Patent Publication Number: US-6706987-B1

Title: Rotary push switch

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a rotary push switch mainly used in a vehicle interior light, and more particularly to a rotary push switch in which its components are simply assembled so as to maximize its assembling efficiency and productivity, and which provides a firm contact between fixed terminals and a movable terminal, and various connections of wirings so as to maximize its convenience in use. 
     2. Description of the Related Art 
     Generally, a conventional push switch comprises in combination a push button, an actuator, a movable terminal, a carrier, and a plurality of fixed terminals, installed between an upper housing and a lower housing. 
     In such a conventional push switch, whenever the push button is pressed and then returned to its original position, the actuator installed under the push button is operated to serve as a cam mechanism so that the carrier is intermittently rotated together with the movable terminal and selectively contacts the plural fixed terminals installed below the movable terminal, thus allowing the push switch to be turned on/off. 
     Several types of the push switch are disclosed by U.S. Pat. No. 4,891,476, and Korean Utility Model Registration Publication Nos. 198345 and 207503 to the present inventor(s). 
     More specifically, the assembled structure of one of the above disclosed conventional push switches is obtained by assembling a push button, an actuator, a return spring, a movable terminal, and a carrier in sequence using an assembling hole provided with a guide groove and installed through an upper housing. In both the push button and the actuator, a sliding protuberance formed along each of their peripheral surfaces is inserted into the guide groove of the assembling hole, and simultaneously a driving cam and an interlocked cam with gearwheel shapes are interlocked so that they are simultaneously operated. In the actuator, the carrier obtained by assembling the movable terminal including a plurality of contact portions and the return spring is intermittently rotated by a user&#39;s pushing of the push button. 
     Further, a substrate provided with a plurality of fixed terminals is assembled below the movable terminal including a plurality of the contact portion into a lower housing. By the rotation of the movable terminal, the plural contact portions of the movable terminal selectively contact the plural fixed terminals, thus allowing the push switch to be turned on/off. 
     The upper and lower housings are fixed to each other by inserting assembling rods formed on one housing into assembling holes formed on the other housing and then thermally fusing protruded ends of the assembling rods. 
     Other types of the conventional push switch disclosed by U.S. Pat. No. 4,996,401, and Korean Utility Model Registration Publication Nos. 128963 and 126988 to the present inventors. Compared to the above types of the conventional push switch, each of these types of the conventional push switch comprise movable and fixed terminals having designated shapes being different from the former types. Here, the fixed terminals are inserted into the inner wall of a lower housing, and the movable terminal is in contact with or out of contact with the fixed terminals by the rotation of the movable terminal, thus allowing the push switch to be turned on/off. The essential operating structures of these push switches are the same as or similar to those of the former push switches. 
     However, the above-described various conventional push switches have several problems, as follows. 
     First, since the push button, the actuator, the return spring, the movable terminal, and the carrier are assembled into one unit using the assembling hole of the upper housing, that is, many components are simultaneously assembled, the assembling efficiency and productivity of the above conventional push switches are reduced. 
     Further, since many components are assembled into the upper housing as they are not fixed or supported to one another, when the obtained upper housing and another component (i.e., the lower housing) are assembled, it is difficult to maintain their assembled condition and the assembling process of the above conventional push switches is inconvenient. 
     Second, since the upper and lower housings are combined by inserting assembling rods formed in one housing into assembling holes formed in the other housing and thermally fusing protruded ends of the assembling rods, the upper and lower housings are fixed to each other via a series of assembling and thermal fusion processes, thus reducing the assembling efficiency of the above conventional push switches. 
     Particularly, since the thermal fusion process requires expert skill, such a thermal fusion process is prone to cause defects in assembling the above conventional push switches and the assembled conventional push switches cannot be separated into their individual components. 
     Third, a plurality of the fixed terminals (i.e., three terminals) are independently assembled into the lower housing, thus causing inconvenience in assembling the above conventional push switches. 
