The present invention generally relates to electrical connectors, and more particularly to an electrical connector coupled to a thermostat in a motor vehicle.

A cooling system for a motor vehicle engine controls the temperature of an engine by means of cooling water. The cooling water is circulated between a water jacket in an engine cylinder block and a radiator. The cooling system includes a thermostat located between the engine and the radiator for controlling the flow of the cooling water. The thermostat is a valve device which opens and closes a cooling water passage. The cooling system maintains the temperature of the cooling water below a predetermined temperature by the opening and closing operation of the thermostat. Recently, an electronic thermostat has been applied to a motor vehicle. The electronic thermostat is electrically connected to an electronic control unit (ECU) of a motor vehicle. For an electrical connection between the thermostat and the ECU, an electrical connector for connection to a cable extending from the ECU is coupled to the electronic thermostat. The thermostat, which is connected to the ECU via such an electrical connector, performs its valve function under the control of the ECU.

It is an object of the present invention to provide an electrical connector, which is configured to transmit electric currents or electric signals between an ECU and a thermostat. It is a further object of the present invention to provide an electrical connector for a thermostat, which achieves reduction in manufacture costs and simplification of manufacture processes.

To achieve the above and other objects, in an exemplary embodiment, the present invention provides an electrical connector for a thermostat, which includes a housing, first and second connection terminals, and first and second contact terminals. The first connection terminal is disposed in the housing and includes a first body. The second connection terminal is preferably coaxially spaced apart from the first connection terminal in the housing. The second connection terminal includes a second body. The first contact terminal is advantageously hollow and is inserted to the first body. The second contact terminal is advantageously hollow and is inserted to the second body. The contact terminal includes bands and a plurality of contact members. The bands are respectively disposed at both longitudinal ends of the contact terminal and are in contact with an inner peripheral surface of the body. The contact members are disposed along a circumferential direction of the contact terminal between the bands. Preferably a cross-sectional area of the contact terminal becomes smaller from the both bands toward a center of the contact terminal.

In an embodiment of the present invention, the first connection terminal further includes an arm terminal extending outwardly from an outer peripheral surface of the first body and/or the second connection terminal further includes an arm terminal extending outwardly from an outer peripheral surface of the second body.

In an embodiment of the present invention, the second connection terminal further includes an extension extending from the second body in a longitudinal direction of the second body and/or an arm terminal extending radially from a free end of the extension.

In an embodiment of the present invention, the housing includes an inner housing receiving the first and second connection terminals and an outer housing, preferably overmolded, on the inner housing. The inner housing includes a first socket receiving the first connection terminal and a second socket receiving the second connection terminal.

In an embodiment of the present invention, the first contact terminal further includes a plurality of first slits, each being formed between the neighboring first contact members. The second contact terminal further includes a plurality of second slits, each being formed between the neighboring second contact members. In another exemplary embodiment, the present invention provides an electrical connector for a thermostat, which includes a housing having a central axis, a first connection terminal disposed in the housing and having a first bonding lug, a second connection terminal disposed in the housing and having a second bonding lug, the second connection terminal being preferably mirror symmetrical to the first connection terminal with respect to the central axis,. A first contact terminal is connected to the first connection terminal and disposed coaxially with the central axis, and a second contact terminal is connected to the second connection terminal, and preferably spaced apart from the first contact terminal along the central axis.

The first contact terminal includes first bands respectively disposed at both longitudinal ends of the first contact terminal, a plurality of first contact members disposed along a circumferential direction of the first contact terminal between the first bands, and a first bonding arm extending outwardly from the first band, and preferably bonded to the first bonding lug.

The second contact terminal includes second bands respectively disposed at both longitudinal ends of the second contact terminal, a plurality of second contact members disposed along a circumferential direction of the second contact terminal between the second bands, and a second bonding arm extending outwardly from the band, and preferably bonded to the second bonding lug.

Preferably, a cross-sectional area of the contact terminals becomes smaller from the both bands toward a center of the contact terminal.

In an embodiment of the present invention, the second bonding lug is offset from a line extending through the first bonding lug among lines orthogonal to the central axis. In an embodiment of the present invention, the first and second bonding lugs protrude outwardly from the central axis. In an embodiment of the present invention, the housing includes a first housing receiving the first and second contact terminal and a second housing separably joined to the first housing. The electrical connector according to the embodiments provides electrical connection between an electrical cable extending from an ECU and a thermostat through the connection terminals and the contact terminals. According to the embodiment, the connection terminal can be made with low costs and simple process. Further, the contact terminal includes the bands and the contact members, thus effecting a reliable electrical connection to the thermostat. The electrical connector according to the embodiment can achieve reduction in manufacturing costs and simplification of manufacturing processes.

Of course, different features, alternatives and/or embodiments of the present invention can be combined with each other in various arrangement to the extent that they are not incompatible or mutually exclusive of others.

