Stretch wrapping apparatus with film roll support

A stretch wrap dispenser includes a support for a roll of stretch wrap packaging material and a core which permits the roll to rotate. The support has an indexing portion with an outer radial area for contacting and indexing one axial end of the stretch wrap packaging material at a predetermined axial position. It also has an inner radial area for permitting any portion of the core that extends beyond the one axial end of the stretch wrap packaging material to extend beyond the predetermined axial position. Relative rotation is provided between dispenser and the load to wrap the stretched sheet around the load.

BACKGROUND OF THE INVENTION 
The invention relates to a stretch wrapping apparatus with a film roll 
support. Stretch wrapping apparatus have been used to wrap a load with a 
sheet of stretch wrap packaging material such as a film web. The sheet is 
usually dispensed from a roll having two axial ends and an axially 
extending core having two axial ends. An example of such a stretch 
wrapping apparatus is shown in U.S. Pat. No. 5,161,349, which is 
incorporated herein by reference. Such apparatus traditionally mount the 
film roll core on a shaft or between two core inserts. These mountings 
permit the roll to rotate while being restrained by a braking device which 
applies an appropriate amount of tension on the film web extending between 
the roll and the load, or between the roll and at least one downstream 
roller which stretches the film before it is wrapped on the load. 
SUMMARY OF THE INVENTION 
According to the invention, an apparatus is provided for stretch wrapping a 
load with a sheet of stretch wrap packaging material. The stretch wrap 
packaging material is dispensed from an axially extending roll of stretch 
wrap packaging material having two axial ends and an axially extended core 
having two axial ends. The apparatus includes a dispenser for dispensing 
and stretching the sheet of stretch wrap packaging material. The dispenser 
includes a support for the roll of stretch wrap packaging material and 
core which permits the roll to rotate. The support has an indexing portion 
with an outer radial area for contacting and indexing one axial end of the 
stretch wrap packaging material at a predetermined axial position and an 
inner radial area for permitting any portion of the core that extends 
beyond the one axial end of the roll of stretch wrap packaging material to 
extend beyond the predetermined axial position. The apparatus also 
includes means for providing relative rotation between the dispenser and 
the load to wrap the stretched sheet around the load. 
The support preferably includes a retaining portion extending inside the 
core for preventing axial movement of the core relative to the support 
when the stretch wrap packaging material on the roll is radially inward of 
the outer radial area of the indexing portion. The retaining portion also 
preferably prevents angular movement of the core relative to the support.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Reference will now be made in detail to the present preferred embodiments 
of the invention as illustrated in the accompanying drawings. 
As shown in FIG. 1, a stretch wrapping apparatus 30 is provided for stretch 
wrapping a load 32 with a sheet 34 of stretch wrap packaging material. The 
sheet 34 is dispensed from a roll 36 of stretch wrap packaging material 
38, such as a film web, wrapped about a core 40, such as a stiff cardboard 
cylinder. A dispenser 44 is provided to dispense and stretch the sheet 34 
of stretch wrap packaging material 38. A prestretch mechanism 78 may be 
mounted in the dispenser 44 to stretch the sheet. Alternatively, the film 
roll can be braked. The dispenser 44 includes a support 46 for the roll 36 
of stretch wrap packaging material 38 and the core 40 which permits the 
roll and core to rotate. 
Means are used to provide relative rotation between the dispenser 44 and 
the load 32 to wrap the stretched sheet 34 around the load. Such means for 
providing relative rotation may include a motor driven turntable 80 which 
rotates the load. Alternatively, it may include an arm or ring or similar 
device which revolves the dispenser 44 around the load 32. Examples of 
such arrangements are shown in U.S. Pat. No. 5,161,349, which is 
incorporated herein by reference. 
As shown in FIG. 4, the stretch wrap packaging material 38 on the roll 36 
extends axially in the direction of a principal axis 42 and has two axial 
ends 38a and 38b. The core 40 extends axially along the principal axis 42 
and has two axial ends 40a and 40b. A portion 40c of the core 40 extends 
beyond one axial end 38a of the roll 36 of stretch wrap packaging material 
38. Similarly, another portion 40d of the core 40 extends beyond the other 
axial end 38b of the roll 36 of stretch wrap packaging material 38. 
As shown in FIGS. 2, 3 and 8, the support 46 includes an indexing portion 
48 with an outer radial area 50 for contacting and indexing one axial end 
38a of the stretch wrap packaging material 38 at a predetermined axial 
position 52, shown in FIG. 8. The support 46 also includes an inner radial 
area 54 which is an open space for permitting any portion 40c of the core 
40 that extends beyond the one axial end 38a of the roll 36 of stretch 
wrap packaging material 38 to extend beyond the predetermined axial 
position 52. 
