Abstract:
A bottom feed newspaper hopper utilizes a shuttle plate that reciprocates across the bottom of a stack of the papers to partially eject each successive lowermost newspaper from the stack during each feed stroke and present it to high speed nip rollers. The rollers grasp the leading edge of the partially ejected newspaper and quickly withdraw it the rest of the way from the stack. The stack of newspapers rests upon a fore-and-aft narrow rail on the shuttle plate so that a stiffening ridge is created in the body of the lowermost paper and at least several papers thereabove. During each feed stroke, a stop at the front of the hopper permits the lowermost paper to exit from the hopper but blocks similar movement of the second paper and all those above it. The stop is offset laterally from the path of travel of the rail so that the area immediately above the rail is open and unrestricted, allowing the peak of the ridge to pass out of the hopper even if the paper has an accidentally rolled up, fat leading edge. A downwardly and laterally outwardly flaring deflecting leg at the lower end of the stop pushes down on the side slope of the ridge as the paper moves forwardly toward the nip rollers so as to bend the side slope downwardly away from the surface of the next paper, thus encouraging separation of the lower paper from those above it in the stack. Several embodiments of separator stops are disclosed, including a dual stop version for thick newspaper products and a single stop version for relatively thin, flimsy newspaper products.

Description:
TECHNICAL FIELD 
     The present invention relates to newspaper handling equipment and, more particularly, to metering hoppers which are used to feed newspapers one at a time from a stack to other collating and handling equipment of the system at a high-speed, metered rate of delivery. 
     BACKGROUND 
     Newspapers and similar articles present unique and challenging problems insofar as feeding them at regular rates of delivery is concerned. At one extreme are large, bulky big city newspapers containing many sections as well as large quantities of loose, advertising inserts. At the other extreme are thin, 6 to 12 page tabloids and similar documents. Yet, a commercially successful metering hopper needs to be capable of handling both types of newspaper products at high speeds, and without jams or misfeeds. Time is always of the essence in the assembly and production of newspaper products; therefore, stoppage of the production line to clear a jammed hopper or address another feeding problem is particularly aggravating and inefficient, all of which contributes to the challenge of providing a metering hopper that can handle a wide range of thicknesses and sizes of newspaper products reliably and at high speeds. 
     My prior metering hoppers have operated on a bottom feed principle by which stacks of newspapers are loaded into the top of the hopper and fed one at a time out of the bottom of the hopper in a transverse direction. In certain of my prior metering hoppers, such as disclosed in U.S. Pat. Nos. 4,557,472 and 4,911,421, I used a reciprocating shuttle across the bottom of the stack to engage the lowermost newspaper and drive it a short distance forwardly into a pair of powered nip rollers which then gripped the newspaper and pulled it the rest of the way from the stack. A barrier or stop at the front of the hopper kept newspapers above the lowermost newspaper in the stack from feeding simultaneously with the lowermost paper, but without blocking or interfering with movement of the lowermost paper. 
     Broadly speaking, the separating stop in some of my prior hoppers operated on the principle of cooperating with the underlying feed shuttle to define a relatively narrow outlet slot through which each successive, lowermost newspaper could be ejected from the hopper. The slot was thick enough to allow passage therethrough of the lowermost newspaper, but was thin enough to prevent any additional newspapers from exiting with the lowermost paper. The thickness of the slot could be adjusted by adjusting the vertical position of the stop, thus making the hopper adaptable for newspapers of different thicknesses. 
     One problem with the ejecting slot concept is that newspapers have a tendency to vary in thickness throughout a production run, even though they theoretically all contain the same number of pages and inserts. Thus, it is difficult to find a perfect thickness for the slot that will permit it to accommodate the random occurrence of overly thick newspapers without having a slot that is simply too thick to prevent the second and third newspapers from also being fed along with the lowermost paper. Such variations in the thickness profile along the leading edge of the newspaper can occur for many reasons such as, for example, when the relatively slick advertising inserts and other loose materials within the inside of the newspaper become shifted around in the paper to a point where, in one paper they may be in line with the separating stop while in another paper they may be offset to one side of the stop and thus present a thinner profile at the exact point of separation by the stop. Furthermore, the hard fold line that presents the leading edge of each newspaper in the stack can sometimes roll up or “balloon” so that, instead of the desired regular profile at the front of the newspaper, the newspaper presents a thick, loose front profile that is considerably wider than the ejecting slot. When such a malformed paper cannot pass through the slot, the machine jams and the line shuts down until the jam can be cleared. 
     Sometimes the rolled front edge of the newspaper is created before the stack is ever placed in the hopper, and at other times it is created during the ejection stroke itself. Due to the slickness of the advertising inserts, there is a natural tendency for the loose newspapers to become disheveled during the considerable handling that occurs both before and during placement in the hopper. This can produce the rolled front edge. Even if the front edge is not in a rolled up condition at first, the inserts may be in such a location that when the feed stroke of the shuttle takes place, the outer section of the paper tends to slide forwardly instead of staying locked together with the inserts and the other sections. This causes the front edge to loosen and roll up, preventing passage of the paper through the metering slot. 
