Field of the Invention

[0001] The present invention relates to a pressing machine. More specifically, the present invention relates to a system for operating a pressing machine.

Background of the Invention

[0002] A pressing machine is used to press intermediate items such as inserts and outsorts which are folded by a paper folding machine. The insert or outsort formed by the paper folding machine is further passed through the pressing machine, wherein the pressing machine presses the insert (or outsort) to make the insert (or outsort) compact and remove the trapped air within the folds of the insert. The existing pressing machines used in the paper folding operation are described in patents US5352179A, US6645134B2.

[0003] Referring now to figure 1, a schematic front view of an existing pressing machine (10') (prior art) is illustrated. The pressing machine (10') includes a first roller (20'), a second roller (30'), a third roller (21') and a fourth roller (31') rotatably arranged over a frame (10a ¹ ) with a first axial distance (20a ¹ ) between the first roller (20') and the second roller (30') and a second axial distance (20b ¹ ) between the third roller (21') and the fourth roller (31'). The first axial distance (20a’) and the second axial distance (20b’) can be equal or unequal based on the predefined settings. Further, one or more endless belts (40’ and 41’) are arranged over the rollers (20’, 30’, 21’ and 31’) to provide apath for an intermediate item (50’) to travel through the first axial distance (20a) or the second axial distance (20b’). [UUU4J The first roller (20') is adapted to rotate in a direction opposite to the direction of rotation of the second roller (30'), and the third roller (21') is adapted to rotate in a direction opposite to the direction of rotation of the fourth roller (3 T). Further, a first driving unit (70') is connected to the first roller (20') and the second roller (30'), as shown in figure 1. The first driving unit (70) rotates the first roller (20’) in a first direction of rotation and the second roller (30’) in a second direction of rotation. Further, a second driving unit (80’) is connected to the third roller (21’) and the fourth roller (31’) the second driving unit (80’) rotates the third roller (21’) in the first direction of rotation and the fourth roller (31 ’) in the second direction of rotation, wherein the first direction and the second direction are rotational directions which are opposite to each other.

[0005] The pressing machine (10’) is adapted to press the intermediate item (50’) to remove errors (71’, 72’, 75’) within the folds of the intermediate item (50’) when as shown in figures 2a and 2b. The errors (71'and 72') are along the ends of the folded intermediate item (50'), and the error (75) is in between layers of folds of the intermediate item (50’) as shown in figures 2a and 2b. The errors (71’, 72’) are spaces or distances between faces (50a’ and 50b’) and faces (50c’ and 50d’) respectively of the intermediate item (50’) as shown in figure 2. The error (75’) is a spacing between the layers of folds of the intermediate item (50) in which air is maybe entrapped, as shown in figures 2a and 2b.

[0006] During operation of the pressing machine (10’) as shown in figure 3, the intermediate item (50’) with errors (71’, 72’ and 75’) as shown in figures 2a and 2b is received between the rollers (20’, 30’, 21’, 31’). When the intermediate item (50) is positioned between the belts (40’, 41’), the first roller (20’), the second roller (30’), the third roller (21’) and the fourth roller (31’) press the intermediate item (50’) to remove the springiness within the intermediate item (50’) by removing the error (75’). After pressing the intermediate item (50), the output from the pressing machine (10) is in the form of a folded state (122) of the intermediate item (50), as shown in figure 3. [0007] However, the existing pressing machine (10’) only removes the springiness of the intermediate item (50’) due to the correction of the error (75’) by keeping the errors (71’ and 72’) unaffected (as shown in figure 3), i.e. producing the intermediate item (50) in the folded state (122) with errors (71’ and 72)’ remaining same as before the entrance of the intermediate item (50’) into the machine (10’). Only the air entrapped between the layers of the intermediate item (50) is removed without significantly affecting errors (71’ and 72’) due to dislocation of folds of the intermediate item (50’), as shown in figures 2a and 2b.

