Abstract: A horizontal-motion vibration isolator utilizes a plurality of bent flexures to support an object to be isolated from horizontal motion. Each bent flexure includes a fixed end coupled to a base and a floating end which is cantilevered and coupled to the object being isolated. The arrangement of bent flexures allows the vertical height of the isolator to be reduced without compromising vibration isolation performance. Compressed springs or spring-like elements can be added to bear some of the weight of the object being isolated thus increasing the payload capacity of the isolator.

Abstract: A horizontal-motion vibration isolator utilizes a plurality of bent flexures to support an object to be isolated from horizontal motion. Each bent flexure includes a fixed end coupled to a base and a floating end which is cantilevered and coupled to the object being isolated. The arrangement of bent flexures allows the vertical height of the isolator to be reduced without compromising vibration isolation performance. Compressed springs or spring-like elements can be added to bear some of the weight of the object being isolated thus increasing the payload capacity of the isolator.

Abstract: A horizontal-motion vibration isolator utilizes a plurality of bent flexures to support an object to be isolated from horizontal motion. Each bent flexure includes a fixed end coupled to a base and a floating end which is cantilevered and coupled to the object being isolated. The arrangement of bent flexures allows the vertical height of the isolator to be reduced without compromising vibration isolation performance. Compressed springs or spring-like elements can be added to bear some of the weight of the object being isolated thus increasing the payload capacity of the isolator.

Abstract: Negative-stiffness-producing mechanisms can be incorporated with structural devices that are used on spacecraft that provide thermal coupling between a vibrating source and a vibration-sensitive object. Negative-stiffness-producing mechanisms can be associated with a flexible conductive link (FCL) or “thermal strap” or “cold strap” to reduce the positive stiffness of the FCL. The negative-stiffness-producing mechanism can be loaded so as to create negative stiffness that will reduce or negate the natural positive stiffness inherent with the FCL. The FCL will still be able to provide maximum thermal conductance while achieving low or near-zero stiffness to maximize structural decoupling.

Abstract: A vertical-motion vibration isolator utilizes negative-stiffness-producing mechanism which includes a plurality of compressed flexures, each having a particular length in the compressed direction of the flexure and being oriented in a horizontal direction, wherein the plurality of compressed flexures are positioned relative to each other such that the length of each compressed flexure substantially overlaps the length of each of the other compressed flexures. At least some of the plurality of compressed flexures can be positioned in a stacked arrangement. The arrangement of compressed flexures forming a portion of the negative-stiffness mechanism can reduce the size of the isolator without compromising vibration isolation performance.

Abstract: A vertical-motion vibration isolator utilizes negative-stiffness-producing mechanism which includes a plurality of compressed flexures, each having a particular length in the compressed direction of the flexure and being oriented in a horizontal direction, wherein the plurality of compressed flexures are positioned relative to each other such that the length of each compressed flexure substantially overlaps the length of each of the other compressed flexures. At least some of the plurality of compressed flexures can be positioned in a stacked arrangement. The arrangement of compressed flexures forming a portion of the negative-stiffness mechanism can reduce the size of the isolator without compromising vibration isolation performance.

Abstract: Negative-stiffness-producing mechanisms can be incorporated with structural devices that are used on spacecraft that provide thermal coupling between a vibrating source and a vibration-sensitive object. Negative-stiffness-producing mechanisms can be associated with a flexible conductive link (FCL) or “thermal strap” or “cold strap” to reduce the positive stiffness of the FCL. The negative-stiffness-producing mechanisms can be loaded so as to create negative stiffness that will reduce or negate the natural positive stiffness inherent with the FCL. The FCL will still be able to provide maximum thermal conductance while achieving low or near-zero stiffness to maximize structural decoupling.

Abstract: A composite vibration isolation system utilizes isolators with negative-stiffness mechanisms to produce low vertical and horizontal natural frequencies to the system by allowing both the horizontal stiffness and horizontal natural frequencies to be adjusted, for example, by turning adjustment screws.

Abstract: Negative-stiffness-producing mechanisms can be incorporated with structural devices that are used on spacecraft that provide thermal coupling between a vibrating source and a vibration-sensitive object. Negative-stiffness-producing mechanisms can be associated with a flexible conductive link (FCL) or “thermal strap” or “cold strap” to reduce the positive stiffness of the FCL. The negative-stiffness-producing mechanism can be loaded so as to create negative stiffness that will reduce or negate the natural positive stiffness inherent with the FCL. The FCL will still be able to provide maximum thermal conductance while achieving low or near-zero stiffness to maximize structural decoupling.

