Tool-less multi-stage insertion and securing mechanism for electronic mezzanine assemblies

A multi-stage mezzanine board mounting assembly within a computer chassis includes a mezzanine tray and mezzanine mounting brackets. The mezzanine tray includes a clamping mechanism. The mezzanine mounting brackets are disposed within the computer chassis and configured to engage with the mezzanine tray when the mezzanine tray is mounted thereon. The clamping mechanism is configured to clamp the mezzanine tray against the mezzanine mounting brackets such that the mezzanine tray is locked in place on the mezzanine mounting brackets. A method of installing a mezzanine board includes disposing mezzanine mounting brackets within a computer chassis; mounting a mezzanine tray onto the mezzanine mounting brackets such that insertion alignment members of the mezzanine tray engage with an engaging portion of the mezzanine mounting brackets; rotating rotatable clamping levers such that the mezzanine tray is locked in place on the mezzanine mounting brackets when the rotatable clamping levers are fully engaged.

BACKGROUND OF INVENTION

1. Field of the Invention

The invention relates generally to a mezzanine board mounting assembly for mounting a mezzanine board in a computer chassis.

2. Background Art

A mezzanine board is a printed circuit board (PCB) used as an extension of a base PCB, e.g., a motherboard. The mezzanine board plugs into and extends the circuitry of the base PCB. Mezzanine boards are an important element in the design of today's high-density computer servers, as they expand the basic functionality of the base PCB and enable higher computational and memory densities.

Mezzanine assemblies are typically used to mount the mezzanine boards onto the base PCB. Mechanical considerations that go into the installation process include proper mounting, securing, and aligning of the mezzanine assembly. When mounting the mezzanine board onto the base PCB, precise alignment of the mezzanine assembly is required to connect high-density connectors of the mezzanine board to the base PCB. Further, due to the weight of the mezzanine board, a significant retention force is required to secure the mezzanine assembly rigidly.

SUMMARY OF INVENTION

In general, in one aspect, the invention relates to a multi-stage mezzanine board mounting assembly within a computer chassis, comprising: a mezzanine tray comprising a clamping mechanism; and mezzanine mounting brackets disposed within the computer chassis and configured to engage with the mezzanine tray when the mezzanine tray is mounted thereon, wherein the clamping mechanism is configured to clamp the mezzanine tray against the mezzanine mounting brackets such that the mezzanine tray is locked in place on the mezzanine mounting brackets.

In general, in one aspect, the invention relates to a multi-stage mezzanine board mounting assembly within a computer chassis, comprising: a mezzanine tray comprising: a pair of rotatable clamping levers, each comprising cam portions attached to opposing side walls of the mezzanine tray and a handle portion connecting the cam portions; and an insertion alignment member disposed on each of the opposing side walls of the mezzanine tray between the cam portions of the rotatable clamping levers; and mezzanine mounting brackets disposed within the computer chassis, comprising: engaging portions configured to engage with the insertion alignment members when the mezzanine tray is mounted thereon; clamping portions configured to be clamped by the cam portions of the mezzanine tray; and elastomer inserts disposed at an interface between the clamping portions of the mezzanine mounting brackets and the cam portions of the rotatable clamping levers, wherein the cam portions of the rotatable clamping levers are configured to clamp the elastomer inserts against the clamping portions of the mezzanine mounting brackets such that the mezzanine tray is locked in place on the mezzanine mounting brackets when the rotatable clamping levers are fully engaged.

In general, in one aspect, the invention relates to a method of installing a mezzanine board onto a base circuit board within a computer chassis, the method comprising: disposing mezzanine mounting brackets within the computer chassis; mounting a mezzanine tray onto the mezzanine mounting brackets such that insertion alignment members of the mezzanine tray engage with an engaging portion of the mezzanine mounting brackets; rotating rotatable clamping levers such that the mezzanine tray is locked in place on the mezzanine mounting brackets when the rotatable clamping levers are fully engaged.

DETAILED DESCRIPTION

Specific embodiments of the invention will be described with reference to the accompanying figures. Like items in the figures are shown with the same reference numbers.

One or more embodiments of the present invention provide a multi-stage inserting and securing mechanisms for a mezzanine mounting board assembly. The mezzanine mounting board assembly according to one or more embodiments of the present invention includes mezzanine mounting brackets disposed within a computer chassis and a removable mezzanine tray configured to mount in the mezzanine mounting brackets. The mezzanine tray and the mounting brackets work together to provide a multi-stage mezzanine mounting architecture for mounting and securing a mezzanine board onto a base printed circuit board (“PCB”).

FIGS. 1-3show a mezzanine mounting brackets110(hereinafter referred to as mounting brackets110) according to one or more embodiments of the present invention. As can be seen inFIGS. 1 and 3, the mounting brackets110may be disposed on side walls of a computer chassis1, so that a base PCB can be disposed therebetween. The mounting brackets110are connected to the chassis, for example, using screws. Those skilled in the art will appreciate many other attachment mechanisms that could be used to connect the brackets to the chassis, for example, clips, hooks, rivets, adhesives, etc.

