Abstract:
A reject mechanism ( 10 ) for use with a slitter (S) which slits a printed metal sheet (B) into segments (s) subsequently used to form containers. The mechanism is mounted at the outlet of the slitter to deflect rejected segments from a collection bin (C) to which acceptable segments are delivered for further use in container manufacture. The mechanism comprises a series of pneumatically actuated reject fingers ( 14 ) normally positioned beneath a path over which the segments pass from the slitter to the collection bin. However, when a reject segment approaches the mechanism, a piston ( 16 ) is activated to extend the fingers into the path of the segment to deflect the segment off its path into another collection area in which rejected segments are collected. The fingers are then retracted so that succeeding acceptable segments pass freely over the path.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     This invention relates to the manufacture of containers such aerosol cans, paint cans and the like, and more particularly, to a reject apparatus for selectively discarding unacceptable can bodies after they have been routed through a slitter mechanism. 
     In the manufacture of cans, a rectangular sheet of steel is sized so a plurality of can bodies can be made from the sheet. In the manufacturing process, the sheet may be first run through a printing press by which a product label and other information is printed on one side of the sheet. The number of labels printed on the sheet corresponds to the number of can bodies which are formed from the sheet. After printing, the sheet is run through a slitter mechanism which first slits the sheet along one of its axes (its longitudinal axis, for example), and then along another axis (for example, crosswise along the orthogonal axis of the sheet). The resulting blanks are then carried to a welding machine where the plates are welded into cylinders used to form can bodies. Because of defects in a sheet, poor printing results, etc., it may be necessary to reject certain portions of the sheet from which can bodies would otherwise be formed. 
     A reject mechanism used to perform this function must solve a number of problems. For example, since the slitter mechanism is adjustable to cut sheets of different sizes, the reject mechanism must be similarly adjustable. In addition, the areas on the sheets where defects occur or where there is bad printing may vary from sheet to sheet. The reject apparatus must therefore be selectably controllable to accurately remove only the unwanted segments from each sheet, and it must be capable of doing so without effecting the high throughput capacity of the slitter apparatus. 
     BRIEF SUMMARY OF THE INVENTION 
     Among the several objects of the present invention may be noted the provision of a reject mechanism for use with a slitter apparatus to selectively remove from a stream of sheet segments produced by the slitter only those segments which are not to be used to form can bodies, and to not otherwise interfere with the movement of acceptable sheet segments from the slitter; 
     the provision of such a reject mechanism by which either the same segments or different segments from different sheets can be removed from the flow of segments; 
     the provision of such a reject mechanism whose operation does not effect the throughput rate of the slitter; 
     the provision of such a reject mechanism which is readily adjusted during changeovers to accommodate different size sheets passing through the slitter; 
     the provision of such a reject mechanism sized to fit between one end of a slitter apparatus and a collection bin in which acceptable sheet segments are collected for transfer to can forming equipment; 
     the provision of such a reject mechanism to include a plurality of fingers spaced across an edge of a slitter table, the fingers being reciprocally movable fingers each of which is selectively activated to move into the path of an unwanted sheet segment to deflect the segment into a reject bin or the like, the fingers moving sufficiently quickly as to move out of the path of the next acceptable sheet segment; 
     the provision of such a reject mechanism to be operable by the person operating the slitter; and, 
     the provision of such a reject mechanism which is easily installed and readily removed from the slitter. 
     In accordance with the invention, generally stated, a reject mechanism is for use with a slitter which slits a printed metal blank into segments subsequently used to form cans for holding and dispensing fluid commodities. The mechanism is mounted at the outlet of the slitter to deflect rejected segments from a collection area to which acceptable segments are delivered for further use in can manufacture. The mechanism comprises a series of pneumatically actuated fingers normally positioned beneath a path over which the segments pass from the slitter to the collection area. However, when a reject segment approaches the mechanism, a piston is activated to elevate the fingers into the path of the segment to deflect the segment off its path into a second collection area in which rejected segments are collected. The fingers are then retracted so that succeeding acceptable segments pass freely over the path. Other objects and features will be in part apparent and in part pointed out hereinafter. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     In the drawings, FIG. 1 is a simplified block diagram of a forming operation for containers; 
     FIG. 2 is a simplified plan view of a slitter mechanism forming multiple can segments from a printed blank; 
     FIG. 3 is a top plan view of a slitter reject mechanism of the present invention; 
     FIG. 4 is a side elevational view, partly in section, of the slitter reject mechanism; and, 
     FIG. 5 is a side elevational view of a second embodiment of the slitter reject mechanism. 
