Abstract:
A carriage for a stretch wrap assembly including a threading assembly for moving a front end of the stretch wrap through the housing. The threading assembly includes a manually movable system moving the front end of the stretch wrap, the manually movable system comprising an endless link moving about a plurality of rotating members and being located at a bottom surface of the top of the housing. The threading assembly includes a handle extending through the top of the housing. Roller axes and thread axes are parallel and spaced from each other such that none of the roller axes are collinear with the thread axes.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This claims the benefit of U.S. Provisional Application No. 61/605,365, filed Mar. 1, 2012, the disclosure of which is hereby incorporated by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention concerns stretch wrapping machines, and more particularly relates to a carriage for a stretch wrapping machine. 
       BACKGROUND OF THE INVENTION 
       [0003]    During the past several decades, considerable developments have been made in the field of wrapping a load with a stretched web of film. Most notably, the film web dispenser used in stretch wrapping operations has developed to the extent that it contains a series of rollers which defines a path through which the web passes so that it can be prestretched prior to being dispensed on the load. 
         [0004]    Such stretch wrapping apparatus performs admirably in accomplishing its intended goal of wrapping a load with a stretched web of film. However, the procedure of threading the film web through the series of rollers in the film web dispenser prior to operation of the stretch wrapping apparatus has been found to be time consuming and difficult. This is especially true now because of the development of film web dispensers having increased numbers of rollers and also because such rollers are often closely spaced and difficult to turn because of their effective interconnection for prestretching the film web prior to dispensing the film web on the load. 
       SUMMARY OF THE INVENTION 
       [0005]    An aspect of the present invention is to provide a stretch wrap assembly comprising a base, a turntable mounted on the base, a column extending upwardly from the base, and a carriage vertically movable upon the column, with the carriage having a housing configured to have stretch wrap move therethrough for wrapping a product on the turntable. The housing includes a plurality of rollers extending between a bottom of the housing and a top of the housing. The plurality of rollers rotate about roller axes. A wrap surface of the stretch wrap engages exterior surfaces of the rollers as the stretch wrap moves therethrough. The housing has a threading assembly for moving a front end of the stretch wrap through the housing during initiation of installation of the stretch wrap through the housing. The threading assembly includes a manually movable system moving the front end of the stretch wrap. The manually movable system comprises an endless link moving about a plurality of rotating members. The rotating members rotate about thread axes. The endless link is configured to be engaged with the front end of the stretch wrap to move the stretch wrap through the housing. The roller axes and the thread axes are parallel and spaced from each other such that none of the roller axes are collinear with the thread axes. 
         [0006]    Another aspect of the present invention is to provide a stretch wrap assembly comprising a base, a turntable mounted on the base, a column extending upwardly from the base, and a carriage vertically movable upon the column, with the carriage having a housing configured to have stretch wrap move therethrough for wrapping a product on the turntable. The housing includes a plurality of rollers extending between a bottom of the housing and a top of the housing. The plurality of rollers rotate about roller axes. A wrap surface of the stretch wrap engages exterior surfaces of the rollers as the stretch wrap moves therethrough. The housing has a threading assembly for moving a front end of the stretch wrap through the housing during initiation of installation of the stretch wrap through the housing. The threading assembly includes a manually movable system moving the front end of the stretch wrap. The manually movable system comprises an endless link moving about a plurality of rotating members. The rotating members rotate about thread axes. The endless link is configured to be engaged with the front end of the stretch wrap to move the stretch wrap through the housing. The endless link is located on a bottom surface of the top of the housing. The threading system includes a handle extending through the top of the housing for manually moving the endless link to move the front end of the stretch wrap through the housing. 
