Abstract:
A plastic bag dispenser holds a continuous roll of bags, connected by perforated separation lines. The dispenser is provided with a tongue, which the bags are dispensed over, that engages the separation line between the bag at the end of the roll and the next bag. This begins the separation of the separation line, as well as holds the next bag behind the tongue. A finger is provided on the upstream side of the tongue, with a gap between the finger and tongue. As a bag is separated, a portion of the front edge of the next bag is held in the gap, holding the bag in position for the next user. The roll of bags rests in curved grooves in the dispenser that cause the roll to abut and frictionally engage an interior surface of the dispenser, preventing free-wheeling of the roll. The curvature of the grooves causes the component of force which creates the frictional engagement to increase as the size of the roll decreases.

Description:
This is a continuation of U.S. patent application Ser. No. 08/215,197 filed Mar. 21, 1994, now U.S. Pat. No. 5,558,262, which is a continuation-in-part of U.S. patent application Ser. No. 08/124,952, filed Sep. 21, 1993, entitled “Plastic Bag Dispenser,” now U.S. Pat. No. 5,433,363, which is a continuation of U.S. patent application Ser. No. 07/821,192, filed Jan. 21, 1992, entitled “Plastic Bag Dispenser,” now U.S. Pat. No. 5,261,585, which is a continuation-in-part of U.S. patent application Ser. No. 07/764,137, filed Sep. 20, 1991, entitled “Roll of Plastic Bags for Use with Bag Dispensing Device,” now U.S. Pat. No. 5,219,424, and a continuation-in-part of U.S. patent application Ser. No. 07/652,031, filed Feb. 7, 1991, entitled “Plastic Bag Dispenser,” now U.S. Pat. No. 5,135,146, all in the name of Ebrahim Simhaee. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to devices for dispensing a continuous web of articles. Specifically, the invention relates to plastic bag dispensers, such as the type used for self-service produce, grocery, or garbage bags. 
     BACKGROUND OF THE INVENTION 
     In a supermarket or food market, fruits and vegetables are often displayed in bulk, possibly in piles of loose items. Consumers must then take a bag from a nearby source and pick and bag their own produce. The most common form of these produce bags are cylindrical rolls of plastic bags, mounted horizontally or vertically on a shaft. The bags have perforated separation lines between them. Separation is accomplished by grabbing the end bag with one hand, anchoring the next bag or the roll with the other hand, and pulling. Unfortunately, this not only separates the bag from the roll, but can deform or even tear the bag. Sometimes, consumers will attempt to simply jerk the bag from the roll, without holding the adjacent bag. This, too, can damage the bag or simply reel out the roll. After any bag separation, the end of the next bag can be difficult to find or grab as it may lie flat on the surface of the roll. 
     It is thus an object of the invention to provide an improved dispenser for a continuous web of articles. 
     It is a further object of the invention to provide a dispenser with improved means for easily separating articles from a continuous web with one-handed operation and retaining the next article in an easily accessible position. 
     It is a further object of the invention to provide an improved means for preventing free-wheeling of the continuous web during dispensing. 
     It is a further object of the invention that the dispenser be economical and simple to manufacture. 
     SUMMARY OF THE INVENTION 
     In accordance with the preferred embodiment of the invention, a plastic bag dispenser holds a continuous roll of bags, connected by perforated separation lines. The dispenser is provided with a tongue, which the bags are dispensed over, that engages the separation line between the bag at the end of the roll and the next bag. This begins the separation of the separation line, as well as holds the next bag behind the tongue. A finger is provided on the upstream side of the tongue, with a gap between the finger and tongue. As a bag is separated, a portion of the front edge of the next bag is held in the gap, holding the bag in position for the next user. The roll of bags is mounted in the dispenser so that the roll frictionally engages an interior surface of the dispenser. 
