US20060192068A1

US20060192068A1 - Method of forming a support structure

Info

Publication number: US20060192068A1
Application number: US11/266,767
Authority: US
Inventors: Song Ser; Ghazali Anwar
Original assignee: Metalform Asia Pte Ltd
Current assignee: Metalform Asia Pte Ltd
Priority date: 2004-11-02
Filing date: 2005-11-02
Publication date: 2006-08-31

Abstract

A method for securing a support member to a plate is provided. The support member includes a stopper. The method comprises forming an aperture on the plate; inserting the support member through the aperture; shearing the support member to form a flange and pressing the flange against the plate. The flange and the stopper secure the support member to the plate. In another embodiment, the support member includes a stopper and a collar. The method comprises forming an aperture on the plate; inserting the support member through the aperture; pressing the collar to form a flange and pressing the flange against the plate. The flange and the stopper secure the support member to the plate. The present methods may be used in disc drive manufacturing to mount components such as ramp, crash stop/latches onto the base without welding.

Description

FIELD OF THE INVENTION

The present invention relates to a support structure and a method of fabricating the structure. In particular, it relates to a method for securing a support member to a plate without die-casting or welding to form the support structure.

BACKGROUND

In disc drive devices, mechanical and electronics components, such as spindle motors and printed circuit boards are supported and/or mounted on a base plate and a top cover. The components are mounted using supporting members such as pins, shafts, mounting sockets, which are provided on the base plate. Combined with the base plate and the top cover, the supporting members form a support structure for these components.
Conventional disc drive base plates, such as those for 3.5-inch or 2.5-in hard disc drives, are made by die-casting through which, supporting members are integrally formed on the base plate. In contrast, the base plates of miniature disc drives, such as 1-inch hard disc drives, are made by stamped metal sheets. Because supporting members are separate articles and cannot be formed in the stamping process, the supporting members are typically attached to the base plate by welding. For example, in a laser-weld process, the pins or shafts and the base plate are fused together using a high temperature laser source.
Forming support structure for miniature disc drives by welding the supporting members onto the base plate causes a number of problems. As welding process involves temperature variations, the support member and the base plate are subject to thermal expansion when heated up, and thermal contraction when cooled down, which may cause the dimension and/or shape of support member and the base plate to distort. Welding process is also prone to porosity, which may cause air leak through the weld joints. Further, both the support member and the base plate need to be held motionless during the welding process. To ensure the positional accuracy, separate fixtures and/or a jig must be used which, further complicates the process and increases the costs.
In view of the above, it is desirable to provide a method to attach support members to a stamped base plate without welding. Such a method however is presently unavailable.

