Multi-unit package rigidity testing

Abstract

A rigidity testing apparatus may be used to test the rigidity of a multi-unit package. The apparatus may, while applying a compression force along a first direction between opposing sides of the multi-unit package, apply a shear force to the multi-unit package in a second direction generally transverse to the first direction such that rigidity may be determined based at least in part on the amount of displacement of the multi-unite package along the second direction relative to the amount of force used to generate the displacement.

Description

MULTI-UNIT PACKAGE RIGIDITY TESTINGBackground of the Invention

[0001] Various packaging techniques have been used to build multi-unit packages, i.e. , packages that include multiple individual products or units. Shrink wrapping or bundling, as one example, is used to bundle together groups of items such as water bottles or other beverage containers into a multi-unit package using a polymer-based material referred to as shrink film that is loosely wrapped around the group of items and that shrinks when exposed to heat to tightly bind the items together into a cohesive package.

[0002] The rigidity of a multi-unit package can impact a number of downstream processes, including palletization, shipping, and storage, and can even impact the ability of a consumer to hold or carry the package during and after purchase. Multi-unit packages, for example, are often stacked on pallets and tightly wrapped with a polymer-based film using a stretch wrapping process to contain, protect, and waterproof the packages for transportation and storage.

[0003] One primary benefit of stretch wrapping is to increase the overall rigidity of a pallet load. Rigidity, in the context of stretch wrapping, may be considered to refer to a load’s resistance to sway back and forth while being subjected to the forces of transport. While the manner in which the stretch wrapping process is performed can have a significant impact on the rigidity of the load, the rigidity of the individual packages that make up the load can also have a significant impact as well.

[0004] In the case of shrink wrapped bundles of water bottles, for example, the rigidity may be impacted by factors such as the pressure in each bottle, the bottle material, the “fit” of the top and bottom of the bundle to the adjacent bundles above and below, the tightness of the alignment of the bottles in the bundles, and / or the final tension and modulus force provided by the shrink film.

[0005] To date, however, no simple and effective metric or test has been developed to set a standard or even to understand the exact impact of changes in any of the aforementioned factors towards the overall rigidity of a multi-unit package. Therefore, a significant need exists in the art for a manner of measuring or evaluating the rigidity of multi-unit packages such as shrink wrapped bundles and the like.Summary of the Invention

[0006] The invention addresses these and other problems associated with the art by providing a rigidity testing apparatus for testing the rigidity of a multi-unit package. The apparatus may, while applying a compression force along a first direction between opposing sides of the multi-unit package, apply a shear force to the multi-unit package in a second direction generally transverse to the first direction such that rigidity may be determined based at least in part on the amount of displacement of the multi-unit package along the second direction relative to the amount of feree used to generate the displacement.

[0007] Therefore, consistent with one aspect of the invention, an apparatus for testing rigidity of a multi-unit package may include first and second members respectively configured to engage opposing sides of the multi-unit package, a compression mechanism coupled to at least one of the first and second members to apply a compressive force along a first direction between the opposing sides of the multi-unit package, a displacement mechanism coupled to at least one of the first and second members to displace the first and second members relative to one another along a second direction generally transverse to the first direction, and a measurement mechanism coupled to at least one of the first and second members and configured to, in response to application of one of feree and displacement along the second direction while the compressive force is applied along the first direction, measure the other of force and displacement along the second direction.

[0008] In some embodiments, the measurement mechanism is configured to measure the other of force and displacement along the second direction in response to application of the one of feree and displacement along the second direction while the compressive force is applied along the first direction by measuring a measured forcealong the second direction in response to application of a predetermined displacement along the second direction. Also, in some embodiments, the measurement mechanism is configured to measure the other of force and displacement along the second direction in response to application of the one of feree and displacement along the second direction while the compressive force is applied along the first direction by measuring a measured displacement along the second direction in response to application of a predetermined force along the second direction.

[0009] Further, in some embodiments, the measurement mechanism includes a force sensor. In some embodiments, the measurement mechanism includes a force gauge that displays the force applied in the second direction. In addition, in some embodiments, the measurement mechanism includes a distance sensor. In some embodiments, the measurement mechanism includes a distance gauge that displays the displacement applied in the second direction.

