the fibrous material into the vibration damping material, based on the total weight of the vibration damping material. Preferably, the fibrous material is a nonmetallic fibrous material, such as glass.

In another preferred embodiment, the vibration damping material also includes an effective amount of a particulate material. The vibration damping material preferably includes an amount of particulate material effective to improve vibrational damping of the article or the structural material of which the article is made by a factor of at least about two in strain energy ratio of at least one vibrational mode. Typically, this requires incorporating about 0.5 to 70 weight percent of the particulate material into the vibration damping material, based on the total weight of the vibration damping material. Combinations of particulate and fibrous materials may be used, typically about 0.5 to about 70 wt. % based on the total damping material. Additionally, in certain preferred embodiments, the vibration damping material that provides the significant portion of the damping for a given material layer also includes an effective amount of an epoxy resin (with or without the particulate or fibrous material) dispersed within the damping material. The vibration damping material preferably includes an amount of epoxy resin effective to improve the mechanical integrity of the rotatable disk storage article or the structural material of which the rotatable disk storage article is made. The epoxy resin material may optionally having damping properties. An example of a suitable damping material incorporating an epoxy resin is disclosed in U.S. Pat. No. 5,262,232 (issued Nov. 13, 1993), incorporated herein by reference. Typically, the amount of epoxy resin incorporated into the vibration damping material is about 0.5 to 95 weight percent, preferably about 5 to about 50 weight percent, based on the total weight of the vibration damping material.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic top view of a "disk type" rotatable storage article of the present invention having a continuous single layer of a vibrational damping material placed near the center of the article's thickness.

FIG. 2 is a schematic of a "disk type" rotatable storage article of the present invention showing a cross-section of the rotatable storage article of FIG. 1 having one layer of damping material.

FIG. 3 is a schematic of an alternative embodiment of the present invention showing a cross-section of a rotatable storage article having two layers of damping material which are not exposed at the article outer perimeter.

FIG. 4 is a schematic of an alternative embodiment of the present invention showing a cross-section of a rotatable storage article having a single discontinuous layer of damping material which is not exposed at the inner or outer perimeter of the article.

FIG. 4b is a schematic of an alternative embodiment of the present invention showing a cross-section of rotatable storage article having a single discontinuous layer of damping material which is not exposed at the inner or outer perimeter of the article.

FIG. 5 is a graph of frequency versus transfer function for Example 1 and Comparative Example 2 identified as A and B, respectively.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a method of improving damping properties of rotatable storage articles, and thereby solving vibration problems in a variety of applications where rotatable storage articles are exposed to vibration or shock. More specifically, the present invention provides a vibration and shock resistant internally damped rotatable storage article that uses a highly dissipative damping material, with a loss factor of at least about 0.01 at a given frequency and temperature, preferably at least about 0.1. This damping material, when placed in the rotatable storage article as inner layer(s), can be exposed to significant amounts of strain energy in various vibrational modes of interest and dissipates a portion of this vibrational energy as heat, thereby diminishing vibration and shock displacement oscillations. The present invention functions so as to damp, i.e., reduce the vibrational or shock amplitude or duration of, a wide variety of vibrational modes, e.g., bending, torsion, sway, and extensional modes, in a wide variety of rotatable storage article designs and over a wide frequency and temperature range. It can be applied to situations in which exterior surface treatments, such as constrained layer treatments, are typically used and are especially useful where overall size of the article is important.

The method of the present invention typically involves the incorporation of a vibration damping material as one or more interior layers of the rotatable storage article laminate. The vibration damping material may be layered in between the structural material, e.g., aluminum and it alloys, polyester, ceramic, polycarbonate, glass, and/or vinyl, etc. of the rotatable storage article. Preferably, the laminated material has the damping material laminated, sprayed, silk screened, or cast onto one or more layers of structural material. The damping material layer can be continuous, or discontinuous. The final rotatable storage article design can have the damping material encased around the edges using, for example, metal or plastic or sealed with adhesive, tape, or by sonic bonding or the like so that the damping material is substantially completely surrounded by, i.e., encased or enclosed within, the structural material, which provides protection of the damping material from environmental conditions. Alternately, the damping material can be exposed at the perimeter edges or cutouts within the rotatable storage article, which is preferred from a damping standpoint. The addition of the damping material into the laminate structure results in creating an inherently damped rotatable substrate laminate that can be further processed to add magnetic or optical recording coatings and an opening for a hub or spindle.

The damping layer may substantially form a layer having about the same dimensions as the substrate layers between which it is sandwiched. Alternately, the layer may be of more limited dimensions and may be situated in an area of greatest vibrational stresses.

Typically, an amount of the damping material is present such that the damping characteristics of the rotatable storage article are improved. Preferably, a sufficient amount of the vibration damping material is used such that the damping is improved by at least about 10% in at least one vibrational mode. As a result of this technique, high mechanical strains are introduced into the damping material when the structure is excited at one or more of its natural frequencies. A portion of the resulting mechanical strain energy in the damping material is then dissipated in the form of heat. The higher the strain energy in the damping material, the more vibration energy is dissipated from the rotatable storage article structure.

The placement of a partial layer of damping material in the rotatable storage article can be influenced by whether the article edges are sealed. This can alter the stiffness of the rotatable storage article and determine areas of greater vibrational activity for a given vibrational or shock excitation of one of the modes of vibration in a certain area of the rotatable storage article. That is, the partial vibration damping material layer(s) are placed in the article where one or more vibrational modes are active. By such placement, the amount of strain energy that is generated in the damping material used for the rotatable storage article can be maximized. The identification of these locations can be determined by one of skill in the art using modal analysis or finite element analysis.

The rotatable storage article's structure damped by the method of the present invention can be prepared from any material suitable for rotatable storage article designs. Useful structural materials include, for example, metals such as aluminum and aluminum alloys; organic materials/resins such as polyester, polycarbonate and vinyl; and inorganic materials such as glass and ceramic. Additional materials such as magnetic or optical coatings, wear resistant overcoats and lubricants may also be used for preparing the data storage surface(s) of the article of the invention.

The vibration damping material can include any material that is viscoelastic. A viscoelastic material is one that is viscous, and therefore capable of dissipating energy, yet exhibits certain elastic properties, and therefore capable of storing energy. That is, a viscoelastic material is an elastomeric material typically containing long-chain molecules that can convert mechanical energy into heat when they are deformed. Such a material typically can be deformed, e.g., stretched, by an applied load and gradually regain its original shape, e.g., contract, sometime after the load has been removed.

Suitable viscoelastic materials for use in the vibration damping materials of the present invention have a storage modulus, i.e., measure of the energy stored during deformation, of at least about 1.0 psi (6.9×103 Pascals). The storage modulus of useful viscoelastic materials can be as high as 500,000 psi (3.45×109 Pascals); however, typically it is about 10-2000 psi (6.9×104 -1.4×107 Pascals).

Suitable viscoelastic materials for use in the vibration damping materials of the present invention have a loss factor, i.e., the ratio of energy loss to energy stored, of at least about 0.01. Preferably the loss factor is at least about 0.1, more preferably about 0.5-10, and most preferably about 1-10, in the frequency and temperature range where damping is required (typically about 1-10,000 Hz and -40° to 100° C. This loss factor is a measure of the material's ability to dissipate energy and depends on the frequency and temperature experienced by the damping material. For example, for a crosslinked acrylic polymer, at a frequency of 100 Hz, the loss factor at 68° F. (20° C.) is about 1.0, while at 158° F. (70° C.) the loss factor is about 0.7.

Preferred viscoelastic materials are those that remain functional over a wide range of temperatures, e.g., -40° F. (-40° C.) to 300° F. (149° C.). Most preferred viscoelastic materials are those that cover the broadest temperature and frequency range at the desired minimum loss factor and storage modulus to achieve acceptable damping of the rotatable storage article, and do not experience a significant degradation in properties due to long times at high temperatures or short excursions beyond these high temperature levels.

Useful viscoelastic damping materials can be isotropic as well as anisotropic materials, particularly with respect to its elastic properties. As used herein, an "anisotropic material" or "nonisotropic material" is one in which the properties are dependent upon the direction of measurement. Suitable viscoelastic materials include urethane rubbers, silicone rubbers, nitrile rubbers, butyl rubbers, acrylic rubbers, natural rubbers, styrene-butadiene rubbers, and the like. Other useful damping viscoelastic materials include polyesters, polyurethanes, polyamides, ethylene-vinyl acetate copolymers, polyvinyl butyral, polyvinyl butyral-polyvinyl acetate copolymers, epoxy-acrylate interpenetrating networks and the like. Specific examples of useful materials are disclosed or referenced in U.S. Pat. No. 5,183,863 (issued Feb. 2, 1993), U.S. Pat. No. 5,262,232 (issued Nov. 16, 1993) and U.S. Pat. No. 5,308,887 (issued May 3, 1994), all of which are incorporated herein by reference.

