FR2503907A1 - Floating reading head for magnetic data cards - uses cylindrical head carried by sprung balls to permit convex surface to fit against passing card - Google Patents

Abstract

The reading head for magnetic identification cards has two restricted degrees of freedom of movement to allow a single head (36) to read, with minimal displacement, warped and bent cards. The head has partial movement along the card track, and also possesses two partial degrees of rotational freedom. The surface of the cylindrically shaped head (36) is lightly convex (37) and has the magnetic inserts flush with the convex surface. Two diametrically opposite grooves (40,41) run along the length of the outer wall of the cylinder and have spring loaded (49,50) balls (47,48) running inside them to support the head. The magnetic card passing over the convex surface exerts a force which tends to tilt or twist the cylindrical head until it lies as closely as possible to the card surface.

Description

The principle of identifying a person as well as reading and
The local writing of information related to this person on a magnetic badge inserted in an appropriate reader has been known for many years.

 This principle is used in a large number of financial transaction systems such as ATMs, as well as in various reservation systems, in particular on behalf of airlines.

 Usually, the magnetic badge is externally constituted by a rectangular plastic card, of small thickness and with rounded edges.

 The dimensions of this badge, generally standardized, are 85 mm x 54 mm.

 The front side notably includes the visual characterization of the type of card and its brand. In addition, we often find embossed on the same front side the patronymic identification of the holder as well as a digital identification code of this holder internal to the card system concerned.

 The reverse side has one or more longitudinal magnetic tracks, parallel to the axis of the card and printed in its body. The different position of these tracks and their number correspond to the three different standard coding systems currently used.

 The multitrack badge reader is usually placed inside a box essentially consisting of: a badge insertion hole, several heads provided with magnetic reading gaps, as well as means suitable for inducing a relative translation of each of the read heads vis-à-vis the magnetic strip they read.

 These systems have enormous advantages for the holder of the badge and for the holder of the processing device. In parricul; er, the speed of execution of the treatment and the legitimacy of the badge make it very appreciated by businessmen and by the general public.

For the badge processing function to be correctly fulfilled by the device, it is important that
- on the one hand, that the relative movements of each of the
air gaps opposite the path of the runway it treats are
nothing alike and in constant contact,
- on the other hand, that the relative translation speed of the heads
vis-à-vis the card is as stable as possible,
- finally, that the pressure exerted by cracking head on the track
that it treats is constant, the usual pressures being
150 grams / cm2.

 Therefore, it is important that the positions of the different air gaps can adapt to the inevitable deformations of the magnetic badge.

Indeed, the latter, generally made of plastic, undergoes plastic macro-deformations which often tend to veil it.

 The known and unified method of processing multitrack magnetic cards consists in associating a processing head provided with a magnetic gap with a track of the badge. In addition, each read head is made to work by applying it against its track independently of the others.

 To do this, each air gap is arranged at the top of a cylindrical head. This head is freely threaded inside a cylindrical cavity with an axis perpendicular to the plane of the card and with a diameter somewhat greater than that of the head. A lamellar spring located at the base of the head body presses the latter against the track. The movements of each head are guided in the vertical movements and limited in the lateral deflections by the internal walls of the cylindrical cavity which contains it.

 Usually, due to their bulk and inertia, the heads are fixed relative to the device and independent of each other. The magnetic badge is set in motion relative to the heads using a roller system driven by an electric motor.

 This drive system consists of a double plane bench of parallel rollers. The interval between these two benches, one being at the top and the other at the bottom, defines the path inside which the badge is directed and driven. The set of rollers is generally set in motion using a single motor by means of a complex set of idler belts.

The use of the multi-track magnetic badge reader system described above leads to a number of usage problems.
- on the one hand, the multiplication of the number of heads leads to a
complication of the device and therefore an increase in the blow
of the last,
- on the other hand, the complication of the drive mechanism of
the card vis-à-vis the heads leads to problems of
reliability and numerous maintenance,
- finally, the mode of application of each head against its track
is often deficient, especially in cases where badges
are very distorted. The contact surfaces of some
air gaps then find it difficult to follow the morphology of their
tracks. It follows very malfunctions
pleasant for the user.