[0010] In addition, in some embodiments, the compression mechanism is configured to apply the compressive force along the first direction by applying a predetermined force between the first and second members along the first direction. Moreover, in some embodiments, the displacement mechanism is configured to apply a shear force to the multi-unit package along the second direction.

[0011] In some embodiments, the multi-unit package is a shrink wrapped bundle of beverage containers. Some embodiments may also include a support frame that includes lower and upper brackets respectively supporting the first and second members. Moreover, in some embodiments, the first member is a base member that supports the multi-unit package and the second member is a press member that is movable relative to the upper bracket by each of the compression and displacement mechanisms.

[0012] In some embodiments, the compression mechanism includes a compression spring extending between the upper bracket and the press member and a ratchet arm configured to controllably compress the compression spring. In addition, in some embodiments, the compression mechanism further includes a pin projectingthrough the compression spring, and the press member includes a slot extending generally in the second direction and through which the pin projects. In some embodiments, the press member is coupled to the upper bracket through a four bar linkage that allows for movement of the press member relative to the upper bracket generally along the second direction. Some embodiments may further include a side bracket including first and second arms pivotably coupled to each of the upper and lower brackets and configured to move the support frame between testing and loading / unloading configurations. Also, in some embodiments, the displacement mechanism includes a screw drive including a threaded rod and wheel configured to displace the press member relative to the upper bracket generally in the second direction.

[0013] Consistent with another aspect of the invention, an apparatus for testing rigidity of a multi-unit package may include first and second members respectively configured to engage opposing sides of the multi-unit package, a compression mechanism coupled to at least one of the first and second members to apply a compressive force to the multi-unit package along a first direction between the opposing sides of the multi-unit package, and a displacement mechanism coupled to at least one of the first and second members to apply a shear force to the multi-unit package along a second direction generally transverse to the first direction.

[0014] Consistent with yet another aspect of the invention, a method of testing rigidity of a multi-unit package may include applying a compressive force along a first direction between opposing sides of the multi-unit package using respective first and second members, displacing the first and second members relative to one another along a second direction generally transverse to the first direction, and in response to application of one of feree and displacement along the second direction while the compressive force is applied along the first direction, measuring the other of force and displacement along the second direction.

[0015] Other embodiments may include a method of manufacturing or operating any of the aforementioned apparatuses.

[0016] These and other advantages and features, which characterize the invention, are set forth in the claims annexed hereto and forming a further part hereof. However, for a better understanding of the invention, and of the advantages and objectives attained through its use, reference should be made to the Drawings, and to the accompanying descriptive matter, in which there is described example embodiments of the invention.Brief Description of the Drawings

[0017] FIGURE 1 is a functional side elevational view of a multi-unit package rigidity testing apparatus consistent with the invention.

[0018] FIGURE 2 is a block diagram illustrating a multi-unit package rigidity test capable of being performed with the multi-unit package rigidity testing apparatus of Fig. 1.

[0019] FIGURE 3 is a block diagram illustrating another multi-unit package rigidity test capable of being performed with the multi-unit package rigidity testing apparatus of Fig. 1 .

[0020] FIGURE 4 is a functional side elevational view of another multi-unit package rigidity testing apparatus consistent with the invention, and illustrating displacement of a multi-unit package during testing.

[0021] FIGURE 5 is a functional side elevational view of the multi-unit package rigidity testing apparatus of Fig. 4, with the multi-unit package rotated 90 degrees.

[0022] FIGURE 6 is a front side perspective view of another multi-unit package rigidity testing apparatus consistent with the invention.

[0023] FIGURE 7 is a right side elevational view of the multi-unit package rigidity testing apparatus of Fig. 6.

[0024] FIGURE 8 is a front side elevational view of the multi-unit package rigidity testing apparatus of Fig. 6.

[0025] FIGURE 9 is a top plan view of the multi-unit package rigidity testing apparatus of Fig. 6.

