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  Method and apparatus for destructible trap/filterUSPTO Application #: 20060077019Title: Method and apparatus for destructible trap/filter Abstract: An electrical filter disconnects a connecting pin when uninstalled. A first filter section includes a first set of electrical filter components, while a second filter section includes a second set of electrical filter components, with the connecting pin connecting the two filter sections. An electrical isolation shield disposed between the first and second filter sections includes a first plate and a second plate which are rotatable with respect to each other, wherein the first plate includes a first cutout portion and the second plate includes a second cutout portion. The first plate is locked to the first filter section while the second plate is locked to the second filter section. When the electrical filter is unscrewed from the port, the first filter section rotates with respect to the second filter section such that the connecting pin breaks electrical connection between the first filter section and the second filter section. (end of abstract) Agent: Pastel Law Firm Christopher R. Pastel - Ithaca, NY, US Inventors: Ray Palinkas, Noah Montena USPTO Applicaton #: 20060077019 - Class: 333185000 (USPTO) The Patent Description & Claims data below is from USPTO Patent Application 20060077019. Brief Patent Description - Full Patent Description - Patent Application Claims
FIELD OF THE INVENTION [0001] This invention relates generally to the field of tunable electrical filters, and more particularly to a tunable electrical filter with a destruction feature that destroys a critical component of the filter when the filter is removed after installation. BACKGROUND OF THE INVENTION [0002] The cable TV (CATV) industry uses traps and filters installed at a subscriber drop to decode or recover a scrambled pay channel. A problem occurs when these filters and traps are stolen and later sold to persons trying to circumvent having to pay for services. [0003] Conventional tunable filters or cable traps of the kind described are typically referred to as "tuned notch filters" which are used for removing frequency scrambling signals provided within, for example, a TV channel band to eliminate reception of that channel. This is referred to as positive trapping in the art. These filters may also be used for negative trapping, which involves removing specific frequencies within the TV channel band, such as the video carrier, in order to prevent reception of the channel information. [0004] Such tunable notch filters should be capable of approximately 80 dB of attenuation at the center frequency of the notch, and in all cases should be capable of 60 dB at the scramble signal frequency, the notch being sufficiently narrow to prevent serious degradation of the video information. In order to achieve such levels of notch attenuation, conventional filters are designed with one or more filter sections which are employed in cascade to achieve the high attenuation required. One such example of a conventional tunable filter with multiple sections is described in U.S. Pat. No. 5,278,525 issued to Palinkas, incorporated herein by reference. [0005] What is needed is a filter that can be installed without a special tool but which breaks the connection between multiple sections when removed, thus rendering the filter useless for unauthorized reinstallation. SUMMARY OF THE INVENTION [0006] Briefly stated, an electrical filter disconnects a connecting pin when uninstalled. A first filter section includes a first set of electrical filter components, while a second filter section includes a second set of electrical filter components, with the connecting pin connecting the two filter sections. An electrical isolation shield disposed between the first and second filter sections includes a first plate and a second plate which are rotatable with respect to each other, wherein the first plate includes a first cutout portion and the second plate includes a second cutout portion. The first plate is locked to the first filter section while the second plate is locked to the second filter section. When the electrical filter is unscrewed from the port, the first filter section rotates with respect to the second filter section such that the connecting pin breaks electrical connection between the first filter section and the second filter section. [0007] According to an embodiment of the invention, an electrical filter includes a housing; a first filter section having a first filter circuit, wherein the first filter section is located within and rotatable with respect to the housing; a second filter section having a second filter circuit, wherein the second filter section is located within and locked to the housing; an electrical connector forming an electrical connection between the first filter circuit and the second filter circuit; wherein the first filter section and the second filter section are in a locked position upon rotating the electrical filter in a first direction into a connecting device, and upon rotating the electrical filter in a second direction from the connecting device, the second filter section rotates with respect to the first filter section, thereby causing the electrical connector to break the electrical connection between the first filter section and the second filter section. [0008] According to an embodiment of the invention, a method for disconnecting a connecting pin in an electrical filter, the filter including a first filter section having a first set of electrical filter components, with the first set of electrical filter components including a plurality of first primary tunable coils arranged parallel to each other, and a second filter section having a second set of electrical filter components, with the second set of electrical filter components including a plurality of second primary tunable coils arranged parallel to each other, includes the steps of (a) providing an electrical isolation shield disposed between the first and second filter sections for electrically isolating the first and second filter sections from one another, wherein the electrical isolation shield includes a first plate and a second plate which are rotatable with respect to each other, wherein the first plate includes a first cutout portion and the second plate includes a second cutout portion; (b) locking the first plate to the first filter section; (c) locking the second plate to the second filter section; and (d) disposing the first and second plates such that when the electrical filter is screwed into a connecting device, the first filter section is limited in its rotation with respect to the second filter section such that an opening formed by the first and second cutout portions permits the connecting pin to electrically connect the first filter section with the second filter section, and when the electrical filter is unscrewed from the connecting device, the first filter section rotates with respect to the second filter section such that the connecting pin breaks electrical connection between the first filter section and the second filter section. [0009] According to an embodiment of the invention, a method of breaking an electrical connection between first and second filter sections of an electrical filter contained within a housing, wherein the first filter section includes a first filter circuit and the second filter section includes a second filter circuit, includes the steps of (a) making the first filter section rotatable with respect to the housing; (b) locking the second filter section to the housing; and (c) electrically connecting the first filter circuit to the second filter circuit, such that upon rotating the electrical filter in a first direction into a connecting device, the first and second filter sections are in a locked position, and upon rotating the electrical filter in a second direction from the connecting device, the second filter section rotates with respect to the first filter section, thereby breaking the electrical connection. BRIEF DESCRIPTION OF THE DRAWINGS [0010] FIG. 1 shows a filter trap assembly according to the prior art. [0011] FIG. 2 shows a sectional view of a portion of the filter trap assembly of FIG. 1. [0012] FIG. 3A shows the major components of the filter trap assembly of FIG. 1. [0013] FIG. 3B shows the filter trap assembly of FIG. 1 in its assembled state. [0014] FIG. 4 shows an isolation shield according to an embodiment of the invention. [0015] FIG. 5 shows a front perspective view of two isolation plates that together make up the isolation shield of FIG. 4. [0016] FIG. 6 shows a rear perspective view of the two isolation plates of FIG. 5. [0017] FIG. 7 shows an embodiment of a key used with the isolation plates of FIG. 5. [0018] FIG. 8 shows a sectional view of an embodiment of one of the isolation plates of FIG. 5 with a keyway that cooperatively acts with the key of FIG. 7. [0019] FIG. 9 shows a front perspective view of an embodiment of two isolation plates that together comprise an isolation shield. [0020] FIG. 10 shows a front perspective view of the assembled isolation shield composed of the isolation plates of FIG. 9. Continue reading... Full patent description for Method and apparatus for destructible trap/filter Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Method and apparatus for destructible trap/filter patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. 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