Field of the Invention

[0001] The present invention relates to a paper folding machine. More specifically, the present invention relates to a system for operating a paper folding machine that is used to perform paper folding operations.

Background of the Invention

[0002] Generally, a paper folding machine is used to perform the paper folding operation to create inserts or outserts widely applied in pharmaceutical or manufacturing industries. The folding operation in the paper folding machine involves the sharp-edged bending of paper sheets under pressure along a bending line. The paper folding machine has two types - buckle paper folding machine (Buckle folder) and knife paper folding machine (Knife folder). The existing knife paper folding machine is disclosed in patent document US7896796B and the buckle paper folding machine in patent document US2688482A.

[0003] Referring to figure 1, a schematic diagram of an existing paper folding machine (10') is illustrated. The paper folding machine (10') is adapted to fold an intermediate item (50'). The intermediate item (50') can be a paper fold (insert or outsert). The paper folding machine (10') includes one or more pairs of driving rollers (20a' and 20b') adapted to rotate in direction opposite to each other. The intermediate item (50) enters between the driving rollers (20a' and 20b') along a direction of entrance (52').

[0004] Further, the paper folding machine (10') includes one or more pairs of folding rollers (30a' and 30b') adapted to rotate in direction opposite to each other with a roller gap (61') therebetween. [0005] Further, a stopping unit (40') is arranged to interrupt the movement of the intermediate item (50') moving through the driving rollers (20a' and 20b'). Due to the rotation of the driving rollers (20a' and 20b'), the intermediate item (50') comes in contact with the stopping unit (40'). Due to continuous rotation of the driving rollers (20a’ and 20b’), the intermediate item (50) gets pushed towards the stopping unit (40’) and starts to buckle along a folding line (51') of the intermediate item (50'). Further, the buckled intermediate item (50) passes through the folding rollers (30a’ and 30b’) where the folding rollers (30a’ and 30b’) press the intermediate item (50’) to form a complete fold.

[0006] However, in existing paper folding machines (10’), more specifically in buckle folding machines, when thickness of the intermediate item (50’) gets increased above a definite value after multiple folds, the intermediate item (50’) offers resistance to the buckling. Due to such resistance, there is a possibility of jamming of the intermediate item (50’) within the rollers and wear and tear of the intermediate item (50’) can also take place due to continuous push exerted by the driving rollers (20a’ and 20b’) on the thick intermediate item (50’).

[0007] Therefore, there is a need for a system for operating a paper folding machine, which overcomes the above-mentioned problems of the prior art.

Objects of the Invention:

[0008] An object of the present invention is to provide a system for operating a paper folding machine.

[0009] Another object of the present invention is to provide a system for operating a paper folding machine, which provides an external assistance to an intermediate item during buckling. [0010] Another object of the present invention is to provide a system for operating a paper folding machine, which assist in folding thick intermediate items which are difficult to buckle.

[0011] Further object of the present invention is to provide a system for operating a paper folding machine, which reduces wear and tear of intermediate items such as paper folds during folding operation.

Summary of the invention

[0012] The present invention relates to a system for operating a paper folding machine. The paper folding machine can be adapted to fold an intermediate item. The system may include one or more pairs of driving rollers adapted to rotate in direction opposite to each other. The intermediate item may enter between the driving rollers along a direction of entrance.

[0013] Further, the system may include one or more pairs of folding rollers adapted to rotate in direction opposite to each other and having a roller gap therebetween. Further, the system may include a knife blade arranged perpendicular to the roller gap. The knife blade can be adapted to move from a non-operating position to an operating position. At the non-operating position, the knife blade may not be in contact with the intermediate item and at the operating position, the knife blade may come in contact with the intermediate item and pushes the intermediate item in between the folding rollers to fold the intermediate item.

[0014] Further, the system may include a stopping unit arranged to interrupt the movement of the intermediate item moving through the driving rollers. Due to the rotation of the driving rollers, the intermediate item may come in contact with the stopping unit and start to buckle along a folding line of the intermediate item. [0015] Also, the system may include a driving unit connected to the knife blade. The driving unit can be adapted to move the knife blade from the nonoperating position to the operating position. The driving unit can be a linear actuator such as a pneumatic or a hydraulic or an electromechanical or a piezoelectric or a cam operated actuator.

