US20020191345A1 - Disc drive ramp that accomodates shipping comb - Google Patents

Abstract

A method of assembling disc drive components involving the use of a shipping comb to deliver one or more head gimbal assemblies to a ramp in a disc drive. The shipping comb is configured to engage the head gimbal assembly by its load beam. The load beam is part of a head gimbal assembly which includes a suspension such that the load beam extends from the head gimbal assembly away from the suspension. In the assembly process, a proximal end of the shipping comb is brought into abutment with a distal end of the ramp. The shipping comb may have first features at its proximal end which are configured for mating with second features at the distal end of the ramp.

Description

• This patent application claims priority from U.S. Provisional Application No. 60/137,756, filed Jun. 4, 1999.[0001]
FIELD OF INVENTION
• This invention relates to disc drives, and in particular to the assembly of a head gimbal assembly to a disc drive.[0002]
BACKGROUND
• A disc drive is more likely to be exposed to large mechanical shock loads when it is not in operation. For example, in portable applications, disc drives may sometimes be dropped. In such situations, the impact of the read/write heads against the discs may cause irreparable damage. One way of preventing such damage is to park the read/write heads off the discs when the disc drive is not in use, as opposed to parking the read/write heads directly on the surfaces of the discs. When the disc drive is in operation, the read/write heads may be found in flight above the disc surfaces.[0003]
• Each read/write head is often mounted to a slider which is attached to one end of a suspension by gimbals. A flex circuit is usually routed from the read/write heads and along a surface of the suspension. This assembly is referred to as the head gimbal assembly (HGA).[0004]
• The other end of the suspension is operably connected to an actuator for moving the HGA. When the disc drive stops operating, the actuator moves the read/write heads away from above the disc surface until the HGA comes to rest on a ramp in a process referred to as “unloading”. At the start of disc drive operations, in a process referred to as “loading”, the actuator moves the HGA away from the ramp towards the discs, thereby bringing the read/write heads into flight above the respective spinning disc. One example of a disc drive incorporating a ramp design is described in the U.S. Pat. No. 4,933,785 issued Jun. 12, 1990, to Morehouse, et al.[0005]
• U.S. Pat. No. 6,032,352 issued Mar. 7, 2000 to Furay, et al., describes an actuator supporting a suspension which has a lift tab attached to one side of the suspension. One end of the load lift tab extends beyond the read/write head to rest on the ramp when it is in the “unloaded” position.[0006]
• In the manufacture of disc drives with a ramp design, the HGA has to be put into an “unloaded” position, with the HGA resting on the ramp. The assembly is complicated by the fact that a typical disc drive includes more than one disc and that there will be at least one read/write head for reading from or writing to each disc surface. A typical disc drive therefore has an array of read/write heads, arranged in opposing pairs. To minimize the overall size of the disc drive, the spacing between neighboring discs is kept as small as possible. In addition, to facilitate low fly-height, the suspension is pre-loaded to bias the read/write heads towards the disc surface. The opposing pairs of read/write heads must therefore be forcibly held apart from one another when not in flight. For this purpose, a shipping comb formed of an array of pins or teeth may be inserted at the suspensions to keep the read/write heads spaced apart before the HGA is delivered to the ramp. Because the flex circuit can be routed along the surface of the suspension adjacent to the head, the conventional shipping comb tends to rub against the flex circuit, which may possibly damage the flex circuit.[0007]
• There remains therefore a need for an improved method and apparatus for delivering the HGA to the ramp in the manufacture of disc drives. As described in the following, the present invention provides this and other advantages over the prior art.[0008]
SUMMARY OF INVENTION
• The present invention provides for an improved method of assembling a disc drive. According to one embodiment of the present invention, the method involves the use of a shipping comb which is configured for engagement with the load beam of a head gimbal assembly. The method involves the use of a ramp which is arranged and configured for engagement with the load beam.[0009]
• In one preferred embodiment, the load beam is transferred from the shipping comb to the ramp when the teeth of the shipping comb is brought into abutment with the ramp. In a most preferred embodiment, the shipping comb and the ramp are brought into self-alignment by first features on the shipping comb and complementary second features on the ramp.[0010]
• In another aspect, the present invention provides for a shipping comb which is configured to receive an array of load beams. Each load beam extends beyond a head gimbal assembly away from the suspension. Preferably, the shipping comb is configured for self-alignment with a ramp. In one embodiment, the shipping comb includes first features complementary to second features of the ramp. Preferably, the first features are at a proximal end of at least one shipping comb tooth, and the second features are at a distal end of at least one corresponding ramp tooth.[0011]
BRIEF DESCRIPTION OF DRAWINGS
• FIG. 1 is a perspective view of a disc drive.[0012]
• FIG. 2 is a schematic diagram of two head gimbal assemblies engaged by a shipping comb.[0013]
• FIG. 3 is a schematic diagram of the shipping comb of FIG. 2 in mating engagement with a ramp.[0014]
DETAILED DESCRIPTION
• FIG. 1 shows an[0015]exemplary disc drive10. Abase12 and acover14 forms an enclosure for the various components in the disc drive. Data is usually stored in concentric tracks on the surfaces of adisc16 which is mounted to aspindle motor18 so that the disc can be rotated. If more than one disc is used, the discs are mounted co-axially on the spindle motor. At least one read/writehead20 is supported on one end of asuspension22 and the other end of the suspension is operably connected to anactuator24 for moving the read/write heads to the desired positions.
