A radio telematic communication unit for a motor vehicle

Abstract

A radio telematic communication unit for a motor vehicle comprises a main casing (2), having therewithin one or more electronic circuits including a plurality of internal antennas, and one or more external antennas (6-10), extending above and outside the main casing (2). The external antennas (6-10) are contained within a cover (11) mounted above the main casing (2). The unit (1) is arranged to be mounted from the inside of the roof of a motor vehicle against a metal wall of the roof, with said cover (11) projecting outwardly from the roof through an opening (12) in the roof. The unit (1) is rigidly connected to a wall (13) of the roof of the motor vehicle by means of a plurality of fastening screws (15), each of which is associated with a screw-retaining bush (16), which is arranged within the hole (300) of a wall (3) of the main casing (2) and which has an enlarged head (161), which is interposed between the upper surface of the wall (3) of the main casing (2) and the wall (13) of the roof. Each fastening screw (15) is inserted through the respective screw-retaining bush (16) and engaged within a nut (17), carried by an auxiliary casing (18) mounted above the roof. In the tightened condition of the screw, pointed protrusions (163) of the upper head (161) of the screw-retaining bush (16) penetrate the material of the metal wall (13) of the roof. The screw-retaining bush (16) has an internal thread (164) at its lower end, which allows the screw (15) to be screwed into the screw-retaining bush (16), but which then prevents an accidental fall of the screw (15) out of the screw-retaining bush (16) as long as the screw (15) is not engaged into the respective nut (17).

Description

[0001] “A radio telematic communication unit for a motor vehicle”

[0002] ****

[0003] Filed of the invention

[0004] The present invention relates to radio telematic communication units for motor vehicles of the type comprising:

[0005] - a main casing, having an upper wall and a lower wall coupled to each other, and configured to be mounted from the inside of the roof of a motor vehicle against a metal wall of the roof,

[0006] - wherein at least the upper wall of said main casing is made of metal material and is configured to be in an electrical conduction contact with the metal wall of the roof in the mounted condition of the main casing,

[0007] - one or more electronic circuits housed within the main casing and including a plurality of internal antennas,

[0008] - one or more external antennas, extending above and outside said main casing, and

[0009] - a cover mounted above the main casing, enclosing therewithin said external antennas and configured to project outwardly from the roof of the motor vehicle, through an opening in the roof, in the condition in which said main casing is mounted against the lower surface of the roof.

[0010] Prior art

[0011] A communication unit of the type indicated above is disclosed for example in the patent document US 9,966,659 B2. In communication units of this type, the upper wall of the main casing, containing the electronic circuits, is in electrical conduction contact with the roof of the motor vehicle, in the mounted condition of the communication unit on the roof, in order to ensure reliable shielding of the electronic circuits contained inside the main casing.

[0012] Document DE 2020 211 00927 U1 illustrates a system for fastening the main casing of the communication unit to the roof of the motor vehicle by means of screws, having the purpose of ensuring good electrical conduction contact between the metal wall of the main casing of the communication unit and the metal wall of the roof of the motor vehicle. However, this solution is complex and expensive and involves laborious mounting operations. A further solution is known from JP 2023 163260 A.

[0013] Object of the invention

[0014] The object of the present invention is to solve the drawbacks of the above-mentioned prior art, by providing a radio telematic communication unit equipped with a fastening system that ensures a correct electrical conduction contact between the metal wall of the main casing of the unit and the metal wall of the roof of the motor vehicle, and which at the same time is simple and economical to construct and easy and quick to install.

[0015] Summary of the invention

[0016] In order to achieve said purpose, the invention has as its object a radio telematic communication unit having the features that have been indicated at the beginning of this disclosure and further characterized in that:

[0017] - at least two fastening screws are associated with said main casing of the communication unit to rigidly connect the main casing to the roof of the motor vehicle,

[0018] - each of said fastening screws has a head engaged against the lower surface of a wall of the main casing and a shank engaged through a respective hole in said wall of the main casing and having a threaded portion adapted to engage a respective nut positioned above the roof of the motor vehicle,

[0019] - to each fastening screw there is associated a screw-retaining bush, made of metal material, which is arranged within said hole in the wall of the main casing and which has an enlarged head resting on the upper surface of said wall of the main casing,

[0020] - said screw-retaining bush has a lower end with an internal thread configured to allow the screw to be introduced by screwing through the screw-retaining bush and to prevent a fall of the screw out of the screwretaining bush, once the screw has been inserted through the screwretaining bush and as long as the screw is not engaged in the respective nut,

[0021] - so that when the screw is tightened within the respective nut, the head of the screw presses said wall of the main casing against the wall of the roof of the motor vehicle, with the enlarged head of the screw-retaining bush pressed between said wall of the main casing and the wall of the roof,

[0022] - and wherein the upper end of said screw-retaining bush has pointed protrusions configured to etch the wall of the roof in the tightened condition of the screw, so as to obtain an electrical conduction contact between the wall of the main casing and the wall of the roof.