     In order to solve the above third problem, there is proposed a method in which a plurality of the fixed terminals are riveted on a separate substrate and then the substrate provided with the fixed terminals is assembled into the lower housing. However, this method requires a step for fixing the fixed terminals to the separate substrate, thus causing inconvenience in assembling the above conventional push switches. 
     Fourth, the above conventional push switches are limited in their method of connection to power. That is, a pin-type terminal connected to a power line is inserted into a connection portion at one end of each of the above fixed terminals. 
     Further, the connection portion includes a hole formed at the end of the fixed terminal and the terminal is tightly fitted with the hole, thus causing inconvenience in assembling the above conventional push switches. Particularly, in case the outer diameter of the terminal does not coincide with the inner diameter of the correspondent hole even if the difference between the diameters is very small, it is difficult to insert the terminal into the hole or even if possible, the terminal is easily released from the hole. 
     SUMMARY OF THE INVENTION 
     Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a rotary push switch in which its components are simply assembled so as to maximize its assembling efficiency and productivity, and which provides a firm contact between a movable terminal and fixed terminals so as to maximize its reliability in use. 
     It is another object of the present invention to provide a rotary push switch which provides various connections of wirings so as to maximize its convenience in use. 
     In accordance with the present invention, the above and other objects can be accomplished by the provision of a rotary push switch formed in a built-up manner by assembling upper and lower housings by elastically inserting a plurality of locking protuberances formed along one housing into a plurality of locking grooves formed along the other housing, wherein: a return spring and an actuator are assembled in a carrier within the upper housing, a push button is inserted into an upper part of the carrier provided with the returning spring and actuator, and a movable terminal is inserted into a lower end of the carrier provided with the returning spring and actuator; and a plurality of fixed terminals are integrally formed with the lower housing and soldering holes are formed through a bottom of the lower housing at positions corresponding to the fixed terminals so that a power line is connected to the fixed terminals using terminals or by soldering. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
     FIG. 1 is an assembled cross-sectional view of a rotary push switch in accordance with one embodiment of the present invention; 
     FIG. 2 is an exploded perspective view of the rotary push switch in accordance with one embodiment of the present invention; 
     FIG. 3 is a cross-sectional view of an essential part of the rotary push switch in accordance with one embodiment of the present invention; 
     FIG. 4 is a plan view of FIG. 3; 
     FIGS. 5 a ,  5   b , and  5   c  illustrate a process for forming a lower housing of the rotary push switch in accordance with one embodiment of the present invention, and more particularly: 
     FIG. 5 a  is a perspective view of fixed terminals; 
     FIG. 5 b  is a plan view of the lower housing formed so that the fixed terminals are inserted into the lower housing; and 
     FIG. 5 c  is a side view of the forming-finished lower housing; and 
     FIGS. 6 a  and  6   b  illustrate a rotary push switch in accordance with another embodiment of the present invention, and more particularly: 
     FIG. 6 a  is a bottom view of a lower housing; and 
     FIG. 6 b  is a cross-sectional view of the lower housing. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Now, preferred embodiments of the present invention will be described in detail with reference to the annexed drawings. 
     As shown in FIGS. 1 to  5 , a rotary push switch in accordance with one embodiment of the present invention is obtained by assembling upper and lower housings  10  and  20 . A push button  30 , an actuator  40 , a return spring  50 , and a movable terminal  60  are inserted into a carrier  70  within the upper housing  10  via an assembling hole  11  so that the push motion of the push button  30  is changed by the actuator  40  into intermittent rotary motions of the carrier  70  and the movable terminal  60 , and a plurality of fixed terminals  81 ,  82 , and  83  are mounted in the lower housing  20  so that ON and OFF positions of a contact between the fixed terminals  81 ,  82  and  83 , and the movable terminal  60  are alternated by the rotation of the movable terminal  60 . 
     Here, each of the plural fixed terminals  81 ,  82 , and  83  includes a connection portion  85  and a filling hole  86 . The connection portion  85  has upper and lower elastic sections  84  and  84 ′, which are curved. The filling hole  86  serves to allow a liquefied resin to be fed therethrough, thus forming the lower housing  10  integrally with the fixed terminals  81 ,  82 , and  83 . 
