Patent Publication Number: US-8534033-B2

Title: Apparatus for wrapping an article and method for doing same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority on U.S. provisional application No. 61/032,485 filed Feb. 29, 2008, which is incorporated herein by reference in its entirety. This application is a national phase of PCT application PCT/CA2009/000225, filed Feb. 27, 2009, designating the United States, now pending, the specification of which is hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to an apparatus for wrapping an article such as a parallelepiped shaped bundle, and to a method of wrapping such an article. 
     BACKGROUND ART 
     It is known to wrap or envelop articles having an essentially orthogonal form, such as bundles of lumber, pulp, plywood or chipboard, or a pile of any adequate type of articles, on five sides thereof by suitable wrapper material. This can be done to protect the articles, for instance to provide protection during transportation and storage, or to provide a solid surface for various markings such as for example, identifiers, labels and/or commercial advertisements. In some instances, the wrapper material is used to give the articles a neater appearance, and/or to hide some details thereof which are not intended to be seen by the public. 
     Placement and folding of the wrapper sheet is usually a manual or semi-automatic operation, whereby a wrapper material Web is supplied from a material roll positioned above the article to be wrapped. The article is placed on a conveyor, and the wrapper is drawn from the roll over the article as the article passes by the roll. When the rear end of the article has passed the material roll, the material web is manually or automatically cut. The wrapper material is then folded around the article. The attachment of the wrapper foldings or tongues may be effected by gluing, taping, riveting, stapling, etc. 
     Known methods of wrapping an article include the use of rollers to apply wrapping material to the faces of the article, and/or blowers to position the wrapper material and optionally heat shrink it in place. However, if the wrapper material is not correctly positioned prior to engagement with the rollers and/or jets from the blowers, the resulting aspect of the wrapped product may be irregular, which is undesirable. 
     SUMMARY 
     It is therefore an aim of the present invention to provide an improved wrapping apparatus and method. 
     Therefore, in accordance with the present invention, there is provided a method for wrapping at least a portion of an article having a substantially parallelepiped shape or a parallelepiped shape with a wrapper material, the method comprising grabbing the wrapper material along at least one first wrapper edge of the wrapper material, proximate to a first end of the wrapper material, extending the wrapper material over at least part of an upper face of the article, folding the wrapper material to cover at least one first peripheral face of the article with the wrapper material, such that each one of at least two first sections of the wrapper material extends beyond a respective first lateral edge of the at least one first peripheral face and such that each one of at least one second section of the wrapper material, extends beyond an upper edge of a respective one of at least one second peripheral face adjacent the at least one first peripheral face, folding each first section about the respective first lateral edge and against one of the at least one second peripheral face, securing each folded first section to the one of the at least one second peripheral face, folding each second section about the upper edge of the respective second peripheral face and against the respective second peripheral face, and securing each folded second section to the respective second peripheral face, wherein the wrapper material remains at least partially grabbed until at least one of the at least one second section is secured. 
     Also in accordance with the present invention, there is provided an apparatus for wrapping a substantially parallelepiped shaped or parallelepiped shaped article with a wrapper material web, the apparatus comprising a wrapper material supply unit, a wrapper holder having two spaced-apart wrapper gripping units, each of the two wrapper gripping unit being mounted on a respective side of the wrapper material supply unit for gripping an edge of the wrapper material web, each gripping unit being movable along at least a vertical direction and a transverse direction of the apparatus, a wrapper material fastening unit for securing the wrapper material to the article, at least one actuator operatively connected to the at least two gripping units and displacing the wrapper holder when activated, and at least one controller operatively connected to the at least one actuator, to the at least two wrapper gripping units for controlling the gripping unit displacement, and to the wrapper material fastening unit, the controller being in communication with the wrapper gripping units and the wrapper material fastening unit for preventing the wrapper gripping units from completely releasing the wrapper material until the wrapper material is secured to the article. 
     Also in accordance with the present invention, there is provided a wrapping apparatus for wrapping an article with a wrapper material web, the apparatus comprising a wrapping station for receiving the article to be wrapped, a wrapper material supply unit including a wrapper material web supply, a wrapper holder for gripping the wrapper material web and carrying the wrapper material web along a wrapper material path extending from the wrapper material supply unit to the wrapping station, and a wrapper material identifying unit mounted between the wrapper material supply unit and the wrapping station along the wrapper material path for adding printed information to the wrapper material prior to article wrapping. 
     Also in accordance with the present invention, there is provided a method for adding printed information on a wrapper material for an article, comprising drawing the wrapper material from a wrapper material roll, adding the printed information on the drawn wrapper material, and wrapping at least a section of the article with the wrapper material including the printed information. 
