JPS646561B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an antenna lifting device equipped with a feeding mechanism for feeding or rewinding a drive cord for lifting and lowering an antenna by rotation of a drive motor. It is something.

[Conventional technology and its issues]

Various antenna devices of this type have already been proposed, but all of them have a feeding mechanism fixed inside the antenna device. For this reason, if the drive cord hardens or the exposed antenna freezes in a cold region and the drive resistance is large, the initial load of motor drive becomes excessive and the motor may burn out. In particular, these conditions are very important recently, as antenna devices have become smaller and motors have also become smaller.

The present invention has been made based on the above circumstances, and can prevent motor burnout during overload, can automatically stop the antenna at the upper or lower limit, and can obtain these functions with a simple structure.
The present invention aims to provide an antenna lifting device that can reduce the size and weight of the entire device.

[Means to solve the problem]

For this purpose, the present invention supports on a housing a wheel that feeds a drive cord for raising and lowering an antenna, and a worm wheel that is configured to transmit power to this wheel and meshes with a worm shaft of a drive motor. The housing is elastically supported so as to be movable back and forth along the worm shaft, and when a load greater than a predetermined load is applied to the wheel via the drive cord, the housing is moved to turn off the drive motor of the drive cord. The present invention is characterized in that a switching mechanism is disposed corresponding to the housing.

〔Example〕

Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings.

In FIGS. 1 to 3, reference numeral 1 denotes a box for the antenna device, and the inside thereof is roughly divided into a motor 2, a drive cord storage section 3, a transmission system 4, and a feeding mechanism 5. The motor 2 has an output shaft 6 connected to a worm shaft 7 constituting a transmission system 4, and a worm wheel 9 that is pivotally supported by the housing 8 of the feeding mechanism 5 is meshed with the worm shaft 7. . Worm wheel 9 above
A V-groove wheel 10 constituting the feeding mechanism 5 is coaxially attached to the V-groove wheel 10, and a drive cord 12 for raising and lowering the antenna is held between a pinch roller 11 and a pinch roller 11 arranged opposite to the V-groove wheel 10. . The pinch roller 11 is pivotally connected to the arm 13,
The arm 13 has one end pivoted to the housing 8 by a pin 14, and the other end connected to a tension spring 15. The tension spring 15 is engaged with a spring hook 16 provided at another location on the housing 8 in order to press the pinch roller 11 toward the V-groove wheel 10.
Then, the V-groove wheel 10 and the pinch roller 1
The drive cord 12 sandwiched between
It is designed to be guided to the drive cord storage section 3 via the. And the guide tube 18
is curved in an arc shape and connected to the drive cord storage section 3, and guides the drive cord 12 so as to be wound into the drive cord storage section 3 shown in FIG. The drive cord storage section 3 is a disc-shaped container with one end open, and there is a pivot shaft in the center.
9, and is designed to be able to rotate within the box 1.

The housing 8 has a drive cord 1
The bullet holding mechanism 20 can move forward and backward in the feeding direction of 2.
(See Figure 4). That is, the housing 8 has slide rods 21 and 22.
are installed at the front and rear of the forward and backward directions, and the box 1
The support members 23 and 24 are fitted in the support members 23 and 24 provided inside the support members 23 and 24 so as to be slidable in the axial direction.
Compression coil springs 25, 26 are interposed between the slide rods 21, 22 and the bases of the slide rods 21, 22. As a result, the housing 8 is elastically supported in its forward and backward directions, and in order to enable this forward and backward movement, the slide rods 21 and 22 are
is slidable parallel to the worm shaft 7. In the figure, reference numeral 27 denotes a bearing that pivotally supports the worm shaft 7, and is fixed to the case 1.

The housing 8 has a switch operator 28 integrally attached thereto, which corresponds to a switch mechanism 29 constituting a three-pole switch. That is, as shown in FIG. 5, the switch mechanism 29 has a fixed contact plate 30 in the center and movable contact plates 31 and 32 on both sides of the fixed contact plate 30. One end of the operator 28 is located there. When the switch operator 28 operates according to the movement of the housing 8, it separates one of the movable contact plates 31 and 32 from the fixed contact plate 30. By switching the switching operation of the switch mechanism 29, the motor 2 is turned on and off. In this embodiment, when the movable contact plate 32 separates from the fixed contact plate 30, the rotation of the motor 2 in the feeding direction is turned off, and when the movable contact plate 31 separates from the fixed contact plate 30, the rotation of the motor 2 in the retracting direction is turned off. It's starting to turn off.

