US3713571A

US3713571A - Method and apparatus for feeding strip material

Info

Publication number: US3713571A
Application number: US00144427A
Authority: US
Inventors: R Simonton
Original assignee: Dale Products Inc
Current assignee: Dale Products Inc
Priority date: 1971-05-18
Filing date: 1971-05-18
Publication date: 1973-01-30
Anticipated expiration: 1990-01-30

Abstract

The invention is illustrated in apparatus for intermittently feeding strip material having spaced registration mark means along the length thereof and for aligning the strip material in a station receiving the material. The strip of material is intermittently advanced into the station. Adjustable means are provided for regulating the length of advancement. Detecting means are provided to find a registration mark means on the strip material. After movement of the material has ceased the registration mark detecting means is moved relative to the material to enable detection of the actual location of a registration mark The actual location of a detected registration mark is compared with a desired location of the registration mark means and an indication of the difference between the actual and the desired locations is provided. When a difference between the actual and desired locations of a detected mark indicates that an advancement length adjustment is required, the adjustable means is adjusted to change the length of advancement of material. A difference between detected and desired locations which is in excess of a predetermined advancement regulation length may be sensed, and the operation of the advancing means may be interrupted in response to an excess length sensing. The difference between a detected location and a desired location may be classified in one of a plurality of the zones, each zone representing a predetermined range of differences. A predetermined magnitude of adjustment of the feeding stroke may be made in accordance with the zone in which the location differance is classified. Alternatively, an output signal may be provided which is proportional to the difference between a detected location and a desired location of a registration mark, and the adjustable means may be adjusted to change the advancement length of the advancing means in proportion thereto to enable correct advancement of the material into a station. Both reciprocating feeder and roll type or arc movement feeders are illustrated in different embodiments of the invention.

Description

United States Patent 1 Simonton 1 Jan. 30, 1973 i541 METHOD AND APPARATUS FOR FEEDING STRIP MATERIAL [75] Inventor: Robert Ohio [73] Assignee: Dale Products, Inc., Fremont, Ohio [22] Filed: May 18,1971

[21] Appl. No.: 144,427

D. Simonton, Fremont,

[52] US. Cl. ..226/2, 226/32, 226/45, 250/219 DR [51] Int. Cl. ..B65h 23/18 [58] Field of Search....226/2, 32,139,140,141,142, 226/45; 250/219 DR [56] References Cited UNITED STATES PATENTS 3,115,999 12/1963 Wythe ..226/32 UX Primary ExaminerAllen N. Knowles Attorney-Myron E. Click [57] ABSTRACT material. After movement of the material has ceased the registration mark detecting means is moved relative to the material to enable detection of the actual location of a registration mark The actual location of a detected registration mark is compared with a desired location of the registration mark means and an indication of the difference between the actual and the desired locations is provided. When a difference between the actual and desired locations of a detected mark indicates that an advancement length adjustment is required, the adjustable means is adjusted to change the length of advancement of material. A difference between detected and desired locations which is in excess of a predetermined advancement regulation length may be sensed, and the operation of the advancing means may be interrupted in response to an excess length sensing. The difference between a detected location and a desired location may be classified in one of a plurality of the zones, each zone representing a predetermined range of differences. A predetermined magnitude of adjustment of the feeding stroke may be made in accordance with the zone in which the location differance is classified. Alternatively, an output signal may be provided which is proportional to the difference between a detected location and a desired location of a registration mark, and the adjustable means may be adjusted to change the advancement length of the advancing means in proportion thereto to enable correct advancement of the material into a station. Both reciprocating feeder and roll type or are movement feeders are illustrated in different embodiments of the invention.

20 Claims, 14 Drawing Figures m PHOTOCELL CONTROL PATENTEDJMO 197s SHEET 1 [IF JOKPZ OU J EUOFOIQ NMN INVENTOR ROBERT D. SIMONTON ATTORNEY PATENTEUJAMO ms SHEET 2 OF 6 Hill I @MELI HM INVENTOR 'ROBERT D. SIMONTON ATTORNEY PATENTEUJAH 30 I975 SHEET 3 [1F 6 has TIG.13

STOCK ssc SCANNER CONTROL REFERENCE Rsc SCANNER CONTROL INVENTOR ROBERT D. SIMONTON ATTORNEY PATENIEDJAN30I975 3.713.571

SHEET 8 [IF 6 ADO PG} TLW DsI ADJUSTABLE ,PuI sE TRANsI ATOR DIRECTION OsCI LLATOR GATE LOGIC sI ECTION I REXT DECADE 3?; COuNTERs CO I O REXT CC FCG O50 sTART COMMAND FD l FEED {2, R D ONE SHOT O'CORRECTIONO OSCILLATOR GATE -r ROTATION .J-RS

ssC sENsOR r I REFERENCE STOCK RsC-=- sCANNER D52 sCANNER CONT ROI. CONTROL 260 RDCT F D RD REVERSE DIRECTION H FORWARD 294 DIRECTION SELECTION DIRECTION FIG. 14

IHHHHHHFIHN ROTATION sENsOR 282 Q O 274 O 276 278 280 O. 12 4 M FQLBERT QARXSETJIZ ATTORNEY METHOD AND APPARATUS FOR FEEDING STRIP MATERIAL BACKGROUND OF THE INVENTION The present invention relates to devices for accurate, continuous feeding of pre-printed sheet material to a punch press or the like wherein both over feeding and under feeding of the sheet or strip material is detected and automatically compensated therefor.

Intermittent feed devices are commonly used with machines such as punch presses to feed sheet or strip material of metal, plastic, cardboard or the like into position to be punched and formed. When the strip material is printed, such as with labels, advertising, or decorative designs, it is essential, in order that each unit appear uniformly and properly printed, that the feeding equipment be provided with means to assure accurate registration of the printed pattern with the punch at all times. A circular design for a dish or a container, for example, must be precisely centered in successive feeding operations to be a punchpress so as to avoid design irregularities and distortions in the punched product.

Slight variations between design spacing and feed stroke are cumulative through successive feed strokes until a serious out-of-register problem may occur.

Now that more and more printed coils of strip material are increasingly being used on many diversified articles of manufacture, the tolerances required in press operations on such strip are becoming exceedingly close. It follows therefore that slight misfeeds, which were heretofore not of sufficient magnitude to justify correction, now sometimes result in a high incidence of scrap. This problem is particularly acute with long coils of stock where feed variations during the lithographing process may create irregularities in the pattern spacing. Such irregularities may occur at random and, if not compensated for as they occur, will make registration of the patterns with the press dies impossible regardless of the accuracies of the feed of the coil strip into the press. For this reason, an adjustment in the length of feed must be able to be made quickly and automatically, while the machine is in operation, since it is no longer possible to rely on manual adjustments to keep a press in operating adjustment to consistently produce acceptable articles of manufacture from pre-printed coils of strip material.