         [0007]    Yet another aspect of the present invention is to provide a carriage for a stretch wrap assembly comprising a housing configured to have stretch wrap move therethrough for wrapping a product on the turntable. The housing includes a plurality of rollers extending between a bottom of the housing and a top of the housing. The plurality of rollers rotate about roller axes. A wrap surface of the stretch wrap engages exterior surfaces of the rollers as the stretch wrap moves therethrough. The housing has a threading assembly for moving a front end of the stretch wrap through the housing during initiation of installation of the stretch wrap through the housing. The threading assembly includes a manually movable system moving a front end of the stretch wrap. The manually movable system comprises an endless link moving about a plurality of rotating members. The rotating members rotate about thread axes. The endless link is configured to be engaged with the front end of the stretch wrap to move the stretch wrap through the housing. The endless link is located at a bottom surface of the top of the housing. The threading system includes a handle extending through the top of the housing for manually moving the endless link to move the front end of the stretch wrap through the housing. The roller axes and the thread axes are parallel and spaced from each other such that none of the roller axes are collinear with the thread axes. 
         [0008]    Another aspect of the present invention is to provide a method of feeding stretch wrap through a carriage of a stretch wrap machine comprising providing a housing having a plurality of rollers extending between a bottom of the housing and a top of the housing, with the plurality of rollers rotating about roller axes, providing the housing with a threading assembly for moving a front end of the stretch wrap through the housing during initiation of installation of the stretch wrap through the housing, providing the threading assembly with a manually movable system comprising an endless link and a plurality of rotating members, extending a handle of the threading system through the top of the housing, locating the endless link at a bottom surface of the top of the housing, providing the rollers with roller axes, engaging a front end of the stretch wrap with the endless link, moving the front end of the stretch wrap through the housing by moving the handle, with the rotating members rotating about thread axes during movement of the handle, and moving the front end of the stretch wrap through the housing includes moving the endless link about the rotating members. The roller axes and the thread axes are parallel and spaced from each other such that none of the roller axes are collinear with the thread axes. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a perspective view of a wrap machine of the present invention. 
           [0010]      FIG. 2  is a schematic view of a carriage of the wrap machine of the present invention in a loaded (threaded) and ready to wrap position. 
           [0011]      FIG. 3  is a schematic view of a sprockets and rollers assembly of the carriage of the wrap machine of the present invention. 
           [0012]      FIG. 4A  is a schematic view of the carriage of the wrap machine of the present invention in a loading position. 
           [0013]    FIG.  4 A′ is a partial front view of the carriage of the wrap machine of the present invention in a first threading position. 
           [0014]      FIG. 4B  is a schematic view of the carriage of the wrap machine of the present invention in a second threading position. 
           [0015]      FIG. 4C  is a schematic view of the carriage of the wrap machine of the present invention in a third threading position. 
           [0016]      FIG. 4D  is a schematic view of the carriage of the wrap machine of the present invention in a fourth threading position. 
           [0017]      FIG. 4E  is a schematic view of the carriage of the wrap machine of the present invention in a fifth threading position. 
           [0018]      FIG. 4F  is a schematic view of the carriage of the wrap machine of the present invention in a sixth threading position. 
           [0019]      FIG. 4G  is a schematic view of the carriage of the wrap machine of the present invention in a seventh threading position. 
           [0020]      FIG. 4H  is a schematic view of the carriage of the wrap machine of the present invention a fully threaded position. 
           [0021]      FIG. 5  is a partial side view of the carriage of the wrap machine of the present invention in the loading position. 
           [0022]      FIG. 6  is a partial top view of the carriage of the wrap machine of the present invention. 
           [0023]      FIG. 7  is a top view of a door assembly of the carriage of the present invention. 
           [0024]      FIG. 8  is a partial front view of the carriage of the present invention, illustrating only a portion of the top of the carriage and a portion of an endless link of a manual threading system. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0025]    For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as orientated in  FIG. 1 . However, it is to be understood that the invention may assume various alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting. 