     As individual bags are dispensed, the roll of bags decreases in weight. This can cause a significant difference in the frictional force between the roll and the interior surface of the dispenser which is needed to prevent freewheeling of the roll as the bags are being dispensed. A large difference is undesirable because it can mean either that there is too much friction when the roll is full or too little friction when the roll is depleted. The frictional force is a component of force due to the weight of the roll. In accordance with this invention, the roll of bags is mounted in such a way that the frictional component of force is increased, as a percentage of the total force, as the weight of the roll decreases. Hence, in this way the maximum and minimum frictional forces which retard freewheeling are maintained within acceptable limits for the entire roll, i.e., when the roll is full and when it is depleted. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other objects and advantages of this invention will become apparent to those skilled in the art upon reading the detailed description of a preferred embodiment in conjunction with a review of the appended drawings in which: 
     FIG. 1 is a perspective view of a dispenser, after a bag has been separated and removed; 
     FIG. 2 is a side cross-section of the tongue/finger assembly shown in FIG. 1, showing the next bag partially inserted in the gap; 
     FIG. 3 is a top view of the tongue/finger assembly of FIG. 2; 
     FIG. 4 is a detail of the separation line between two adjacent bags on the continuous roll; 
     FIG. 5 is a perspective view of the axle; 
     FIG. 6 is a partial cross-section of the embodiment of FIG. 1, showing the axle and the O-ring; 
     FIG. 7 illustrates the preferred configuration of the plastic bags in accordance with the invention; 
     FIG. 8 is a perspective view of a dispenser in which the roll is supported so that it frictionally engages a surface of the dispenser; 
     FIG. 9 is a front view of the dispenser of FIG. 8; 
     FIG. 10 is a side partial cross-section view of the dispenser of FIG. 8; 
     FIG. 11 is a detail view of the tongue/finger assembly of the dispenser of FIG. 8, showing the next bag partially engaged by the tongue; 
     FIG. 11A is a detail view as in FIG. 11, after dispensing a bag; 
     FIG. 12 is a cross-section taken along the line  12 — 12  of FIG. 11A; 
     FIG. 13 is a perspective view of a dispenser according to the preferred embodiment of the invention; 
     FIG. 14 is a front view of the dispenser of FIG. 13; 
     FIG. 15 is a side partial cross-section view of the dispenser of FIG. 13; 
     FIG. 16 is a cross-section taken along the line  16 — 16  of FIG. 15; 
     FIG. 17 is a cross-section taken along the line  17 — 17  of FIG. 15; and 
     FIG. 18 is a side partial cross-section view of the dispenser of FIG.  13 . 
    
    
     DETAILED DESCRIPTION 
     Referring to FIGS. 1-7, a dispenser includes a generally rectangular box  10  for housing a continuous roll of articles  12 . Individual articles  14  may be sheets of plastic, preferably pre-fabricated into sealed bag-like containers disposed in a unitary end-to-end relationship. The top of the box  10  is open for quick replacement of the roll  12 , which rotates on an axle  16 . The two ends of the axle  16  rest in two grooves  18  cut into the interior faces of the side walls of the box  10 . The grooves  18  extend to the top of the side walls, where the axle  16  is inserted. One end of the axle  16  preferably has notches  19  and the corresponding groove  18  is narrowed to prevent rotation of the axle  16  during rotation of the roll  12 . One end wall  20  has a lower top surface than the other three walls. The bags  14  are dispensed over the top surface of the end wall  20 . 
     Each bag  14  is sealed at one end and connected to adjacent bags by a perforated separation line  22 . At the center of the separation line  22  is a slot  24 , although the slot  24  can be placed at other positions on the separation line  22 . Integrally molded with the end wall  20  and extending upward beyond the wall  20  is a tongue  26 . The tongue  26  is positioned at the center of the top surface of the wall  20  to receive the slot  24 . The tongue  26  preferably has a half-oval shape with its top surface angled upward, the higher side being toward the inside of the box  10 . 
     Either integrally molded with or preferably attached to the interior surface of the end wall  20 , adjacent the tongue  26 , is a finger  28  that extends inwardly from the wall  20 . The upper limit of the finger  28  is below the top of the tongue  26 , but above the upper surface of the end wall  20 . The top of the finger  28  is preferably rounded convexly in the direction of travel of bags  14  to facilitate the movement of bags over the finger  28 . Between the upper portions of the tongue  26  and finger  28  is a V-shaped gap  30 , perpendicular to the direction of travel of the bags  14 , which receives the leading edge of an upstream bag after a slot  24  between two bags  14  has been engaged by the tongue  26 . 