[0016] Further, the system may include a fold detection unit adapted to detect the buckling of the intermediate item along the folding line. The fold detection unit can detect the buckling of the intermediate item by detecting the contact of the intermediate item with the stopping unit.

[0017] The fold detection unit can be a camera or an image sensor or a camcorder. Further, a processing unit can be connected to the fold detection unit and the driving unit. The processing unit can be a microprocessor or a microcontroller or a processor or a controller or a microcomputer or a workstation.

[0018] During the operation of the system, when the intermediate item is buckling, the fold detection unit may send information about the buckling of the intermediate item to the processing unit. Based on the information received from the fold detection unit, the processing unit may actuate the driving unit to move the knife blade from the non-operating knife position to the operating knife position synchronously with the buckling of the intermediate item to push the intermediate item through the roller gap to completely fold the intermediate item.

[0019] In an embodiment, the paper folding machine can be a knife folder and the stopping unit can be a flat surface that is oriented perpendicular to the direction of entrance of the intermediate item into the paper folding machine.

[0020] Further, in another embodiment, the paper folding machine can be a buckle folder and the stopping unit can be angularly oriented with respect to the direction of entrance of the intermediate item. The stopping unit may include a pocket and a guide. The pocket may have an opening thereon. The guide can be positioned at the opening of the pocket. The guide may deviate the entered intermediate item into the pocket through the opening. After deviating from the guide, the intermediate item may come in contact with the pocket. Due to the continuous rotation of the driving rollers, the intermediate item may buckle along a folding line.

[0021] In another embodiment, the guide may include one or more slots alternately arranged to provide space for movement of the knife blade from the nonoperating position to the operating position.

[0022] In an embodiment, the guide can be adjustable along the length of the pocket. During the movement of the knife blade from the non-operating position to the operating position, the guide can be retracted from a first position to a second position to provide a space for movement of the knife blade from the nonoperating position to the operating position. At the first position, the guide is positioned across a line of actuation of the knife blade and at the second position, the guide is not positioned across the line of actuation of the knife blade.

[0023] In another embodiment, the guide can be retracted from the first position to the second position manually or by a linear actuator operated by the processing unit in synchronous with buckling of the intermediate item.

Brief Description of the Drawings

[0024] The advantages and features of the present invention will be understood better with reference to the following detailed description of some embodiments of the and claims taken in conjunction with the accompanying drawings, wherein like elements are identified with like symbols, and in which; [0025] Figure 1 shows a schematic diagram of an existing paper folding machine;

[0026] Figure 2a and 2b show a schematic front view of an intermediate item during a buckling operation;

[0027] Figure 3 shows a schematic diagram of an embodiment of a system for operating a paper folding machine in accordance with the present invention;

[0028] Figure 4 shows a schematic diagram of an embodiment of a system for operating a paper folding machine in accordance with the present invention;

[0029] Figure 5 shows a schematic diagram of a guide in the system as shown in figure 3;

[0030] Figure 6 shows a schematic diagram of an embodiment of a system for operating a paper folding machine in accordance with the present invention; and

[0031] Figure 7 shows a schematic diagram of an operation of a knife blade of the system as shown in figure 3 during buckling of an intermediate item.

Detailed Description of the Invention

[0032] An embodiment of this invention, illustrating its features, will now be described in detail. The words "comprising, "having, "containing," and "including," and other forms thereof, are intended to be equivalent in meaning and be open-ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items or meant to be limited to only the listed item or items.

[0033] The terms "first," "second," and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another, and the terms "an" and "a" herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items.

[0034] The disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms.

[0035] The present invention relates to a system for operating a paper folding machine. The system provides external assistance to buckling the intermediate item, thereby enabling efficient folding of the thick intermediate items that are difficult to fold by conventional folding machines. The system involves synchronous operation of a knife blade along with buckling of an intermediate item such as a paper fold (inserts or outserts), thereby eliminating the wear and tear of the intermediate item.