SUMMARY OF THE INVENTION

Described herein is a method for securing a support member to a plate that may be used in a variety of applications, for example for securing mounting pins or shafts on a base plate in disc drives. The present method avoids the drawbacks of those using welding technology, for example, by providing a method for securing support members to a plate without heating up the support members and the plate.
In one embodiment, the support member includes a stopper, and an aperture is formed on the plate. The support member is inserted into the aperture. The support member is sheared to form a flange which is then pressed against the plate. The flange and the stopper therefore secure the support member to the plate.
In another embodiment, the support member includes a stopper and a collar. An aperture is formed on the plate. The support member is inserted into the aperture. The collar is pressed to form a flange, which is then pressed against the plate. The flange and the stopper therefore secure the support member to the plate.
These and other features and advantages of the present invention are discussed in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example, and not limitation, in the figures of the accompanying drawings in which like reference numerals refer to similar elements and in which:
FIGS. 1 to 4 are partial cross sectional perspective views showing a method for securing a support member to a plate according to one embodiment of the present invention;
FIGS. 5A to 5F are partial cross sectional perspective views showing applications of the support structure according embodiments of the present invention;
FIG. 5G is an enlarged view of FIG. 5F;
FIG. 5H is an enlarged view showing a support structure formed according to an embodiment of the present invention.
FIGS. 6A to 6D are partial cross sectional views showing a method for attaching a support member to a plate according to another embodiment of the present invention;
FIG. 7 is a flow chart showing a method according to one embodiment of the present invention.
FIG. 8 is a flow chart showing a method according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A method for securing a support member 110 to a plate 120 according to one embodiment of the present invention is shown in FIGS. 1 to 4. In the present embodiment, support member 110 is formed of a metal such as aluminum, mild steel, or stainless steel, which is deformable. Plate 120 is a metal sheet, and includes an aperture 122 formed thereon. Aperture 122 may be a round through hole. Those skilled in the art would appreciate, however, aperture 122 may also be of other shapes, such as a rectangle, triangle or irregular shape.
Support member 110 includes a body portion 112 and a stopper 114, which may be formed by processes such as molding, forging, pressing, or machining. In a preferred embodiment, support member is formed by forging. Body portion 112 has a diameter 113 smaller than the aperture diameter 123. Stopper 114 has a diameter 115 greater than the aperture diameter 123.
Support member 110 is inserted into aperture 122, with body portion 112 passing through the aperture 122 and with stopper portion 114 abutting against the bottom surface 120 a of plate 120, as shown in FIG. 2A. A press 10 is then lowered towards support member 110. Press 10 has a bore 12 with a diameter 13 smaller than diameter 113 of body portion 112. Press 10 further has a cutting edge 14 with a side surface 16, which in this embodiment is flat.
When pressed down towards support member 110, cutting edge 14 shears a flange 212 from body portion 112, as shown in FIG. 3A. An alternative type of press 20 maybe used, as shown in FIG. 2B. Press 20 has a curved side surface 26. When pressed down towards support member 110, cutting edge 14 cuts and separates body portion 112 to form flange 212. Lowering the press 20 further cuts and separates body portion 112 and in the meantime, curved side surface 26 guides or presses the flange 212 towards plate 110, as shown in FIGS. 3A and 3B. At the end of the process, a support structure 200 is formed as shown in FIG. 4. In support structure 200, flange 212 and stopper 114 are used to secure the support member 110 to the plate 120.
By applying the appropriate pressure to press 10 or 20, supporting member 110 may further be used to create an air-tight seal over aperture 122. The air-tight seal may be formed by the abutment of the flange 212 and the plate 110, the abutment of the stopper 114 and the plate 120, or both. This particular feature of the present invention is particularly useful if support structure 200 is used in hard disc drive technology. In particular, it is important for certain types of hard disc drive base plates and top covers to be air-tight to form an air-tight internal chamber and/or to prevent particles and other contaminants from entering and damaging the sensitive instruments inside the hard disc drive.
Support structure 200 formed according to the above method may have many applications. For example, support member 110 attached to plate 120 may serve as a shaft for supporting a functional element, such as a bearing 32 as shown in FIG. 5A, a bush 34 as shown in FIG. 5B or a spindle motor 5C as shown in FIG. 5C. Alternatively, support member 110 may have a recess 116 formed thereon, such as a threaded blind hole which serves to provide a mounting point for fixing a functional element thereon, such as a printed circuit board 38, as shown in FIG. 5D.
In disc drives, in particular certain types of miniature 1-inch or 1.8-inch hard disc drives as shown in part in FIGS. 5E, 5F and 5G, a ramp 510 may be provided for unloading read/write heads 522 mounted on an actuator arm 520. Crash stops/latches 530 may also be provided to limit the movement of actuator arm 520. In these types of disc drives, ramp 510 and crash stop/latches 530 are to be mounted to base 540.
According to an embodiment of the present invention, support members, such as mounting pins 550 each having a stopper 554 formed thereon, are inserted into apertures formed on base 540. Each of the mounting pins 550 is then sheared to form a flange 552, which may be further pressed against base 540. Mounting pins 550 may be secured to base 540 by the abutment of the flange 552 and stopper 554. Ramp 510 may also include recesses, such as blind holes or through holes 512 formed thereon. The ramp 510 is then fixed to the mounting pins 550, by inserting the mounting pins 550 into recesses 512 of ramp 510. The ramp 510 is therefore mounted to base 540. Crash stop/latches 530 may also be mounted to base 540 in a matter similar to that of the ramp 510.
In one example as shown in FIG. 5H, after shearing, a ring-shaped flange 212 is formed which is separated from a shaft portion 214 at the center portion. The shaft portion has a diameter of about 0.8 mm to about 1.5 mm. The flange 212 has a width of about 0.1 mm, and a height of about 0.2 mm. The pressure applied to the mounting pins 550 for shearing and pressing may be provided by a press of about 1000 Kg.
FIGS. 6A to 6D are cross sectional views showing a support structure 600 formed by attaching a support member 610 to a plate 620, according to another embodiment of the present invention. Support member 610 has a collar 612 and a stopper 614 integrally formed thereon. Collar 612 is formed surrounding, and separated from, a shaft 616. Support member 620 is inserted into an aperture 622 formed on plate 620, with collar 612 passing through aperture 622, until stopper 614 abuts bottom surface 620 a of plate 620. In the present embodiment, shearing of the support member is not needed. Instead, collar 612 is pressed and deformed outwardly to form a flange 632. Flange 632 and stopper 614 are then to secure support member 610 to plate 620, as shown in FIG. 6D.
FIG. 7 is a flow chart showing a method 700 for securing a support member to a plate according to one embodiment of the present invention. The support member includes a stopper formed thereon. In block 710, an aperture is formed on the plate. The support member is then inserted into the support member, as shown in block 720. The support member is then sheared to form a flange, shown in block 730 and further, the flange is pressed against the plate so as to secure the support member to the plate together with the stopper, as shown in block 740.
FIG. 8 is a flow chart showing a method 800 for securing a support member to a plate according to another embodiment of the present invention. The support member includes a stopper and a collar formed thereon. In block 810, an aperture is formed on the plate. The support member is then inserted into the support member with the collar passing through the aperture, as shown in block 820. The collar is then pressed to form a flange, shown in block 830 and further, the flange is pressed against the plate so as to secure the support member to the plate together with the stopper, as shown in block 840.
A method of securing support members onto a plate according to embodiments illustrated above has many advantages over those using welding technology. For example, the present invention enables the attachment of support members onto a plate without heating and melting the support members and the plate. The risks of shape and/or dimension variation of the parts due to thermal expansion and shrinkage inherent in a welding process are thus avoided. Because the method is processed under the room temperature, there is no need to wait for the relevant parts to cool down, hence production process time is shortened. Further, the aperture formed on the plate may also serve as an alignment guide for precisely securing the support member. Therefore the positional accuracy of the support member can be ensured without using additional fixtures or jigs, which are required by the welding process.
The methods according to embodiments of the present invention maybe used in miniature disc drive manufacturing processes in which, disc drive components such as the ramp, the crash stop/latch are mounted through mounting pins secured to the disc drive base by the present methods. Securing the mounting pins to the base through the abutment of the stopper provided and the flange formed on the mounting pins, the present method successfully overcomes the drawbacks of the prior art.
Although embodiments of the present invention have been illustrated in conjunction with the accompanying drawings and described in the foregoing detailed description, it should be appreciated that the invention is not limited to the embodiments disclosed, and is capable of numerous rearrangements, modifications, alternatives and substitutions without departing from the spirit of the invention as set forth and recited by the following claims.