• A most preferred embodiment of the present invention which can be used in conjunction with a head gimbal assembly (HGA)[0016]26 is shown in FIG. 2. The HGA is configured with aload beam28 extending from the suspension beyond each read/write head such that a force applied in a direction generally perpendicular to a flat surface of the suspension can be used to hold apart the read/write heads of neighboring HGAs. For clarity, the lower HGA is shown without the read/write head. The load beams are engaged with ashipping comb30 such that the opposing pairs of read/write heads are held apart from one another. The shipping comb is provided withcomb teeth32. Eachrecess34 formed by two neighboring comb teeth is configured to receive a load beam. Thetop-most load beam36 is shown to rest against anupper side38 of thetop-most comb tooth40. The top-most load beam and the lower-most load beam in an array of HGAs may therefore be engaged by the shipping comb in an alternative manner, other than being held in a recess of the shipping comb. In this manner, the read/write heads can be held apart before delivery to theramp42 without risking damage to the flex circuits that are routed on thesurfaces43 of the suspensions.
• As shown in FIG. 2, the HGA is mounted to the disc drive with the shipping comb still in assembly with the HGA. According to the present invention, the ramp is located further away from the actuator than is commonly found in a disc drive, such that the HGA will come to rest on the ramp at the load beam and not at the suspension. The ramp is provided with an array of[0017]ramp teeth44 corresponding in number to the comb teeth. Each ramp tooth is configured with oneend54 or surface facing away from the discs which for convenience is referred to here as the distal end. The end or the surface of each comb tooth that is nearest to the discs is referred to here as theproximal end52 for convenience. The disc drive components are arranged such that, as the HGA is delivered to the ramp, each proximal end of the comb teeth comes into abutment with each distal end of the ramp teeth as illustrated in FIG. 3. The load beams can then be transferred from the shipping comb to the ramp, for example, by sliding the load beam across aseam50 formed by a shipping comb tooth and a corresponding ramp tooth.
• Preferably, the proximal end of each comb tooth is configured to complement the corresponding distal end of the ramp teeth. Whilst in the conventional designs the shipping comb has to be positioned so that it does not interfere with the ramp, the present invention provides for self-alignment and facilitates the delivery of the HGA to the desired unloaded position by having the shipping comb and the ramp configured to mate. A variety of shapes and configurations can be applied to achieve the self-alignment effect. According to a preferred embodiment, each shipping comb tooth has first features[0018]52 in the form of its proximal end being shaped like a dovetail. Second features54 are found on eachramp tooth44 in the form of the distal end of the ramp tooth being shaped in a complementary tapered shape.
• To maximize the number of discs that can fit inside the enclosure, the distance between neighboring discs is usually kept as small as possible. Furthermore, as there is usually very little spare room in the disc drive, it is difficult to remove the conventional shipping comb even though the HGA has been delivered to the ramp. In contrast, the unconventional position of the shipping comb in the present invention facilitates the removal of the comb after the heads have been moved to the ramp. The comb can therefore by re-used in another assembly process.[0019]
• Alternatively, preferred embodiments of the invention may be described as follows:[0020]
• A method of assembling disc drive components involves the use of a[0021]shipping comb30 to engage aload beam28. Theload beam28 is part of ahead gimbal assembly26 which includes asuspension22 such that theload beam28 extends from thehead gimbal assembly26 away from thesuspension22. The method may further include disengaging theload beam28 from theshipping comb30 and engaging theload beam28 to aramp42. Preferably, theshipping comb30 is brought into abutment with theramp42. In a preferred embodiment, the method involves bringing aproximal end52 of theshipping comb30 into abutment with adistal end54 of theramp42. In a most preferred embodiment, the method includes mating first features52 on the shipping comb with complementarysecond features54 on the ramp.
• A[0022]shipping comb30, which can be used for delivering at least onehead gimbal assembly26 to aramp42 in adisc drive10, has at least onetooth32 which is configured to engage aload beam28. Oneload beam28 extends from eachhead gimbal assembly26 away from thesuspension22. Theramp42 has adistal end54 which faces away from the disc, or discs,16 in thedisc drive10. Theshipping comb30 has aproximal end52 which is formed by one ormore teeth32. Preferably, theproximal end52 of theshipping comb30 is configured to abut thedistal end54 of theramp42. Theshipping comb30 may have first features at itsproximal end52 which are configured for mating with second features at thedistal end54 of theramp42.
• The present invention is not limited to the configurations described above, which is only given for the purpose of illustration. It will be understood by those skilled in the art that the foregoing description merely illustrates preferred embodiments and that modifications and changes can be made to the embodiments without departing from the scope of the present invention. For example, the shape and configuration of the first features and the second features may be varied to suit the desired thickness and size of the shipping comb and the ramp. The abutment or mating between the shipping comb and the ramp has been described in respect of the proximal end of the shipping comb and the distal end of the ramp. This does not exclude modifications in which the ends are not generally perpendicular to the HGAs. In addition, the attachment of the shipping comb to the actuator for support is not shown as it is easily understood by person skilled in the art to provide the necessary framework for the desired attachment.[0023]