The printed pattern on the web or strip of material usually repeats at preselected or predetermined intervals along the length of the web. The material is fed into the punch press by a feeding unit which advances the printed web by increments equal to the defined repeat interval of the printing. Ideally, once the position of the printed pattern in the die of the punch press or similar machine is established, it should remain fixed after every feeding stroke because the feeding increment equals the defined repeat pattern of the printed web. However, as a result of inaccuracies in the printing, stretching of the web material, errors in setting up the proper feed length increment, and slight variations in feed length,.position of the pattern relative to the die will not necessarily remain fixed after a number of successive feed strokes. For instance, if the feeding increment is only one one-thousandths of an inch shorter than the defined repeat interval of the printing stock,

then after one thousand feeding strokes to the press, the pattern will be one inch out of registration or position with respect to the die.

Many print registration devices have been used in conjunction with roll feed units. The feed length of the roll feeder was set slightly longer than the repeat interval and, when the registration mark comes under the scanning head, a photoelectric circuit starts a sequence of control events which disengages the feed rolls from the strip material and brakes the advance of the strip. However, the scanning speed is very high because the scanning head is looking for the registration mark while the stock is being fed into the die. Moreover, there is a significant time delay in the control system between the instant the photoelectric eye sees the registration mark and when the printed material actually stops. This is because the control circuit includes ones or more switching means which must operate in order to actuate the electric clutch-brake or air cylinder to stop the material. Possibility for error is not caused by that time delay itself, but by the variations in the time delay. In addition, the feed length is dependent upon sliding friction of the clutch-brake or the air cylinder operated brake. This means that the length being fed then becomes dependent upon moisture, line voltage, friction plate wear, and the like.

In an attempt to improve the feeding adjustment, apparatus has been introduced to the art which scans the stock or strip material after a feed movement, to establish an adjustment in the feeding stroke so that the next pattern fed to the die will be in registration therewith. A roll feed adjustment arrangement is disclosed in US. Pat. NO. 2,821,388, and a reciprocating gripper feeding adjustment is illustrated in US. Pat. No. 3,289,507. Both devices scan the stock after the stock has stopped moving, but both use a plurality of stationary photoelectric sensing means for scanning a plurality of different spots on a stock in search for a registration mark. While the above noted systems were an advance over the prior art methods of adjustment, a substantial number of photocells are required for scanning a suitable length of the strip, and a measurement to provide a signal which is directly proportional to displacement from a desired position for a pattern, or to provide anexact location of a detected registration mark is impossible. Moreover, neither of the above systems can tell the difference between a mark which is in registration, that is, located between the two spaced areas which are being monitored by photoelectric sensing elements, and a mark that is completely out of the detection zone.

Accordingly, it is an object of this invention to provide an improved method and apparatus for feeding strip material to a station for operation thereon and for aligning the strip material precisely in the operation station.

It is a further object of this invention to provide an improved method and apparatus for automatically adjusting the increment of feed of a strip feeder by utilizing movable scanning means which enables finding an exact location of a registration mark or a pattern and thus enables much closer control, whether zone correction is utilized or whether directly proportional correction is utilized.

It is a still further object of this invention to provide an improved method and apparatus for incrementally feeding strip material which can detect the difference between a mark in a detection zone and a mark completely out of the detection zone, and to interrupt operation of the apparatus to afford a correction of the cause of the mark being completely out of the zone before a substantial amount of strip material is junked.

Still another object of this invention is to provide a method and apparatus for feeding strip material which, because of the movable scanning method, does not require that registration marks for aligning a pattern printed thereon in an operation station be spaced identical intervals apart.

SUMMARY OF THE INVENTION In carrying out the above objects, the invention is illustrated in two embodiments of systems for automatically adjusting the incremental feed length of strip material. In a first system a reciprocating feeder device is operable to move the strip material into the work piece forming means so that a pre-printed pattern is in registration to permit the forming of a work piece therefrom. The feeder device has a reciprocating gripper means for engaging the material and moving the material an amount equal to the distance between successive patterns on the material. Spaced forward and rear stop means are provided for limiting movement of the gripper means. Means are provided for detecting the actual location of a pre-printed pattern on the material. After completion of a forward or material advancing stroke of the gripper means, motion is imparted to the detecting means relative to the strip of material to enable detection of the actual location of the pre-printed pattern. The actual location of the detected pre-printed pattern is compared with a desired location of the pattern and an indication is provided of the difference between the actual and the desired location. If the actual location of a pre-printed pattern is too far from a desired location for the pattern, an indication may be so made by the system and the operation of the apparatus interrupted.

Adjustable means are provided for moving one of the stop means to adjust the length of the strokes of the gripper means. Means responsive to the comparing means adjusts the adjustable means when a difference between actual and desired location of a pre-printed pattern indicates that a stroke length adjustment is required. A first member or element of the adjustable means carries one of the stop means, and a second adjustable element is positioned adjacent the first element. The first and second elements have cooperating inclined plane surfaces formed thereon so that movement of the second element causes movement of the first element to adjust the relative position of the stop means carried thereby.

The motion imparting means advantageously includes means for providing movement of the detecting head substantially parallel to the feed direction of the material. The comparing means includes means for providing an indication of a reference position of the detecting head as it moves along the material, the reference position representing the desired location of a pre-printed pattern. The comparing means provides a first signal when the detecting means is on a first side of the desired location of a pattern, and also provides a second signal when the detecting means is on a second side of a desired location of the pattern. The first and second signals and a signal from the detecting means is utilized to determine the direction of the actual location of a pattern from a desired location therefor.

In a second embodiment of the invention the apparatus for advancing strip material into a press or the like includes means operable to engage and advance the strip material into the work piece forming means so that a pre-printed pattern is in registration therewith. Means are provided for intermittently moving the strip engaging portion of the advancing means through an arc to advance successive pre-printed patterns into the work piece forming means. As was noted hereinbefore with respect to the first embodiment, after completion of an intermittent movement of the advancing means and the cessation of movement of the strip material, motion is imparted to a detecting head relative to the strip of material to enable detection of the actual location of the pre-printed pattern. The actual location is compared with a desired location and a signal is provided indicating the difference between the actual and desired locations.

The material advancing means in the second embodiment advantageously includes roll means for engaging the material. The intermittent movement means advantageously includes means for intermittently rotating the roll means through an arc, such as a ratchet mechanism.

In the second embodiment the comparing means includes means for providing a reference signal when the detecting means should be locating the pre-printed pattern at a desired location. The detecting means includes means for providing a located signal when the pattern is actually located. The difference between the time of occurrence of a reference signal and a located signal provides a measure of the distance of registration error. Adjustable means are provided for regulating the length of the arc of movement of the advancing means. The occurrence of one of t the reference or located signals initiates adjustment of the adjustable means. The occurrence of the other of the reference and located signals interrupts operation of the adjusting means.