[0008] Further, in the existing pressing machines (10’), the relative velocity between the first roller (20’) and the second roller (30’) and the relative velocity between the third roller (21’) and the fourth roller (31 ’) is zero. Further, there are no mechanisms/systems for adjusting the relative rotational speeds of the rollers (20’, 30’, 21’ and 31’) according to the errors within the folded intermediate item (50’). Hence, the existing pressing machines (10’) fail to provide compact folds of the intermediate items (50’). Also, the existing machines (10) require manual intervention for adjusting the rotational and pressure parameters of the rollers (20’, 30’, 21’ and 31’).

[0009] Therefore, there is a need for a system for operating a pressing machine, which overcomes the above-mentioned problems of the prior art.

Objects of the Invention:

[0010] An object of the present invention is to provide a system for operating a pressing machine. Lu 11 J Further object of the present invention is to provide a system for operating a pressing machine, which reduces the formation of errors within the folds of the intermediate items such as paper folds.

[0012] Another object of the present invention is to provide a system for operating a pressing machine, wherein the rotational parameters of pressing rollers can be adjusted to reduce the errors in paper folds.

[0013] Further object of the present invention is to provide a system for operating a pressing machine, which eliminates the need for human intervention to adjust rotational parameters of pressing rollers.

[0014] Yet another object of the present invention is to provide a system for operating a pressing machine, which provides compact folds of the intermediate items such as paper folds.

Summary of the invention

[0015] The present invention relates to a system for operating a pressing machine. The pressing machine may include a first roller, a second roller, a third roller, and a fourth roller rotatably arranged over a frame with a first axial distance between the first roller and the second roller and a second axial distance between the third roller and the fourth roller. The first and second axial distances can be equal or unequal in magnitude.

[0016] Further, the first roller can be adapted to rotate in a direction opposite to the direction of rotation of the second roller, and the third roller can be adapted to rotate in a direction opposite to the direction of rotation of the fourth roller. An intermediate item can be received through the first axial distance or the second axial distance, and the first roller, the second roller, the third roller and the fourth roller can press the intermediate item.

[0017] Further, the system may include a first driving unit connected to the first roller and the second roller. The first driving unit may include a servo motor or a stepper or torque motors directly coupled to the first roller and the second roller, respectively, or coupled through a power transmission mechanism such as a belt drive or a gear drive, or a chain drive. The first driving unit may rotate the first roller around a first axis at a first speed in a first direction of rotation and the second roller around a second axis at a second speed in a second direction of rotation.

[0018] Further, a second driving unit can be connected to the third roller and the fourth roller. The second driving unit may include a servo motor or a stepper or a torque motor directly coupled to the third roller and the fourth roller, respectively, or coupled through a power transmission mechanism such as a belt drive or a gear drive. The second driving unit can rotate the third roller around a third axis at a third speed in the first direction of rotation and the fourth roller around a fourth axis in the second direction of rotation. In an embodiment, the first direction of rotation is opposite to the second direction of rotation.

[0019] Further, the system may include a control unit connected to the first driving unit and the second driving unit. The control unit can be a microprocessor or a microcontroller or a controller or a processor or a logic controller or a computer, or a workstation. The control unit can be further connected with a detecting unit which detects a folded state of the received intermediate item and send the details of the detected folded state of the intermediate item to the control unit. The detecting unit can be a camera system or an ultrasonic sensor or an infrared sensor, or a distance sensor.

[0020] The control unit may compare the received details from the detecting unit with a predefined state of the intermediate item and actuate the first driving unit and the second driving unit to rotate the first roller, the second roller, the third roller and the fourth roller with different speeds to deform as well as press the intermediate item to the predefined state.

[0021] In an embodiment, the folded state of the intermediate item may include a first folded state. When the intermediate item is at the first folded state, the first roller and the third roller can be in contact with a head face of the intermediate item, and the second roller and the fourth roller can be in contact with a tail face of the intermediate item. Further, a first face of the intermediate item can be at a first position, and a second face of the intermediate item can be at a second position with an error between the first face and the second face. Further, a third face of the intermediate item can be at a third position, and a fourth face of the intermediate item can be at a fourth position with an error between the third face and the fourth face.