Examples of thermoplastic materials suitable for use as the vibration damping material in rotatable storage articles according to the present invention include, but are not limited to, those selected from the group consisting of polyacrylates, polycarbonates, polyetherimides, polyesters, polysulfones, polystyrenes, acrylonitrile-butadiene-styrene blockcopolymers, polypropylenes, acetal polymers, polyamides, polyvinyl chlorides, polyethylenes, polyurethanes, and combinations thereof.

Useful viscoelastic materials can also be crosslinkable to enhance their strength. Such viscoelastics are classified as thermosetting resins. When the viscoelastic material is a thermosetting resin, then prior to the manufacture of the damped storage article. The thermosetting resin is in a thermoplastic state. During the manufacturing process, the thermosetting resin is cured and/or crosslinked typically to a solid state, although it could be a gel upon curing as long as the cured material possesses the viscoelastic properties described above. Depending upon the particular thermosetting resin employed, the thermosetting resin can include a curing agent, e.g., catalyst, which when exposed to an appropriate energy source (such as thermal energy) the curing agent initiates the polymerization of the thermosetting resin. Particularly preferred viscoelastic damping materials are those based on acrylates.

In general, any suitable viscoelastic material can be used. The choice of viscoelastic material for a particular set of conditions, e.g., temperature and frequency of vibration, etc., is within the knowledge of one of skill in the art of viscoelastic damping. It is to be understood that blends of any of the foregoing materials can also be used.

In addition to the viscoelastic material, the vibration damping material of certain preferred embodiments of tile present invention includes an effective amount of a fibrous and/or particulate material. Herein, an "effective amount" of a fibrous material or particulate is an amount sufficient to impart at least improvement in desirable characteristics to the viscoelastic material, but not so much as to give rise to any significant detrimental effect on the structural, magnetic, optical (e.g., degrade read/write capability), or electrical integrity of the rotatable storage article in which the viscoelastic material is incorporated. Generally, the fibrous or particulate material is used in an amount effective to increase the strain energy ratio of a component containing the same amount and type of viscoelastic material without the fibrous or particulate material. Generally, an increase in the strain energy ratio of a factor of at least about two in at least one vibrational mode is desired. Typically, the amount of the fibrous material in the viscoelastic material is within a range of about 3-60 wt %, preferably about 10-50 wt %, more preferably about 15-45 wt %, and most preferably about 20-40 wt %, based on the total weight of the vibration damping material. Typically, the amount of the particulate material in the viscoelastic material is within a range of about 0.5-70 wt %, preferably about 1-45 wt %, more preferably about 5-40 wt %, and most preferably about 5-30 wt %, based on the total weight of the vibration damping material.

The fibrous material can be in the form of fibrous strands or in the form of a fiber mat or web, although fibrous strands are preferred. The fibrous strands can be in the form of threads, cords, yarns, filaments, etc., as long as the viscoelastic material can wet the surface of the material. They can be dispersed randomly or uniformly in a specified order. Preferably, the fibrous strands, i.e., fibers or fine threadlike pieces, have an aspect ratio of at least about 2:1, and more preferably an aspect ratio within a range of about 2:1 to about 10:1. The aspect ratio of a fiber is the ratio of the longer dimension of the fiber to the shorter dimension.

The fibrous material can be composed of any material that increases the damping capability of the viscoelastic material. Examples of useful fibrous materials in applications of the present invention include metallic fibrous materials, such as aluminum oxide, magnesium or steel fibers, as well as nonmetallic fibrous materials, such as fiberglass. Generally, high Young's modulus fibrous materials, i.e., those having a modulus of at least about 1,000,000 psi (6.9×109 pascals), are preferred. Most preferably, the fibrous material is nonmetallic. The nonmetallic fibrous materials can be a variety of materials, including, but not limited to, those selected from the group consisting of glass, carbon, minerals, synthetic or natural heat resistant organic materials, and ceramic materials. Preferred fibrous materials for rotatable storage articles of the present invention ate organic materials, glass, and ceramic fibrous material.

By "heat resistant" organic fibrous material, it is meant that useable organic materials should be sufficiently resistant to melting, or otherwise softening or breaking down under the conditions of manufacture and use of the rotatable storage article of the present invention. Useful natural organic fibrous materials include, but are not limited to, those selected from the group consisting of wool, silk, cotton, and cellulose. Examples of useful synthetic organic fibrous materials include, but are not limited to, those selected from the group consisting of polyvinyl alcohol, nylon, polyester, rayon, polyamide, acrylic, polyolefin, aramid, and phenol. The preferred organic fibrous material for applications of the present invention is aramid fibrous material. Such a material is commercially available from Dupont Co., Wilmington, Del. under the tradenames of "Kevlar" and "Nomex".

Generally, any ceramic fibrous material is useful in applications of the present invention. An example of a ceramic fibrous material suitable for the present invention is NEXTEL™ which is commercially available from Minnesota Mining and Manufacturing Co., St. Paul, Minn. Examples of useful, commercially available, glass fibrous material are those available from PPG Industries, Inc. Pittsburgh, Pa., under the product name E-glass bobbin yarn; Owens Corning, Toledo, Ohio, under the product name "Fiberglass" continuous filament yarn; and Manville Corporation, Toledo, Ohio, under the product name "Star Rov 502" fiberglass roving.

Advantages can be: obtained through use of fibrous materials of a length as short as about 100 micrometers. The fibers are not limited in length but much longer fibers may provide insufficient fiber interface and therefore decreased shearing surfaces between fibers. The fiber thickness or diameter for typical fibrous material ranges from about at least 5 micrometers. The thinner the fiber, the higher the surface area of the fibrous material. Thus, preferred fibrous materials are very thin. The thickness of the fiber is also dependent upon the desired thickness; of the overall damping material layer that will be used in the rotatable storage article. Thus, many common fibers may not be suitable if the overall damping material thickness is relatively thin (e.g., 4-10 micrometers).

The particulate material useful in the invention can be in the form of glass and ceramic bubbles or beads, flakes, or powder, as long as the viscoelastic can wet the surface of the material. The particulate material can vary in size, but should not be greater than the thickness of the damping material layer. Preferably, the particulate material is on the size order of about 0.1 to about 5 micrometers and more preferably about 0.1 to about 2 micrometers.

The particulate material can be composed of any material that increases the damping capability of the viscoelastic damping material.

Examples of usefill particulate materials in applications of the present invention include coated or uncoated glass and ceramic bubbles or beads such as thermally conductive bubbles, powders such as aluminum oxide powder and aluminum nitride powder, silica, cured epoxy nodules, and the like, i.e., those having a modulus of at least about 10,000 psi (6.9×107 Pascals), are preferred. More preferably, useful particulate materials have a Young's modulus of about 100,000 psi (6.9×108 Pascals), and most preferable are those with a modulus of at least 1,000,000 psi (6.9×109 Pascals). Blends of a particulate material and fibrous material can be used from about 0.5 wt % to about 70 wt % based on the weight % of damping material.

In addition to fibers and particulate material, the vibration damping material of the present invention can include additives such as fillers (e.g. talc, etc.), colorants, toughening agents, fire retardants, antioxidants, antistatic agents, and the like. Sufficient amounts of each of these materials can be used to effect the desired result.

The damped rotatable storage article of the invention utilizes the damping of viscoelastic materials with a minimum impact on the rotatable storage article structural geometry and stiffness. Thus, the rotatable storage articles of the present invention are good candidates for products that require added vibration and shock resistance in tight geometry applications and/or sensitive weight applications. In addition, the damped storage article allows storage (e.g., data, information, etc.) on one or both sides of the rotatable storage article, if desired, whereas an add-on free layer or constrained layer damper would limit storage to one side of the article. Thinner articles may also be possible, as the addition of damping material to an inner layer of the laminate may eliminate the need for added stiffness or mass to help reduce the effects of vibrations or shock.

The internally damped laminate of the present invention will be better understood by reference to the following FIGS. 1-4.

FIG. 1 is a schematic of one embodiment of the present invention showing a top view of a rotatable disk storage article 1 having an interior continuous single layer of a damping material. The rotatable storage article 1 has an overcoat 3a such as polycarbonate to protect the information storage layer, outer radius 7, and inner radius 5.

