Electrical connector having a spring with parallel legs with biased mid-sections

An electrical connector is provided and includes an insulating housing, a contact, and a metal spring. The insulating housing includes a body with a substantially planar lower wall and a receptacle extending through the body. The contact is disposed in the insulating housing and includes an inner portion extending into the receptacle and an outer portion disposed along an outer periphery of the insulating housing. The metal spring is disposed in the receptacle and includes a mid-section extending into and bias towards the receptacle.

FILED OF THE INVENTION

The present invention relates to an electrical connector and, in particular, to an electric SMD connector

BACKGROUND

CN 200520075293 U disclosed a known electrical connector having a spring formed of a bent metal rod of circular cross section. However, due to such a design, the spring of the known connector is sensitive for variations in the diameter of the plug. In other words, the spring force exerted on the plug for holding the same in place may vary and be insufficient dependent on the tolerance allowed for the plug and/or wear of the plug due to multiple plug-in and plug-out operations.

SUMMARY

Accordingly, an electrical connector is provided in view of the aforementioned issues and includes an insulating housing, a contact, and a metal spring. The insulating housing includes a body with a substantially planar lower wall and a receptacle extending through the body. The contact is disposed in the insulating housing and includes an inner portion extending into the receptacle and an outer portion disposed along an outer periphery of the insulating housing. The metal spring is disposed in the receptacle and includes a mid-section extending into and bias towards the receptacle.

DETAILED DESCRIPTION OF THE EMBODIMENT(S)

In the following, the present invention is described in detail based on an embodiment shown in the accompanying drawings.

With reference toFIG. 1the connector according to the invention is shown and includes a housing100, a shell200, plurality of contacts300,310,320,330, a spring400, and a switch500.

The housing100is made of a polymeric material by injection-molding and the shell200to be attached to the housing100. The plurality of contacts300,310,320,330are provide within the housing100and covered by the shell200. The contacts to provide an electrical path between a plug (not shown) which may be introduced into the housing100and received therein in the plug-in state and the outer periphery of the housing100. Further, the spring400is also provided in the housing100and used to secure the plug with the housing100. Finally, a switch500is also provided housing100.

The housing100defines four contact receiving spaces102, each being assigned to receive one of the contacts300,310,320,330. Each contact receiving space102has a receiving opening104recessed in an upper wall106which is substantially planar and extends essentially parallel to a lower wall108. The lower wall108is adapted to extend essentially parallel to a board of a printed circuit (not shown) on which the connector will be provided. Those upper and lower walls106,108are connected by side walls110extending along the long side of the housing100. A front face112defines a receptacle opening114for a longitudinal receptacle116extending in lengthwise direction of the housing100, which on its other longitudinal end is closed by an opposing front face118of the housing100(seeFIG. 3).

As shown inFIGS. 2 and 3, the upper wall106includes a central portion106C and two lateral portions106L. In the shown embodiment, the lateral portions106L are slightly bent downward, i.e. toward the side walls110. The central portion106C of the upper wall106extends parallel with the lower wall108, while the lateral portions106L are slightly inclined relative to the central portion106C with an angle of 3°. The angle of inclination between the lateral portion106L and the central portion106C is usually selected to be between 1° and 15°, preferably between2° and 10°.

As shown inFIG. 1, grooves120are disposed along one side wall110and correspond with the contacts300,310,320,330. Respective grooves122are provided on the opposite side wall110for contact sections of a movable electrical switch contact510and a mating electrical switch contact530of the switch500. The housing100also includes a switch compartment124accessible from the upper wall106through a switch receiving opening126(seeFIG. 3).

The switch compartment124is separately portioned from the receptacle116by a wall128(seeFIG. 8, 9). The other end of the switch compartment124as seen in the sectional views in accordance withFIGS. 8 and 9is defined by a rim section130of the housing100. A respective rim section132defines an outer wall of each contact receiving space102(seeFIG. 5).

A stop134is provided between the two rim sections130of the switch compartment124and includes a recess adapted to receive an activator512of the movable electrical contact310. The activator512is injection-molded around an arm514of the movable electrical switch contact510extending in the extension direction of the receptacle116(seeFIG. 1, 7). The activator512is slidably held in a direction perpendicular to the extension direction of the receptacle116within an activator holding-slot136, which tightly receives the activator512. In other words, only a small gap exists on the circumference around the activator512and a recess in the wall128surrounding the holding-slot136. The wall128separates the receptacle116from the switch compartment124.

Now with reference toFIGS. 6 and 7, the switch500will be discussed.

