FIELD OF INVENTION The invention relates to a vibration damping apparatus. More particularly, the invention relates to an apparatus for dissipating mechanical energy of a frame structure such as a steel tower, a tall building, a horizontal panel, and floor.

BACKGROUND OF THE INVENTION

There are a few patented technologies over the prior art relating to the vibration- damping system. Of interest in respect to a vibration-damping floor device is US4805359A. The patent discloses a floor vibration-damping device comprising a movable support portion for supporting respective support points of a floor structure and a spring damper portion disposed between said floor structure and a fixed floor, said movable support portion comprising a lower ball receiving steel plate disposed on said fixed portion, a bearing ball disposed on said lower steel plate and an upper ball receiving steel plate secured to said floor structure and placed on said bearing ball, said spring damper portion comprising a damper main body of a shallow and flat vessel shape mounted on and secured to said fixed floor a viscous fluid contained by a predetermined amount in said damper main body, a movable member attached to said floor structure, immersed in said viscous fluid and ensuring a predetermined gap between a lower surface of said movable member and a bottom of said damper main body, a coil spring secured to said fixed floor at one end thereof, a rope-like member not transmitting a compressive force and being connected to the other end of said coil spring at one end thereof and connected to said movable member at the other end thereof, and a reaction force receiving roller attached to said rope-like member and abutted against an inner surface of said damper main body. Another vibration damping apparatus is disclosed in US4480731A. The patent provides a vibration damping apparatus comprising two rotatable members disposed opposite to each other while defining a gap therebetween so as to be rotatable relative to each other around substantially a single axis of rotation, a resistive body disposed in the gap between said rotatable members, and four pairs of link bars, each link in each pair of link bars being pivoted to each other at one end thereof by a pin and coupled to said rotatable members in such a relation that the end of one of said link bars in each pair and the end of the adjoining one of said link bars in the next adjacent pair are coupled by pin means to the associated one of said rotatable members.

Although visco-elastic or frictional dampers are proven to be effective in suppressing structural motions, the overall lateral stiffness of the structure under dynamic loads is reduced. Therefore, a need exist for the prior apparatus to replace visco-elastic or frictional material with natural rubber for a better damping efficiency and improvement in lateral stiffness. This invention provides such an apparatus.

SUMMARY OF INVENTION The invention provides a damper device for stabilising a generally rectangular frame structure comprises first and second rigid plates with an elastic member sandwiched therebetween, each plate having at least two connection lugs spaced around its periphery for attachment of cables extending from the corners of the frame structure. Preferably, the rigid plates are of a circular shape and made of metal material. Each rigid plate has four connection lugs equally spaced around its circumference. Furthermore, the elastic member is made of rubber material.

At least one of the preceding objects is met, in whole or in part, by the present invention, in which the embodiment of the present invention describes a system for stabilising a generally rectangular frame structure incorporating the described damper device, comprises a pair of cables extended from each corner of the frame structure, one being attached to a connection lug of the first rigid plate and the other being attached to a connection lug of the second rigid plate such that the first and second plates rotate in opposite directions when the frame structure is under a lateral movement. Advantageously, the lugs to which each pair of cables are attached are offset.

One skilled in the art will readily appreciate that the invention is well adapted to carry out the objects and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments described herein are not intended as limitations on the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of facilitating an understanding of the invention, there is illustrated in the accompanying drawing the preferred embodiments from an inspection of which when considered in connection with the following description, the invention, its construction and operation and many of its advantages would be readily understood and appreciated.

Figure 1 is a schematic diagram illustrating a damping apparatus which embodies therein the principle features of the invention.

Figure 2 shows an exploded view of the damping apparatus.

Figure 3 is a schematic diagram illustrating a frame structure with the damping apparatus attached. DETAILED DESCRIPTION OF THE INVENTION The invention will now be described in greater detail, by way of example, with reference to the drawings.

Referring to figure 1 and figure 2, an overall view of a damper (1) illustrated therein comprises first (2) and second (3) circular metal plates with a rubber shim (6) sandwiched therebetween, each plate having four lugs (4) equally spaced around its periphery for attachment, and each lug (4) has a bore (5) for receiving cable (8) extending from the corners of the frame structure (7). The damper (1) may further include a bore at a generally centre position. Referring to figure 3, the damper (1) is preferably fastened at a centre position of a frame structure (7) by a pair of cables (8) extending from its corners. One of the pair of cables (8) is being attached to a lug (4) of the first circular metal plate (2), the other is being attached to a lug (4) of the second circular metal plate (3), and the lugs (4) to which each pair of cables (8) are attached are also offset so that the first (2) and second (3) plates rotate in opposite directions when the frame structure (7) is under a lateral movement. The movements of the first (2) and second (3) plates will twist or deform the rubber member of the damper (1) and the rubber member with the elastic properties will return to their original shape after being deformed. The present disclosure includes as contained in the appended claims, as well as that of the foregoing description. Although this invention has been described in its preferred form with a degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangements of parts may be resorted to without departing from the scope of the invention.