FIG. 2 is a schematic of one embodiment of the present invention showing a cross section of a rotatable disk storage article 1 of FIG. 1 taken along line 2--2. The article 1 has a continuous layer of a damping material 8 bonded between supporting; structural materials 4a and 4b. The disk 1 also includes information storage layers 6a and 6b, and overcoat layers 3a and 3b.

FIG. 3 is a schematic of an alternative embodiment of the present invention showing a cross section of a rotatable storage article 10 having two layers of damping material 12a and 12b, which are not exposed at the article outer perimeter. The damping layers 12a and 12b are positioned between supporting structural material 14. The article 10, which has an inner radius 18 and an outer radius 20, also includes information storage layers 16a and 16b and overcoat layers 13a and 13b.

FIG. 4 is a schematic of an alternative embodiment of the invention showing a cross section of a rotatable storage article 30 having a single discontinuous layer of damping material 32, which is not exposed at the article 30 outer perimeter. The damping layer 33 is made up of adjacent sections of a first damping material 33 and a different damping material 35. Alternatively the material 35 could, for example represent a nondamping material or even a space. The damping layer 32 is placed within supporting structural material 34. The article 30 which has an inner radius 36 and an outer radius 38 also includes information storage layers 40a and 40b, as well as overcoat layers 39a and 39b.

FIG. 4b is a schematic of an alternative embodiment of the invention showing a cross section of a rotatable storage article 50 having a single discontinuous layer of damping material 52, which is not exposed at the article 50 outer perimeter. The damping layer 52 is made up of adjacent sections of a first damping material 53 and spaces 54. The damping layer 52 is placed within supporting structural material 56. The article 50 which has an inner radius 57 and an outer radius 59 also includes information storage layers 60a and 60b, as well as overcoat layers 62a and 62b.

Those skilled in the art can select the best means to introduce the damping material into a specific process based on the needs of the final damped laminate rotatable storage article and also limitations in processing capabilities of the laminate input materials.

The vibrational damping material can include a viscoelastic material or a combination of viscoelastic material with a fibrous or particulate material. It is to be understood that the vibration damping material can include a blend of viscoelastic materials as well as a variety of different fibrous or particulate materials. Blends of fibreous and particulate material are also possible.

The desired thickness of the damping material is typically 0.002 mm to 0.5 mm; preferably, 0.02 mm to 0.15 mm; and most preferably, 0.02 mm to 0.05 mm. Typically, the thickness of the damping material is about 0.5 to about 50% of the thickness of the article, more typically about 1 to about 25%. The rotatable storage article of the invention typically contains at least 1 damping layer, more typically 1-3 layers, preferably 1-2, most preferably 1 for reasons of simplicity of the storage article's manufacturing process and cost. Stiffness may be sacrificed when more than 1 layer is included. However, a wider temperature range of damping is possible when multiple layers of different damping materials are included. The amount of damping material used can vary. Sufficient material should be used to obtain the desired damping effect while balancing the structural requirements of the article. The vibration damping layer may be continuous or discontinuous. A continuous layer may comprise the same material or adjacent sections of different vibration damping materials, for example. A discontinuous layer may comprise sections of damping material separated by nondamping material and/or spaces, for example. When 2 or more layers are present the layers may comprise the same or different damping material and each may be continuous or discontinuous.

When the article contains a single layer of vibration damping material preferably the layer is positioned within the article at a distance of at least about 5%, more preferably at least about 30% of the thickness of the article from an upper and lower surface of the article. When the article has one layer of damping material most preferably it is positioned equidistant from an upper surface of the article and a lower surface of the article. When the article contains at least two layers of vibration damping material preferably each damping material layer is positioned within the article such that it is at least about 5% of the thickness of the article away from an upper and lower surface of the article and each vibration damping material layer is preferably at least about 5%, more preferably at least about 20% and most preferably at least about 30% of the thickness of the article away from another vibration damping layer.

The rotatable storage article of the present invention can be made by any suitable technique for creating rotatable storage articles as understood by those in the industry. These techniques are generally known to those of skill in the art. For example, a damped rotatable rigid disk for a disk drive application can be made by adding a single layer of a damping material 0.025 mm thick near the center of a disk by laminating a layer of aluminum with a layer of suitable damping material and as additional layer of aluminum. This laminate is then stamped with a tool to yield a disk that has an inner damping layer. The disk "blank" is further processed to define edge and surface requirements and a read and writable data storage surface is added. The finished damped rotatable disk will have increased damping over the non-damped disk of the same process.

Examples of rotatable storage articles which may be damped internally include but are not limited to those selected from the group consisting of magnetic rotatable storage articles such as rigid disks, floppy disks, and drums; optical rotatable storage articles such as compact disks, optical disks, and drums; magneto optical rotatable storage articles such as compact disks, optical disks, drums; and mechanical rotatable storage articles such as vinyl records.

EXAMPLES

The invention has been described with reference to various specific and preferred embodiments and will be further described by reference to the following detailed examples. It is understood, however, that there are many extensions, variations, and modifications on the basic theme of the present invention beyond that shown in the examples and detailed description, which are within the spirit and scope of the present invention. All parts, percentages, ratios, etc. in the Specification and the Examples are by weight unless indicated otherwise.

Example 1 and Comparative Examples 1-3

In order to evaluate the performance of an internally damped rotatable article a sample article was prepared by adding a layer of a 0.051 mm damping material into the aluminum disk construction (Example 1) and compared to the performance of a disk construction that was bonded together with a non-damping adhesive material adhesive (Comparative Example 2), and a disk construction without a damping layer or adhesive layer (Comparative Example 1).

Description of Sample

For the purpose of demonstrating the invention, an acrylic damping material was used in the damped disk build-up in a single layer. The damping material used was an acrylic polymer that had a loss factor greater than 0.5 for a broad frequency range (±1000 Hz) at the desired test temperature (20° C./72° F.). The acrylic damping polymer selected was 3M Scotchdamp™ ISD-112, SJ2015 type 1202 available from Minnesota Mining and Manufacturing Company, St. Paul, Minn.).

Example 1

A 0.051 mm thick sheet of acrylic polymer damping material (3M Scotchdamp™ ISD-112) was placed between two 68.26 mm diameter aluminum disks, each having a 17.46 mm diameter center hole and a thickness of 0.7112 mm, to form a construction. The acrylic polymer sheet completely covered the inner surface of each aluminum disk. The construction was subjected to hand pressure for about 1 minute and then rolled with a 4.5 kg. roller to affect a bond between the acrylic polymer sheet and the two aluminum disks to provide an internally damped disk article. Although the disk article did not have any information storage layers we believe, it is representative of a disk that would have such storage layers.

The internally damped disk article was then tested as follows: Using a C-clamp, the internally damped disk article was secured at its center to a rigid table. The disk was then excited with an electromagnetic transducer (Electro 3030 HTB A) at a point 2 mm from its outer edge where a small piece of steel had been bonded. The resulting acceleration was measured with an accelerometer (Endevco Model 22) at a point diametrically opposite to the excitation point and at 2 mm from its outer edge. The transfer function was calculated from the acceleration measurement using a Tektronix 2630 Fourier Analyzer. Each transfer function was the average of 100 measurements. The transfer function thus obtained is represented graphically as a function of frequency in FIG. 5, as plot A.

The measurement of the damping is determined by calculating the system loss factor for the disk article design at the desired resonant frequency. The "system loss factor" is defined as: the width (Hz) of the resonant peak at 3 db below the resonant frequency of peak amplitude/the resonant frequency (Hz) at peak amplitude.

The system loss factor and the frequency are reported in Table 1 under Ex. 1.

Comparative Example 1

In this comparative example, a laminate was prepared and tested as in Example 1 except that no acrylic polymer sheet was used and the two aluminum disks were merely placed one on top of the other. The system loss factor and the frequency are reported in Table 1 under Comp. Ex. 1. The C-clamp used in the test method served to hold the two disks together during testing.

Comparative Example 2

In this comparative example, a laminate was prepared and tested as in Example 1 except that a 0.0254 mm thick layer of non-damping cyanoacrylate adhesive (Pronto™ Brand Instant Adhesive CA-8, available from 3M Company) was used in place of the acrylic polymer sheet. The transfer function thus obtained is represented graphically in FIG. 5, as plot B. The system loss factor and the frequency are reported in Table 1 under Comp. Ex.

              TABLE 1______________________________________Example No.  Frequency (Hz)                   System Loss FactorEx. 1        1850       0.243Comp. Ex. 1        2200               0.022Comp. Ex. 2       2500                  0.020______________________________________

From the data in Table 1 it can be seen that the system loss factor of the internally damped disk article (Ex. 1) is about 10 times greater than disk constructions of Comparative Examples 1 and 2 which demonstrates the superior damping performance of the internally damped disk article. FIG. 5 demonstrates the superior damping properties of a laminate representing the rotatable storage article of the invention compared to a laminate containing an internal adhesive layer which is not a damping material.