Other objects, advantages and features of this invention will become apparent when the following description is taken in conjunction with the accompanying drawings, in which: why

FIG. 1 is a side elevational view of a first embodiment of the teachings of this invention;

FIG. 2 is a plan view of the apparatus illustrated in FIG. 1;

FIG. 3 is an enlarged, more detailed plan view of the apparatus for adjusting the feed length of the machine illustrated in FIG. 1;

FIG. 4 is a cross-sectional view of the apparatus illustrated in FIG. 3 taken along lines IVIV;

FIG. 5 is an enlarged, more detailed plan view of the scanning mechanism which is illustrated diagrammatically in FIGS. 1 and 2;

FIG. 6 is an enlarged plan view of a fixed and movable shutter arrangement utilized in the scanning apparatus of FIG. 5;

FIG. 7 is a cross-sectional view taken along lines VIIVII of the shutter illustrated in FIG. 6;

FIG. 8 is a cross-sectional view taken along lines VIII-VIII of the shutters of FIG. 6;

FIG. 9 is a cross-sectional view taken along lines IXIX of the shutters illustrated in FIG. 6;

FIGS. 10 and 11 are schematic control circuits for the apparatus illustrated in FIGS. 1 and 2, the circuits being laid out in line diagram form;

FIG. 12 is a diagrammatic side elevational view of apparatus illustrating a second embodiment of the teachings of this invention;

FIG. 13 is a plan view of apparatus for scanning strip material being fed through the feeder illustrated in FIG. 12; and

FIG. 14 is a block diagram illustration of a control circuit useful with the apparatus illustrated in FIGS. 12 and 13.

PREFERRED EMBODIMENTS OF THE INVENTION Referring to FIGS. 1 and 2 there is illustrated a reciprocating strip feeder generally indicated at 70. A roller and guide means 72 at the left or rear of the feeder supports and guides strip material from the rear or the left of the machine toward a holddown bar 74 at the right or forward portion of the machine. Guide rollers 76 beneath the bar 74 guide the directional feed of the strip material. The material is passed through a reciprocating gripper clamp assembly 78 mounted for reciprocation on slide rails 80. An air cylinder rod 82 extends from an air cylinder arrangement, not shown, and reciprocates the assembly 78 in response to the switching of a pressurized air supply between input of a standard air cylinder. A forward stop wall 84 limits the forward movement of the assembly 78 and a rear stop button 86 is provided on the assembly 78. A holding clamp means 88 is operable to clamp and hold the strip material after the material has been advanced by the reciprocating assembly 78 and releases its engagement with the strip to return to the position shown in FIG. 2.

A stroke length adjustment assembly is indicated generally at 100 in FIG. 2 and is illustrated in more detail in FIGS. 3 and 4. A manually adjusted stop or limit member 102 is externally threaded to be received by an internally threaded aperture formed in a wedge member 104. The position of the stop 102 may be manually adjusted and locked into a desired position by the tightening of the position locking nut 106. The wedge member 104 is movable back and forth in the direction of feed and is held between guideblocks 108 which has ways or grooves 110 formed in the opposing faces of the blocks 108 to receive tongues 112 projecting laterally from the wedge 104.

Springs 114 are positioned between the lower part of wedge 104, below the limit member 102, and a spring support plate 116. The springs 114 yieldingly urge the wedge 104 rearwardly toward and against a wedge member 118. An inclined plane surface 120 is formed on wedge 104 which abuts against and cooperates with an inclined plane surface 122 formed on wedge member 118. Thus when wedge 118 moves laterally back and forth there is a corresponding movement of wedge 104 back and forth in the feed direction.

An upper shaft 124, best seen in FIG. 3, is journally supported in bearing blocks 126 and 128 attached to a frame plate 130. The upper shaft 124 has an externally threaded land 132 which cooperates with an internally threaded nut or member 134 secured to wedge member 118. Rotation of shaft 124 in one direction will traverse wedge 1 18 to the left, while rotation of shaft 124 in the opposite direction will traverse wedge 118 to the right.

Collars

136 and 138 on each side of the bearing block 126 restrain the shaft 124 against lateral movement. A long feed correction gear 140 is secured to one end of the shaft 124, and a short feed" correction timing pulley 142 is secured to the other end of the shaft 124.

Referring now to FIG. 4, a lower shaft 144 is journally supported in spaced bearing blocks 146, 148, 150, 152 and 154 secured to the underside of the frame plate 130. A motor is connected to rotate the shaft 144 constantly via a gear reducer 156 having an output shaft 158 carrying a driving pulley 160. The pulley 160 is connected to a driven pulley 162 on the shaft 144 by a timing belt 164.

An electric clutch assembly LEC on shaft 144 has an output gear 166 meshed with gear 140 on the upper shaft 124. An electric clutch assembly SEC on shaft 144 has an output timing pulley 168 which is connected to drive the timing pulley 142 on the upper shaft 124 via a timing belt 170. When the clutch LEC is energized, gear 166 is connected to the constantly running shaft 144 and drives the gear 140 to rotate the upper shaft 124 in a first direction. When the clutch assembly SEC is energized, pulley 168 is connected to the constantly running shaft 144 to drive the timing pulley 142 to rotate the upper shaft 124 in a second direction. Therefore, the wedge member 118 will be moved laterally in a direction dependent upon whether the gear 140 or the timing pulley 142 is being driven.

An electrically operated one-revolution scanning clutch SC is carried on the shaft 144 and is operable to rotate an eccentric cam 172 and a proximity cam as sembly 174 in response to energization. A proximity switch PX is responsive to rotation of the proximity can 174 to gate signals from the scanning assembly only on the forward stroke of the scanning assembly.

A scanning assembly is diagrammatically shown in FIGS. 1 and 2, and is shown in enlarged detail in FIG. 5. A scanning head 182is positioned for movement in a direction parallel to the feed direction of and above the strip stock, although a similar arrangement may .be used to scan the underside of the stock. When a registration mark is detected a light signal is transmitted via a fiber optic cable 184 to a photocell control unit PC (shown in FIG. 1). The position of the scanning head 182 may be adjusted relative to a reference scanning arrangement, by rotation of a knurled adjusting nut 186 which causes movement of a threaded shaft in the nut 186, the shaft 188 being journally carried in a scanning head support member 190. Movement of the shaft 188 back and forth through the adjusting nut 186 moves the scanning head 182 back and forth on slide guides 192.

A support bar 193 extends from head support member 186 to a reference head support block 194. The block 194 is mounted on a shaft support means 196 slidably carried in a frame support member 198.

Although only one shaft 196 has been shown for purposes of clarity, there may be several arrangements in which the block 194 is supported in an upright position to maintain the head 182 a required distance above the stock. For example, two shafts may be utilized, a rectangular or noncircular shaft may be used, or a tongue and groove arrangement may be utilized to maintain the reference head support block 194 in an upright position.

A spring 200 is mounted between frame support member 198 and an adjustable collar 202 fixedly secured on shaft 196 by a set screw 204, and urges a scanner cam follower 206 against the end of a pushrod 208. The cam follower 206 may be screwed on shaft 196 to permit adjustment of the position of the scanning mechanism with respect to the pushrod 208.

A reference position indicating means 210 is carried on the reference head support block 194 and includes a fixed shutter 212 and a movable shutter 214 (best shown in FIGS. 6 through 9). The shutter 212 is secured to a frame support member 216 by bolts 218 extending through an elongated slot 220, the slot enabling adjustment of the fixed shutter parallel to the feed direction. The shutter 212 has a pair of laterally aligned

apertures

222 and 224 for receiving a pair of light transmitting fiber optic cables 226 connected to the photocell control PC.

The movable shutter 214 has a forward aperture 228 and a rearwardly spaced aperture 230 positioned to successively register with

apertures

222 and 224, respectively. When aperture 228 is in registration with aperture 222 of the fixed shutter, the aperture 230 of the movable shutter is spaced rearwardly a distance which'defines a tolerance zone or a reference zone in which the registration mark on the stock may be located without requiring adjustment of the feed length of the feeding apparatus 70. Each of the

apertures

228, 230 is connected by light transmitting cables 232 to the photocell control unit PC.