 The aim of the present invention is to globally solve all of the above-mentioned problems currently posed by multitrack magnetic card reader readers.

 Another object of the invention is to propose a system for reading and writing magnetic badge tracks, in particular multitrack and the design of which is very simplified and the reliability of use increased.

 More generally, the object of the present invention is to provide an original solution to the very common problem of the intimate frontal application of a locally planar convex material surface against a deformed track vis-à-vis which this surface is in movement.

 To this end, one of the principles of the invention essentially consists in considering that the appearance of a deformed magnetic badge is very close to a set surface. In particular, and in a differential manner, we can admit that a deformed magnetic badge is constituted by the juxtaposition edge to edge of a series of elementary rectangles whose median of the major axis moves on the deformed curve of the initial axis of the plan badge, that is to say of the badge not deformed.

 This remark being made, it becomes possible to conceive an original articulation process which makes it possible to apply intimately a locally planar convex material surface and in particular a magnetic head multitrack against a track vis-à-vis which it is in motion.

 The method essentially consists in giving the head two degrees of partial freedom in rotation with respect to the badge, and this with respect to two privileged axes. The rotation relative to one of these axes makes it possible to get rid of the veiling of the badge and the freedom of rotation relative to the other axis ensures compensation for local bending.

 Furthermore, the method according to the invention proposes the production of a type of multitrack read head capable of precisely following the possible deformations of a badge along its axis.

Thus, because of the simplification which it brings, due to the limitation of the size and the inertia of the integrated head, the invention no longer recommends moving the badge vis-à-vis several fixed heads but instead of moving and guiding an integrated multitrack head of the articulated type according to the method of the invention, with respect to the fixed badge.

 Other characteristics and advantages of the invention will emerge from the description which follows with reference to the appended drawings, which descriptions and drawings are given only by way of nonlimiting example.

 For simplicity of understanding, the description of the general guiding method according to the invention, as well as the characteristic members intended to implement it, has been made in the particular case of solving the problem of application of a magnetic head. multitrack against a badge against which this head is moving. Of course, this example is not restrictive and the articulation methods which are described can be used in all cases where precise tracking of a track is required by a material surface applied against this track and in movement with respect to it.

On these drawings
- Figure 1 is a schematic perspective view of a
distorted magnetic badge, as modeled according to
principle of the invention
- Figure 2 and Figure 3 are block diagrams of the
kinematics of two preferred modes of articulation according to
the invention
- Figure 4 and Figure 5 are sectional views of two
practical embodiments of the principles of articulation
described in FIG. 2 and in FIG. 3, preferred according to the invention
tion
- Figure 6 is a detailed perspective view of a head
magnetic as that described in figure 4, applied
against a badge and setting in motion of screw translation
vis-à-vis the latter according to a preferred embodiment of the invention.

 In FIG. 1, a slightly deformed magnetic badge 1 is seen. This one is provided with three magnetic tracks 2, 3 and 4. We notice that this badge is both twisted and twisted. This is due to an earlier thermoplastic deformation.

 At the upper part of this figure, there is a magnetic tripod reading and writing head 6. The active part of the head 7 is constituted by a locally planar convex material surface and of non-negligible dimensions. It is a slightly curved ruled surface.

 On the surface of this active part, three magnetic gaps 10, 11 and 12 are arranged.

 The processing principle of the magnetic badge consists in translating the head 6 opposite the badge 1 according to f. During this treatment, each of the magnetic gaps 10, 11 and 12 must be in constant contact with each of the tracks 2, 3 and 4.

 As can be seen in f; gure 1, the deformed magnetic badge can be considered as a regulated surface constituted by the juxtaposition edge to edge of a series of small elementary rectangles 16, 17, 18, ... 23 , ... We note that the median of these small rectangles moves along curve 25, deformed from the axial median of the magnetic badge.

