WO1993018517A1

WO1993018517A1 - Mounting assembly for multiple disk drives

Info

Publication number: WO1993018517A1
Application number: PCT/US1993/002519
Authority: WO
Inventors: Michael Brown; Naniappa Bakthavachalam
Original assignee: Digital Equipment Corp
Current assignee: Digital Equipment Corp
Priority date: 1992-03-09
Filing date: 1993-03-08
Publication date: 1993-09-16
Anticipated expiration: 1994-09-09

Abstract

A mounting assembly for disk drives has a plurality of disk drive units of one form factor mounted in the same physical space in a data processing system as would be occupied by a disk drive having a larger form factor, generally from a previous technological generation. The mounting assembly facilitates the use of a redundant array of inexpensive disk drives (RAID) in place of a single disk drive in data processing systems. The mounting assembly holds a plurality of uniform disk drives and each drive is secured in the assembly with a separate latch mechanism. Operation of each of these latch mechanisms mechanically locks the drive within the assembly and enables the application of power to only the associated disk drive. The disk drive unit cannot be removed from the assembly when power is connectd to the drive. Opening each one of the latch mechanisms removes the mechanical lock and disables the application of power to only the associated disk drive. Each of the drives is independently removable from the assembly without disconnecting the power from the other drives or otherwise affecting their operation.

Description

MOUNTING ASSEMBLY FOR MULTIPLE DISK DRIVES

FIELD OF THE 1

The present invention relates to mounting frames for holding a plurality of disk drives during operation in a data processing system. More particularly, the present invention relates to a mounting assembly for holding a plurality of smaller form-factor disk drives in the same physical space as a smaller number of larger form factor disk drives of an earlier technological generation.

PACKQRQVFD ΩE.THE ΪNNE πO

Conventional assemblies for holding disk drives house either single or multiple disk drives of a predetermined form-factor or specific set of physical dimensions. Disk drive dimensions are typically limited by a form-factor which is an industry standard set of length, width and height dimensions and mounting configurations. If a disk drive is removed from the associated computer for any reason, the computer user loses the capability of accessing information stored thereon. To overcome this limitation a disk drive configuration comprising redundant arrays of inexpensive disk drives ("RAID") has been developed and is well known to those of ordinary skill in the field. Using RAID, multiple disk drives are configured so that the information stored on any single disk drive is also redundantly stored on at least one of the other disk drives. Therefore, if one disk drive is removed from the sy stem for repair or replacement the information stored thereon is not lost and the data processing system remains operational.

In RAID configurations power is supplied to all disk drives. Thus, before one disk drive is removed, power must be removed from the entire RAID configuration.

If a disk drive is intentionally or accidently removed with power applied there is a high risk of doing damage to the disk drive. An assembly for storing a plurality of disk drives in a RAID configuration while allowing the removal of power to a single disk drive without the removal of power from the other disk drives is desirable.

Furthermore, in such an assembly for storing a plurality of disk drives it would be desirable to prevent any disk drive from being removed from the assembly either intentionally or accidently, while power is still applied to the disk drive.

Another problem relates to the conversion of a standard data processing system having a single large form-factor disk drive into a RAID configuration. In the standard data processing system a predetermined physical space is allocated to the disk drive mounting. If the multiple disk drive assembly does not fit within the standard space allocated then it must be mounted in a separate housing and connected to the data processor through cables or the like. In addition, the unused physical opening in the data processor must be covered to prevent accidental or intentional contact with the interior of the processor. Accordingly, it is desirable for the mounting assembly for the RAID configuration to fit within the physical space allocated for a single disk drive in the standard data processing system.

SUMMARY OF THE INVENTION

The invention in its broad form resides in a mounting assembly for a plurality of disk drives, as recited in claim 1.

Described herein is an assembly for mounting a plurality of disk drive units

of one form factor in the same physical space in a data processing system as would be occupied by a disk drive having a larger form factor, generally from a previous technological generation. The mounting assembly taught herein can be used in original equipment manufacture or to modify equipment already in the field. The mounting assembly of the present invention facilitates the use of a redundant array of inexpensive disk drives (RAID) in place of a single disk drive in data processing systems such as a standard personal computer (PC). The mounting assembly comprises a housing and a plurality of mounting units which are positioned substantially within the housing. Each mounting unit holds one of a plurality of uniform disk drives. Each mounting unit is equipped with its own separate latch mechanism. Operation of one of these latch mechanisms positively or mechanically secures the mounting unit to the housing and enables the application of power to the corresponding disk drive. Accordingly, while power is being supplied to the disk drive, its associated mounting unit cannot be removed from the housing.

