WO1999065022A2

WO1999065022A2 - E-block actuator assembly

Info

Publication number: WO1999065022A2
Application number: PCT/US1999/013067
Authority: WO
Inventors: Jeffrey L. Castleman
Original assignee: Xolox Corporation
Priority date: 1998-06-09
Filing date: 1999-06-09
Publication date: 1999-12-16
Also published as: AU4558599A; AU4677599A; WO1999065020A2

Abstract

An E-block actuator assembly having a plurality of arms separated by spaces formed concentrically about a hub. Each arm having a collar formed at one end that is fitted into the hub adjacent at least one spacer. The assembly also having a thermoplastic body molded about the hub and a portion of arms.

Description

E-BLOCK ACTUATOR ASSEMBLY

Related Applications

The present application is based upon United States Provisional Application

Serial No. 60/088,677, filed on June 9, 1998, the complete disclosure of which is hereby expressly incorporated by reference.

Technical Field

The present invention relates to an actuator assembly for positioning read/write heads in memory storage devices. More particularly, the present invention relates to an E-block actuator assembly.

Background Art

Numerous actuators for computer disk drives are known in the art. Please see U.S. Pat. No. 5,691,581 and U.S. Pat. No. 5,629,820 as illustrative examples. Such actuators may include several spaced apart arms. A read/write head is mounted to each arm for reading data from and writing data to computer disks that are spinning between the arms. The actuators may be mounted about a pivot bearing that is attached to the disk drive, around which the actuators pivot. Voice coils may be positioned opposite the arms and disposed in a magnetic field. Lead wires from the coil are joined to terminal pins that connect to a power supply. When current is applied to the coil, a new magnetic field is formed about the coil. This causes the coil to move within the fields. As the coil moves, the arms attached thereto also move, thereby positioning the read/write head to a selective part of the disk.

Many actuator assemblies have become quite complicated. More complicated actuator assembly structures translate into more cost. A simplified actuator assembly having a minimum number of different parts and coupled together by a simple means, translates into less cost. Summary of the Invention

According to certain features, characteristics, embodiments and alternatives of the present invention which will become apparent as the description thereof proceeds below, the present invention provides an E-block actuator assembly having an arm sub- assembly comprising a plurality of actuator arms each having a collar formed at one end thereof. A hub having at least one spacer is formed concentrically about same and is configured to receive the collar adjacent the spacer. In one embodiment the collar is open. A fastener means, illustratively at least one weld, attaches each one of the plurality of actuator arms to the hub. The fastener may create an electrical contact between the arms and the hubs. The actuator arms may also have a tear-drop hole disposed therethrough.

A pivot bearing bore is disposed through the longitudinal axis of the hub. The hub may also have a hole laterally disposed therethrough relative to the longitudinal axis of the hub. The arm sub-assembly may have a thermoplastic body overmolded about a portion of the arms and hub.

In a further embodiment, the actuator assembly has an arm sub-assembly comprising a plurality of actuator arms, each having a closed collar formed at one end thereof. The closed collar has a substantially circular aperture and a plurality of indents intermittently formed about its periphery. A hub having at least one set of intermittent flanges formed concentrically about same, is configured to receive the closed collar fitting adjacent at least one set of flanges. And in a still further embodiment, the arm sub-assembly comprises a single actuator arm and a hub having at least one spacer.

Additional features of the invention will become apparent to those skilled in the art upon consideration of the following detailed description exemplifying the best mode of carrying out the invention as presently perceived.

