1. Field of the Invention
The present invention relates to an electrical connector, and more particularly to an electrical connector having a guide-in arrangement in which an inserted substrate, such as a memory card, is pivotally supported at one end of the connector, and then cam-into the connector centered by the end so as to reduce the insertion force.
2. Description of the Prior Art
An electrical connector is used to detachably or separately interconnect two electrical devices together. It embodies a variety of configurations as well as structures in view of its application and intended performance.
U.S. Pat. No. 4,846,734 issued to Lytle and U.S. Pat. No. 4,996,766 issued to Piorunnect disclose the so-called card-edge connector in which a memory module or add-in circuit card can be electrically interconnected to a motherboard through the connectors disclosed.
U.S. Pat. Nos. 4,995,825 and 5,013,257 issued to Korsunsky disclosed a memory connector similar to the card-edge connector discussed above.
U.S. Pat. No. 5,074,800 issued to Sasao et al. disclose another memory card connector in which an ejector is incorporated so as to easily remove the inserted memory card from the connector.
The electrical connector disclosed above comprises an insulative housing defining a slot therein and a plurality of electrical terminals mounted on the insulative housing and electrically contacted with conductive pads of the memory module inserted into the slot of the insulative housing. An insertion force needed to insert the memory module into the slot of the electrical connector is made up of two subsets: (1) when the memory module first approaches the electrical connector, the terminals must be displaced for insertion of the memory module. The degree or magnitude of this force is a function of: the Young's module of the terminal, the shape of the leading edge of the memory module, and the number of the terminals displaced by the inserted memory module. (2) After the terminals are deflected and initial engagement between the electrical terminals of the connector and conductive pads on the memory module is attained, the insertion force is then a function of the coefficient of friction between the conductive pads and terminals, the normal force exerted by the terminals, and finally the number of the terminals.
With the development in the electrical connector field, the electrical connectors are required to transmit signals in a more and more larger quantity per unit and in a more and more faster speed. In turn, the number of the electrical terminals of each electrical connector is increased and an insertion force needed to insert the memory module into the electrical connector is increased accordingly, which is undesirable for the user who mounts the memory module onto the electrical connector. In addition, it is also undesirable for the user since a large force is still needed to eject the memory module from the electrical connector. Proposals to reduce the insertion force include: reducing the normal force, chamfering the memory module, adding a secondary cam mechanism, applying lubricant and reducing the number of terminals deflected at one time by staggering the terminal heights, such as Piorunnect disclosed in his invention.
U.S. Pat. Nos. 5,660,552 (the '552 patent) and 6,276,950 (the '950 patent) issued to Suzuki et al and Yodogawa, respectively, address the problem of extracting the inserted memory module from the electrical connector. The Suzuki et al. disclose an electrical connector extracting a memory module received therein when a push-button of a first crank arm formed on one of two longitudinal ends of the insulative housing thereof is pushed to rotate the first crank arm outwardly to rotate a second crank arm to lift up one side edge of the memory module. As clearly shown in FIG. 5A of Suzuki and FIG. 1 of the Yodogawa, the memory card is inserted substantially to the prior arts discussed above.
U.S. Pat. No. 5,470,240 issued to Suzuki discloses another electrical connector which is very similar to Sasao. Suzuki's 240 provides a dynamic pivotal support to the inserted memory module by a first lever. The memory module is then by rotated and gradually inserted into the insulative housing. When the module is to be ejected, a wrench arm of the second lever is pried so as to eject the memory module. The electrical connector of the '240 patent is purported to address the problem of decreasing the force needed to insert the memory module into the insulative housing. However, it is often difficult to manipulate the insertion process since both the memory module and the lever are floatable. This is not easy to manipulate. Furthermore, the memory module moves a relatively longer distance and conductive pads thereof are often scratched by electrical terminals of the electrical connector which are not the ones intended to finally mate with. In such a way, a reliable and easy electrical interconnection between the memory module and the electrical connector is highly expected.
A first object of the present invention is to provide an electrical connector which correctly receives a memory module therein with a low insertion force.
A second object of the present invention is to provide an electrical connector which ensures a reliable electrical connection with a memory module received therein.
