Plural Magnetic Head Assembly With Independently Supporting Structure

This invention relates generally to transducer head assemblies and more particularly to transducer head assemblies in which there are a plurality of transducer heads mounted therein.

It has long been recognized that a problem exists in reading simultaneously all three channels on a card having magnetic strips with a single-head structure because the strip surface is bowed and in general forms a concave cylinder, having an axis parallel to the direction of the card movement across the head. Consequently, pneumatic gap line which lies in a plane cannot simultaneously make contact with the entire magnetic strip surface and the sagittal separation causes "spacing losses" in one or more of the channels.

This invention provides a solution to the problem and consists of a special transducer head assembly especially suitable for reading three channels on credit cards having parallel magnetic strips or other magnetic strip media. The invention consists of means for providing compliance for each of three jointly mounted magnetic heads, such that each head can individually track its respective channel independent of distortions in the track or warpage in the card. Intimate contact between the magnetic media and the heads is maintained and spacing losses are minimized. An additional advantage of this head assembly is that the individual heads can have different core structures. That is, some heads are for read only, while other heads can have core structures which permit them to be used for both reading and writing. Either of these heads can be mounted in this mounting assembly because of the individual translation permitted.

It is an object of the transducer head assembly of this invention to permit the heads to translate individually.

Another object of the present invention is to permit the individual tracking heads to compensate for distortions in the recorded material.

Another object of the present invention is to permit the mounting of heads on a single assembly which can have different core structures.

These and other objects of the present invention will become apparent when the detailed description is considered in conjunction with the accompanying drawings.

FIG. 1 is a front elevation of the transducer head mounting assembly.

FIG. 2 is a view of the transducer head mounting assembly taken along 2--2 of FIG. 1.

FIG. 3 is a rear view of the transducer mounting head assembly taken along 3--3 of FIG. 2.

FIG. 4 is a sectional view taken through one of the transducer heads taken along line 4--4 of FIG. 1.

FIG. 5 is a sectional view taken along 5--5 of FIG. 4.

Referring now to FIG. 1, there is shown a transducer head mounting assembly comprised of a support 10, transducer heads 12, 14 and 16, and leaf springs 18 attached to the support at one end and to the transducer heads at the opposite end. Preferably the support 10 is a rectangular frame or ring provided with gimbal sockets 20 and 22 on either end. The leaf springs 18 are substantially parallel, forming a parallelepiped and are attached to the support 10 by any suitable means 24 such as screws or rivets.

The rear view of the transducer head mounting assembly of FIG. 3 shows a second set of leaf springs 26 for supporting the transducer heads 12, 14 and 16. Each leaf spring 18, 26 can be individual or have a common base as shown in the figures. The mounting of the leaf springs 18, 26 can best be seen in FIG. 4, in which identical reference numerals are used to identify like parts. The leaf springs 18 and 26 are attached to the housing 10 by screws or rivets 24 and are attached to the transducer head 14 by being embedded in the insulated housing 28 at 30. The leaf springs 18, 26 are retained in the slots of the insulated housing 28 of the transducer 14 with an adhesive compound.

In order to limit the translational motion of the transducer heads 12, 14 and 16, a shoulder 36 is provided on frame 10 which engages a slot 38 in the transducer heads. This can best be seen in FIG. 4. The slot 38 is large enough to allow sufficient translation to track any deformities in the cards while preventing excessive bending of the springs 18 and 26.

The tabs 32 and 34 are fastened to the frame 10 for the purpose of providing tie-downs for electrical leads 40, as shown in FIGS. 2 and 5, to dress the electrical leads away from the transducer heads. The electrical leads 40 are tied down to provide a constant loop which will not impede the translational movement of the transducer heads.

As can be seen in FIG. 5, the tracking edge of each transducer head 12, 14 and 16 extends out of the frame 10 so that it may bear against the planar surface of the credit card magnetic track. Also, each transducer head 12, 14 and 16 is relatively thin and the mounting springs 18, 26 are generally parallel and disposed in the plane of each head.

Since the leaf springs 18 and 26 are attached to the transducer heads 12, 14 and 16 to permit only translational movement, without rotation, the sockets 20 and 22 are provided. These sockets permit the transducer head assembly to be pivotally mounted. The sockets 20 and 22 are formed as an integral part of the frame 10 at the top and bottom as is shown in FIGS. 1 and 4. The entire frame 10, including the sockets 20, 22 and shoulder stop 36, should be constructed of a non-magnetic material, such as a non-magnetic metal or plastic.

Obviously, many other modications and variations of the present invention are possible in the light of the above teaching. It is therefore to be understood that within the scope of the intended claims the invention may be practiced otherwise than as specifically described.