     The carrier  70  includes a prominence  71  formed along an upper part of its outer circumference spaced from a flange  73  formed along a lower part of its outer circumference, and an elastic groove  72  formed through the upper part in a designated depth for allowing the upper part of the carrier  70  to be elastic so that the return spring  50  and the actuator  40  inserted into the carrier  70  are firmly fixed to the prominence  71  so as to prevent the return spring  50  and the actuator  40  from separating from the carrier  70 , and then the push button  30  is assembled into the upper part of the carrier  70  and the moveable terminal  60  is assembled into the lower part of the carrier  70 . 
     A plurality of locking grooves  12  are formed along the external surface of one housing of the upper and lower housings  10  and  20 , and a plurality of locking protuberances  22  corresponding to the locking grooves  12  are formed along the external surface of the other housing of the upper and lower housings  10  and  20 . Thus, the upper and lower housings  10  and  20  are combined with each other by elastically inserting the locking protuberances  22  into the corresponding locking grooves  12 . 
     The actuator  40  includes an insertion hole  42  formed therein for allowing the carrier  70  with a rectangular cross-section to pass through the actuator  40  thereby. A tapered portion  43  having a hollow rectangular shape is formed at an entrance of the insertion hole  42  so that the carrier  70  is guided and inserted into the insertion hole  42  by the tapered portion  43 . 
     The movable terminal  60  includes a plurality of upper and lower contact portions  61  and  62  protruding from its upper and lower surface so that the upper contact portions  61  on the upper surface alternate with the lower contact portions  62  on the lower surface, and the movable terminal  60  can be inserted into the carrier  70  at any surface thereof. 
     Although the number of the upper or lower contact portions  61  or  62  is four in the drawings of the present invention, the upper and lower contact portions  61  and  62  are not limited in their number. That is, the number of the upper or lower contact portions  61  or  62  may be three or another number. 
     As shown in FIG. 6, the lower housing  20  includes soldering holes  25 ,  25 ′ and  25 ″ formed through its bottom at positions corresponding to the fixed terminals  81 ,  82 , and  83  so that a power line is connected to the fixed terminals  81 ,  82 , and  83  using terminals or by soldering. 
     Here, a non-described number  23  denotes an assembling hole formed through the lower housing  20  for receiving the carrier  70 , and a non-described number  90  denotes a terminal. 
     Hereinafter, the operation and function of the rotary push switch in accordance with the preferred embodiment of the present invention is described in detail. 
     First, the lower housing  20  is integrally formed with the plural fixed terminals  81 ,  82 , and  83 . Accordingly, it is possible to minimize the number of components of the rotary push switch of the present invention. As shown in FIG. 5, the fixed terminals  81 ,  82 , and  83 , which are curved, are integrally formed by punching, and then a liquefied resin is fed into the fixed terminals  81 ,  82 , and  83  via each filling holes  86 , thus forming the lower housing  20  integrally with the fixed terminals  81 ,  82 , and  83 . 
     In this state, scrap portions  87  formed between the fixed terminals  81 ,  82 , and  83  are cut away. Thereby, the lower housing  20  integrally formed with the fixed terminals  81 ,  82 , and  83  is completely manufactured. 
     Next, the lower housing  20  integrally formed with the fixed terminals  81 ,  82 , and  83 , the upper housing  10 , and other components are assembled. 
     More specifically, the push button  30 , the actuator  40 , the return spring  50 , and the carrier  70  are assembled in sequence in the upper housing  10 . Here, the actuator  40  and the return spring  50  are first assembled into the carrier  70 , and then the carrier  70  provided with the actuator  40  and the return spring  50  is assembled in the upper housing  10 . 
     That is, the return spring  50  and the actuator  40  are fixed to the prominence  71  formed along the upper part of the outer circumference of the carrier  70  so that the return spring  50  and the actuator  40  are prevented from separating from the carrier  70 . Then, the carrier  70  provided with the return spring  50  and the actuator  40  fixed thereto is assembled in the upper housing  10 . The push button  30  is fixed to the upper part of the carrier  70 . 
