CA2131217C - Tube assembly for housing a multistage telescopic antenna for a vehicle - Google Patents
Tube assembly for housing a multistage telescopic antenna for a vehicleInfo
- Publication number
- CA2131217C CA2131217C CA 2131217 CA2131217A CA2131217C CA 2131217 C CA2131217 C CA 2131217C CA 2131217 CA2131217 CA 2131217 CA 2131217 A CA2131217 A CA 2131217A CA 2131217 C CA2131217 C CA 2131217C
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- outer tube
- tube
- insulating sleeve
- tube assembly
- periphery surface
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Abstract
There is provided an tube assembly for housing a multistage telescopic antenna for a vehicle. The tube assembly comprises an outer tube for housing a multistage telescopic antenna, an insulating sleeve inserted in the outer tube, an electrically conductive sleeve inserted in the outer tube, first sealing means for sealing an upper end portion and a lower end portion of an annular space formed between the insulating sleeve and the outer tube, second sealing means for sealing an upper end portion of an annular space formed between the electrically conductive sleeve and the outer tube, and a stopper member provided at a lower end portion of the annular space formed between the insulating sleeve and the outer tube.
Description
~13~17 TITLE OF THE INVENTION
Tube AssemblY for Housing a Multistage Telescopic Antenna for a Vehicle BACKGROUND OF THE INVENTION
The present invention relates to a tube assemblY for housing a multistage telescopic antenna for a vehicle, and more ParticularlY, to a tube assemblY for housing a vehicle antenna having its waterproof property improved.
A vehicle antenna is usuallY constructed as having a plurality of antenna rods fitted within one another in a telescopic relation. The central rod of the antenna is connected with a driving cord having a number of rack teeth which are adaPted to engage with a driving gear. The plurality of antenna rods together constitute an antenna element which maY thus be operated to extend or retract in a telescoPic manner through the movement of the driving cord.
Japanese UtilitY Model ApPlication Laid-open 1-100508 has disclosed a vehicle antenna having a structure as shown in Fig. 5. Referring to Fig. 5, a plurality of antenna rods 11, 12 and 13 are slidably connected with one another in a telescopic relation and are housed in an outer tube 30 which is vertically provided on a housing 20. The central rod 11 is connected with a driving cord 14 which is adapted to render an antenna element 10 including the rods 11 - 13 to extend or retract in a telescoPic manner.
The housing 20 contains a driving gear 21 engaging with 2 ;~ ~
rack teeth 15 formed on the driving cord 14. The antenna .
element lO is caused to extend or retract through the movement of the driving cord 14 into and out of the housing 20. At this time, the driving cord 14 is pressed by a pressing roller 22 against the driving gear 21, thereby maintaining an engagement of the rack teeth 15 with the driving gear 21.
The driving gear 21 itself is rotated by a driving Power from an electric motor 40 contained with a motor bonnet 41.
Namely, an outPut Power of the motor 40 is transmitted to the driving gear 21 through a worm 42,a worm wheel 43, and a decelerating gear train 44. In Fig. 5, a reference numeral 45 represents a counter gear.
The driving cord 14, after being dragged into the housing through the rotation of the driving gear 21, will be disengaged from the driving gear 21 and be guided by a guide member 23 to move towards and into a receiving drum 24.
The receiving drum 24 is a free drum provided coaxially with the driving gear 21. Further, another guide member 25 is provided in the receiving drum 24 to further guide the driving cord 14 moved hereto.
However, a vehicle antenna as described above has a severe Problem of rain water invasion. That is, rain water is easy to flow along the driving cord 14 into the housing 20.
In order to solve such problem, there have been proposed manY
ideas trying to provide a kind of improved connecting means and a kind of improved insertion condition for each antenna lt~
rod, so as to obtain a higher waterproof property for a vehicle antenna. Nevertheless, the present situation is that it is still impossible to completely Prevent rain water invasion.
