A connector producing method and a connector produced by insert molding and a use thereof

Abstract: To enable the production of a connector having a smaller thickness. A group of upper side male terminal fittings 2A and lower side male terminal fittings 2B are secured to the upper and lower surfaces of a mount plate 8 formed as a separate piece by pressing projections 12 into mount holes 16, thereby forming a core member 7. A housing 1 is formed by insert molding using this core member 7 as a core material. Since insert molding can be performed with the outer surfaces of the male terminal fittings 2A, 2B opposite from those secured to the mount plate 8 exposed, only the thickness of the housing 1 is added at the outer surfaces of the male terminal fittings 2A, 2B. Thus, there can be obtained a connector having a small thickness T around the male terminal fittings 2A, 2B.

Description: The present invention relates to a connector producing method, a connector produced by insert molding and a use thereof. As an example of a connector produced by insert molding is known the one disclosed in Japanese Unexamined Utility Model Publication No. 7-11771. As shown in FIG. 7, this connector is constructed such that a group of terminal fittings a, b are assembled into a housing c by insert molding, and male connector portions d, e are provided at the opposite ends. This connector is used as an intermediate connector or the like. In producing such a connector by insert molding, the housing c may be molded according to the following method. A group of terminal fittings a, b are accommodated in a cavity of a mold and the ends thereof are inserted into mount grooves formed in the wall surface of the cavity. By filling the cavity with synthetic resin by injection, the housing c is molded. However, if the above method is adopted particularly when the terminal fittings a, b have a long length, the terminal fittings a, b are elastically deformed upon being subjected to an injection pressure of the resin, with the result that the lengths of the terminal fittings a, b projecting in the male connector portions d, e may vary and, in an extreme case, the terminal fittings a, b may be brought into contact with each other. As a countermeasure, the respective terminal fittings a, b are formed with intermediate members f, g for preventing a deformation by insert molding as shown in FIG. 8. The housing c is produced by insert molding using an assembly of the intermediate members f, g and the terminal fittings a, b as a core material. This prevents the terminal fittings a, b from being elastically deformed during the insert molding of the housing c. On the other hand, the connector is required to have a smaller thickness for a space-saving purpose. However, if the connector is produced according to the prior art method, there is a limit in suppressing the thickness of the connector as a whole since there is the thickness of the intermediate members f, g surrounding the respective terminal fittings a, b in addition to that of the housing c. US-A-4 826 443 discloses an electrical block connector comprising a dielectric contact carrying member having signal contact members secured to one side of the contact carrying member at spaced intervals therealong. A dielectric housing member is secured onto the contact carrying member so that the contact members are partly covered. US-A-3 086 251 discloses a method of moulding electrical connectors on the end of a cable, whereby a block of thermoplastic insulating material is provided onto which a plurality of contacts are secured. Then, thermoplastic material is injected into a mould cavity into which the block with the contact secured thereto has been inserted, thereby finishing the electrical connector. It is the object of the present invention to provide an improved connector and a method for producing such a connector. The present invention was developed in view of the above problems, and a further object thereof is to enable the production of a connector having a smaller thickness. This object is achieved by the invention with a method according to claim 1, a connector according to claim 6 and a use according to claim 11. Preferred embodiments of the present invention are subject of the dependent claims. According to the invention there is provided a method for producing a connector by assembling a plurality of terminal fittings into a housing preferably of a synthetic resin by insert molding, comprising the steps of: forming a core member by securing the terminal fittings on surfaces of a nonconductive mount plate, and performing insert molding using the core member as a core material. Furthermore, the step of forming a core member comprises the step of providing a nonconductive mount plate having an opening formed as a through hole, and the step of performing insert molding comprises the step of inserting or filling material of the housing into to the opening of the nonconductive mount plate. Accordingly, insert molding can be performed with the outer surfaces of the male terminal fittings preferably opposite from those secured to the mount plate exposed. Accordingly, only the thickness of the housing is added at the outer surfaces of the male terminal fittings, with the result that the thickness of the connector as a whole can be reduced or suppressed. Furthermore the displacement of the terminal fittings during the insert molding of the housing can be securely prevented. According to a preferred embodiment of the invention, there is provided a method for producing a connector by assembling a plurality of terminal fittings which are not in contact with each other into a housing of a synthetic resin by insert molding, wherein a core member is formed by securing the terminal fittings on the opposite surfaces of a nonconductive mount plate, and insert molding is performed using the core member as a