The foregoing detailed description and example have been given for clarity of understanding only. No unnecessary limitations are to be understood therefrom. The invention is not limited to the exact details shown and described, for variations obvious to one skilled in the art will be included within the invention defined by the claims.

Claims (33)

What is claimed is:
1. An internally damped rotatable storage article .Iadd.comprising.Iaddend.:
.Iadd.a structural material selected from the group consisting of metals and ceramics; and.Iaddend.
.[.having.]. at least one layer of vibration damping material contained therein, comprising a viscoelastic material, said vibration damping material having a loss factor of at least about 0.01 and a storage modulus of at least about 6.9×103 Pascals, wherein the thickness of each of said layer(s) ranges from about 0.002 mm to about 0.5 mm, and wherein the vibration damping is improved by at least about 10% in at least 1 vibrational mode.
2. The rotatable storage article of claim 1 wherein the thickness of each of said layer(s) ranges from about 0.002 mm to about 0.15 mm.
3. The rotatable storage article of claim 1 wherein the thickness of each of said layer(s) ranges from about 0.002 mm to about 0.05 mm.
4. The rotatable storage article of claim 1 wherein the thickness of each of said layer(s) of vibration damping material is about 0.5 to about 50% the thickness of the article.
5. The rotatable storage article of claim 1 wherein the thickness of each of said layer(s) of vibration damping material is about 1 to about 25% the thickness of the article.
6. The rotatable storage article of claim 1 wherein the viscoelastic material has a loss factor greater than about 0.1 and a storage modulus of at least about 6.9×104 Pascals.
7. The rotatable storage article of claim 1 wherein the viscoelastic material has a loss factor of 0.5 to about 10 and a storage modulus of about 6.9×104 to about 1.4×107 Pascals.
8. The rotatable storage article of claim 1 wherein the viscoelastic material is selected from the group consisting of thermoplastic polymers, thermosetting polymers, and mixtures thereof.
9. The rotatable storage article of claim 1 wherein the viscoelastic material is a thermosetting polymer.
10. The rotatable storage article of claim 9 wherein the thermosetting polymer is an acrylate.
11. The rotatable storage article of claim 1 selected from the group consisting of magnetic rotatable storage articles.[., optical rotatable storage articles, magneto-optical rotatable storage articles,.]. and mechanical rotatable storage articles.
12. The rotatable storage article of claim 1 selected from the group consisting of magnetic rigid disks, magnetic floppy disks, magnetic drums, .[.optical compact disks, optical disks, optical drums, magneto-optical compact disks, magneto-optical disks, magneto-optical drums.]. and vinyl records.
13. The rotatable storage article of claim 1 wherein said rotatable storage article contains at least 2 layers of vibration damping material.
14. The rotatable storage article of claim 1 wherein the vibration damping material further comprises a fibrous material.
15. The rotatable storage article of claim 14 wherein the vibration damping material includes about 3 to about 60 weight percent fibrous material, based on the total weight of the vibration damping material.
16. The rotatable storage article of claim 1 wherein the vibration damping material further comprises a particulate material.
17. The rotatable storage article of claim 16 wherein the particulate material is selected from the group consisting of glass bubbles, glass beads, ceramic bubbles, ceramic beads, thermally conductive bubbles, aluminum oxide powder, aluminum nitride powder, silica, and cured epoxy nodules.
18. The rotatable storage article of claim 1 wherein the vibration damping material includes about 0.5 to about 70 weight percent of particulate material based on the total weight of the vibration damping material.
19. The rotatable storage article of claim 1 wherein the vibration damping material further comprises a fibrous material and a particulate material.
20. The rotatable storage article of claim 1 which contains a single layer of vibration damping material wherein said layer is positioned within the article at a distance of at least about 5% of the thickness of the article from an upper and lower surface of the article.
21. The rotatable storage article of claim 1 which contains a single layer of vibration damping material wherein said layer is positioned within the article at a distance of at least about 30% of the thickness of the article from an upper and lower surface of the article.
22. The rotatable storage article of claim 1 wherein the rotatable storage article has one layer of damping material positioned equidistant from an upper surface of the article and a lower surface of the article.
23. The rotatable storage article of claim 1 which contains at least two layers of vibration damping material wherein each damping material layer is positioned within the article such that it is at least about 5% of the thickness of the article away from an upper and lower surface of the article and each vibration damping material layer is at least about 5% of the thickness of the article away from another vibration damping layer.
24. The rotatable storage article of claim 1 which contains at least two layers of vibration damping material wherein each damping material layer is positioned within the article such that it is at least about 5% of the thickness of the article away from an upper and lower surface of the article and each vibration damping material is at least about 20% of the article thickness away from another damping layer.
25. The rotatable storage article of claim 1 which contains at least two layers of vibration damping material wherein each damping material layer is positioned within the article such that it is at least about 5% of the thickness of the article away from an upper and lower surface of the article and each vibration damping material is at least about 30% of the article thickness away from another damping layer.
26. The rotatable storage article of claim 1 wherein the vibration damping material further comprises an epoxy resin material, wherein said epoxy resin material may optionally have vibration damping properties.
27. The rotatable storage article of claim 1 wherein the vibration damping layer is a continuous layer.
28. The rotatable storage article of claim 1 wherein the vibration damping layer is a continuous layer made up of adjacent sections of different vibration damping materials.
29. The rotatable storage article of claim 1 wherein the article contains at least 2 layers of vibration damping material, wherein at least 2 of the layers comprise different damping materials.
30. The rotatable storage article of claim 1 wherein the vibration damping layer is a discontinuous layer.
31. The rotatable storage article of claim 30 wherein the discontinuous layer comprises sections of damping material separated by non-damping material or spaces.
32. The rotatable storage article of claim 1 wherein each vibration damping material layer is encased within the storage article.
33. A method of improving the viscoelastic damping characteristics of a rotatable storage article .Iadd.comprising a structural material selected from the group consisting of metals and ceramics, the method .Iaddend.comprising providing at least one layer of vibration damping material within the rotatable storage article, each vibration damping material layer comprising a viscoelastic material, said vibration damping material having a loss factor of at least about 0.01 and a storage modulus of at least about 6.9×103 Pascals, wherein the thickness of each of said layer(s) ranges from about 0.002 mm to about 0.5 mm, and wherein the vibration damping is improved by at least about 10% in at least 1 vibrational mode. .Iadd.34. An internally damped rotatable storage article having at least one layer of vibration damping material contained therein, comprising a viscoelastic material, said vibration damping material having a loss factor of at least about 0.01 and a storage modulus of at least about 2.0×105 Pascals, wherein the thickness of each of said layer(s) ranges from about 0.002 mm to about 0.5 mm, and wherein the vibration damping is improved by at least about 10% in at least 1 vibrational mode..Iaddend..Iadd.35. The rotatable storage article of claim 1, wherein the article is a magnetic rotatable storage article..Iaddend..Iadd.36. A disk drive comprising the rotatable storage article of claim 1..Iaddend..Iadd.37. A computer comprising the disk drive of claim 36..Iaddend..Iadd.38. A disk drive comprising the rotatable storage article of claim 34..Iaddend..Iadd.39. A computer comprising the disk drive of claim 38..Iaddend..Iadd.40. A disk drive comprising:
an internally damped magnetic rotatable storage article comprising:
at least one layer of vibration damping material comprising a viscoelastic material contained therein, said vibration damping material having a loss factor of at least about 0.01 and a storage modulus of at least about 6.9×103 Pascals,
wherein the thickness of each of said layer(s) ranges from about 0.002 mm to about 0.5 mm, and
wherein the vibration damping is improved by at least about 10% in at least 1 vibrational mode..Iaddend..Iadd.41. A computer comprising the disk drive of claim 40..Iaddend..Iadd.42. The disk drive of claim 40, wherein the internally damped magnetic rotatable storage article comprises a glass structural material..Iaddend..Iadd.43. The internally damped rotatable storage article of claim 1, wherein the structural material is metal..Iaddend.
US09313336 1994-07-29 1999-05-17 Internally damped rotatable storage article Expired - Fee Related USRE36806E (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US08282574 US5538774A (en) 1994-07-29 1994-07-29 Internally damped rotatable storage article
US09313336 USRE36806E (en) 1994-07-29 1999-05-17 Internally damped rotatable storage article

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US09313336 USRE36806E (en) 1994-07-29 1999-05-17 Internally damped rotatable storage article

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US08282574 Reissue US5538774A (en) 1994-07-29 1994-07-29 Internally damped rotatable storage article