The present invention will be better understood and other features and advantages will become apparent upon reading the following detailed description including embodiments for illustrative purposes with reference to the figures, presented as non- limitative examples, which can be used to complete the understanding of the present invention and the description and, where appropriate, contribute to its definition, in which:

- FIG. 1 is a perspective view of an electrical connector according to a first embodiment of the present invention,

- FIG. 2 is an exploded perspective view of the electrical connector according to the first embodiment of the present invention,

- FIG. 3 is a perspective view showing first and second connection terminals shown in FIG. 2,

- FIG. 4 is a perspective view showing an alternative example of the first and second connection terminals,

- FIG. 5 is a perspective view showing first and second contact terminals shown in FIG. 2,

- FIG. 6 is a sectional view of the electrical connector shown in FIG. 1 , wherein a thermostat plug is inserted to the electrical connector,

- FIG. 7 is a partially enlarged view of FIG. 6,

- FIG. 8 is an exploded perspective view showing an electrical connector according to a second embodiment of the present invention,

- FIG. 9 is a perspective view showing a first connection terminal and a second contact terminal shown in FIG. 8,

- FIG. 10 is a perspective view showing a second connection terminal and a first contact terminal shown in FIG. 8,

- FIG. 11 is an exploded perspective view showing an electrical connector according to a third embodiment of the present invention,

- FIG. 12 is a perspective view showing a first connection terminal and a first contact terminal shown in FIG. 1 1 ,

- FIG. 13 is a perspective view showing a second connection terminal and a second contact terminal shown in FIG. 11 ,

- FIG. 14 is an exploded perspective view showing an electrical connector according to a fourth embodiment of the present invention, and

- FIG. 15 is an exploded perspective view showing an electrical connector according to a fifth embodiment of the present invention.

It should be noted that, on figures, structural and/or functional elements which are common to different embodiments may have the same reference sign. Thus, unless otherwise stated, these elements have structural, dimensional and material properties which are identical.

Descriptions are made as to a first embodiment of an electrical connector for a thermostat for use in a motor vehicle, which is, hereinafter, briefly referred to as an electrical connector, according to the present invention with reference to FIGS. 1 to 7.

Referring now to FIGS. 1 and 2, an electrical connector 100 according to the first embodiment includes an outer housing 110, an inner housing 120, first and second connection terminals 130, 140, first and second contact terminals 150, 160, a holder 170 and an O-ring 180.

The electrical connector 100 of this embodiment, and electrical connectors according to another embodiment to be described below, is a male-type connector. The electrical connector 100 is mated to a corresponding female connector 10, as shown on FIG. 2, which is, at the one hand, electrically connected to an ECU of a motor vehicle and, on the other hand, is coupled or joined to a thermostat plug 20, as shown on FIG. 6, of a thermostat equipped in the motor vehicle, at its opposite or lateral side.

The electrical connector 100 is configured to transmit electric currents or electric signals between the ECU and the thermostat as coupled to the female connector 10 as well as the thermostat plug 20.

The outer housing 110 has preferably a T-shape. The outer housing 110 has a connection section 111 a, for a connection to the female connector 10, and a plug insertion section 111 b, for an insertion of the thermostat plug 20. The connection section 111 a defines a cavity 112 in which a portion of the female connector 10 is inserted.

A longitudinal end of the plug insertion section 111 b is closed while the opposite end thereof is open so as to receive the thermostat plug 20.

The outer housing 110 comprises a single part that may be formed by molding. Some embodiment may include the outer housing 110 having two half parts, which have the same shape and are configured to receive the assembled inner housing 120. The inner housing 120 is disposed in the plug insertion section 111 b of the outer housing 110. The inner housing 120 has a cylindrical shape and comprises semi- cylindrical first and second halves 121 a, 121 b having the same shape. A longitudinal end of each half 121 a, 121 b, which faces toward the closed end of the plug insertion section 111 b, comprises a closed end, while its longitudinal opposite end comprises an open end for insertion of the thermostat plug 20. The inner housing 120 includes a first socket 122a for receiving the first connection terminal 130 and a second socket 122b for receiving the second connection terminal 140, in its inside. The first and second sockets 122a, 122b have a semi-cylindrical shape and are formed respectively in each half 121 a, 121 b. The first and second sockets 122a, 122b are spaced apart from each other via a spacer 123 and are coaxially disposed in the inner housing 120. Advantageously, the second socket 122b has a diameter greater than that of the first socket 122a.

Tap portions 124a, 124b, to which a portion of the connection terminals 130, 140, particularly arm terminals 132, 142 of the connection terminal 130, 140 which are to be described below, are secured, protrude from each half 121 a, 121 b in the vicinity of the open end of each half 121 a, 121 b.

The tap portions 124a, 124b are formed with a first terminal channel 125a, to which the arm terminal 132 of the first connection terminal 130 is seated or fitted, and a second terminal channel 125b, to which the arm terminal 142 of the second connection terminal 140 is seated or fitted.