 Let us consider that the magnetic head is at the level of rectangle 23 For more understanding, the image of rectangle 23 has been elevated and represented at 33 opposite the head 6. The active surface of the head must closely follow the variations in direction of these little rectangles. It is understood that in order to pass from rectangle 23 to rectangle 24, the head must undergo a certain number of orientation transformations which are shown diagrammatically opposite rectangle 33.

It's about
- a partial translation in the direction y intended to make
follow the head badge's average level variations,
- a partial rotation such as r, intended to compensate for the
local bending of the badge,
- a partial rotation such as 1, intended to af
clear the head of the local twist of the badge,
- and of course, the overall translation f.

 print at the head 6, the translation f constitutes a problem of relative movement q; l will be raised later. Furthermore, the translation g is generally resolved by simple action of a spring shown diagrammatically by 27 and acting on the back of the head.

 By cons, the present invention seeks to find an original solution to the realization of two partial rotations r and I of the head vis-à-vis the badge.

 In FIGS. 2 and 3, the kinematics of two modes of resolution of the preceding problem are shown diagrammatically.

 In these figures, the badge is represented by the reference mark R (x, y, z). Furthermore, at the place where the head is located at the instant t taken as a reference, the latter is represented by the reference frame Ri (x1, yl, tel). Following the two rotations resulting from the implementation of the method, the reference frame of the head will transform successively, in the moments which follow t, into R2 (x2, y2, z2) then R3 (x3, y3 z3).

 For simplicity and without removing any generality from the description, the reference frame R1 has been shown at time t as parallel to the reference frame R. Furthermore, the translation effects have been neglected. Therefore, the marks representing the head have all the same origin 01.

 In FIG. 2, we note that the reference frame R1 first undergoes a rotation ri around the axis y1 coincident with the axis y. This rotation, which appears in the form of the displacement angle al, transforms the reference frame (x1, yl, zi) of the head into (x2, y2, z2). y = y1 = y2.

 Independently of rl, the head undergoes a rotation 11 around x2 which transforms (x2, y2, z2) into (x3, y3, z3). x2 = x3. This rotation appears in the form of the angle bl.

 In FIG. 3, the reference frame R1 undergoes a rotation 12 around the axis xl coinciding with x. This rotation, which appears in the form of the displacement angle b2, transforms the coordinate system (x1, yl, zî) of the head into (x2, y2, z2). x = xl = x2.

 Independently of 12, the head undergoes a rotation r2, around the axis y2, which transforms (x2, y2, z2) into (x3, y3, z3). y2 = y3. This rotation appears in the form of the angel a2.

 It is noted that the principles of articulation described in FIGS. 2 and 3 leave the head a freedom of rotation along an axis close to x and along an axis close to y. That is to say, they theoretically make it possible to protect the head from the problems of veiling and bending of the badge.

 Referring to Figures 4 and 5, we discover two practical embodiments of the principles described in Figures 2 and 3.

 In Figure 4, we see a cylindrical magnetic head 36 whose active part is located at the top at 37. This head has two grooves 40 and 41 hollowed out longitudinally and symmetrically on its side walls.

 We also note that the head 36 is freely introduced inside a cylindrical cavity 42 of axis a a ', formed inside a frame 43. This frame is pierced with two cylindrical recesses 44 and 45 coaxial to the same axis cc 'orthogonal to the axis aa' and intersecting the latter at A.

 Inside each of the recesses 44 and 45, are partially introduced two balls 47 and 48, also engaged in each of the grooves 40 and 41. These two balls are pushed frontally against the two grooves 40 and 41 and cooperate with them thanks to the action of two springs 49 and 50 located behind the balls inside the two recesses 44 and 45.

 It clearly appears that this type of articulation allows a free rotation of the head around the axis y = c c secured to the frame as well as around the axis x2 secured to the head.

 In FIG. 5, we can see a magnetic head of cylindrical shape 55 with a design quite similar to the previous one and whose active part is located at 56.