     In order to accommodate the sometimes rolled-up front edge of the newspapers, I have provided previous designs in which the separating stop at the front of the hopper is flexible rather than rigid. While the rigid stop blocks the enlarged newspaper from passing through the slot, a resilient stop is more forgiving and will allow problem papers to pass. 
     However, the accommodating nature of a resilient stop sometimes limits its effectiveness as a separator. There is a tendency for the stop to flex forwardly all the time and permit the front edges of the newspapers to become progressively stairstepped under the stop. This causes increased down pressure from the stop on the second and third newspapers such that the bottom newspaper has difficulty breaking free from the stack during the feed stroke. Consequently, it may encourage the feeding of doubles and triples, which is undesirable. 
     At the other extreme are very thin newspapers, such as tabloids and advertising pieces on the order of from 5 to 10 pages. The small number of pages in this type of product makes the products so thin that it is difficult to place the separating stop at exactly the right height to yield a perfectly dimensioned, thin slot. Although there is less tendency for these particular products to produce a rolled up front edge, the risk of feeding doubles and triples is much greater. 
     My prior U.S. Pat. No. 4,911,421 explains the discovery that forming a longitudinal ridge in the newspaper product as it is being separated from the bottom of the stack is very helpful. The ridge tends to lock in place loose advertising inserts and the like within the inside of the newspaper and provide a stiffening column within the body of the newspaper that can be pushed against by the feed shuttle as it ejects the paper. It also has the effect of creating side slopes in the ridge that angle down away from the next overhead paper so that friction between the two papers is reduced. Generally speaking, I have found that the narrower the ridge the better; however, having a narrow support rail under the bottom newspaper to create the ridge also reduces the degree of surface contact between the rail and the newspaper, thus decreasing the ability of the rail to grip the newspaper and feed it forwardly. When using a support rail, the metering or separating slot at the front of the hopper is defined between the separating stop and the stop edge of the rail so that the peak of the ridge passes through the slot during each feed stroke. 
     However, I have found that having the separating stop located directly above the narrow support rail in this manner tends to aggravate the problem of feeding doubles and triples in relatively thin products. Moreover, it does nothing to relieve the jamming problem that occurs when the leading edge rolls up on larger size newspapers. 
     SUMMARY OF THE DISCLOSURE 
     Accordingly, a primary object of the present invention is to provide a more universal high speed metering hopper for newspaper products that can more reliably handle products at both extremes of thickness and thinness while reducing the frequency of jams and the misfeeding of multiples. 
     Pursuant to the foregoing, I have now discovered that significantly better performance can be obtained in a metering hopper by not placing the separating stop directly above and in line with the ridge-forming support rail of the feed shuttle. Instead, I have found that by placing the stop in a laterally offset position relative to the support rail so that the area immediately above the rail is opened and relieved, very good results can be obtained over a wider range of newspaper thicknesses. With thick newspapers, having an occasional rolled-up front edge is no longer a problem. Although the bottom edge of the stop and the top edge of the support rail may still be a smaller distance apart than the thickness of the rolled-up front edge, by having the stop offset to the side of the rail rather than directly in line with it, the enlarged front edge of the peak of the ridge passes smoothly through the unrestricted open space above the rail. Furthermore, the drooping side slopes in the ridge of the newspaper deflect down and under the side of the stop as the rail pushes the paper forwardly. Consequently, jams are reduced. 
     With respect to thin newspaper products, having the stop off to the side of the support rail seems to make the height of the stop less critical. That is, there is less of a need to place the bottom edge of the stop at exactly the right place in order to avoid the feeding of doubles and triples. 
     In implementing this discovery, I have found that a number of different designs for the separating stop can be utilized, so long as the area immediately above the support rail is left open and relieved. For example, a preferred form of stop that is suitable for most big city newspapers is shaped somewhat like a two-pronged fork which straddles the support rail at its front end with the two stop prongs disposed on opposite sides of the rail. Although the stops are integrally joined to one another at their upper ends, such interconnection occurs at a significant distance above the top edge of the rail so that a sizable open space is presented immediately above the rail. The stops are vertically adjustable as a unit in accordance with the flexibility and thickness of the newspapers to be metered so that the open space above the rail is significantly taller than the thickness of the newspaper and the lower terminations of the two stops are generally in line with the side slopes of the ridge in the next newspaper in the stack. 
     Preferably, each of the stops is generally L-shaped as viewed in side elevation, with a generally upright blocking leg and a generally fore-and-aft deflecting leg. The deflecting leg projects downwardly at an incline from the blocking leg and flairs out at an angle so that, as the ridge of the lowermost newspaper passes between the stops, the deflecting legs cause the side slopes of the ridge to deform downwardly and inwardly toward one another, thus intensifying the ridging configuration and forcing the side slopes to separate more completely in a downward direction from the overhead surfaces of the next newspaper. Once the lowermost newspaper has thus been partially ejected from the stack, high speed nip rollers grab the leading edge and jerk the paper the rest of the way out of the stack. 