Thus, if a registration mark on the stock is picked up by the scanning head 182 when the

apertures

222, 228 of the

shutters

212, 214 are in registration, the photocell control circuit PC gates the signal from scanning head 182 to a PCS relay indicating that the preceding feed stroke has been too short. If a registration mark on the stock is picked up while the

apertures

228, 230 of the movable shutter 214 are straddling or on each side of the laterally aligned

apertures

222, 224 of the fixed shutter 212, a signal from the head 182 is gated to the PCM relay by the photocell control PC, indicating that the registration mark of the stock is located within an allowable tolerance zone. If a registration mark is picked up by the scanning head 184 when the aperture 230 is in registration with the aperture 224, the photocell control PC gates a signal to energize relay PCL indicating that the preceding feed stroke was too long.

The push rod 208 is slidably carried in a frame support member 234 and has a cam follower assembly 236, on the end thereof remote from the scanning assembly, which is riding against and responsive to movement of the eccentric cam 172. Rotation of the eccentric cam 172 for one revolution causes a forward and rearward scanning motion or stroke of the rod 208, the scanning head 182, and the movable shutter 214.

Referring to FIGS 10 and 11 there are illustrated circuits for controlling the embodiment of this invention illustrated in FIGS. 1 through 9.

It will be noted that the circuits have been laid out in line diagram form. The components can be readily located by reference to the line number where the component is positioned. Further, contact switching operations may normally be noted without designating a mechanical tie between the contacts and the actuating means for the contacts. Thus the contacts may be located at any convenient position, even though quite remote from their actuating means. Cross reference between the actuating means and its associated contacts is easily accomplished by noting in the right hand margin of the drawing the reference character of the actuating means, for example relay CR1 adjacent line number 21 in FIG. 10, the line in which the contact ac tuating relay coil CR1 is located for energization. Fol lowing the reference character CR1 the line numbers in which the CR1 contacts appear are noted, i.e., 22, 23, 25, 26, 27, 53. A contact line number notation that is not underlined indicates that those contacts are normally open, as in line 22. A contact line number notation that is underlined indicates that those contacts are normally closed, i.e. as in line 23. Other actuating means and their associated contacts are similarly noted.

A limit switch LS1 having LS1 contacts in line 21 of FIG. 10 is responsive to the position of a press flywheel. The contacts LS1 open on the top 180 of the flywheel stroke when the punch is lifting to signal that the feeder apparatus may feed a length of strip material to the press. Opening of the LS1 contacts deenergizes the press stroke counter relay CR1 and line 21.

When relay CR1 is deenergized, CR1 front contacts in line 53 open to signal to the feeder control FC that the connections between the ports of the air cylinder should be reversed to move the piston rod 82 forwardly to advance material into the press. CR1 front contacts open in line 22 and CR1 back contacts close in line 23 to deenergize and energize two terminals of a counter CTR.

The counter CTR includes relay LU and flip flop circuits IFF and 2FF. The counter CTR counts to three for the three strokes of the press which have been utilized to set up the control cycle. Although the control circuit herein may effect the same type of control on a single stroke of the press, this embodiment is chosen to illustrate that patterns are printed on a printing press which may imprint a plurality of patterns per revolution of the impression coil. Therefore, it is assumed that there will be no substantial error in the spacing of the plurality of patterns, in this instance three, since the printing roll and printing stock should stay in registration for a single revolution. Therefore, there should be no substantial error for three strokes of the press and the control circuit has accordingly been set up to reduce the number of operations performed by the control and adjustment mechanisms to reduce the number of corrections required and thus reduce the wear on the control unit.

The press relay CR1 contacts in lines 25, 26, and 27 have been connected in a circuit with flip flop contacts lFF and 2FF of the counter CTR to separate the top and bottom halves of the press stroke into a repetitive six step sequence. Back contacts CR1 in line 51 close at the beginning of every feed stroke of the assembly 78, to enable an energization circuit for the correction time delay relay TDR2. Back contacts CR1 in line 51 open at the beginning of every return stroke of the assembly 78 to reset the time delay relay TDR2 if it has been previously energized.

Let us now assume that a forward feed stroke of the reciprocating gripper assembly 78 has been completed, and we are ready to start the control sequence. Limit switch contacts LS1 close in line 21 to energize press stroke counter relay CR1. Front contacts CR1 close in line 53 of FIG. 11 to signal to the feeder control FC that the connections to the ports of the air cylinder should be reversed to return the piston rod 82 and the assembly 78 to the position shown in FIGS. 1 and 2.

Closure of CR1 front contacts in line 25 supplies a voltage through closed back contacts 2FF, closed back contacts lFF, and closed back contacts RR2, all in line 25, to energize the one-revolution scan clutch SC in line 41 through time delay relay back contacts TDRl in the same line. Thus, rotation of the eccentric cam 172 and the proximity cam assembly 174 is initiated. The proximity cam 174 closes contacts in the proximity switch control in line 42 to supply voltage to energize the forward scan stroke relay RR4 during the forward portion of the stroke of the push rod 208. The forward stroke relay front contacts RR4 close in line 35 to enable or gate the photo sensing circuit for short feed or long feed signals in lines 35 and 36. Front contacts RR4 also close in line 39 to enable or gate the photocell middle or within tolerance zone sensing by relay output contacts PCM.

Voltage is also being supplied at this time through back contacts 2FF and IFF in line 25 to energize a start scan relay RRl in line 40. Front contacts RRl close in line 54 to illuminate a scan light to indicate that a scan is in process. Back contacts RRl open in line 62 to deenergize the time delay relay TDRl and initiate the timing period which must expire before the TDRl contacts in line 41 drop out. After a preset delay the TDRl contacts open in line 41 to deenergize or disable the energization circuit for the scanning clutch SC in line 41.

If a registration mark on the stock is picked up by the scanning head 182 when the aperture 228 is in registration with the aperture 222 of the fixed shutter plate 212, the length of the previous feed stroke was too short and the photocell control PC gates a signal to energize the PCS relay to close contacts PCS in line 35, energizing the short feed relay RRS in that line. Back contacts RRS open in line 36 to disable the long feed sensing circuit. Front contacts RRS close in line 37 to apply an energizing voltage to a latching coil L of a short feed latching relay LRS. Front contacts RRS also close in line 61 to illuminate a lamp indicating that the feed was too short.

The energization of the short feed latching relay LRS in line 37 closes front contacts LRS in line 29 to enable the circuit for energizing the short feed correction electric clutch SEC. The electric clutch SEC in FIG. 4 may thus be energized upon closure of the insert correction relay contacts RR2 in line 28 during the succeeding feed stroke of assembly 78 to drive the timing pulley 142 and rotate upper shaft 124 to move the wedge member 118 to the left in FIG. 3 to adjust the position of the wedge member 104, and thus the position of the adjustable stop 102.

Front contacts LRS also close in line 52 to enable the energization circuit for the correction timer relay TDR2. When CR1 back contacts close in line 51 during a feed stroke the relay TDR2, after a present interval, will drop out back contacts TDR2 in line 28 to terminate the correction movement of wedge member 1 18, and close front contacts TDR2 in line 33 to enable an energization circuit for the unlatching coil of the LRS relay. But, since RR3 contacts are not closed at this time, nothing happens.