The first terminal channel 125a is located at the longitudinal open end of the first socket 122a and communicates with the first socket 122a. The second terminal channel 125b is located adjacent to the first terminal channel 125a and communicates with the second socket 122b. The first and second connection terminals 130, 140 are respectively placed in the first and second sockets 122a, 122b of the first half 121 a and the arm terminals 132, 142 are fitted to the respective terminal channels 125a, 125b. Then, the second half 121 b is joined to the first half 121 a.

The first and second halves 121 a, 121 b of the inner housing 120 are preferably snap- engaged to each other. For snap engagement, the first half 121 a has hook-shaped or claw-shaped snapping protrusions 126a and the second half 121 b has engaging protrusions 126b respectively corresponding to the snapping protrusions 126a. The first connection terminal 130 and the second connection terminal 140 are disposed coaxially in the inner housing 120 and are spaced apart from each other.

The first connection terminal 130 includes a first body 131 , preferably a first hollow ring-shaped first body 131 , and the arm terminal 132, that is electrically connected to the first body 131 , and extends outwardly from an outer peripheral surface of the first body 131. The arm terminal 132 has a bar shape and is located near the second connection terminal 140. The second connection terminal 140 includes a second body 141 , preferably a second hollow ring-shaped second body 141 , and the arm terminal 142 that is electrically connected to the second body 141 and extends outwardly from an outer peripheral surface of the second body 141. The arm terminal 142 has a bar shape and is located near the first connection terminal 130.

The first body 131 and the arm terminal 132 of the first connection terminal 130 are integrated with each other. Further, the second body 141 and the arm terminal 142 of the second connection terminal 140 are integrated with each other.

Preferably, the second body 141 of the second connection terminal 140 has a diameter, or a cross-sectional area, greater than that of the first body 131 of the first connection terminal 130.

The first and second connection terminals 130, 140 may be formed by bonding a base end of the arm terminal 132, 142 to the outer peripheral surface of the first body 131 , 141 by means of a bonding means such as laser welding. Alternatively, the first and second connection terminals 130, 140 may comprise a single part.

Referring to FIG. 4, as an alternative, the first connection terminal 130 may include a first body 131 ', preferably a ring-shaped first body 131 ', and an arm terminal 132' integrally formed to the first body 131 '. Further, the second connection terminal 140 may include a second body 141 ', preferably a ring-shaped body 141 ', and an arm terminal 142' integrally formed to the second body 141 '. Such first and second connection terminals 130, 140 may be formed by bending a thin plate having a rectangular section to form the bodies 131 ', 141 ' and an elongated extension section that extends an edge of the rectangular section and forms the arm terminals 132', 142'. The bodies 131 ', 141 ' are formed by bending the rectangular section of the thin plate into a ring shape.

The arm terminals 132', 142' are formed by outwardly bending the extension section from the ring-shaped bodies 131 ', 141 '. The arm terminals 132', 142', which are formed in the above-described manner, eliminate the bonding process between the bodies 131 ', 141 ' and the arm terminals 132', 142', thus reducing manufacturing time and cost.

Whatever the manufacturing process of first and second connection terminals 130, 140, according to the present invention, the first contact terminal 150 and the second contact terminal 160 are respectively inserted or fitted into the first first body 131 of the first connection terminal 130 and the second body 141 of the second connection terminal 140.

Referring to FIG. 5, the first contact terminal 150 and the second contact terminal 160 have a cylindrical shape with a concave middle portion. The first contact terminal 150 includes a pair of bands 151 , a plurality of contact members 152 and a plurality of slits 153. Similarly, the second contact terminal 160 includes a pair of bands 161 , a plurality of contact members 162 and a plurality of slits 163.

Preferably, the first and second contact terminals 150, 160 have the same shape and configuration except that the second contact terminal 160 has a diameter, or cross- section area, greater than that of the first contact terminal 150. The bands 151 of the first contact terminal 150 have a ring shape and are respectively located at both longitudinal ends of the first contact terminal 150. The contact members 152 extend between the bands 151 in a longitudinal direction of the first contact terminal 150. The contact members 152 are disposed in a circumferential direction of the first contact terminal 150.

Advantageously, an outer diameter of the first contact terminal 150 at the contact members 152 is smaller than that of the first contact terminal 150 at the bands 151. The contact terminal 150 has an outer diameter that becomes gradually smaller from the both bands 151 toward a longitudinal center thereof. Thus, the contact members 152 are inwardly concave at the longitudinal center of the first contact terminal 150.

The slits 153 extend, in the longitudinal direction of the first contact terminal 150, between the neighboring contact members 152.

Some embodiments may include the first contact terminal 150 without the slits 153, instead the neighboring contact members 152 are cut therebetween along the longitudinal direction of the first contact terminal 150. The second contact terminal 160 has a similar shape and design than that of the first contact terminal 150. Nevertheless, dimensions, diameters and/or cross-section areas may differ from those of the first contact terminal 150.

