US3144525A

US3144525A - Punched card reader

Info

Publication number: US3144525A
Application number: US233623A
Authority: US
Inventors: George S Fenn; Robert F Kiddle
Original assignee: Fma Inc
Current assignee: Fma Inc
Priority date: 1962-10-29
Filing date: 1962-10-29
Publication date: 1964-08-11
Anticipated expiration: 1981-08-11
Also published as: GB952440A; CH399030A; BE628060A; LU44437A1; NL288995A

Description

Aug. 11, 1964 G. S. FENN ETAL PUNCHED CARD READER Filed Oct. 29, 1962 INVENTORS GEORGE 3. FE/V AOBE/PT F E BY Z 13% ,477'OR/VEY United States Patent 3,144,525 PUNCHED CARD READER George S. Fenn, Rolling Hills, and Robert F. Kiddie, San Pedro, Calif, assignors to FMA, Inc., El Segundo, Calif., a corporation of Caiifornia Filed Oct. 29, 1962, Ser. No. 233,623 3 (Ilaims. ((31. 200-46) The present invention relates to a new and greatly improved punched card reader apparatus.

Punched card operated devices have been invented and used before, typical devices of this sort being illustrated and described in Patents 2,903,529 and 2,825,773. Thus, typically, when a card through which a predetermined pattern of holes has been punched is inserted in one of these earlier devices, spring-driven connector pins pass through the card whereat the holes are located and, on the other side of the card, mate with and thereby make electrical contact with a corresponding number of female parts. In this way, an output pattern of voltages is produced that corresponds to the pattern of punched holes on the card. While the punched card operated apparatus referred to above is suitable for most purposes, it is grossly inadequate where relatively large numbers of pins are to be used and accurate output voltages are required. In other words, because of the manner in which these earlier devices are mechanized, they cannot very readily be adapted for fine work.

More specifically, considering the limitations of these earlier devices, each connector pin is driven by its own spring so that there are as many springs as there are connector pins. Consequently, as may be expected, the driving forces applied to the different pins will vary from one to the other, especially with the passage of time, and this has proven to be most important in some instances since different mechanical forces on the pins means different degrees of electrical contact on the other side, thereby introducing the possibility of error. Furthermore, where large numbers of pins are to be used, they are customarily made much thinner than when relatively few pins are involved in order to save space, weight and expense. As a result, they have a tendency to be bent in due time by the spring forces acting upon them, thereby throwing them out of alignment which, of course, greatly reduces the effectiveness of the electrical contacts made. In addition, where accuracy is important, poor output results are also obtained due to the fact that a correspondingly large number of metal sleeves or female parts are used to receive the pins. It should be obvious that dirt of various kinds will ultimately lodge or become deposited in these sleeves and this will also have the effect of reducing the possibility of good electrical contact.

The several disadvantages of these earlier forms of card reader devices are avoided by means of the present invention, the essence of which lies in the fact that on one end of the connector pins means are used that insure a uniform pressure on the pins and on their other end means are employed that insure a uniform electrical contact for them. In particular, in an embodiment of the invention, a rubber pad is used to provide the spring action for the pins and a single metal plate is employed for making the necessary electrical contact with them. Thus, the individual spring and metal sleeve elements are eliminated and so are the attendant limitations. It will be obvious to any one skilled in the art that, in addition to the already mentioned benefits, the present invention is also inherently simpler, less costly to make, and easier to maintain.

It is, therefore, an object of the present invention to provide a punched card reader apparatus that at all times maintains its pins in good electrical contact.

It is another object of the present invention to provide 3,144,525 Patented Aug. 11, 1964 a punched card reader apparatus that will at all times apply a constant driving force to its pins.

It is an additional object of the present invention to provide a punched card reader apparatus that may be used with confidence where accurate output Voltages are to be obtained.

Further objects and advantages of the present invention, together with the novel features thereof, will be better understood from the following description considered in connection with the accompanying drawings in which an embodiment of the invention is illustrated by way of example. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention.

FIG. 1 shows a card through which a pattern of holes has been punched; and

FIG. 2 presents a cross-sectional view of a punched card reader apparatus according to the present invention.

