Card feed mechanism

Abstract

A feed mechanism for punch cards or like sheet material whereby the punch card is quickly advanced and accurately positioned at a work station. The trailing edge of the punch card is used as a reference to register the punch card at the work station. The advancement and final registration are the result of two synchronized steps involving a register roll and a pusher blade. The register roll is effective during the first step to rapidly advance the trailing edge of the punch card into operative relationship with the reciprocating pusher blade; the latter at the commencement of the second step is cooperatively positioned to pick up the trailing edge of the punch card and carry it forward into final registration with respect to the work station. In the preferred embodiment of the present invention, the final registration involves the positioning of the punch card such that the first and second columnar positions are accurately aligned with respect to corresponding punches of a punch mechanism. Once registration has been effected, further advancement of the punch card is accomplished by somewhat independent indexing means. The system is further adapted to accomodate punch cards of different lengths.

Description

BACKGROUND OF THE INVENTION

The present invention relates to a feed mechanism for punch cards and the like and more particularly to a feed mechanism adapted to rapidly advance a punch card, or like sheet material, from a supply and very accurately position each punch card with respect to a reference point within an associated data processing system such that subsequent operations including the punching and printing of the punch card may be performed with a high degree of accuracy, i.e., with assurance that the punch card is properly positioned to receive such information.

Accurate positioning of a punch card during the preparation thereof very measurably influences the relative degree of accuracy with which the information stored therein may later be interrogated. Thus, the instant invention is pertinent both with respect to the initial positioning of punch cards during the preparation thereof and also subsequent thereto when the cards are being interrogated.

An equally important consideration in the design of a punch card positioning mechanism is the speed and flexibility with which punch cards may be transferred from one work station to the next. Thus, whereas some prior art devices have concentrated on improving the accuracy with which a card is positioned they have done so at the expense of speed and/or flexibility. One such prior art approach is that disclosed in U.S. Pat. No. 3,276,774 which makes use of a shuttle arrangement in which a punch card, after being released from an input hopper is advanced column-by-column through an associated punch station. Although the aforementioned positioning and advancing technique is very accurate, the shuttling arrangement is relatively slow and the design permits very limited control to be exercised over the punch card once it has been released from the input hopper.

SUMMARY OF THE INVENTION

The present invention overcomes the deficiencies of the prior art in that a punch card after being delivered from an input hopper is advanced to a visible station where previously entered information may be visually observed by the operator. The punch card remains in the visible station until released by the operator at which time the card is advanced to the next work station. In the preferred embodiment of the present invention the succeeding work station comprises a punch mechanism, the punch card being advanced thereto and accurately positioned with respect to indexing means comprising a part of the punch station.

One of the particular features of interest of the present invention concerns the construction details of the mechanism for rapidly advancing and accurately positioning the punch card with respect to the indexing system at the punch station. This mechanism hereinafter referred to as the register roll assembly includes a register roll and a synchronously driven pusher blade both being activated by a single-cycle wrap-spring clutch. The rapid advancement of the punch card is accomplished by the register roll and a cooperating pinch roll. The pusher blade executes a reciprocative motion whereby the punch card is advanced into final registration at a work station.

In the preferred embodiment, the wrap spring clutch after being energized is designed to complete one revolution of an associated output shaft on which the register roll is mounted and to which the pusher blade is mechanically linked by means of a cam follower assembly. This results in turn in one revolution of the register roll and correspondingly one reciprocative cycle of the pusher blade. The register roll and its cooperating pinch roll engage the punch card and advance it to within a short incremental distance of final registration with respect to the indexing system at the work station. As the trailing edge of the punch card passes the center line of the register roll and associated pinch roll, i.e., "drops-off" the rollers, the cam controlled pusher blade picks up the trailing edge of the card and carries the card into final registration with the indexing means comprising a portion of the work station.

A significant feature of the register roll assembly concerns the provision of a substantially flat section on the periphery of the register roll. At the beginning and end of each operative cycle of the subject advancement and positioning mechanism the flat section of the register roll is positioned parallel to the path of travel of the punch card. The resultant separation between the register roll and the pinch roll permits a substantial portion of a punch card, being advanced by independent means from an input hopper, to pass therethrough prior to the initiation of an operative cycle of the register roll assembly. In this manner, the path length or distance of travel of a punch card from the time it leaves the card stripping and advancement mechanism until it is registered at the succeeding work station, may be substantially reduced. This feature further permits a punch card to be advanced therethrough without any need for equipping the unit with potentially expensive hardware otherwise required to pivot the register roll or alternatively its cooperating pinch roll, out of the path of the advancing punch card.

