Latch mechanism for securing an expansion card module in a computer chassis

A latch mechanism for securing an expansion card assembly in a computer chassis includes a lever, a stop member, a rotary latch, a first biasing structure, and a second biasing structure. The lever includes a latching end and an opposing pinned end. The stop member extends from the pinned end. The rotary latch is connected to the latching end and includes a receiving chamber and a hook structure. The hook structure includes a notch for receiving a stop pin. The first biasing structure extends from the lever into the receiving chamber and is configured to urge the rotary latch into a locked position. The second biasing structure is configured to urge the lever about the pinned end to an open position.

FIELD OF THE INVENTION

The present invention relates generally to a latch mechanism, and more specifically, to a latch mechanism for securing a printed circuit board module (“PCB”) in computer chassis.

BACKGROUND OF THE INVENTION

Expansion cards have common applications in computing systems, such as computing and input/output operations in a server. High quality connections for expansion cards within servers are needed to allow for high performance operations during computing and input/output activities. To provide high quality signals within a server, a vertical expansion card is assembled in a riser module to allow the vertical expansion card to be physically steady and remain operable, when exposed to mechanical shock or vibrations. Expansion cards are typically constrained within a module that is secured to a computer chassis using a screw. However, conventional constraining mechanisms can lead to the connectors on an expansion card to wear prematurely causing signal loss, for example, at the riser module slot for a vertical expansion card.

Accordingly, there is a need for improved mechanisms for securing an expansion card module in a computing device to maintain a high quality connection with the expansion card. In addition, there is a need for increasing the efficiency in the building and servicing of expansion cards in computer devices.

SUMMARY OF THE INVENTION

According to certain aspects of the present disclosure, a latch mechanism for securing an expansion card assembly in a computer chassis comprises a lever including a latching end and an opposing pinned end. A stop member extends from the pinned end, and a rotary latch is connected to the latching end. The rotary latch includes a receiving chamber and a hook structure. The hook structure includes a notch for receiving a stop pin. A first biasing structure extends from the lever into the receiving chamber. The first biasing structure is configured to urge the rotary latch into a locked position. A second biasing structure is configured to urge the lever about the pinned end to an open position.

In a further aspect of the latch mechanism implementation, the pinned end of the lever is configured to receive a first cylindrical shaft extending from a side structure of the expansion card assembly. The first cylindrical shaft at least partially connects the lever to the side structure. In a further aspect, the lever rotates about the first cylindrical shaft.

In a further aspect of the latch mechanism implementation, the stop member is configured to engage a first stop pin protruding from a side structure of the expansion card assembly. In a further aspect, rotation of the lever about the first cylindrical shaft is at least partially controlled by a second stop pin and a third stop pin protruding from a side structure of the expansion card assembly. In yet a further aspect, the first biasing structure is configured to urge the rotary latch from the unlocked position to the locked position. In a further aspect, the notch is configured to receive the second stop pin. In yet a further aspect, the hook structure includes a chamfered end configured to engage the second stop pin.

In a further aspect of the latch mechanism implementation, the first biasing structure is a coil spring. In a further aspect, the second biasing structure is a torsion spring.

In a further aspect of the latch mechanism implementation, the lever includes an angled portion along a top edge of the lever. The angled portion is in contact with the second biasing structure. In a further aspect, the rotary latch is connected to the lever with a second cylindrical shaft about which the rotary latch rotates.

According to certain aspects of the present disclosure, an expansion card assembly comprises a peripheral frame defining an interior space, a printed circuit board at least partially positioned within the interior space, and a latch mechanism. The latch mechanism includes a lever with a latching end and a pinned end, a stop member extending from the pinned end, and a rotary latch connected to the latching end. The rotary latch includes a receiving chamber and a hook structure. The hook structure includes a notch for receiving a stop pin. A first biasing structure extends from the lever into the receiving chamber. The first biasing structure is configured to urge the rotary latch into a locked position. A second biasing structure is configured to urge the lever about the pinned end to an open position.

In a further aspect of the expansion card assembly implementation, the printed circuit board is a vertical printed circuit board. In a further aspect, the stop member is configured to engage a first stop pin protruding from the peripheral frame. In yet a further aspect, the pinned end of the lever is configured to receive a first cylindrical shaft protruding from the peripheral frame. The first cylindrical shaft at least partially connects the lever to the peripheral frame. In a further aspect, rotation of the lever about the first cylindrical shaft is at least partially controlled by a second stop pin and a third stop pin protruding from the peripheral frame. In a further aspect, the first biasing structure is configured to urge the rotary latch from an unlocked position to the locked position. In yet a further aspect, the notch is configured to receive a second stop pin. In a further aspect, the hook structure includes a chamfered end configured to engage the second stop pin.