         [0026]    The reference number  10  ( FIG. 1 ) generally designates a wrap machine of the present invention. The wrap machine  10  includes a base  12  having a turntable  14  mounted thereon. The wrap machine  10  further includes a column  16  having a vertically movable carriage  18  (shown schematically) located thereon. Stretch wrap  20  moves with the carriage  18 . The stretch wrap  20  wraps a package  24  mounted on the turntable  14  and rotating therewith. Although not shown, the wrap machine  10  may also include a gripping and cutting device for gripping the stretch wrap  20  and cutting the stretch wrap  20  during certain portions of the process of wrapping the stretch wrap  20  about the package  24 . Such gripping and cutting devices are well known to those skilled in the art. 
         [0027]    In the illustrated example, the carriage  18  is used to prestretch the stretch wrap  20 .  FIG. 2  illustrates schematically prestretching components of the carriage  18  of the present invention. As illustrated in  FIG. 2 , the carriage  18  includes a source of the stretch wrap  20  in the form of a roll  22  of stretch wrap  20 , a first guide roller  23 , a second guide roller  27 , a first nip roller  25 , a first pre-stretch roller  26 , an idler roller  28 , a second pre-stretch roller  30 , a second nip roller  32  and a dancer roller  34 . The stretch wrap  20  travels through the carriage  18  from the roll  22  of stretch wrap  20 , around a portion of the circumference of the first guide roller  23 , around a portion of the circumference of the second guide roller  27 , around a portion of the circumference of the first nip roller  25 , around a portion of the circumference of the first pre-stretch roller  26 , around a portion of the circumference of the idler roller  28 , around a portion of the circumference of the second pre-stretch roller  30 , around a portion of the circumference of the second nip roller  32 , around a portion of the circumference of the dancer roller  34 , and to the package  24 . The first pre-stretch roller  26  and the second pre-stretch roller  30  are driven (rotated) at different speeds and/or have a different circumference in order to stretch the stretch wrap  20  as it passes by the first pre-stretch roller  26  and the second pre-stretch roller  30  (as is well known to those skilled in the art). The idler roller  28  rotates freely and is positioned to maintain the stretch wrap  20  against the first pre-stretch roller  26  and the second pre-stretch roller  30 . The first nip roller  25  is configured to maintain the stretch wrap  20  against the first pre-stretch roller  26  as the stretch wrap  20  is stretched by the first pre-stretch roller  26 . The first nip roller  25  is allowed to move towards and away from the first pre-stretch roller  26  as discussed in more detail below. Likewise, the second nip roller  32  is configured to maintain the stretch wrap  20  against the second pre-stretch roller  30  as the stretch wrap  20  is stretched by the second pre-stretch roller  30 . 
         [0028]    An aspect of the present invention provides for a manual threading system  50  for threading the stretch wrap  20  through the carriage  18  and around the rollers. The manual threading system  50  includes a rotating handle  52 , an endless link  54  having a hook  56  and a plurality of rotary members  58  supporting the endless link  54  at a plurality of locations. In the illustrated embodiment, the endless link  54  is a chain and the rotary members  58  are sprockets. However, it is contemplated that other endless links and rotary members could be used. As illustrated in  FIGS. 1 ,  5  and  8 , the rotating handle  52  extends upward out of a top  60  of the carriage  18  and the endless link  54  and the rotary members  58  extend downward from the top  60  of the carriage  18 . 
         [0029]    In the illustrated embodiment, the manual threading system  50  uses the rotary members  58  to thread the stretch wrap  20  through the carriage  18 . In the illustrated example as shown in  FIG. 3 , the manual threading system  50  includes a drive sprocket  62 , a first driven sprocket  64 , a second driven sprocket  66  and a third driven sprocket  68 . As discussed in more detail below, the drive sprocket  62  is rotated by manual rotation of the rotating handle  52 . As the drive sprocket  62  rotates, the drive sprocket  62  moves the endless link  54  and the hook  56  about the first driven sprocket  64 , the second driven sprocket  66  and the third driven sprocket  68 .  FIG. 3  illustrates the relative location of the drive sprocket  62 , the endless link  54 , the first driven sprocket  64 , the second driven sprocket  66  and the third driven sprocket  68  relative to the first nip roller  25 , the first pre-stretch roller  26 , the idler roller  28 , the second pre-stretch roller  30 , and the second nip roller  32 . However, the position of the rotatory members  58  can be altered if the locations of the first nip roller  25 , the first pre-stretch roller  26 , the idler roller  28 , the second pre-stretch roller  30 , and the second nip roller  32  are altered. 