Another feature facilitating the uninhibited passage of a punch card being advanced from the supply to the work station concerns the flexure mounted nature of the pusher blade. The pusher blade is designed to reciprocate in the path of travel of the punch card; however, the blade is equipped with ramp shaped surfaces and is mounted on a flexible spring steel member such that the blade is readily moved aside by an oncoming card and continues its reciprocatory motion on the face of the punch card without apparent damage thereto.

The positioning mechanism of the present invention should not be confused with simpler prior art arrangements which rely on the use of the leading edge of a punch card for reference purposes. Such arrangements very conveniently interpose a stop in the path of a punch card to assure the accurate positioning thereof. An example of such a leading edge positioning device is disclosed in the U.S. patent to Suzuki et al, Pat. No. 3,636,316. Although much more simple to implement, leading edge referencing techniques have other deficiencies which limit their usefulness in data processing equipment.

The alternative technique, and that employed in the practice of the present invention, utilizes the trailing edge of the punch card for reference purposes. It should be understood that switching between leading and trailing edge techniques within a single system is not permitted and once a commitment is made to reference positions on the punch card with respect to the trailing edge (or alternatively with respect to the leading edge) all further positional determinations must be consistently made in the same manner.

The flexibility of design of the subject advancement and positioning mechanism is demonstrated in an alternative embodiment of the present invention which features the use of two such register roll assemblies to accomodate punch cards of different lengths. This feature is important in light of the current trend toward increasing the variety of punch card lengths available for processing.

Still additional flexibility would be afforded by placing a number of register roll assemblies in line and operatively interconnecting these by means of an appropriate control system such that a punch card would be advanced by more than one of the register roll assemblies but only the last of the assemblies would be effective in positioning the card.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevational view of a card advancing and positioning mechanism constructed in accordance with the principles of the present invention.

FIG. 2 is a fragmentary plan section showing the register roll assembly portion of the card advancement and positioning mechanism of FIG. 1 taken on the line 2--2 of FIG. 1.

FIG. 3 depicts the position of the trailing edge of a punch card relative to the register roll assembly of FIG. 2 after the latter has been rotated to an intermediate position some 30.degree. from its starting position.

FIG. 4 depicts the register roll of FIG. 2 after being rotated to a point where the trailing edge of the punch card "drops-off" the rollers.

FIG. 5 depicts the register roll of FIG. 2 after being rotated to a point where the pusher blade reaches the trailing edge of the punch card.

FIG. 6 shows the overall relationship of the punch card with respect to the indexing wheel at the punch station and the register roll assembly of FIG. 2 at the point in time where the pusher blade reaches the trailing edge of the punch card.

FIG. 7 shows the overall relationship of the punch card with respect to the indexing wheel and the register roll assembly of FIG. 1 at the point in time where the pusher blade has advanced the punch card to its full forward position.

FIG. 8 is an isometric assembly view of the register roll assembly of FIG. 2.

FIG. 9 is a detailed view of the housing for the register roll assembly of FIG. 2.

FIG. 10 is a cross sectional view of the register roll assembly housing of FIG. 9 taken on the line 10--10 of FIG. 9.

FIG. 11 is a detail view of the pusher blade of the register roll assembly of FIG. 8.

FIG. 12 is a side view of the pusher blade of FIG. 11.

FIG. 13 is a plan view of the cam follower arm of the register roll assembly of FIG. 8.

FIG. 14 is a side view of the cam follower arm of FIG. 13.

FIG. 15 is a vertical sectional view on the line 15-15 of FIG. 1 illustrating a card aligning and braking mechanism which is used to partially control the path of travel of the punch card toward the work station.

FIG. 16 is a plan section illustrating a modification of the invention employing a pair of horizontally spaced register roll assemblies for enabling the processing of cards of variable lengths.

FIG. 17 is a detailed plan view of the pusher blade actuating cam and cam follower arm of FIG. 8.

FIG. 18 is a kinematic projection of the cam surface of FIG. 17.

