US20070017420A1

US20070017420A1 - Pallet with skids connected by self-aligning detachable joint

Info

Publication number: US20070017420A1
Application number: US11/183,921
Authority: US
Inventors: Nir Hadar
Original assignee: Polymer Logistics BV
Current assignee: Polymer Logistics BV
Priority date: 2005-07-19
Filing date: 2005-07-19
Publication date: 2007-01-25

Abstract

A pallet with a deck element supported above skids by a number of spacers employs a self-aligning detachable joint to interconnect at least one of spacers with an adjacent region of either the skid or the deck element. The self-aligning detachable joint is made up from complementary parts of a snap-fit inter connection integrally formed with the spacer and the adjacent region of either the skid or the deck element, and an alignment pin extending from the adjacent region into a complementary channel formed in the spacer. The snap-fit interconnection is configured to separate non-destructively under excess separating force. The alignment pin and complementary channel allow separation of the snap-fit joint while maintaining alignment of the parts of the joint. This allows simple reengagement of the snap-fit interconnection to return the pallet to its normal operational configuration.

Description

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to pallets and, in particular, it concerns a pallet with skids which are connected to the pallet by self-aligning detachable joints.
It is known to provide pallets for supporting and transporting loads of various types. An example of a pallet of a type particularly relevant to the present invention is shown in FIG. 1. The pallet as shown includes a deck element 10 providing a generally rectangular load-bearing surface having a length L and a width W. The deck element is supported by two skids 12 each of which extends along a majority, and preferably an entirety, of either the length L or the width W. Deck element 10 is supported in spaced relation above each skid 12 by at least two, and in this case three, spacers 14. The size and spacing of spacers 14 is chosen to define a fork entry which allows insertion of a pallet jack or forklift under the deck element. Spacers 14 are interconnected with both skid 12 and deck element 10. In the case of pallets made primarily from polymer materials, the spacers are typically integrally formed with either the skid or the deck element, and are connected to the second element (the deck element or the skid, respectively) by a connection such as a snap-fit joint, as is known in the field of plastic product engineering.
FIG. 2 illustrates the normal manner of using the pallet of FIG. 1 with a pallet jack 16. The pallet jack is slid through the fork entry so that the front wheels lie beyond both skids of the pallet and the lifting surfaces are then actuated to raise the pallet relative to the pallet jack wheels which remain on the floor.
FIG. 3 illustrates the damaging effects of improper use of the pallet jack 16. More specifically, FIG. 3 illustrates a case where the pallet jack was not inserted sufficiently far for its wheels to clear the skid before the pallet jack lifting mechanism was operated. According to this non-uncommon scenario, operation of the pallet jack lifting mechanism directly applies a separating force between the skid and the deck element which is orders of magnitude greater than the force which the pallet is designed to withstand. This scenario typically results in breaking apart of the joints of the pallet, as illustrated in FIGS. 4A and 4B. Flexing of the skid and/or deck also typically results in misalignment of the snap-fit connection such that, even after the pallet jack is lowered and withdrawn, the parts of the snap-fit connection cannot readily be reconnected, for example, due to outward deflection of the spacer 14 as illustrated in FIGS. 5A and 5B. The skid and spacer are typically too strong to be bent back to position manually, instead requiring either special tools or intensive hammering to knock the spacer back into alignment. The realignment of the joint is particularly problematic if the pallet is loaded, and may require unloading of the pallet in order to reassemble the pallet before work can continue. This results in significant inconvenience and lost work time during the reassembly of the crate. Furthermore, there is a significant risk of parts of the pallet being damaged, both during breaking apart of the pallet by the pallet jack and during attempts to realign the components for reassembly.
There is therefore a need for a pallet which would separate non-destructively under application of excess separation forces between the parts and which would facilitate quick reassembly of the pallet after such separation so as to minimize disruption to use of the pallet.