The invention provides a space or a displaceable area on the reference 
plane of predetermined axial position 52 at the radial location of the 
core between a central area, such as post 62, and the outer radial area 50 
of indexing portion 52 which contacts the stretch wrap packaging material 
38. 
Thus, the indexing portion 48 of the support 46 permits one side 34a of the 
sheet 34 of stretch wrap packaging material 38 to always be indexed and 
dispensed at the reference plane of the predetermined axial position 52 
regardless of how far the portion 40c of the core extends beyond the axial 
end 38a of the roll 36 of stretch wrap packaging material. This is useful 
because core portions of various film rolls may extend various 
unpredictable distances from the axial ends of their respective stretch 
wrap packaging material. 
The support also preferably includes a retaining portion 56 extending 
within the core 40 for preventing axial movement of the core relative to 
the support 46 when the outside layer of the stretch wrap packaging 
material 38 on the roll 36 is disposed radially inward of the outer radial 
area 50 of the indexing portion 48. As shown in FIGS. 2, 3, and 5, the 
retaining portion 56 preferably includes a plurality of leaf springs 58 
and 60 which are positioned on a post 62. 
One set of leaf springs 58 is located at a plurality of angular positions 
around the top half of the post, and as shown, includes four leaf springs 
positioned 90.degree. from each other. The leaf springs 58 each includes 
end portions 58e and a middle portion 58m which bows outward from the end 
portions 58e. One end 58e is fastened to the post 62 with a rivet, or a 
screw 64 and nut 65, and the other end 58e is positioned in a slot 66 in 
the post 62. 
The second set of leaf springs 60 is similarly arranged at the lower 
portion of the post 62. With one set of leaf springs 58 at the upper 
portion of the post 62 and another set of leaf springs located at the 
lower portion of the post 62, leaf springs are located at a plurality of 
axial positions to provide stability to the film roll 36. In addition, the 
second set of leaf springs 60 is positioned at an angular orientation 
which is not aligned with the first set of leaf springs 58. 
The upper end of the post 62 is fitted with a plug 68 that holds the upper 
ends 58e of the leaf springs 58 in place. Similarly, the support 46 
includes a plug portion 70 which fits on the lower end of the post 62 to 
stabilize the post and hold the ends 60e of the leaf springs 60 in place. 
A cap 72 is secured to the plug 68 by a screw 74. An alternative 
arrangement of almost entirely overlapping leaf springs is shown in FIG. 
8. While leaf springs are currently the preferred embodiment of the 
retaining portion for preventing axial movement of the core relative to 
the support, other mechanisms may also be used. 
The retaining portion 56 preferably biases the core in the radial direction 
and is flexible and moveable. As shown in FIGS. 6 and 7, the springs 58 
and 60 of the retaining portion 56 can thus conform to and retain cores 
140 and 240, respectively, having various diameters, such as three or 
three and one half inches. It also permits the retaining portion 56 to 
conform to and retain cores having varying diameters, such as core 140 in 
FIG. 6, which has been crushed or deformed in some places. 
The retaining portion 56 also preferably prevents angular movement of the 
core relative to the support 46. While support 46 permits the roll 36 to 
rotate relative to the dispenser 44 on which the support 46 is mounted, 
the retaining portion 56 prevents relative rotation or angular movement of 
the core 40 relative to the support 46. The rotation of the support 46 in 
dispenser 44 can be restrained by a frictional mount or a brake which 
maintains a generally constant tension on the portion of the film 34 that 
extends between the roll 36 and a prestretch device 78, or between the 
roll 36 and the load 32 if a prestretch device is not used in the 
dispenser 44. 
FIG. 6 shows a film roll 36 in which the outer circumference 138 of stretch 
wrap packaging material on the roll 136 extends over and outward of the 
outer radial area 50 of the support 46. In contrast to FIG. 6, FIG. 7 
shows the film roll 36 after it has been depleted to the point where the 
outer circumference 238 of stretch wrap packaging material on the roll 236 
is radially inward of the outer radial area 50 of the indexing portion 48. 
In the situation shown in FIG. 7, the stretch wrap packaging material is 
no longer indexed by the outer radial area 50, but is prevented from 
moving axially by the engagement of the leaf springs 58 and 60 of the 
retaining portion 56 which are positioned on the inside of the core 240. 
Additional advantages and modifications will readily occur to those skilled 
in the art. The invention in its broader aspect is, therefore, not limited 
to the specific details, representative apparatus and illustrative 
examples shown and described. Accordingly, departures may be made from 
such details without departing from the spirit or scope of the general 
inventive concepts as defined by the appended claims and their 
equivalents.