     Within the gap  30  are means  32  to impede but not prohibit the upward movement of a portion of a bag  14  out of the gap  30 , while not impeding downward movement into the gap. This means is preferably a set of downwardly-angled horizontal teeth  32  on the surface of the finger  28  within the gap  30 , as shown in FIG.  2 . 
     In practice, a consumer would find the dispenser in a condition as in FIG. 1, with a portion of a leading edge of an end bag  34  within the gap  30  and the two leading corners of the end bag  34  extending forward past the end wall  20 . The consumer grabs the portion of the end bag  34  extending forward of the end wall and pulls it upward and forward, away from the roll  12 , extricating the bag  34  from the gap  30 . The teeth  32  are designed so that only minimum force is required to extricate the bag  34  from the gap  30 , avoiding damage to the bag. While pulling the end bag  34  away from the roll  12 , the consumer pulls the bag  34  over the tongue  26  and then at an angle below horizontal, preferably to below the level of the bottom of the gap  30 , so that the tongue will contact the underside of the bag  34  as the bag travels. Eventually, the tongue  26  will engage the slot  24  at the trailing end of the end bag  34 , splitting the slot  24  over the tongue  26 . The center of the leading edge of the next bag will then travel down into the gap  30  and remain there. 
     Further forward motion of the end bag  34 , in response to force by the consumer, will result in the ends of the separation line  22  bending forward around the tongue  26 . The separation line  22  will then separate starting at the slot  24  and progressing outward toward both ends of the line  22 . After complete separation and removal of the end bag  34 , the dispenser will again be as in FIG. 1, with a new end bay ready for the next consumer. Because of the downward-facing teeth  32  in the gap, the bag  34  will tend to remain in the gap  30  until such time as a consumer pulls upward on the leading edge. The dispenser will thus constantly be in a ready state, until the roll of bags  12  is depleted. 
     Many different types of plastic bag configurations are commonly used and the principles of the invention do not require a specific configuration; however, in the preferred embodiments, a so-called “star seal” configuration as shown in FIG. 7 is employed because it is somewhat easier to open and provides a strong seal at the bottom. Whatever the configuration, the width of the roll relative to the width of the tongue  26  should be such that when a bag is severed from the roll, the edges of the next contiguous bag are pulled forwardly of the tongue a sufficient distance so that they can be grasped readily by the user. 
     When a consumer pulls on the end bag  34 , a significant amount of rotational momentum is gained by the roll  12 . In this embodiment, the bags are wrapped around a cylindrical core  15  which is mounted on the axle  16  with sufficient clearance that the core  15  and roll  12  can rotate relative to the axle  16 . To prevent the roll  12  and core  15  from free-wheeling and reeling out several bags as the end bag  34  is dispensed, the axle  16  with notches  19  is preferably provided with a rubber O-ring  38 , as in FIG. 5, that frictionally engages the core  15  of the roll  12 . Other materials besides rubber will work similarly. In known devices, an O-ring is slipped onto the axle, and over time, tends to slip off one of the ends. To prevent axial movement of the O-ring  38  on the axle  16 , the axle  16  is provided with a circumferential groove  36 , in which the O-ring  38  rests. The groove  36  is dimensioned so that a portion of the O-ring  38  will extend beyond the outer surface of the axle  16 . 
     The construction of the dispenser allows for simple mounting to any surface, be it horizontal, vertical or otherwise, by conventional means, such as with screws or glue. It also can be free standing, with one hand holding the box  10 , if necessary, while the other pulls the end bag  34 . The dispenser may also be formed of a light-transmissive material to give the owner of the dispenser ample warning that a roll  12  is nearly depleted. 
     In the dispenser of FIGS. 8-13, a dispenser  10 ′ is preferably mounted at a few degree angle from the vertical. From one end wall  20 ′, a tongue  26 ′ and finger  28 ′ are mounted on and perpendicular to the top surface of the wall  20 ′, facing inward. The entire dispenser is preferably mounted on a pole  40  or any other surface that will maintain its angled configuration with respect to the vertical, as described more fully below. 