     Further in accordance with the present invention, there is provided a method for adding printed information on a wrapper material for an article, comprising determining an information position on the article, determining a printing position for the printed information on the wrapper material in accordance with a size of the article, a wrapping method used, and the information position, drawing the wrapper material from a wrapper material roll, adding the printed information on the wrapper material at the printed position; and wrapping at least a section of the article with the wrapper material including the printed information, the printed information being located at the information position on the wrapped article. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Reference will now be made to the accompanying drawings, showing by way of illustration a particular embodiment of the present invention and in which: 
         FIG. 1  is a perspective view of a wrapping apparatus according to a particular embodiment of the present invention; 
         FIG. 2  is a side elevation view of the wrapping apparatus of  FIG. 1 , showing a wrapping step where an article to be wrapped is moved to a wrapping station; 
         FIG. 3A  is a side elevation view of the wrapping apparatus shown in  FIG. 1  showing a wrapping step where a section of the wrapper material is applied to a front end face of the article; 
         FIG. 3B  is a schematic front view of the article during the step illustrated in  FIG. 3A ; 
         FIG. 4  is a side elevation view of the wrapping apparatus shown in  FIG. 1 , showing a wrapping step where sections of the wrapper material are folded around front lateral edges of the article and over lateral faces thereof; 
         FIG. 5  is a side elevation view of the wrapping apparatus shown in  FIG. 1 , showing a wrapping step where sections of the wrapper material are folded around upper edges of the article and over the lateral faces; 
         FIG. 6  is a side elevation view of the wrapping apparatus shown in  FIG. 1 , showing a wrapping step where the wrapper material is extended towards a rear end face of the article to cover an upper face thereof; 
         FIG. 7  is a side elevation view of the wrapping apparatus shown in  FIG. 1 , showing a wrapping step where the wrapper material is cut and extended beyond the rear end face; 
         FIG. 8  is a side elevation view of the wrapping apparatus shown in  FIG. 1 , showing a wrapping step where the wrapper material is folded around an upper edge of the article and over the rear end face; 
         FIG. 9  is a side elevation view of the wrapping apparatus shown in  FIG. 1 , showing a wrapping step where sections of the wrapper material are folded around rear lateral edges of the article and over the lateral faces; 
         FIG. 10  is a side elevation view of the wrapping apparatus shown in  FIG. 1 , showing a wrapping step where sections of the wrapper material are folded around upper edges of the article and over the lateral faces; 
         FIG. 11  is a side elevation view of the wrapping apparatus shown in  FIG. 1 , showing the article completely wrapped and moving away from the wrapping station; 
         FIG. 12  is a flowchart showing schematically the various steps of a method to wrap an article; 
         FIG. 13  is a perspective schematic view of an article being wrapped in accordance with an alternate embodiment of the present invention, showing a wrapping step where the wrapper material is grabbed; 
         FIG. 14  is a perspective schematic view of the article of  FIG. 13 , showing a wrapping step where the wrapper material is extended beyond the front end face of the article and folded over the lateral faces thereof; 
         FIGS. 15 ,  16  and  17  are perspective schematic views of the article of  FIG. 13 , showing successive wrapping steps where the sections of the wrapper material are folded around front lateral edges of the article and over the front end face thereof; 
         FIGS. 18 and 19  are perspective schematic views of the article of  FIG. 13 , showing successive wrapping steps where a section of the wrapper material is folded around an upper edge of the article and over the front end face; 
         FIG. 20  is a perspective schematic view of the article of  FIG. 13 , showing a wrapping step where the wrapper material is extended beyond the rear end face of the article and applied over the upper face thereof; 
         FIGS. 21 and 22  are perspective schematic views of the article of  FIG. 13 , showing successive wrapping steps where the sections of the wrapper material are folded around rear lateral edges of the article and over the rear end face thereof; 
         FIG. 23  is a perspective schematic view of the article of  FIG. 13 , showing the article after a section of the wrapper material has been folded around an upper edge of the article and over the rear end face. 
     
    
    
     It will be noted that throughout the appended drawings, like features are identified by like reference numerals. 
     DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS 
     Referring now to the drawings and, more particularly, referring to  FIG. 1 , there is shown a wrapping apparatus  20  in accordance with a particular embodiment of the present invention. The wrapping apparatus  20  is designed for wrapping an article, more particularly a parallelepiped shaped or substantially parallelepiped shaped article  22  such as, without being limitative, a bundle of lumber, plywood or chipboard or a pile of other articles, for instance, articles used in construction work, or a paper or pulp bale or any other adequate type of article. 
     The generally shaped parallelepiped article  22  has an upper face  28  and an opposed lower face (now shown), which are interconnected by four (4) peripheral faces. The peripheral faces includes a front (first) end face  24 , a rear (second) end face  26  opposed to the front end face  24 , and two opposed lateral faces  30  extending between the front and the rear end faces  24 ,  26 . The front end face  24  and the lateral faces  30  meet at front lateral edges  32 . Similarly, the rear end face  26  and the lateral faces  30  meet at rear lateral edges  34 . The lateral faces  30  each extend between a lower longitudinal edge  36  and an upper longitudinal edge  38 . Each of the front and the rear end faces  24 ,  26  meets with the upper face  28  at an upper transversal edge  40  and meets with the lower face at a lower transversal edge  42 . 
     The wrapping apparatus  20  has a wrapping station frame  44  defining a longitudinal direction  46  (see  FIG. 2 ). A conveyor  48  extends along the longitudinal direction  46  below the wrapping station frame  44 . In a particular embodiment, the conveyor  48  is omitted, and the article is placed under the wrapping station frame  44  through any adequate means, and remains in a fixed location during the wrapping process. 
     Referring to  FIG. 2 , the apparatus  20  includes a wrapper delivering unit  52  with a wrapper delivering unit frame  54  carrying a web material roll  50 . The wrapper delivering unit frame  54  includes two supporting rolls  56  on which the web material roll  50  is rotatably mounted. The supporting rolls  56  can be motorized rolls to facilitate web delivery. 
     The web material roll  50  supplies wrapper material  60 . The wrapper material  60  extends from the web material roll  50 , around the supporting rolls  56  and around a plurality of guiding rolls  58 , and to a wrapper dispenser  62 . 
     The wrapper dispenser  62  can translate between a lower position ( FIGS. 2 to 5 ) and a higher position ( FIGS. 6 to 10 ). It includes a dispenser frame having a fixed arm  63   a  and a moveable arm  63   b , which in the embodiment shown is slidable, but can alternately be pivotable. The fixed arm  63   a  carries a wrapper guiding member  64  while the moveable arm  63   b  carries a wrapper dispensing stopper  66 , opposed to the guiding member  64 . The fixed arm  63   a  can include a wrapper cutter  68  to cut the wrapper material web  60  at a predetermined length, which is adjusted in accordance with the article  22  being wrapped. In a particular embodiment, the wrapper cutter  68  includes a blade cutter. The wrapper cutter can include alternate cutting mechanisms, such as for example a heated wire. 
     It is appreciated that the embodiments described above for the wrapper dispenser  62  and the wrapper cutter  68  are exemplary only and several variations can be foreseen. 
     Thus, the wrapper dispenser  62  allows wrapper material dispensing when the wrapper dispenser  62  is in a dispensing configuration (for example in  FIG. 3A ) and prevents wrapper material dispensing when the wrapper dispenser  62  is a non-dispensing configuration (for example in  FIG. 2 ). In the non-dispensing configuration, the wrapper dispensing stopper  66  abuts the guiding member  64 , with the wrapper material  60  extending therebetween. On the opposite, in the wrapper material dispensing configuration, the wrapper dispensing stopper  66  slides away from the guiding member  64  to be spaced-apart therefrom. 