FIG. 2shows a close-up view of one of the mounting brackets110. Each of the mounting brackets110includes an engaging portion112and clamping portions113. Each of the mounting brackets110also includes elastic members disposed at an interface between the mounting brackets110and the clamping mechanism, e.g., elastomer inserts150disposed at an interface between the clamping portions113and the cam portions122bof the rotatable clamping levers122. These elastomer inserts compress upon engagement of the mezzanine tray (described below) and lock the tray into place more securely.

FIGS. 4-6show a removable mezzanine tray120(hereinafter referred to as tray120) according to one or more embodiments of the present invention. The tray120is configured to mount the mounting brackets110disposed within a computer chassis. The tray120includes insertion alignment members121and a clamping mechanism. The insertion alignment members121may be attached to opposing side walls of the tray120. The clamping mechanism is configured to clamp the mounted tray120against the mounting brackets110, so as to lock the tray120in place.

In one or more embodiments, the clamping mechanism may be a pair of rotatable clamping levers122. As can be seen inFIG. 4, each of the rotatable clamping levers122may include cam portions122battached to opposing side walls of the tray120and a handle portion connecting the cam portions122b. The rotatable clamping levers122are configured to rotate about the cam portions122b, and are rotatable between an open position and a closed position.FIG. 4shows the tray120in which both of the clamping levers122are in an open position, andFIG. 5shows the tray120in which one of the rotatable clamping levers122has been rotated to a closed position.

In one or more embodiments, the insertion alignment members121may be attached to opposing side walls of the tray120between the cam portions122b. These insertion alignment members121ensure that the tray120is properly aligned with the mounting brackets110upon insertion and, accordingly, ensures that the mezzanine board connectors will align with the base PCB connectors correctly.

The mezzanine board mounting assembly100functions in multiple stages. In one or more embodiments, the mezzanine board mounting assembly100operates in two stages: the inserting stage and the securing stage.

In the inserting stage, the tray120is mounted on the mounting brackets110. The tray120holds the mezzanine board to be connected to the main PCB. The handle portions122amay be used to carry the tray120and lower it onto the mounting brackets110such that the insertion alignment members121slide along the engaging portions112of the mounting brackets110. As shown inFIG. 2, a guide rail may be formed on each of the mounting brackets110to guide the insertion alignment members121into the engaging portions112. The insertion alignment members121may be of various shapes and forms, e.g., flat trapezoidal shape, that allow for a low-friction sliding interaction with the engaging portions112. The tray120is lowered until the insertion alignment members121have fully engaged with the engaging portions112and the tray120is completely mounted on a mounting surface, e.g., mounting surfaces115, of the mounting brackets110.

In the securing stage, the rotatable clamping levers122of the tray120(now mounted on the mounting brackets110) are rotated to a closed position as shown inFIG. 7. As the rotatable clamping levers122rotate, the cam portions122bclamp the elastomer inserts150against the clamping portions113of the mounting brackets110. Once the levers122have fully rotated to the closed position, the tray120is securely locked in place by the retention forces created by the compression of the elastomer inserts150. The clamping effect creates the retention forces without altering the alignment location of the mezzanine mounting assembly100.

The tray120can be unlocked and removed by rotating the levers122to an open position, whereby the elastomer inserts150are released by the cam portions122b, and then lifting the tray120off the mounting brackets110.

Advantages of the present invention, in accordance with one or more embodiments, may include one or more of the following. The multi-stage insertion and securing mechanisms provide tool-less installation and removal of mezzanine mounting assemblies, and effectively retain heavy mezzanine assemblies while ensuring that precise alignment requirements are met for high-density interconnects.

During the inserting stage, the handle portions122aallow for easy and safe handling of the tray120. The alignment of the mezzanine mounting assembly is driven by the connectors and associated alignment features, and the configuration of the engaging portions112and the insertion alignment members121allow for uniform installation of the mezzanine mounting assembly100, even with offset asymmetrical placement of high-density connectors. Further, the configuration of the engaging portions112and the insertion alignment members121enables the tray120to have a low-friction sliding interaction with the mounting brackets110during mounting, thereby reducing the insertion force necessary to install the tray120onto the mounting brackets110. As a result, smooth insertion of the mezzanine board is made possible.

During the securing stage, the clamping effect created by the interaction between the cam portions122band the integrated elastomer inserts150ensures that the mezzanine mounting assembly is held securely in place once the rotatable clamping levers122are fully engaged, i.e., fully rotated to the closed position. Due to the multi-stage architecture, the retention forces created by the compression of the clamped elastomer inserts150can be applied only after all the alignment requirements have been met, and the clamping effect does not alter the alignment location of the mezzanine mounting assembly100.

The elastic nature of the elastomer inserts150provides effective clamping and prevents over-compression. Once clamped in place, any forces exerted on the mezzanine mounting assembly100due to, e.g., shock or vibration, are directed to the computer chassis1, thus preventing interconnect components from carrying loads of the exerted force. As a result, any pre-loaded force or stress on the system interconnects can be prevented.

According to one or more embodiments of the multi-stage mezzanine mounting assembly as described above, robustness and precision can both be achieved. The multi-stage architecture also provides ease of assembly, as the automatic aligning and clamping features eliminate the need for additional user attention or special precision tools. This allows a user to repeatedly install or uninstall heavy mezzanine assemblies with ease. Further, because the retention features of the securing mechanism is independent of the alignment features of the insertion mechanism, the mezzanine mounting assembly can be aligned with more precision and secured with greater retention force.