Referring now to the drawings, reference is made first to the punched card shown in FIG. 1, the card itself being designated 10 and the holes therethrough being designated 11. The pattern in which holes 11 are arranged is in accordance with a predetermined code, while the size of and the spacing between adjacent holes respectively correspond to the thickness or diameter of the connector pins and the spacings between them.

Referring now to FIG. 2, the card reader is shown to include a metal contact plate 12 mounted on an insulative board 13, the plate and board combination, in turn, being fixedly mounted on a base 14 which may or may not be metal and which constitutes a part of the housing structure for the card reader. Also mounted on base 14 and of the same thickness as the plate 12 and board 13 combination is a plate or board 15, board 15 being mounted on base 14 in such a manner that it overhangs the base in a cantilevered fashion. Fixedly mounted above contact plate 12 and board 15 and in faceto-face relationship with them is still another plate or board member 16 made of an insulative material. The spacing between plate 12 and board 15 on the one hand and member 16 on the other hand is only enough to permit a punched or perforated card 10 to be inserted in the space therebetween and it is for this reason that element 15 is cantilevered, namely, to facilitate the insertion of a card. Finally, member 16 has as many holes or channels through it as there are connector pins, the purpose of these channels, which are designated 17, being to protect and properly direct the movement of the pins into contact with plate 12, as will be seen later. Accordingly, upon insertion of a card 10, holes or channels 17 come into registration with or, stated differently, respectively become positioned over all the points on the card Whereat perforations or holes may possibly be located. Thus, a channel 17 is positioned over each spot on card 10 whereat a hole may be punched through it.

Also included in the card reader is a housing block 18 whose walls may or may not be made of metal and which is moveably positioned above board member 16. Inside housing block 18 and held by the walls thereof is a pin housing block 20 that faces board member 16. Pin housing block 20 is made of an insulative material and has U-shaped recesses 21 into which connector pins 22 respectively fit, there being as many recesses and, therefore, as many connector pins as the number of channels 17 through board 16. At the bottom part of pin housing block 20 are a plurality of holes or chanenls 23 that extend upwards to respectively meet with recesses 21, as shown in the figure, and which are respectively in alignment or registration with channels 17 in member 16. Inside housing block 18 and cemented or otherwise mounted to the surface of the top wall thereof is a rubber pad 24 whose bottom face is covered with a sheet of Mylar 25 or other similar material for the purpose of protecting the rubber pad from damage by the pins.

With respect to pins 22, they respectively include a thin metal rod and a thicker body structure that rides in recesses 21. The abovesaid body structure may be made of metal, in which case the entire connector pin would probably be made of the same metal material. On the other hand, the body structure need not be made of metal and, therefore, may be built up around the rod or pin with a non-metallic substance. As previously mentioned, the body structure portion of pins 22 are slideably mounted in recesses 21, the extremities of the pins on one side of it extending through

channels

23 and 17 until the tips thereof are contiguous to contact plate 12, the extremities of the pins on the other side extending upwards until they come into pressure contact with rubber pad 24 or, more accurately, protective film 25 on the bottom surface of the pad. Pins 22 are rounded at their upper tips so as to reduce the possibility of damage to rubber pad 24 as much as possible and they are tapered at their bottom tips so that they can make good electrical contact with plate 12 when they are allowed to do so.

Housing block 18 may be moved slightly up or down, that is, away from or toward board member 16, the distance through which it can be moved being only enough to raise pins 22 so that a punched card 10 may be easily inserted in the space between contact plate 12 and member 16. Housing block 18 may be raised and lowered in any one of a number of ways, all of them being well known in the mechanical arts. Thus, merely by way of example, a simple lever apparatus may be coupled to the housing block 18 to manually raise or lower it very much in the same manner that a drill bit is raised or lowered in a drill press. Since the manner in which the housing block is raised and lowered involves a state-of-the-art mechanical arrangement, it is not shown in the figure for sake of expediency. Also not shown in the figure is a source of either positive or negative potential connected to contact plate 12. In other words, for reasons that will become clearer below, contact plate 12 is maintained at either a positive or a negative potential and for this reason, as mentioned just above, it is connected to either a positive or a negative potential source, such as a battery. Since this involves the simplest kind of connection, it was not deemed necessary to show it. Finally, in order to detect or determine whether or not voltage potentials exist in any one or more of pins 22, leads or wires 26 are respectively electrically connected to the pins, the leads or wires being coupled to external circuitry which does not form a part of this invention.