 However, this head is pierced with an axial recess 57.

 We also note that the head 55 is freely introduced inside a cylindrical cavity 58 of axis d ', formed inside a frame 59. This frame is hollowed out longitudinally and symmetrically with respect to its axis of two grooves 60 and 61.

 Inside the recess 57, two balls 62 and 63 are partially introduced, also engaged in each of the grooves 60 and 61. These two balls are pushed frontally between the two grooves 60 and 61 and cooperate with them thanks to the action of a spring 64 located between them inside the cylindrical recess 57.

 It is understood that an obvious variant of the above mode consists of partitioning the recess 57 and using not a spring 64 but two small springs located on either side of the partition.

 We can easily imagine that this type of articulation allows free rotation of the head around the x axis secured to the frame as well as around the y2 axis secured to the head.

 Referring to Figure 6, there is a head 36 during activity along the badge 1. The badge has been raised slightly so as not to clutter the figure.

 The head 36 is engaged and articulated inside the cavity 42 according to the mode of rotation described in FIG. 4. We note the presence of a ball, 48 cooperating with the groove 41 of the head 36. This ball is applied against the groove 48 by means of the spring 50 guided inside the recess 44 drilled in the frame 43. The pressure of this spring on the ball is adjusted by means of the screw 70.

 At the upper part of the head 36, we notice the presence of three air gaps 71, 72 and 73 which are intended to process the magnetic tracks 2, 3 and 4 located on the front of the badge 1.

 The badge 1 is kept in a fixed position by means of conventional suitable means, not shown.

 The relative translation of the head 36 tripists, vis-à-vis the badge 1, is ensured by a carriage of the latter along the axis of the badge. For this purpose, we note the presence of two recesses 75 and 76 inside the side walls of the frame. One of the recesses 76 is of circular section and the other 75 of square section. Inside the two recesses 75 and 76 are introduced two fixed cylindrical rails 77 and 78. A conventional system, not shown, comprising in particular two pulleys, a belt and a motor gives the frame a translational movement along f guided by the two rails 77 and 78.

 Note at the lower part of the head 36 the presence of the spring 27 intended to apply along g the head provided with its three air gaps against the magnetic badge.

 The head, articulated using the principle described above, closely follows the deformations of the badge during its translation along its tracks.

 We realize that the type of multitrack magnetic head previously described is of a remarkably simplified design. Instead of being made up of several bulky independent modules, this head includes a single integrated block. Furthermore, guiding in translation no longer of the badge relative to the heads but on the contrary of a head relative to the badge considerably rationalizes the overall production technology.

 It is also realized that the modes of articulation and guidance proposed by the invention make it possible to completely solve the problem of following any surface deformed by another moving surface. In particular, the modes of articulation described above make it possible to apply intimately and very reliably a magnetic head along a deformed badge.

 The invention having now been exposed and its interest justified in detailed examples, the applicant reserves exclusivity for the entire duration of the patent, without limitation other than that of the terms of the claims below.

Claims (16)

