Converter for receiving satellite broadcasting

Abstract: A converter for receiving satellite broadcasting includes a converter main body (11), a junction portion (16), provided to converter main body (11), to connect an interconnection member (14), and an extensible/retractable waterproof cover (13, 17, 23, 33) attached to junction portion (16). As waterproof cover (13, 17, 23, 33) is retracted, interconnection member (14) is connected to junction portion (16). After the attaching operation, waterproof cover (13, 17, 23, 33) is expanded for preventing water penetration.

Description: BACKGROUND OF THE INVENTION Field of the Invention The present invention relates generally to a converter for receiving satellite broadcasting, and more particularly, to a converter for receiving satellite broadcasting having a junction impervious to water. Description of the Background Art A converter for receiving satellite broadcasting attached to a parabolic antenna and provided outdoors has a junction portion for connecting a cable, and water penetrating through the junction could adversely affect the state of receiving broadcasting. Hence, a waterproof cap is fit on the junction having a connector connected thereto, or a tape is wound therearound to prevent water penetration. The manner to wind the tape is complicated, the operation efficiency is low, and if the adhesiveness of the tape deteriorates, the effect of preventing water could be spoiled. Thus, Japanese Patent Laying-Open No. 5 - 109449 discloses a converter having a water drip wall provided around the outer periphery of the fitting part of a waterproof cap, which provides improved attachability and waterproofness. Fig. 1 is an exploded perspective view of a conventional converter 51 for receiving satellite broadcasting. Converter 51 is secured to an attaching arm 56 connected to a parabolic antenna which is not shown. At the bottom of converter 51, a junction portion 52 connecting a high frequency circuit inside and a coaxial cable for external output are provided. Junction portion 52 includes a screw portion 54 provided at a base 53 for engaging a connector and a water drip wall 55 provided concentrically around base 53. A coaxial cable 58 having a connector 57 coupled at its tip end is inserted through a waterproof cap 59 formed by soft, composite resin, and connector 57 is engaged to screw portion 54. Then, junction portion 52 and connector 57 are covered with waterproof cap 59 by fitting the opening of waterproof cap 59 through base 53, such that rainwater may be prevented from penetrating. In general, as is often the case, an engineer selects such a waterproof cap depending upon the shape of a connector at the tip end of a cable, the kind of the cable or the manner to attach an antenna when the cable is attached. In order to secure a high waterproofing effect, a suitable waterproof cap should be selected. In other words, if a suitable waterproof cap is not selected, water could come into the junction. The converter for receiving satellite broadcasting described above has a waterproof cap inserted and secured to the cable. As a result, the waterproof cap could come off when the cable is pulled or moved after it is attached, which may allow water to come into the junction portion. US 3449706 discloses a bellows type protective enclosure for an electrical junction, wherein the enclosure is screw mounted to the junction box. SUMMARY OF THE INVENTION It is desirable to provide a converter for receiving satellite broadcasting without impairing the working efficiency when a cable is attached and without impairing the waterproofness if the cable is moved. According to the present invention, there is provided a converter as claimed in claim 1. Since the operator can attach a cable to a converter for receiving satellite broadcasting as the waterproof cover is retracted, the working efficiency is not lowered. Furthermore, since a waterproof cover is attached to the junction portion in an extended state, the movement of the cable does not adversely affect the waterproofness. In order that the present invention be more readily understood, specific embodiments thereof will now be described with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an exploded perspective view showing a conventional converter for receiving satellite broadcasting; Fig. 2A is a side view of a satellite broadcasting antenna having a converter for receiving satellite broadcasting according to an embodiment of the present invention; Fig. 2A is a side view of a satellite broadcasting antenna having a converter for receiving satellite broadcasting according to the present invention; Fig. 2B is a side view of another example of a conventional converter for receiving satellite broadcasting; Figs. 3A to 3D are schematic cross sectional views of the junction portion of a converter for receiving satellite broadcasting according to a first embodiment of the present invention; Fig. 4 is a view showing the external configuration of the junction portion of the converter for receiving satellite broadcasting according to the first embodiment; Figs. 5A and 5B are schematic