     The wrapper dispenser  62  can be operatively connected to a controller which controls for example the wrapper material dispensing timing and/or the quantity of wrapper material dispensed. Both variables can be adjusted in accordance with the length of the article being wrapped. 
     Referring back to  FIG. 1 , the wrapping apparatus also includes a wrapper holder  70  which includes two wrapper gripping units  72 . Each wrapper gripping unit  72  is mounted on a respective side of the apparatus  20 , i.e. on a respective side of the conveyor  48 . Only one gripping unit  72  will be described below since both gripping units  72  are similar. 
     Each wrapper gripping unit  72  includes spaced apart first and second wrapper grippers  74 ,  76 . Both wrapper grippers  74 ,  76  are designed to grab the wrapper material  60  proximate to a longitudinal edge thereof. In a particular embodiment, the distance between the wrapper grippers  74 ,  76  can be adjusted, either before the wrapping process or during the wrapping process as required, either manually or automatically. 
     Referring to  FIG. 1 , in the embodiment shown, the wrapper holder  70  includes a horizontally extending transverse frame member  71  slidably mounted on a top rail member  79  which extends from on a top portion of the wrapping station frame  44 . As such, the transverse frame member  71  can be translated along the longitudinal direction  46  of the apparatus  20 . The wrapper holder  70  also includes a vertical frame member  73  on each side of the conveyor  48 , each vertical frame member  73  having a top end slidably mounted to the transverse frame member  71  such that the vertical frame member  73  can be translated along a transverse direction, i.e. toward and away from the conveyor  48 . Each gripping unit  72  has a base member  83  slidably mounted to a respective one of the vertical frame members  73 , such that the base member  83  can be translated along an at least substantially vertical axis. As such each wrapper gripper  72  can be moved relative to the article to be wrapped along longitudinal, transverse and vertical directions. 
     Each gripping unit  72  includes a rotatable arm  82  which is substantially T-shaped with a first arm section  84  having one end rotationally mounted to the base member  83  and an opposed end attached to a second arm section  86 . The second arm section  86  extends perpendicularly to the first arm section  84  and has two opposed ends carrying a respective one of the wrapper grippers  74 ,  76 . As mentioned above, in a particular embodiment, the second arm section  86  and wrapper grippers  74 ,  76  are configured so that the distance between the wrapper grippers  74 ,  76  can be varied. 
     Thus, the wrapper grippers  74 ,  76  are spaced apart. They can be oriented relative to one another along a substantially vertical plane, along a substantially horizontal plane, or along any other plane extending therebetween to manipulate the wrapper material  60 . 
     In a particular embodiment, the wrapper grippers  74 ,  76  include clamps designed to clamp the wrapper material  60 , proximate to the longitudinal edge. 
     The wrapper grippers  74 ,  76  can be controlled independently, i.e. the task or the position of each gripper is controlled independently to the task or the position of the other gripper, or simultaneously, i.e. each task or position of a gripper is associated with a predetermined task or position from the associated gripper. 
     It is appreciated that, in alternate embodiments (not shown), the gripping units  72  can include only one or more than two wrapper gripper(s). 
     It is appreciated that either the gripping unit  72  can be displaced along the apparatus  20  for carrying the various wrapping steps or that the article  22  can be displaced relatively to the gripping units  72 . Moreover, in an alternate embodiment, the various steps can be carried out with a combination of griping unit displacement and article displacement. 
     In an embodiment, each wrapper gripping unit  72  is operatively connected to a servomotor (not shown) such as to be movable along the three perpendicular directions. Thus, the mechanical position (or other parameters) of the wrapper grippers  74 ,  76  is controlled with a device including an error-sensing feedback to correct the performance of the mechanism. It is also operatively connected to a controller and a sensor, as will be described in more details below. 
     Each wrapper gripping unit displacement is limited by a predetermined target which can be, for instance and without being limitative, the position of one or both of the wrapper grippers  74 ,  76 , the measured distance of the displacement, the stress or pressure sensed by sensor(s) or load cells resulting from the stress within the wrapper material slightly stretched over the article, or the torque applied to the wrapper grippers  74 ,  76 , for example as measured by the servomotors. 
     It is appreciated that, in an alternate embodiment, each wrapper gripping unit  72  can be connected to a pneumatic system instead of or in combination with the servomotor. 
     In the embodiment shown, the wrapping apparatus  20  also includes a wrapper material fastening unit  89  which is designed to secure the wrapper material  60  to the article  22 . The fastening unit  89  includes a pair of movable stapling mechanisms  91 , one mechanism  91  being provided on each side of the article  22  and mounted on a transverse member slidably retained on the wrapping station frame  44 . In an alternate embodiment (not shown), the stapling mechanism  91  are slidably retained on rails fixed to the floor. The stapling mechanisms  91  each include a stapling head which is movable along the height or the article as well as towards and away from the article, in order to be able to staple the wrapper material to the article in any desired location. The wrapper material fastening unit  89  is preferably operatively connected to a controller for controlling the timing for the insertion and the position of the fasteners. 
     In an alternate embodiment (not shown), the wrapper material fastening unit can be integrated with the wrapper grippers  74 ,  76 , for example by including an integrated stapling head with at least one of the wrapper grippers  74 ,  76 . The fastening unit can also alternately be manually operated. 
     Referring to  FIG. 2 , the wrapping apparatus  20  can also include one or several spare wrapper material rolls  90  (only one is shown in  FIG. 2 ), which are mounted on spare wrapper delivering units  92 . 
     In the embodiment shown, the wrapping apparatus includes a wrapper material identifying unit  94  such as a printer or a labeling apparatus. In a particular embodiment, the wrapper material identifying unit  94  is a printer. The identifying unit  94  is mounted next to the web material roll and the wrapper dispenser  62  and has a printing head juxtaposed to one of the supporting rolls  56 , such that the wrapper material  50  extends between the printing head and the supporting roll  56 . Thus, the supporting roll  56  provides support for the printing step. 
     Thus, when the wrapper material  60  is drawn by the wrapper holder  70 , the wrapper material printer  94  prints on the wrapper material to indicate printed information such as information regarding the article being wrapped or advertising information or any other desired information. 