Another suggestion to solve the rain water invasion is to provide a drain hole at a lower portion of the housing 20, trying to enable the rain water entered in the housing 20 to flow away through the drain hole. However, whenever there is a heavY rain shower which usuallY results in a severe water invasion into the housing 20, it is difficult to drain off the entered rain water as immediatelY as is required. As a result, the rain water entered in the housing 20 is aPt to flow up into the outer tube 30. Moreover, the rain water flows from outside through gaPs between antenna rods 11 - 13 into a space formed between the outer tube 30 and an insulating sleeve 31. In addition, rain water is easy to flow down the antenna rods 11 - 13 into the same space between the outer tube 30 and the insulating sleeve 31.
In the above-discussed conventional vehicle antenna, the outer tube 30 is usuallY made of aluminium or an aluminium alloy so as to render an antenna structure light in weight and obtain a good corrosion resistance. However, after such an outer tube 30 has been exPosed to rain water, a corroding phenomena such as pitting corrosion is apt to occur on the surface thereof. Consequently, many fine holes resulting from the pitting corrosion are formed thereon, the outer tube 2 1 3 ~ ~ 1 7 can no longer be used for a vehicle antenna. The corrosion problem is particularly severe when the outer tube is exposed to an acid rain caused by increasingly deteriorating environment.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a tube assembly for housing a multistage telescopic antenna for a vehicle, in which rain water invasion can be effectively prevented and corrosion resistance has been improved.
According to the present invention, there is provided a tube assembly for housing a multistage telescopic antenna for a vehicle. The tube assembly of the present invention comprises an outer tube for housing a multistage telescopic antenna, an insulating sleeve inserted in the outer tube, an electrically conductive sleeve inserted in the outer tube, first sealing means for sealing an upper end portion and a lower end portion of an annular space formed between the insulating sleeve and the outer tube, second sealing means for sealing an upper end portion of an annular space formed between the electrically conductive sleeve and the outer tube, and a stopper member provided at a lower end portion of the annular space formed between the insulating sleeve and the outer tube. The annular space formed between the insulating sleeve and outer tube is sealed at the lower end portion thereof further by the stopper member whose inner surface is pressed by a rubber ring member provided adjacent to the lower end of the insulating sleeve.
~ .
,~
~ .
~ 1 3 ~ ~ 1! 7 In an aspect of the present invention, the first sealing means includes said rubber ring member provided on the outer periphery surface of the insulating sleeve adjacent to the lower end thereof and another rubber ring member provided on the outer periphery surface of the insulating sleeve adjacent to the upper end thereof. The second sealing means includes a sealing ring member mounted on the upper end of the electrically conductive sleeve.
The other objects and features of this invention will become understood from the following descriptions with reference to the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
Fig. 1 is a schematic view showing a vehicle antenna in which a tube assembly of the present invention is applied.
Fig. 2 is an exploded cross sectional view showing an internal structure of the tube assembly of the present invention.
Figs. 3a and 3b are front and bottom views respectively showing a stopper member of the tube assembly of the present invention.
Fig. 4 is a cross sectional view showing an assembled condition of the tube assembly of the present invention.
Fig. 5 is a schematic view showing a conventional vehicle antenna.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the drawings from Fig. 1 to Fig. 4 the same items as those in Fig. 5 are represented by the same reference numberals.
R~- Referring to Fig. 1, an outer tube 30 of a tub assembly of the Present invention is verticallY Provided on a housing 20 as in a conventional vehicle antenna. A feeding section 50 is inserted in the outer tube 30 so as to become conductive with an antenna element 10. The feeding section 50 has a terminal 51 and a terminal 52 which are respectively connected to a core conductor and an external conductor of a coaxial cable.
The terminal 51 is electrically connected to an antenna element 10 through a terminal 53 projectively formed on the inner periphery surface of the outer tube 30 and through an electrically conductive sleeve 54, as shown in Fig. 2.
Another terminal 52 is earthed through the outer tube 30.
Referring to Fig. 2, the electrically conductive sleeve 54 has a lower end portion of a smaller diameter which is formed with a notch (not shown). Such lower end portion of the electrically conductive sleeve 54 serves to Position a starting point for an antenna rod 13. In order to form a complete feeding system for the vehicle antenna, a leaf spring (not shown) connected to the coaxial cable ( serving as a feeding cable ) is introduced into the electricallY
conductive sleeve 54 through said notch formed thereon, so as to become contacted with the antenna rod 13.