cross sectional views of a waterproof cover for a converter for receiving satellite broadcasting according to a second embodiment of the invention; Fig. 5C is a view showing the external configuration of the waterproof cover for the converter for receiving satellite broadcasting according to the second embodiment; Figs. 6A to GD are schematic cross sectional views of a waterproof cover for a converter for receiving satellite broadcasting according to a third embodiment of the invention; Fig. 6E is a view showing the external configuration of the waterproof cover for the converter for receiving satellite broadcasting according to the third embodiment; Figs. 7A to 7D are schematic cross sectional views of a waterproof cover for a converter for receiving satellite broadcasting according to a fourth embodiment of the invention; Fig. 7E is a view showing the external configuration of the waterproof cover for the converter for receiving satellite broadcasting according to the fourth embodiment; Figs. 8A and 8B are schematic cross sectional views of the junction portion of a converter for receiving satellite broadcasting according to a fifth embodiment of the invention; Figs. 9A and 9B are schematic cross sectional views of the junction portion of a converter for receiving satellite broadcasting according to a sixth embodiment; Figs. 10A and 10B are schematic cross sectional views of the junction portion of a converter for receiving satellite broadcasting according to a seventh embodiment of the invention; and Figs. 11A and 11B are schematic cross sectional views of the junction portion of a converter for receiving satellite broadcasting according to an eighth embodiment of the invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to Fig. 2A, an antenna for receiving satellite broadcasting includes a converter 10 for receiving satellite broadcasting, an arm 25 to secure a cabinet 17 for converter 10, a parabolic antenna 26, and a support base 27 to secure arm 25 and parabolic antenna 26. Converter main body 11 is stored in cabinet 17 for converter 10 for receiving satellite broadcasting, and a primary horn 18 is attached to cabinet 17. Converter main body 11 is connected to a coaxial cable 14, an interconnection member at a junction portion 16. A waterproof cover 13 provided at junction portion 16 prevents water from coming into converter main body 11 through junction potion 16. Herein, the junction portion refers to a portion related to connecting the output connector of converter main body 11 and the output connector. Waterproof cover 13 is extensible/retractable and folded before coaxial cable 14 is attached. After coaxial cable 14 is attached to converter 10 for receiving satellite broadcasting, waterproof cover 13 extended to a prescribed length covers the connection of the connector and coaxial cable 14 to prevent water from coming into junction portion 16. Waterproof cover 13 is directed perpendicularly to the ground and prevents water from penetrating through junction portion 16. Thus extensible/retractable waterproof cover 13 may be attached to various kinds of converters for receiving satellite broadcasting, and the same waterproof cover may be used for different kinds of cables and in different manners to attach an antenna. Waterproof cover 13 may be formed by a soft, composite resin or rubber. These materials may contain a conductive material such as metal powder or a ferrite-based material to reduce electric wave leakage or unwanted radiation in the junction portion. Electric waves from a satellite are collected to primary horn 18 attached to converter 10 for receiving satellite broadcasting by parabolic antenna 26. Signals in the 12 GHz band is frequency-converted into signals in the 1 GHz band by converter 10 for receiving satellite broadcasting, and the resultant signals are sent to a BS tuner unit (not shown) by coaxial cable 14 connected through junction portion 16. Referring to Fig. 2B, coaxial cable 14 is connected through junction portion 16 at the backside of converter 10 for receiving satellite broadcasting. Extensible/retractable waterproof cover 13 is provided at junction portion 16, and waterproof cover 13 is attached in the direction close to the horizontal direction. Waterproof cover 13 covering junction portion 16 may prevent water penetration if junction portion 16 is directed close to the horizontal direction. Referring to Figs. 2A and 2B, since waterproof cover 13 is secured to converter 10 for receiving satellite broadcasting, waterproof cover 13 does not come off or slip off if the coaxial cable is for example pulled or moved by wind. Figs. 3A to 3D are schematic cross sectional views of a junction for a converter for receiving satellite broadcasting according to a first embodiment of the invention. Fig. 4 is a view showing the external configuration of the junction for the converter for receiving satellite broadcasting according to the first embodiment. In Fig. 3A, a female screw 11b to secure an output connector 12 and a recess 11c for fitting a waterproof cover 13 are formed in a chassis 11a, the outer frame of converter main body 11. A