In the shown embodiment, the switch500is includes two bent pieces of sheet metal. One of those sheet metal pieces is bent to form the movable electrical switch contact510while the other sheet metal piece is bent to form the mating electrical switch contact530. The mating electrical switch contact530and the movable electrical switch contact510have a partially identical design which will be described hereinafter by referring to the movable electrical switch contact510, only. The sheet metal material is bent to define a U-shaped fastening section516adapted to encompass and thereby fix against the rim section132(seeFIG. 8, 9). The outer end of the U-shaped fastening section516is bent to define a contact lug518extending essentially coincident with the surface of the lower wall108. The outer part of the U-shaped fastening section516is received within the groove122of the housing100. The sheet metal piece is bent to essentially embody a double U-shaped configuration with the U-shaped fastening section516on the outer side and a counter bent U-shaped contact section520on the inner side, both U-shaped sections516,520having one leg522in common. An inner leg524of the U-shaped contact section520has an end section526which is bent to lie flush against a reference surface138defined by the wall128(seeFIGS. 8, 9). From this end section526the arm514extends parallel to the extension direction of the receptacle116, which overlaps with an inner leg532of the mating electrical switch contact530(seeFIG. 9). At this overlap the free end of the arm514is cold worked to define a convex projection528that defines the contacting surface cooperating with the inner leg532. Further, the arm514abuts against the reference surface138.

As evident fromFIG. 9, the free end of the inner leg532of the mating electrical switch contact530is likewise bent to abut against the reference surface138. Thus, both switch contacts510,530of the switch500are pushed against the reference surface138if the activator512projects into the receptacle116in absence of a plug received therein. Accordingly, the switch contacts510,530are protected from being damaged by misuse and overstress. If a plug is introduced into the receptacle116, the activator512slides along the activator holding-slot136until the activator512abuts against the stop134. In the course of this movement, electrical contact is made between the projection528and the inner leg532and thus, between the movable electric contact510and the mating electrical switch contact530. Again, and due to the assignment of the stop134to the activator512, damage by excessive bending of the movable electrical switch contact510and/or the mating electrical switch contact530is avoided.

Further, the switch500is adapted to minimize the space for mounting the same. The only open area to the receptale116is the holding-slot136through which the activator512projects. The rest of the switch500is arranged behind the wall128to eliminate possible contamination from the usage of the embodiment, e.g. by multiple introductions of the plug into the receptacle116. Thanks to the reference surface138, the movable electrical switch contact510and the mating electrical switch contact530, namely, the U-shaped contact sections520of both switch contacts510,530, are assembled within the switch compartment in the housing100in a predetermined preloaded state, which gradually reduces assembly tolerances.

Further, since the switch500and the contacts300,310,320,330are introduced from the same side, i.e. through the upper wall106, no rotation of the housing100is required when assembling the shown embodiment, which reduces production costs.

As shown hereinafter, this advantage is further enhanced as the spring400which is also introduced into the housing100through the upper wall106.

In the following, the spring400will be described, in particular by referring toFIG. 11. The spring400includes a U-shaped section402with a base404from which two identical spring legs406extend. Those spring legs406extend essentially parallel to each other and normal to the flat base404of the U-shaped section402. The spring400is made of a sheet metal which is cut and bent to achieve the configuration depicted inFIG. 11. In particular by bending of the sheet metal in a mid-section of the spring legs406a chamfered lead-in configuration412is provided along a forward end408thereof. A respective chamfered lead-out configuration414is also provided at the rearward end410thereof. The chamfered lead-in and lead-out configurations412,414facilitate passing of a forward tip of the plug when inserted into the receptacle116and wear is reduced. Since the spring400is made of a sheet metal having a considerably larger width, i.e. extension in extension direction of the plug, than thickness, i.e. extension in radial direction relative to the receptacle116, a sufficient spring force can be exerted on the plug to hold the same in place within the housing100while at the same time providing a long stroke to cope with plug tolerances.

Securing legs416are provided along the free end of the spring legs406and are bent upwardly from a lower end of the spring legs406toward the base404. As shown, the spring leg406define a V-shaped configuration. As shown inFIG. 4, the securing legs416have an essentially straight extension and abut against an inner wall140of the housing100defining a spring compartment142with a sharp angle of approximately 20° to 40°. Thus, the free end of the securing legs416are adapted to claw against the inner wall140, thereby fixing the spring400within the housing100by positive locking As shown inFIG. 4, the U-shaped section402of the spring400surrounds the plug along three sides of a rectangle. The lowermost delimination of the plug is provided by a concave base surface144defined by the housing100(seeFIG. 4). Supported by this base surface144, a plug with a circular cross section will have its maximum extension in the width direction of the housing100, i.e. in a direction parallel to the extension of the lower wall108at the level of the chamfered lead-in and lead-out configurations412,414. The plug may have a groove or the like recessed on the outer circumference of the plug, which cooperates with a remaining abutment face418between the lead-in and the lead-out configurations412;414. A mid-section of the spring legs406corresponds with the position of the plug in which the same has the maximum diameter in the width direction of the housing100(seeFIG. 4). For this, the extension of the spring legs406in height direction is adapted to cooperate with the ground of the spring compartment142that is defined by the housing100.

The spring400is inserted into the housing100through a spring receiving opening146(seeFIG. 4).

