Mechanism for feeding cardboard or like blanks
[ Apr. 1, 1975 United States Patent 1191 Holt et al.  
 [ MECHANISM FOR FEEDING CARDBOARD OR LIKE BLANKS Primary Examiner-Even C. Blunk Assistant Examiner-Bruce H. Stoner, Jr.  
 [75] Inventors: Barry I-Iolt, New Mills; Norman Frank Buckley, Didsbury both of Attorney, Agent, or F1rmNorr1s &amp; Bateman England Assignee: Henry Simon Limited, Stockport,  
 ABSTRACT Cheshire, England May 11, 1973 Mechanism for feeding cardboard or like blanks one [22] Filed:  
 at a time from the underside of a stack thereof comprising a table, the forward part of which is comprised [21] Appl. No.: 359,329  
 by three reciprocatory suction feed cups adapted, in  
 [30] Foreign Application Priority Data use, to pull the leading edge of the lowermost blank in the stack positively downwardly and progress it forwardly beneath a feed gate and carry it into the nip May 25, 1972 United Kingdom..,...,....  
 between a pair of feed rollers having a relieved central 27l/992I4/85 section, the central reciprocatory feed cup being adapted on its forward stroke to advance to a greater 93, 102, 214/85 D extent than the feed cups on elther s1de thereof to [58] Field of Search 271/14, 108;  
 carry the blank right into the nip between the feed rollers, the central feed cup then being located within the [56] References Cited UNITED STATES PATENTS relieved central section of the feed rollers, the reciprocatory feed cups to either side being arranged to be 2,827,290 3/1958 Dixon et al. 271/99 UX arrested once they have carried the leading edge of 1965 the blank beneath the feed gate.  
  Bishop 10/1966 FOREIGN PATENTS OR APPLICATIONS 12 Claims, 3Drawing Figures 916,180 1/1963 UnitedKingdom..............271/99 PATENTED APR 1 5 SHEEI 2 SF 2 MECHANISM FOR FEEDING CARDBOARD OR LIKE BLANKS This invention relates to mechanism for feeding cardboard or like blanks from a stack thereof, one at a time from the underside of the stack, beneath a feed gate and into the nip between a pair of feed rollers for onward feed thereby for processing.  
  A well-known feed mechanism of this kind comprises a table on which the stack of cardboard or like blanks rests and includes a reciprocatory suction feed device which moves to and fro in the direction of feed and in the plane of the table. In one known such mechanism, the suction feed device is mounted for reciprocatory movement in the centre of the table, there being to either side of the suction feed device at the forward edge of the table auxiliary suction means comprised by apertures in the table through which suction is applied to pull down positively each blank across the whole of its leading edge to ensure that it can pass freely under the feed gate, it being understood that many such blanks are warped when loaded onto the table. Such an arrangement has a serious disadvantage in that when the lowermost blank is being progressed forwardly by the reciprocatory suction feed device on its forward stroke, the suction which must be applied for such movement must be sufficiently great to overcome the additional frictive forces created by the cohesion between the blank and the auxiliary stationary suction means. If these latter means have a sufficient suction force to be sure of positively pulling down the most severely warped boards, then the problem becomes substantial.  
  It is an object of the present invention to provide a feed mechanism which overcomes, at least to some extent, the disadvantage aforesaid.  
  According to the present invention, mechanism for feeding cardboard or like blanks one at a time from the underside of a stack thereof comprises a table, the forward part of which is comprised by three reciprocatory suction feed cups adapted, in use, to pull the leading edge of the lowermost blank in the stack positively downwardly and progress it forwardly beneath a feed gate and carry it into the nip between a pair of feed rollers having a relieved central section, the central reciprocatory feed cup being adapted on its forward stroke to advance to a greater extent than the feed cups on either side thereof to carry the blank right into the nip between the feed rollers, the central feed cup then being located within the relieved central section of the feed rollers, the reciprocatory feed cups to either side being arranged to be arrested once they have carried the leading edge of the blank beneath the feed gate.  
  Preferably suction is applied continuously to the suction feed cups on either side of the central suction feed cup and the central suction feed cup applies suction only during its forward or feeding stroke, being ported to atmosphere during at least the initial part of its return stroke.  