     Further, the movable terminal  60  is fixed to the lower part of the carrier  70 . 
     Accordingly, the rotary push button of the present invention is simply obtained by assembling five components such as the upper housing  10 , the push button  30 , the carrier  70  provided with the actuator  40  and the return spring  50 , the movable terminal  60 , and the lower housing  20 . 
     Particularly, the actuator  40  and the return spring  50  are assembled in the carrier  70 , and the carrier  70  provided with the actuator  40  and the return spring  50  is assembled with other components. Accordingly, it is possible to simplify the assembling process of the rotary push switch of the present invention compared to the conventional push switch, while maintaining its assembled state the same as the conventional push switch. 
     Further, in the rotary push switch in accordance with the present invention, the assembly of the components is simplified. Since the movable terminal  60  includes a plurality of the upper and lower contact portions  61  and  62  alternately protruding from its upper and lower surfaces, the movable terminal  60  can be inserted into the carrier  70  at any surface thereof. 
     That is, when the movable terminal  60  is inserted into the carrier  70  at the upper surface thereof, the upper contact portions  61  are used to contact the fixed terminals  81 ,  82 , and  83 . On the other hand, when the movable terminal  60  is inserted into the carrier  70  at the lower surface thereof, the lower contact portions  62  are used to contact the fixed terminals  81 ,  82 , and  83 . 
     Further, the tapered portion  43  having a hollow rectangular shape is formed at the entrance of the insertion hole  42  of the actuator  40 . Thus, when the carrier  70  with a rectangular shape is inserted into the insertion hole  42 , the carrier  70  is guided by the tapered portion  43  to be easily inserted into the insertion hole  42 . 
     Moreover, the upper and lower housings  10  and  20  are simply combined with each other by elastically inserting a plurality of the locking protuberances  22  formed along the external surface of the lower housing  20  into a plurality of the locking grooves  12  formed along the external surface of the upper housing  10  at positions corresponding to the locking protuberances  22 . 
     The upper and lower housings  10  and  20  are assembled by inserting the above locking protuberances  22  into the locking grooves  12  as well as using the conventionally employed thermal fusion method. Accordingly, in case that inner components of the upper and lower housings  10  and  20  are defective, it is possible to simply separate the upper and lower housings  10  and  20  from each other, thus being capable of replacing the defective inner components with new components and improving economic efficiency of the rotary push switch. 
     In order to supply power to the rotary push switch, the terminal  90  connected to a power line is inserted into the connection portions  85  of the fixed terminals  81 ,  82 , and  83 , each connection portion  85  including the upper and lower elastic sections  84  and  84 ′. Alternatively, a power line may be directly connected to the connection portions  85  of the fixed terminals  81 ,  82 , and  38  by soldering via the soldering holes  25 ,  25 ′, and  25 ″ formed through the bottom of the lower housing  20 . 
     Although the fixed terminals  81 ,  82 , and  83  contact the movable terminal  60  in a vertical direction in the preferred embodiment of the present invention, the contact between the fixed terminals  81 ,  82  and  83 , and the movable terminal  60  is not limited thereto, but may be variously modified. However, since the vertical contact between the fixed terminals  81 ,  82  and  83 , and the movable terminal  60  is most excellent and stable, this type of the contact is described above. 
     Further, although the movable terminal  60  is installed at the lower part of the carrier  70  as shown in the drawings, the position of the movable terminal  60  is not limited thereto, but may be at the upper part of the carrier  70  so that the movable terminal  60  contacts the lower end of the return spring  50 . 
     As apparent from the above description, the present invention provides a rotary push switch in which its components are simply assembled or partially integrally formed with each other, thus reducing the number of the components and improving the assembled structure of the components. Accordingly, it is possible to maximize the assembling efficiency and productivity of the rotary push switch and provide a firm contact between a movable terminal and fixed terminals. 
     Further, the rotary push switch of the present invention is connected to a power supply by various methods such as the use of terminals or a soldering method, thus maximizing its convenience in use. 
     Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.