core material. Preferably, the securing step of the terminal fittings comprises engaging mount holes preferably formed in the terminal fittings, with projections preferably formed on the mount plate. In other words, the terminal fittings are secured by engaging mount holes formed in the terminal fittings with projections formed on the mount plate. Accordingly, the terminal fittings are secured to the mount plate by the engagement of the projections and the mount holes. Further preferably, the terminal fittings are secured to the mount plate while being connected with each other via a carrier and separated or cut from each other after being secured. Accordingly, the plurality of terminal fittings can be integrally or unitarily secured to the mount plate, enabling an efficient securing operation. Still further preferably, the method further comprises the step of orienting or mounting the terminal fittings on the mount plate by or in or on mount grooves provided thereon. Accordingly a correct positioning and/or orientation of the terminal fittings with respect to each other or with respect to the housing itself can be easily achieved. Most preferably, the securing of the terminal fittings on the mount plate is performed by means of press fitting and/or ultrasonic welding and/or gluing and/or clamping. Accordingly the terminal fittings are securely fixed to the mount plate such that their position remains substantially unchanged during the subsequent step of insert molding to form the housing. According to still a further preferred embodiment there is provided a method for producing a connector having a plurality of terminal fittings and a synthetic resin housing comprising the steps of forming a nonconductive mount plate, securing the terminal fittings on surfaces of the nonconductive mount plate to form a core member, inserting the core member into a mold cavity and insert molding synthetic resin around the core member to define the synthetic resin housing. Preferably, the terminal fittings each have at least one mount hole formed therein, the step of forming the nonconductive mount plate comprises forming projections on outer surfaces thereof, and wherein the step of securing the terminal fittings comprises engaging the mount holes of the terminal fittings on the projections of the mount plate. Further preferably, the terminal fittings initially are connected with each other via a carrier, the step of securing the terminal fittings on the surfaces of the nonconducative mount plate comprising securing the terminal fittings to the mount plate while the terminal fittings are connected via the carrier and the method further comprises the step of separating the terminal fittings from the carrier after the terminal fittings are secured to the mount plate. More further preferably, the method further comprises the step of forming the nonconductive mount plate comprising forming mount grooves on surfaces of the mount plate, and the step of orienting the terminal fittings on the mount plate in the mount grooves provided thereon. Still further preferably, the step of securing the terminal fittings on the mount plate comprises a step selected from the group consisting of press fitting, ultrasonic welding, gluing and clamping. According to the invention, there is further provided a connector, preferably produced by a method according to the invention, comprising: a nonconductive mount plate, a plurality of terminal fittings secured to surfaces of the mount plate, and a housing formed by insert molding using the terminal fittings mounted on the mount plate as a core material. Furthermore the mount plate comprises at least one opening formed as a through hole, into which the material, preferably the synthetic resin of the housing is insertable or fillable upon forming the housing by insert molding. Accordingly the housing and the mount plate carrying the terminal fittings are even more intimately connected and fixed to each other. According to a preferred embodiment of the invention, there is provided a connector produced by assembling a plurality of terminal fittings which are not in contact with each other into a housing of a synthetic resin by insert molding, comprising: a nonconductive mount plate, a plurality of terminal fittings secured to the opposite surfaces of the mount plate, and a housing formed by insert molding using the terminal fittings mounted on the mount plate as a core material. Preferably, the connector further comprises mount holes, preferably formed in the terminal fittings, and projections preferably formed on the mount plate, being engageable with each other to secure the terminal fittings on the mount plate. Accordingly, the terminal fittings can be easily secured to the mount plate. Further preferably, the mount plate is made out of the same material, in particular the same synthetic resin as the housing and preferably comprises mount grooves into which the terminal fittings are insertable. Accordingly, the terminal fittings can be easily oriented and held in a preferred orientation during the insert molding and/or curing of the housing. Still further preferably, the terminal fittings are secured or fixed to the mount plate by press fit and/or and/or ultrasonic welding and/or gluing and/or clamping. Most preferably, at least two projections are provided for each terminal fitting. According to the invention, there is further provided a use of a connector according to the invention, as or for a socket for an electric or electronic component or equipment such as a bulb, a fuse, a transistor, a resistor, an IC chip or the like, wherein at least one terminal fitting is provided for the connection with the electric or electronic component and wherein at least one further terminal is provided for an electric connection with an electric circuit. These and other objects, features and advantages of the present