1. Field of the Invention
The invention relates to wrapping a load with packaging material, and, more particularly, to stretch wrapping.
2. Description of the Prior Art
Various packaging techniques have been used to build a load of unit products and subsequently wrap them for transportation, storage, containment and stabilization, protection and waterproofing. One system uses stretch wrapping machines to stretch, dispense, and wrap stretch packaging material around a load. Stretch wrapping can be performed as an inline automated packaging technique which dispenses and wraps packaging material in a stretched condition around a load on a pallet to cover and contain the load. Pallet stretch wrapping, whether accomplished by turntable, rotating arm, or rotating ring typically covers the four vertical sides of the load with a stretchable film such as polyethylene film. In each of these arrangements, relative rotation is provided between the load and a packaging material dispenser to wrap packaging material about the sides of the load.
Conventionally, fork trucks were used to deliver loads to and remove loads from a wrapping area. The fork truck would bring an unwrapped load to a wrapping area, set the unwrapped load aside, remove a wrapped load from a wrapping station and set it aside, place the unwrapped load on the wrapping station, initiate the wrapping sequence, and pick up and remove the wrapped load from the wrapping area. Such a process requires multiple handling of each load, a large amount of maneuvering on the part of the fork truck, and requires the fork truck driver to exit the fork truck in order to initiate the wrapping sequence. Alternatively, more than one fork truck was used to deliver and remove the loads from the wrapping station. However, use of more than one truck led to inefficiency.
Conveyorized wrapping apparatus have been used to reduce fork truck usage during the wrapping process. Powered conveyors may be used to deliver and remove a load from a wrapping station. Such powered conveyors require a large amount of space and are expensive to build and maintain. Powered conveyors mounted on turntables have been used to eliminate multiple handling of the load. However, such devices are mechanically complex and therefore are costly to maintain. In addition, such devices generally require an electrical or pneumatic transfer device under the turntable to effectuate transfer from the wrapping station, which increases the cost and complexity of the device. Dual turntables without conveyors have also been used to provide dual wrapping stations, however, problems with material handling interfaces and synchronizing of the infeed and outfeed flow exist. Finally, non-powered conveyors on turntables have been used, but such conveyors require the operator to push the load along the conveyor surface, leading to safety and stress problems.
In light of these drawbacks, there is a need to move the load to and from a wrapping station in a simple, reliable, and inexpensive manner.
Accordingly, the present invention is directed to a method and apparatus for wrapping a palletized load with packaging material which provides advantages and obviates a number of problems in earlier methods and apparatus for wrapping a load.
To achieve the advantages and in accordance with the purpose of the invention, as embodied and broadly described, one aspect of the invention includes a method of wrapping a palletized load with packaging material, including placing a palletized load to be wrapped onto a non-powered conveyor load wrapping surface of a rotatable turntable, the non-powered conveyor load wrapping surface being isolated from any electrical or fluid power source by the rotatable turntable, dispensing packaging material from a packaging material dispenser and rotating the turntable to wrap packaging material around sides of the load, and pushing the wrapped load from the non-powered conveyor load wrapping surface of the rotatable turntable to a non-driven conveyor load storage surface adjacent the non-powered wrapping surface.
According to another aspect of the invention, a method of wrapping a palletized load includes building a palletized load to be wrapped on a non-driven conveyor load building surface, pushing the load from the non-driven conveyor load building surface to a non-powered conveyor load wrapping surface of a rotatable turntable, the non-powered conveyor load wrapping surface being isolated from any electrical or fluid power source by the rotatable turntable, dispensing packaging material from a packaging material dispenser and rotating the turntable to wrap packaging material around sides of the load, and removing the wrapped load from the non-powered conveyor load wrapping surface.
According to yet another aspect of the invention, an apparatus for wrapping a palletized load is provided. The apparatus includes a dispenser for dispensing packaging material, a rotatable turntable for providing relative rotation between the dispenser and the load to wrap packaging material around the load, a non-powered conveyor load wrapping surface on the rotatable turntable being isolated from any electrical or fluid power source by the rotatable turntable, at least one non-powered conveyor load storage surface for storing the load prior and subsequent to wrapping, and a pusher assembly for pushing the load between the non-powered conveyor load wrapping surface and the at least one non-powered conveyor load storage surface.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and together with the description, serve to explain the principles of the invention. In the drawings,
Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
As embodied herein and shown in
As shown in
In a preferred embodiment, stretch wrap packaging material is used. In the stretch wrapping art, stretch wrap packaging material is known to have a high yield coefficient to allow the material a large amount of stretch during wrapping. Various other packaging materials, generally not considered to be stretch wrap materials, such as netting, strapping, banding, and tape, can be used as well. Dispenser 102 may also include a variety of rollers, optionally including prestretch rollers for stretching the packaging material longitudinally and/or transversely, to position, dispense, and stretch the packaging material as packaging material 116 is being dispensed from the roll of packaging material.
