SLIDER-BASED HBA INTERNAL LOCK

Abstract

A device for locking one or more printed circuit boards (118) in their position between a pair of guide rails (204, 206; 402; 500), the device comprising the following: a slider (302; 400; 506) which is attached to a side wall of a guide rail (204, 206; 402; 500), wherein the slider (302; 400; 506) can slide within a predetermined range along the guide rail (204, 206; 402; 500); and one or more piston-spring assemblies (304, 306), each piston-spring assembly (304, 306) comprising a piston (210; 412; 518, 520) and a spring (334; 418; 524) surrounding the piston (210; 412; 518, 520), the piston (210; 412; 518, 520) being inserted into a through-hole on the side wall of the guide rail (204, 206; 402; 500) such that a first end of the piston (210; 412; 518, 520) can be aligned with a notch (208) on a corresponding circuit board and a second end of the piston (210; 412; 518, 520) is in contact with the slide (302; 400; 506) is; and wherein the sliding of the slider (302; 400; 506) causes the spring (334; 418; 524) to be compressed and relaxed and causes the first end of the piston (210; 412; 518, 520) to move in and out of the notch (208) on the circuit board (118), thereby facilitating the locking and unlocking of the circuit board (118).

Description

BACKGROUND

[0001] This disclosure generally relates to a locking mechanism for locking printed circuit boards in position. More specifically, the locking mechanism is mounted laterally and may include a pull rod to facilitate front access. JP H11-8483 A describes a device for preventing a printed circuit board from falling, comprising a locking element provided so as to be protrudable from a guide groove of the guide rail provided on a shelf, a spring for biasing the locking element toward the printed circuit board, a stopper groove formed on the printed circuit board into which the locking element fits, and a guide formed on the printed circuit board for guiding the locking element into the stopper groove. SHORT DESCRIPTION

[0002] A device according to claims 1 to 10 and a circuit board subassembly according to claims 11 to 20 are disclosed. BRIEF DESCRIPTION OF THE ILLUSTRATIONS Fig. shows a schematic representation of a partial top view of an input / output module (IOM) with a locking mechanism according to one aspect of the application. The Fig. show the operating principle of the locking mechanism according to one aspect of the application. Fig. shows a side-mounted slide lock for locking a pair of printed circuit boards in position, according to one aspect of the present application. Fig. shows a slider of the slider according to one aspect of the present application. Fig. shows a piston-spring assembly of the slide lock according to one aspect of the present application. Fig. shows the enlarged view of the chamber roofs and the piston-spring assembly when the slide lock is in the locked state, according to one aspect. Fig. shows the enlarged view of the chamber roofs and the piston-spring assembly when the slide lock is in the unlocked state, according to one aspect. Fig. shows the enlarged view of the chamber roofs and the piston-spring assembly when the slide lock is in the locked state, according to one aspect. Fig. shows the enlarged view of the chamber roofs and the piston-spring assembly when the slide lock is in the unlocked state, according to one aspect. Fig. shows a slide lock installed on the side of a guide rail according to one aspect of the present application. Fig. shows the cross-section of the slide lock and guide rail when the lock is in the locked state, according to one aspect of the present application. Fig. shows the cross-section of the slide lock and guide rail when the lock is in the unlocked state, according to one aspect of the present application.

[0003] In the figures, like numbers refer to the same elements of the figure. DETAILED DESCRIPTION

[0004] The following description is intended to enable one skilled in the art to make and use the examples and is provided in the context of a specific application and its requirements. Various modifications to the examples shown will be readily apparent to one skilled in the art, and the general principles defined herein may be applied to other examples and applications without departing from the spirit and scope of the present disclosure. Therefore, the scope of the present disclosure is not limited to the examples shown, but is intended to have the widest possible scope consistent with the principles and features disclosed herein.

[0005] The ever-increasing demand for computing and storage capacity has led to a continuous increase in component density in computer servers, and there is increasingly less space for installing add-in cards and devices required for a specific application. For example, a chassis may use input / output modules (IOMs) to meet the input / output needs of the storage nodes mounted on the chassis, and each IOM may require up to four hot-swappable host bus adapter (HBA) cards to connect host systems to the corresponding storage devices. Because the IOM is typically housed in a 1U chassis, the four HBA cards do not fit on the same level. One solution is to stack two HBA cards (i.e., place one HBA card on top of another).However, this HBA stacking configuration poses a challenge for hot swapping HBA cards because the traditional locking and unlocking mechanisms for HBA cards are mounted at the top. When multiple (e.g., two) HBA cards are stacked in a 1U input / output module (IOM) chassis, the traditional top-mounted locking mechanism is no longer applicable.