     In the case of very thin newspaper products, such as on the order of 6-12 pages, I have found that improved results can be obtained by using only a single stop rather than dual stops. The single stop remains offset laterally from the path of travel of the support rail so that the stop does not present a restriction directly above the rail. Best results have been obtained when an auxiliary support member is utilized beneath the front edge of the stack on the same side of the rail as the separating stop so that the slope of the ridge on that side of the rail is not as extreme as on the opposite side. Thus, the extremely flimsy, thin newspapers are not permitted to droop so far out of a horizontal plane that two or more of them can accidentally slip between the side of the stop and the rail. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a fragmentary side elevational view of a metering hopper incorporating the principles of the present invention; 
     FIG. 2 is a view similar to FIG. 1 but with the near side wall of the hopper removed and parts shown in cross section for clarity, the feed shuttle being illustrated at the rear end of its return stroke; 
     FIG. 3 is a view of the hopper similar to FIG. 2 but showing the feed shuttle at the front end of its feed stroke; 
     FIG. 4 is a top plan view of the hopper with certain components partially broken away to reveal details of construction; 
     FIG. 5 is a front elevational view of the hopper with the nip rollers removed and illustrating the condition of a short stack of papers in the hopper at the beginning of a feed stroke; 
     FIG. 6 is similar to FIG. 5 but with the feed shuttle advanced part way through its feed stroke; 
     FIG. 7 is similar to FIGS. 5 and 6 but with the feed shuttle near the end of its feed stroke so that the lowermost newspaper is partially ejected from the stack and the nip rollers are clamped down onto the front edge of the paper; 
     FIG. 8 is an enlarged, fragmentary vertical cross sectional view through the hopper looking rearwardly and illustrating in particular the one way, free wheeling support roller at the back of the hopper; 
     FIG. 9 is a fragmentary side elevational view of the support roller of FIG. 8; 
     FIG. 10 is an enlarged front elevational view of the preferred dual stop separate for thick, big city newspapers; 
     FIG. 11 is a top plan view thereof; 
     FIG. 12 is a side elevational view thereof showing the generally L-shaped configuration of the dual stop; 
     FIG. 13 is an enlarged, fragmentary front elevational view of a second embodiment of a separating stop according to the present invention; 
     FIG. 14 is an enlarged, fragmentary front elevational view of a third embodiment of the invention in the form of a single stop separator having particular utility for very thin newspaper products; 
     FIG. 15 is a fragmentary front elevational view of the hopper employing the single stop separator of FIG.  14  and illustrating its manner of use with thin newspaper products; 
     FIG. 16 is a fragmentary, vertical cross-sectional view through the hopper showing the addition of an auxiliary support fin having particular utility for use in connection with the thin newspaper separator of FIGS. 14 and 15; 
     FIG. 17 is an enlarged, fragmentary front elevational view of a fourth embodiment of the invention; 
     FIG. 18 is an enlarged, fragmentary front elevational view of a fifth embodiment of the invention; 
     FIG. 19 is an enlarged, fragmentary front elevational view of a sixth embodiment of the invention; 
     FIG. 20 is a front elevational view of the separator of FIG. 19; 
     FIG. 21 is a left side elevational view of the separator of FIG. 19; and 
     FIG. 22 is an enlarged, fragmentary front elevational view of a seventh embodiment of the invention. 
    
    
     DETAILED DESCRIPTION 
     The hopper  10  has a framework  12  that supports a pair of upright, laterally spaced sidewalls  14  and  16 . The sidewalls  14  and  16  are held in place by various members of the framework  12 , including a number of transversely extending pieces. The sidewalls serve to define an open top receiving zone for a stack of newspapers or the like, the lateral dimensions of which can be varied through the use of adjustable side plates  18  and  20  located somewhat inboard of the respective sidewalls  14  and  16 . The front of the hopper is defined in part by a plurality of upright, rigid straps  22 ,  24  and  26 . The hopper is open across the back. 
     A reciprocable feed shuttle broadly denoted by the numeral  28  defines the floor of the hopper and is supported by a plurality of rollers  30  for movement across the bottom of a stack of newspapers in the hopper through alternate feed and return strokes. The shuttle  28  is somewhat inclined downwardly and forwardly as illustrated in FIGS. 2 and 3, for example, and includes a main flat plate  32  that rides on the rollers  30 . In the center of the plate  32 , the shuttle  28  has a narrow, fore-and-aft extending support rail  34  that extends over substantially the full fore-and-aft dimension of the plate  32 . The support rail  34  includes an upper, rectangular fore-and-aft strip of plastic material  36  whose upper extremity defines an uppermost longitudinal, relatively narrow edge  34   a  of the rail. 
     A set of five spike units  38  are lined up at spaced intervals along one side of the rail  34  for use in connecting the rail with the lowermost newspaper during the feed stroke of the shuttle. Each of the spike units  38  includes a spike holder  40  that is pivotally attached to the rail by a horizontal pivot  42 . Each unit  38  also has a biasing spring  44  anchored to the rail at one extremity and to a bottom corner of the holder at the other extreme so as to yieldably bias the holder in a counterclockwise direction viewing FIGS. 2 and 3. An abutment  46  projecting outwardly from the rail in the vicinity of the spring  44  is engaged by the holder  40  to limit the amount of counterclockwise rotation thereof. Thus, as illustrated in FIGS. 2 and 3, when the holders  40  are in engagement with the abutment  46 , spikes  48  of the spike units  38  project angularly upwardly and forwardly to penetrate the lowermost newspaper to a sufficient extent as to securely connect the paper to the support rail  34 . 