SUMMARY OF THE INVENTION

The present invention is a pallet with skids which are connected to the pallet by self-aligning detachable joints.
According to the teachings of the present invention there is provided, a pallet for supporting a load above an underlying surface, the pallet being transportable by use of a pallet lifter, the pallet comprising: (a) a deck element providing a generally rectangular load-bearing surface having a length and a width; (b) at least one skid for engaging the underlying surface, the skid extending along a majority of one of the length and the width; and (c) for each skid, at least two spacers for supporting the deck element above the skid so as to allow insertion of a pallet lifter under the deck element, each of the spacers being interconnected with both the skid and the deck element, wherein at least one of the spacers of each skid is interconnected to an adjacent region of one of the skid and the deck element at a self-aligning detachable joint made up from: (i) a first part of a snap-fit connection integrally formed with the spacer; (ii) a second part of a snap-fit connection integrally formed with the adjacent region, the first and second parts being complementary parts configured for snap-fit interconnection, the first and second parts being further configured to separate non-destructively under application of a separating force in excess of a given value; and (iii) an alignment pin extending from the adjacent region into a complementary channel formed in the spacer, the alignment pin and the complementary channel being configured such that, on separation of the first and second parts, the alignment pin slides within the complementary channel to allow separation of the first and second parts while maintaining alignment of the first and second parts such that, on removal of the separating force, the first and second parts remain correctly aligned for reengagement of the snap-fit interconnection.
According to a further feature of the present invention, the spacers are integrally formed with the skid, the self-aligning detachable joint being formed between at least one of the spacers and the deck element.
According to a further feature of the present invention, the spacers are integrally formed with the deck element, the self-aligning detachable joint being formed between at least one of the spacers and the skid.
According to a further feature of the present invention, the at least one skid is implemented as two skids.
According to a further feature of the present invention, for each skid, the at least two spacers are implemented as three spacers.
According to a further feature of the present invention, all three of the spacers for each skid are implemented with the self-aligning detachable joint.
According to a further feature of the present invention, two of the three spacers for each skid are implemented with the self-aligning detachable joint, and wherein the third of the spacers rigidly interconnects between the skid and the deck element so as to withstand a separating force between the skid and the deck element in excess of the given value.
According to a further feature of the present invention, the alignment pin is configured to be separable from the remaining elements of the pallet for individual replacement.
According to a further feature of the present invention, the deck element is formed primarily from a first material and the alignment pin is formed primarily from a second material, the second material being harder than the first material.
According to a further feature of the present invention, the alignment pin is formed primarily from reinforced polymer material.
According to a further feature of the present invention, the alignment pin is formed primarily from glass-fiber reinforced polyamide.
According to a further feature of the present invention, the alignment pin is formed primarily from a metallic material.
According to a further feature of the present invention, the alignment pin is formed primarily from steel.
According to a further feature of the present invention, the self-aligning detachable joint is configured such that the alignment pin is separately insertable into and removable from the complementary channel through an externally accessible opening after assembly of the snap-fit interconnection.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein:
FIG. 1 is an isometric view of a conventional pallet;
FIG. 2 is an isometric illustration of correct use of the pallet of FIG. 1 with a pallet jack;
FIG. 3 is an isometric illustration of misuse of the pallet of FIG. 1 with a pallet jack;
FIG. 4A is an isometric illustration showing the separation of parts of the pallet of FIG. 1 resulting from the misuse of FIG. 3;
FIG. 4B is an enlarged view of an encircled portion of FIG. 4A;
FIG. 5A is an isometric illustration showing the misaligned parts of the pallet of FIG. 1 subsequent to the misuse of FIG. 3 after the pallet jack has been removed;
FIG. 5B is an enlarged view of an encircled portion of FIG. 5A;
FIG. 6 is a cross-sectional view taken through a pallet, constructed and operative according to the teachings of the present invention, including a self-aligning detachable joint;
FIG. 7A is an isometric illustration showing the separation of parts of the pallet of FIG. 6 resulting from misuse similar to that of FIG. 3;
FIG. 7B is an enlarged view of an encircled portion of FIG. 7A;
FIG. 8A is an isometric illustration similar to FIG. 7A after the pallet jack has been removed;
FIG. 8B is an enlarged view of an encircled portion of FIG. 8A;
FIG. 9A is an isometric illustration showing the pallet of FIG. 6 after reengagement of the self-aligning detachable joint; and
FIG. 9B is an enlarged view of an encircled portion of FIG. 9A.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is a pallet with skids which are connected to the pallet by self-aligning detachable joints.
The principles and operation of pallets according to the present invention may be better understood with reference to the drawings and the accompanying description.
Referring now to the drawings, FIGS. 6-9B illustrate a pallet, generally designated 18, constructed and operative according to the teachings of the present invention, for supporting a load above an underlying surface, and which is transportable by use of a pallet lifter. Generally speaking, pallet 18 includes the main structural elements of the pallet of FIG. 1, similarly labeled. Specifically, pallet 18 includes: a deck element 10 providing a generally rectangular load-bearing surface having a length L and a width W; at least one, and preferably at least two, skids 12 for engaging the underlying surface, the skids extending along a majority of either the length or the width; and for each skid 12, at least two, and preferably three, spacers 14 for supporting deck element 10 above the skids 12 so as to allow insertion of a pallet lifter under the deck element. Each of the spacers 14 is interconnected with both its corresponding skid 12 and the deck element 10.
