Abstract:
A lid lock mechanism in an automobile switch panel device. The mechanism includes an open-top case, a switch panel accommodated in said case, a lid to cover the open-top case, pivotal shafts provided in the open-top case, and clutch members provided in a pair of holes in the lid. At a predetermined opening angle, the lid is maintained in a locked condition while the lid is easily closed manually with a force stronger than a predetermined level.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a switch panel device for a vehicle, and more particularly to a lid locking mechanism for maintaining the lid of a remote control unit provided near a rear seat or the like of an automobile opened for the operation of switches on the switch panel. 
     Some automobiles are provided with a remote control unit beside a rear seat thereof. 
     The remote control unit has a lid formed by a part of an arm rest beside the rear seat. A switch panel on which switches or the like are arranged is accommodated in the remote control unit. When a passenger in the rear seat opens the lid to operate the switches on the switch panel, he can remotely control air conditioning or the like in the compartment at his own will. Thus, the remote control unit has the advantages that the passenger&#39;s convenience may be enhanced, and that the driver may be relieved from the work of switch operation. 
     While the remote control unit is operated, the lid must be maintained open such that the operation is not hindered. 
     FIG. 1 shows a conventional remote control unit. In the drawing, a lid 3 is rotatably supported to shafts 2 fixed to a control unit body 1. When the lid 3 is fully opened counterclockwise, it is supported by a bumper 4 formed of rubber or the like which is mounted on the control unit body 1 at a position below the shafts 2, thereby maintaining the lid under the open condition such that the operation of the control unit is not hindered. Further, referring to FIG. 2 which shows a lid locking mechanism in the prior art, the lid 3 is formed at its side surface with a recess 5, while the control unit body 1 is formed with a hole la having an opening opposed to the recess 5 under the lid open condition. The opening has a diameter smaller than that of the hole 1a. A spherical guide ball 6 having a diameter greater than that of the opening is inserted into the hole la. A spring 7 is inserted into the hole 1a to bias the guide ball 6 in such a manner that the guide ball 6 may be partially projected from the opening. 
     Accordingly, when the lid 3 is opened as shown in FIG. 1, the guide ball 6 abutting against the end surface of the lid 3 and being maintained retracted is brought into engagement with the recess 5, thereby locking the lid 3 and maintaining the lid under the open condition. 
     However, the lid 3 under the closed condition constitutes a part of the arm rest in the rear seat of the automobile, and the outer surface of the lid 3 is sometimes trimmed with a cloth or a leather for the purpose of affording a good external appearance to the arm rest. 
     In this case, when the lid 3 is abutted against the bumper 4, and it is supported by the lid locking mechanism, the nap of the cloth on the outer surface of the lid 3 is flattened by the contact between the cloth and the bumper 4, marring the external appearance of the lid 3. In the case of trimming the outer surface of the lid with a leather, the leather will be similarly damaged, this diminishing the good external appearance of the lid 3. 
     Further, in forming the lid locking mechanism, a high tolerance of size is required so as to position the recess 5 of the lid 3 in accordance with the guide ball 6 inserted into the hole 1a of the control unit body 1 under the full open condition of the lid 3. Further, it is troublesome to install the guide ball 6 and the spring 7 to be inserted from the inside of the control unit body 1. Additionally, a degree of freedom of design is disadvantageously limited in the conventional lid locking mechanism. 
     SUMMARY OF THE INVENTION 
     The present invention eliminates the above-mentioned problems, and provides a lid locking mechanism which may be easily worked and assembled without damaging the outer surface of the lid, and may also save space. 
     The present invention comprises a lid locking mechanism formed in a lid of a remote control unit and a pivotal shaft for supporting the lid, wherein the lid locking mechanism is adapted to engage at a predetermined open angle of the lid and maintain a lid open condition, and when a lid closing force greater than a predetermined level is applied, the lid locking mechanism is unlocked. 