Disengaging one of these latching mechanisms releases the mechanical locking of the mounting unit to the housing and disables the application of power from only the associated disk drive. When the latching mechanism of one of the mounting units is disengaged, the individual mounting unit can be removed from the assembly without causing damage to the disk drive since the power to that disk drive is disconnected and without affecting the basic operation of the other disk drives since their power is not interrupted. Accordingly, each of the mounting units and its associated disk drive is independently removable from the assembly after power to it is disconnected but without disconnecting the power from the other drives or otherwise affecting their basic operation.

gftEF ESCPJFnQ QE.THE DRA I GS

A more detailed understanding of the invention can be had from the following

description of a preferred embodiment, given by way of example only, and to be understood in conjuction with the accompanying drawing wherein:

FIG. 1 is a perspective view of the assembly of the present invention with one of the mounting units removed from the housing.

FIG. 2 is a perspective view of one of the mounting units of FIG. 1 holding a single disk drive and including a latching mechanism and with a portion of the mounting unit cut away for clarity.

FIG. 3 is a perspective view of a mounting assembly of an embodiment having a plurality of smaller disk drives of one form factor positioned in the standard space normally occupied by a disk drive of another larger form factor in a typical

PC.

FIG. 4 is a cut away view of the housing of the assembly of FIG. 1 showing the internal structure of the housing.

FIG. 5a is a front view of one of the mounting units of FIG. 1 showing the latch mechanism in the unlocked position.

FIG. 5b is a front view of one of the mounting units of FIG. 1 showing the latch mechanism in the locked position.

FIG. 6a is a side view of one of the mounting units of FIG. 1 with a cut away portion showing the latch mechanism in the unlocked position.

FIG. 6b is a side view of one of the mounting units of FIG. 1 with a cut away portion showing the latch mechanism in the locked position.

FIG. 7 is a schematic diagram showing the connection between the power source and the disk drive through the respective switches.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed. On the contrary, the applicant's intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. nnτAπ.κn ΠRSCRIPΠON OF A PREFERRED EMBODIMENT

Referring to the drawings, wherein the reference characters designate like or corresponding parts throughout the views, FIG. 1 is a perspective view of the mounting assembly 100 of an embodiment. The assembly 100 includes a housing 102 that is adapted to receive a plurality of disk drive mounting units 104a through e. Each of the disk drive mounting units 104 a through e is identical and is more fully described hereinafter. It should be understood that in the preferred embodiment, five disk drive mounting units are described but that as few as two such units or more than five units could be used without departing from the scope of the present invention. The inside of the housing 102 is equipped with a backplane connector of the type commonly known in the art to accommodate the disk drives associated with each of the disk drive mounting units 104a through e but is not shown herein for the sake of clarity. In a manner well known to those of ordinary skill in the art the backplane connector interfaces the disk drives with a host computer such as a standard PC. In addition to a backplane connector for each disk drive, the housing includes power connectors 103a through e of the type commonly known in the art for each disk drive, refer to FIG. 4.

As will be readily apparent to those of ordinary skill in the art, the general details of the construction of the housing 102 and the mounting units 104a through e are not essential features of the present invention. Preferably, the overall width W, length L and height H of the housing 102 must be the same as the conventional or standard single disk drive unit so that the housing 102 will fit into and mount in the same space as the standard single disk drive unit. The housing 102 and the mounting units 104a through e may be constructed from any suitable material. An example of a particularly beneficial material is conductive plastic, which may be injection molded for production quantities. In addition, in the preferred embodiment,

one or more fans are disposed in the housing 102 or are secured in a separate unit connected to the back of the housing 102 to facilitate cooling of the unit but are not shown herein for the sake of clarity. This latter configuration is desirable because it allows the fans to be changed without opening the housing 102. The fans do not form a part of the present invention.