[0026] FIGURE 10 is a front side perspective view of the multi-unit package rigidity testing apparatus of Fig. 6, shown in a loading configuration.

[0027] FIGURE 11 is a left side cross-sectional view of another multi-unit package rigidity testing apparatus consistent with the invention.Detailed Description

[0028] Embodiments consistent with the invention may be used to test the rigidity of a multi-unit package, e.g., a shrink wrapped bundle of water bottles or other beverage containers. A multi-unit package, in this regard, may be considered to include practically any package having multiple individual unit products bound or otherwise unitized into a single packaged product. The individual unit products within a multi-unit package may themselves be multi-unit packages, although from the standpoint of a multi-unit package, its individual unit products may generally be considered to be discrete items from one another. In some embodiments, for example, a palletized and stretched wrapped load may be considered to be a multi-unit package, such that rigidity testing may be performed to test the rigidity of the overall load.

[0029] The discussion herein, for example, will focus on shrink wrapped bundles including multiple beverage containers such as water bottles secured to one another in a two or three dimensional array using shrink wrapped plastic, and it will be appreciated that the rigidity of such bundles may be based on a number of factors, including the pressure in each beverage container, the container material, the “fit” of the top and bottom of the bundle to the adjacent bundles above and below, the tightness of the alignment of the containers in the bundles, and / or the final tension and modulus force provided by the shrink film used to secure the bundles. It will be appreciated, however, that in other embodiments, other multi-unit packages may be used, with different individual unit products as well as different packaging materials and techniques (e.g., stretch or shrink wrap, tape, straps, cardboard, boxes, etc.), so other factors may impact the rigidity of such alternative multi-unit packages.

[0030] In some embodiments consistent with the invention, rigidity of a multiunit package may be tested by applying a compressive force in a first direction between opposing sides of the multi-unit package and then applying a shear force in a second direction that is generally perpendicular to the first direction to displace the opposing sides relative to one another along the second direction. The rigidity may then be generally represented based on the relationship between the shear force applied and the amount of displacement resulting therefrom, e.g., in the form of equation (1 ):where R is rigidity, D is displacement, F is shear force, and k is a constant that is dependent at least in part on the respective units (e.g., the effective spring rate of the multi-unit package due to the combined effects of the various packaging factors associated with manufacturing and packaging the multi-unit package) and the structure of the rigidity testing apparatus used. As such, for a given compressive force, a more rigid multi-unit package will produce less displacement in response to a predetermined shear force than a less rigid multi-unit package. Likewise, for a given compressive force, a more rigid multi-unit package will require a higher applied shear force to produce the same displacement as a less rigid multi-unit package.

[0031] Fig. 1 , for example, illustrates a multi-unit package rigidity testing apparatus 10 consistent with some embodiments of the invention, and capable of testing the rigidity of a multi-unit package 12 including a plurality of beverage containers 14 arranged in a two dimensional array (e.g., 40 beverage containers arranged in a 5 x 8 array) and bundled together using shrink wrap 16. In this embodiment, a pair of members 18, 20 engage opposing sides, e.g., the top and bottom sides, of multi-unit package 12, and a compression mechanism 22 coupled to at least one of members 18, 20 applies a compressive force along a first direction (e.g., along a compression axis Ac) between the opposing sides of the multi-unit package. A displacement mechanism 24 is coupled to at least one of members 18, 20 to displace members 18, 20 relative to one another along a second direction generally transverse to the first direction (e.g., along a displacement axis AD), and thereby apply a shear force to the multi-unitpackage 12 along the second direction. A measurement mechanism 26 coupled to at least one of members 18, 20 may then, in response to application of one of feree and displacement along the second direction while the compressive force is applied along the first direction, measure the other of force and displacement along the second direction to generate an indicator of the rigidity of the multi-unit package.