Claims (8)

1. A method of assembling disc drive components, the method comprising steps of:

(a) providing a shipping comb;

(b) providing a head gimbal assembly including a suspension;

(c) engaging a load beam to the shipping comb, wherein the load beam extends from the head gimbal assembly away from the suspension;

(d) providing a ramp;

(e) disengaging the load beam from the shipping comb; and

(f) engaging the load beam to the ramp.

2. A method ofclaim 1 further comprising a step (g) of bringing the shipping comb into abutment with the ramp.

3. A method ofclaim 2 wherein the bringing step (g) further includes bringing a proximal end of the shipping comb into abutment with a distal end of the ramp.

4. A method ofclaim 2 wherein the bringing step (g) further includes mating first features on the shipping comb with complementary second features on the ramp.

5. In a disc drive comprising:

at least one disc;

a ramp with a distal end facing away from the at least one disc;

at least one head gimbal assembly comprising:

a load beam; and

a suspension, wherein the load beam extends from the at least one head gimbal assembly away from the suspension; and

a shipping comb for delivering the at least one head gimbal assembly to the ramp, wherein the shipping comb comprises at least one tooth configured to engage the load beam.

6. In a disc drive ofclaim 5, the shipping comb further including a proximal end formed by the at least one tooth, the proximal end being configured for abutment with the distal end of the ramp.

7. In a disc drive ofclaim 6, the shipping comb further including first features at the proximal end configured for mating with second features at the distal end of the ramp.

8. A shipping comb for use with a disc drive having a ramp for receiving a head gimbal assembly, the shipping comb comprising:

at least one tooth which engages the head gimbal assembly; and

means for spatially aligning the head gimbal assembly with the ramp.

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