Referring to Figs. 1 and 2, an insulating sleeve 31 is inserted in the outer tube 30 to form an insulation between the outer tube 30 and the antenna element 10. The insulating sleeve 31 comprises a sleeve body 31a made of a synthetic resin, a rubber ring member 31b Provided on the outer periphery surface of the sleeve adjacent to the upper end thereof and another rubber ring member 31c provided on the outer periPherY surface of the sleeve adjacent to the lower end thereof. The rubber ring members 31b and 31c together constitute a first sealing means. Each of the rubber rings members 31b and 31c has a plurality of small projections 31d formed integrallY and circumferentiallY on the outer peripherY
surface thereof. Such small Proiections 31d Possess an excellent waterProof ProPertY so that a rubber ring member as a whole acts as a good packing.
The insulating sleeve 31 has an aPProPriate length such that when it is inserted into the outer tube 30 the rubber ring member 31b presses against an insulating layer 30a formed on the inner surface of the outer tube 30. Accordingly, a possible gap between the outer tube 30 and the insulating sleeve 31 may be sealed bY the rubber ring member 31b so as to prevent rain water invasion into the space formed between the insulating sleeve 31 and the outer tube 30.
Further referring to Fig. 2, the insulating layer 30a has a flange portion 30b formed at the upPer end thereof, which is adapted to engage with the upper end face of the outer tube 30. Alternatively, an electricallY conductive resin may be utilized to form a layer on the inner surface of the outer tube 30, instead of using the insulating layer 30a and the terminal 53 . In such a case, the electrically conductive ~ 1 3 ~
resin layer should be formed in a manner such that it is insulated through proper means from the outer tube 30 and conducted with the terminal 51.
The electricallY conductive sleeve 54, into which the antenna element 10 is to be inserted, is Provided with a sealing ring member 32 named herewith as a second sealing means and mounted on the upper end portion thereof. The sealing ring member 32 has a flange Portion 32a which is adapted to engage with and Press against the flange Portion 30b of the insulating layer 30a when the electrically conductive sleeve 54 is inserted in the outer tube 30, as shown in Fig. 4.
Further, the outer tube 30 has a male screw Portion 30c formed on the outer periphery surface of the outer tube adiacent to the upper end thereof. The male screw portion 30c is formed so as to engage with a female screw portion 33a formed on the inner peripherY surface of a cap member 33.
When the cap member 33 is screwed onto the outer tube 30 with the electrically conductive sleeve 54 inserted in the outer tube 30, an annular tightening portion 33b formed on the inner periphery surface of the cap member 33 Presses on the flange portion 32a of the sealing ring member 32, which in turn presses against the flange portion 30b of the insulating layer 30a. Therefore, a possible gap is completely prevented which otherwise is apt to occur between the outer tube 30 and the electrically conductive sleeve 54, thereby preventing rain water invasion.
The insulating sleeve 31 has a diameter smaller than that of the outer tube 30. Thus, an annular space 34 as shown in Figs. 1 and 4 is formed between the insulating sleeve 31 and the outer tube 30 after the former is inserted in the later.
Such annular space 34 is sealed at the upper end portion thereof bY the rubber ring member 31b Pressing against the inner surface of the insulating layer 30a, and is sealed at lower end Portion thereof by a stopper member 35 and the rubber ring 31c Pressing against the inner surface of the stopper member 35.
Referring to Figs. 3a and 3b, the stopper member 35 has a cYlindrical bodY 35a, a flange portion 35b, an annular recess 35c and a plurality of guide elements 35d. The guide elements 35d are arranged in directions toward the central axis of the stoPPer member 35, as shown in Fig. 3b. A
space 35e is formed surrounded bY the guide elements 35d.
The space 35e serves as a guide hole to guide a driving cord 14 when it is raised up or lowered down along the tube assemblY. Further, the stoPPer member 35 has an annular inner tightening portion 35f formed on the inner surface thereof.
In addition, the stopper member 35 has an 0-shaped ring 36 engaged in the annular recess 35c thereof. When the outer tube 30 with the antenna element 10 contained therein is inserted into the housing 20, the 0-shaPed ring 36 acts to seal a possible gaP formed between the outer wall of the stopper member 35 and the inner wall of an insertion recess 26 formed in the housing 20, as shown in Figs. 1 and 4.