         [0030]      FIGS. 4A-4G  illustrate the steps for threading the stretch wrap  20  through the carriage  18  using the manual threading system  50 . As illustrated in FIGS.  4 A and  4 A′, threading of the carriage  18  begins with pulling a front end  70  of the stretch wrap  20  off of the roll  22  of stretch wrap  20  and in front of the first guide roller  23  and the second guide roller  27 . The front end  70  of the stretch wrap  20  is then wrapped around the first nip roller  25  and bunched up into a ball  71  at a top edge  72  of the stretch wrap  20 . As shown in  FIG. 4A  and as discussed in more detail below, the first nip roller  25  can be moved away from the first pre-stretch roller  26  along line  74  into a load position to allow the stretch wrap  20  to be easily and manually wrapped around the first nip roller  25 . 
         [0031]    Once the stretch wrap  20  is pulled about the first nip roller  25  as illustrated in  FIG. 4A , the ball  71  at the front end  70  of the stretch wrap  20  is placed within the hook  56  of the manual threading system  50 . As illustrated in  FIG. 4B , the ball  71  is located adjacent a front edge of the first pre-stretch roller  26  before the rotating handle  52  of the manual threading system  50  is rotated. It is noted that, except for the first nip roller  25 , the stretch wrap  20  is wrapped about axles of the rollers, at a location above the rollers. This allows the stretch wrap  20  to be threaded through the carriage  18  without powering the carriage  18  to turn the pre-stretch rollers. However, it is contemplated that the carriage  18  could be powered and the stretch wrap  20  could be threaded about the rollers, with the power to the system moving the pre-stretch rollers during the threading (either with the first nip roller  25  moved back along line  74  to a home position or with the first nip roller  25  moved with a door to an open position). As the rotating handle  52  of the manual threading system  50  is rotated, the drive sprocket  62  begins rotating. As the drive sprocket  62  begins rotating, the endless link  54  starts moving about the drive sprocket  62  and the first driven sprocket  64 . Since the first driven sprocket  64  is located outside an axle  200  of the first pre-stretch roller  26 , the hook  56  carrying the ball  71  at the front end  70  of the stretch wrap  20  will carry the stretch wrap  20  about axle  200  of the first pre-stretch roller  26 , thereby pulling the stretch wrap  20  off of the roll  22 , about the first guide roller  23 , about the first nip roller  25 , and about the axle  200  of the first pre-stretch roller  26  as illustrated in  FIG. 4C . 