[0032] Members 18, 20 may be configured in various manners in different embodiments. In some embodiments, for example, members 18, 20 may be planar members such as platens that have planar facing surfaces or surfaces otherwise adapted to engage with multi-unit package 12. Members 18, 20 may also be constructed of various materials suitable for engaging multi-unit package 12 without slippage during displacement, e.g., metal, rubber, silicone, etc. Furthermore, in some embodiments, members 18, 20 may be configurable in testing and loading / unloading configurations. In a testing configuration, such as illustrated in Fig. 1 , members 18, 20 are positioned to apply the compressive force in the first direction. In a loading / unloading configuration (not shown in Fig. 1 ), members 18, 20 may be separated from one another, e.g., through relative rotation and / or linear movement of one or both of members 18, 20, to allow for a multi-unit package to be placed into apparatus 10 for testing and then removed after testing is complete.

[0033] Compressive mechanism 22 may also be implemented in a number of different manners in various embodiments. In some embodiments, for example, only one of members 18, 20 may be movable along the compression axis or direction, while the other of members 18, 20 may be fixed, while in other embodiments, both of members 18, 20 may be movable along the compression axis or direction. Compression may be implemented, for example through one or more of linear and rotational movement of one or both of members 18, 20. In some embodiments, for example, a press configuration may be used, e.g., using any of a linear actuator, screw drive, pneumatic drive, hydraulic drive, etc., to apply the compressive force. Likewise, displacement mechanism 24 may be implemented in a number of different manners to allow for relative displacement between members 18, 20 along the displacement axis or direction, e.g., using one or more of linear and rotational movement of one or both ofmembers 18, 20 that causes members 18, 20 to move relative to one another along the displacement axis or direction. It will also be appreciated that mechanisms 22, 24 may also be implemented utilizing mechanical and / or electronic controls, and in some instances, utilizing human powered motion and / or force, as will become more apparent below.

[0034] Measurement mechanism 26 may also be implemented in a number of different manners in various embodiments, and may be used to measure one or both of a displacement or shear force and an amount or distance of displacement. Measurements may be made electronically in some embodiments, while in other embodiments, measurements may be made manually and / or mechanically, e.g., through the use of mechanical or printed scales, as will become more apparent below. In some embodiments, for example, measurement mechanism 26 may be configured to measure an amount of displacement, such that through application of a predetermined shear or displacement force, a rigidity may be determined from the measured displacement. Alternatively, measurement mechanism 26 may be configured to measure a shear or displacement force, such that through displacement of members 18, 20 a predetermined amount, a rigidity may be determined from the measured shear or displacement force. In still other embodiments, a rigidity value may be measured or otherwise indicated directly by measurement mechanism 26, e.g., where a conversion is made based upon measured or predetermined displacement force and amount. For example, where a predetermined displacement force is applied, the scale of measurement mechanism 26 may be configured to indicate a rigidity value rather than a distance, and where a predetermined displacement amount is applied, the scale of measurement mechanism 26 may be configured to indicate a rigidity value rather than a force. In still other embodiments, both displacement force and displacement amount may be measured and a rigidity value calculated therefrom, e.g., using equation (1 ).

[0035] As noted above, in different embodiments, rigidity testing may incorporate application of a predetermined applied shear or displacement force and measurement of a resulting displacement amount, or alternatively, application of a predetermined displacement amount and measurement of a resulting applied shear ordisplacement force. Fig. 2, for example, functionally illustrates a test 30 capable of being performed using rigidity testing apparatus 10, whereby a predetermined compressive force 32 and a predetermined shear or displacement force 34 are applied to multi-unit package 12, resulting in a measured displacement amount 36 that is indicative of the rigidity of the multi-unit package, which is calculated in block 38. Similarly, Fig. 3 functionally illustrates another test 40 capable of being performed using rigidity testing apparatus 10, whereby a predetermined compressive force 42 and a predetermined displacement amount 44 are applied to multi-unit package 12, resulting in a measured shear or displacement force 46 that is indicative of the rigidity of the multi-unit package, which is calculated in block 48.

