AU2005273115B2

AU2005273115B2 - Apparatus and method for opening case blanks

Info

Publication number: AU2005273115B2
Application number: AU2005273115A
Authority: AU
Inventors: John Raymond Bannister
Original assignee: AUTOMAC ENGINEERING Ltd
Current assignee: AUTOMAC ENGINEERING Ltd
Priority date: 2004-08-18
Filing date: 2005-08-18
Publication date: 2011-12-08
Anticipated expiration: 2025-08-18
Also published as: WO2006019319A1; AU2005273115A1

Abstract

An opening apparatus for opening case blanks having: a rotating member (8) adapted to grip a first face of a case blank (5), and an opening means (11) adapted to grip the opposite face of the blank wherein said rotating means is capable of rotating the case blank to present the opposite face of the blank to said opening means such that the blank can be simultaneously gripped on both sides and, the opening means and the rotating member are capable of moving relative to one another to thereby enable the blank to be opened.

Description

5 APPARATUS AND METHOD FOR OPENING CASE BLANKS FIELD OF INVENTION This invention relates to a case blank opening apparatus and method for opening case blanks. More particularly it relates to an automated or semi-automated case blank opening apparatus and method for opening blanks from lay flat format. 10 BACKGROUND Cases (or boxes) are used to package product into for transport or storage. Commonly used cases are, for example, regular slotted cases (RSC's) and half slotted cases (HSC's). A variety of products are loaded into these cases including food products such as bottles, bagged food or loose produce. 15 The erection of these cases from a blank lay flat format is often automated. The blank must first be opened from its lay flat format so the inside walls and flaps of the case are no longer in contact and form an open-ended case profile. The flaps at one end of the case can then be closed and held in place with glue of tape. The case is then transported away so it can be loaded. A machine that performs this process is normally referred to as a 20 "case erector". Alternatively, the open-ended case profile is loaded automatically prior to or in conjunction with closing the case. A machine which incorporates the step of loading the case is commonly referred to as a "case packer". Irrespective of their functions, both case erectors and case packers require the blank to first be opened. Prior art case erectors or case packers use a variety of opening methods for 25 opening cases. Most commonly blanks are stacked together to form a magazine or blank feed system. Using vacuum and/or a shearing technique one blank at a time is taken from the magazine or blank feed system. This is often referred to as "plucking". Once the blank is removed it is typically opened by one or a combination of the following prior art methods: 30 Method I After the lay flat blank is plucked from the magazine it is slid across a forming profile, which typically contacts with one of the two minor side walls which opens the blank to form an open-ended case. This method is unreliable as often the glue used in the manufacturing joint of the 35 side walls of the blank (when it was originally made) has escaped from the joint and inadvertently caused the inside walls of the blank to stick together. If this has occurred the blank will not open and instead crumples and jams the machine halting production. The 1 5 jammed case must then be manually removed from the machine. In addition cases that are not folded exactly square can be difficult to open (this is often referred to as fish-tailing. Finally, this method offorming a case has a typically slow cycle time due to the fact that once the case is formed from a blank it must be removed f-om the system before 10 the rotating member can return to the magazine to grip another blank. Method 2 The blank is plucked from the magazine. Vacuum cups grip opposing sides of the blank. The blank is then opened by moving one or both sides of the blank. The grip on the blank provided by both sets of vacuum cups assists in the opening of the blank despite the 15 insides of the blank being inadvertently glued together when the manufacturing joint in the blank was glued. Accordingly this method is more reliable than method I, however it is more cumbersome. To achieve higher output rates this system requires separate stations for completing each step whereby more than one blank is being processed at each station. As an example, this system may have a shearing station for plucking the blanks and a 20 separate station for opening the blanks. Because such a system is so complex and needs to be comparatively large it is not commercially viable unless the processing is on a large scale. What is required is a case blank opening apparatus and method for opening case blanks which is capable of being used in a case erector or case packer which is not only 25 reliable but also efficient. It is advantageous if the system is easy to adjust to accommodate different blanks and is commercially viable to manufacture. OBJECT It is an object of the present invention to provide an improved case blank opening apparatus and method of opening case blanks, or at least provide the public with a useful 30 choice. STATEMENT OF INVENTION In a first aspect the present invention relates to a case blank opening apparatus having a rotatable member adapted to grip a first face of a case blank, and an opening means adapted to grip