EP0957039A1

EP0957039A1 - Unitary top frame

Info

Publication number: EP0957039A1
Application number: EP98201572A
Authority: EP
Inventors: Maurice J. Pigott; Peter S. Pigott; Schuyler F. Pigott; Brandon L. Pigott; Michel Trapp; Eric Stofferis
Original assignee: Nucon Europe NV; Nv Injextru Plastics
Current assignee: Nucon Europe NV; Nv Injextru Plastics
Priority date: 1998-05-12
Filing date: 1998-05-12
Publication date: 1999-11-17
Also published as: WO1999058420A1; AU4142299A

Abstract

The invention relates to a plastic unitary top frame (1) for use with palletized goods comprising substantially parallel side members (2,3) and substantially parallel end members (4,5) substantially perpendicular to said side members, forming a rectangular frame with a substantially flat upper surface, wherein said side and end members are made up of portions of extruded hollow plastic profile having a flat upper surface and a flat lower surface, assembled into a rectangular frame with a substantially flat upper and lower surface.

The invention also relates a process for manufacturing such unitary top frames by assembling portions of extruded hollow plastic profile having a flat upper surface and a flat lower surface are assembled into a rectangular frame.

Description

The invention relates to frames used in conjunction with pallets, and more in particular to top frame or protective cover devices for use on top of goods resting on a pallet. The goods on the pallet may thus be more properly protected or more adequately held together and a further pallet may be placed on top of such top frame.
It is generally known to store and /or transport goods on pallets, to maintain those goods in a position above the floor and to handle the goods with lifting equipment, such as forklifts. In order to maintain the goods on a pallet while moving the pallets and to avoid damage to the goods, the pallets and surrounding goods and equipment, due to slipping or sliding of the goods from the pallets, the goods are secured on the pallets by means of straps and/or wrapping foil. To further improve proper securing it has been proposed to use top frames placed on top of the goods. The entire assembly may thus be secured together by means of encircling straps or wrapping foil.
Thus a so called compression frame has been proposed in US patent 3,917,066, which frame engages the upper periphery of the load to transmit the hold down force from strapping. The sides and ends of the frames consist of a lattice of intersecting ribs united to each other at the intersections
US patent 5,160,029 describes a moulded plastic unitary top frame which has a substantially flat first surface and a second surface with a reinforcement structure projecting outwardly.
US patent 5,577,608 discloses a protective cover for palletized materials which includes a first and a second member of laminated paper composite, each comprising two hinged legs having a substantially L-shaped profile, which two members are assembled into a rectangular frame.
The top frames of the known art present a number of drawbacks in that they are still rather difficult to manufacture and/or still rather heavy, or that they are insufficiently durable and/or not sufficiently easily reversible, and that at least some of their surfaces are non-smooth which becomes less and less acceptable in view of increasingly stringent requirements in respect of hygiene and dirt-proofness.
It is the purpose of the present invention to provide top frames which avoid these drawbacks of the known devices and which are more appropriate in respect of weight, durability, reversability and ease of manufacture, as well as a simplified process for producing such top frames from intermediate elements that are easy and cheap to manufacture.
Therefor the invention provides a plastic unitary top frame for use with palletized goods, comprising substantially parallel side members and substantially parallel end members substantially perpendicular to said side members, forming a rectangular frame, wherein said side and end members and said rectangular frame have a substantially flat upper surface and a substantially flat lower surface.
The completely closed and smooth surface of the top frames according to the invention provide a considerable progress in respect of cleanlyness and cleanability of the frames, and in view of the very strict hygiene requirements in the food industry in particular.
In a preferred embodiment of the invention the side and/or end members of the unitary top frame comprise anti-slip devices on at least one of their flat surfaces.
According to the invention such anti-slip device may suitably be selected from anti-slip strips (such as adhesive anti-slip strips), anti-slip dots or bumps (sticked or otherwise attached to the frame surface), mechanical locking means (such as rims or ribs, interlocking dovetail means, etc), or any device, provided to the surface of the side and/or end members of the unitary top frames, which prevents said unitary frames from slipping away from the goods on a pallet on top of which the frames are placed, and/or from slipping away from each other when piled up on each other, or which may even hold the frames together (in case of appropriate mechanical locking means).