     With this arrangement, the lid and the pivotal shaft for supporting the lid are engaged at a predetermined open angle of the lid to maintain the lid open condition. Furthermore, the engagement of the lid and the pivotal shaft may be released by applying a lid closing force greater than the predetermined level. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an elevational view of the control unit body in the prior art; 
     FIG. 2 is a vertical sectional view of the locking mechanism of FIG. 1; 
     FIG. 3 is an exploded view of one embodiment of the present invention; 
     FIG. 4A is an illustration of the pivotal shaft attached to the control unit body; 
     FIG. 4B is an illustration of the clutch member inserted in the lid; 
     FIG. 5A is an elevational view of the pivotal shaft of FIG. 4A; 
     FIG. 5B is an elevational view of the clutch member of FIG. 4B; and 
     FIGS. 6 and 7 are perspective views of the stoppers provided on the pivotal shaft and the lid. 
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     There will now be described a preferred embodiment of the present invention with reference to the drawings, in which the same parts as of the prior art are designated by the same reference numerals. 
     Referring to FIG. 3, a remote control unit A provided in an arm rest beside the rear seat of the automobile is generally constituted of a control unit body 1 including a switch panel 5 provided with switches or the like and an electronic circuit unit (not shown) located under the switch panel 5 and connected to the switches for generating a signal, and of a lid 3 openably supported to a pair of pivotal shafts 6 fixedly attached to the control unit 1. 
     The lid 3 is formed at both sides with a pair of holes 3a for receiving the pivotal shafts 6. Each hole 3a of the lid 3 is formed at its inner periphery with a pair of key ways. A spring 7 and a clutch member 8 having a pair of keys 8k are inserted into each hole 3a. 
     The pair of keys 8k of the clutch member 8 are engaged with the pair of key ways of the hole 3a such that the clutch member 8 is axially slidable in the hole 3a with a biasing force of the spring 7 being applied to one end surface of the clutch member 8. 
     Referring to FIGS. 4A through 5B, the other axial end surface of the clutch member 8, and the opposing axial end surface of the pivotal shaft 6 are formed with respective clutch surfaces to engage with each other. 
     The clutch surface of the pivotal shaft 6 is, as shown in FIG. 4A and FIG. 5A, formed of a flat recessed portion 6a extending substantially in a diametrical direction and a pair of projecting portions 6b on both sides thereof, each having a flat top surface 6b 1 . On both sides of said flat top surface 6b 1 , there are formed a vertical wall 6b 2  and inclined surface 6b 3 . Further, an intermediate concave surface 6b 4  is formed to connect said vertical wall 6b 2  and inclined surface 6b 3 . Thus, the flat recessed portion 6a is made contiguous to said flat top surface 6b 1  by way of the vertical wall 6b 2 , the inclined wall 6b 3  and the intermediate concave wall 6b 4 . 
     On the other hand, the clutch surface of the clutch member 8 has a complementary shape to the clutch surface of the pivotal shaft 6. That is to say, said complementary clutch surface is, as shown in FIG. 4B and FIG. 5B, composed of a projecting portion 8a having a flat top surface 8a 1  extending diametrically at an axial end of the clutch member 8 and recessed portions 8b formed on both sides of the projecting portion 8a. Each recessed portion 8b is formed of a flat bottom 8b 1 , a vertical wall 8b 2 , an inclined wall 8b 3  and an intermediate convex wall 8b 4  between the vertical wall 8b 2  and the inclined wall 8b 3  to connect said walls. Thus, the flat bottom 8b 1  is made contiguous to said flat top surface 8b by way of the vertical wall 8b 2 , the inclined wall 8b 3  and the intermediate convex wall 8b 4 . 
     The lid locking mechanism as mentioned above is operated as follows: 
     When the lid is in a closed condition, the projecting portions 8a of the clutch member 8 are abutted against the projecting portion 6b of the pivotal shaft 6. As the lid 3 is upwardly rotated to open, the projecting portions 8a are also rotated under surface contact with the projecting portion 6b. When the lid 3 approaches a maximum open angle, the surface contact between the projecting portions 8a and the projecting portion 6b is released, and both the inclined surfaces 6b 3  and 8b 3  are brought into contact with each other. Then, the projecting portions 8a are gradually inserted into the recessed portions 6a. 