the opposite face of the blank, wherein the rotatable member is 35 capable of plucking the case blank from a magazine of blanks and rotates the blank as it translates it to an opening station to present the opposite face of the blank to the opening means such that the blank can be gripped on opposite sides and the opening means is 2 5 capable of moving relative to the rotatable member to thereby enable the blank to be opened. Preferably the rotatable member is mounted on a first carriageway and is capable of linear movement along the first carriageway. Preferably the opening station is adjacent a second carriageway and a carriage is 10 mounted to the second carriageway and is adapted to grip the blank and move it in a direction away from the opening station. Preferably the second carriageway provides a linear pathway for the carriage and opened case to be moved from the opening station. Preferably the opening means additionally acts as the carriage. 15 Preferably the opening means is mounted to the second carriageway and is adapted to move relative to the rotatable member at the opening station in the direction of the second carriageway to cause the blank to open and also moves the opened case from the opening station. Preferably the opening means is a pivoting arm capable of gripping the opposite 20 face of the blank and pivoting relative to the second carriageway to open the case at the opening station and is also adapted to move along the second carriageway to move the opened case from the opening station. Alternatively the opening means is a pivoting arm capable of gripping the opposite face of the blank and pivoting relative to the second carriageway to open the blank at the 25 opening station and the second carriageway has carriages mounted thereupon which move and/or guide the opened case along the second carriageway away from the opening station. Preferably the carriageway is in the form of two parallel chain conveyors and the carriages are drive dogs mounted upon the chain conveyors. The apparatus is designed so that once the blank has been opened the rotatable 30 member can quickly return to pluck the next blank from the magazine without waiting for the opened blank to be moved away. In addition, since both opposing faces of the blank are gripped the blank is positively opened which improves the reliability of the apparatus. Preferably the carriageways are adjacent one another at one end and diverge outwardly at an angle to one another. This enables the carriages to become sufficiently 35 proximate to one another for the blank to be gripped on opposing faces and allows for the opened blank to be moved away so another blank can be processed. 3 5 Preferably the carriageways are substantially perpendicular to one another. This arrangement is preferred as it is the most efficient for opening the case. In a second aspect the invention relates to a case erector including the case blank opening apparatus as hereinbefore described in any one of the preceding statements. In a third aspect the invention relates to a case packer including the case blank 10 opening apparatus as hereinbefore described in the relevant preceding statements. In a further aspect the invention relates to an automated method of opening a case blank having opposing first as second faces which includes the steps of: a) Gripping a first face of a case blank, b) Plucking the blank from a magazine of blanks, 15 c) Rotating and translating the blank to an opening station to present the opposite face of the blank to an opening means which grips the opposite face of the blank, d) Moving the opening means to open the case, e) Releasing the grip from the first face of the blank, and f) Transferring the opened case from the opening station. 20 Preferably the grip on the second face of the blank is released at the same time as step e) or at least prior to step f). Preferably step f) occurs with a first blank at substantially the same time step a) occurs with a subsequent blank. Preferably step d) involves pivoting the opening means to open the case 25 Preferably step f) involves moving the opened case along a linear pathway. More preferably the relative movement of the first and second faces is controlled using software. BRIEF DESCRIPTION OF THE DRAWINGS Throughout the body of the description reference will be made to the 30 accompanying drawings, in which: Figure 1 is a schematic perspective view of the apparatus in example I showing the blank being gripped at the beginning of a cycle. Figure 2 is a schematic perspective view of the apparatus in example I showing the blank undergoing translational and rotational movement. 35 Figure 3 is a schematic perspective view of the apparatus in example I showing the blank in position at the opening station prior to being opened. Figure 4 is a schematic perspective view of the apparatus in example I showing the 4 5 opening of the blank at the opening station. Figure 5 is a schematic perspective view of the apparatus in example I showing the opened case being moved from the opening station. Figure 6 is a schematic perspective view of the apparatus in example 1 showing the opened case being taped and rotatable member returning to grip another blank. 