Now with reference to theFIG. 5, the contacts300,310,320,330will be described. In the shown embodiment, each contact300,310,320,330includes a U-shaped fastening section340, which cooperates with the associated rim section132of the associated contact receiving space102(seeFIG. 5). By this, the contacts300,310,320and330are each secured to the housing100. The contact receiving space102is adapted to receive a U-shaped bent section342. The U-shaped bent section342has an inner leg344of the U-shaped fastening section340in common with said U-shaped fastening section340(seeFIG. 5). Each contact receiving space102has a contact opening148recessed within concave walls surrounding the receptacle116and defined by the housing100. An inner portion346of the contact300,310,320,330protrudes through each contact opening148and into the receptacle116to cooperate with a mating contact provided by the plug when the same is received within the receptacle160and secured by the spring400. Thus, each contact300,310,320,330provides a conductive path between the associated contact element of the plug and an outer portion348exposed on the outer periphery of the housing100and defining contact lugs350(seeFIG. 5), which contact lugs350will be fixed to a printed circuit board.

Next, with reference toFIG. 10, the shell200will be discussed. As shown inFIGS. 1 and 10, the shell200is U-shaped to define a sealing wall202, which is designed to extend co-planar to the surface or surface sections of the planar upper wall106. In accordance with the constitution of the housing100, the shell200defines a sealing wall202with a central portion202C and two lateral portions202L extending in lengthwise direction of the shell200. When not mounted with the housing100, all portions202C, L extend essentially parallel with each other. There may be provided a bending line between the central portion202C and the neighboring lateral portions202L to facilitate bending at a predetermined position, i.e. along a predetermined line. This line is identified inFIG. 10.

The shell200furthermore defines two lateral side walls204, which encompass opposing side walls110of the housing100. Respective side walls110of the housing100are projected by notches150, which are arranged to cooperate with notch openings206recessed within the lateral side walls204. The notches150have an inclined sliding surface152against which the free end of the lateral side walls204will abut and slide, thereby bending the lateral side walls204outwardly to finally effect a snapping movement in which the notches150snap into the associated notch openings206to thereby secure the shell200against the housing100. A sealing pad208is provided between the upper wall106and the inner surface being adjacent to the upper wall106when the shell200is mounted to the housing100. The sealing pad208is attached to the shell200. The sealing pad208has at least one compressible layer, which compressible layer may be a foam layer, which is covered by a further layer like a thin flexible polymer sheet or the like. According to an embodiment of the invention, the sealing pad208is a multi-layer foam, in which at least one layer is an adhesive suitable to glue the adhesive foam against the shell200or the housing100and at least one compressible material adhered to the inner side of the adhesive by an adhesive bonding layer, which compressible material may be a natural or synthetic rubber and will have a thickness of between 0.1 to 0.4 mm, preferably of between 0.2 to 0.35 mm. The outer layer of the multi-layer foam is—on a regular basis—provided by a polymeric film covering the foam material. The polymeric film may be made of polyimide protecting the sealing pad208from higher temperatures during soldering.

As shown inFIG. 2, the notches150are adapted to cooperate with the notch-openings206of the shell200. For this, however, the shell200has to assume a bent shape in which the shield, which originally has a U-shaped form with an essentially straight sealing wall202will be deformed. Accordingly, the lateral portions202L will be bent downwardly to assume a shape in essentially parallel with the lateral portions106L of the upper wall106compressing there between the sealing pad208. As a cause of this elastic deformation of the sealing wall202the sealing pad208is pressed against the housing100thereby enhancing sealing of the outer side of the housing100. Further, and as a reaction of the elastic deformation of the sealing wall202made of a sheet material, the sealing pad208will be pressed into the slight recesses provided near a lateral end of the housing100where the contacts300,310,320,330or contacts of the switch500pass the apex of the rim sections130or132. There, the semi-circular radius of each U-shaped fastening section340or516will not necessarily be flush with the upper wall106. In other words, the compressible sealing pad208will be squeezed into recesses provided on the upper wall to prevent water having entered through the longitudinal receptacle116from leaking to the outside of the housing.

As further shownFIGS. 1 and 10, the shell200includes two guiding slots212which guiding slots212along its lateral side walls204to cooperate with a projection154projecting the side wall110of the housing100and guide the shell200during mounting with housing100and to avoid misplacement of the shell200relative to the housing100. Further, and projecting the forward notch opening206of the shell200, contact lugs214are formed by bending the sheet metal defining the shell200outwardly, whereby contact lugs214are to connect the shell200to mass for grounding the shell200.

The afore-mentioned description has been made by referring to an electrical connector. This connector may be provided in various devices, in particular, mobile electronic devices like cellular phones, tablet PCs or music players. They may likewise be provided in laptops or stationary devices like desktop computers, television or the like. Each of the afore-mentioned aspects has to be regarded as independently realizing the invention. For the second and the third aspect of the present invention, the spring is not a mandatory feature. Thus, the spring may be omitted and the plug may be secured to the connector by other means.