The present invention relates to a triboelectric transducer cable for generating an electrical signal in response to movement or deformation of the cable and, more specifically, to such a triboelectric transducer cable including a novel combination of components for substantially enhancing the ability of the cable to generate a signal in response to movement or deformation.
The basic triboelectric effect contemplated by the present invention is well known in the prior art. For example, the construction and use of a specially configured cable for generating a signal in response to movement or deformation of the cable is described in U.S. Pat. No. 2,787,784 issued Apr. 2, 1957. As is demonstrated by that patent, for example, the triboelectric effect referred to herein comprises the construction of an electrical cable with "noisy" characteristics. Normally, in the construction of electrical cable, it is desirable to avoid such noisy characteristics because of the interference with a signal being carried along the cable. However, in a triboelectric transducer cable, this same characteristic is desirable for initiating or generating a signal in response to movement or deformation of the cable. Thus, the cable may be used for detection systems where activity adjacent the cable tends to result in movement or deformation of the cable to initiate an electrical signal. Thus, such cable may be used for example in security and surveillance systems.
The triboelectric effect known in the prior art is achieved by constructing a cable having two or more conductor members with a dielectric or insulating material arranged between and generally closely adjacent one or both of the conductor members. The insulating material is commonly a flexible, deformable material formed as a conduit loosely surrounding one or both of the conductor members so that relative movement between the conductor member and dielectric or insulator member tends to initiate an electrical signal because of the triboelectric effect. Such a triboelectric cable may also be formed with a shield member in order to minimize the effect of stray electrical fields surrounding the cable. In addition, the cable may commonly be provided with a protective cover or seal as is conventional for many conducting electrical cables.
In the prior art, however, substantial movement or deformation of the cable has been required in order to generate a suitable signal. At the same time, because of the substantial movement or deformation required, it has generally been necessary to provide insulators which have relatively high resilience so that they may recover and maintain their ability to provide the triboelectric effect.
Accordingly, there has been found to remain a need for a triboelectric transducer cable capable of generating a signal in response to relatively limited movement or deformation of the cable.