Preferably, the insertion recess 26 is tapered on the inner wall thereof. BY using the guide elements 35d which also constitute a tapered face, such tapered inner wall of the insertion recess 26 not only facilitates the positioning of the outer tube 30 in it, but also improves the sealing effect of 0-shaped ring 36.
Under the central bottom of the insertion recess 26, there is formed an insertion hole 27, as shown in Fig. 1.
The driving cord 14 connected with the antenna rod 11 of the antenna element 10 passes through the insertion hole 27 into the housing 20, so that rack teeth 15 become engaged with a driving gear 21. The movements of the driving cord 14 into the housing 20 and out therefrom using the driving gear 21 are similar to those in a conventional vehicle antenna as described above with reference to Fig. 5.
After the insulating sleeve 31 and the electrically conductive sleeve 54 are successively inserted in the outer tube 30, the annular space 34 formed between the outer tube 30 and the insulating sleeve 31 may be sealed at upper and lower portions thereof, as shown in Fig. 4.
Namely, the uPPer end Portion of the annular space 34 formed between the insulating sleeve 31 and the outer tube 30 is sealed bY the rubber ring member 31b with the small projections 31d thereof Pressing against the insulating laYer 30a. Further, an annular sPace formed between the electrically conductive sleeve 54 and the outer tube 30 is sealed bY the sealing ring member 32 mounted on the upper end of the electrically conductive sleeve 54 and pressing against the uPPer end face of the outer tube 30 through the flange portion 30b of the insulating layer 30a. AccordinglY, it is impossible for rain water flowing along the antenna element 10 to reach the inner surface of the outer tube 30.
The lower portion of the annular space 34 is sealed by the rubber ring member 31c Provided on the outer periphery surface of the insulating sleeve 31 and pressing against the inner surface of the stopPer member 35, further bY the stopper member 35 with the flange portion 35b thereof Pressing against the lower end face of the outer tube 30. Accordingly, it is impossible for rain water to reach the inner surface of the outer tube 30 even if the rain water flows up with the rising of the driving cord 14 or the rain water flows up back from the housing 20.
Since the inner surface of the outer tube 30 is protected from being contacted with water, the tube itself can be used for a comparatively longer period. The tube assembly of the present invention, having a waterproof structure as described above in this Preferred embodiment, is particularly suitable for use in an area where an environment problem such as acid rain is still existing.
2 1 ~
While the presently preferred embodiment of the present invention has been shown and described above, it is to be understood that this disclosure is onlY for the Purpose of illustration and that various changes and modifications may be made without departing from the scope of the invention as set forth in the appended claims.
Tube AssemblY for Housing a Multistage Telescopic Antenna for a Vehicle BACKGROUND OF THE INVENTION
The present invention relates to a tube assemblY for housing a multistage telescopic antenna for a vehicle, and more ParticularlY, to a tube assemblY for housing a vehicle antenna having its waterproof property improved.
A vehicle antenna is usuallY constructed as having a plurality of antenna rods fitted within one another in a telescopic relation. The central rod of the antenna is connected with a driving cord having a number of rack teeth which are adaPted to engage with a driving gear. The plurality of antenna rods together constitute an antenna element which maY thus be operated to extend or retract in a telescoPic manner through the movement of the driving cord.
Japanese UtilitY Model ApPlication Laid-open 1-100508 has disclosed a vehicle antenna having a structure as shown in Fig. 5. Referring to Fig. 5, a plurality of antenna rods 11, 12 and 13 are slidably connected with one another in a telescopic relation and are housed in an outer tube 30 which is vertically provided on a housing 20. The central rod 11 is connected with a driving cord 14 which is adapted to render an antenna element 10 including the rods 11 - 13 to extend or retract in a telescoPic manner.
The housing 20 contains a driving gear 21 engaging with 2 ;~ ~
rack teeth 15 formed on the driving cord 14. The antenna .
element lO is caused to extend or retract through the movement of the driving cord 14 into and out of the housing 20. At this time, the driving cord 14 is pressed by a pressing roller 22 against the driving gear 21, thereby maintaining an engagement of the rack teeth 15 with the driving gear 21.