FIG. 19 is a sectional view of a punching mechanism used in conjunction with the present invention.

FIG. 20 is a partial plan view of the punching mechanism of FIG. 19.

FIG. 21 is an enlarged fragmentary view of the punch dies used in conjunction with the punching mechanism of FIG. 19.

FIG. 22 is a timing diagram depicting the sequence of operations and control cycles employed in the positioning and preparation of an 80 column punch card.

FIG. 23 is a timing diagram depicting the control cycles employed in the positioning and preparation of a punch card of abbreviated length.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Turning now to FIG. 1, there is illustrated an elevational view of a card advancing and positioning mechanism 10 embodying the principles of the present invention and illustrating a punch card 12 positioned in the "visible station" of a card preparation and interpretation apparatus such as is disclosed in the patent to McPherson et al filed Nov. 16, 1970 as Ser. No. 81,250 now U.S. Pat. No. 3,706,074. The visible station dimensionally speaking, comprises an area which is slightly larger than the surface area of a punch card, and in the embodiment of FIG. 1 encompasses essentially all of the area beneath a plexiglass cover identified therein as member 14. FIG. 1 further depicts the relative position of the punch card 12 in its path of travel from the preceding work station the latter being herein depicted as a read station identified by feed rolls 16 mounted on shaft 18 positioned within brackets 20.

After being released from the visible station by the operator, in the manner discussed further hereinbelow, the punch card is advanced to a punching station depicted generally herein as member 21 and comprising a plurality of rectangular punch pins 22A and 22B, a pair of which are mounted within each of 12 cylindrical apertures 24. Details of a punch mechanism which may be used in conjunction with the present invention are disclosed in FIGS. 19, 20 and 21, and reference is now made thereto. The plural punch pins 22A and 22B are selectively actuated within a punch guide 26 by means of a conventional high speed punch mechanism of the interposer type. For each of the punch pins 22A and 22B there is provided separate actuating means comprising a flexure mounted bail 27 which carries an interposer 29 for each of the punch pins, the interposer being connected at one end to a rocker arm 31. The latter includes a cam follower portion 31A which is normally spring biased by a spring 34 against a cam shaft 36. As seen more clearly in FIG. 1 the shaft 36 is mechanically coupled to a crank shaft 33. Mounted on crank shaft 33 is a connecting rod 33A carrying a drive link 33B. The rotational motion of crank shaft 33 is translated into reciprocating motion by way of the connecting rod 33A and this motion is in turn effective in moving drive punch pins 22A and 22B into punch relationship with a corresponding location of the punch card 12 depending on the position of the interposer 29. In the event it is not desired to make an entry on the punch card in a particular location, appropriate control signals are generated in punch logic (not shown); these signals in turn are used to selectively energize a coil 35 which in turn magnetically latches the armature portion of the rocker arm 31 after the latter has been rotated about its pivot point 31B such that the armature is moved into close proximity of coil 35 by means of the cam shaft 36. The plural nature of punch pins 22A and 22B facilitate the simultaneous entry of information into up to two adjacent columns of the punch card 12 when the latter is properly positioned with respect thereto.

Indexing means comprising an index roll 28 and a retractable pinch roll 30 are adapted to engage the punch card 12 after the latter has been properly positioned at the punch station. As will be seen from the explanation of the card advancing and positioning mechanism discussed below, the index wheel 30 is mounted so as to permit a slight separation to be introduced between it and the index roll thereby facilitating the uninhibited entry of the punch card therebetween during the card advancing and positioning operation.

As is seen most clearly in FIG. 19, the pinch roll 30 is mounted on an arm 32. A spring 34 urges the pinch roll 30 toward the index wheel 28. A coil 37A of a solenoid 37 when energized, by means of a signal OPR discussed hereinbelow, attracts and holds the arm 32 thus moving the pinch roll away from the index wheel 28 sufficiently to permit a punch card to be readily positioned therebetween.

The index wheel 28 is mounted on a shaft 39 which in turn is mounted in bracketed bearing 41, the shaft 39 being in turn driven by a servo system indicated generally as member 45.

