US3474365A - Magnetic switch assembly for operation by magnetic cards - Google Patents

Description

Oct. 21, 1969 w. w. BARNEY MAGNETIC SWITCH ASSEMBLY FOR OPERATION BY MAGNETIC CARDS Original Filed June 50, 1967 W N W m N 7 5 United States Patent 3,474,365 MAGNETIC SWITCH ASSEMBLY FOR OPERATION BY MAGNETIC CARDS Walter W. Barney, 4837 Woodley Ave., Encino, Calif. 91316 Original application June 30, 1967, Ser. No. 650,483, now Patent No. 3,430,200, dated Feb. 25, 1969. Divided and this application July 5, 1968, Ser. No. 742,760 Int. Cl. H01h 9/54 U.S. Cl. 335206 6 Claims ABSTRACT OF THE DISCLOSURE A plate has a plurality of parallel openings in which respective axially poled magnets are slidable. The magnets are normally urged toward one face of the magnet, as by iron rings in said one face or by magnetic cylinders around the openings where the plate is magnetic. Each movable magnet is adapted to be repelled by a magnet at said one face to engage a fixed contact at the other face of the plate. Each opening is closed at both ends to prevent contaminants entering therein.

CROSS-REFERENCE TO RELATED APPLICATION This application is a division of my application, Magnetic Card and Validator Apparatus, Serial No. 650,483, filed June 30, 1967, now Patent No. 3,430,200.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to so-called magnetic card readers, and more particularly to an improved magnet operable switch and reader plate assembly employing a plurality of such switches.

Description of the prior art In devices heretofore known which employ switches operable from magnets embedded in a card, the card magnets are flat strips with their poles on lines parallel to the card faces. The movable magnets are supported with their poles in planes parallel to the card magnets, and are adapted for sliding or pivotal movement in such planes to close respective pairs of switch contacts. The direction of movement of such a magnet depends upon whether a card magnet adjacent thereto is in polarity opposing or attracting relation thereto.

A disadvantage in such arrangements is that a significant portion of the available magnetic fields linking aligned card and movable magnets is needed to overcome magnetic force components tending to subject the movable magnets to transverse movement. In this connection, it will be seen that when relatively fixed and movable parallel magnets are brought close together, the movable magnet tends to be drawn toward or moved apart from the fixed magnet, depending upon whether their corresponding ends are of like or opposite poles.

Still further, magnets mounted for pivotal movement have inherent bearing friction. A substantial portion of available magnetic fields linking aligned card and pivotal magnets necessarily is used to overcome such friction.

For such reasons, movable magnets frequently fail to operate properly, thereby preventing the establishment of signal information for authentic magnetic cards. Such prior art arrangements are thus not suitable for magnetic credit and security card systems which require a high degree of repeatability and reliability in. operation of magnet switches in response to properly coded magnetic cards.

Summary of the invention My invention embraces a plate having a plurality of openings wherein respective magnets are slidable away from one face of the plate in response to magnets in a card placed adjacent said one face, and means normally holding said magnets in predetermined positions. Further my invention embraces means closing the ends of said openings to prevent their exposure to dirt, moisture and the like, and also the combination of such assembly with a card having axially poled magnets to be aligned with the movable magnets.

I thus eliminate the prior art problems involving the loss of a significant portion of fields of aligned card and movable magnets needed for the task of overcoming magnetic and mechanical friction forces that resist the desired movement of switch magnets. Further, my assembly is one in which I eliminate the likelihood of exposure of contacts to and the contamination of contacts by dirt, moisture and the like.

Brief description of the drawing FIGURE 1 is a perspective view of a plate for supporting magnet operable switches, in accordance with my invention;

FIGURE 2 is a fragmentary perspective view of a plate carrying a plurality of fixed contacts to be aligned with the openings in the plate of FIGURE 1;

FIGURE 3 is an enlarged sectional view of the plates of FIGURES 1 and 2 assembled; and

FIGURES 4 and 5 are fragmentary sectional views of modified forms of magnet operable switch assemblies in accordance with my invention.

Description of illustrative embodiments Referring to FIGURES 1-3, there is shown a nonmagnetic plate 130 having openings 132 arranged in four rows of ten. In one face of the plate 130, grooves 134 surround around each opening 132, and deposited in each groove is magnetic material 136, e.g., a ring of soft iron. The wall of each opening 132 is plated, as with gold or silver (indicated at 138 in FIGURE 3). Slidable in each opening 132 is a magnet 140, such magnet also being coated along its length and on the end opposite the grooves 134.

After the magnets 140 are located in the openings 132, the face of the plate 130 in which the grooves 134 are located is covered with a sheet 142 of nonmagnetic material, e.g., a thin sheet of brass or aluminum, or plastic. Also, the opposite face of the plate 130 is covered with a sheet 144 of nonconductive material, e.g., plastic, which has openings 146 aligned with the openings 132 in which the magnets 140 are located. The openings 146 are substantially larger in diameter than the plated magnets 140. Thus, the plated ends of the magnets 140 can readily move through the openings 146, as when such a magnet is repelled by a magnet in a card 88 when the card is placed alongside the face sheet 142.

