JPH0321068Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention is a communal antenna used in communal listening equipment that receives television radio waves with a communal antenna and supplies the received signals to multiple television receivers via a main coaxial cable. This paper relates to improvements to serial units for

[Technical background of the invention]

Generally, a series unit for a common antenna is a TV terminal that houses a branch, a distributor, a matching box, etc. in one, and as shown in Figure 1, this series unit 1 is embedded in the wall of each room. It is connected in series to a main coaxial cable 3 connected to an antenna 2 to supply television radio waves to a television receiver 4 in each room.

A conventional series unit for a common antenna (hereinafter simply referred to as a series unit) houses a television signal common listening circuit (not shown) such as a branching and distribution circuit, as shown in Figs. 2 to 4, for example. an input terminal 11a and an output terminal 11b connected to the public listening circuit and protruding from opposing outer surfaces of the case 10, respectively; and a television set on the front surface of the case 10. It is provided with a mounting seat 13 for mounting a plug seat 12 for connecting an image machine. Mounting members extend from the upper and lower ends of the case 10, and each mounting member has a wall mounting screw hole 20, a flash plate mounting screw hole 21, and an outlet box mounting screw hole. 22 are provided. In addition, the input terminal 11a and the output terminal 11b are composed of a nut and a screw connected respectively to the input and output ends of a public listening circuit provided in the case 10, and an insulating member that insulates the nut and screw from the case 10. is,
The center conductor of the trunk coaxial cable 3 is clamped by the nut and screw. On the other hand, the input/output terminal 11a,
Ohm bands 23a and 23b are attached to the side of the case near 11b, respectively, and these ohm bands 23a and 23b connect the trunk coaxial cable 3.
is fixed to the side surface of the case, and the braid (i.e., the outer conductor) of the main coaxial cable 3 is brought into contact with the case 10.

In the above configuration, the outlet box 3 for storing serial units is embedded in the wall of each room.
To install the series unit 1 in the
The free ends of the input main coaxial cable 3a and the output main coaxial cable 3b, which have been previously routed through the outlet box 30, are pulled out from the outlet box 30.
Then, the outer jacket of the free end of each trunk coaxial cable 3a, 3b is removed, each outer conductor is fixed with an ohm band 23a, 23b, and each center conductor is connected with the nut and screw of each input/output terminal 11a, 11b. Fix it. After that, the series unit 1 is rotated approximately half a turn so that the slack of the input/output main coaxial cables 3a and 3b of the length required for installation is wrapped around the outer surface of the series unit 1, and the cable is inserted into the outlet box 30. Push it in and screw the screws 32, 32 into the screw holes 22, 22 to fix the series unit 1 to the outlet box 30. Then, by applying a flush plate (not shown) to the front surface of the serial unit 1 and fixing the flush plate by screwing the screws into the screw holes 21, 21, the front opening of the outlet box 30 can be secured to the front surface of the outlet box 30. Covered by a plate. In this way, the series unit 1
Since the main coaxial cables 3a and 3b on the input/output side are inserted into the outbox 30 and fixed while rotating approximately half a turn, the slack of the input/output side main coaxial cables 3a and 3b is stored in the outlet box 30, simplifying the installation work of the series unit 1. It has the advantage of being accurate.

[Problems with background technology]

However, in the case of this type of series unit 1, as shown in FIG. Output main coaxial cable 3b is input terminal 11
There was a risk that the electrical characteristics would deteriorate because the wire passed over the point a. That is, each input/output terminal 11a, 11b
The heads of the screws for connecting the center conductors of the main coaxial cables 3a and 3b are exposed, so connect the main coaxial cables 3a and 3b over these screws.
When the screw passes through, the head of the screw and the main coaxial cable 3a, 3
The external conductor b is brought close to the external conductor, resulting in poor electrical characteristics such as poor impedance characteristics, as well as poor insertion loss and reverse coupling characteristics.

For example, Figure 5 shows the return loss versus frequency, and the characteristic curve t=0
As shown in FIG. 4, the input/output terminals 11a and 11
b screw head and input/output main coaxial cable 3a,
The reflection loss curve when the distance t between the inside of 3b is 0 mm, that is, the two are in contact.Similarly, the characteristic curve t=1.0 shows the distance t is 1.0 mm, and the characteristic curve t=1.8 shows the distance t 1.8 mm. The reflection loss curves are shown for each case. As is clear from Fig. 5, for example, a shallow switch box (depth: 35 mm) specified in JISC8337 as an outlet box 30.
When the above-mentioned interval t is used for household construction,
becomes smaller and the electrical characteristics deteriorate. Furthermore, this electrical characteristic has the disadvantage that it deteriorates in the high frequency range of television signals, especially in the intermediate frequency range (950 to 1450 MHz) for satellite broadcast reception, which has recently been used.