It will be seen from a further analysis of FIG. 1 and also from FIG. 15 that a punch card being advanced from feed rolls 16 to the index roll 28 travels in front of back plate 40. A substantial portion of the back plate 40 is covered by the plexiglass shield 14; the latter being spaced from the surface of the back plate 40 in all areas proximate to the path of travel of the punch card to permit the punch card to be advanced unrestrictively therebetween. Bottom clips in the nature of members 42 and top magnetized brackets 42a secured to the plexiglass cover 14 are provided to restrain the plexiglass cover 14 in proper position with respect to the back plate 40.

A register roll assembly identified generally as member 43 is seen in the embodiment of FIG. 2 as being mounted adjacent the back plate 40. A more detailed representation of the register roll assembly 43, is depicted in FIG. 8, being shown therein as comprising a housing 44 which carries a register roll shaft 46 and a pusher blade and follower arm shaft 48. Vertically spaced register rolls 50, hereinafter sometimes referred to as drive rolls, are provided with a flat portion 50a covering a substantial portion of the periphery thereof, are mounted on the register roll shaft 46. As viewed in FIG. 2, the register rolls 50 are positioned to cooperate with pinch rolls 52 during all but that portion of a revolution thereof during which the flat section 50a of the register rolls 50 are oriented proximate to the pinch rolls 52. As explained hereinbefore, the function of the flat sections 50a of the register rolls 50 is to thereby provide a gap between the register rolls 50 and the pinch rolls 52 so as to facilitate the transmission of a substantial portion of a punch card therethrough by means of feed rolls 16 prior to the initiation of an operative cycle of the register roll assembly. The relative percentage of the flat section 50a compared to the balance of the peripheral surface on a roll 50 determines the extent of advancement capable of being imparted to a punch card by this means.

Mounted on the shaft 48 is a specially configured pusher blade 54 which, as is seen more clearly from FIGS. 11 and 12 is flexure mounted by means of a flat section of spring steel 56 to a pusher arm 58 which in turn is adjustably mounted on the shaft 48 by means of clamping screws 60. In addition to the rather coarse adjustment afforded by clamping screws 60, provision is made for fine adjustment of the punch card engaging surface 54a of the pusher blade 54 with respect to the punch card 12; this appears in the form of a fine adjusting screw 62 in the embodiment of the pusher arm 58 disclosed in FIG. 11. It will be noted, particularly from FIGS. 11 and 12, that a ramp shaped configuration has been imparted to the card contacting surfaces of the pusher blade 54 to enable a punch card to uninhibitedly ride underneath the blade independent of the direction of relative motion of the pusher blade with respect to the punch card.

Also mounted on shaft 48 is a cam follower assembly comprising a follower arm 64 clamped on shaft 48 by means of a clamping screw 66, as may be seen from FIGS. 13 and 14. The follower arm 64 carries a freely rotating roller 68. The roller 68 cooperates with the specially configured surface of a cam 70 mounted on the register roll drive shaft 46 to cause reciprocation of the pusher blade upon rotation of the shaft. The roller 68 is held in contact with the cam 70 by means of a tension or retaining spring 72 connected at its ends to posts 74 and 76. The posts 74 and 76 are supported on the housing 44 and follower arm 64 respectively.

The drive means for the register roll assembly 43 preferably comprises a wrap spring clutch 80 which is mounted on the register roll shaft 46. The wrap spring clutch used in the preferred embodiment of the present invention is of conventional design, a suitable form of which is supplied by Precision Specialties, Inc. of Pitman, N.J., the same being described in detail in U.S. Pat. No. 3,373,851. As will be seen from an explanation of the operation of the register roll assembly 43, given hereinbelow, the wrap spring clutch 80, activated upon release of a clutch pawl 82 (FIG. 1), functions to rapidly advance a punch card by means of the register roll 50 and to thereafter accurately position the card at a work station by means of the pusher blade 54, the latter being mechanically linked to the wrap spring clutch by means of the aforementioned cam follower assembly. Release of the pawl 82 causes the wrap spring clutch 80 to initiate rotation of shaft 46 which in turn results in the rotation of register roll 50. Cam 70 being mounted on shaft 46 is also rotated thereby causing a rocking motion to be translated to the pusher blade 54 via the cam follower roller 68.