[0023] Due to the above features, the invention allows to achieve a series of important advantages. First, in the tightened condition of each fastening screw, the pointed protrusions formed on the upper end of the screwretaining bush associated with the fastening screw penetrate the metal material of the wall of the roof, significantly improving the electrical conduction contact between the screw-retaining bush and the wall of the roof. At the same time, in said tightened condition of the fastening screw, the upper head of the screw-retaining bush is tightly pressed between the wall of the roof and the metal wall of the main casing of the communication unit. Therefore, the metal wall of the main casing is in thermal conduction contact with the metal roof of the motor vehicle via the upper head of the screw-retaining bush.

[0024] Of course, in addition to the electrical conduction contact provided at the fastening screws, the upper wall of the main casing of the communication unit may have additional contact areas pressed against the wall of the roof of the motor vehicle due to the tightening of the fastening screws.

[0025] A further advantage of the invention compared to the solution known from DE 2020 211 00927 U1 lies in the fact that said screw-retaining bush constitutes a single accessory element associated with each fastening screw, in addition of course to the respective nut, to ensure correct electrical conduction contact between the main casing of the communication unit and the roof of the motor vehicle in the tightened condition of each fastening screw. The solution provided according to the invention therefore involves a reduced number of parts, is simple and inexpensive to manufacture and allows for easy and rapid installation.

[0026] A further advantage of the invention lies in the fact that each fastening screw can be initially associated with the respective screwretaining bush, after which, as long as the screw is not mounted in position and tightened within the respective nut, said internal thread at the lower end of the screw-retaining bush prevents any accidental separation of the screw from the screw-retaining bush. Again, this result is also achieved with simple and inexpensive means.

[0027] In a preferred embodiment, the engagement nut of each fastening screw is carried by an auxiliary outer casing covering said cover and being adapted to be secured from the outside onto the roof of the motor vehicle.

[0028] In one example, the enlarged upper head of the screw-retaining bush has a star-shaped configuration, with a plurality of radial lobes for engagement between the upper wall of the main casing and the wall of the roof, said pointed protrusions being distributed circumferentially at positions interposed between said radial lobes.

[0029] Detailed description of the invention

[0030] Further features and advantages of the invention will be apparent from the following description with reference to the attached drawings, provided purely by way of non-limiting example, in which:

[0031] - figure 1 is a perspective view of an embodiment of a radio telematic communication unit according to the invention,

[0032] - figure 2 is a further partially sectioned perspective view of the unit of figure 1 ,

[0033] - figure 3 is an exploded perspective view of the unit of figure 1 ,

[0034] - figure 4 illustrates a detail of figure 3 on an enlarged scale,

[0035] - figure 5 is a perspective view of a portion of a wall of a motor vehicle roof, configured to receive the communication unit according to the invention,

[0036] - figures 6, 7 illustrate a sectional view on an enlarged scale of the detail of a fastening screw of the communication unit according to the invention, respectively in a non-operating condition and in an operating tightened condition of a fastening screw,

[0037] - figure 8 is a partially sectioned perspective view of the assembly consisting of a fastening screw with the associated screw-retaining bush, and

[0038] - figure 9 is a perspective view from above of the screw-retaining bush forming part of the assembly in Figure 8.

[0039] In the drawings, reference 1 indicates as a whole a radio telematic communication unit for a motor vehicle.

[0040] The unit 1 includes a main casing 2 having an upper wall 3 made of metal material and a lower wall 4, also made of metal material or plastic material. The walls 3, 4 are coupled to each other to define a closed chamber within which a card 5 is housed, including one or more electronic circuits comprising a plurality of internal antennas.

[0041] In one example, the electronic circuits carried by the card 5 include a Wi-Fi antenna, a UWB (Ultra-Wide Band) antenna, a Bluetooth antenna and a backup cellular antenna.

[0042] The unit 1 also includes a plurality of external antennas, extending above and outside the main casing 2 and connected to the electronic circuits of the card 5 through openings A, formed in the upper wall 3 of the main casing 2 (see figure 4).