[0006] The present disclosure describes a locking mechanism for locking host bus adapter (HBA) cards in position between a pair of guide rails. The proposed internal locking mechanism can be mounted on the side of a guide rail and can include a slider and one or more piston-spring assemblies. The slider can be attached (e.g., via snap-fits) to the side of the guide rail and can include one or more chambers for receiving the piston-spring assemblies. Each chamber can have a lower roof and an upper roof, with the upper roof being farther from the guide rail than the lower roof.When an HBA card is inserted into a slot on the guide rails, one end of the piston can be inserted via a through-hole on the guide rail into a notch on the HBA card, locking the HBA card in position. The other end of the piston can be forced by the spring against the lower roof of the corresponding slide chamber. As the slide slides along the guide rail, the compressed spring can push the piston far enough to slide along an internal ramp within the slide until the piston makes contact with the upper roof of the chamber, retracting the piston from the notch on the HBA card to unlock the HBA card. Fig. shows a diagram illustrating a partial top view of an input / output module (IOM) with a locking mechanism according to one aspect of the application. In Fig. An IOM 100 may include a pair of HBA subassemblies 102 and 104. Each subassembly may include a pair of guide rails for accommodating one or more HBA cards. For example, HBA subassembly 102 may include guide rails 106 and 108 that can accommodate a number of HBA cards, including HBA card 110. Note that additional HBA cards may be placed beneath HBA card 110 and in Fig. are not shown. Fig. also shows that each HBA card can be coupled with a handle to slide or pull the HBA card along the guide rails when replacing the HBA card. For example, HBA card 110 can be connected to a handle 112 that can be used to slide the HBA card 110 out of the HBA subassembly 102 from the front of the IOM module 100 when replacing the HBA card 110.

[0007] Because the HBA card can slide along the guide rails to facilitate hot-swapping or maintenance, a locking mechanism can be used to secure the HBA card in position when in use. In conventional systems where the HBA cards are on the same level and not stacked, a locking mechanism can be mounted above the HBA card to lock the HBA card in place (e.g., via a notch on the HBA card). However, when multiple HBA cards are stacked, the top-mounted locking mechanism may no longer be applicable. Given the limited vertical clearance of the 1U IOM chassis (which, in one example, can be approximately 38.7 mm, considering the sheet thickness of the IOM chassis' top and bottom covers), a top-mounted locking mechanism may not fit within the 1U IOM chassis.

[0008] To facilitate locking / unlocking of the stacked HBA cards, a side-mounted locking mechanism may be employed to access and lock the stacked HBA cards from the side. In one aspect, each HBA subassembly may include a slide lock mounted on the side of its guide rail for locking the stacked HBA cards. To facilitate front access to the slide lock, a pull rod may be attached to the slide lock. Fig. For example, FIG. 1 shows a side-mounted sliding lock 114 attached to the side of the guide rail 108 of the HBA subassembly 102. The side-mounted sliding lock 114 can lock the stacked HBA cards, including the HBA card 110, in the HBA assembly 102 so that, when locked, the HBA cards can be prevented from sliding along the guide rails 106 and 108. A pull rod 116, accessible from the front panel of the IOM 100, is coupled to the side-mounted sliding lock 114. The pull rod 116 can be made of a plastic material (e.g., polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), etc.). The length of the pull rod 116 can be determined based on the depth of the 1U IOM chassis. The pull rod 116 may typically have an elongated body and a handle that allows the user to grasp the handle and pull on it.The handle can have various shapes and sizes. The pull rod 116 can be attached to the slide lock 114 using a suitable fastening mechanism (e.g., a screw). In one aspect, to remove the HBA card 110 from the subassembly 102, a user can pull / push on the pull rod 116 to place the side-mounted slide lock 114 into an unlocked state.

[0009] Fig. also shows a printed circuit board 118 arranged between the HBA subassemblies 102 and 104. Since the printed circuit board 118 is generally not hot-swappable, its position can be fixed, and an additional locking mechanism may not be required. Note that Fig. shows only a portion of the components within the IOM 100. Additional components, such as a motherboard, are not shown.

[0010] The Fig. show the operating principle of the locking mechanism according to one aspect of the application. In particular, Fig. and Fig. Each shows a top view of the HBA subassembly, which includes the HBA card and the guide rails. In one aspect, the HBA card can conform to the Open Compute Project (OCP) standard. For example, an OCP HBA card can have a clearly defined dimension such as 16.8 cm × 6.9 cm. Fig. shows an OCP HBA card 202 positioned between guide rails 204 and 206. Each of the guide rails may include a slot (defined by the dashed lines) into which a corresponding edge of the OCP HBA card 202 may be inserted. The OCP HBA card 202 may then slide along the guide rails, facilitating hot-swapping of the HBA card 202. Fig. also shows that the HBA card 202 may have a notch 208 on one of its longer edges. The location and size of the notch 208 may be based on the OCP standard. For example, an OCP HBA card may have a notch on each side, and the notch opening may be approximately 3.5 mm. The tip of a plunger 210 may be inserted through a through-hole (in Fig. not shown) in the guide rail 206 into the notch 208. Since the plunger 210 is clamped by the through-hole in the guide rail 206, the HBA card 202 can be locked in position and prevented from sliding along the guide rails when its tip is inserted into the notch 208.

[0011] Although the piston 210 cannot move along the longitudinal direction (as indicated by a dashed line 212) of the guide rail 206, it can move in a vertical direction. Fig. shows that the piston 210 can move to the right, as indicated by an arrow 214, thereby retracting the tip of the piston 210 from the notch 208. When the piston 210 is retracted, the HBA card 202 can move freely along the guide rails.