[0036] Now turning to Figs. 4-5, another rigidity testing apparatus 50 is illustrated, including a pair of opposing members 52, 54 joined by a linkage arrangement 56 including a pair of bars or fixed length members 58, 60 rotatably coupled to members 52, 54 at four hinge points 62, 64, 66, 68. It will be appreciated that another pair of bars or fixed length members may also be disposed on an opposite side of apparatus 50 (not shown in Fig. 4) to support members 52, 54 in substantially parallel planes. Linkage arrangement 56 is a four bar linkage that maintains members 52, 54 in a substantially parallel relationship as member 52 moves along the displacement axis or direction relative to member 54 (as illustrated in dashed lines in Fig. 2), such that, in response to the application of a compressive force Fc and a displacement force FD, member 54 will move a distance D that is dependent on the rigidity of multi-unit package 12 (note the shear force applied to beverage containers 14 in multi-unit package 12 is also illustrated in dashed lines in Fig. 4).

[0037] In addition, as illustrated in Fig. 5, rigidity testing apparatus 50 may be used to test the rigidity of multi-unit package 12 in multiple directions. In this instance, multi-unit package 12 has been rotated ninety degrees such that the shear or displacement force is applied across the relatively smaller lateral dimension of the multi-unit package 12 (which is five beverage containers wide) than the relatively larger lateral dimension (which is eight beverage containers wide) illustrated in Fig. 4.

[0038] Now turning to Figs. 6-10, another rigidity testing apparatus 100 consistent with the invention is illustrated. Apparatus 100 includes a support frame 102 including a lower bracket 104, an upper bracket 106, and a pair of side brackets 108, 110 that support upper bracket 106 in a fixed position above lower bracket 104. Lower bracket 104 is coupled to a first, base member 112 upon which a multi-unit package 114 including an array of units 116 (e.g., cans) may be positioned. A second, press member 118 is suspended from upper bracket 106 to engage a top of multi-unit package 114, and a compression mechanism 120, including a pair of ratchet arms 122, 124 that progressively compress a pair of springs 126, 128 that extend along a pair of pins 130, 132 projecting through respective slots 134, 136 in press member 118 to apply a compressive force to press member 118 along a compression axis or direction Ac (Fig. 7). A pair of four bar linkage arrangements, including respective arms 138, 140 and 142, 144 pivotably coupled to both upper bracket 106 and press member 118, support press member 118 under upper bracket 106 and, along with slots 134, 136, operate as a displacement mechanism that allows for displacement of press member 118 relative to upper bracket 106, and thus also relative to base member 112, along a displacement axis or direction AD (Fig. 7).

[0039] Each side bracket 108, 110 includes first and second arms 146, 148 pivotably coupled to each of lower bracket 104 and upper bracket 106, and configured to allow for support frame 102 to move between testing (Fig. 6) and loading / unloading (Fig. 10) configurations. Each first arm 146 includes a pin 150 that engages a catch 152 disposed on a spring-loaded release mechanism 154 that is biased to a locked configuration by one or more springs 156, such that when release mechanism 154 is rotated to an unlocked configuration, each pin 150 disengages from its respective catch 152 to allow for upper bracket 106 to move from the testing configuration to the loading / unloading configuration. In addition, as may be seen in Fig. 10, a slip-resistant material 158, e.g., rubber, may be disposed on an underside of press member 118 to restrict slippage between press member 118 and a multi-unit package 114 during testing.

[0040] Also in this embodiment, and with specific reference to Fig. 6, a measurement mechanism 160 may be provided to measure the displacement amount between press member 118 and base member 112. In this embodiment, the measurement mechanism may include a distance gauge whereby a marked ruler 162 is coupled to press member 118 and configured to extend through a body 164 coupled to upper bracket 106 such that the displacement amount can be determined by reading the markings exposed on the portion of ruler 162 that projects beyond body 164. The application of the displacement force may be made, for example, using a force gauge 166 that is connected to press member 118 (e.g., by a wire or chain 168) and manually pulled by a user until a desired predetermined displacement force is indicated by the force gauge. Once the predetermined displacement force is indicated, the current displacement amount indicated by ruler 162 may be used to determine the rigidity of the multi-unit package as discussed above.

[0041] Alternatively, in some embodiments force gauge 166 may be considered to be a measurement mechanism, such that a user may pull on force gauge 166 until a predetermined displacement amount is indicated by ruler 162, and the current displacement force indicated by force gauge 166 may be used to determine the rigidity of the multi-unit package as discussed above.