     Each of the holders  40  has a depth limiting shoulder  50  that prevents the spike  48  from digging in too deeply into the newspaper. The springs  44  are weak enough to permit the spike units  38  to be forcibly rotated in a clockwise direction against the return action of the springs during return strokes of the feed shuttle as the spikes  48  bear against the underside of the overhead newspaper. As will be seen from the discussion below, the lowermost newspaper is being withdrawn from the shuttle as the shuttle begins its return stroke, and such forward movement of the newspaper also has the effect of rotating the spike units downwardly into a non-penetrating position. 
     The feed shuttle  28  is reciprocated in its feed and return strokes by drive mechanism broadly denoted by the numeral  52 . Drive mechanism  52  includes a transverse, continuously rotating drive shaft  54  having a crank  56  fixed thereto for rotation therewith. The drive mechanism further includes a drive link  58  pivotally connected at one end to the crank  56  and at the other end to a collar  60  fixed to the rear end of a drive sleeve  62 . The collar  60  and the sleeve  62  are in turn fixed to the bottom of the main plate  32  of feed shuttle  28 . Sleeve  62  receives a fore-and-aft guide rod  64  that is fixed to the framework  12 . Thus, rotation of the drive shaft  54  causes reciprocation of the sleeve  62  along the guide rod  64 , which results in reciprocation of the feed shuttle  28 . 
     As shown particularly in FIGS. 2 and 3, two pairs of driven nip rollers  66  and  68  are provided at the front of the hopper. The nip rollers  66  and  68  are slightly in front of the stack receiving zone of the hopper so that when the feed shuttle  28  is in its fully retracted position of FIG. 2, the leading edge of the rail  34  is positioned slightly behind the nip rollers  66  and  68  with respect to the direction of feed. However, as shown in FIG. 3, when the feed shuttle  28  is in its forwardmost position, the rail  34  projects forwardly somewhat beyond the upper feed rollers  66  and the lower feed rollers  68 . 
     It will also be noted that the upper nip rollers  66  are alternately clamped down against and spaced up away from the lower nip rollers  68 . The apparatus for accomplishing such opening and closing of the nip rollers  66  and  68 , and for driving the same, is illustrated in FIGS. 1 and 4, and is broadly denoted by the numeral  70 . As shown, the apparatus  70  includes a sprocket  72  fixed to the drive shaft  54 , such sprocket receiving driving input power and communicating it to the shaft  54  via a chain  74  that leads from a main source of driving power (not shown). A second, larger sprocket  76  is fixed to the shaft  54 , which sprocket  76  is entrained by a drive chain  78  looped around an upper idler sprocket  80  and a lower driven sprocket  82  fixed to ajackshaft  84  that spans the sidewalls  14 , 16  and is supported thereby as shown in FIG. 7. A chain and sprocket assembly  85  (FIG. 7) drivingly connects the jackshaft  84  with the shaft  87  of the lower nip rollers  68 . 
     The apparatus  70  further includes a sprocket  86  (FIG. 1) that is backwrapped by the chain  78 . Sprocket  86  is carried on the same shaft as a companion sprocket  88  that is in turn entrained by a fore-and-aft extending endless chain  90 . The chain  90  at its front end is looped around a sprocket  92  fixed to the shaft  94  associated with the upper nip rollers  66 . Thus, the chain  90  takes driving power from the chain  78  and supplies it to the upper nip rollers  66 . 
     The shaft  94  of the upper nip rollers  66  is carried by a pair of fore-and-aft extending arms  96  on opposite sides of the hopper. Each of the arms  96  can swing up and down for a limited distance about respective horizontal pivots  100 , the pivot  100  for the left side of the machine as shown in FIG. 1 being coaxial with the axis of rotation of the sprocket  86  and  88 . Vertical clearance slots  102  are provided in the sidewalls  14  and  16  as illustrated in FIG. 1 (only the sidewall  14  being illustrated) to provide room for the shaft  94  to move up and down as the nip rollers  66 , 68  open and close. 
     In order to effect the raising and lowering of the arms  96 , the apparatus  70  further includes a linkage  104  on each side of the hopper, as well as a pair of return springs  106  on opposite sides of the hopper. The linkages  104  each include a short crank  108  fixed to opposite ends of ajack shaft  110  that extends completely across the back of the hopper and projects outwardly through and beyond the sidewalls  14  and  16 . Each crank  108  has a pivot connection  112  with a longer intermediate link  114  that has pivot connection  116  at its upper end with a short link  118 . The link  118 , in turn, has a pivot connection  120  with the corresponding arm  96  near its rearmost end. The rearmost end of each arm  96  also carries an outturned ledge  122  that projects laterally outwardly from the face of the arm  96  into the path of travel of the short link  118 . A rubber cushion  124  is carried on the ledge  122  with an upper surface that substantially coincides with the lower extremity of the arm  96 . 
