Abstract:
A slidably supporting feeding apparatus having fingers movable to stop and to release the stock for regulating delivery of the stock to a press, the fingers being driven by inertia to a complete release position in timed relation with a press feed mechanism, which during the interval of complete release of the stock by the fingers, grasps and moves the stock into the press.

Description:
BACKGROUND OF THE INVENTION 
     Article feeding devices for presses have been heretofore provided of varying complexity for registering the position of an article with an imprinting device of the press to accurately position the printing on the article. These devices include vacuum feeds with their vacuum pumps and hoses etc. or precisely geared or chain driven mechanisms which grasp the article and move it in time relation with the plate cylinder of the press so that the article is fed precisely between the plate cylinder and the opposing impression cylinder. Difficulty is experienced in attempting to correlate the function of the various mechanisms with the texture of the article being fed and its thickness, surface condition and other characteristics. 
     DISCUSSION OF THE PRIOR ART 
     In the prior art in the devices under consideration, stop fingers are generally used to hold the article at its leading edge, the article being such as a sheet of paper or an envelope, and the fingers are withdrawn at a prearranged time to allow the article to advance into the printing press. The article is normally fed to pairs of friction feed rollers after being released by the fingers. Difficulty is experienced to maintain the proper synchronization between the release of the fingers and the advance of the article into the press and in many instances laborious adjustments are required because the mechanism will not admit to wide tolerances and therefore minute incremental tuning is necessary. 
     SUMMARY OF THE INVENTION 
     This invention relates to a feed mechanism of novel concept which utilizes the momentum of the parts to withdraw the stop fingers in the last increment of their movement from hold to release position. 
     The invention contemplates making the fingers and their mounting as well as their depressor mechanism to swing about a horizontal axis such that when the motivating mechanism operating the depressor is at the end of its stroke, the fingers and depressor mechanism will, due to inertia, continue to move in a fingerdepressing direction to complete withdrawal of the fingers from the leading edge of an article being stopped by the fingers, the entire dissappearance of the fingers occuring substantially at the instant that a pair of feed rollers are caused to grasp the article while power is being applied to the feed rollers to drive them and propel the article over the disappeared fingers and thus into the press. This feature provides the lag time for the article to advance over the fingers without interference into the grasping and conveying mechanism of the press, and eliminates the necessity of providing hold down mechanisms for holding the article against bridging over the stop fingers while it is being forced against the fingers prior to the fingers being completely moved to unobstructing position. The movement of the fingers at their last increment is tantamount to a lost motion in that the motivating mechanism separates from the finger depressors and the depressors as well as the fingers move due to the forces of inertia. The instant mechanism entirely eliminates the precise mechanisms which must constantly positively hold the article during its entire travel on the conveyor and at the same time prevent the article from prematurely jumping over the fingers and feed into the press. 
     A general object of this invention is to provide an improved simplified and effective mechanism for orienting imprintable stock and feeding the same in registering sequence to a press. 
    
    
     These and other objects and advantages inherent in and encompassed by the invention will become more apparent from the the specification and the drawings, wherein; 
     FIG. 1 is a fragmentary side elevational view partly in section showing the mechanism in feeding position; 
     FIG. 2 is a fragmentary top plan view partly broken away; 
     FIG. 3 is a fragmentary bottom plan view; 
     FIG. 4 is an enlarged bottom perspective of a lower feed roller assembly; 
     FIG. 5 is a fragmentary side elevational view partly in cross-section showing the parts in a non-feeding position and with the upper feed wheel removed; 
     FIG. 6 is an enlarged view of one of the lift spring arrangements for the finger depresser assembly; 
     FIG. 7 is a perspective view of the cam pin slide; 
     FIG. 8 is a cross-section on line 8--8 of FIG. 2 including the upper feed roller; 
     FIG. 9 is a perspective view of the stock guide assembly; and 
     FIG. 10 is a fragmentary perspective view of the antihammering mechanism. 
    
    
     DESCRIPTION OF THE INVENTION 
     This invention is shown with a typical press 1, fragmentarily illustrated, and which includes a side frame or wall 2 at each side between which are mounted various cylinders(not shown) including an impression cylinder 6 fragmentarily shown, rotatable on a horizontal axis and in front of which are mounted a pair of cooperative feed rollers 8 and 10 which are positioned in receiving relation to stock items, such as sheets of paper 12 or envelopes etc., being delivered thereto by a conveyor generally designated 14. 