In the present invention, apparatus 100 includes means for providing relative rotation between the dispenser and the load to wrap packaging material around the load. As embodied herein and shown in
As shown in
Alternatively, instead of non-powered rollers 132, the non-powered conveyor load wrapping surface 130 may use drag chains, belts, transfer ball bearings, or other non-powered, low friction elements such as a smooth surface.
The non-powered rollers 132 of the conveyor load wrapping surface 130 are preferably capable of being locked into a non-rolling position during wrapping. That is, when the load 124 is being wrapped, the non-powered rollers 132 of the load wrapping surface do not move, reducing the chance that the load 124 will shift during wrapping. Prior and subsequent to the wrapping cycle, the non-powered rollers 132 of the conveyor load wrapping surface 130 are preferably in an “unlocked” or rolling position. Thus, the rollers 132 are capable of rolling to assist in moving a load onto or off of the non-powered conveyor load wrapping surface 130. Alternatively, tabs or pins can be used, projecting through the rollers 132, to prevent travel of the load.
Such a locking device for the non-powered conveyor load wrapping surface 130 may be engaged or disengaged by various unpowered actuation processes, such as centrifugal force, by relative movement of the pusher arm 152 over the wrapping surface 130, or by a mechanical actuator.
Preferably, rotatable turntable 122 further includes a packaging material holder assembly 110 for holding a leading end of the packaging material during wrapping of the load. The packaging material holder assembly 110 is preferably positioned at an end of the load wrapping surface 130 opposite the end adjacent to a load storage surface 140, as described below. Alternatively, instead of a packaging material assembly 110, a clamp or other means may be used to restrain the leading end of the packaging material during wrapping.
Positioned proximate to turntable assembly 120 is a conveyor load storage surface 140 including non-driven rollers 142, as shown in
As shown in
According to another aspect of the invention, wrapping apparatus 100 is provided with at least one hand palletizing area for building loads. As embodied herein and shown in
Instead of non-driven rollers, other suitable surfaces, such as smooth, low friction surfaces, may be used for load building surface 141. Load building surface 141 is preferably at the same height as the non-powered conveyor load wrapping surface 130 and, if present, load storage surface 140, in order to facilitate movement of a load between load building surface 141 and wrapping surface 130 and storage surface 140, if present. This may be accomplished by raising load building surface 141 on leveling feet as discussed with respect to the load storage surface, or by any other suitable means. Although depicted with only one load building surface 141, it is possible that two load building surfaces 141 could be used, one on either side of the turntable assembly 120.
Alternatively, both the load building surface 141 and the load storage surface 140 may be areas of the floor adjacent to the load wrapping surface 130. If areas of the floor are used, any configurations discussed with respect to the load building surface 141 and load storage surface(s) 140 are feasible. In such an embodiment, the load building surface 141 and the load storage surface 140 will not be at the same height as the non-powered conveyor load wrapping surface 130. Instead, ramps would be provided on either side of, or on two different sides of, the turntable assembly 120 to provide access to load wrapping surface 130. The gradient of the ramps would be gradual enough to permit the pusher arm 152 of pusher assembly 150 to push a load 124 onto and off of turntable assembly 120.
Although load building surface 141 is preferably adjacent to one of the load storage surface 140 and the load wrapping surface 130, it is preferable that a walk plate 143 is provided between the load building surface 141 and either the load wrapping surface 130 or the load storage surface 140, as shown in
If a hand palletizing area is provided, as shown in
In such an embodiment, a product infeed conveyor 147 is also provided. Product infeed conveyor 147 supplies products 149 to be palletized in the hand palletizing area. Products 149 are moved from the infeed conveyor 147 by the workers or robots which place them on the load building surface 141 as the load is built.