10 Figure 7 is a plan view of a case blank at different stages during its opening and shows the relative movement of the first and second faces of the blank in example 1. Figure 8 is a schematic perspective view of the apparatus in example 2 looking from behind the magazine prior to erection of the case. Figure 9 is a schematic perspective view of the apparatus in example 2 looking 15 from in front of the magazine prior to erection of the case. Figure 10 is a schematic perspective view of the apparatus in example 2 looking from behind the magazine showing the erected case. Figure 11 is a schematic perspective view of the apparatus in example 2 looking from in front of the magazine showing the erected case. 20 Figure 12 is a schematic perspective view of the apparatus in example 3 showing a blank being gripped by the rotatable member Figure 13 is a schematic perspective view of the apparatus in example 3 showing the blank being plucked and commencing translational and rotational movement. Figure 14 is schematic perspective view of the apparatus in example 3 showing the 25 blank in position at the opening station prior to opening taking place. Figure 15 is a schematic perspective view of the apparatus in example 3 showing the opened box prior to being moved from the opening station PREFERRED EMBODIMENT The following examples are given by way of illustration only and shall not be 30 taken as being in any way limiting as to the spirit or scope of the invention. Referring to the drawings, wherein like numerals designate corresponding parts throughout the several figures. The invention in the following examples is described using a case erector application. It will be apparent to those skilled in the art that the opening apparatus and 35 method could also be applied to a case packer application or any other application requiring an open case blank. The present invention relates to a case blank opening apparatus having a rotatable 5 5 member adapted to grip a first face of a case blank, and an opening means adapted to grip the opposite face of the blank, wherein the rotatable member is capable of plucking the case blank from a magazine of blanks and rotates the blank as it translates it to an opening station to present the opposite face of the blank to the opening means such that the blank can be gripped on opposite sides and the opening means is capable of moving relative to 10 the rotatable member to thereby enable the blank to be opened. The rotatable member is preferably in the form of a first carriage mounted on a first carriageway and is capable of both translating and rotating the blank. In the following examples the carriage undergoes both rotation and linear movement along the first carriageway. The opening station is located adjacent a second carriageway and a 15 second carriage is mounted to the second carriageway and is adapted to grip the blank and move it in a direction away from the opening station. Example I Referring to Figure 1 it can be seen that the apparatus consists of two fixed carriageways which, in this example, take the form of linear tracks (3 & 4). These tracks 20 run perpendicular to one another. Simple tracks have been chosen but it will be obvious to those skilled in the art that other linkages could be used to achieve a similar motion. The rotatable member (9) comprises of a plate which slidably engages with linear track (3) and can travel the length of the track in the direction as indicated by the arrow marked "A" in Figure 1 and an arm (8) which rotates relative to the plate. The opening 25 means takes the form of a carriage (11) slidably engaged with linear track (4) and can travel the length of the track in the direction as indicated by the arrow marked "B" in Figure 1. The case blanks to be opened will be in lay flat format and will typically have two opposing faces, hereinafter referred to as first and second faces. With rectangular-shaped 30 cases, each face will have a fold line dividing what will form a major side wall and a minor side wall. The major side wall simply being bigger than the minor side wall. It is this type of case which is used in this example though different cases may also be used. Vacuum cups (6) and (7) are fixed to arm (8) of the rotatable member (9). Vacuum cups (6) grip the blank on the major side wall of the case; vacuum cups (7) grip the blank on the 35 minor side wall of the case. The tracks (3&4) need not run strictly perpendicular to one another however the tracks should be configured such that at some point both carriages will be able to grip the 6 5 blank. However, a substantially perpendicular arrangement is the most viable arrangement for manufacturing. In use a magazine (2) is positioned so that when it is loaded with blank cases (5) the vacuum cups (6 & 7) contact the first face of each blank. The rotatable member (9) and carriage (11) could be driven by a variety of methods. 10 Stepper, Servo, or AC motors could be used in conjunction with a ball screw or timing belt system to generate linear motion. Alternatively pneumatics could be used. Typically these methods use a control from a PLC with suitable software. Magazine (2) ensures that blanks (5) are always engaged with holding plates (1). There are a variety of prior art methods for doing this. Pushing the blanks via an arm (not shown) or 15 conveying the blanks (5) on small belts to the holding plates (1) would be typical. Cycle sequence 1. Ref Figure 1. Using a form of vacuum generation (not shown) a vacuum is pulled between the blank (5) and vacuum cups (6 & 7). 