Browse Prior Art Database

Reset and Overtravel Stops for Head-Access Cam

IP.com Disclosure Number: IPCOM000046171D
Original Publication Date: 1983-Jun-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 3 page(s) / 58K

Publishing Venue

IBM

Related People

Hogan, RE: AUTHOR [+4]

Abstract

In a diskette drive using stepped cam 24 (Fig. 1) to index read/write head 18 to one of several possible track positions on the recording disk, it is desirable to provide a cam stop to prevent cam overtravel and to define a home track position. Cam overtravel would result in the head arm (or a head carriage) striking or dropping off the end 84 of the cam. In either event, the head or the head carrier could be damaged. In addition and more importantly, it is desirable to use a cam stop to define a home track position. Both of these functions can be accomplished by cam stop 80 and cam engaging rib 82 shown in Fig. 2.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 53% of the total text.

Page 1 of 3

Reset and Overtravel Stops for Head-Access Cam

In a diskette drive using stepped cam 24 (Fig. 1) to index read/write head 18 to one of several possible track positions on the recording disk, it is desirable to provide a cam stop to prevent cam overtravel and to define a home track position. Cam overtravel would result in the head arm (or a head carriage) striking or dropping off the end 84 of the cam. In either event, the head or the head carrier could be damaged. In addition and more importantly, it is desirable to use a cam stop to define a home track position. Both of these functions can be accomplished by cam stop 80 and cam engaging rib 82 shown in Fig. 2.

Magnetic recording head 18, shown in Fig. 1, is mounted on flexure arm 20. It writes and reads the lower surface of a disk (not shown). Arm 20, carrying the head, is pushed radially towards disk spindle 16 by spring 22. The head and flexure arm are pushed radially out from the spindle by head-indexing cam 24.

In Fig. 2, cam 24 is shown lifted off hub 27 and tilted upward so that the underside of the cam is visible. Pulley 25, for the timing belt that drives cam 24, is molded into the cam. Further, rib 82 is molded into the inner surface of pulley
25. When cam 24 is mounted on hub 27, rib 82 limits the rotation of cam 24 by striking cam stop 80. Cam stop 80 is preferably molded into frame 31 as is hub
27.

In operation, cam 24 rotates clockwise until rib 82 strikes surface 80A of cam stop 80. This position corresponds to locating the recording head at the innermost track on the disk. When the cam rotates counterclockwise, rib 82 eventually strikes the opposite face of cam stop 80 corresponding to the recording head being located at the outermost track on the recording disk. Thus, rib 82, by engaging cam stop 80, prevents the head carrier from striking or falling off edge 84 of cam 24.

In addition, surface 80A of cam stop 80 that enga...