The operation of register roll assembly 43 will now be described with reference to FIGS. 1 through 7. It should be noted that prior to the time the register roll assembly is actuated, a substantial portion of the punch card will have already been advanced through the gap separating register roll 50 and pinch roll 52. This initial advancement of the punch card 12 is unhampered by the register roll assembly in that the flat section 50A of the register roll 50 is positioned proximate to and parallel with the back plate 40 thus permitting the punch card to pass freely between the register roll 50 and its associated pinch roll 52. Further, the flexure mounted nature of the pusher blade 54 permits the latter to ride up and over the advancing punch card. The flexure mounted nature of the flat section of the spring 56 assures that as the card continues to advance, no damage will be rendered to the surface thereof even during the initial portion of an operative cycle of the register roll assembly during which time the pusher blade is moving in a direction opposite to the direction of the advancing punch card.

As mentioned above, substantially all of the punch card 12 is visible to the operator while the punch card remains in the position of FIG. 1. The operator is thus free to assimilate any information from the punch card which may be needed in further preparation of the same or yet another punch card. At such time as the operator wishes to advance the punch card presently in the visible station to the succeeding work station a release key on the keyboard of the associated data processing and preparation is depressed. The signal generated thereby in turn actuates a solenoid connected to the clutch pawl 82 of FIG. 1 which in turn releases the wrap spring clutch initiating one revolution of the register roll shaft 46. Subsequent positions of the register roll 50, the pusher blade 54 and the punch card 12 are seen in FIGS. 3 through 7 as the punch card is rapidly advanced and finally becomes accurately positioned with respect to the punch station.

In FIG. 3, the register roll 50 has rotated through approximately 30.degree. to a point where the periphery thereof is now in cooperative relationship with respect to the pinch roll 52 so as to drive the punch card 12 toward the punching station. The clockwise rotation of the register roll 50 as indicated in FIG. 3 drives the punch card 12 to the observer's left. At this time the pusher blade 54 has been partially retracted from its most forward position, i.e., the position assumed during final registration of the preceding punch card. Accordingly, the card-cooperating-surface 54a of the pusher blade is now approximately in line with the center line of the register roll shaft 46 and the pinch roll 52.

As the register roll 50 continues to rotate, the punch card 12 advances toward the punching station until as seen in FIG. 4, after the register roll has rotated through approximately 200.degree. from the start position the trailing edge 12A of the punch card passes over the center line connecting the register roll shaft to the pinch roll 52 and thus drops-out of drive relationship with respect thereto. At this point in time the pusher blade 54 is in its fully retracted position.

As seen in FIG. 5, the register roll shaft 46 continues to rotate; however, the trailing edge of the punch card remains stationary, having "dropped-off" the register roll after having passed over the center line bisecting the register roll shaft 46 and the pinch roll 52. After completing some 235.degree. of rotation, the pusher blade 54 moves into contact with the trailing edge of the punch card.

As seen in FIG. 6, at this point in time the leading edge of the punch card 12 has arrived at the punch station and is within approximately one-eighth inch of final registration. To facilitate uninhibited entry of the punch card 12 at the punching station the preferred embodiment of the present invention provides means for separating slightly the index wheel 28 from its cooperating drive position with respect to pinch roller 30. This slight separation between the index wheel 28 and the pinch roll 30 remains until such time as final registration of the punch card 12 has been achieved.

As may be seen in FIG. 7, during the balance of the single revolution of the register roll shaft 46, the pusher blade 54 continues to advance the punch card toward the final registration point at the punching station and at the conclusion of the single revolution this position has been achieved. At this point in time the index wheel 28 is moved into restraining contact with the surface of the punch card 12 and further advancement of the punch card is subject to the control of the indexing mechanism. The indexing mechanism as well as the punching mechanism may take the form of devices well known in the art in that the specific details of the indexing and punching mechanisms form no part of the instant invention.

Before turning to a further analysis of the operation of the subject punch card advancement and positioning mechanism, reference is made to FIG. 16 which discloses an alternative embodiment of the present invention designed to accommodate punch cards of varying lengths and particularly adapted to accommodate the very popular 80 column and 51 column punch cards. For this purpose register roll assembly 43A of FIG. 16 is operatively constructed in the same manner as the corresponding assembly of FIG. 1 while the register roll assembly 43B of FIG. 16 is similarly constructed but operatively differs slightly from assembly 43 of FIG. 1. More specifically, the register roll assembly 43B of FIG. 16 is designed to accommodate 51 column punch cards which, being proportionately shorter than the 80 column variety, necessitates that the register roll assembly 43B be positioned closer to the punch station than the corresponding assembly handling 80 column punch cards in order that final registration of the punch cards can be accommodated in the same manner. In order to insure the capability of accommodating 80 column punch cards in the same system, the register roll assembly 43B must necessarily be displaced further from the feed roll 16 than is the corresponding assembly 43A.