According to the present invention, and as embodied in
Alternatively, as shown in
Referring to
Pusher arm 152 is moveable between an upright, vertical position, see
As shown in
Alternatively, as shown in FIGS. 9A and 10A-10C, it is possible to use the pusher arm 152′ to move the load 124 from the load storage surface 140a or the load building surface 141 to the load wrapping surface 130a. In such a case, the arm 152′ would not move the load 124 if another load is present on the wrapping surface 130a. In addition, as shown in FIGS. 9B and 11A-11C, in an embodiment where storage surfaces 140a, 140b or a load building surface 141 and load storage surfaces 140a, 140b are provided on either side of turntable 120, a pusher guide 156a extending along the length of the apparatus may be provided such that the pusher arm 152″ can move a load from a first load storage surface 140b to the wrapping surface 130a and move a wrapped load from the load wrapping surface 130a to a second storage surface 140a. If desired, more than one pusher arm 152″, 152′″ may be used. These pusher arms 152″, 152′″ may or may not be linked to move together. In addition, as shown in
A fork truck or other means, such as a pallet jack (a hand operated load moving device), may be used to initially provide a load to be wrapped to the apparatus, either to a load storage surface 140 or to the load wrapping surface 130. In addition, a fork truck or other device, such has a pallet jack, may be used to finally remove the wrapped load from either a load storage surface 140 or the load wrapping surface 130. As shown in
A method of wrapping a palletized load using the wrapping apparatus of the present invention will now be described. As embodied herein and shown in
If a hand palletizing area is provided for building loads, an empty pallet 123 is moved from the gravity conveyor 145 to the load building surface 141 by a fork truck or other means. Products 149 are removed from infeed conveyor 147 and are stacked on the pallet 123 on the load building surface 141 to form a load 124. Load 124 is then moved by pusher arm assembly, onto either a load storage surface 140 or the load wrapping surface 130. After the load 124 is moved, building of a new load 124a commences.
Once the load 124 is positioned on the load wrapping surface 130, relative rotation is provided between the load 124 and the dispenser 102 by rotating rotatable turntable 122. As turntable 122 rotates, packaging material 116 is wrapped around the sides of the load 124.
During the last rotation of the wrapping cycle, pusher arm 152 moves along pusher guide 156 in an upstream direction from position 1 (“home position”) to position 2. When pusher arm 152 reaches position 2, a position slightly beyond the end of the load being wrapped, pusher arm 152 rotates approximately 90 degrees, into the horizontal pushing position 3 (“pushing position”). Pusher arm 152 then begins to move in the opposite direction (downstream) along pusher guide 156 while in the horizontal pushing position. Thus, as shown in
Once the wrapped load 124 has been moved onto load storage surface 140, a new palletized load 124a to be wrapped can be placed on load wrapping surface 130 (
If more than one load storage surface 140a, 140b has been provided (FIGS. 9B and 9C), an unwrapped load 124a is provided to the first load storage surface 140b, pusher arm 152″ moves load 124a onto the wrapping surface 130a, in the same manner as described above with respect to
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
This application claims the right to priority based on Provisional Patent Application No. 60/244,900 filed Nov. 2, 2000, and entitled “Method and Apparatus for Wrapping a Load,” the entire contents of which is incorporated herein by reference.
Number | Name | Date | Kind |
---|---|---|---|
2962163 | Thompson | Nov 1960 | A |
3453167 | Arvidson et al. | Jul 1969 | A |
3514920 | Hofffler et al. | Jun 1970 | A |
3589102 | Zenick | Jun 1971 | A |
3867806 | Lancaster et al. | Feb 1975 | A |
3977158 | Jennings et al. | Aug 1976 | A |
3989094 | Gorenflo et al. | Nov 1976 | A |
4036364 | Ambrose | Jul 1977 | A |
4077179 | Lancaster et al. | Mar 1978 | A |
4152879 | Shulman | May 1979 | A |
4283903 | Mayhall et al. | Aug 1981 | A |
4598534 | Rosenthal et al. | Jul 1986 | A |
4641484 | Popelka | Feb 1987 | A |
4995224 | Yourgalite et al. | Feb 1991 | A |
5006336 | Payne | Apr 1991 | A |
5020300 | Casteel | Jun 1991 | A |
5046303 | Becicka et al. | Sep 1991 | A |
5107657 | Diehl et al. | Apr 1992 | A |
5117961 | Nicholson | Jun 1992 | A |
5217174 | Martin et al. | Jun 1993 | A |
5445493 | Yourgalite et al. | Aug 1995 | A |
5447008 | Martin-Cocher | Sep 1995 | A |
5489185 | Reichert | Feb 1996 | A |
5758471 | Denley et al. | Jun 1998 | A |
5893258 | Lancaster, III | Apr 1999 | A |
5911666 | Lancaster et al. | Jun 1999 | A |
3170228 | Zeman, III | Jan 2001 | A1 |
6729754 | Midas | May 2004 | B1 |
6775956 | Lacey | Aug 2004 | B1 |
Number | Date | Country |
---|---|---|
36 15 450 | Nov 1987 | DE |
0 086 045 | Aug 1983 | EP |
0 086 045 | Jan 1993 | EP |
0 849 175 | Jun 1998 | EP |
Number | Date | Country | |
---|---|---|---|
20020056253 A1 | May 2002 | US |
Number | Date | Country | |
---|---|---|---|
60244900 | Nov 2000 | US |