     It is appreciated that the wrapper material identifying unit  94  can be mounted anywhere between the wrapper material supply unit and the wrapping station along the wrapper material path for adding printed information to the wrapper material  60  prior to article wrapping. In the embodiment shown, the printed information is added to the outer surface, i.e. the surface which faces outwardly on the wrapped article, of the wrapper material  60 . However, in an alternate embodiment, printed information could be provided on the inner surface of the wrapper material  60 . It is appreciated that printed information can be added to the wrapper material  60  simultaneously while the wrapper holder  70  draws the wrapper material  60  from the wrapper material roll  50 . In an alternate embodiment, the wrapper holder  70  can temporarily stop drawing the wrapper material  60  from the roll  50  for adding printed information of the wrapper material  60  at a predetermined printed information position along the wrapper material  60 . Once the printed information is added, the wrapper holder  70  can continue drawing the wrapper material  60  from the wrapper material roll  50 . 
     The wrapper material identifying unit  94  and wrapper holder  70  can be operatively connected to a controller (not shown) which controls the identification of the wrapper material web. Thus the controller determines when the identification is provided on the wrapper material  60 , based on the wrapper holder  70  drawing speed or position. If a specific position of the identification is required on the article, the controller also determined when and where the identification is provided on the wrapper material  60  also based on the desired position of the identification on the wrapped article and on the article dimensions. 
     When wrapping an article, the wrapper material  60  is first drawn from the wrapper material roll  50 . Printed information is added by the wrapper material identifying unit  94  on the drawn wrapper material  60  and, following the addition of printed information on the drawn wrapper material, at least a section of the article is wrapped with the wrapper material including the printed information. 
     As mentioned above, in an embodiment, the surface of the wrapper material  60  which includes the printed information faces outwardly of the wrapped article. If the printed information added to the wrapper material  60  needs to be added at a predetermined position on the wrapper material, the method for adding printed information on the wrapper material  60  also includes a step where a printed information position is determined on the wrapper material  60  in accordance with the size of the article to be wrapped. The printed information is added to the drawn wrapper material at the predetermined identification position and at least a section of the article is wrapped with the wrapper material including the added printed information. The printed information added to the wrapper material is located at the printed information position on the wrapped article. 
     Now the various steps for wrapping an article  22  will be described in reference to the apparatus shown in the embodiment of  FIG. 1 , and in reference to  FIGS. 2 to 11 , where only a portion of the wrapper gripping units  72  is shown for improved clarity. 
     Referring to  FIG. 2 , the article  22  to be wrapped is moved along the conveyor  48  until it reaches the wrapping area. In the embodiment shown, the article  22  is placed under the wrapper dispenser  62 , with the front end face  24  extending forwardly of the wrapper dispenser  62 . The wrapper material  60  extending from the web material roll  50  is grabbed by the gripping units  72  in a first wrapper gripping configuration, where each wrapper gripping unit  72  grabs the wrapper material  60  proximate to a respective one of its longitudinal edges, with the first wrapper grippers  74  being located proximate to a respective corner of the wrapper material  60  and the second wrapper grippers  76  being spaced from the corresponding first wrapper gripper  74  along the respective longitudinal edge of the wrapper material  60 . In the initial position, the wrapper grippers  74 ,  76  of each wrapper gripping unit  72  are vertically aligned with one another with the first wrapper gripper  74  being located under the second wrapper gripper. 
     Referring to  FIG. 3A , a relative movement is provided between the wrapper material  60  and the article  22  to be wrapped wherein either the article  22  is conveyed along the conveyor  48  to the wrapping station or the wrapper material  60  is moved towards the front end face  24  of the article  22 . In a particular embodiment, the conveyor  48  is omitted, and the wrapper material  60  is brought in place over the article  22 . In the embodiment shown, the wrapper gripping units  72  are displaced forwardly, in front of the front end face  24 , while the article  22  remains at the same position. In a particular embodiment, the rotatable arm  82  is rotated during this movement, such that the wrapper gripping units  72  are displaced from the initial vertically aligned position, to a configuration with the second arm section  86  extending horizontally as the wrapper gripping units  72  travel over the upper face  28  of the article, and back to a vertical position with the first wrapper gripper being located under the second wrapper gripper  76  as the wrapper gripping units  72  reach the front end face  24 . To supply wrapper material  60  during the relative movement, the wrapper dispenser  62  is in the dispensing configuration. It is appreciated that, in alternate embodiments, the relative movement can be provided from the article or from a combination of the wrapper material and the article. 
     Thus, the wrapper material  60  is folded around the upper transversal edge  40  and superposed to the first end face  24  of the article  20 , and a lower edge of the wrapper material  60  is substantially aligned with the lower transversal edge  42  of the article  22 . The wrapper material  60  is substantially aligned transversally with the article  22 , i.e. it extends substantially equally beyond both front lateral edges  32  of the article  22 . The positions of the first and the second wrapper grippers  74 ,  76  correspond respectively and substantially to the height of the lower edges  36 ,  42  and of the upper edges  38 ,  40  of the article  22 . 
     As shown in  FIG. 3B , the wrapper gripping units  72  extend the wrapper material  60  beyond the front lateral edges  32  of the article  22  until a first predetermined target is reached. As mentioned above, the wrapper gripping units  72  are controlled and, more particularly, they are operatively connected to a servomotor. Thus, the displacement of the wrapper gripping units  72 , holding the wrapper material  60 , stops when the first predetermined target is reached. As mentioned above, the target can be for example the position of the wrapper grippers  74 ,  76 , the distance of the displacement carried out, the stress applied to the wrapper material and sensed by sensor(s), the torque within the wrapper grippers  74 ,  76 , etc. 
     Referring now to  FIG. 4 , there is shown a subsequent folding step wherein the wrapper gripping units with the second arm sections  86  still in a vertical orientation fold the section of the wrapper material  60  extending beyond each front lateral edge  32 . Each section is folded around the respective lateral edge  32  and against the respective lateral face  30  until a second predetermined target is reached. Similar information than for the first predetermined target can be used for the second predetermined target. 
     For folding the wrapper material  60  around the front lateral edges  32 , the wrapper gripping units  72  are displaced rearwardly, towards the rear end face  26 , while remaining at the same height and thus maintaining a section of the wrapper material  60  covering the front end face  24 . The first wrapper gripping configuration is maintained, i.e. the wrapper grippers  74 ,  76  do not release the wrapper material  60  during this folding step. 