1. Method of guidance and multidirectional frontal application  tangent  - a convex material surface  locally flat,  and having significant dimensions,  - on a track  having a certain length,  and capable of being veiled and deformed axially,  said material surface  - being in relative translational movement along the axis of  Track,  - in particular having a partial degree of freedom in transla  tion along an axis close to the local vertical of the runway,  - and undergoing in particular a request applying it  frontally against said track following this direction of  freedom in translation,  said process being characterized in that  - on the one hand, the material surface is left  two degrees of partial freedom of instant rotation  opposite the runway  along two privileged axes,  - on the other hand, we give  to one of said privileged axes a quasi-gold direction  thogonal to the axis of the runway and almost parallel to the plane  way of this track,  and to the other axis a direction almost parallel to the axis of  this track,  - finally, we fix  the direction of one of the axes relative to that of the  track  and the direction of the other axis with respect to said on  material side. 2. Guidance method according to claim 1, characterized in that  that is given to said material surface with respect to said track  - a degree of partial freedom in rotation compared to a  axis  secured to said material surface,  direction orthogonal to the main axis of application  of this material surface against the runway as well as at the  direction of translation of this surface with respect to the  track.  . and fixed relative to the direction of the latter.  parallel to the track,  axis  - and a degree of partial freedom in rotation compared to a 3. Guidance method according to claim 1, characterized in that  that is given to said material surface with respect to the track  - a degree of partial freedom in rotation with respect to an axis  secured to said moving material surface,  whose direction is located in a plane passing through  the main axis of application of said material surface  and by the axis of translation of the material surface  opposite the runway,  and orthogonal to said main axis of application of the  material surface,  - and a partial degree of freedom in rotation with respect to a  fixed steering axis with respect to the runway  . orthogonal to the direction of translation of said surface  material vis-à-vis the track,  . and orthogonal to the local perpendicular to said track  instead of contact with the material surface. 4. Method for producing the guidance mode according to claim  2, consisting in positioning said material surface at the top  a support head, in particular cylindrical, metallic or in  molded plastic, with an axis almost parallel to the local perpendicular to  Track,  said method being characterized in that, to give said  material surface its two so-called partial degrees of freedom in  rotation with respect to said two privileged axes,  - said support head is hollowed out along two of its genera  trices, following two symmetrical grooves with respect to the axis  of the head,  - And we introduce inside each of these grooves a  ball, in particular metallic, allowing a sanding rotation  tuelle  . each of the two balls being applied facing the groove  by means of a spring secured to a frame in  relative translation compared to the track in the di  desired rection,  the thrust axes of each of the two springs being  coaxial and parallel to the direction of the transla axis  tion of the surface vis-à-vis the runway. 5. Guidance method according to claim 3, consisting in posi  the said material surface at the top of a support head,  in particular cylindrical, metallic or molded plastic, of axis  almost parallel to the local perpendicular to the runway,  said method being characterized in that, to give said  material surface its two so-called degrees of freedom in rotation by  relation to the two so-called privileged axes,  - two recesses, in particular cylindrical, are provided at  the interior of said support head,  - These recesses are drilled along an axis perpendicular to  the axis of the head and passing through it,  - We introduce inside each of these recesses a  ball, in particular metallic, allowing a sanding rotation  tual vis-à-vis each of them,  - we push each of the two balls from the inside to the outside  laughter of the head, in particular using a spring arranged  behind it inside the recess,  - we have the crew previously made inside a  cavity in a frame in relative translation vis-à-vis  of the track in the desired direction, after having  formed on the inner sides of said cavity two grooves  longitudinal, symmetrical with respect to the axis of the cavity,  - and finally, the crew is positioned so that the two  balls are introduced inside the two said grooves  previous and applied head-on against them  in order to cooperate with them. 6. Guidance method according to claim 5, characterized in that  than  - we communicate the two recesses made perpen  specifically to the axis of the head,  - and we push the two balls through a system  spring which is left free in translation  between the two balls  and inside the recess that contains them. 7. Method of guidance and multidirectional frontal application  tangent  - a vector of information in relative movement of trans  lation along and against  - an information support track  . having a certain length  . and capable of being veiled and deformed axially,  this in order to carry out mutual information transfers between the  vector and the information carrier track,  said method consisting in particular of giving said vectors  information an external hardware configuration locally  flat and having non-negligible dimensions,  said process being characterized in that the guidance is carried out  according to one of the methods described in one of claims 1 to  6, the outer surface of the vector with respect to the track being  assimilated to said related material surface. 