The driving gear 21 itself is rotated by a driving Power from an electric motor 40 contained with a motor bonnet 41.
Namely, an outPut Power of the motor 40 is transmitted to the driving gear 21 through a worm 42,a worm wheel 43, and a decelerating gear train 44. In Fig. 5, a reference numeral 45 represents a counter gear.
The driving cord 14, after being dragged into the housing through the rotation of the driving gear 21, will be disengaged from the driving gear 21 and be guided by a guide member 23 to move towards and into a receiving drum 24.
The receiving drum 24 is a free drum provided coaxially with the driving gear 21. Further, another guide member 25 is provided in the receiving drum 24 to further guide the driving cord 14 moved hereto.
However, a vehicle antenna as described above has a severe Problem of rain water invasion. That is, rain water is easy to flow along the driving cord 14 into the housing 20.
In order to solve such problem, there have been proposed manY
ideas trying to provide a kind of improved connecting means and a kind of improved insertion condition for each antenna lt~
rod, so as to obtain a higher waterproof property for a vehicle antenna. Nevertheless, the present situation is that it is still impossible to completely Prevent rain water invasion.
Another suggestion to solve the rain water invasion is to provide a drain hole at a lower portion of the housing 20, trying to enable the rain water entered in the housing 20 to flow away through the drain hole. However, whenever there is a heavY rain shower which usuallY results in a severe water invasion into the housing 20, it is difficult to drain off the entered rain water as immediatelY as is required. As a result, the rain water entered in the housing 20 is aPt to flow up into the outer tube 30. Moreover, the rain water flows from outside through gaPs between antenna rods 11 - 13 into a space formed between the outer tube 30 and an insulating sleeve 31. In addition, rain water is easy to flow down the antenna rods 11 - 13 into the same space between the outer tube 30 and the insulating sleeve 31.
In the above-discussed conventional vehicle antenna, the outer tube 30 is usuallY made of aluminium or an aluminium alloy so as to render an antenna structure light in weight and obtain a good corrosion resistance. However, after such an outer tube 30 has been exPosed to rain water, a corroding phenomena such as pitting corrosion is apt to occur on the surface thereof. Consequently, many fine holes resulting from the pitting corrosion are formed thereon, the outer tube 2 1 3 ~ ~ 1 7 can no longer be used for a vehicle antenna. The corrosion problem is particularly severe when the outer tube is exposed to an acid rain caused by increasingly deteriorating environment.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a tube assembly for housing a multistage telescopic antenna for a vehicle, in which rain water invasion can be effectively prevented and corrosion resistance has been improved.
According to the present invention, there is provided a tube assembly for housing a multistage telescopic antenna for a vehicle. The tube assembly of the present invention comprises an outer tube for housing a multistage telescopic antenna, an insulating sleeve inserted in the outer tube, an electrically conductive sleeve inserted in the outer tube, first sealing means for sealing an upper end portion and a lower end portion of an annular space formed between the insulating sleeve and the outer tube, second sealing means for sealing an upper end portion of an annular space formed between the electrically conductive sleeve and the outer tube, and a stopper member provided at a lower end portion of the annular space formed between the insulating sleeve and the outer tube. The annular space formed between the insulating sleeve and outer tube is sealed at the lower end portion thereof further by the stopper member whose inner surface is pressed by a rubber ring member provided adjacent to the lower end of the insulating sleeve.
~ .
,~
~ .
~ 1 3 ~ ~ 1! 7 In an aspect of the present invention, the first sealing means includes said rubber ring member provided on the outer periphery surface of the insulating sleeve adjacent to the lower end thereof and another rubber ring member provided on the outer periphery surface of the insulating sleeve adjacent to the upper end thereof. The second sealing means includes a sealing ring member mounted on the upper end of the electrically conductive sleeve.
The other objects and features of this invention will become understood from the following descriptions with reference to the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
Fig. 1 is a schematic view showing a vehicle antenna in which a tube assembly of the present invention is applied.