     The jack shaft  110  has a sprocket  126  (FIG. 1) fixed thereto that is entrained by an endless chain  128  extending forwardly to another sprocket  130  fixed to the drive shaft  54 . Thus, the jack shaft  110  receives driving power from the chain  128 , and as the jack shaft  110  rotates, the cranks  108  also rotate so that the pivot connection  112  moves in a circular path of travel about the axis of the jack shaft  110 . As this occurs, the intermediate link  114  has the effect of alternately pulling down and pushing up on the short link  118 . During the down pulling portion of each cycle, the short link  118  comes down into abutting engagement with the cushion  124  on arm  96 . As the intermediate link  114  continues toward the mid-point of its cycle, such continued motion thereafter causes the short link  118  to effectively become drivingly engaged with the rear end of the arm  96  through the cushion  124 , thus swinging down the rear end of the arm  96  about its pivot  100 . Thus, in this part of the cycle, both of the arms  96  become raised at their front ends, opening the nip rollers  66  and  68 . 
     As the pivot connection  112  continues on into the last 180° of its cycle, the intermediate link  114  swings the short link  118  upwardly away from the cushion  124 , thus allowing the return spring  106  to pull the front end of the arm  96  downwardly. Consequently, the nip rollers  66  close against the lower nip rollers  68 . Due to the timing involved, the nip rollers  66  and  68  are open when the feed shuttle  28  is filly retracted as in FIG.  2  and are closed when the feed shuttle is filly forward as in FIG.  3 . 
     As illustrated perhaps most clearly in FIG. 4, the two side plates  18  and  20  of the hopper carry a pair of free wheeling rollers  132  and  134  respectively that are located to underlie and support the newspaper stack in the area of the rear comers. In addition, in the central rear portion of the hopper, a special one-way free wheeling roller  136  is located beside the path of travel of the support rail  34  in disposition to engage and underlie the central rear extremity of the newspaper stack. As illustrated in detail in FIGS. 8 and 9, the one-way roller  136  is carried by a fore-and-aft extending arm  138  fixed to a portion of the framework  12  at the rear of the hopper. The roller  136  has an outer, annular rim  140  of rubber material or the like that encircles a one-way clutch  142  on a rotatable hub  144  of the wheel. The rim, clutch  142  and hub  144  are adapted to freely rotate about the axis of the mounting bolt  146  that attaches the hub to the arm  138 , but such rotation is only in a counterclockwise direction viewing FIG. 9 so that the upper periphery of the wheel  136  rotates generally in the direction of feed in a free-wheeling manner. The clutch  142  precludes rotation of the wheel in a clockwise direction viewing FIG. 9, i.e., in a direction opposite to the direction of feed. As illustrated in FIGS. 8 and 9, the upper periphery of the wheel  136  projects slightly above the upper edge  34   a  of the support rail  34 . 
     The embodiment of the invention disclosed in FIGS. 1-12 utilizes a dual stop separator at the front of the hopper broadly denoted by the numeral  148 . The separator  148  is located at the bottom of the center upright strap  24  and is shaped somewhat in the nature of a fork having two prongs. Details of the dual stop separator  148  are illustrated in FIGS. 10-12. 
     As illustrated in those figures, the separator  148  includes a pair of generally L-shaped stops  150  and  152  that are spaced apart laterally from one another and are fixed to opposite sides of an upright, rectangular mounting plate  154 . The mounting plate  154  is adapted to butt up against the backside of the strap  24  and to be secured thereto by machine screws or the like passing through a pair of countersunk holes  156  and  158  in the plate  154 . 
     Using the stop  150  as an example, each stop includes an upright blocking leg  160  and a lower, outwardly and downwardly projecting deflecting leg  162 . In addition to projecting forwardly and downwardly from the blocking leg  160 , the deflecting leg  162  also angles laterally outwardly and downwardly as shown in FIG. 10, such that the two deflecting legs  162  of the stops  150  and  152  flare outwardly or diverge from one another in the feeding direction of the newspapers. 
     Each stop  150  and  152  is constructed from a single unitary piece of metal rod having a circular cross section configuration. Thus, the legs  160  and  162  are integrally joined to one another at a bend or knee  164 . Preferably, viewing FIG. 10, each deflecting leg  162  projects laterally outwardly from the upright axis of the leg  160  at an approximate 45° angle, while viewing FIG. 12, it will be seen that each deflecting leg  162  projects forwardly from the upright axis of the leg  160  at an approximate 60° angle. The backside of each leg  160  presents a blocking surface  160   a  that faces the front edges of the newspapers within the stack and which has a lower termination  164   a  at the knee  164 . Similarly, each deflecting leg  162  has a deflecting surface  162   a  along its inside stretch that generally faces the opposite deflecting leg  162  in disposition for engaging a corresponding side slope of the ridge in the lowermost newspaper as it is ejected from the stack as will hereinafter be explained in more detail. The outermost free end of the deflecting leg  162  terminates in a rounded tip  166 . 