Publications (1)

Publication Number Publication Date
USRE36806E true USRE36806E (en) 2000-08-01

Family

ID=23082110

Family Applications (2)

Application Number Title Priority Date Filing Date
US08282574 Expired - Lifetime US5538774A (en) 1994-07-29 1994-07-29 Internally damped rotatable storage article
US09313336 Expired - Fee Related USRE36806E (en) 1994-07-29 1999-05-17 Internally damped rotatable storage article

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US08282574 Expired - Lifetime US5538774A (en) 1994-07-29 1994-07-29 Internally damped rotatable storage article

Country Status (5)

Country Link
US (2) US5538774A (en)
EP (2) EP0772874A1 (en)
JP (2) JPH10503612A (en)
CA (1) CA2194274A1 (en)
WO (1) WO1996004651A1 (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6688439B2 (en) * 2000-08-16 2004-02-10 Rolls-Royce Plc Vibration damping system and a method of damping vibrations
US6697213B2 (en) 2000-03-31 2004-02-24 Seagate Technology Llc Cover including multiple cover plates with damped layers
US6715200B2 (en) 1999-02-12 2004-04-06 General Electric Company Methods for making data storage media
US6764734B2 (en) * 1998-05-19 2004-07-20 Seagate Technology Llc High modulus and high damping plastic composite disc substrate for improved servo control by injection and co-injection molding
US7147906B2 (en) * 2003-06-24 2006-12-12 General Electric Company Data storage medium comprising polyimides

Families Citing this family (33)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5538774A (en) * 1994-07-29 1996-07-23 Minnesota Mining And Manufacturing Company Internally damped rotatable storage article
US5842686A (en) * 1995-11-01 1998-12-01 Pre Finish Metals Incorporated Patterned noise damping composite
US5725931A (en) * 1995-11-03 1998-03-10 Minnesota Mining And Manufacturing Company Constrained layer damper with slit(s) and/or cutout(s)
US5902656A (en) * 1996-06-21 1999-05-11 Minnesota Mining And Manufacturing Company Dampers for internal applications and articles damped therewith
US6055140A (en) * 1997-07-25 2000-04-25 Seagate Technology, Inc. Rigid disc plastic substrate with high stiffness insert
DE19802919C1 (en) * 1998-01-27 1999-10-07 Schott Glas Shape-stable glass for high speed hard disk substrates
US6214430B1 (en) * 1998-04-10 2001-04-10 Lg Electronics Inc. Disc recording medium and method of fabricating the same
US6202462B1 (en) 1998-05-26 2001-03-20 Material Sciences Corporation Method of forming noise-damping material with ultra-thin viscoelastic layer
JP4026234B2 (en) 1998-06-19 2007-12-26 ソニー株式会社 Information recording medium
US6285525B1 (en) 1998-07-01 2001-09-04 3M Innovative Properties Company Damped spacer articles and disk drive assemblies containing damped spacer articles
US6177173B1 (en) 1998-07-01 2001-01-23 3M Innovative Properties Company Damped laminates having welded through holes and/or edges with decreased spring back and improved fastener force retention and, a method of making
DE19838198C2 (en) 1998-08-24 2002-06-27 Schott Glas Glasses and glass-ceramics with high modulus of elasticity and their uses
DE19850744C1 (en) 1998-11-04 2000-10-05 Schott Glas Use of glasses for the manufacture of hard disk substrates
US6473263B2 (en) 1998-11-17 2002-10-29 Samsung Electronics Co., Ltd. Cover structure of hard disk drive with air damping layer
US6401510B1 (en) 1999-04-07 2002-06-11 3M Innovative Properties Company Method for stamping a part from a multi-layered strip
DE69930244T2 (en) * 1999-04-07 2006-11-23 3M Innovative Properties Co., St. Paul A method for punching a multilayer strip
US6366426B1 (en) 1999-04-21 2002-04-02 Seagate Technology Llc Apparatus and method for reducing structural vibrations in a disc drive utilizing fusible alloys
US6599602B2 (en) 1999-06-02 2003-07-29 3M Innovative Properties Company Polycarbonate articles and adhesive composition therefor
JP2001082537A (en) * 1999-08-26 2001-03-27 Three M Innovative Properties Co Constraint type viscoelastic damper
US6731591B2 (en) 2000-08-01 2004-05-04 Tdk Corporation Optical information medium
US6381196B1 (en) 2000-10-26 2002-04-30 The United States Of America As Represented By The Secretary Of The Navy Sintered viscoelastic particle vibration damping treatment
US6606221B2 (en) 2000-11-15 2003-08-12 Seagate Technology Llc Viscoelastic disc clamp using adhesive with radial compliance
US7227717B1 (en) * 2001-06-18 2007-06-05 Seagate Technology Llc Asymmetric disk surface properties in one head disk drives
US20030015440A1 (en) * 2001-07-20 2003-01-23 Downs Thomas Paul Protective divider and enclosure disc assembly for laser discs and laser disc drives
US7269124B2 (en) * 2001-07-20 2007-09-11 Thomas Paul Downs Protective divider and enclosure disc assembly for laser discs and laser disc drives
US7172800B2 (en) * 2003-11-03 2007-02-06 Material Sciences Corporation Sheet molding compound damper component, and methods for making and using the same
US7573674B1 (en) 2004-12-23 2009-08-11 Maxtor Corporation Storage disk having increased damping characteristics in a disk drive
US7879422B2 (en) 2005-11-03 2011-02-01 Princo Corp. Optical disc and method for fabricating the same
US20070104084A1 (en) * 2005-11-07 2007-05-10 Chen Kuo C External optical disk stabilizer and method of use
GB2445573B (en) * 2007-01-10 2009-08-26 Vistec Lithography Ltd Apparatus support structure
US20080248274A1 (en) * 2007-04-06 2008-10-09 Material Sciences Corporation High Damping, High Stiffness Multilayer Metal Polymer Sandwich Structure and Method
US9903434B2 (en) * 2013-08-21 2018-02-27 General Electric Company Components having vibration dampers enclosed therein and methods of forming such components
US9263094B2 (en) 2014-02-25 2016-02-16 HGST Netherlands B.V. Hard disk drive disk separator plate construction