     When the lid 3 reaches the maximum open angle, both the vertical walls 6b 2  and 8b 2  are brought into abutting contact with each other, thereby stopping the rotation of the lid 3. 
     Such an engaged condition of the projecting portions 8a in the recessed portions 6a is maintained by the biasing force of the spring 7. Accordingly, even when an external force in a lid opening direction is applied to the lid 3, the lid 3 is prevented from being rotated to angles greater than the maximum open angle. Further, when a weak external force in a lid closing direction is applied to the lid 3, the surface clutch is not disengaged. 
     In the closing operation of the lid 3, when an external force in the lid closing direction is applied to the lid 3 to rotate the clutch member 8 along the inclined surfaces 6b 3  and 8b 3  against the biasing force of the spring 7, the projecting portions 8a and 6b are again brought into abutment against each other, thus releasing the locked condition of the lid 3. After releasing the locked condition of the lid 3, the lid 3 may be closed by a weak external force. 
     As described above, the lid locking mechanism of the present invention is provided in the lid and the pivotal shafts for supporting the lid. Accordingly, the locking mechanism may be incorporated in the lid. 
     Referring to FIG. 6, the pivotal shaft 6 is formed at its outer periphery with a key-shaped stopper 6c on the opposite side of the clutch, and is further formed with a stopper 6d having a vertical wall 6e on the opposite side of the clutch. Referring to FIG. 7, a stopper 3c having a vertical wall 3b is formed to project from the end surface of the hole 3a of the lid 3. Further, a stopper 3d is formed in the hole 3a near the end surface thereof so as to make abutment against the stopper 6b. At the fixed open angle of the lid 3 where the surface clutches 8b and 6a are engaged, the stoppers 6d and 3c abut against each other, and the stoppers 6b and 3d abut against each other. 
     The lid supporting mechanism as mentioned above is operated as follows: 
     When the lid 3 is opened to reach a fixed open angle, the surface clutches 6a and 8b are engaged with each other to stop the lid 3. Simultaneously, the stoppers 6d and 3c abut against each other, and the stoppers 6b and 3d abut against each other, thereby supporting the lid 3. 
     Accordingly, even when an external force F in the lid opening direction is applied to the lid 3 as shown in FIG. 1 to generate a large opening torque, the torque is mainly received by the stoppers 6d and 3c and the stoppers 6b and 3d, thereby supporting the lid 3 and protecting the surface clutches 6a and 8b and the key 8a. 
     The present invention has the following effects. 
     (a) As the lid locking mechanism for locking the lid at the maximum open angle may be incorporated in the lid, the outer surface of the lid is not damaged when it is trimmed with a cloth or a leather, and the external appearance is therefore not diminished. 
     (b) As the external force required for unlocking the lid may be easily adjusted by changing a strength of the spring or changing a length of the clutch member, designing and modification of design may be made easy. 
     Further, as the locking mechanism is simple in structure, and constructed with a reduced number of parts, it is easily manufactured. 
     (c) As the pivotal shaft for supporting the lid is commonly utilized for the locking mechanism, it is not necessary to independently provide a locking mechanism as in the prior art. Further, there is no possibility that the locking mechanism is partially exposed to the outside when the lid is opened, thus diminishing the external appearance of the unit body as in the prior art. 
     (d) The working accuracy of the components of the locking mechanism need not be so high, and the components may be easily assembled. 
     (e) As the lid supporting mechanism is constructed to have stoppers formed on the lid and the pivotal shafts for supporting the lid, it is not necessary to independently provide a lid supporting mechanism. Therefore, the lid supporting mechanism of the invention may be constructed with a reduced number of parts, and it is easily manufactured.