invention will become more apparent upon a reading of the following detailed description and accompanying drawings in which: FIG. 1 is a perspective view showing the external construction of a connector according to one embodiment of the invention, FIG. 2 is a section of the connector, FIG. 3 is an exploded perspective view of a core member, FIG. 4 is a front view showing how the core member is to be assembled, FIG. 5 is a section of the assembled core member, FIG. 6 is a perspective view of the assembled core member, FIG. 7 is a section of a prior art connector, and FIG. 8 is a section of a portion of the prior art connector corresponding to a core material thereof. Hereafter, one embodiment of the invention is described with reference to FIGS. 1 to 6. A connector according to this embodiment is an intermediate connector used by being mounted on, e.g. a fuel tank. As shown in FIGS. 1 and 2, a total of e.g. seven male terminal fittings 2A, 2B are assembled into a housing 1 which is preferably L-shaped as a whole. First and second male connector portions 3, 4 are formed at the opposite ends of the housing 1. The first male connector portion 3 has a substantially circular tubular shape, and tabs 5A, 5B at one side of the respective male terminal fittings 2A, 2B project substantially in alignment inside them so as to be engageable with unillustrated mating female connectors and fittable into an unillustrated mount hole opened in a lid e.g. of the fuel tank. The second male connector portion 4 has a substantially rectangular tubular shape, and tabs 6A, 6B at the other side of the respective male terminal fittings 2A, 2B similarly project in alignment inside the second male connector portion 4 so as to be engageable with unillustrated other female connectors. This connector is comprised of a core member 7 and the housing 1 formed by insert molding using the core member 7 as a core material. The core member 7 includes a mount plate 8 and a total of e.g. seven male terminal fittings 2A, 2B mounted on this mount plate 8. The mount plate 8 is formed, as a separate piece, preferably of the same synthetic resin as the material of the housing 1 to be described later. This mount plate 8 has a specified thickness and a substantially square shape when viewed from front. An opening 10 is formed at one side of the mount plate 8. In each of first and second, in particular upper and lower surfaces of the mount plate 8, e.g. four mount grooves 11 in which the male terminal fittings 2A, 2B are fittable are formed substantially in parallel at specified intervals in such a manner as to cross at an angle different from 0° and 180°, preferably substantially normal the opening 10. Preferably two or more projections 12 project from the bottom surface of each mount groove 11. One group of projections 12-1 (left side projections in FIG. 3) are substantially aligned along a first edge, in particular the left edge of the opening 10. The other group of projections 12-2 are formed substantially along a second edge, in particular the right edge of the opening 10 in the two inner mount grooves 11 and in positions spaced apart from the second, in particular right edge of the opening 10 in the two outer mount grooves 11. Accordingly, the spacing between the two projections 12-1/12-2 in one mount groove 11 is longer in the two preferably outer mount grooves 11 than in the two preferably inner mount grooves 11. The positions of the projections 12 are preferably substantially same in the upper and lower surfaces. Preferably four male terminal fittings 2A and preferably three male terminal fittings 2B are secured to the upper and lower surfaces of the mount plate 8, respectively while being individually fitted in the mount grooves 11. Each of the upper side male terminal fittings 2A is shaped such that the tabs 5A, 6A are provided at the opposite ends of a substantially linear base portion 14A. In the base portion 14A, at least two mount holes 16 into which the projections 12 can be pressed or inserted or fitted are formed at the substantially same intervals as the projections 12 of the corresponding mount groove 11. The tab 5A is formed e.g. by bending one end of the base portion 14A (right side of FIG. 3) downward at an angle different from 0° and 180°, preferably substantially right angles, and the tab 6A is formed e.g. by narrowing the other end of the base portion 14A. The e.g. four upper side male terminal fittings 2A are loaded while being integrally or unitarily assembled, for example, via a carrier 18 (see chain line of FIG. 3) extending over and interconnecting the tabs 5A preferably in a rigid or stiff manner. The e.g. three lower side male terminal fittings 2B are fitted into the second to fourth lower mount grooves 11 from the front end of the mount plate 8. Each of the lower side male terminal fittings 2B is similarly shaped such that the tabs 5B, 6B are provided at the opposite ends of a linear base portion 14B. In the base portion 14B, at least two mount holes 16 into which the projections 12 can be pressed or inserted or fitted are formed at corresponding, preferably the substantially same intervals as the projections 12 of the corresponding mount groove 11. The tab 5B is formed e.g. by bending one end of the base portion 14B (right side of FIG. 3) downward at an angle different from 0° or 180°, preferably substantially right angles, whereas the other tab 6B is formed by narrowing the other end of the base portion 14B. The three lower side male terminal fittings 2B are preferably loaded while being integrally or unitarily assembled, for example, via a carrier 19 (see chain line of FIG. 3) extending over and interconnecting the base portions 14B. Next, a process for producing the connector according to this embodiment is described. First, the mount plate 8 formed as a separate piece is prepared. On the other hand, the four upper side