[0043] With reference to figure 2, the external antennas include a primary cellular antenna 6, a Wi-Fi / Bluetooth antenna 7, a broadcast antenna (AM / FM / DAB) metal cap 8, a C-V2X antenna 9, and a Global Navigation Satellite System (GNSS) module 10.

[0044] The external antennas 6-10, extending outside and above the main casing 2, are enclosed within a cover 11 mounted above the main casing 2 and having, in this example, a shark fin-like configuration.

[0045] According to the prior art, the assembly consisting of the main casing 2 with the cover 11 and the components arranged inside the main casing 2 and the cover 11 is mounted as a unit from the inside of the roof of a motor vehicle, against a metal wall of the roof, with the cover 11 projecting outwardly from the roof through an opening 12 (figure 5).

[0046] In the illustrated embodiment, in the mounted condition of the main casing 2 against the lower surface of the wall of the roof 13, the cover 11 , projecting outwardly from the roof, is overlaid by an auxiliary outer casing (not illustrated in figures 1 -3), which for example has a shark fin-like configuration similar to that of the cover 11 and which is fixed from the outside of the roof above a lowered portion 14 (Figure 5) of the outer surface of the wall of the roof 13.

[0047] According to the prior art, in the mounted condition of the main casing 2 against the lower surface of the wall of the roof 13, an electrical conduction contact is obtained between the upper metal wall 3 of the main casing 2 and the metal wall 13 of the roof, serving to shield the electronic circuits contained within the main casing 2. On the upper surface of the unit 1 there are areas of contact with the wall of the roof, in particular at the fastening screws (in this example being three in number, positioned at the three circular holes visible in figure 4) which rigidly connect the unit 1 to the roof of the motor vehicle.

[0048] Figure 6 illustrates in section one of these fastening screws 15, indicated as a whole with the reference number 15, in a non-operating condition, before tightening within a respective nut. At least two fastening screws of the type of screw 15 illustrated in figure 6 are provided, for example in the two areas located in front and behind the cover 11 .

[0049] Figure 6 shows a portion of the upper wall 3 mounted in contact with the lower surface of the metal sheet wall 13 of the roof of the motor vehicle. In the engagement area of the fastening screw 15, the wall 3 has a neck portion 30, projecting downwards, defining a hole 300, within which a screwretaining bush 16 of metal material is arranged, better visible in figures 8, 9.

[0050] The screw-retaining bush 16 has a main body 160 that is substantially cylindrical or slightly conical with convergence downwards (with reference to the figures) and an enlarged upper head 161 which, in the condition mounted within the hole 300 of the screw-retaining bush 16, rests against the upper surface of the upper wall 3 of the casing 2 (see figure 6).

[0051] Still with reference to figure 6, the reference 17 indicates a nut carried by the auxiliary outer casing 18, which is mounted on the outside of the roof 13 above the cover 11 .

[0052] Still referring to figures 8, 9, the enlarged upper head 161 of the screw-retaining bush 16 has a star-like configuration defined by a plurality of radial lobes 162 which in the mounted condition (see Figure 6) are interposed between the upper wall 3 of the casing 2 and the wall 13 of the roof of the motor vehicle.

[0053] As illustrated in figure 7, in the tightened condition of the screw 15, a threaded end portion 150 of the screw is engaged within the threaded internal surface of the nut 17. In this condition, the head 151 of the screw 15 presses the wall 3 against the wall 13 of the roof, with the upper head 161 of the bush 16 pressed between the wall 3 of the casing 2 and the wall 13 of the roof. In this condition, therefore, an electrical conduction contact is provided between the wall 3 of the casing 2 and the wall 13 of the roof, via the upper head 161 of the bush 16.

[0054] The screw-retaining bush 16 includes a plurality of pointed protrusions 163 which in the example are at positions interposed between the radial lobes 162. The pointed protrusions 163 are configured in such a way that in the tightened condition of the screw 15 within the respective nut 17, illustrated in figure 7, they etch the material of the metal wall 13 of the roof, penetrating inside it, so as to obtain a reliable thermal conduction contact between the head 161 of the screw-retaining bush 16 and the wall 13 of the roof.

[0055] The screw-retaining bush 16 is also characterized in that at its lower end it has an internal thread 164 (figure 9) configured to allow the screw 15 to be screwed into the bush 16, by rotating the screw, until it reaches the condition illustrated in figure 8, in which the threaded portion 150 of the screw has passed the thread 164. The shank of the screw 15, indicated as a whole with 15A, has a smooth portion 152, which has a diameter smaller than the internal diameter of the thread 164, so that it is free to slide within this thread. As a result of the configuration described above, the screw 15 can be initially associated with the screw-retaining bush 16 by screwing the screw 15 through the thread 164 of the bush, until the threaded portion 150 of the screw has passed the internal thread 164. In this condition, as long as the screw 15 is not screwed into the nut 17, the internal thread 164 prevents a fall of the screw out of the bush 16.