2. Ref Figure 2. Using the vacuum between blank (5) and cups (6 & 7) one 20 blank (5) can be removed from the magazine and holding plates via a linear motion from rotatable member (9). As the rotatable member (9) is translated away from the magazine (2), arm (8) begins to rotate inside the plate of the rotatable member (9). The method of rotation could be done a variety of ways, a cam system, electric motor or pneumatic drive would be typical. 25 3. Ref Figure 3. Blank (5) will rotate until the face of the blank (5) is parallel to the face of the vacuum cups (10) on carriage (11). Rotatable member continues to move until it reaches the point where vacuum cups (10) engage the face of blank (5). Once this is complete the vacuum is released from vacuum cups (7). A vacuum is then generated between blank (5) and cups (10). 30 4. Ref Figure 4. Through the vacuum generated on both sets of cups (6) and (10) the case is effectively gripped on opposite sides. Rotatable member (9) and carriage (11) now begin to move away from each other, as indicated by the arrows. The velocity and acceleration of the rotatable member (9) and carriage (11) is proportionally controlled relative to the blank (5) dimensions. This proportional movement opens the blank (5). 35 5. Ref Figure 5. Once the blank (5) is fully opened the major (14) and minor flaps (15) are folded in sequence via a sequence of folding arms (not shown). Once the major (14) and minor flaps (15) are closed the vacuum between cups (6) and blank (5) is 7 5 vented. 6. Ref Figure 6, Rotatable member (9) then travels back to the magazine (2), arm (8) rotates in the opposite manner and returns to its original position. When the rotatable member (9) is in this position is has completed the cycle and is ready to begin again. 10 Also seen in Figures 5 & 6 is the travel of the opened case over a tape applicator (12) which tapes the bottom flaps of the case (5) closed. It will be apparent that if the case blank opener is instead applied to a case packer the opened blank would be loaded before or during the case being closed. During travel of the carriage the case (5) is held not only by the vacuum from cups (10) but it is also pushed/guided by arm (13) which is best seen 15 in use in Fig. 5 (this ensures the case (5) remains square). Once Carriage (11) reaches the position shown in Figure 6 the vacuum in cups (10) is vented and the case (5) is released. Arm (13) then swings back (as shown in Fig 6). Carriage (11) then travels back to its original position. Steps I & 2 can be happening in conjunction with carriage (11) travelling back to its original position. This reduces the 20 time required to complete a cycle. Referring to Fig 7 a more detailed view of the movments of case blank (5) at 9 different stages during its opening is depicted. It can be seen in step 9 of this figure that the total movement of the rotatable member (9) and carriage (11) is proportional to the minor side length of the case. For example if the minor side length of the case is 400 units 25 then the travel of rotatable member (9) and carriage (11) will also be 400 units. However it can be clearly seen that the distance that the rotatable member (9) and carriage (11) travel during the opening of case (5) is not a linear relationship. It will be seen particularly in Step 2 of this figure that rotatable member (9) has moved 69 units compared with carriage (11) moving 6 units. The difference in the movement of the first and second carriages 30 decreases with each subsequent step can also be seen until both carriages have moved the same total distance. The ratios of movement between the carriages should be constant, therefore once it has been established it is simple to adjust to accommodate different sized cases. Example Two 35 The following example uses the same principle of opening case blanks as used in example I but has been modified to reduce the size and costs in manufacturing the system. The system still uses the same rotatable member as used in example 1 however the 8 5 carriage on the second carriageway differs. The carriageways still run substantially perpendicular to one another. A first face of the blank is still gripped by vacuum cups allowing it to be plucked from the magazine. The blank is still gripped by the rotatable member (9) and undergoes rotation as it is translated along the length of the first carriageway presenting a further face to be gripped by gripping means on the opening 10 means/carriage. The apparatus in this example is best seen with reference to Figures 8 to 11 Referring to Fig 8 it can be seen that the majority of the components in this example are substantially the same as those in example 1. The blanks are stacked in magazine 20 and are plucked using rotatable member 22. From the figures it can be seen that the blank 21 is 15 plucked from the magazine and moved along the length of the first carriageway (not shown here) in the direction indicated by arrow A. The blank 21 also undergoes rotation along the length of the first carriageway as described in example 1. Slidably mounted to the second carriageway 23 is the opening member in the form of a carriage 24. In this example the carriage is in the form of an arm 24 having two limbs 20 with vacuum cups mounted thereupon. It will be obvious to persons skilled in the art that the specific configuration of the arm 24 can be varied depending on the size of the blank and/or the size or number of the vacuum cups. In addition to linear movement along the second carriageway 23 the arm is adapted to be capable of pivoting