     The stops  150  and  152  are integrally connected to one another by the mounting plate  154 . Viewed from the front, as in FIG. 10, it will be seen that the two stops  150 , 152  and the plate  154  cooperate to yield a somewhat inverted U-shape or V-shape for the separator  148 . The bottom edge  154   a  of the mounting plate  154  is spaced a distance above the knees  164  of the stops  150  and  152  so that an open space  168  is defined below the edge  154   a  and between the blocking legs  160 . The vertical distance between the bottom edge  154   a  of the plate  154  and the knees  164  of the stops  150 , 152  should substantially exceed the thickness of the newspapers being fed by the hopper. In the embodiment of FIGS. 1-12, each blocking leg  160  is approximately the same length as each deflecting leg  162 . 
     As illustrated in FIG. 5,  6  and  7 , the dual stop separator  148  is situated symmetrically with respect to the rail  34  so that the two stops  150  and  152  are disposed on opposite sides of the path of travel of the rail  34  in laterally offset relationship to the rail  34 . This causes the open space  168  to be disposed directly above the rail  34 . The vertical dimension of the space  168  can be adjusted as a result of the fact that the strap  24  on which the separator  148  is mounted is vertically adjustable. To this end, the strap  24  is slidably received within a vertically disposed guide channel  170  so that when a clamping knob assembly  172  is loosened, the strap  24  may be shifted upwardly and downwardly relative to the guide  170  that is fixed to the framework of the hopper. The clamping knob assembly  172  is carried by the strap  24  during its shifting movement and projects through a vertically elongated clearance slot  174  in the guide channel  170 . An adjusting screw  176  is threaded into an outwardly projecting tab  178  on the central strap  24  and bears against the top of the guide channel  170  such that rotation of the adjusting screw  176  when the clamp knob  172  is released causes the strap  24  to be incrementally advanced upwardly or downwardly depending upon the direction and extent of rotation of the adjusting screw  176 . 
     OPERATION 
     FIGS. 5,  6  and  7  are particularly illustrative of the separating action performed by the dual stop separator  148 . As illustrated in FIG. 5, when a stack of newspapers is placed within the hopper and laid to rest on the support rail  34 , the support rollers  132 , 134 , and the one-way free-wheeling roller  136 , a central elongated ridge is formed in the newspapers above the rail  34 . The ridge in each newspaper has an uppermost peak that directly overlies the rail  34 , and a pair of side slopes that diverge downwardly away from the peak on opposite sides of the rail  34 . 
     The condition of things in FIG. 5 corresponds to the condition illustrated in FIG. 2, i.e., the rail  34  is fully retracted and is ready to begin a feed stroke. The dual stop separator  148  has been adjusted that so that the open space  168  directly above the rail  34  is substantially greater than the thickness of the lowermost newspaper, preferably thicker or taller than the predicted thickness of the thickest rolled up front edge that may be encountered on newspapers being fed. In the position illustrated in FIG. 5, the space is approximately three newspaper sections thick. The knees  164  of the stops  150  and  152  are located in line with the second newspaper in the stack so that the second newspaper and all of those above it are blocked by the blocking legs  160  of the stops, and the rearwardly facing surface of the strap  24 , as well as the rearwardly facing surfaces of the straps  22  and  26 . 
     As the feed shuttle  28  begins its forward stroke, the spikes  48  penetrate into the bottom newspaper to lock the newspaper with the rail  34 . As the rail  34  then moves forwardly, the lowermost paper moves forwardly with it, and the ridge of the paper starts to pass through the separator  148 . The peak of the ridge in the lowermost newspaper is unobstructed as it attempts to move forwardly, and it moves in an unhindered manner through the open space  168 . On the other hand, the slide slopes of the lowermost paper begin to contact the deflecting surfaces of the deflecting legs  162  of the stops, causing the side slopes to bend downwardly more completely away from the next overhead newspaper as illustrated in FIG.  6 . By the time the feed shuttle reaches its forwardmost position at the end of the feed stroke as illustrated in FIGS. 3 and 7, the side slopes of the paper will have deflected downwardly even further and the nip rollers  66  and  68  will have clamped down onto the leading edge of the paper. Such clamping action by the nip rollers causes the leading edge to be bent down slightly away from the top edge of the rail  34  inasmuch as the point of engagement between the roller  66  and  68  is somewhat lower than the top edge of the rail. Such down bending of the leading edge of the newspaper also assists in the separating or breaking away of the lower newspaper from the next paper in the stack. 
     Once the nip rollers  66  and  68  have grabbed a hold of the lower newspaper, they quickly begin pulling it off the rail  34  and the rest of the way out of the stack. At the same time, the rail  34  commences its return stroke. This simultaneous forward movement of the lower paper and rearward movement of the rail  34  causes the spike units  38  to rotate clockwise viewing FIGS. 2 and 3 as permitted by the springs  44  such that the spikes do not hinder withdrawal of the paper from the stack by the nip rollers. Additionally, as the rail  34  returns to its full rearward position, the spikes wipe against the bottom of the next newspaper in the stack but do not penetrate the paper at this time. Thus, there is no tendency for the spikes to drive the next newspaper toward the rear as the rail  34  is moving rearwardly. Moreover, the one-way free wheeling roller  136  is helpful in this respect. Inasmuch as the roller  136  can only rotate in a counterclockwise direction viewing FIG. 9, it resists rearward movement of the next newspaper but freely allows forward movement thereof during the feed stroke. Moreover, since the upper periphery of the roller  136  is slightly above the upper edge  34   a  of the rail  34 , the wheel  136  tends to hold the back portion of the newspaper slightly above the rail. 