[0036] Referring to figures 3, 4 and 6, schematic diagrams of a system (lOOa/lOOb/lOOc) for operating a paper folding machine (10) in accordance with the present invention are illustrated. The paper folding machine (10) is adapted to fold an intermediate item (50). In the present embodiment, the intermediate item (50) is a folded paper i.e., insert or outsert which is at an intermediate stage before final fold. The system (lOOa/lOOb/lOOc) includes one or more pairs of driving rollers (20a and 20b) adapted to rotate in direction opposite to each other as shown in figures 3, 4 and 6. The intermediate item (50) enters through a gap between the driving rollers (20a and 20b) along a direction of entrance (52). The direction of entrance (52) of the intermediate item (50) is shown with an arrow mark as shown in figures 3, 4 and 6. [0037] Further, the system (100a/ 100b/ 100c) includes one or more pairs of folding rollers (30a and 30b) as shown in figures 3, 4, and 6. The folding rollers (30a and 30b) are adapted to rotate in direction opposite to each other. The folding rollers (30a and 30b) have a roller gap (61) therebetween. Further, the system (lOOa/lOOb/lOOc) includes a knife blade (60) arranged perpendicular to the roller gap (61).

[0038] The knife blade (60) is adapted to move from a non-operating position (60a) to an operating position (60b) as shown in figures 3,4, and 6. The non-operating position (60a) is a position of the knife blade (60) where the knife blade (60) is not in contact with the intermediate item (50), whereas the operating position (60b) is a position of the knife blade (60) where the knife blade (60) comes in contact with the intermediate item (50) and pushes the intermediate item (50) in between the folding rollers (30a and 30b) to fold the intermediate item (50).

[0039] Further, the system (lOOa/lOOb/lOOc) includes a stopping unit (40) arranged to interrupt the movement of the intermediate item (50) moving through the driving rollers (20a and 20b) as shown in figures 3, 4, and 6. Due to rotation of the driving rollers (20a and 20b), the intermediate item (50) comes in contact with the stopping unit (40) and may start to buckle along a folding line (51) of the intermediate item (50). The buckling of the intermediate item (50) is shown in figures 2a and 2b. The folding line (51) divides the intermediate item (50) into a first face (50a) and a second face (50b). Before buckling of the intermediate item (50), an angle (0) between the first face (50a) and the second face (50b) is 180° (as shown in figure 2a). When the intermediate item (50) starts to buckle, the angle (0) between the first face (50a) and the second face (50b) becomes deviates from 180° (as shown in figure 2b) and becomes 0° after complete folding of the intermediate item (50).

[0040] Further, the system (lOOa/lOOb/lOOc) include a driving unit (70) connected to the knife blade (60). The driving unit (70) is adapted to move the knife blade (60) from the non-operating position (60a) to the operating position (60b). The driving unit (70) can be a linear actuator such as a pneumatic or a hydraulic or an electromechanical or a piezoelectric or a cam operated actuator. In the present embodiment, the driving unit (70) is a cam operated actuator coupled to a pneumatic actuator.

[0041] Further, the system (lOOa/lOOb/lOOc) includes a fold detection unit (80) adapted to detect the buckling of the intermediate item (50) along the folding line (51). The fold detection unit (80) detects the buckling of the intermediate item (50) by detecting the contact of the intermediate item (50) with the stopping unit (40).

[0042] The fold detection unit (80) can be a camera or an image sensor or a camcorder. In case of the camera or camcorder as the fold detection unit (80), the camera or camcorder is arranged with the stopping unit (40) at a suitable location to continuously capture images or videos of stopping unit (40). When the intermediate item (50) comes in contact with the stopping unit (40), the camera or camcorder captures image or video of the stopping unit (40) along with the intermediate item (50). In case of image sensor, the image sensor captures the light (or photons) coming from the stopping unit (40) and converts them into electric signals.

[0043] Further, a processing unit (90) is connected to the fold detection unit (80) and the driving unit (90). The fold detection unit (80) is connected to an input connection of the processing unit (90) and the driving unit (90) is connected to an output connection of the processing unit (90). In the present embodiment, the processing unit (90) is a microprocessor or a microcontroller or a processor or a controller or a microcomputer or a workstation.

[0044] During operation of the system (100a/ 100b/ 100c), when the intermediate item (50) is buckling, the fold detection unit (80) sends information about the buckling of the intermediate item (50) to the processing unit (90). The images or videos captured by the fold detection unit (80) are converted into electric signals and sent to the processing unit (90). Based on the information received from the fold detection unit (80), the processing unit (90) actuates the driving unit (70) to move the knife blade (60) from the non-operating position (60a) to the operating position (60b) synchronously with the buckling of the intermediate item (50) to push the intermediate item (50) through the roller gap (61) to completely fold the intermediate item (50).