[0022] The control unit can actuate the first driving unit to decrease the first speed of the first roller and actuate the second driving unit to decrease the third speed of the third roller based on the magnitude of the errors to deform the intermediate item to the predefined state.

[0023] In an embodiment, the folded state of the intermediate item may include a second folded state. When the intermediate item is at the second folded state, the first roller and the third roller are in contact with the tail face, and the second roller and the fourth roller can be in contact with the head face of the intermediate item. The first face of the intermediate item can be at a fifth position, and the second face of the intermediate item can be at a sixth position with an error between the first face and the second face. The third face of the intermediate item can be at a seventh position, and the fourth face of the intermediate item can be at an eighth position with an error between the third face and the fourth face.

[0024] The control unit can actuate the first driving unit to decrease the second speed of the second roller and actuate the second driving unit to decrease tne rourtn speed of the fourth roller based on the magnitude of the errors to press the intermediate item to the predefined state.

[0025] The system may include a memory unit that stores the details of the predefined state of the intermediate item. The memory unit can be a cloud server or a hard drive or an loT memory.

Brief Description of the Drawings

[0026] 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;

[0027] Figure 1 shows a schematic diagram of an existing pressing machine (Prior art);

[0028] Figure 2a and 2b show schematic diagrams of an intermediate item with errors (prior art);

[0029] Figure 3 shows a schematic diagram of a pressing operation in an existing pressing machine (prior art);

[0030] Figure 4a shows a schematic diagram of an intermediate item at a first folded state; and

[0031] Figure 4b and 4c shows a schematic diagram of an intermediate item at a second folded state;

[0032] Figure 5a shows a schematic diagram of an intermediate item at a predefined state; [0033] Figure 5b shows a schematic diagram of an intermediate item at a predefined state;

[0034] Figure 6a shows a schematic diagram of an embodiment of a system for operating a pressing machine in accordance with the present invention;

[0035] Figure 6b shows a schematic diagram of an embodiment of a system for operating a pressing machine in accordance with the present invention;

[0036] Figure 7a shows a schematic diagram of an operation of rollers in the system as shown in figure 6a; and

[0037] Figure 7b shows a schematic diagram of an operation of rollers in the system, as shown in figure 6b.

Detailed Description of the Invention

[0038] 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.

[0039] 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. [UU4UJ The disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms.

[0041] The present invention relates to a system for operating a pressing machine. The system improves the operation of folding the intermediate items, which reduces the possibility of forming errors within the folds of intermediate items. Also, the system provides compact folds and reduce error in final outsorts or inserts. The system also provides a way of adjusting motional parameters of pressing rollers to rectify errors. Further, the system eliminates the need for human intervention for adjusting rotational parameters of the pressing rollers in the pressing machine.

[0042] Referring to figures 6a and 6b, schematic diagrams of a system (100a/ 100b) for operating a pressing machine (10) in accordance with the present invention are illustrated. The pressing machine (10) includes at least one pair of rollers. In the present embodiment, the pressing machine (10) includes a first roller (20), a second roller (30), a third roller (21), and a fourth roller (31) rotatably arranged over a frame (10a), as shown in figures 6a and 6b. The frame (10a) can be any machine structure where the rollers (20, 30, 21, 31) are pivotally arranged.

[0043] The first roller (20) and the second roller (30) have a first axial distance (20a) therebetween, and the third roller (21) and the fourth roller (31) have a second axial distance (20b) therebetween as shown in figure 6a and 6b. The first axial distance (20a) and the second axial distance (20b) can be equal or unequal in magnitude.