     The dual stop separator  148  is very forgiving insofar as thickness variations in the newspapers is concerned. For example, if a newspaper with a rolled up front edge is presented to the stop, the rail  34  has no problem in feeding that paper through the two stops  150  and  152  of the separator. Even though the rolled up front edge may be thicker than the distance between the top edge of the rail  34  and the knees  164  of the stops  150  and  152 , the central portion of that rolled front edge at the peak of the ridge is aligned with the open space  168  which will be substantially greater in vertical width than the thickness of the rolled up edge. Thus, the rolled up front edge can pass freely through the open space  168 . And, as long as the newspaper is flexible enough that the side slopes of the ridge can be deflected down to pass under the deflecting legs  162  of the stops, the mis-shapened newspaper will pass through the separator  148  without hesitation. In the event that the newspaper is particularly thick and resistant to flexure, it may be necessary to adjust the height of the separator  148  accordingly. 
     ALTERNATIVE EMBODIMENTS 
     FIG. 13 shows a slightly different configuration for the dual stop separator. In FIG. 13, the dual stop separator  200  is identical to the dual stop separator  148 , except that some of the dimensions of the stops  202  and  204 , as well as the height of the open space  206 , are different from the corresponding dimensions in the separator  148 . In this regard, the blocking leg  208  of each stop  202 , 204  is somewhat longer than the corresponding blocking legs  160  of stops  150  and  152 . This permits the open space  206  of the separator  200  to likewise be taller than the corresponding open space  168 . This extra height for the open space  206  is helpful in the event that the newspapers are significantly thicker than those illustrated in FIGS. 5,  6  and  7 . The deflecting legs  210  of the stops  202  and  204  may remain of the same length as the corresponding deflecting legs  162  of stops  150  and  152 . 
     The action of the newspapers moving through the separator  200  is the same as that with respect to the separator  148 , except that with the separator  200  the newspapers will be subjected to less flexing action. Due to the presence of the open space  206  directly above the rail  34 , the blocking legs  208  of the stops  202  and  204  prevent newspapers above the lowermost section from moving forwardly with the support rail  34  during the feed stroke. However, there is no downward pressure applied to the peak of the ridge in the newspaper directly above the rail  34  which could otherwise encourage the feeding of doubles, and so long as the side slopes on the ridge of the newspaper can be deflected downwardly by the deflecting legs  210  and passed between the knees  212  of the stops and the rail  34 , the newspapers can be readily fed by the rail even if a newspaper with a rolled up front edge is presented. For best results, the open space  206  should not only be substantial taller than the thickness of the lowermost newspaper, but should also be taller than the anticipated thickness of a rolled up front edge. In that way, the rolled up front edge, in the area of the peak in the ridge, can pass readily through the open space  206 . The flexibility of the newspaper is not particularly effected by the presence or absence of a rolled up front edge and, thus, allowance simply needs to be made for increased resistance to deflection by newspapers having inserts bunched up in the center of the edge or otherwise providing increased resistance to bending when engaged with the knees  212  and the deflecting legs  210 . 
     FIGS. 14,  15  and  16  are directed toward a single stop separator that is particularly useful when the newspaper products to be metered are quite thin and flimsy. As shown in FIG. 14 in particular, the single stop separator  300  has a single stop  302  that is offset laterally to one side of the rail  34 . As with the previous stops, the stop  302  has an upright blocking leg  304 , a downwardly, forwardly and outwardly angled deflecting leg  306 , and a rounded knee  308  between the legs  304  and  306 . The knee  308  is located at the lower termination of a rearwardly facing blocking surface of the leg  304  and at the commencement of the deflecting surface of the leg  306 . Due to the fact that the stop  302  is laterally offset from the rail  34 , an open space  310  is defined directly above the rail  34 , beside the blocking leg  304  and beneath the lower edge  312   a  of the mounting plate  312  of the separator  300 . 
     In the feeding of flimsy newspapers such as those illustrated in FIG. 15, the use of a stiffening ridge in the body of such papers is particularly important. However, because of their inherent flimsiness, the newspapers also have a tendency to droop down so completely when the ridge is formed that the side slopes of more than one newspaper can fit between the stop  302  and the rail  34 . Consequently, as shown in FIGS. 15 and 16, while it is helpful to maintain the droop of the newspapers on one side of the rail  34  so as to achieve some semblance of a stiffening ridge, it is helpful on the other side of the rail, where the stop  302  is located, to keep the leading edges of the newspapers fairly level. 