about axis X, shown in figure 9. The arm 24 should be capable of 25 rotating at least 90 degrees and this can be achieved by way of an actuator. It can be seen that the arm in this example provides the function of squaring arm 13 in example I as it holds the case square as it is moved along the length of the second carriageway. Cycle sequence 30 The step of plucking the case blank 21 from the magazine 20 and rotating it to present a second face to be gripped is the same as that used in example 1. This can be seen in figures 8 & 9. In this example the minor side wall of the second face of the blank is gripped by the arm 24 via suction cups. Simultaneously the vacuum pulled on the minor side wall of 35 the first face of the blank is released. The arm 24 then rotates about axis X in the direction indicated by arrow B opening the case. Once the case is opened the cycle is essentially the same as the previous 9 5 embodiment. Major and minor flaps are folded at the bottom of the case via folding arms (not shown). The vacuum on the rotating member 22 is released allowing it to return to magazine 20 to pluck another blank. Simultaneously the arm 24 moves along the second carriageway 23 away from the opening station in the direction indicated by arrow C. During this travel the base of the case may then be taped or glued shut. 10 Once arm 24 has reached the end of its travel along second carriageway 23 the vacuum on the gripping cups is released and the arm returns to its original position ready to begin another cycle. Example Three This example is best described with reference to figures 12 to 15. The opening arm 15 34 is only capable of pivotal movement to open the blank. Once the case is opened an (independently acting) second carriage 35 moves the opened case out of the machine by pushing on the back minor face of the case. The second carriageway in this example takes the form of one or more chain conveyors 33 & 37 and the carriages takes the form of one or more drive dogs 35 & 36 mounted to the 20 chains. A further advantage of using a rotating member is that this motion allows the blank 31 to be placed between the two chain conveyors 33 & 37 without the colliding with the chain conveyors 33 & 37. In prior art systems with a linear plucking action this could not be achieved due to the blank colliding with the chain conveyors. 25 Major and minor flap folding arms are the same as in previous examples. Cycle sequence The blank 31 is gripped on its first face/then plucked and rotated (movement indicated as arrow "D") during travel along the first carriageway (movement indicated as arrow "C"). Opening means 34 then pivots about axis X to contact with the minor wall of 30 the second face of the blank. The vacuum cups on the opening means then grip the minor wall of the second face of the blank and this is best seen with reference to Figure 14. The opening arm 34 then pivots about axis X, back to its original position thereby opening the case which is seen with reference to Figure 15. The major and minor flaps of the case can then be closed via flap folding arms. 35 Vacuum on the rotating member 32 is then released allowing the rotating member to return to the magazine 30 to pluck another blank. Vacuum via the suction cups on the opening arm can then be released. The drive dogs 35 10 5 & 36 now drives the case out of the system by pushing on the back minor face. It then returns to its start position by travelling around the circumference of the conveyor chain 33 &37 ready for another case. It will be obvious to a person skilled in the art that more the one chain conveyor can be used. In addition, more than one driving dog can be used on a chain conveyor 10 enabling some of the drive dogs to be driving cases out of the system while others are returning to the start position. ADVANTAGES Cases are positively opened which will minimize problems caused by over-gluing of the manufacturing joint or fish tailing of the cases. Moreover this is achieved with a 15 simplified machine function and an over-lapping cycle time. The result is a faster cycle time and a more cost-effective apparatus. The apparatus also makes adjusting the system to accommodate different case sizes quick and simple. This is mainly due to the proportionally controlled velocity and acceleration of each face of the blank. 20 VARIATIONS The magazine and holding plates may be orientated with a different angular relationship to that shown in the figures. As an example the blanks and magazine/holding plates could be orientated at 45 degrees to horizontal. This would in turn mean that the path of travel of the rotating member would alter to accommodate this change. 25 Furthermore the carriageways could be orientated in different positions, for example below the blanks. This would then mean rotating member could be mounted vertically - therefore the blank would be rotated in the vertical plane. Adding an out-feed conveyor to convey the erected cases over the tape head or glue gun would minimize the travel distance of the second carriage. This would reduce the cycle 30 time of the apparatus allowing cases to be erected at a higher rate. It will be obvious to persons skilled in the art that the carriageways need not strictly run perpendicular to one another but it is advantageous that the carriageways run in different directions to assist in clearing the case so the rotating member may return to retrieve another blank more quickly. 11