Fig. 2 is an exploded cross sectional view showing an internal structure of the tube assembly of the present invention.
Figs. 3a and 3b are front and bottom views respectively showing a stopper member of the tube assembly of the present invention.
Fig. 4 is a cross sectional view showing an assembled condition of the tube assembly of the present invention.
Fig. 5 is a schematic view showing a conventional vehicle antenna.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the drawings from Fig. 1 to Fig. 4 the same items as those in Fig. 5 are represented by the same reference numberals.
R~- Referring to Fig. 1, an outer tube 30 of a tub assembly of the Present invention is verticallY Provided on a housing 20 as in a conventional vehicle antenna. A feeding section 50 is inserted in the outer tube 30 so as to become conductive with an antenna element 10. The feeding section 50 has a terminal 51 and a terminal 52 which are respectively connected to a core conductor and an external conductor of a coaxial cable.
The terminal 51 is electrically connected to an antenna element 10 through a terminal 53 projectively formed on the inner periphery surface of the outer tube 30 and through an electrically conductive sleeve 54, as shown in Fig. 2.
Another terminal 52 is earthed through the outer tube 30.
Referring to Fig. 2, the electrically conductive sleeve 54 has a lower end portion of a smaller diameter which is formed with a notch (not shown). Such lower end portion of the electrically conductive sleeve 54 serves to Position a starting point for an antenna rod 13. In order to form a complete feeding system for the vehicle antenna, a leaf spring (not shown) connected to the coaxial cable ( serving as a feeding cable ) is introduced into the electricallY
conductive sleeve 54 through said notch formed thereon, so as to become contacted with the antenna rod 13.
Referring to Figs. 1 and 2, an insulating sleeve 31 is inserted in the outer tube 30 to form an insulation between the outer tube 30 and the antenna element 10. The insulating sleeve 31 comprises a sleeve body 31a made of a synthetic resin, a rubber ring member 31b Provided on the outer periphery surface of the sleeve adjacent to the upper end thereof and another rubber ring member 31c provided on the outer periPherY surface of the sleeve adjacent to the lower end thereof. The rubber ring members 31b and 31c together constitute a first sealing means. Each of the rubber rings members 31b and 31c has a plurality of small projections 31d formed integrallY and circumferentiallY on the outer peripherY
surface thereof. Such small Proiections 31d Possess an excellent waterProof ProPertY so that a rubber ring member as a whole acts as a good packing.
The insulating sleeve 31 has an aPProPriate length such that when it is inserted into the outer tube 30 the rubber ring member 31b presses against an insulating layer 30a formed on the inner surface of the outer tube 30. Accordingly, a possible gap between the outer tube 30 and the insulating sleeve 31 may be sealed bY the rubber ring member 31b so as to prevent rain water invasion into the space formed between the insulating sleeve 31 and the outer tube 30.
Further referring to Fig. 2, the insulating layer 30a has a flange portion 30b formed at the upPer end thereof, which is adapted to engage with the upper end face of the outer tube 30. Alternatively, an electricallY conductive resin may be utilized to form a layer on the inner surface of the outer tube 30, instead of using the insulating layer 30a and the terminal 53 . In such a case, the electrically conductive ~ 1 3 ~
resin layer should be formed in a manner such that it is insulated through proper means from the outer tube 30 and conducted with the terminal 51.
The electricallY conductive sleeve 54, into which the antenna element 10 is to be inserted, is Provided with a sealing ring member 32 named herewith as a second sealing means and mounted on the upper end portion thereof. The sealing ring member 32 has a flange Portion 32a which is adapted to engage with and Press against the flange Portion 30b of the insulating layer 30a when the electrically conductive sleeve 54 is inserted in the outer tube 30, as shown in Fig. 4.
Further, the outer tube 30 has a male screw Portion 30c formed on the outer periphery surface of the outer tube adiacent to the upper end thereof. The male screw portion 30c is formed so as to engage with a female screw portion 33a formed on the inner peripherY surface of a cap member 33.