     This is achieved through the use of an auxiliary support  314  fixed to the plate  32  of shuttle  28  for reciprocation therewith. The support  314  is generally L-shaped in cross sectional configuration and presents an upstanding, fore-and-aft extending fin  316  that is spaced laterally outwardly from the rail  34  and the stop  302 . The fin  316  has an uppermost edge  318  that extends generally parallel to the plate of the shuttle for the front half of the fin  316 , and then slopes downwardly and rearwardly for the rear half. The edge  318  is disposed to engage the bottom surface of the lowermost newspaper, and in its front portion is disposed at a slightly lower level than the upper edge of the rail  34 . Thus, the lowermost surface of the lower newspaper extends generally parallel to the plate  32  of the shuttle for a short distance rearwardly from the leading edge of the newspaper, and then slopes downwardly and rearwardly until the rear extremity of the fin  316  is reached, whereupon it rides directly against the shuttle plate. The fin  316  terminates at its rear end slightly forwardly of the fore-and-aft midpoint of the shuttle plate. In the case of the feeding of relatively thin newspapers, it has also been found beneficial to completely remove the rear rollers  132  and  134  from the side plates  18  and  20 , although the one-way free wheeling roller  136  is still used. 
     As illustrated in FIG. 15, the single stop separator  300  is adjusted vertically into such a position that the open space  310  immediately above the rail  34  is substantially taller than the thickness of the lowermost newspaper product. With the knee  308  of the stop  302  positioned low enough that it is at or below that portion of the next higher newspaper in the stack directly behind it, each successive lowermost newspaper can be fed by the rail  34  outwardly past the stop  302  and into the awaiting nip rollers. As the front edge of the ejecting lowermost newspaper engages the deflecting leg  306  of the stop  302 , the newspaper deflects downwardly under the leg  306  to breakaway cleanly from the next overhead newspaper. Due to the absence of downward pressure from the stop  302  against the newspapers and the rail  34 , there is a reduced tendency to feed doubles and triples of the thin products. Yet, if the front edge of one of the products should be rolled up and enlarged for any reason, such product can still be fed out of the hopper without malfunction. 
     FIG. 17 illustrates another embodiment of a single stop separator which is less preferred than the separator  300 , but which may provide satisfactory results under some conditions. The separator  400  of FIG. 17 has a single stop  402  that is offset laterally from the rail  34  and has only an upright blocking leg  404  without a deflecting leg. The lower termination  406  of the blocking leg  404  is rounded but does not bend forwardly as do the knees in the stops of the previous embodiments. Due to the laterally offset nature of the stop  402 , an open space  408  is defined above the rail  34 , beside the stop  402  and beneath the bottom edge  410 a of the mounting plate  410 . 
     FIG. 18 illustrates a dual stop separator  500  having two stops  502  and  504  that are provided with upright blocking legs  506  only and no deflecting legs. The terminations  508  of the lower ends of the blocking legs  506  are rounded but do noted forwardly in the nature of knees as in certain of the other embodiments. A relieved, open space  510  is defined above the rail  34 , between the blocking legs  506 , and beneath the lower edge  512 a of the mounting plate  512 . 
     FIGS. 19,  20  and  21  show another form of dual stop separator made from flat plate material instead of rod stock as in the prior embodiments. The dual stop separator  600  of FIGS. 19-21 also differs from certain of the prior embodiments in that the open space  602  directly above the rail  34  is located below what may be termed a bend or knee  604  in the device. In this respect, the mounting plate and upright blocking face of the separator  600  are integrated into one another so as to present an upright blocking leg  606  that is actually centered above the rail  34  and is symmetrical therewith. The separator plate is bent outwardly at the knee  604  and has a generally inverted V-shaped cutout at its lower front edge, the apex of which defines the open space  602 . A pair of deflecting legs  608  project downwardly, forwardly and laterally outwardly from the knee  604  on opposite sides of the rail  34  and are twisted outwardly about their longitudinal axes to a slight extent. The tips  610  of the deflecting legs  608  are rounded. 
     Although the plate-like separator  600  of FIGS. 19-21 is capable of performing the separation of successive lowermost newspapers in the stack from those above it, this particular embodiment has been found to be less preferred than the embodiment disclosed in FIGS. 1-12, for example. The open space  602  prevents a pinching or clamping pressure against the ridge of the newspapers as in prior embodiments, but the plate-like separator  600  seems to be less forgiving of those occasional newspapers having fat, rolled-up front edges. 
     FIG. 22 illustrates another embodiment of a separator utilizing certain principles of the present invention. The separator  700  of FIG. 22 comprises a plate  702  that extends for a distance across the hopper in the central region thereof. The plate  702  is entirely within a single vertical plane, although the plate may be curled up slightly along its lower extremity if desired. A notch  704  along the lower extremity of the plate directly above the rail  34  serves to define an open space  706 , and the neighboring lower portions of the plate  702  on opposite sides of the space  706  serve to define blocking stops  708  and  710 . The stops  708  and  710  are laterally offset from the rail  34  so that the peak of the ridge of the lowermost newspaper passes through the open space  706  and the side slopes of the ridge are deflected downwardly under the lower terminations  708   a  and  710   a  of the stops  708  and  710 . 
     The preferred forms of the invention described above are to be used as illustration only, and should not be utilized in a limiting sense in interpreting the scope of the present invention. Obvious modifications to the exemplary embodiments, as hereinabove set forth, could be readily made by those skilled in the art without departing from the spirit of the present invention. 
     The inventor hereby states his intent to rely on the doctrine of equivalents to determine and assess the reasonably fair scope of the present invention as pertains to any apparatus not materially departing from but outside the literal scope of the invention as set forth in the following claims.