LRS front contacts also close in line 30 to enable an energization circuit to the long feed electric clutch in line 28 to enable the correction being inserted to be removed after the next incremental feeding by the feeder apparatus 70. LRS back contacts open in line 38 to disable the energization circuit for the latching coil L of the long feed latching relay LRL. LRS front contacts close in line 57 to provide a pulse to a too short counter TSC. Back contacts LRS open in line 59 to disable the energization circuit for the press interlock relay PSR.

1f the registration mark on the stock is picked up when the

apertures

228 and 230 of the movable shutter 214 are straddling the

apertures

222, 224 of the fixed shutter 212, the photocell control unit PC receives no gating signal to direct energization of the short feed relay PCS or the long feed relay PCL. Thus the signal picked up is utilized to energize the within tolerance zone relay PCM and close PCM contacts in line 39.

Closure of the front contacts PCM in line 39 energizes the latching coil L of the normal feed latching relay LRM in line 39 through the RR4 contacts which were closed by the proximity switch. LRM front contacts close in line 55 to provide a pulse to a within tolerance counter OKC. LRM back contacts open in line 59 to disable an energizing circuit for the press interlock relay PSR in line 58.

If a registration mark has been picked up by the scanning head 182 and is not gated by the movable shutter 214 to energize either the short feed photocell output relay PCS or the long feed photocell output relay PCL, then the back contacts LRS and LRM in line 59 remain closed. However, if no mark was picked up in the within tolerance zone then the PCM contacts would not have closed closed in line 39 to energize the normal feed latching relay LRM and open back contacts LRM in line 59. Thus, when the insert correction relay RR2 is energized in line 26, closure of RR2 front contacts in line 59 would energize the press interlock relay PSR in line 58. Front contacts PSR would close in line 58 to establish a holding circuit, and press relay interlock back contacts PSR would open in line 63 to shut down the press and the feeder apparatus until it is determined why a registration mark was not picked up during the entire scan. This shut down will be maintained until the pushbutton contacts P81 in line 58 are opened to deactivate the holding circuit through the PSR contacts in line 58.

If the registration mark on the stock is picked up when the aperture 230 is aligned with aperture 224, the length of the feed was too long and the photocell control PC energizes long feed relay PCL to close PCL contacts in line 36. Closure of the PCL contacts energizes the long feed relay RRL in line 36. Back contacts RRL open in line 35 to disable the short feed sensing circuit. Front contacts RRl close in line 60 to illuminate the long feed" lamp. Front contacts RRL in line 38 close to energize the latching coil L of the long feed latching relay coil LRL.

Long feed latching relay front contacts LRL close in line 28 to enable the energization circuit for the long feed electric clutch LEC. When the insert correction relay RR2 in line 26 is energized on a succeeding feed stroke of the assembly 78, the RR2 front contacts close in line 28 to energize the long feed electric clutch and connect gear 166 to the rotating shaft 144. The gear 166 drives the gear 140 on the upper shaft 124 to rotate the shaft 124 in a direction which causes movement of the wedge member 118 away from the gear 140. Wedge member 104 is urged forwardly and thus reduces the length of the stroke of the reciprocating gripper mechanism on its next forward stroke.

Front contacts LRL in line 31 close to enable an energization circuit to the short feed electric clutch SEC in line 29 to enable the correction inserted for the next feed stroke to be removed after that feed stroke is completed by closure of the takeout correction relay contacts RR3 in line 30.

LRL back contacts in line37 open to disable the energization circuit for the short feed latching relay LRS. LRL contacts close in line 51 to enable the energization circuit for the time delay relay TDR2 in line 28 to control the time of energization of the long feed electric clutch LEC as described hereinbefore with respect to the clutch SEC. LRL contacts also close in line 56 to provide a pulse to the long feed counter TLC. Back contacts LRL open in line 59 to prevent energization of the press interlock relay PSR.

The corrections are initiated during the feeding stroke of the clamping assembly 78, which follows the return stroke thereof during which the scanning was accomplished. The counter CTR has been stepped by the operation of CR1 contacts so that the back contacts 2FF in line 25 remain closed, but the back contacts lFF in line 25 have been opened. Therefore the scan relay RRl, the scan clutch SC, and the proximity relay RR4 cannot be energized. However, front contacts lFF in line 26 are now closed to enable the energization of the insert correction relay RR2 through closed back contacts CR1 of the press counter relay in line 26.

Energization .of the insert correction relay RR2 opens back contacts RR2 in line 25 to disable the energization circuit for the one-revolution scan clutch SC in line 41, the energization circuit for the proximity switch, and the forward feed stroke relay RR4 in line 42. Front contacts RR2 close in line 28 to enable energization of either the long feed electric clutch LEC in line 28 or the short feed correction clutch SEC in line 29, depending upon whether a correction is needed and, if a correction is needed, in which direction the correction is to be applied. Front contacts RR2 also close in line 59 to enable the no mark" sensing circuit to be energized ifa mark has not been picked up by the scanning head 182. The time delay relay TDR2 times out and opens back contacts TDR2 in line 28 to terminate the energization period for the clutches LEC and SEC.

When the counter has been stepped so that the back contacts 2FF in lines 25 and 27 are reversed from that position shown in FIG. 10, the closure of the CR1 back contacts in line 27 energizes the takeout correction relay RR3. This occurs during the second feed stroke of the assembly 78 in the control cycle. Front contacts RR3 close in line 30 to enable the energization of either the long feed electric clutch LEC or the short feed electric clutch SEC in

lines

28 and 29, if a correction was made during the correction step of the sequence. Closure of RR3 front contacts in line 30 also applies a reset or unlatching voltage to the normal feed latching relay section in line 32. Front contacts RR3 also close in line 33 to enable application of a reset or unlatching voltage to the short feed and long feed latching relay sections LRS and LRL in

lines

33 and 34, when the time delay relay TDR2 times out and contacts TDR2 in line 33 close.

During the last return and feed strokes of the assembly 78 during the control cycle, no correction is attempted since the third pattern is now being fed to the press and no correction is desired. This six step sequence is repeated for every three strokes of the press which is being fed by the reciprocating feeding apparatus 70.

Referring now to FIGS. 12, 13, and 14, there is shown a second embodiment of the teachings of this invention. In FIG. 12 a roll feed adjustment assembly is indicated at 250 and may be secured to the end of a crank shaft of a press for rotation therewith. A pin 256 is adjustably secured to a circular crank block or base mounting plate 258 to receive thereon the yoke portion 260 of a connecting rod 262. The connecting rod has been partially broken away to enable a clearer showing of the means for adjusting the position of the pin 256. The lower end 264 of the connecting rod is pivotally secured to an extended arm portion 266 of a bell crank 268. The other arm 270 of the bell crank 268 is pivotally secured to a trammel bar 272 which pivotally connects a pair of feed rolls 274 and 276 through ratchet

arms

278 and 280 to intermittently rotate these rolls.