When the cap member 33 is screwed onto the outer tube 30 with the electrically conductive sleeve 54 inserted in the outer tube 30, an annular tightening portion 33b formed on the inner periphery surface of the cap member 33 Presses on the flange portion 32a of the sealing ring member 32, which in turn presses against the flange portion 30b of the insulating layer 30a. Therefore, a possible gap is completely prevented which otherwise is apt to occur between the outer tube 30 and the electrically conductive sleeve 54, thereby preventing rain water invasion.
The insulating sleeve 31 has a diameter smaller than that of the outer tube 30. Thus, an annular space 34 as shown in Figs. 1 and 4 is formed between the insulating sleeve 31 and the outer tube 30 after the former is inserted in the later.
Such annular space 34 is sealed at the upper end portion thereof bY the rubber ring member 31b Pressing against the inner surface of the insulating layer 30a, and is sealed at lower end Portion thereof by a stopper member 35 and the rubber ring 31c Pressing against the inner surface of the stopper member 35.
Referring to Figs. 3a and 3b, the stopper member 35 has a cYlindrical bodY 35a, a flange portion 35b, an annular recess 35c and a plurality of guide elements 35d. The guide elements 35d are arranged in directions toward the central axis of the stoPPer member 35, as shown in Fig. 3b. A
space 35e is formed surrounded bY the guide elements 35d.
The space 35e serves as a guide hole to guide a driving cord 14 when it is raised up or lowered down along the tube assemblY. Further, the stoPPer member 35 has an annular inner tightening portion 35f formed on the inner surface thereof.
In addition, the stopper member 35 has an 0-shaped ring 36 engaged in the annular recess 35c thereof. When the outer tube 30 with the antenna element 10 contained therein is inserted into the housing 20, the 0-shaPed ring 36 acts to seal a possible gaP formed between the outer wall of the stopper member 35 and the inner wall of an insertion recess 26 formed in the housing 20, as shown in Figs. 1 and 4.
Preferably, the insertion recess 26 is tapered on the inner wall thereof. BY using the guide elements 35d which also constitute a tapered face, such tapered inner wall of the insertion recess 26 not only facilitates the positioning of the outer tube 30 in it, but also improves the sealing effect of 0-shaped ring 36.
Under the central bottom of the insertion recess 26, there is formed an insertion hole 27, as shown in Fig. 1.
The driving cord 14 connected with the antenna rod 11 of the antenna element 10 passes through the insertion hole 27 into the housing 20, so that rack teeth 15 become engaged with a driving gear 21. The movements of the driving cord 14 into the housing 20 and out therefrom using the driving gear 21 are similar to those in a conventional vehicle antenna as described above with reference to Fig. 5.
After the insulating sleeve 31 and the electrically conductive sleeve 54 are successively inserted in the outer tube 30, the annular space 34 formed between the outer tube 30 and the insulating sleeve 31 may be sealed at upper and lower portions thereof, as shown in Fig. 4.
Namely, the uPPer end Portion of the annular space 34 formed between the insulating sleeve 31 and the outer tube 30 is sealed bY the rubber ring member 31b with the small projections 31d thereof Pressing against the insulating laYer 30a. Further, an annular sPace formed between the electrically conductive sleeve 54 and the outer tube 30 is sealed bY the sealing ring member 32 mounted on the upper end of the electrically conductive sleeve 54 and pressing against the uPPer end face of the outer tube 30 through the flange portion 30b of the insulating layer 30a. AccordinglY, it is impossible for rain water flowing along the antenna element 10 to reach the inner surface of the outer tube 30.
The lower portion of the annular space 34 is sealed by the rubber ring member 31c Provided on the outer periphery surface of the insulating sleeve 31 and pressing against the inner surface of the stopPer member 35, further bY the stopper member 35 with the flange portion 35b thereof Pressing against the lower end face of the outer tube 30. Accordingly, it is impossible for rain water to reach the inner surface of the outer tube 30 even if the rain water flows up with the rising of the driving cord 14 or the rain water flows up back from the housing 20.
Since the inner surface of the outer tube 30 is protected from being contacted with water, the tube itself can be used for a comparatively longer period. The tube assembly of the present invention, having a waterproof structure as described above in this Preferred embodiment, is particularly suitable for use in an area where an environment problem such as acid rain is still existing.