[0012] There are various mechanisms for pushing and pulling the plunger into and out of the notch on the HBA card to lock and unlock the HBA card. Some mechanisms, such as a push-pull lever, can be bulky or difficult to operate. According to some aspects of the present application, a compact slider can be used to push or pull the plunger. More specifically, the plunger and slider can be coupled so that the sliding movements of the slider along the guide rail can be converted into movements of the plunger moving in and out of the notch on the HBA card.

[0013] Fig. shows a side-mounted slider lock for locking a pair of printed circuit boards in position, according to one aspect of the present application. The slider lock 300 may include a slider 302, a pair of plunger-spring assemblies 304 and 306, and a screw 308. According to one aspect, the plunger-spring assemblies 304 and 306 can move in a direction perpendicular to the guide rail as the slider 302 moves along the guide rail, meaning that the plunger-spring assemblies 304 and 306 can move in and out of the notches on the corresponding printed circuit boards, thereby locking and unlocking the printed circuit boards.

[0014] Fig. shows a slider of the slider lock according to one aspect of the present application. The slider 302 may include a series of snap fasteners that serve to secure the slider 302 to the side of a guide rail. In the Fig. In the example shown, the slider 302 may have snap fasteners 312, 314, 316, and 318 at its four corners. According to one aspect, the snap fasteners may comprise snap hooks. More specifically, these snap fasteners may engage the edges of the predefined slots on the guide rail to secure the slider 302 to the guide rail. Furthermore, the snap fasteners and the edges of the predefined slots on the guide rail may have a smooth surface to allow the slider 302 to slide relatively easily on the guide rail. It should be noted that both the slider 302 and the guide rail may be made of a rigid plastic material such as polytetrafluoroethylene (PTFE) or polyvinyl chloride (PVC). In addition to the Fig. In addition to the snap hooks shown, the slider 302 may use a different fastening mechanism for attachment to the guide rail, as long as the fastening mechanism allows the slider 302 to slide along the guide rail. Instead of the snap hooks, the slider 302 may also be attached to the guide rail with screws, for example. In the Fig. In the example shown, the slider 302 may, in addition to the snap hooks, also have a slot 310 which allows a screw (ie the one in Fig. shown screw 308) to engage a threaded hole in the guide rail to further secure the slider 302 to the guide rail. Unlike a normal circular through-hole that fits into the typical cylindrical body of a screw, the slot 310 may have an elongated shape to allow the slider 302 to slide along the length of the slot 310. In one aspect, the slot 310 may be shaped like a rectangle with rounded corners or an eclipse. The sliding range of the slider 302 may be determined by the length of the slot 310, which may be between 5 and 20 mm (e.g., about 10 mm). In one example, the length of the slot 310 may be between 1 / 2 and 2 / 3 the length of the slider 302.

[0015] The slider 302 may include a pair of chambers 320 and 322 for receiving the piston-spring assemblies, with each chamber corresponding to a piston-spring assembly. The shape of each chamber may be designed such that the piston-spring assemblies can move in a direction perpendicular to the guide rail as the slider 302 slides along the guide rail (i.e., move in and out of the notches on the corresponding circuit boards). More specifically, each chamber may have a lower roof and an upper roof. When the slider 302 is mounted to the side of the guide rail, the lower roof of each chamber may be closer to the guide rail than the upper roof of the chamber. When the slider 302 slides to a position where the lower roof of each chamber engages the corresponding piston-spring assembly (e.g.,In the position shown in FIG. 1, the tip of each plunger can be pushed into the notch on the circuit board to lock the circuit board. On the other hand, when the slider 302 slides into a position where the upper roof of each chamber is engaged (e.g., in direct contact) with the corresponding plunger-spring assembly, the tip of each plunger can be retracted from the notch on the circuit board to unlock the circuit board. In the position shown in FIG. 1, the plunger can be pushed into the notch on the circuit board to lock the circuit board. Fig. In the example shown, the chamber 322 may include a lower roof 324, an upper roof 326, and a ramp 328 disposed between the lower roof 324 and the upper roof 326. The ramp 328 may allow the piston-spring assembly to slide back and forth between the lower roof 324 and the upper roof 326.

[0016] Fig. shows a piston-spring assembly of the slider lock according to one aspect of the present application. The piston-spring assembly 306 may include a piston rod 330, a piston head 332, a spring 334, and a spring retainer 336. The piston rod 330 and the piston head 332 together form the plunger, which may be a one-piece construction or consist of two separate parts that are joined together. The piston rod 330 may be cylindrical, and the piston head 332 may be wider than the piston rod 330 and substantially in the shape of a right-angled prism. For example, the piston rod 330 may have a diameter between 1 and 5 mm, and the width of the piston head 332 may be between 20 and 50% larger than the diameter of the piston rod 330. The overall length of the piston-spring assembly 306 may be between 10 and 15 mm.The piston head 332 can essentially serve as the locking element of the slide lock, and its entry into and exit from the notch on the circuit board can result in locking and unlocking of the circuit board. In addition to the locking action shown in . Fig. In addition to the shape of a right-angled triangular cylinder shown, the piston head 332 may also have other shapes, such as a cube or a rectangular prism. The size of the piston head 332 may vary depending on the size of the notch (e.g., notch 208 in Fig. be configured on the circuit board. For example, the piston head 332 may have a width slightly smaller than the width of the notch so that it can easily enter or exit the notch. On the other hand, the piston head 332 must not be so small that it cannot securely lock the circuit board. The notch may be a few millimeters wide (e.g., between 2 and 10 mm), and the piston head 332 may have approximately the same width. In one aspect, the piston, including the piston rod 330 and the piston head 332, may be made of metal, such as die-cast aluminum, die-cast zinc, etc. It should be noted that the free end (i.e., the end opposite the piston head 332) of the piston rod 330 may have a dome-shaped surface 338, which can reduce the friction between the piston and the inner surface of the slider 302 when the slider 302 slides along the guide rail.The dome-shaped surface 338 can be half a sphere or less than half a sphere. The diameter of the sphere can be between 1 and 10 mm. Alternatively, the dome-shaped surface 338 can also be a parabolic dome.