male screw 12a to engage female screw 11b in converter main body 11 is formed in output connector 12. Output connector 12 is provided with a circular brim portion 12b for securing waterproof cover 13 to chassis 11a and a hexagonal brim portion for engaging male screw 12a to female screw 11b. Output connector 12 is further provided with a male screw 12d for connecting a coaxial cable. As shown in Fig. 3B, male screw 12a and female screw 11b are engaged to secure output connector 12 to chassis 11a, whereby junction portion 16 is formed. A sealing material such as silicon resin is injected into the tip end of output connector 12 in order to keep converter main body 11 airtight inside. In this state, the brim portion 13b of waterproof cover 13 is fit into recess 11c. Brim portion 13b is pressed and held by the brim portion 12b of output connector 12 such that waterproof cover 13 is secured to chassis 11a. A connection portion 14a is formed at the tip end of coaxial cable 14, in which a female screw is formed. Fig. 3B shows the state to be delivered to the market. Furthermore, as shown in Fig. 3C, connection portion 14a is engaged to male screw 12d. As shown in Fig. 3D, the bellows 13a of waterproof cover 13 is expanded to cover connection portion 14a, and junction portion 16 is thus fully covered. Since the attaching operation completes simply by connecting coaxial cable 14 to junction portion 16 and expanding waterproof cover 13, the work load involved in attaching an antenna for receiving satellite broadcasting is alleviated. In addition, waterproof cover 13 attached to junction portion 16 is hardly affected by the movement of coaxial cable 14, and therefore waterproof cap 13 does not come off or slip off. As shown in Fig. 4, waterproof cover 13 is attached to chassis 11a to cover output connector 12 and connection portion 14a. Since waterproof cover 13 is folded until coaxial cable 14 is connected and the connecting operation of the connector or the cable is not hindered, the working efficiency improves. Waterproof cover 13 having bellows 13a is easily bent along a coaxial cable and can cope with any sharp curve of the coaxial cable. Converters for receiving satellite broadcasting according to second to eighth embodiments of the invention will be now described, in which the portions in the same construction and having the same function as the above will be denoted with the same reference characters and the description is not repeated. Figs. 5A to 5C are views of a waterproof cover for a converter for receiving satellite broadcasting according to the second embodiment of the invention. Figs. 5A and 5B are schematic cross sectional views thereof, and Fig. 5C shows the external configuration thereof. The groove of a waterproof cover 17 is in a spiral form, and water coming into waterproof cover 17 for some reason could be advantageously let out along the spiral groove. Figs. 6A to 6E are views of a waterproof cover for a converter for receiving satellite broadcasting according to a third embodiment of the invention. Figs. 6A to 6D are schematic cross sectional views thereof, and Fig. 6E is a view showing the external configuration thereof. In Fig. GA, a waterproof cover 23 is formed by combining truncated conical tubes 23a, 23b and 23c. As shown in Fig. 6B, waterproof cover 23 is inserted and secured between chassis 11a and output connector 12, and as shown in Fig.6C, coaxial cable 14 is attached to output connector 12. Subsequently, as shown in Figs. 6D and GE, tubes 23a, 23b and 23c may be expanded to cover output connector 12 and connection portion 14a. Figs. 7A to 7E are views of a waterproof cover for a converter for receiving satellite broadcasting according to the fourth embodiment of the invention. Figs. 7A to 7D are schematic cross sectional views thereof and Fig. 7E is a view showing the external configuration thereof. In Fig. 7A, a waterproof cover 33 is formed by connecting thick cylindrical tubes 33a, 33b and 33c by thin portions 34a and 34b folded between the tubes. As shown in Fig. 7B, waterproof cover 33 is placed and secured between chassis 11a and output connector 12, and as shown in Fig. 7C, coaxial cable 14 is attached to output connector 12. As shown in Figs. 7D and 7E, waterproof cover 33 is pulled downward to pull out thin portions 34a and 34b held between the tubes, so that waterproof cover may be expanded to cover output connector12 and connection portion 14a. Figs. 8A and 8B are schematic cross sectional views of a junction portion for a converter for receiving satellite broadcasting according to the fifth embodiment of the invention. In Fig. 8A, a recess 11c formed in chassis 11 is provided with a groove 11d for fitting an O-ring 21. As shown in Fig. 8B, O-ring 21 is fit into groove 11d and waterproof cover 13 is fit into the recess, and then output connector 12 is engaged to chassis 11a whereby junction portion 16 is formed. Furthermore, after coaxial cable 14 is attached, the bellows 13a of waterproof cover 13 is expanded.. O-ring 21 functions to completely prevent water from coming into the gap between chassis 11a and waterproof cover 13, so that