In another preferred embodiment of the invention said side and end members of the unitary top frame are made up of portions of extruded hollow plastic profile having a flat upper surface and a flat lower surface, assembled into a rectangular frame with a substantially flat upper and lower surface.
Preferably the extruded hollow plastic profile will in particular, in accordance with the invention, comprise one or more continuous strips of soft anti-slip material, coëxtruded with the extruded profile on at least one of its flat surfaces, i.e. only on the upper surface, or only on the lowe surface, or on both surfaces.
The extruded plastic profile may consist of one or more thermoplastic materials selected from rigid PVC, acrylonitril-butadiene-styrene polymers (ABS), polypropylene (PP), reinforced polypropylene (R-PP), high density polyethylene (HDPE), polystyrene (PS), acrylonitril-styrene-acrylesters (ASA), polycarbonate (PC), polymethylmethacrylate (PMMA), polyphenyleneoxide (PPO), ABS-Polycarbonate blends, and similar materials. Particularly suitable materials comprise PVC, PP, R-PP, HDPE, ABS, PC, ABS/PC-blends.
Most preferred materials are rigid PVC ("hard" PVC) including recycled PVC, polypropylene, talc-reinforced PP, HDPE and/or ABS.
The coëxtruded soft anti-slip strip may consist of one or more thermoplastic materials selected from soft PVC, low density polyethylene (LDPE), thermoplastic polyurethane (PU), ethylene-vinylacetate copolymer (EVA), thermoplastic elastomer (TPE), vulcanised elastomers such as vulcanised TP, and similar types of polymers.
Particularly suitable materials comprise ultra high molecular weight soft PVC (UHMW S PVC), PU-rubber (PUR), EVA, and/or TPE.
Most preferred materials are PUR, EVA, TPE and vulcanised TP.
According to a specific feature of the "extruded profile" embodiment of the invention the extruded plastic profile may suitably comprise inner reinforcement ribs, in particular longitudinal inner reinforcement ribs.
In accordance with the invention, the extruded hollow plastic profile may furthermore very suitably comprise at least one rounded side rim, used as the inner rim of the assembled rectangular frame.
Such a rounded inner rim of the top frame is very appropriate for using (more or less conventionnal) automated mechanical means for liftig the top covers.
The extruded hollow plastic profile may also comprise a flattening or downward lip (or flush) along one side rim, used as the outer rim of the assembled rectangular frame. Such a flattening or downward lip or flush can be very convenient for applying identification tapes or name indications. A downward extending lip may also assist in hitching the frames into each other when piling them up for separate transport.
The extruded plastic profiles may be attached to one another in one of several ways. Attachment may be by heat welding, sonic welding, conventional fasteners or with separate corner members. Such corner members would include corner members made of thermoplastic material which fit into the extruded profile, at the corners of the rectangular frame, with or without supplementary welding or glueing. All external sides of the corner members have a closed surface.
For certain applications it may furthermore be most appropriate to avoid sharp edges on the frame, in particular at the corners; according to an optional embodiment of the invention this may in particular be achieved by removing part of the corner of the frame and introducing a soft corner part or a radius insert part into said corner. The material for such corner part may suitably be selected from soft PVC, low density polyethylene (LDPE), thermoplastic polyurethane (PU), ethylene-vinylacetate copolymer (EVA), thermoplastic elastomer (TPE), vulcanised elastomers such as vulcanised TP, and similar types of polymers.
According to a preferred more general feature of the invention, the inner and/or outer rims of the frame may be adapted to allow mechanical lifting of the frames. Alternatively or additionally at least one portion of the upper surface of the frames is sufficiently smooth to allow pneumatic lifting of the frames, and/or the frames are provided at their upper surface with metal plates to allow magnetic lifting of the frames.
As stated the invention also provides a process for manufacturing unitary top frames for use with palletized goods, by asssembling side and end members having a substantially flat upper surface into a rectangular frame, wherein portions of extruded hollow plastic profile having a flat upper surface and a flat lower surface are assembled into a rectangular frame.
More in particular the portions of plastic profile may, in accordance with the invention, be welded together at the corners of the rectangular frame, or they may be assembled by means of corner members fitting into the profile ends at the corners of the rectangular frame.
The extruded hollow plastic profiles used for the manufacturing process of this invention may be any type of flat hollow plastic profile with closed surface. Profiles showing the features described above in setting forth the preferred top frame devices according to the invention are preferred.