In the alternative embodiment of FIG. 16 the distance between the "drop-off" point of the register roll 50B and the "drop-off" point of feed rolls 16 is less than the length of a 51 column punch card. Thus, when it is desired to feed a 51 column punch card to the punch station it is only necessary to deactivate register roll assembly 43A and permit the entire advancement and positioning function, from the time the punch card leaves the feed roll 16, to be performed by the register roll assembly 43B.

However, as was noted in the explanation of operation of the invention for processing 80 column punch cards a substantial portion of the punch card is advanced through the register roll assembly by means of the feed roll 16 prior to the actuation of the register roll assembly. In that embodiment at such time as the punch card drops off of the feed roll 16 registration of the punch card at the final registration point is achieved through a single revolution of the wrap spring clutch since the length of punch card remaining to be advanced is less than the circumferential contact surface length of the register roll 50. This assures that the trailing edge of the 80 column punch card will dropoff of the register roll 50 prior to the time the pusher blade moves into contact therewith.

Because of the desire to accommodate both 51 column punch cards and 80 column punch cards in the embodiment of the invention depicted in FIG. 16 it is not possible to position the register roll assembly 43B such that the trailing edge of a 51 column punch card will project forward of the center line defined by the register roll 50B and the pinch roll 52B after only a single revolution of the register roll shaft 46B. However, by allowing the shaft 46B of the register roll assembly 43B to complete two revolutions the trailing edge of the 51 column punch card 12 is assured to pass over the center line thereby enabling the pusher blade 54B to complete the accurate positioning of the punch card at the punching station at the conclusion of the second revolution.

The alternative embodiment of the invention disclosed in FIG. 16 is implemented in such a manner that when the unit is being used to process 51 column cards a switch on the keyboard (not shown) is set to indicate this condition whereafter all subsequent operations are effected automatically in accordance therewith. Since in the processing of the 51 column card the 80 column card register roll assembly is not needed it remains unactivated. By reason of the flat 50a on the register roll 50 and the flexure mounting of the pusher blade 54, the 51 column cards may be advanced from the feed roll 16 to the register roll assembly 43B unhindered by the register roll assembly 43A.

Although specifically designed to accomodate 51 column and 80 column punch cards, the embodiment of FIG. 16 with slight alterations could be used to process punch cards of shorter length. Thus, the so called "soap" cards, so designated because of their common usage as a promotional coupon included in a carton of soap powder, could be processed by modifying the embodiment of FIG. 16 to include yet a third register roll assembly to be positioned between the register roll assembly 43B and the indexing assembly comprising the index roll 28 and the pinch roll 30. In such an embodiment it would be necessary to utilize both of the register roll assemblies 43A and 43B to advance the punch card from the feed roll 16 to the newly added register roll assembly. To this end register roll assembly 43A would pick up the soap card from the feed rolls 16 and advance it during the initial portion of its operative cycle to register roll assembly 43B which in turn would advance it during the initial portion of its operative cycle to a position where the newly added register roll assembly could complete the advancement and final registration of the soap card at the work station. It should be noted that by properly timing the operative cycles of both register roll assembly 43B and the newly added register roll assembly with respect to the energization of register roll assembly 43A, it would be possible to ignore the pusher blade registration portion of the operative cycle for the register roll assemblies 43A and 43B thus utilizing the latter assemblies for advancement purposes only.

Another embodiment of the invention similar to that depicted in FIG. 16 includes the provision of photoelectric or other appropriate means to establish the length of a punch card being processed by detecting both the leading and trailing edge and in accordance generates signals to activate one or more of the register roll assemblies as may be required to effect the advancement and registration of a punch card of any predetermined length from the feed roll 16 to the work station. The means needed to implement such recognition equipment including the logic required to generate the necessary control signals should be readily apparent to those having ordinary skill in the art.