Citations (82)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2819032A (en) * 1953-10-20 1958-01-07 Douglas Aircraft Co Inc Aircraft fuselage having panel damping material
US3071217A (en) * 1960-01-15 1963-01-01 Avro Aircraft Ltd Vibration damping in sheet metal structures
US3078969A (en) * 1959-06-15 1963-02-26 Lord Mfg Co Damped beam
US3159249A (en) * 1960-01-27 1964-12-01 Univ Minnesota Damping means
US3160549A (en) * 1960-12-29 1964-12-08 Minnesota Mining & Mfg Vibration damping structures
US3282763A (en) * 1962-03-08 1966-11-01 Ralph R Gunderson Method of adhering a light reflector unit to a mounting surface
US4195713A (en) * 1974-05-29 1980-04-01 Reduc Acoustics Ab Sandwich structures with partial damping layers
US4334233A (en) * 1979-07-16 1982-06-08 Tokyo Shibaura Denki Kabushiki Kaisha Optical recording element and its manufacturing method
JPS6039962A (en) * 1983-07-14 1985-03-02 Standard Telephones Cables Ltd Radio receiver
US4503531A (en) * 1981-12-22 1985-03-05 Pioneer Electronic Corporation Optical disc
DE8504837U1 (en) * 1985-02-21 1985-08-14 Fuhrmann, Udo, 5980 Werdohl, De
JPS60187951A (en) * 1984-03-08 1985-09-25 Toshiba Corp Optical disk record
JPS60242347A (en) * 1984-05-16 1985-12-02 Nippon Soken Inc Detector for abnormality of rotating body
US4571124A (en) * 1982-11-18 1986-02-18 Sumitomo Cement Co., Ltd. Method of forming cast-in-place concrete pile
US4583102A (en) * 1983-05-04 1986-04-15 Matsushita Electric Industrial Co., Ltd. Optical disc and method of manufacturing
US4686543A (en) * 1984-12-12 1987-08-11 Fuji Photo Film Co., Ltd. Information recording medium
US4711798A (en) * 1985-12-16 1987-12-08 Ricoh Company, Ltd. Optical information recording medium
JPS6350932A (en) * 1986-08-20 1988-03-03 Matsushita Electric Ind Co Ltd Optical recording medium
US4731620A (en) * 1986-02-12 1988-03-15 Fuji Photo Film Co., Ltd. Information recording medium
US4731780A (en) * 1984-07-11 1988-03-15 U.S. Philips Corporation Optical recording element
US4740947A (en) * 1984-04-25 1988-04-26 Sharp Kabushiki Kaisha Dual surface optical memory disc
JPS63137893A (en) * 1986-11-29 1988-06-09 Dainippon Printing Co Ltd Optical recording medium
US4760012A (en) * 1985-07-04 1988-07-26 Matsushita Electric Industrial Co., Ltd. Signal recording disk
US4800112A (en) * 1986-04-10 1989-01-24 Seiko Epson Corporation Optical recording medium
US4847827A (en) * 1987-12-09 1989-07-11 Pioneer Electric Corporation Optical information recording disk
EP0330197A2 (en) * 1988-02-24 1989-08-30 Nitto Denko Corporation Optical disk
US4865949A (en) * 1986-01-22 1989-09-12 Ricoh Company, Ltd. Optical information recording medium
US4871429A (en) * 1981-09-11 1989-10-03 Learonal, Inc Limiting tin sludge formation in tin or tin/lead electroplating solutions
EP0341785A1 (en) * 1988-05-11 1989-11-15 Philips and Du Pont Optical Company Optical disc having an antiresonance ring
US4892606A (en) * 1986-08-28 1990-01-09 Canon Kabushiki Kaisha Optical recording medium having space therein and method of manufacturing the same
JPH0294141A (en) * 1988-09-30 1990-04-04 Nec Corp Optical disk carrier
US4917751A (en) * 1984-05-11 1990-04-17 Sharp Kabushiki Kaisha Method of producing double sided optical memory disks
CA2001152A1 (en) * 1988-11-24 1990-05-24 Masayoshi Kurisu Information recording medium
EP0390413A2 (en) * 1989-03-27 1990-10-03 Mitsubishi Denki Kabushiki Kaisha Optical disc and method for making same
EP0243517B1 (en) * 1986-04-28 1991-02-27 Matsushita Electric Industrial Co., Ltd. Method for producing information storage disk
EP0430629A2 (en) * 1989-11-27 1991-06-05 Mitsui Petrochemical Industries, Ltd. Information recording media
JPH03142893A (en) * 1989-10-27 1991-06-18 Nec Corp Electronic circuit board
EP0443797A2 (en) * 1990-02-22 1991-08-28 Sony Corporation Optical disc having signal recording layer on each side and method for producing same
JPH03203828A (en) * 1989-12-29 1991-09-05 Hitachi Maxell Ltd Optical information recording medium
US5077120A (en) * 1981-07-01 1991-12-31 Pioneer Electronic Corporation Optical disk
EP0463382A2 (en) * 1990-05-30 1992-01-02 Philips Electronics N.V. Method of making double-sided magneto-optical disks having reduced birefringence
JPH0428031A (en) * 1990-05-23 1992-01-30 Mitsubishi Electric Corp Optical disk
JPH0453837A (en) * 1990-06-21 1992-02-21 Hayakawa Rubber Co Ltd Fiber-containing rubber sheet
US5151310A (en) * 1990-05-28 1992-09-29 Pioneer Electronic Corporation Information recording medium
EP0507515A2 (en) * 1991-04-01 1992-10-07 Minnesota Mining And Manufacturing Company Magneto-optical disk with vibration dampening
JPH04341943A (en) * 1991-05-17 1992-11-27 Sony Corp Optical disk
JPH04344344A (en) * 1991-05-21 1992-11-30 Hitachi Maxell Ltd Tight sticking type optical information recording medium
US5183863A (en) * 1991-05-31 1993-02-02 Toyo Boseki Kabushiki Kaisha Viscoelastic resin composition for vibration-damping material
EP0526244A2 (en) * 1991-07-31 1993-02-03 Sgs-Thomson Microelectronics, Inc. Method of forming a polysilicon buried contact
US5188875A (en) * 1989-08-25 1993-02-23 Mitsui Petrochemical Industries, Ltd. Information recording medium and adhesive composition therefor
US5197060A (en) * 1989-01-11 1993-03-23 Seiko Epson Corporation Dual substrate optical recording medium
US5213947A (en) * 1990-03-06 1993-05-25 Ricoh Company, Ltd. Optical recording medium
US5219708A (en) * 1989-05-02 1993-06-15 Tdk Corporation Optical disk
JPH05182241A (en) * 1991-12-27 1993-07-23 Nec Corp Optical disk medium
US5244775A (en) * 1991-03-20 1993-09-14 Hitachi, Ltd. Method of manufacturing an optical disc
US5262232A (en) * 1992-01-22 1993-11-16 Minnesota Mining And Manufacturing Company Vibration damping constructions using acrylate-containing damping materials
EP0581536A1 (en) * 1992-07-24 1994-02-02 Japan Synthetic Rubber Co., Ltd. Epoxy group-containing resin composition
US5308887A (en) * 1991-05-23 1994-05-03 Minnesota Mining & Manufacturing Company Pressure-sensitive adhesives
US5310588A (en) * 1991-08-13 1994-05-10 H. B. Fuller Licensing & Financing Inc. High temperature sealant containing phenyl silicone
US5356715A (en) * 1992-07-31 1994-10-18 Morton International, Inc. Vibration damping resins and vibration damping composites
US5360652A (en) * 1991-11-18 1994-11-01 Pioneer Electronic Corporation Optical recording disc
EP0624870A2 (en) * 1989-03-27 1994-11-17 Mitsubishi Denki Kabushiki Kaisha Apparatus for making optical discs
US5399220A (en) * 1992-10-22 1995-03-21 Optical Disc Corporation Composite disc media and method for making same
US5445855A (en) * 1987-12-08 1995-08-29 Mitsui Petrochemical Industries, Ltd. Active energy ray-curable composition and optical recording medium having cured product of the composition
JPH0822639A (en) * 1994-07-05 1996-01-23 Toshiba Corp Optical disk and its production
US5487926A (en) * 1990-11-22 1996-01-30 Tdk Corporation Optical disk
WO1996005249A2 (en) * 1994-07-29 1996-02-22 Minnesota Mining And Manufacturing Company Acrylic syrup curable to a crosslinked viscoelastomeric material
EP0706178A2 (en) * 1994-10-03 1996-04-10 Matsushita Electric Industrial Co., Ltd. Optical information medium, method for producing the optical information medium, and unit for producing the optical information medium
JPH0896415A (en) * 1994-09-21 1996-04-12 Toshiba Corp Optical information recording medium
EP0720159A2 (en) * 1994-12-28 1996-07-03 Matsushita Electric Industrial Co., Ltd. Optical recording medium having dual information surfaces
US5538774A (en) * 1994-07-29 1996-07-23 Minnesota Mining And Manufacturing Company Internally damped rotatable storage article
EP0725396A2 (en) * 1995-01-31 1996-08-07 Kabushiki Kaisha Toshiba Optical disk and optical disk apparatus
EP0729142A1 (en) * 1995-02-27 1996-08-28 Sony Corporation Optical recording medium and method of manufacturing same
EP0735530A1 (en) * 1995-03-31 1996-10-02 Toshiba-Emi Limited Method and apparatus for manufacturing bonded disks
WO1996031875A2 (en) * 1995-04-07 1996-10-10 Matsushita Electric Industrial Co., Ltd. Optical information recording medium, manufacturing method therefor, manufacturing apparatus therefor, and optical information recording and reproducing apparatus
JP3142893B2 (en) 1991-04-24 2001-03-07 リコー応用電子研究所株式会社 Thin-film semiconductor device
JP3203828B2 (en) 1992-10-19 2001-08-27 村田機械株式会社 Turret punch press
JP4028031B2 (en) 1996-08-15 2007-12-26 ゼロックス コーポレイションXerox Corporation The method for maintaining the topology of the curve transformation method and node-link diagram of the link arbitrary shape
JP4344344B2 (en) 2005-06-22 2009-10-14 テクファーマ・ライセンシング・アクチェンゲゼルシャフト Dispensing device
JP4341943B2 (en) 2000-06-28 2009-10-14 大日本印刷株式会社 Slip spelling with media
JP5182241B2 (en) 2009-07-15 2013-04-17 トヨタ自動車株式会社 Mounting method and automotive electrical equipment of the cooling unit of the cooling unit of the electric equipment for vehicles
JP6039962B2 (en) 2012-08-01 2016-12-07 日本板硝子株式会社 Cover glass for a photoelectric conversion device

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4569881A (en) * 1983-05-17 1986-02-11 Minnesota Mining And Manufacturing Company Multi-layer amorphous magneto optical recording medium
JPS62205554A (en) 1986-03-05 1987-09-10 Sumitomo Chem Co Ltd Optical disk
JPH0639962A (en) * 1992-07-23 1994-02-15 Kawasaki Steel Corp Composite oscillation damping material