Brief Description of the Drawings

The present invention will be described with reference to the attached drawings which are given as non-limiting examples only, in which: Fig 1 is top, right isometric view of an arm sub-assembly of an E-block actuator,

Fig 2 is a top, left isometric view of a single arm from the arm sub-assembly shown in Fig 1, Fig 3 is an isometric view of a hub from the arm sub-assembly shown in Fig 1,

Fig 4 is a top, left isometric view of another embodiment of the arm sub- assembly,

Fig 5 is a top, left isometric view of a single actuator arm from the arm sub- assembly shown in Fig 4, Fig 6 is an isometric view of a hub from the arm sub-assembly shown in Fig 4,

Fig 7 is a top, left isometric view of the actuator assembly according to the present invention,

Fig 8 is a top, rear isometric view of the actuator assembly from Fig 7, and

Fig 9 is a top, left isometric view of the actuator assembly from Fig 8 Corresponding reference characters indicate corresponding parts throughout the figures The exemplification set out herein illustrates preferred embodiments of the invention, and such exemplification is not to be construed as limiting the scope of the invention in any manner

Detailed Description of the Drawings

The present invention relates to an actuator assembly for positioning read/write heads m memory storage devices More particularly, the present invention relates to an E-block actuator assembly The following description will be described herein with reference to Figs 1-9 While the described embodiments are considered by the inventor to be the best mode of carrying out the invention, it should be understood that the claims presented below are not limited to the particular details of the described embodiments Numerous variations may be readily apparent to those of skill in the art which would provide for construction of the E-block actuator assembly which incorporates the principles of the present invention as claimed

A top, right isometric view of an arm sub-assembly 1 of an E-block actuator is shown in Fig 1 Arm sub-assembly 1 comprises at least two arms 2 separated by integral spacers 4 formed concentrically about hub 3. Illustratively, several spacers 4 may be positioned along the longitudinal axis of hub 3 as shown in Fig. 3. It is appreciated that several arms 2 may be fitted about hub 3 between integral spacers 4, as shown in Fig. 1. Each arm 2 is illustratively about 0.100 inches thick and is illustratively made from stamped aluminum or other suitable material. In an alternative embodiment not pictured, arm sub-assembly 1 may comprise only a single arm 2 fitted adjacent at least one integral spacer 4.

In one embodiment, each arm 2 comprises a tip 6 and a collar 7 opposite tip 6, as shown in Fig. 2. Collar 7 is illustratively an open collar sized to receive hub 3. Each of the actuator arms has at least one wire guide 32 and configured to attach a read/write head at tip 6. In another embodiment, arm 2 also comprises a tear-drop hole 22 for purposes of reducing mass, and for balance and weight distribution.

Hub 3 can be made from aluminum, plastic, or any other rigid material. Hub 3 comprises at least one integral spacer 4 illustratively formed concentrically about the outer circumference of hub 3, as previously discussed. Partition space 28 is formed between each spacer 4 about hub 3 consecutively along the longitudinal axis of hub 3 as shown in Fig. 3. Each partition space 28 is sized to receive open collar 7 of arm 2. For example, four partitions 28 and three spacers can accommodate four arms 2 as shown in Fig. 4. It is appreciated, however, that hub 3 may be configured to accommodate any number of arms 2 by simply increasing or decreasing the number of spacers and partitions 28 consecutively formed about the longitudinal axis of hub 3. Illustratively, a weld 5 fixedly attaches each arm 2 to hub 3 for purposes of mechanical rigidity and integrity, as well as for purposes of electrical conductivity of arm sub-assembly 1. It is appreciated, however, that any variety of fastening or fusing means may be made between each arm 2 and hub 3. For example, arms 2 and hub 3 may be attached by brazing or laser reflowing. In addition, suitable fasteners include arms that form an interference fit with the spacers, screws or pins.

Illustratively, a hole 8 may be disposed laterally through hub 3, as shown in Figs. 1 and 9, if necessary to receive a set screw (not shown) for purposes of attaching the actuator to a pivot bearing (not shown). A counter sunk area 9 may also be formed about hole 8 to provide a seat for the fastener head (not shown). Illustratively shown in Fig. 1, hole 8 and counter sink 9 may remove portions of open collar 7 of one or more arms 2. It is appreciated, however, that the pivot bearing may be attached to the actuator by any variety of means.