     In the embodiment shown, during this folding step, the wrapper dispenser  62  is in a dispensing configuration. Alternately, if sufficient wrapper material is already provided to complete the folding step, the wrapper dispenser  62  can be in a non-dispensing configuration. 
     Then, the wrapper material  60  is secured to each lateral face  30 , again without releasing the wrapper material  60 . The wrapper material  60  is secured with a first fastener  100  to the corner of each lateral face  30  defined by the intersection of the respective front lateral edge  32  and of the respective upper longitudinal edge  38 , and with a second fastener  102  near the corner of the wrapper material held by the first (lower) wrapper gripper  74 , i.e. proximate to the lower longitudinal edge  36 . 
     Referring to  FIG. 5 , the gripping units  72  then switch to a second wrapper gripping configuration, where the first (lower) wrapper gripper  74  releases the wrapper material  60  while the second wrapper gripper  76  remains engaged to the wrapper material  60 . In other words, the second wrapper gripper  76  remains engaged at a same location on the wrapper material  60  during the first and second wrapper gripping configurations. With the gripping units  72  now in the second wrapper gripping configuration, the rotatable arm  82  of each wrapper gripping unit  72  rotates to lower the second wrapper gripper  76 . The second wrapper gripper  76  is thus displaced along the front lateral edge  32  toward the lower longitudinal edge  36  of the article  22 , without releasing the wrapper material  60 . The second arm section is tilted from the horizontal such that the second wrapper gripper  76  is slightly lower than and frontward of the first wrapper gripper  74 . During this folding step, the wrapper dispenser  62  is in the dispensing configuration. Alternately, if sufficient wrapper material is already provided to complete the folding step, the wrapper dispenser  62  can be in a non-dispensing configuration. 
     Thus, in this folding step, the sections of the wrapper material  60  which extend over a width of the article upper face  28  proximate to the front end face  24  are folded around the respective upper longitudinal edge  38  and against the respective lateral faces  30  until a third predetermined target is reached. Similar information as for the previous predetermined targets can be used for the third predetermined target. As in the previous folding step, the second wrapper gripper  76  does not release the wrapper material as it is folded. 
     Once the third predetermined target is reached, the wrapper material  60  is secured to each lateral face  30  of the article  22  with a respective fastener  104  positioned near the front lateral edge  32  and the wrapper gripper  76 , and the wrapper gripper  76  then releases the wrapper material. The wrapper material can be additionally secured by an additional fastener  106  (see  FIG. 6 ) engaged at the position previously held by the wrapper gripper  76 , i.e. near the lower longitudinal edge  36 , once the wrapper material is released. 
     The front end of the article  22  is thus wrapped. In the next steps, the rear end of the article  22  will be wrapped, thus completing also the wrapping of the lateral faces  30  and of the upper face  28 . 
     Referring to  FIG. 6 , a relative movement is provided between the article  22  to be wrapped and the wrapper material  60 , such that the wrapper material  60  is applied to the upper face  28  and the lateral faces  30  towards the rear end face  26 . To provide the relative movement, the article  22  can be further conveyed along the conveyor  48  and/or the wrapper material  60  can be moved towards the rear end face  26  of the article  22 . 
     In the embodiment shown, to provide the relative movement, the article  22  is further conveyed along the conveyor  48 . 
     The wrapper gripping units  72  grab the longitudinal edges of the wrapper material  60  proximate to the wrapper dispenser  62  in the first wrapper gripping configuration, this time with the second wrapper gripper  76  located below the first wrapper gripper  74 , with the wrapper dispenser  62  in the lower position (as shown in  FIG. 5 ). As such each wrapper gripping unit  72  grabs the wrapper material  60  proximate to a respective one of the longitudinal edges thereof, proximate to a rear edge. The first wrapper gripper  74  of each wrapper gripping unit  72  is located proximate to where the corner of the wrapper material  60  will be located. The second wrapper gripper  76  is spaced apart along the longitudinal edge of the wrapper material  60  from the first wrapper gripper  74 . The second arm section  86  of each wrapper gripping unit  72  extends along a substantially vertical axis. 
     Either prior to, simultaneously with or following the relative movement, but after the wrapper gripping units  72  grab the wrapper material  60 , the wrapper material  60  is cut to a desired length. The length of the wrapper material  60  is adjustable in accordance with the size of the article  22  being wrapped. 
     The wrapper dispenser  62 , in the dispensing configuration, dispenses the length of wrapper material  60  necessary to wrap the article  22  and then, the moveable arm  63   b  moves to the non-dispensing configuration. The wrapper dispenser  62  remains in the non-dispensing configuration until another article is carried to the wrapping station to be wrapped. 
     Now referring to  FIG. 7 , the rotatable arm  82  of the wrapper gripping units  72  is rotated until the second arm section  86  of each wrapper gripping units  72  extends along a substantially horizontal axis and below the upper face  28  of the article. The gripping units  72  move rearwardly and laterally away from the article, so that the wrapper material  60  is extended beyond the rear end face  26  of the article  22  until a fourth predetermined target is reached. Similar information can be used for the fourth predetermined target as for the previous targets. 
     Then, referring to  FIG. 8 , the wrapper gripping units  72  fold the portion of the wrapper material  60  which extends rearwardly from the article  22  around the upper transversal edge  40 . For carrying this folding step, the rotatable arm  82  is rotated 180° until the second arm section  86  of each wrapper gripping unit  72  extends along a substantially vertical axis with the first wrapper gripper  74  being below the second wrapper gripper  76 . The gripping units  72  are laterally spaced apart from the article such as to extend the wrapper material on each side of the article, similarly to the position shown in  FIG. 3B . The wrapper material  60  is thus folded against the rear end face  26  of the article. The wrapper gripping units  72  are rotated until a fifth predetermined target is reached. Similar information can be used for the fifth predetermined target as for the previous targets. 
     When the wrapper material  60  is folded against the rear end face  26  of the article, the positions of the first and the second wrapper grippers  74 ,  76  correspond respectively and substantially to the height of the lower edges  36 ,  42  and the upper edges  38 ,  40  of the article  22 . 