[0045] The synchronous operation of the knife blade (60) involves the movement of the knife blade (60) at the same time when the intermediate item (50) starts buckling. When the knife blade (60) is in operating position (60b), a tip (60c) of the knife blade (60) comes in contact with the intermediate item (50) to buckle the intermediate item (50) as shown in figure 7.

[0046] In another embodiment, the fold detection unit (80) detects the distance of the stopping unit (40) from the driving rollers (20a and 20b) and speed of the driving rollers (20a and 20b) and sends signals to the processing unit (90). The processing unit (90) calculates the time of actuation of the knife blade (60) based on the distance of the stopping unit (40) and the speed of the driving rollers (20a and 20b). Here, the linear speed of driving rollers (20a and 20b) is equivalent to the linear speed of the intermediate item (50).

[0047] For example, the intermediate item (50) moving between the driving rollers (20a and 20b) come in contact with the stopping unit (40) at time T1 seconds. When the contact of the intermediate item (50) with the stopping unit (40) is detected by the fold detection unit (80), the knife blade (60) gets actuated at the same time T1 seconds so that both buckling and knife blade (60) actuation are in synchronous. [0048] Referring to figures 3 and 4, an embodiment (lOOa/lOOb) of a system for operating a paper folding machine (10) in accordance with the present invention is illustrated. In the embodiment (lOOa/lOOb), the paper folding machine (10) is a buckle folding machine (or buckle folder). The patent number US2688482A discloses a buckle folder. In buckle folder, the folding of the intermediate item (50) takes place solely due to buckling of the intermediate item (50). However, after repeated folding of the intermediate item (50), the thickness of the fold increases, and there is a lesser deflection of the intermediate item (50) takes place. To assist the buckling of the intermediate item (50), the actuation of knife blade (60) is enabled.

[0049] In the embodiment (lOOa/lOOb), the stopping unit (40) is angularly oriented with respect to the direction of entrance (52) of the intermediate item (50) as shown in figures 3 and 4. The stopping unit (40) includes a pocket (40a) and a guide (40b). The pocket (40a) is a hollow linear extension closed at an end (40c) and has an opening (41) at another end as shown in figures 3 and 4. The guide (40b) is positioned at the opening of the pocket (40b).

[0050] When the intermediate item (50) comes in contact with the guide (40b), the guide (40b) deviates the entered intermediate item (50) and makes the intermediate item (50) to enter into the pocket (40a) though the opening (41). After deviating from the guide (40b), the intermediate item (50) comes in contact with the pocket (40a) as shown in figure 3. Due to continuous rotation of the driving rollers (20a and 20b), the intermediate item (50) buckles along the folding line (61).

[0051] In the embodiment (100b) as shown in figure 5, the guide (40b) includes one or more slots (43) alternately arranged thereon to provide space for movement of the knife blade (60) from the non-operating position (60a) to the operating position (60b). During actuation of the knife blade (60), the knife blade (60) passes through one of the slots (43) to fold the intermediate item (50). [0052] Referring to figure 4, an embodiment (100b) of the system for operating a paper folding machine (10) in accordance with the present invention is illustrated. In the embodiment (100b), the guide (40b) is adjustable along the length of the pocket (40a) as shown in figure 4. During the movement of the knife blade (60) from the non-operating position (60a) to the operating position (60b), the guide (40b) is retracted from a first position (40e) to a second position (40f) (as shown in figure 4) to provide a space for movement of the knife blade (60) from the nonoperating position (60a) to the operating position (60b).

[0053] At the first position (40e), the guide (40b) is positioned across a line of actuation (62) of the knife blade (60) and at the second position (40f), the guide (40b) is not positioned across the line of actuation (62) of the knife blade (60) (as shown in figure 4). The line of actuation (62) of the knife blade (60) is the linear path along which the knife blade (60) travels. Before buckling of the intermediate item (50), the guide (40b) is at the first position (40e) and the intermediate item (50) gets deviated by the guide (40b) towards the pocket (40a). When the buckling of the intermediate item (50) starts (i.e., when the intermediate item (50) touches the pocket (40a)), the guide (40b) is retracted to the second position (40f) to provide path for actuation of the knife blade (60).