Patent Citations (96)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2819032A (en) * 1953-10-20 1958-01-07 Douglas Aircraft Co Inc Aircraft fuselage having panel damping material
US3078969A (en) * 1959-06-15 1963-02-26 Lord Mfg Co Damped beam
US3071217A (en) * 1960-01-15 1963-01-01 Avro Aircraft Ltd Vibration damping in sheet metal structures
US3159249A (en) * 1960-01-27 1964-12-01 Univ Minnesota Damping means
US3160549A (en) * 1960-12-29 1964-12-08 Minnesota Mining & Mfg Vibration damping structures
US3282763A (en) * 1962-03-08 1966-11-01 Ralph R Gunderson Method of adhering a light reflector unit to a mounting surface
US4195713A (en) * 1974-05-29 1980-04-01 Reduc Acoustics Ab Sandwich structures with partial damping layers
US4334233A (en) * 1979-07-16 1982-06-08 Tokyo Shibaura Denki Kabushiki Kaisha Optical recording element and its manufacturing method
US5077120A (en) * 1981-07-01 1991-12-31 Pioneer Electronic Corporation Optical disk
US4871429A (en) * 1981-09-11 1989-10-03 Learonal, Inc Limiting tin sludge formation in tin or tin/lead electroplating solutions
US4503531A (en) * 1981-12-22 1985-03-05 Pioneer Electronic Corporation Optical disc
GB2153298A (en) * 1981-12-22 1985-08-21 Pioneer Electronic Corp Optical disc
US4571124A (en) * 1982-11-18 1986-02-18 Sumitomo Cement Co., Ltd. Method of forming cast-in-place concrete pile
US4583102A (en) * 1983-05-04 1986-04-15 Matsushita Electric Industrial Co., Ltd. Optical disc and method of manufacturing
JPS6039962A (en) * 1983-07-14 1985-03-02 Standard Telephones Cables Ltd Radio receiver
JPS60187951A (en) * 1984-03-08 1985-09-25 Toshiba Corp Optical disk record
US4740947A (en) * 1984-04-25 1988-04-26 Sharp Kabushiki Kaisha Dual surface optical memory disc
US4917751A (en) * 1984-05-11 1990-04-17 Sharp Kabushiki Kaisha Method of producing double sided optical memory disks
JPS60242347A (en) * 1984-05-16 1985-12-02 Nippon Soken Inc Detector for abnormality of rotating body
US4731780A (en) * 1984-07-11 1988-03-15 U.S. Philips Corporation Optical recording element
US4686543A (en) * 1984-12-12 1987-08-11 Fuji Photo Film Co., Ltd. Information recording medium
DE8504837U1 (en) * 1985-02-21 1985-08-14 Fuhrmann, Udo, 5980 Werdohl, De
US4760012A (en) * 1985-07-04 1988-07-26 Matsushita Electric Industrial Co., Ltd. Signal recording disk
US4711798A (en) * 1985-12-16 1987-12-08 Ricoh Company, Ltd. Optical information recording medium
US4865949A (en) * 1986-01-22 1989-09-12 Ricoh Company, Ltd. Optical information recording medium
US4731620A (en) * 1986-02-12 1988-03-15 Fuji Photo Film Co., Ltd. Information recording medium
US4800112A (en) * 1986-04-10 1989-01-24 Seiko Epson Corporation Optical recording medium
EP0243517B1 (en) * 1986-04-28 1991-02-27 Matsushita Electric Industrial Co., Ltd. Method for producing information storage disk
JPS6350932A (en) * 1986-08-20 1988-03-03 Matsushita Electric Ind Co Ltd Optical recording medium
US4892606A (en) * 1986-08-28 1990-01-09 Canon Kabushiki Kaisha Optical recording medium having space therein and method of manufacturing the same
JPS63137893A (en) * 1986-11-29 1988-06-09 Dainippon Printing Co Ltd Optical recording medium
US5445855A (en) * 1987-12-08 1995-08-29 Mitsui Petrochemical Industries, Ltd. Active energy ray-curable composition and optical recording medium having cured product of the composition
US4847827A (en) * 1987-12-09 1989-07-11 Pioneer Electric Corporation Optical information recording disk
EP0330197A2 (en) * 1988-02-24 1989-08-30 Nitto Denko Corporation Optical disk
US4939011A (en) * 1988-02-24 1990-07-03 Nitto Denko Corporation Optical disk
JPH0218730A (en) * 1988-05-11 1990-01-23 Philips & Du Pont Opt Co Optical disk
EP0341785A1 (en) * 1988-05-11 1989-11-15 Philips and Du Pont Optical Company Optical disc having an antiresonance ring
JPH0294141A (en) * 1988-09-30 1990-04-04 Nec Corp Optical disk carrier
US5059462A (en) * 1988-11-24 1991-10-22 Mitsui Petrochemical Industries, Ltd. Information recording medium
CA2001152A1 (en) * 1988-11-24 1990-05-24 Masayoshi Kurisu Information recording medium
EP0370622A2 (en) * 1988-11-24 1990-05-30 Mitsui Petrochemical Industries, Ltd. Information recording medium
US5197060A (en) * 1989-01-11 1993-03-23 Seiko Epson Corporation Dual substrate optical recording medium
EP0624870A2 (en) * 1989-03-27 1994-11-17 Mitsubishi Denki Kabushiki Kaisha Apparatus for making optical discs
EP0390413A2 (en) * 1989-03-27 1990-10-03 Mitsubishi Denki Kabushiki Kaisha Optical disc and method for making same
US5540967A (en) * 1989-03-27 1996-07-30 Mitsubishi Denki Kabushiki Kaisha Optical disc
US5219708A (en) * 1989-05-02 1993-06-15 Tdk Corporation Optical disk
US5188875A (en) * 1989-08-25 1993-02-23 Mitsui Petrochemical Industries, Ltd. Information recording medium and adhesive composition therefor
US5290877A (en) * 1989-08-25 1994-03-01 Mitsui Petrochemical Industries, Ltd. Information recording medium and adhesive composition therefor
EP0414258B1 (en) * 1989-08-25 1995-06-28 Mitsui Petrochemical Industries, Ltd. Information recording medium and adhesive composition therefor
JPH03142893A (en) * 1989-10-27 1991-06-18 Nec Corp Electronic circuit board
EP0430629A2 (en) * 1989-11-27 1991-06-05 Mitsui Petrochemical Industries, Ltd. Information recording media
US5167996A (en) * 1989-11-27 1992-12-01 Mitsui Petrochemical Industries, Ltd. Information recording media
JPH03203828A (en) * 1989-12-29 1991-09-05 Hitachi Maxell Ltd Optical information recording medium
EP0443797A2 (en) * 1990-02-22 1991-08-28 Sony Corporation Optical disc having signal recording layer on each side and method for producing same
US5284538A (en) * 1990-02-22 1994-02-08 Sony Corporation Optical disc having signal recording layer on each side and method for producing same
US5213947A (en) * 1990-03-06 1993-05-25 Ricoh Company, Ltd. Optical recording medium
JPH0428031A (en) * 1990-05-23 1992-01-30 Mitsubishi Electric Corp Optical disk
US5151310A (en) * 1990-05-28 1992-09-29 Pioneer Electronic Corporation Information recording medium
EP0463382A2 (en) * 1990-05-30 1992-01-02 Philips Electronics N.V. Method of making double-sided magneto-optical disks having reduced birefringence
US5146438A (en) * 1990-05-30 1992-09-08 E. I. Du Pont De Nemours & Co. Method of making double-sided magneto-optical disks having reduced birefringence
JPH0453837A (en) * 1990-06-21 1992-02-21 Hayakawa Rubber Co Ltd Fiber-containing rubber sheet
US5487926A (en) * 1990-11-22 1996-01-30 Tdk Corporation Optical disk
US5244775A (en) * 1991-03-20 1993-09-14 Hitachi, Ltd. Method of manufacturing an optical disc
US5543271A (en) * 1991-03-20 1996-08-06 Hitachi, Ltd. Optical recording and reproduction apparatus
EP0507515A2 (en) * 1991-04-01 1992-10-07 Minnesota Mining And Manufacturing Company Magneto-optical disk with vibration dampening
JP3142893B2 (en) 1991-04-24 2001-03-07 リコー応用電子研究所株式会社 Thin-film semiconductor device
JPH04341943A (en) * 1991-05-17 1992-11-27 Sony Corp Optical disk
JPH04344344A (en) * 1991-05-21 1992-11-30 Hitachi Maxell Ltd Tight sticking type optical information recording medium
US5308887A (en) * 1991-05-23 1994-05-03 Minnesota Mining & Manufacturing Company Pressure-sensitive adhesives
US5183863A (en) * 1991-05-31 1993-02-02 Toyo Boseki Kabushiki Kaisha Viscoelastic resin composition for vibration-damping material
EP0526244A2 (en) * 1991-07-31 1993-02-03 Sgs-Thomson Microelectronics, Inc. Method of forming a polysilicon buried contact
US5310588A (en) * 1991-08-13 1994-05-10 H. B. Fuller Licensing & Financing Inc. High temperature sealant containing phenyl silicone
US5360652A (en) * 1991-11-18 1994-11-01 Pioneer Electronic Corporation Optical recording disc
JPH05182241A (en) * 1991-12-27 1993-07-23 Nec Corp Optical disk medium
US5262232A (en) * 1992-01-22 1993-11-16 Minnesota Mining And Manufacturing Company Vibration damping constructions using acrylate-containing damping materials
EP0581536A1 (en) * 1992-07-24 1994-02-02 Japan Synthetic Rubber Co., Ltd. Epoxy group-containing resin composition
US5399604A (en) * 1992-07-24 1995-03-21 Japan Synthetic Rubber Co., Ltd. Epoxy group-containing resin compositions
US5530036A (en) * 1992-07-24 1996-06-25 Japan Synthetic Rubber Co., Ltd. Epoxy group-containing copolymer and radiation sensitive resin compositions thereof
US5356715A (en) * 1992-07-31 1994-10-18 Morton International, Inc. Vibration damping resins and vibration damping composites
JP3203828B2 (en) 1992-10-19 2001-08-27 村田機械株式会社 Turret punch press
US5399220A (en) * 1992-10-22 1995-03-21 Optical Disc Corporation Composite disc media and method for making same
JPH0822639A (en) * 1994-07-05 1996-01-23 Toshiba Corp Optical disk and its production
US5538774A (en) * 1994-07-29 1996-07-23 Minnesota Mining And Manufacturing Company Internally damped rotatable storage article
WO1996005249A2 (en) * 1994-07-29 1996-02-22 Minnesota Mining And Manufacturing Company Acrylic syrup curable to a crosslinked viscoelastomeric material
JPH0896415A (en) * 1994-09-21 1996-04-12 Toshiba Corp Optical information recording medium
EP0706178A2 (en) * 1994-10-03 1996-04-10 Matsushita Electric Industrial Co., Ltd. Optical information medium, method for producing the optical information medium, and unit for producing the optical information medium
EP0720159A2 (en) * 1994-12-28 1996-07-03 Matsushita Electric Industrial Co., Ltd. Optical recording medium having dual information surfaces
EP0725396A2 (en) * 1995-01-31 1996-08-07 Kabushiki Kaisha Toshiba Optical disk and optical disk apparatus
EP0729142A1 (en) * 1995-02-27 1996-08-28 Sony Corporation Optical recording medium and method of manufacturing same
EP0735530A1 (en) * 1995-03-31 1996-10-02 Toshiba-Emi Limited Method and apparatus for manufacturing bonded disks
WO1996031875A2 (en) * 1995-04-07 1996-10-10 Matsushita Electric Industrial Co., Ltd. Optical information recording medium, manufacturing method therefor, manufacturing apparatus therefor, and optical information recording and reproducing apparatus
JP4028031B2 (en) 1996-08-15 2007-12-26 ゼロックス コーポレイションXerox Corporation The method for maintaining the topology of the curve transformation method and node-link diagram of the link arbitrary shape
JP4341943B2 (en) 2000-06-28 2009-10-14 大日本印刷株式会社 Slip spelling with media
JP4344344B2 (en) 2005-06-22 2009-10-14 テクファーマ・ライセンシング・アクチェンゲゼルシャフト Dispensing device
JP5182241B2 (en) 2009-07-15 2013-04-17 トヨタ自動車株式会社 Mounting method and automotive electrical equipment of the cooling unit of the cooling unit of the electric equipment for vehicles
JP6039962B2 (en) 2012-08-01 2016-12-07 日本板硝子株式会社 Cover glass for a photoelectric conversion device