     Then, as shown in  FIG. 9  and with the wrapper gripping units still in the first wrapper gripping configuration, the wrapper gripping units  72  are moved frontwardly and towards the lateral faces  30  of the article to fold the portions of the wrapper material  60  which extend over the width of the rear end face  26  around the rear lateral edges  34  of the article  22 . The wrapper material  60  is folded against the corresponding lateral faces  30  until a sixth predetermined target is reached. Similar information as for the previous predetermined targets can be used for the sixth predetermined target. 
     For folding the wrapper material  60  around the rear lateral edges  34 , the wrapper gripping units  72  are displaced forwardly, towards the front end face  24 , while remaining at the same height and maintaining a section of the wrapper material  60  covering the rear end face  26 . The wrapper grippers  74 ,  76  do not release the wrapper material  60  during this folding step. 
     Then, the wrapper material  60  is secured to each lateral face  30 , again without releasing the wrapper material. The wrapper material  60  is secured to the corner of the lateral face  30  defined by the intersection of the rear lateral edge  34  and the upper longitudinal edge  38  with a first fastener  110 , and proximate to the corner of the wrapper material  60  held by the first (lower) wrapper gripper  74 , i.e. proximate to the lower longitudinal edge  36  of the article  22 , with a second fastener  112 . 
     Referring to  FIG. 10 , the gripping units  72  then switch to the second wrapper gripping configuration, where the first (lower) wrapper gripper  74  releases the wrapper material  60  while the second wrapper gripper  76  remains engaged to the wrapper material  60 . The rotatable arm  82  of the wrapper gripping units  72  rotates to lower the second wrapper gripper  76 . The second wrapper gripper  76  is thus displaced along the rear lateral edge  34  toward the lower longitudinal edge  36  of the article  22 , without releasing the wrapper material  60 . It is moved to fold the portions of the wrapper material  60 , which extend over a width of the upper face  28  and proximate to the rear end face  26  around the upper longitudinal edges  38  of the article  22  and against the lateral faces  30 . The gripping units  72  are thus moved so that the second arm section is tilted from the horizontal such that the second wrapper gripper  76  is slightly lower than the first wrapper gripper  74 . The second wrapper gripper  76  is moved until a seventh predetermined target, which is similar to the previously described targets, is reached, without releasing the wrapper material  60 . 
     Then, the wrapper material  60  is secured to each lateral face  30  of the article  22  with a respective fastener  114  positioned near the rear lateral edge  34  and the wrapper gripper  76 , and the wrapper gripper  76  then releases the wrapper material. The wrapper material can be additionally secured by an additional fastener  116  (see  FIG. 11 ) engaged at the position previously held by the wrapper gripper  76 , i.e. near the lower longitudinal edge  36 , once the wrapper material is released. 
     In a particular embodiment, the fasteners  100 ,  102 ,  104 ,  106 ,  110 ,  112 ,  114 ,  116  include nails or staples. Alternate types of fasteners can also be used, and alternate fastening means can replace the fasteners  100 ,  102 ,  104 ,  106 ,  110 ,  112 ,  114 ,  116 , such as for example an adequate type of adhesive, or fusion of the wrapper material  60  on the article. 
     Referring to  FIG. 11 , the article  22  is thus wrapped and can continue its path along the conveyor  48 . Another article can be moved to the wrapping station to be wrapped. 
     The wrapper gripping units remain engaged to the wrapper material throughout the wrapping of the forward portion of the article, and disengage the wrapper material to re-engage it and remain in engagement therewith throughout the wrapping of the rearward portion of the article. In particular, one of the wrapper grippers remains engaged to a first same location on the wrapper material throughout a first part of the wrapping process, and remains engaged to a second same location on the wrapper material throughout a remaining part of the wrapping process. 
     As mentioned above, when targets are reached, the motion of the wrapper gripping units  72  stops and the next step begins. The wrapper gripping units  72  are operatively connected to a servomotor to provide energy for their displacement and control the latter. Depending on the needs, the targets can be, for instance and without being limitative, the position of the wrapper grippers  74 ,  76 , the distance carried out, the stress applied to the wrapper material  60  and sensed by sensor(s) or the torque within the wrapper grippers  74 ,  76 . In an embodiment, the various steps can be associated with different target types. For example and without being limitative, the first predetermined target can be a wrapper gripper position while the second predetermined target can be the distance carried by the wrapper grippers. Moreover, if several predetermined targets are of the same type, the values associated with each predetermined target can be the same or can be different. 
     Now an alternate method for wrapping an article  22  will be described in reference to  FIGS. 13 to 25 , wherein the wrapper material is folded and secured to the front and rear end faces  24 ,  26  of the article  22 . 
     Referring to  FIG. 13 , the wrapper material  60  extending from the web material roll is grabbed by two wrapper gripping units  172  each including a pair of wrapper grippers  174 ,  176 . In one particular embodiment, the wrapper gripping units  172  are similar to the wrapper gripping units  72  of the embodiment previously described. In an alternate embodiment, each wrapper gripping unit  172  is a human being, with each hand thereof playing the role of one of the wrapper grippers  174 ,  176 . In an alternate embodiment, each wrapper gripping unit  172  is part of an adequate wrapping machine different than that shown in the previous figures. 
     Each wrapper gripping unit  172  grabs the wrapper material  60  along a front transversal edge thereof in a first gripping configuration. The first wrapper gripper  174  of each wrapper gripping unit is located proximate to a corner of the wrapper material  60 . The second wrapper gripper  176  is spaced apart along the transversal edge of the wrapper material from the first wrapper gripper  174 . 
     Referring to  FIG. 14 , a relative movement is provided between the wrapper material  60  and the article  22  to be wrapped to superpose the wrapper material  60  to a section of the upper face  28  of the article  22  and fold the wrapper material  60  about the upper longitudinal edges  38  of the article. The wrapper material  60  is extended past the front end face  24  and the front lateral edges  32  of the article. 
     Referring now to  FIGS. 15 and 16 , there is shown a subsequent folding step wherein the wrapper gripping units  172  fold the portions of the wrapper material  60  extending beyond the front lateral edges  32 . This portion of the wrapper material is folded around these lateral edges  32  and against the article front end face  24  until a predetermined target is reached. Similar information than for the predetermined targets of the first wrapping embodiment can be used for this target and the following targets of this embodiment. 