[0056] In mounting, the unit 1 is arranged with each bush 16 inserted from above into the respective hole 300 of the wall 3 of the unit 1 , and with the fastening screws 15 inserted from below into the respective bushes 16, in the condition illustrated in figure 6. In this condition, the unit 1 is approached from below to the lower surface of the wall of the roof 13, with the cover 11 projecting outwardly from the roof through the opening 12, whereupon the outer casing 18 is applied over the cover 11 , from the outside of the roof, and the fastening screws 15 are screwed into the respective nuts 17 carried by the outer casing 18, so as to rigidly connect the unit 1 to the roof and provide an electrical conduction contact between the upper wall 3 of the unit 1 and the wall 13 of the roof, through the heads 161 of the bushes 16.

[0057] Of course, notwithstanding the principle of the invention, the construction details and the embodiments may vary widely with respect to what is described and illustrated purely by way of example, without thereby departing from the scope of the present invention, as defined in the attached claims.

Claims

CLAIMS1. A radio telematic communication unit (1 ) for a motor vehicle, comprising:- a main casing (2), having an upper wall (3) and a lower wall (4) coupled to each other and configured to be mounted from the inside of the roof of a motor vehicle, against a metal wall (13) of the roof,- wherein at least the upper wall (3) of said main casing (2) is made of metal material and is configured to be in an electrical conduction contact with the metal wall (13) of the roof in the mounted condition of the main casing (2),- one or more electronic circuits (5) housed within the main casing (2) and including a plurality of internal antennas,- one or more external antennas (6-10), extending above and outside said main casing (2),- a cover (11 ), mounted above the main casing (2), enclosing therewithin said external antennas and configured to project outwardly from the roof of the motor vehicle, through an opening (12) in the roof, in the condition in which said main casing (2) is mounted against the lower surface of the roof, said unit being characterized in that:- at least two fastening screws (15) are associated with said main casing (2) to rigidly connect the main casing (2) to the roof (13),- each of said fastening screws (15) has a head (151 ), engaged against the lower surface of a wall (3) of the main casing (2), and a shank (15A) engaged through the respective hole (300) of said wall (3) of the main casing (2) and having a threaded portion (150) adapted to engage a respective nut (17), which is positioned above the roof (13) in the mounted condition of the main casing (2),- to each fastening screw (15) there is associated a screw-retaining bush (16) of metal material, which is arranged within said hole (300) in the wall (3) of the main casing (2) and having a head (161 ) which is enlarged with respect to the lower end of the screw-retaining bush (16), said enlarged head (161 ) resting on the upper surface of said wall (3) of the main casing,- the lower end of said screw-retaining bush (16) having an internalthread (164) and being configured to allow the screw (15) to be introduced by screwing through the screw-retaining bush (16) and to prevent a fall of the screw (15) out of the screw-retaining bush (16), once the screw (15) has been inserted through the screw-retaining bush (16) and as long as the screw (15) is not engaged in the respective nut (17),- so that when the screw (15) is tightened within the respective nut (17), in the mounted condition of the main casing (2), the head (151 ) of the screw (15) presses said wall (3) of the main casing (2) against the wall (13) of the roof of the motor vehicle, with the enlarged head (161 ) of the screwretaining bush (16) pressed between said wall (3) of the main casing (2) and the wall (13) of the roof,- and wherein the upper end of said screw-retaining bush (16) has pointed protrusions (163), configured to etch the wall (13) of the roof in the tightened condition of the screw (15), in the mounted condition of the main casing (2), so as to obtain an electrical conduction contact between the upper wall (3) of the main casing (3) and the wall (13) of the roof.

2. The unit according to claim 1 , characterized in that the enlarged upper head (161 ) of the screw-retaining bush (16) has a star-like configuration, with a plurality of radial lobes (162) for engagement between the wall (3) of the main casing (2) and the wall (13) of the roof, and in that said pointed protrusions (163) are distributed around the screw-retaining bush (16), at positions interposed between said radial lobes (162) of the head (161 ) of the screw-retaining bush (16).

3. The unit according to claim 1 , characterized in that said unit comprises an auxiliary outer casing (18) covering said cover (11 ) and being adapted to be secured from the outside onto the roof (13) of the motor vehicle, the nut (17) associated with each of said fastening screws (15) being carried by said outer casing (18).

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