     The conveyor 14 is adapted for removable attachment to the press and comprises a bottom or horizontal base wall or plate 16 which has a downwardly turned flange 18 at its forward or delivery end 20. Flange 18 is adapted to extend into a slot 21 in a horizontal guide plate 22 which is affixed to the side frames or walls 2 of the press and positioned in front of, that is, the receiving side of the feed rollers 8 and 10. 
     The plate 16 is apertured at 24 centrally thereof and the bottom section of a metering feed roller assembly 25 is mounted on the plate 16 and comprises a free rolling feed wheel or roller 26 protruding through the aperture 24 above the top stock-support surface 30 of the bottom plate 16 of the forward portion of the conveyor 14. The wheel 26, which is made of suitable plastic material such as soft polypropylene or other elastomeric material such as neoprene and the like, is rotatably mounted on the center shaft 32 which at its ends is positioned in upwardly open slots 34,34 in vertical side flanges 36,36 of brackets 38,38. The shaft 32 is biased upwardly to the top of its respective slot 34 by one end of a torsion spring 42 which has its other end formed as a coil 44 wrapped about a cylindrical mounting block 45 attached to the side flange of the respective bracket 38 . The other end of the coil is anchored to the associated block 45. Each bracket has a horizontal flange 48 which is attached by bolt and nut assemblies 49 to the underside of the conveyor plate 16. 
     The lower feed wheel 26 is positioned in alignment longitudinally of the conveyor in the direction of feed of the stock with a feed belt 50 trained about a pulley 52 rotatably supported on a horizontal shaft 54 which is carried at opposite ends from the walls 56,56 of the conveyor 14, said side walls 56,56 being connected at their upper ends to the lateral edges of of the plate 16 which may be transversely split at 58 to facilitate manufacture and assembly. 
     A shaft 59, supported between the side walls 56, 56 provides a pivotal mount about a horizontal axis for the rear bearings 60,60 formed on the rear ends 62,62 of operating arms 64,64 of a pair of finger assemblies 65,65 which flank the pulley 52. The arms extend to adjacent the forward end of the conveyor 14 and are connected at their forward ends to the lower ends bf upright fingers 66,66 which project through slots or apertures 68,68 formed in the forward end portion of plate 16. 
     The fingers 66 in raised position as shown in FIG. 5 project upwardly through the respective apertures 68 in intercepting position to articles issuing from the conveyor as best seen in FIG. 5. 
     The finger assemblies are each individually biased upwardly by a torsion spring 70 which has its coil 71 wound about a mounting sleeve 72 fastened to the stationary shaft 59 and having one end anchored to sleeve 72 and the other end 74 anchored to the respective end of 64 at 75 in lifting relation thereto. 
     A U-shaped depressor assembly 76 is provided for lowering the fingers in timed relation to the press operation and comprises a cross-bar 77 at its front end disposed between and connected to the forward ends of a pair of lower legs 78,78, the rear ends of which are each connected to the lower end of a respective bight portion 80. The upper end of each bight portion is connected to the rear end of a forwardly extending leg 82. Each bight portion 80 is pivoted on shaft 59 and with its upper and lower legs is biased upwardly by a torsion spring 84 having its coil 85 wrapped about a mounting collar 86 sleeved on and secured to the stationary shaft 59. The spring coil has one end portion anchored as at 87 to the respective collar 86 and the other end anchored to a clip 88 on the adjacent bight 80 and biases the depressor assembly in a direction raising the legs 82 upwardly as well as the bar 77 which overlies and contacts the arms 64,64 of the finger assemblies. 
     A drive wheel 90 (FIG. 8) is positioned above and in vertical alignment with the lower feed wheel 26 and is mounted through a one way clutch 91 to a horizontal drive shaft 92 which at opposite ends is provided with journal bearings mounted in vertically elongated slots 93 formed in the side walls 2,2 of the printer. The shaft 92 and the wheel 90 are adapted to move vertically, shaft 92 being movable in the slots 93 to engage the wheel 90 with the wheel 26 and upwardly to disengaged position. 
     In the disengaged position of the wheels or rollers 90, 26 each stock item is moved in timed sequence by the belt 50 over the pullout wheel 26 and the stock is brought with its leading edge against the upraised fingers. If the stock arrives sooner than required, the top 96 of the belt abrades against the bottom 97 of the paper sheet and slides under the paper while constantly urging the sheet against the extended fingers. The belt is made of materials providing a sufficient coefficient of friction as is described in my U.S. Pat. No. 4,470,349. At this time as seen in FIG. 5 the impression roller has its smooth cylindrical sector 98 facing the conveyor. 