  The invention will be further apparent from the following description with reference to the several figures of the accompanying drawings which show, by way of example only, one form of feed mechanism embodying the invention.  
 Of the drawings:  
  FIG. 1 shows a partially cut-away perspective view of the mechanism;  
  FIG. 2 shows a cross-section through the mechanism on the line IIII of FIG. 1; and  
  FIG. 3 shows a fragmentary partially cut-away plan view of the mechanism.  
  Referring now to the drawings, it will be seen that the mechanism is essentially comprised by a feed table which consists of a fixed rear part comprised by a plate 10 and a forward part comprised by three reciprocatory suction feed cups 11, 12 and 13 respectively. Each of thesuction feed cups 11, 12 and 13 is essentially comprised by a box having a perforated top wall, the top walls being in the plane of the plate 10 to form the forward part of the feed table.  
  The central suction feed cup 12 is adapted, when the mechanism is in use, to be reciprocated longitudinally, (that is in the direction of feed) by means of a pair of rams l4 and 15 which are controlled by cams l6 and 17 mounted on a cam shaft 18 via the intermediary of cam followers 19 and 20 and a lever system generally indicated at 21. Likewise the suction feed cups 11 and 13 lying to either side of the central feed cup 12 are mounted on rams 22 and 23 respectively, which are controlled from cams 24 and 25, and 26 and 27 mounted on the shaft 18 via cam followers 28 and 29, and 30 and 31 and lever systems generally indicated at 32 and 33 respectively.  
  As best seen from FIG. 2, the table comprised by the plate 10 and suction feed cups 11, 12 and 13 is adapted to support a stack of cardboard or like blanks B, which is located between a front wall 34, whose lower edge is upwardly spaced from the plane of the table by a distance slightly greater than the thickness of an individual blank B to form a feed gate 35 and a rear wall 36.  
  In front of the feed table is a pair of feed rollers comprised by upper and lower rollers 37 and 38 respectively, defining a nip therebetween which is at the same level as the surface of the feed table. The central sections of the rollers 37 and 38 are relieved as best seen from FIG. 3 for a purpose which will be apparent hereinafter.  
 The interiors of the boxes defining the suction feed.  
 cups 11 and 13 are connected by flexible hoses 39 and 40 with a chamber 41 which is itself connected by means of a hose 42 with a suction fan. In use, the fan (not shown) is kept running whereby air is continuously drawn through the perforations in the top walls of the boxes defining the cups l1 and 13.  
  As best seen from FIG. 2, the box defining the central suction feed cup 12 has a rearward extension and base plate 43 containing a port 44 and which slides in sealed relationship over a fixed block 45 provided with recesses 46 and 47 which are adapted to communicate in turn with the port 44 as the cup 12 is reciprocated. The recess 46 is connected by means of a pipe 48 with a vacuum pump (not shown) whilst the recess 47 communicates via a pipe 49 with atmosphere.  
  In use, with each of the feed cups 11, 12 and 13 in its rearmost position with the rear edges therof abutting the forward edge of the plate 10, vacuum is applied to the interior of the central suction feed cup 12 and air is drawn in through the perforations in the top walls of the boxes defining all three feed cups. In this way the lowermost blank B in the stack thereof on the feed table is pulled down under the influence of the suction, positively into engagement with the suction feed cups along its front edge, even if the blank is severely warped. The suction cups 11, 12 and 13 move forwardly under the control of the cams on the shaft 18 and pass the leading edge&#39;of the lowermost blank beneath the feed gate 35. The cups continue to move forwardly carrying the blank towards the nip between the rolls 37 and 38. The feed cups 11 and 13 cease to move forwardly before they would otherwise foul the peripheries of the end unrelieved portions of the feed rolls 37 and 38 whilst the central cup continues to move forwardly to carry the board right into the nip between the rolls 37 and 38, the forward part of the feed cup 12 being located within the relieved sections of the rolls 37 and 38 at the end of its forward stroke. In this position the port 44 connects with the recess 47 thereby con necting the interior of the feed cup 12 with atmosphere and permitting the feed rolls 37 and 38 to progress the blank forwardly further without difficulty. The cups 1], l2 and 13 then execute their reverse strokes, the suction still being applied through the cups 1 1 and 13 helping to ensure that the next blank to be progressed is properly squared against the rear wall 36. As the central cup returns to its initial position, the port 44 communicates with the recess 46 so that suction is reapplied ready for the next forward feeding stroke.  