     As seen most clearly in FIG. 10, the grooves  18 ′ in the sidewalls  21 ′ are preferably formed by guides  42 , although they could be impressed into the walls  21 ′ as with the embodiment of FIG.  1 . The grooves  18 ′ also are angled with respect to wall  20 ′ so that the roll of bags  12 ′ will be biased against the interior bottom surface  44  of the dispenser  10 ′, engaging the surface  44  at position A. As seen in FIG. 10, the area of frictional contact between the roll  12 ′ and the surface  44  will move closer or farther from wall  20 ′ depending on the size of the roll  12 ′. The angle of the grooves  18 ′ with respect to the vertical of course depends on the mounting angle of the dispenser  10 ′, so the mounting angle should be chosen so that gravitational force alone will move the axle  16 ′ down the grooves  18 ′ and force the roll  12 ′ against the surface  44 . Due to this frictional contact with the surface  44 , the axle  16 ′ need not include notches at its end (see FIG. 10) to prevent free-wheeling, nor the O-ring and groove seen in FIG. 6, since the frictional contact between the outer bag of the roll  12 ′ and the bottom surface  44  will serve the same purpose. 
     The roll  12 ′ is placed into the dispenser  10 ′ merely by slipping the axle  16 ′ into the grooves  18 ′, since there are no axle notches to be aligned with the groove as in the embodiment of FIG.  1 . The tolerance with respect to the length of the axle  16 ′ and the corresponding distance between the grooves  18 ′ should be relatively close, since an axle that is too short may become angled from its normal position perpendicular to the walls, causing the edges of the roll  12 ′ to engage the grooves  18 ′ or guides  42  as it turns, potentially damaging the bags  14 ′. 
     It can be seen that the roll  12 ′ is preferably positioned within the dispenser  10 ′ so that the bags  14 ′ will be dispensed from the underside of the roll  12 ′, instead of over the top as shown in FIG.  1 . Preferably, the pole  40  and dispenser  10 ′ would be mounted on a table top surface (not shown) so that the dispenser  10 ′ is approximately at least the height of an average standing consumer&#39;s abdomen. This will allow the consumer to pull outward and downward on the end bag  34 ′ in a natural movement of the arm. This will also make it convenient for a person to pull up slightly on the leading edge of the end bag  34 ′ to dislodge it from the gap  30 ′ for dispensing. With the bags dispensed from the underside of the roll  12 ′ and the position and angle of the tongue  26 ′ and finger  28 ′, the possibility of a consumer pulling a bag  34 ′ from the dispenser above and away from the tongue  26 ′, which would defeat a significant purpose of the invention, is greatly decreased. 
     The essential functioning of the tongue  26 ′ and finger  28 ′ with respect to engaging and separating bags  14 ′ is identical to that of the embodiment of FIG. 1, except that the tongue  26 ′ to and finger  28 ′ are perpendicular to the position of FIG.  1 . Similar teeth  32 ′ are also present in the gap  30 ′. An end bag  34 ′ being separated and dispensed is shown in FIGS. 11-12. 
     Some economy of material is possible with the dispensers of the present invention. For example, the embodiment of FIGS. 8-12 has only three walls, the fourth being unnecessary. In the same embodiment, the roll  12 ′ may be directly mounted onto an axle  16 ′, without the need for a core as in the embodiment of FIG. 1 The axle  16 ′ may also formed of a hollow, recyclable material. 
     The preferred embodiment of the invention is shown in FIGS. 13-18 wherein a number of the elements are similar to the elements of FIGS. 8-12. For example, extending from the bottom wall  120  (since the dispenser is preferably mounted vertically in this embodiment), a tongue  126  and finger  128  are mounted on and perpendicular to the top surface of the wall  120 , facing upward and inward. The tongue and finger  128  act in essentially the same manner as in the previous embodiments, except that the downward-facing teeth  32  in the gap  30  of the embodiment of FIGS. 1-7 has been replaced with ridges  132  along the length of the finger  128 . These ridges  132  serve the same purpose as the teeth, which is to help prevent the leading edge of the bag  114  to be dispensed from inadvertently leaving the gap  130 . An end bag  134  in the process of being dispensed is shown in FIG.  14 . 