An electrical connector in accordance with the present invention comprises an insulative housing and a plurality of electrical terminals mounted to the insulative housing. The insulative housing defines a first end, an opposite second end and a slot extending from the first end to the second end. The first end is formed with a tower extending upwardly therefrom and comprising a supporting section thereon. The second end comprises a lever pivotally assembled thereto. A memory module comprises a first side portion having a side engaging section, a second side portion having a locking section and a plurality of conductive pads.
When the memory module is to mate with the electrical connector, the side engaging section engages with the supporting section and the memory module is rotated on the supporting section to mate the conductive pads with the electrical terminals sequentially from the first end to the second end. The lever is rotated inwardly to lock with the locking section to hold the memory module in the slot of the electrical connector. When the memory module is to be withdrawn from the slot of the electrical connector, the lever is rotated outwardly to lift up the second side portion of the memory module firstly. In the course of the movement of the memory module with respect to the electrical connector, each electrical terminal only contacts with one corresponding conductive pad with which it is finally mated.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of the present embodiment when taken in conjunction with the accompanying drawings.
Referring to
The electrical connector 1 comprises an insulative housing 10, a plurality of electrical terminals 12 mounted to the insulative housing 10. The insulative housing 10 defines a first end 14, an opposite second end 16, a slot 18 extending from the first end 14 to the second end 16 to receive the electrical terminals 12 partially extending thereinto, and a key 180 protruding into the slot 18. The key 180 corresponds to the key slit 23 of the memory module 2 to ensure the memory module 2 is received in the electrical connector 1 in a correct way. The number and the location of the key 180 and the key slit 23 may be changed according to specific application environments. The first end 14 comprises a tower 11 extending upwardly therefrom and comprising a supporting section 13, a protrusion configured corresponding to the side engaging section 26 in this preferred embodiment, at an upper section thereof. The second end 16 comprises a shoulder 15 and a lever 17 pivotally assembled to the shoulder 15. The lever 17 is formed with a hook section 170 at a lower end thereof and a projection 171 at an upper end thereof.
When the memory module 2 is to be inserted into the slot 18 of the insulative housing 10, the side engaging section 26 of the first side portion 20 of the memory module 2 engages with the supporting section 13 of the tower 14 of the insulative housing 10 in such a way that the lower end 25 of the memory module 2 defines an angle a with respect to a bottom face 19 of the slot 18 of the insulative housing 10. The angle α is preferably an acute angle and is about 8-9 degrees. The memory module 2 is then pressed to move clockwisely toward the insulative housing 10 until the lower end 25 of the second side portion 22 thereof reaches the bottom face 19 of the slot 18. Referring to
Referring to
Referring to
A third distance Z is defined between the lateral end of the first side portion 20 and the final point F of the first conductive pad 21 measured from the first side portion 20 of the memory module 2. The third distance Z is substantially equal to a distance Z′ (
A fourth distance K is defined between the lower end 25 of the lower portion 24 and a pivot point P about which the memory module 2 is rotated. The pivot point P can be set in the supporting section 13 or wherever appropriate. The fourth distance K is substantially equal to a distance K′ (
Referring to
Referring to
When the memory module 2 is inserted into or withdrawn from the electrical connector 1, the memory module 2 is pivoted about the supporting section 13, 13′, 13″ of the stationary tower 11, 11′, 11″ in such a way that the conductive pads 21 on the first side portion 20 contact with corresponding terminals 12 in the first end 14 earlier than the conductive pads 21 on the second side portion 22 and the second side portion 22 extends into the slot 18 later than the first side portion 20. Thus, a total force needed to insert the memory module 2 is significantly reduced due to the sequential engagement of the conductive pads 21 and the electrical terminals 12. Taking a memory module having 240 conductive pads for mating with an electrical connector having 240 electrical terminals for example, an insertion force needed to insert the memory module into the electrical connector in a way as disclosed in the present invention gets a more than 50%, 66%, reduction with respect to in convention way in which the memory module is inserted into the electrical connector parallelly.
Furthermore, since the supporting section 13, 13′, 13″ is stationary, only the memory module 2 needs to be manipulated, it is more easy for the user to manipulate the insertion process of the memory module 2 into the electrical connector. In addition, since the distances K and Z are well controlled, each terminal 12 mechanically contacts and electrically connects only and exactly with the very conductive pad 21 intended to be mated with in the course of mating the memory module with the electrical connector. A reliable electrical connection between the memory module and the electrical connector is ensured.
It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.