Abstract: A passive thermally responsive element (TRE) is used to eliminate or substantially reduce the sensitivity of the axial (vertical) position and axial (vertical) natural frequency of a negative-stiffness vibration isolator to changes in temperature. The TRE will compensate for the inherent thermal sensitivity of the isolator without this added element. The TRE can be a thermally responsive spring that produces forces in response to temperature changes to keep the isolator at or near its ideal equilibrium operating position in order to control the equilibrium position and also to maintain the low natural frequency characteristic of the negative-stiffness vibration isolator.

Abstract: A horizontal-motion vibration isolation system for supporting an object in an equilibrium position relative to a base while suppressing the transmission of horizontal vibratory motion between the object and the base includes a plurality of columns, each column having a rigid member with a first end and a second end. A tilt mechanism is operatively connected to each first end of the rigid members and the object. Likewise, a tilt mechanism is operatively connected to each second end of the rigid members and the base. Each tilt mechanism exhibits a tilt rotational stiffness and the horizontal translation of the object relative to the base causes tilt rotation of the columns. The tilt rotational stiffness of the tilt mechanisms is approximately proportional to the compression load transmitted to the columns by the weight of the object, so that the horizontal natural frequency of the system is nearly insensitive to the payload weight.

Abstract: The present invention provides improvements in the design of radial flexures and beam-columns used in vibration isolation systems which rely on a principle of loading a particular elastic structure which forms the isolator or a portion of it to approach the elastic structure's point of elastic instability. The improved radial flexure includes a region along the flexure in which there is reduced stiffness than the stiffness substantially along the length of the flexure. In one preferred form of the invention, the region of reduced stiffness is created by machining or forming a notch near each end of the flexure. Likewise, the improved design of the beam-column includes a region in which the stiffness of the beam-column in less than the stiffness along substantially the length of the beam-column. In one preferred embodiment, the region of reduced stiffness of the beam-column is formed by machining or otherwise forming notches near the ends of the beam-column.

Abstract: An auto-adjust apparatus adjusts a vibration isolator to help accommodate varying weight loads and other effects which can cause the isolator to go out of adjustment, such as variations caused by changes in ambient temperature and creep of the isolator's main support spring. A small secondary spring is positioned in parallel with the main support spring of the isolator and is precompressed such that its compression increases the load on the main support spring by a small amount. An increase in the compression of this secondary spring will cause an increase in the load on the main support spring. Similarly, a decrease in the compression on this secondary spring will cause a decrease in the load on the main support spring. Sensors for sensing a deviation in the equilibrium position of the object relative to the base from its optimum equilibrium position are provided and generate an electrical signal indicating such deviations.

Abstract: An improved version of vibration isolation systems using negative stiffness incorporates a payload and payload platform on just one 6-DOF isolator in a unique and innovatively compact configuration. The isolator includes a platform supported on an assembly of independently acting flexure mechanisms which are connected in serial fashion, tilt on top of horizontal on top of vertical, and in turn connected a base. Proper arrangement of the mechanisms and the payload/platform center of mass provides highly effective decoupled isolator performance. In addition, an innovative flexure preloading method which significantly improves vertical isolation performance is incorporated. This method can be used with prior (unsymmetric) designs or combined with a set of shear flexures in an innovative symmetric arrangement described below to provide more assurance of ideal decoupled response to mutually perpendicular base excitation input.

Abstract: An improved omnidirectional vibration isolating suspension apparatus for supporting an object in an equilibrium position relative to a base while suppressing transmission of vibratory motion between the object and the base, in which an isolator internal structure resonant frequencies can be significantly increased while the isolator provides low vertical and horizontal stiffness and low resonant frequencies.

Abstract: An improved vibration isolation system utilizes at least one pair of structures connected vertically in series with each other and with a base structure and preloaded vertically, with a payload platform disposed between and connected to the structures. Each structure has a negative-stiffness effect in response to vertical compressive load for reducing its horizontal stiffness. The system passively accommodates changes in payload weight or weight distribution by providing a prescribed change in horizontal-motion isolator stiffness with change in weight load. The invention also provides an improved means of retrofitting existing vibration-isolating suspension systems to reduce their stiffness and increase their damping.

Abstract: An improved vibration isolation system utilizes a damped elastic structure loaded to approach a point of elastic instability to reduce the stiffness of the structure and to increase the damping. The system provides very low amplification at system resonant frequencies and effectively isolates at higher frequencies.

Abstract: A vibration isolation system utilizes various configurations of elastic structures loaded to approach a point of elastic instability. In one form of the invention, the system uses a combination of a negative-stiffness mechanism and a positive spring to support a payload and provide low net stiffness in the vertical direction. Horizontal motion is generally isolated by utilizing one or more axially-symmetric columns loaded to approach their critical buckling loads to provide low stiffness in any horizontal direction.