[0017] The spring 334 may surround the piston rod 330. Fig. also shows that the spring 334 can be limited by the spring retainer 336. In the Fig. In the example shown, the spring retainer 336 may be a C-shaped disc (metal or plastic) secured via a groove near the free end of the rod 330. In another example, the spring retainer 336 may be a built-in spring retainer of the rod 330. In such a case, the piston head 332 may be a separate part that can be removed from the rod 330 to allow the passage of the rod 330 from one side of the guide rail to the other through a through hole in the guide rail. When the slide lock is installed, the spring 334 may be clamped between the spring retainer 336 and the guide rail.

[0018] Fig. shows the enlarged view of the chamber roofs and the piston-spring assembly when the slide lock is in the locked state, according to one aspect. More specifically, Fig. a partial view of a slider 400 and a guide rail 402. The inner surface (i.e., the surface facing the guide rail 402) of the slider 400 may include a lower chamber roof 404, an upper chamber roof 406, a ramp 408, and a hump 410. Fig. also shows a piston-spring assembly, which may include a piston 412 (with a rod 414 and a head 416), a spring 418, and a spring retainer 420. The rod 414 may be inserted into a through-hole in the guide rail 402. The length of the rod 414 and the distance between the lower chamber roof 404 and the guide rail 402 may be configured such that the head 416 may protrude beyond the inner surface (i.e., the surface facing the circuit board) of the guide rail 402 when the free end of the rod 414 is in direct contact with the lower chamber roof 404. As shown in the Fig. In the example shown, the head 416 of the piston 412 can penetrate the notch on the circuit board held by the guide rail 402 and lock the circuit board in position.

[0019] As in Fig. As shown, the spring 418 surrounding the rod 414 can be compressed by the spring retainer 420 and the outer surface of the guide rail 402 when the slide lock is in this locked state. This is because the diameter of the spring 418 is larger than that of the through hole in the guide rail 402 and smaller than that of the spring retainer 420. In this case, the compressed spring 418 can press the piston 412 against the lower chamber ceiling 404.

[0020] To release the lock or to withdraw the head 416 from the notch on the circuit board, the slider 400 can be moved to the right, i.e., in a direction pointing from the upper chamber roof 406 to the lower chamber roof 404, as indicated by the arrow above the slider 400. In this example, the front panel of the circuit board assembly is on the right side, meaning that the circuit board is loaded and unloaded from the right. As the slider 400 slides along the guide rail 402, the free end of the rod 414 can slide on the inner surface of the slider 400. As shown in Fig. As shown, the free end of rod 414 may include a dome-shaped surface 422, which can significantly reduce friction between the inner surface of slider 400 and rod 414. As slider 400 slides to the right, ramp 424 connecting bump 410 and lower chamber roof 404 can push piston 412 downward (further compressing spring 418) to allow bump 410 to pass piston 412. Note that bump 410 is configured to prevent inadvertent movement of slider 400. External forces are required to move slider 400 past piston 412. The height and inclination of the hump 410 can be carefully designed so that the slider 400 can only pass the piston 412 with a reasonable force (e.g., forces of a few Newtons) exerted on the slider 400 (e.g., when a user pulls the slider 400 to the right).In one example, the height of the bump 410 (relative to the lower chamber roof 404) may be between one and two times the radius of the dome-shaped end face of the rod 414, and the minimum force required to push or pull the slider 400 to pass the bump 410 may be between 2 and 10 N.

[0021] When the protrusion 410 of the slide 400 passes the piston 412, the compressed spring 418 can begin to relax, pushing the piston 412 against the slide 400. As the slide 400 slides further to the right, the piston 412 can be pushed by the spring 418 and slide over the ramp 408 until it reaches the upper chamber roof 406. When the piston 412 is in direct contact with the upper chamber roof 406, the slide lock is in the unlocked state.

