Latch mechanism for a pluggable optical module

[0001] The present invention relates to a latch mechanism for a pluggable optical module and particularly to a latch mechanism for a pluggable optical module that is reliable and convenient.

[0002] In optical communication applications, the optical transceiver is an important element in a photoelectric transforming interface. Signal transmission speed may range from 155 Mb/s to 1.25 Gb/s or even 10 Gb/s. Various types of packages are available depending on application environments, such as a 1×9 pin, GBIC (GigaBit Interface Converter), SFF (Small Form Factor), SFP (Small Form Factor Pluggable), and the like. The 1×9 pin and SFF adopt a fixed packaging method that are difficult to remove once the module is installed in the system. The GBIC and SFP adopt a pluggable approach that can be removed and replaced after installing in the system.

[0003] In the design of the pluggable module, many factors have to be considered, such as electricity issues while plugging the module, reliability and convenience of the plugging mechanism. For instance, U.S. Pat. Nos. 6,439,918 and 6,533,603 assigned to Finisar Co. disclose a SFP module that has a latching mechanism ramming the bottom of the module through a lever to extend or retract the latching mechanism in the module. U.S. Pat. No. 6,494,623 assigned to Infineon Co. also discloses a SFP release mechanism, which has a lever turnable to press a locking reed of a transceiver to extend a latch of the module to escape a locking reed for releasing the module.

[0004] Another example is U.S. patent application No. 20030171016, which has a lever and elastic latch reeds located on two sides of a module for anchoring. In normal conditions, the elastic latch reeds maintain the anchor condition through a spring located therein. When the lever is moved downwards, the elastic latch reeds are moved outwards and the jutting distal ends thereof are disengaged.

[0005] Those references mostly employ latch mechanisms that are complex and require expensive elements. They also are difficult to fabricate and assemble. For instance, U.S. patent application No. 20030171016 requires two elastic latch reeds and a spring in each of them. It involves too many elements. Fabrication and assembly are difficult.

[0006] In order to solve the aforesaid disadvantages, the present invention aims to provide a latch mechanism for a pluggable optical module that is simply structured, easy to fabricate and assemble, reliable and convenient.

[0007] The latch mechanism for a pluggable optical module according to the invention includes a lever, a sliding member and a latch trough to selectively anchor the optical module on an electronic device. The lever has at least one boss to be mounted in the latch trough and is coupled with the sliding member. By turning the lever, the boss is turned at the same time to slide on a sloped surface on one side of the latch trough to a datum plane of the latch trough and change the relative position of the lever in horizontal direction, and drive the sliding member to move as well so that the optical module may be released from or anchor on the electronic device. Such a mechanism requires fewer elements, and is easier to fabricate and assemble, and also is more stable and reliable.

[0008] The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.

[0013] The latch mechanism according to the invention is applicable to any pluggable optical module such as an optical transceiver, light emitter, optical receiver, and the like. The following discussion is based on an optical transceiver.

[0014] Referring to FIG. 1, a latch mechanism 20 is adopted for use on an optical module 10 for selectively coupling the optical module 10 on an electronic device (not shown in the drawings). Also referring to FIG. 2, the optical module 10 includes an upper lid 11, a circuit board 12 and a lower lid 13. The latch mechanism 20 includes a lever 21, a sliding member 22 and a latch trough 23. The lever 21 is located on the front end of the optical module 10, and has a handle 212 and two struts extended from two ends of the handle 212 to fasten to an axle 213. The axle 213 is coupled with at least one boss 211. Their functions will be discussed later.

[0015] The sliding member 22 includes two sliding sections 221 and 222 that have one end bridged by a coupling section 223 and other ends with jutting latch sections 2211 and 2221 formed thereon. The latch trough 23 is to hold the boss 211 of the lever 21.

[0016] The lever 21 is coupled with one end of the optical module 10 in a turnable fashion by nestling the boss 211 in the latch trough 23. The sliding member 22 clips the optical module 10 and is slidable thereon, and also is coupled with the lever 21.

[0017] Referring to FIGS. 3A and 3B, in normal conditions, the sliding sections 221 and 222 of the sliding member 22 clip the optical module 10, and the boss 211 of the lever 21 has one side in contact with a datum plane 231 of the latch trough 23 and another side in contact with a side wall of the latch trough 23. As shown in the drawings, the cross section of the boss 211 is formed substantially in a fan shape with two chords defined as a first contact side 2111 and a second contact side 2112. The bottom side of the latch trough 23 is the datum plane 231. When the first contact side 2111 is in contact with the datum plane 231, the second contact side 2112 presses one sidewall of the latch trough 23. When the second contact side 2112 is in contact with the datum plane 231, the first contact side 2111 presses another sidewall of the latch trough 23. When the first contact side 2111 is in contact with the datum plane 231, the lever 21 and the sliding member 22 are positioned in a normal condition. The latch sections 2211 and 2221 are extended to couple on an electronic device (not shown in the drawings). With the first contact side 2111 of the boss 211 in contact with the datum plane 231, the module is in a latched and anchored condition without escaping the electronic device.

[0018] When the lever 21 is turned about the axle 213, it also turns relative to the optical module 10. The boss 211 also turns, and the first contact side 2111 leaves the datum plane 231. Referring to FIGS. 5A and 5B, with the lever and the boss 211 turning continuously, the second contact side 2112 slides over one sidewall of the latch trough 23 and moves to the datum plane 231 to form a contact condition. Meanwhile, the position of the axle 213 is shifted to push the lever 21 to move horizontally, and consequently drags the sliding member 22 coupled on the lever 21 to slide outwards. The latch sections 2211 and 2221 also slide outwards and separate from the electronic device to form a released condition.

[0019] The mechanism set forth above has a simple structure and requires fewer elements. It's also cheaper, and fabrication and assembly are easier. The sliding sections 221 and 222 may be formed in a reed or become a single element rather than two arms as shown in the drawings. Similarly, the latch sections 2211 and 2221 that are jutting to the left and the right sides serve only as an example and are not the limitation. They may be formed in an up and down manner or become a single latch section. The boss 211 on the axle of the lever aims to slide on the contact sides of the latch trough 23 to generate a horizontal movement for the lever. It may be formed in various shapes such as containing two bosses 211 (referring to FIGS. 6A and 6B), or a member with substantially a circular cross section to couple with the axle 213 on an eccentric location (referring to FIGS. 6C and 6D), or a member with substantially a square cross section to couple with the axle 213 on an eccentric location (referring to FIGS. 6E and 6F); or the latch trough may have a plurality of protrusive elements formed on the datum plane to couple with the boss (referring to FIGS. 6G and 6H).

[0020] While the preferred embodiments of the invention have been set forth for the purpose of disclosure, modifications of the disclosed embodiments of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments, which do not depart from the spirit and scope of the invention.