US3482752A - Apparatus for two-directional feed of perforated tapes - Google Patents

Description

G. VORBA'CH APPARATUS FOR TWO-DIRECTIONAL FEED OF PERFORATED TAPES Filed Jan. 25. 1968 2 Sheets-Sheet 1 ERROR SCANNING DEVICE Dec. 9,

c. VORBACH APPARATUS FOR TWO-DIRECTIONAL FEED OF PERFORATED TAPES Filed Jan. 25, 1968 Fig. 2

2. Sheets-Sheet 2 PERFORATION STAMPING VERTICAL POSITION 0F GEAR 8 FORWARD FEEDING GEAR 8 FORWARD TO REVERSE FEEDING mllllllllllll/lllllll/l,

GEAR 8 REVERSE FEEDING GEAR 8 REVERSE T0 FORWARD FEEDING GEAR 8 MAGNET 23 ARMATURE BLADE 24 United States Patent O 3,482,752 APPARATU FOR TWO-DIRECTIONAL FEED F PERFORATED TAPES Gunther Vorbach, Schloss-Siedlung, Germany, assrgnor to Siemens Aktiengesellschaft Filed Jan. 25, 1968, Ser. No. 700,456 Claims priority, application Germany, Feb. 1, 1967, S 108,115 Int. Cl. B6511 17/40, 43/00 US. Cl. 22651 8 Claims ABSTRACT OF THE DISCLOSURE A tape advancing gear is moved between engaging and disengaging positions with respect to perforated tape. A mechanism shifts the gear back and forth in the forward and reverse directions and the direction of tape feed is determined by the interval during which the gear is engaged and disengaged. The shifting mechanism includes two cams mounted on a drive shaft and transposed with respect to their angular position. The cams act on associated shift levers to coordinate the timing of the forward and reverse movements of the gear with the engagement and disengagement of the gear. One or the other of the two levers is rendered inoperative by a blocking mechanism to determine whether the feed of the tape is in the forward or reverse directions.

BACKGROUND OF THE INVENTION Apparatus have been known in the past which provide two directional feed of perforated tape, however, they have required a great amount of energy for reversing the direction of advancement. Moreover, the reversal takes place quite slowly since two pairs of cams have had to be shifted axially.

Accordingly, it is the object of the invention to provide an advancing mechanism which provides fast feeding of perforation tapes or perforated cards at a speed of about 30 characters per second with great separation accuracy. It is also an object to provide an apparatus which permits a reversal of the direction of advancement with a very low expenditure of energy, within the shortest possible period of time and which permits the reversal to be remotely controlled.

SUMMARY The invention relates to an apparatus for feeding perforation tapes in either a forward or reverse direction and includes a tape advancing gear which is mounted for cyclical engagement and disengagement with the perforations of the tape. A first lever is provided for advancing the tape advancing gear in a forward direction when the tape advancing gear is in engagement with the tape; and a second lever is provided for advancing the tape advancing gear in a forward direction when the tape advancing gear is disengaged from the tape. The tape advancing gear is biased in a direction opposite to the advancement imparted thereto by the levers to return the tape advancing gear after each cycle. The first and second levers are normally biased toward an operative position with respect to the tape advancing gear and facilities are provided for blocking one or the other of the levers to render one of the levers inoperative during each feeding cycle. A drive shaft having two spaced cams which are transposed with respect to their angular position is provided to alternately urge the levers away from said tape advancing gear. Facilities are provided for controlling the b ocking device to determine which of the levers is rendered inoperative and thereby control whether the tape is advanced in a forward or a reverse direction.

DRAWINGS Other objects, advantages and aspects of the invention will become apparent by reference to the following detailed description of the invention and drawings of a specific embodiment thereof, wherein:

FIG. 1 is a perspective view showing an apparatus for two directional feed of a perforated tape in conjunction with a perforation device; and

FIG. 2 is a time-motion diagram showing the relative movement with respect to time of the various mechanical and electrical elements disclosed in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION In FIG. 1 there is schematically shown a perforation device 1 for eight-code perforation tape or corresponding perforation tape cards. The feed system for advancing a tape 33 is controlled by a shaft 2 in association with the various cooperating elements which will hereafter be described in detail.