In such a configuration, when motor 2 is started,
The worm shaft 7 rotates to decelerate and rotate the worm wheel 9 with a relatively large torque. Therefore, the V-groove wheel 10 provided coaxially therewith operates to feed out the drive cord 12, and by the action of this V-groove wheel 10 and the pinch roller 11, the drive cord 12 is fed out outward. I can do it.
At that time, the V-groove wheel 10 and the pinch roller 1
1 performs a feeding action by pinching the straight portion of the drive cord 12, so there is no buckling of the drive cord 12, and the drive cord 12 can be forcefully fed out to the outside. Therefore, even if the drive cord 12 hardens in a cold region or the antenna rod attached to its tip freezes, the antenna rod can be extended relatively smoothly. If an abnormal load is applied to the drive cord 12, the rotation of the V-groove wheel 10 is restricted, and the housing 8 moves backward against the spring 25, causing the movable contact plate 32 of the switching mechanism 29 to move backward. The switch operator 28 operates to stop the motor 2. Such automatic stopping of the motor 2 is similarly performed when the antenna rod reaches its extension limit.

When the rotation direction of the motor 2 is reversed, the V-groove wheel 10 operates to retract the drive cord 12. In this case as well, even if the drive cord 12 is hardened or the antenna rod is frozen, the retracting operation of the antenna rod can be performed relatively smoothly. When the antenna rod reaches its contraction limit, the drive cord 12
When an excessive load is applied to the housing 8, the housing 8 moves forward against the spring 26, and the switch operator 28 pushes the movable contact plate 31, thereby stopping the motor 2.

〔Effect of the invention〕

As detailed above, according to the present invention, when a load of more than a predetermined value is applied to the wheel in the drive cord payout mechanism, the drive motor is switched by the movement of the housing and the driving of the drive cord is stopped. The antenna can be automatically stopped at its upper or lower limit, and even in cold regions where the drive cord is hardened or the antenna rod is frozen, it is possible to prevent the drive motor from burning out due to overload. Moreover, since the above switching operation is performed by moving the drive cord forward and backward using the housing of the drive cord payout mechanism, there is no need for a separate device such as an overload cutoff clutch, the structure is simplified, and the elevating device The entire structure can also be made smaller and lighter.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional side view showing an embodiment of the present invention;
Fig. 2 is a longitudinal cross-sectional view of the main part taken on another cross-section, Fig. 3 is a cross-sectional view taken along the line A-A in Fig. 1, Fig. 4 is a cross-sectional view taken along the line B-B in Fig. 1, and Fig. 5 is a cross-sectional view taken along the line B-B in Fig. 1. FIG. 3 is a side view of the switch mechanism. DESCRIPTION OF SYMBOLS 1... Box, 2... Motor, 3... Drive cord storage part, 4... Transmission system, 5... Feeding mechanism, 6... Output shaft, 7... Worm shaft, 8... Housing, 9... Worm wheel, 10... V-groove wheel , 11... pinch roller, 12... drive cord, 13... arm, 14... pin, 15... tension spring, 16...
Spring hook, 17, 18... Guide tube, 19
... Pivot, 20... Resilient mechanism, 21, 22... Slide rod, 23, 24... Support member, 25, 26... Compression spring, 27... Bearing, 28... Switch operator, 29... Switch mechanism, 30... Fixed contact plate, 3
1, 32...Movable contact plate.

Claims (1)

[Claims] 1. A wheel that feeds a drive cord for raising and lowering the antenna, and a worm wheel that is configured to transmit power to this wheel and meshes with the worm shaft of the drive motor are supported on a housing, and the housing is supported along the worm shaft. The housing is adapted to move forward and backward, and to move the housing and turn off the drive motor of the drive cord when a load greater than a predetermined load is applied to the wheel via the drive cord. An antenna elevating device characterized in that a switching mechanism is provided.