The present invention relates to a vibration damped laminate article having improved force (torque and/or pressure and/or stress) retention, a method of making one article type and novel tools used to make the one article type. The first laminate comprises at least one layer of damping material (88) between at least two substrate layers (86, 90). At least one deformation area (84) is present in the laminate wherein the substrate(s) are plastically deformed such that they are closer than non-deformed areas of the substrate and wherein the damping material has less mass than in a non-deformed area of the article; the deformation areas providing the areas of good force retention, for an attachment device (82) attached thereto. The second laminate, which is not deformed, contains an additive of sufficient modulus, diameter and loading, in a vibration damping layer to provide improved force retention.

Damped laminates with improved fastener force retention, a method of making, and novel tools useful in making

A vibration attenuating device (5, 20, 20', 42, 70, 110) for loudspeaker enclosures (41, 90, 96, 97) and other mechanical vibrating bodies (51, 61, 80) includes one or more damping plates 1(a, b), 4(a, b), 5a, 7(a, b, c, d), 9(a, b, c, d, e), 20(a, b, c, d), 70(a, b, c, d, e), 110(a, b, c, d, e) of viscoelastic material positioned to receive vibration energy transferred from the vibrating body. The vibration energy is transferred away from the speaker enclosure (41, 90, 96, 97) or other body (51, 61, 80) and is dissipated as heat due to the internal molecular structure of the viscoelastic material, suppressing noise normally produced by the vibrating body. In various different embodiments, the vibration damping device includes damping plates shaped or mounted in such a way as to provide for attenuation of a wide band of frequencies of vibration. The damping plates themselves may each have a configuration providing for continuously varying frequency response along the length or circumference of the plate, and may be included a plurality of different-sized plates, each responding essentially to a different frequency band.

Vibration damping device

An adjustable length golf club shaft having a grip portion with an end point is disclosed. A locking element is located within the grip portion and a lower shaft having an inner surface that is in frictional contact with the locking element is also disclosed. The locking element is configured to engage the inner surface of the lower shaft. A total length of the golf club shaft is adjustable by a distance of at least one inch and a total weight of the golf club shaft in a weight zone is less than 110 g. The weight zone is defined as a region of the golf club shaft extending from the end point of the grip portion up to 11″ along a central axis of the golf club shaft toward a tip portion of the shaft.

Golf club shaft

An acoustic attenuator includes a housing having an inner side surface which defines an interior chamber and at least one dampening member both physically and acoustically coupled to the housing and projecting into the interior chamber. Acoustic energy propagating within the housing is deflected into the dampening members for acoustically dispersal within the interior chamber. In various aspects thereof, the dampening members may include one or a group of two or more generally cylindrical sleeves having one end both physically and acoustically coupled to the housing and a second end projecting into the interior chamber. Preferably, when a group of two or more cylindrical sleeves are employed, the sleeves are nested within one another. The dampening members may further include a second, oppositely disposed, group of two or more acoustic attenuators nested within one another and interdigitated with the first group of cylindrical sleeves.

Low frequency acoustic attenuator for use in downhole applications

A vibration isolation platform utilizes a plurality of viscoelastic polymer blocks sandwiched between rigid plinths or boards and stacked on top of one another to provide vibration damping additively per layer of the sandwich. Smaller viscoelastic blocks are positioned between the edges of the plinths and the sidewalls of a framework in which the sandwich is mounted to compensate for lack of shear stress in the larger blocks. The platform is pre-loaded to optimum isolation and locked down at the required compression. Optimum isolation is achieved for any electronic component positioned on the platform up to the design weight limit.

Vibration isolation damper for electronic equipment

A vibration damping assembly incorporating an attenuating body (A) formed from viscoelastic material is disclosed. The body (A) may, in a preferred embodiment, be made up of a plurality of plates (1) stacked together and separated with spacers (2). The viscoelastic material is preferably high impact polystyrene. The damping system is advantageously mounted on an enclosure panel of a loudspeaker (8) to attenuate the vibrations of the panel, thereby minimizing audio signals which usually emanate therefrom and interfere with the desired speaker output.

Viscoelastic damping system

A selectively tuned vibration absorber comprising a stack of viscoelastic polymer damping plates, secured together with spacers at both ends and having metal tuning weights attached onto the topmost plate in the stack. The apparatus is secured to the low frequency drive unit of an in-wall loudspeaker with a metal mounting plate between the vibration absorber and the low frequency drive unit. Both ends of the vibration absorber are cantilevered over a tuning mounting plate centered between the ends of the unit, the degree of cantilever and the mass in the metal weights added to the topmost damping plate being variable such that the vibration absorber may be tuned to resonate at the fundamental resonance frequency of the low frequency drive unit.

Leonard N. Thomasen

Papers

Viscoelastic damping system

Selectively tuned vibration absorber