Arms

278 and 280 are mounted on ratchet means (not shown) of any suitable construction so as to intermittently rotate the rolls 274 and 276 in one direction only, namely the direction of the feed of stock S to a press. A pair of

upper rolls

282 and 284 are positioned above adjacent lower rolls 274 and 276, respectively, to grip the stock S therebetween and assist in advancing stock between the punch and the die of a press.

The pin 256 is rigidly secured to a non-rotatable nut 292 threaded onto a rotatable shaft 294 joumaled at 296 on one end thereof in crank block 258 and connected at the other end thereof to a stepping motor SM2. The stepping motor SM2 is connected in a recessed portion 298 of the crank block 258 by bolts 300. Energization of the stepping motor SM2 will rotate the threaded shaft 294 and traverse the nonrotatable nut 292 radially with respect to the axis of the press crank shaft. A suitable switching means, such as the rotation sensor RS, is provided to enable enrgization of the stepping motor SM2 and a scanning motor SMl only after the stock material S has come to a rest at its forwardmost position, this period occurring when the

ratchet arms

278 and 280 are passing through the return stroke prior to advancing the material another increment.

Referring to FIG. 13 there is shown a means for scanning the position of the stock S after it has come to rest. Registration marks on the stock S are indicated at 310. A stock scanning head assembly 312 is carried on a reciprocable scan support structure 314 and is connected to a stock scanner control SSC by a light transmissive cable 316.

A reference mark or indicia 320 is formed on the machine frame or other member 322 which is in a fixed position with respect to the press and the scanning assembly. A reference scanning head 324 is also carried on the reciprocable scanning support 314 and is connected to a reference scanner control RSC by a light transmitting cable 326.

A pinion 328 is mounted for rotation by the shaft of a stepping motor SM1, and is meshed with a rack 330 formed on the reciprocable support structure 314. Thus, when the shaft of the stepping motor SM1 rotates clockwise, support 314 moves forward. When the shaft of the motor SM1 is rotated counterclockwise, the support 314 is moved.to the rear. Any suitable means may be used for slidably supporting structure 314 for reciprocable movement substantially parallel to the direction of the feed of the stock S.

Referring to FIG. 14 there is shown in block diagram form a control circuit suitable for use with the apparatus illustrated in FIGS. 12 and 13. The stepping motors SM1 and SM2 are commercially available motors and are available along with control components which may be connected thereto.

Depending upon the angular movement of a stepping motor which is desired, the correct count is preset on a decade counter control DEC for the stepping motor SM1 which is to advance the scanning head assemblies. A command signal in the form of a switch closure may be provided by a rotation sensor RS as a start command to the control gate CG. Gate circuits in the control gate CG enables the pulse gate PG to pass pulses from an adjustable oscillator ADO to a translator logic circuit TL. The translator logic circuit TL converts the pulses into the switching sequence needed to advance the motor shaft of the stepping motor SM1 in steps. When the count is completed the control gate CG turns off the pulse gate PG and actuates an external relay REXT.

Closure of REXT contacts energizes a one-shot oscillator OS and provides a second start command to the control gate CG. Closure of external relay contacts REXT in the direction selection circuit DSl reverses the application of the new series of pulses now being applied to the stepping motor SM1 so that the stepping motor SM1 rotates in a reverse direction to bring the

scanning head assemblies

312, 324 back to the starting position. When the stepping motor SM1 has returned to its starting position the control again turns off the pulse gate and deactuates or deenergizes the external relay REXT.

When the stock scanning head assembly 312 sees a registration mark 310 a signal is provided to the stock scanner control SSC. Similarly, when the reference scanner head 324 sees the reference mark 320 a signal is provided to the reference scanner control RSC. If the stock scanner control SSC receives a signal before the reference scanner control, the correction should be in the forward direction and a forward direction control unit FDC receives a signal which energizes forward direction relay FD. Back contacts FD between the reference scanner control and the feed correction gate FCG are opened to disable the gating circuit from the reference scanner control. Front contacts FD between the stock scanner control SSC and the feed correction gate are closed to complete a gating circuit to the feed correction gate FCG. Therefore pulses which are being supplied from the translator logic circuit TL to the scanning assembly stepping motor SM1 now are also supplied through external relay REXT back contacts, the feed correction gate FCG and a direction selection unit DS2 to the stepping motor SM2. The motor SM2 radially adjusts the position of the pin 256 on the crank block 258. The selection of the direction is connected from the forward direction control through back contacts RD to the direction selection unit DS2.

When the reference scanner head assembly 324 picks up the reference mark 320, an output is provided to the reverse direction control RDC to energize the reverse direction relay RD. No reverse direction signal can be forwarded from the reverse direction control unit RDC to the direction selection unit DS2, however, since the FD back contacts therebetween are opened because of the previous energization of the forward direction relay FD. However, energization of the reverse direction relay RD opens back contacts RD between thestock scanner control SSC and the feed correction gates FCG to terminate the delivery of pulses from the translator logic TL through the feed correction gate FCG to the stepping motor SM2. The stepping motor SM2 has thus adjusted the position of pin 256 an amount proportional to the time of the occurrence between a signal from the stock scanning assembly head 312 and the later occurrence of the signal from the reference scanner head 324.

When the stepping motor SM1 is being stepped in the reverse direction to return the scanning head assemblies to the starting point, application of pulses to the stepping motor SM2 is prevented by the opening of the REXT back contacts between the translator logic circuit TL and the feed correction gate FCG.

Similarly, when the reference head assembly 324 sees the reference mark or indicia 320 before a stock registration mark is picked up by the stock scanner head 312, a signal is provided from the reference scanner control. RSC to energize the reverse direction circuit RDC to energize the reverse direction relay RD. A signal is provided from the reverse direction control circuit to the direction selection circuit DS2 so that the stepping motor SM2 has reverse winding energized to cause rotation in the reverse direction. Closure of RD front contacts between the reference scanner control RSC and the feed correction gate FCG enables application of pulses from the translator logic circuit TL to the stepping motor SM2 to correct the stroke length.

If a registration mark is not picked up by the stock scanning head during its travel, then a no mark signal may be generated in the manner set forth for the first embodiment described herein, and the operation of the arc feeder apparatus and/or press or the like may be interrupted.

The roll or arc movement advancing means has been disclosed in combination with means for effecting a directly proportional adjustment of a succeeding stroke. The reciprocating gripper means has been disclosed in combination with means for effecting a zone type of stroke adjustment. However, it should be noted that arc movement advancing means could be controlled with zone detection and adjustment, while the reciprocating feeder could be adjusted an amount directly proportional to the error distance of the registration mark, both in accordance with the teachings of this invention. For example, one or more stepping motors could control the lateral movement of the wedge member 118. Conversely, the error distance of a registration mark 310 could be classified into one of a plurality of zones and an adjustment of predetermined magnitude made in accordance with the zone of classification.

It should also be noted that the first embodiment uses only three zones a short" zone, a within tolerance zone, and a long zone. This is intended to be representative of a plurality of zones, with some appli cations perhaps requiring more detection zones on one side of the within tolerance zone than on the other side.

Zone classification and adjustment may be more advantageous in those applications where the requirements for very exact positioning of a pattern are less, the zone adjustment than reducing the amount of hunting by the control equipment. Directly proportional adjustment may be more advantageous in those applications wherein a very, very exact positioning of a pattern is required.