     Corresponding reference characters indicate corresponding parts throughout the drawings. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the drawings, FIG. 1 illustrates the manufacturing process for containers such as aerosol cans, paint cans, and the like. As shown in the drawing, a plain blank B of a desired size and thickness is first routed through a print station P for labels and other information to be printed on one side of the sheet. The printing is repeated both across and along the sheet since numerous containers will be formed from the single sheet. After printing, the sheet is routed to a slitter mechanism S where the sheet is cut into a plurality of segments each of which is used to form a separate container. Finally, and as previously described above, the segments are routed to a forming line F where the cans are formed. Or, if the blanks are unacceptable, they are rejected as indicated at R and not used. 
     As shown in FIG. 2, after printing, blanks B are placed on a slitter table T where the blank is cut into segments. The slitting operation generally comprises three stages S 1 -S 3 . At stage S 1 , printed tin plate thin sheets B (approx. 36″ wide by 32″ long) are placed on the table. As the blank then moves along the table, a series of top and bottom rotation slitter cutters, X and Y respectively, cut the sheet in one direction along the sheet (stage S 2 ). This produces a series of strips which are then cut crosswise with respect to the first cuts (at stage S 3 ) to produce the individual segments s from which containers are made. At stage S 3 , the cuts are again made by a series of top and bottom rotation slitter cutters X and Y. The cutters turn the continuous sheet into the numerous smaller rectangular segments s (for example, four rectangular segments each of which is 9″×8″). It will be understood by those skilled in the art that the slitter mechanism can accommodate blanks of different sizes and that the size of the resulting segments also can vary. After the second series of cuts are made, the segments are pushed off the end of the table and fall into collection bin C. In doing so, the segments pass over a reject mechanism  10  of the present invention. As described hereinafter, mechanism  10  is selectively operable to deflect “bad” or unacceptable segments from bin C and direct these rejected segments into another bin (not shown) so that these segments will not be used in forming containers. The slitter and its operation form no part of this invention. 
     Referring to FIGS. 3 and 4, a support bar  12  extends between the output end of slitter mechanism S and collection bin C. Reject mechanism  10  is mounted on this support bar. The support bar extends across the entire width of the slitter mechanism. Since as shown in FIG. 2, segments formed from the blank extend across the width of the machine, a separate reject mechanism is mounted on support bar  10  for each row of segments produced by the slitter mechanism. Each reject mechanism is separately and selectively operable to reject unacceptable segments. Each reject mechanism includes a plurality of reciprocally movable fingers  14  which are spaced from each other across the length of the reject mechanism. Four such fingers  14   a - 14   d  are shown in FIG. 3; although only two or three fingers  14  would also work. The fingers are movable by a piston  16  from a first, out-of-the-way position, at which movement of segments from the slitter mechanism into container C is unimpeded. As described hereinafter, the fingers are movable into a second position (see FIG. 4) in which they deflect unacceptable segments into the reject container. 
     Piston  16  is secured to an L-shaped piston bracket  18  using a hex nut  20 . The bracket has a long bracket leg  18   a  and a short leg  18   b . Leg  18   b  has an opening sized to received the end of piston  16  from which a reciprocal piston rod  22  extends. This end of the piston is threaded to receive the hex nut. The outer end of rod  22  is threaded, and a clevis  24  is threaded onto this end of the piston rod. 
     The piston  16 /bracket  18  sub-assembly is now secured to a bearing rail  26 . Rail  26  is rectangular in plan. A recess  26   a  is formed in an upper surface  28  of the rail at the lower, rear end of the rail as viewed in FIG.  4 . Bracket leg  18   a  abuts up against this recessed portion of the rail. Concentric bores (not shown) are formed in the bracket leg and recess for the piston  16 /bracket  18  sub-assembly to be secured to the rail by a pin  30  and cap screw  32 . 
     Bearing rail  26  is now secured to an assembly adjustment mount  34 . Mount  34  includes an elongate plate section  34   a  and a body section  34   b . An upper end portion  26   b  of bearing rail  26  abuts against an inner face  36  of mount  34 . Concentric bores (not shown) extend through body section  34   b  of mount  34 , and extension  26   b  of bearing rail  26 . Cap screws  38  are threaded into these bores to attach the bearing rail and mount together. 