     For folding the wrapper material around the front lateral edges  32 , the wrapper gripping units are displaced towards the front end face  24  while remaining at the same height. Both sides of the wrapper material  60  can be folded simultaneously or sequentially. 
     Then, the wrapper material  60  is secured to the front end face  24  of the article, proximate to the corners of the wrapper material  60 , i.e. proximate to the lower transversal edge  42  of the article being wrapped, with a fastener  200 ,  202  positioned proximate to the first wrapper gripper  174 , i.e. the lower one. The first wrapper gripper  174  does not release the wrapper material  60  until the latter is secured to the article. 
     Once the respective fastener  200 ,  202  retains the portion of the wrapper material  60  to the front end face  24 , the respective gripping unit  172  switches to a second wrapper gripping configuration, where the first (lower) wrapper gripper  174  releases the wrapper material  60  while the second wrapper gripper  176  remains engaged to the wrapper material  60 . In other words, the second wrapper gripper  176  remains engaged at a same location on the wrapper material  60  during the first and second wrapper gripping configurations. 
     Thus, when the wrapper material  60  is secured to the article, the first wrapper gripper  174  of each gripping unit  172  releases the wrapper material.  FIG. 17  shows both wrapper gripping units  172  in the second gripping configuration. 
     A subsequent folding step is carried out as shown in  FIGS. 18 and 19 . The second wrapper grippers  176  are each displaced towards the adjacent respective front lateral edge  32  and toward the lower transversal edge  42  of the article  22 , without releasing the wrapper material  60 . 
     Thus, in this folding step, the portion of the wrapper material  60  which extends over a length of the article upper face  28  proximate to the front end face  24  of the article is folded around the upper transversal edge  40  and against the front end face  24  until a predetermined target is reached. 
     Once the predetermined target is reached, the wrapper material  60  is secured to the article with fasteners  204 , as shown in  FIG. 19 . The wrapper material  60  is secured to the front end face  24  of the article near the corners defined by the junction of the front lateral edges  32  and the lower transversal edge  42 . The second wrapper grippers  176  do not release the wrapper material  60  until the wrapper material  60  is secured to the article. 
     The front end of the article  22  is thus wrapped. The gripping units  172  release the wrapper material  60 , and grab it back in the first gripping configuration along the rear transversal edge to wrap the rear end of the article  22  together with the lateral faces and the upper face. The first wrapper gripper  174  of each wrapper gripping unit  172  is located proximate to a corner of the wrapper material  60 . The second wrapper gripper  176  is spaced apart along the transversal edge of the wrapper material  60  from the first wrapper gripper  174 . 
     A relative movement is provided between the article  22  to be wrapped and the wrapper material  60 , such that the wrapper material is applied to the upper face  28  and the lateral faces  30  towards the rear end face  26 . Either prior to, simultaneously with or following this relative movement, the wrapper material is cut to a desired length. The wrapper material  60  is extended beyond the rear end face  26  of the article  22  until a predetermined target is reached. 
     Then, the wrapper gripping units  172  fold the portions of the wrapper material which extend over the width of the article around the upper longitudinal edges  38  against the lateral faces  30  of the article, as shown in  FIG. 20 . The wrapper gripping units  172  are displaced until a predetermined target is reached. 
     When the wrapper material  60  is folded against the lateral faces  30  of the article  22 , the positions of the first and the second wrapper grippers  174 ,  176  correspond respectively and substantially to the height of the lower edges and of the upper edges of the article  22 . 
     Then, as shown in  FIGS. 21 and 22 , the wrapper gripping units  172  are moved, simultaneously or sequentially, towards the rear end face  26  of the article to fold around the rear lateral edges  34  the portions of the wrapper material  60  which extend over the length of the article. The wrapper material is folded against the rear end face  26  until a predetermined target is reached. 
     For folding the wrapper material  60  around the rear lateral edges  34 , the wrapper gripping units  172  are displaced towards the rear end face  26  while remaining at the same height. 
     Then, the wrapper material is secured to the rear end face  26  of the article, proximate to the lower transversal edge  42  and to the corners of the wrapper material  60 , with fasteners  206 ,  208 . The first wrapper grippers  174  do not release the wrapper material  60  until it is secured to the article. 
     Once the respective fastener  206 ,  208  retains the portion of the wrapper material  60  to the rear end face  26 , the respective gripping unit  172  switches to the second wrapper gripping configuration, where the first (lower) wrapper gripper  174  releases the wrapper material  60  while the second wrapper gripper  176  remains engaged to the wrapper material  60 . Thus, when the wrapper material  60  is secured to the article, the first wrapper gripper  174  of each gripping unit  172  releases the wrapper material. 
     When the first wrapper grippers  174  have released the wrapper material, a subsequent folding step is carried similarly to that shown in  FIGS. 18 and 19  and previously described. The second wrapper grippers  176  are each displaced towards the adjacent respective rear lateral edge  34  and toward the lower transversal edge  42  of the article  22 , without releasing the wrapper material  60 . 
     Thus, in this folding step, the portion of the wrapper material  60  which extends over a length of the article upper face  28  proximate to the rear end face  26  of the article is folded around the upper transversal edge  40  and against the rear end face  26  until a predetermined target is reached, as shown in  FIG. 23 . 
     Then, the wrapper material is secured to the rear end face  26  with fasteners  210  provided in the corners defined by the junction of the lower transversal edge  42  with each rear lateral edge  34 . The second wrapper grippers  176  do not release the wrapper material  60  until it is secured to the article. 
     The article is thus wrapped and can continue its path along the conveyor. Another article can be moved to the wrapping station to be wrapped. 
     Now referring to  FIG. 12 , an exemplary method for wrapping at least part of an article  22  will be further discussed below. 
     With the article to be wrapped moved to a wrapping station, the wrapper material is grabbed proximate an end thereof, as shown in step  122 . In a particular embodiment, a front end is gripped with gripping units in a first configuration such as described above. 
     The wrapper material is extended over at least part of the upper face of the article, as illustrated in step  124 . This can be done through a relative movement provided between the article to be wrapped and the wrapper material. 
