Abstract:
A dispenser suited for applying plastic packing film under tension about an object of large volume and comprising a base with a handle and a roll support structure at opposite ends. The roll support structure comprises a tube that is adjustable relative to the base to accommodate different widths of rolls and has a means to secure the tube in a selected position, together with a tension applying means in connection with a handgrip attached to the upper end of the roll support structure permitting adjustment of the tension on the film during dispensing.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to the field of hand-held dispensers particularly suited for dispensing and wrapping plastic packing film under tension about an object of large volume. 
     Heretofore, it has been the usual practice to use the plastic stretch film or stretch wrap to secure a plurality of containers on a pallet. The most conventional prior art film wrapping dispenser is shown in FIG. 1 and comprises a platform-shaped base 100, and handle 200 set on the base and a sliding pole 300. To use this kind of dispenser, as shown in FIG. 2, the plastic stretch film roll 400 is put onto the sliding pole 300 and can be rotated. By grasping the dispenser and moving around the object, the film is dispensed from the roll and wrapped around the object to cover it and protect it from moisture and the like. 
     In the above mentioned film dispenser, the length of the sliding pole 300 is fixed and is therefore suitable only for one size of stretching film. Although some attempts have been made to improved hand-held dispensers, for example, in U.S. Pat. No. 4,102,513, these have not been entirely satisfactory from the standpoint of a uniformity of wrap, tension adjustment, simplicity, durability, balance or ease of manipulation for various types of objects. 
     SUMMARY OF THE INVENTION 
     It is an object of this invention to provide a simple, durable and easy to use dispenser for stretch wrap film operations and the like. 
     It is a further object to provide a packing film wrap dispenser having good balance and facilitating the application of the film under substantially uniform tension across the full width of the film for a uniform wrap. 
     Another object of the present invention is to provide a film dispenser on which the roll is readily replaced. 
     It is a still further object of the present invention to provide a film dispenser which can be easily adjusted to accommodate different widths of film rolls and on which the tension on the film can be suitably adjusted for practical use. 
     A more complete understanding of these and other features and advantages of the present invention will become apparent from a careful consideration of the following detailed description of certain embodiments illustrated in the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view showing a fully assembled example of prior art dispensers. 
     FIG. 2 shows the common method of use of such film dispensers. 
     FIG. 3 is a perspective view showing a fully assembled embodiment of the invention. 
     FIG. 4 is a side elevation cross-sectional view of the assembled embodiment of the invention. 
     FIG. 5 is an exploded perspective view showing the components of the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIGS. 3, 4 and 5, there is shown a stretch film dispenser having a platform-shaped, rigid base 1 which, as shown in plan, has a wide end portion and becomes gradually smaller in width toward a narrower end portion with the ends thereof being rounded and semi-circular in shape. The base 1 is formed by a top plate 15 and a bottom plate 16, wherein the outer edge of the bottom plate 16 is formed as a mounting furrow 160. The lower edge 150 of the surrounding surface of the top plate 15 is bent upward forming a bead that fits into the furrow 160 thus enabling the top plate 15 and the bottom plate 16 to mount firmly together. On the top plate 15, at each of the ends, there is a hole or an opening 151, 152. Screw seats 17, 18 are insertable in each of the holes 151, 152 respectively. The bottom plate 16, at its wider end, has an upward concavity 161 with an opening 162 coaxial with the hole 151 in the top plate 15. A pipe-shaped handle 11 is screwed into the screw seat 17 at the narrower end of the base 1, the lower end of the handle 11 being formed with threads 111 and a locking nut 171 being provided to engage the handle and bear against the screw seat to hold the handle 11 fixed onto the base 1. The top plate 15 