     The sub-assembly now formed by mount  34  and bearing rail  26  are fitted onto a mating surface  40  of a reject assembly mount  42 . Mount  42  is generally L-shaped (when viewed in elevation as in FIG.  4 ). A back wall  42   a  of the reject assembly mount is chamfered to form an angled surface the angle of which corresponds to that of a mating surface of mount  34 . This latter angled surface is formed by the angle at which elongate plate section  34   a  extends from body section  34   b  of mount  34 . A jack plate  44  is fitted against an outer face of the reject assembly mount. Bores (not shown) extend through the jack plate, the body of the reject assembly mount, and into extension  34   a  of the bearing rail. Screws  46  are used to attach these three components together. In addition, an upright leg portion  42   b  of mount  42  has an inner face  42   c  which angles inwardly as shown in FIG. 4. A mating wall surface of main support  12  is similarly contoured to facilitate attachment of mount  42  to the main support bar. A bore (not shown) extends horizontally through the main support bar and into leg  42   b  of mount  42  for the mount to be attached to the main support bar using screws  47 . 
     The reject fingers  14   a - 14   d  are mounted to a finger support bar  50  using cap screws  52  (FIG. 3) and t-nuts  54  (FIG.  4 ). As shown in FIG. 4, support bar  50  includes a channel  56  through which the reject fingers slide into a desired position along the length of the assembly. The base of channel  56  is sufficiently wide so to accommodate a head of the t-nuts  54 . The upper end of the channel then narrows to accommodate a shank portion of the t-nut. Each reject finger comprises a curved body  58  which is wide at its base, curves upwardly and inwardly as viewed in FIG. 4, and narrows to a point at its upper end. A cavity  60  is formed in the base of each finger, the contour of this cavity conforming to the walls of support bar  50  defining channel  56  so the base of the finger fits over the upper end of support bar  50  in which channel  56  is formed. Each finger  14  slides over channel  56  as the reject fingers are moved into their position as shown in FIG.  3 . Each finger has a vertical bore (not shown) and a t-nut is slid through the channel with the finger so to be positioned immediately beneath the bore. A cap screw  52  is inserted through the bore in the finger and threaded onto the t-nut to lock each finger in place. To reposition or remove a finger from mechanism  10 , screw  52  is simply loosened which allows the finger to be moved. 
     As shown in FIG. 4, the lower, base end of finger support bar  50  curves downwardly and outwardly. A raised shoulder  62  extends the length of the base of the support bar. A saddle support  64  has an upper end in which a recess  66  is formed to accommodate shoulder  62  so that the finger support bar and saddle support interfit with one another. These two components are attached to each other using screws (not shown). At the base of the saddle support an extension is formed which comprises a saddle  68 . Clevis  24 , which is U-shaped, straddles saddle  68  and is attached to the saddle by a pin  69 . Movement of piston rod  22  therefore produces a corresponding movement of saddle  68  and saddle support  64 . 
     A bearing saddle  70  is slidably received on extension  26   b  of bearing rail  26  so the bearing rail can guide movement of the reject fingers between their retracted and extended positions. The bearing saddle fits about the upper end portion  26   b  of bearing rail  26  as shown in FIG. 3 for the bearing saddle to move back and forth over the rail. Bearing saddle  70  and saddle support  64  are attached to each other again using screws (not shown). A deflector plate  72  comprises a rectangular plate whose width corresponds to the width of saddle support  64 . The length of the deflector plate is such that it extends from the underside of finger support bar  50 , as viewed in FIG. 4, along the underside of saddle support  64 , and substantially along the length of piston  16 . The deflector plate attaches to the saddle support and finger support bar in any convenient manner, for example, with flat head socket cap screws (not shown). 