In operation, prior to the time a card 10 is placed in the card reader, housing block 18 is in its raised position so that the space into which the card is inserted is free of pins 22 which might otherwise interfere with the proper insertion of the card. Once a punched card is inserted in the space provided between

elements

12 and 16, the housing block is then lowered and when this is done, the tips of pins 22 are brought into contact with the card which, in consequence thereof, exerts an upward or backward push on the pins. More specifically, those pins that are in registration with the holes punched through the card will be urged by rubber pad 24 to pass through the holes and make contact with plate 12, it being those pins that do not pass through the card that are pushed back by it.

Looking to FIG. 2, the pins that pass through card 10 and into electrical contact with plate 12 are shown in black to distinguish them from those that do not and as for these other pins, they are held firmly by the card on one end and the rubber pad on the other end. It will be noticed from the figure that the pins that do not encounter holes in the card are actually moved upward slightly as indicated by the slight spacings between these pins and their associated recesses 21. This upward displacement of the pins is taken up by the rubber pad which indents or becomes deformed at the points whereat these pins press against the pad. As for the pins in contact with plate 12, these pins now have the same potential on them as is found on plate 12, the signals thereby produced being fed elsewhere by leads 26. To remove the card, housing 18 is raised, thereby also raising the pins and allowing room for the card to be withdrawn. It will be recognized that upon raising the housing block, those of pins 22 that Were previously moved upward by card 10 will now be moved downward the same amount by rubber pad 24. As a result, the bottom tips of the pins are once again in the same plane and ready for the next punched card to be inserted.

It is thus seen that by using a rubber pad 24, the desired forces can be maintained on the pins. It is also seen that by using a metal plate 12, the same potential within very accurate limits is applied to the pins, thereby reducing the possibility of errors in the output signals fed over lines 26.

Although a particular arrangement of the invention has been illustrated and described above, it is not intended that the invention be limited thereto. Accordingly, the invention should be considered to include any and all modifications, alterations or equivalent arrangements falling within the scope of the annexed claims.

Having thus described the invention, what is claimed is:

1. A punched card reader comprising: an electrically conductive plate; a housing structure positioned over said plate and adapted to be selectively moved toward and away from said plate; a resilient pad mounted in said housing structure and parallel to said plate; and a predetermined number of electrically conductive pins slidably mounted in said housing structure in a position that is perpendicular to both said pad and said plate, said pins being in pressure contact with said pad at one end and contiguous to said plate at the other end thereof.

2. A punched card reader comprising: a base structure including an electrically conductive plate upon which the punched card is positioned; and a housing structure positioned over said plate and adapted to be selectively moved toward and away from said plate, said housing structure including a wall facing said plate having a plurality of recesses therein equal in number to and in registration with the points on the card whereat holes may be punched therethrough, a plurality of electrically conductive pins slidably positioned in said recesses, respectively, whereby said pins are also in registration with the points on the card whereat holes may be punched therethrough, and a rubber-like pad mounted over said pins and in contact with the tips at one end thereof to apply a forward moving pressure thereto, whereby said pins extend through the card and are in contact with said plate wherever there are holes punched through the card.

3. A punched card reader comprising: a base structure including an electrically conductive plate; voltage means for applying an electrical potential to said plate; a housing structure postioned over said plate, said structure ineluding an electrically insulative wall facing said plate and having a plurality of recesses and connecting pin holes therethrough equal in number to and in registration with the points on the card whereat holes may be punched, a plurality of electrically conductive pins slidably positioned in said recesses and extending through said connecting holes toward said metal plate, and a rubber-like pad mounted over said pins and in contact therewith for applying a forward pressure thereto, whereby said pins are forced through the holes in the card and into contact with said plate; and means for spacing said base and housing structures to permit a punched card to be inserted therebetween and thereafter removed.

References Cited in the file of this patent UNITED STATES PATENTS 2,575,052 Foltzer Nov. 13, 1951