[0042] In order to perform a testing operation using apparatus 100, a user may initially place multi-unit package 114 on base member 112 while support frame 102 is in the loading / unloading configuration illustrated in Fig. 10. Support frame 102 is then transitioned to the testing configuration illustrated in Fig. 6, whereby pins 150 engage with catches 152 to lock the support frame in the testing configuration.

[0043] Next, ratchet arms 122, 124 are rotated to apply a desired compressive force to press member 118, and thus to multi-unit package 114, and as illustrated in Fig. 6, markings 170 may be disposed on upper bracket 106 to indicate the amount of force being applied. The user then pulls force gauge 166 while monitoring both force gauge 166 and ruler 162 until either a desired applied displacement force or a desired displacement amount is achieved, and either the measured displacement force ordisplacement amount is recorded, thereby enabling a rigidity value to be determined for the multi-unit package 114 in the manner described above.

[0044] Thereafter, release mechanism 154 may be actuated to disengage pins 150 from catches 152 and allow upper bracket 106 to swing upwards into the configuration illustrated in Fig. 10. Multi-unit package 114 may then be removed from rigidity testing apparatus 100.

[0045] A wide variety of other configurations will be apparent to those of ordinary skill having the benefit of the instant disclosure. Fig. 11 , for example, illustrates another rigidity testing apparatus 200 that is configured similarly to rigidity testing apparatus 100, and includes a base member 202 opposing a press member 204 supported by a support frame 206, with a pair of ratchet arms 208 configured to apply a compressive force to press member 204 in a similar manner to apparatus 100. Displacement of press member 204 relative to support frame 206 may also be configured in a similar manner to apparatus 100, but instead of requiring a user to pull press member 204 using a force gauge, a screw drive 210, including a wheel 212 mounted to a threaded rod 214, is used for displacement of press member 204. One end of threaded rod 214 is rotatably supported by a bracket 216 that couples to one end of a force sensor 218 (e.g., a digital force gauge), with the other end of feree sensor 218 coupled to a bracket 220 mounted on support frame 206. The other end of threaded rod 214 is threadably coupled to a mounting block 222 that is coupled to press member 204, such that rotation of wheel 212 and threaded rod 214 causes press member 204 to be displaced along the displacement axis or direction. A ruler 224 similar to ruler 152, or alternatively, an electronic distance sensor illustrated in dashed lines at 226, may be used to measure the displacement amount of press member 204.

[0046] In use, rotation of wheel 212 and threaded rod 214 causes displacement of press member 204 relative to base member 202, and monitoring of the displacement force using force sensor 218, and of the displacement amount using ruler 224 or distance sensor 226 allows for a rigidity value for the multi-unit package 114 to be determined.

[0047] In still other embodiments, a rigidity testing apparatus may be electronic in nature, and may, upon placement of a multi-unit package in the apparatus, automatically apply compressive and displacement forces, and measure displacement force and / or displacement amount. In addition, in some embodiments, a rigidity value may be calculated and displayed to a user (e.g., via an electronic display).

[0048] In other embodiments, additional adjustability may be supported to enable use of a rigidity testing apparatus with different sizes and shapes of multi-unit packages. For example, rather than utilizing fixed length members 58, 60 in rigidity testing apparatus 50 of Figs. 4-5, adjustable length members may be used to allow for usage with multi-unit packages of differing heights.

[0049] It will be appreciated that, while certain features may be discussed herein in connection with certain embodiments and / or in connection with certain figures, unless expressly stated to the contrary, such features generally may be incorporated into any of the embodiments discussed and illustrated herein. Moreover, features that are disclosed as being combined in some embodiments may generally be implemented separately in other embodiments, and features that are disclosed as being implemented separately in some embodiments may be combined in other embodiments, so the fact that a particular feature is discussed in the context of one embodiment but not another should not be construed as an admission that those two embodiments are mutually exclusive of one another. Various additional modifications may be made to the illustrated embodiments consistent with the invention. Therefore, the invention lies in the claims hereinafter appended.