Claims

1. A method for securing a support member to a plate, wherein the support member includes a stopper, comprising:

forming an aperture on the plate;

inserting the support member into the aperture;

shearing the support member to form a flange, and pressing the flange against the plate, wherein the flange and the stopper are to secure the support member to the plate.

2. The method as recited in claim 1, further comprising sealing the aperture with the support member after the flange is formed.

3. The method as recited in claim 1, wherein pressing the flange is to seal the aperture.

4. The method as recited in claim 3, wherein the flange is to abut the plate to seal the aperture.

5. The method as recited in claim 4, wherein the stopper is to abut the plate to seal the aperture.

6. The method as recited in claim 1, wherein the support member includes a shaft and the flange is to form a ring surrounding the shaft.

7. The method as recited in claim 6, wherein the shearing separates the flange from the shaft.

8. The method as recited in claim 6, wherein the shaft is substantially perpendicular to the plate.

9. The method as recited in claim 1, wherein the pressing is performed while shearing.

10. A method for securing a support member to a plate, the support member includes a stopper and a collar, the method comprising:

forming an aperture on the plate;

inserting the support member into the aperture;

pressing the collar to form a flange; and

pressing the flange against the plate,

wherein the flange and the stopper are to secure the support member to the plate.

11. The method as recited in claim 10, wherein the support member includes a shaft and the flange forms a ring to surround the shaft.

12. The method as recited in claim 10, wherein the support member forms a recess and the flange is a ring surrounding the recess.

13. The method as recited in claim 10, further comprising sealing the aperture with the support member.

14. The method as recited in claim 10, wherein pressing the flange is to seal the aperture.

15. The method as recited in claim 14, wherein the flange is to abut the plate to seal the aperture.

16. The method as recited in claim 14, wherein the stopper is to abut the plate to seal the aperture.

17. A method for attaching a component to a base of a disc drive, the component has a recess formed thereon, the method comprising;

forming an aperture on the base;

inserting a support member through the aperture, wherein the support member includes a stopper;

shearing the support member to form a flange;

pressing the flange against the base, wherein the flange and the stopper secure the support member to the base, and

inserting the support member into the recess.

18. The method as recited in claim 17, wherein the support member includes a shaft portion and the flange is a ring surrounding the shaft portion.

19. The method as recited in claim 18, wherein the shaft portion has a diameter of about 0.8 mm to about 1.5 mm, and the ring has a width of about 0.1 mm.

20. The method as recited in claim 19, wherein the ring has a height of about 0.2 mm.

21. The method as recited in claim 17, wherein the support member is sheared with a force provided by a press of about 1000 Kg.

22. The method as recited in claim 17, wherein the flange is pressed against the base with a force provided by a press of about 1000 Kg.

23. The method as recited in claim 17, wherein the component is one selected from a ramp, a ramp post or a crash stop.