[0022] Fig. shows the enlarged view of the chamber roofs and the piston-spring assembly when the slide lock is in the unlocked state, according to one aspect. How Fig. shows Fig. the partial view of a slider 400 and a guide rail 402. More precisely, Fig. that the free end of the rod 414 of the piston 412 is now in direct contact with the upper chamber ceiling 406. As can be seen from the comparison of Fig. with Fig. As can be seen, the height difference between the upper chamber ceiling 406 and the lower chamber ceiling 404 can cause the piston 412 to move upwards and retract the head 416 into the through hole of the guide rail 402. As shown in the Fig. In the example shown, the head 416 of the plunger 412 can exit the notch on the circuit board held by the guide rail 402, thereby unlocking the circuit board (i.e., the circuit board can slide freely along the guide rail 402). In this unlocked state, the spring 418 can be relieved. With the slider lock unlocked, a user can remove the old circuit board from the slot on the guide rails and insert a new circuit board into the slot. To lock the new circuit board in position, the user can push / pull the slider 400 to the left (as shown in Fig. (indicated by the arrow above the slider 400) to push the piston 412 downward and compress the spring 418 until the piston 412 contacts the lower chamber roof 404 and the piston head 416 is pressed into the notch on the new circuit board. In some aspects, a user may need to apply force to the slider 400 to compress the spring 418. The minimum force required to compress the spring 418 may be between 2 and 10 N.

[0023] In the Fig. The front panel of the subassembly is located on the right side of the drawing, and the slider 400 can be moved from a locked position to an unlocked position by sliding it to the right (or toward the front panel). If a pull rod accessible from the front panel is used (e.g., as shown in Fig. (shown), a user can pull the pull rod forward to unlock the circuit board and push the pull rod backward to lock the circuit board. If no pull rod is present, the user may need to remove the 1U IOM top cover to pull the slider 400 forward to unlock the circuit board or push the slider 400 backward to lock the circuit board.

[0024] It is also possible to configure the slider lock differently so that a user can slide the slider backward to unlock the circuit board and pull it forward to lock the circuit board. Fig. shows the enlarged view of the chamber roofs and the piston-spring assembly when the slide lock is in the locked state, according to one aspect. Fig. is Fig. Very similar, except that the slider has been configured so that to unlock the slider lock, the slider must be moved to the left, as indicated by the arrow above the slider. If the front panel is on the right side of the drawing, unlocking the slider lock may require a push from the user. Fig. shows the enlarged view of the chamber roofs and the piston-spring assembly when the slide lock is in the unlocked state, according to one aspect. Fig. is Fig. Very similar, except that the slider is configured so that locking the slider lock may require movement of the slider to the right, as indicated by the arrow above the slider. If the front panel is on the right side of the drawing, locking the slider may require a pulling motion by the user. As shown in the Fig. As shown, a user can apply a force to the slider to push or pull the slider to unlock or lock the circuit board. The minimum force applied to the slider can range from 2 to 10 N.

[0025] Fig. shows a slide lock installed on the side of a guide rail according to one aspect of the present application. In Fig. A guide rail 500 may include a pair of slots (e.g., slots 502 and 504) for receiving printed circuit boards, one slot per card. In this example, the HBA subassembly can accommodate two stacked HBA cards. Fig. also shows a slider 506 mounted on the outer sidewall (the sidewall facing away from the circuit boards) of the guide rail 500. More specifically, the slider 506 can be secured to the guide rail 500 by a series of snap fasteners (e.g., fasteners 508 and 510). In addition to the snap fasteners, a screw 512 can also be used to secure the slider 506 to the sidewall of the guide rail 500. Note that the snap fasteners and screw 512 do not rigidly fix the position of the slider 506. Instead, the slider 506 can slide within a certain range along the guide rail 500. The range of motion of the slider 506 can be defined by the position of the screw 512 and a slot 514 on the slider 506.The slider 506 can move between a first position in which the screw 512 contacts one end of the slot 514 and a second position in which the screw 512 contacts the opposite end of the slot 514. In one aspect, the slider lock can be in a locked state when the slider 506 is moved to the first position and in an unlocked state when the slider 506 is moved to the second position, or vice versa. Fig. also shows that the slider 506 may include a handle 516. A user may pull / push the slider 506 along the guide rail 500 by holding the handle 516 and exerting a pulling / pushing force. In some aspects, a pull rod (in Fig. A locking bar (not shown) can be attached to handle 516 to allow access to the slider lock from the front panel of the printed circuit board subassembly. For example, by pulling / pushing the pull bar, a user can pull / push the slider 506 without opening the top cover of the 1U IOM chassis. Various coupling mechanisms can be used to attach the pull bar to handle 516, including snap locks, screws, adhesive, solder, etc.

[0026] Fig. shows the cross-section of the slide lock and the guide rail when the lock is in the locked state, according to one aspect of the present application. In Fig. the slider 506 is brought into a position in which the slider lock is in the locked state. More specifically, Fig. that the pistons 518 and 520 are in contact with the lower roof of their respective chambers so that their piston heads protrude into the slots 502 and 504, respectively. As in the Fig. In the example shown, the extended pistons 518 and 520 can lock the circuit boards inserted into the slots 502 and 504 in place. When the slots 502 and 504 are empty and no circuit board is inserted, the extended pistons 518 and 520 can prevent the insertion of circuit boards into the slots 502 and 504.