A top, left isometric view of an arm sub-assembly 10 in accordance with another embodiment of the present invention, is shown in Fig. 4. Arm 11 is formed in a similar manner to arm 2 in the prior embodiment, except for a closed collar 12 that replaces open collar 7. Closed collar 12 comprises a substantially circular aperture 15 sized to receive hub 13, and illustratively having three indents 16 intermittently formed about the periphery of aperture 15 as shown in Fig. 5. Other features discussed with reference to arm 2 in the previous embodiment may also be included in arm 11. A set comprising a plurality of intermittent flanges 17 form concentrically about hub 13, as best shown in Fig. 6. Several sets of these intermittent flanges 17 form along the longitudinal axis of hub 13. Partition space 28 is formed between each spacer 4 along the longitudinal axis of hub 3. Each partition space 28 is sized to receive closed collar 12. Illustratively shown in Fig. 6 are four partitions 29 and three sets if intermittent flanges 17. This combination can accommodate four arms 11. It is appreciated, however, that hub 13 may be configured to accommodate any number of arms 11 by simply increasing or decreasing the number of sets of flanges 17 and partitions 29. Hub 13 may be illustratively formed from aluminum or any other suitable material. Hub 13 illustratively has a pivot bearing bore 27 disposed therethrough along the longitudinal axis. Pivot bearing bore 27 is sized to accommodate a pivot bearing (not shown) on the hard drive about which arm sub-assembly 10 will pivot to read the data disk.

Arm sub-assembly 10 is assembled by placing circular aperture 15 over hub 13 such that each flange 17 fits within an indent 16 allowing hub 13 to extend through arm 11. Once arm 11 is positioned at a desired location between a partition 29, it is rotated so that indent 16 is positioned between a pair of intermittent flanges and the periphery of aperture 15 rests upon the plurality of flanges 17, as shown in Fig. 4

Each arm 11 is fixedly attached to hub 13 illustratively by a weld 14, as shown in Fig. 4. Weld 14 also may create an electrical contact between hub 13 and arms

11.In the illustrative embodiment weld 14 is made at three locations for purposes of mechanical rigidity and integrity. It is appreciated, however, that any variety of fastening or fusing means may be made between each arm 11 and hub 13. For example, arms 11 and hub 13 may be attached by brazing or laser reflowing. In addition, suitable fasteners include arms that form an interference fit with the spacers, screws or pins. A top, left isometric view of arm sub-assembly 1 (or illustratively assembly 10) is shown in Fig. 7 also comprising an overmold 18 forming an actuator assembly 30. Illustratively, overmold 18 is a block body, typically made from a thermoplastic that is molded over actuator assembly 1 (or assembly 10). Any suitable thermoplastic material like PPS or a liquid crystal polymer may be used. Attached to overmold 18 is a voice coil 20. Voice coil 20 is illustratively placed opposite tip 6 of arm 2. If necessary, a tear-drop hole 23 may be formed in voice coil 20 for purposes of reduced mass, and for balance and weight distribution, similar to hole 22 disposed through arm 2. During operation, voice coil 20 is placed within a magnetic field. Power is selectively applied to voice coil 20 causing it to create its own magnetic field. This causes the voice coil to pivotally move back and forth about the pivot bearing, causing arms 2 or arms 11 to move back and forth over disks.

Any variety of voice coil or similar motor structures may be useful in conjunction with this actuator. A pivot bearing aperture 19 is formed about pivot bearing bore 27 allowing the pivot bearing to extend therethrough. A flexhook 34 is attached to overmold 18 securing a flexible conductor (not shown) that attaches to the read/write heads. In addition, a tang 24 is attached to voice coil 20 interacting with a stop member (not shown) to limit the laterally rotational movement of the actuator.

In one illustrative embodiment, termination pins 21 extend horizontally from voice coil 20, as shown in Fig 7. It is appreciated, however, that termination pins 21 can be oriented in any direction suitable to the hard drives' requirements. Other embodiments where the termination pins 21 are oriented vertically are shown in Figs. 8 and 9. In addition, other coil lead termination means like flying leads 14 (not shown), may be used with this assembly.