The shaft 2 is coupled for start-stop operation every one-half revolution (30 milliseconds) by a drive mechanism (not shown) in a counter-clockwise direction (FIG. 1). In order to raise and lower (engage and disengage) a tape advancing gear 8, there is provided a cam 3 mounted on the shaft 2. The cam 3 acts against a roller 4 which is mounted on a rail 7 which rotates around a stationary axis 6. A tension spring 5 normally urges the rail 7 in a counter-clockwise direction (FIG. 1) to urge the tape advancing gear 8 into engagement with the perforations of the tape. The cam 3 is effective to disengage the gear 8 cyclically during the return stroke of the gear.

The tape advancing gear 8 is rotatable around an axis 9 which is also mounted on the rail 7. The upper end portion 8a of the tape advancing gear 8 is controlled by two limit stops 10 and 11. The positioning of the limit stops 10 and 11 can be adjusted by rotation of eccentric supports 36 and 37, respectively. A torsion spring 12 normally urges the tape advancing gear 8 to the right toward limit stop 10, insofar as the gear 8 is not influenced by other forces.

The tape advancing gear 8 includes at its lower end a pressure plate 812 which cooperates with two control levers 14 and 15 mounted on an axis 13. The control levers 14 and 15 are provided with rollers 16 and 17, respectively, which are operated by cams 18 and 19, respectively, affixed to the shaft 2. The earns 18 and 19 are transposed with respect to each other in their angular position and are shaped differently. The control levers 14 and 15 are each biased in a counterclockwise direction (FIG. 1) by tension springs 20 and 21, respectively. When the control levers 14 and 15 are not blocked from engagement with the pressure plate 812, the respective tension springs 20 and 21 are effective to exert a counterclockwise turning moment on the tape advancing gear 8 which is about twice as high as the clockwise turning moment of the torsion spring 12.

The control levers 14 and 15 must be coordinated so that only one or the other is operative at a given time or for a given cycle. In the arrangement shown the control lever 14, when operative, advances the tape 33 in a forward direction, and the control lever 15, when operative, advances the tape 33 in a reverse direction. A double acting magnetic system 23 having an armature 22 and a blade or tongue 24 is effective to render one of the control levers 14 and 15 operative while rendering the other inoperative. The blade 24 is fixedly connected to the armature 22 and is movable between two stationary limit stops 26 and 27 while resting on a support 25. There is also provided a dead center spring 30 on a stationary support 29 which is located in such a way that a connecting line runs between the support and a rotary bolt 28 approximately centered between the limit stops 26 and 27. This provides for a short mechanical switching time of only about 0.5 to 1 millisecond. This short period of time results from the double acting magnetic system which has a very small load.

The control levers 14 and 15 sense the position of the armature blade 24 with their arms (unnumbered) so that in each case one of the control levers can descend while the other supports itself on the blade 24. A set of spring contacts 32 is operated by an additional cam 31 which is mounted on the shaft 2. The spring contact 32 effectuates the energization of the magnet 23 in cooperation with the approaching of the right angle position of the shaft 2. The tension springs 20 and 21 as well as the torsion spring 12 are designed in the enample being described for a tape or card advancing of 100 grams.

The system is designed so that an advancement of the tape in a reverse direction can be rapidly elfectuated. This high speed reversal is very advantageous when combined with an error scanning device 38, of known design. The error scanning device 38 is electrically connected to the spring contacts 32 in order to send a reverse signal to the magnet 23 upon any error in perforation. In this way the error scanning device 38 is operable to reverse the direction of feed in the next perforation cycle after sensing an error.

OPERATION The operation of the device will now be described with reference being made to the time-motion diagram shown in FIG. 2. Approximately 3 milliseconds after the coupling of the perforator shaft 2, the perforation stamping commences (see line a) whereby the perforation tape 33 is grasped at least by a perforator stamp 34 for the perforation feeding. This occurs for a period of 15 milliseconds, i.e., until 18 milliseconds after the initiation of the coupling of the perforator shaft 2. The code perforation stamps are not shown in the drawing for reasons of sim= plicity.