Metal plates/strips can be secured to the upper surfaces of the profiles. This can be accomplished by direct adhesion, material permitting, or by channels build into the upper surface of the profile. Specifically, the profile can be extruded with a longitudinal channel, e.g., dovetail mortise, formed into the upper surface. A longitudinal metal plaste can thus be slid into the channel and secured into place by either conventional means, such as rivets, or friction.
Other advantages and further aspects of the present invention will be explained in the following description of the drawings and detailled description of the invention. While these drawings and this detailled description illustrate two specific embodiments of the invention, it will be readily understood that numerous modifications are possible without significantly departing from the spirit of the invention and the scope of protection as defined in the accompanying claims.
In the drawings,
Figure 1 is a perspective view of a top frame according to the invention in a first embodiment with a flattening on the external rim, with one corner cut away to show parttly the extruded hollow plastic profile of the frame in cross section;
Figure 2 is a cross section of three stacked top frames according to figure 1, in a cross section perpendicular to the longitudinal direction a profile;
Figure 3 is a perspective view of a top frame according to the invention in another embodiment with a downward lip on the external rim, with one corner cut away to show parttly the extruded hollow plastic profile of the frame in cross section;
Figure 4 is a cross section of three stacked top frames according to figure 3, in a cross section perpendicular to the longitudinal direction a profile.
In these figures like numerals designate corresponding parts.
Figure 1 shows a first preferred embodiment of a top frame according to the invention, designated as a whole with reference numeral 1. The top frame 1 is made up of four portions of an extruded hollow plastic profile (shown in cross section at 10 and more in detail on figure 2) constituting the two parallel "side" members 2, 3 and the two parallel "end" members 4, 5 of the rectangular frame. The profile shows a rounded side rim 6 on the inner rim of the rectangular frame, and a flattened side rim 7 on the outer rim of the rectangular frame. The flattened side rims shown in figure 1 are provided with name and date indications 13.
The profile of the example is furthermore provided with two strips 8, 9 of soft anti-slip material at the upper surface 14 of the frame and with two strips 11, 12 of soft anti-slip material at the lower surface of the frame.
The two strips 8, 9 of soft anti-slip material at the upper surface of the frame and two strips 11, 12 of soft anti-slip material at the lower surface of the frame are attached to the frame by coextrusion, by a separate heat sealing process or by employing an adhesive. In this specific example the upper strips 8, 9 are not vertically aligned with the lower strips 11, 12. In this manner, when the frames are stacked upon one another, with the strips projecting slightly above the upper surface of the frame or slightly below the lower surface of the frame, the strips will not contact one another. More particularly, the strips will not adversely affect the alignment and seating of abutting frames; rather the strips will form parallel stops or bumpers reducing slippage between abutting frames.
Appropriate results may however also be achieved by suitably providing the anti-slip devices on only the upper surface of the frames, for instance.
The cross section of the profile (represented at 10 on figure 1 and more in detail on figure 2) shows the closed surface of the profile consisting of the flat surfaces 14 (upper) and 15 (lower), and the longitudinal reinforcing ribs.
Another preferred embodiment of a top frame according to the invention is designated as a whole with reference numeral 1 on figure 3. The top frame shown on this figure comprises a downward lip 17. The cross section of the profile used for this embodiment of the top frame is represented at 10 on figure 3 and in more detail on figure 4. All other parts and details of the top frame shown on figures 3 and 4 correspond to those shown on figures 1 and 2 and are designated with the same referense numerals.
The downward lip 17 shown in the profile of Figure 4 is extruded of the same material and with the rest of the profile. The lip 17 can be removed (by cutting) and recycled if the lip is not desired. Or, the extruder's die configuration can also be changed so that one die produces an extruded profile with a lip and one without a lip.
While the Figures show the rounded side rim 6 on the inner rim of the rectangular frame and a flattened side rim 7 on the outer rim of the rectangular frame it is appreciated that during construction of the frame, these rims may be reversed if so desired. Specifically, the roundel side rim 6 can be the outer rim of the rectangular frame and the flattened side rim 7 can be the inner rim of the rectangular frame.