[Purpose of invention]

The present invention was devised to eliminate the above-mentioned drawbacks of the conventional art, and aims to provide a series unit with a simple structure and excellent electrical characteristics.

[Summary of the idea]

In order to achieve the above object, the present invention provides an insulating member that insulates the input/output terminals from the case in a conventional series unit as shown in Fig. In order to prevent this, a protrusion is provided that is higher than the input/output terminal and protrudes to the outside of the case.

[Example of idea]

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 6 to 11. In the following drawings, the same elements as those in FIG. 1 are given the same reference numerals.

6 to 9 are structural explanatory diagrams of the series unit according to this embodiment. This series unit 100
differs from that in Figure 2 is that the input/output terminal 11
The difference is that the structures of insulating members 110a and 110b made of resin or the like that insulate between a and 11b and the metal case 10 are different. That is, each insulating member 1
10a and 110b, as shown in FIG. 7, a substrate 111 that is fitted into mounting holes (not shown) provided on both sides of the case 10 in close proximity to the ohm bands 23a and 23b; a nut mounting hole 112 provided approximately in the center of the board 111, and shield plates 113, 113 protruding from both sides of the board 111;
A separation plate 11 that protrudes from the upper edge of the substrate 111 (i.e., the upper edge in a direction substantially orthogonal to the main coaxial cables 3a, 3b) and is higher than the shrinkage plates 113, 113.
4, and a groove 11 provided in the separation plate 114 for inserting the center conductor of the main coaxial cables 3a, 3b.
5, the shield plates 113, 113 and the separation plate 11
A protective plate 116 is provided inside the nut mounting hole 112 and protrudes from the outer periphery of the nut mounting hole 112, and the center conductors of the main coaxial cables 3a and 3b are inserted on the upper edge of the protective plate 116 facing the groove 115. Groove 1 for
17, and an opening 118 for inserting the trunk coaxial cables 3a, 3b provided at the lower end side of the protection plate 116. Each of the insulating members 110a and 110b configured in this manner is fitted onto both side surfaces of the case 10, with the substrate 111 thereof being close to the ohmic band 23a. Here, as shown in FIG. 7, the input terminal 11a and the output terminal 11b are connected to a nut 120 and a nut 12, respectively, which are fitted into the nut mounting hole 112 and connected to the public listening circuit in the case 10.
0 through a washer 121. Note that it is desirable to caulk the tip of the screw 122 to prevent it from falling off the nut 120 during installation work or the like.

In order to install the series unit 100 configured as described above into the outlet box 30 embedded in the wall surface, the input/output side trunk coaxial cable 3
While fixing each external conductor exposed at the free ends of a and 3b with ohm bands 23a and 23b,
Each center conductor is inserted between the nut 120 and the washer 121 through the opening 118 of the insulating members 110a and 110b, and the screw 122 is tightened to sandwich the center conductor between the nut 120 and the washer 121. On this occasion,
If the center conductor of the input/output side trunk coaxial cables 3a, 3b is long, insert the tip of this center conductor into the grooves 117, 115 of the insulating members 110a, 110b, fix this center conductor with the screw 122, and then remove the unnecessary wire. Cut a long piece. After that, the series unit 100 is rotated approximately half a turn to wind the input/output side trunk coaxial cables 3a, 3b, and the cables 3a, 3b are
hooked on the back surfaces of the separation plate 114 and the insulation plate 113 (that is, the lower surfaces of the separation plate 114 and the insulation plate 113 in FIG. 8) and pushed into the narrow outlet box 30, and screwed the screws 32, 32
The series unit 100 is fixed to the outlet box 30 by means of the screws. Then, as shown in FIG. 9, the input/output main coaxial cable 3a,
3b is disposed between the bottom of the outlet box 30 and the lower part of the separating plate 114 and the shrinking plate 113. In this way, the input/output side main coaxial cables 3a, 3b and the input/output terminals 11a, 11
As shown in FIG. 5, electrical characteristics such as impedance characteristics, insertion loss, and reverse coupling characteristics are improved because the distance between the two electrodes and b is separated by a predetermined distance. Here, the series unit 100 is connected to a wide outlet box 30.
When storing the input/output main coaxial cables 3a and 3b in the outlet box 3,
There is a risk that the cables may move upward from the bottom of the 0, but in this case as well, since there is a separation plate 114, the main coaxial cables 3a, 3b on the input/output side and the input/output terminals 11a,
11b are separated from each other by a predetermined distance without coming into contact with each other, thereby preventing deterioration of the electrical characteristics.