[0044] Further, the first roller (20) is adapted to rotate in a direction opposite to the direction of rotation of the second roller (30). Similarly, the third roller (21) is adapted to rotate in a direction opposite to the direction of rotation of the fourth roller (31). During the operation of the pressing machine (10), a folded intermediate item (50) is received either through the first axial distance (20a) or the second axial distance (20b). The intermediate item (50) can be a paper fold having information printed thereon (i.e., insert or outsert) as shown in figures 2a and 2b. The intermediate item (50) undergoes a series of folding operations to become a final fold. In the present embodiment, the intermediate item (50) can be the paper fold at an intermediate stage (during folding operation) before converting to the final fold (as shown in figures 2a and 4c) or the final fold itself (as shown in figures 2b and 4a). In the present embodiment, as shown in figure 6a or 6b, the intermediate item (50) is received through the second axial distance (20b) and pushed towards the first axial distance (20a), i.e., from right to left.

[0045] After insertion of the intermediate item (50) between the rollers (20, 30, 21 and 31), the first roller (20), the second roller (30), the third roller (21) and the fourth roller (31), press the intermediate item (50) to make the folded intermediate item (50) compact and reduce the tendency of springiness within the layers of folds of the intermediate item (50).

[0046] Further, the system (100a, 100b) includes a first driving unit (70) which is connected to the first roller (20) and the second roller (30). The first driving unit (70) rotates both the first roller (20) and the second roller (30) together. In the present embodiment of the system (100a, 100b), the first driving unit (70) consists of a servo motor or a stepper motor or a torque motor directly coupled to the first roller (20) and the second roller (30). In another embodiment, the first driving unit (70) is a servo motor or a stepper motor or a torque motor which is coupled to the first roller (20) and the second roller (30) through a power transmission mechanism such as a belt drive or a gear drive or a chain drive or any other power transmission mechanism known to the person skilled in the art.

[0047] The first driving unit (70) rotates the first roller (20) around a first axis (22) at a first linear speed (Vi) in a first direction of rotation. The first direction of rotation can be clockwise or anticlockwise. In the present embodiment, the first direction of rotation is clockwise. Also, the first driving unit (70) rotates the second roller (30) around a second axis (23) at a second linear speed (V2) in a second direction of rotation, as shown in figures 6a and 6b. The second direction of rotation can be clockwise or anticlockwise. In the present embodiment, the second direction of rotation is in an anticlockwise direction. In the present embodiment, the first direction of rotation is opposite to the second direction of rotation.

[0048] Further, the system (100a, 100b) includes a control unit (90), as shown in figures 6a and 6b. The control unit (90) is connected to the first driving unit (70) and the second driving unit (80). The control unit (70) is a microprocessor or a microcontroller or a controller or a processor or a logic controller or a computer, or a workstation.

[0049] Further, a detecting unit (110) is connected to the control unit (90), as shown in figures 6a and 6b. The detecting unit (110) is adapted to detect a folded state (120) of the received intermediate item (50). The detecting unit (110) is a camera system or an ultrasonic sensor or an infrared sensor or a distance sensor. The detecting unit (110) sends the received details of the detected folded state ( 120) of the intermediate item (50) to the control unit (90). The folded state (120) of the intermediate item (50) includes a first folded state (120a) (as shown in figure 4a) and a second folded state (120b) (as shown in figure 4b).

[0050] Further, the control unit (90) includes a memory unit (90a), as shown in figures 6a and 6b. The memory unit (90a) includes the details of a predefined state (130) of the intermediate item (50). The predefined state (130) of the intermediate item (50) is a standard folded state of the intermediate item where a third face (50c) of the intermediate item (50) is coplanar with a fourth face (50d) of the intermediate item (50) as shown in figures 5a and 5b. The third face (50c) and fourth face (50d) are surfaces or edges of the folded intermediate item (50) at the ends perpendicular to the direction of folding. The memory unit (90a) is a cloud server or a hard drive or an IOT memory. [uuo i] Further, the control unit (90) compares the received details from the detecting unit (110) with the predefined state (130) of the intermediate item (50) stored in the memory unit (90a) and actuates the first driving unit (70) to rotate the first roller (20) and the second roller (30) and the second driving unit (80) to rotate the third roller (21) and the fourth roller (31). The first driving unit (70) actuates the first roller (20) and the second roller (30) with different speeds. Also, the second driving unit (80) actuates the third roller (21) and the fourth roller (31) with different speeds based on the magnitude of errors present in the folded state (120) of the intermediate item (50). The linear speeds (Vi, V2, V3 and V4) of the rollers (20, 30, 21, 31) are varied by the control unit (90) to deform the intermediate item (50) to the predefined state (130). In the present embodiment, the linear speed (Vi) of the first roller (20) and the linear speed (V3) of the third roller (21) are the same, and the linear speed (V2) of the second roller (30) and the linear speed (V4) of the fourth roller (31) are same.

