Description

TECHNICAL FIELD The present invention refers to a dispenser for a roll of plastic t-shirt bags. BACKGROUND ART

There are many known dispensers for rolls of plastic t-shit bags that include a pair of rollers between which the bags pass, which are designed to enable the user to pull and tear each bag separately from the roll. However, in many cases the user pulls the bag out diagonally down (or sometimes upwards) and then the bag slides down between the pair of rollers, so that the bag interrupts the sensors to identify when one bag has passed (identifying the spacing gap between each bag and the bag next to it) and consequently the user pulls many bags together. If the rollers are coated with a rough coating with a relatively high friction coefficient to prevent the bag from sliding downwards, then the rollers that should be tight to each other are tight at such strength that makes it hard to pull out the bags. The present invention has come to provide an effective solution to these and other problems. DESCRIPTION OF THE DRAWINGS

The intention of the drawing attached to the application is not to limit the scope of the invention and its application. The drawing is intended only to illustrate the invention and it constitutes only one of its many possible implementations. FIG. 1 depicts the first roller (31) and the second roller (32) when they are adjacent to each other and create the sinusoidal path (43).

FIG. 2 depicts a roll (5) and few plastic t-shirt bags (51).

FIG. 3 depicts the bags when passing between the rollers (31) and (32).

FIG. 4 depicts the dispenser when is opened.

FIG. 5 depicts the dispenser when is closed, a part of a bag protrudes outside from the dispenser through the opening (22). THE INVENTION

The main objective of the present invention is to provide a dispenser (1) for a roll (5) of plastic t-shirt bags. The dispenser (1) includes a casing (2) that is designed to contain the roll (5). The dispenser (1) includes a first roller (31) that is attached to the inner wall (21) of the casing. It is preferably that the first roller will be attached to both side walls (21) of the casing to make it more stable. The first roller (31) is designed to rotate freely on its longitudinal axis (311). At least a part (312) of the first roller (31) is covered with a first set of rubber teeth (41). The dispenser (1) also includes a second roller (32) that is attached to the inner wall (21) of the casing. The second roller too is designed to rotate freely on its longitudinal axis (321) and at least part (322) of it is covered with a second set of rubber teeth (42). The rollers are designed to be adjacent one to the other in a way that the teeth of the first set of rubber teeth slot together with the teeth of the second set of rubber teeth, in a way that create a sinusoidal path (43) between them. Figure 1 depicts the first roller (31) and the second roller (32) when they are adjacent to each other and create the sinusoidal path (43).

When the casing (2) is closed and the dispenser (1) is ready for use the rollers (31) (32) are designed to be tight together in a way that enables a user to pull forward the plastic t-shirt bags between the rollers and through the sinusoidal path and causes the rollers to rotate about their longitudinal axis by the friction of the plastic t-shirt bags when they move forward, and disables the plastic t- shirt bags to move forward when one of the rollers is disabled to rotate.

The dispenser (1) includes also a sensor (61) that is designed to detect gaps (53) between handles (52) of the plastic t-shirt bags (51). Figure 2 depicts a roll (5) and few plastic t-shirt bags (51) that show the handles (52), the gaps (53) and the perforation lines (54). The sensor (61) can be of a variety of known types, for example an optical sensor that identifies when a plastic sheet is in front of it and when there is no plastic sheet in front of it.

The dispenser (1) also includes a stop mechanism (7) that is designed to disable one of the rollers to rotate. The stop mechanism can be of a variety of known types that are capable to prevent a roller to rotate. For example, a stopping tooth that disables the rollers to rotate or a brace plate that clings to the rollers or one of them and prevents it from rotating. The stop mechanism (7) also includes actuator (71) that is designed to activate the stop mechanism and make it to stop the relevant roller. The stop mechanism (7) stops to disable the rotation of the rollers automatically after few seconds as it is determined in settings of the electronic cards or manually.

The dispenser (1) also includes an electronic card (62) that is designed to operate the dispenser in general and particularly to receive a signal from the sensor when detecting gaps and accordingly to send stop commands actuator (71) of the stop mechanism (7) for disabling the rollers to rotate.

The operation of the dispenser (1): when the sensor detects a gap (53) of a plastic t-shirt bag (51C) then the stop mechanism disables the rollers to rotate in a way that the adjacent plastic t-shirt bag (5 IB) gets stuck between the rollers and in the sinusoidal path and by that enables the user to tear along a the perforation lines (54) of the bag another plastic t-shirt bag (51 A) that is next to the adjacent plastic t-shirt bag, as depicted for example in Figure 3.

One of the main innovative aspects of the dispenser (1) is that the teeth of the sets when are slotted together and create the sinusoidal path prevent side movement of the plastic t-shirt bags when they pass forward between the rollers and through the sinusoidal path and in the same time enable an easy pull forward of the bags from the dispenser. The sinusoidal path makes it easy to pull forward the bags and makes it hard to slide it upward or downward. This capability overcome the problem of the prior art.

The dispenser (1) may also include a rotational encoder (64) that is designed to measure the rotations of at least one of the rollers and to provide the data to the electronic card. The electronic card may be designed to send the stop command with delays of predetermined certain periods of time depending on the rotational speed or rotation amounts of the rollers. In this way, the electronic card sends the command to stop the rollers after a certain amount of rolls so that the handles of the next bag will be seen from the opening (22) of the dispenser. This components and features are designed also for cases where the user pulls quickly the bag protruding from the dispenser and before the stop mechanism stops the rollers the user pulls more than one bag. Therefore, when the encoder detects a high rotational speed then the stop command is with a short delay, and vice versa. The encoder (64) can be of a variety of known types, for example an optical speed sensor or magnetic speed sensor as known in the art. In addition to that, the electronic card can activate the motor (that is described hereinafter) and employ it as a means to slow the rotational speed of the rollers. The dispenser (1) may include a control panel (63) for controlling the electronic card (62) to enable the user to enter the number of bags that he or she wants to pull out together, so that the stop mechanism will operate only after the required number of bags have passed in front of the sensor. The control panel may include several indicator lights, for example: a green light that indicates that the dispenser is ready and the bag can be pulled out and an orange light that indicate that the user may now tear the bag from the next bag that in part protrude outside from the dispenser.

Figure 4 depicts the dispenser when is opened, and Figure 5 depicts the dispenser when is closed, a part of a bag protrudes outside from the dispenser through the opening (22).

We use the term “plastic t-shirt bags” because this is the most popular bag used in supermarkets. However, the invention relates to other kinds of rolls of bags, including rectangular bags without handles and without gaps that may include a special mark that indicates that the end of the bag is near and bags made of other kind of materials and not only of plastic. In addition, we use the term “rubber teeth” because that this is the most popular material for this purpose. However, the term “rubber teeth” in this application and in the claims refers also to other equivalent materials that make the same effect as rubber. In some cases a user may pull the bag early and strongly and then the handles of the bag may not protrude out enough of the dispenser (1) and therefore it may be not possible to pull another bag. To solve such problem, the dispenser (1) may further includes a motor (90) that is designed to rotate at least one of said rollers, by employing a rotational means (91) such as a belt or a gear for example, during at least a part of a period of time from the moment that said electronic card receives said signal from the sensor when detecting the gaps to the moment in which the electronic card sends the stop command. By that, ensuring that the rollers will roll until the handles of the bag will be out of the dispenser and by that enabling the user to pull another bag and so forth.