male terminal fittings 2A integrally or unitarily connected via the carrier 18 and the three lower side male terminal fittings 2B integrally or unitarily connected via the carrier 19 are loaded. The at least one carrier 19 is preferably arranged in one or more positions corresponding to the opening 10 such that the carrier 19 may be cut or removed by a cutting device, e.g. a knife, which is or can be inserted through the opening 10 of the mount plate 8. Then, as indicated by an arrow of FIG. 4, the four upper side male terminal fittings 2A are pressed or inserted or fitted into the upper side mount grooves 11 while the respective mount holes 16 are positioned with respect to the corresponding projections 12, thereby pressing the projections 12 into the mount holes 16. As a result, the male terminal fittings 2A are secured to the upper surface of the mount plate 8 preferably by press fit or gluing or ultrasonic welding or clamping while being fitted into the mount grooves 11. The carrier 18 is cut at the same time or after this pressing operation, thereby separating the respective upper side male terminal fittings 2A from one another. The three lower side male terminal fittings 2B are also pressed into the corresponding three mount grooves 11 on the lower surface of the mount plate 8 while the respective mount holes 16 are positioned with respect to the corresponding projections 12. The projections 12 are similarly pressed into the mount holes 16, with the result that the three male terminal fittings 2B are secured to the lower surface of the mount plate 8 preferably by press fit or gluing or ultrasonic welding or clamping while being fitted into the mount grooves 11. The carrier 19 is cut at the same time or after this pressing operation, thereby separating the respective upper side male terminal fittings 2B from one another. It should be noted that one mount groove 11 on the lower surface is or may be empty. In this way, there is formed the core member 7 in which the four male terminal fittings 2A and the three male terminal fittings 2B are secured to the upper and lower surfaces of the mount plate 8 as shown in FIGS. 5 and 6. The corresponding tabs 6A, 6B of the upper and lower side male terminal fittings 2A, 2B substantially face each other while being spaced apart in a direction A (FIG. 5) at an angle different from 0° or 180°, preferably substantially normal to the longitudinal direction of the tabs 6A, 6B, e.g. in the vertical direction by a specified distance. Further, the corresponding tabs 5A, 5B face each other while being spaced apart by a specified distance along a direction B arranged at an angle different from 0° or 180°, preferably substantially normal with respect to the direction A, e.g. the transverse direction of FIG. 5. The tab 5B of one, preferably the farthest lower side male terminal fitting 2B from the front end of the mount plate 8 is positioned between the corresponding tabs 5A, 5B. Subsequently, the thus assembled core member 7 is set in a cavity of a mold, and the housing 1 having substantially the same shape as the cavity is formed e.g. by insert molding around the core member 7 by filling the cavity with molten resin by injection. At this time, since the mount plate 8 is provided, the elastic deformation of the male terminal fittings 2A, 2B is prevented even if an injection pressure acts. After the resin is cooled, the above mentioned connector shown in FIGS. 1 and 2 is taken out by opening the mold. According to this embodiment, the core member 7 which serves as a core material is formed by securing the male terminal fittings 2A, 2B to the upper and lower surfaces of the mount plate 8, and insert molding can be performed with the outer surfaces of the male terminal fittings 2A, 2B opposite from those secured to the mount plate 8 exposed. Accordingly, only the thickness of the housing 1 is added at the outer surfaces of the male terminal fittings 2A, 2B, and the connector is enabled to have a thickness T of FIG. 2 around the male terminal fittings 2A, 2B. Thus, an installation space for the connector can be made smaller. Further, despite a plurality of upper and lower side male terminal fittings 2A, 2B, they can be rapidly and efficiently secured to the mount plate 8 since they are integrally or unitarily connected via the carrier 18 or 19. < Other Embodiments > The present invention is not limited to the described and illustrated embodiments. For example, the following embodiments are also embraced by the technical scope of the present invention as defined in the claims. Besides the following embodiments, a variety of changes can be made without departing from the scope of the present invention as defined in the claims. (1) The male terminal fittings may be secured by welding or gluing or clamping. Specifically, after the projections formed on the mount plate are fitted into the mount holes formed in the male terminal fittings, these projections are welded by ultrasonic waves so as not come out of the mount holes, thereby securing the male terminal fittings to the mount plate. (2) A desired number of terminal fittings may be arranged on the opposite surfaces of the mount plate. (3) The present invention is applicable not only to the intermediate connector illustrated in the foregoing embodiment, but also to connectors in general used for other purposes in which a group of terminal fittings are so arranged as to face each other within the housing. (4) A socket for a bulb, a fuse, a transistor, a resistor, an IC chip or the like electric or electronic component or equipment, in which a group of terminal fittings are assembled in a housing and a bulb receptacle and a connector portion are provided at one and the other ends, respectively can be conceived as a connector in a broader sense. Such bulb sockets are also embraced by the scope of the present invention as defined in the claims.