At a point in time at 4 milliseconds the tape advancing gear 8 is withdrawn from the perforations of the tape by the rail 7 and cam 3. The tape advancing gear 8 is reengaged with the perforations of the tape at a point in time at 17 milliseconds. These actions take place in the same manner with every symbol. As shown in FIG. 2, line a represents the perforation stamping motion and line b represents the vertical movement of the tape advancing gear 8.

For continuing the feeding in the forward direction the following conditions exist (see FIG. 2, line In the rest position the tape advancing gear 8 lies against the forward limit stop 11 and is in mesh with the feed perforation; For successive forward feeding, the armature blade 24 lies against the limit stop 27 and the tape advancing gear 8 movement is controlled by the lever 14. The reverse movement of the tape advancing gear 8 below the perforated tape occurs within the time period from to 10 milliseconds until the tape advancing gear 8 lies at the rearward limit stop 10. The advance of the tape commences at milliseconds and ends at 27 milliseconds, the terminal position of the tape advancing gear 8 being determined by the forward limit stop 11.

In order to change the direction of feed from forward to reverse (see FIG. 2, line d) the following occurs. In the rest position the tape advancing gear 8 lies at the forward limit stop 11 in mesh with the tape 33. The armature blade 24 still lies against the limit stop 27 and the control lever 14 has descended and lies at the bottom of the cam 18. The rearward motion of the tape advancing gear 8 below the tape path occurs from 5 to 10 milliseconds. The command to reverse generally occurs beginning with the 0 point in time of the diagram; however at the latest it should occur early enough so that the switching of the armature 22 is possible from a point in time at 5 milliseconds on; it is limited in time (see FIG. 2, line g) by the cam 31 and the spring contacts 32 which are effective to energize the magnet 23 by the winding 23a. However, the armature 22 can only be attracted and shifted if the control lever 14 is on top of the camlii (at 9.4 milliseconds) and releases the blade 24. The dead center spring 30 insured a short switching of the blade 24 which occurs within 0.5 to l millisecond. The control lever 14 is rendered inoperative and the control lever 15 can follow its respective cam 19 within the time period from 11 to 16 milliseconds and can advance the tape advancing gear 8 below the tape path from the rearward limit stop 10 to the forward limit stop 11. The feeding movement in the reverse direction occurs by reason of the force of the torsion spring 12 between the points in time of 20 milliseconds and 27 milliseconds; and the tape advance gear 8 remains at the rearward limit stop 10 in the tape.

If continuous reverse feeding is to occur (see FIG. 2, line a) the following takes place. The tape advancing gear 8 is, in the rest position, at the rearward limit stop 10 and is in mesh with the feed perforation. Upon continuing reverse feeding, the armature blade 24 lies against the limit stop 26 and the tape advance gear 8 movement is controlled by the lever 15. The forward movement below the tape path takes place within the time from 11 milliseconds to 16 milliseconds until the tape advancing gear lies at the forward limit stop 11. The rearward feed occurs between 20 milliseconds and 27 milliseconds until the tape advance gear 8 reaches the limit stop 10.

When the feed direction is to be changed from reverse to forward, (see FIG. 2, line 7) the following occurs. The tape advancing gear 8 lies in its rest position at the rearward limit stop 10 in mesh with the tape 33. The armature blade 24 lies against the right hand limit stop 26 and the control lever 15 is on top of the cam 19. The control lever 14 supports itself on the armature blade 24. When the command feed forward occurs, by reason of the cam 31 and the spring contact 32 at 5 milliseconds, the winding 23b of the magnet 23 is energized and the armature blade 24- switches positions. This occurs if the rollers 16 of the control lever 14 lies on the top of its respective cam 18 at approximately 9.4 in time thereby permitting the armature blade 24 to advance to the limit stop 27. The control lever 15 is thereby prevented from descending and the control lever 14 again takes over the advancement of the tape within the time period from 20 milliseconds to 27 milliseconds. The switching of the armature 22 is shown in line h of FIG. 2.