Each of the mounting units 104a through e may be separately removed from the housing 102. The mounting units 104a through e shown in FIG. 1 each include a pair of forward brackets 106 and 108 and a pair of rear brackets 110 and 112 for securely holding a disk drive 114, shown in dotted lines. The disk drive 114 is secured to the mounting unit 104 by any conventional fastening means. An aperture 118 is provided to allow passage of a disk drive connector (not shown) and a power connector (not shown), thereby allowing the disk drive to be interfaced with the backplane connector and power connector in the housing 102. The front face of each mounting unit 104a through e includes an aperture 120 to accommodate a latch mechanism 122 shown in greater detail in FIGs. 2, 5 and 6. The aperture 120 is generally circular with an enlarged quarter circle portion extending from the horizontal axis counterclockwise to the 270° position of the vertical axis (fourth quadrant) and including a wedge shaped portion in third quadrant. The latch mechanism 122 is operated to both supply power to the disk drive

114 and physically or mechanically lock the mounting unit 104 to the housing 102.

The latch mechanism 122 is disengaged to release the physical lock between the mounting unit 104 and the housing 102 and to remove power from the individual disk drive 114 associated with the mounting unit 104 prior to removal of the mounting unit 104 from the housing 102. In the preferred embodiment, a detent 126 is provided in the upper surface of the mounting units 104 a through e. The detent

126 is a small rounded protrusion. The detent 126 cooperates with an upper surface mating portion 128 shown in dotted line of the housing 102 to align or position the mounting unit 104 in the housing 102 and to provide tactile feedback that the mounting unit has been properly positioned within the housing 102. A similar detent arrangement may be positioned on another surface of the mounting unit 104 such as the bottom surface.

FIG. 2 shows a single mounting unit 104 of the present invention in additional detail. Dashed lines represent a disk drive unit 114 secured within the brackets 106, 108, 110 and 112. A latch mechanism 122 is positioned within the aperture 120. The latch mechanism includes a knob 129 for rotating between a first disengaged position and a second latched position, a spring 130, a stop tab 132 shown in FIGs. 5 and 6, a shaft 134, a cam locking member 136 mounted on the shaft 134 and a contact member 138 mounted on the shaft 134. The shaft 134 extends through the aperture 120 and both the locking member 136 and die contact member 138 are positioned on the shaft 134. When the mounting unit 104 is slid into place in the housing 102, the disk drive 114 engages a corresponding backplane connector in the housing 102 as is well known in the art, the disk drive also engages the associated power connector 103 and the detent 126 snaps into the matting recess

128. The latch mechanism 122 operates to mechanically secure the associated mounting unit 104 to the housing 102 when the latch mechanism 122 is positioned to switch power to the disk drive secured therein. The latch mechanism 122 also operates to mechanically release the associated mounting unit 104 when positioned to remove power from the associated disk drive. The construction and operation of the preferred latch mechanism 122 is fully described below with respect to FIGs. 5 and

6.

A particularly beneficial use of the described arangement is to allow a

plurality of technologically advanced (for example, smaller and/or faster) disk drives to be mounted in the same space as a single disk drive of a previous technological generation. This concept allows multiple drives to be configured in various well- known arrangements, such as RAID, to improve the IO operation of the computer using the disk drives. In the preferred embodiment, five 63 mm (2 1/2") disk drives are mounted in the same space as a standard 132 mm (5 1/4") disk drive slot on a conventional PC. FIG. 3 is a general illustration of the typical PC having a processor base 139, a display monitor 140, a mouse or similar I/O device 142. The housing 102 is positioned within the standard opening normally used for a single disk drive unit. Thus, the RAID configuration is implemented without the expense and inconvenience of mounting disk drives external to the host computer or structurally modifying the PC housing to accommodate a different size assembly.

FIG. 4 is a cut away illustration of the housing 102 with connectors or plugs

103a through e positioned on the back wall 150. Five compartments 152a through e are formed by the backplane 150, the front plane 154, the side walls 156 and 158 and the four separating panels 160a through d. Contact switches 162a through e are mounted respectively on each separating wall 160a through d and side wall 158.

