The invention relates to optical transceiver modules. More particularly, the invention relates to an optical transceiver module having a latching/delatching mechanism that is well suited for use with symmetric and asymmetric cage latches.
State-of-the-art digital communication switches, servers, and routers currently use multiple rows of duplex LC connector optical transceivers to meet information bandwidth and physical density needs. To be a commercially fungible product, the optical transceivers must have basic dimensions and mechanical functionality that conform to an industry standard Multi-Source Agreement (MSA). Of course, many optical transceiver designs that comply with and add value beyond the basic mechanical functionally set forth in the MSA are possible.
One known optical transceiver design that complies with such an MSA is the Quad Small Form-Factor Pluggable (QSFP) optical transceiver module. QSFP optical transceiver modules are designed to mate with an opening formed in a cage. The module housing has one or more receptacles configured to mate with one or more respective optical connector modules, such as one or more LC optical connector module. An optical fiber cable mates with each receptacle. Each optical fiber cable typically includes a plurality of transmit and/or receive optical fibers. A plastic pull tab is connected on its proximal end to a delatch device that is mechanically coupled to the module housing.
When the transceiver module housing is in the stored position in the cage, catches formed in opposite sides of the module housing engage respective latches formed in opposite sides of the cage to prevent the module housing from inadvertently coming out of the cage opening. When a user pulls on the distal end of the pull tab in the direction away from the cage opening, slider portions of the delatch device that run along opposite sides of the module housing slide to a limited extent along the respective sides of the module housing in the direction in which the pull tab is pulled. This movement of the slider portions causes outwardly-curved ramps formed on the ends of the slider portions to press outwardly against the respective latches of the cage to delatch, or disengage, them from the respective catches of the module housing. This allows the module housing to then be retracted from the cage opening.
In some QSFP mounting configurations, the cages have multiple openings arranged side-by-side for mating with the optical transceiver modules that are arranged side-by-side. The side-by-side optical transceiver modules that mate with the side-by-side cage openings share a common side wall of the cage. In such side-by-side configurations, the latches on the left and right sides of the cage are asymmetrically located relative to the bottom of the cage to allow the modules to share the common side walls of the cage. In such mounting configurations, the left-side latch of the cage is typically lower than the right-side latch of the cage. In other words, the distance between the left-side latch of the cage opening and the bottom of the cage is smaller than the distance between the right-side latch of the cage opening and the bottom of the cage. The asymmetric configuration of the cage latches allows transceiver module mounting density to be maximized and reduces cage costs.
One of the problems with the side-by-side QSFP mounting configuration is that the asymmetric configuration of the cage latches sometimes prevents the cage latches from catching the respective catches of the module housings. The catches of the module housings are symmetrically located, which can result in a catch failing to engage the respective latch due to the spatial offset between them. This, in turn, can result in the module housings inadvertently sliding out of the respective cage openings. In addition, the asymmetric configuration of the cage latches sometimes prevents the outwardly-curved ramps formed on the ends of the slider portions from fully engaging the respective latches of the cage when the user pulls on the pull tab. The outwardly-curved ramps are symmetrically located, and therefore may not fully engage the respective asymmetrically-located cage latches. This can make it difficult or impossible to remove a module housing from its respective cage opening. Another potential problem with the asymmetric configuration of the cage latches is that engagement between the symmetric outwardly-curved ramps and the asymmetric cage latches can twist and thereby damage the cage latches, which are typically made of sheet metal and easily bent.
Accordingly, a need exists for side-by-side mounting configuration that overcomes these problems. More particularly, a need exists for an optical transceiver module having a latching/delatching mechanism that is well suited for use in such side-by-side mounting configurations having symmetric or asymmetric latches.