DETAILED DESCRIPTION

Various embodiments are described with reference to the attached figures, where like reference numerals are used throughout the figures to designate similar or equivalent elements. The figures are not necessarily drawn to scale and are provided merely to illustrate aspects and features of the present disclosure. Numerous specific details, relationships, and methods are set forth to provide a full understanding of certain aspects and features of the present disclosure, although one having ordinary skill in the relevant art will recognize that these aspects and features can be practiced without one or more of the specific details, with other relationships, or with other methods. In some instances, well-known structures or operations are not shown in detail for illustrative purposes. The various embodiments disclosed herein are not necessarily limited by the illustrated ordering of acts or events, as some acts may occur in different orders and/or concurrently with other acts or events. Furthermore, not all illustrated acts or events are necessarily required to implement certain aspects and features of the present disclosure.

For purposes of the present detailed description, unless specifically disclaimed, and where appropriate, the singular includes the plural and vice versa. The word “including” means “including without limitation.” Moreover, words of approximation, such as “about,” “almost,” “substantially,” “approximately,” and the like, can be used herein to mean “at,” “near,” “nearly at,” “within 3-5% of,” “within acceptable manufacturing tolerances of,” or any logical combination thereof. Similarly, terms “vertical” or “horizontal” are intended to additionally include “within 3-5% of” a vertical or horizontal orientation, respectively. Additionally, words of direction, such as “top,” “bottom,” “left,” “right,” “above,” and “below” are intended to relate to the equivalent direction as depicted in a reference illustration; as understood contextually from the object(s) or element(s) being referenced, such as from a commonly used position for the object(s) or element(s); or as otherwise described herein.

For the present disclosure, the terms “computer system” or “computer device” or “computing system” refer to any electronically-powered or battery-powered equipment that has hardware, software, and/or firmware components, where the software and/or firmware components can be configured for operating features on the device.

In some implementations, an expansion card assembly, such as a vertical printed circuit board (“PCB”) module or other PCB modules, include a peripheral frame or housing having an interior space. The PCB is at least partially positioned within the interior space of the peripheral frame.

In some aspects, it is contemplated that a latch mechanism is connected to or a part of the expansion card assembly. The latch mechanism includes a lever with a latching end and a pinned end, along with a stop member extending from the pinned end. A rotary latch is further connected to the latching end. The rotary latch includes a receiving chamber for receiving a first biasing structure, such as a coil spring. In addition, the rotary latch includes a hook structure with a notch for receiving a stop pin that protrudes from the peripheral frame, such as a side wall. The first biasing structure extends from the lever into the receiving chamber and is configured to urge the rotary latch into a locked position when the notch receives a stop pin. A second biasing structure, such as a torsion spring, is configured to urge the lever away about the pinned end to an unlocked position, such as when the notch of the rotary latch is disengaged from the stop pin.

The present disclosure provides improved flexibility and higher bandwidth for expansion cards, including allowing high quality connections to be maintained by an expansion card installed in a computing device, such as a server. The latch mechanism and expansion card assembly described by the present disclosure are particularly desirable as signal speed and stability needs of computing devices, such as servers, continue to increase. For example, for a vertical printed circuit board (“PCB”) module in a1U server or other high performance computing devices, the latch mechanism of the present disclosure minimizes signal loss resulting from vibrations of the computing device itself or the surrounding environment. The latch mechanism provides multiple points on the expansion card assembly for securing the latch mechanism and further provides an improved manufacturing and maintenance experience when installing and removing an expansion card assembly, such as a vertical PCB module.

Turning now toFIG.1, a top left interior perspective view of an exemplary computing device100is depicted, such as a server. The computing device100includes the computer chassis110and one or more expansion card assemblies122,124located anywhere within the computer chassis110, including a location such as the rear portion120, as depicted inFIG.1.