While the patterns have been described as printed, it should be noted that patterns may be formed on the material being fed by embossing, engraving, cut-outs, and the like. Moreover, a reference to a registration mark means on the material includes the pattern itself, since the embodiments described herein may be used to sense the pattern directly, rather than a separate registration mark per se on the edge of the material.

Finally, the registration mark means may include a dark mark on light material, a light mark on dark material, an aperture in the material, a solid cross bar at the end of a slot in the material, and the like. In short, a change which may be sensed electrically, optically, mechanically, or other ways to provide a signal.

It is also important to note that the scanning velocity may be much slower than that required where the registration mark is being sensed during a feed stroke, and thus enables a more accurate sensing and control. In contrast to the scanning by a plurality of stationary photo cells, the present embodiments provide a much more accurate location of a registration mark and enables both proportional and zone correction.

There has thus been disclosed a method for intermittently feeding strip material which includes the steps of intermittently advancing a strip of material into a station, detecting the actual location of a pattern on the material relative to the station by moving a scanning means along the strip of material between the intermittent advancements thereof, comparing the actual location of the detected pattern with the desired location for the detected pattern, and regulating the length of intermittent advancement of the strip material-when a difference between the actual location and a desired location of detected pattern indicates that a length advancement adjustment is required. The scanning distance of the movable detecting means may be limited, and the operation of the apparatus may be interrupted if the pattern is not detected in the limited scanning distance.

In conclusion, it is pointed out that while the illustrated examples constitute practical embodiments of the invention, it is not intended to limit the invention to the exact details shown, since modifications may be made without departing from the spirit and scope of the invention disclosed.

I claim: I

1. Apparatus for intermittently feeding strip material having spaced registration mark means along the length thereof and for aligning the strip material in a station receiving the material, comprising a. means for intermittently advancing a strip of material into a station, adjustable means for regulating the length of advancement of material by said intermittent advancing means,

c. means for detecting a registration mark means on the strip of material,

. means operable after movement of said material has ceased for moving said detecting means relative to said material to enable detection of the actual location of a registration mark means on said material, and

e. means for comparing the actual location of a detected registration mark means with a desired location of the registration mark means and providing an indication of the difference between the actual and desired locations.

2. Apparatus as defined in claim 1 which further includes means responsive to said comparing means for adjusting said adjustable means when a difference between actual and desired locations of a detected mark means indicates that an advancement length adjustment is required.

3. Apparatus for intermittently feeding strip material having spaced registration mark means along the length thereof and for aligning the strip material in a station receiving the material, comprising a. means for intermittently advancing a strip of material into a station,

b. adjustable mans for regulating the length of advancement of material by said intermittent advancmg means,

c.'means for detecting a registration mark means on the strip of material,

. means operable after movement of said material has ceased for moving said detecting means relative to said material to enable detection of the actual location of a registration mark means on said material,

. means for comparing the actuallocation of a detected registration mark means with a desired location of the registration mark means and providing an indication of the difference between the actual and desired locations, and

f. means responsive to said comparing means for adjusting said adjustable means when a difference between actual and desired locations of a detected mark means indicatesthat an advancement length adjustment is required.

4. Apparatus as defined in claim 1 in which said comparing means includes,

a. means for providing an output signal proportional to the difference between a detected location and a desired location of a registration mark means, and which further includes means responsive to said output signal for adjusting said adjustable means to change the advancement length of said advancing means to enable correct advancement of said material into a station.

5. Apparatus as defined in claim 1 which further includes means responsive to said comparing means for indicating a difference between detected and desired locations which is in excess of a predetermined advancement regulation length.

6. Apparatus as defined in claim 1 which further includes means responsive to said excess length indication means for interrupting operation of said advancing means.

7. Apparatus for advancing strip material into a press or the like having means for forming a work piece from the material, the strip material being pre-printed with a repetitive pattern, comprising a. a reciprocating feeder device operable to move said strip material into said work piece forming means so that a pre-printed pattern is in registration to permit the forming of said work piece therefrom,

. said feeder device having a reciprocating gripper means for engaging said material and moving same an amount equal to the distance between successive patterns on the material,

c. spaced forward and rear stop means for limiting movement of said gripper means, i

. means for detecting the actual location of a preprinted pattern on said material,

e. means operable after completion of a forward stroke of said gripper means for imparting motion to said detecting means relative to said strip of material to enable detection of the actual location of said pre-printed pattern, and

f. means for comparing the actual location of a detected pre-printed pattern with a desired location of a pre-printed pattern and providing an indication of the difference between the actual and desired locations.

8. Apparatus as defined in claim 7 which further includes means responsive to said detecting means for indicating that an actual location of a pre-printed pattern is too far from a desired location for the pattern.

9. Apparatus as defined in claim 7 which further includes a. adjustable means for moving one of said stop means to adjust the length of the stroke of said gripper means, and

b. means responsive to said comparing means for adjusting said adjustable means when a difference between actual and desired locations of a preprinted pattern indicates that a stroke length adjustment is required.

10. Apparatus as defined in claim 9 in which said adjustable means includes a. a first element carrying one of said stop means,

and a second element positioned adjacent said first element,

c. said first and second elements having cooperating inclined plane surfaces formed thereon so that movement of said second element causes movement of said first element.

11. Apparatus as defined in claim 7 in which a. said motion imparting means includes means for providing movement of said detecting means substantially parallel to the feed direction of said material, and in which b. said comparing means includes means for providing an indication of a reference position of said detectingmeans representing the desired location of a pre-printed pattern.

12. Apparatus as defined in claim 7 in which said comparing means includes a. means for providing a first signal when said detecting means is on a first side of a desired location of a pre-printed pattern,

b. means for providing a second signal when said detecting means is on a second side of a desired location of a pre-printed pattern, and

c. means responsive to said first and second signals and to said detecting means for determining the direction of the actual location of a pre-printed pattern from a desired location therefor.

13. Apparatus for advancing strip material into a press or the like having means for forming a work piece from the material, the strip material being pre-printed with a repetitive pattern, comprising a. means operable to engage and advance said strip material into said work piece forming means so that a pre-printed pattern is in registration to permit the forming of said work piece therefrom,

. means for intermittently moving the strip engaging portion of said advancing means through an arc to advance successive pre-printed patterns into said work piece forming means,

. means operable after completion of an intermittent movement of said advancing means for imparting motion to said detecting means relative to said strip of material to enable detection of the actual location of said pre-printed pattern, and

e. means for comparing the actual location of a detected pre-printed pattern with a desired location of a pre-printed pattern and providing an indication of the difference between the actual and desired locations.

14. Apparatus as defined in claim 13 in which a. said material advancing means includes roll means for engaging said material, and in which b. said intermittent movement means includes means for intermittently rotating said roll means through an arc.

15. Apparatus as defined in claim 13 which further includes a. adjustable means for regulating the length of the arc of movement of said advancing means, and

b. means responsive to said comparing means for adjusting said adjustable means when a difference between actual and desired locations of a preprinted pattern indicates that an arc length adjustment is required.

16. Apparatus as defined in claim 13 in which a. said comparing means includes means for providing a reference signal when said detecting means should be locating said pre-printed pattern, and in which b. said detecting means includes means for providing a located signal when said pattern is actually located,

c. the difference between the time of occurrence of said reference signal and said located signal providing a measure of the distance of registration error.