Note that the protective plates 116 provided around the input/output terminals 11a and 11b are
a, 11b and the main coaxial cables 3a, 3b to improve the insulation between them. Set it lower than the head of 122. In this way, the electrical inspection of the common listening circuit provided in the case 10 can be easily performed. That is, FIG. 10 shows an example of the configuration of a test jig for electrically testing a common listening circuit.
Support plates 202, 202 protruding from both sides of 1
and a pair of support pins 2 protruding from the substrate 201.
03, 203, plugs 204, 204, and contact pins 2 protruding from the inside of each support plate 202, 202.
05, 205, and a pair of grounding contact pieces 206, 20 protruding from the inside of each support plate 202, 202.
It consists of 6. And this inspection jig 200
is detected by a test circuit (not shown). In order to test a common listening circuit using such a test jig 200, as shown in FIG. Then, insert the outlet box mounting screw holes 22, 22 into the support pins 20.
3,203. Then, the series unit 100
The connector seats 12, 12 on the front of the connectors 204, 204
The input/output terminals 11a and 11b on both sides of the series unit 100 are connected to contact pins 20, respectively.
5,205 and the ohm band 23
a and 23b contact the contact pieces 206 and 206, respectively. Therefore, a test circuit (not shown) connects the input/output terminal 11 through the contact pins 205, 205.
A test signal is given to the connectors a and 11b, and the connector 20
4,204 to a test circuit, which tests the electrical characteristics of the series unit 100. Here, since the protection plate 116 is lower than the head of the screw 122, the series unit 100
There is an advantage that the protective plate 116 does not get caught on the contact pins 205 when it is attached to the inspection jig 200, and can be easily attached and detached.

It goes without saying that the present invention is not limited to the embodiments described above, and can be modified in various ways without changing the gist thereof.

[Effect of idea]

As explained above, according to the present invention, an insulating member provided on the side surface of the case is provided with a portion that protrudes higher than the input/output terminal, and this protrusion allows the input/output wire wrapped around the case to approach the input/output terminal. Since this is prevented and the input/output lines and the input/output terminals are separated from each other, the structure can be simplified and deterioration of electrical characteristics such as impedance characteristics, insertion loss, and reverse coupling characteristics can be prevented.

[Brief explanation of the drawing]

Figure 1 is a general explanatory diagram of a series unit, Figure 2
Figure 3 and Figure 3 are diagrams showing the structure and installation state of a conventional series unit, Figure 4 is a cross-sectional view of Figure 3, Figure 5 is an electrical characteristic diagram of a conventional series unit, and Figure 6 is the present invention. FIG. 7 is a perspective view of the input/output terminal and insulating member in FIG. 6, FIG. 8 is an installation state diagram of the series unit in FIG. 6, and FIG. 9 is a perspective view of a series unit according to an embodiment. 8 is a cross-sectional view, FIG. 10 is a configuration diagram of the inspection jig, and FIG. 11 is a diagram showing the inspection state of the series unit in FIG. 6. 3, 3a, 3b... Trunk coaxial cable, 10
...Metal case, 11a...Input terminal, 11b
... Output terminal, 12 ... Connection seat, 30 ... Outlet box, 110a, 110b ... Insulating member, 114 ... Separation plate.

Claims (1)

[Claims for Utility Model Registration] A substantially rectangular parallelepiped-shaped metal case that houses a TV signal common listening circuit such as a branching and distribution circuit and is fixed in a box embedded in a wall, and a connection to the common listening circuit. and an input terminal and an output terminal protruding from opposing outer surfaces of the case, respectively, and an insulating member for insulating the input terminal and the output terminal from the case, and an input terminal for a main line drawn into the box. wires and output wires are connected to the input terminal and output terminal, respectively, and the case is rotated approximately half a turn to wrap the input wire and output wire around the outer surface of the case, and then fixed in the box. In the antenna series unit, the insulating member is provided with a wire that is higher than the input terminal and the output terminal outside the case in order to prevent the wound input wire and the output wire from coming close to the output terminal and the input terminal, respectively. A series unit for a communal antenna characterized by having a protruding part on the side surface.