Another significant feature of the present invention concerns the control exercised over the pusher blade so as not to cause the card to overshoot its final registration position at the punching station. This could occur were the pusher blade permitted to impact too strongly against the idling punch card when the pusher blade comes forward and picks up the punch card at about 235.degree. of revolution of the shaft 46 as shown in FIG. 5. In order to avoid this situation the surface of the cam 70 is specially configured (See FIGS. 17 and 18) such that as the pusher blade moves forward and across the center line defined by the center of the register roll shaft 46 and the pinch roll 52, the forward velocity of the pusher blade is decreased theoretically to zero, but increases immediately thereafter as the blade picks up the trailing edge of the punch card. Thereafter, the forward speed of the pusher blade reaches a maximum before again being reduced to zero at the final registration point. As seen in FIG. 18 zero forward velocity of the pusher blade is insured by introducing a dwell point on the cams' surface from 230.degree. to 240.degree. as measured from start of rotation of the shaft 46 and another dwell point at 350.degree. to 380.degree. as measured from the start of revolution thereof.

As a further means of insuring that the punch card does not overshoot the final registration position at the punching station, there is provided in the preferred embodiment of the present invention a power actuated punch card aligner which, as seen in FIGS. 1 and 15 comprises an arm 84 pivoted about pivot point 86 by means of a selectively actuated solenoid 88, the other end of the arm being provided with a substantial end section or shoe 90 adapted to move vertically into engagement with the edge of the punch card 12 and urge it against a projecting horizontal stop edge 92 of the back plate 40. In addition to acting as a retarding or braking means for preventing overshooting of the card, the power actuated punch card aligner also serves to insure lateral positioning of the punch card.

Reference is now made to FIGS. 22 and 23. A description of the operation of the subject invention will now be given in terms of the control cycles and sequence of operation defined in these figures. Reference is first made to FIG. 22 which depicts the signals employed in advancing an 80 column punch card from the feed roll 16 through the punching of the final columns thereof. Some 45 clock cycles are shown as being involved in the overall operation from the time of release of the punch card from the feed rolls 16 to the completion of punching of the last columns thereof. It should be stressed that FIG. 22 is only given as an example and as such is not truly representative of the average number of clock cycles required to effect the advancement, positioning, and punching of a punch card since for purposes of this drawing it was assumed that either punching will be effected in all columns or else the indexing system is not capable of selectively advancing the card to desired punch positions only. For purposes of understanding and evaluating the advancement and positioning mechanism constituting the subject of this invention it is unnecessary to consider the subsequent steps involved in indexing and punching and any showing of these steps is intended only for the purpose of putting the overall operation in perspective.

Another point to be made with respect to FIG. 22 is that in the aforementioned description of the subject invention it was mentioned that after the trailing edge of a punch card has dropped off the feed rolls 16 it is discretionary with the operator as to when the punch card is to be further advanced to the punching station; however, in the timing diagram of FIG. 22 there is but a single clock cycle indicated as elapsing between the time the card is dropped off of the feed roll 16 and the time of energization of the register roll assembly 43. Although it is possible to achieve this close sequence of operations it applies to situations in which the transfer of the punch card from the feed station to the punch station advances automatically without the intervention of the operator.

Proceeding now with the explanation of FIG. 22, as the punch card drops off the feed rolls 16 an energize card aligner (ECA) signal is generated causing the power card aligner of FIGS. 1 and 15 to urge the punch card against the stop edge of the back plate 40. The ECA signal will remain "up" until such time as the punch card has advanced to final registration and the indexing system has further clamped the punch card.

One clock cycle after the punch card has dropped off the trailing edge of the feed roll 16 the register roll assembly solenoid is energized by an energize register roll signal (ERR) which results in the movement of clutch pawl 82 so as to release the wrap spring clutch 80 thus initiating a single rotation of the register shaft 46. At this same point in time the index roll 28 is opened under control of a signal (OPR) to prepare for the admission of the advancing punch card. The punch card does not advance by way of the register roll assembly for approximately the first 30.degree. of rotation of the register roll because of the flat section 50a; however, some 20.degree. after initiation of rotation the pusher blade 54 commences its withdrawal movement preparatory to its later advance on the trailing edge of the punch card.

Some two clock cycles after the trailing edge of the punch card drops off the feed roll 16 the register roll 50 contacts the punch card and continues to advance the punch card through approximately two-thirds of that clock cycle until, as was noted with respect to FIG. 4, the punch card passes over the center line of the register rollpinch roll combination.

