(A) Field of the Invention
The present invention is related to an assembly of a clamping mechanism and an LNB and a dish antenna using the same, and more specifically, to a fastening apparatus for the tuning of the dish antenna angle.
(B) Description of Related Art
A satellite television system employs a dish antenna to collect satellite signals, and the signals are then reflected to low noise block down converters (LNB) positioned at the focus of the dish antenna for amplifying the signals and reducing their frequencies down to around 1 GHz, i.e., to an intermediate frequency. The adjusted signals are transmitted via a cable to an indoor television channel selector for selecting the signals of a desired channel, and the selected signals are then amplified, modulated and converted into video and audio signals for television viewing.
A dish antenna is a highly directional receiving device, which has to be precisely directed toward satellites in orbit at 36,000 kilometers altitude. For example, if a dish antenna with a 180 cm diameter shifts 2 cm horizontally, or 3 cm vertically, the signals will become weak or even disappear. In addition, if a dish antenna uses the Ka band, i.e., 26 to 40 GHz, an adjustment accuracy of 0.1 degrees is needed, and the tolerance has to be within 0.02 degrees for aiming at satellites precisely.
Normally, a dish antenna using the Ka band is adjusted by using a programmable logic controller (PLC) in control of servo motors; however, the high cost significantly limits its popularity.
The present invention provides an assembly of a clamping mechanism and an LNB and a dish antenna using the same. After the clamping mechanism and the LNB are combined, the angle of the LNB can be fine-tuned relative to the clamping mechanism while the clamping mechanism still holds the LNB. The fine angle adjustment is conducted while the LNB is fastened, and the clamping mechanism does not need to be unfastened. Consequently, the optimal receiving position is easily located, and the position is not by a screwing or fastening movement.
In accordance with an embodiment of the present invention, an assembly of a clamping mechanism and an LNB comprises a clamping mechanism and an LNB (low noise block down converter). The clamping mechanism includes a first clamping part, a second clamping part, and a plurality of rectangular grooves. The LNB includes a shell, at least one flexible portion, and at least one rib portion. The first clamping part and the second clamping part clasp around the LNB, and are combined with each other by at least one fastening part. The at least one flexible portion is disposed on the shell of the LNB, and the rib portion is on the flexible portion. The plurality of rectangular grooves are closely arranged in parallel on the inner surface of the second clamping, and the rib portion is contained in one of the rectangular grooves. By rotating the combination of the first clamping part and the second clamping part, the rib portion is forced to move between the rectangular grooves and then is positioned again. During the movement, the flexible portion is temporarily deformed.
In accordance with an embodiment of the present invention, a dish antenna comprises a dish, an LNB, a clamping mechanism, an angle adjustment apparatus, and an adjustable stand. The dish is mounted on the angle adjustment apparatus, and the angle adjustment apparatus is connected to the adjustable stand. The clamping mechanism is fixed on the dish, and includes a first clamping part, a second clamping part, and a plurality of rectangular grooves. The LNB includes a shell, at least one flexible portion, and at least one rib portion. The first clamping part and the second clamping part clasp around the LNB, and are combined with each other by at least one fastening part. The at least one flexible portion is disposed on the shell of the LNB, and the rib portion is on the flexible portion. The plurality of rectangular grooves are closely arranged in parallel on the inner surface of the second clamping part, and the rib portion is contained in one of the rectangular grooves. By rotating the combination of the first clamping part and the second clamping part, the rib portion is forced to move between the rectangular grooves and then is positioned again. During the movement, the flexible portion is temporarily deformed.
As shown in
By rotating the combination of the first clamping part 22 and the second clamping part 23, the rib portion 2141 is forced to move between the rectangular grooves 233 and then is positioned again. During the movement, the flexible portion 212 is temporarily deformed. The flexible portion 212 is a cantilever defined by a C-shaped slit 213 on the shell 211. When the combination of the first clamping part 22 and the second clamping part 23 is rotated, the rib portion 214 staying in one of the rectangular grooves 233 will mount a high partition between the rectangular grooves 233, and then will fall into the next one of the rectangular grooves 233. Accordingly, the flexible portion 212 can absorb force applied to the rib portion 214 by the second clamping part 23. Because the shell 221 is partially pushed down, the rib portion 214 on it can successfully pass through the high partition between two rectangular grooves 233.
When the combination of the first clamping part 22 and the second clamping part 23 is rotated, the finger 261 on the first clamping 22 or the second clamping 23 can be aligned with one of the angle indexes 262 on the shell 211 so the angle adjustment is easy and definite. To further stabilize and limit the rotation movement, an external guiding groove 272 is provided on the shell 211. An external guiding rail 271 disposed on the first clamping part 22 can engage with the external guiding groove 272 so the external guiding rail 271 slides in the external guiding groove 272 and is constrained by the inner walls of the external guiding groove 272.
The above-described embodiments of the present invention are intended to be illustrative only. Numerous alternative embodiments may be devised by those skilled in the art without departing from the scope of the following claims.
Number | Date | Country | Kind |
---|---|---|---|
098132414 | Sep 2009 | TW | national |