Referring toFIG.2, a top left partial interior perspective view of a computing device200(e.g., a server) is depicted. The computing device200includes an expansion card assembly220having a peripheral frame230with a latch mechanism240connected thereto. The peripheral frame230at least partially houses one or more of a horizontal PCB250and a vertical PCB260. As depicted inFIG.2, the expansion card assembly220is being installed into a computer chassis210of the computing device200. The latch mechanism240is shown in an open position during the initial placement of the expansion card assembly220. Once the vertical PCB260is installed into, for example, a connector associated with the motherboard (not shown), the installer rotates the latch mechanism240in a downward direction as depicted by the arrow. The downward rotation places the latch mechanism240in a locked position to secure the expansion card assembly220to the computer chassis210.

Referring now toFIGS.3A and3B, a top right perspective view and a partially exploded perspective view of a latch mechanism340is depicted for securing an expansion card assembly to a computer chassis (seeFIGS.1and2). The expansion card assembly (see element220inFIG.2) can include a peripheral frame360to which the latch mechanism340is connected. The latch mechanism340is depicted in an open or unlocked position.

The latch mechanism340includes a lever342having a latching end344and a pinned end348. The latching end344includes a rotary latch346connected to the lever342. The pinned end348includes a stop member349extending from the lever342. The lever342is connected to the peripheral frame360at, for example, a side wall362. A pinned connection may be used including a first cylindrical shaft330that extends through the pinned end348of the lever342and is secured to the side wall362. A shaft cap335can further be used to keep the lever342from sliding off the first cylindrical shaft330. A biasing structure350such as, but not limited to, a torsion spring, is disposed between the lever342and the side wall362of the peripheral frame360. The biasing structure350is supported by fixing pins352,354that protrude from side wall362.

Referring now toFIGS.4A and4B, a side view is depicted of the latch mechanism340ofFIGS.3A and3Bfor an expansion card assembly transitioning from an unlocked or open position to a locked position.FIG.4Bdepicts a side view of a pinned end348of the latch mechanism340ofFIG.4Awith the latch mechanism340in the locked position. The lever342includes an angled portion370along a top edge372of lever342that engages with the biasing structure350.

Lever342starts in a fully open position with an edge of the lever342at the pinned end348resting against a third stop pin399. In response to urging of the lever342in direction A, the lever342rotates in direction B from the depicted open position about the pinned end348until the rotary latch346engages with and is secured about a second stop pin397protruding from the peripheral frame360. When the rotary latch346is fully engaged with the second stop pin397further rotation of the lever342is limited. During rotation of the lever342in direction B, the biasing structure350compresses and the stop member349protruding of the lever342engages with a first stop pin398, that protrudes from a chassis frame560(seeFIG.5) adjacent to the peripheral frame360. Upon full engagement of the stop member349with the first stop pin398, the lever342is also limited from moving up or down along the z-axis depicted inFIG.4B.

Referring toFIG.5, a top view of the latch mechanism340ofFIGS.4A to4Bis depicted as part of an expansion card assembly520. The biasing structure350is shown to be positioned below the angled portion370that extends laterally from the top edge372of the lever342between the latching end344and the pinned end348.

Referring toFIGS.6A and6B, a top right perspective view and a partial exploded perspective view of the latch mechanism340ofFIGS.4A and4Bis depicted. The view provided is of the opposite side of the latch mechanism340depicted inFIGS.3A-Band4A-B and includes additional details of the rotary latch346at the latching end344and the stop member349at the pinned end348of the lever342. In some implementations, the stop member349is parallel to but laterally offset from the surface of lever342.

Another biasing structure390such as, but not limited to, a coil spring, is positioned between the lever342and a receiving chamber395of the rotary latch346. The rotary latch346can include a hook structure392that defines the boundaries of a notch393for receiving a stop pin. The rotary latch346is connected to the latching end344of the lever342using a cylindrical shaft380that is secured to the lever342on one end and has a shaft cap385on the other end. When the rotary latch346is urged in direction C, the rotary latch346rotates about the cylindrical shaft380.

Referring now toFIG.7, a top perspective view of a portion of the latching end344(seeFIGS.3A,4A,5, and6A) of the latch mechanism340inFIGS.6A and6Bis depicted, including an interior hidden view of the biasing structure390within the receiving chamber395of the rotary latch346. As discussed forFIG.6B, the biasing structure390is positioned within and constrained on one end by a receiving chamber395of the rotary latch346and on the other end by the lever342at interface391. The biasing structure390is depicted in a substantially uncompressed state (e.g., with minimal compression; with no compression; with enough compression so that the spring does not move within the receiving chamber395). As the rotary latch346is urged toward the interface391causing rotation of the rotary latch346about the cylindrical shaft380, the biasing structure390transitions to a compressed state.