The first contact terminal 150 and the second contact terminal 160 are formed by stamping and then bending a thin flat elastic plate. Specifically, the thin flat plate is first stamped to thereby remove portions of the slits 153 to thus form the contact members 152 through such removal. Then, the stamped plate, preferably the stamped elastic plate, is bent in a ring shape thus forming a general shape of the first contact terminal 150, respectively the second contact terminal 160.

Thereafter, the middle portion of the first contact terminal 150, respectively the second contact terminal 160, of the general shape is inwardly pressed to form the concave shape of the contact members 152, thereby finally forming the first contact member 150, respectively the second contact terminal 160.

The band 151 does not continue in its entirety, but separates at its some point. That is, the band 151 has opposing spaced ends.

When the first contact terminal 150 is inserted to the first body 131 , the band 151 is resiliently deformed and then restored. Thus, with the bands 151 , the first contact member 150 is resiliently inserted and affixed to the first body 131.

Some embodiments may include the band 151 , the opposing ends of which are bonded to each other by means of a bonding means such as laser welding.

The holder 170 is located at the open end of the plug insertion section 111 b and is joined to an edge of the second body 141 of the second connection terminal 140. The holder 170 has a ring shape to thus define a circular opening, to allow the thermostat plug 20 to pass therethrough.

The O-ring 180 is fitted to an annular groove 113 formed in an outer peripheral surface of the plug insertion section 111 b of the outer housing 110. The O-ring 180 seals up a gap between the electrical connector 100 and the thermostat.

Referring to FIG. 6, the first body 131 of the first connection terminal 130 is fitted to the first socket 122a and its arm terminal 132 extends toward the connection section 111 a of the outer housing 110.

Further, the second body 141 of the second connection terminal 140 is fitted to the second socket 122b and its arm terminal 142 extends toward the connection section 111 a of the outer housing 110.

The first contact terminal 150 is fitted to the inside of the first body 131 of the first connection terminal 130 and the second contact terminal 160 is fitted to the inside of the second body 141 of the second connection terminal 140. When fitted, the bands 151 of the first contact terminal 150 are in surface contact with an inner peripheral surface of the first body 131 , thus providing electrical connection between the first contact terminal 150 and the first connection terminal 130, i.e. the first body 131 and the arm terminal 132. Further, the bands 161 of the second contact terminal 160 are in surface contact with an inner peripheral surface of the second body 141 , thus providing electrical connection between the second contact terminal 160 and the second connection terminal 140, i.e. the second body 141 and the arm terminal 142. The thermostat plug 20 includes a first plug section 21 and a second plug section 22. The first and second plug sections 21 , 22 have a shape of a cylindrical pin. Preferably, the first plug section 21 has a diameter smaller than the second plug section 22. When the thermostat plug 20 is inserted to the electrical connector 100, the first plug section 21 is fitted to the inside of the first contact terminal 150. Thus, the contact members 152 of the first contact terminal 150 are resiliently radially deformed. The bands 152 are brought into strong close contact with the inner peripheral surface of the first body 131 due to a reaction force, or spring , caused by the resilient deformation of the contact members 152, thereby firmly maintaining the electrical connections between the first connection terminal 130 and the first contact terminal 150, as well as between the first plug section 21 and the first contact terminal 150.

Similarly, when the thermostat plug 20 is inserted to the electrical connector 100, the second plug section 22 is fitted to the second contact terminal 160. Thus, the contact members 162 of the second contact terminal 160 are resiliently radially deformed, as particularly shown in FIG. 7. The bands 161 are brought into strong close contact with the inner peripheral surface of the second body 141 due to a reaction force, or spring force, caused by the resilient deformation of the contact members 162, thereby firmly maintaining the electrical connections between the second connection terminal 140 and the second contact terminal 160, as well as between the second plug section 22 and the second contact terminal 160. When the electrical connector 100 is mated to the female connector 10 and the thermostat plug 20 is fitted to the electrical connector 100, electric current, or electric signals, passes through:

- a first path including the arm terminal 132, the first body 131 , the bands 151 , the contact members 152 and the first plug section 21 , and

- a second path including the arm terminal 142, the second body 141 , the bands 161 , the contact members 162 and the second plug section 22. In such flow of the electric current, or electric signals, the terminal located on the first path may function as a plus terminal, while the terminal located on the second path may function as a minus terminal.

The above-described electrical connector 100 may be manufactured by overmolding an assembly wherein the first and second contact terminals 150, 160 and the first and second connection terminals 130, 140 are fitted to the inner housing 120 and the holder 170 is joined to the second connection terminal 140.

FIGS. 8 to 10 show an electrical connector 200 according to a second embodiment of the present invention. In FIGS. 8 to 10, the same elements or parts as those of the electrical connector 100 of the foregoing first embodiment are denoted by the same reference numerals.

Referring to FIG. 8, the electrical connector 200 according to the second embodiment includes a first housing 210, a second housing 220, first and second connection terminals 230, 240, first and second contact terminals 250, 260 and the O-ring 180.