[0052] Referring to 6a, an embodiment of the system (100a) for operating a pressing machine (10) in accordance with the present invention is illustrated. In the embodiment (100a), the folded state (120) of the intermediate item (50) includes a first folded state (120a), as shown in figure 4a. When the intermediate item (50) is at the first folded state (120a), the first roller (20) and the third roller (21) are in contact with a head face (61) of the intermediate item (50) and the second roller (30) and the fourth roller (31) are in contact with a tail face (62) of the intermediate item (50) as shown in figure 6a. The head face (61) and the tail face (62) of the intermediate item (50) are surfaces of the intermediate item (50) along the direction of folding of the intermediate item (50), as shown in figure 4a.

[0053] Further, at the first folded state (120a), a first face (50a) of the intermediate item (50) is at a first position (51), and a second face (50b) of the intermediate item (50) is at a second position (52) with an error (71) between the first face (50a) and the second face (50b) as shown in figure 4a. The error (71) is a spacing or a distance between the first face (50a) and the second face (50b). The first race pua) and the second face (50b) of the intermediate item (50) are edges or surfaces of the intermediate item (50) at the ends perpendicular to the direction of folding of the intermediate item (50). Similarly, the third face (50c) of the intermediate item (50) is at a third position (53), and the fourth face (50d) of the intermediate item (50) is at a fourth position (54) with an error (72) between the third face (50c) and the fourth face (50d) as shown in figure 4a. The error (72) is a spacing or a distance between the third face (50c) and the fourth face (50d). Also, at the first folded state (120a), there is an error (75) between the folds of the intermediate item (50), as shown in figure 4a. The error (75) is a spacing between layers of folds of the intermediate item (50) in which air is entrapped. When the intermediate item (50) is at the stage before a final fold, as shown in figure 2a, only the errors (71 and 75) are present, and when the intermediate item (50) is at the final folded state (as shown in figure 2b), the errors (71, 72 and 75) all exist together.

[0054] When the intermediate item (50) at the first folded state (120a) enters in the pressing machine (10), as shown in figure 6a, the detecting unit (110) arranged at a suitable location with the pressing machine (10) detects the first folded state (120a) of the intermediate item (50). Further, the detecting unit (110) sends information about the first folded state (120) of the intermediate item (50) to the control unit (90). Based on the magnitude of the errors (71 and 72) within the intermediate item (50), the control unit (90) directs the first driving unit (70) and the second driving unit (80) to decrease the first speed (Vi) of the first roller (20) and the third speed (V3) of the third roller (21) respectively to press the intermediate item (50) to the predefined state (130). Due to the application of pressure on the intermediate item (50), the errors (71 and 72) are also corrected along with the error (75), which is an advancement over prior art.

[0055] Referring to figure 7a, when the speeds (VI and V3) are decreased, a centrifugal force (F) is applied by the rollers (20 and 21) on the intermediate item (50) (as shown in figure 7a), which causes the third face (50c) towards the fourth face (50d) and the second face (50b) of the intermediate item to move towards the first face (50a) and to attain the predefined state (130) of the intermediate item (50).

[0056] Referring to figure 6b, an embodiment of the system (100b) for operating a pressing machine (10) in accordance with the present invention is illustrated. In the embodiment (100b), the folded state (120) of the intermediate item (50) includes a second folded state (120a), as shown in figure 4b. When the intermediate item (50) is at the second folded state (120b), the first roller (20) and the third roller (21) are in contact with the tail face (62) and the second roller (30) and the fourth roller (32) are in contact with the head face (61) of the intermediate item (50) as shown in figure 6b.