Claims: A method for producing a connector by assembling a plurality of terminal fittings (2A; 2B) into a housing (1) preferably of a synthetic resin by insert molding, comprising the steps of: forming a core member (7), whereby the step of forming a core member (7) comprises the step of securing the terminal fittings (2A; 2B) on surfaces of a nonconductive mount plate (8), and performing insert molding using the core member (7) as a core material, characterized in that the step of forming a core member comprises the step of providing a nonconductive mount plate (8) having an opening (10) formed as a through hole, and the step of performing insert molding comprises the step of inserting or filling material of the housing (1) into the opening (10) of the nonconductive mount plate (8). A method according to claim 1, wherein the securing step of the terminal fittings (2A; 2B) comprises engaging mount holes (16) preferably formed in the terminal fittings (2A; 2B), with projections (12-1; 12-2) preferably formed on the mount plate (8). A method according to one or more of the preceding claims, wherein the terminal fittings (2A; 2B) are secured to the mount plate (8) while being connected with each other via a carrier (18; 19) and separated or cut from each other after being secured. A method according to one or more of the preceding claims, further comprising the step of orienting the terminal fittings (2A; 2B) on the mount plate (8) by mount grooves (11) provided thereon. A method according to one or more of the preceding claims, wherein the securing of the terminal fittings (2A; 2B) on the mount plate (8) is performed by means of press fitting and/or ultrasonic welding and/or gluing and/or clamping. A connector, preferably produced by a method according to one or more of the preceding claims, comprising: a nonconductive mount plate (8), a plurality of terminal fittings (2A; 2B) secured to surfaces of the mount plate (8), and a housing (1) formed by insert molding using the terminal fittings (2A; 2B) mounted on the mount plate (8) as a core material, characterized in that the nonconductive mount plate (8) comprises at least one opening (10) formed as a through hole into which material of the housing (1) is insertable or fillable upon forming the housing (1) by insert molding. A connector according to claim 6, further comprising mount holes (16), preferably formed in the terminal fittings (2A; 2B), and projections (12-1; 12-2) preferably formed on the mount plate (8), being engageable with each other to secure the terminal fittings (2A; 2B) on the mount plate (8). A connector according to claim 6 or 7, wherein the mount plate (8) is made out of the same material, in particular the same synthetic resin as the housing (1) and preferably comprises mount grooves (11) into which the terminal fittings (2A; 2B) are insertable. A connector according to one or more of the preceding claims 6 to 8, wherein the terminal fittings (2A; 2B) are secured to the mount plate (8) by press fit and/or ultrasonic welding and/or gluing and/or clamping. A connector according to one or more of the preceding claims 7 to 9, wherein at least two projections (12-1, 12-2) are provided for each terminal fitting (2A; 2B). Use of a connector according to one or more of the preceding claims 6 to 10, as a socket for an electric or electronic component such as a bulb, a fuse, a transistor, a resistor, an IC chip or the like, wherein at least one terminal fitting (2A; 2B) is provided for the connection with the electric or electronic component and wherein at least one further terminal (2A; 2B) is provided for an electric connection with an electric circuit.

Inventors: UCHIYAMA TAKAHIRO, UCHIYAMA, TAKAHIRO
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEMS, LTD.
Application year: 1998
Main classification: H01R43
IPC codes: B29C33, H01R13, B29C45, H01R43, B29L31