Particular advantages can be obtained with the aid of the above described apparatus according to the invention by providing the error scanning device 38 for scanning the last perforated row in the adjacent perforation row. The error scanning device 38 is associated with the perforation means 1 for the purpose of supervision. More particularly, it is possible within the framework of the subject apparatus to carry out the supervisory scanning within the range of 2730 milliseconds on the diagram of FIG. 2. In FIG. 2 in line a it is shown in broken lines that the scanning can take place, for example, at 29 milliseconds of the diagram. Upon ascertaining an error, a return command can be emitted by the error scanning device 38 which will lead to the initiation of a reverse feed during the immediately following perforation cycle. Thus, no additional time is needed for the change in the feeding direction.

I claim:

1. Apparatus for two directional feed of perforated tape, which comprises:

a tape advancing gear (8) mounted for engagement and disengagement in the perforations of the tape; means (3, 4, 7) for cyclically engaging and disengaging said gear in said tape perforations;

a first lever (14) for advancing said gear in a forward direction when the gear is in engagement with the tape;

a second lever (15) for advancing said gear in a forward direction when the gear is disengaged from the tape;

means (20, 21) for normally biasing said first and second levers toward an operative position with respect to said gear;

means (24) for blocking one or the other of said levers to render that particular lever inoperative;

a drive shaft (2) having two spaced cams (18, 19) mounted thereon, said cams being transposed with respect to their angular position and said cams being designed to alternately urge said levers away from said gear;

means (12) for biasing said gear in a direction opposite to the advancement imparted thereto by said levers to return said gear after each cycle, said last mentioned biasing means (12) being weaker than the biasing means (20, 21) of said levers; and

means (23) for controlling said blocking means to determine which lever is rendered inoperative and thereby control whether the tape is advanced in a forward or a reverse direction;

whereby rotation of said cams (18, 19) causes one or the other of said levers (14, 15) to advance and then permit retraction of said gear thereby advancing the tape in either a forward or reverse direction depending on whether the gear is engaged in the perforrations when one of said levers advances or is engaged in the perforations when said gear biasing means (12) returns said gear.

2. Apparatus as recited as in claim 1 wherein said lever biasing means (20, 21) comprises tension springs and said gear biasing means (12) comprises a torsion spring having approximately one-half the strentgh of said lever biasing means.

3. Apparatus as recited in claim 1 wherein said means for controlling said blocking means comprises:

an electromagnet (23) having an armature (22), the

of said levers (14, 15) in an inoperative position; and which further comprises:

a dead center spring (30) associated with the free end of said blade to prevent the armature from remaining in an intermediate position; and wherein said electromagnet further includes:

two alternately energizable windings (23a, 23b) for controlling the position of said armature to determine which of said levers is blocked in an inoperative position.

5. Apparatus as recited in claim 1, which further comprises:

a first limit stop (10) for limiting the movement of the gear (8) by said gear biasing means (12); and

a second limit stop (11) for limiting the movement of the gear by said first and second levers 14, 15

6. Apparatus as recited in claim 5 wherein said limit stops (10, 11) are mounted on eccentrics (36, 37) for adjustment of the position thereof.

7. Apparatus as recited in claim 3 wherein said cams (18, 19) and said engaging and disengaging means (3, 4, 7) for said gear (8) are designed so as to provide a pause between the time periods during which said gear is advanced in one direction or the other, during which pause said means (31, 32) for supplying electric pulses to said electromagnet (23), can operate to change the setting of said blocking means (24) thereby reversing the direction of feed of said perforated tape.

8. Apparatus as recited in claim 7 which further comprises:

error scanning means (38) for sensing an error in perforations, said means being connected to said means (32) for supplying electric pulses to said electromagnet and being operable to reverse the direction of feed of the perforated tape during the next succeeding perforation cycle upon the sensing of an error.

References Cited UNITED STATES PATENTS 2,933,931 4/1960 Lisinski.

3,292,832 12/1966 Drillick 22649 X M. HENSON WOOD, JR., Primary Examiner R. A. SCHACHER, Assistant Examiner US. Cl. X.R. 22662

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