2 1 ~
While the presently preferred embodiment of the present invention has been shown and described above, it is to be understood that this disclosure is onlY for the Purpose of illustration and that various changes and modifications may be made without departing from the scope of the invention as set forth in the appended claims.
Claims (8)
1. A tube assembly for housing multistage telescopic antenna for a vehicle, comprising:
an outer tube for housing a multistage telescopic antenna;
an insulating sleeve inserted in the outer tube;
an electrically conductive sleeve inserted in the outer tube;
first sealing means for sealing an upper end portion and a lower end portion of an annular space formed between the insulating sleeve and the outer tube;
second sealing means for sealing an upper end portion of an annual space formed between the electrically conductive sleeve and the outer tube;
and a stopper member provided at a lower end portion of the annular space formed between the insulating sleeve and the outer tube;
wherein the annular space formed between the insulating sleeve and the outer tube is sealed at the lower end portion thereof further by the stopper member whose inner surface is pressed by a rubber ring member provided adjacent to the lower end of the insulating sleeve.
an outer tube for housing a multistage telescopic antenna;
an insulating sleeve inserted in the outer tube;
an electrically conductive sleeve inserted in the outer tube;
first sealing means for sealing an upper end portion and a lower end portion of an annular space formed between the insulating sleeve and the outer tube;
second sealing means for sealing an upper end portion of an annual space formed between the electrically conductive sleeve and the outer tube;
and a stopper member provided at a lower end portion of the annular space formed between the insulating sleeve and the outer tube;
wherein the annular space formed between the insulating sleeve and the outer tube is sealed at the lower end portion thereof further by the stopper member whose inner surface is pressed by a rubber ring member provided adjacent to the lower end of the insulating sleeve.
2. The tube assembly according to claim 1, wherein the first sealing means includes said rubber ring member provided on the outer periphery surface of the insulating sleeve adjacent to the lower end thereof and another rubber ring member provided on the outer periphery surface of the insulating sleeve adjacent to the upper end thereof.
3. The tube assembly according to claim 1, wherein the second sealing means includes a sealing ring member mounted on the upper end of the electrically conductive sleeve.
4. The tube assembly according to claim 2, wherein each of the rubber ring members has a plurality of small projections formed integrally and circumferentially on the outer periphery surface thereof.
5. The tube assembly according to claim 1, wherein an insulating layer is formed on the inner periphery surface of the outer tube, said insulating layer having a flange portion contacted with the upper end face of the outer tube.
6. The tube assembly according to claim 3, wherein the sealing ring member provided on the upper end of the electrically conductive sleeve has a flange portion in contact with the flange portion of the insulting layer formed on the inner periphery surface of the outer tube.
7. The tube assembly according to claim 6, wherein the outer tube is provided with a cap member at the upper end portion thereof, said cap member having an annular tightening portion formed on the inner periphery surface thereof so as to press against the flange portion formed on the sealing ring member.
8. The tube assembly according to claim 7, wherein the outer tube has a male screw portion formed on the outer periphery surface thereof, and the cap member has a female screw portion formed on the inner periphery surface thereof, the outer tube and the cap member being fixed with each other through the engagement of the male screw portion with the female screw portion.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5-217421 | 1993-09-01 | ||
| JP21742193A JP2923177B2 (en) | 1993-09-01 | 1993-09-01 | Outer tube structure for vehicle antenna with improved waterproofness |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2131217A1 CA2131217A1 (en) | 1995-03-02 |
| CA2131217C true CA2131217C (en) | 1998-07-14 |
Family
ID=16703952
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2131217 Expired - Lifetime CA2131217C (en) | 1993-09-01 | 1994-08-31 | Tube assembly for housing a multistage telescopic antenna for a vehicle |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP2923177B2 (en) |
| CA (1) | CA2131217C (en) |
-
1993
- 1993-09-01 JP JP21742193A patent/JP2923177B2/en not_active Expired - Fee Related
-
1994
- 1994-08-31 CA CA 2131217 patent/CA2131217C/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JP2923177B2 (en) | 1999-07-26 |
| JPH0774522A (en) | 1995-03-17 |
| CA2131217A1 (en) | 1995-03-02 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKEX | Expiry |
Effective date: 20140902 |