     In order to drive the sheet into the grasping feed rollers of the press, the shaft 92 is forced downwardly at each end by a trip lever 99 (fragmentarily shown in FIG. 2), which is part of the press mechanism, such that the top pullout drive wheel 90 grasps the stock item with the bottom wheel 26 as seen in FIG. 8. 
     The shaft 92 pivotally supports adjacent to each end a cam member 100 which has a bottom camming surface 102 overlying and opposing the upper edge 104 of the adjacent top leg of the depressor. The cam is caused to rotate in a camming direction by a pin 106 which protrudes from one side of the cam member and rests on top of the camming profile 108 formed on top of the projection 110 of a cam hook 112 (FIG. 7) which is fastened to the adjacent side frame of the press. Thus as the shaft is caused to move downwardly as predetermined, the cam members rotate bringing their surfaces 102 against the edges 104 and depressing the upper legs 82 and thus pivoting the lower legs downwardly and causing the depressor bar 77 to move the finger assemblies downwardly. 
     The upper wheel 90 obtains a positive purchase or grasp on the stock item therebelow with the yieldable free rolling lower wheel 26 attendant to depressing the same and before rotating simultaneously the cams stop pivoting since shaft 92 has reached the lowermost position or end of its stroke at this time, the upper ends of the fingers barely protrude above the plate 16 and continue to hold the stock items from advancing beyond the fingers. Thereafter the inertia of the depressor and of the finger assembly causes the upper legs 82 to depart or disengage from the cams and the depressor continues to swing with the fingers in a direction causing the lower legs of the depressor to move downwardly with the depressor bar connected thereto thus causing the fingers 66 to withdraw their uppermost ends 106&#39; below the plate 16 thereby releasing the paper stock. At this moment the power train 110&#39; which is shown as a sprocket and chain drive at each end of the shaft 92 is driven thereby rotating the shaft 92 and wheel 90 which advances the stock over the retracted fingers and into the feed rollers 8 and 10 of the press which at this time close and grasp the paper stock and then advance the paper stock onto the grippers 112&#39; on the rotating impression cylinder (see FIG. 1) which is timed to position the grippers as shown. As the grippers clamp onto the leading edge of the paper stock, the rollers 90 and 26 and the rollers 8 and 10 begin to separate and the impression cylinder rotates as shown by the arrow. The stock is then wrapped about cylinder 6 and presented to the other printing components of the press such as the plate cylinder or offset blanket (not show) as is well known to those skilled in the art. Any lag in the release of the paper by wheels 90,26 is accommodated by the overrunning clutch 91 and the free rolling of the wheel 26. 
     After feeding each piece of stock individually, the shaft 52 is moved upwardly and the depressor likewise swings in a direction to cause its upper and lower legs to swing upwardly allowing the fingers to be spring biased to lift to stop position. The next sequentially fed stock item is then advanced between the rollers 90,26 and the leading edge of the stock is brought into contact with the raised fingers by the conveyor and the previously described cycle is repeated. 
     In order to prevent the paper 12 from flying over the top ends of the fingers when they are in raised position as seen in FIG. 5, there are provided a pair of holddown guides 120,120 which are carried at their rear upper end on a transverse rod 122 which is mounted on and supported between the side panels 2,2 of the press. 
     In FIG. 10 there is shown a spring-biased anti-hammering control assembly 125 for controling and holding under yieldable spring load the upward and downward movement of the shaft 92 which is pulled in its downward movement by a tension spring 126 connected at its lower end to a bolt type of anchor 128 threadedly mounted on the adjacent side wall 2 of the press and at its upper end is connected to one leg of a hook 130 which is hooked over the shaft 92. There is one such assembly 125 at each end of the shaft 92 and they serve not only to take up the back lash between the operating forks 99 and the associated bearings on shaft 92, but also serve as a positive means for pulling the shaft 92 downwardly. 
     The fingers 65 also designate gate means or stop means which swing vertically and are only lightly biased upwardly as also is the depressor, both of which constitute the driven component or section, whereas the shaft 92 and cam 100 constitute the driving component or section and is part of the actuating means with the cam. 
     The raised position of the fingers is also designated the intercept position. FIG. 8 shows the complete release position of the fingers and the partial release intermediate position at the time when the cam is at the end of its stroke and the leg 92 engages the cam profile 102.