         [0032]    As the rotating handle  52  continues to be rotated, the endless link  54  will pull the hook  56  with the ball  71  at the front end  70  of the stretch wrap  20  towards the second driven sprocket  66 . As illustrated in  FIG. 3 , the endless link  54  wraps about an inside of the second driven sprocket  66 . Therefore, the hook  56  with the ball  71  at the front end  70  of the stretch wrap  20  will pull the stretch wrap  20  about an outside of the axle  200  of the first pre-stretch roller  26  and an inside of an axle  300  of the idler roller  28  as illustrated in  FIG. 4D . Continuing rotation of the rotating handle  52  causes the endless link  54  will pull the hook  56  with the ball  71  at the front end  70  of the stretch wrap  20  towards the third driven sprocket  68 . As illustrated in  FIG. 3 , the endless link  54  wraps about an outside of the third driven sprocket  68 . Therefore, the hook  56  with the ball  71  at the front end  70  of the stretch wrap  20  will pull the stretch wrap  20  along an inside of the axle  300  of the idler roller  28  and toward and around the axle  400  of the second pre-stretch roller  30  as illustrated in  FIG. 4E . Further rotation of the rotating handle  52  causes the endless link  54  to pull the hook  56  with the ball  71  at the front end  70  of the stretch wrap  20  back towards the drive sprocket  62 . As illustrated in  FIG. 3 , the endless link  54  wraps about an outside of the drive sprocket  62 . Therefore, the hook  56  with the ball  71  at the front end  70  of the stretch wrap  20  will pull the stretch wrap  20  about the axle  400  of the second pre-stretch roller  30  and along an inside of an axle  500  of the second nip roller  32  as illustrated in  FIG. 4F  and thereafter toward an axle  600  of the dancer roller  34  as illustrated in  FIG. 4G . At this point, the ball  71  at the front end  70  of the stretch wrap  20  is removed from the hook  56  and then pulled around the axle  600  of the dancer roller  34  and towards the package  24  for wrapping about the package  24  as illustrated in  FIG. 4H . At this point, the first nip roller  25  can be moved back along line  74  to the position shown in  FIG. 2 . As discussed in more detail below, the wrap about the axles of the rollers will move downward over the rollers during use of the machine (or before use of the machine one the pre-stretch rollers are powered) to position the stretch wrap  20  about the rollers as illustrated in  FIG. 2 . 
         [0033]      FIGS. 5-8  illustrate various aspects of an embodiment of the carriage  18  of the wrap machine  10  of the present invention.  FIG. 5  is a side view of the carriage  18 , with the first guide roller  23 , the second guide rollers  27 , the second nip roller  32 , the idler roller  28 , the roll  22  of stretch wrap  20  and the dancer roller  34  removed for clarity. In the illustrated example, the carriage  18  includes a bottom  80 , a rear wall  82  having a rail  84  extending rearwardly therefrom for insertion into a track in the column  16  for vertically moving the carriage  18  on the column  16  as well known to those skilled in the art, the top  60  and a pivoting front door  86 . The first-pre-stretch roller  26  and the second pre-stretch roller  30  include roller axles  88  that extend into the top  60  and the bottom  80  of the carriage  18 . The first-pre-stretch roller  26  and the second pre-stretch roller  30  pivot about the roller axles  88 . While not shown, the first guide roller  23 , the second guide roller  27 , the second nip roller  32  and the idler roller  28  also include roller axles  88  that extend into the top  60  and the bottom  80  of the carriage  18 . As is well known to those skilled in the art, the dancer roller  34  is connected to top and bottom links (shown schematically as links  92  in  FIG. 2 ) that allow the dancer roller  34  to pivot about a vertical axis  94  located at an end of the links opposite to the dancer roller  34 . 
         [0034]    In the illustrated example, the manual threading system  50  is connected to the top  60  of the carriage  18 . As illustrated in  FIGS. 5 and 8 , the first driven sprocket  64 , the second driven sprocket  66  and the third driven sprocket  68  each include sprocket axles  96  connected to a center thereof and extending into the top  60  of the carriage  18  for allowing the first driven sprocket  64 , the second driven sprocket  66  and the third driven sprocket  68  to rotate. A drive link  98  extends through the top  60  of the carriage  18  and connects the rotating handle  52  to the drive sprocket  62  such that rotation of the rotating handle  52  rotates the drive sprocket  62 . 