8. Method of guidance and multidirectional frontal application  tangent  a soft magnetic reading and / or writing system  relative movement of translation along and against  - a track or muiti-track  magnetic information carrier, and in particular a  magnetic badge,  . having a certain length,  and capable of being veiled and deformed axially,  this in order to transfer information in the form  magnetic between the magnetic reading and / or writing system  and said track,  said process being characterized in that it is carried out, according to the  The method of claim 7, the reading system and so on.  magnetic ture being assimilated to said information reader. 9. As a new industrial product, etiou reading system  magnetic badge writing, especially multi-track, using  one of the guiding methods according to one of claims 2 and 4,  this system including a badge insertion area  magnetic and means suitable for positioning them,  said magnetic badoe reading and writing system being  characterized in that it comprises  - a head  including cyiindr # ue, metallic or plastic mold.  head being connected to the frame by means of two balls.  vity, in particular cy'indrique, formed in a bat, said  this head being introduced freely inside a ca  and equipped with magnetic air gaps at its upper part,  tracing in relation to the axis of the head,  provided with two longitudinal recesses arranged sy-  of the track.  preferably being located on the same axis parallel to the axis  cylindrical res made in the frame, these two lights  - the two springs being in particular engaged in two lumiè  and urged by a spring bearing on the frame,  dinals of said head,  being engaged in one of said longitu recesses  - each of these balls 10. As a new industrial product, reading system and. or  writing of magnetic badges, in particular multitrack, using a  guidance methods according to one of claims 3 and 3,  this system including a badge insertion area  magnetic and means suitable for positioning the latter,  said system for reading and / or writing magnetic badges  being characterized in that it comprises  - a head  in particular cylindrical and made of metal or of material  molded plastic,  provided with two recesses, in particular cylindrical, and  arranged along a diametra axis!  and equipped with magnetic air gaps at its upper part,  this head being freely inserted inside  - a cylindrical cavity formed in a frame, the sides of  said cavity being provided with  - two longitudinal grooves symmetrical with respect to the axis  from the cavity,  a ball, in particular metallic, being partially introduced  inside each said head recess, each of  these balls being pushed towards the outside of the head by  The intermediary  - a spring system located inside their recess  is lying,  each of these two balls being introduced inside one of the  two said longitudinal grooves of the frame and cooperating with this  last. 11. Method for guiding in relative translational movement  - of a system according to one of claims 9 and 10 of lec  ture and / or writing of magnetic badges, in particular multi  tracks, opposite  - magnetic badges, in particular distorted,  said process being characterized in that  - the magnetic badge is kept inside the means of  positioning,  - said frame containing the head is guided  along the axis of the badge tracks  in particular using a system of cooperating fixed rails  with longitudinal recesses on the frame,  - and we print a translational movement to the frame, in particular  using a pulley system, belt and a  engine. 12. As a new industrial product, read / write head  of magnetic badges intended to implement one of the  methods according to one of claims 2 and 4 and intended to make  part of a system according to claim 9, this head having a  elongated shape, in particular cylindrical, and being provided in its part  upper magnetic air gap., said head being characterized  in that it is provided on its lateral flanks with recesses  longitudinal arranged symmetrically with respect to the axis of the  head. 13. As a new industrial product, read / write head  of magnetic badges intended to implement one of the  methods according to one of claims 3 and 5 and intended to make  part of a system according to claim 10, this head having  an elongated shape, in particular cylindrical, and being provided at its  upper part of magnetic air gaps,  said head being characterized in that it is provided with two  recesses, in particular cylindrical and arranged along an axis  diametrical. 14. Read-write head of magnetic badges according to the revenue  dication 13, intended to implement the method according to the  claim 6, said head being characterized in that its two  said diametrical recesses communicate and form a single  obviously. 15. As a new industrial product, a building intended to  uses one of the methods according to one of claims 2 to 4, and  for cooperating with a magnetic head according to claim  12 to be part of a system according to claim 9,  said frame being characterized in that  - it includes a cavity, in particular cylindrical,  - and two lights opening into this cavity, these two  lights being located in particular on an axis coincident with  the axis of the runway.  16. As a new industrial product, a building intended to  uses one of the methods according to one of claims 3 and 5, and  for cooperating with a magnetic head according to claim  13,  said frame being characterized in that  - it includes a cavity, in particular cylindrical,  - two longitudinal grooves symmetrical with respect to the axis  being provided on the walls of said cavity.