     Two of the differences between the embodiment of FIGS. 13-18 and that of FIGS. 8-12 are the curved grooves  118  and the addition of a friction roller  150 . The purposes for these two differences are related, as if further discussed below. 
     In the embodiment of FIGS. 8-12, the grooves  18 ′ are straight over their functioning lengths. Thus, the angle between the grooves  18 ′ and the bottom surface  44  remains essentially constant. Therefore, the component of the weight of the roll  12 ′ pressing against the bottom surface  44  to create the frictional force at point A (see FIG. 10) remains a constant fraction. It is well known that the weight of the roll of bags  12 ′ is not related to the radius of the roll in a linear relationship, but rather in a squared relationship. Thus, when the roll  12 ′ is new and large, the frictional force at point A will be much greater than the frictional force when the roll  12 ′ is near empty. The force may be too great for the convenience of consumers using the dispenser. 
     To compensate for the squared relationship between the radius and weight of the roll, the grooves  118  in the embodiment of FIGS. 13-18 curve downwardly from the upper front portion of the container to the lower rear portion of the container, the front portion of the container being that portion of the container from which the bags are dispensed. Grooves  118  are defined by curved flanges  142 . The row of bags  112  is wound on a hollow core  116  which differs from conventional cores on which plastic bags are typically wound in that it is slightly longer than the bags are wide so that the ends of the core which project beyond the roll can be received within the grooves  118 . The grooves are open at their upper extremities so that a roll of plastic bags can be positioned within the container by simply placing the projecting ends of core  116  into the axles  118  from above. 
     The curve of each groove is such that at its upper portion the groove extends at close to 90 to the back wall  144 , which is the surface which frictionally engages the roll at point B. In this position, the component of force exerted by the roll in the horizontal direction against the back wall  144  is relatively low. As the plastic bags are removed from the roll and the roll diminishes in size, the core  116  drops to the position shown in FIG.  18 . As the roll drops, the horizontal component of force exerted by the roll relative to the total force is increased so that despite the loss of weight the horizontal component of force is not excessively diminished and, indeed, may actually remain substantially constant. 
     In FIG. 18, the roll  112  is nearly depleted and is positioned near the bottom of the grooves  118  where the angle is steep. Because the angle of the grooves  118  is so steep in this area, it is desirable to prevent the now small roll  112  from becoming wedged into the bottom of the grooves  118  and thus difficult to rotate. Therefore, the friction roller  150 , a preferably hollow tube, is mounted near the bottom of the grooves  118 . The roller  150  is held within the dispenser  110  by pins or rivets  152  that extend inward from the side walls  121 . The roller is free to move and rotate, supported on the pins  152 , the side walls  121 , and the guides  142 . Pins  153  prevent the roller  150  from falling out of the container if it is upended for any reason. 
     As can be seen in FIG. 18, when the roll  112  is small, it will contact the roller  150  (at area C) without contacting the back wall  144  of the dispenser. The placement of the roller  150  and the pins  152  will cause the roller  150  to frictionally contact the guide flange  142  nearest the back wall  144 . Thus, the weight of the roll  112  will be transferred through the roller  150  to cause friction between the roller  150  and the guide flange  142 . This friction, taking into account the low weight of the roll  112  and the steep angle of the grooves  118 , will be sufficient to prevent free spinning of the roll  112  with easy dispensing of bags  114  by the consumer. 
     While the embodiments of the invention shown and described are fully capable of achieving the results desired, it is to be understood that these embodiments have been shown and described for purposes of illustration only and not for purposes of limitation. 
     The embodiment shown at FIGS. 13-18 is the currently preferred embodiment of the invention. In addition to the benefits provided by the curved grooves as explained above, this embodiment is advantageous insofar as cost of manufacture is concerned and provides a container which provides substantial protection for the bags themselves as compared to standard prior art arrangements in which the roll of plastic bags is mounted on an axle (either horizontally or vertically) and exposed on all sides. Although the preferred means for separating the individual bags from the roll is the combination of the tongue and finger as described in each of the embodiments herein, the concept of the container having curved grooves for supporting a roll of bags as described would have utility with other types of separating devices.