Approximately three clock cycles after initial drop-out of the punch card from the feed rolls 16 the pusher blade 54 moves into contact position with the edge of the punch card and during the balance of that clock cycle moves the punch card forward into final registration position at which time the index roller 28 is closed and the power card aligner is de-energized. The punch card is now ready for punching and, as is indicated in the preferred embodiment of the present invention, punching is initiated two columns at a time. For this purpose an energize punch signal (EP) is generated. The punching function is followed by indexing under the control of an energize index signal (EI). As discussed hereintofore a dotted line representation has been used to depict successive indexing and punching signals since it is not expected that information will be entered in each of the columns of the 80 column punch card.

FIG. 23 indicates the nature and duration of control signals used in the advancing and positioning of a 51 column punch card and differs from the similar representation for an 80 column card only to reflect the fact that in handling the 51 column card two revolutions of the register roll shaft 46 are permitted in order to bring the trailing edge of the punch card into proper position to permit the pusher blade 54 to complete the final registration of the card at the punch station. Thus, each of the signals ECA, ERR, and OPR are extended an additional three clock cycles. Although the number of clock cycles permitted to effect the additional revolution will vary with the speed of rotation of the shaft 46 as imparted by the wrap spring clutch it is only necessary to permit sufficient time to complete the additional revolution of the shaft. This in turn permits the register roll assembly to effect an overall advancement of the 51 column punch card some 31/2 inches rather than the 11/2 inches of advancement afforded by the register roll assembly operative in conjunction with the 80 column card unit.

It should be noted that the embodiment of the present invention adapted to accomodate cards of variable lengths has been effected at the expense of duplicate hardware, this is not deemed to be an undue limitation when consideration is given to the positional accuracy which is achieved thereby. In this respect it should be noted that alternative arrangements are possible which still retain the spirit of the invention in that rather than duplicating hardware it would be possible to shift a single register roll assembly from position A of FIG. 16 to position B thereof by way of a conventional mechanical slide and clamping arrangement.

While the particular form of the device has been shown and described, it is not intended to limit the scope of the invention to the particular form disclosed herein in that any alternative forms of the device will immediately be evident to those skilled in the art.

Claims

I claim:

1. A feed mechanism for quickly advancing and accurately positioning a punch card being fed from a first station through a visible station to a second station, said first station comprising a feed roll for feeding punch cards one at a time from said first station into said visible station, said visible station comprising a selectively actuated register roll assembly, said second station comprising indexing means operative to engage said punch card after said punch card has been released from said visible station whereby said punch card is brought into final registration with said indexing means, said register roll assembly positioned intermediate said feed roll and said indexing means, said register roll assembly comprising a pressure roll and a pusher blade synchronously driven with respect to said pressure roll, means operatively connected to said pressure roll assembly to selectively initiate the operation thereof, said register roll being so configured and operatively conditioned during the initial portion of each operative cycle such that a substantial portion or said punch card being advanced from said first station to said second station passes said register roll and remains stationary thereat prior to initiation of a cycle of operation of said register roll assembly.

2. A feed mechanism for advancing a card from a supply station along a predefined path into a visible station and thereafter selectively releasing said punch card for advancement to a work station, said work station comprising means for accurately positioning said card, said visible station comprising a card drive roll adjacent said path, drive means for selectively rotating said card drive roll during an operating cycle, the outer periphery of said card drive roll having a portion configured to provide unrestricted clearance for a card during an initial portion of a feed cycle during which said drive means is not rotating said card drive roll, said card drive roll having another portion configured to advance the card along the feed path during a subsequent portion of a feed cycle during which said drive means is operative to rotate said card drive roll, a pusher blade mounted adjacent said card drive roll, said pusher blade being adapted to contact the trailing edge of said card during the terminal portion of a feed cycle, and means operable in synchronism with said card drive roll for advancing said pusher blade to move said card a final increment into accurate position at said work station during said terminal portion of said feed cycle.

3. A feed mechanism constructed in accordance with the principles of claim 2 wherein said pusher blade is operatively connected to a cam, said cam having a surface comprising two dwell points, one of said dwell points imparting a near zero forward velocity component at the point in each operative cycle where said pusher blade comes into contact with the trailing edge of said card and the other of said dwell points imparting another near zero forward velocity component at the point in each operative cycle where registration of the card at said work station is complete.