The invention is directed to an optical transceiver module and assembly having a latching/delatching mechanism that is well suited for use cages or receptacles having asymmetrically-located or symmetrically-located latches. In accordance with an embodiment of the optical transceiver module, the module comprises a module housing and a delatching device mechanically coupled to the module housing. The module housing has a top, a bottom, a first side, a second side, a first end and a second end. The first and second sides have first and second sets of stops formed therein, respectively. Each of the first and second sets of stops has N stops, where N is a positive integer that is equal to or greater than 2. The delatching device comprises an actuator mechanism and first and second slider portions having proximal ends that are mechanically coupled to the actuator mechanism and distal ends that are opposite the respective proximal ends. The first and second slider portions are positioned along the first and second sides of the module housing, respectively. The distal ends of the first and second slider portions have first and second sets of delatching features disposed thereon, respectively. The first and second sets of delatching features each have at least N+1 delatching features. When the delatching device is in a non-actuated state, the stops of the first and second sets of stops are interleaved with the delatching features of the first and second sets of delatching features, respectively.
In accordance with an embodiment of the optical transceiver module assembly, the assembly comprises a cage, a module installed inside of an opening of the cage, and a delatching device mechanically coupled to the module housing. The cage has a first end, a second end, a top, a bottom, a first side, and a second side. The first and second sides of the cage have first and second latches thereon, respectively, that extend a distance into the cage opening. The module housing has a top, a bottom, a first side, a second side, a first end and a second end. The first and second sides of the module housing have first and second sets of stops formed therein, respectively, each of which has N stops, where N is a positive integer that is equal to or greater than 2. The delatching device comprises an actuator mechanism and first and second slider portions. The first and second slider portions have proximal ends that are mechanically coupled to the actuator mechanism and distal ends that are opposite the respective proximal ends. The first and second slider portions are positioned along the first and second sides of the module housing, respectively. The distal ends of the first and second slider portions have first and second sets of N+1 delatching features disposed thereon.
In accordance with another embodiment of the optical transceiver module, the module includes a module housing, a slider and a delatching handle. The slider has first and second side slide members that are in parallel planes and a transverse member interconnecting proximal ends of the first and second side slide members. The transverse member is mechanically coupled to a distal end of the delatching handle. The first and second side slide members have distal ends that each have N+1 ramped features thereon, where N is a positive integer that is equal to or greater than 2. Adjacent ramped features are separated from one another by respective spaces. The module housing is mechanically coupled to the slider. The module housing has first and second catch features disposed on first and second sides of thereof, respectively, for engaging first and second latch features, respectively, disposed on opposite sides of a receptacle when the module is fully inserted into the receptacle and the delatching handle is in an unpulled, or non-actuated, state.
These and other features and advantages of the invention will become apparent from the following description, drawings and claims.
In accordance with illustrative embodiments of the invention, an optical transceiver module is provided with a latching/delatching mechanism that is well suited for use with cages or receptacles that have symmetrically-located or asymmetrically-located latches. The latching/delatching mechanism comprises stops that engage the latches in the stored, or non-actuated, state and comprises delatching features that engage the latches in the pulled, or actuated, state. The configurations of the stops and of the delatching features ensure that the engagement of the stops with the latches in the stored, or non-actuated, state is sufficient to provide latching and that the engagement of the delatching features with the cage latches in the pulled, or actuated, state is sufficient to provide delatching, regardless of whether the cage latches are asymmetrically located or symmetrically located on the cage. Illustrative, or exemplary, embodiments will now be described with reference to
With reference to
The optoelectronic components (not shown) typically include one or more light sources (e.g., laser diodes, light emitting diodes (LEDs), etc.) and/or one or more light detectors (e.g., photodiodes, P-I-N diodes, etc.). The electrical components (not shown) typically include driver circuitry for driving the light sources to convert electrical data signals into optical signals and receiver circuitry for receiving and decoding optical signals into electrical data signals. The electrical components may also include a controller chip for controlling the operations of the transceiver module 1. The electrical and optoelectronic components are typically mounted on a circuit board 4, such as a printed circuit board (PCB), for example. The circuit board 4 has electrical contacts 5 on a back end thereof that come into contact with electrical contacts disposed inside of a receptacle at the back of the cage 40 (
The latching/delatching mechanism 10 comprises the delatching device device 20 (
The first and second slider portions 26 and 27 grip opposite sides of the module housing 2 when the delatching device 20 is installed on the module housing 2 as shown in
In
In accordance with embodiments described herein, there are N stops 22 and N+1 ramps 28, where n is a positive integer that is equal to or greater than 2. Thus, in the illustrative embodiment depicted in
It should be noted that while the spatially-distributed arrangement of stops 22 and ramps 28 is particularly well suited for arrangements in which the cage latches are asymmetrically located, the spatially-distributed arrangement of stops 22 and ramps 28 is equally well suited for arrangements in which the cage latches are symmetrically located. Because the slider portions 26 and 27 and their respective ramps 28 are symmetric, at least one of the ramps 28 will come into direct contact with the respective symmetrically-located cage latch when the delatching device 20 is in the pulled, or actuated, state or position. Because the stops 22 on opposite sides of the lower housing portion 2b are symmetric, at least one of the stops 22 on each side of the module housing 2 is direct contact with the respective symmetrically-located cage latch when the delatching device 20 is in the unpulled, or stored, state.