The first housing 210 has an L-shape. The first housing 210 has a connection section 211 a for connection to the female connector 10 and a plug insertion section 211 b to which the thermostat plug 20 is inserted. The plug insertion section 211 b has a semi- cylindrical shape and extends perpendicularly from the connection section 211 a. An annular groove 214, to which the O-ring 180 is fitted, is formed between the connection section 211 a and the plug insertion section 211 b.

Further, the first housing 210 includes a first socket 212a, for receiving the first contact terminal 250, and a second socket 212b, for receiving the second contact terminal 260. The first and second sockets 212a, 212b are formed in a semi- cylindrical shape and are located in the plug insertion section 211 b. The first and second sockets 212a, 212b are disposed coaxially with a central axis CA1 and are spaced apart from each other via a spacer 213. Preferably, the second socket 212b has a diameter greater than that of the first socket 212a.

The second housing 220 has a semi-cylindrical shape and is separably joined to the plug insertion section 211 b of the first housing 210. The second housing 220 secures the first and second contact terminals 250, 260 to the first housing 210.

Further, the second housing 220 includes respectively semi-cylindrical sockets configured to correspond to the first and second sockets 212a, 212b.

The first and second housings 210, 220 are snap-engaged to each other. The second housing 220 has a hook-shaped or claw-shaped snapping protrusions 221 at its edge and the first housing 210 has engaging protrusions 215, to which the snapping protrusions 221 engages respectively, at an edge of the plug insertion section 211 b.

The first and second connection terminals 230, 240 are bent in an L-shape and thus correspond to the shape of the first housing 210. The first and second connection terminals 230, 240 may be made by bending an elongated metallic plate.

Referring to FIG. 9, the first connection terminal 230 has a bar-shaped arm terminal 231 , a first horizontal section 232, a second horizontal section 233 and a bonding lug 234.

The first horizontal section 232 perpendicularly extends from the arm terminal 231 and is preferably parallel to the central axis CA1. The second horizontal section 233 extends from the first horizontal section 232 and is preferably parallel to the central axis CA1. Further, the second horizontal section 233 is preferably spaced further away from the central axis CA1 than the first horizontal section 232. The bonding lug 234 protrudes from a fixed end of the second horizontal section 233, which is the end connected to the first horizontal section 232, outwardly of the central axis CA1. The second contact terminal 260 is connected to the first connection terminal 230. The second contact terminal 260 has the bands 161 , the plurality of contact members 162, the plurality of slits 163 and a bonding arm 264.

When compared to the second contact terminal 160 in the first embodiment, the first contact terminal 260 of the second embodiment further includes the bonding arm 264 which extends radially outwardly from the band 161 located longitudinally inward. The bonding arm 264 is bonded to the bonding lug 234 of the first connection terminal 230, thus connecting the first contact terminal 260 to the first connection terminal 230. The bonding lug 234 and the bonding arm 264 may be bonded to each other by means of a bonding means such as laser welding or soldering.

Referring to FIG. 10, the second connection terminal 240 has a bar-shaped arm terminal 241 , a first horizontal section 242, a second horizontal section 243 and a bonding lug 244.

The arm terminal 241 and the first and second horizontal sections 242, 243 of the second connection terminal 240 are preferably mirror-symmetrical to the arm terminal 231 and the first and second horizontal sections 232, 233 of the first connection terminal 230 with respect to the central axis CA1.

The bonding lug 244 protrudes from a free end of the second horizontal section 243 outwardly of the central axis CA1. The bonding lug 244 of the second connection terminal 240 is offset from an offset line OL, which extends through a longitudinal end of the bonding lug 234 of the first connection terminal.

That is, the bonding lug 234 of the first connection terminal 230 and the bonding lug 244 of the second connection terminal 240 are spaced apart from each other along the central axis CA1.

The first contact terminal 250 is connected to the second connection terminal 240. The first contact terminal 250 has the bands 151 , the plurality of contact members 152, the plurality of slits 153 and a bonding arm 254.

When compared to the first contact terminal 150 in the first embodiment, the first contact terminal 250 of the second embodiment further includes the bonding arm 254 which extends radially outwardly from the band 151 located longitudinally inward. The bonding arm 254 is bonded to the bonding lug 244 of the second connection terminal 240, thus connecting the second contact terminal 250 to the second connection terminal 240. The bonding lug 244 and the bonding arm 254 may be bonded to each other by means of a bonding means such as laser welding or soldering. In the electrical connector 200 of the second embodiment, the first and second contact terminals 250, 260 are respectively fitted to the first and second sockets 212a, 212b. Thus, the first and second contact terminals 250, 260 are disposed coaxially with the central axis CA1 and are spaced apart from each other along the central axis CA1.