     Saddle support  64 , finger support bar  50 , reject fingers  14 , deflector plate  72 , and bearing saddle  70 , are first assembled together. The resultant sub-assembly is then slid onto bearing rail  26  for subsequent sliding movement along the rail when piston  16  is actuated. In so doing, saddle  68  is aligned with clevis  24  and secured with to the clevis with pin  69 . The reject mechanism assembly is now secured to main support bar  12  using screws (not shown) which fit through a slotted channel  74  formed in the main support bar and extending the length of the main support bar. The main support bar allows reject mechanism  10  to be moved into different positions depending upon the size of the segments s being formed by slitter mechanism S. As shown in FIG. 2, several reject mechanisms  10  are mounted on main support bar  12  with the number of reject mechanisms so installed being a function of how many segment are being cut by the slitter mechanism. 
     In addition to the reject mechanisms which are attached to the main support bar, a guide finger  80 , one for each reject mechanism  10 , is also attached to the main support bar. Each guide finger comprises a rectangular plate the length of which is such that when main support bar  12  is attached to a frame F of slitter mechanism S (see FIG.  2 ), the finger provides a path over which acceptable can segments s to be collected in bin C travel. Because of this, the guide finger for each reject mechanism is mounted on the main support bar between or next to fingers  14  of the reject mechanism. This is as shown in FIG.  3 . Attachment of the guide fingers to the main support bar is similar to that in which the reject fingers are mounted to finger support bar  50 . That is, channel  74  allows the guide fingers  80  to be moved into a desired position along the length of the main support bar. The base of channel  74  is sufficiently wide so to accommodate the head of t-nuts (not shown). The upper end of the channel then narrows to accommodate a shank portion of the t-nut. When the guide finger is in position, a cap screw  82  is inserted through a bore in the guide finger and threaded onto the t-nut to lock the guide finger in place. Once the reject mechanisms and guide fingers are attached to main support bar  12 , the main support is attached mounted to frame F of the slitter mechanism in any convenient manner. 
     In operation, good sheets s (those with no printing or other discernible defects) pass over the guide fingers  80  and fall into collection bin C. When the operator of the machine spots segments which are defective, or if printing defects are discerned prior to the printed blanks B being loaded onto the slitter mechanism, a pre-programmable or operator controlled reject controller  90  supplies an input, via a control line  92 , to a pressure control unit (pneumatic actuator)  94 . An air hose  96  or the like connects between unit  94  and piston  16 . Controller  90  momentarily actuates piston  16  to extend rod  22  by means of unit  94  and air hose  96 . This, in turn, extends the reject fingers  14  into the path of the rejected segment s now exiting the slitter mechanism. The reject fingers are extended into the path of the rejected segment by piston  16  causing the assembly comprising bearing saddle  70 , saddle support  64 , finger support  50 , fingers  14 , and deflector plate  72  to slide a short distance along bearing rail  26  and so interpose the reject fingers into the path of a segment. The timing of this operation is such that piston  16  retracts rod  22  and the above described assembly before the next segments s is ejected from the slitter mechanism so that if this next segment is acceptable it will move over guide finger  80  and into bin C. 
     Referring to FIG. 5, a second embodiment of the invention is indicated generally  10 ′. This embodiment differs from the above described embodiment in that it is designed for use with a different type slitter in which the space available to install  10 ′ is much smaller. As a consequence, rather than having the angled orientation shown in FIG. 4, the embodiment in FIG. 5 is mounted to a support bar  12 ′ so to extend vertically. Embodiment  10 ′ includes a plurality of fingers  14 ′ which, as previously described are spaced from each other across the width of the mechanism. A piston  16 ′ is attached tog a leg  18   b  of an L-shaped bracket  18 ′ by a hex nut  20 ′. A reciprocal piston rod  22 ′ extends through the hex nut and the outer end of the rod attaches to a clevis  24 ′ by a pin  69 ′. The clevis attaches to a saddle  68 ′ of a saddle support  64 ′. 
     What has been described is a reject mechanism for use with a conventional slitter mechanism to selectively remove an unwanted sheet segment from a stream of such segments produced by the slitter mechanism. The reject apparatus is operable by the operator of the slitter and includes a plurality of reject fingers spaced across the outlet end of the slitter mechanism to selectively remove unwanted segments. The reject mechanism operates to quickly and efficiently remove the unwanted segments while not interfering with the throughput rate of the slitter. The mechanism is readily installed and removed and can be used either as original equipment or as a retrofit installation. The mechanism can be employed with most conventional slitters so to provide a low cost enhancement to this equipment. 
     In view of the foregoing, it will be seen that the several objects of the invention are achieved and other advantageous results are obtained. 
     As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.