17. Apparatus as defined in claim -16 which further includes a. adjustable means for regulating the length of the arc of movement of said advancing means, and

b. means responsive to the occurrence of one of said reference and located signals for initiating adjustment of said adjustable means.

18. Apparatus as defined in claim 17 which further includes means responsive to the occurrence of the other of said reference and located signals for interrupting operation of said adjusting means.

19. A method for intermittently feeding strip material having spaced patterns along the length thereof and for aligning the patterns in a station receiving the material, comprising a. intermittently advancing a strip of material into a station,

b. detecting the actual location of a pattern on said material relative to the station by moving a scanning means along the strip of material between intermittent advancements thereof,

c. comparing the actual location of the detected pattern with a desired location for the detected pattern, and

d; regulating the length of intermittent advancement of the strip of material when a difference between the actual location and a desired location of a detected pattern indicates that a length advancement adjustment is required to position the detected pattern in alignment in the station.

20. A method for intermittently feeding strip material having spaced patterns along the length thereof and for aligning the patterns in a station receiving the material, comprising a. intermittently advancing a strip of material into a station,

. comparing the actual location of the detected pattern with a desired location for the detected pattern,

. regulating the length of intermittent advancement of the strip of material when a difference between the actual location and a desired location of a detected pattern indicates that a length advancement adjustment is required to position the detected pattern in alignment in the station,

e. limiting the scanning distance of said pattern detecting movement, and

f. interrupting the feeding of the strip material if a pattern is not detected in the limited scanning distance.

Claims

1. Apparatus for intermittently feeding strip material having spaced registration mark means along the length thereof and for aligning the strip material in a station receiving the material, comprising a. means for intermittently advancing a strip of material into a station, b. adjustable means for regulating the length of advancement of material by said intermittent advancing means, c. means for detecting a registration mark means on the strip of material, d. means operable after movement of said material has ceased for moving said detecting means relative to said material to enable detection of the actual location of a registration mark means on said material, and e. means for comparing the actual location of a detected registration mark means with a desired location of the registration mark means and providing an indication of the difference between the actual and desired locations.

3. Apparatus for intermittently feeding strip material having spaced registration mark means along the length thereof and for aligning the strip material in a station receiving the material, comprising a. means for intermittently advancing a strip of material into a station, b. adjustable mans for regulating the length of advancement of material by said intermittent advancing means, c. means for detecting a registration mark means on the strip of material, d. means operable after movement of said material has ceased for moving said detecting means relative to said material to enable detection of the actual location of a registration mark means on said material, e. means for comparing the actual location of a detected registration mark means with a desired location of the registration mark means and providing an indication of the difference between the actual and desired locations, and f. means responsive to said comparing means for adjusting said adjustable means when a difference between actual and desired locations of a detected mark means indicates that an advancement length adjustment is required.

4. Apparatus as defined in claim 1 in which said comparing means includes, a. means for providing an output signal proportional to the difference between a detected location and a desired location of a registration mark means, and which further includes b. means responsive to said output signal for adjusting said adjustable means to change the advancement length of said advancing means to enable correct advancement of said material into a station.

7. Apparatus for advancing strip material into a press or the like having means for forming a work piece from the material, the strip material being pre-printed with a repetitive pattern, comprising a. a reciprocating feeder device operable to move said strip material into said work piece forming means so that a pre-printed pattern is in registration to permit the forming of said work piece therefrom, b. said feeder device having a reciprocating gripper means for engaging said material and moving same an amount equal to the distance between successive patterns on the material, c. spaced forward and rear stop means for limiting movement of said gripper means, d. means for detecting the actual location of a pre-printed pattern on said material, e. means operable after completion of a forward stroke of said gripper means for imparting motion to said detecting means relative to said strip of material to enable detection of the actual location of said pre-printed pattern, and f. means for comparing the actual location of a detected pre-printed pattern with a desired location of a pre-printed pattern and providing an indication of the difference between the actual and desired locations.

9. Apparatus as defined in claim 7 which further includes a. adjustable means for moving one of said stop means to adjust the length of the stroke of said gripper means, and b. means responsive to said comparing means for adjusting said adjustable means when a difference between actual and desired locations of a pre-printed pattern indicates that a stroke length adjustment is required.

10. Apparatus as defined in claim 9 in which said adjustable means includes a. a first element carrying one of said stop means, and b. a second element positioned adjacent said first element, c. said first and second elements having cooperating inclined plane surfaces formed thereon so that movement of said second element causes movement of said first element.

11. Apparatus as defined in claim 7 in which a. said motion imparting means includes means for providing movement of said detecting means substantially parallel to the feed direction of said material, and in which b. said comparing means includes means for providing an indication of a reference position of said detecting means representing the desired location of a pre-printed pattern.

12. Apparatus as defined in claim 7 in which said comparing means includes a. means for providing a first signal when said detecting means is on a first side of a desired location of a pre-printed pattern, b. means for providing a second signal when said detecting means is on a second side of a desired location of a pre-printed pattern, and c. means responsive to said first and second signals and to said detecting means for determining the direction of the actual location of a pre-printed pattern from a desired location therefor.

13. Apparatus for advancing strip material into a press or the like having meaNs for forming a work piece from the material, the strip material being pre-printed with a repetitive pattern, comprising a. means operable to engage and advance said strip material into said work piece forming means so that a pre-printed pattern is in registration to permit the forming of said work piece therefrom, b. means for intermittently moving the strip engaging portion of said advancing means through an arc to advance successive pre-printed patterns into said work piece forming means, c. means for detecting the actual location of a pre-printed pattern on said material, d. means operable after completion of an intermittent movement of said advancing means for imparting motion to said detecting means relative to said strip of material to enable detection of the actual location of said pre-printed pattern, and e. means for comparing the actual location of a detected pre-printed pattern with a desired location of a pre-printed pattern and providing an indication of the difference between the actual and desired locations.

15. Apparatus as defined in claim 13 which further includes a. adjustable means for regulating the length of the arc of movement of said advancing means, and b. means responsive to said comparing means for adjusting said adjustable means when a difference between actual and desired locations of a pre-printed pattern indicates that an arc length adjustment is required.

16. Apparatus as defined in claim 13 in which a. said comparing means includes means for providing a reference signal when said detecting means should be locating said pre-printed pattern, and in which b. said detecting means includes means for providing a located signal when said pattern is actually located, c. the difference between the time of occurrence of said reference signal and said located signal providing a measure of the distance of registration error.

17. Apparatus as defined in claim 16 which further includes a. adjustable means for regulating the length of the arc of movement of said advancing means, and b. means responsive to the occurrence of one of said reference and located signals for initiating adjustment of said adjustable means.

19. A method for intermittently feeding strip material having spaced patterns along the length thereof and for aligning the patterns in a station receiving the material, comprising a. intermittently advancing a strip of material into a station, b. detecting the actual location of a pattern on said material relative to the station by moving a scanning means along the strip of material between intermittent advancements thereof, c. comparing the actual location of the detected pattern with a desired location for the detected pattern, and d. regulating the length of intermittent advancement of the strip of material when a difference between the actual location and a desired location of a detected pattern indicates that a length advancement adjustment is required to position the detected pattern in alignment in the station.