The electrical connector 200 may be manufactured through the following:

- forming the first housing 210 by disposing the first and second connection terminals 230, 240 in a mold and then molding the same,

- forming the second housing 220 by molding,

- fitting respectively the first and second contact terminals 250, 260 to the first and second sockets 212a, 212b,

- bonding respectively the bonding arms 264, 254 to the bonding lug 234, 244, and

- joining the second housing 220 to the plug insertion section 211 b of the first housing 210. FIGS. 11 to 13 show an electrical connector 300 according to a third embodiment of the present invention. In FIGS. 11 to 13, the same elements or parts as those of the electrical connectors 100, 200 of the foregoing first and second embodiments are denoted by the same reference numerals. Referring to FIG. 11 , the electrical connector 300 according the third embodiment includes a first housing 310, a second housing 320, first and second connection terminals 330, 340, the first and second contact terminals 350, 360 and the O-ring 180. The first housing 310 has an l-shape. The first housing 310 has a connection section 311 a for connection to the female connector 10 and a plug insertion section 311 b to which the thermostat plug 20 is inserted. The connection section 311 a defines a cavity 312 to which a portion of the female connector 10 is inserted. The plug insertion section 311 b has a semi-cylindrical shape and extends following the connection section 211 a.

An annular groove 313, to which the O-ring 180 is fitted, is formed between the connection section 311 a and the plug insertion section 311 b. Further, the first housing 310 includes a first socket 312a, for receiving the first contact terminal 350, and a second socket 312b, for receiving the second contact terminal 360. The first and second sockets 312a, 312b have a semi-cylindrical shape and are located in the plug insertion section 311 b. The first and second sockets 312a, 312b are disposed coaxially with a central axis CA2. Preferably, the second socket 312b has a diameter greater than that of the first socket 312a and extends from the first socket 312a in the central axis CA2. The second housing 320 has a semi-cylindrical shape and is separably joined to the plug insertion section 311 b of the first housing 310. The second housing 320 secures the first and second contact terminals 350, 360 to the first housing 310. Further, the second housing 320 includes respectively semi-cylindrical sockets configured to correspond to the first and second sockets 312a, 312b.

The second housing 320 is snap-engaged with the plug insertion section 311 b of the first housing 310. The second housing 320 has a hook-shaped or claw-shaped snapping protrusions 321 and the first housing 310 has engaging protrusions, not currently shown, which correspond respectively to the snapping protrusions 321 , at the plug insertion section 311 b.

The first and second connection terminals 330, 340 have an l-shape and thus correspond to the shape of the first housing 310. The first and second connection terminals 330, 340 may be made by bending an elongated metallic plate.

Referring to FIG. 12, the first connection terminal 330 has a bar-shaped arm terminal 331 , a horizontal section 332 and a bonding lug 333. The horizontal section 332 extends from the arm terminal 331 preferably parallel to the central axis CA2 and is spaced further away from the central axis C2 than the arm terminal 331.

The bonding lug 333 protrudes from a free end of the horizontal section 332 outwardly of the central axis CA2.

The first contact terminal 350 is connected to the first connection terminal 330 via its bonding arm 354. The first contact terminal 350 has a configuration similar to that of the first contact terminal 250 of the foregoing second embodiment. Therefore, the first contact terminal 350 includes a pair of bands 351 , a plurality of contact members 352, a plurality of slits 353 and the bonding arm 354. The bonding arm 354 radially outwardly extends from the band 351 located longitudinally inward. The bonding lug 333 and the bonding arm 354 may be bonded to each other by means of a bonding means such as laser welding or soldering.

Referring to FIG. 13, the second connection terminal 340 has a bar-shaped arm terminal 341 , a horizontal section 342 and a bonding lug 343.

The horizontal section 342 extends from the arm terminal 341 preferably parallel to the central axis CA2 and is spaced further away from the central axis CA2 than the arm terminal 341. Advantageously, the horizontal section 342 is longer than the horizontal section 332 of the first connection terminal 330 by more than a length of the first contact terminal 250.

The bonding lug 343 protrudes from a free end of the horizontal section 342 outwardly of the central axis CA2.

The second contact terminal 360 is connected to the second connection terminal 340 via its bonding arm 364. The second contact terminal 360 has a configuration similar to that of the second contact terminal 260 of the foregoing second embodiment. The second contact terminal 360 includes a pair of bands 361 , a plurality of contact members 362, a plurality of slits 363 and the bonding arm 364. The bonding arm 364 radially outwardly extends from the band 361 located longitudinally inward. The bonding lug 343 and the bonding arm 364 of the second contact terminal 360 may be bonded to each other by means of a bonding means such as laser welding or soldering.

The electrical connector 300 may be manufactured through the following:

- forming the first housing 310 by disposing the first and second connection terminals 330, 340 in a mold and then molding the same,

- forming the second housing 320 by molding,

- fitting respectively the first and second contact terminals 250, 260 to the first and second sockets 312a, 312b, - bonding respectively the bonding arms 254, 264 to the bonding lug 333, 343, and

- joining the second housing 320 to the plug insertion section 311 b of the first housing 310.