at the wider end of the base 1 is formed with a raised film roll support 12. Associated with the film roll support 12 is an adjusting means which includes an elongated pipe 2 fixed onto the film roll support 12 by means of threads at the lower end of the pipe 2 for engaging the screw seat 18 and a locking nut 181 engaging the pipe 2 and bearing against the screw seat 18. The upper end of the elongated pipe 2 is cut at an angle 21 to match with a pressing post 3 having a complimentary angle at its lower end. On the upper surface of the pressing post 3 there is a non-rounded hollow 31 coaxial with a hole 30 to accept a pillar or bolt 33 threaded at its lower end and with a head 31a of the same shape as the above-mentioned hollow 31. The bolt 33 passes through the hole 30 and the elongated pipe 2 to extend through the hole 162 in the concavity 161 of the bottom plate 16; an adjusting knob 34 is then screwed onto threads at the lower end of the bolt 33. Telescoping over the pipe 2 and the pressing post 3 is a sliding tube 4 having an inside diameter larger than the outside diameters of the pipe 2 and the pressing post 3. Inside the upper end of the sliding tube 4 is a nut 41. A screw post 5 with the threads 5a on its lower end screws into the nut 41. At the lower end of the screw post 5 there is also a pin 51 thrust through it. The upper end of the screw post 5 has a pair of short cylindrical sections 52, 53 wherein the upper section 53 is inserted into a support pipe 54 which itself is inserted into the handgrip 50. Beneath the handgrip 50 are a pair of telescoping mounting cases 61, 62 with openings opposite each other. The upper case 61 is welded onto the support pipe 54 and telescopes over the lower case 62 as shown in FIG. 4. Between the mounting cases 61, 62 and confined thereby is a spring 6. On the lower short cylindrical section 52 of the screw post 5 is a wheel 8. The wheel 8 is flat, with the center portion of the wheel concaved downward for clamping the stretch film roll 9 put on the base 1. At the center of the wheel 8 is a shaft hole 80 and between the shaft hole 80 and the outer edge of the wheel 8 there is an elongated opening 81 with its width being larger than the diameter of the screw post 5. As shown in FIGS. 3 and 4 in using the dispenser of this invention the wheel 8 is moved downward to separate it from the lower short cylindrical section 52 of the screw post then removed by means of the screw post passing through the elongated opening 81. Following this the adjusting knob 34 on the bottom plate 16 of the base 1 is rotated to loosen the pressing post 3 within the elongated pipe 2 thus enabling the sliding tube 4 to be adjusted to the desired length. At this point, the adjusting knob 34 is rotated in the opposite direction and the bolt 33 will pull on the pressing post 3 causing a distortion relative to the pipe 2 and the pressing post 3 will press against the inner wall of the sliding tube 4 to fix the sliding tube 4 in the desired position. The stretch film roll 9 is then put onto the dispenser by sliding it over the handgrip 50. After the stretch film roll 9 is put over the sliding tube 4 onto the base 1, wheel 8 is replaced on the screw post 5. Because the mounting case 62 is pushed downward to the wheel 8 by the spring 6, the wheel 8 will press against the upper end of the stretch film roll 9. By rotating the handgrip 50, the tension to the upper end of the stretch film roll 9 by the bottom of the wheel 8 will be adjusted to the optimum condition. When the user grasps the handle 11 and the handgrip 50, and moves the dispenser around the object (for example, a plurality of containers on a pallet as shown in FIG. 2), the wheel 8 and the stretch film roll 9 will be rotated and the plastic stretch film will be pulled from the roll for wrapping. 
     In the stretch film dispenser mentioned above, because the sliding tube 4 can be adjusted to any position, the distance between the wheel 8 and the base 1 is adjustable to accommodate stretch film rolls of different widths. After the plastic stretch film roll is put onto the base of the dispenser, the tension force on the plastic stretch film roll will be adjustable by rotating the handgrip. It is simple in structure, conveniently adjustable and suitable to any size of film. 
     Although the present invention has been described with a certain degree of particularity, it is understood that the present disclosure has been made by way of example and that changes in details of structure may be made without departing from the spirit thereof.