[0057] At the second folded state (120b), the first face (50a) of the intermediate item (50) is at a fifth position (55), and the second face (50b) of the intermediate item (50) is at a sixth position (56) with an error (73) between the first face (50a) and the second face (50b) as shown in figure 4b. The error (73) is a spacing or a distance between the first face (50a) and the second face (50b) of the intermediate item (50). Similarly, at the second folded state (120b), the third face (50c) of the intermediate item (50) is at a seventh position (53), and the fourth face (50d) of the intermediate item (50) is at an eighth position (58) with an error (74) between the third face (50c) and the fourth face (50d) as shown in figure 4b.

[0058] The error (74) is a spacing or a distance between the third face (50c) and the fourth face (50d) of the intermediate item (50). Also, at the second folded state (120b), there is an error (76) between the folds of the intermediate item (50), as shown in figure 4b. The error (76) is a spacing between layers of folds of the intermediate item (50) in which air is may be entrapped. When the intermediate item (50) is at a stage before the final fold, only the errors (73 and 76) are present (as shown in figure 4c), and when the intermediate item (50) is at the final folded state, the errors (73, 74 and 75) exist together (as shown in figure 4a). |oo?y| When the intermediate item (50) at the second folded state (120b) enters the pressing machine (10), as shown in figure 6b, the detecting unit (110) detects the second folded state (120b) of the intermediate item (50), the detecting unit (110) sends information about the second folded state (120b) to the control unit (90). The information about the second folded state (120b) includes the magnitudes and positions of the errors (73 and 74) within the intermediate item (50).

[0060] Based on the magnitudes of errors (73 and 74), the control unit (90) directs the first driving unit (70) and the second driving unit (80) to increase the first speed (Vi) of the first roller (20) and the third speed (V3) of the third roller (21). Also, the control unit (90) directs the first driving unit (70) and the second driving unit (80) to decrease the second speed (V2) of the second roller (30) and the fourth speed (V4) of the fourth roller (31) to press the intermediate item (50) to the predefined state (130). Due to the application of pressure on the intermediate item (50), the errors (73 and 74) are also corrected along with the error (76), which is an advancement over prior art.

[0061] Referring to figure 6b, when the speeds (V2 and V4) are decreased, a centrifugal force (F) is applied by the rollers (30, 31) on the intermediate item (50), which causes the second face (50b) of the intermediate item (50) to move towards the first face (50a) and the third face (50c) towards the fourth face (50d) to attain the predefined state (130) of the intermediate item (50).

[0062] Further, in an embodiment (not shown in figures), one or more pressing members are arranged with the first roller (20) and the third roller (21) to displace the first roller (20) and the third roller (21) for pressing the intermediate item (50) to remove errors within the folds of the intermediate item (50). The pressure exerted by the first roller (20) and the third roller (21) can be adjusted by adjusting the stiffness of the pressing members. The pressing members can be springs, disc springs or bellows. Further, the speeds (VI, V2, V3, V4) can be adjusted by changing the diameters of the rollers (20, 30, 21, 31), the number of rollers (ZU, U, 21, 31) can be increased or decreased based on the requirements of an operator.

[0063] Thus, the present system (100a, 100b) provides an advantage of correcting the errors such as springiness and the like within the intermediate items (50). Also, the system (100a, 100b) provides compact folds by varying the rotational speeds of pressing rollers (20, 30, 21, 31) by eliminating the need of replacing the whole set of pressing rollers every time according to the number of errors. The system (100a, 100b) corrects the errors (71, 72, 73, 74) within the intermediate item (50) along with errors (75, 76) which are formed due to air entrapped between layers of folds of the intermediate item (50). Also, the system (100a, 100b) is adapted to change the rotational parameters of rollers (20, 30, 21, 31) with the help of a sensor-based mechanism, thereby eliminating the frequent need for human intervention.

[0064] 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 utilize 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.