FIG. 14 shows an electrical connector 400 according to a fourth embodiment of the present invention. In FIG. 14, the same elements or parts as those of the electrical connector 100 of the foregoing first embodiment are denoted by the same reference numerals.

Referring to FIG. 14, the electrical connector 400 according to the fourth embodiment includes an outer housing 410, an inner housing 420, first and second connection terminals 430, 440, the first and second contact terminals 150, 160, the holder 170 and the O-ring 180.

The outer housing 410 has an L-shape. The outer housing 410 has a connection section 411 a for connection with the female connector 10 and a plug insertion section 411 b to which the thermostat plug 20 is inserted. The connection section 411 a defines a cavity112 to which a portion of the female connector 10 is inserted. A longitudinal end of the plug insertion section 411 b is closed, while its longitudinal opposite end comprises an open end for insertion of the thermostat plug 20.

The connection section 411 a extends from the plug insertion section 411 b in the vicinity of the closed end of the plug insertion section 411 b.

The outer housing 410 comprises a single part that may be formed by molding. Some embodiments may include the outer housing 410 having two half parts which have the same shape and are configured to receive the assembled inner housing 420. The inner housing 420 is disposed in the outer housing 410 and receives the first and second connection terminals 430, 440. The inner housing 420 has a cylindrical shape and comprises semi-cylindrical first and second halves 421 a, 421 b having the same shape. A longitudinal end of each half 421 a, 421 b, which faces toward the closed end of the plug insertion section 411 b, comprises a closed end, while its longitudinal opposite end comprises an open end for insertion of the thermostat plug 20. The inner housing 420 includes a first socket 422a for receiving the first connection terminal 430 and a second socket 422b for receiving the second connection terminal 440, in its inside. The first and second sockets 422a, 422b have a cylindrical shape and are formed respectively in each half 421 a, 421 b. The first and second sockets 422a, 422b are spaced apart from each other via a spacer 423 and are coaxially disposed in the inner housing 420. Advantageously, the second socket 422b has a diameter greater than that of the first socket 422a.

Tap portions 424a, 424b, to which a portion of the connection terminals 430, 440, particularly arm terminals 432, 442 of the connection terminal which are to be described below, is secured, protrude from each half 421 a, 421 b in the vicinity of the closed end of the inner housing 420.

The tap portions 424a, 424b are formed with a first terminal channel 425a, to which the arm terminal 432 of the first connection terminal 430 is seated or fitted, and a second terminal channel 425b, to which the arm terminal 442 of the second connection terminal 440 is seated or fitted.

The first terminal channel 425a is adjacent to the closed end of the inner housing 420 and communicates with the first socket 422a. The second terminal channel 425b is L- shaped with a portion thereof extending parallel to the first socket 422a. The second terminal channel 425b communicates with the second socket 422b. The first and second connection terminals 430, 440 are respectively placed in the first and second sockets 422a, 422b of the first housing 421 and the arm terminals 432, 442 are fitted to the respective terminal channels 425a, 425b. Then, the second half 421 b is joined to the first half 421 a.

The first and second halves 421 a, 421 b of the inner housing 420 are preferably snap- engaged to each other. For snap engagement, the first half 421 a has hook-shaped or claw-shaped snapping protrusions 426a and the second half 421 b has engaging protrusions 426b, which the snapping protrusions 426a engage respectively. The first connection terminal 430 includes a first body 431 , preferably a first hollow ring-shaped body 431 , and the arm terminal 432, that is electrically connected to the first body 431 , and extends radially from an outer peripheral surface of the first body 431. The arm terminal 432 has a bar shape and is located near the closed end of the plug insertion section 411 b. The second connection terminal 440 includes a second body 441 , preferably a second hollow ring-shaped body 441 , and the arm terminal 442 and an extension 443.

Preferably, the second body 441 of the second connection terminal 440 has a diameter, or a cross-sectional area, greater than that of the first body 431 of the first connection terminal 430.

The extension 443 extends from the second body 441 in a longitudinal direction of the second body 441 toward the closed end of the plug insertion section 41 1 b. The arm terminal 442 extends perpendicularly from the extension 443.

Similar to the first and second connection terminals of the first embodiment, the first and second connection terminals 430, 440 may be formed by bonding the arm terminal and/or the extension to the body by means of laser welding, or bending a single thin plate with portions to be respectively formed into the body and the arm terminal and/or the extension.

The first contact terminal 150 is fitted to the inside of the first body 431 of the first connection terminal 430 and the second contact terminal 160 is fitted to the inside of the second body 441 of the second connection terminal 440.

The holder 170 is joined to an edge of the second body 441 of the second connection terminal 440. The O-ring 180 is fitted to an annular groove 113 formed in an outer peripheral surface of the plug insertion section 411 b.

