Browse Prior Art Database

Head Retraction Latch Mechanism

IP.com Disclosure Number: IPCOM000089576D
Original Publication Date: 1977-Nov-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 3 page(s) / 51K

Publishing Venue

IBM

Related People

Hall, JD: AUTHOR [+2]

Abstract

Disclosed is a mechanical latching and unlatching mechanism for magnetic stripe read and write heads. Magnetic read/write heads are retracted from the magnetic stripe during a return-to-home pass of a mechanism in which moving heads are used to scan a fixed magnetic stripe bearing media. The life of the read/write heads is approximately doubled by reducing the wear, and document feed time is reduced by reducing the head contact time.

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Head Retraction Latch Mechanism

Disclosed is a mechanical latching and unlatching mechanism for magnetic stripe read and write heads. Magnetic read/write heads are retracted from the magnetic stripe during a return-to-home pass of a mechanism in which moving heads are used to scan a fixed magnetic stripe bearing media. The life of the read/write heads is approximately doubled by reducing the wear, and document feed time is reduced by reducing the head contact time.

Fig. 1 illustrates a carrier 1 for the read and write heads 7 and 8, respectively. With carrier 1 in the extreme right position in Fig. 1, latch rod 2 will contact the home latch stop bracket 3, pushing latch rod 2 toward the left. This brings latch block 4 out from under bosses 5A, which are a part of the head mounting pivot arms 5, as shown. Since latch block 4 does not interfere with the bottom portion of the bosses 5A when the pivot arms pivot about the pivot points 6, the pivot arms 5 are free to be pivoted about the axis of pivot 6, as indicated.

The read/write support arms 5 are pivoted by means of fixed surface cams 11 interacting with the cam follower rollers 11A mounted on the pivot arms 5. The arms 5 are also spring-loaded in torsion such that the arms 5 are constantly under tension to rotate in the upward direction to contact a medium bearing a magnetic stripe which would be in position above the read and write heads 7 and 8, respectively. The two arms 5 and their respective read and write heads 7 and 8 are independent of one another insofar as pivoting motion is concerned.

A lead screw 9 serves as a drive means to drive carrier 1 back and forth from left to right. As carrier 1 travels, cam follower rollers 11A interact with the cam surfaces 11 by rolling down from the cam surfaces and allowing arms 5 to pivot counterclockwise about the pivot 6. This brings the read and write heads 7 and 8 up into contact with the magnetic stripe medium. Magnetic data is read or altered and then read with the encode head 7 and the read head 8, respectively. The heads 7 an...