         [0035]    The illustrated first nip roller  25  is connected to the pivoting front door  86  to allow the first nip roller  25  to move along the line  74 . The pivoting front door  86  includes a front plate  100  pivotally attached at a bottom horizontal pivot joint  102  to a front of the bottom  80  of the carriage  18 . The front plate  100  includes a handle  104  extending from a front face thereof for easily moving the pivoting front door  86  from a loading position wherein the pivoting front door  86  is fully rotated outward to a threading position wherein the pivoting front door  86  is in a closed and upright position. As discussed above, the stretch wrap  20  is pulled from the roll  22  and pulled about the first nip roller  25  when the pivoting front door  86  is in the loading position. Furthermore, the ball  71  of the stretch wrap  20  is connected to the hook  56  of the manual threading system  50  and the manual threading system  50  is actuated to thread the stretch wrap  20  about the axles of the rollers before the pivoting front door  86  is pivoted to the closed and upright position. The front plate  100  of the pivoting front door  86  can have a locking mechanism  106  for locking the pivoting front door  86  in the closed and upright position. The locking mechanism  106  is configured to engage a mating portion on the top  60  of the carriage  18 . The locking mechanism  106  can be a T-shaped knob that extending through an opening and then turned to prevent the T-shaped knob from exiting the opening, a biased turning mechanism including a knob with a pair of plates configured to extend through or into slots, with a biasing member preventing the knob from turning or any other locking mechanism  106 . 
         [0036]    In the illustrated example, the first nip roller  25  is connected to a C-shaped roller holder  108  extending rearward from a rear face of the front plate  100  of the pivoting front door  86 . The C-shaped roller holder  108  includes a top panel  110 , a bottom panel  112  and a side panel  114 . The axle  90  of the first nip roller  25  extends through slots  91  in the top panel  110  and the bottom panel  112 . The slots  91  allow the axle  90  of the first nip roller  25  to move laterally to allow the axle  90  and the first nip roller  25  to move towards and away from the first pre-stretch roller  26  as the pivoting front door  86  is opened and closed. Once the carriage is threaded, the stretch wrap  20  will pull the first nip roller  25  towards the first pre-stretch roller  26 . However, it is contemplated that the first nip roller  25  could be spring biased toward the first pre-stretch roller  26  (to the left in  FIG. 6 ). The side panel  114  is opposite the first pre-stretch roller  26  when the pivoting front door  86  is in the closed and upright position as illustrated in  FIG. 6 . The side panel  114  includes a bent extension lip  116  that extends between the first nip roller  25  and the second nip roller  32  when the pivoting front door  86  is in the closed and upright position as illustrated in  FIG. 6 . The bent extension lip  116  prevents the stretch wrap  20  surrounding the first nip roller  25  from engaging the stretch wrap  20  leaving the second nip roller  32 , thereby preventing jamming of the stretch wrap  20  within the carriage  18 . 
         [0037]    It is contemplated that axle the first guide roller  23 , the axle of the second guide roller  27 , the axle of the first nip roller  25 , the axle  200  of the first pre-stretch roller  26 , the axle  300  of the idler roller  28 , the axle  400  of the second pre-stretch roller  30 , the axle  500  of the second nip roller  32  and the axle  600  of the dancer roller  34  could have conical tops  200  for allowing the stretch wrap  20  to easily move down the axles of the rollers and the rollers as the stretch wrap  20  is threaded through the carriage  18 .  FIG. 5  illustrates the first pre-stretch roller  26  and the second pre-stretch roller  30  having the conical tops  200 , but it is contemplated that any of the rollers could have the conical tops  200 . As illustrated in  FIG. 5 , the conical tops  200  have a smaller end at a top thereof and the larger end has the same (or similar) circumference as the pre-stretch roller connected thereto. However, it is contemplated that the conical tops  200  could have a smaller end at the bottom thereof, with the smaller end still having the same (or similar) circumference as the pre-stretch roller connected thereto. 
         [0038]    The above description is considered that of the one embodiment only. Modification of the invention will occur to those skilled in the art and to those who make or use the invention. Therefore, it is understood that the embodiment shown in the drawings and described above is merely for illustrative purposes and not intended to limit the scope of the invention.