[0054] In the embodiment (100b), the guide (40b) is retracted from the first position (40e) to the second position (40f) manually or by a linear actuator (42) operated by the processing unit (90) in synchronous with buckling of the intermediate item (50) as shown in figure 4. When the intermediate item (50) starts to buckle, the fold detection unit (80) sends signal to the processing unit (90) and the processing unit (90) actuates the linear actuator (42) to move the guide (40b) from the first position (40e) to the second position (40f). Further, after folding of the intermediate item (50), when the knife blade (60) moves back to the nonoperating position (60a), the linear actuator (42) actuates the guide (40) to move back to the first position (40e) and the process is repeated for each folding operation to deviate next intermediate item (50) towards the stopping unit (40). [0055] In the buckle paper folding machine, there is requirement of the guide (40b) to deviate the intermediate item (50) towards the stopping unit (40). Also, thick fold of the intermediate item (50) after repeated folding operation are difficult to buckle. Hence, the assistance from the knife blade (60) is required to buckle thick intermediate item (50). But due to position of guide (40b), there is hindrance for movement of the knife blade (60). Hence, the guide (40b) is in two configurations - firstly, in the form of alternate slots (43) (as shown in figure 6), where slots (43) provide space for the movement of the knife blade (60). Secondly, the guide (40b) is movably arranged to provide a path for movement of the knife blade (60) during operation.

[0056] In the embodiments (100a, 100b, 100c), the fold detection unit (80), the driving unit (70), the knife blade (60) and the stopping unit (40) are not limited to only single units. As the intermediate item (50) undergo multiple folding operations until formation of the final fold, multiple fold detection units (80), driving units (70), the knife blades (60), and stopping units (40) can be arranged at positions wherever buckling operation takes place in the folding machine (10). Each fold detection unit (80), driving unit (70), knife blade (60), and stopping unit (40) are operated by the (single or a common) processing unit (90).

[0057] Further, the synchronous actuation of the knife blade (60) with the buckling of the intermediate item (50) in the buckle folding operation (as mentioned in embodiments (100a) and (100b)) avoids jamming of the intermediate item (50) within the folding machine (10). As the buckle folding operation is continuous (without any interruption as in case of knife folding machine) and in such case, the knife blade (60) actuation and the buckling are asynchronous, there is possibility of locking of the intermediate item (50) between the folding rollers (30a and 30b).

[0058] Referring to figure 6, an embodiment (100c) of the system for operating a paper folding machine (10) in accordance with the present invention is illustrated. In the embodiment (100a), the paper folding machine (10) is a knife folder and the stopping unit (40) is a flat surface which is oriented perpendicular from the direction of entrance (52) of the intermediate item (50) into the paper folding machine (10). The intermediate item (50) enters into the driving rollers (20a and 20b), proceeds in a linear path towards the stopping unit (40) and get stopped by coming in contact with the stopping unit (40).

[0059] When the intermediate item (50) comes in contact with the stopping unit (40), the processing unit (90) actuates the driving unit (70) synchronously to move the knife blade (60) to the operating position (60b) to completely fold the intermediate item (50). In case of knife folding machine, the synchronous actuation of the knife blade (60) with the buckling of the intermediate item (50) reduces the cycle time of folding operation as compared to conventional knife folding machines, where there is a time lag between the contact of the intermediate item (50) and the actuation of the knife blade (60).

[0060] Thus, the present system (100a/ 100b/ 100c) provides an advantage to assist the folding of thick intermediate items (50), which requires significant effort in conventional paper folding machines. Also, the synchronous actuation of the knife blade (60) along with buckling of the intermediate item (50) reduces wear and tear of the intermediate item (50) due to reduction in time variation between the knife blade (60) and the buckling of the intermediate item (50). Further, the system (lOOa/lOOb/lOOc) produces compact folds of the intermediate item (50) by combining two ways (knife actuation and buckling) of folding the intermediate item (50).

[0061] The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or limit the present invention to the precise forms disclosed, and obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described to explain best the principles of the present invention and its practical application and to thereby enable others skilled in the art to best utilise the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the scope of the claims of the present invention.