In FIGURE 3, the top tow magnets 140, the bottom magnet, 140, and the corresponding magnets in the card 88 are so poled that the magnets 140 are attracted by the magnets 80, and hence are retained against the sheet 142. However, the third magnet 80 in the card 88 has had its polarity reversed (as by initially magnetizing all the magnets 80 in a predetermined pattern, and then coding the card by reversing the polarities of selected ones of the magnets 80). Accordingly, the third magnet 140 in FIGURE 3 is repelled, so that the plated end thereof moves past the adjacent face of the plate and through the adjacent opening 146 in the plastic sheet 144.

A magnet that is subjected to such movement is brought into engagement with an electrical contact. In this connection, and referring to FIGURE 2 along with FIGURE 3, a block 150 is provided in which a plurality of contacts 152 are embedded. As best seen in FIGURE 3, each of the contacts 152 is formed as a short rod-like element that extends through the block 150, and which has an enlarged head that is substantially larger in diameter than the openings 140 in the plastic sheet 144. The block 150 is fastened at 156 to the plate 130, so that the end faces of the heads of the contacts 152 are brought firmly into abutment with the adjacent face of the sheet 144. Thus, when a movable magnet 140 is repelled by a magnet 80 in the card 88, the plated end of the magnet comes into contact with the adjacent surface of the head of the contact 152. To enhance conductive contact, the enlarged heads of the contacts 152 may be similarly plated.

As will be observed, the magnets 146 are housed in a contaminant-free environment. The sheet 142 on the one face of the plate 130 covers the openings 132 in the surface. At the opposite ends of the magnets 141), the

outer ends of the openings 146 are closed by the enlarged contact 152 establishes a conductive connection between i such contact 152 and the plate 131). The plate 130 is shown connected to a point of reference or ground potential, and leads 119 conductively secured to the outer ends of the contacts 152 are adapted for conection to a network for providing signal information identifiable with the card.

The soft iron rings 136 shown in FIGURE 3 serve to bias the magnets so they are normally retracted into the late. Thus, when the card 88 is Withdrawn from adjacent the plate 131), the extended magnet 140 is retracted into the plate 130 due to the attractive force between the iron ring 136 and the adjacent end of such magnet.

FIGURE 4 illustrates a modified form of the arrangement shown in FIGURE 3. In this case, the nonmagnetic plate 130 is replaced with a plate 162 of magnetic material. Instead of the small openings 132 and grooves 134 of the plate 130, the plate 162 is provided with relatively large openings 164, and cylindrical inserts 166, e.g., brass or aluminum, are press-fit into the openings 164. The inner walls of the inserts 166 are plated at 168 and the plated magnets 14-0 are slidably mounted in the plated inserts 164. As indicated, this arrangement is one in which each magnet 140 is provided with a completed magnetic path through the material of the plate 162. In such arrangement, when such a magnet is repelled by a magnet in a credit card, so as to make contact with the fixed contact 152, withdrawal of the card results in the magnet 140 automatically being retracted to its normal position within the plate 162.

FIGURE 5 illustrates a further modification wherein a plate 130' for housing magnets 140 is made of nonmagnetic material, like the plate 130 of FIGURE 3. Nonmagnetic inserts 166' are provided which are like the inserts 166 of FIGURE 4. The inserts 166 are press-fit into inserts 170 of magnetic material, and these in turn are press-fit into openings 172 provided in the plate 130. As will be seen, the magnetic inserts 170, like the plate 162 of FIGURE 4, provide a magnetic path for each of the magnets 140, to aid in retracting the magnets following 4 their movement into engagement with the fixed contact 152. The plastic sheet 174 covering the outer face of the plate 130' serves the same purpose as the nonmagnetic plate 142 of FIGURES 3 and 4.

From the foregoing, it will be apparent that various modifications and extensions of the above-described embodiments can be made Without departing from the spirit and scope of my invention. Accordingly, I do not intend that my invention shall be limited, except in accordance With a reasonable interpretation of the appended claims.

I claim:

1. In combination:

a plate having a plurality of openings therethrough,

wherein portions of the plate surrounding the openings are nonmagnetic;

a fixed contact at each opening adjacent one surface of said plate;

an axially poled permanent magnet in each opening,

each magnet carryingcontact means and being axially slidable toward and away from the associated fixed contact to elfect make and break switching between the fixed contact and contact means;

and magnetic bias means normally biasing each magnet to a predetermined position of its contact means with respect to the associated fixed contact.

2. The combination of claim '1, wherein said plate is nonmagnetic said plate having a groove around each opening in the surface thereof opposite said one surface;

and magnetic material disposed in each groove.

3. The combination of claim 1, wherein said plate is nonmagnetic;

and a respective magnetic cylinder in said plate surrounding each opening.

4. The combination of claim 1, wherein said plate is magnetic;

and a nonmagnetic cylinder in said plate surrounding each Opening.

5. The combination of claim 1, including a nonconductive sheet covering said one surface of said plate and having openings aligned with the openings in said plate, said fixed contacts abutting said sheet around the openings therein, the openings in said sheet being large enough to permit the associated magnets to move therethrough to engage said fixed contacts;

and a nonmagnetic sheet overlaying the opposite surface of said plate and the grooves and the ends of the openings therein.

6. The combination of claim 5, including:

a nonconductive plate, said fixed contacts being embedded in and extending through said nonconducplate;

and means supporting said nonconductive plate with said fixed contacts abutting said nonconductive sheet.

References Cited UNITED STATES PATENTS 8/1951 Cooley 335-205 X 5/1952 Cooley 335205 X 10/1964 OGorman 335-207 X

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