Each switch 162a through e is positioned to engage the contact member 138 of latching mechanism 122 when the mechanism is rotated to the locked position refer to HGs. 5 and 6. Any type of well known switch or switch circuit capable of closing the circuit from the power source to the disk when engaged by the contact member 138 and opening the circuit when disengaged from the contact member 138 can be used for this purpose. Recesses 164a through e are positioned respectively in each separating wall 160a through d and side wall 156. Each recess 164a through e is positioned in a location substantially forward of switches 162a through e respectively on the opposing wall and adapted to engage cam member 136 of latch mechanism 122 when the mechanism is rotated to the locked position, refer to HGs. 5 and 6.

FIG. 5a and FIG. 5b are front views of the mounting unit 104 showing the latch mechanism 122 in the unlocked and locked position respectively. As previously noted, the latch mechanism 122 is used to selectively enable a switch to apply power to the individual disk drive secured in a corresponding mounting unit 104 in the housing 102. Because individual disk drives may be powered down independently, mounting units 104 containing disk drives 114 may be removed from the assembly 100 of the arrangement without disruption to the operation of the host computer. In addition, when the latch mechanism 122 is in the locked position the

corresponding mounting unit 104 cannot be accidently or intentionally removed from the housing 102 thereby preventing possible damage to the disk drive cased by removing the mounting unit 104 while power is applied to die disk drive.

FIG. 5a illustrates the latch mechanism 122 in the unlocked position. A knob or handle 129 is in a substantially horizontal position. The aperture 120 as described above receives the shaft 134 including the cam member 136 and contact member

138. FIG. 6a shows a partial cross sectional view of the mounting unit 104 including the latching mechanism 122 still in the unlocked position. The stop tab 132 is mounted on the shaft 134 and is positioned for movement within the enlarged quarter circle or fourth quadrant portion of aperture 120. When the handle 129 is in the substantially horizontal position, the stop tab 132 contacts the top most portion of the aperture 120 at the 0° point. In this position the cam locking member 136 points in a substantially downward direction and contact member 138 points in substantially the upward direction. In this unlocked position the spring 130 is not compressed.

FIG. 5b illustrates the latch mechanism 122 in the locked position. The entire latch mechanism 122 has been pressed into the mounting unit 104 compressing the spring 130. After compressing the spring 130, the knob 129 is rotated counterclockwise 90°. The contact member 138 is now substantially horizontal and the cam locking member 136 is substantially horizontal. By pressing the know 129 inwardly, comprising the spring 130 and moving the shaft 134, the contact member

138 aligns with the switch 162 and die locking cam 136 aligns widi the recess 164.

After rotating the knob 129 by 90°, the locking member 136 moves within the recess 164 and the contact member 138 engages the switch 162. When inward pressure is removed from the latching mechanism 122, the^' spring 130 is prevented from

returning the shaft 134 to the forward unlocked position since the locking cam 136 is held within the recess 164. As a result, the contact member 138 remains in contact with switch 162 and electrical power is supplied to die respective disk drive 114. FIG. 6b shows the shaft 134 moved into me housing 104 and the spring 130 compressed. While the latching mechanism 122 is in the locked position, if an attempt is made to remove the mounting unit 104 from the housing 102, the locking cam member 136 in contact with the recess 164 prevents movement of the mounting unit 104 and absorbs the force being applied. Accordingly, little or no force is exerted between the contact member 138 and switch 162 thereby preventing damage to the switch 162. In order to release the mounting unit 104 the knob 129 is rotated counterclockwise. This action removes the cam 136 from contact with the recess 164 and disengages contact member 138 from switch 162, allowing the spring 130 to force the shaft 134 forward. FIG. 7 is a simplified circuit diagram showing me switches 162a through e in circuit between each of the disk drives 114 and die source of electrical power 166 when the mounting units 104a through e are positioned widiin the housing 102. As explained above, when the latching mechanism 122 in one of the mounting units

104a through e is in the latched position as shown in FIGs. 6a and 6b d e contact

member 138 engages one of the respective switches 162a through e closing the electrical circuit from the power source 166 to the respective disk drive 114.

Similarly, when the latching mechanism 122 in one of the mounting units 104a through e is in the unlocked position as shown in FIGs. 5a and 5b die contact member 138 does not engage one of die respective switches 162a through e and d e electrical circuit from the power source 166 to the respect disk drives is open.