The module housing 2 is typically made of a die-cast metallic material, such as zinc, for example. The stops 22 are typically on the order of about 1.0 millimeters (mm) in width to ensure that they provide sufficient surface area for making contact with the cage latches to perform the latching operation. The longitudinal reinforcement member 24, the lateral member 25, the first a second slider portions 26 and 27, and the first and second sets of outwardly-curved ramps 28 are typically formed as a unitary piece of metallic material (e.g., sheet metal) that is been die cut or laser cut and bent into the shape shown in
In
In the stored positions of the optical transceiver modules depicted in
The above description of the illustrative embodiments demonstrates that having multiple ramps 28 and multiple stops 22 that are interleaved, i.e., the ramps 28 and stops 22 are alternately positioned in the plane in which portions of the stops 22 and the ramps 28 both lie, provides redundancy that ensures that at least one of the stops 22 and at least one of the ramps 28 will directly encounter the respective cage latch 51, 52 on each side of the cage 40. It should be noted that while the illustrative embodiments depict an example where N=3, N can be any value equal to or greater than 2.
It should be noted that while the invention has been described with reference to an optical transceiver module, the invention is not limited to use with optical transceiver modules, but may also be used with optical receiver modules and optical transmitter modules. Therefore, the term “optical transceiver module,” as that term is used herein, describes any of the following: (1) a module that has both optical transmit and optical receive capability for transmitting and receiving optical signals over an optical waveguide; (2) a module that has optical transmit, but not optical receive, capability for transmitting optical signals over an optical waveguide; and (3) a module that has optical receive, but not optical transmit, capability for receiving optical signals over an optical waveguide.
It should be noted that the invention has been described with reference to a few illustrative embodiments for the purposes of demonstrating the principles and concepts of the invention. As indicated above, many modifications may be made to the embodiments described herein without deviating from the scope of the invention. For example, while the delatching device 20 is shown in the figures as having a particular configuration, it may have a variety of configurations that allow the goals of the invention to be achieved.
For example, some latching/delatching mechanisms use a bail instead of a pull tab in conjunction with slider portions to delatch the module from a cage. The principles and concepts of the invention apply equally to those types of actuator mechanisms that use bails for that purpose rather than pull tabs. Like the pull tab, the bail is an actuator mechanism that causes a force to be exerted on the slider portions to pull them in a direction away from the cage opening. In such arrangements, the bail is typically mechanically coupled to a lateral member and is rotational coupled to the module housing by pins. The lateral member, which is similar to the lateral member 25, is mechanically coupled to the slider portions such that rotating the bail in opposite directions causes the slider portions to move in opposite directions. A bail, a pull tab or any other suitable actuator mechanism can be used to perform this function.
Also, the outwardly-curved ramps 28 are only examples of possible delatching features disposed on the distal ends of the slider portions 26 and 27 that perform the function of pressing outwardly on the cage latches 51 and 52 to delatch them from the stops 22. Delatching features that have other shapes may also perform this function, as will be understood by those of skill in the art in view of the description being provided herein. In addition , while the latching/delatching mechanism 10 has been described for use with an optical transceiver module and a cage, mechanism 10, and modifications of it, are suitable for use with other types of modules for latching/delatching the modules to and from receptacles other than cages of the type described herein. Persons skilled in the art will understand, in view of the description provided herein, the manner in which these and other modifications may be made and that all such modifications are within the scope of the invention.