Claims

What is claimed is:1 . An apparatus for testing rigidity of a multi-unit package, the apparatus comprising: first and second members respectively configured to engage opposing sides of the multi-unit package; a compression mechanism coupled to at least one of the first and second members to apply a compressive force along a first direction between the opposing sides of the multi-unit package; a displacement mechanism coupled to at least one of the first and second members to displace the first and second members relative to one another along a second direction generally transverse to the first direction; and a measurement mechanism coupled to at least one of the first and second members and configured to, in response to application of one of feree and displacement along the second direction while the compressive force is applied along the first direction, measure the other of force and displacement along the second direction.

2. The apparatus of claim 1 , wherein the measurement mechanism is configured to measure the other of force and displacement along the second direction in response to application of the one of feree and displacement along the second direction while the compressive force is applied along the first direction by measuring a measured force along the second direction in response to application of a predetermined displacement along the second direction.

3. The apparatus of claim 1 , wherein the measurement mechanism is configured to measure the other of force and displacement along the second direction in response to application of the one of feree and displacement along the second direction while the compressive force is applied along the first direction by measuring a measured displacement along the second direction in response to application of a predetermined force along the second direction.

4. The apparatus of claim 1 , wherein the measurement mechanism comprises a force sensor.

5. The apparatus of claim 1 , wherein the measurement mechanism comprises a force gauge that displays the force applied in the second direction.

6. The apparatus of claim 1 , wherein the measurement mechanism comprises a distance sensor.

7. The apparatus of claim 1 , wherein the measurement mechanism comprises a distance gauge that displays the displacement applied in the second direction.

8. The apparatus of claim 1 , wherein the compression mechanism is configured to apply the compressive force along the first direction by applying a predetermined force between the first and second members along the first direction.

9. The apparatus of claim 1 , wherein the displacement mechanism is configured to apply a shear force to the multi-unit package along the second direction.

10. The apparatus of claim 1 , wherein the multi-unit package is a shrink wrapped bundle of beverage containers.

11. The apparatus of claim 1 , further comprising a support frame that includes lower and upper brackets respectively supporting the first and second members.

12. The apparatus of claim 11 , wherein the first member is a base member that supports the multi-unit package and the second member is a press member that is movable relative to the upper bracket by each of the compression and displacement mechanisms.

13. The apparatus of claim 12, wherein the compression mechanism includes a compression spring extending between the upper bracket and the press member and a ratchet arm configured to controllably compress the compression spring.

14. The apparatus of claim 13, wherein the compression mechanism further includes a pin projecting through the compression spring, and wherein the press member includes a slot extending generally in the second direction and through which the pin projects.

15. The apparatus of claim 11 , wherein the press member is coupled to the upper bracket through a four bar linkage that allows for movement of the press member relative to the upper bracket generally along the second direction.

16. The apparatus of claim 11 , further comprising a side bracket including first and second arms pivotably coupled to each of the upper and lower brackets and configured to move the support frame between testing and loading / unloading configurations.

17. The apparatus of claim 11 , wherein the displacement mechanism comprises a screw drive including a threaded rod and wheel configured to displace the press member relative to the upper bracket generally in the second direction.

18. An apparatus for testing rigidity of a multi-unit package, the apparatus comprising: first and second members respectively configured to engage opposing sides of the multi-unit package; a compression mechanism coupled to at least one of the first and second members to apply a compressive force to the multi-unit package along a first direction between the opposing sides of the multi-unit package; anda displacement mechanism coupled to at least one of the first and second members to apply a shear force to the multi-unit package along a second direction generally transverse to the first direction.

19. A method of testing rigidity of a multi-unit package, the method comprising: applying a compressive force along a first direction between opposing sides of the multi-unit package using respective first and second members; displacing the first and second members relative to one another along a second direction generally transverse to the first direction; and in response to application of one of feree and displacement along the second direction while the compressive force is applied along the first direction, measuring the other of force and displacement along the second direction.

20. A method of testing rigidity of a multi-unit package using the apparatus of any one of claims 1-18.

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