[0027] Fig. also shows the side view of the snap fastener 508 and the cross-section of the screw 512. In this example, the snap fastener 508 includes a snap hook that can hook into a predefined groove of the guide rail 500. The smooth interface between the hook and the groove can allow the slider 506 to slide along the guide rail 500.

[0028] Fig. also shows the cross-sectional view of the spring retainer attached to each piston and the spring surrounding each piston (e.g., spring retainer 522 attached to piston 520 and spring 524 surrounding piston 520). As shown in Fig. As shown, the diameter of the through-hole in the guide rail 500 may be slightly larger than the diameter of the rod of the piston 520, but slightly smaller than that of the spring 524, so that the rod of the piston 520 can be guided through the through-hole, but the spring 524 can be clamped between the outer wall of the guide rail 500 and the spring retainer 522. For example, the diameter of the through-hole may be between 5 and 20% larger than the diameter of the rod of the piston 520, and the diameter of the spring 524 may be between 5 and 10% larger than the diameter of the through-hole. In the Fig. In the example shown, the slide lock is in the locked state, and the free ends of the pistons are in direct contact with the lower chamber roofs. For example, the free end of piston 520 can be pressed against the lower chamber roof 526 by spring 524, and spring 524 can be compressed between the outer wall of guide rail 500 and spring retainer 522.

[0029] According to Fig. Installation of the slide lock may include inserting the piston rods of pistons 518 and 520 from the inside (i.e., the left side) of the guide rail 500 into the through holes of the guide rail 500; attaching the springs (e.g., spring 524) from the outside (i.e., right side) of the guide rail 500 around the extruded portion of the piston rods; installing the spring retainer (e.g., spring retainer 522) on the piston rods; and then covering the piston rods with the slide 506 and securing the slide 506 to the side wall of the guide rail 500. Note that securing the slide 506 may also include sliding the snap locks (e.g., lock 508) into the correct position and screwing the screw 512 into the preset screw hole of the guide rail 500.

[0030] Fig. shows the cross-section of the slide lock and the guide rail when the lock is in the unlocked state, according to one aspect of the present application. In Fig. The slide lock is in an unlocked state in which the pistons 518 and 520 are retracted from the slots of the guide rail 500. For example, the piston 518 is retracted from the slot 502 and the piston 520 is retracted from the slot 504. Fig. also shows that the retraction of the pistons can be caused by the relaxed springs pushing the pistons toward the slide 506. In this case, the relaxed springs can push the pistons into direct contact with the upper chamber roofs. For example, the relaxed spring 524 can press the free end of the piston 520 against the upper chamber ceiling 528. As can be seen from the comparison of Fig. with Fig. As can be seen, the upper chamber ceiling 528 may be farther from the guide rail 500 than the lower chamber ceiling 526. This greater distance may enable the retraction of the piston heads.

[0031] In the examples in Fig. The slide lock can lock / unlock two circuit boards held by the guide rails simultaneously. In other words, a single slide lock functions for both slots. This is advantageous for the 1U IOM due to the compact design of the slide lock. In cases where the vertical distance is greater, it is also possible to use separate slide locks for the different circuit board receiving bays. Each individual slide lock can be provided with its own sliding handle to accommodate independent operations. In this way, the circuit boards in the multiple (e.g., two) slots can be locked and unlocked independently of each other. To save space, the two sliding handles can also be attached to opposite ends of the slide locks. In the Fig. In the example shown, the slider handle is located at the far end of the slider. It is also possible to place the slider handle at the near end of the slider. In cases where the circuit boards have cutouts on both edges, the slider locks for the two PCB slots can be mounted on opposite guide rails, one lock per guide rail.

[0032] In addition, the Fig. Pull-to-Unlock configuration shown and the one in Fig. Pull-to-Unlock configuration shown and the one in the Fig. The configurations shown can be used according to practical requirements, as one configuration may be preferred over the other in certain applications. One aspect also allows for the two configurations to be mixed and matched. For example, the slide lock mounted on the upper slot of the guide rail may use one configuration (e.g., the pull-to-unlock configuration), while the slide lock mounted on the lower slot of the guide rail may use a different configuration (e.g., the push-to-unlock configuration).

[0033] In general, this disclosure provides a solution to the problem of locking hot-swap printed circuit boards stacked on top of each other. More specifically, a slider lock may be used, where the sliding of a slider along a guide rail may cause plungers constrained by the guide rail and the slider to move in and out of the notches of printed circuit boards held between a pair of guide rails. For space constraints, the slider lock may be mounted on the side of the guide rail, and the plungers may engage the printed circuit boards from the side (e.g., the plungers move in a plane parallel to the component mounting surface of each printed circuit board).Because the chambers that house the pistons have a bottom and top cover, the relative position between the pistons and the guide rail can change depending on whether the pistons are in contact with the bottom or top cover, and such a relative position can determine whether the slide lock is in the locked or unlocked state. Throughout this disclosure, OCP-HBA cards have been used as examples to describe the operation of the slide lock. In practice, the side-mounted slide lock can be used to lock any type of circuit board, as long as the circuit board has a predefined notch that allows the head of the piston to engage the circuit board. Also, the OCP-HBA card has one notch to secure its position, while another type of circuit board may have more than one notch (e.g., one notch on each edge). In such a case, more than one (e.g., a single) notch may be used.Two slide locks (e.g., one lock per rail) must be attached to the guide rails to lock the circuit board. The . Fig. show the guide rails for holding two stacked circuit boards. In practice, fewer (e.g., one) or more (e.g., four) circuit boards can be held between a pair of guide rails, and one or more slide locks can be used to lock these circuit boards in position. Also shown is Fig. a special design of the slider. In practice, the shape and size of the slider can vary from the Fig. The shape shown may vary. For example, different coupling mechanisms can be used to attach the slider to the guide rail. Furthermore, the interface between the upper and lower roofs can be connected not only by a ramp, but also by a 90° angle or several steps.