Although the present invention has been described with reference to particular means, materials and embodiments, from the foregoing description, one skilled in the art can easily ascertain the essential characteristics of the present invention and various changes and modifications may be made to adapt the various uses and characteristics without departing from the spirit and scope of the present invention as set forth in the following claims.

Claims

What is claimed is:

1. An E-block actuator which includes an arm sub-assembly, comprising: a plurality of actuator arms, each actuator arm having a collar formed at one end thereof; and a hub having at least one spacer formed concentrically and extending outwardly from the hub; and wherein the collar from each one of the plurality of actuator arms is disposed adjacent at least one spacer formed on the hub.

2. The arm sub-assembly of claim 1, wherein the collar is an open collar.

3. The arm sub-assembly of claim 1, wherein at least one of the plurality of actuator arms has a tear-drop hole disposed therethrough.

4. The arm sub-assembly of claim 1, further comprising a fastener means that attaches each one of the plurality of actuator arms to the hub.

5. The arm sub-assembly of claim 4, wherein the fastener means comprises at least one weld attaching each one of the plurality of actuator arms to the hub.

6. The arm sub-assembly of claim 5, wherein the weld creates an electrical contact between each one of the plurality of actuator arms and the hub.

7. The arm sub-assembly of claim 1, wherein the hub has a pivot bearing bore disposed through the longitudinal axis of the hub.

8. The arm sub-assembly of claim 7, wherein the hub has a hole laterally disposed therethrough relative to the longitudinal axis of the hub.

9. The arm sub-assembly of claim 1, wherein each one of the plurality of actuator arms is a stamping.

10. The arm sub-assembly of claim 7, further comprising a thermoplastic body overmolded around at least a portion of the actuator arms and the hub.

11. The arm sub-assembly of claim 10, further comprising a voice coil attached to the body substantially opposite the plurality of actuator arms, said voice coil also has a plurality of terminal pins attached thereto.

12. An E-block actuator which includes a arm sub-assembly, comprising: a plurality of actuator arms, each actuator arm having a closed collar formed at one end thereof comprising a substantially circular aperture and a plurality of indents intermittently formed about the periphery of the aperture; and a hub having at least one set of flanges comprising a plurality of intermittent flanges formed concentrically about the hub, the hub configured to receive the closed collar fitting adjacent at least one set of flanges.

13. The arm sub-assembly of claim 12, wherein at least one of the plurality of actuator arms has a tear-drop hole disposed therethrough.

14. The arm sub-assembly from claim 11, further comprising a fastener means that attaches each one of the plurality of actuator arms to the hub.

15. The arm sub-assembly from claim 14, wherein the fastener means comprises at least one weld attaching each one of the plurality of actuator arms to the hub.

16. The arm sub-assembly from claim 15, wherein the weld creates an electrical contact between each one of the plurality of actuator arms and the hub.

17. The arm sub-assembly from claim 12, wherein the hub has a pivot bearing bore disposed through the longitudinal axis of the hub.

18. The arm sub-assembly of claim 11, wherein each one of the plurality of actuator arms is a stamping.

19. The arm sub-assembly of claim 17, further comprising a thermoplastic body overmolded around at least a portion of the actuator arms and the hub.

20. The arm sub-assembly of claim 19, further comprising a voice coil attached to the body substantially opposite the plurality of actuator arms, said voice coil also has a plurality of terminal pins attached thereto.

21. An E-block actuator which includes an arm sub-assembly, comprising: at least one actuator arm having a collar formed at one end thereof; and a hub having at least one spacer formed concentrically and extending outwardly from the hub; and wherein the collar from the actuator arm is disposed adjacent at least one spacer formed on the hub.

22. The arm sub-assembly of claim 21, wherein the collar is an open collar.

23. An E-block actuator which includes a arm sub-assembly, comprising: at least one actuator arm having a closed collar formed at one end thereof comprising a substantially circular aperture and a plurality of indents intermittently formed about the periphery of the aperture; and a hub having at least one set of flanges comprising a plurality of intermittent flanges formed concentrically about the hub, the hub configured to receive the closed collar fitting adjacent at least one set of flanges.