Non-Patent Citations (10)

* Cited by examiner, † Cited by third party
Title
"Design and Manufacture of Loudspeakers," translated by Chi-Hsueh Publisher, 1979, pp. 213-216.
D. J. Perettie et al., "The Alternate Alternative Substrate--"Chemically Strengthened" Aluminum," Diskon Conference, Sep. 1995.
D. J. Perettie et al., The Alternate Alternative Substrate Chemically Strengthened Aluminum, Diskon Conference, Sep. 1995. *
Design and Manufacture of Loudspeakers, translated by Chi Hsueh Publisher, 1979, pp. 213 216. *
Jeff McAllister, "Disk flutter: Causes and potential cures," Data Storage, May/Jun. 1997, pp. 29-34.
Jeff McAllister, Disk flutter: Causes and potential cures, Data Storage , May/Jun. 1997, pp. 29 34. *
Masao Nakamura, "Two-Sided Tape Used To Glue DVDs Together," Denshi Zairyo, (Electronic Materials-Japanese), Special Edition, Jun. 1996, pp. 46-49 (translation attached).
Masao Nakamura, Two Sided Tape Used To Glue DVDs Together, Denshi Zairyo , (Electronic Materials Japanese), Special Edition, Jun. 1996, pp. 46 49 (translation attached). *
Trade Magazine, "Tape-Disc Business," 10, (1996), #9, p. 13.
Trade Magazine, Tape Disc Business, 10, (1996), 9, p. 13. *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6764734B2 (en) * 1998-05-19 2004-07-20 Seagate Technology Llc High modulus and high damping plastic composite disc substrate for improved servo control by injection and co-injection molding
US6715200B2 (en) 1999-02-12 2004-04-06 General Electric Company Methods for making data storage media
US6752952B2 (en) 1999-02-12 2004-06-22 General Electric Company Embossing methods
US6697213B2 (en) 2000-03-31 2004-02-24 Seagate Technology Llc Cover including multiple cover plates with damped layers
US6688439B2 (en) * 2000-08-16 2004-02-10 Rolls-Royce Plc Vibration damping system and a method of damping vibrations
US7147906B2 (en) * 2003-06-24 2006-12-12 General Electric Company Data storage medium comprising polyimides

Also Published As

Publication number Publication date Type
US5538774A (en) 1996-07-23 grant
JPH10503612A (en) 1998-03-31 application
JP2001155382A (en) 2001-06-08 application
EP0772874A1 (en) 1997-05-14 application
WO1996004651A1 (en) 1996-02-15 application
EP1043719A3 (en) 2000-11-22 application
EP1043719A2 (en) 2000-10-11 application
CA2194274A1 (en) 1996-02-15 application

Similar Documents

Publication Publication Date Title
US5936803A (en) Disk drive having a mass balanced head gimbal assembly
US3832815A (en) Modular insulation of fibrous material
Nashif et al. Vibration damping
Batra et al. Natural frequencies of a functionally graded anisotropic rectangular plate
US5186996A (en) Sound damping multi-layer structure
US7555182B2 (en) Multi-layered water blocking cable armor laminate containing water swelling fabrics and associated methods of manufacture
US5187625A (en) Laminated load beam
US4190131A (en) Noise abatement techniques and systems
US5690035A (en) Vibration-damping material, its manufacturing method, and structural section for transport vehicle
US4223073A (en) High-temperature damping composite
US5858509A (en) Attenuating vibrations in a mounting shelf for multiple disk drives
US5407034A (en) Noise damped brake pad assembly
US6549376B1 (en) Gimbal suspension with vibration damper
US5063098A (en) Vibration damping materials and soundproofing structures using such damping materials
US4857388A (en) Magnetic recording medium
US5590524A (en) Damped heat shield
US6316083B1 (en) Wet type friction material
US6498719B1 (en) Apparatus and method for reducing impact-induced shock and vibration in a portable computer
US20040168853A1 (en) Acoustic tile and its use in vehicle sound proofing
US5240221A (en) Viscoelastic damping system
US5895013A (en) Low frequency noise suppression system
US6790520B1 (en) Vibration dampening laminate
US20090003781A1 (en) Optical Fiber Cable Having A Deformable Coupling Element
US4278726A (en) Energy absorbing elements comprising rigid non-elastomeric layer and visco-elastic layer with twisted fiber bundles embedded therein
US5796553A (en) Disk drive head suspension having gaps in the load beam which are at least partially filled with or covered by damping material

Legal Events

Date Code Title Description
FPAY Fee payment

Year of fee payment: 8

REMI Maintenance fee reminder mailed
LAPS Lapse for failure to pay maintenance fees