[0034] One aspect of the present application provides a device for locking one or more printed circuit boards between a pair of guide rails. The device may comprise a slider attached to a sidewall of a guide rail. The slider can slide along the guide rail within a predetermined range, and one or more piston-spring assemblies. A corresponding piston-spring assembly comprises a piston and a spring surrounding the piston, and the piston is inserted into a through-hole on the sidewall of the guide rail such that a first end of the piston can be aligned with a notch on a corresponding printed circuit board and a second end of the piston is in contact with the slider.Moving the slider compresses and relaxes the spring and moves the first end of the piston in and out of the notch on the circuit board, making it easier to lock and unlock the circuit board.

[0035] In a variation of this aspect, the slide may include one or more chambers for receiving the one or more piston-spring assemblies.

[0036] In a further variation, a respective chamber may have a lower roof and an upper roof, the lower roof being closer to the side wall of the guide rail than the upper roof, so that when the slider slides into a position where the second end of the piston contacts the lower roof, the first end of the piston can slide into the notch on the circuit board to lock the circuit board.

[0037] In another variation, the first end of the piston can be moved out of the notch on the circuit board to unlock the circuit board when the slider slides into a position where the second end of the piston is in contact with the upper roof.

[0038] In another variant, the chamber can also have a ramp between the lower roof and the upper roof.

[0039] In another variant, the interface between the ramp and the lower roof can have a hump to prevent the slider from accidentally slipping.

[0040] In a variation of this aspect, the piston-spring assembly may further include a spring retainer disposed proximate the second end of the piston.

[0041] In another variant, the spring can be positioned between the spring holder and the side wall of the guide rail.

[0042] In a variation of this aspect, the device may further comprise a pull rod attached to the slider. The pull rod is accessible from a front panel of a subassembly enclosing the printed circuit boards, thereby facilitating locking and unlocking of the printed circuit board using the pull rod.

[0043] In a variation of this aspect, the piston may be made of metal (e.g., die-cast aluminum, die-cast zinc, etc.), and the slide may be made of plastic (e.g., polytetrafluoroethylene (PTFE) and polyvinyl chloride (PVC)).

[0044] One aspect of the present application provides a printed circuit board subassembly. The printed circuit board subassembly may include a pair of guide rails for holding one or more printed circuit boards and a slide lock for locking the printed circuit boards in position. A respective printed circuit board has a notch on an edge adjacent to a guide rail. The slide lock may include a slider attached to a sidewall of the guide rail and capable of sliding along the guide rail within a specified range, and one or more piston-spring assemblies. A piston-spring assembly corresponding to the printed circuit board may include a piston and a spring surrounding the piston.The plunger is inserted into a through-hole on the side wall of the guide rail so that a first end of the plunger is aligned with the notch on the corresponding circuit board and a second end of the plunger is in contact with the slider. Moving the slider compresses and relaxes the spring, moving the first end of the plunger into and out of the notch on the corresponding circuit board, facilitating the locking and unlocking of the corresponding circuit board.

[0045] The foregoing descriptions are for purposes of illustration and description only. They are not intended to be exhaustive or to limit the scope of this disclosure to the forms disclosed. Accordingly, many modifications and variations will be apparent to those skilled in the art.