Claims

1. A case blank opening apparatus having: a rotatable member adapted to grip a first face of a case blank, and an opening means adapted to grip the opposite face of the blank, 10 wherein the rotatable member is capable of plucking the case blank from a magazine of blanks and rotates the blank as it translates it to an opening station to present the opposite face of the blank to the opening means such that the blank can be gripped on opposite sides and the opening means is capable of moving relative to the rotatable member to 15 thereby enable the blank to be opened.

2. A case blank opening apparatus as claimed in claim 1, wherein the rotatable member is mounted on a first carriageway and is capable of linear movement along the first carriageway. 20

3. A case blank opening apparatus as claimed in either one of claims I or 2, wherein the opening station is adjacent a second carriageway and a carriage is mounted to the second carriageway and is adapted to grip the blank and move it in a direction away from the opening station. 25

4. A case blank opening apparatus as claimed in claim 3, wherein the second carriageway provides a linear pathway for the carriage and opened case to be moved from the opening station. 30

5. A case blank opening apparatus as claimed in claim 3, wherein the opening means additionally acts as the carriage.

6. A case blank opening apparatus as claimed in claim 5, wherein the opening means is mounted to the second carriageway and is adapted to move relative to the rotatable 35 member at the opening station in the direction of the second carriageway to cause the blank to open and also moves the opened case from the opening station. 12 5

7. A case blank opening apparatus as claimed in claim 5, wherein the opening means is a pivoting arm capable of gripping the opposite face of the blank and pivoting relative to the second carriageway to open the case at the opening station and is also adapted to move along the second carriageway to move the opened case from the opening station. 10

8. A case opening apparatus as claimed in any one of claims 3 or 4, wherein the opening means is a pivoting arm capable of gripping the opposite face of the blank and pivoting relative to the second carriageway to open the blank at the opening station and the second carriageway has carriages mounted thereupon which move and/or guide the opened case along the second carriageway away from the opening station. 15

9. A case opening apparatus as claimed in claim 7, wherein the carriageway is in the form of two parallel chain conveyors and the carriages are drive dogs mounted upon the chain conveyors. 20

10. An automated method of opening a case blank having opposing first as second faces which includes the steps of: a) Gripping a first face of a case blank, b) Plucking the blank from a magazine of blanks, c) Rotating and translating the blank to an opening station to present the 25 opposite face of the blank to an opening means which grips the opposite face of the blank, d) Moving the opening means to open the case, e) Releasing the grip from the first face of the blank, and f) Transferring the opened case from the opening station. 30

11. An automated method of opening a case blank as claimed in claim 10, wherein the grip on the second face of the blank is released at the same time as step e) or at least prior to step f).

12. An automated method of opening a case blank as claimed in either of claims 10 or 35 11, wherein step f) occurs with a first blank at substantially the same time step a) occurs with a subsequent blank.

13 5 13. An automated method of opening a case blank as claimed any one of claims 10 to 12, wherein step f) involves moving the opened case along a linear pathway.

14 An automated method of opening a case blank as claimed any one of claims 10 to 13, wherein step d) involves pivoting the opening means to open the case. 10

15. A case erector including the case blank opening apparatus as claimed in any one of claims I to 9.

16. A case packer including the case blank opening apparatus as claimed in any one of 15 claims I to 9.

17. A case blank opening apparatus as claimed in any one of claims I to 9, substantially as hereinbefore described with reference to the accompanying examples and/or any appropriate selection or combination of the accompanying figures. 20

18. An automated method of opening a case blank as claimed in any one of claims 10 to 14, substantially as hereinbefore described with reference to the accompanying examples and/or any appropriate selection or combination of the accompanying figures. 14