Thus there has been described herein an assembly for mounting a plurality of disk drive units of one form factor in the same physical space in a data processing system normally allocated to holding a single disk drive of a larger form factor. Each of the disk drives is positioned within a mounting unit which has a latching mechanism and is removable from the assembly. When the latching mechanism is enabled, it physically retains the mounting unit within the assembly and provides power to the disk drive. When the latching mechanism is disengaged no power is applied to die disk drive and die mounting unit can be withdrawn from the assembly. Accordingly, individual mounting units and their respective disk drives can be disconnected from the power source and removed from the assembly without affecting the operation of the other disk drives. Furthermore, the mounting units and their associated disk drives cannot be accidently or intentionally removed from the housing while power is connected to die disk drive. It will be understood that various changes in the details, arrangements and configurations of the parts and system which have been described and illustrated above in order to explain the nature of the present invention may be made by those skilled in the art within the principle and scope of d e present invention as expressed in the appended claims.

Effect of the Invention

Described hereinbefore is a housing assembly for holding multiple disk drives which might comprise redundant arrays of inexpensive disk drives (RAID). Insuch assemblies, if one disk drive is removed, the system can still operate since the information stored on die disk being removed is redundandy stored on at least - another disk drive. The problem however, is that a disk drive should not be removed for maintenance or replacement purposes when the power supply to die disk drive is on. Each disk drive, as described hereinbefore, has its own latching mechanism. Disengaging a latching mechanism not only releases the mechanical locking of the mounting unit to die housing, but also disable the application of electrical power from only the associated disk drive whereby the system is not damaged.

Claims

What is claimed is:

1. A mounting assembly for mounting a plurality of disk drives in a data processing system so that said plurality of disk drives can be accessed by said data

processing system, comprising a housing and a plurality of mounting units positioned within said housing, each of said mounting units securing one of said plurality of disk drives, each of said mounting units having latching means to selectively secure a respective mounting unit in said housing and to connect electrical power to said disk drive when secured in said respectivce mounting unit, and to release said respective mounting unit from said housing and to disconnect electrical power from said disk drive which is secured in said respective mounting unit.

2. A mounting assembly for mounting a predetermined plurality of disk drives each having a first-form factor in a given space in lieu a smaller number of disk drives having a second form factor, said smaller number being less than said predetermined plurality, said plurality of disk drives being connected to a data processing system so mat said plurality of disk drives can be accessed by said data processing system, said mounting assembly comprising a housing and a plurality of mounting units positioned within said housing, each of said plurality of mounting units holding at least one disk drive having said first form factor, said housing being dimensioned to occupy die same space in said data processing system as said smaller number of disk drives having said second form factor.

3. The mounting assembly according to claim 1 wherein each of said mountmg units includes a latching means for selectively securing said mounting unit

in said housing and switching power to said disk drive held in said mounting unit or releasing said mounting unit from said housing and removing power from said disk drive secured in said mounting unit.

4. The mounting assembly according to claim 3 wherein said plurality of disk drives are configured so that d e information stored on any single disk drive having said second form factor is also redundantly stored on at least one of the other disk drives having said second form factor to allow a user of said data processing system to access all information stored on said plurality of disk drives having said second form factor if one of said mounting units is removed from said housing.

5. A mounting assembly for mounting five 63mm ( 2 1/2") disk drives in a data processing system in die same space as a single 132mm (5 1/4") disk drive so that said five 63mm ( 2 1/2") disk drives can be accessed by said data processing system, said mounting assembly comprising a housing, five mounting units positioned within said housing, each of said mounting units holding one of said 2 1/2" disk drives, said housing being dimensioned to occupy die same space in said data processing system as said 132mm ( 5 1/4") disk drive.

6. The mounting assembly according to claim 5 wherein said 63mm (2 1/2") disk drives are configured so that the information stored on any one of said 63mm (2 1/2" ) disk drives is also redundandy stored on at least another of said 63mm (2 1/2") disk drives to allow a user of said data processing system to access all

information stored on said five 63mm (2 1/2") disk drives if one of said mounting units is removed from said housing.