  It will be understood that during the forward feeding stroke the blank being fed attains some momentum before the suction cups 11 and 13 are stopped whereby the central feed cup 12 is able to continue to progress the board forwardly without undue difficulty notwithstanding the fact that there is an additional frictive force to be overcome between the cups l1 and 13 and the underside of the blank respectively on account of the continuing suction in the cups 11 and 13.  
  It will be appreciated that it is not intended to limit the invention to the above example only, many variations, such as might readily occur to one skilled in the art, being possible without departing from the scope thereof.  
 What is claimed is:  
  1. Mechanism for feeding cardboard or like blanks one at a time from the underside of a stack thereof comprising a table, the forward part of which is comprised by three reciprocably mounted suction feed cups adapted, in use, to pull the leading edge of the lowermost blank in the stack positively downwardly and upon forward stroke progress it forwardly beneath a feed gate, a pair of feed rollers defining a nip forwardly of said feed gate having a relieved central section, means for moving all of said cups together on the forward stroke in such relation that the central reciprocatory feed cup on its forward stroke advances to a greater extent than the feed cups on either side thereof to carry the blank right into the nip between the feed rollers, part of the central feed cup then being located within the relieved central section of the feed rollers, and the reciprocatory feed cups to either side are arrested on the forward stroke short of the feed roller nip once they have aided in carrying the leading edge of the blank beneath the feed gate.  
  2. Mechanism according to claim 1 wherein the suction feed cups are reciprocated by synchronized cam means via intermediary cam followers an lever systems.  
  3. Mechanism according to claim 2 wherein suction is applied continuously to the suction feed cups on either side of the central suction feed cup and wherein suction is applied to the central suction feed cup only during its forward or feeding stroke and part of its return stroke, the central suction feed cup being ported to atmosphere during at least the initial part of its return stroke.  
  4. Mechanism according to claim 3 wherein each of the suction feed cups is comprised by a box having a perforated top wall, the top walls being in the plane of a plate forming the rear parts of the table.  
  5. Mechanism according to claim 4 wherein the interiors of the boxes defining the suction feed cups lying to either side of the central suction feed cup are connected by means of hoses with a suction fan.  
  6. Mechanism according to claim 5 wherein the box defining the central suction feed cup has a rearward extension and base plate containing a port which slides in sealed relationship over a fixed block provided with recesses which are adapted to communicate in turn with the port as the cup is reciprocated, one of said recesses being connected with a vacuum pump whilst the other of said recesses communicates with atmosphere.  
  7. Mechanism according to claim 4 wherein the box defining the central suction feed cup has a rearward extension and base plate containing a port which slides in sealedrelationship over a fixed block provided with recesses which are adapted to communicate in turn with the port as the cup is reciprocated, one of said recesses being connected with a vacuum pump whilst the other of said recesses communicates with atmosphere.  
  8. Mechanism according to claim 1 wherein suction is applied continuously to the suction feed cups on either side of the central suction feed cup and wherein suction is applied to the central suction feed cup only during its forward or feeding stroke and part of its return stroke, the central suction feed cup being ported to atmosphere during at least the initial part of its return stroke.  
  9. Mechanism according to claim 8 wherein each of the suction feed cups is comprised by a box having a perforated top wall, the top walls being in the plane of a plate forming the rear parts of the table.  
  10. Mechanism according to claim 9 wherein the interiors of the boxes defining the suction feed cups lying to either side of the central suction feed cup are connected by means of hoses with a suction fan.  
  11. Mechanism according to claim 10 wherein the box defining the central suction feed cup has a rearward extension and base plate containing a port which slides in sealed relationship over a fixed block provided with recesses which are adapted to communicate in turn with the port as the cup is reciprocated, one of said recesses being connected with a vacuum pump whilst the other of said recesses communicates with atmosphere.  
  12. Mechanism according to claim 9 wherein the box defining the central suction feed cup has a rearward extension and base plate containing a port which slides in sealed relationship over a fixed block provided with recesses which are adapted to communicate in turn with the port as the cup is reciprocated, one of said recesses being connected with a vacuum pump whilst the other of said recesses communicates with atmosphere.