It is a particular feature of pallet 18 that at least one of spacers 14 of each skid is interconnected to an adjacent region of either the skid 12 or the deck element 10 at a self-aligning detachable joint 20. As best seen in FIG. 7B, self-aligning detachable joint 20 is made up from: a first part 22 of a snap-fit connection integrally formed with spacer 14; a second part 24 of a snap-fit connection integrally formed with the adjacent region of either the skid or the deck element; and an alignment pin 26 extending from the adjacent region into a complementary channel 28 formed in the spacer. First and second parts 22 and 24 together form a snap-fit interconnection configured to separate non-destructively under application of a separating force in excess of a given value. Alignment pin 26 and its complementary channel 28 are configured such that, on separation of first and second parts 22 and 24, alignment pin 26 slides within complementary channel 28 to allow separation of first and second parts 22 and 24 while maintaining alignment of the first and second parts as shown in FIGS. 7A and 7B. As a result, on removal of the separating force, the first and second parts remain correctly aligned for reengagement of the snap-fit interconnection as shown in FIGS. 8A and 8B. After this, all that is required is a moderate downward pressure to reengage the snap-fit interconnection in order to return the pallet to its normal operational configuration.
It will be immediately apparent that self-aligning detachable joint 20 provides great advantages over the prior art pallets. Firstly, the provision of an interconnection which is configured to separate non-destructively avoids damage to the pallet under conditions of accidental misuse of the pallet jack. Furthermore, the presence of the alignment pin 26 and complementary channel 28 maintain alignment of the parts while separated, thereby avoiding the difficult, time-consuming, and possibly damaging procedure of knocking the joint back into alignment as described above with reference to FIGS. 5A and 5B. These and other advantages of the present invention will become clearer from the following detailed description.
It will be noted that the present invention is intended primarily, although not exclusively, to be used in pallets formed primarily from molded plastic materials. In such pallets, spacers 14 are preferably integrally formed with either the skid or the deck element. In the preferred implementation illustrated here, spacers 14 are integrally formed with skid 12 and the self-aligning detachable joint 20 is formed between at least one of spacers 14 and deck element 10. In an alternative implementation (not shown), spacers 14 are integrally formed with deck element 10 and the self-aligning detachable joint 20 is formed between at least one of spacers 14 and skid 12. Also within the scope of the invention is the possibility of using separately formed spacers 14 which snap-lock with both the skids and the deck element where either one or both of the snap-lock interconnections is a “detachable joint” according to the teachings of the present invention.
It should be noted that not all of the spacers need to be implemented with detachable joints at all. In other words, so long as a section of skid is connected on one side at a detachable joint, the separation forces exerted by misuse of a pallet jack can typically be accommodated by flexing of the skid and/or deck element without causing damage to the components of the pallet. Thus, according to one version of a preferred implementation of pallet 18 with three spacers for each skid, the two outer spacers are implemented with self-aligning detachable joints 20 while the remaining spacer near the middle of the skid forms a rigid interconnection 30 between skid 12 and deck element 10 so as to withstand a separating force between the skid and the deck element in excess of the separating force under which the detachable joints separate. This option ensures that the skid remains correctly positioned relative to the deck element so that the components of the pallet do not completely disassemble.
Although the option of using a combination of detachable joints and rigid interconnections is believed to be advantageous in many cases, it should be appreciated that implementations in which all of the spacers are implemented with a self-aligning detachable joint may in certain cases be preferred.
The number of skids provided for each pallet may vary considerably. In a particularly preferred implementation as illustrated, each pallet has two skids which extend parallel to the longer dimension of the load-supporting surface, termed length L. It should be noted, however, that certain pallets may employ a single skid combined with one or more isolated legs or wheels for supporting the pallet in a region away from the single skid. Conversely, depending upon the dimensions and intended loading of the pallet, three or more skids may be used.
Turning now to the details of pin 26, although it could in principle be integrally formed as part of deck element 10 or skid 12, pin 26 is preferably a separate element configured to be separable from the remaining elements of the pallet for individual replacement. This allows the alignment pin to be made of structural materials with suitable properties. Thus, alignment pin 26 is preferably formed primarily from a material harder than the material used for deck element 10 and other parts of the pallet. Most preferred materials for alignment pin 26 include, but are not limited to: reinforced polymer material, and in particular, glass-fiber reinforced polyamide; and metallic material, in particular, steel.
Most preferably, self-aligning detachable joint 20 is configured such that alignment pin 26 is separately insertable into and removable from complementary channel 28 through an externally accessible opening 32 after assembly of the snap-fit interconnection. This facilitates and renders more economical servicing of the pallets by allowing replacement of the pin individually and without requiring disassembly of the entire pallet.
Although described herein in the context of an open pallet, it should be noted that the present invention may also be applied to wheeled dollies and a wide range of bins and other containers wherein fork entries are formed by a similar base structure to that described herein. Accordingly, the term “pallet” in the appended claims should be interpreted broadly to refer generically to any and all load handling platforms or containers in which skids or similar horizontal elements extend horizontally spaced below the primary load-bearing surface.
It will be appreciated that the above descriptions are intended only to serve as examples, and that many other embodiments are possible within the scope of the present invention as defined in the appended claims.