Referring now toFIG.8A, a cross-sectional side view through a portion of the latching end344(seeFIGS.3A,4A,5, and6A) of the latch mechanism340fromFIGS.6A and6Bis depicted prior to the latch mechanism340locking an expansion card assembly to a computer chassis (e.g., see expansion card assembly220and computer chassis210inFIG.2).FIG.8Bis a side view of the latch mechanism340, prior to locking an expansion card assembly to a computer chassis. The latch mechanism340as depicted includes hidden features, such as the biasing structures350,390, the rotary latch346, the hook structure392, and the notch393.

In response to the urging of the lever342in direction A, the lever342of the latch mechanism340transitions by rotating about the cylindrical shaft330in direction B such that the pinned end348(seeFIGS.3A,4A,5, and6A) is no longer seated at the third stop pin399. The rotary latch346at the latching end344(seeFIGS.3A,4A,5, and6A) includes a chamfered end396on hook structure392that is in contact with the second stop pin397. Upon further rotation of the lever342in direction B, contact between the chamfered end396and the second stop pin397causes the rotary latch346to rotate about the cylindrical shaft380in direction C′ until the second stop pin397locks into the notch393at which point any further rotation in direction B is limited.

As rotary latch346rotates in direction C′, biasing structure390is compressing due to being constrained within receiving chamber395on one end of the biasing structure390and on the other end by lever342. Similarly, as the lever342continues to rotate in direction B, the other biasing structure350also compresses because the biasing structure350is configured to urge the lever342in a direction causing rotation opposite that of direction B.

Referring now toFIG.9A, a side view of the latch mechanism340ofFIG.8Bis depicted with the latching end344and the pinned end348in a locked position to secure the expansion card assembly to the computer chassis (e.g., see expansion card assembly220and computer chassis210inFIG.2).FIG.9Bdepicts the side view ofFIG.9A, except with hidden features, such as the biasing structure350, the biasing structure390, the notch393, the hook structure392, the second stop pin397, and the cylindrical shafts330,380(seeFIGS.9B and10). As discussed forFIGS.4A and4B, during rotation of the lever342in direction B, the biasing structure350compresses and the stop member349protruding for the lever342engages with the first stop pin398(shown in cross-section with cross-hatching inFIGS.8B,9A, and11), which extends from an adjacent chassis frame560(seeFIG.5). Upon full engagement of the stop member349with the first stop pin398, as depicted inFIG.9A, the latch mechanism340has limited movement.

With the latch mechanism340constrained from rotation by the second stop pin397and further locked by the friction contact between stop member349and the first stop pin398, a vertical PCB260(seeFIG.2) that may be a part of an expansion card assembly, is prevented from being dislodged in a vertical direction that could cause a deterioration of a connection, for example, with a motherboard of the computing device100.

Referring now toFIGS.10and11, a side view of the latch mechanism340ofFIGS.9A and9Bis depicted, as the latching end344is released to unlock an expansion card assembly from a computer chassis. This allows the latch mechanism340to be rotated to an opened position. The rotary latch346is urged in direction D causing the rotary latch346to rotate about the cylindrical shaft380and causing the biasing structure390to compress. The rotation of the rotary latch346also causes the notch393of the hook structure392to disengage from the second stop pin397to allow the latch mechanism340to move to the open position depicted inFIG.4A. The biasing structure350(see, e.g.,FIG.11) then urges the lever342in an upward direction such that the stop member349dislodges from the first stop pin398and the latch mechanism340rotates in direction B′ until the pinned end348(seeFIGS.3A,4A,5, and6A) comes into contact with the third stop pin399. Once the latch mechanism340is stopped by the third stop pin399, the latch mechanism340is in a fully opened position. In addition, as the force applied in direction D ceases, the biasing structure390causes the rotary latch346to rotate in direction D′ (seeFIG.11).

The implementations described above forFIGS.1to11are primarily in the context of a latch mechanism for securing an expansion card assembly in a computer chassis. However, the described latch mechanism is applicable to other types of expansion card assemblies having printed circuit boards or other high-performance computer components. The described latch mechanism and expansion card assembly have been presented by way of example only, and not limitation, and can include different combinations of the described elements.