water penetration may be more surely prevented. It is clearly understood that a packing may be used instead of the O-ring to achieve the same effect. Figs. 9A and 9B are schematic cross sectional views of a junction portion for a converter for receiving satellite broadcasting according to the sixth embodiment of the invention. In Fig. 9A, the brim portion 43b of a waterproof cover 43 is provided with a female screw 43c to engage the male screw 12d of an output connector 12. As shown in Fig. 9B, output connector 12 is engaged to a chassis 11a to form a junction portion 16. Subsequently, a female screw 43c is engaged to male screw 12d to attach waterproof cover 43. The shape of the screw portion of output connector 12 is standardized and therefore may be attached to any types of converters. If waterproof cover 43 is damaged, output connector 12 does not have to be removed for replacement, and only waterproof cover 43 may be removed for replacement. In addition, since waterproof cover 43 is attached to junction 16, it is less susceptible to the movement of coaxial cable 14, and waterproof cover 43 does not come off or slip off. Fig. 10A and 10B are schematic cross sectional views of a junction for a converter for receiving satellite broadcasting according to the seventh embodiment of the invention. In Fig. 10A, an O-ring 22 is provided between a chassis 11a and a waterproof cover 43, and O-ring 22 has a thickness slightly larger than that of a hexagonal brim portion 12c. After a male screw 12a and female screw 11b are engaged to attach output connector 12 to chassis 11a to constitute a junction portion 16, O-ring 22 is inserted through output connector 12 and waterproof cover 43 is attached to output connector 12. As shown in Fig. 10B, a female screw 43c is engaged to a male screw 12d, and O-ring 22 is pressed against chassis 11a by a brim portion 43b. O-ring 22 is thus pressed to elastically deform to seal the gap between waterproof cover 43 and chassis 11a. Therefore, water may be surely prevented from coming in between waterproof cover 43 and chassis 11a. Figs. 11A and 11B are schematic cross sectional views of a junction for a converter for receiving satellite broadcasting according to the eighth embodiment of the invention. As shown in Fig. 11A, resin 24 such as silicon resin having a sealing characteristic is applied on the female screw 43C of a waterproof cover 43. Then, an output connector 12 is attached to a chassis 11a, and a male screw 12d is engaged with the female screw 43c of waterproof cover 43, such that waterproof cover 43 is attached as shown in Fig. 11B. Thus applying resin 24 prevents water from coming in between a hexagonal brim portion 12c and a brim portion 43, so that water penetration through the gap between waterproof cover 43 and output connector 12 may be more completely prevented.

Claims: A converter for receiving satellite broadcasting, comprising: a converter main body (11); a cable (14) having an output connector (12) a junction portion (16) provided to said converter main body (11) for connecting with said output connector (12); and an extensible/retractable waterproof cover (13, 17, 23, 33, 43) protecting said junction portion (16) characterized in that said waterproof cover is fixed against said converter main body (11) at said junction portion (16) by said output connector (12). The converter for receiving satellite broadcasting as recited in claim 1, wherein said waterproof cover (13, 17, 23, 33, 43) is formed by a soft material including a conductive material. The converter for receiving satellite broadcasting as recited in claim 1, wherein said waterproof cover (13, 17, 23, 33, 43) is formed by a soft material including a ferrite-based material. The converter for receiving satellite broadcasting as recited in claim 1, wherein said waterproof cover (13) has a groove in a bellows shape. The converter for receiving satellite broadcasting as recited in claim 1, wherein said waterproof cover (17) has a spiral shape. The converter for receiving satellite broadcasting as recited in claim 1 wherein said waterproof cover (23) is formed by coupling a plurality of truncated conical tubes (23a, 23b, 23c). The converter for receiving satellite broadcasting as recited in claim I, wherein said waterproof cover (33) includes thick cylindrical tubes (33a, 33b, 33c); and a thin portion (34a, 34b) attached and folded between said thick tubes (33a, 33b, 33c). The converter for receiving satellite broadcasting as recited in claim, further comprising an O-ring (22) provided between said waterproof cover (43) and said converter main body (11). The converter for receiving satellite broadcasting as recited in any preceding claim, wherein said waterproof cover (13, 17, 23, 33, 43) includes a brim portion (43b) having a female screw (43c) engageable to said output connector (12), and said converter for receiving satellite broadcasting further comprising resin (24) applied on said female screw (43c).

Inventors: HATAZAWA KENJI, HATAZAWA, KENJI
Applicants: SHARP KK, SHARP KABUSHIKI KAISHA
Application year: 1998
Main classification: H01Q1
IPC codes: H01Q1, H01R13