     A first folding step  126  is performed, where the wrapper material is folded downwardly about at least one upper edge against at least one peripheral face of the article. For example, in the embodiment of  FIGS. 2-11 , the at least one peripheral face corresponds to the front end face  24 , and the upper edge corresponds to the corresponding upper transversal edge  40 . In the embodiment of  FIGS. 13-23 , the at least one peripheral face corresponds to the two lateral faces  30 , and the upper edge corresponds to the respective upper longitudinal edge  38 . 
     After this folding step, the wrapper material defines at least two first sections each extending beyond a respective first lateral edge of the at least one first peripheral face, as well as at least one second section each extending beyond an upper edge of a respective one of at least one second peripheral face adjacent the at least one first peripheral face. For example, in the embodiment of  FIGS. 2-11 , the at least one second peripheral face corresponds to the two lateral faces  30 , two first sections each extend laterally from the front end face beyond a respective lateral edge thereof, and two second section each extend laterally from the upper face beyond the upper edge of the respective lateral face. In the embodiment of  FIGS. 13-23 , the at least one second peripheral face corresponds to the front end face  24 , two first sections each extend frontwardly from the lateral faces  30  beyond a respective lateral edge thereof, and a single second section extends frontwardly from the upper face beyond the upper edge of the front end face. 
     A second folding step  128  follows, where the first sections are each folded around the respective lateral edge and against the one second peripheral face. 
     Corners of each first section of the wrapper material are then secured to the corresponding second peripheral face proximate to the lower edge in step  130 . 
     Optionally, the grip on the wrapper material is then switched in step  131 , wherein the switch between the first and second gripping configurations is done without completely releasing the wrapper material. In a particular embodiment, this is done with gripping units switching from the first to the second gripping configurations described above. 
     A third folding step  134  is carried out in which each second section is folded downwardly around the respective upper edge and against the respective second peripheral face. 
     The second section of the wrapper material is then secured over the respective second peripheral face in step  136 . Throughout the steps following the grabbing step  122 , the wrapper material is continuously retained on at least one fixed location thereon. 
     The wrapper material is then released in subsequent step  138 , and a first portion of the article is wrapped. In some embodiments, wrapping of the article is stopped here, and at least one face of the article in addition to the bottom face is left without wrapping. For example, the above-described method can be used to completely wrap the longitudinal faces  30 , upper face  28  and front end face  24 , while the rear end face remains free of wrapping. 
     In a particular embodiment, a relative movement is provided between the article and the wrapper material to position the article for the wrapping of the second portion thereof, and the steps  122 ,  124 ,  126 ,  128 ,  130 ,  132 ,  134 ,  136  and  138  are repeated for the second portion of the article. 
     For example, for the wrapping of the second portion of the embodiment of  FIGS. 2-11 , the at least one peripheral face now corresponds to the rear end face  26 , and the upper edge corresponds to the corresponding upper transversal edge  40 . The at least one second peripheral face corresponds again to the two lateral faces  30 , two first sections each extend laterally from the rear end face beyond a respective lateral edge thereof, and two second section each extend laterally from the upper face beyond the upper edge of the respective lateral face. For the wrapping of the second portion of the embodiment of  FIGS. 13-23 , the at least one peripheral face still correspond to the two lateral faces  30 , and the upper edge corresponds to the respective upper longitudinal edge  38 . The at least one second peripheral face corresponds to the rear end face  26 , two first sections each extend rearwardly from the lateral faces  30  beyond a respective lateral edge thereof, and a single second section extends rearwardly from the upper face beyond the upper edge of the rear end face. 
     It is appreciated that several steps can be carried out sequentially, simultaneously or in inverted order comparatively the to the step sequence described above in reference to  FIG. 12 . Moreover, steps can be added to or removed from the step sequence described above in reference to  FIG. 12 . The method of  FIG. 12  has been correlated with the described embodiments in an exemplary fashion which should not be viewed as limitative. 
     Generally, the step sequence is designed to first wrap the front end face  24  of the article  22 , then to cover the upper face  28  and the lateral faces  30  of the article  22 , and finally to wrap the rear end face  26  of the article  22  with the wrapper material  60  being folded and secured to peripheral faces of the article  22 . Only one wrapper holder  70  is provided for wrapping both ends faces  24 ,  26 . 
     It is appreciated that the conveyor  48  can be any suitable type used to move articles such as, without being limitative, roller track, band conveyor, chain conveyor or similar. The conveyor path is adapted to pass through or by a wrapping station of the wrapping apparatus  20 . In an embodiment, the wrapper material source, such as the wrapper material roll  50 , is disposed above the conveyor path. However, in alternate embodiments, it is appreciated that the wrapper material source can be disposed on either side of or even below the article. 
     The same wrapper holder  70  is used to grab and folds the wrapper material  60 . 
     The wrapping apparatus  20  provides a simple, reliable and automatic manner for wrapping parallelepiped shaped articles. It can be used for wrapping articles having different widths and/or lengths and/or heights. Once the article is wrapped, the wrapper has a substantially uniform appearance and is tight enough to withstand the stresses caused by various handlings, such as transportation and storage. 
     The wrapping apparatus and the method can be used to wrap articles having irregular surfaces, concavities in the surfaces or inclined surfaces. 
     Moreover, the wrapping apparatus  20  can be used to wrap articles of various lengths. The length of the apparatus  20  is relatively short comparatively to prior art apparatus. 
     Several wrapper materials can be used, for instance and without being limitative, paper, board or plastic sheets, such as for example polyethylene. The wrapper material can be woven or non-woven. It can be made of various material layers. For example and without being limitative, it can be made of a polymer layer laminated on a paperboard layer. If the wrapper material is a polymer layer, it can be stretchable or non-stretchable. The wrapper material can be provided as sheets or from a wrapper material roll. The width of the wrapper material can be adapted to be modified according to the dimensions of the article to be wrapped in the beginning or during the wrapping procedure. The apparatus can include several wrapper rolls and wrapper delivering unit frame, each roll wrapper roll having a different width and the wrapper roll being selected in accordance with the article being wrapped. 
     The embodiments of the invention described above are intended to be exemplary. Those skilled in the art will therefore appreciate that the foregoing description is illustrative only, and that various alternate configurations and modifications can be devised without departing from the spirit of the present invention. For instance, the wrapper material can be printed on either prior the wrapping step or following the wrapping step. Accordingly, the present invention is intended to embrace all such alternate configurations, modifications and variances which fall within the scope of the appended claims.