Claims

[1] An apparatus for locking one or more printed circuit boards (118) in position between a pair of guide rails (204, 206; 402; 500), the apparatus comprising: a slider (302; 400; 506) attached to a side wall of a guide rail (204, 206; 402; 500), the slider (302; 400; 506) being able to slide within a predetermined range along the guide rail (204, 206; 402; 500); and one or more piston-spring assemblies (304, 306), each piston-spring assembly (304, 306) comprising a piston (210; 412; 518, 520) and a spring (334; 418; 524) surrounding the piston (210; 412; 518, 520), the piston (210; 412; 518, 520) being inserted into a through-hole on the side wall of the guide rail (204, 206; 402; 500) so that a first end of the piston (210; 412; 518, 520) can be aligned with a notch (208) on a corresponding circuit board and a second end of the piston (210; 412; 518, 520) is in contact with the slider (302; 400; 506); and wherein the sliding of the slider (302; 400; 506) causes the spring (334; 418; 524) to compress and relax and the first end of the piston (210; 412; 518, 520) to move into and out of the notch (208) on the circuit board (118), thereby facilitating the locking and unlocking of the circuit board (118). [2] The device of claim 1, wherein the slide (302; 400; 506) comprises one or more chambers (320; 322) for receiving the one or more piston-spring assemblies (304, 306). [3] The apparatus of claim 2, wherein a respective chamber (320; 322) comprises a lower roof (324) and an upper roof (326), and wherein the lower roof (324) is closer to the side wall of the guide rail (204, 206; 402; 500) than the upper roof (326) such that when the slider (302; 400; 506) slides into a position where the second end of the piston is in contact with the lower roof (324), the first end of the piston can move into the notch (208) on the circuit board (118) to lock the circuit board (118). [4] The device of claim 3, wherein the first end of the piston can be moved out of the notch (208) on the circuit board (118) to unlock the circuit board (118) when the slider (302; 400; 506) slides into a position in which the second end of the piston is in contact with the upper roof (326). [5] The apparatus of claim 3, wherein the chamber (320; 322) further comprises a ramp (328; 408) disposed between the lower roof (324) and the upper roof (326). [6] The apparatus of claim 5, wherein an interface between the ramp (328; 408) and the lower roof (324) includes a hump (410) to prevent inadvertent sliding of the slider (302; 400; 506). [7] The apparatus of claim 1, wherein the piston-spring assembly (304, 306) further comprises a spring retainer (336; 420; 522) disposed proximate the second end of the piston. [8] The device according to claim 7, wherein the spring (334; 418; 524) is arranged between the spring holder (336; 420; 522) and the side wall of the guide rail (204, 206; 402; 500). [9] The device according to claim 1 further comprising a pull rod (116) attached to the slider (302; 400; 506), the pull rod (116) being accessible on a front panel of a subassembly enclosing the printed circuit boards (118), thereby facilitating the locking and unlocking of the printed circuit board (118) by means of the pull rod (116). [10] The device according to claim 1, wherein the piston (210; 412; 518, 520) comprises metal and the slider (302; 400; 506) comprises plastic. [11] A printed circuit board subassembly, the printed circuit board subassembly comprising: a pair of guide rails (204, 206; 402; 500) for holding one or more circuit boards (118), each circuit board (118) including a notch (208) at an edge adjacent to a guide rail (204, 206; 402; 500); and a slide lock (114) for locking the circuit boards (118) in position, the slide lock (114) comprising: a slider (302; 400; 506) which is attached to a side wall of the guide rail (204, 206; 402; 500) and can slide within a predetermined range along the guide rail (204, 206; 402; 500); and one or more piston-spring assemblies (304, 306), wherein a piston-spring assembly (304, 306) corresponding to the circuit board (118) comprises a piston (210; 412; 518, 520) and a spring (334; 418; 524) surrounding the piston (210; 412; 518, 520), wherein the piston (210; 412; 518, 520) is inserted into a through-hole on the side wall of the guide rail (204, 206; 402; 500) such that a first end of the piston is aligned with the notch (208) on the corresponding circuit board (118) and a second end of the piston is in contact with the slider (302; 400; 506); and wherein the sliding of the slider (302; 400; 506) causes the spring (334; 418; 524) to compress and relax and the first end of the piston to move into and out of the notch (208) on the corresponding circuit board (118), thereby facilitating the locking and unlocking of the corresponding circuit board (118). [12] The circuit board subassembly of claim 11, wherein the slider (302; 400; 506) comprises one or more chambers (320; 322) for receiving the one or more piston-spring assemblies (304, 306). [13] The circuit board subassembly of claim 12, wherein a respective chamber (320; 322) comprises a lower roof (324) and an upper roof (326), and wherein the lower roof (324) is closer to the side wall of the guide rail (204, 206; 402; 500) than the upper roof (326) such that when the slider (302; 400; 506) slides into a position where the second end of the piston is in contact with the lower roof (324), the first end of the piston can move into the notch (208) on the circuit board (118) to lock the circuit board (118). [14] The circuit board subassembly of claim 13, wherein the first end of the piston can be moved out of the notch (208) on the circuit board (118) to unlock the circuit board (118) when the slider (302; 400; 506) slides into a position where the second end of the piston is in contact with the upper roof (326). [15] The circuit board subassembly of claim 13, wherein the chamber (320; 322) further comprises a ramp (328; 408) disposed between the lower roof (324) and the upper roof (326). [16] The circuit board subassembly of claim 15, wherein an interface between the ramp (328; 408) and the lower roof (324) includes a bump (410) to prevent inadvertent sliding of the slider (302; 400; 506). [17] The circuit board subassembly of claim 11, wherein the piston-spring assembly (304, 306) further comprises a spring retainer (336; 420; 522) disposed proximate the second end of the piston. [18] The circuit board subassembly of claim 17, wherein the spring (334; 418; 524) is disposed between the spring retainer (336; 420; 522) and the side wall of the guide rail (204, 206; 402; 500). [19] The circuit board subassembly of claim 11, wherein the slider lock (114) further comprises a pull rod (116) attached to the slider (302; 400; 506), the pull rod (116) being accessible at a front panel of the circuit board subassembly, thereby facilitating locking and unlocking of the circuit board (118) using the pull rod (116). [20] The circuit board subassembly of claim 11, wherein the guide rails (204, 206; 402; 500) are to hold a plurality of stacked Open Compute Project host bus adapter cards.

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