The above-described electrical connector 400 may be manufactured by overmolding an assembly wherein the first and second contact terminals 150, 160 and the first and second connection terminals 430, 440 are fitted to the inner housing 420 and the holder 170 is joined to the second connection terminal 440.

FIG. 15 shows an electrical connector 500 according to a fifth embodiment of the present invention. In FIG. 15, the same elements or parts as those of the electrical connector 100 of the foregoing first embodiment are denoted by the same reference numerals.

Referring to FIG. 15, the electrical connector 500 according to the fifth embodiment includes a first housing 510, a second housing 520, preferably perpendicularly joined to the first housing 510, first and second connection terminals 530, 540, preferably disposed in the second housing 520, first and second contact terminals 150, 160, preferably respectively fitted to the first and second connection terminals 530, 540, and the O-ring 180. The first housing 510 has an L-shape and is connected to the female connector 20, as shown on FIG. 2. The first housing 510 has a connection section 511 for connection to the female connector 10 and having a cavity to which a portion of the female connector 10 is inserted. Further, the first housing 510 includes a joint section 512, which participates in coupling to the second housing 520, at a closed end of the connection section 511. The joint section 512 has a cylindrical shape.

The joint section 512 has a flange 513 at its end and a first annular groove 514, to which a portion of the second housing 520 is fitted, inwardly of the flange 513. T he second housing 520 is perpendicularly joined to the first housing 510, thus making the L-shape of the electrical connector 500.

A second annular groove 515, to which the O-ring 180 is fitted, is formed inwardly of the first annular groove 514.

The second housing 520 has a cylindrical shape and comprises semi-cylindrical first and second halves 521 a, 521 b having the same shape. An end of each half 521 a, 521 b, which faces toward the joint section 512, comprises a closed end, while its opposite end comprises an open end for insertion of the thermostat plug 20.

The second housing 520 includes a first socket 522a, for receiving the first connection terminal 530, and a second socket 522b, for receiving the second connection terminal 540. The first and second sockets 522a, 522b have a semi- cylindrical shape and are formed in each half 521 a, 521 b respectively. The first and second sockets 522a, 522b are disposed coaxially and are spaced from each other via a spacer 523. Preferably, the second socket 522b has a diameter greater than that of the first socket 522a.

The second housing 520 is separably joined to the joint section 512 of the first housing 510.

Further, each half 521 a, 521 b of the second housing 520 are preferably snap- engaged to each other, more preferably separably snap-engaged to each other. In the closed end of each half 521 a, 521 b is formed a semi-cylindrical groove 524, to which a flange 513 of the joint section 512 is fitted. The flange 513 of the joint section 512 is fitted to the groove 524 of each half 521 a, 521 b, thus joining each half 521 a, 521 b to the joint section 512. Further, for snap engagement, the second half 521 b has hook-shaped or claw- shaped snapping protrusions 525b at its edge and the first half 521 a has engaging protrusions 521 a respectively corresponding to the snapping protrusions 525b, advantageously at its edge.

The first connection terminal 530 includes a first body 531 , preferably a first hollow ring-shaped body 531 , a arm terminal 532, that is electrically connected to the first body 531 , and an extension 533. The extension 533 extends from a longitudinal end of the first body 531 toward the first housing 510 in a longitudinal direction of the first body 531. The arm terminal 532 preferably extends perpendicularly from an end of the extension 533. The second connection terminal 540 includes a second body 541 , preferably a second hollow ring-shaped body 541 , a arm terminal 542, that is electrically connected to the second body 541 , and an extension 543. The extension 543 extends from a longitudinal end of the second body 541 toward the first housing 510 in a longitudinal direction of the second body 541. The extension 543 is preferably longer than the extension 533 of the first connection terminal 530 by a length of the first body 531 of the first connection terminal 530. The arm terminal 542 preferably extends perpendicularly from an end of the extension 543.

Preferably, the second body 541 has a diameter, or a cross-sectional area, greater than that of the first body 531 of the first connection terminal 530.

Similar to the first and second connection terminals of the first embodiment, the first and second connection terminals 530, 540 may be formed by bonding the arm terminal and/or the extension to the body by means of laser welding, or bending a single thin plate with portions to be respectively formed into the body and the arm terminal and/or the extension.

The first contact terminal 150 is fitted to the inside of the first body 531 of the first connection terminal 530 and the second contact terminal 160 is fitted to the inside of the second body 541 of the second connection terminal 540.

The electrical connector 500 may be manufactured through the following: - forming the first housing 510 by disposing the first and second connection terminals 530, 540 in a mold and then molding the same,

- forming the second housing 520 by molding,

- fitting respectively the first and second contact terminals 150, 160 to the first and second connection terminals 530, 540, and

- joining the second housing 520 to the joint section 512 of the first housing 510.

Obviously, the present invention is not limited to embodiments which are here above described and provided only as examples. It also includes different modifications, and alternatives that may be considered by the person skill in the art as part of the present invention, including all combinations of different embodiments here above described, taken alone or in combination.