Claims

1. A pallet for supporting a load above an underlying surface, the pallet being transportable by use of a pallet lifter, the pallet comprising:

(a) a deck element providing a generally rectangular load-bearing surface having a length and a width;

(b) at least one skid for engaging the underlying surface, said skid extending along a majority of one of said length and said width; and

(c) for each skid, at least two spacers for supporting said deck element above said skid so as to allow insertion of a pallet lifter under said deck element, each of said spacers being interconnected with both said skid and said deck element,

wherein at least one of said spacers of each skid is interconnected to an adjacent region of one of said skid and said deck element at a self-aligning detachable joint made up from:

(i) a first part of a snap-fit connection integrally formed with said spacer;

(ii) a second part of a snap-fit connection integrally formed with said adjacent region, said first and second parts being complementary parts configured for snap-fit interconnection, said first and second parts being further configured to separate non-destructively under application of a separating force in excess of a given value; and

(iii) an alignment pin extending from said adjacent region into a complementary channel formed in said spacer, said alignment pin and said complementary channel being configured such that, on separation of said first and second parts, said alignment pin slides within said complementary channel to allow separation of said first and second parts while maintaining alignment of said first and second parts such that, on removal of said separating force, said first and second parts remain correctly aligned for reengagement of the snap-fit interconnection.

2. The pallet of claim 1, wherein said spacers are integrally formed with said skid, said self-aligning detachable joint being formed between at least one of said spacers and said deck element.

3. The pallet of claim 1, wherein said spacers are integrally formed with said deck element, said self-aligning detachable joint being formed between at least one of said spacers and said skid.

4. The pallet of claim 1, wherein said at least one skid is implemented as two skids.

5. The pallet of claim 1, wherein, for each skid, said at least two spacers are implemented as three spacers.

6. The pallet of claim 5, wherein all three of said spacers for each skid are implemented with said self-aligning detachable joint.

7. The pallet of claim 5, wherein two of said three spacers for each skid are implemented with said self-aligning detachable joint, and wherein the third of said spacers rigidly interconnects between said skid and said deck element so as to withstand a separating force between said skid and said deck element in excess of said given value.

8. The pallet of claim 1, wherein said alignment pin is configured to be separable from the remaining elements of the pallet for individual replacement.

9. The pallet of claim 1, wherein said deck element is formed primarily from a first material and said alignment pin is formed primarily from a second material, said second material being harder than said first material.

10. The pallet of claim 1, wherein said alignment pin is formed primarily from reinforced polymer material.

11. The pallet of claim 1, wherein said alignment pin is formed primarily from glass-fiber reinforced polyamide.

12. The pallet of claim 1, wherein said alignment pin is formed primarily from a metallic material.

13. The pallet of claim 1, wherein said alignment pin is formed primarily from steel.

14. The pallet of claim 1, wherein said self-aligning detachable joint is configured such that said alignment pin is separately insertable into and removable from said complementary channel through an externally accessible opening after assembly of said snap-fit interconnection.