Claims

Plastic unitary top frame for use with palletized goods comprising substantially parallel side members and substantially parralel end members substantially perpendicular to said side members, forming a rectangular frame, characterised in that said side and end members and said rectangular frame have a substantially flat upper surface and a substantially flat lower surface.
Unitary top frame according to claim 1, characterised in that the side and/or end members comprise anti-slip devices on at least one of their flat surfaces.
Unitary top frame according to claim 2, characterised in that the anti-slip devices comprise one or more strips of anti-slip material on at least one of their flat surfaces.
Unitary top frame according to claim 1, characterised in that said side and end members are made up of portions of extruded hollow plastic profile having a flat upper surface and a flat lower surface, assembled into a rectangular frame with a substantally flat upper and lower surface.
Unitary top frame according to claim 4, characterised in that the extruded hollow plastic profile comprises one or more continuous strips of soft anti-slip material, coëxtruded with the extuded profile on at least one of its flat surfaces.
Unitary top frame according to any one of claims 4 and 5, characterised in that extruded hollow plastic profile comprises at least one rounded side rim, used as the inner rim of the assembled rectangular frame.
Unitary top frame according to any one of claims 4 and 6, characterised in that the extruded hollow plastic profile comprises a downward lip along one side rim, used as the outer rim of the assembled rectangular frame.
Unitary top frame according to any one of claims 4 and 7, characterised in that the portions of extruded hollow plastic profile are welded together.
Unitary top frame according to any one of claims 4 to 7, characterised in that the portions of extruded hollow plastic profile are assembled by means of corner members fitted into the extruded profile portions at the corners of the rectangular frame.
Unitary top frame according to any one of the preceding claims, characterised in that the frames are provided at their upper surface with metal plates to allow magnetic lifting of the frames.
Unitary top frame according to any one of claims 1 to 9, characterised in that the at least one portion of the upper surface of the frames is smooth to allow pneumatic lifting of the frames.
Unitary top frame according to any one of claims 1 to 9, characterised in that the inner and/or outer rims of the frame are adapted to allow mechanical lifting of the frames.
Process for manufacturing unitary top frames for use with palletized goods, by asssembling side and end members having a substantially flat upper surface into a rectangular frame, characterised in that portions of extruded hollow plastic profile having a flat upper surface and a flat lower surface are assembled into a rectangular frame.
Manufacturing process according to claim 13, characterised in that the portions of plastic profile are welded together at the corners of the rectangular frame.
Manufacturing process according to claim 13, characterised in that the portions of plastic profile are assembled by means of corner members fitted into the profile ends at the corners of the rectangular frame.
Manufacturing process according to any one of claims 12 to 14, characterised in that use is made of plastic profiles as described in any one of claims 5 to 7.